Bridgestone Corporation

Nissan Motor Company Limited

Takao Ushijima

Hiroshi Kojima

Takeshi Noguchi

Kazuya Takano

Tatsuro Ishiyama

Toshiyuki Tabata

Naomi Sato

Takuya Dan

Harumichi Yamazaki

Masaru Saotome

Hajime Takeguchi

Takao Okubo

Atsuo Tanaka

Toshihiko Aihara

Tsutomu Nakao

A main liquid chamber communicates with a first auxiliary liquid chamber and a second auxiliary liquid chamber via a first limiting passage and a second limiting passage, respectively. The first and second auxiliary liquid chambers are located adjacent first and second air chambers via first and second diaphragms, respectively. As a solenoid valve is changed over, the second air chamber is made to communicate with the negative pressure of an engine or with the atmospheric pressure. The second liquid chamber is disposed in a hollow cylindrical member. When frequencies of vibrations are below a predetermined frequency, the negative pressure of the engine is transmitted to the second air chamber, causing the second diaphragm to be brought into close contact with and fixed to an inner wall of the second air chamber. As a result, a liquid passing through the first limiting passage absorbs the vibrations. When the frequencies of the vibrations become high, the first limiting passage becomes incapable of absorbing the vibrations, and the atmospheric pressure is imparted to the second air chamber. For this reason, the second diaphragm becomes deformable, so that the liquid passes through the second limiting passage to absorb the vibrations.

Vibration isolator with diaphragm and air chamber in a side wall and

A main liquid chamber communicates with a first auxiliary liquid chamber and a second auxiliary liquid chamber via a first limiting passage and a second limiting passage, respectively. The first and second auxiliary liquid chambers are located adjacent first and second air chambers via first and second diaphragms, respectively. As a solenoid valve is changed over, the second air chamber is made to communicate with the negative pressure of an engine or the with atmospheric pressure. The second liquid chamber is disposed in a hollow cylindrical member. When frequencies of vibrations are below a predetermined frequency, the negative pressure of the engine is transmitted to the second air chamber, causing the second diaphragm to be brought into close contact with and fixed to an inner wall of the second air chamber. As a result, a liquid passing through the first limiting passage absorbs the vibrations. When the frequencies of the vibrations become high, the first limiting passage becomes incapable of absorbing the vibrations, and the atmospheric pressure is imparted to the second air chamber. For this reason, the second diaphragm becomes deformable, so that the liquid passes through the second limiting passage to absorb the vibrations. In addition, a third auxiliary liquid chamber and accompanying third limiting passage can be provided to absorb high-frequency vibrations. The length of this third limiting passage is made shorter than that of the second limiting passage and the resonance of the liquid in the third limiting passage is made higher than that in the second limiting passage.

Vibration isolator with diaphragms in each side wall

Vibration isolator with a diaphragm in a side wall

A vibration isolation apparatus comprises a first auxiliary fluid chamber communicating through a first restricted path with a main fluid chamber and a second auxiliary fluid chamber communicating through a second restricted path with the main fluid chamber. The second restricted path has electrode plates whose power supply condition is controlled by a control unit. Further, an electric viscous fluid is filled in the main fluid chamber, the first and second auxiliary fluid chambers, and the first and second restricted paths. When shake vibration is generated, the electrode plates are energized by the control unit so that none of the electric viscous fluid flows through the second restricted path. The electric viscous fluid causes a resonance of the fluid, and has flow resistance in the first restricted path to absorb the shake vibration. Idle vibration sets the first restricted path in the loading condition to prevent the electric viscous fluid from flowing through the restricted path. On the other hand, the electric viscous fluid flows through the second restricted path so that a resonance of the fluid is caused in the second restricted path to decrease the dynamic spring constant and absorb the idle vibration.

Vibration isolation apparatus

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

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 bushing type vibration insulator, for example, used as a suspension bushing of an automotive vehicle. The vibration insulator consists of an outer cylindrical member connected to one member of the suspension. The outer cylindrical member is connected through an elastomeric member with an inner cylindrical member which is connected to another member of the suspension. The inner and outer cylindrical members share a common central longitudinal axis. Two fluid chambers are formed between the outer cylindrical member and the elastomeric member and filled with a fluid. The fluid chambers are communicable through a communication passage formed through an actuator fixedly secured directly to the outer cylindrical member. The actuator is constructed and arranged to block fluid flow through the communication passage under a predetermined condition, thereby raising the spring constant of the vibration insulator.

Bushing type vibration insulator

A vibration isolating apparatus is interposed between a vibration generating portion and a vibration receiving portion. The apparatus includes a main body which has a portion thereof constituted by a resilient member. The main body is provided with a liquid chamber which is capable of being expanded and contracted. The liquid chamber is divided by a partition member into small liquid chambers which are communicated with each other through an orifice. The orifice is able to absorb low-frequency vibrations but unable to absorb high-frequency vibrations. For this reason, a resilient membrane is provided between the small liquid chambers in such a manner as to suppress the rise in pressure inside the small liquid chambers so that high-frequency vibrations are also absorbed. It is possible to enhance the high-frequency vibration absorbing effect by providing, together with the resilient membrane, an opening means having a cross-sectional opening area which is larger than that of the orifice but smaller than the effective cross-sectional opening area of the resilient membrane.

Vibration isolating apparatus

A vibration insulating device to be installed between two members of a vibration system of an automotive vehicle. The device consists of an annular elastic member disposed between coaxial inner and outer cylindrical members and located coaxial with the outer cylindrical member. The elastic member is formed at its outer peripheral surface with a deep annular groove coaxial with the outer cylindrical member which groove is covered with the outer cylindrical member to define an annular hollow chamber. A generally cylindrical flexible diaphragm member is secured between the outer cylindrical member and the elastic member in such a manner that its central annular section divides the hollow chamber into a radially outward gas chamber and a radially inward liquid chamber, thereby effectively absorbing even high frequency small amplitude vibration transmitted to the device under deformation of the flexible diaphragm member.

Vibration insulating device with flexible diaphragm between radially

A vibration isolating device is disclosed, which comprises a main vibration-absorbing body provided with a hollow chamber containing a vibration-damping liquid, and plural partition members each provided with a restricted passage to divide the hollow chamber into at least three small liquid chambers. In this device, one of the partition members is provided with a restricted passage having a sectional area larger than that of the restricted passage formed in the other remaining partition members.

Vibration isolating devices

A vibration isolating apparatus employed for mounting, for example, the engine of an automobile includes a tube communicated with a hollow chamber which is expanded and contracted by vibrations generated in the engine. The tube is provided therein with a mass member which has a larger density than that of a fluid sealed inside the hollow chamber. The mass member is movable by means of the circulation of the fluid inside the tube. Accordingly, the mass member encourages the occurrence of resonance of the fluid inside the tube, whereby the vibrations are absorbed by means of the air-column resonance.

Growing community of inventors

Chigasaki, Japan

Takao Ushijima