Komatsu Galeo PC800-8 Shop Manual page 267

10 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 hold-
OFF
ing brake
Swing brake ON
Operation of swing holding brake release 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 holding brake release switch can be oper-
ated to cancel the swing lock and allow the swing
to be operated.
a Even when the swing holding brake release
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.
PC800, 850-8
Swing brake
Swing lock
solenoid
monitor
valve
See diagram
OFF
on right
ON De-energized
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. 10
sec; when any swing or work equipment lever is
operated, brake is canceled and swing can be oper-
ated 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 run.
Swing
holding ON
brake (when controller is
release abnormal)
switch
Swing lock
ON
switch
Swing
Swing
lock
brake
applied
SEN00386-03
Actuation
OFF
(when controller is
normal)
OFF ON OFF
Swing
Swing Swing
holding
lock lock
brake
canceled applied
applied
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