Mannesmann Rexroth (compendio 2) - Tecnica De Valvulas Proporcionales Y De Servovalvulas

Electric Drives and Controls

Hydraulics

Linear Motion and Assembly Technologies

Pneumatics

Project manual Proportional valve technology Trainer's manual

Service

RE 00847/10.08 Replaces: 07.07

Foreword

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Bosch Rexroth AG I RE 00847/07.07

Foreword The present trainer's manual is intended for trainers and instructors in the field of proportional valve technology. It describes projects that are oriented specifically towards practical application examples of electrohydraulic control technology. It is assumed that the trainee has a basic knowledge of hydraulics and electrics. Generally, it must be noted that the project results documented in this manual are intended as a guideline for the trainer and instructor. We recommend that the projects be worked off starting from 01. Before the projects are dealt with, the experiments relating to basic principles of hydraulics should have been carried out. The existing set of components was extended for the projects covering proportional valve technology. Explanations with regard to the training stand can be found in the relevant operating instructions. Project / trainer information

Specific project/trainer information is provided at the end of each project exercise. This information is included exclusively in the trainer's manual.

Foreword

Notes

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Introduction

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Introduction History of proportional valves

The first hydraulic systems were operated using water; the origins date back to the medieval times. The use of oil has turned out to be more advantageous due to the lubrication of pumps and the reduced risk of corrosion and erosion. In the beginnings of hydraulics for industrial applications, only on/off and servovalves were available. As long as the traversing speed of the moved masses was relatively slow, it was sufficient to use on/off valves. For dynamic applications that also demand precision, e.g. in steel rolling mills, servo-valves were employed. Servo-valves have their origin in aviation hydraulics in the 1930s. The use of on/off valves reaches its limits, if large masses are to be moved at higher speeds. An on/off valve of size 6 can close within 50 ms. However, this means that the machine part is decelerated within this time. Also a changeover to another speed is accordingly abrupt. Here, large acceleration and deceleration forces are generated, which result in corresponding stress on the machines. Deceleration valves are used for the position-dependent, stepless acceleration or deceleration of hydraulically moved masses.

Deceleration valve and cylinder with switching mechanism

Initial position open, with check valve, main flow throttle and off-line throttle

Introduction

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Mechanically operated proportional valves were developed, which were actuated by means of roller plungers and mechanical profiled bars. This technology was perfected in mechanical-hydraulic copiers in machine tools, which exactly follow a mechanical profile. Unfortunately, these controls were very difficult to adjust, for a new profile had to be implemented in each case.

Section, deceleration valve with lever actuation, main flow throttle (5), off-line throttle (7) and bypass check valve (6), type FRH

Notes

Introduction

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The emerging open and closed-loop control technology with its high flexibility necessitated electronically controllable hydraulic valves. Servo-valves meet this requirement, but were much to complex and expensive for most of the applications. Hydraulic valves had therefore to be developed, which can be steplessly adjusted by means of an electronic system, while being simple, rugged and cost-efficient. This was the "birth" of proportional valve technology. Proportional directional valves were developed on the basis of on/off directional valves, that is, a spool in a cast iron housing. Decisive features of proportional valves are spools with control lands, specific solenoids and special electronics for optimum operation of the valves. With the help of the electronics it was now possible to steplessly adjust the valve aperture (command value) and the spool velocity (ramp), which allowed the machine speed and in particular acceleration to be exactly controlled. Now, it was possible to adjust the machine movement continuously and proportionally to an electrical signals. This resulted in the designation "proportional valve“. This technology provided higher speeds and hence higher productivity. Another aspect was that the motion sequences could be programmed with an electronic control. The trend in the further development of proportional valves and electronics was towards reliability, higher dynamics, increased accuracy and further cost reduction. With today's proportional valves, the valve electronics can be mounted directly onto the valve.

Modern proportional directional valve with integrated On-Board Electronics (OBE)

Introduction

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Application, advantages Due to their ability to handle large forces and their compact design, hydraulic controls provide the greatest benefit, wherever large masses are to be moved at high dynamics. The use of proportional valve is often generally necessary in these applications. Modern machines are electronically open- or closed-loop controlled; the transformation of electrical signals into hydraulic movements and forces is accomplished with proportional valves. They can be used to efficiently control velocities and acceleration, and the machine can follow the motion profiles given by the control. This is difficult and complicated to realize with on/off valves and leads to jerky and abrupt operation of the machine. In many applications, a machine part is to move forward quickly, then decelerate and approach a certain position or the end position at low velocity, e.g. in plastics processing machines, presses, machine tools, lifting platforms, etc. Heavy machine parts are not be decelerated abruptly, because the forces generated by this process would exert great stress on structural parts. It can easily be imagined what happens, when two machine parts clash at high velocity. The idle stroke is to be performed as quickly as possible, and the actual working stroke at a velocity that is optimal for the individual process. All of these requirements can be met with proportional valves.

Modern hydraulic press

Introduction

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Imparting knowledge through project work The present Project Manual Proportional Valve Technology can be used to impart the required specialist knowledge of hydraulic control technology in practice-oriented applications. The logically structured project work is to make the trainee familiar with: Training contents

• the physical laws of, for example, pressure differential, opening cross-section and flow • specific symbols • signal flows • the relationship between command value and velocity • function and meaning of ramps • commissioning and optimization of an electrohydraulic system • adjusting a control according to specified values The project tasks and project work described in the Project Manual Proportional Valve Technology provide trainers and trainees with information and instruments that will help them comply with the demands made on the transfer of specialist know-how in the field of hydraulics.

Specialist competence

The objectives described are geared to the development of competence to act. The trainee will develop his or her competence to act from the capability and willingness to solve tasks and problems and evaluate results in a target-oriented manner, skillfully, methodically and independently on the basis of technical knowledge and skills.

Introduction

Professional competence to act

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As mentioned before, the trainee is to work off the project task or the project order in 6 steps. 1. Informing Based on the project definition, the trainee is to get a clear idea of the finished solution, including any required details. This is achieved through a systematic analysis of the project documentation and, if required, by asking questions. Possible questions:

• What is to be done? • Have I understood the task completely? • Which hydraulic component/system is to be dealt with?

2. Planning Planning means the theoretical preparation and anticipation of the concrete execution. In detail, planning requires competence to handle the project order and to organize the project handling steps. Possible questions:

• • • •

How to proceed? What knowledge is required? Which aids are available? Are there comparable applications in my company?

3. Decision-making After the planning stage, the trainee determines the aids to be used, e.g. which data sheets are required for coping with the project task. He/she decides on the sequence and the interrelationships of the individual project steps. Moreover, a decision should be made as to whether it would be easier to solve the project task in a team. Possible questions: • Which hydraulic components will be used? • How can you know that technical data sheets are up to date? • Have I utilized all available sources of information? • Are the prescribed safety instructions at hand?

Introduction

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4. Executing: The order is to be executed according to the work instructions given in the chapter "order execution", taking all safety notes into account. After a thorough preparatory phase, the trainee is to carry out the project order largely on his/her own. After the solution was worked out in writing, it should be verified or questioned, whether the right attempt at a solution was selected. Depending on the project order, the possibilities of execution may be limited. This is valid, for example, in the case of costly work in the field of information technology. Possible questions: •

Have I chosen the correct sequence?

5. Checking The trainee must check intermediate results as early as during the execution stage and finally the result of the customer requirement. In some cases, the result can be compared with the manufacturer's documents. In the case of measuring exercises, it must be checked, whether the measured results are realistic. The documentation should also be finally corrected, improved and completed. This also includes the preparation of a final report. After completion, the trainer makes a final check. Possible questions: • • • • •

Was the control properly installed? Has the project objective been complied with? Is the customer satisfied with the project result? Which documentation is required? Is the result completely documented in the correct order?

6. Evaluating In the final evaluation phase, an external or self-evaluation is to be carried out on the basis of a comparison of project order documents, the installed control and results of measurements and checks. Faults, if any, and their causes must be analyzed and possibilities discussed as to how faults can be avoided in the future. The trainee must learn to assess his/her strengths and weaknesses and develop objective quality standards for his/her acting, which ultimately leads to personal competence. The evaluation can be finalized in a technical discussion, possibly also in a discussion with the customer.

Introduction

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General notes: For didactic reasons, we refer exclusively to trainees and trainers in the present manual. We expressly point out that these terms include all persons involved in the basic and advanced training: Instructors, teachers, project managers, etc., whether male or female. Procedural knowlege

In this manual, we do not give notes on procedural knowledge (explanatory knowledge). It is the knowledge of how to achieve a certain result with which measures, procedures or processes. In this case, how the learning target can be reached. The present manual must be understood as a tool for providing the required core and specialist qualification that must be imparted in an integrated form through independent planning, executing and checking according to regulations for vocational training in industrial metalworking professions.

Pictograms

The pictograms, which are used as recurrent symbols, are to transfer important information as quickly as possible in the form of a simplified graphical representation and independently of languages.

Introduction

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Safety aspects Safety and the economic use of resources are essential demands that are placed on modern plant and machinery and serve to protect people. These two requirements have in common that they have to be taken into account as early as possible, that is, at the product concept stage. Only in this way can optimized and low-priced solutions be found. Safe machines with low consumption demonstrate that the manufacturer masters his processes; they are a quality feature. In order that hazards to plant and machinery can be recognized, safety regulations, product information and operating instructions must be observed. Only if these operating instructions, safety notes and product information are observed can the trouble-free operation of Rexroth products be ensured. The present Project Manual Proportional Valve Technology includes warning notes, which precede instructions for activities that involve a risk of personal injury or damage to property. The prescribed precautions for averting risks must be taken.

Conventions This symbol refers to imminent danger that, if not avoided, can lead to severest injuries or death. Warning This symbol refers to a potential risk, which can lead to light or serious injuries or damage to property. Caution This symbol refers to supplementary information.

Note: The electrohydraulic components and systems described in this Project Manual are technical equipment, which is not intended for private use. The use for the intended purpose also includes that the safety regulations, product information and operating instructions described in the following are read and understood.

Introduction

Qualification of personnel

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Installation, commissioning and operation, disassembly, upkeep and maintenance require fundamental knowledge of mechanics and electrohydraulics as well as the knowledge of related technical terms. In order to ensure operational safety, these activities may only be carried out by a corresponding specialist or by an instructed person under the supervision of a specialist. A specialist is, who, due to his/her professional training, his/her knowledge and experience and the knowledge of relevant regulations, can asses the duties assigned to him/her, recognize potential risks and take suitable precautions. A specialist must observe relevant technical rules. Consequently, this means that the trainer must point out potential risks to the trainee and provide information of how to avert such risks.

Warning

Liability

Work carried out improperly on electrohydraulic components and systems involves the risk of injury and represents a safety risk during operation of the system, including danger to life!

In the case of damage resulting from improper use and unauthorized interventions, which are not provided in the Mobile Hydraulics Project Manual, any liability claims for defects or other liability claims vis-à-vis Bosch Rexroth AG become void. If Projects 01 to 09 described in the Project Manual Proportional Valve Technology are carried out on training stands and with electrohydraulic components that were not delivered by Rexroth, that is, products of competitors' make, any defect or liability claims vis-à-vis Bosch Rexroth AG shall be void as well.

When using competitors' products, observe the safety notes of the manufacturer and make sure that the components and systems comply with currently valid EU Directives.

Warning

For this reason, commissioning is prohibited until it was established that the electrohydraulic components and systems to be used meet the stipulations of all relevant EU Directives.

Introduction

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Note: The required safety regulations, product information documents* and operating instructions must be handed over or be accessible to the trainee in their latest issue. In the description of Project exercises 01 to 07 in the Proportional Valve Technology Project Manual, the correct handling of hydraulic fluids is not referred to in detail. Corresponding information can be found in the safety data sheet. The correct handling of hydraulic fluids is dealt with in a separate chapter in the following, which also describes potential hazards and precautions for averting risks. * Rexroth product information sheets are valid exclusively for hydraulic products, which are operated with hydraulic fluids based on mineral oil, unless the use of other hydraulic fluids is expressly permitted in the operating instructions.

Introduction

Notes

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Basic principles principles of ofproportional proportionalvalve valve technology

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Bosch Rexroth AG I RE 00847/07.07

Basic principles of proportional valve technology Pressure differential, valve opening, velocity To be able to understand proportional hydraulics, some fundamental principles must be known. The flow through a valve and hence the actuator velocity depends on two factors. These are the opening cross-section and the pressure differential across this cross-section. The larger the cross-section (A) and the higher the pressure differential (∆p), the larger is the flow (q). This applies by analogy also in the field of electrical engineering. The crosssection corresponds to resistance (R), the pressure differential to voltage (U) and the flow to electric current (I). A descriptive example is to illustrate the relationship of cross-section, pressure differential and flow. Load 2 = 30 bar Load 1 = 30 bar Load 0 = 10 bar

∆ d = 5 mm

psys - pL Load 0 100 - 10 Load 1 100 - 40 Load 2 100 - 70

= = = =

Dp → q 90 bar 117 l/min 60 bar 96 l/min 30 bar 68 l/min

The valve opening is to correspond to a bore of d = 5 mm, the system pressure is assumed to be 100 bar; the load acting on the cylinder and hence the load pressure (pL) is changed with the loading. The formula q ≈ f • A • ∆p can be used to approximately calculate the flow in l/min ( A = d 2 • π / 4 ; f = 0, 68 ). A detailed computation depends on further factors and conditions, which are not to be dealt with in detail at this point. For hydraulic valves, the flow rates are measured, because calculations are very difficult due to the flow situation and the geometry in the housing. It can be seen that with increasing load, the ∆p, and consequently the flow becomes smaller. In practice, this means that with the same valve opening a cylinder without load moves faster than with load.

Basic principles of proportional valve technology

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Structure and function

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Type 4WRA 6 ... -2X/

4/2 and 4/3 proportional directional valves are direct operated valves of sandwich plate design. They are operated by proportional solenoids with central thread and detachable coil. The solenoids can be optionally controlled by external control electronics. The valves basically consist of: Structure

– Housing (1) with mounting face – Control spool (2) with compression springs (3 and 4) – Solenoids (5 and 6) with central thread

Function

– In the non-operated condition of the solenoids (5 and 6), the control spool (2) is held by compression springs (3 and 4) in the central position – Direct operation of the control spool (2) by energizing a proportional solenoid, e.g. activation of solenoid "b“ (6) → The control spool (2) is shifted to the left in proportion to the electrical input signal → Connection from P to A and B to T through orifice-type cross-sections with progressive flow characteristics – Deactivation of the solenoid (6) → The control spool (2) is brought again to the central position by the compression spring (3). In this way, the function of the valve spool in the de-energized condition is always clearly defined.

Basic principles of proportional valve technology

Spool

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Control lands are cut in the spools, with the help of which throttling crosssections with progressive flow characteristics can be adjusted steplessly in dependence upon the stroke. Standard spools are check spools (E) and spools A, B unloaded to T (W).

In the case of E-spools, all ports have a 15 % overlap in the central position. This means that the control lands open only after a spool stroke of 15 %.

With W-spools, in the central position, ports A, B are opened via small lands to T for unloading purposes, if, for example, pilot operated check valves are installed in service lines A, B. Port P has a 15 % overlap. Characteristic curves

To obtain as high a resolution as possible, up to three different spools with control lands of different sizes are available per valve size. These control spools are dimensioned for certain nominal flows at a valve pressure differential of 10 bar. For example, with a WRA6 valve with E07 spool, the nominal flow is 7 l/min at a pressure differential of 10 bar. This value merely serves to define the spool. At a higher pressure differential, the valve flow rate is accordingly higher. For this reason, it is important to always observe the flow values given in the diagrams of the technical data. This is to be illustrated with the help of an example : Flow q required for a certain cylinder velocity is 25 l/min, system pressure p is 150 bar, load pressure pA is 100 bar. Consequently, the valve pressure differential is (∆p) p - pA = 150 - 100 = 50 bar. If an E07 spool was selected, only 15 l/min can be achieved at a pressure differential (4) of 50 bar and 100 % valve opening. This means that the required cylinder velocity cannot be achieved. With an E30 spool, 25 l/min can already be achieved with a valve opening of 80 %, the remaining 20 % are useless. This would mean a poor resolution of the valve stroke. With an E15 spool, 25 l/min can be achieved at 98 %, and only 2 % are useless. This is a better resolution of the valve stroke. In this case, an E15 must be selected. The better the resolution of the valve stroke, the easier to adjust is the control.

Basic principles of proportional valve technology

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Another example: In this example, flow q is 10 l/min, the valve pressure differential is again 50 bar. If spool E30 was selected, 10 l/min is achieved at a valve stroke of only 53 %. With spool E07, it is achieved at a valve stroke of 80 %. Here, spool E07 must be selected. For the engineering of circuits with proportional valves, it is always important to know the pressure differentials across the valve. When maintenance and repair work is carried out on systems, valves of different nominal flows must not be mixed up. Otherwise, the system would move at completely different velocities, even if the settings remained unchanged. Characteristic curves (measured with HLP46, q = 40 °C ± 5 °C) 7 l/min nominal flow at 10 bar valve pressure differential

15 l/min nominal flow at 10 bar valve pressure differential

30/l/min nominal flow at 10 bar valve pressure differential 1 Dp = 10 bar constant

2 Dp = 20 bar constant

3 Dp = 30 bar constant 4 Dp = 50 bar constant

5 Dp = 100 bar constant Dp = Valve pressure differential (inlet pressure pP less load pressure pL less return flow pressure pT)

Characteristic curves of a WRA6 proportional valve

Types of controlling

Proportional valves can be controlled in two different ways, One type is "open-loop controlled" without feedback of the spool position, the other is "closed-loop controlled" with spool position feedback by a position transducer. The WRA valve presented so far, is operated in the open-loop control mode. This function is now to be dealt with in more detail. The higher the current flowing through the solenoid, the greater is its force (F). This magnetic force acts on the spool, which is loaded by the spring located on the opposite side.

Basic principles of proportional valve technology

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If the magnetic force is greater than the spring force, the spring is compressed until a balance is obtained. As the current increases, the magnetic force becomes greater and the spring is compressed further. As the current is reduced, it is the other way round. Because the spool stroke is always identical with the spring travel, corresponding opening cross-sections are obtained on the control lands. An important factor for this principle is the precise matching of the magnetic force with the spring constants, because otherwise, no defined opening crosssections can be achieved. At this point, the problem of this principle becomes apparent. If a part of the magnetic force is lost, e.g. due to increased friction, this force is missing on the spring side, which will consequently perform a shorter stroke. Thus, a smaller opening cross-section is available, which results in a smaller flow. In practice, a cylinder would move at a correspondingly lower velocity. Depending on the change in the friction situation of the spool, the cylinder velocity changes as well. Small flows require only small openings and hence lower magnetic forces. In this case, friction has an even stronger effect. It is easily conceivable what happens if contaminated oil is used, which strongly increases friction. To obtain a reliable proportional valve, the position of the spool in the housing is measured by means of a position transducer and the result fed to a controller. This controller increases the solenoid current until the required position in the housing is reached. The controller can always work with the max. solenoid current, if required. The function of a closed-loop controlled system can be explained in a simplified way in the following. The command value is provided by a machine control. It corresponds to a certain valve opening in % or Volt (100 % = 10 V). The actual value corresponds to the actual position of the spool in % or Volt. The task of the controller is to achieve and maintain a system deviation of: command value – actual value = 0. To this end, the controller issues a control output to the relevant solenoid. The greater the difference between command value and actual value, the greater is the control output. The controller is continuingly active and corrects any deviation. Should frictional forces occur, the controller increases the solenoid current accordingly until the difference becomes 0. Friction, springs and forces acting on the spool have no influence on the function.

Basic principles of proportional valve technology

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This principle offers some advantages: 1. Higher functional reliability 2. The proportional valves operates more dynamically and is more efficient 3. The required valve opening is exactly adhered to 4. The spool position can be measured for fault analysis and monitoring purposes

Proportional directional valve with position transducer (7), type 4WRE 6 ... -2X/ ...

1

Housing

2

Control spool

3,4

Compression springs

X1, X2

Spring plates

5,6

Solenoids

P1,P2

Pole tubes

7

Position transducer

9

Sealed plug screw of the mechanical position transducer adjustment element

11

Plug screw in the case of single-sided actuation

Basic principles of proportional valve technology

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Electronics In order to ensure optimum operation of proportional valves, special amplifiers were developed for each valve series. These amplifiers can be designed as Euro-card, module or integrated On-Board Electronics (OBE). The general operating principle of the amplifiers is to be explained in the following. Integrated On-Board Electronics (OBE) Interface

Integrated electronics (OBE)

Valve

The electronics is located on the valve, thus forming a functional unit. A power supply unit is supplied with 24 V and generates the required internal voltages. An analog voltage of ±10 V or a current of 4 - 20 mA is applied to the differential amplifier. The valve opens proportionally to the value applied. The analog signals must be generated by the machine control, e.g. a PLC. Further possibilities of generating command values are command value cards, modules and closed-loop control electronics. The ramp generator can be used to adjust the gradient of the command values, unless this was effected by means of analog signals. If the ramps are generated by the machine control, the setting of the ramp potentiometer should not be changed. The actual value is brought out for diagnosis purposes. With the help of the zero point, the position of the spool at a command value of 0 % can be adjusted. This is, however, only required in exceptional cases for control purposes; for this reason, the zero point potentiometer setting should not be changed. In the case of undervoltage, the solenoid currents are switched off in order to prevent uncontrolled movements. The controller works as described before.

Basic principles of proportional valve technology

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Amplifier cards (external electronics)

Simplified functional description

Power supply unit 1 provides all the required voltages. External command values can be applied to two analog inputs 2, 3 in the form of voltage of ±10 V or current of 4 - 20 mA. This possibility is used, if, for example, the command values are provided by a PLC. If command value selection logic 4 is used, the command values on the card can be adjusted by means of potentiometers W1 - W4. The set command values are activated with digital 24 V signals to command value call-ups. If several command values are called up simultaneously, the command value with the highest number becomes active. Negative command values must be activated with inversion. This is required, if, for example, the cylinder is to retract. The ramp generator is used to adjust the gradient of the command values. The gradient has an influence on the opening and closing speed of the valve, and hence on the acceleration and deceleration of the moved machine. Controller 17 receives the internal command value voltage and the voltage value from the position transducer and outputs a voltage that corresponds to the system deviation to current output stage 18, which generates the individual, clocked solenoid currents up to 2.5 A. The solenoid current is clocked to approx. 5 kHz. Clocking allows a low-loss variation of the magnetic force.

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Detailed functional description Power supply unit [1]

The amplifier card is equipped with a power supply unit with switch-on current limitation, which provides all the internally required positive and negative supply voltages. The switch-on current limitation prevents high switch-on current peaks caused by smoothing capacitors in the current output stage.

Command value provision

The internal command value signal is created from the sum (summation [6]) of the external command value applied at differential input [2], at current input [3], the called up signal [4] and the zero point offset [5] (zero point potentiometer “Zw”).

The following is valid: Standard values

Current input

Differential input

-100 % 0% 100 % 0

4 mA 12 mA 20 mA 1 mA**

-10 V 0V 10 V 0V

Command value test socket -10 V 0V 10 V

Direction of flow

P to B, A to T P to A, B to T

** If the current input is not connected, or in the case of a cable break on the current command value line, the resulting internal command value signal corresponds to 0 %. There is no changeover between current and voltage input. The inputs are permanently available (see terminal assignment). Command value call-ups [4]

Four command value signals "w1“ to "w4“ can be called up. The external command value voltages (command values 1 to 4) are provided either directly by the regulated voltage outputs +10 V and –10 V or via external potentiometers. If the command value sources are connected directly to the regulated voltages, the command values can be adjusted by means of potentiometers "w1“ to "w4“. If external potentiometers are used, the internal potentiometers act as attenuators or limiters. Only one call-up is possible at a time. If several call-ups are made simultaneously, call-up "1" has the lowest priority, call-up "4" the highest priority. The currently active call-up is signaled by a yellow LED on the front panel.

Command value inversion [7]

The command value created internally from the input signals, command value call-ups and zero point offset signal can be inverted by means of an external signal or jumper J1. The application of an external inversion is signaled by an LED ("–1“) on the front panel.

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Enable function [8]

The enable function is used to enable the current output stages and pass the internal command value signal on to the ramp generator. The enable signal is indicated by an LED on the front panel. When the enable is granted, the internal command value changes by the set ramp time (with any command value input). A valve will therefore not open abruptly when activated.

Ramp generator [9]

The ramp generator limits the gradient of the control variable. The ramp time is not shortened or extended by downstream jump functions and amplitude attenuators. Jumper J2 can be used to set the ramp time is set to minimum (< 2 ms) (ramp off). External ramp time adjustment: The internally set ramp time can be extended by means of an external potentiometer. The setting can be verified at the test socket. In the case of a cable break, the internal pre-setting becomes automatically valid.

Characteristic curve generator [11]

The adjustable characteristic curve generator serves to adjust jump heights and maximum values separately for positive and negative signals to suit the hydraulic requirements. The actual path of the characteristic curve through the zero point is not step-like, but linear.

Amplitude limiter [12]

The internal command value is limited to approx. ±110 % of the nominal range.

Oscillator [14]

The oscillator generates the control signal for the inductive position transducer.

Demodulator [15]

The demodulator provides the actual value signal of the valve spool position from the position transducer signal. 100 % = 10 V

Position controller [17]

The position controller is optimized specifically to the relevant valve.

Current output stage [18]

The current output stage generates the clocked solenoid current for the proportional valve. The solenoid current is limited to 2.5 A to 2.8 A per output. The output stage outputs are short-circuit-proof. The output stages are de-energized in the event of an internal fault signal or missing enable.

Fault detector [19]

Monitoring of the position transducer cable for cable break and short-circuit on the primary side as well as overcurrent of the output stage. [ ] = Cross-reference to the block circuit diagram

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Ramp → The ramp prolongs the rise of the command value in order that the valve is closed or opened more slowly. This is to be illustrated by an example: The command value is changed from 0 % to 100 % in 2 ms; without a ramp, the valve would open abruptly and the machine accelerate equally abruptly. If the command rises now in 500 ms from 0 % to 100 %, because the ramp was set accordingly, the valve opens more slowly and the machine is softly accelerated. A ramp time of 250 ms can improve the machine behavior significantly in many applications. This depends on the design, the masses and velocities. If the ramp time is set much too long, it may happen that, for example, limit switches are passed too far. In this case, the valve closes only very slowly after the limit switch was activated, and the cylinder continues to move during this time.

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Signal sequence Now that the functions of the individual components are know, they are to be joined together to form a system. The block diagram is to represent the flow of signals.

Signal encoder

Machine control

Command value generation

Electrical gain

Hydraulic gain

Hydraulic movement

Relay PLC

Command value potentiometer, ramp generator

Controller Output stage

Directional valve ∆p

Cylinder or motor

Digital signal

Analog signal

External encoders such as switches, push-buttons, limit switches, pressure switches issue signals to the machine control, where they are logically linked. This can be accomplished with relays or programmable controls. A digital signal from the control is used to call up a command value. According to the command value and ramp settings, an analog signal is fed to the valve controller and then to the output stages, in which it is amplified until a solenoid current of up to 2.5 A is reached. In the solenoids the current generates a force, which shifts the directional valve spool. The proportional valve converts an electric current analogously into a hydraulic oil flow. Depending on the hydraulic conditions such as the pressure differential the actuator will perform a movement and actuate the machine.

Basic principles of proportional valve technology

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Symbol The symbol of a proportional valve differs from the symbol of an on/off valve in the following features: Uninterrupted lines (2) are drawn above and below the control element (1), which symbolize stepless adjustability. The actuating solenoids (3) are drawn with an arrow (4), which stands for the adjustability of the solenoid current. In the case of valves with feedback of the spool position, the symbol of a position transducer (5) is provided additionally on the solenoid. If the electronics is mounted on the valve, the symbol for the amplifier (6) is shown on the solenoid. Proportional directional valve with integrated electronics

5

6

2 1

3

Pressure control with integrated electronics

1

2

3

4 6

4

Basic principles of proportional valve technology

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Bosch Rexroth AG I RE 00847/07.07

Analog command value module VT-SWMA-1 Proportional valves with integrated electronics (OBE) require analog signals, +/- 10 V or 4 - 20 mA, as control signal. The valve opens in proportion to the intensity of the control signal. 10 V corresponds to a valve opening of 100 % . The signal can be continuously changed and the valve opening must follow without delay. This technology can be used to continuously control a machine velocity. Electronics such as position controllers, position transducers, solenoid current regulators, etc., which are required for operating the valve, can be provided externally on an amplifier card in the control cabinet or internally on the valve. The electronics is optimized by the manufacturer and cannot be changed by the user. On some OBE the valve zero point and the valve ramp can be adjusted. Such adjustments are, however, only required in special cases. If the control signals are generated by a control, no settings are necessary on the valve; on the contrary, this could cause malfunction. Therefore, never make any settings on the valve electronics, unless you have the required knowledge. Analog control signals can be generated by various sources. The simplest possibility is, for example, a manually operated potentiometer. In PLC controls with analog outputs, analog control signals can be programmed. Controllers output the continuously changed actuating signals, which form the control signals for the valves. If a control cannot generate analog signals, for example a relay control or a PLC with digital outputs, special electronic circuits are required to generate analog signals. These circuits convert digital switching signals into analog signals. Analog command value modules are electronics, with are optimized to suit the requirements of hydraulic drive technology. Command value modules can be used to adjust rapid and creep speed sequences with separate ramps for acceleration and deceleration for both directions of movement. The relevant direction and velocity are called up digitally by the machine control (PLC, relay, switch). On the command value module, the velocities are adjusted by means of command value potentiometers. Acceleration and deceleration rates are adjusted by means of ramp potentiometers. The analog signals from the command value module are converted into a corresponding valve opening by power electronics on the valve. In such an arrangement, command value generation and valve electronics are separated. Alternatively to the command value module, analog and digital command value cards can be employed. Another method is the common arrangement of command value generator and valve electronics on an amplifier card.

Basic principles of proportional valve technology

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Bosch Rexroth AG I RE 00847/07.07

In industrial practice, the separate arrangement of command value generator and valve electronics is now the most common solution. - Valve and electronics form a functional, tested unit with a standard +/- 10 V or 4 - 20 mA interface. - No amplifier card needs to be installed in the control cabinet. - Only one 7-pin cable is required to the valve when compared with 3 cables for an external amplifier card. - The command value can be generated flexibly and independently of the valve. - This arrangement is less susceptible to faults.

Notes

Basic principles of proportional valve technology

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Operation of the command value module

Front of the VT-SWMA-1 command value module Potentiometers "w1-4“ are used for adjusting the command values and hence also the cylinder velocities. The set values are activated by means of command value call-ups. Command values "w1“ and "w2“ are positive, whereas "w3“ and "w4“ are negative. In this way, a cylinder can, for example, extend with "w1“ and "w2“ and retract with "w3“ and "w4“. A ramp is assigned to each command value "w1“ → "t1“, "w2“ → "t2“, etc. This means that when command value "w1“ is active, only ramp "t1" is also activated. Ramp "t5“ is active, when no command value is active. This is to be illustrated by means of an example: A cylinder is to extend at rapid speed and, after having reached a certain position, at creep speed and stop at a further position. Command value "w1“ is activated for rapid speed, command value "w2“ for creep speed. When "w1“ is active, "t1“ is active as well. Consequently, the acceleration for starting up the cylinder can be adjusted with the help of ramp "t1“. Upon the switch signal "creep speed", command value "w2“ and ramp "t2“ become active. The creep speed is adjusted via command value "w2“, the associated deceleration with ramp "t2“. After the switch signal "halt" command value "w2“ is switched off and, because no command value is active at that time, the deceleration is adjusted by means of "t5“ .

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"4-Q“ is used for activating quadrant recognition. 4-quadrant operation means retracting, extending and accelerating, decelerating, which is required for motion sequences with cylinders. 2-quadrant operation means accelerating and deceleration in only one direction; this is applicable for motors with only one direction of rotation. With the help of quadrant recognition all of the 4 possible changes in velocity can be adjusted optimally and individually. This is a very useful function for motion sequences. In this mode, ramps "t1 - 4“ are no longer firmly assigned to the command values, but to polarity and signal direction. The electronics recognizes the direction of the new command value and selects the corresponding ramp. "t1“ → accelerating - extending "t2“ → decelerating - extending "t3“ → accelerating - retracting "t4“ → decelerating - retracting "t5“ → decelerating when "4Q“ and command values are switched off, Quadrant recognition When quadrant recognition [8] is activated, the electronics automatically recognizes polarity [9] and the change (up/down) [10] of the control output and assigns a ramp time to the current signal state. Ramp time

Polarity of the control output

t1

+

t2

+

t3

-

t4

-

Signal changes towards Maximum value 0% Maximum value 0%

0%

Maximum value (+)

Maximum value (+) 0%

0% Maximum value (-)

Maximum value (-)

0%

e.g. emergency stop The function is to be illustrated with the help of an example: A cylinder is to extend and retract. The acceleration rates are to be high, and decelerations are to be realized softly. Different values are therefore required for extending and retracting. "w1“ is the command value for extending, "w3“ the command value for retracting. The command values are used for adjusting the velocity. The acceleration of the cylinder in the direction of extending is adjusted with "t1“. The deceleration of the cylinder in the direction of extending is adjusted with "t2“. The acceleration of the cylinder in the direction of retracting is adjusted with "t3“. The deceleration of the cylinder in the direction of retracting is adjusted with "t4“.

