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. 23, 2003
Filed:
Sep. 25, 2001
Takeshi Nakamura, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A front A/F sensor ( ) which detects an air-fuel ratio of exhaust flowing into a first three-way catalyst ( ), a first rear O sensor ( ) which detects an oxygen concentration of exhaust flowing out of the first three-way catalyst, a second three-way catalyst ( ) interposed downstream of the first three-way catalyst, and a second rear O sensor ( ) which detects an oxygen concentration of the exhaust flowing out of the second three-way catalyst ( ), are provided. During normal running, the oxygen storage amount of the first three-way catalyst ( ) is computed based on the detected air-fuel ratio, and the air-fuel ratio of the engine is controlled based on the computed oxygen storage amount so that the oxygen storage amount of the first three-way catalyst ( ) is a target amount. However, after running at a lean air-fuel ratio due to fuel cut, the air-fuel ratio is controlled based on the oxygen concentration detected by the second rear O sensor ( ) so that the oxygen storage amounts of the catalysts are target values.