Maeda MK0003, Service Manual, Page: 107 / 348

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2. When solenoids (SOLs 1 to 8) are excited
The following describes the status when right side solenoid is excited:
Pilot valve (3) on the right is pushed down by push pin (6). Consequently, pilot chamber (b) is connected to pilot
path via filter (8) to supply the pilot pressure.
In this state, left pilot chamber (a) remains connected to the drain path. Thus, the diffrential pressure between
pilot pressure and drain pressure acts on pilot piston (7) to move spool (1) leftward.
With the move of spool (1), central bypass path (e) is closed. On the other hand, pump path (c) and actuator path
(d1) on the right side are connected together, and concurrently, actuator path (d2) and tank path (f) are
connected together, and thus the actuators begin to move.
When the solenoid on the left is excited, a configuration of paths in reverse to the above-mentioned results,
where spool (1) moves rightward, while the actuator moves in the reverse direction.
Demagnetizing the solenoid allows spool (1) to return to the neutral position (the state described under item 1
above) by the force of return spring (2), and the actuator stops when returning to the neutral position.
Left SOL
Right SOL
Actuator
From pump
Pilot pressure
Tank
Oil path when switching the pilot
To drain path
1. Spool
2. Return spring
3. Pilot valve
4. Pilot valve spring
5. Socket
6. Push pin
7. Pilot piston
8. Filter