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In this way, all changes in the movement can be adjusted separately. "INV“ can be used for changing the polarity of the command values. This is required, if more than 2 command values are required for one direction of movement. If, for example, a third velocity is required for extending, it can be adjusted by means of "w3“. "w3“ has a negative polarity. In order to be effective in the direction of extending, the polarity must be changed to positive. To this end, "w3“ is to be activated together with "INV“. Amplitude attenuator "G“ only acts on the differential input (terminal 4,5). The amplitude attenuator can be used to reduce the voltage signal applied at the differential input to a certain value. Example: 10 V is applied at the differential input. The amplitude attenuator reduces the signal to 7.5 V. Consequently, the valve opens to only 75 %. It is therefore possible to limit the maximum velocity with the help of the amplitude attenuator, if the command value signal is provided via the differential input from another open or closed-loop control. This function is particularly important in closed-loop controls, if a maximum cylinder velocity must not be exceeded. "G" should normally be set to 110 % (right-hand limit stop). Zero point balancing "Z" can be used for adjusting a command value up to +/3 V without a command value being activated or a signal being applied at the differential input. This is useful for commissioning purposes. The command value should always be 0 V, when no command value is activated or no signal is present at the differential input. If that is not the case, the command value must be set to 0 V with the help of "Z". The voltages for command values "w" and ramps "t" can be measured at the test sockets. Only the latest values are present at the test sockets. To be able to measure a set value, the associated command value or ramp must be activated by means of a command value call-up. For the command valves, 10 V corresponds to a valve opening of 100 %.

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The following is valid for the ramps: Note on the adjustment and measurement of the ramp time. It is recommended that 4-quadrant recognition be switched off and the call-ups be made when the ramp time potentiometers are to be adjusted. Value at test socket "t“ Ut in V Current ramp time (±20 %), t in ms

5

3

2

1

0.5

0.3

0.2

0.1

0.05

0.03

0.02

20 33 50 100 200 333 500 1000 2000 3333 5000

The following is valid:

t = 100 V ms Ut

Example:



provides:

t = 100 V ms = 20 ms 5V

Ut = 5 V

It can be seen from the table that the voltage is inversely proportional to the ramp time. In most of the cases, the ramps are not set on the basis of time, but the machine behavior. Thus, the voltage measured mainly serves as test voltage, e.g. for documentation purposes.

Notes

Safety notes

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Bosch Rexroth AG I RE 00847/07.07

Fundamental safety notes In order that potential risks for plant and machinery can be recognized, safety regulations, product documentation and operating instructions must be observed. The trainer must make the required documents available to the trainee. When competitors' products are used, the safety notes of the relevant manufacturer are applicable, and it must be ensured that the components and systems comply with currently valid, relevant EU Directives.

Warning

Commissioning is therefore prohibited until it was established that the electrohydraulic components and systems that are to be used, conform with all relevant EU Directives.

Fundamental, general safety notes Observe

Warning

• danger signs and safety notes on the machine • instructions, which prescribe the behavior during operation in order to prevent accidents and health damage and must be prepared by the operator/employer on the basis of, for example, regulations for the prevention of accidents, • operating instructions, which ensure the proper use of the hydraulic system in accordance with its intended purpose.

The operating instructions are intended for information purposes and for the prevention of risks when hydraulic components are being installed in a system - in this case mounting of electrohydraulic components on the training stand -, and include information and notes on transport, storage and maintenance (inspection, servicing, corrective maintenance) of the hydraulic system. Only when the operating instructions are strictly observed can accidents and damage to property be avoided and the troublefree operation of the hydraulic system be ensured. Moreover, observing the operating instructions helps to: • reduce downtimes and repair costs • prolong the service life of the hydraulic system.

Safety notes

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Bosch Rexroth AG I RE 00847/07.07

Hydraulic oil based on mineral oil is water-endangering and inflammable. It may only be used when the corresponding safety data sheet is available and all precautions prescribed therein were taken. The hydraulic system may only be operated when in technically perfect condition. The use for the intended purpose, performance data and operating conditions must not be changed. Protective equipment / components must not be rendered inoperable, e.g. by bridging limit switches, valves or other control components. If protective equipment must be bridged to allow servicing work to be carried out, precautions must be taken to ensure that no dangerous situation can arise. The higher-order machine operating instructions must be observed. Adjustment features on components may only be operated or changes to programmable control systems made exclusively by authorized personnel within the framework of the intended use of the hydraulic system. In the case of an emergency, fault or other irregularities: • hydraulic systems must be switched off and the main circuit breaker be secured against restarting, • the danger zone must be fenced off in order that nobody can enter the danger zone unknowingly or in an uncontrolled manner, • immediately inform the responsible specialist personnel. Uncontrolled access by external persons to the direct operating area of the hydraulic system is prohibited (even in case that the hydraulic system is at rest).

Note: These are the fundamental safety regulations that must be observed for every project task.

Safety notes

Effects of air in the oil

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Air can be present in hydraulic oils in the following forms: as dissolved air (invisible), as surface foam (visible), and as undissolved, dispersed air (visible). While dissolved air and minor surface foam hardly show any adverse effects, dispersed air can cause severe problems. Since the oil contains very small air bubbles, which are finely dispersed and can rise to the surface only very slowly, the following troubles can occur: • Uneven or jerky movements of hydraulic spools, vibration in the system due to increased compressibility, changed actuating times of servo-valves • Pump noise • Damage to pumps, lines and seals caused by cavitation • Accelerated aging of the oil • Micro-diesel effect, a form of thermal cracking due to high temperatures in compressed air bubbles To prevent undissolved air in the oil, the following must be observed: No leakage in the system on the suction side, optimum storage tank size, installation of baffles in the oil storage tank, favorable design of the suction system without throttling points, sufficient oil level, low oil circulation rates, immersed pumps instead of great suction heights.

Environmental aspects

Hydraulic systems are closed systems. When hydraulic systems are used properly, hydraulic fluid does therefore not get into the environment. Care must be taken that power units are leak-free and maintenance/repairs are carried out in due time. Especially hydraulic hoses and hose connections must be intensively observed and inspected. Oil changes must be made properly and thoroughly; waste oil must be disposed of in accordance with all relevant legal stipulations.

Safety aspects

Hydraulic fluids based on mineral oil are water-endangering and inflammable. Hydraulic fluids may only be used, if the corresponding safety data sheet of the manufacturer is at hand and all precautions prescribed therein are observed.

Danger

If leakage on the hydraulic product can lead to the contamination of water and soil, the hydraulic product must be placed in a suitable oil drip tray.

Safety notes

Filtration

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An essential precondition for the trouble-free operation of a hydraulic system is the flawless condition of the hydraulic fluid, for one of the main causes of failure of hydraulic components was and still is contamination. The sketch below shows various types of contaminaion that can lead to contamination of the hydraulic fluid.

1 2 3 4 5

External contamination Installation + repair Fresh oil Abrasion in the pump Abrasion of seals

Sources of contamination

Classification

Technical data sheets include notes on the assessment of solid particle contents in hydraulic fluids with the help of classification systems (standardized cleanliness classes). The most common standards today are NAS 1638 (National American Standard) and ISO DIS 4406. The indication of the filter rating in µm is no longer common practice today, but is often applied when circuit diagrams are created. Note: The comprehensive subject of filtration and maintenance is not dealt with in detail in the Project Manual Proportional Valve Technology. A specific project for a later, extended issue is in preparation. Notes on the topic of filtration can be found in information sources such as data sheets, operating instructions and technical books, which are referred to in the Project Manual Proportional Valve technology.

Project exercises for propotional valve technology

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Bosch Rexroth AG I RE 00847/07.07

Project order: Modernization of a hydraulic press

An old hydraulic press, which is still in good shape in terms of the mechanics, is to be modernized. The objective of the modernization is: 1. to increase productivity 2. to become more flexible with regard to product changes 3. to achieve better accuracy 4. to automate the press control The press is used for deep-drawing kitchen sinks of different designs. The sequence of a press is: • Initial position ram up, press open → Rapid speed downwards → Decelerating → Slow pressing → Pressure holding → Decompression → Rapid return

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The operating modes are setup mode and production mode. Up until now, the press has been operated semi-automatically by a press operator and a feeder. It was controlled by means of a linkage with manually operated hydraulic directional valves. The pressing pressure was adjusted by means of chain-operated pressure relief valves. Rapid speed was initiated by the press operator using a lever. Decelerating and the pressing velocity were adjusted by means of cams and a roller-operated deceleration valve. Decompression and return were also initiated by the press operator by means of levers. The quality of the produced sinks depended, of course, strongly on the experience and routine of the press operator. In the case of a product change and hence a die change, the press had to be newly run in. Moreover, the quality produced by the individual press operators also showed fluctuations. Now, the order is to realize a fully automatic control for the hydraulic press. Machine controls today are electrical, and for this reason, only electrically adjustable valves and electrical sensors are used. Components: - Proportional directional valve 4WREE6E08/2X - Inductive limit switch

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Safety aspects Safety and the economic use of resources are essential demands that are placed on modern plant and machinery and serve to protect people. These two requirements have in common that they have to be taken into account as early as possible, that is, at the product concept stage. Only in this way can optimized and low-priced solutions be found. Safe machines with low consumption demonstrate that the manufacturer masters his processes; they are a quality feature. In order that hazards to plant and machinery can be recognized, safety regulations, product information brochures and operating instructions must be observed. Corresponding notes on handling electrohydraulic components and systems of Bosch Rexroth can be found in: • General product information on hydraulic products RE 07008/02.05 • Operating instructions for hydraulic systems AB 01-01.02 • Hydraulic cylinders of tie rod/mill-type design (operating instructions) RE 07100-B/10.04 • Operating instructions DS4 – 1X RE 00225-B/05.05 The safety notes and product information in the above documentation are exclusively valid for Bosch Rexroth hydraulic products. Only if these operating instructions, safety notes and product information are observed can the trouble-free operation of Rexroth products be ensured. The present Project Manual Proportional Valve Technology includes warning notes, which precede instructions for activities that involve a risk of personal injury or damage to property. The described precautions for averting risks must be taken.

Conventions This symbol refers to imminent danger that, if not avoided, can lead to severest injuries or death. Warning This symbol refers to a potential risk, which can lead to light or serious injuries or damage to property. Caution This symbol refers to supplementary information.

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Note: The electrohydraulic components and systems described in this Project Manual are technical equipment, which is not intended for private use. The use for the intended purpose also includes that the safety regulations, product information and operating instructions described in the following are read and understood.

Qualification of personnel

Installation, commissioning and operation, disassembly, upkeep and maintenance require fundamental knowledge of mechanics and electrohydraulics as well as the knowledge of related technical terms. In order to ensure operational safety, these activities may only be carried out by a corresponding specialist or by an instructed person under the supervision of a specialist. A specialist is, who, due to his/her professional training, his/her knowledge and experience and the knowledge of relevant regulations, can asses the duties assigned to him/her, recognize potential risks and take suitable precautions. A specialist must observe relevant technical rules. Consequently, this means that the trainer must point out potential risks to the trainees and provide information of how to avert such risks.

Warning

Liability

Work carried out improperly on electrohydraulic components and systems involves the risk of injury and represents a safety risk during operation of the system, including danger to life!

In the case of damage resulting from improper use and unauthorized interventions, which are not provided in the Project Manual Proportional Valve Technology, any liability claims for defects or other liability claims vis-à-vis Bosch Rexroth AG become void. If the Projects 01 to 09 described in the Project Manual Proportional Valve Technology are carried out on training stands and with electrohydraulic components that were not delivered by Rexroth, that is, products of competitors' make, any defect or liability claims vis-à-vis Bosch Rexroth AG shall be void as well.

Project exercises for propotional valve technology

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Bosch Rexroth AG I RE 00847/07.07

When using competitors' products, observe the safety notes of the manufacturer and make sure that the components and systems comply with currently valid EU Directives.

Warning

For this reason, commissioning is prohibited until it was established that the electrohydraulic components and systems to be used meet the stipulations of all relevant EU Directives.

Note: The required safety regulations, product information documents* and operating instructions must be handed over or be accessible to the trainee in their latest issue. * Rexroth product information sheets are valid exclusively for hydraulic products, which are operated with hydraulic fluids based on mineral oil, unless the use of other hydraulic fluids is expressly permitted in the operating instructions.

Project exercises for propotional valve technology

Notes

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Bosch Rexroth AG I RE 00847/07.07

Project 01: Moving a cylinder with the help of a potentiometer

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Bosch Rexroth AG I RE 00847/07.07

Project 01: Moving a cylinder with the help of an external potentiometer for the provision of a command value Project definition For commissioning the machine control, which is still unknown to us, it should first be moved carefully by hand. In this way, the behavior of the hydraulic machine control can be understood. Of particular interest is the relationship between the command value and the cylinder velocity.

Fig. 01.01 Section of a 4WREE6 proport. directional valve with integrated electronics OBE

Project tasks • Testing of the valve function by measuring the command value and the actual value • Determining the command value voltage for the start of movement • Testing of polarities; with positive command values the cylinder must extend • Determining the relationship between cylinder traversing time and command values

01

Project 01: Moving a cylinder with the help of a potentiometer

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Bosch Rexroth AG I RE 00847/07.07

01

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of sketches of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

Project 01: Moving a cylinder with the help of a potentiometer

Hydraulic circuit diagram

Fig. 01.02 Hydraulic circuit diagram

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Bosch Rexroth AG I RE 00847/07.07

01

Project 01: Moving a cylinder with the help of a potentiometer

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Bosch Rexroth AG I RE 00847/07.07

01

Electrical block circuit diagram

Command value provision Inputs Supply 0V 24 V

Output Command value ±10 V Signal ⊥ Reference BPS 5.2

Command/actual value display

Connection panel Inputs Command value (D) ± 10 V (E) ⊥ Reference Supply (B) 0 V (A) 24 V

Outputs Actual value ±10 V (F) ⊥ Reference (C) Valve

0V + 24V

Fig. 01.03 Electrical block circuit diagram

Fig. 01.04 Command value source/connection panel/command/actual value display

BPS 21.0

Display 1 ±10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

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01

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS 2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Symbol

Table 01.01 Parts list for hydraulic circuit diagram Fig. 01.02

Item



Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Distributor

BPS 13.1

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

Table 01.02 Parts list for electrical block circuit diagram Fig. 01.03

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Component arrangement

Fig. 01.05 Recommended component arrangement with component designations for parts list Table 01.01 and hydraulic circuit diagram Fig. 01.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

01

Project 01: Moving a cylinder with the help of a potentiometer

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Bosch Rexroth AG I RE 00847/07.07

01

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise during operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted by means of a 4/3 proportional directional valve. The cylinder must extend with positive command values. The system pressure is to be limited. Note for trainers: The command value polarity for opening the valve is defined in data sheet RE 29061 on page 8. A positive command value corresponds to P→A and B→T, which results in the fact that the cylinder piston side must be connected to A. The trainees are to understand this with the help of the data sheet and implement it in the circuit diagram.

Project 01: Moving a cylinder with the help of a potentiometer

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Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, use pressure hoses DZ 25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses. 2. Electrical control The electrical control must be set up so that proportional valve 4WREE6 DW40E-D can be operated with command value source BPS5.2. The command value and actual value are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Testing the valve function Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the pump is not switched on and the by-pass valve is open. Generally, when taking voltage measurements, the signal (+/-10 V) must always be measured against a reference (^). The measuring points used on the BPS 21.0 are sockets D (+/-10 V), E (^) for the command value, and F (+/-10 V), C (^) for the actual value. Run command values from 0 V to 10 V with positive and negative polarity with the help of command value source BPS 5.2. Observe the voltages on command/actual value display BPS 6.1. The command value and the actual value must always have the identical value +/- 0.02 V. If the actual value deviates significantly from the command value, a fault must be present in the valve or valve electronics.

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Project 01: Moving a cylinder with the help of a potentiometer

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Bosch Rexroth AG I RE 00847/07.07

Causes of faults: •

Actual value always 0 V



→ Valve electronics defective, no voltage supply

•

Actual value always e.g. 2.7 V



→ Valve spool jammed in the housing

•

Actual value gets stuck at e.g. 3.1 V



→ Valve spool blocked at 3.1 V Integrated valve electronics are factory-set on test rigs and must not be modified by the user.

Caution

Adjustments of the integrated valve electronics on the system are necessary in exceptional cases only and require special knowledge. Unqualified modifications can lead to unexpected valve characteristics.

Fig. 01.06 Integrated electronics

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Project 01: Moving a cylinder with the help of a potentiometer

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4. Moving the cylinder by providing a command value At a command value of 0 V the cylinder must be at rest. Otherwise, the setting of the proportional valve must have been changed. First set the command value input to 0 V and turn the potentiometer to 0 V, otherwise, the cylinder starts to move as soon as pressure is built up in the system. Fully unload the system pressure relief valve. Fully unload the load pressure relief valve. Switch on the hydraulic pump and the control voltage. Close the by-pass valve. Check the hydraulic circuit for leakage. Set the pressure relief valve to 20 bar. Use command value source BPS5.2 to slowly increase the command value from 0 V with positive polarity, and observe, at which value the cylinder starts to move. Note this command value. Slowly increase the command value further while observing the cylinder velocity. Reverse the cylinder's direction of movement with the help of the +/- polarity switch. With positive values the cylinder must extend. Note for trainers: The movement starts at approx. 1.2 V = opening of 12 %. At an opening of 12 % leakage has reached an amount at which a clear cylinder movement can be observed. The valve overlap is 15 %; at this value, the control lands are opened. Minor deviations can be traced back to housing tolerances. The start of movement is not a creeping movement, but a clearly visible movement; this is, of course, a subjective perception, which also results in tolerances of the relevant values. For this reason, exact and reproducible values must be measured by means of measuring instruments. If a cylinder does not extend with positive values, hoses A and B were exchanged or the polarity of the command value input (D, E) for the valve was reversed. Also observe the correct polarity on the command/actual value display. The measuring points for the command value are the output sockets of the command value source, that for the actual value the test sockets "actual value" on operator module BPS 21.0.

01

Project 01: Moving a cylinder with the help of a potentiometer

11

Bosch Rexroth AG I RE 00847/07.07

To get a grasp of the relationship of command value and cylinder velocity, measure the extending times of the cylinder over the entire stroke using the stopwatch. Set the system pressure to 50 bar on the pressure relief valve. The load pressure relief valve remains fully unloaded. Increase the command values in 0.5 V increments The starting position of the cylinder is the fully retracted position, the end position is the fully extended cylinder position.

Caution

Notes

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- to depressurize the working line and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

01

Project 01: Moving a cylinder with the help of a potentiometer

Measured values

12

Bosch Rexroth AG I RE 00847/07.07

Command value Traversing time 1.5 V

20.0 s

2.0 V

6.6 s

2.5 V

4.0 s

3.0 V

2.7 s

3.5 V

2.0 s

4.0 V

1.8 s

4.5 V

1.6 s

5.0 V

1.6 s

5.5 V

1.6 s

Velocity 20 mm/s 61 mm/s 100 mm/s 148 mm/s 200 mm/s 220 mm/s 250 mm/s 250 mm/s 250 mm/s

Table 01.03 Table of measured values

Diagram 01.01 Command value/velocity

Note for trainers: The velocity behaves almost linear in relation to the command value. The control spools are provided with circular lands. The pressure differential across the valve also has an influence, because it is not constant. From a value of approx. 4.5 V on, the velocity does no longer increase, because the displacement of the pump limits the possible max. velocity. At identical command values, the cylinder extends faster than it retracts; this depends on the different pressure differentials during extending and retracting. This will be dealt with in more detail in a later project.

01

Project 01: Moving a cylinder with the help of a potentiometer

13

Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. At which command value has the cylinder noticeably performed a movement? At a command value of 1.2 V the cylinder moved noticeably. II. Why does the cylinder not yet start to move at 0.5 V? The spool has a 15 % overlap in the housing. III. How did the cylinder velocity change in relation to the command value? As the command value increases, the cylinder velocity rises linearily. IV. What limits the max. cylinder velocity and from which command value on? The max. velocity is limited by the max. displacement of the pump. This starts at 4.5 V. V. What determines the cylinder's direction of movement? The polarity of the command value determines the direction of flow in the valve and thus the direction of movement.

Project/trainer info In Project 01 basic knowledge is to be imparted of the behavior of proportional valves in a practical setup. The project order is the first part of the general project "press modernization“ and represents the first step of commissioning. In the practical setup, the following knowledge is to be imparted: • Testing the valve function by measuring command value and actual value • Knowledge of measuring points • The amount of the command value determines the cylinder velocity. • The polarity determines the cylinder's direction of movement. • The cylinder only starts to move notieably at approx. 1.2 V due to the positive valve overlap.

01

Project 01: Moving a cylinder with the help of a potentiometer

Notes

14

Bosch Rexroth AG I RE 00847/07.07

01

Project 02: Traversing a cylinder with a command value module

1

Bosch Rexroth AG I RE 00847/07.07

Project 02: Traversing a cylinder with command value module SWMA1 as command value source

02 Project definition For commissioning the machine control, which is still unknown to us, the latter is to be tested for function first. During this, trainees will be made familiar with the signal flow and function of command value module BPS 20.0.

Fig. 02.01 Command value module SWMA1

Project tasks • Activation of a command value with a digital signal • Adjustment of the command value voltage on the command value module • Testing of polarities • Measurement of the command value voltage at the test sockets

Project 02: Traversing a cylinder with a command value module

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of sketches of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

02

Project 02: Traversing a cylinder with a command value module

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

02

Fig. 02.02 Hydraulic circuit diagram

Project 02: Traversing a cylinder with a command value module

Bosch Rexroth AG I RE 00847/07.07

4

Electrical block circuit diagram 1

+ 24V S1

02

2

3

3

S2 4

4

Command value module Outputs Inputs Comm. value Measurands Comm. value w Call-up 4 Reference ⊥ Call-up 3 Ramp time t Call-up 2 Reference ⊥ Call-up 1 Inversion Control Inv. output Differential ±10 V input Reference ⊥ ± 10 V ⊥ reference Ramp 4Q BPS 20.0 Supply 0V + 24 V

Comm./act.display Connection panel Inputs Comm. Val. ± 10 V (D) ⊥ ref. (E) Supply 0V (B) + 24 V (A)

Outputs Act. value (F) ± 10 V (C) ⊥ ref. Valve BPS 21.0

0V + 24V

Fig. 02.03 Electrical block circuit diagram

Fig. 02.04 Command value module/connection panel/command/actual value display

Display 1 ± 10 V signal ⊥ reference Display 2 ±10 V signal ⊥ reference Supply 0V + 24 V BPS 6.1

Project 02: Traversing a cylinder with a command value module

5

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS 2.1

0.1-0.3

3

Pressure gauge with minimess line

Dz1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Symbol

Table 02.01 Parts list for hydraulic circuit diagram Fig. 02.02 Item

S1-S3

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

1

Command value/actual value display

BPS 6.1

Stopwatch, 2 mm screw driver, Allan key set Table 02.02 Parts list for electrical block circuit diagram Fig. 02.03 1

02

Project 02: Traversing a cylinder with a command value module

6

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

02

Fig. 02.05 Recommended component arrangement with component designations for parts list Table 02.01 and hydraulic circuit diagram Fig. 02.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 02: Traversing a cylinder with a command value module

7

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted using a 4/3 proportional directional valve. With positive command values the cylinder must extend. The system pressure is to be limited. Note for trainers: The command value module is described in data sheet RE 29902. On the basis of this data sheet, the trainees are to make themselves familiar with the function of digital call-ups and command value settings and apply this knowledge in a circuit diagram. Moreover, the position and function of control and indicator elements is to be taken from the data sheet. All of the ramp potentiometers should be set to their left-hand limit stop, because the ramp function will only be dealt with in later projects.

02

Project 02: Traversing a cylinder with a command value module

8

Bosch Rexroth AG I RE 00847/07.07

Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, use pressure hoses DZ 25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses. 2. Electrical control The electrical control must be set up so that proportional valve 4WREE6 DW40E-D can be operated using command value module BPS 20.0. Command value "w1" is called up using an S2 switch. The inversion is called up using an S1 switch. The command value and actual value are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Testing of the command value module function Switch the control voltage on. Hydraulic pressure is not yet necessary; for this reason, the hydraulic pump is not switched on and the by-pass valve is open. Run command value "w1" from 0 V to 10 V with positive and negative polarity using the command value module. The command value must be activated with S2 "call-up 1“. To change the polarity, activate the call-up "inversion" with S1. Measuring points are w, ┴ on command value module BPS 20.0 for the command value, and F(+/-10V), C(┴) on BPS 21.0 for the actual value. Observe the voltages on command/actual value display BPS 6.1. When no command value is activated, the command value must be 0 V. If a value is displayed, potentiometer "Z" must have been improperly trimmed. In this case, use "Z" to set the command value to 0 V.

02

Project 02: Traversing a cylinder with a command value module

9

Bosch Rexroth AG I RE 00847/07.07

4. Traversing the cylinder with the help of the command value module First set command value "w1“ to 0 V, otherwise, the cylinder moves at an undefined velocity as soon as "w1" is activated with S2. Fully unload the pressure relief valve. Unload the load pressure valve. Switch on the hydraulic valve and the control voltage. Close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the pressure relief valve to 50 bar. Operate switch "S2“ to call up command value "w1“. Slowly increase command value "w1" from 0 V with positive polarity on the command value module. Slowly increase the command value further while observing the cylinder velocity. Activate the call-up "inversion" by means of switch "S1“ and change the direction of movement of the cylinder. With positive values the cylinder must extend. Note for trainers: This project focuses exclusively on the adjustment and activation of command values. Further functions will be dealt with in the subsequent projects. The position of elements is shown on page 5 of data sheet RE 29902. It is important to understand that a command value and inversion must be activated with a digital signal. An LED indicates, which function is active. This digital signal can be provided by a switch, relay or PLC output. The measuring points for the command value are the test sockets at command value module BPS 20.0, for the actual value the "actual value" test sockets of operator module BPS 21.0. When no command value is active, the value at test socket "w“ must be 0 V. Values up to +/- 1 V can be corrected with potentiometer "Z“. A voltage potential may build up at the differential input due to electrical interference. In this case, the differential input must be short-circuited. In practice, open differential inputs can cause so-called "ghost movements" or high-frequency vibration. The voltage at the differential input always adds to the called up command values.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- in order to unload the pressure in the working line and in the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

02

Project 02: Traversing a cylinder with a command value module

10

Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. Which components are used for adjusting command values? Command values are adjusted on the command value module with the help of potentiometers. II. How are the command values activated (called up)? Command values must be activated (called up) with a digital 24 V signal. III. How can the polarity be changed? To change the polarity you must activate the signal inversion. IV. Where can the current command value be measured? The current command value can be measured at test socket "w“ against "┴“. V. Which value may the command value voltage take, when no command value is activated, and where can the value be adjusted, if required? When no command value is activated, the command value voltage must be 0 V; if required, it can be adjusted by means of "Z“.

Project/trainer info In Project 02 basic knowledge is to be imparted with regard to the operation of command value module BPS 20.0 in a practical setup. The project order is an integral part of the general project "press modernization" and is intended to make the trainees familiar with the signal flow and the operating principle of the control. The following knowledge is to be gained in the practical setup: • Function of "digital call-ups“ • Command value adjustment • Function of "inversion“ • Measuring point for command value

02

Project 03: Adjusting the command value module

1

Bosch Rexroth AG I RE 00847/07.07

Project 03: Adjusting command value module SWMA1 with 4 command values Project definition For commissioning the machine control, which is still unknown to us, the latter is to be tested for function first. During this, the trainees will be made familiar with the signal flow and function of the command value module.

Fig. 03.01 Press control block with proportional valves

Project tasks • Activation of various command values with digital signals • Adjustment of command value voltages on the command value module • Testing of polarities • Measurement of the command value voltage at test socket "w“ against ┴ .

03

Project 03: Adjusting the command value module

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

03

Project 03: Adjusting the command value module

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

03

Fig. 03.02 Hydraulic circuit diagram

Project 03: Adjusting the command value module

4

Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1

+ 24V

3

1

4

S3

3 4

3

3

S5

S4 4

4

3

2

3

03

S6 4

4

Command value module Outputs Inputs Comm. value Measurands Comm. value w Call-up 4 Reference ⊥ Call-up 3 Ramp time t Call-up 2 Reference ⊥ Call-up 1 Inversion Inv. Differential Control output ±10 V input Reference ⊥ ± 10 V ⊥ reference Ramp 4Q Supply 0V BPS 20.0 + 24 V

Comm./act. display Connection panel Inputs Comm. Val. ± 10 V (D) ⊥ ref. (E) Supply 0V (B) + 24 V (A)

Outputs Act. value (F) ± 10 V (C) ⊥ ref.

0V + 24V

Fig. 03.03 Electrical block circuit diagram

Fig. 03.04 Command value module/connection panel/command/actual value display

Valve BPS 21.0

Display 1 ± 10 V signal ⊥ reference Display 2 ±10 V signal ⊥ reference Supply 0V + 24 V BPS 6.1

Project 03: Adjusting the command value module

5

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Symbol

Table 03.01 Parts list for hydraulic circuit diagram Fig. 03.02 Item

S1-S6

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

Table 03.02 Parts list for electrical block circuit diagram Fig. 03.03

03

Project 03: Adjusting the command value module

6

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

03

Fig. 03.05 Recommended component arrangement with component designations for parts list Table 03.01 and hydraulic circuit diagram Fig. 03.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 03: Adjusting the command value module

7

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. With positive command values the cylinder must extend. The system pressure is to be limited. Note for trainers: The command value module is described in data sheet RE 29902. On the basis of the data sheet the trainees are to make themselves familiar with the function of digital call-ups and the adjustment of the command values and apply this knowledge in the circuit diagram. Moreover, the position and function of the control and indicator elements are to be taken from the data sheet. The ramp potentiometers should all be set to the left-hand limit stop, because the ramp function is dealt with in subsequent projects.

03

Project 03: Adjusting the command value module

8

Bosch Rexroth AG I RE 00847/07.07

Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware training according to the circuit diagram and connect them by means of hoses. To connect pressure gauges with measuring line DZ 1.4 use pressure hoses DZ 25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses. 2. Electrical control The electrical control must be set up so that with the help of the command value module proportional valve 4WREE6 DW40E-D can be operated with 4 different command values. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0, display BPS 6.1 must be permanently connected to 24 V. The control voltage for switches, push-buttons, relays is switched with the help of an "S1" switch. It should be possible to call up the command values with the help of pushbuttons "S3-6“ . The command value and actual value are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Testing the command value module function Switch the control voltage on. Hydraulic pressure is not yet necessary; for this reason, the hydraulic pump is not switched on and the by-pass valve is open. Set the command values "w1-w4" to 2 V at the command value module. The command values must be activated with 24 V of the relevant "call-up" in order that the values can be read off. This is accomplished by operating switch "S3-6“. The measuring points are w, ┴ on command value module BPS 20.0 for the command value, and F (+/-10V), C (┴) on BPS 21.0 for the actual value. Observe the voltages for the command value and the actual value on command/actual value display BPS 6.1. What happens, if two command values are activated simultaneously?

03

Project 03: Adjusting the command value module

9

Bosch Rexroth AG I RE 00847/07.07

What are the polarities of the individual command values? When no command value is activated, the command value must be 0 V. If a value is displayed, potentiometer "Z" must be improperly trimmed. In this case, adjust the command value to 0 V by means of "Z“. Note for trainers: This project focuses exclusively on the adjustment and activation of command values. Further functions are dealt with in subsequent projects. It is important to understand that command values are activated with a digital signal. An LED signals, which value is active. This digital signal can come from switches, push-buttons, relays, or PLC outputs. If two command values are activated, "w1" has the lowest priority and "w4“ the highest priority. "w1“, "w2“ have an internally positive connection, and "w3“, "w4“ a negative connection. The measuring points for the command value are test sockets “w“ "┴“ on the command value module, those for the actual value test sockets "actual value" on operator module BPS 20.0. 4. Traversing the cylinder with the help of the command value module Switch the control voltage on. Make the following settings on the command value module: Command value "w1“ = 6 V, call up command value "w1" with push-button "S3“. Command value "w2“ = 2.5 V, call up command value "w2" with push-button "S4“. Command value "w3“ = -6 V, call up command value "w3" with push-button "S5“. Command value "w4“ = -2.5 V, call up command value "w4" with push-button "S6“ Fully unload the pressure relief valve. Switch the hydraulic pump on and close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the pressure relief valve to 50 bar. Unload the load pressure valve. 1. Move the cylinder with the help of push-buttons "S3-6“. 2. First operate push-button "S3“, then "S4“ and watch what happens. The cylinder moves according to the pre-set command values when they are activated. If two command values are activated simultaneously, the higher number has always priority.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- to depressurize the working line and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

03

Project 03: Adjusting the command value module

10

Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. How many command values "w“ are provided on the command value module? 4 different command values can be set on the command value module. II. How can these command values be activated (called up) ? The individual command values must be activated (called up) with a digital 24 V signal. III. How is signaled, which command value is active? The active command value is indicated by an LED. IV. What are the polarities of the individual command values? The polarity of command values "w1“, "w2“ is positive, that of "w3“, "w4“ is negative. V. What are the priorities of command values "w1-4“? Command value "w1“ has low, "w4“ high priority. VI. How can the current command value be measured? The current command value can be measured at test socket "w“, "┴“. If no command value is activated, the command value voltage must be 0 V; if required, it can be adjusted by means of "Z“ .

Project/trainer info In Project 03 knowledge is to be imparted with regard to the operation of the command value module in a practical setup. The project order is an integral part of the general project "press modernization" and is to help understand the signal sequence and the operating principle of the control. The practical setup is to impart knowledge of: • Function of "digital call-ups“ • Command value adjustment • Measuring point for command value

03

Project 04: Command values and ramps

1

Bosch Rexroth AG I RE 00847/07.07

Project 04: Adjusting command value module SWMA1 with 4 command values and ramps Project definition During commissioning of the machine control, the customer was dissatisfied with the hard acceleration and deceleration. This should be much smoother with the new technology.

