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:
May. 21, 2002
Filed:
Feb. 26, 2001
Akihiko Serizawa, Tochigi, JP;
Masaru Ishiwata, Tochigi, JP;
Showa Corporation, , JP;
Abstract
A hydraulic power steering apparatus for a vehicle is provided with a main control valve in which a valve opening degree is controlled on the basis of a relative movement between an input shaft interlocking with a steering wheel and an output shaft interlocking with a steering mechanism for turning a steered wheel, a power cylinder mechanism generating a steering assist force, a pump apparatus discharging a fixed flow amount of working oil, a first flow passage including a supply passage communicated with the main control valve, and a control unit controlling an assist control valve. The main control valve controls a supply amount of the working oil in the first flow passage to the power steering apparatus, and the assist control valve controlling a flow amount of a part of the working oil discharged from the pump apparatus is controlled to a set valve opening degree set on the basis of a vehicle speed and an oil pressure of the working oil in the first flow passage, by the control unit.