Komatsu PC58UU-3, Руководство по ремонту

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STRUCTURE, FUNCTION AND MAINTENANCE STANDARD ELECTRICAL SYSTEM
PC58UU-3
10-127
12
BOOM END CUSHIONING FUNCTION
•
In the boom up move, this function reduces
speed of the boom before it reaches the
stroke end to lighten resulting impacts and,
thus, to prevent spillage of dirt or dust as well
as lighten load to the machine body and cyl-
inder.
[Operation]
• A cushioning zone is provided before the
boom-up stroke end (approximately 35°).
• This function reduces move speed of the
boom in this zone by reducing output pres-
sure from the boom PPC valve to the boom
operation valve (UP move) at the EPC valve.
• This arrangement helps reducing undesirable
impacts at the stroke end.
ARM END CUSHIONING FUNCTION
•
In the arm retract move, this function reduces
speed of the arm before it reaches the stroke
to lighten resulting impacts and, thus, to pre-
vent spillage of dirt or dust as well as lighten
load to the machine body and cylinder.
[Operation]
• A cushioning zone is provided before the arm
retract stroke end (approximately 20°.
• This function reduces move speed of the arm
in this zone by reducing output pressure from
the arm PPC valve to the arm operation valve
(RETRACT move) at the EPC valve.
• This arrangement helps reduce undesirable
impacts at the stroke end.
SELF-TEST FUNCTION
1. Error code indication and alarm function
• The controller constantly monitors electronic
equipment consisting the system for normal
operation. These components include the
controller itself, potentiometers to generate
input signals, and solenoid valves and EPC
valves to receive output signals.
• If any of the electric equipment fails, the con-
troller diagnoses the symptom and notifies
the results to the operator by displaying a
corresponding error code on the monitor
panel. At the same time, it alerts the operator
attention by flashing the electric system cau-
tion lamp and sounding the alarm buzzer.
• For further information on the display and
remedial actions, refer to the "Checkups and
Adjustment" section
.
2. Error code memory function
• If the advanced system has any trouble, it
executes the self-diagnosis and stores the
error code.
• For further information on the display, reset,
etc., refer to the "Checkups and Adjustment"
section.
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