Fig. 04.01 Control block with on/off and proportional valves

Project tasks • Activation of different command values with digital signals • Adjustment of command value voltages and ramps on the command value module • Testing of ramp voltages at test socket "t“ • Measurement of command value voltage at test socket "w“

04

Project 04: Command values and ramps

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

04

Project 04: Command values and ramps

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

04

Fig. 04.02 Hydraulic circuit diagram

Project 04: Command values and ramps

4

Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1

+ 24V

3

1

4

S3

3

3

S5

S4 4

4

4

3

2

3

3

S6 4

4

Command value module Inputs Command value Call-up 4 Call-up 3 Call-up 2 Call-up 1 Inversion Inv. Differential Input ± 10 V ⊥ Reference Ramp 4Q Supply 0V + 24 V

Outputs Measurands Command value w Reference ⊥ Ramp time t Reference ⊥

Control output ±10 V Reference ⊥

Connection panel

Command/actual value display

Outputs Input Actual value Command value (F) ± 10 V (C) ⊥ ± 10 V (D) Reference ⊥ Reference (E) Supply Valve 0V (B) BPS 21.0 + 24 V (A)

Display 1 ± 10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

BPS 20.0

0V + 24V

Fig. 04.03 Electrical block circuit diagram

Fig. 04.04 Command value module/connection panel/command/actual value display

04

Project 04: Command values and ramps

5

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

Symbol

04 1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Table 04.01 Parts list for hydraulic circuit diagram Fig. 04.02 Item

S1-S6

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

Table 04.02 Parts list for electrical block circuit diagram Fig. 04.03

Project 04: Command values and ramps

6

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

04

Fig. 04.05 Recommended component arrangement with component designations for parts list Table 04.01 and hydraulic circuit diagram Fig. 04.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 04: Command values and ramps

7

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. With positive command values the cylinder must extend. The system pressure is to be limited. Note for trainers: The command value module is described in data sheet RE 29902. With the help of the data sheet the trainees are to make themselves familiar with the function of ramps and their assignment to command values. An important point is the table "ramp time" and the formula for converting the measured voltage into a ramp time. Moreover, the position and function of control and indicator elements is to be taken from the data sheet.

04

Project 04: Command values and ramps

8

Bosch Rexroth AG I RE 00847/07.07

Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4 use pressure hoses DZ25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses. 2. Electrical control The electrical control must be set up so that with the help of the command value module proportional valve 4WREE6 DW40E-D can be operated with 4 different command values. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0, and display BPS 6.1 must be permanently connected to 24 V. A switch "S1“ is used to switch the control voltage for switches, push-buttons and relays. It should be possible to call up the command values by means of push-buttons "S3-6“. Command value and ramp voltage are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Testing of the command value module function Switch the control voltage on. Hydraulic pressure is not yet necessary; for this reason, the hydraulic pump is not switched on and the by-pass valve is open. The command values must be activated with 24 V at the relevant "call-up" in order that the values can be read off. The ramps "t1-4“ are activated simultaneously with command values "w1-4“. Set ramps "t1-5" to > 5 V (20 ms) on the command value module; this is the minimum ramp time. This is accomplished by operating push-buttons "S3-6“. Ramp "t5“ is active, when no command value is activated. Observe the command value voltage (test socket "w“, ┴) and the ramp voltage (measuring socket "t“, ┴) on command/actual value display BPS 6.1.

04

Project 04: Command values and ramps

9

Bosch Rexroth AG I RE 00847/07.07

What happens, if two command values are activated simultaneously? Which polarity have the individual command values? If no command value is activated, the command value must be 0 V. If a value is displayed, potentiometer "Z“ must be improperly trimmed. In this case, adjust the command value to 0 V by means of "Z“. Note for trainers: This project deals exclusively with the adjustment of command value with the associated ramps. It is important to understand that command values and ramps are activated simultaneously by digital signals. An LED indicates, which values are active. The digital signal can come from switches, push-buttons, relays or PLC outputs. The measuring point for the command value and the ramp are the measuring sockets on the command value module. 4. Traversing the cylinder with the help of the command value module Switch the control voltage on. Command value "w1“ = 10 V, call up command value "w1" with push-button "S3“. Command value "w2“ = 0 V, call up command value "w2" with push-button "S4“. Command value "w3“ = -10 V, call up command value "w3" with push-button "S5“. Command value "w4“ = -0 V, call up command value "w4" with push-button "S6“. The values can be measured at test socket "w“, "┴“. Fully unload the pressure relief valve. Switch the hydraulic pump on and close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the pressure relief valve to 50 bar. Unload the load pressure valve. Move the cylinder by operating push-buttons "S3-6“ and stop before the end positions. The cylinder moves according to the pre-set command values when these are activated. Because the ramp time of 20 ms is very short, the cylinder accelerates abruptly and also comes abruptly to a standstill when the push-button is released. To improve this behavior, the ramps are to be adjusted.

04

Project 04: Command values and ramps

10

Bosch Rexroth AG I RE 00847/07.07

While the adjustments are being made, the by-pass valve can be opened. Make the following settings on the command value module: Command value "w1“ = 10 V, ramp "t1“ 1.0 V (100 ms); call up command value "w1" by means of push-button "S3“. Command value "w2“ = 0 V, ramp "t2“ 5.0 V (20 ms); call up command value "w2" by means of push-button "S4“. Command value "w3“ = -10 V, ramp "t3“ 0.5 V (200 ms); call up command value "w3" by means of push-button "S5“. Command value "w4“ = -0 V, ramp "t4“ 0.05 V (2000 ms); call up command value "w4" by means of push-button "S6“. Ramp "t5“ 0.2 V (500 ms); do not operate any push-button After having made the adjustments, close the by-pass valve and traverse the cylinder with the help of the push-buttons while observing the changed behavior. Operate "S3" for extending; when the cylinder is in motion, release "S3“. When no command value is active, the cylinder is decelerated with ramp "t5“. To retract the cylinder operate "S5“. First operate "S3“; when the cylinder has set into motion, operate "S4" additionally. Because of the higher priority, "w2" is again active; since the command value is 0 V, the cylinder is decelerated with ramp "t2“. For retracting, operate "S5“; when the cylinder starts to move, release "S5“. If no command value is active, the cylinder is decelerated with ramp "t5“. Operate "S3“ to extend the cylinder again. First operate "S5“; when the cylinder has set into motion, operate "S6" additionally. Because of the higher priority, "w4" is active; since the command value is 0 V, the cylinder is decelerated with ramp "t4“. Note: Because ramp time "t4“ is relatively long with 2000 ms, the cylinder may already be in its end position when the command value reaches 0 V. For this reason, "S6“ should be operated already after a short cylinder stroke.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- to depressurize the working line and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

04

Project 04: Command values and ramps

11

Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. How many ramps can be set? 4 different command values and 5 ramps can be set on the command value module. II. How can the ramps be activated (called up)? The individual command values with ramps must be activated (called up) with a digital signal. III. How are the ramps assigned to the command values? The ramps are assigned to command values "w1, t1“, "w2, t2“, "w3, t3“, "w4, t4“; "t5“ is not firmly assigned to a command value. IV. Where can the ramp time be measured? The current command value can be measured at test socket "w“. V. What is the relationship between the measured voltage and the actual ramp time? The current ramp time can be measured at test socket "t“ . VI. What is the relationship between the measured ramp voltage and the actual ramp time? The measured ramp voltage is inversely proportional to the actual ramp time. VII. Which ramp is active, when no command value is active? When no command value is activated, "t5“ is active. VIII. What do ramps influence? The ramps have an influence on acceleration and deceleration characteristics.

04

Project 04: Command values and ramps

12

Bosch Rexroth AG I RE 00847/07.07

IX. Which effect has an excessively long ramp time? Due to the ramp time, the cylinder moves on after the push-button was released. X. Did the hard characteristics improve after the ramp time was adjusted? It was possible to improve the characteristics.

Project/trainer info In Project 04 the trainees are to become familiar with the operation of command value module BPS 20.0 in a practical setup. The project order is an integral part of the general project "press modernization" and is to help the trainees to understand the signal sequence and function of the control. The following knowledge is to be gained in the practical setup: • Function of the ramp • Assignment of ramps to the command values • Ramp adjustment • Measuring point for the ramp adjustment

04

Project 05: Braking distance after proximity switch

1

Bosch Rexroth AG I RE 00847/07.07

Project 05: Adjusting a braking distance following a proximity switch signal Project definition To get a better understanding of the braking characteristics of the press, the press is to be decelerated from max. velocity to "0" with a braking distance of 50 mm. How does the braking system behave with other command values? The function and application of ramps is to be understood.

Fig. 05.01 Control block with on/off and proportional valves in the field

Project tasks • Adjustment of a defined braking distance after a proximity switch • Adjustment of command value voltages and ramps on the command value module • Examination of influences on the braking distance

05

Project 05: Braking distance after proximity switch

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

05

Project 05: Braking distance after proximity switch

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

05

Fig. 05.02 Hydraulic circuit diagram

Project 05: Braking distance after proximity switch

4

Bosch Rexroth AG I RE 00847/07.07

Electrical circuit diagram

05

Fig. 05.03 Electrical circuit diagram

Project 05: Braking distance after proximity switch

5

Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1

+ 24V

3

7

4 24

K1 21

8 24

K3 21

Command value module Outputs Inputs Measurands Command value Command value w Call-up 4 Call-up 3 Reference ⊥ Ramp time t Call-up 2 Call-up 1 Reference ⊥ Inversion Inv. Control output Differential input ±10 V ± 10 V Reference ⊥ ⊥ Reference Ramp 4Q Supply 0V + 24 V BPS 20.0

Command/ actual display Connection panel S2 3

4

Inputs Outputs Actual Command value value (F) ± 10 V ± 10 V (D) (C) ⊥ Reference ⊥ Reference (E) Supply Valve 0V (B) + 24 V (A) BPS 21.0

0V + 24V

Fig. 05.04 Electrical block circuit diagram

Fig. 05.05 Command value module/connection panel/command/actual value display

Display 1 ± 10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

05

Project 05: Braking distance after proximity switch

6

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

Symbol

05 1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS2.1

0.10.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Table 05.01 Parts list for hydraulic circuit diagram Fig. 05.02

Project 05: Braking distance after proximity switch

Item

7

Bosch Rexroth AG I RE 00847/07.07

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

K1-K3

1

Control module

BRS1.2

B1

1

Proximity switch, inductive

DE2.2

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

S1-S6

Table 05.02 Parts list for electrical block circuit diagram Fig. 05.03 + Fig. 05.04

Notes

05

Project 05: Braking distance after proximity switch

8

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

05

Fig. 05.06 Recommended component arrangement with component designations for parts list Table 05.01 and hydraulic circuit diagram Fig. 05.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 05: Braking distance after proximity switch

9

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. With positive command values the cylinder must extend. The system pressure is to be limited. Note for trainers: The command value module is described in data sheet RE 29902. With the help of this data sheet the trainees are to make themselves familiar with the function of ramps and their assignment to command values. An important point is the ramp time table and the formula for converting the measured voltage into a ramp time. Moreover, the position and function of indicator elements is to be taken from the data sheet.

05

Project 05: Braking distance after proximity switch

10

Bosch Rexroth AG I RE 00847/07.07

Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring lines DZ1.4 use pressure hoses DZ25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses. 2. Electrical control The electrical control must be set up so that after a start signal the cylinder extends, and after a proximity switch signal the cylinder is decelerated. After a further signal the cylinder is to retract. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0, and display BPS 6.1 must be permanently connected to 24 V. An "S1“ switch is used for switching the control voltage for switches, pushbuttons, and relays. An "S2“ switch is used to connect BSP 20.0 output "+/- 10 V“ to BSP 21.0 input "D“, which is necessary for the command value adjustment in order that proportional directional valve 4WREE6 DW40E-D is not operated while adjustments are being made. Push-button S3 → Extending the cylinder with command value "w1“. Proximity switch B1 → Deceleration to standstill Push-button S4 → Retracting the cylinder with command value "w3“, even if B1 has not switched. The command value and ramp voltage are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

05

Project 05: Braking distance after proximity switch

11

Bosch Rexroth AG I RE 00847/07.07

3. Pre-settings on the command value module Hydraulic pressure is not yet required; the by-pass valve is to be opened. Switch the control voltage on by operating "S1“. "S2“ is open. Set command values "w1" to 1.5 V, "w3" to -5 V on the command value module. Set ramps "t1“, "t3“, "t5“ to > 5 V (20 ms), which is the minimum ramp time. The command values and ramps must be activated with the relevant "call-up" in order that the values can be read off. Ramps "t1-4“ are activated simultaneously with command values "w1-4“. This is accomplished by operating push-button "S3“ or "S4“. Ramp "t5“ is active, when no command value was activated. Which ramp is active for decelerating the cylinder? Observe the voltages on command/actual value display BPS 6.1. Note for trainers: This project focuses on the adjustment of command values with the associated ramps. It is important to understand that the velocity can be adjusted by means of command values, and the braking distance by means of ramps. Clarify, with which ramp the braking distance can be adjusted. It is "t5“, because no command value is active. The amount of the command value has an influence on the braking distance, even if the ramp setting remains unchanged. The ramp corresponds to the gradient of the command value signal. This must be illustrated with the help of a diagram. (See Basic principles of proportional valve technology, page 12) The measuring points for the command value and the ramp are test sockets "w“ and "t“ on the command value module. The proximity switch has an operating distance of 8 mm; it must therefore be placed very closely to the plexiglass guard. In order that the cylinder cannot move while command value settings are being made and reach the proximity switch faster than the values can be read off and set, the command value signal to the valve is enabled by switch "S2“. The ramp voltage for a braking distance of 50 mm is 0.12 V (+/-0.01 V).

05

Project 05: Braking distance after proximity switch

12

Bosch Rexroth AG I RE 00847/07.07

05

Fig. 5.7 Definition of the position and adjustment of the proximity switch

4. Adjustment of the braking distance The proximity switch is to be mounted at 250 mm. Fully unload the pressure relief valve. Switch the hydraulic pump on. Close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the pressure relief valve to 50 bar. Traverse the cylinder with the help of push-buttons "S3-4“ and operate "S2“ to enable the command value. The cylinder moves according to the pre-set command values (1.5 V and -5 V). It must be verified whether the proximity switch outputs a signal when the cylinder passes. Because the ramp time of 20 ms is very short, the cylinder is quickly accelerated and stops immediately after having reached the proximity switch. To simplify the determination of the switching point, the cylinder is to move at low velocity "w1“ = 1.5 V. The proximity switch must be adjusted so that the cylinder comes to rest at 250 mm +/- 1mm. This is signal position "250 mm“, where the braking distance starts. Then the braking distance of 50 mm for max. velocity "w1“ = 5 V is to be adjusted by means of ramp "t5“ To this end, extend the cylinder several times with "w1“ = 5 V, read off the braking distance and adjust "t5“ until the braking distance is 50 mm. Note the ramp voltage for a braking distance of 50 mm. Thus, the initial setting is completed. To examine the influence of the command value on the braking distance, the braking distance is to be measured with different command values while ramp "t5“ remains unchanged . With the setting of "w1“ the command value must not be enabled to the valve by "S2" , since otherwise, the cylinder extends faster than the command value

Project 05: Braking distance after proximity switch

13

Bosch Rexroth AG I RE 00847/07.07

can be read off or adjusted. When making adjustments, see to it that command value "w1“ is activated with "S3“. This can also be recognized by LED "w1“. After having adjusted the command value, enable the command value with "S2“. The cylinder will then extend up to the proximity switch. Enter the braking distance in the table.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- to depressurize the working line and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

05

Project 05: Braking distance after proximity switch

Measured values

14

Bosch Rexroth AG I RE 00847/07.07

Command value Braking distance Position 0 250 1.5 V 2.5 V

2 6

252 256

3.0 V

12

262

3.5 V

21

271

4.0 V

30

280

4.5 V

40

290

5.0 V

50 mm

300 mm

5.5 V

60

310

6.0 V

70

320

7.0 V

90

340

8.0 V

112

362

9.0 V

133

383

10.0 V

150

400 limit stop!

2.0 V

Table 05.03 Table of measured values

Note for trainers: The established braking distances can differ from the given values. If several training stands are used, different results and deviations are possible. Causes: Distance between the proximity switch and the cylinder pin Different control behavior of the pumps Reading tolerances, different temperatures, oil viscosities, loads Position 250 mm at 1.5 V and the braking distance of 50 mm at 5 V must be correct; otherwise the basic settings must have been made improperly. These deviations also reflect the problem of open-loop controlled systems and their multitude of influences on the position. In practice, it can often be observed that each machine must be individually adjusted, although they are all of the same design. If a precise and reproducible position is required, closed-loop controlled systems must be used, in which the cylinder position is measured and corrected. This principle is increasingly applied in many modern systems. One of the findings in this project is also to recognize the limits of simple, open-loop controlled systems.

05

Project 05: Braking distance after proximity switch

15

Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. What is adjusted by means of the command value with reference to the cylinder? The command value is used to adjust the velocity. II. What can be adjusted by means of the ramp with reference to the position? The ramp can be used to adjust a braking distance. III. Remains the braking distance unchanged if the command value is increased? As the command value is increased, the braking distance becomes longer. IV. Can difference in the braking distance have an adverse effect on the function of the press? The braking distance can have an adverse effect as a result of wide differences.

Project/trainer info In Project 05 the trainees are to learn more about the operation of command value module BPS 20.0 in a practical setup. The project order is an integral part of the general project "press modernization" and helps trainees to understand the signal sequence and function of the control. The following knowledge is to be imparted in the practical setup: • Function of the ramp • Assignment of ramps to the command values • Ramp adjustment • Measuring point for the ramp adjustment

05

Project 05: Braking distance after proximity switch

16

Bosch Rexroth AG I RE 00847/07.07

Notes

05

Project 06: Pressure relationships

1

Bosch Rexroth AG I RE 00847/07.07

Project 06: Pressures of the proportional valve and their influence on velocity and braking distance Project definition So far, the press has been operated without die. Now we are going to install dies of different weights. It can be seen that the press operates at different velocities although the settings remain unchanged. How can we explain this "phenomenon“ to the surprised customer? How does the braking distance behave at other velocities?

06

Fig. 06.01 Result of excessive speed and too long a braking distance.

Project tasks • Adjustment of a defined braking distance after a proximity switch • Adjustment of the command value voltages and ramps on the command value module • Examination of ∆p influences on the velocity and braking distance

Project 06: Pressure relationships

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

06

Project 06: Pressure relationships

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

06

Fig. 06.02 Hydraulic circuit diagram

Project 06: Pressure relationships

4

Bosch Rexroth AG I RE 00847/07.07

Electrical circuit diagram

06

Fig. 06.03 Electrical circuit diagram

Project 06: Pressure relationships

5

Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1

+ 24V

3

7

4 24

K1 21

8 24

K3 21

Command value module Outputs Inputs Measurands Command value Command value w Call-up 4 Call-up 3 Reference ⊥ Ramp time t Call-up 2 Call-up 1 Reference ⊥ Inversion Inv. Control output Differential input ±10 V ± 10 V Reference ⊥ ⊥ Reference Ramp 4Q Supply 0V + 24 V BPS 20.0

Command/ actual display Connection panel S2 3

4

Inputs Outputs Actual Command value value (F) ± 10 V ± 10 V (D) (C) ⊥ Reference ⊥ Reference (E) Supply Valve 0V (B) + 24 V (A) BPS 21.0

0V + 24V

Fig. 06.04 Electrical block circuit diagram

Fig. 06.05 Command value module/connection panel/command/actual value display

Display 1 ± 10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

06

Project 06: Pressure relationships

6

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Table 06.01 Parts list for hydraulic circuit diagram Fig. 06.02

Symbol

06

Project 06: Pressure relationships

Item

7

Bosch Rexroth AG I RE 00847/07.07

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

K1-K3

1

Control module

BRS1.2

B1

1

Proximity switch, inductive

DE2.2

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

S1-S6

Table 06.02 Parts list for electrical block circuit diagram Fig. 06.03 + Fig. 06.04

Notes

06

Project 06: Pressure relationships

8

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

06

Fig. 06.06 Recommended component arrangement with component designations for parts list Table 06.01 and hydraulic circuit diagram Fig. 06.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 06: Pressure relationships

9

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. The annulus side of the cylinder is to be pre-loaded by means of a pressure relief valve for the simulation of a load. The pressure relief valve is to be by-passed for retracting. With positive command values the cylinder must extend. The system pressure is to be limited. Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, use pressure hoses DZ 25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses.

06

Project 06: Pressure relationships

10

Bosch Rexroth AG I RE 00847/07.07

2. Electrical control The electrical control must be set up so that the cylinder starts to extend after a start signal and decelerates after a proximity switch signal. After a further signal, the cylinder is to retract. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0, display BPS 6.1 are permanently connected to 24 V. An "S1“ switch is used to switch the control voltage for switches, push-buttons and relays. An "S2“ switch is used to switch BSP 20.0 output "+/- 10 V“ to BSP 21.0 input "D“; this is required for command value adjustments in order that proportional directional valve 4WREE6 DW40E-D is not operated while adjustments are being made. The command value and the ramp voltage are to be measured and displayed. Push-button S3 → Extending cylinder with command value "w1“. Proximity switch B1 → Deceleration to standstill Push-button S4 → Retracting cylinder with command value "w3“, even if B1 did not operate. The command value and the ramp voltage are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Pre-setting the command value module Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the by-pass valve is open. "S2“ is open. Set command values "w1“ to 3 V, "w3“ to 5 V on the command value module. Set ramps "t1, 3, 5“ to 5 V (20 ms), which is the minimum ramp time. The command values and ramps must be activated by the relevant "call-up" in order that the values can be read off. Ramps "t1-4“ are activated simultaneously with command values "w1-4“. This is accomplished by actuating push-buttons "S3-4“. Ramp "t5“ is active when no command value is activated. Which ramp is active for decelerating the cylinder? Observe the voltages on command/actual value display BPS 6.1.

06

Project 06: Pressure relationships

11

Bosch Rexroth AG I RE 00847/07.07

Note for trainers: In this project we deal with the simulation of different loads by pressurizing the annulus cylinder chamber. This also changes the pressure in the cylinder piston chamber. The ∆p is changed while the system pressure remains unchanged. Thus, the cylinder velocity varies although the command value remains unchanged. It is important to understand that the ∆p has an influence on the velocity. This also has an influence on the braking distance, with unchanged command value and ramp settings. A diagram is to illustrate this phenomenon. (See Basic principles of proportional valve technology, page 12) The measuring points for the command value and the ramp are the test sockets on the command value module. The proximity switch has an operating distance of 8 mm; it must therefore be located very closely to the plexiglass guard. A further possibility is to vary the ∆p in order to change the system pressure.

Fig. 06.07 Definition of the position and setting of the proximity switch

06

Project 06: Pressure relationships

12

Bosch Rexroth AG I RE 00847/07.07

4. Establishment of the velocity at different load pressures Fully unload the system pressure relief valve. Fully unload the load pressure relief valve. Switch the hydraulic pump on and close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the system pressure relief valve to 50 bar. The proximity switch is not yet mounted. Operate "S2“ for the command value enable and traverse the cylinder by operating push-buttons "S3-4“. While making command value settings, switch the command value enable "S2" off. After having made the settings, switch command value enable "S2" on again, and the cylinder will extend to its limit stop. To examine the influence of the ∆p on the velocity, extend the cylinder with unchanged system pressure (50 bar), command value (3 V) and ramp (5 V) at different load pressures from end position to end position. The load pressure is the pressure in the cylinder piston chamber. The load pressure is set by means of the load pressure valve and can only be read off while the cylinder is extending.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve once again in both directions +/- in order to depressurize the working line and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

06

Project 06: Pressure relationships

13

Bosch Rexroth AG I RE 00847/07.07

Measured values Measure the time from start to stop using a stopwatch.

Dp

Load pressure 10 bar 15 bar 20 25 30 35 40 45 50

40 bar 35 30 25 20 15 10 5 0

Table 06.03 Table of measured values

Diagram 06.01 Dp/velocity

Time 2.6 s 2.8 3.1 3.3 3.8 4.3 5.6 7.4

Velocity 154mm/s 143 129 121 105 93 71 54 0

06

Project 06: Pressure relationships

14

Bosch Rexroth AG I RE 00847/07.07

5. Adjustment of the braking distance Mount the proximity switch at 250 mm. Operate "S2“ to grant the command value enable and traverse the cylinder by operating push-buttons "S3-4“. Verify whether the proximity switch outputs a signal when the cylinder passes. Because the ramp times "t1“ and "t5“ of 20 ms are very short, the cylinder will quickly accelerate and come abruptly to a halt after having reached the proximity switch. The proximity switch must be adjusted so that the cylinder stops at 250 mm +/- 1mm.

Pre-setting: Command value "w1“ = 3 V. 10 bar load pressure in the cylinder piston chamber. The load pressure can only be read off while the cylinder is extending. Ramp "t5“ determines the braking distance of 30 mm at a load pressure of 10 bar.

To examine the influence of the ∆p on the braking distance, the braking distance is measured at various load pressures, while the system pressure (50 bar), command value "w1“ = 3 V and ramp "t5“ remain unchanged. Enter the braking distance at different load pressures in the table. The velocity values are taken from table 06.01. From position 250 mm on, the command value is reduced to 0 V with ramp "t5“.

Load pressure

Dp

Velocity

Braking distance

Position

10 bar 15 bar

40 bar 35 bar

154 mm/s 143 mm/s

30 mm 28 mm

280 mm 278 mm

20 bar 25 bar

30 bar 25 bar

129 mm/s 121 mm/s

26 mm 23 mm

276 mm 273 mm

30 bar

20 bar

105 mm/s

20 mm

270 mm

35 bar

15 bar

93 mm/s

15 mm

265 mm

40 bar

10 bar

71 mm/s

11 mm

261 mm

45 bar

5 bar

54 mm/s

4 mm

254 mm

50 bar

0 bar

0

-

-

Table 06.04 Table of measured values

mm/s

06

Project 06: Pressure relationships

15

Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. How does the cylinder velocity behave, when the ∆p is reduced? When the ∆p is reduced, the cylinder velocity slows down. II. Which influence does this have on the braking distance? As the ∆p is reduced, the braking distance becomes shorter. III. Can the difference in the ∆p and the braking distance have an adverse effect on the function of the press? The position depends on the ∆p, if the other settings remain unchanged; this has an adverse effect, because the positions are different.

Project/trainer info In Project 06 knowledge is to be imparted with regard to the pressure situation of proportional valves and their influence on the system characteristics in a practical setup. The project order is an integral part of the general project "press modernization" and helps to understand the pressure relationships of proportional valves. The following knowledge is to be gained in the practical setup: • Pressure differential ∆p • Flow in dependence upon ∆p and command value • Influence on the braking distance

06

Project 06: Pressure relationships

16

Bosch Rexroth AG I RE 00847/07.07

Notes

06

Project 07: 4-quadrant ramps

1

Bosch Rexroth AG I RE 00847/07.07

Project 07: Adjusting a motion sequence with 4-quadrant ramps Project definition Optimum settings is to be found for operating the press. To this end, the motion sequence of the press is to be configured with rapid speed, creep speed and return. After a proximity switch B1 the press is to be decelerated to creep speed. The ramps are to be selected in the 4Q mode, that is, one ramp each for acceleration for extending, deceleration for extending, and acceleration for retracting, deceleration for retracting.

Fig. 07.01 Press

Project tasks

• Adjustment of a motion sequence • Adjustment of the command value voltages and 4Q ramps on the command value module

07

Project 07: 4-quadrant ramps

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

07

Project 07: 4-quadrant ramps

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

07

Fig. 07.02 Hydraulic circuit diagram

Project 07: 4-quadrant ramps

4

Bosch Rexroth AG I RE 00847/07.07

Electrical circuit diagram

07

Fig. 07.03 Electrical circuit diagram

Project 07: 4-quadrant ramps

5

Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1 + 24V

3

8

7

4 3

S2

34

K1 4

31

10

9 34

K2 31

34

K3 31

Command value module Outputs Inputs Measurands Command value Command value w Call-up 4 Reference ⊥ Call-up 3 Ramp time t Call-up 2 Reference ⊥ Call-up 1 Inversion Inv. Control output Differential input ±10 V ± 10 V Reference ⊥ ⊥ Reference Ramp 4Q Supply 0V + 24 V BPS 20.0

Command/ actual display Connection panel Outputs Actual Inputs value Command value (F) ± 10 V (C) ⊥ Reference ± 10 V (D) ⊥ Reference (E) Supply Valve 0V (B) + 24 V (A) BPS 21.0

0V + 24V

Fig. 07.04 Electrical block circuit diagram

Fig. 07.05 Command value module/connection panel/command/actual value display

Display 1 ± 10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

07

Project 07: 4-quadrant ramps

6

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

Symbol

07

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Throttle check valve

DZ 2.2

0.1-0.3

3

Pressure gauge with minimess line

Dz1.9

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Table 07.01 Parts list for hydraulic circuit diagram Fig. 07.02

Project 07: 4-quadrant ramps

Item

7

Bosch Rexroth AG I RE 00847/07.07

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

K1-K3

1

Control module

BRS1.2

B1

1

Proximity switch, inductive

DE2.2

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

S1-S3

Table 07.02 Parts list for electrical block circuit diagram Fig. 07.03

Notes

07

Project 07: 4-quadrant ramps

8

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

07

Fig. 07.06 Recommended component arrangement with component designations for parts list Table 07.01 and hydraulic circuit diagram Fig. 07.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 07: 4-quadrant ramps

9

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual. If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Warning

Caution

Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. The annulus cylinder side is to be pre-loaded by means of a pressure relief valve for the simulation of a load. This pressure relief valve is to be by-passed for retracting. With positive command values the cylinder must extend. The system pressure is to be limited. Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. For the connection of pressure gauges with measuring lines ADZ1.4 use pressure hoses DZ25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses.

07

Project 07: 4-quadrant ramps

10

Bosch Rexroth AG I RE 00847/07.07

2. Electrical control The electrical control must be set up so that the cylinder starts to extend with a start signal and decelerates after a proximity switch signal. After a further signal, the cylinder is to retract. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0, and display BPS 6.1 are permanently connected to 24 V. An "S1“ switch is used to switch the control voltage for switches, push-buttons and relays. With the help of an "S2“ switch, 4Q operation is to be switched on. With push-button S3 → Extending the cylinder with command value "w1“. After proximity switch B1 → Decelerating With push-button S4 → Retracting the cylinder with command value "w3“, even if B1 has not switched. The command value and the ramp voltage are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Pre-settings on the command value module Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the by-pass valve is opened. Set the following command values on the command value module: "w1“ to 10 V,

t1

= 0.5 V

"w2“ to 10 V,

t2

= 0.5 V

"w3“ to -10 V, t3

= 0.5 V

Ramps "t1-5“ to 0.5 V = 200 ms. The command values and ramps must be activated with the relevant "call-up" in order that the values can be read off. Ramps "t1-4“ are activated simultaneously with command values "w1-4“, when 4Q is switched off. This is accomplished by operating push-buttons "S3-4“ and assigning "B1“. Call-up "w4“, "t4“ is only briefly connected to 24 V for pre-setting purposes. Ramp "t5“ is active, when no command value is active. Which ramp is when active in 4Q operation? Observe the voltages on the command/actual value display BPS 6.1.

07

Project 07: 4-quadrant ramps

11

Bosch Rexroth AG I RE 00847/07.07

Note for trainers: This project deals with the adjustment of the motion sequence by means of 4-quadrant ramps. Of particular importance is the assignment of ramps to the relevant changes in velocity (acceleration). "t1“ accelerating - extending "t2“ decelerating - extending "t3“ accelerating - retracting "t4“ decelerating - retracting Use the diagram (see Basic principles of proportional valve technology, page 12) for the representation.

07

Fig. 07.07 Definition of the position and adjustment of the proximity switch

4. Adjustment of creep speed The proximity switch is to be mounted at 200 mm. Verify whether the proximity issues a signal when the cylinder passes. Fully unload the system pressure relief valve. Fully unload the load pressure relief valve. Switch the hydraulic pump on and close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the system pressure relief valve to 50 bar. The load pressure is 15 bar in the cylinder piston chamber.

Project 07: 4-quadrant ramps

12

Bosch Rexroth AG I RE 00847/07.07

Traverse the cylinder by operating push-buttons "S3-4“. Reduce creep speed "w2" by 1 V after each cycle. Observe the system pressure during the cylinder movement and note the value. At which command value becomes the cylinder remarkably more slowly? Reduce command values "w2“ progressively further down to 1.5 V. Command value "w2“ is adjusted when the cylinder is in its extended end position. LED "w2“ signals whether the command value is active.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- in order to depressurize the working lines and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

07

Project 07: 4-quadrant ramps

13

Bosch Rexroth AG I RE 00847/07.07

Measured values Read the system pressure off during rapid and creep speed with different command values "w2“. Command value "w2“

System pressure Rapid speed

System pressure Creep speed

10 V 9V 8V 7V 6V 5V 4V 3.5 V

25 bar 25 bar 25 bar 25 bar 25 bar 25 bar 25 bar 25 bar

25 bar 25 bar 27 bar 29 bar 32 bar 34 bar 43 bar 46 bar slower

3.0 V

25 bar

48 bar

2.5 V

25 bar

50 bar

2.0 V

25 bar

50 bar

1.5 V

25 bar

50 bar

Table 07.03 Table of measured values

Note for trainers: The cylinder velocity is only significantly reduced with command values below 4.0 V, because before, the cylinder velocity is determined by the displacement of the pump. Only when the proportional valve throttles the flow to a value, at which the maximum system pressure is reached and the pressure controller reduces the pump output, becomes the cylinder slower. Here, the off-stroke behavior of the pump is also of significance, for the pressure controller starts to reduce the pump output even before 50 bar is reached. Characteristic curves (measured at n=1450 min-1, v=41 mm2/s and q = 50 °C) PV7/10-14

07

Project 07: 4-quadrant ramps

14

Bosch Rexroth AG I RE 00847/07.07

5. Adjustment of the braking distance The cylinder is to accelerate swiftly and decelerate smoothly.

Rapid speed for extending Accelerating Creep speed for extending Decelerating Rapid speed for retracting Accelerating Decelerating

"w1“ "t1“ "w2“ "t2“ "w3“ "t3“ "t4“

= = = = = = =

10 V 200 ms 1.5 V 1000 ms 10 V 100 ms 5V

Traverse the cylinder using "S3-4“ and observe it. Operate switch "S2“ to activate the 4Q ramps. Also other settings may be tested in this project.

