Hidraulica

Electro-hydraulics
Basic level

D. Merkle

• K. Rupp • D. Scholz

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093611
E.-HYDR.LEHRB.
D.LB-TP601-GB
4/92
A. Reulecke
16.6.93, C. Paproth, M. Schwarz
A. Zimmermann
D. Merkle, K. Rupp, D. Scholz
T. Tranter

© Copyright by Festo Didactic KG, D-73734 Esslingen, 1994
All rightsreserved, including translation rights. No part of this publication may
be reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without the prior written permission of Festo
Didactic KG.
ISBN 3-8127-3611-X

Table of contents

Festo Didactic

Conception of the book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 6 Table of contents

Part A: Course
1.
1.1
1.2
1.3

Introduction 9
Advantages of electro-hydraulics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Fields of application of electro-hydraulics . . . . . . . . . . . . . . . . . . . . . . . 10
Design of an electro-hydraulic system . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.
2.1
2.2
2.32.4
2.5
2.6
2.7
2.8
2.9
2.10

Circuit and graphic symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Pumps and motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Directional control valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Pressure valves . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . 16
Flow valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Non-return valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Energy transfer andpreparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Measuring instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Equipment combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Electrical circuit symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.
3.1
3.2
3.3
3.4Electro-hydraulic control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Hydraulic circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Electrical circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Function diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 35
Procedure for the construction
of an electro-hydraulic system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.
4.1

Actuation of a single-acting cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Exercise 1: Direct solenoid valve actuation
(example: pressure roller) . . . . . . . . . . . . . . . . . . . . . . . . . 45
Exercise 2:Indirect solenoid valve actuation
(example: pressure roller) . . . . . . . . . . . . . . . . . . . . . . . . . 50
Exercise 3: Boolean basic logic functions
(example: tank forming press) . . . . . . . . . . . . . . . . . . . . . . 54

4.2
4.3

5.
5.1

Actuation of a double-acting cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Exercise 4: Signal reversal
(example: tankforming press) . . . . . . . . . . . . . . . . . . . . . . 64

6
6.1

Logic operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Exercise 5: Conjunction (AND function) and negation (NOT function)
(example: plastic injection moulding machine) . . . . . . . . . 72
Exercise 6: Disjunction (OR function)
(example: boiler door) . . . . . . . . . . . ....