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:
May. 12, 1998
Filed:
Mar. 06, 1996
Yuki Nakajima, Yokosuka, JP;
Mikio Matsumoto, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
In an engine provided with a catalytic converter in an exhaust passage, the degree of deterioration of the catalyst in the converter is determined. Sensors detecting whether the air-fuel mixture supplied to the engine is rich or lean, are installed upstream and downstream of the converter, and an air-fuel ratio is feedback controlled based on the signal output from the upstream sensor. The soundness of the catalyst is assessed based on a difference between a change-over time of the upstream sensor and a change-over time of the downstream sensor, and a distinction is made between full catalyst deterioration and medium catalyst deterioration by introducing a dispersion value in the assessment process.