Do not exceed the permissible working pressure see data sheets. Use only extra-low voltage of up to 24V. Notes on procedureConstructionThe following steps are to be observed when constructing a control cir-cuit.
Post on Dec views. Category: Documents 56 download. Tags: training packages learning packages basic packages deal application packages training documentation technology packages individual packages training media. The Training packages are structured accordingly: Basic packages deal with basic knowledge spanning a wide range of technologies.
Technology packages deal with important areas of control technol- ogy. Function packages explain the basic functions of automation sys- tems. All learning packages are of an identical structure: Hardware Teachware Software Courses The hardware consists of industrial components and installations,adapted for didactic purposes.
The courseware is matched methodologically and didactically to thetraining hardware and comprises: Textbooks with exercises and examples Workbooks with practical exercises, supplementary notes, solutions and data sheets Overhead transparencies and videos to provide a lively, interactive classroom atmosphere Teaching and training media are available in several languages.
Authentic industrial components, nominal size 4 mm, on the profile plate. Development of key qualifications: Technical competence, methodological competence, social compe-tence and personal competence. Practice in teamwork, cooperation, study technique, independence and organisational ability. The following points have been included in the design concept of thehydraulic components: Simple handling Secure attachment Environmentally friendly coupling technology Compact components Practice-oriented measuring technology The following are recommended for the practical implementation of theexercises: Hydraulic and electrical components of equipment sets TP and TP A hydraulic power pack Several hoses A power supply unit A set of cables A slotted profile plate or corresponding laboratory equipment The measuring set with the necessary sensors TP Festo Didactic 10 The aim of this workbook is to familiarise the student with the equipmentand basic circuits of proportional hydraulics.
Optimum harmonisation of components by means of setting pa- rameters. A Festo Didactic slotted profile plate for the attachment of compo- nents. The following additional training material for hydraulics is also availablefrom Festo Didactic: Magnetic symbols Hydraulic slide calculator Set of overhead transparencies Set of transparent models Interactive video Symbols library Simulation program TP Festo Didactic 11 Safety recommendationsThe following safety advice must be observed in the interest of your ownsafety: Caution!
Cylinders may advance as soon as the hydraulic power is switched on! The hydraulic power pack and the electrical supply unit must beswitched off during the co. Proportional Hydraulics - 3 days. A short summary of this paper. Download Download PDF. Translate PDF. Order no. Designation: D. Merkle, H. Offenders will be held liable for the payment of damages.
All rights reserved, in particular the right to carry out patent, utility model or ornamental design registrations. Parts of this training documentation may be duplicated, solely for train- ing purposes, by persons authorised in this sense.
Technology Packages deal with the technologies of pneumatics, elec- tropneumatics, programmable logic controllers, automation with PCs, hydraulics, electrohydraulics, proportional hydraulics and application technology handling.
It is possible, for example, to use PLCs to control pneumatic, hydraulic and electrical actuators. The courseware is matched methodologically and didactically to the training hardware.
They have been designed for use in classroom teaching but can also be used for self-study purposes. In the software field, CAD programs, computer-based training programs and programming software for programmable logic controllers are avail- able.
The Training Package TP is designed to provide an introduction to the fundamentals of electrohydraulic control technology. This package comprises a basic level and an advanced level. The basic level package TP teaches basic knowledge of electrohydraulic control technology. It is, however, equally suitable for use in providing a practical introduction to electrohydraulics for students at universities and technical colleges.
The modular design of the hardware allows theoreti- cal questions to be dealt with experimentally in a simple and efficient form.
Cylinders may move unexpectedly when the hydraulic power pack is switched on. See the relevant data sheets. Use a tool for this. The hydraulic power pack and electrical power supply must be switched off during the assembly of the circuit. All components must be securely fitted to the profile plate or mount- ing frame.
Connect up the hydraulic hose lines. All valves, other components and hose lines are fitted with self- closing quick-acting couplings. Do not exceed the maximum permis- sible pressure of 12 MPa bar.
The maximum operating pres- sure is 6 MPa 60 bar. Connect up the electrical cables. Connect test leads to the component sockets by means of 4 mm plugs. Before commissioning a hydraulic control circuit, check that all return lines are connected and that all connectors are secure. Dismantling 8. Before dismantling the circuit, ensure that pressure in hydraulic com- ponents has been released: Couplings must be disconnected only under zero pressure!
Switch off the hydraulic power pack first and then the electrical power supply. In the interests of safety, the pressure is limited to approx. Every time a control circuit is assembled on the pro- file plate, a second pressure relief valve is used. We recommend that this should be set to a maximum pressure of 5 MPa 50 bar. The maximum pressure for all components in the training package is 12 MPa bar.
