Komatsu PC600LC-7 Manual page 189

STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Swing lock, swing holding brake function
• The swing lock (manual) can be locked at any
desired position, and the swing lock and swing
holding brake (automatic) are interconnected
with the swing, so they prevent any hydraulic drift
after the swing is stopped.
Actuation
Swing lock
Mode
switch
Swing holding
OFF
brake
Swing brake ON
Operation of swing lock prolix switch
• If any abnormality should occur in the controller,
and the swing holding brake is not actuated nor-
mally and the swing cannot be operated, the
swing lock prolix switch can be operated to can-
cel the swing lock and allow the swing to be op-
erated.
a Even when the swing lock prolix switch is turned
ON, the swing lock switch stays ON and the
swing brake is not canceled.
a When the swing brake is canceled, the swing
has only a hydraulic brake operated by the
safety valve, so if the swing is stopped on a
slope, there may be hydraulic drift.
PC600, 600LC-7
Swing lock Swing brake
monitor solenoid valve
See diagram
OFF
on right
ON De-energized
MACHINE CONTROL SYSTEM
a Swing brake solenoid valve
For details of the structure and function, see
SOLENOID VALVE.
a Swing motor
For details of the structure and function, see
SWING MOTOR.
When swing and work equipment levers are placed at
neutral, swing brake is applied after approx. 7 sec;
when any swing or work equipment lever is operated,
brake is canceled and swing can be operated freely.
Swing lock is actuated and swing is held in position.
Even when swing lever is operated, swing lock is not
canceled and swing does not move.
Swing lock ON
prolix (when controller is
switch abnormal)
Swing lock
ON
switch
Swing
Swing
lock
brake
applied
Actuation
OFF
(when controller is
normal)
OFF ON OFF
Swing
Swing Swing
holding
lock lock
brake
canceled applied
applied
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