2-70
When the push rod(12) is stroked, the spool(11) moves downwards.
Then port P is connected with port(1) and the oil supplied from the pilot pump flows through
port(1) to generate the pressure.
When the pressure at port(1) increases to the value corresponding to the spring force set by tilting
the handle, the hydraulic pressure force balances with the spring force. If the pressure at port(1)
increases higher than the set pressure, port P is disconnected from port(1) and port T is
connected with port(1). If it decreases lower than the set pressure, port P is connected with
port(1) and port T is disconnected from port 1.
In this manner the secondary pressure is kept at the constant value.
Case where handle is tilted
3
T
1
P
11
12
(2)
R35Z72RL04