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. 27, 2003
Filed:
Feb. 21, 2001
Hajime Oguma, Zama, JP;
Takeshi Nakamura, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A controller computes an oxygen storage amount of a catalyst based on the characteristics of an exhaust flowing into the catalyst, and controls the air-fuel ratio of an engine so that the oxygen storage amount of the catalyst is a target value. When it is determined that the engine starts from the warmed-up state when the engine starts, the air-fuel ratio of the engine is controlled to rich until the exhaust flowing out of the catalyst becomes rich. In this way, all the oxygen stored by the catalyst is first released, the NOx purification performance of the catalyst is maintained, and the NOx release amount immediately after engine startup is suppressed.