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. 08, 1989
Filed:
Jan. 12, 1988
Tatsuya Uesugi, Hiroshima, JP;
Eiji Nakai, Hiroshima, JP;
Mazda Motor Corporation, Hiroshima, JP;
Abstract
An oil pressure control apparatus for a valve driving system for an internal combustion engine, in which a main oil supply passage feeds oil to a hydraulic actuator of the engine valve driving apparatus. A control valve is provided for closing the oil supply passage. A bypass oil passage bypasses the control valve continuously. The control valve, when closed, regulates the oil pressure to below a predetermined value and the oil pressure is insufficient to actuate the hydraulic actuator. When the control valve is opened, responsive to an engine operating condition such as engine speed, oil pressure is above the predetermined value, and the hydraulic actuator is actuated rapidly to shift the valve driving system from low speed to high speed operation.