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. 06, 2009
Filed:
Nov. 07, 2006
Hideki Takubo, Tokyo, JP;
Hideki Takubo, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An air-fuel ratio control device for an internal combustion engine can detect the deteriorated purification state of a catalyst without delay after completion of rich or lean control, and can rapidly restore the purification state. A filter process constant for a downstream Osensor output is set smaller when rich or lean control are performed, thus allowing detection of the deteriorated purification state of the catalyst without delay. After the rich or lean control is completed, a dual Ocontrol system is used to rapidly restore the purification state. Further, the impact of downstream Osensor output variation when the catalyst is deteriorated can be suppressed, and stability of the dual Ocontrol system can be maintained.