Bridgestone Corporation

Nissan Motor Company Limited

Tatsuro Ishiyama

Toshiyuki Tabata

Michihiro Orikawa

Takeshi Noguchi

Takao Ushijima

Takuya Dan

Hajime Takeguchi

Toshihiko Aihara

A vibration isolating apparatus in which a vibrating body, which is disposed within a pressure-receiving liquid chamber and is connected to a mounting member such that a gap is formed between an inner wall surface of the pressure-receiving liquid chamber and the vibrating body, is disposed. An elongated limiting passage is formed in the vibrating body so as to penetrate therethrough. The limiting passage communicates the pressure-receiving liquid chamber and an auxiliary liquid chamber provided within the mounting member. When there is low-frequency vibration, there is liquid-column resonance of a liquid within the limiting passage. However, because the limiting passage is elongated, the liquid-column resonance of the liquid therein is large, and a high loss factor is obtained. Therefore, the low-frequency vibration is reliably absorbed. When there is high-frequency vibration, there is liquid-column resonance of the liquid in a vicinity of the gap. A dynamic spring constant decreases, and the high-frequency vibration is reliably absorbed.

Vibration isolating apparatus

A liquid-containing type vibration isolating apparatus includes a first restricting passage, which connects a pressure-receiving liquid chamber and a first sub-liquid chamber and which is substantially U-shaped, and a longitudinal second restricting passage, which connects the pressure-receiving liquid chamber and a second sub-liquid chamber and which is provided at a substantially U-shaped inner side of the first restricting passage. The liquid-containing type vibration isolating apparatus can reliably absorb vibration of a wide range of frequencies and requires little space.

Liquid-containing type vibration isolating apparatus

A vibration isolation apparatus comprises an outer cylinder, an inner cylinder, an elastic member disposed between the outer and inner cylinders and deforming when vibration is generated, a main fluid chamber able to expand and contract according to deformation of the elastic member, an auxiliary fluid chamber able to expand and contract according to deformation of a membrane, and a restricted path communicating between the main and auxiliary fluid chambers. The main and auxiliary fluid chambers are communicated with each other around the inner cylinder. The restricted path is disposed at sides in the axial direction of main and auxiliary fluid chambers. Therefore, the restricted paths can be connected to the main and auxiliary fluid chambers at the positions where the fluid chambers are separated farthest from each other. As a result, the restricted paths can be extended.

Vibration isolation apparatus

An opening which is formed in a cylindrical outer housing of a bush and which facilitates the draining of superfluous working fluid after an assembly process which is carried out totally immersed in the fluid, and which is reinforced by a bridged portion which extends in the direction in which a force and reaction to that force act and spans the opening so as to resist deformation when the bush is force fitted into an associated bracket.

Fluid filled vibration damping mount with bridge reinforced air chamber

A vibration isolating device has a liquid chamber which is hollow space defined mainly by a vibration absorbing main body made of an elastic material containing a natural rubber having a low loss factor and a flexible membrane made of an elastic material containing a heat- and ozone-resistant rubber and in which a liquid is charged, the liquid chamber being divided into liquid sub-chambers which communicate through a passage. The vibration absorbing main body in which an inner cylinder is inserted and the flexible membrane are attached by vulcanizing to an intermediate cylindrical case. A metallic cylinder in which the aforementioned passage is formed and the intermediate cylindrical ase are press fitted in an outer cylinder. The passage exctends from the outer circumference of the intermediate cylindrical case to the outer cylinder.

Vibration isolating device, and method for manufacturing same

An anti-vibration bush comprises: an outer casing adapted to be mounted on either a vibration generating member or a vibration receiving member; a shaft disposed in the outer casing and adapted to be mounted on the other member; and an elastic member disposed between the outer casing and the shaft and having a plurality of small liquid chambers filled with electrorheologic fluid. Electrodes for electrically activating the electrorheologic fluid are provided in a restricted path which permits the small liquid chambers to be in communication with each other. The electrical activation of the electrodes causes the fluid's viscosity to vary, so that the resistance to flow of the fluid passing through the restricted path is changed.

Electrorheological anti-vibration bush

A power unit mount through which a power unit is supported on a vehicle body in a manner to insulate vibration transmission. The power unit mount is comprised of an elastomeric support body fixedly interposed between inner and outer cylindrical members which are connected respectively to the vehicle body and the power unit. The elastomeric support body is formed with a hollow defining a main fluid chamber. An elastomeric diaphragm is provided to define an auxiliary fluid chamber which is communicable with the main fluid chamber through first and second orifice passages which extend along the inner periphery of the outer cylindrical member. Liquid fills the main and auxiliary fluid chambers and the orifice passages. In the first orifice passages, the resonance point of the liquid is tuned to increase the loss factor of the power unit mount in response to relatively low frequency vibration, thereby dampening engine shake. In the second orifice passage, the resonance point of the liquid is tuned to lower the dynamic spring constant of the power unit mount in response to relatively high frequency vibration, thereby dampening idling vibration of the power unit. Additionally, a movable plate arrangement is disposed in the second orifice passage and adapted to close the orifice passage in response to the relatively low frequency vibration, thereby permitting fluid passage through only the first orifice passage during input of the relatively low frequency vibration.

