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:
Apr. 13, 2004
Filed:
Jul. 24, 2002
Hideaki Kobayashi, Yokohama, JP;
Shigeaki Kakizaki, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A three-way catalyst ( ) is provided in the exhaust passage ( ) of an engine ( ) which stores and releases oxygen according to the oxygen concentration in the exhaust gas. A controller ( ) calculates an oxygen storage amount of the catalyst ( ) by accumulating a variation rate of the oxygen storage amount of the catalyst ( ) based on the oxygen amount in the exhaust gas (S -S ). A target oxygen amount in the exhaust gas is calculated which reduces the difference of the oxygen storage amount from a target oxygen storage amount (S ). A target air/fuel ratio is calculated based on a catalyst deterioration coefficient, an exhaust gas flowrate and the target oxygen amount (S ). Due to this process, it is possible to increase the speed and accuracy of control of the oxygen storage amount of the catalyst ( ) towards the target oxygen storage amount.