Eagle Industry Co., Ltd.

Advics Co., Ltd.

Nok Corporation

Tatsuhiro Arikawa

Koji Sato

Kuniaki Miyake

Matsuyoshi Yamashita

Yoshiyuki Shimada

Eiji Mizutani

Yuta Okamoto

Takashi Ota

Noriyuki Hosoi

Tomoki Seki

Kenji Sasaki

Shinya Nakaoka

Tomoo Ogura

A fluid circuit includes first switching valve that switches between flow passages and first flow passages according to a change in a fluid pressure to be applied, a second switching valve that is switched to a flow passage which applies the fluid pressure to the first switching valve, when a piston has reached an initial position or an end position, and second flow passages. A biasing force of a biasing member when the piston reaches the end position is smaller than a pressing force acting on the piston due to the fluid pressure caused by a fluid supply device, and a biasing force of the biasing member when the piston reaches the initial position is larger than a sum of a flow passage resistance force acting on the first flow passages and a flow passage resistance force acting on the second flow passages.

Fluid circuit

A first switching valve that switches between flow passages which allow communication between a first pressure-receiving chamber and a fluid supply device side and flow passages which allow communication between a second pressure-receiving chamber and the fluid supply device side, according to a change in a fluid pressure to be applied, and a second switching valve that is switched to flow passages which apply the fluid pressure to the first switching valve, are provided. The second switching valve includes return device, and is provided to be reciprocatable between an operation position to which the second switching valve is moved by a stroke of a piston and a return position to which the second switching valve is moved by the return device. The piston and the second switching valve are movable independently of each other.

Provided is an accumulator for easier maintenance of a metal bellows. The accumulator includes a housing having a shell provided with an opening portion and a disk-shaped base body to which one end of a metal bellows with an outside diameter smaller than the inside diameter of the opening portion is welded and fixed, the interior of the housing partitioned on the inside and outside of the metal bellows in a tightly closed manner, in which the base body is formed to have an outside diameter greater than the outside diameter of the metal bellows, and the base body is fixed detachably to the shell.

Accumulator

Fluid equipment includes a container configured for having first and second fluids therein, a first fluid outlet/inlet path provided for outflow and inflow of the first fluid, a second fluid outlet/inlet path for outflow and inflow of the second fluid, and a member configured for moving in the container in response to pressure of the first fluid, the fluid equipment transmitting energy from the first to the second fluid. A first bellows is configured such that one end is closed in a sealed state by the moving member, the other end is fixed to an inner surface part of the container in a sealed state, and the inside of the first bellows communicates with the first fluid outlet/outlet path.

Fluid equipment

An accumulator a housing having a sealing face and a fluid inlet/outlet passage; a bellows fixed at least one end to the housing such that an inner space of the housing such that an inner space of the housing is hermetically partitioned by the bellows into an interior and an exterior of the bellows, the bellows including a bellows main body capable of expanding and contracting and a bellows cap including an annular seal holder, and a sealing member formed by covering a disc-shaped substrate with an elastic body that is opposed to and capable of being closely attached to the sealing face of the housing. At least a center part of a surface of the substrate opposing the sealing face is a curved surface having an arc shape in a sectional view.

An accumulator includes a housing having a sealing face and a fluid inlet/outlet passage, a bellows fixed at least one end to the housing such that an inner space of the housing is hermetically partitioned by the bellows into an interior and an exterior of the bellows, the bellows including a bellows main body capable of expanding and contracting and a bellows cap including an annular seal holder, and a sealing member formed by covering a disc-shaped substrate with an elastic body that is opposed to and capable of being closely attached to the sealing face of the housing, the sealing member is held by a holding portion of the annular seal holder on an inner diameter side of the annular seal holder, the fluid inlet/outlet passage of the housing being closed upon a close attachment of the elastic body to the sealing face.

The accumulator includes a housing having a sealing face and a fluid inlet/outlet passage; and a bellows fixed at one end to the housing such that an inner space of the housing is hermetically partitioned by the bellows into an interior and an exterior of the bellows. The bellows includes a bellows main body capable of expanding and contracting and a bellows cap provided with a sealing member covered with an elastic body that is opposed to and capable of being closely attached to the sealing face of the housing. The fluid inlet/outlet passage of the housing is closed upon a close attachment of the elastic body to the sealing face. The accumulator further includes a spacer placed between the housing and the bellows cap so as to surround the sealing member. The spacer has a communication passage providing communication between an inside and an outside of the spacer.

