Komatsu Galeo PC800-8 Shop Manual page 213

Hydraulic excavator

Table of Contents

10 Structure, function and maintenance standard

When solenoid is de-energized

When the signal current does not flow from the

PPC lock switch or swing lock switch, solenoid

(3) is de-energized.

For this reason, spool (5) is pushed fully to the

left by spring (6).

As a result, the circuit between ports P and A

closes and the pressurized oil from the control

pump does not flow to the actuator.

At the same time, the pressurized oil from the ac-

tuator flows from port A to port T, and is then

drained to the tank.

When solenoid is energized

When the signal current flows from the PPC lock

switch or swing lock switch to solenoid (3), sole-

noid (3) is energized.

For this reason, spool (5) is pushed to the right

in the direction of the arrow.

As a result, the pressurized oil from the control

pump flows from port P through the inside of

spool (5) to port A, and then flows to the actua-

tor. At the same time, port T is closed, and this

stops the oil from flowing to the tank.

PC800, 850-8

1. Connector

2. Movable core

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