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:
Jul. 22, 2003
Filed:
Aug. 15, 2002
Koichi Yoshiki, Saitama-ken, JP;
Tomoya Furukawa, Saitama-ken, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
There is provided a valve timing control system for an internal combustion engine, which is capable of properly controlling valve timing while maintaining the accuracy of degradation determination of an oxygen concentration sensor or an exhaust gas-purifying device. The valve timing control system for an internal combustion engine includes a degradation-determining system that performs degradation determination of at least one of the oxygen concentration sensor and the exhaust gas-purifying device in a state in which the air-fuel ratio of a mixture supplied to the engine is controlled to a predetermined state, and controls valve timing by changing the cam phase. An ECU determines whether or not executing conditions for the degradation determination by the degradation-determining system are satisfied. When it is determined that the executing conditions for the degradation determination are satisfied, a change in setting of the target cam phase, which is to be executed in dependence on operating conditions of the engine, is restricted.