Hitachi ZW180, Technical Manual

Page: 298 / 374

COMPONENT OPERATION / Ride Control Valve
T3-8-4
OPERATION
1. In neutral, port Pi and the ouput port are not
connected via the spool.
2. When the signal from MC (Main Controller) enters
the solenoid, the solenoid is excited.
3. As the solenoid pushes the spool with the force
corresponding to the signal from MC, port Pi and
the output port are connected and pilot pressure
oil pushes the main spool.
4. When the main spool is pushed toward spring 2,
port A (the bottom side of the lift arm cylinder) and
the ride control accumulator are connected, and
port B (the rod side of the lift arm cylinder) and
port T are connected.
5. Therefore, the pushing force of the lift arm
cylinder is absorbed by the accumulator, and the
load generated by the pushing-up force is
absorbed by drawing hydraulic oil from the tank
port.
T4GB-03-08-006
*: Refer to T3-8-1.
Pilot Pressure
Port A
To Ride Control
Accumulator
Port B
Spring 1
Spring 2
Tank Port
Main Spool
Section A
*
Port Pi
Spool
Output Port