Komatsu PC20R-8 Shop Manual page 56

TCC VALVE
Function
. When discharge pressure P
area of opening of the control valve becomes lar-
ger, and even if the LS valve tries to increase pump
discharge amount Q, the TCC valve carries out
control to prevent any increase above fixed dis-
charge amount Q to match discharge pressure P
It carries out approximate horsepower control to
prevent the hydraulic horsepower absorbed by
the pump from exceeding the engine horsepower.
. In other words, if the load during operations be-
comes larger and pump discharge pressure P
rises, pump discharge amount Q is reduced; and
if pump discharge pressure P
discharge amount Q is increased.
. The relationship between pump discharge pressure
P and pump discharge amount Q is as shown in
P
the diagram on the right.
10-38
becomes higher, the
P
.
P
P
goes down, pump
P
Pump discharge pressure P
P
RKP01181
PC20R-8 PC27R-8