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:
May. 25, 2004
Filed:
Jul. 17, 2002
Shinichi Kitajima, Wako, JP;
Asao Ukai, Wako, JP;
Shigetaka Kuroda, Wako, JP;
Futoshi Nishioka, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention provides an air-fuel ratio feedback control apparatus for an internal-combustion engine. The apparatus includes an air-fuel ratio detector that is disposed in an exhaust system of the engine so as to detect an air-fuel ratio of exhaust gas, NOx purifier for purifying NOx contained in the exhaust gas during a lean operation and feedback controller for making a feedback control upon an air-fuel ratio of air-fuel mixture to be supplied to the engine based on an output of the air-fuel ratio detector. A diagnostic system diagnoses the NOx purifier based on an output of an O2 sensor disposed downstream of the NOx purifier when the air-fuel ratio of the air-fuel mixture to be supplied to the engine has been changed from lean to rich and gain changer for making a feedback control gain of the feedback controller smaller when the air-fuel ratio is changed from lean to rich.