Evaluating the work results I. Why becomes creep speed only effective below a relatively small command value? Less oil flows to the cylinder only, when the max. system pressure has been reached and the pump starts to come off stroke. This takes place only with small command values due the relatively small displacement of Q = 8 l/min. II. How are the ramps assigned in 4Q operation? In 4Q operation, the ramps are assigned to the 4 possible changes in the movement. III. Which benefit offers 4Q operation ? In 4Q operation acceleration and deceleration for retracting and extending can be optimally adjusted separately.

07

Project 07: 4-quadrant ramps

15

Bosch Rexroth AG I RE 00847/07.07

Project/trainer info In Project 07 the transition from rapid speed to creep speed is adjusted, and the function of 4-quadrant ramps is applied in a practical setup. The project part is an integral part of the general project "press modernization" and helps to understand the function of 4-quadrant ramps. The following knowledge is to be gained in the practical setup: • Application of 4-quadrant ramps • Adjustment of a motion sequence

07

Project 07: 4-quadrant ramps

16

Bosch Rexroth AG I RE 00847/07.07

Notes

07

Project 08: Sequence with 2 proximity switches

1

Bosch Rexroth AG I RE 00847/07.07

Project 08: Adjusting a sequence with 2 proximity switches Project definition So far, the cylinder has always been moved to its end position; now, a certain halt position is to be approached. For the production, it is interesting, how exactly a position can be approached and which effect changes in the load have. The motion sequence of the press is to be adjusted with rapid speed, creep speed and a defined halt position. The press is to be decelerated to creep speed with the help of proximity switch B1. A proximity switch B2 is to be used to decelerate the press to a defined position. The ramps are selected in 4Q operation, i.e. one ramp each for "accelerating - extending", "decelerating - extending" and "accelerating - retracting", "decelerating - retracting“.

08

Fig. 08.01 Press die

Project tasks

• Adjustment of a motion sequence and a defined position • Adjustment of command value voltages and 4Q-ramps on the command value module

Project 08: Sequence with 2 proximity switches

2

Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

08

Project 08: Sequence with 2 proximity switches

3

Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

08

Fig. 08.02 Hydraulic circuit diagram

Project 08: Sequence with 2 proximity switches

4

Bosch Rexroth AG I RE 00847/07.07

Electrical circuit diagram

08

Fig. 08.03 Electrical circuit diagram

Project 08: Sequence with 2 proximity switches

5

Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1 + 24V

3

8

7

4 3

S2

34

K1 4

31

10

9 34

K2 31

34

K3 31

Command value module

22

K4 21

Outputs Inputs Measurands Command value Command value w Call-up 4 Reference ⊥ Call-up 3 Ramp time t Call-up 2 Reference ⊥ Call-up 1 Inversion Inv. Control output Differential input ±10 V ± 10 V Reference ⊥ ⊥ Reference Ramp 4Q Supply 0V + 24 V BPS 20.0

Command/ actual display Connection panel Outputs Actual Inputs value Command value (F) ± 10 V (C) ⊥ Reference ± 10 V (D) ⊥ Reference (E) Supply Valve 0V (B) + 24 V (A) BPS 21.0

0V + 24V

Fig. 08.04 Electrical block circuit diagram

Fig. 08.05 Command value module/connection panel/command/actual value display

Display 1 ± 10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

08

Project 08: Sequence with 2 proximity switches

6

Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

Symbol

08 1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Table 08.01 Parts list for hydraulic circuit diagram Fig. 08.02

Project 08: Sequence with 2 proximity switches

Item

7

Bosch Rexroth AG I RE 00847/07.07

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

K1-K6

2

Control module

BRS1.2

B1-B2

1

Proximity switch, inductive

DE2.2

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

S1-S3

Table 08.02 Parts list for electrical block circuit diagram Fig. 08.03

Notes

08

Project 08: Sequence with 2 proximity switches

8

Bosch Rexroth AG I RE 00847/07.07

Component arrangement

08

Fig. 08.06 Recommended component arrangement with component designations for parts list Table 08.01 and hydraulic circuit diagram Fig. 08.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 08: Sequence with 2 proximity switches

9

Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. The annulus cylinder side is to be pre-loaded by means of pressure relief valve for the simulation of a load. This pressure relief valve is to be by-passed for retracting. With positive command values the cylinder must extend. The system pressure is to be limited. Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. Use pressure hoses DZ25.1 for the connection of pressure gauges with measuring line DZ1.4. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses.

08

Project 08: Sequence with 2 proximity switches

10

Bosch Rexroth AG I RE 00847/07.07

2. Electrical control The electrical control must be set up so that with a start signal the cylinder extends, and after a proximity switch signal the cylinder is decelerated to creep speed. The cylinder is then to be stopped with the help of a second proximity switch. After a further signal, the cylinder is to retract. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0 and display BPS 6.1 are to be permanently connected to 24 V. An "S1" switch is used to switch the control voltage for switches, push-buttons and relays. An "S2“ switch is to be used to switch on 4Q operation. Use push-button S3 → to extend the cylinder with command value "w1“ After proximity switch B1 → the cylinder is to decelerate to creep speed "w2“ After proximity switch B2 → deceleration to standstill, no command value, no 4Q operation Use push-button S4 → to retract the cylinder with comand value "w3“ The command value and the ramp voltage are to be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Pre-settings on the command value module Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the by-pass valve is opened. Set the following command values on the command value module: "w1“ to 5 V "w2“ to 1.5 V "w3“ to -5 V Ramps "t1-5“ to 0.5 V (200 ms). The command values and ramps must be activated with the relevant "call-up" in order that the values can be read off and adjusted. Ramps "t1-4“ are simultaneously activated with command values "w1-4“, when 4Q is switched off. This is accomplished by operating push-buttons "S3-4“ and assigning "B1“. Call-up "w4“, "t4“ is to be connected only briefly to 24 V for the purpose of

08

Project 08: Sequence with 2 proximity switches

11

Bosch Rexroth AG I RE 00847/07.07

presetting. Ramp "t5“ is active, when no command value is activated. Which ramp is when active in 4Q operation? Read off the voltages for command values and ramps from command/actual value display BPS 6.1. Note for trainers: In this project we deal with the adjustment of the motion sequence by means of 4-quadrant ramps and a defined halt position. This halt position is to be approached at a very low velocity; for this reason, ramp "t5“ can be very short. With such a short ramp time, changes in the velocity have no strong effect on the position. An important point is the assignment of the ramps to the relevant changes in the velocity (acceleration). "t1“ accelerating - extending "t2“ decelerating - extending "t3“ accelerating - retracting "t4“ decelerating - retracting "t5“ decelerating to standstill

Fig. 08.07 Definition of the position and adjustment of the proximity switch

08

Project 08: Sequence with 2 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

4. Adjustment of the braking distance Proximity switch B1 is to be mounted at 300 mm. Proximity switch B2 is to be mounted at 390 mm. Fully unload the system pressure relief valve. Fully unload the load pressure relief valve. Switch the hydraulic pump on and close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the system pressure relief valve to 50 bar. Set the load pressure to 15 bar in the cylinder piston chamber. Activate 4Q-ramps. Traverse the cylinder by operating push-buttons "S3-4“. Check whether the proximity switches issue a signal when the cylinder passes. Adjust decelerating to creep speed so that braking is performed softly with a braking distance of 50 mm. Adjust the halt position at 390 mm with proximity switch B2 and ramp "t5“. Measure the halt position at different load pressures. To check the repeatability, operate the cylinder 4 times per setting.

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- in order to depressurize the working lines and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

08

Project 08: Sequence with 2 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Measured values To check the repeatability, traverse the cylinder 4 times with each setting.

Load pressure 1st position 2nd position 3rd position 4th position 15 bar 20 bar 25 bar 30 bar 35 bar 40 bar 45 bar

390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 389 mm

390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 389 mm

390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 389 mm

390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 389 mm

Table 08.03 Table of measured values

Read off the halt position every 30s at a system pressure of 50 bar, a load pressure of 45 bar, 15 bar and a command value of 0 V.

Time

Position at 45 bar

Position at 15 bar

0s 30 s 60 s 90 s 120 s 150 s 180 s 210 s 240 s

390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 390 mm 391 mm

390 mm 391 mm 392 mm 393 mm 394 mm 395 mm 396 mm 397 mm 398 mm

Table 08.04 Table of measured values

08

Project 08: Sequence with 2 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Note for trainers: Depending on the setting of "t5" the halt position may vary; the shorter "t5“, the smaller are the deviations. The results can absolutely differ for each group. If required, repeat the exercise with "t5“ = 50 ms for all groups. The deviation will be < 1 mm. At standstill, the cylinder will drift and slowly extend due to the valve leakage. Also here, the ∆p is the decisive factor for the amount of leakage oil. In practice, this means that a position cannot be maintained for a long period of time. Whenever exact positions must be maintained under all circumstances, closedloop control systems are required.

08 Evaluating the work results I. Which measures resulted in an increase in the repeatability of the end position? The repeatability is improved at low velocity and with a short ramp. II. Is the halt position exactly adhered to in the long run? The position can not be maintained for a long period of time, because the proportional valve is subject to leakage.

Project/trainer info In Project 08 the transition from rapid speed to creep speed and a defined halt position are to be set. The project order is an integral part of the general project "press modernization" and is to explain the application of 4-quadrant ramps. The following knowledge is to be gained in the practical setup: • Training in the application of 4-quadrant ramps • Adjsutment of a motion sequence and a defined position

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Project 09: Adjustment of an automatic sequence with 3 proximity switches Project definition So far, we have worked with a provisional control during commissioning, because not all of the components required for an automatic control were available. Now, we are going set up an automatic control which will be ready for operation. During commissioning, particular emphasis is to be put on safety. The motion sequence of the press with rapid speed, creep speed and return is to be adjusted according to the customer's requirements. With the help of a proximity switch B1 the press is to be decelerated to creep speed. With the help of a proximity switch B2 the press is to be stopped at the end position. After a holding time, the return stroke is to be initiated. With the help of a proximity switch B3 the press is to be stopped with a defined braking distance for the retracted cylinder. The ramps are selected for 4Q operation. With the help of the command value source, the press is to be operated manually at reduced velocity.

Fig. 09.01 Commissioning a power unit

Project tasks

• Safe commissioning • Adjustment of a defined motion sequence and defined positions • Adjustment of command value voltages and 4Q-ramps on the command value module

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Project steps • Informing:

In which condition is the machine? What exactly is to be carried out?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How have the components to be connected to each other (hydraulically and electrically)?

• Executing: Preparation of hydraulic and electrical circuit diagrams and selection of the required drive elements and accessories with short description. • Checking:

Is the polarity correct?

• Evaluating: How does the system behave?

Notes

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Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Hydraulic circuit diagram

09

Fig. 09.02 Hydraulic circuit diagram

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Electrical circuit diagram

09

Fig. 09.03 Electrical circuit diagram

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Electrical block circuit diagram S1 + 24V

3

10

4 3

S2

4

11 24

K1 21

12 34

13 18

K2 KT1 31

15

Command value module

32

K3 31

Command value provision Inputs Supply 0V 24 V

Outputs Command value ±10 V Signal ⊥ Reference

Outputs Inputs Measurands Command value Command value w Call-up 4 Reference ⊥ Call-up 3 Ramp time t Call-up 2 Reference ⊥ Call-up 1 Inversion Inv. Control output Differential input ±10 V ± 10 V Reference ⊥ ⊥ Reference Ramp 4Q Supply 0V + 24 V BPS 20.0

Command/ actual display Connection panel Outputs Actual Inputs value Command value (F) ± 10 V (C) ⊥ Reference ± 10 V (D) ⊥ Reference (E) Valve Supply 0V (B) BPS 21.0 + 24 V (A)

Display 1 ± 10 V Signal ⊥ Reference Display 2 ±10 V Signal ⊥ Reference Supply 0V + 24 V BPS 6.1

BPS 5.2

0V + 24V

Fig. 09.04 Electrical block circuit diagram

Fig. 09.05 Command value source/command value module/connection panel/command/actual value display

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Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

4/3 proportional directional valve with load pressure valve

DW40E-D.

1.2

1

Pressure relief valve

DD1.1N

1.4

1

Check valve

DS2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

1

Hydraulic hose

VSK1. N-W

Table 09.01 Parts list for hydraulic circuit diagram Fig. 09.02

Symbol

09

Project 09: Sequence with 3 proximity switches

Item

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Bosch Rexroth AG I RE 00847/07.07

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

K1-K6

2

Control module

BRS1.2

B1-B3

3

Proximity switch, inductive

DE2.2

1

Command value/actual value display

BPS 6.1

1

Stopwatch, 2 mm screw driver, Allan key set

1

Time relay

S1-S3

KT

Table 09.02 Parts list for electrical block circuit diagram Fig. 09.03

Notes

BRS2.1

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Component arrangement

09

Fig. 09.06 Recommended component arrangement with component designations for parts list Table 09.01 and hydraulic circuit diagram Fig. 09.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use on the DS4 fastening grid.

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk during can arise operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening by-pass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is to be set up so that the cylinder can be extended and retracted with the help of a 4/3 proportional directional valve. The annulus cylinder side should be pre-loaded with the help of a pressure relief valve for the simulation of a load. This pressure relief valve is to be by-passed for retracting. With positive command values the cylinder must extend. The system pressure is to be limited. Set the circuit up by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the hardware trainer according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, use pressure hoses DZ 25.1. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components with pressure hoses by turning the hoses.

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

2. Electrical control The electrical control must be set up so that with a start signal the cylinder extends. After a first proximity switch the cylinder is to be decelerated to creep speed. After a second proximity switch, the cylinder is to come to a halt at a defined position. The holding time is to be adjustable by means of a time relay. When the holding time has elapsed, the return stroke is to be initiated. A third proximity switch is used to decelerate the cylinder in the retracted position. Command value source BPS 5.2, command value module BPS 20.0, BPS 21.0, display BPS 6.1 are to be permanently connected to 24 V. An "S1“ switch is to be used for switching the control voltage for switches, push-buttons, relays. An "S2“ switch is to be used for switching on 4Q operation. It should only be possible to start the cycle when the cylinder is retracted; this is to be monitored by proximity switch B3. Push-buttons S3+B3 → Extending the cylinder with command value "w1“. Proximity switch B1 → Decelerating to creep speed "w2“ Proximity switch B2 → Decelerating the cylinder to standstill, 4Q OFF, start of holding time; when the holding time has elapsed, retracting the cylinder with command value "w3“. Proximity switch B3 → Decelerating to standstill; 4Q operation remains active Manual operation should be possible with the help of command value source BPS 5.2 at the differential input of the command value module. The max. velocity should be limited in manual operation, even if higher values are selected on the command value source. The command value voltage and ramp voltage should be measured and displayed. Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/- 10 V; never connect them to 24 V. This can cause damage to electronic components.

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

3. Pre-settings on the command value module Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the by-pass valve is opened. Since the new control is not yet known, particular attention should be paid to safety. It is dangerous, if the press operates at excessive velocity due to an incorrect switching operation. For this reason, all command values should be set to 0 V. Should an incorrect command value be activated in the event of a fault, no movement can be initiated. The ramps are to be set to 200 ms. Long ramp times are more dangerous, because after a stop signal the proportional valves closes only very slowly. The cylinder then continues to move during this time. The value from the differential input can be limited with the help of potentiometer "G“. Set the following command values on the command value module: "w1“ to 0 V "w2“ to 0 V "w3“ to 0 V "G“ to 2.0 V with 10 V at the differential input Ramps "t1-5“ to 0.5 V (200 ms). The command values and ramps must be activated with the relevant "call-up" in order that the values can be read off. Ramps "t1-4“ are simultaneously activated with command values "w1-4“, when 4Q is switched off. This is accomplished with the operation of pushbutton "S3“ and activation of "B1-3“. Call-up 4 can only be connected to 24V for adjustment purposes. Ramp "t5“ is active, when no command value is activated Which ramp is when active? Read off the voltages from command/actual value display BPS 6.1. Note for trainers: In this project, knowledge is to be applied which was gained in the preceding projects. Also safety during commissioning of new controls is to be discussed. For example, the activation of an incorrect command value should not result in an uncontrolled movement. If the command values are set to 0 V, the cylinders stops and nothing will happen. If the command value is set to, e.g. 10 V, the cylinder moves at max. velocity. With long ramp times, the proportional valve has long reaction times. Consequently, it is possible that the cylinder moves on after the command value was switched off or that the position of a proximity switch is passed to far. This can cause damage to the machine.

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

In manual operation, e.g. during setup, a certain velocity must not be exceeded for safety reasons. This can be adjusted by means of "G“ on the command value module. Thus, only 2.0 V may be applied to the output, even with 10 V at the differential input. In practice, this means that the operator has no chance to move the system faster in manual operation. In manual operation, the control voltage for the relays must be switched off by means of "S1“.

09

Fig. 09.07 Definition of the position and adjustment of the proximity switch

4. Adjustment of velocities and the halt position Proximity switch B1 is to be mounted at 300 mm. Proximity switch B2 is to be mounted at 390 mm. Proximity switch B3 is to be mounted at 50 mm. Verify whether the proximity switches issue a signal when the cylinder passes. Fully unload the system pressure relief valve. Fully unload the load pressure relief valve. Switch the hydraulic pump on, close the by-pass valve. Inspect the hydraulic circuit for leakage. Set the system pressure relief valve to 50 bar. Set the load pressure to 15 bar in the cylinder piston chamber.

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Specification: Starting position Rapid speed time Deceleration starting at Creep speed time Halt position Holding time Return time Halt/starting position

50 mm 1s 300 mm 3s 390 mm 3s 2s 50 mm

09

Diagram 09.01 travel/time

Execution: Traverse the cylinder manually to proximity switch B3 with the help of the command value source. Start the sequence with S3. Adjust rapid speed, "w1“, "t1“. Adjust creep speed, "w2“, "t2“ braking distance 40 mm. Set halt position at 390 mm, B2, "t5“. Adjust holding time KT1. Adjust return stroke velocity, "w3“, "t3“. Set stop position to 50mm, B3, "t4“.

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Note for trainers: The cylinder must first be moved to the starting position with the help of the command value source, because without a B3 signal, starting is impossible. The command value source must then be switched back to "0“, because otherwise, the cylinder would move on with the value of the command value source. Position 50 mm must be set so that the cylinder operates the proximity switch. The signal forms the start condition. Position 390 mm is to be set with a short "t5" ramp time. Documentation: Command values : W1: 5 V W2: 1.5 V W3: -5 V G: +/- 2 V Ramps : T1: 0.5 V T2: 0.15 V T3: 0.5 V T4: 0.18 V T5: 3.0 V Pressures : Rapid/creep speed System pressure Extending: 35/50 bar Retracting: 47 bar Piston side Extending: 15/17 bar Retracting: 20 bar Annulus side Extending: 22/27 bar Retracting: 40 bar Proximity switch position: B1: 300 mm B2: 390 mm B3: 50 mm

Caution

After completion of practical work, switch the hydraulic pump on the training system off! Open the proportional valve again in both directions +/- to depressurize the working line and the cylinder. Set the pressure relief valves to minimum pressure. No pressure gauge may indicate a pressure.

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Evaluating the work results I. Which measures were taken to improve safety during commissioning? Command values set to 0 V means more safety during commissioning, since no movement can take place. II. How have long ramp times to be assessed? With long ramp times, the machine continues to run, after the stop signal was issued. III. Which measure was provided for manual operation? The velocity in manual operated was limited by means of "G“. IV. What are the advantages of documentation? In the event of a fault, the original settings are available.

Project/trainer info In Project 09 an automatic sequence is to be set, in which a complete cycle is performed upon a start signal and the initial position is approached again.

The project order is an integral part of the general project "press modernization" and is intended to apply the knowledge gained so far. In the practical setup, the following knowledge is to be deepened: • Training in the application of 4-quadrant ramps • Adjustment of a defined motion sequence

09

Project 09: Sequence with 3 proximity switches

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Bosch Rexroth AG I RE 00847/07.07

Notes

09

Project 10: Adjusting the system pressure with a potentiometer

1

Bosch Rexroth AG I RE 00847/10.08

Project 10: Adjusting the system pressure with the help of an external potentiometer Project definition A baling press is to be operated with variable forces. The forces are to be adjusted by means of remote control with an electrical signal. For commissioning the machine control which is still unknown to us, it should first be adjusted carefully by hand. In this way, the behavior of the hydraulic machine control can be understood. Of particular interest is the relationship between command value and system pressure.

10

Fig. 10.01 Example of proportional pressure valve (type DBEP6 is shown)

Project tasks • Working out the function of the proportional valve • Testing the valve function by measuring command value and pressure • Determining the command value voltages for different pressures

Project 10: Adjusting the system pressure with a potentiometer

2

Bosch Rexroth AG I RE 00847/10.08

Project steps

Notes

• Informing:

In which condition is the machine? What in detail is to be done?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points? How must the components be connected with each other (hydraulically and electrically)?

• Executing:

Preparation of sketches of hydraulic and electrical circuit diagrams. Set-up of the hydraulic control and the electrical circuit. Determining the required values and their documentation.

• Checking:

Which values can be set?

• Evaluating:

How does the system behave?

10

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Hydraulic circuit diagram

Measuring glass

Aggregate limit

10

Fig. 10.02 Hydraulic circuit diagram

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Electrical block circuit diagram Command value provision Inputs Supply 0V 24 V

Outputs Comm. value ±10 V Signal > Reference

BPS 5.2

Comm./actual value display Connection panel Inputs Outputs Comm. value Actual value ±10 V (D) (F) ±10 V > Refer. (E) (C) Refer. > Supply 0V (B) Valve +24 V (A)

BPS 21.0

Diplay 1 ±10 V Signal > Reference Diplay 2 ±10 V Signal > Reference Supply 0V +24 V

BPS 6.1

T

0V

P A (Y)

+24 V

Fig. 10.03 Electrical block circuit diagram

10

Fig. 10.04 Command value source/connection panel/command/actual value display

5

Project 10: Adjusting the system pressure with a potentiometer

Bosch Rexroth AG I RE 00847/10.08

Component selection with parts list Item

Qty

Component designation

Type designation

1.1

1

Proportional pressure valve

DD18E

1.4

1

Check valve

DS2.1

0.1

1

Pressure gauge with minimess line

DZ1.4

1

Hydraulic hose with minimess connection

DZ25.1 N-W

2

Hydraulic hose

VSK1. N-W

Symbol

10

Table 10.01 Parts list for hydraulic circuit diagram Fig. 10.02

Item



Qty

Component designation

Type designation

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Distributor

BPS 13.1

1

Command value/actual value display

BPS 6.1

Table 10.02 Parts list for the electrics

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Component arrangement

Measuring glass

VSK1

DS2.1

DD18E

VSK1

DZ1.4

D

Note: In connection elements marked with D, the components are directly plugged into each other.

DZ25.1

P

Connection block T T P

D

Fig. 10.05 Recommended component arrangement with component designations according to parts list Table 10.01 and hydraulic circuit diagram Fig. 10.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use of the DS4 fastening grid.

10

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk can arise during operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening bypass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is set up so that the system pressure is limited by means of a proportional pressure valve. Set-up the circuit by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the fastening grid according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, pressure hoses DZ25.1 are used. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components to the pressure hoses by turning the hoses.

10

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

2. Electrical control Requirements: The electrical control must be set up so that proportional valve DBEE6 (DD18E) can be operated with command value source BPS 5.2. The command value is to be measured and displayed. Tasks: Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine the measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/–10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Testing the valve function Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the pump is not switch on and the bypass valve is open. Generally, when taking voltage measurements, the signal (+/–10 V) must always be measured against a reference (^). The measuring points used on the BPS 21.0 are sockets D (+/–10 V) and E (^) for the command value. Run command values from 0 V to 10 V with positive polarity with the help of command value source BPS 5.2. Observe the voltage on command/actual value display BPS 6.1. With a command value of 0 V, the lowest pressure possible is set. First set the command value input to 0 V and turn the potentiometer to 0 V, otherwise, an unwanted pressure is built up in the system. Switch the hydraulic pump on. Close the bypass valve. Check the hydraulic circuit for leakage. Note the minimum pressure. Slowly increase the command value from 0 V with positive polarity with the help of command value source BPS 5.2 and observe the system pressure.

Caution

Integrated valve electronics are factory-set on test rigs and must not be modified by the user. Adjustments of the integrated valve electronics on the system are necessary in exceptional cases only and require special knowledge. Unqualified modifications can lead to unexpected valve characteristics.

10

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

4. Adjusting the system pressure by providing a command value With a command value of 0 V, the lowest pressure possible is set. With a command value of 10 V, the highest pressure possible is set. Adjust the command values according to the table by means of the command value source BPS 5.2 and read off and enter the pressures Note for trainers: Function and structure of the DBEE6 proportional valve are described in detail in the data sheet RE 29158 (pages 3 and 4). Due to the existing pressure losses in the system (hose lines, couplings, valve), the system pressure cannot be set to 0 bar. A system-specific minimum pressure results that also depends on the flow. The pressureless connection of A(Y) is important as otherwise, the control oil cannot flow off. In this case, the maximum system pressure also results with a command value of 0 V. The maximum system pressure is determined by the pump's pressure controller. Command value (in volt) 0.5

Pressure (in bar) 10

1.0

12

1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0

15 17 20 22 25 27 30 32 35 37 40 43 46 48 50 50 50 50

10

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Pressure in bar 50 45 40 35 30 25 20 15 10 5 1

2

3

4

5

6

7

8

9

10 Command value in V

Fig. 10.06 Command value/pressure characteristic curve

Note for trainers: The pressure behaves almost linear in relation to the command value. The flow in the pressure valve also has an influence because it is not constant. From a value of approx. 8.5 V, the pressure does no longer increase as the pump's pressure controller limits the maximally possible pressure.

Caution

After completion of practical work, set the command value at the training system to 0 V. Switch off the pump. No pressure gauge may indicate a pressure.

10

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Evaluating the work results I. With a command value of 0 V, which pressure is available in the system? With a command value of 0 V, the minimum pressure is available in the system. II. Why can the pressure not be set to 0 bar with a command value of 0 V? The pressure is determined by the pressure losses in the system and the flow rate. III. How has the system pressure changed in relation to the command value? The system pressure has risen almost linearly. IV. What limits the maximum system pressure? The maximum system pressure is limited by the pump's pressure controller.

10 Project / trainer information In Project 10, basic knowledge is to be imparted of the behavior of proportional pressure valves in a practical set-up. In the practical set-up, the following knowledge is to be imparted: • Testing the valve function by measuring command value and pressure • Knowledge of measuring points • The amount of the command value determines the pressure.

Project 10: Adjusting the system pressure with a potentiometer

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Bosch Rexroth AG I RE 00847/10.08

Notes

10

Project 11: Moving the cylinder

1

Bosch Rexroth AG I RE 00847/10.08

Project 11 Moving a cylinder with to different pressures Project definition In a baling press, two different materials are compressed. The maximum pressing power is 20 bar for material A and 40 bar for material B. The pressing power must be complied with so that the materials get the desired characteristics. It is thus necessary to operate the baling press with two preselectable pressures. The powers are to be adjusted by means of remote control with an electrical signal.

11

Fig. 11.01 Cylinder in tie rod design

Project tasks • Preselection of a preset pressure • Adjusting the command value voltages for different pressures

Project 11: Moving the cylinder

2

Bosch Rexroth AG I RE 00847/10.08

Project steps

Notes

• Informing:

In which condition is the machine? What in detail is to be done?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points located? How must the components be connected with each other (hydraulically and electrically)?

• Executing:

Preparation of sketches of hydraulic and electrical circuit diagrams. Set-up of the hydraulic control and the electrical circuit. Determining the required values and their documentation.

• Checking:

Are the powers complied with?

• Evaluating:

How does the system behave?

11

Project 11: Moving the cylinder

3

Bosch Rexroth AG I RE 00847/10.08

Hydraulic circuit diagram

Measuring glass

Aggregate limit

Fig. 11.02 Hydraulic circuit diagram

11

Project 11: Moving the cylinder

4

Bosch Rexroth AG I RE 00847/10.08

Electrical circuit diagram

11

Fig. 11.03 Electrical circuit diagram

Project 11: Moving the cylinder

5

Bosch Rexroth AG I RE 00847/10.08

Electrical block circuit diagram 7

+24 V

8 3

3

S1

4

S2

4

Command value module Inputs Outputs Comm. value Measurands Call-up 4 Comm. val. w Call-up 3 Reference > Call-up 2 Ramp time t Call-up 1 Reference > Inversion Inv. Control Differential variable input ±10 V ±10 V Reference > > Reference Ramp 4Q Supply 0V +24 V

BPS 20.0

0V

Comm./actual value display Connection panel Inputs Outputs Comm. value Actual value ±10 V (D) (F) ±10 V > Refer. (E) (C) Refer. > Supply 0V (B) Valve +24 V (A)

BPS 21.0

Diplay 1 ±10 V Signal > Reference Diplay 2 ±10 V Signal > Reference Supply 0V +24 V

BPS 6.1

T

P A (Y)

+24 V

Fig. 11.04 Electrical block circuit diagram

Fig. 11.05 Command value module/connection panel/command/actual value display

11

Project 11: Moving the cylinder

6

Bosch Rexroth AG I RE 00847/10.08

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

Proportional pressure valve

DD18E.

1.2

1

4/3 directional valve

DW13E

1.4

1

Check valve

DS2.1

0.1-0.3

3

Pressure gauge with minimess line

DZ1.4

Symbol

11 3

Hydraulic hose with minimess connection

DZ25.1 N-W

4

Hydraulic hose

VSK1. N-W

Table 11.01 Parts list for hydraulic circuit diagram Fig. 11.02

Project 11: Moving the cylinder

Item

S1-S6 K1-K3

7

Bosch Rexroth AG I RE 00847/10.08

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

1

Control module

BRS 1.2

1

Command value/actual value display

BPS 6.1

1

2 mm screw driver

Table 11.02 Parts list for electric block circuit diagram Fig. 11.03

11 Notes

Project 11: Moving the cylinder

8

Bosch Rexroth AG I RE 00847/10.08

Component arrangement

P

Connection block T T P

Measuring glass

VSK1

ZY1.7

DZ1.4

DZ1.4

DW13E VSK1

DS2.1

DD18E

D DZ1.4

VSK1

DZ25.1

D

Note: In connection elements marked with D, the components are directly plugged into each other.

11 Fig. 11.06 Recommended component arrangement with component designations according to parts list Table 11.01 and hydraulic circuit diagram Fig. 11.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use of the DS4 fastening grid.

Project 11: Moving the cylinder

9

Bosch Rexroth AG I RE 00847/10.08

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk can arise during operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening bypass or operating directional valves.

11 Execution of the order Demands placed on the control: The hydraulic circuit is set up so that the system pressure is limited by means of a proportional pressure valve. A cylinder is to be extended/retracted and stopped by means of a directional valve. Set-up the circuit by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the fastening grid according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, pressure hoses DZ25.1 are used. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components to the pressure hoses by turning the hoses.

Project 11: Moving the cylinder

10

Bosch Rexroth AG I RE 00847/10.08

2. Electrical control Requirements: The electrical control must be set up so that proportional valve DBEE6 (DD18E) can be adjusted with command value source BPS 20.0. Low pressure and high pressure are to be preselected by means of two push-buttons. For this purpose, one command value is in each case called up at the command value module. The cylinder movement for retracting and extending is activated and stopped by means of push-buttons. The command value and the pressure are to be measured and displayed. Tasks: Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine the measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/–10 V; never connect them to 24 V. This can cause damage to electronic components.

3. Pre-setting of the pressures Switch the control voltage on. Hydraulic pressure is not yet required; for this reason, the pump is not switch on and the bypass valve is open. Generally, when taking voltage measurements, the signal (+/–10 V) must always be measured against a reference (^). The measuring points used on the BPS 20.0 are sockets (+/–10 V) and ^ for the command value. Using switch S1, activate command value 1 and at the command value module BPS 20.0, set a voltage for 20 bar (value see table in Project 10). Using switch S2, activate command value 2 and at the command value module BPS 20.0, set a voltage for 40 bar (value see table in Project 10). Read off the voltage from command/actual value display BPS 6.1. With a command value of 0 V, the lowest pressure possible is set if no switch has been actuated.

Caution

Integrated valve electronics are factory-set on test rigs and must not be modified by the user. Adjustments of the integrated valve electronics on the system are necessary in exceptional cases only and require special knowledge. Unqualified modifications can lead to unexpected valve characteristics.

11

Project 11: Moving the cylinder

11

Bosch Rexroth AG I RE 00847/10.08

4. Moving the cylinder with 20 bar or 40 bar Switch the hydraulic pump on. Close the bypass valve. Check the hydraulic circuit for leakage. Using S1, preselect a pressure of 20 bar and extend the cylinder. Using S2, preselect a pressure of 40 bar and extend the cylinder. Observe the cylinder's behavior and the pressure values If necessary, adjust the command values for the necessary pressure. Note the command values W1, W2: 20 bar → W1 = ..,. V 40 bar → W2 = ..,. V Note for trainers: The set pressure can only be reached in the cylinder's end position as the load determines the system pressure.

