Relief Valve - Kubota BX1860 Workshop Manual

BX1860, BX2360, BX2660, RCK48(P)-18BX, RCK54(P)-23BX, RCK60B-23BX, LA203, LA243, WSM

5. RELIEF VALVE

The implement control system circuit has a relief valve to restrict the maximum pressure in the circuit. The relief
valve is located in the hydraulic control valve assembly.
The relief valve is a guide piston type with damping effect.
Among direct acting relief vales, this type is suited to higher pressure and has large capacity. Furthermore, this
type is free from unstable operation, such as chattering, which occurs often in direct acting relief valves.
As shown in the figure, the guide is attached to the poppet (7) and a valve chamber D.C. (called the damping
chamber) is formed at the top of the guide piston. The inlet of the valve leads to the chamber via a clearance between
the sliding portion of the guide and the seat (6), minimizing valve vibration with the damping effect of the chamber.
5-M7
HYDRAULIC SYSTEM
(1) Hydraulic Pump Gear
(2) Hydraulic Pump Case
(3) Plug
(4) Flow Priority Valve
(5) Relief Valve
(6) Seat
(7) Poppet
EF :EF Port (To 3 Points Hitch
Control Circuit)
PF :PF Port (To Power
Steering, PTO Clutch and
HST Circuit)
D.C.:Damping Chamber
P : Pump Port (Suction)
T : Tank Ports
W1015272
KiSC issued 06, 2009 A