Fluid-filled power unit mount

A bush-type vibration damping device having an inner cylinder and an outer cylinder arranged in such a way that their axes extend in parallel with each other, and an elastic member is interposed between the inner and outer cylinders. A pressure receiving chamber, a first sub-liquid chamber and a second sub-liquid chamber are provided at one side of the inner cylinder. The first sub-liquid chamber has a not smaller resistance to expansion by pressure than the second sub-liquid chamber. The first and second sub-liquid chambers are connected to the pressure receiving liquid chamber through first and second communication passages, respectively. The second communication passage produces a not smaller resistance to flowing liquid than the first communication passage. Vibration of a comparatively low frequency and large amplitude is adsorbed by the flow resistance encountered by a liquid displaced through the second communication passage, while vibration of a comparatively high frequency and small amplitude causes a resonance of the liquid in the first passage so as to limit increase in the dynamic spring constant.

Vibration damping device

The invention provides an improved vibration isolator for use, for example, in an automotive engine mounting. The vibration isolator has a hollow outer cylinder and an inner cylinder disposed in and parallel to the outer cylinder. One of the two cylinders is to be connected with a member that vibrates and the other with another member to be isolated from vibration. An elastic body tightly interposed between the outer and inner cylinders is formed with a hollow so that tensile force may not act on this body. Opposite to the hollow with respect to the inner cylinder the elastic body is formed with radially inner and outer liquid chambers which are connected to each other by a flow restrictive passage. An elastic membrane is attached to the inner surface of the outer cylinder, and a part of the membrane serves as a flexible diaphragm defining the radially outer periphery of the outer liquid chamber. In a region where the elastic membrane is used as the diaphragm, the cylindrical wall of the outer cylinder is formed with an opening to expose the diaphragm to the atmosphere. This vibration isolator can be easily and accurately assembled in the liquid to be filled into the liquid chambers without the need for any extra operation for extracting unneeded liquid from any other space or chamber in the assembled device.

Vibration isolator of bushing type with liquid chambers an elastic body

A vibration insulating device for preventing vibration from being transmitted from an engine to a vehicle body in an automotive vehicle. The vibration insulating device is comprised of an elastic support member bonded between an inner cylinder connected to the engine and an outer cylinder connected to the vehicle body. The elastic support member is formed with a hollow which is located on an upper side of an imaginary horizontal plane containing the axis of the inner cylinder. The hollow functions to prevent a considerable tensile force from being applied to the elastic support member. Two small liquid chambers are formed between a part of the elastic support member and the inner periphery of the outer cylinder, and located on a lower side of the imaginary vertical plane. The two small liquid chambers communicate through an orifice passage. Additionally, one of the two small liquid chambers is adjacent to an air chamber through a flexible diaphragm.

Vibration insulating device

A vibration absorbing apparatus disposed between a vibration source and a vibration receiving portion and having a tubular member which is formed such as to pass through an expandable liquid chamber and which is attached to one of the vibration source and the vibration receiving portion. A partitioning plate is secured to the outer periphery of the tubular member such as to divide the liquid chamber into a plurality of liquid sub-chambers. The liquid sub-chambers communicate with each other via an orifice. Accordingly, even if the direction in which vibration acts upon the apparatus is shifted, it is possible to prevent the occurrence of 'pinch' between the partitioning plate and the tubular member.

Vibration absorbing apparatus

A vibration isolating apparatus is provided with a liquid chamber which is capable of being expanded and contracted for the purpose of absorbing vibrations. The liquid chamber is partitioned into small liquid chambers by a resilient membrane, the chambers being communicated with each other through an orifice. Vibrations are transmitted to the small liquid chambers through a transmission shaft which extends through the resilient membrane and which is slidable relative to the membrane. Accordingly, even when the direction in which vibrations act changes, vibrations applied to one small liquid chamber are reliably transmitted to the other small liquid chamber. Thus, contraction of one small liquid chamber causes the other small liquid chamber to expand, and a liquid is forced to pass through the orifice while generating fluid resistance whereby the vibrations are absorbed.

A vibration isolating apparatus having a support shaft connected to either one of a vibration generating portion and a vibration receiving portion, a base member connected to the other of the two, and a resilient member interposed between the base member and the support shaft and deformable in response to the movement of the support shaft in a direction substantially perpendicular to the axis thereof. A stopper is provided on the side of the support shaft which is remote from a vibration absorbing liquid chamber for limiting the movement of the support shaft. Accordingly, even when a load acts on the support shaft and the base member in a direction in which they are pulled away from each other, the support shaft can reliably be supported by way of the stopper.

A vibration isolating apparatus wherein an inner tube and an outer tube are disposed coaxially or axially parallel with each other, and a pair of liquid chambers are formed in a vibration absorbing resilient member disposed between the inner and outer tubes. The liquid chambers are communicated with each other through a limiting passage. Each of the liquid chambers is divided by a partition having a flow passage, and one wall of each liquid chamber is defined by a flexible membrane which is capable of expanding and contracting the liquid chamber. Accordingly, low-frequency vibrations of relatively large amplitude are damped by virtue of the limiting passage. When high-frequency vibrations of relatively small amplitude occur, the flexible membranes are deformed in response to the rise and fall in internal pressure in the liquid chambers, causing liquid-column resonance to occur at each flow passage, and thus allowing the dynamic scale factor to be lowered.

Growing community of inventors

Yokohama, Japan

Tatsuro Ishiyama