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:
Jan. 03, 2006
Filed:
Feb. 26, 2004
Yohei Katayama, Kanagawa-ken, JP;
Hiroyuki Matsumoto, Kanagawa-ken, JP;
Kenichi Nakamura, Kanagawa-ken, JP;
Masaaki Uchiyama, Tokyo, JP;
Yohei Katayama, Kanagawa-ken, JP;
Hiroyuki Matsumoto, Kanagawa-ken, JP;
Kenichi Nakamura, Kanagawa-ken, JP;
Masaaki Uchiyama, Tokyo, JP;
Kabushiki Kaisha Hitachi Seisakusho, Tokyo, JP;
Abstract
In a controllable damping force shock absorber, a piston member connected to a piston rod is disposed in a cylinder in which a magnetic fluid is contained. A disc valve having an extension-stroke pressure-receiving portion and a compression-stroke pressure-receiving portion is provided in the piston member, and a pilot chamber is formed on a rear side of the disc valve. A coil is provided adjacent to passages communicated with the pilot chamber. By energizing the coil, a magnetic field that acts on the magnetic fluid flowing through the passages is generated, changing the viscosity of the magnetic fluid to control a damping force. A valve-opening pressure of the disc valve is controlled according to the pressure in the pilot chamber, such a way that the magnetic fluid exposed to the magnetic field can flow at a low flow rate, thus achieving low power consumption.