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. 07, 2008
Filed:
Dec. 27, 2004
Yuichi Kohara, Toyota, JP;
Takahiro Uchida, Susono, JP;
Yuichi Kohara, Toyota, JP;
Takahiro Uchida, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
To provide an apparatus for evaluating the deterioration condition of a catalyst of an internal combustion engine that can improve the accuracy of an evaluation of the deterioration condition of a catalyst and can suppress a worsening of emissions. The apparatus forcedly sets the air/fuel ratio upstream of a catalyst provided in an exhaust system of an internal combustion engine at a rich condition or a lean condition on the basis of a detected value of a sub Osensor downstream of the catalyst in the internal combustion engine and evaluates the deterioration condition of the catalyst. The air/fuel ratio control is reversed so that the air/fuel ratio upstream of the catalyst becomes a lean condition or a rich condition when 'egasum' has reached a predetermined value Ga, 'egasum' being an integrated value of an admitted air volume (an integration count of the amount of exhaust gas passing through the catalyst) in the period after the sub Osensor outputs a detected value, which shows a rich condition or a lean condition, until the reversing of the output of the sub Osensor.