Series 51 Hydraulic Proportional Controls HZ, HA ... - Sauer-Danfoss

Series 51 Hydraulic Proportional Controls
Service Manual
H1, H2, K1, K2 Controls
Operation Functional Description
The H1, H2, K1, and K2 controls consist of a ported housing mounted on the multiblock.
It contains a solenoid valve and internal porting to direct the external variable signal
pressure through the solenoid valve to the end of the 4-way valve. A threshold spring
and ramp spring(s) act on the opposite end of the 4-way valve.
Solenoid Valve
The solenoid valve (M1) is a 2-position 3-way valve that passes the external signal
pressure to the end of the 4-way valve, or blocks the external signal and drains the end of
the 4-way valve to the motor case. The H1 and K1 solenoid valves have a 12-volt coil with
DIN connector. The H2 and K2 solenoid valves have a 24-volt coil with DIN connector.
The 4-way valve and the solenoid valve are the same for H1, H2, K1, and K2 controls. The
control housings are different between the H1, H2, and the K1, K2 controls. The logic for
the control is:
• If H1 or H2 are energized operation is proportional; if de-energized output is
maximum displacement.
• If K1 or K2 are energized, output is maximum displacement; if de-energized,
operation is proportional.
Refer to page 9-14 for multiblock, PCOR and brake pressure defeat information.
H1, H2 Schematic
PCOR Valve
BPD Spool Shuttle
U7
T5
11009446 • Rev AC • November 2010
U6
XA XB
T4
T6
Multiblock
A
B
M7
Loop Flush
X1
M4 M3
max.
disp.
T2
T1
T3
T7 T8
4-Way Valve
M1
L1
L2
M2
P107 825
M3 (M5)
23