| 摘要 |
PROBLEM TO BE SOLVED: To prevent any attack of a rubber-made seal ring by a gate mark formed in an end face of a guide ring in a piston device of a type in which a seal member formed by assembling the rubber-made seal ring and a slide ring with each other is arranged between a piston and a cylinder with the piston being inserted therein, and the resin-made guide ring for regulating the displacement in a radial direction of the piston is arranged on the outer circumference of the piston adjacent to the seal member.SOLUTION: A gate mark G is formed in an end face of a guide ring 19 at the position of a resin introducing gate of an injection mold, and the gate mark G is in an area opposing an end face of a slide ring 18 to be combined with a rubber-made seal ring 17. |