Caution

After completion of practical work, set the command value at the training system to 0 V. Switch off the pump. No pressure gauge may indicate a pressure.

Evaluating the work results I. In which position of the cylinder has the preselected pressing power been reached? The preselected pressing power has been reached in the end position. II. Why is no max. pressure possible during the cylinder movement? The pressure is determined by the load of the cylinder.

11

Project 11: Moving the cylinder

12

Bosch Rexroth AG I RE 00847/10.08

Project / trainer information In Project 11, basic knowledge is to be imparted of the behavior of proportional pressure valves in a practical set-up. In the practical set-up, the following knowledge is to be imparted: • Presetting pressures • Pressure build-up • The amount of the command value determines the pressure.

Notes

11

Project 12: Automatic sequence with proportional valve

1

Bosch Rexroth AG I RE 00847/10.08

Project 12: Automatic sequence with proportional valve Project definition In a dewatering press, sludge is compressed for dewatering purposes. Sludge may only be compressed slowly and with little force as otherwise, the material becomes inhomogeneous and too much sludge is pressed through the dewatering openings. Only if the material has been dewatered is it to be compressed slowly with higher pressure. The pressing power for dewatering is 15 bar, the stroke is to be carried out in 3 s. The maximum pressing power for the final compression is 45 bar and is to slowly increase in 4 s. The return stroke must only be performed if the pressing power has been discharged so that impacts are avoided. The movement is controlled by means of a directional on/off valve, the pressure by means of a proportional valve.

12

Fig. 12.01 Section of a DBEE proportional directional valve with integrated electronics

Project tasks • Developing a control for satisfying the requirements • Adjusting the command value voltages for different pressures • Adjustment of the ramps for pressure increase and discharge

Project 12: Automatic sequence with proportional valve

2

Bosch Rexroth AG I RE 00847/10.08

Project steps

Notes

• Informing:

In which condition is the machine? What in detail is to be done?

• Planning:

Select and read documents for information.

• Deciding:

Selection of components. Where are the components and measuring points located? How must the components be connected with each other (hydraulically and electrically)?

• Executing:

Preparation of sketches of hydraulic and electrical circuit diagrams. Set-up of the hydraulic control and the electrical circuit. Determining the required values and their documentation.

• Checking:

Are the powers complied with?

• Evaluating:

How does the system behave?

12

Project 12: Automatic sequence with proportional valve

3

Bosch Rexroth AG I RE 00847/10.08

Hydraulic circuit diagram

Measuring glass

12 Aggregate limit

Fig. 12.02 Hydraulic circuit diagram

Project 12: Automatic sequence with proportional valve

4

Bosch Rexroth AG I RE 00847/10.08

Electrical circuit diagram

12

Fig. 12.03 Electrical circuit diagram

Project 12: Automatic sequence with proportional valve

5

Bosch Rexroth AG I RE 00847/10.08

Electrical block circuit diagram S1 3

+24 V

11

4

34

K1

31 22 21

12 34

K2

31

13 34

K3

31

K2

Command value provision Inputs Supply 0V 24 V

Outputs Comm. value ±10 V Signal > Reference

BPS 5.2

Command value module Inputs Outputs Comm. value Measurands Call-up 4 Comm. val. w Call-up 3 Reference > Call-up 2 Ramp time t Call-up 1 Reference > Inversion Inv. Control Differential variable input ±10 V ±10 V Reference > > Reference Ramp 4Q Supply 0V +24 V

Comm./actual value display Connection panel Inputs Outputs Comm. value Actual value ±10 V (D) (F) ±10 V > Refer. (E) (C) Refer. > Supply 0V (B) Valve +24 V (A)

BPS 21.0

BPS 20.0

a

0

P

BPS 6.1

B

A

G

a

0V

Diplay 1 ±10 V Signal > Reference Diplay 2 ±10 V Signal > Reference Supply 0V +24 V

b

T

b

+24 V

Fig. 12.04 Electrical block circuit diagram

12

Fig. 12.05 Command value source/command value module/connection panel/command/actual value display

6

Project 12: Automatic sequence with proportional valve

Bosch Rexroth AG I RE 00847/10.08

Component selection with parts list Item

Qty

Component designation

Type designation

1.0

1

Hydraulic cylinder

ZY1.7

1.1

1

Proportional pressure valve

DD18E

1.2

1

4/3 directional valve

DW13E

1.4

1

Check valve

DS2.1

1.5

1

Throttle check valve

DF2.2

Symbol

12 1.6

1

Pressure switch

DD6E.1

0.1 0.3

2

Pressure gauge with minimess line

DZ1.4

3

Hydraulic hose with minimess connection

DZ25.1 N-W

4

Hydraulic hose

VSK1. N-W

Table 12.01 Parts list for hydraulic circuit diagram Fig. 12.02

Project 12: Automatic sequence with proportional valve

Item

7

Bosch Rexroth AG I RE 00847/10.08

Qty

Component designation

Type designation

1

Command value module

BPS 20.0

1

Command value source

BPS 5.2

1

Connection panel of integrated electronics

BPS 21.0

1

Switch and push-button

BPS 7.4

1

Distributor

BPS 13.1

K1-K3

1

Control module

BRS 1.2

B1

1

Proximity switch, inductive

DE 2.2

KT

1

Time relay

BRS 2.1

1

Command value/actual value display

BPS 6.1

1

Stop watch, 2 mm screw driver

S1-S6

Table 12.02 Parts list for electric block circuit diagram Fig. 12.03

Notes

12

Project 12: Automatic sequence with proportional valve

8

Bosch Rexroth AG I RE 00847/10.08

Component arrangement

VSK1

ZY1.7 DZ1.4

DF2.2

P

Connection block T T P

Measuring glass

DD6E.3

DW13E VSK1

DS2.1

DD18E

D DZ1.4

VSK1 DZ25.1

D

Note: In connection elements marked with D, the components are directly plugged into each other.

Fig. 12.06 Recommended component arrangement with component designations according to parts list Table 12.01 and hydraulic circuit diagram Fig. 12.02

Note: The designations of components in the parts list and the component arrangement are Rexroth-specific designations. Also the grid arrangement is Rexrothspecific and adapted for use of the DS4 fastening grid.

12

Project 12: Automatic sequence with proportional valve

9

Bosch Rexroth AG I RE 00847/10.08

Safety notes To ensure the operability of plant and machinery, and consequently to allow the recognition of potential risks, safety regulations must be observed before and during the execution of the order. Relevant sources of regulations are given in the introduction of the present manual.

Warning

Caution

If work on electrohydraulic components is carried out improperly, risks of injury and a safety risk can arise during operation of the system, including danger to life. Before starting work on the training stand, check that the electrical ON/OFF switch on the hydraulic power unit is pressed in, i.e. that the system is switched off. Use the system pressure gauges to check that the system is depressurized. Hydraulic systems can store residual energy also after having been disconnected from any energy source. This residual energy must be discharged without any risk, e.g. by opening bypass or operating directional valves.

Execution of the order Demands placed on the control: The hydraulic circuit is set up so that the system pressure is limited by means of a proportional pressure valve. A cylinder is to be extended/retracted and stopped by means of a directional valve. For the loading and for setting the extending time of 3 s, an outlet throttle is installed on the annulus side of the cylinder. Switch-over to the higher pressing power is only effect shortly before the end position at 350 mm by means of a proximity switch. The pressing time of 4 s is adjusted by means of a ramp. Discharge and return stroke are initiated by a pressure switch signal at 45 bar. The discharge time of 2 s is adjusted by means of a ramp. The return stroke is activated in a delayed form by means of a time relay. The delay time is to be adjusted so that the return stroke is only activated after the pressure has been discharged.

12

Project 12: Automatic sequence with proportional valve

10

Bosch Rexroth AG I RE 00847/10.08

Set-up the circuit by following the steps below: 1. Hydraulic control Prepare a circuit diagram and parts list in order to meet the requirements. Mount the hydraulic components on the fastening grid according to the circuit diagram and connect them using hoses. To connect pressure gauges with measuring line DZ1.4, pressure hoses DZ25.1 are used. Tighten the pressure gauge measuring lines at the relevant measuring point of the pressure hose hand-tight. Check the correct and tight connection of components to the pressure hoses by turning the hoses. 2. Electrical control Requirements: The electrical control must be set up so that proportional valve DBEE6 (DD18E) can be adjusted with command value source BPS 20.0. By means of a switch, the sequence can be interrupted at any time. The working process is started by means of a push-button. The extending time is set to 3 s by means of the outlet throttle. Switch-over to the higher pressing power is only effect shortly before the end position at 350 mm by means of a proximity switch. The pressing time of 4 s is adjusted by means of a ramp. Discharge and return stroke are initiated by a pressure switch signal at 45 bar. The discharge time of 2 s is adjusted by means of a ramp. The return stroke is activated in a delayed form by means of a time relay. The delay time is to be adjusted so that the return stroke is only activated after the pressure has been discharged The return stroke is carried out with a lower pressure of 12 bar. The command value and the pressure are to be measured and displayed Tasks: Prepare a circuit diagram in order to meet the requirements. Set up the prepared circuit. Determine the measuring points.

Caution

The yellow sockets are exclusively provided for a signal voltage of +/–10 V; never connect them to 24 V. This can cause damage to electronic components.

12

Project 12: Automatic sequence with proportional valve

11

Bosch Rexroth AG I RE 00847/10.08

3. Adjustments Switch the pump on and close the bypass valve. Check the hydraulic circuit for leakage. Switch the control voltage on by operating S1. Using push-button S2, activate command value 1 and at the command value module BPS 20.0, set a voltage for 15 bar as command value W1 and a ramp time of 1 s. So that the cylinder does not extend, the outlet throttle is closed for the adjustment. Adjust the outlet throttle for an extending time of 3 s. The proximity switch is adjusted so that there is a signal at 350 mm. The command value W2 is adjusted for 45 bar and the ramp time to 4 s. The pressure switch will switch at 45 bar. The command value W3 is adjusted for 12 bar and the ramp time to 2 s. The time relay is adjusted so that the return stroke is only carried out if the pressure has been discharged. Generally, when taking voltage measurements, the signal (+/–10 V) must always be measured against a reference (^). The measuring points used on the BPS 20.0 command value module are the sockets W (+/–10 V) and ^ for the command value. Read off the voltage from command/actual value display BPS 6.1. With a command value of 0 V, the lowest pressure possible is set if no switch has been actuated.

Caution

Integrated valve electronics are factory-set on test rigs and must not be modified by the user. Adjustments of the integrated valve electronics on the system are necessary in exceptional cases only and require special knowledge. Unqualified modifications can lead to unexpected valve characteristics.

Note for trainers: The pressure to be set can only be reached in the cylinder's load as the load determines the system pressure.

Caution

After completion of practical work, switch the pump on the training system off. Afterwards, actuate the directional valve once again for the pressure discharge. No pressure gauge may indicate a pressure.

12

Project 12: Automatic sequence with proportional valve

12

Bosch Rexroth AG I RE 00847/10.08

Evaluating the work results I. Why is no maximum pressure possible during the cylinder movement? The pressure is determined by the load of the cylinder.

Project / trainer information In Project 12, knowledge is to be imparted regarding the use of proportional pressure valves with directional on/off valves in a practical set-up. In the practical set-up, the following knowledge is to be imparted: • Working out an automatic sequence • Presetting pressures • Pressure build-up and pressure discharge • The amount of the command value determines the pressure. • The ramp determines the pressure build-up or the discharge.

Notes

12

Project 12: Automatic sequence with proportional valve

13

Bosch Rexroth AG I RE 00847/10.08

12

4/2 and 4/3 proportional directional valves, direct operated, with electrical position feedback, without/with integrated electronics (OBE)

RE 29061/11.12 Replaces: 05.12

1/22

Type 4WRE and 4WREE

Size 6 and 10 Component series 2X Maximum operating pressure 315 bar Maximum flow: 80 l/min (size 6) 180 l/min (size 10)

Table of contents Contents

Features Page

Features1 Ordering code

2

Symbols3 Function, section

4, 5

Technical data

6, 7

Electrical connection, mating connectors

8, 9

Block diagram of the integrated electronics (OBE) for type 4WREE

10

Characteristic curves

11 to 17

Unit dimensions

18 to 22

– Direct operated proportional directional valve with electrical position feedback and integrated electronics (OBE) with type 4WREE – Control of flow direction and size – Operation by means of proportional solenoids with central thread and detachable coil – For subplate mounting: Porting pattern according to ISO 4401 – Spring-centered control spool – Control electronics • Type 4WREE: integrated electronics (OBE) with voltage or current input (A1 and/or F1) • Type 4WRE (4/3 version), separate order: - digital and analog amplifier in Euro-card format - analog amplifier in modular design • Type 4WRE…A (4/2 version), separate order: - analog amplifier in modular design

Information on available spare parts: www.boschrexroth.com/spc

2/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Ordering code 4WRE Without integrated electronics (OBE) With integrated electronics (OBE)

2X G24

V

Further details in the plain text

= no code =E

V =

=6 = 10

Size 6 Size 10 Control spool symbols





Electrical connection Type 4WRE: K4 = Without mating connector, with connector according to DIN EN 175301-803 Mating connector (solenoid, position transducer), separate order, see page 8 Type 4WREE: K31 = Without mating connector, with connector according to DIN EN 175201-804 Mating connector – separate order, see page 9

  = E E1–

= V V1–

= W W1–



G24 =  2X = 

  

  



= EA

= WA

With symbol E1–, V1– and W1–: P → A: qV max B → T: qV/2 P → B: qV/2 A → T: qV max Notice: In the zero position, spools W and WA have a connection from A to T and B to T with approx. 3 % of the relevant nominal cross-section.

Seal material FKM seals 1)

Electronic interface A1 = Command value ±10 V F1 = Command value 4 to 20 mA no code = Type 4WRE

  

*

04 = 08 = 16 = 32 = 25 = 50 = 75 = 1) Design

Supply voltage Direct voltage 24 V 20 to 29 (20 to 29: unchanged installation and connection dimensions)

Rated flow at valve pressure differential Δp = 10 bar Size 6 4 l/min 8 l/min 16 l/min 32 l/min Size 10 25 l/min 50 l/min 75 l/min SO660 with NBR seals at the valve connection surface

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

3/22

Symbols Proportional directional valve without integrated electronics

Proportional directional valve with integrated electronics

Type 4WRE…

Type 4WREE…



 







 







 



 









Type 4WREE…A…

Type 4WRE…A…















 



 





 

 

4/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Function, section Type 4WRE …-2X/… The 4/2 and 4/3 proportional directional valves are designed as direct operated devices in plate design. Operation is effected by proportional solenoids with central thread and detachable coil. The solenoids are controlled by external electronics.

Function:

Set-up:

– Direct operation of the control spool (2) by controlling a proportional solenoid, e.g. solenoid "b" (8)

The valve basically consists of:

– With de-energized solenoids (7 and 8), central position of the control spool (2) by compression springs (3 and 4) between spring plates (5 and 6)

→ Displacement of the control spool (2) to the left proportional to the electric input signal

– Housing (1) with connection surface – Control spool (2) with compression springs (3 and 4) and spring plate (5 and 6)

→ Connection from P to A and B to T via orifice-type cross-sections with progressive flow characteristic

­­– Solenoids (7 and 8) with central thread

– Switching off of the solenoid (8)

­­– Position transducer (9)

→ The compression spring (3) brings the control spool (2) back into the central position In the de-energized condition, the control spool (2) is held in a mechanical central position by the return springs. With control spool symbol "V", this position does not correspond to the hydraulic central position! When the electric valve control loop is closed, the control spool is positioned in the hydraulic central position.

Important note! The PG fitting (11) must not be opened. Mechanical adjustment of the adjustment nut located below is prohibited and damages the valve!





















    



Valve with 2 spool positions: (Type 4WRE…A…)

 to the The function of this valve design basically corresponds valve with three spool positions. The 2 spool position valves are, however, only equipped with solenoid "a" (7). Instead of the 2nd proportional solenoid, there is a plug screw (10).

 



Notice!

Notice!

Due to the design principle, internal leakage is inherent to the valves, which may increase over the life cycle.













The tank line must not be allowed to run empty. With corresponding installation conditions, a pre-charge valve (pre-charging pressure approx. 2bar) is to be installed.

 

  









RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

5/22

Function, section Type 4WREE …-2X/… Function:

The 4/2 and 4/3 proportional directional valves are designed as direct operated devices in plate design. Operation is effected by proportional solenoids with central thread and detachable coil. The solenoids are controlled by the internal electronics.

– With de-energized solenoids (7 and 8), central position of the control spool (2) by compression springs (3 and 4) between spring plates (5 and 6) – Direct operation of the control spool (2) by controlling a proportional solenoid, e.g. solenoid "b" (8)

Set-up: The valve basically consists of:

→ Displacement of the control spool (2) to the left propor input signal tional to the electric



– Housing (1) with connection surface





– Control spool (2) with compression springs (3 and 4) and spring plate (5 and 6)

→ Connection from P to A and B to T via orifice-type crosssections with progressive flow characteristic

­­– Solenoids (7 and 8) with central thread

– Switching off of the solenoid (8)

­­– Position transducer (9)

→ The compression spring (3) brings the control spool (2) back into the central  position



­– Integrated electronics (13)

­– Electric zero point adjustment (12) accessible via Pg7 Important note!









The PG fitting (11) must not be opened. Mechanical adjustment of the adjustment nut located below is prohibited and damages the valve!



In the de-energized condition, the control spool (2) is held in a mechanical central position by the return springs. With control  spool  symbol "V", this position does not correspond to the hydraulic position! When the electric valve control loop  central     is closed, the control spool is positioned in the hydraulic central position.





 











 

  









Valve with 2 spool positions: (Type 4WREE…A…) The function of this valve design basically corresponds to the valve with three spool positions. The 2 spool position valves are, however, only equipped with solenoid "a" (7). Instead of the 2nd proportional solenoid, there is a plug screw (10).

Notice! Due to the design principle, internal leakage is inherent to the valves, which may increase over the life cycle.

Notice! The tank line must not be allowed to run empty. With corresponding installation conditions, a pre-charge valve (precharging pressure approx. 2 bar) is to be installed.

6/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

outside these parameters please consult us!) Technical data (For applications

general Sizes

Size

Weight

6

10

– Type 4WRE

kg

2.2

6.3

– Type 4WREE

kg

2.4

6.5

– Type 4WRE

°C –20 to +70

– Type 4WREE

°C –20 to +50

Installation position

Any, preferably horizontal

Ambient temperature range Storage temperature range

°C –20 to +80

MTTFd values according to EN ISO 13849

Years 150 1) (for more information see data sheet 08012)

hydraulic (measured with HLP46, ϑOil = 40 °C ± 5 °C and p = 100 bar) Maximum operating pressure

– Port A, B, P

bar

315

– Port T

bar

210

Rated flow qV rated with Δp = 10 bar

l/min

4, 8, 16, 32

25, 50, 75

l/min

80

180

Recommended maximum flow Hydraulic fluid

See table below

Hydraulic fluid temperature range

°C –20 to +80 (preferably +40 to +50) mm2/s 20 to 380 (preferably 30 to 46)

Viscosity range

Maximum admissible degree of contamination of the hydraulic fluid, cleanliness class according to ISO 4406 (c)

Class 20/18/15 2)

Hysteresis

% ≤ 0.1

Range of inversion

% ≤ 0.05

Response sensitivity

% ≤ 0.05

Zero shift upon change of hydraulic fluid temperature and operating pressure

%/10 K ≤ 0.15 %/100 bar ≤ 0.1

1) With

control spool types E, E1, EA, W, W1, WA; in longitudinal control spool direction, there is sufficient positive overlap without shock/vibration load; observe the installation orientation with regard to the main direction of acceleration.

2) The

cleanliness classes specified for the components must be adhered to in hydraulic systems. Effective filtration prevents faults and at the same time increases the service life of the components. For the selection of the filters see www.boschrexroth.com/filter

Hydraulic fluid

Classification

Suitable sealing materials

Standards

Mineral oils and related hydrocarbons

HL, HLP

NBR, FKM

DIN 51524

Flame-resistant

HFC (Fuchs HYDROTHERM 46M, Petrofer Ultra Safe 620)

NBR

ISO 12922

– Containing water

Important information on hydraulic fluids! – For more information and data on the use of other hydraulic fluids refer to data sheet 90220 or contact us! – There may be limitations regarding the technical valve data (temperature, pressure range, service life, maintenance intervals, etc.)! – The flash point of the process and operating medium used must be 40 K higher than the maximum solenoid surface temperature.

– Flame-resistant – water-containing: Maximum pressure differential per control edge 175 bar. Pressure pre-loading at the tank port > 20 % of the pressure differential; otherwise, increased cavitation. Life cycle as compared to operation with mineral oil HL, HLP 50 % to 100 %.

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

7/22

Technical data (For applications outside these parameters please consult us!) electric Size

6

10

Ω

2.65

4.55

Ω

4.05

6.82

Size

Voltage type

Direct voltage

Solenoid coil resistance

– Cold value at 20 °C – Maximum hot value

Duty cycle

% 100 °C up to 150

Maximum coil temperature 1) Electrical connection

– Type 4WRE

With connector according to DIN EN 175301-803 and ISO 4400 Mating connector according to DIN EN 175301-803 and ISO 4400 2)

see page 8 and 9 – Type 4WREE

With connector DIN EN 175201-804 Mating connector DIN EN 175201-804 2)

Protection class of the valve according to EN 60529

IP65 with mating connector mounted and locked

Control electronics Type 4WRE

4/3 version Amplifier in euro-card format 2)

Digital

VT-VRPD-2-2X/V0/0 according to RE 30126

Analog

VT-VRPA2-1-1X/V0 according to data sheet 30119

VT-VRPA2-2-1X/V0 according to data sheet 30119

Module amplifier 2)

Analog

VT-MRPA2-1 according to data sheet 30219

VT-MRPA2-2 according to data sheet 30219

Analog

VT-MRPA1-1 according to data sheet 30219

VT-MRPA1-2 according to data sheet 30219

Type 4WRE…A… 4/2 version Module amplifier 2) Type 4WREE

Supply voltage

Current consumption of the amplifier 1) Due

Integrated in the valve, see page 9 analog command value module

VT- SWMA-1-1X/... according to data sheet 29902

analog command value module

VT-SWMAK-1-1X/... according to data sheet 29903

analog command value card

VT-SWKA-1-1X/... according to data sheet 30255

digital command value card

VT-HACD -1-1X/... according to data sheet 30143

Nominal voltage

VDC 24

lower limit value

V 19.4

upper limit value

V 35

Imax

A <2

Pulse current

A 3

to the temperatures occurring at the surfaces of the solenoid coils, the European standards ISO 13732-1 and EN ISO 4413 need to be adhered to!

2) Separate

order

Notice: For information on the environmental simulation testing for the areas EMC (electromagnetic compatibility), climate and mechanical load see data sheet 29061-U (declaration on environmental compatibility).

8/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Electrical connection, mating connectors (dimensions in mm) Type 4WRE (without integrated electronics) Connection to connector

Connection to mating connector

 

 









 



to the amplifier



to the amplifier



Mating connector CECC 75 301-803-A002FA-H3D08-G according to DIN EN 175301-803 and ISO 4400





 





Solenoid a, color gray separate order under the Material no. R901017010







Solenoid b, color black separate order under the Material no. R901017011 1 Mounting screw M3 Tightening torque MA = 0.5 Nm + 0.1 Nm





Inductive position transducer Connection to plug-in connector

to the amplifier

Ground signal    

Ground supply

   

Signal supply

to the amplifier

Coil connection

Coil

Mating connector 4-pole Pg7-G4W1F







separate order under the Material no. R900023126



Connect shield to PE only on the supply side.



Recommendation: up to 50 m cable length type LiYCY 4 x 0.25 mm2



Connection cable:

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

9/22

Electrical connection, mating connectors (dimensions in mm) Type 4WREE (with integrated electronics (OBE) Mating connector according to DIN EN 175201-804 separate order under the Material no. R900021267 (plastic version) Angular design – separate order under the Material no. R900217845 Pin assignment see also block diagram page 10







  

 Device connector allocation Supply voltage

Contact

Signal with A1 interface

C

Differential amplifier input

D E

Measuring output (actual value)

F PE



Signal with F1 interface

24 VDC (u(t) = 19.4 to 35 V); Imax = 2 A

A B

Reference potential actual value





Mating connector according to DIN EN 175201-804 separate order under the Material no. R900223890 (metal version)



0 V

Reference contact F; Re > 50 kΩ

Reference contact F; Re < 10 Ω

±10 V command value; Re > 50 kΩ

4 to 20 mA command value; Re > 100 Ω

±10 V actual value (limit load 5 mA)

4 to 20 mA actual value, load resistance max. 300 Ω

Reference potential command value

Connected to cooling element and valve housing

Command value: Positive command value 0 to +10 V (or 12 to 20 mA) at D and reference potential at E result in flow from P → A and B → T. Negative command value 0 to –10 V (or 12 to 4 mA) at D and reference potential at E result in flow from P → B and A → T.

For valves with 1 solenoid on side a (e. g. variant EA and WA), a positive command value 0 to +10 V (or 4 to 20 mA) at D and reference potential at E result in flow from P → B and A → T.

Actual value:

 ctual value 0 to +10 V (or 12 to 20 mA) at F and reference potential at C result in flow from P → A and A B → T, actual value 0 to –10 V (or 4 to 12 mA) result in flow from P → B and A → T.

With valves with 1 solenoid, a positive actual value 0 to +10 V (or 4 to 20 mA) at F and reference potential at C result in flow from P → B and A → T. Connection cable: Recommendation: – up to 25 m cable length type LiYCY 7 x 0.75 mm2 – up to 50 m cable length type LiYCY 7 x 1.0 mm2

External diameter see sketch of mating connector



Connect shield to PE only on the supply side.

10/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Integrated electronics (OBE) type 4WREE Block diagram / pin assignment Interface

Command value

Integrated electronics (OBE)



Reference potential



Actual value



Reference potential



Supply ­voltage­

24 V

GND Protective earthing conductor 1)

Differential amplifier 



 Ramp generator 2)

Controller





Undervoltage detection

 



Actual value 



Valve



Locking

Power supply unit     

Oscillator 

Demodulator 



 Zero point

Sensitivity

3)

Position transducer

Notice: Electric signals taken out via control electronics (e.g. actual value) must not be used for switching off safetyrelevant machine functions!

±10 V/4...20 mA actual position

1) The

protective earthing conductor (PE) is connected to cooling element and valve housing!

+24 V

2) Ramp

can be set from 0 to 2.5 s from the outside, identical for Tup and Tdown

3) Zero





point can be set from the outside



 



0V Reference actual position ±10 V/4...20 mA signal input





  





  

 

Reference input

Symbol





   

 

 

 



Material no. Internal manufacturing order no.

Valve type Serial valve no. to the manufacturing order Year of construction, week of construction + country code

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

11/22

Characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C) Size 6 and 10 Pressure signal characteristic curve (control spool V), ps = 100 bar Size 6

  

 







pS

ΔpL

in % →











←

   

←

UE UEN

 in % →

Size 10   

 







pS

ΔpL

in % →



←

   

←

UE UEN

 in % →

12/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C) Size 6 and 10 Zero flow with central control spool position Type 4WREE 10 V75

Type 4WREE 6 V32



Zero flow in l/min →

Zero flow in l/min →















 



 







Operating pressure in bar →



 



 

Operating pressure in bar →

Characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C and p = 100 bar) Size 6 4 l/min rated flow with 10 bar valve pressure differential

Flow in l/min →

 

or P→B/A→T



 











1 Δp

= 10 bar constant

2 Δp

= 20 bar constant



3 Δp

= 30 bar constant

  

4 Δp

= 50 bar constant

5 Δp

= 100 bar constant



P→A/B→T







    Command value in % →













Control spool V

Control spool E- and W

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

13/22

Characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C and p = 100 bar) Size 6 8 l/min rated flow with 10 bar valve pressure differential

Flow in l/min →

 



P→A/B→T or

   

P→B/A→T







 

















    Command value in % →









1 Δp

= 10 bar constant

2 Δp

= 20 bar constant

3 Δp

= 30 bar constant

4 Δp

= 50 bar constant

5 Δp

= 100 bar constant

Control spool V

Control spool E- and W



16 l/min rated flow with 10 bar valve pressure differential





P→A/B→T

Flow in l/min →



or P→B/A→T









1 Δp

= 10 bar constant

2 Δp

= 20 bar constant

3 Δp

= 30 bar constant

4 Δp

= 50 bar constant

5 Δp

= 100 bar constant

 









 

















    Command value in % →









Control spool V  Control spool E- and W

32 l/min rated flow with 10 bar valve pressure differential    Flow in l/min →



P→A/B→T



or P→B/A→T



3 Δp

= 30 bar constant

4 Δp

= 50 bar constant

5 Δp

= 100 bar constant

Maximum admissible flow













  

 

= 20 bar constant







1 Δp

= 10 bar constant

2 Δp

















    Command value in % →













Notice:

Observe the performance limits on page 15! Δp = Valve pressure differential (inlet pressure pP minus load pressure pL minus return flow pressure pT) Control spool V

Control spool E- and W

14/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C and p = 100 bar) Size 10

Flow in l/min →





25 l/min rated flow with 10 bar valve pressure differential



P→A/B→T



P→B/A→T

1 Δp

= 10 bar constant

2 Δp

= 20 bar constant



3 Δp

= 30 bar constant

4 Δp

= 50 bar constant



5 Δp

= 100 bar constant

or

 







  



Flow in l/min →



















    Command value in % →













Control spool E- and W 

50 l/min rated flow with 10 bar valve pressure differential



P→A/B→T



P→B/A→T

Control spool V



or

 



1 Δp

= 10 bar constant

2 Δp

= 20 bar constant

3 Δp

= 30 bar constant

4 Δp

= 50 bar constant

5 Δp

= 100 bar constant

 







    

Flow in l/min →





















    Command value in % →













75 l/min rated flow with 10 bar valve pressure differential



Control spool V

Control spool E- and W



P→A/B→T or

Maximum admissible flow Notice: Observe the performance limits on page 15! 1 Δp

P→B/A→T 

 











   



























    Command value in % →







= 10 bar constant

2 Δp

= 20 bar constant

3 Δp

= 30 bar constant

4 Δp

= 50 bar constant

5 Δp

= 100 bar constant

Δp = Valve pressure differential (inlet pressure pP minus load pressure pL minus return flow pressure pT) Control spool V

Control spool E- and W

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

Transition function with stepped electric input signals: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C and ps = 10 bar) 4/3 valve version

15/22

Size 6

Signal change in %

Control spool E





 



Stroke in % →

 



  



  

















Time in ms →

Frequency response characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C, ps = 10 bar)

Size 6

4/3 valve version Control spool V 



























 







Frequency in Hz → Signal ±10 % Signal ±25 % Signal ±100 %





 

Phase angle in ° →

Amplitude ratio in dB →



16/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Transition function with stepped electric input signals: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C and ps = 10 bar) 4/3 valve version

Size 10

Signal change in %

Stroke in % →

Control spool E























  Time in ms →







Frequency response characteristic curves: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C, ps = 10 bar)

Size 10

4/3 valve version 







 





















 



Signal ±10 % Signal ±25 % Signal ±100 %

  Frequency in Hz →







Phase angle in ° →

Amplitude ratio in dB →

Control spool V

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

Flow: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C)

17/22

Size 6

Load function with maximum valve opening Rated flow 4, 8, 16 and 32 l/min Control spool V

Maximum admissible flow



Flow in l/min →



  

P→A/B→T



or P→B/A→T





 



  Valve pressure differential in bar →





Observe the maximum admissible flow of 80 l/min!

Flow: Type 4WREE (measured with HLP46, ϑOil = 40 °C ± 5 °C)

Size 10

Load function with maximum valve opening Rated flow 25, 50 and 75 l/min Control spool V

 Maximum admissible flow 

Flow in l/min →



P→A/B→T 



or P→B/A→T













  Valve pressure differential in bar →

Observe the maximum admissible flow of 180 l/min!





