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:
Sep. 11, 2012
Filed:
Jul. 20, 2010
Yuichi Takemura, Toyohashi, JP;
Yuichi Takemura, Toyohashi, JP;
Denso Corporation, Kariya, JP;
Abstract
A variable valve timing control apparatus is provided for an internal combustion engine that has a crankshaft, a camshaft, a hydraulic variable valve timing unit, a lock pin, and a hydraulic control valve. The hydraulic control valve is configured to control oil pressure that actuates the variable valve timing unit and the lock pin. The control apparatus switches a control, based on an operational state, between (a) a variable cam timing (VCT) phase control for controlling the VCT phase to a target phase and (b) a lock pin projection control for allowing the lock pin to project. The control apparatus executes, when an abnormality occurs, a foreign object release control for changing a control amount of the hydraulic control valve based on a predetermined pattern, wherein the control apparatus changes the predetermined pattern depending on the abnormality in the execution of the foreign object release control.