Komatsu Galeo BR380JG-1E0 Shop Manual page 97

SEN01351-00
1. LS valve
PA : Pump port
PDP : Drain port
PLP : LS control pressure output port
PLS : LS pressure input port
PP : Pump port
PPL : Control pressure input port
PSIG : LS mode selector pilot port
Function
The LS (load sensing) valve detects the load
q
and controls the discharge amount.
This valve controls pump delivery (Q) according
q
to differential pressure (
called the LS differential pressure (the differ-
ence between pump discharge pressure PP
and control valve outlet port pressure PLS).
Pump discharge pressure (PP), pressure
q
(PLS) (called the LS pressure) coming from
the control valve output, and pressure (PSIG)
(called the LS selector pressure) from the pro-
portional solenoid valve enter this valve.
The relationship between the LS differential
q
pressure between the pump discharge pres-
sure (PP) and LS pressure (PLS) (
(PP) – (PLS)] and pump delivery (Q) changes
as shown in the diagram according to LS
selector current (ISIG) of the LS-EPC valve.
If (ISIG) changes from 0 to 1A, setting force
q
the spring changes, too. As the result, the
specified median of the pump delivery volume
switching point changes as shown in the dia-
gram. It will change in the range of 0.69 to 2.2
MPa {in the range of 7 to 22 kg/cm
10
d
PLS)[= PP – PLS],
d PLS) [=
2
}.
10 Structure, function and maintenance standard
1. Sleeve
2. Piston
3. Spool
4. Spring
5. Sheet
6. Sleeve
7. Plug
8. Locknut
BR380JG-1E0