Komatsu PC500LC-10R Shop Manual page 268

COMPONENT PARTS OF HYDRAULIC SYSTEM
When travel lever is operated
1.
By performing right travel REVERSE (or FORWARD) operation, the pilot pressure from travel PPC valve
pushes spool (7) to the left side (or right side).
2.
Spool (7) pushes piston (3), and orifice (5) closes and cuts off the drain circuit of stroke control signal cham-
ber (a) and travel PPC valve.
3.
By performing right travel REVERSE (or FORWARD) operation, the pilot pressure from travel PPC valve is
sent through orifice (6) of piston (4) to the left end surface of piston (8) to push piston (8) to the right side.
4.
When the arm is moved IN, spool (1) moves to the left.
5.
Maximum stroke of spool is reduced by the moving amount of piston (8) to the right side (st2), and be-
comes (st1).
10-174
10 STRUCTURE AND FUNCTION
PC500LC-10R
AEP21628