1. ELECTRO – PROPORTIONAL VALVES1

2. HYDRAULIC CONTROL TECHNOLOGY
Servo valve
New Series
Proportional valves
Closed Loop
Proportional
Hybrid series
Performance
Increasing
Open Loop
Proportional
Proportional Valves
Conventional
Valves 2

3. COMPARISON BETWEEN CONVENTIONAL AND PROPORTIONAL VALVES
Mechanical
Single
In Steps
Complex
Large
Complicated
Not Available
SL.
No. 1 2 3 4 5 6 7
Description
Setting
Stage Control
Slope Control
Circuit
Size of Blocks, Pipes
Power Saving Circuit
Feedback
Proportional
Electrical
Multiple
Smooth Slope
Simple
Small
Available 3

4. DEVELOPMENT OF ELECTRO - PROPORTIONAL VALVES
Year
1965 ~ 1970
1975 ~ 1980
1980 ~ 1985
1990 ~
Pressure Control
&
Flow Control Valves
Combination of Pressure & FlowControl Valves
Power Matching Systems.
Directional & Flow Control Valves
EH- Series
Pressure & Flow , Directional & Flow Control Valves.
Power Matching Systems 4

5. SALIENT FEATURES OF ELECTRO PROPORTIONAL VALVES
Just Like Conventional Valve
Basic Structure
Simple
High Reliability
Longer Service Life
Easy to Use
Easy to Maintain
Wet Armature Type
Solenoid
High Resistance Against Contamination
Directly Operated Type
Powerful Driving
With Current Feedback Function, Dither
Amplifier
Stable Control

6. DEVICES FOR THE PROPORTIONAL CONTROL
Indication
Feedback signal in Closed Loop Circuit
Power Amplifier
Setting Device
Sensor
Prop. Valve
Manual
Dialing
Program
Control
Computer
DC input
type
with
feedback
Slow up –
down.
Pilot Relief Valve
Relief Valves
Relieving &
Reducing valves
Flow control
(& check) valves
Throttle Valves
Power Saving
Valves
Direction & Flow
control Valves
The Sensor detects the Controlled Pressure, Flow Rate and Speed etc., and converts it to electric signal.
DC VOLTAGE
DC CURRENT 6

7. Hydraulic Power Supply
SIGNAL SEQUENCE
Control Power Supply
Hydraulic Power Supply
Control Panel
0~10V
Command Signal
Prop. Valve
Amplifier
Actuator
Sensor 7

8. PRINCIPLE OF OPERATION
D C Current
Magnetic Force
Spring Force
Plunger
Coil
( Schematic Diagram of Solenoid ) 8

9. PRINCIPLE OF SOLENOID OPERATION
ELECTRO MAGNET
PERMANENT MAGNET 9

10. PRINCIPLE OF BASIC SOLENOID OPERATION
NO ELECTRIC CURRENT
PLUNGER
COIL
Magnetic Field created which must travel through air.
ELECTRIC CURRENT
1.) Attracts Plunger to an equilibrium position.
2.) Creates an output force.
3.) so that magnetic field can pass 100% through the iron.
ELECTRIC CURRENT 10

11. COMPARISON : FORCE V/S STROKE
Conventional
Proportional
Force
Force
Stroke
Stroke
100 %
100 %
Force
70 %
70 %
Force
30 %
50 %
30 %
Stroke
Stroke 11

12. COMPARISON : FORCE V/S STROKE
Proportional
Conventional
Force
Spring Curve
100 %
70 %
50 %
100 %
70 %
30 %
30 %
Stroke
Stroke 12

13. COMPARISON OF SOLENOID CONSTRUCTION
Air Gap
COIL
CONVENTIONAL SOLENOID
ARMATURE
Air Gap
COIL
PROPORTIONAL SOLENOID
ARMATURE 13

14. CONSTRUCTION DETAILS OF PROP. SOLENOID
Manual Adj.
Screw
Iron Core
Bearing
Air Vent
Coil
Spring
Air Gap
Plunger 14

15. TORQUE MOTOR ASSEMBLY Signal from Amplifier AIR VENT COIL ARMATURE
NULL ADJUSTER
ROD 15

16. PROPORTIONAL HYDRAULIC CONTROL - RANGE03 06 10 01 04
Kgf/Cm2
245
Pilot Relief Valves
Relief Valves
Reducing & Relieving Valves
Flow Control (& Check)Valves
Flow Control & Relief Valves
Directional & Flow Cont.Valves
High Response Type
157
EH Series
E Series
206
EBG 02 W 1 2 5 20 50
100
200
300
Maximum Flow
Maximum
Operating
Pressure
Valve Type L /
min 3 30
500
1000 16

