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. 18, 2001
Filed:
Oct. 15, 1999
Akira Tayama, Kanagawa, JP;
Hirofumi Tsuchida, Kanagawa, JP;
Kazuhiko Kanetoshi, Yokohama, JP;
Keiji Okada, Kanagawa, JP;
Nissan Motor Co., LTD, Yokohama, JP;
Abstract
A catalyst in an exhaust passage for an engine is capable of storing oxygen. A memory stores, as an oxygen storage capacity, an oxygen storage amount at the time of change of the downstream air-fuel ratio on the downstream side of the catalyst from stoichiometric to lean. A processor calculates the current oxygen storage amount accurately in due consideration of a fast oxygen absorbing rate in the case of the downstream air-fuel ratio being stoichiometric, and a slow oxygen absorbing rate in the case of the downstream air-fuel ratio being lean, and controls the air-fuel ratio of the exhaust gas mixture flowing into the catalyst so as to bring the oxygen storage amount in a region under the oxygen storage capacity.