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:
Nov. 05, 2002
Filed:
May. 08, 2000
Nobuaki Takaoka, Saitama, JP;
Hiroshi Oono, Saitama, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A proportional oxygen sensor, a three-way catalyst, a binary O sensor, a NOx purification device, and a binary O sensor are positioned in the named order in the exhaust system of an internal combustion engine. A correction coefficient KMON which is set in accordance with the degree of deterioration of a three-way catalyst, is used to correct the timer value tmMON used to measure the time extending from the time at which the output of the O sensor is changed when the air-fuel ratio is increased, until the time at which the output of the O sensor is changed. When the corrected timer value tmMON is smaller than a reference time TNOxREF, it is ascertained that deterioration of the NOx purification device has occurred.