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:
Oct. 03, 2000
Filed:
Dec. 02, 1996
Nissan Motor Co., Ltd., Kanagawa, JP;
Abstract
In a water-cooled engine comprising a catalyst for purifying exhaust in an exhaust pipe, a catalyst is rendered active at an early stage by arranging an air-fuel ratio of a fuel mixture supplied to the engine to be lean on startup. A catalyst activation water temperature corresponding to full activation of this catalyst is set, and the air-fuel ratio is arranged to be leaner than a theoretical air-fuel ratio during a period from engine startup to when a cooling water temperature reaches the catalyst activation water temperature. After the cooling water temperature reaches the catalyst activation water temperature, the air-fuel ratio is shifted to the stoichiometric air-fuel ratio. In this way, lean control is optimized to activate the catalyst.