Honda Motor Co., Ltd.

Yamashita Rubber Kabushiki Kaisha

Yamashita Rubber Co., Ltd.

Jun Saito

Nobuo Kubo

Hiroshi Yanagase

Masatomo Nishizaka

Masashi Furuya

Hisashi Ishimatsu

Tetsu Ogawa

Takahiro Kato

Taiyo Gon

Shigeo Kojima

Keiichi Arakawa

Shunji Nagakura

Yasuharu Akai

A bush () includes a base material () that is disposed at a vehicle body (), an inter ring () that is integrally disposed at the base material (), and a surface layer () that is disposed inside the inter ring (). The inter ring () is arranged along an opening () in such a manner as to surround the opening (). The surface layer () includes an insertion hole () and is integrally formed from a self-adhesive elastic material into a thin wall shape. A stabilized rod () is inserted into the insertion hole ().

Bush

A partition member is provided with an elastic body for absorbing hydraulic pressure fluctuation of the primary liquid chamber and a frame member for supporting an outer circumferential portion of the elastic body while aiming to prevent the rotation of the elastic body. A relief aperture communicating between the primary liquid chamber and the secondary liquid chamber is located on the outer circumferential side in the elastic body supporting region of the frame member. A relief valve for opening and closing the relief aperture is integrally formed on the outer circumferential side of the elastic body. The relief valve is formed of a pair of right and left relief valves. A width across flat sections are formed on a thick-walled outer circumferential section of the elastic body which is located between the right and left relief valves, such as to serve as a detent means.

Liquid sealed vibration isolating device

A liquid sealed vibration isolating device has an elastically movable diaphragm capable of preventing elastic deformation of a relief valve to realize high damping while preventing a cavitation phenomenon. The relief valve is provided in the elastic movable diaphragm arranged in a partition member in order to open and close a leak passage so as to prevent occurrence of the cavitation phenomenon. The relief valve is integrally formed with a fixing portion of the elastic movable diaphragm. There is provided an upwardly open concavity that the relief valve faces. The relief valve is made thicker and provided with an opening and closing adjustment groove at a basal portion of its inclined wall. The opening and closing adjustment groove is formed with a locally thin bending portion functioning as a starting point of bending in an opening and closing operation of the relief valve.

To form a relief valve for preventing the generation of the cavitation phenomenon into a simple and accurately operable structure, there are provided a central thin wall portion and a fixing portion in an elastic diaphragm provided in the partition member to have the fixing portion fixed in position. A relief valve is integrally formed with an outer peripheral portion of the fixing portion. The relief valve is provided with an inclined surface formed on the side of a secondary liquid chamber and a recessed portion opened on the side of a primary liquid chamber and has a difference in rigidity in the circumferential direction. When the primary liquid chamber turns negative pressure, a hydraulic liquid in the secondary liquid chamber opens the relief valve and leaks to the primary liquid chamber so as to prevent the generation of the cavitation phenomenon.

A vibration isolating device includes an insulator for isolating the transmission of an inputted vibration by an elastic deformation. A principal vibration input portion is provided in a central area of a concave curved wall portion formed in the insulator. A thin wall portion and a thick wall portion are formed by relatively varying a thickness of the insulator around the vibration input portion, wherein the concave curved wall portion of the insulator is formed in a substantially circular shape when viewed in a principal vibration inputted direction. The thick wall portion is formed substantially in the shape of a belt of a predetermined width and extends across the concave curved wall portion in the diametrical direction thereof while passing the vibration input portion. A rigid body covering portion for covering a surface of a metallic member of the vibration input portion is provided in the central area of the thick wall portion. A thickness of the rigid body covering portion is at least 1.7 mm.

To block the transmission to a vehicle body side of the vibration due to the cavitation phenomenon occurred in a primary liquid chamber so as to prevent the generation of noises, at the same time, to make the device compact, and to improve the fitting accuracy to obtain the reliable positioning, a first metallic fitting and a second metallic fitting are connected by an insulator. A primary liquid chamber and a secondary liquid chamber formed inwardly are partitioned by a partition member and communicated therebetween by an orifice passage. The partition member is floatingly supported between an extended portion of the insulator and an outer peripheral thick wall portion of a diaphragm, and the tuning is performed to generate the rigid resonance at the predetermined frequency. An outer ring is provided in the outer peripheral thick wall portion so as to be securely fixed by a fixing portion formed by bending an end of an outer cylindrical fitting. The floatingly supporting structure does not become large-sized and complicated since the partition member is simply floatingly supported.

Growing community of inventors

Fujimino, Japan

Jun Saito