17. STEP RESPONSE STEP SIGNAL 0 ~ 100 % Fig. Shows the Valve requires
80 ms to go from 0 to 100% Stroke and
70 ms to fully close.
i.e., 150 ms is required to complete one cycle.
150 ms Cycle
1000ms ( 1 Sec ) - ? Cycles
1000 X 1 = 6.6 Cycles / Sec ( Or 6.6 Hz )
150
100
STROKE % 50 80 70
TIME ( ms )
STEP SIGNAL 25 ~ 100 %
STEP SIGNAL 10 ~ 90 % 25
100 75 50 40
TIME ( ms ) 70 60 50 90
STROKE %
STROKE %
TIME ( ms )
STEP RESPONSE : A RESPONSE MADE WHEN THE INPUT SIGNAL SUDDENLY CHANGES FROM A GIVEN VALUE TO ANOTHER GIVEN VALUE 17

18. Amplitude Response ( Gain )
FREQUENCY RESPONSE
Frequency
Is the number of times any action occurs in a given measure of time Unit is Hz (Cycles per Second)
Amplitude Response ( Gain )
Is a ratio of output change to input change Measured in dB (Decibels) 18

19. PHASE LAG
The time required for the output to recreate the input command. Measured in Degrees.
Cyclic Input
Cyclic Out put
Phase Lag in Degrees
90°
Time
90° Phase Lag
Phase Lag in Degrees
Time 19

20. PROPORTIONAL ELECTRO – HYDRAULIC PILOT RELIEF VALVE
FREQUENCY RESPONSE
Frequency ( Hz )
2 L
30 cm
-10
-20
-30
- 20
- 40
- 60
- 80
-100
-120
-140
-160
-180
0.1
0.2
0.4
0.7 1 2 4 7 10 20 40 70
Gain ( dB )
Phase (
deg.
Flow Rate
Pressure
Trapped Oil Volume
Viscocity : /
min 80
16 Kgf / Cm2 3
30 cSt
Phase
Gain 20

21. Hysterisis without Dither Hysteresis with Dither
200
180
160
140
120
100 80 60 40 20
200
180
160
140
120
100 80 60 40 20
Pressure Kgf / Cm2
Pressure Kgf / Cm2
Current ( mA )
Current ( mA )
Dead Band
Dead Band 21

22. PROPORTIONAL ELECTRO – HYDRAULIC PILOT RELIEF VALVE
With Safety Valve
PLUNGER
COIL
SPRING
POPPET
PLUNGER
SEAT
SPRING
AIR VENT
Pr. Adj. Screw for Safety valve
MANUAL PR. ADJ. SCREW
IRON CORE
TANK PORT
PRESSURE PORT
Without Safety Valve 22

23. PROPORTIONAL ELECTRO – HYDRAULIC PILOT RELIEF VALVE
STEP RESPONSE
min
Flow Rate
Trapped Oil
Volume
Viscocity :
2 L /
40 cm3
30 cSt
Time 90 70 50 30 10
0.2 Sec
Step Signal
Pressure
Kgf / Cm2 23

24. PROPORTIONAL ELECTRO – HYDRAULIC PILOT RELIEF VALVE
FLOW RATE VS PRESSURE
Viscosity
250
235
220
160
145
130 70 55 40 1 2 L /
min B C A
Pressure Kgf / Cm2
: 30 cSt
Flow Rate 24

25. PROPORTIONAL ELECTRO – HYDRAULIC PILOT RELIEF VALVE
FREQUENCY RESPONSE
Frequency ( Hz )
2 L
30 cm
-10
-20
-30
- 20
- 40
- 60
- 80
-100
-120
-140
-160
-180
0.1
0.2
0.4
0.7 1 2 4 7 10 20 40 70
Gain ( dB )
Phase (
deg.
Flow Rate
Pressure
Trapped Oil Volume
Viscocity : /
min 80
16 Kgf / Cm2 3
30 cSt
Phase
Gain 25

26. PROPORTIONAL ELECTRO – HYDRAULIC PILOT RELIEF VALVE
CONTROL PRESSURE VS INPUT CURRENT
250
200
150
100 50
400
600
800
1000 C B
Input Current mA A
Pressure Kgf / Cm2 26

