The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 05, 2014
Filed:
Mar. 31, 2009
Takao Nakadate, Yamato, JP;
Takashi Nezu, Yokohama, JP;
Yohei Katayama, Kawasaki, JP;
Shigeo Katayama, Yokohama, JP;
Hiroyuki Yabe, Kawasaki, JP;
Takao Nakadate, Yamato, JP;
Takashi Nezu, Yokohama, JP;
Yohei Katayama, Kawasaki, JP;
Shigeo Katayama, Yokohama, JP;
Hiroyuki Yabe, Kawasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
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.