Thanks to their design, the couplings reduce leakage during connection and disconnection to a minimum. With an area ratio of The pressure relief device can be used to release this pressure. Exception: This is not possible in the case of hose lines and non-return valves. Ensure therefore that control cir- cuits are depressurised before hose lines are disconnected and the circuit is dismantled. This prevents the accidental spillage of hydraulic fluid.
In the interests of simplicity, these couplings are not shown in circuit diagrams. The crossover position is on the right and the parallel position on the left. Working port A is, however, on the right, and port B is therefore on the left. The crossover position is on the left and the parallel position on the right. Working port A is now on the left and port B on the right.
This symbolic representation is hardware-oriented. The two different symbolic representations describe all functions of a given valve.
In practice, valves by different manufacturers with identical functions are sometimes given different symbols. It is not necessary to seal these ports by means of plugs. Embed Size px x x x x Order no. SchwarzAuthors: D. Merkle, B. Schrader, M.
The copying, distribution and utilization of this document as well as thecommunication of its contents to others without expressed authorizationis prohibited.
Offenders will be held liable for the payment of damages. All rights reserved, in particular the right to carry out patent, utilitymodel or ornamental design registrations. Chapter 1 Tasks of a hydraulic installation. Chapter 2 Fundamental physical principles of hydraulics.
Chapter 3 Hydraulic fluid. Chapter 4 Components of a hydraulic system. Chapter 5 Graphic and circuit symbols.
Chapter 7 Components of the power supply section. Chapter 8 Valves. Chapter 9 Pressure valves. Chapter 10 Directional control valves.
Chapter 11 Non-return valves. In the case of the circuit with a flow control valve exercise 9 , the travel speed remains constant. Reason: The throttle valve varies only the cross-section of the line through which flow passes. The flow rate produced is dependent on the difference in the pressures upstream and downstream of the restriction. The flow rate through the throttle valve is thus dependent on pressure, in fact on both the supply and load pressures.
The flow control valve incorporates a pressure compensator which maintains the internal pressure difference at a constant value. The flow rate is thus not dependent on the supply and load pressures. Close the shut-off valve 0V2 and the flow control valve 0V3. Now switch on the hydraulic power pack and set a system pressure of 50 bar by means of the pressure relief valve 0V1. Now open the shut-off valve 0V2 and also open the flow control valve until the piston rod advances.
The measurements can now be carried out. Only when the ratio of travel pressure to back pressure becomes equal to the area ratio a is an equilibrium of forces achieved, causing the piston to stop. Reason: The flow rate required on the piston side is double that necessary on the piston rod side.
During the advance stroke, this flow rate is supplied from the pump and the annular piston side. During the return stroke, only supply from the pump is available. The return-stroke speed is produced by this. This is demonstrated by task 2 piston in forward end position. This task also shows that the pressure regulator maintains a pressure of 15 bar even without through-flow. The valves 1V3 and 1V4 provide a bypass of the pressure regulator to allow a faster return stroke to be achieved.
If the advance stroke is opposed by a resistance, as in task 3, a flow pressure of only 12 - 15 bar is achieved, despite the system pressure of 50 bar.
By closing the throttle valve 1V5, it is possible to increase the counter pressure until the pressure gauge p1Z2 shows 15 bar; the piston will then stop, i. In task 5, it is demonstrated that increased counter pressure during the return stroke causes the valve to the tank to open, resulting in only the set pressure of 15 bar being attained.
The piston can be pushed into the retracted end position. With the piston in this position, as in task 6, the 15 bar pressure is initially maintained. Due to internal leakage within the valve, the pressure then falls below 15 bar, causing the pressure regulator to switch from A - T to P - A. In practice, a pressure relief valve with bypass must be used in place of the one-way flow control valve 1V5.
This prevents the high pressures which would arise upstream of the one-way flow control valve due to pressure intensification during the advance stroke of the piston. A oneway flow control valve has been used in this case to simplify the circuit configuration. Excessive pressures cannot arise in this case due to the fact that the system is being operated with reduced pressure.
Piston advanced to end position with shut-off valve closed Cases of examination p1Z1 p1Z2 p1Z3 1. Advance stroke 5 bar 2 bar 1 bar 2. End position 50 bar 15 bar 0 bar 3. Advance stroke with counter pressure 49 bar 13 bar 20 bar 4. End position 50 bar 16 bar 0 bar 5. Advance stroke with pressure regulator 49 bar 14 bar 20 bar 6. End position 50 bar 16 bar 0 bar p1Z1 p1Z2 p1Z3 1. Return stroke 4 bar 7 bar 16 bar 2. End position 0 bar 0 bar 50 bar 3.
