| 摘要 |
PURPOSE: To prevent a sealing member from gas leakage resulting from gas permeation and enhance the sealing performance by forming a gas shield layer inside a ring-shaped elastomer to be interposed between two opposing members, and embedding or pinching this gas shield layer in such a condition as across the gas leaking direction. CONSTITUTION: A piston type accumulator is structured so that a sealing member 10 is compressedly interposed between the bottom of a groove 4a formed at the periphery of a piston 4 and the inside surface of a cylindrical shell 1. Thus sealing is generated for a gas chamber 2 in which gas G is encapsulated. The sealing member 10 is accomplished by embedding a gas shield layer 12 formed in a flexible film continuing in the circumferential direction from a metal foil or synthetic resin to shut off the gas permeating inside a ring-shaped elastomer 11 having a circular section across the axis 0 in the non-mounted condition. The synthetic resin film constituting the gas shield layer 12 is formed from polyvinyl alcohol, ethylene vinyl alcohol, etc. |
