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. 17, 1995
Filed:
Jan. 21, 1994
Tsuyoshi Takizawa, Wako, JP;
Yasunari Seki, Wako, JP;
Yoichi Iwata, Wako, JP;
Toshihiko Sato, Wako, JP;
Takayoshi Nakayama, Tochigi, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A catalyst deterioration-detecting system is provided for an internal combustion engine having an oxygen concentration sensor arranged in an exhaust system downstream of a catalyst provided therein. An electronic control unit (ECU) controls the air-fuel ratio of a mixture supplied to the engine in response to an output from the oxygen concentration sensor. The ECU detects a value of an inversion period with which the output from the oxygen concentration sensor is inverted with respect to a predetermined reference value. Operating parameter sensors detect a value of at least one operating parameter of the engine related to a flow rate of the exhaust gases in the exhaust system. The ECU determines whether the catalyst is deteriorated, based on the detected value of the inversion period and the detected value of the at least one operating parameter. The ECU corrects the value of the inversion period in dependence on the detected value of the at least one operating parameter.