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. 23, 2001
Hideaki Kobayashi, Yokohama, JP;
Shigeaki Kakizaki, Yokohama, JP;
Masatomo Kakuyama, Yokohama, JP;
Osamu Matsuno, Ayase, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A catalyst which has oxygen storage performance is installed in an engine exhaust passage an oxygen storage amount is estimated based on the output of an upstream air-fuel ratio sensor installed in the upstream of the catalyst and an air-fuel ratio is controlled so that this oxygen storage amount coincides with a target value. When the output of a downstream air-fuel ratio sensor has become lean or rich for longer than a fixed time, the output of the upstream air-fuel ratio sensor is corrected based on the output of the downstream air-fuel ratio sensor placed in the downstream of the catalyst In this way, the output fluctuation due to deterioration of the air-fuel ratio sensor upstream of the catalyst is corrected, and the catalyst oxygen storage amount is always precisely controlled to the target value.