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:
Dec. 21, 1999
Filed:
Aug. 11, 1997
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
The present invention aims to provide a fluid pressure control apparatus which allows the gradient of pressure increase to be adjusted finely without using any accumulator. The fluid pressure control apparatus of the present invention includes a hydraulic pump driven by a drive motor and a wheel brake. A first orifice is provided in a passage portion on the side of an outlet of the hydraulic pump. Another passage portion on the side of an inlet of the hydraulic pump is connected to the passage portion between the first orifice and the hydraulic pump through a return passage. A switching valve and a second orifice are connected in series along the return passage. The pressure increase gradient can be set to a small value by changing the amount of fluid flowing into the wheel brake. This is effected, for example, by changing the ratio of the fluid passage area of the first orifice to that of the second orifice, the operational speed of the hydraulic pump, or the duty ratio of the switching valve.