27. PROPORTIONAL ELECTRO – HYDRAULIC RELIEF VALVE
PROPORTIONAL PILOT RELIEF VALVE WITH SAFETY VALVE
AIR VENT
MANUAL PR. ADJ. SCREW
SLEEVE SEAT
SPRING
POPPET
Graphic Symbol
VENT PORT
PR. PORT
TANK PORT 27

28. PROPORTIONAL ELECTRO – HYDRAULIC RELIEF VALVE
STEP RESPONSE
200
160
120 80 40
0.2s
Flow Rate :
200 L /
min )
Time
Step Signal
Pressure
Kgf/Cm2
Loading
Volume
Viscocity :
1 ltr.
30 cSt 28

29. COMPARISON OF CONVENTIONAL & PROPORTIONAL PRESSURE CIRCUIT
Conventional Circuit
Proportional Circuit
Switch ON Sol. a – d to get 4 different pressures
Only One Valve is required ., By changing the Input Current, the Pressure can be changed. 29

30. PROPORTIONAL ELECTRO – HYDRAULIC RELIEVING AND REDUCING VALVE
PROPORTIONAL PILOT RELIEF VALVE
AIR VENT
SPOOL
MANUAL PR. ADJ. SCREW
Graphic Symbol
SPRING
DRAIN PORT
TANK PORT
PRIMARY PR. PORT
SECONDARY PR. PORT 30

31. PROPORTIONAL ELECTRO – HYDRAULIC FLOW CONTROL VALVE
PR. COMPENSATOR PISTON
40 Series ( Direct Type )
INLET PORT
DRAIN PORT
Graphic Symbol O M
OUTLET PORT
SPOOL
ORIFICE SLEEVE 31

32. PROPORTIONAL ELECTRO – HYDRAULIC FLOW CONTROL VALVE
10 Series ( Pilot Operated Type )
REDUCING VALVE
PILOT PR. PORT
INLET PORT
DRAIN PORT
Graphic Symbols
Pilot
Int
Ext O M O M
OUTLET PORT
PILOT SPOOL
SPOOL 32

33. PROPORTIONAL ELECTRO – HYDRAULIC FLOW CONTROL VALVE
10 Series ( Pilot Operated Type ) 33

34. STEP RESPONSE 40 Ohm 10 Ohm Time 125 L / min 60 L 0.2s Step Signal 140
120
100 80 60 40 20
Flow Rate
125 L
min /
60 L
0.2s
Step Signal
150 L
125
100 75 50 25
Time
Flow Rate 34

35. FREQUENCY RESPONSE 40 Ohm Frequency ( Gain deg. Phase Phase ( - 10 20- 10 20
0.2
0.7 1 2 4 7 30 40 60 80
100
120
140
160
180
0.1
Gain
Phase
Frequency ( Hz )
Phase (
deg.
Gain ( dB
Input Current :
460
70 mA
Pressure :
70 Kgf / Cm2
40 Ohm 35

36. FREQUENCY RESPONSE 10 Ohm Frequency ( deg. Phase ( Gain ( dB )
0.1
0.2
0.4
0.7 1 2 4 7 10 20 40 70
Gain ( dB )
Flow Rate :
65  15 L / min
Supply Pressure :
140 Kg / Cm2
Gain
-10
-20
-30
-40
-60
-80
-100
-120
-140
-160
-180
Frequency ( Hz
Phase (
deg.
Phase 36

37. COMPARISON OF CONVENTIONAL & PROPORTIONAL FLOW CIRCUITS
Backward
Forward
Intermediate Speed
Low Speed
High Speed
PUMP
EFG-* -
Sol. 1
Sol. 2
Sol. 1
Sol. 2
Signal
Sol. 3
Sol. 4
Conventional
Proportional 37

38. LOAD SENSING - COMPARISON OF HEAT GENERATION
HEAT GENERATED
= P x Q x 860 Kcal / Hr
612
= 40 x 40 x 860
= Kcal / Hr 38

39. LOAD SENSING - COMPARISON OF HEAT GENERATION
Increase pressure
VENT LINE
REMOTE CONTROL RELIEF VALVE
Set At 100 Bar P T 39

40. LOAD SENSING - COMPARISON OF HEAT GENERATIONw
Load Pr Kgf/Cm2
( = 15 Kfg/Cm2 )
Load Pressure = 10 Kgf / Cm2
Flow Control Valve
Set At 100 Bar P T 40

