TYM T233 HST, Service Manual

Page: 167 / 232

-When the solenoid is switched
「
「 「
「
OFF
」
:
The fluid in the PTO clutch is unloaded to the bank through port P2. Consequently pressure P2
at PTO valve block becomes zero, whereas the pressure at P2 is port A through T2. Then the force
imposed upon the left side of spool P2 overcomes the force imposed upon the right side by spring force.
So that the spool is pushed rightwards to connect port T2 and port A. Therefore no fluid from the
steering valve is branched off to the PTO clutch; that is, all fluid flows to the control valve.
Fig. 9-5 PTO solenoid switch
「
「 「
「
OFF
」
position
(1) Pressure-reducing valve.
This valve is composed of the spool, spring and piston, and the surplus fluid from the steering valve
flows into
the tank and the HST unit by actuating the spool when the fluid pressure exceeds the
regulated pressure at port P2
9-6