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:
Jan. 18, 1994
Filed:
Dec. 23, 1992
Noriaki Kurita, Nagoya, JP;
Shuji Sakakibara, Okazaki, JP;
Hideki Suzuki, Aichi, JP;
Katsuhiko Kodama, Toyota, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
Disclosed is an apparatus for detecting deterioration of a catalyst of an internal combustion engine having a plurality of cylinder banks in such a manner that the deterioration of the catalyst can be assuredly discriminated regardless of the presence of deviation of a control phase with respect to each cylinder bank. The influence of change of the air/fuel ratio can be eliminated considerably by reducing the air/fuel ratio correction coefficient for a right bank, or by also using the correction coefficient for the left bank as that for the right bank to cause the phases of them to be synchronized with each other, or by dither-controlling the right bank. Therefore, the change of the air/fuel ratio with respect to the left bank can be assuredly detected while necessitating one sub air/fuel ratio sensor. By discriminating the state of deterioration of the catalyst in accordance with results of detections made by the left air/fuel ratio sensor and the sub air/fuel ratio sensors, the deterioration of the catalyst can be assuredly discriminated regardless of the presence of deviation of control phase with respect to the two banks.