Komatsu PC88MR-10 Shop Manual page 161

Since the open area of the right and left travel valve spool is large, the differential pressure between pump
discharged pressure (PP1)/(PP2) and LS pressure (PLS1)/(PLS2) is small.
The differential pressure between pump discharged pressure (PP1)/(PP2) and LS pressure (PLS1)/
(PLS2) does not reach the load at installed height of spring (2) (2.45 MPa {25.0 kg/cm
Spring (2) pushes spool (1).
Pump circuits (PP1) and (PP2) are disconnected from tank circuit (T) and all of pump discharged volume
(Q) flows to the actuator circuit.
When only one side operation of travel is performed
Function
On the side of the travel operation being performed, the demand flow corresponding with the travel of the
travel valve spool is supplied to the travel circuit.
On the side of the travel operation being not performed, all of pump discharged volume is drained into the
tank circuit.
Since the merge-divider spool is located at the divide position, pump discharged pressures (PP1) and
(PP2) are divided from each other.
LS pressures (PLS1), (PLS2), and (PLS3) are divided.
The swash plate angle becomes maximum and the discharged volume becomes maximum. (For details,
see "merge-divider valve")
Operation
When left travel operation is performed to maximum and right travel is in HOLD
When L.H. travel valve is operated to the stroke end, LS pressure (PLS1) is generated.
PC88MR-10
10 Structure and function
Control valve
2 }).
10-83