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. 17, 2002
Filed:
Feb. 16, 2001
Applicant:
Inventors:
Hajime Oguma, Zama, JP;
Ritsuo Sato, Yokohama, JP;
Assignee:
Nissan Motor Co., Ltd., Yokohama, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01N 3/00 ;
U.S. Cl.
CPC ...
F01N 3/00 ;
Abstract
A controller controls an air-fuel ratio of an engine to maintain the oxygen storage amount of a catalyst provided in an exhaust passage at a predetermined amount. At this time, the controller first estimates the initial value of the oxygen storage amount based on the catalyst temperature on engine startup, and then computes an oxygen storage characteristic using this estimated initial value. In this way, the oxygen storage amount can be precisely computed even immediately after engine startup, and the conversion efficiency of the catalyst is maintained at a high level.