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:
Jan. 30, 2007
Filed:
Feb. 23, 2005
Naoharu Ueda, Tokyo, JP;
Manabu Miura, Zushi, JP;
Naoharu Ueda, Tokyo, JP;
Manabu Miura, Zushi, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
To determine whether an exhaust gas purification catalyst () of an engine () has deteriorated, first deterioration of the catalyst () is determined on the basis of an excess air ratio difference, which is a value expressing a difference in the oxygen concentration on the upstream side and downstream side of the catalyst (). When the catalyst () is determined to have deteriorated on the basis of the excess air ratio difference, the air-fuel ratio of the engine () is feedback-controlled to a stoichiometric air-fuel ratio, and deterioration of the catalyst () is determined again on the basis of a value expressing a difference in the air-fuel ratio variation on the upstream side and downstream side of the catalyst () at that time.