18/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12

Unit dimensions: Type 4WRE (dimensions in mm)

Size 6

 























 









 



 

  















 

 



 





 Required surface quality of the valve mounting face

 1 2 3 4

Valve housing Proportional solenoid "a" with inductive position transducer Proportional solenoid "b" Mating connector "A", color gray, separate order – see page 8 5 Mating connector "B", color black, separate order – see page 8 6 Mating connector for inductive position transducer, separate order – see page 8 7 Plug screw for valve with one solenoid (2 spool positions, version EA or WA) 8 Identical seal rings for ports A, B, P, and T 9 Space required to remove the mating connector 10 Name plate 11 Machined valve mounting face, porting pattern according to ISO 4401-03-02-0-05 (with locating hole) Deviating from the standard: - without locating hole "G" - Ports P, A, B and T with Ø 8 mm Subplates and valve mounting screws see page 22

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

19/22

Unit dimensions: Type 4WREE (dimensions in mm) 





Size 6









 













 





 

 

   





 









 

1 2 3 7 8 10 11

2 1 13



 Required surface quality of the valve mounting face General tolerances according to ISO 2768-mK

Valve housing Proportional solenoid "a" with inductive position transducer Proportional solenoid "b" Plug screw for valve with one solenoid (2 spool positions, version EA or WA) Identical seal rings for ports A, B, P, and T Name plate Machined valve mounting face, porting pattern according to ISO 4401-03-02-0-05 (with locating hole) Deviating from the standard: - without locating hole "G" - Ports P, A, B and T with Ø 8 mm Integrated electronics (OBE) Mating connector, separate order – see page 9

Subplates and valve mounting screws see page 22

20/22

Bosch Rexroth AG Hydraulics

4WRE; 4WREE RE 29061/11.12











Size 10 









Unit dimensions: Type 4WRE (dimensions in mm)





 

















  















 

 









Required surface quality of the valve mounting face General tolerances according to ISO 2768-mK

 

1 2 3 4

Valve housing Proportional solenoid "a" with inductive position transducer Proportional solenoid "b" Mating connector "A", color gray, separate order – see page 8 5 Mating connector "B", color black, separate order – see page 8 6 Mating connector for inductive position transducer, separate order – see page 8 7 Plug screw for valve with one solenoid (2 spool positions, version EA or WA) 8 Identical seal rings for ports A, B, P, T and T1 9 Space required to remove the mating connector 10 Name plate 11 Machined valve contact surface, porting pattern according to ISO 4401-05-04-0-05 differing from the standard: Connection T1 Ø 11.2 mm Subplates and valve mounting screws see page 22

RE 29061/11.12 4WRE; 4WREE

Hydraulics Bosch Rexroth AG

Unit dimensions: Type 4WREE (dimensions in mm) 









size 10 





21/22

 

















  















 











Required surface quality of the valve mounting face General tolerances according to ISO 2768-mK

 

1 2 3 7 8 10 11 2 1 13

Valve housing Proportional solenoid "a" with inductive position transducer Proportional solenoid "b" Plug screw for valve with one solenoid (2 spool positions, version EA or WA) Identical seal rings for ports A, B, P, T and T1 Name plate Machined valve contact surface, porting pattern according to ISO 4401-05-04-0-05 differing from the standard: Connection T1 Ø 11.2 mm Integrated electronics (OBE) Mating connector, separate order – see page 9

Subplates and valve mounting screws see page 22

22/22

Bosch Rexroth AG Hydraulics

4WRE; 4 WREE RE 29061/11.12

Unit dimensions Hexagon socket head cap screws Size 6

Material number 4x ISO 4762 - M5 x 50 - 10.9-flZn-240h-L Tightening torque MA = 7 Nm ±10 % or 4x ISO 4762 - M5 x 50 - 10.9 Tightening torque MA = 8.9 Nm ±10 %

Size 10

4x ISO 4762 - M6 x 40 - 10.9-flZn-240h-L Tightening torque MA = 12.5 Nm ±10 % or 4x ISO 4762 - M6 x 40 - 10.9 Tightening torque MA = 15.5 Nm ±10 %

R913000064

R913000058

Notice: This tightening torque of the hexagon socket head cap screws refers to the maximum operating pressure! Subplates

Data sheet

Size 6

45052

Size 10

45054

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Phone +49 (0) 93 52 / 18-0 [email protected] www.boschrexroth.de

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

RE 29061/11.12 4WRE; 4 WREE

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Phone +49 (0) 93 52 / 18-0 [email protected] www.boschrexroth.de

Hydraulics Bosch Rexroth AG

23/22

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

24/22

Bosch Rexroth AG Hydraulics

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Phone +49 (0) 93 52 / 18-0 [email protected] www.boschrexroth.de

4WRE; 4 WREE RE 29061/11.12

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

Proportional pressure relief valve, pilot operated

RE 29158/04.05 Replaces: 11.02

1/12

Types (Z)DBE and (Z)DBEE

Size 6 Component series 1X Maximum operating pressure 315 bar Maximum flow 30 L/min H/A 3598/93

Table of contents

Features Page

– Valve for limiting a system pressure

Features

1

– Operation by proportional solenoid

Ordering code

2

Preferred types

2

Contents

Function, section

3, 4

– For subplate mounting or sandwich plate design: Position of ports to DIN 24340 (without locating bore) and ISO 4401 (with locating bore) Subplates to data sheet RE 45052 (separate order, see page 10 and 11)

Technical data

5, 6

– Valve and control electronics from a single source

Control electronics

6, 7

– External control electronics for types DBE and ZDBE: • Analogue amplifier type VT-VSPA1-1 in Euro-card format (separate order), see page 6

Symbols

Electrical connection, cable socket Characteristic curves Unit dimensions

3

6 8, 9 10, 11

• Digital amplifier type VT-VSPD-1 in Euro-card format (separate order), see page 6 • Analogue amplifier of modular design type VT 11131 (separate order), see page 6 – Integrated electronics (OBE) on types DBEE and ZDBEE: • Low manufacturing tolerances for the command value/ pressure characteristic curve • Up and down ramps can be adjusted independently of each other

2/12

Bosch Rexroth AG

Hydraulics

(Z)DBE; (Z)DBEE

RE 29158/04.05

Ordering code DBE

6

1X

G24

*

Subplate mounting = No code Sandwich plate =Z

Further details in clear text

Proportional pressure relief valve

Seal material NBR seals, suitable for mineral oil (HL, HLP) to DIN 51524 V= FKM seals, suitable for phosphate esters

For external control electronics = No code With integrated electronics (OBE) =E Size 6

M=

=6

Subplate mounting Sandwich plate P → T

= No code = VP

Position of cable socket for type ZDBE Position of housing with electronics (OBE) for type ZDBEE Housing with electronics (OBE) Cable socket =1 1)

K4 =

=3

1)

=2 1) 1)

K31 =

=4 1)

Valve mounting side (R-ring recesses in the housing)

Component series 10 to19 = 1X (10 to 19: unchanged installation and connection dimensions) Max. set pressure Pressure stage 50 bar Pressure stage 100 bar Pressure stage 200 bar Pressure stage 315 bar

G24 =

= 50 = 100 = 200 = 315

Electrical connection for DBE; ZDBE: Without cable socket, with component plug to DIN EN 175301-803 Cable socket– separate order, see page 6 for DBEE; ZDBEE: Without cable socket, with component plug to DIN EN 175201-804 Cable socket– separate order, see page 6

Supply voltage of electronics 24 V DC

No code = Internal pilot oil drain (recommendation: suplate mounting up to qVmax =15 L/min) Y= External pilot oil drain (possible only with subplate mounting)

Preferred types Type DBEE

Type ZDBEE

Type

Material no.

Type

Material no.

DBEE 6-1X/50YG24K31M

R900954432

ZDBEE 6 VP2-1X/50G24K31M

R900954434

DBEE 6 -1X/100YG24K31M

R900919359

ZDBEE 6 VP2-1X/100G24K31M

R900954435

DBEE 6-1X/200YG24K31M

R900954433

ZDBEE 6 VP2-1X/200G24K31M

R900954436

DBEE 6-1X/315YG24K31M

R900546987

ZDBEE 6 VP2-1X/315G24K31M

R900954437

Further preferred types and standard components can be found in the EPS (standard price list).

RE 29158/04.05

Hydraulics Bosch Rexroth AG

(Z)DBE; (Z)DBEE

3/12

Symbols (for sandwich plate symbol: 1 = component side, 2 = plate side) Type DBE 6…

Type DBE 6…Y..

T

T

P

P

Type DBEE 6…

Type ZDBE 6 VP… 1

Y

P

Type DBEE 6…Y..

T

T

P

P

A

2

B

T

B

T

Type ZDBEE 6 VP… 1

Y

P

A

2

Function, section Types DBE and ZDBE Proportional pressure relief valves of types DBE and ZDBE are operated by means of a proportional solenoid. These valves are used to limit a system pressure. With these valves it is possible to infinitely adjust the system pressure to be limited in relation to the electrical command value. These valves basically consist of a proportional solenoid (1), housing (2), valve insert (3), spool (4) and pilot poppet (8). The proportional solenoid proportionally converts the electrical current into a mechanical force. An increase in the current intensity causes a corresponding rise in the magnetic force. The solenoid armature chamber is filled with hydraulic fluid and is pressure-balanced. The system pressure is adjusted by the proportional solenoid (1) in relation to the command value. Pressure applied by the system in port P acts on the right hand side of the spool (4). At the same time, the system pressure acts via the pilot line (6), which is fitted with an orifice (5), on the spring-loaded side of the spool (4).

9

1

8

Via a further orifice (7) the system pressure acts on the pilot poppet (8) against the force of the proportional solenoid (1). Once the system pressure has reached the pre-set value, the pilot poppet (8) lifts from its seat. Depending on the model, pilot oil can now drain externally via port A (Y) or internally into the tank, which results in a limitation of the pressure on the spring-loaded side of the spool (4). If the system pressure continues to rise slightly, then the higher pressure on the right hand side of the spool pushes the spool to the left into control position P to T. At a minimum control current - corresponds to a command value of zero - the minimum settable pressure will be set. Note! To ensure optimim function, the valve must be bled during commissioning: – Remove bleed screw (9), – pour hydraulic fluid into the open threaded hole, item 9, – when no more bubbles appear, re-fit screw, item 9. – The tank should be prevented from draining. Where installation conditions allow, a pre-load valve should be installed (pre-load pressure approx. 2 bar).

7

3

2

5

Type DBE ...K4...

A(Y)

T

P

6

4

12

4/12

Bosch Rexroth AG

Hydraulics

(Z)DBE; (Z)DBEE

RE 29158/04.05

Function, section Types DBEE …K31… and ZDBEE …K31… – with integrated electronics (OBE)

10

11

In terms of function and design, these valves correspond to types DBE and ZDBE. An additional housing (10) is fitted on the proportional solenoid which accommodates the integrated electronics (OBE). Supply and command value voltages are connected to the cable socket (11).

The command value/pressure characteristic curve (zero point at the valve insert, see page 3, item 12, and the gradient on the Imax potentiometer (R30) in the electronics) is factory pre-set with minor manufacturing tolerances. The ramp time for pressure build-up and pressure reduction can be adjusted independently of each other using two potentiometers. For further information about the integrated electronics, see page 7.

RE 29158/04.05

Hydraulics Bosch Rexroth AG

(Z)DBE; (Z)DBEE

Technical data (for applications outside these parameters, please consult us!) General Weight

– DBE and ZDBE

kg

2.4

– DBEE and ZDBEE

kg

2.5

Installation orientation

Optional

Storage temperature range

°C

– 20 to + 80

Ambient

– DBE and ZDBE

°C

– 20 to + 70

temperature range

– DBEE and ZDBEE

°C

– 20 to + 50

Hydraulic (measured with HLP 46; ϑoil = 40 °C ± 5 °C) Max. operating pressure

Max. set pressure

– Port P; P1 – P2 A1 – A2; B1 – B2

bar

315

– Port T

bar

50

– Pressure stage 50 bar

bar

50

– Pressure stage 100 bar

bar

100

– Pressure stage 200 bar

bar

200

– Pressure stage 315 bar

bar

315

bar

See characteristic curve on page 9

Min. set pressure at command value 0

Return flow pressure in port A; with external pilot oil drain (Y)

Separate at zero pressure to tank

Pilot oil flow

L/min

0.6 to 1.2

Max. flow

L/min

30

Hydraulic fluid

Mineral oil (HL, HLP) to DIN 51524. Further hydraulic fluids on enquiry!

Hydraulic fluid temperature range

°C mm2/s

Viscosity range

– 20 to + 80 15 to 380 Class 20/18/15 1)

Max. permissible degree of contamination of the hydraulic fluid - cleanliness class to ISO 4406 (c) Hysteresis

%

± 1.5 of max. set pressure

Repeatability

%

< ± 2 of max. set pressure

Linearity

%

± 3.5 of max. set pressure

Tolerance of the command – DBE and ZDBE

%

± 2.5 of max. set pressure

value/pressure curve,

%

± 1.5 of max. set pressure

– DBEE and ZDBEE

referred to the hysteresis curve, increasing pressure Step response Tu + Tg

1)

10 % → 90 %

ms

approx. 80

90 % → 10 %

ms

approx. 50

The cleanliness classes specified for components must be adhered to in hydraulic systems. Effective filtration prevents malfunction and, at the same time, increases the service life of components. For the selection of filters, see data sheets RE 50070, RE 50076, RE 50081, RE 50086 and RE 50088.

depends on system

5/12

6/12

Bosch Rexroth AG

Hydraulics

(Z)DBE; (Z)DBEE

RE 29158/04.05

Technical data (for applications outside these parameters, please consult us!) Electrical Supply voltage

V

24 DC

Min. control current

mA

100

Max. control current

mA

1600

Coil resistance

– Cold value at 20° C

Ω

5.4

– Max. hot value

Ω

7.8

%

100

Duty cycle Electrical connection

With component plug to DIN EN 175301-803

– DBE and ZDBE

Cable socket to DIN EN 175301-803 2) With component plug to DIN EN 175201-804

– DBEE and ZDBEE

Cable socket to DIN EN 175201-804 2) Type of protection of the valve to EN 60529

IP 65 with cable socket mounted and locked

Control electronics – For DBEE and ZDBEE

Integrated in the valve, see page 7

– For DBE and ZDBE Amplifier in Euro-card format (separate order)

VT-VSPA1-1 according to data sheet RE 30111

digital

VT-VSPD-1 according to data sheet RE 30123

analogue

Amplifier of modular design (separate order) 2)

analogue

VT 11131 according to data sheet RE 29865

Separate order, see below Note: For details regarding environment simulation testing in the fields of EMC (electromagnetic compatibility),

climate and mechanical stress, see RE 29158-U (declaration on environmental compatibility).

Electrical connection, cable sockets (nominal dimensions in mm) For types DBE and ZDBE – for external control electronics

27,5

Cable socket to DIN EN 175301-803 Separate order: Material no. R901017011

2

18

10A 250V

Connection to cable socket

1

GDM

Connection to component plug

43

2

2

1

34,2

PE

PE 1

10

2

to amplifier

1 Fixing screw M3

For types DBEE and ZDBEE – with integrated electronics (OBE)

Tightening torque MT = 0.5 Nm

Cable socket to DIN EN 175201-804 Separate order: Material no. R900021267 (version made of plastic)

Ø27

91

A

Ø6,5…Ø11

For the pin assignment, see block circuit diagram on page 7

5,5

1

B C

D

F E

RE 29158/04.05

7/12

Hydraulics Bosch Rexroth AG

(Z)DBE; (Z)DBEE

Integrated electronics (OBE) for types DBEE, ZDBEE Function The integrated electronics is controlled via the two differential amplifier connections D and E.

The current regulator controls the solenoid current independently of the solenoid coil resistance.

The ramp generator generates from a command value step change (0 to 10 V or 10 to 0 V) a delayed rise or drop in the solenoid current. The rise time of the solenoid current can be adjusted by means of potentiometer R14, the drop time by means of potentiometer R13.

The gradient of the command value/current characteristic curve, and hence also the gradient of the command value/ pressure characteristic curve of the proportional pressure valve may be altered using potentiometer R30.

The maximum ramp time of 5 s is only possible over the entire command value range. With smaller command value changes the ramp time shortens accordingly. The command value/solenoid current characteristic curve is matched to the valve by the characteristic curve generator, so that non-linearities in the hydraulics can be compensated for and hence a linear command value/pressure characteristic curve is obtained.

Potentiometer R43 is used to adjust the biasing current. This setting should not be altered. If necessary, the zero point of the command value/pressure characteristic curve can be adjusted at the valve seat. The power stage of the electronics for controlling the proportional solenoid is a chopper amplifier. It is pulse-width-modulated with a clock frequency of 300 Hz. The solenoid current can be measured at the two measurement sockets MP1 and MP2. A voltage drop of 0.352 V at the measurement resistor corresponds a to solenoid current of 1.6 A.

Block circuit diagram / pin assignment of integrated electronics

Command value 0 to 10 V 0V reference potential

Supply voltage: Ueff: 22 to 33 V

D +

Differential amplifier

U

E – F n.c. C n.c. A +

Ramp generator R 14 R 13

Char. curve generator

R 30 I

U

B

Chopper amplifier

R 43 Solenoid

Ramp Ramp "up" "down" +U

MP1

300 Hz

+7,5 V

=

Internal reference point 0V

+U

Current regulator Imin Imax

=

-7,5 V

=

Measuring resistor R=0.22 Ω

Oscillator

Power supply unit

1,6 A = 0,352 V MP2 0V

Supply voltage Power supply unit with rectifier Single phase rectification or three phase bridge: Ueff = 22 to 33 V Residual ripple content at power supply unit: < 5 % Supply cable:

– Recommended: 5-core 0.75 or 1 mm2 with PE conductor and shield – Outside diameter 6.5 to 11 mm – Shield to 0 V supply voltage – Max. permissible length 100 m

The minimum supply voltage of the power supply unit depends on the length of the supply cable (see diagram). For lengths > 50 m a capacitor of 2200 µF must be installed near the valve in the supply line.

Min. supply voltage in V →

Output current: Ieff = max. 1.4 A 0,75 mm2

30 28

1 mm2 26 24 22 20

40

60

80

100

Length of supply cable in m →

8/12

Bosch Rexroth AG

Hydraulics

(Z)DBE; (Z)DBEE

RE 29158/04.05

Characteristic curves (measured with HLP 46; ϑoil = 40 °C ± 5 °C ) 60

Pressure stage 50 bar (external and internal) Pressure in P or P2 in bar →

Pressure in P or P2 in bar →

Pressure in port P or P2 in dependence upon the command value (qV = 5 L/min)

50 40 30 20 10 0

10 20 30 40 50 60 70 80 90 100 Command value in % →

120 100 80 60 40 20 0

Pressure stage 200 bar (external and internal)

200 160 120 80 40 0

Pressure in P or P2 in bar →

Pressure in P or P2 in bar →

50 40 30 20 10

250

5

10 15 20 Flow in L/min →

25

200 150 100 50 0

5

10 15 20 Flow in L/min →

200 150 100 50

125

25

30

10 20 30 40 50 60 70 80 90 100 Command value in % →

Pressure stage 100 bar

100 75 50 25 0

400

Pressure stage 200 bar

Pressure stage 315 bar (external and internal)

250

30

Pressure in P or P2 in bar →

Pressure in P or P2 in bar →

Pressure stage 50 bar

10 20 30 40 50 60 70 80 90 100 Command value in % →

300

0

10 20 30 40 50 60 70 80 90 100 Command value in % →

60

0

Pressure in P or P2 in bar →

Pressure in P or P2 in bar →

350 240

Pressure stage 100 bar (external and internal)

5

10 15 20 Flow in L/min →

25

30

25

30

Pressure stage 315 bar

350

300 250 200 150 100 50 0

5

10 15 20 Flow in L/min →

The characteristic curves were measured without backpressure in port A (external pilot oil drain) and T (internal pilot oil drain). With internal pilot oil drain the pressure in P or P2 increases by the output pressure present in port T.

RE 29158/04.05

Hydraulics Bosch Rexroth AG

(Z)DBE; (Z)DBEE

Characteristic curves (measured with HLP 46; ϑoil = 40 °C ± 5 °C ) Pilot oil drain –––––– internal

10 8 6 4 2

14

Min. set pressure in bar →

Min. set pressure in bar →

12

0

14

5

10 15 20 Flow in L/min →

25

8 6 4 2

0

Pressure stage 200 bar

14

10 8 6 4 2

Pressure stage 100 bar

10

30

12

– – – external

12

Min. set pressure in bar →

Min. set pressure in bar →

Min. set pressure in port P or P2 at command value 0. Pressure stage 50 bar 14

5

10 15 20 Flow in L/min →

25

30

Pressure stage 315 bar

12 10 8 6 4 2

5 10 15 20 25 30 0 10 15 20 25 30 Flow in L/min → Flow in L/min → The characteristic curves were measured without backpressure in port A (external pilot oil drain) and T (internal pilot oil drain). With internal pilot oil drain the pressure in P or P2 increases by the output pressure present in port T.

Pressure differential in bar →

5

Pressure differential A1 → A2 and B1 → B2

4 3 2 1

0 5

Pressure differential in bar →

5

Pressure differential in bar →

0

5

10 15 20 Flow in L/min → Pressure differential T1 → T2

25

30

25

30

4 3 2 1

0

5

10 15 20 Flow in L/min →

5

Pressure differential P1 → P2

4 3 2 1

0

5

10 15 20 Flow in L/min →

25

30

9/12

10/12

Bosch Rexroth AG

Hydraulics

(Z)DBE; (Z)DBEE

RE 29158/04.05

Unit dimensions: Types DBE and DBEE (nominal dimensions in mm) 271 (with integrated electronics) 204,9

7

9

6

3

8 15

Ø 10

50

42

1,3+0,1

87

Ø 5,5

Ø 12,2+0,1

2

4

1

5 (71,4)

199,6 133,5 43,5

T B

45

A P

99,4

10

103

T

F1

F2

Rzmax 4 F4

P

G F3 Required surface quality of the mating part

1 Valve housing 2 Proportional solenoid 3 Nameplate

0,01/100mm

B

A

47

8

45

Tolerances to:

4 Identical seal rings for ports A, B, P and T

– General tolerances ISO 2768-mK – Tolerancing principle ISO 8015

5 With version Y, pilot oil drain external via port A (Y) 6 Cable socket for type DBE (separate order, see page 6) 7 Cable socket for type DBEE (separate order, see page 6)

Subplates to data sheet RE 45052 and valve fixing screws must be ordered separately.

8 Space required to remove cable socket

Subplates:

9 Integrated electronics (OBE) 10 Machined mounting face, position of ports to DIN 24340 (without locating bore) and ISO 4401 (with locating bore)

G 341/01 (G 1/4) G 342/01 (G 3/8) G 502/01 (G 1/2)

Valve fixing screws: 4 socket head cap screws M5 x 50 DIN 912 10.9 Tightening torque MT = 7 Nm

RE 29158/04.05

Hydraulics Bosch Rexroth AG

(Z)DBE; (Z)DBEE

11/12

Unit dimensions: Types ZDBE and ZDBEE (nominal dimensions in mm) 271 (with integrated electronics) 204,9

6

9

8

7

15

"1"

50

87

Ø 5,5

"3" 4

10

3 1

30,5 11

2 (240,5) (174,4)

62

"2"

T A

F4

B P 99,4

F2 F3

62

45

F1

"4" "1" to "4" – position of cable socket or housing with integrated electronics (see ordering code)

1 Valve housing 2 Proportional solenoid 3 Nameplate

Required surface quality of the mating part Tolerances to:

4 Identical seal rings for ports A, B, P and T 6 Cable socket for type ZDBE (separate order, see page 6) 7 Cable socket for type ZDBEE (separate order, see page 6) 8 Space required to remove cable socket 9 Integrated electronics (OBE) 10 Machined mounting face, position of ports nach DIN 24340 (without locating bore) and ISO 4401 (with locating bore)

0,01/100mm Rzmax 4

– General tolerances ISO 2768-mK – Tolerancing principle ISO 8015

Subplates to data sheet RE 45052 and valve fixing screws must be ordered separately. Subplates:

G 341/01 (G 1/4) G 342/01 (G 3/8) G 502/01 (G 1/2)

Valve fixing screws: 4 socket head cap screws M5 DIN 912 10.9 Tightening torque MT = 7 Nm

12/12

Bosch Rexroth AG

Hydraulics

(Z)DBE; (Z)DBEE

RE 29158/04.05

Notes

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Phone +49 (0) 93 52 / 18-0 Fax +49 (0) 93 52 / 18-23 58 [email protected] www.boschrexroth.de

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. Without their consent it may not be reproduced or given to third parties. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

Analogue command value module

RE 29902/05.14 Replaces: 07.05

1/6

Type VT-SWMA-1

Series 1X H5999

Table of contents

Features

Contents Page

– Suitable for controlling valves with integral electronics

Features 1

– Possibility of realising simple hydraulic functions via digital controlling

Ordering code, preferred types

2

Functional description

2

Block circuit diagram / pin assignment

3

Technical data

4

Terminal assignment

5

Unit dimensions

5

Engineering / maintenance notes / supplementary information 6

– Adjustment elements: 1 potentiometer for zero point adjustment (command value offset) 1 potentiometer for command value attenuation (for differential input) 4 potentiometers for command value preselection 5 potentiometers for ramp time adjustment – LED lamps: Command value call-up (4 x) Active ramp time (4 x) Quadrant recognition Polarity reversal Power – Measuring sockets for command value and ramp time – Differential input – 4 call-up possibilities each for command value and ramp time – Ramp generator with 5 ramp times; 4-quadrant recognition – Control signal output – Power supply unit without raised zero point – Without power part

2/6

Bosch Rexroth AG Hydraulics

VT-SWMA-1

RE 29902/05.14

Ordering code VT-SWMA-1

1X V0

0

*

Analogue command value module

Further details in clear text = 1X

Series 10 to 19 (10 to 19: unchanged technical data and pin assignment)

0 = V0 =

Basic version Basic version

Functional description General The command value module is to be snapped onto top hat rails to EN 60715. The electrical connection is made using screwtype terminals. The module is operated with 24V DC voltage. A power supply unit [1] provides the internally required positive and negative supply voltages. The green LED (power) lights up as soon as the power supply unit is in operation. Internal command value The internal command value is generated from the external command value signal applied to differential input [2], a called up signal and an offset signal (zero point potentiometer “Z“ [3]). The external command value signal can be changed from 0 % to approx. 110 % by means of potentiometer “G“ (amplitude attenuator [4]). Command value call-ups Call-up signals w1 to w4 [5] can also be adjusted between 0 % and 110 %. Call-up signals w1 and w2 have a positive, callup signals w3 and w4 a negative polarity. This allows the realisation of two forward and two reverse movements of the hydraulic drive without requiring any additional circuitry. For applications that require more than two signals of the same polarity, command value inversion is provided [6]. If this is activated, for example, together with call-up 3, call-up signal w3 also provides a positive control variable. Only 1 call-up is possible at a time. If several call-ups are activated simultaneously, the following is valid: Call-up “1“ has the lowest priority, call-up “4“ has the highest priority [7]. Quadrant recognition When quadrant recognition [8] is activated, the electronics automatically recognises the polarity [9] and any changes (up/ down) [10] in the control variable and assigns a ramp time to the current signal state. Ramp time

Polarity ofSignal changes control output in direction of…

t1

+

Maximalwert

t2

+

0%

t3

–

Maximalwert

t4

–

0%

0%

Maximum value (+)

Maximum 0% value (+) Maximum 0% value (–) Maximum value (–)

0%

As long as the signal is being changed, the LED assigned to the current ramp is alight. Ramp time call-ups [11] When quadrant recognition is not activated, a separate ramp time “t1” to “t4” is assigned to each command value call-up “w1” to “w4”. As long as a signal is being changed, the LED assigned to the current ramp time is alight. Ramp time “t5“ [12] If neither quadrant recognition nor a call-up is activated, ramp time “t5” is always valid. This ramp time can be used, among others, for an emergency stop function. The valve can be closed with the defined ramp time “t5“. Ramp time adjustment The current ramp time can be checked at measuring socket “t“ [13]. Ramp times “t1” to “t4” can be adjusted with the help of the ramp time potentiometers. Through activation of a call-up signal, ramp time signal “t” at the measuring socket is clearly assigned to one of the ramp times t1 to t4. t5 is assigned to the ramp time signal at the measuring socket, if neither a callup nor quadrant recognition is activated. The adjustment range of the ramp time is selected so that these can be set reproducibly (for details, see “Technical data”). Output The output signal of the ramp generator can be checked at measuring socket “w“ [14]. The downstream matching amplifier [15] provides the control signal for the valve via output “control variable” [16]. [ ]

= Cross-reference to block circuit diagram on page 3

5

6

Operating voltage

0V

+U + U0B

Quadrant operation

Call-up command value 4

Call-up command value 3

Call-up command value 2

Call-up command value 1

12

11

2

1

3

u

2

DC

14 Measuring socket “internal command value“ 15 Matching amplifier

5 Call-up signals

4 Amplitude attenuator

9 Polarity recognition

+/– 9

15

10 Recognition of changes in the contol variable (up/down)

13

t

12 Ramp time potentiometer “t5“

t

d

13 Measuring socket “ramp time signal“

t5 12

g

7 Priority logic

t4

10

b

8 Quadrant recognition

11

t3

d

a

14

2 Differential amplifier

t2

t1

g

6

±1

w

3 Summator with zero point potentiometer

b

a

Ramp time selection logic

S

3

11 Ramp time call-ups

M0

– 15 V + Uref – Uref

+ 15 V

8

7

G

6 Command value inversion

5

4

Z

Inv

potential

8 Reference

variable

7 Control

VT-SWMA-1

1 Power supply unit

1

–Uref w4

4-Q

–Uref w3

u

DC

+Uref

w2

L0

+Uref

w1

10

9

Reference potential 4

Command value ± 10 V

Differential input:

Command value inversion

RE 29902/05.14 Hydraulics Bosch Rexroth AG

Block circuit diagram / pin assignment

3/6

4/6

Bosch Rexroth AG Hydraulics

VT-SWMA-1

RE 29902/05.14

Technical data (for applications outside these parameters, please consult us!) Operating voltage

Uo 24 VDC +40 % –10 %

Operating range: – Upper limit value

uo(t)max 35 V

– Lower limit value

uo(t)min 18 V

Power consumption

PS 12 VA

Current consumption

Imax 0.5 A

Fuse

Thermal overload protection (reactivation when temperature falls below threshold)

Inputs – Command value (differential input with attenuator)

Ui 0 to ±10 V; Ri > 50 kΩ

– Quadrant operation “4-Q“ • active

U4-Q 8.5 V to 35 V; Ri > 50 kΩ

• inactive

U4-Q 0 to 6.5 V

– Command value inversion “Inv“ • active

UInv 8.5 V to 35 V; Ri > 50 kΩ

• inactive

UInv 0 to 6.5 V

– Command value call-ups 1 to 4 • active

U 8.5 V to 35 V; Ri > 50 kΩ

• inactive

U 0 to 6.5 V

Adjustment ranges: – Zero balancing (potentiometer “Z“)

±30 %

– Amplitude attenuator (potentiometer “G“)

0 % to ca. 110 %

– Command values (potentiometers “w1“ to “w4“)

0 % to ca. 110 % (factory setting 100 %)

– Ramp times (potentiometers “t1“ to “t5“)

20 ms to 5 s

Outputs: – Control variable – Measuring socket for control variable “w“ – Measuring socket for ramp time “t“

U 0 to ±10 V; ±6 mA; RL > 5 kΩ Uw 0 to ±10 V (+100 % ≙ +10 V; –100 % ≙ –10 V) Ut 0,01 V to +10 V 0,01 V(tmax  ca. 10 s); 10 V(tmin  ca. 10 ms)

Type of connection

12 screw terminals

Type of mounting

Top hat rail TH 35/7.5 to EN 60715

Type of protection

IP 20 to EN 60529

Dimensions (W x H x D)

40 x 79 x 85,5 mm

Permissible operating temperature range

ϑ 0 to +50 °C

Storage temperature range

ϑ –25 to +85 °C

Weight

m 0.3 kg

Note: For details regarding environment simulation tests in the field of EMC (electro-magnetic compatibility), climate and mechanical stress, see RE 29902-U (declaration on environmental compatibility).

RE 29902/05.14

Hydraulics Bosch Rexroth AG

VT-SWMA-1

5/6

Note on the adjustment and measurement of the ramp time For adjusting the ramp time potentiometers we recommend that 4-quadrant recognition be switched off and call-ups be activated.

Value at measuring socket “t“

Ut in V

5

3

2

1

0,5

0,3

0,2

0,1

0,05

0,03

0,02

Current ramp time (± 20 %)

t in ms

20

33

50

100

200

333

500

1000

2000

3333

5000

The following is valid:

t=

100 V ms Ut

Example:

Measured

Ut = 5 V



Results in

t=

100 V ms = 20 ms 5V

Terminal assignment

+U0

1

7

Control variable output

0V

2

8

Reference potential

+U4-Q

3

9

Call-up command value 1

Reference potential 4

10

Call-up command value 2

±Ucomm

5

11

Call-up command value 3

+UInv

6

12

Call-up command value 4

Operating voltage Quadrant operation Differential input Command value inversion

Unit dimensions (Dimensions in mm) Top hat rail TH 35-7.5 to EN 60715

7 8 9 10 11 12 REXROTH VT-SWMA-1 4-Q Inv w1 w2 w3 w4 G t w Z

79

t1 t2 t3 t4 t5

1 2 3 4 5 6 85,5

40

Potentiometers (some with LED lamps): “t1“ to “t5“ → Ramp times “w1“ to “w4“ → Command value call-ups “G“ → Amplitude attenuator for differential input “Z“ → Zero point balancing LED lamps: “4-Q“ → Quadrant recognition “Inv“ → Inversion active green → Ready for operation “power“ (no lettering) Measuring sockets: “t“ → Current ramp time “w“ → Internal control variable “⊥“ → Reference potential / ground

6/6

Bosch Rexroth AG Hydraulics

VT-SWMA-1

RE 29902/05.14

Engineering / maintenance notes / supplementary information – The amplifier module may only be unplugged when disconnected from the power supply! – Ensure a sufficient distance to aerial lines, radio sources and radar equipment (>> 1 m)! – Shield command value lines, do not lay near power cables! – Caution: When the differential input is used, both inputs must be activated or deactivated simultaneously! Note: Electrical signals (e.g. control variable) brought out via control electronics must not be used for switching safety-relevant machines functions! (See also the European standard “Safety requirements for fluid power systems and components – hydraulics”, EN 982)

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Telefon +49 (0) 93 52 / 18-0 Telefax +49 (0) 93 52 / 18-23 58 [email protected] www.boschrexroth.de

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

RE 29902/05.14

VT-SWMA-1

Hydraulics Bosch Rexroth AG

7/6

Notizen

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Telefon +49 (0) 93 52 / 18-0 Telefax +49 (0) 93 52 / 18-23 58 [email protected] www.boschrexroth.de

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

8/6

Bosch Rexroth AG Hydraulics

VT-SWMA-1

RE 29902/05.14

Notizen

Bosch Rexroth AG Hydraulics Zum Eisengießer 1 97816 Lohr am Main, Germany Telefon +49 (0) 93 52 / 18-0 Telefax +49 (0) 93 52 / 18-23 58 [email protected] www.boschrexroth.de

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging.

