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:
Jan. 04, 2005
Filed:
May. 16, 2002
Norio Moteki, Wako, JP;
Kotaro Miyashita, Wako, JP;
Yuichiro Tanabe, Wako, JP;
Mitsuo Hashizume, Wako, JP;
Hiroaki Hasumi, Tochigi, JP;
Norio Moteki, Wako, JP;
Kotaro Miyashita, Wako, JP;
Yuichiro Tanabe, Wako, JP;
Mitsuo Hashizume, Wako, JP;
Hiroaki Hasumi, Tochigi, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An exhaust emission control system for an internal combustion engine is disclosed. The system includes a NOx removing device provided in an exhaust system of the engine for removing NOx contained in exhaust gases, and an oxygen concentration sensor provided in the exhaust system. The air-fuel ratio of the air-fuel mixture to be supplied to the engine is changed from a value which is leaner than the stoichiometric ratio to a value which is richer than the stoichiometric ratio. It is determined whether or not a sulfur oxide concentration in the exhaust gases is high according to a transient characteristic of an oxygen concentration detected by the oxygen concentration sensor after the air-fuel ratio is changed.