Toyota 7FBEF 15, Service Manual

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(5) As the result of (4) above, differential pressure relations stand as follows when the tilt lever is
operated for forward tilting: C3 pressure > Logic valve left side pressure = Logic valve right side
pressure.
(6) Here, because of the difference in area between a and b of the logic valve, the pressure at the C3
port generates a greater force that pushes the tilt logic valve to the right side in the figure. It opens
the logic valve and the main circuit is connected from the C3 port to the tank port.
(7) The choke valve at the tilt spool prevents abrupt forward tilting caused by a load to the mast
forward tilting side when the tilt lever is operated.
3. Forward tilt operation at key-OFF (key-OFF tilt lock)
Operating the tilt lever to the forward tilting side when the key switch is turned OFF, the tilt spool moves
to the right in the figure. The hydraulic oil at the C3 port is led to the right side of the tilt logic valve, but
it is cut off by the check valve in the solenoid valve ahead because the tilt solenoid valve is OFF.
Therefore, no pressure difference is generated between the C3 port and the right side of the logic
valve. Consequently, the logic valve does not open. Thus the mast does not tilt forward if it is
attempted while the key switch is OFF because the circuit between the C3 port and the tank port is
closed.
C2
C3
a
b
Tilt spool
Part A
Tilt cylinder
Logic valve right side
Check valve
Poppet
Solenoid valve
Tilt logic valve
Tank port
Pump port
Logic valve right
side
C2 C3
Tilt spool
Tilt cylinder
Logic valve right
side
Pump port
Tilt spool constriction
Tank port
Solenoid valve
Logic valve right side
Check valve