| 摘要 |
In a case where liquid pressure of an inflow opening rapidly increases, a pressure liquid of an inflow opening can be released from a state where the liquid pressure is lower than those of conventional cases. In addition, the generation of high surge pressure at the inflow opening can be prevented by starting an increase in liquid pressure of the inflow opening from a state where the liquid pressure is low as above. In a relief valve (R1) configured to adjust relief pressure in such a manner that: a plunger (3) configured to be pushed forward by an elastic member to block communication between an inflow opening (2a) and an outflow opening (1a) moves rearward by an increase in pressure of the inflow opening (2a) against an elastic force of the elastic member to cause the inflow opening (2a) and the outflow opening (1a) to communicate with each other; and a piston (4) configured to push a rear end of the elastic member forward moves forward by the increase in the pressure of the inflow opening (1a) to compress the elastic member, the elastic member includes a first elastic member (5a) and a second elastic member (5b) arranged in series, and the second elastic member (5b) has a smaller elastic constant than the first elastic member (5a). |
