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:
Apr. 19, 1994
Filed:
Oct. 06, 1992
Yasuhiro Shimizu, Nishikamo, JP;
Nobuyuki Kobayashi, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
A device for determining deterioration of a catalytic converter for an engine equipped with a catalytic converter disposed in the exhaust passage and upstream and downstream air-fuel ratio sensors disposed in the exhaust passage upstream and downstream of the catalytic converter, respectively, wherein the device calculates the area surrounded by the output response curve of the downstream air-fuel ratio sensor and a predetermined reference value line, the device determining whether or not the catalyst is deteriorated in accordance with the area calculated when the output of downstream air-fuel ratio sensor stays on a rich side or lean side air-fuel ratio for more than a predetermined time during feedback control of air-fuel ratio by the output of upstream air-fuel ratio sensor.