5-10t Internal Combustion Counterbalance Forklift Truck Operation & Maintenance Manual
-99-
7.5 Work of Main Safety Valve
(1)The main safety valve is installed between the HP joint and the LP passage of the cylinder. The oil
flowing through the valve core C acts on the two surface A and surface B of different diameters, and
consequently the valve core K of the one-way valve and the valve core D of the main safety valve
both firmly drop into the valve seat (Refer to Fig 7-5.).
(2)When the oil pressure in HP joint of cylinder exceeds the set pressure of the spring force, at this
point, the pilot valve core “E” is opened, the oil flows into the hole through around the valve core,
and then flows into the LP passage (Refer to Fig 7-6).
(3)When the pilot valve core E is opened, the pressure after the valve core C drops, and therefore, the
valve core C will move rightwards, and be seated on the pilot valve core E. As a consequence, the oil
circuit b after the safety valve core D is cut off, and accordingly its internal pressure drops as well
(Refer to Fig 7-7).
(4)Compared with the joint “HP of cylinder, the internal pressure turns to be imbalanced with it, and
as a result, the safety valve core D is opened, thus the oil at the HP side flows directly into the
low-pressure passage “LP” (Refer to Fig 7-8.).
F
ig
7-5
Fig
7-6
Fig 7-7
Fig 7-8
Summary of Contents for FD100T
Page 12: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 12 ...
Page 15: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 15 ...
Page 63: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 63 ...
Page 65: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 65 ...
