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. 08, 2011
Filed:
Apr. 01, 2009
Masahiko Yamaguchi, Kariya, JP;
Masahiko Yamaguchi, Kariya, JP;
Denso Corporation, Kariya, Aichi-Pref., JP;
Abstract
There is provided a dither control means that performs a dither control, which compulsively changes an air-fuel ratio alternately to rich side and to lean side by increasing and decreasing fuel injection quantity of an injector (fuel injection valve) in a stepped manner. A predicted value (ideal A/F value ID), which indicates an ideal change of a detection value of an A/F sensor (oxygen concentration sensor) in a case where the A/F sensor is not degraded, is set as a standard value. Then, an integral of a difference between the detection value of the A/F sensor, which changes in accordance with the dither control, and the standard value is calculated. If a calculated value of the integral is larger than a predetermined value, it is determined that the A/F sensor is degraded.