| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a sheet surface from being scratched even when pistons are vertically stacked.SOLUTION: In an annular piston 1, disc-shaped leaf valves 7 are stacked at one side, and the piston 1 includes a seat surface 19 formed at one side for making the leaf valves 7 seat thereon, and a leg portion 10b vertically disposed in the circumferential direction at an outer peripheral part at the other side. A supporting portion 20 is circumferentially disposed at an outer periphery of the sheet surface 19, a hollow 21a is formed at an inner peripheral side of an end portion 21 of the leg portion 10b, and the leg portion 10b is kept into contact with the supporting portion 20 while avoiding the sheet surface 19, when being stacked in the axial direction.</p> |
