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. 30, 1996
Filed:
Jul. 02, 1993
Yukihiro Yamashita, Kariya, JP;
Kenji Ikuta, Rolling Hills Estates, CA (US);
Shigenori Isomura, Kariya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
An air-fuel ratio control system for an internal combustion engine includes two air-fuel ratio sensors, one upstream of a catalytic converter and the other downstream of the catalytic converter. When an output of the downstream air-fuel ratio sensor has been inverted between rich and lean, a target air-fuel ratio is corrected by a skip amount in a direction opposite to that of the inversion. On the other hand, at no inversion, the target air-fuel ratio is corrected by an integral amount in a direction opposite to deviation of the output of the downstream air-fuel ratio sensor. A fuel injection amount is derived based on a differential between the target air-fuel ratio and an output of the upstream air-fuel ratio sensor. An engine operating condition, the output of the downstream air-fuel ratio sensor or a deterioration degree of the catalytic converter may be used to change the skip amount and the integral amount.