Nissan Motor Company Limited

Bridgestone Corporation

Hitachi, Ltd.

Kinugawa Rubber Ind. Co., Ltd.

Toshiyuki Tabata

Tatsuro Ishiyama

Takao Ushijima

Hajime Takeguchi

Hiroyuki Saito

Mitsuru Nakamura

Mitsuhide Sasaki

Takuya Dan

Noriharu Sato

Shin Takehara

Yoshinari Fujiwara

Norio Yoda

Hiroshi Aikawa

Masaru Takeda

Satoshi Hasegawa

Toshihiko Aihara

An automatic sound suppression system is automatically disengaged whenever noise in an area and generated counter noise deviate in their reverse phase relationship or if the amplitude of the counter noise deviates from that of the noise. The system can also be automatically disengaged whenever divergence prediction means predicts that sounds of the noise and the counter noise diverge or whenever divergence prediction means predict that sounds of the noise and the counter noise are about to diverge. The system can also operate as a vibration reducing apparatus which is also automatically disengaged whenever divergence prediction means predicts that a vibration and a generated countervibration diverge.

Apparatus for reducing noise in a closed space having divergence detector

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

An insulating bushing through which an engine is supported on a vehicle body. The insulating bushing is comprised of a support elastomeric member tightly interposed between inner and outer cylinders. One of the inner and outer cylinders is connected to one of the engine and the vehicle body while the other is connected to the other of the engine and the vehicle body. The support elastomeric member is formed with main and auxiliary fluid chambers which are separate from each other in the peripheral direction. The main and auxiliary fluid chambers are in communication with each other through an orifice passage formed along the inner periphery of the outer cylinder. Additionally, a flange plate is fixedly disposed within main fluid chamber to divide the fluid chamber into two chambers located side by side in the diametrical direction. The flange plate is located in such a manner that the periphery thereof is separate from the inner side wall surface of the main fluid chamber to form therebetween a clearance through which the two chambers are in communication with each other. The orifice passage constitutes a first dynamic damper system for damping low frequency and large amplitude vibrations while the clearance around the periphery of the flange plate constitutes a second dynamic damper system for damping high frequency and small amplitude vibrations.

Fluid-filled insulating bushing

A power unit mount through which a power unit is mounted on a vehicle body. The power unit mount is comprised of an elastic support member securely disposed between inner and outer cylindrical members which are respectively connected to the power unit and the vehicle body. The elastic support member is formed with a hollow a part of which serves as a main fluid chamber. A diaphragm member is secured to the inner peripheral surface of the outer cylindrical member to define an auxiliary fluid chamber which is communicated through an orifice passage to the main fluid chamber. The diaphragm member is disposed separate and independent from the elastic support member, thereby enabling damped vibration frequencies to be tuned within a low frequency region corresponding to engine shake and/or idling vibration, regardless of the rigidity of the elastic support member.

Fluid-filled power unit mount

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.

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 power unit mount includes a housing in which first and second electrode bodies are suspended and which is filled with a fluid which exhibits a change in viscosity when a voltage is applied thereacross. The control of the voltage application is determined by a control circuit which is operatively connected to a plurality of sensors which include an engine speed sensor, a road wheel speed sensor, a relative displacement sensor and an absolute displacement sensor. A variant includes a solenoid powered vibration generator which can be energized under predetermined conditions in a manner to improve vibration attenuation.

Electronically controlled vibration damper for mounting automotive

Disclosed herein is a fluid-filled mounting device which comprises an inner cylindrical member; an outer cylindrical case surrounding the inner cylindrical member; a cylindrical elastomer block disposed between the inner cylindrical member and the outer cylindrical case; a structure defining in the elastomer block a main recess; a structure defining in the elastomer block a deformable chamber at a portion diametrically opposite to the portion where the main recess is defined, the deformable chamber having an outer wall which includes first and second diaphragms, the first diaphragm having a spring constant different from that of the second diaphragm; an annular hollow structure disposed about the elastomer block in a manner to cover the main recess and the first and second diaphragms, thereby to define a main fluid chamber by the main recess, a first auxiliary fluid chamber by the first diaphragm and the annular hollow structure and a second auxiliary fluid chamber by the second diaphragm and the annular hollow structure; a first flow restricting path defined by the annular hollow structure for fluid communication between the main fluid chamber and the first auxiliary fluid chamber; and a second flow restricting path defined by the annular hollow structure for fluid communication between the main fluid chamber and the second auxiliary fluid chamber.

Power unit mounting device

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 fluid-filled power unit mount device consists of a mount rubber securely interposed between two base plates. A partition plate is securely connected to one of the base plate so as to define fluid and auxiliary chambers on the opposite sides thereof. The partition plate is formed with an orifice to provide fluid communication between the fluid and auxiliary chambers, and provided with two parallely arranged movable mechanisms each having a movable member. The movable member is movable under small amplitude high frequency vibration causing booming noise, but restrained from its movement under large amplitude low frequency vibration, thereby effectively damping even vibration which is slightly higher in frequency than the booming noise generating high frequency vibration.

Fluid-filled power unit mount device

A liquid-filled type vibration damping structure consisting of a liquid-filled vibration isolator and a bracket member in which the liquid-filled vibration isolator comprises first and second frames each to be mounted on a vibration source side such as power unit and on a vehicle body side, a resilient member provided between the first and second frames, a baffle member secured on the first frame and dividing the internal space surrounded by the resilient member, a diaphragm and one of the frames into two liquid chambers, said baffle member further having a ring-shaped orifice portion so as to damp a low frequency band vibration through the orifice portion. The liquid-filled vibration isolator further comprises a movable plate placed within an enclosure formed between the baffle member and at least one auxiliary plate having an aperture at the center thereof respectively so as to communicate with the two liquid chamber and to damp a high frequency band vibration, and at least one mass body attached to the resilient member. With this construction, the residual frequency peak of a first vibration transmission characteristic caused by the movable plate according to the prior art can be effectively cancelled by a bottoming frequency of a second vibration transmission characteristic due to the mass body and the resilient member, in accordance with the adjustment of the angle of inclination of the bracket member and the mass body, thereby preventing a booming sound or confined sound inside a vehicle from occuring and obtaining quietness inside the vehicle.

Liquid-filled type vibration damping structure

A structure for supporting a power unit for a vehicle wherein the power unit comprises an engine proper and a transmission housing. The transmission housing is connected with the engine proper in a direction transversely of the vehicle body. The engine proper is supported on one of two longitudinally extending side members on or near a principal axis of inertia of the power unit and the transmission housing is supported on the other of the side members at two points in opposed relation to each other with respect to the axis.

Growing community of inventors

Sagamihara, Japan

Toshiyuki Tabata