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. 13, 1992
Filed:
Jul. 24, 1991
Hiroaki Nakane, Anjo, JP;
Noriaki Kurita, Nagoya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
According to the present invention, in a system wherein O.sub.2 sensors are disposed on upstream and downstream sides, respectively, of a catalytic converter, and an air-fuel ratio coefficient for the amount of fuel to be injected is determined on the basis of an output of the upstream-side O.sub.2 sensor, the deterioration of the upstream-side O.sub.2 sensor. More particularly, a delay is added to the output of the upstream-side O.sub.2 sensor in accordance with an output signal provided from the downstream-side O.sub.2 sensor, then an air-fuel ratio F/B control is performed in accordance with the delayed output, and when the F/B control period has become longer than a predetermined value, it is judged that the upstream-side O.sub.2 is deteriorated. As a result, not only the deterioration of response characteristic but also the deterioration caused by the Z characteristic center can be detected because it appears as a change of the F/B control period.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile