Hitachi Automotive Systems, Ltd.

Hitachi, Ltd.

Shigeo Katayama

Yohei Katayama

Umi Tanabe

Takashi Nezu

Takao Nakadate

Hiroyuki Yabe

Hideki Hata

Osamu Yuno

Yusei Kimura

Tomoyuki Ri

Osamu Shioume

Hiroyuki Matsumoto

Yoshie Midorikawa

Motohiro Hirao

An intermediate cylinder is disposed between an outer cylinder and an inner cylinder. The intermediate cylinder forms a passage between the inner cylinder and itself, through which a hydraulic fluid as an electrorheological fluid flows. The intermediate cylinder is supplied (applied) with a voltage through an electrode connector. The intermediate cylinder includes a ring member. The ring member is provided with an extending portion which extends toward the outer cylinder. The extending portion of the ring member is inserted with an electrode pin as an imparting unit for imparting a voltage to the intermediate cylinder.

Cylinder device

A shock absorber includes a reservoir between a cylinder and an outer tube, in which hydraulic liquid and gas are sealed; a middle tube between the cylinder and the outer tube; a connecting pipe in the lateral wall of the middle tube, which includes a tip end extending toward the outside of the outer tube; an opening in the outer tube, allowing hydraulic liquid to flow from the outside of the outer tube into the reservoir through the outer side of the connecting pipe; and a partition member in the reservoir, which includes a partition wall that configured to regulate hydraulic liquid's upward flow from the opening in the reservoir. The partition member is made of flexible resin or rubber, provided with a fitting hole, and fitted to the connecting pipe with interference with the connecting pipe inserted through the hole.

Shock absorber

A shock absorber including a piston inserted into a cylinder () having a hydraulic oil sealed therein. An outer tube () is provided around the outer periphery of the cylinder to form a reservoir () therebetween. A bottomed circular cylindrical casing () is joined to a side surface portion of the outer tube, and a damping force control valve () is housed in the casing. The bottomed circular cylindrical casing has a bottom (A) formed with a joint surface (B) curved along the outer peripheral surface of the outer tube and a flat inner surface (C). The casing is integrally formed by forging.

A damping force adjustable hydraulic shock absorber, in which response delay of a pressure control valve and self-excited vibration of a valve body can be prevented. A damping force is generated by controlling an oil flow between an annular oil passage () and a reservoir () generated by sliding movement of a piston in a cylinder with use of a back-pressure type main valve () and a pressure control valve (). The damping force is directly generated by the pressure control valve, and valve-opening pressure of the main valve is adjusted by adjusting an inner pressure of a back-pressure chamber. In the pressure control valve, a valve spring is disposed between a valve body and a plunger. A mass of the valve body is sufficiently less than that of the plunger, and a spring stiffness of the valve spring is higher than that of a plunger spring.

Damping force adjustable shock absorber

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Yokohama, Japan

Shigeo Katayama