General product information on hydraulic products

DE EN FR IT FI ES NL SV PT DA EL

RE 07008/02.05

Ihre Sprache? – Siehe Rückseite! Your language? – See back page! Votre langue ? – Voir au dos ! La vostra lingua? – Vedi retro! Kohdekielet? – Katso takankatta! ¿Su idioma? – ¡Vea al dorso! Uw taal? – Zie achterzijde! Ditt sprak? – Se omslagets baksida! O seu idioma? – Consulte a contracapa! Dit sprog? – Se bagside! Η γλώσσα σα; – Βλέπε πίσω πλευρά!

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Bosch Rexroth AG

Hydraulics

Contents 1

2

3

4

5

6

General product information

Page

Important basic information

4

1.1

Conventions used in this product information

4

1.2

What you need to know about this product information

4

1.3

The contents of this product information

4

Scope of delivery and responsibilities

5

2.1

Scope of delivery and responsibilities of Bosch Rexroth

5

2.2

Responsibilities of the plant operator

5

2.3

Liability, guarantee, warranty

6

2.4

Copyright

6

Important basic safety instructions

7

3.1

What to do in an emergency

7

3.2

Safety labelling on the hydraulic product

7

3.3

Proper use

7

3.4

Requirements for personnel, duty of care

8

3.5

General ancillary dangers and protective measures when operating hydraulic products

9

Technical data and ambient conditions

11

4.1

Information about pressure fluids

11

4.2

Ambient conditions

11

What you need to know about pressure fluids

13

5.1

How to handle pressure fluids safely

13

5.2

Functions and effectiveness

13

5.3

Viscosity

13

5.4

Leakage fluid

14

5.5

Topping up/refilling

14

Construction and mode of operation of a hydraulic system

15

6.1

Definitions of terms

15

6.2

Schematic

15

6.3

Safety concept

15

7

Moving hydraulic units/components

16

8

Storage and longer standstills

16

8.1

Hydraulic systems - subsequent bringing into use after storage

16

8.2

Seals, hoses and hose lines

17

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General product information

Hydraulics

Bosch Rexroth AG

Contents 9

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Page

Assembly and bringing into first use

18

9.1

Safety advice for assembly and bringing into first use

18

9.2

Before bringing into first use

18

9.3

Bringing into first use, subsequent bringing into use

19

10

Operation

22

11

Trouble-shooting

22

11.1

What to do in the event of a fault

22

11.2

The basic approach to trouble-shooting

22

11.3

Trouble-shooting tables

23

12

13

14

Maintenance

24

12.1

Definitions of terms

24

12.2

Safety during maintenance tasks

24

12.3

Inspection and servicing

25

12.4

Service and storage lives of hose lines

28

12.5

Topping up the pressure fluid

29

12.6

Servicing pressure accumulators

29

12.7

Repair

29

General information about hydraulic pressure accumulators

30

13.1

General

30

13.2

Safety devices relating to hydraulic pressure accumulators

30

Hydraulic systems

31

14.1

31

Effects of leaks in the hydraulic system on the machine

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1 1.1

Bosch Rexroth AG

Hydraulics

Important basic information Conventions used in this product information

Cross-references are printed in italics.

DANGER This symbol indicates a threat of danger which will result directly in death or very serious injury if not avoided.

WARNING This symbol indicates a threat of danger which may result in death or very serious injury if not avoided.

CAUTION This symbol indicates possible danger which may lead to minor or serious injury and/or to material damage.

IMPORTANT

General product information

Observing the product information and Operating Instructions Ø

reduces downtimes and maintenance costs

Ø

increases the service life of your hydraulic products.

The Operating Instructions must be directly accessible to one of the personnel at the hydraulic product and kept readily available at all times in a place known to the personnel. The Operating Instructions must be read and understood and all its provisions observed by those responsible and by the operative personnel. We recommend that a record is made in writing of the employees’ familiarisation with all the relevant parts. The cross-references to directives, standards and regulations contained in this product information refer to the versions current at the time of writing of this product information, which can be obtained from the title page of this product information.

1.3

What you need to know about this product information

This product information applies to the following types of hydraulic products: Ø

Hydraulic components

Ø

Hydraulic power units

Ø

Hydraulic systems.

The contents of this product information

In addition to this document, product information for Rexroth hydraulic products normally includes Operating Instructions consisting of three parts: Ø

Part I, the general Operating Instructions for the relevant class of products

Ø

Part II, the Technical Datasheet

Ø

Part III, the Product- and Application-specific Operating Instructions.

This symbol indicates additional information.

1.2

RE 07008

If you do not have all three parts, please request the missing part from Bosch Rexroth. Only if all the information contained in all parts of the three-part Operating Instructions is observed can safe operation of Rexroth hydraulic products be ensured. Specific cross-references are used to draw your attention to information that you can find in the Operating Instructions. The Operating Instructions contain detailed information about the product, including Ø

Information about the scope of delivery

Ø

Safety instructions

This product information applies exclusively to hydraulic products that are operated with mineral-oil-based pressure fluids, if the Operating Instructions do not expressly permit the use of other pressure fluids.

Ø

Technical data and operating limits

Ø

Information about bringing into (first) use and maintenance

Ø

Information about the mode of operation

IMPORTANT

Ø

Layouts, drawings

As this product information for Rexroth hydraulic products applies in a general sense, some of the content may not necessarily apply to the hydraulic product you have purchased.

Ø

Parts lists if appropriate

Ø

Information about replacement parts and accessories.

However, only by strictly observing this product information and the Operating Instructions can accidents be prevented and problem-free operation of your Rexroth hydraulic product be guaranteed.

RE 07008

General product information

Hydraulics

Bosch Rexroth AG

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2

Scope of delivery and responsibilities

Installation of Rexroth hydraulic products in a machine or system may increase this value, and if so, the manufacturer of the machine/system must document this.

2.1

Scope of delivery and responsibilities of Bosch Rexroth

At or above 85 dB(A), the plant operator must make suitable hearing protection available to the personnel.

Rexroth hydraulic products fulfil all safety requirements applicable to fluid power systems and their components.

IMPORTANT For the scope of delivery and the responsibilities of Bosch Rexroth with respect to the product, please refer to the Product-specific Operating Instructions.

2.2

Responsibilities of the plant operator

CAUTION If Rexroth hydraulic products are positioned in the vicinity of sources of ignition or strong radiators of heat, protection must be put in place that would prevent any escaping pressure fluid from igniting and the hose lines from aging prematurely. Mineral-oil-based pressure fluid is hazardous to water and flammable. It may only be used if the relevant safety datasheet from the manufacturer is available and all the measures stipulated therein have been implemented. If there is a risk of fluid leaking from the hydraulic product and contaminating water or the ground, the hydraulic product in question must be placed in a suitable collecting trough. In connection with this, the applicable statutory regulations must be observed. You must also observe the EU directives for the use of work equipment (Directive 89/391/EC) and the associated individual directives, especially Directive 1999/92/EC for the protection from the danger arising from potentially explosive atmospheres and their implementations in national legislation. The legislation contains minimum requirements with respect to the making available by the employer of work equipment and for the use of work equipment by employees at work, including the regulations for operating equipment requiring supervision and the obligation to produce explosion protection documentation. This involves, for example, dividing areas endangered by potentially explosive atmospheres into zones and specifying suitable work equipment and procedures for these areas.

2.2.1 Noise protection The A-weighted equivalent continuous sound power level of Rexroth hydraulic products can be obtained from the relevant Operating Instructions. If no values are documented then it can be taken that the value is less than 70 dB(A).

2.2.2 Special points concerning the installation of certain products A Rexroth hydraulic product is intended above all for installation in machines, systems and power units as a part machine or a component for installation into another machine or system and is not a complete machine in the sense of the EU directive. In addition to the Machinery Directive, still further directives may apply, such as the Pressure Equipment Directive or the Explosion Protection Directive. A wide range of dangers can arise from the combined actions of the hydraulic product and the machine or system in which the hydraulic product is installed. Therefore you must always make sure that the hydraulic product is also suitable without restriction for the proposed application at the installation location. The interfaces with the overall machine and the operating conditions are also of the greatest importance. We recommend that the results of the hazard analysis (risk assessment) of the overall machine are taken into account in the design of the hydraulic product. The functioning of the hydraulic product is also influenced by the machine or system in which it is installed. For this reason, you must also always observe the Operating Instructions of the overall system in which your hydraulic product is installed. It is most important for you to also consider the possible use of the hydraulic product in a potentially explosive atmosphere (see 94/9/EC).

IMPORTANT Bosch Rexroth points out that, at the time of their first introduction on to the market, hydraulic products comply with the requirements of all relevant EU directives and/or their implementation into national legislation in Germany. If the scope of delivery is intended to be installed in a machine or system, then the Machinery Directive applies as appropriate – including the then currently applicable amendments – in that the scope of delivery does not necessarily comply with the requirements of the Machinery Directive because the scope of delivery is intended for installation in a machine or because the scope of delivery is intended for combination with other machines into a machine or a hydraulic system. The bringing into use of the scope of delivery shall therefore not be permitted until the machine or system in which the scope of delivery is to be installed or of which it represents a component complies with the requirements of all relevant EU directives. Details of further responsibilities can be found in 3 Important basic safety instructions and in the Operating Instructions.

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2.3

Bosch Rexroth AG

Hydraulics

Liability, guarantee, warranty

Bosch Rexroth shall not be liable for damages that result from non-compliance with or disregard of these and other parts of the Operating Instructions. Unauthorised tampering shall render the warranty null and void. Bosch Rexroth shall only be liable if the scope of delivery was shown to be defective. Bosch Rexroth shall not be liable if a deficiency occurs that involves parts having been replaced by the customer with equivalent but not identical parts as specified by the manufacturer. Please refer to our general terms of supply or your contract for details of the guarantee and manufacturer’s warranty.

2.4

Copyright

This product information may only be reproduced – electronically or mechanically, in whole or in part – with the express written permission of Bosch Rexroth. It may likewise not be distributed, amended, transmitted, translated into another language or employed or copied for other purposes or by other parties without such consent.

General product information

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3 3.1

General product information

Hydraulics

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Important basic safety instructions

IMPORTANT

What to do in an emergency

The hydraulic product shall be operated exclusively with pressure fluids complying with DIN 51524. Where other pressure fluids are permitted, for example brake fluids for brake valves, this is specially mentioned in the Operating Instructions.

In the event of an emergency, fault or other abnormal occurrences: 1.

Switch off the hydraulic system.

2.

Secure the main switch against being unintentionally switched on again.

3.

Secure the danger area so that no one can enter the danger area unknowingly or uncontrolled.

4.

Notify the relevant specialist personnel immediately.

5.

In the event of fire, observe the provisions of the safety datasheets issued by the manufacturer of the pressure fluid and the fire precautions specifically applicable to your place of work, which must be documented in the plant operator’s operating manual.

For details on proper use see 4 Technical data and ambient conditions. The following information can be found in the Operating Instructions: Ø

the proper use, specific to the hydraulic product

Ø

where applicable, the safety category in accordance with EN 954-1

Ø

non-permitted and improper use.

3.3.1 Proper use, requirements before operation Ø

WARNING Fighting fires with materials other than those permitted can lead to explosions and/or more rapid spread of the fire! Danger to life from smoke inhalation!

3.2

Bosch Rexroth AG

Safety labelling on the hydraulic product

Rexroth hydraulic products may only be operated if they are in perfect technical condition. •

In the event of disturbances in the power supply and/ or damage to the electrical equipment, switch off immediately and secure the main switch against being switched on again without authorisation.

•

Report and rectify all faults and damage indicated by the system or discovered by other means.

Ø

The connections, operating conditions and performance data specified in the Operating Instructions must be observed and never changed.

Ø

Rexroth hydraulic products shall not be converted or otherwise modified without prior consultation with Bosch Rexroth.

IMPORTANT Ø

The meanings of the safety labelling on the Rexroth product are explained in the Operating Instructions.

Ø

The plant operator shall not modify the program code of programmable control systems.

Ø

For a diagram of the nameplate and an explanation of the information on it please refer to the Operating Instructions.

Ø

Dependencies and time factors shall not be modified without prior consultation.

Ø

Rexroth hydraulic products are designed and constructed for the provision, transmission, control or regulation of energy and signals using the flow of oil.

The safety devices fitted by Rexroth must be present, properly installed and in full working order – except when this is impractical during setting up or maintenance work. They shall not be relocated, bypassed or rendered ineffective.

Ø

Unless otherwise agreed, the Rexroth hydraulic product satisfies at least safety category B in accordance with EN 954-1.

Safety components such as limit switches, valves and other control components shall not be rendered inoperative.

Ø

If the hazard analysis/risk assessment of the overall machine in which the Rexroth hydraulic product is to be installed indicates that a safety category higher than category B in accordance with EN 954-1 is required for the Rexroth hydraulic product, then a correspondingly higher rated hydraulic product can be supplied and installed only after special agreement with Bosch Rexroth.

Tamperproof lead seals installed by the manufacturer shall not be removed or damaged except when this is necessary in the course of maintenance tasks defined in the Operating Instructions.

Ø

The specified maintenance tasks in the Operating Instructions shall be carried out at the intervals stated in the Operating Instructions.

3.3

Proper use

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Ø

Ø

3.4

Bosch Rexroth AG

Hydraulics

General product information

RE 07008

Uncontrolled access by persons unfamiliar with the system to the immediate operating zone of Rexroth hydraulic products is prohibited (even if the product in question has been shut down).

Servicing personnel (who carry out filter and oil changes, for example) shall fulfil the following requirements: Ø

They have been instructed in the relevant activity.

Rexroth hydraulic products must never be assembled, operated or maintained by persons under the influence of alcohol, drugs or other medication which affect one’s ability to react.

Ø

Specialist knowledge of hydraulics is not required to carry out servicing work.

Requirements for personnel, duty of care

3.4.1 Qualifications of specialist personnel A specialist person is someone who, using his specialist training, knowledge and experience as well as familiarity with the relevant conditions, can Ø

safely carry out the tasks allocated to him and correctly assess the scope and implications of his work

Ø

recognise possible dangers

Ø

undertake the necessary measures to eliminate possible accidents.

3.4.2 Requirements for hydraulics maintenance personnel In accordance with DIN 31051, maintenance comprises the individual activities of inspection, servicing and repair. All personnel involved in maintenance shall be familiar with and observe all parts of the Operating Instructions and this product information. Inspection personnel shall fulfil the following requirements:

Repair personnel shall fulfil the following requirements: Ø

The personnel must be hydraulics experts, who have been instructed and meet the definition given above,

Ø

Repair personnel must be familiar with the function of the hydraulic system as a whole, from subsystems to their interaction with the function of the entire machine.

Ø

Repair personnel must be able to read hydraulic circuit diagrams, interpret individual functions from their symbols and understand function diagrams.

Ø

Repair personnel must possess knowledge of the function and construction of hydraulic elements.

3.4.3 Requirements for electrical maintenance personnel All work on electrical equipment shall only be carried out by an authorised, qualified electrician, or by instructed persons under the guidance and supervision of a qualified electrician, in accordance with the rules applicable to electrotechnical products.

3.4.4 Minimum age Persons under the age of 18 who are currently receiving instruction or training or are working under supervision may not work on Rexroth hydraulic products.

Ø

They have been instructed in the relevant activity.

This does not apply to young persons of 16 or over if

Ø

Specialist knowledge of hydraulics is not required for purely inspection activities but the personnel must be aware of the particular dangers associated with hydraulic products.

Ø

working on Rexroth hydraulic products is necessary in order for them to accomplish a training objective

Ø

their protection is guaranteed by the supervision of an experienced, competent person

Ø

they are allowed to use only tools, work implements and protective gear that preclude the risk of injury.

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General product information

3.4.5 Training

Hydraulics

Observation and use of the Operating Instructions and legal requirements

Ø

Proper operation of the Rexroth hydraulic product

Ø

Observation of the instructions of safety officers and the plant operator’s operating manual

Ø

What to do in an emergency.

IMPORTANT Bosch Rexroth can provide you with training support in specialist areas.

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3.5.1 Dangers from pressure fluid

The plant operator using Bosch Rexroth hydraulic products shall train his personnel regularly in the following subjects: Ø

Bosch Rexroth AG

CAUTION Handling pressure fluid without protection is hazardous to health. Please observe the manufacturer’s safety instructions and the safety datasheets for the pressure fluid that you are using.

DANGER Serious damage to health or death may result if pressure fluid enters the blood stream or is swallowed. If this occurs, contact a doctor immediately!

An overview of the training can be found on the Internet at http://www.boschrexroth.de/didactic.

3.5.2 Malfunctions due to contamination of pressure fluid

3.5

General ancillary dangers and protective measures when operating hydraulic products

Contamination of the pressure fluid can be caused by: Ø

Wear during operation of the machine/system (metallic and non-metallic abrasion)

Ø

Leaks of the hydraulic product

Ø

Contaminants introduced during servicing/repair

In the interests of your safety, all safety instructions shall be carefully observed, especially those in the Operating Instructions.

Ø

The use of dirty (unfiltered) pressure fluid when the pressure fluid is changed.

In spite of the high intrinsic safety of Rexroth hydraulic products, the risk of personal injury or damage to the environment cannot be excluded, even when the equipment is properly used.

Contaminants lead to malfunctions, increased wear and shorter service life of the hydraulic product. This can have negative effects on the safety and reliability of the hydraulic product.

DANGER

New, additional dangers may arise if the hydraulic product is installed in another machine or installed with other machines in a system. This shall apply in particular to mechanical movements generated by the hydraulic product. Information on these additional dangers can be found in the overall operating manual of the supplier of the overall system in which the hydraulic product is installed.

Therefore the maintenance tasks specified in the Operating Instructions shall be carried out at regular intervals and the utmost cleanliness is required during work on the hydraulic product.

CAUTION When changing the pressure fluid, always use factory-fresh pressure fluid and filter it before filling to remove any contaminants in the pressure fluid that it often contains from the packaging container (drum). Flush out lines and hoses before installation. The cleanliness class of a pressure fluid is specified in accordance with ISO 4406. Detailed information can be obtained from the relevant datasheet or the Operating Instructions.

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Bosch Rexroth AG

Hydraulics

In older datasheets, the cleanliness class is sometimes specified in accordance with NAS 1638. The following table can be used to convert this to an equivalent ISO 4406 cleanliness class: Comparison table for cleanliness classes Earlier class to Current class to NAS 1638 ISO 4406 (c) Class 7 Class 18/16/13 Class 9 Class 20/18/15

3.5.3 Electrical dangers

General product information

RE 07008

3.5.4 Product-specific ancillary dangers All product-specific ancillary dangers and precautions can be found in the relevant Operating Instructions.

3.5.5 Disposal Ø

Take metal, cable and plastic ducts to a recycling materials collection centre.

Ø

Dispose of electronic components as electronic waste.

Ø

Dispose of back-up batteries as special waste.

Ø

Cleaning agents, operating fluids and other materials:

When working on electrical systems: •

De-energise the hydraulic system before beginning any maintenance work.

•

Cordon off the working area with red-white safety chain and warning signs.

•

Lock the main switch, remove the key and keep it in a safe place until the work is completed.

•

Attach a warning sign to the main switch.

•

Check that there is no voltage using a two-pole voltage detector.

•

Earth and short-circuit the point where you are working.

•

Cover neighbouring live parts.

•

Clear your workplace to prevent contact with live parts as a result of tripping or slipping. Wear safety footwear.

•

Always use electrically insulated tools.

•

Disconnect plugs at sensors and valves – even those with low voltages – after the system has been de-energised.

DANGER Even after disconnection of the electrical supply (main switch OFF) the following supply systems/danger areas can still give rise to life-threatening voltages: Ø

Electrics, electronics, hydraulics (e.g. accumulators, rechargeable batteries)

Ø

Main switch

Ø

Power supply cables

Ø

Points identified with an electric shock warning sign.

CAUTION Please observe the disposal regulations specified in the appropriate Safety Datasheets.

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4

General product information

Technical data and ambient conditions

IMPORTANT The product-specific technical data, operating limits and ambient conditions for the operation of your Rexroth hydraulic product can be found in the Operating Instructions. This includes the following information: Ø

Minimum flow rate for adequate cooling

Ø

Permissible maximum temperature of the coolant

Ø

Performance data

Ø

Type of control and regulation functions

Ø

Permissible pressures, flow rates

Ø

Connections.

4.1

Information about pressure fluids

Unless otherwise indicated in the Operating Instructions, the following specification applies to the pressure fluid to be used: Ø Ø

Mineral-oil-based pressure fluid complying with the requirements of DIN 51524. Operating temperature range 0 °C…+80 °C (in tank < 72 °C).

Any deviations from this can be found in the Operating Instructions.

IMPORTANT Bosch Rexroth recommends a maximum operating temperature of 55 °C, because the rate of ageing of the pressure fluid increases and the service life of the seals and hoses is reduced at higher temperatures. Ø

Viscosity ranges: see RE 07075 and RE 90220

Ø

Max. permissible contamination class of the pressure fluid in accordance with ISO 4406: see 3.5.2 Malfunctions due to contamination of pressure fluid.

The maximum permissible cleanliness class can be found in the Operating Instructions. The following types of pressure fluids shall be used.

IMPORTANT Rexroth hydraulic components are tested with test oil MZ45 manufactured by ESSO (class ISO VG 46 at 40 °C), (Viscosity η = approx. 46 mm2/s).

Hydraulics

4.2

Bosch Rexroth AG

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Ambient conditions

4.2.1 Use in potentially explosive atmospheres

DANGER Rexroth hydraulic products shall be used in potentially explosive atmospheres only if they are designed for this purpose and this is expressly stated in the Operating Instructions.

IMPORTANT Directive 1999/92/EC of the European Parliament and Council dated 16 December 1999 concerning the minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres governs protection from danger from potentially explosive atmospheres. Observe the requirements contained in the regulations for operating equipment requiring supervision and the obligation to produce explosion protection documentation. This involves, for example, dividing areas endangered by potentially explosive atmospheres into zones and specifying suitable work equipment and procedures for these areas. Observe the requirements of Directive 94/9/EC of the European Parliament and Council dated 23 March 1994 on the approximation of laws of the member states concerning equipment and protective systems intended for use in potentially explosive atmospheres (ATEX Product Directive) and/or the corresponding national legislation by means of which the Directive was implemented in law in the EU member states. The directive contains requirements for the use of equipment and protective systems in potentially explosive atmospheres.

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Bosch Rexroth AG

Hydraulics

4.2.2 Climatic operating conditions Unless otherwise indicated in the Operating Instructions, the permissible ambient temperature Ø

for control units: 0 °C…+50 °C

Ø

for drive units with electric motors without heat exchangers, surface-cooled by free air circulation: 0 °C…+30 °C

Ø

for drive units with heat exchangers: < +40 °C.

Unless otherwise specified, Rexroth hydraulic products are designed for use in temperate climate zones and in covered areas (not in the open air) at relative air humidities of < 70 % and at room temperatures of 22 °C.

IMPORTANT For systems with oil-air heat exchangers: Observe the information given in the circuit diagram in the Operating Instructions.

In relation to the electronic equipment, the permissible ambient conditions apply to installed and protected electrical connections of class IP 55. Ø

Ambient temperature +5 °C…+40 °C assuming that the average air temperature over a 24 hour period does not exceed +35 °C.

Ø

Relative air humidity: 23…95 %, non-condensing.

Ø

Altitude: up to 1000 m above national datum.

DANGER Rexroth hydraulic products shall not be used in aeronautical equipment, except where they have been specially approved and appropriately labelled to this effect.

General product information

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5

5.1

General product information

What you need to know about pressure fluids

Hydraulics

Bosch Rexroth AG

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IMPORTANT Observe the following rules of thumb: At pressure fluid temperatures >70 °C, the rate of ageing doubles for each 10 °C.

How to handle pressure fluids safely 5.3

Viscosity

DANGER Mineral-oil-based pressure fluid is hazardous to water and flammable. It may only be used if the relevant safety datasheet from the manufacturer is present and all the measures stipulated therein have been implemented.

5.3.1 Viscosity grades The most important characteristic of a pressure fluid is its viscosity, i.e. stickiness. Viscosity range always plays a priority role in the selection of a pressure fluid. Viscosity is measured in the SI unit [mm2/s]. Many manufacturers still provide their information in centiStoke [cSt], the equivalent of [mm2/s].

5.2

Functions and effectiveness

Due to the many tasks of pressure fluid, its selection, inspection and maintenance are of vital importance for: Ø

proper functioning

Ø

operating safety

Ø

service life

Ø

and the cost effectiveness of the hydraulic product.

The tasks of pressure fluid: Ø

to transmit hydraulic energy from the pump to the hydraulic cylinder/motor

Ø

to lubricate parts moving against one another

Ø

corrosion protection

Ø

to remove contaminants

Ø

to remove locally accumulated heat.

5.2.1 Reduced function due to ageing The effectiveness of pressure fluid diminishes as it ages (undergoes chemical changes). Acids and resinous residues form, which may cause valve spools to stick. The following factors accelerate the ageing process: Ø

high temperatures

Ø

oxygen in the pressure fluid

Ø

air humidity

Ø

water

Ø

metallic catalysers

Ø

operating pressure

Ø

contaminants.

The viscosity grades (VG = viscosity grade) in accordance with ISO 3448 relate to the viscosity at 40 °C. The viscosity grade is appended to the type designation or the commercial name of the pressure fluid. Example: A pressure fluid with a viscosity grade of ISO VG 46 has a viscosity of 46 mm2/s at 40 °C. The relationship between medium temperature and viscosity for hydraulic oil (example) Medium temperature 3 °C 8 °C 25 °C 60 °C 77 °C

Viscosity 800 mm2/s 500 mm2/s 100 mm2/s 20 mm2/s 12 mm2/s

Too high a viscosity leads to the formation of air and vapour bubbles as a result of low pressure (cavitation). Too low a viscosity leads to increased leakage losses. Increased leakage losses cause the pressure fluid to heat up more, leading in turn to a further reduction in viscosity. The pressure fluid then loses its ability to lubricate. Valves, pumps and hydraulic motors, in particular, require exact compliance with the defined viscosity ranges. For certain ambient and operating temperatures, not all the requirements can always be covered with the available ranges of the viscosity grades. In order to comply with all the requirements, high viscosity pressure fluids with viscosity index improvers or a pressure fluid cooler/heater may be used.

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5.4

Bosch Rexroth AG

Hydraulics

Leakage fluid

Clearances and play mean that some leakage fluid escapes from all hydraulic products. Leakage fluid can be lead away internally or externally, depending on the component. It can be fed back into the tank or must be disposed of.

CAUTION Make sure that the leakage fluid is fed back into the tank in a proper manner. Dispose of leakage fluid that is not fed back into the tank properly, in compliance with the applicable environmental protection regulations.

5.5

Topping up/refilling

CAUTION When topping up/refilling your hydraulic system, make sure that you use pressure fluid of the same sort and type and from the same manufacturer. If the fluid is heavily contaminated or prematurely aged, then the system, including the tank must be cleaned and flushed before refilling. New pressure fluid must always be filtered in accordance with the required cleanliness class, as it does not normally meet the required cleanliness class in the as-supplied state.

General product information

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6

6.1

General product information

Bosch Rexroth AG

Hydraulics

Construction and mode of operation of a hydraulic system

9

Definitions of terms

8

Hydraulics (fluid technology)

7

Transmission, control and distribution of energy and signals using a pressurised fluid medium.

6

Hydraulic system

5

Arrangement of interconnected components for transferring and controlling hydraulic energy.

4 3

Component A single unit (e.g. a valve, filter, cylinder, motor) that consists of one or more parts and which is a functional constituent of a hydraulic system.

Drive A component that converts the energy of the hydraulic fluid into mechanical energy (e.g. motor, cylinder).

6.2

Schematic

In a system operated with hydraulic oil, first of all mechanical energy is converted into hydraulic energy, transported and controlled in this form, to finally be converted once more into mechanical work. The hydraulic elements are arranged in accordance with these functions. The following diagram shows a schematic representation of the elements of a complete hydraulic system. To demonstrate their operating principle, standardised symbols (ISO 1219) are used instead of sectional diagrams of the various devices. Line connections are represented by simple lines, as can be seen in the example.

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2 1 1

Tank

2

Filter

3

Pump

4

Pressure limiting valve

5

Directional valve

6

Check valve

7

Throttle valve

8

Hydraulic cylinder

9

Hydraulic motor

6.3

Oil preparation Energy conversion

Energy control

Energy conversion

Safety concept

Hydraulic products contain sensors and actuators, the interaction of which is particularly important with regard to the fulfilment of technical safety functions. Individual hydraulic products form part of an overall safety concept. Applications required to perform safety functions are designed using special hydraulic components that satisfy the requirements of the relevant directives, such as the Pressure Equipment Directive and other standards. The manufacturer of the overall machine or system defines and bears responsibility for the safety category to EN 954-1 to be fulfilled.

IMPORTANT A more detailed description of the safety concept and the specific safety components installed can be found in the Operating Instructions and the Operating Instructions of the supplier of the overall system in which the hydraulic product is installed.

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Bosch Rexroth AG

Hydraulics

Moving hydraulic units/components

Hydraulic units or components may be moved by a fork-lift truck or a hoist, depending on their size and the local conditions.

IMPORTANT For details see the Operating Instructions.

General product information

RE 07008

IMPORTANT The factory-applied corrosion protection is adequate provided that Ø

no condensation or leakage water can enter the system

Ø

long standstills are avoided.

Contact Bosch Rexroth if you are not clear about the consequences of long standstills on the state of the hydraulic product.

CAUTION Always ensure hydraulic products are empty of pressure fluid for transportation. Rexroth hydraulic products are delivered empty of pressure fluid. However, products may contain oil residues left over from the final inspection at our factory.

8

Storage and longer standstills

8.1

Hydraulic systems - subsequent bringing into use after storage

Corrosion, especially oxidation, can cause metal surfaces to lose the standard of surface finish required for the hydraulic system to function properly. Rust and other metallic and non-metallic particles lead to abrasive wear (erosion), which detrimentally affects the functioning of the hydraulic system.

CAUTION If a hydraulic system is to be brought into use again following a long standstill, it must first be flushed clean.

8.1.1

Factory-applied corrosion protection

Rexroth hydraulic products are tested in accordance with Class III using a hydraulic oil that has additional anti-corrosive properties. The film of oil that remains in the product after the test provides sufficient internal corrosion protection. This factory lubrication ensures that valves do not stick during subsequent use of the hydraulic product, and guarantees compatibility with seals and the pressure fluid to be used.

8.1.2 Storage times in relation to the ambient conditions Delays in bringing into use, long shipping and storage times or long periods of non-use can lead to rust formation in Rexroth hydraulic products. Additional corrosion protection measures must be implemented to prevent this.

IMPORTANT If all the openings on the hydraulic products are not sealed so as to be air-tight, this will reduce the storage life of the hydraulic product by nine months. After the specified storage time has expired, in any event not longer than 24 months, the corrosion protection must be checked and further conservation measures applied if necessary.

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8.2

General product information

Seals, hoses and hose lines

CAUTION Seals: Observe the requirements of ISO 2230 and/or DIN 7716 and the specific manufacturer’s data on seals. Hoses and hose lines: In the Federal Republic of Germany, please observe the requirements of DIN 20066, ZH 1/74 Safety rules for hydraulic hose lines and the specific manufacturer’s data on hoses and hose lines. In addition, the following conditions shall be observed: Ø

Seals, hoses and hose lines are stored in cool, dry and dust-free conditions.

The hoses and hose lines can be enclosed in plastic foil to ensure low-dust storage conditions. Ideal storage conditions for hoses and hose lines are temperatures from +15 °C to +25 °C and a relative humidity of below 65 %. Ø

Do not store elastomers below –10 °C. The ideal storage conditions for seals are temperatures from +10 °C to +20 °C and a relative humidity of between 65 % and 75 %.

Ø

Store hoses and hose lines in the original packaging if possible. Prevent the entry of air.

Ø

Avoid direct sunlight and UV radiation and shield from nearby sources of heat.

Ø

Darkened storage locations are preferred.

Ø

Do not use ozone-forming light sources or equipment (e.g. fluorescent lamps, mercury-vapour lamps, copiers, laser printers) or electrical spark-forming devices in the vicinity of hoses and hose lines.

Ø

Seals, hoses and hose lines must not come into contact in particular with materials or vapours that could damage them (e.g. acids, alkalis, solvents).

Ø

Store seals, hoses and hose lines lying down and free from tension. If the hoses and hose lines are coiled, take care not to bend them to less than the smallest bending radius specified by the manufacturer.

Maximum storage times Ø

NBR seals: 4 years

Ø

FKM seals: 10 years

Ø

Hoses: 4 years

Ø

Hose lines: 2 years

For reasons of safety, seals, hoses/hose lines shall not be used once these permissible storage times are reached or exceeded. Permissible storage times could be considerably reduced if the permissible storage conditions are not maintained. If you are not clear about the storage times and/or storage conditions then you should not use the product.

Hydraulics

Bosch Rexroth AG

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Bosch Rexroth AG

Hydraulics

Assembly and bringing into first use

IMPORTANT

General product information

RE 07008

Bringing into (first) use shall only be done by an instructed, authorised hydraulics expert who has the required specialist knowledge.

Only the permissible pressure fluids given in the Operating Instructions are to be used. Information on other pressure fluids can be found in the Operating Instructions or are available on request.