Return stroke with counter pressure 6 bar 10 bar 18 bar 4. End position 0 bar 0 bar 50 bar 5. Return stroke with pressure regulator 0 bar 26 bar 46 bar 6. Note that increased pressures occur which act on port A of the pressure regulator. These pressures must be discharged to the tank. Mount the cylinder 1A on the profile in such a way that it can advance downwards. First close the shut-off valve 0V2.
Switch on the hydraulic power pack and then use the pressure relief valve 0V1 to set a system pressure of 50 bar. Open the shut-off valve and adjust the pressure relief valve 1V2 in such a way that the piston rod advances in approx. The throttle valve setting should be retained while manipulating the circuit using the weight 1Z3, with counter-holding provided by the pressure relief valve 1V3.
For the return stroke, a non-return valve 1V4 is required as a bypass for the pressure relief valve. After the measurements have been completed, first remove the weight and then retract the cylinder. Now depressurise the circuit by closing the shut-off valve and then opening the pressure relief valve 1V3. Dismantle the circuit only when the pressure has fallen to zero, as shown by the pressure gauge 1Z2.
Reason: The piston is pulled out by the load. Without counter-holding, the movement is uncontrolled and jerky. A constant advance-stroke speed is obtained only with counter-holding. The generation of a counter pressure clamps the piston hydraulically. The travel and back pressures remain constant, which means that the travel speed also remains constant. A circuit with counter-holding is advisable both with and without a load. It is also possible to adjust the counter-holding to suit the load.
Mount the cylinder 1A on the profile plate in such a way that it can advance downwards. First close the shutoff valve 0V2. Open the shut-off valve and adjust the pressure relief valve 1V3 in such a way that the piston rod advances in approx.
The flow control valve setting should be retained throughout the series of measurements. Only the circuit should be modified. It advances jerkily. With counter-holding, the same speed is achieved with and without a load.
If, however, the flow control valve is installed in the outlet line to provide counter-holding, very high pressures will occur on the outlet side. This is often unacceptable in practice. A suitable circuit is thus one with a flow control valve in the inlet line and counter-holding by means of a pressure relief valve in the outlet line.
Ensure that the non-return valves are installed correctly. Open the pressure relief valves fully. If a sufficient number of pressure relief valves are not available, the system pressure can also be set on the pressure relief valve of the hydraulic power pack. Check the circuit and then switch on the hydraulic power pack.
Now set the system pressure to 50 bar. When the directional control valve 1V1 is actuated, the cylinder advances and retracts at maximum speed.
The travel motion can be slowed down by closing the two pressure relief valves 1V3 and 1V4. Adjustment is carried out using the pressure relief valve in the outlet line in each case. The non-return valves 1V2 and 1V5 are used to bypass the pressure relief valves fitted in each inlet line.
The counter-holding pressures are shown on the pressure gauges 1Z1 and 1Z2. If the non-return valves are installed incorrectly, the travel speed will not change even when the pressure relief valves are closed. With the pressure relief valves fully closed, the cylinder will no longer retract due to the pressure intensification effect present.
Before the circuit is dismantled, the pressure relief valves must once again be fully opened to ensure that no pressure is trapped. A non-return valve is required as a bypass in each direction.
Take account of the cylinder area ratio when setting the pressure. Conclusions In practice, skip handling is controlled using proportional valves. Dynamic adjustment of the proportional valves allows better control of fast and slow travel motions. Due to the pressure intensification effect, the system pressure of 50 bar is not sufficient to open the pressure regulator from A to T.
Conclusions If a pressure relief valve is fitted in the bypass, the overall system pressure will fall to 30 bar during the advance stroke. If a pressure regulator is used, the system pressure of 50 bar is maintained, and only the cylinder is supplied with the reduced pressure of 30 bar. This allows further actuators to be supplied with full system pressure by the same hydraulic power pack.
Check, however, that the pump delivery is sufficient for this. The pressure relief valve gives an advantage in this application, since, in the case of long standstill periods with the directional control valve actuated, the pump need only develop the set pressure of 30 bar.
When assembling the circuit, ensure that the non-return valves are installed correctly, since otherwise pressure may become trapped. If a sufficient number of pressure relief valves is not available, the system pressure can be set on the pressure relief valve of the hydraulic power pack.
Once the circuit has been assembled and checked, switch on the hydraulic power pack. The shut-off valve should be closed at this time. The system pressure of 50 bar can now be set on the pressure relief valve 0V1.
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