Patent ID: 7810522
Filing Date: 2010-10-12
Classification: F15B,F16L

Abstract:
1. An accumulator comprising: an accumulator housing provided with an oil port connected to a pressure piping; and a bellows arranged in an inner portion of said housing to compart an internal space of said housing into a gas chamber in which a high pressure gas is charged and a liquid chamber communicating with a port hole, a fixed end of said bellows being fixed to said oil port so as to set an outer peripheral side of said bellows to the gas chamber and to set an inner peripheral side thereof to the liquid chamber, and an inner surface of said oil port being provided with a seal for closing the liquid chamber at a time of zero-down i.e. when the liquid within the liquid chamber is discharged through the port hole and the seal plate comes into contact with the seal, so as to seal a part of the liquid in said liquid chamber, wherein the accumulator has a pressure difference regulation mechanism for reducing a pressure difference generated at a time when the liquid sealed in said liquid chamber and the charged gas are thermally expanded at a time of zero-down, wherein said regulation mechanism is structured such that a seal plate is arranged in an inner peripheral side of a floating end of said bellows, an elastically deformable thin plate is bonded to a surface at the gas chamber side of said seal plate, an outer peripheral portion of said thin plate is bonded to said floating end of the bellows, said seal plate and said floating end of the bellows are made relatively displaceable in a bellows expanding and contracting direction in a range in which said thin plate is elastically deformed, and a distance in a radial direction from an outer peripheral edge portion of said seal plate to the thin plate bonded portion is set to be larger than a distance in a radial direction from an outer peripheral edge portion of said seal plate to a seal contact portion, i.e. a portion where the seal plate comes into contact with the seal, in a state in which said seal plate comes into contact with said seal at a time of zero-down, and wherein said seal plate is away from said seal in a state in which said seal plate is held to said bellows and the thin plate at a time of a steady operation, said seal plate comes into contact with said seal at a time of zero-down, and said thin plate is elastically deformed to a state in which liquid pressure balances with gas pressure while said seal plate being kept in contact with said seal at a time when said liquid and the charged gas are thermally expanded.