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. 12, 2006
Filed:
Sep. 16, 2005
Applicant:
Shigeo Ohkuma, Gunma, JP;
Inventor:
Shigeo Ohkuma, Gunma, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02D 41/14 (2006.01);
U.S. Cl.
CPC ...
Abstract
An air fuel ratio control system includes an exhaust gas sensor to sense an oxygen concentration in an exhaust passage of an internal combustion engine, and a controller. The controller is configured to judge that the exhaust gas sensor is in an active state, by monitoring a decrease of an output of the exhaust gas sensor from a level greater than a first predetermined value, to a level smaller than or equal to the predetermined first predetermined value, and to allow the air fuel ratio control when the exhaust gas sensor is judged to be in the active state.