Hitachi ZW180 Technical Manual page 100

Operational principle, wheel loader
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Lift Arm Kick-Out Control
Purpose: Automatically to locate the lift arm at proper
height when returning the lift arm to the
highest position.
Operation:
1. When lowering the lift arm, the plate is located in
front of the lift arm proximity switch.
When the plate is passing near the lift arm prox-
imity switch, the lift arm proximity switch is turned
ON. Therefore, the kick-out relay and the elec-
tromagnet at the lift arm raise side are excited.
2. When the lift arm control lever is moved farther
than the lift arm raise detent position (position to
pull farther than the raise position), the bucket
control lever is retained by the electromagnet on
the lift arm raise side, and pressure oil from the
pilot valve moves the lift arm spool in the control
valve to the raise side.
3. Pressure oil from the main pump flows to the
bottom side of the lift cylinder through the lift arm
spool in the control valve, and extends the lift arm
cylinder. When the lift arm cylinder is extended,
the plate also passes by the lift arm proximity
switch.
4. When the plate moves apart from the lift arm
proximity switch, the lift arm proximity switch is
turned OFF, and the electromagnet on the lift arm
raise side is also turned OFF. This moves the lift
arm control lever to the neutral position. As the lift
arm spool in the control valve also returns to
neutral, the lift arm cylinder stops. Consequently,
the lift arm stops.
SYSTEM / Control System
T2-1-58

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