41. LOAD SENSING - COMPARISON OF HEAT GENERATION
HEAT GENERATED
= P x Q x 860 Kcal / Hr
612
= 40 x 15 x 860
= Kcal / Hr 41

42. CONVENTIONAL POWER SAVING VALVE
FLOW CONTROL VALVE
RELIEF VALVE
TANK PORT
DRAIN PORT
INLET PORT
OUTLET PORT 42

43. PROPORTIONAL ELECTRO – HYDRAULIC RELIEF & FLOW CONTROL VALVE
40 - 10 Series
FLOW CONTROL SOLENOID
PROPORTIONAL PILOT RELIEF VALVE WITH SAFETY VALVE
TANK PORT
DRAIN PORT
INLET PORT
OUTLET PORT 43

44. PROPORTIONAL ELECTRO – HYDRAULIC RELIEF & FLOW CONTROL VALVE
10 - 10 Series
FLOW CONTROL SOLENOID
REDUCING VALVE
PROPORTIONAL PILOT RELIEF VALVE WITH SAFETY VALVE
INLET PORT
DRAIN PORT
OUTLET PORT
PILOT PR. PORT
TANK PORT 44

45. POWER SAVING CIRCUIT Conventional Circuit Proportional Circuit Q Q Q Q
Energy Saving
Energy Saving
Energy Saving Q Q Q Q
Power loss
Power loss
Power loss
Power loss P P P P
Load Sensing Circuit
Flow Matching Circuit 45

46. PROPORTIONAL ELECTRO – HYDRAULIC DIRECTIONAL AND FLOW CONTROL VALVE
Max. Op. Pr. : 250 Kgf / Cm2
Max. Flow : 01  30 L/ min
03  60 L/ min 46

47. PROPORTIONAL ELECTRO – HYDRAULIC DIRECTIONAL AND FLOW CONTROL VALVE
Graphic Symbol A B a b P T Y X X T A P B Y 47

48. PROPORTIONAL ELECTRO – HYDRAULIC DIRECTIONAL AND FLOW CONTROL VALVE
INPUT CURRENT V/S FLOW A B P T
200
400
600
800
1000 mA
Input Current L /
min 20 40 60 80
100
120
Flow Rate 48

49. PROPORTIONAL ELECTRO – HYDRAULIC DIRECTIONAL AND FLOW CONTROL VALVE
PRESSURE DIFFERENCE V/S FLOW L /
min
140 A B
750 mA
120
700 mA P T
Flow Rate 80
Valve Pres. Diff. 40
Kgf / Cm2
245
210
140 70
600 mA 70
140
210
245
Kgf / Cm2
600 mA
Valve Pres. Diff. 40 80
Flow Rate A B
700 mA
120
750 mA L /
min P T
140 49

50. PROPORTIONAL ELECTRO – HYDRAULIC DIRECTIONAL AND FLOW CONTROL VALVE
High Response Type
AMPLIFIER
TORQUE MOTOR
MAIN SPOOL
PILOT SPOOL
LVDT
REDUCING VALVE
PILOT PORT 50

51. LINEAR VARIABLE DIFFERENTIAL TRANSFORMER ( LVDT )
INPUT
SECONDARY COIL
PRIMARY COIL
SECONDARY COIL
MOVEMENT
IRON CORE
OUTPUT 51

52. HYBRID SERIES PROPORTIONAL VALVES
24 V DC Power Supply
Pressure display panel (option)
Power Amplifier
Command Signal Voltage Input
Pressure Sensor Incorporated
Voltage Output for Pr. monitor
Alarm Signal Output
Proportional Electro Hydraulic Relief Valve 52

53. PROPORTIONAL PRESSURE & FLOW CONTROL PISTON PUMP53

54. INSTALLATION REQUIREMENT
Air Vent
SOL
Air Vent
SOL
GOOD EXAMPLE
BAD EXAMPLE
Air Vent
SOL
SOL
Air Vent 54

55. INJECTION MOULDING MACHINES PRESSES SURFACE GRINDING MACHINES
TYPICAL APPLICATIONS
ELEVATORS
ROLLING MILLS
PLANERS
INJECTION MOULDING MACHINES
PRESSES
SURFACE GRINDING MACHINES 55

56. Proportional Direction and Flow Control Valve with LVDT55