TCM FB-8 Series, Service Manual

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Flow regulator valve operation (3.5-ton trucks)
The oil returning from the lift cylinder flows into the chamber
F , past the chambers E , D , C ,
B , and A , and then back into the control valve.
In this step, the more the oil flows via the hole
C in the piston
⑤
, the greater the pressure
differential across the piston
⑤
becomes to shift the piston
⑤
to the right. Therefore, the hole D
is narrowed by the hole C
so that the quantity of oil flowing through the hole
D is restricted to
reduce the forks lowering speed.
When the forks are raised, the high-pressure oil from the control valve flows through the
chambers A , B , C , D , E , and F to the lift cylinders.
自由流
制御流
Fig. 7.14 Flow Regulator Valve (3.5-ton Trucks)
1. SPRING
2. CASE
3. SPRING
4. BALL
5. PISTON
6. SLEEVE
7. ORIFICE
8. SPRING
9. “O”-RING
10. NIPPLE
Lift cylinder side
Free flow
Regulated
flow
Control valve side
7. HYDRAULIC SYSTEM