| 摘要 |
A relief valve includes a high-pressure port ( 14 ) communicating to a hydraulic circuit ( 41 ), a low-pressure port ( 15 ) communicating to a drain circuit ( 42 ), a valve ( 11 ) supported so as to be movable in back and forward in the axial direction thereof to open and close between these ports ( 14, 15 ), a piston (12) supported so as to be movable in the coaxial direction in relation to the valve ( 11 ), a spring ( 13 ) interveningly provided between the valve ( 11 ) and the piston ( 12 ) for biasing the valve ( 11 ) to a valve closing direction against the pressure of the high-pressure port ( 14 ), a damping chamber ( 20 ) defined at back side of the piston ( 12 ), pressure guiding paths ( 26, 27 ) for guiding the pressure in the upstream side of the valve ( 11 ) to the damping chamber ( 20 ), and a plurality of orifices ( 30 a to 30 d) exchangeably arranged in series in the pressure guiding paths ( 26, 27 ).
|
