Patent ID: 7770599

Claim:
An accumulator comprising: an accumulator housing provided with an oil port connected to a pressure piping; a stay arranged in an inner side of said oil port in said accumulator housing and provided with a liquid inlet-and-outlet in an end surface portion in a top end of a tubular portion of the stay; a bellows arranged in an outer peripheral side of said stay and coupled to said oil port by its fixed end; a bellows cap coupled to a floating end of said bellows; a gasket holder provided on a surface of said bellows cap close to the stay; and a disc-like gasket held in a state of being relatively movable in an expanding and contracting direction of said bellows by said gasket holder, said disc-like gasket having a first surface close to said bellows cap and a second surface close to said stay, wherein a gas chamber is set at an outer peripheral side of said bellows and a liquid chamber is set at an inner peripheral side of said bellows, and wherein said disc-like gasket moves together with the bellows cap at a time of a steady operation, said disc-like gasket moves together with the bellows cap so as to come into contact with said end surface portion of the stay, thereby closing the liquid chamber at a time when the liquid within the liquid chamber is discharged from the oil port, and said bellows cap is movable toward a position where liquid pressure and gas pressure are balanced, while said disc-like gasket keeps in contact with the stay on the basis of a difference of pressure receiving areas in the first and second surfaces of said disc-like gasket, when the liquid sealed in the liquid chamber is thermally expanded at a time when the liquid within the liquid chamber is discharged from the oil port.