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. 25, 2010
Filed:
Oct. 30, 2007
Applicant:
Yoshinori Maegawa, Obu, JP;
Inventor:
Yoshinori Maegawa, Obu, JP;
Assignee:
DENSO Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01N 11/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A cylinder deviation of an actual air-fuel ratio before an air-fuel-ratio dither control is obtained based on a variation of an actual air-fuel ratio by the dither control, a variation amount of detected air-fuel ratio, and a cylinder deviation of detected air-fuel ratio before the dither control. A cylinder deviation of actual air-fuel ratio of each cylinder is accurately estimated. When the number of times in which the cylinder deviation of air-fuel ratio exceeds a decision value is greater than a predetermined number, it is determined that an abnormality occurs in the cylinder.