Specialist hydraulics knowledge means, among other things, that the person can read and fully understand hydraulics drawings. In particular, he must fully comprehend the range of functions of the integrated safety components as part of the overall safety concept.

Filling the pressure fluid tank must always take place through a suitable filter unit. Experience has shown that even new pressure fluid can often have more than the maximum permissible level of contamination.

9.2

All information specific to assembly and bringing into first use can be found in the Operating Instructions.

1.

Check the scope of delivery for transport damage.

Pay attention to cleanliness:

2.

Check that the Operating Instructions for the Rexroth hydraulic product are present and complete. Contact us if the Operating Instructions are not there or are incomplete.

3.

Assemble the hydraulic product.

Ø

Do not use cleaning wool or cloths containing fibres for cleaning. Depending on the condition of the system or machine, cleaning with fibre-free cloths may be sufficient. Use suitable liquid cleaning agents to remove lubricants and other stronger contaminants. Make sure that cleaning agent does not get into the hydraulic system.

Ø

•

Observe the Operating Instructions and this product information.

•

Assemble the hydraulic components, so that they are mounted strain-free on even surfaces.

•

Tighten the fastening bolts evenly using the specified tightening torque.

Never use hemp and putty as sealants.

The functional or failure behaviour of identical hydraulic products may vary due to conditions specific to the machine or system in which the hydraulic product is installed (mass, speed, electrical triggering at setpoint values, etc.), see also Section 11 Trouble-shooting.

9.1

Before bringing into first use

4.

Ensure that the interfaces of the system/machine and the installation conditions provide for safe operation of the hydraulic product. If in doubt, consult the people responsible for the overall system/functional machine.

5.

Check the construction of the hydraulic product against the circuit diagrams, lists of equipment and assembly drawings. If there are any differences, draw this to the attention of the people responsible. If important documents are missing, they can be requested from Bosch Rexroth. Only documents issued by the bodies authorised to do so shall be used.

6.

Based on the Operating Instructions for the system or machine in which the hydraulic product is installed, check whether bringing the hydraulic system into use could lead to uncontrolled, dangerous movements. Where appropriate, take into account the hazard analysis/risk assessment for the system or machine.

7.

Take the precautions appropriate to the anticipated dangers, e.g.

Safety advice for assembly and bringing into first use

DANGER Hydraulic products are generally intended for installation in machines/systems or devices. The function of the hydraulic product must therefore always be seen in relation to the function of this machine – i.e. seemingly identical hydraulic products may demonstrate different functional behaviours as a result of the function of the machine in which they are installed. For this reason, a hydraulic drive must not be brought into use until it has been determined that the machine in which it is installed conforms to EU standards. Do not bring hydraulic drives into use until you have familiarised yourself completely, firstly with the function of the hydraulic product and hydraulic equipment and secondly with the hydraulically powered machine functions, and have clarified and dealt with any possible dangers.

•

Ensure that the cylinder piston rod can move out without danger.

•

Use a hoist or other lifting device to additionally secure lifted loads.

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8.

General product information

As part of bringing into (first) use, check whether the electric motors and valve solenoids can be switched manually using the electrical controls of the system/machine. If they cannot be switched manually – or can but with difficulty – you must provide a remote control (e.g. test boxes for Rexroth proportional valves) for the internal function test of the hydraulic system.

IMPORTANT Starting up the hydraulics solely by means of emergency manual operation is not recommended, as several valves at once cannot be switched as required in the correct sequence. 9.

Hydraulics

9.3

Bosch Rexroth AG

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Bringing into first use, subsequent bringing into use

DANGER Before bringing into (first) use, have all pressure accumulators and safety systems checked by an expert or specialist in accordance with national regulations. 1.

Clean the lock on the transport and storage container before opening.

Draw up a sequential program for bringing into (first) use and store it with the technical documentation as an appendix to the Operating Instructions. For this you should consider the following: Hydraulic drives basically consist of the following functional groups

2.

Clean the hydraulic unit and all other component groups, so that no dirt can get into the hydraulic system during bringing into (first) use.

3.

Check the paint on the tank for integrity.

4.

Flush the connection lines to remove dirt, scale, chips etc.

Ø

Pump circuit (generation of pressurised oil flow); pump, electric motor, oil tank, filters, monitoring devices, etc.

5.

Pickle and flush welded pipes.

Ø

Control system for at least one hydraulic consumer (cylinder, motor); directional control valves, pressure and flow control valves, check valves

Ø

Hydraulic consumers (cylinders, motors) with specially assigned valves, e.g. braking valve.

CAUTION Remove all residues of water and cleaning agents before performing further work.

6.

10. Divide the functional circuit diagram into separate mini-circuits that can each be started up in succession.

Clean the interior of the hydraulic components to get rid of contaminants: •

Clean the filler plug of the pressure fluid tank.

11. Read the functional circuit diagram and seek clarification of any unclear text or diagrams. More information about the functioning of components, e.g. a pump regulator, is available in the Technical Datasheet.

•

Remove dust and chips using an industrial vacuum cleaner, by rinsing parts or similar cleaning method.

•

Completely remove any oil residues left over from the factory test.

12. Establish into which position valves are to be switched, or how valves are to be set.

•

Remove any gummed oil which may have formed due to incorrect storage.

13. Put up any necessary directional, prohibitive or informative signs and check whether the meaning of these signs are explained in the Operating Instructions.

7.

IMPORTANT

14. Follow this sequence for bringing into (first) use Ø

Pump circuit

Ø

Parts of control system: e.g. pressure cut-off and switchover, open centre, pressure reduction etc.

Ø

Cylinder and motor circuits: First move, fill and bleed, then finally optimise all settings.

Connect up all connection lines.

Observe the installation instructions from the manufacturer of the connection components.

DANGER Make sure that pipes and hoses are connected at all ports or that the ports are sealed with screw plugs. 8.

Carry out a special check to make sure that the union nuts and flanges are correctly tightened at the pipe connections and flanges.

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Bosch Rexroth AG

Hydraulics

General product information

IMPORTANT

CAUTION

Mark all the checked connections, e.g. with paint. Make sure that all pipes and hoses and every combination of connection pieces, couplings or connection points with hoses or pipes are checked for their operational safety by someone who has the appropriate knowledge and experience. 9.

Connect the hydraulic consumers. Dimension the connection lines in accordance with the performance data in the Circuit Diagram and the Operating Instructions.

10. Install the electrical system for the drive and control system: •

Check the connected loads.

•

Connect coolant water if necessary.

•

Check the direction of rotation of the pumps (e.g. as indicated by attached arrow markings).

11. Check the pressure fluid to ensure that no water has entered it. 12. Before filling the pressure fluid tank, please observe the following requirements: Ø

The pressure fluid must conform to the specification in the Operating Instructions.

Use oil filler units (filter units) suitable for pressure fluids. •

Do not remove the filter strainers from filler necks or the filter element from filters before filling the pressure fluid tank.

13. Fill the pressure fluid tank up to the upper mark on the inspection window. Observe the maximum fluid level, taking into consideration the volume in the connection lines and hydraulic consumers. 14. Set the pressure and flow control valves, pump regulator, signalling elements such as pressure switches, limit switches and temperature regulators to the settings and values defined in the sequential program (see 9.2 Before bringing into first use).

DANGER Do not change the settings of valves with a safety function, valves with a position switch or valves with preset electronics. •

Set operating-pressure valves and flow control valves to the lowest possible values.

•

Set directional control valves to their basic setting.

•

Reduce the setpoint values of proportional valves to minimum values.

•

Do not remove the tamperproof lead seals. Damaged or removed tamperproof lead seals indicate improper use of the hydraulic product.

CAUTION Never fill new hydraulic products with used pressure fluid. Ø

The drums of pressure fluid must be sealed and clean on the outside.

IMPORTANT

RE 07008

15. If applicable: Fill the pressure accumulator to the specified gas precharge pressure and then check the pressure, see Operating Instructions.

If the pressure fluid has a high level of initial contamination (see 4 Technical data and ambient conditions):

16. Fill the pump body: Use the leakage oil port to fill pump bodies that have this feature, see Operating Instructions.

Use a filter unit to fill the pressure fluid tank. Ensure that the filter element is clean.

17. If applicable: Open the cocks in the suction line.

IMPORTANT

18. Start the drive motors:

The fineness of the filter shall correspond to the cleanliness class required by the overall system and if possible be even finer. The filter unit used shall fulfil the requirements for functional safety and service life. •

If possible, fill the pressure fluid tank via a filling coupling, using a return filter if possible.

•

With electric motor in jogging mode, allow to start briefly

•

Combustion engines in idle

•

Pay attention to the direction of rotation.

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General product information

19. Bleed the hydraulics (valve, pump, motor, line, cylinder).

IMPORTANT Details on bleeding can be found in the Operating Instructions. •

Operate the hydraulic product at low pressure until it is fully bled.

•

Bleed the hydraulics lines to consumers or measuring points at the highest point, if possible.

•

Operate the directional valves in jogging mode.

•

Next, advance and retract all hydraulic consumers several times.

•

Increase the load slowly. Check the pressure fluid level in the pressure fluid tank. If necessary, top it up with pressure fluid.

Bleeding has been accomplished fully and correctly if the pressure fluid in the tank does not foam, if the hydraulic consumers do not make any jerky movements and if no abnormal noises can be heard. 20. Set the valves and sensors and start up the machine: •

•

Set the switching operations of valves with a switching time adjustment/ramp in accordance with the dynamic conditions, see Operating Instructions. Finely adjust and optimise the setting of proportional valves without on-board electronics (OBE).

Manufacturing tolerances mean that valves and amplifiers have to be adjusted in line with one another. Valves with in-built electronics (OBE, On Board Electronics) have the valve and amplifiers adjusted in line with one another at the factory. Amplifiers for valves without OBE are supplied from the factory with a basic setting. Depending on the type of valve and amplifier, you may have to fine-tune the null point and sensitivity before bringing the valve into use.

IMPORTANT Details on fine-tuning can be found in the Operating Instructions. 21. Check the operating temperature after the machine has been running continuously for several hours. Too high an operating temperature indicates that there are faults that need to be analysed and rectified. 22. Rectify any leakages, e.g. by relieving couplings from pressure and then retightening.

IMPORTANT Apart from moisture, which should not be sufficient to form one drop, no measurable, unintentional leakage shall be found.

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Bosch Rexroth AG

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23. After bringing the machine into first use, have a sample of the pressure fluid analysed to ensure that it achieves the required cleanliness class. Change the pressure fluid if the required cleanliness class is not achieved. If the pressure fluid is not tested in the laboratory after bringing the machine into first use: Change the pressure fluid. 24. Replace the pressure fluid filter. 25. Document and file all set values.

DANGER 26. To ensure the safety of persons and the system, after bringing the machine into first use, perform the following tests using the defined maximum values: •

Function test

•

Pressure test.

Prepare a record of the bringing into (first) use or acceptance and have it signed by the plant operator. This record is an important document and requires to be filed.

IMPORTANT Information on how to perform the function test and pressure test can be found in the Operating Instructions.

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Bosch Rexroth AG

Hydraulics

Operation

General product information

Ø

RE 07008

Is there a machine record book that may document similar malfunctions in the past?

IMPORTANT Please refer to the Operating Instructions for all information on how to operate the Rexroth hydraulic product.

11

Trouble-shooting

11.1 What to do in the event of a fault

11.2.2 Recommended way of working when trouble-shooting Successful trouble-shooting for a hydraulic product requires precise knowledge about the structure and method of operation of the individual components. Where hydraulics are combined with electrics/electronics, in particular, trouble-shooting is rendered more difficult and cooperation between electricians and hydraulic specialists is required. •

Even if you are under time pressure, proceed systematically and methodically. Indiscriminate, hasty dismantling and readjustments may, in the worst case, result in the original cause of failure being impossible to determine.

•

Make sure that you gain an overview of the function of the hydraulics in respect of the overall system in which the hydraulics are installed.

•

Try to find out whether the hydraulics performed the required function in the overall system prior to the occurrence of the fault.

•

Try to determine any modifications to the overall system in which the hydraulics are installed:

DANGER In the event of abnormal occurrences or malfunctions, stop all work on the Rexroth hydraulic product immediately and inform the responsible personnel.

IMPORTANT A table for product-specific trouble-shooting can be found in the Operating Instructions. If the responsible personnel are unable to rectify the problem immediately: •

Switch off the main switch. If applicable, turn off any combustion engines used as drive motors.

•

Secure the main switch against being unintentionally switched on again.

•

Inform the machine manufacturer.

11.2 The basic approach to trouble-shooting The information in this section is intended to help you create the ideal conditions for carrying out trouble-shooting as efficiently as possible.

11.2.1 General conditions

Ø

Have the operating conditions or operating range of the hydraulics been changed?

Ø

Have modifications (e.g. retrofitted equipment) or repairs been carried out on the overall system (machine/system, electrics, control system) or on the hydraulics? If yes: What were they?

Ø

Have the set values of the hydraulics been changed?

Ø

Have the hydraulics recently undergone maintenance?

Ø

Has the hydraulic product/machine been operated improperly?

Ø

How does the malfunction manifest itself?

•

Form a clear picture of the cause of the fault. Ask the machine operators directly, if necessary.

Ø

Is all the necessary technical documentation to hand?

•

Document any work undertaken, changed set values, etc.

Ø

If no hydraulic circuit diagram is available: Can a hydraulic circuit diagram be drawn using the structure, signs and labelling of the equipment?

•

Document any amendments/additional information that should be included in the Operating Instructions.

Ø

Are there enough measuring points?

Ø

Has the customer provided useful information about how the malfunction manifests itself and about the functional behaviour of the system/component prior to the malfunction?

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General product information

11.2.3 Systematic trouble-shooting procedure Ø

Ø

Is there an inspection and maintenance book which might provide information about the trend of test parameters (e.g. temperature of hydraulic fluid, replacement intervals of filter elements, noises)? Have there been any identical or similar failures in the past? •

Make a note of causes of failures with a low probability. Only investigate the failure causes you have noted down if all failure causes with a high probability have been proven to be inapplicable.

•

Draw up a list of priorities of the most probable failure causes.

•

Verify these listed failure causes one after the other (by means of theoretical conclusions, disassembly, measurements or tests).

•

Document the causes of failure you have discovered, and note down how you discovered them.

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11.3 Trouble-shooting tables

IMPORTANT The causes of failure in hydraulic systems can be extremely complex. Therefore, general rules for trouble-shooting can only be laid down to a limited degree. Please refer to the relevant Operating Instructions for product specific information about trouble-shooting the Rexroth hydraulic product.

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Bosch Rexroth AG

Hydraulics

Maintenance

General product information

RE 07008

Before undertaking any manual intervention in the Rexroth hydraulic product:

12.1 Definitions of terms

DANGER

The term Maintenance as defined in DIN 31051 encompasses all measures to maintain and restore the desired conditions and to determine and assess the actual condition of the technical devices of a system .

Please refer to the Operating Instructions for all the necessary information on depressurisation and on those parts of the Rexroth hydraulic product that are not depressurised automatically.

These measures are divided into the following categories:

•

Advance all cylinders to their safe end position.

Ø

Inspection (determining the actual condition)

•

Lower all loads.

Ø

Servicing (maintaining the desired condition)

•

Switch off all pumps.

Ø

Repair (restoring the desired condition).

•

Mechanically support vertical cylinders so that they cannot drop. Never perform any maintenance work on raised units without external support.

•

Relieve any accumulators of pressure in the proper manner.

•

Switch off the pressure supply and secure the hydraulic product against being inadvertently switched on again.

•

Ensure that only authorised personnel remain in the work zone.

•

Wear safety glasses, gloves and boots.

•

Allow pressure lines and sections of the system which have to be opened to cool down before commencing maintenance work.

•

Open with care any segments that have to remain under pressure.

The above measures include: Ø

Adapting maintenance objectives to suit company objectives

Ø

Determining appropriate maintenance strategies.

12.2 Safety during maintenance tasks

DANGER In the interests of safety, please observe all the following safety instructions carefully and at all times. •

Check safety devices regularly to see that they are working properly.

•

Perform all maintenance work properly, completely and within the stipulated periods and make a record of the work.

•

Inform all personnel before commencing maintenance work.

•

Generously cordon off the maintenance zone before commencing work.

•

Inform all persons of ongoing maintenance work by means of the appropriate signs. In particular, attach warning signs to the control cabinet, main switch, actuators and points of access.

If you have to switch off the hydraulic product, secure it against being unintentionally switched on again as follows: •

Switch off all drives, disconnect the hydraulics from the mains at the main switch.

•

Depressurise the hydraulic product (relieve any pressure accumulators of pressure).

•

Secure the main switch against being unintentionally switched on again.

Since check valves are located in the pressure lines above the pumps, the hydraulic system may still be under pressure even after it has been disconnected from the actual pressure supply. Certain segments, such as servo cylinders, also continue to remain under pressure because the proportional valves remain in the closed position (all valves are illustrated in their basic position in the hydraulics diagram). Observe the following: Ø

Only new, interchangeable and tested components, replacement parts and lubricants in original-equipment quality are approved for use/replacement.

Ø

For reasons of safety, the installation of used and/or untested components is strictly prohibited and leads to loss of EU Conformity.

Exercise extreme vigilance when operating the hydraulic product in maintenance mode, which may in certain circumstances necessitate the temporary removal of certain safety devices.

RE 07008

General product information

Make sure that all safety devices are properly installed and have undergone a function test before bringing the system (back) into use. •

Perform welding, burning or grinding work on the hydraulic unit or its attachments only with the approval of local safety authorities/fire brigade and with suitable protective covering to prevent ingress of contaminants.

•

When performing assembly work above your height, use the steps and platforms provided by the plant operator. Do not climb on any parts of the system.

•

Remove all tools and materials needed for maintenance from the hydraulic product.

•

Always rectify any leakage from the hydraulic product immediately.

•

Always inform personnel before (re)starting the hydraulic product.

12.3 Inspection and servicing The objective of inspection and servicing is Ø

To maintain all system functions along with the initial parameters of the system

Ø

To ensure continual availability of the system

Ø

To detect weak points

Ø

To ensure that the system attains the required service life.

IMPORTANT The following general specifications are based on use of the hydraulic product in central Europe and under the usual operating conditions of commercial and industrial plants. We strongly recommend the use of an inspection and servicing book, in which all work specific to that site, and all inspection and servicing intervals should be defined and documented. An inspection and servicing book is also helpful in that Ø

It provides comparison values to aid with early detection of malfunctions

Ø

It allows warranty claims to be dealt with more easily.

CAUTION Ensure cleanliness during all work. •

Please observe the requirements for pressure fluids mentioned in Section 9 Assembly and bringing into first use.

•

Clean the external environment of couplings/joints and devices before disassembly. Do not use cleaning wool or cloths containing fibres for cleaning.

•

Seal all openings using protective caps.

•

Bleed the hydraulic product after each item of servicing work.

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•

Document and file details of any work undertaken, changed set values, etc.

•

Document and file details of any amendments/additional information that should be included in the Operating Instructions.

•

Modifications and additions could affect the validity of the EU Conformity Declaration/Manufacturer’s Declaration. Always consult Bosch Rexroth about any proposed modifications or additions.

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Bosch Rexroth AG

Hydraulics

12.3.1 Inspection procedures and test equipment, general The following are some of the typical inspection and testing procedures that are regularly used in connection with hydraulic systems and components.

IMPORTANT

General product information

RE 07008

12.3.2 Location of testing and measuring points

IMPORTANT Please refer to the Operating Instructions for the installation location of filling level indicators, filling points, drainage points, filters, testing points, strainers, solenoids, etc. that require regular inspection and servicing.

Keep the indicated typical test equipment ready for this type of work. Type of test

Typical test equipment

Typical testing activities

Pressure measurement

Pressure gauge or sensor with suitable measuring range and connection pipe and connection coupling

Checking of

Visual inspection

–

•

specified pressure

•

opening pressure

•

pressure difference before and after the object under test

Temperature inspection

Acoustic inspection

–

•

all components securely seated

•

damage

•

wear

•

leakage (formation of oil droplets)

–

presence of all warning and informative signs

Checks for •

Temperature measuring instrument

The graph illustrates the concept of wear/wear margin. The wear margin is a characteristic feature used to describe the condition of the system for the purpose of maintenance. 5 ��

����

Checks for

•

Touch inspection

12.3.3 Inspection and servicing plan, hydraulic products, general

unusual local vibrations

Checks for •

unusual local temperature zones

Checks for •

changes in running noise of the unit

•

changes in flow noise

•

changes in operating noise in the unit and valve control.

1 4

�

�� 2

1 2

6 �� 3

Wear margin Z0 Time t

3

Repair (corrective maintenance) time (ti2 – ti1)

4

Damage threshold (damage time tS)

5 6

��� ���

Desired condition after corrective maintenance Failure

The reduction in the wear margin reflects wear. The curve represents one possible form of the wear profile during the period of use. It is determined during inspection and varies depending, firstly, on the system itself (e.g. material selection, surface treatment, quality) and secondly on external influences or boundary conditions such as servicing levels, corrosive circulating air and dust. Thirdly, it depends on how the system is operated; whether with partial load or partially with excess load, whether it is subject to surge loads or steady load, etc. Where hydraulic systems are concerned, the curve is also influenced by the cleanliness class and degree of fouling of the pressure fluid, the number of cycles and the ambient conditions.

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General product information

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All the factors mentioned above can exert an influence on the curve but this need not necessarily adversely affect the quality of its information, as wear always signifies the reduction in the wear margin, which is understood to be the primary initial variable before wear commences.

12.3.5 Inspection and servicing plan: electrics and control system

Consequently, this means that a sudden change in the wear margin must also count as wear, and that the element of time on its own is not of decisive importance for wear, but is of considerable interest in the assessment and evaluation of such wear.

The product-specific inspection and servicing plan for electrics and control systems can be found in the Operating Instructions.

An increase in the wear margin to over 100 % above its baseline may be achieved through corrective maintenance, if such measures entail an improvement and this increase is established as the new desired condition for future corrective maintenance. Certain system parts may be subject to a wear margin which diminishes in such a way that the time available for use is insufficient for the requirements of the plant or operation. In this case, investigations must be carried out to ascertain whether the introduction of suitable technical measures might counter this reduction in the wear margin to a satisfactory extent. The time and expenditure required for such measures must naturally be kept in reasonable proportion to the expected degree of success.

IMPORTANT

12.3.6 Lubrication points, lubricants, intervals

IMPORTANT The details of the specified lubricants, lubrication points and associated lubrication cycles can be found in the Operating Instructions.

12.3.7 Set values of valves, regulators and signalling elements

If such conditions arise, we refer to these parts as weak points. Since their elimination may provide economic and safety advantages, weak points require to be rectified immediately.

Pressure and flow control valves, pump regulators and signalling elements such as pressure sensors, pressure switches, limit switches and temperature regulators are given their optimum setting when the system is brought into first use.

IMPORTANT

Check regularly whether all values are correctly set with the aid of the hydraulics diagram and the documented values.

The inspection and servicing plan for your particular product can be found in the Operating Instructions.

12.3.4 Inspection and servicing plan, electrohydraulic systems Electrohydraulic systems with proportional valves must be serviced in accordance with hydraulic requirements and strategies. However, technical control components must also be incorporated in these servicing cycles. On this basis, an overall strategy for system servicing must be developed and documented.

IMPORTANT The appropriate component characteristics relevant to servicing can be found in the Operating Instructions.

DANGER The set values of valves with position switches shall only be calibrated or readjusted at the factory. The set values of safety valves shall not be altered by the user. Any readjustment shall be performed by authorised testing bodies only. Too low a pressure difference between the operating pressure and the opening pressure can lead to frequent opening of safety valves. This leads to increased power losses and an unacceptable increase in temperature of the pressure fluid. In this event, select a lower operating pressure.

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12.3.8 Replacement of pressure fluid filters and ventilation filters

CAUTION Unfiltered pressure fluid filters lead to increased wear of all the system’s hydraulic products and can cause functional failures with dangerous effects. Therefore, always replace contaminated oil filters immediately. Clogged ventilation filters result in inadequate cooling and can therefore cause excessive heating up and malfunctions of the hydraulic system. Therefore, always replace contaminated ventilation filters immediately. •

Clogged filters must always be replaced immediately. Do not clean clogged filters.

•

Allow the contents of the replaced oil filter to drip and fully drain.

•

Dispose of the filter in accordance with the applicable regulations.

Exact instructions on how to replace a filter can be found in the Filter manufacturer’s instructions for use.

12.3.9 Checking filters with a contamination indicator Filters with contamination indicators continuously measure the degree of fouling. The dirt-retention capacity of the filter is utilized to the full.

IMPORTANT Check the contamination indicator when the pressure fluid is warm (during or immediately after operation). If the ambient temperature is low or the pressure fluid is cold, its high viscosity may cause clogging to be indicated, although the pressure fluid is in fact clean. Procedure: 1.

Wait until the hydraulic product has reached operating temperature.

2.

Press the indicator button (check function): If the indicator button pops out again immediately, the filter must be replaced by the end of the shift at the latest.

Due to the progressive loss in pressure as the filter becomes increasingly contaminated, the indicator point has a certain reserve capacity, i.e. generally sufficient for a work shift of 8 h. If the filter is not replaced after 8 h, dirt may penetrate the system, resulting in contamination of the hydraulic product.

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CAUTION In certain circumstances the contamination indicator does not show a required filter replacement. If the check function never indicates filter replacement and the contamination indicator is functioning correctly, this may have the following causes: Ø

Faulty filter

Ø

A bypass valve may have been installed and is not closing correctly, e.g. due to the entry of dirt particles.

12.4 Service and storage lives of hose lines

IMPORTANT In terms of the service life of hydraulic hose lines in these Operating Instructions, replacement and storage lives are measured from the date of manufacture of the hose line. Even when properly stored and subjected to permissible loads, seals, hoses and hose lines undergo a natural ageing process. The replacement and storage lives of seals, hoses and hose lines are therefore limited (see 8.2 Seals, hoses and hose lines).

DANGER Hose lines must be replaced in accordance with the provisions of the servicing plan, even if there are no detectable technical defects in the hose line. Hoses that have already been used as part of a hose line shall not be reused in a hose line. The first use may have changed the properties of the hose material to such an extent that reuse of the hose represents a very high risk.

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General product information

Hydraulics

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12.5 Topping up the pressure fluid

12.7 Repair

IMPORTANT

IMPORTANT

Only pressure fluids specified in the Operating Instructions are to be used.

Repair (corrective maintenance) is the restoring of the desired condition.

When changing or topping up the pressure fluid, fill the pressure fluid tank on the hydraulic product as follows:

In addition, observe the special safety instructions in 12 Maintenance and the safety instructions in the Operating Instructions.

1.

Fill the pressure fluid tank using a special filling unit with an integral filter (min. 10 µm).

2.

Drop the system pressure right down by resetting the pump. Set the pressure setting value on the pump pressure control to minimum or zero pressure.

3.

Fill and bleed the line system of the hydraulic product from the unit to the cylinder. To do this actuate the cylinder in both directions, see Operating Instructions.

4.

Top up the pressure fluid volume to the specified quantity.

5.

Raise the pump pressure to the system pressure.

The hydraulic product is ready for operation. 6.

Carry out a test run.

7.

Check the level of the fluid after the hydraulic product has warmed up to the operating temperature and adjust if necessary.

IMPORTANT Check the contamination indicator when the pressure fluid is warm (during or immediately after operation). If the ambient temperature is low or the pressure fluid is cold, its high viscosity may cause clogging to be apparently indicated.

12.6 Servicing pressure accumulators

DANGER Pressure accumulators are subject to the national legislation on safety requirements for pressure vessels applicable in the place of installation. Observe the Pressure Equipment Directive 97/23/EC.

IMPORTANT The gas precharge pressure is measured with a testing and filling device. Details of the procedure can be found in the Operating Instructions. Inspection and servicing •

Carry out the tests required by law.

•

Test and monitor the gas precharge pressure regularly.

DANGER Ensure cleanliness during all work. •

Clean the external environment of couplings/joints and devices before disassembly. Do not use cleaning wool or cloths containing fibres for cleaning.

•

Seal all openings using protective caps.

•

Bleed the hydraulic product after each item of repair work.

•

If appropriate, follow the procedure for bringing into first use, see 9.3 Bringing into first use, subsequent bringing into use.

•

Document any amendments/additional information that should be included in the Operating Instructions.

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12.7.1 General safety instructions for repair work

DANGER Repair work shall only be done by an authorised hydraulics expert who has the required specialist hydraulics knowledge. Specialist hydraulics knowledge means, among other things, that the person can read and fully understand hydraulics drawings. In particular, he must fully comprehend the range of functions of the integrated safety components. Components may only be dismantled for the purpose of repair to the extent described in the Operating Instructions. Never repair a defective safety valve. It must be completely replaced. Faulty parts may only be replaced by new, interchangeable, tested components in original-equipment quality. Any deviations from this can be found in the Operating Instructions. Before each subsequent bringing into use after repair work, the hydraulic product shall be accepted by a hydraulics expert. The operator of the hydraulic product is required to check by means of a servicing record that the inspection and servicing plan as been complied with. Pressure vessels have to be pressure tested every 10 years and the information recorded in accordance with the Pressure Equipment Directive 97/23/EC or its implementation in national legislation.

13

General information about hydraulic pressure accumulators

13.1 General The regulations applicable at the place of installation concerning hydraulic pressure accumulators (hydrostatic accumulators) must be observed before bringing into use and during operation. The plant operator bears sole responsibility for compliance with the existing regulations. Hydrostatic accumulators are subject to the national implementation of the EU Pressure Equipment Directive 97/23/EC. Documents supplied with accumulators must be preserved with care; they will be required during recurring inspections by specialists. The bringing into use of hydrostatic accumulators shall be carried out by trained expert personnel only.

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WARNING Do not perform any welding, soldering or mechanical work on accumulator vessels. Welding and soldering carry a risk of explosion! Mechanical tampering may cause the vessel to burst and the operating permit will be withdrawn. Do not charge hydrostatic accumulators with oxygen or air. Risk of explosion! Depressurise the system before working on hydraulic installations. Improper installation can lead to serious damage to persons and property.

13.2 Safety devices relating to hydraulic pressure accumulators The equipping, installation and operation of hydrostatic accumulators is regulated by the national implementation of the EU Pressure Equipment Directive 97/23/EC and additionally in the Federal Republic of Germany by the Technical Regulations for Pressure Vessels (TRB). This legislation requires the following safety equipment: Ø

Device to protect against excessive pressure (prototype-tested)

Ø

Pressure relief device

Ø

Pressure measuring device

Ø

Test gauge connection

Ø

Shut-off device

Ø

Optional: electromagnetically operated pressure relief device

Ø

Safety device to protect against overheating.

IMPORTANT See the Operating Instructions.

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14

General product information

Hydraulic systems

Hydraulic systems are generally intended for installation in machines or systems. In addition to the basic information about the installed components, the information contained in the Operating Instructions made available for each hydraulic system by Bosch Rexroth also applies to hydraulic systems. By installing the hydraulic system in a machine or system, the interaction of the hydraulic system with the overall machine may give rise to changes in the potential dangers. In particular the effect of hydraulic and electrical control of hydraulic drives that create mechanical movement are to be considered. This information shall be included in the hazard analysis/risk assessment of the overall machine carried out by its supplier and in the Operating Instructions of the overall machine. This also applies to the specification of the interfaces between the hydraulic system and the overall machine. Hydraulic systems are subject to legislation including the Pressure Equipment Directive and other relevant EU directives that have been implemented in national legislation. Exact information can be found in the EU Conformity Declaration or Manufacturer’s Declaration that is supplied with the hydraulic system or the hydraulic product.

WARNING Before installing a hydraulic system in a machine or modifying an existing hydraulic system in a machine, satisfy yourself that Ø

the hydraulic system is suitable for its application in the machine

Ø

the ambient conditions in the machine are suitable and/or permissible for the use of the hydraulic system

Ø

other installed items on or in the machine cannot disturb or endanger the functioning or the safe operation of the hydraulic system.

If the overall machine is to be used in a potentially explosive atmosphere, then it must be ensured that the hydraulic system has been designed and is suitable for this use.

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14.1 Effects of leaks in the hydraulic system on the machine If pressure fluid escapes from the hydraulic system and comes into contact with hot surfaces on the machine, this can lead to the generation of life-threatening smoke, fire and/or other dangerous operating conditions. These risks shall be determined by the machine manufacturer by means of a hazard analysis and if necessary provision made for the appropriate safety devices.

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Bosch Rexroth AG Hydraulics Zum Eisengiesser 1 97816 Lohr am Main, Germany Tel. + 49 (0) 93 52 / 18-0 Fax + 49 (0) 93 52 / 18-23 58 [email protected] www.boschrexroth.de

© All rights reserved, Bosch Rexroth AG, including applications for intellectual property rights. We reserve all power of disposal, rights of reproduction and issue. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The given information does not release the user from the obligation of own judgement and verification. It must be remembered that our products are subject to a natural process of wear and aging.

Bosch Rexroth AG Drive & Control Support Maria-Theresien-Straße 23 97816 Lohr am Main, Germany Phone +49 9352 18-1041 Fax +49 9352 18-1040 [email protected] www.boschrexroth.de/trainingsystems

© This document, as well as the data, specifications and other information set forth in it, are the exclusive property of Bosch Rexroth AG. It may not be reproduced or given to third parties without its consent. The data specified above only serve to describe the product. No statements concerning a certain condition or suitability for a certain application can be derived from our information. The information given does not release the user from the obligation of own judgment and verification. It must be remembered that our products are subject to a natural process of wear and aging. Printed in Germany RE 00847/10.08 Mat. no. R961003873