Yanmar ViO12-2A, Service Manual

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6.
HYDRAULIC SYSTEM
6-
6
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5. Anti-Cavitation Valve
(The anti-cavitation valve is installed on the cylinder rod side of the boom swing section.)
This anti-cavitation valve consists of a body, a piston and a spring. The valve is located between the actuator port P
in the section and the tank port T. It operates as follows :
(1) The pressure oil in the port P flows through the
inside of the piston to the piston chamber, so that it is
filled with oil. The balance is kept with the spring
force in the piston chamber and the oil flow to the
tank passage is being blocked.
(2) When the pressure in the tank passage exceeds that
in the port P, pressing force is applied to the piston.
This creates an opening between the section body
seat and the valve and oil flows from the tank pas-
sage to the port P, so that the space in the port P is
filled with oil.
Spring
Tank passage
Section body seat
Piston
P
(Operating state)