2-42
RELIEF VALVE
The relief valves determine the drive force and the brake force for hydraulic shovel swing and are
installed in the main port A and B lines. The circuit is configured to return the relief valve return oil to
the counterpart main low pressure line.
A shockless function is also incorporated to reduce shock produced at the start of both acceleration
and deceleration.
Construction of the relief valve
A direct-acting differential area type relief valve
A shockless piston
The installation of a shockless type relief valve helps reduce shock and stress produced in the
strength members.
3)
Η
Θ
Direct-acting differential area type relief valve
Shockless piston
R35Z72SM05
(1)
Time
Pressure
Conventional type
Time
Pressure
Shocklessl type
Comparison of pressure wave forms
R35Z72SM08
