Komatsu F30791, Shop Manual

Page: 82 / 298

6. Throttling LS introduction of pressure compensation valve
FUNCTION
. In the other actuator is relieved during compound operations, LS introduction throttle b of reducing valve (1) di-
vides the flow and sends more oil to the side receiving compensation.
OPERATION
. If the other actuator (right side) is relieved during
compound operations, each circuit pressure ( P
PA
,
P
A
) of the other actuator becomes the same as
the pump circuit pressure ( P
P
=relief pressure).
. In this case, spring chamber P
LS2
of the other ac-
tuator (right side) becomes the same as pump cir-
cuit pressure P
P
because of the balance of redu-
cing valve (1).
. P
LS2
passes through LS introduction throttle b of
reducing valve (1) and becomes P
LS
. P
LS
is con-
nected to the tank circuit from LS by-pass plug
(4), so pressure loss is generated at LS introduction
throttle b (the condition becomes P
LS
< P
LS2
).
. As a result, even if the other actuator is relieved, a
pressure differential is created between P
P
and
P
LS
, so more oil flows to actuator circuit A on this
side (left side).
10-64
PC20R-8 PC27R-8
W W
RKP00414
P
PA
A
a
P
A
P
LS1
1
P
P
P
LS
P
A
a
P
PA
4
P
LS2
b
1
Side receiving
compensation Side providing
compensation