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:
Feb. 20, 2007
Filed:
Sep. 20, 2005
Hiroshi Katoh, Yokohama, JP;
Hiroshi Katoh, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
An engine air-fuel ratio control system is configured to use a rich air-fuel ratio immediately after starting an engine such that the air-fuel ratio converge rapidly toward a stoichiometric value and then afterwards start an air-fuel ratio feedback control. Upon determining an air-fuel ratio sensor is active, a stabilization fuel quantity increasing factor that is a component of a target air-fuel ratio revising coefficient is decreased at a higher rate than the rate used before the air-fuel ratio sensor was determined to be active. Air-fuel ratio feedback control is started when the air-fuel ratio corresponds to a stoichiometric air-fuel ratio. After starting air-fuel ratio feedback control, an unburned fuel quantity compensating value is set based on the stabilization fuel quantity increasing factor in effect at that point in time and added to the target air-fuel ratio revising coefficient while, simultaneously, the stabilization fuel quantity increasing factor is set to zero.