| 摘要 |
PROBLEM TO BE SOLVED: To provide a stable and long-life relief valve in which there is no adhesion of valve means, even in a situation where the relief valve is not actuated for a long period.SOLUTION: Valve means 2 includes a shaft 21 supported so as to be moved in an axial direction in a housing 1 and packing 22 made of an elastic material, which is held on the shaft and includes an annular seal lip of which the diameter is expanded toward a first port 11 side. On an inner peripheral surface of the housing in an area where the seal lip comes in sliding contact, a large-diameter cylinder inner peripheral surface 14, a small-diameter cylinder inner peripheral surface 15 and an inclined plane 16 connecting the large-diameter cylinder inner peripheral surface to the small-diameter cylinder inner peripheral surface are formed. A notch part 17 extended in an axial direction for discharging fluid pressure is formed on the inclined plane 16, the valve means 2 is moved to the second port 12 side by the fluid pressure against spring means 3, and in a stage that the seal lip reaches an area where the notch part is present, the fluid pressure is discharged from the notch part. |