An accumulator includes a bellowshaving a plurality of outer ridge portions and a plurality of inner annular ridge portions and configured to be capable of expanding and contracting, and a housing having a fluid supply port and fixed to one end of the bellows serving as a fixed end. An interior of the housing is partitioned in a sealed state into an inside and an outside of the bellows. The outer annular ridge portions are divided into at least a first sector and a second sector which are distributed in an expansion and contraction direction of the bellows such that the second sector is positioned between the first sector and the fixed end. The outer annular ridge portions included in the first sector have an outer diameter smaller than an outer diameter of the outer annular ridge portions included in the second sector.

A seal structure is provided which enables a reduction in the number of components and an improvement of the stability in sliding of the seal portion or the backup ring portion. A sealing structure seals two members which move relative to each other, in which a seal portion or a backup ring portion placed between the two members and a bearing portion similarly placed between the two members are formed into an integral structure. The seal portion or the backup ring portion is integrally provided to one end portion in the axial direction or both end portions in the axial direction of the bearing portion having a cylindrical shape. The seal structure is used as a piston seal or a rod seal in hydraulic and pneumatic devices in which a piston is inserted into a shell or a cylinder tube.

Sealing structure

A bellows excellent in durability has an accordion shape where crest parts with U-shaped cross sections and trough parts with U-shaped cross sections are repeatedly formed via slope parts, the slope parts leading to the crest part includes first portions, second portions, third portions and fourth portions which are continuously connected, in order, to one another from the crest part toward the adjacent trough parts, and in a free length state of the bellows, a separation distance between the second portions of the both slope parts is longer than separation distances between the first portions and between the third portions.

Bellows

An accumulator capable of suppressing collision of a metal bellows with a pressure vessel. A partition unitincludes: a tubular metal bellows, one end of which is side fixed to a pressure vesseland which expands and contracts according to pressure in a fluid chamber and pressure in a gas chamber; and a bellows capwhich is fixed to another end side of the metal bellows, the partition unitfurther including: a seal memberwhich is provided between the bellows capand a portand seals a working fluid on the side of the fluid chamber via the metal bellowswhen the metal bellowscontracts; and a sliding unitwhich is fixed to the bellows capand slides in an expansion/contraction direction of the metal bellowsrelative to a stay

A metal bellows of great durability capable of preventing breakage at both end portions of the metal bellows is provided. The metal bellows is annular-shaped and has, axially repeatedly, a structure in which, from an axial end portion, a belly, a valley, a belly, a peak, and a belly are integrally formed in series sequentially in this order. The end portionhas a first connection bellyconnected to a fitting member, and a connection valleyand a second connection bellyextending sequentially from the first connection bellyaxially inward. The axial width bof the connection valleyin a free state is set larger than the axial width of valleys, . . . or peaks, . . . in a portion other than the end portion

Metal bellows

An accumulator includes a pressure container, a tubular bellows, a bellows cap divisionally defining a liquid chamber and a gas chamber in cooperation with the bellows. A stay provided with a through hole partitions the liquid chamber into a closed liquid chamber on a side of the bellows and an open liquid chamber on a side of the liquid pressure port. The bellows cap includes an elastic abutment part provided with an annular sealing part positioned around the through hole to face the through hole, a buffering part is positioned on a radially inner side of the sealing part, and communication passages always communicating with the through hole are formed in the buffering part of the elastic abutment part.

An accumulator has a pressure vessel, a partition portion comparting an internal space of the pressure vessel into a gas chamber having sealed gaseous matter and a liquid chamber having introduced liquid, and a bellows connected to the partition portion. The partition portion is provided with a bellows connection portion connected to the bellows, a seal arranged in a liquid chamber side of the bellows connection portion, and a seal retention portion fixed to the bellows connection portion and retains the seal. The seal retention portion is constructed by a leaf spring which is elastically deformable in a part thereof, and is structured by integrally forming a fixed portion fixed to the bellows connection portion, and a retention portion retaining the seal. Accordingly, the accumulator can reduce the number of parts of a pressure fluctuation absorbing mechanism, can be easily assembled, and can reduce a parts cost.

An impact on the tips of peaks of a metal bellows on contact is reduced, and deformation of the tips of the peaks even on contact is reduced to a minimum. In a free length state of a metal bellowsin an early stage of incorporation without extension and contraction, valleys each turn around in a U shape in cross section, peaks each turn around in an arc shape in cross section, the peaks are each provided in a position offset with respect to the center of a pitch between valleys adjacent to the peaks on both sides, and of bellies connected to the peaks on both sides, at least bellies located on the offset side are provided with a constriction protruding inward of the metal bellows.

Growing community of inventors

Tokyo, Japan

Tatsuhiro Arikawa