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. 09, 2016
Filed:
Mar. 28, 2013
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
Yasushi Watanabe, Kanagawa, JP;
HITACHI AUTOMOTIVE SYSTEMS, LTD., Hitachinaka-Shi, JP;
Abstract
In a variable displacement oil pump employing a return spring for forcing a cam ring in a clockwise direction, and a control chamber configured to displace the cam ring in a counterclockwise direction with a discharge pressure introduced thereto, a pilot valve is provided to selectively switch between an oil-discharge from the control chamber and an oil-introduction to the control chamber by moving a spool in one direction by a biasing force of a valve spring or by moving the spool in the other direction against the biasing force by the discharge pressure and applied at an oil introduction port of the pilot valve. Also provided is an electromagnetic valve configured to variably control timing at which switching between the oil-discharge and the oil-introduction occurs, with respect to the discharge pressure applied at the oil introduction port, by appropriately changing the preload setting of the valve spring.