Hyundai HL955 Manual page 410

3. STEERING VALVE (EHPS ; Electro Hydraulic Power Steering) 3. STEERING VALVE
1) 1) STRUCTURE STRUCTURE
The main spool in the steering valve (EHPS) can either be activated by the pilot unit or by the joy-
stick selected through the shuttle valves on each end of the main spool.
Joystick steering(opt)
LS EF
7 2 8
1 To tank
2 To emergency system
3 To main control valve
4 From main pump
5 To steering unit P port
6 From steering unit T port
1 6
L CL CR R
T TS
PS
P
3 9 4 10 11 5
13
14
7 From steering unit L port
8 Shock & suction valve (left side)
9 To steering cylinder (left side)
10 To steering cylinder (right side)
11 Shock & suction valve (right side)
12 From steering unit R port
Joystick
Controller
ELECTRONICS
2 4
12
1 3
17
15
18
16
5-6
Joystick steering(opt)
CL CR
Steering
Shock valves
valve
block
Suction valves
Main spool
S3
KV2
KV1
12bar
EF 30bar
Pressure
CF
reducing
valve
P T
EF LS
Hydraulic circuit
75795SE17
13 Relief valve
14 Check valve
15 Main steering spool
16 Pressure reducing valve
17 Metering spool
18 Priority spool
L
R
Ps
Ts