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. 26, 2002
Filed:
May. 26, 2000
Toshikatsu Takanohashi, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An object of the invention is to reliably judge if a NO absorbent has deteriorated due to sulfur poisoning, or has heat deteriorated. At the time of executing rich spiking, a sulfur poisoning stoichiometric conversion time threshold value tm: LMT-S deterioration, for judging if a NO absorbent has been sulfur poisoned, and a heat deterioration stoichiometric conversion time threshold value tm: LMT heat deterioration, for judging if the NO absorbent has heat deteriorated to an extent that the NO absorption capacity has been lost, are set in relation to the time (stoichiometric conversion time) taken for an output signal from a second O sensor to change from lean to rich. When a measurement value of the stoichiometric conversion time is shorter than the heat deterioration stoichiometric conversion time threshold value tm: LMT heat deterioration, it is judged that the NO absorbent has completely heat deteriorated, and when this is longer than the heat deterioration stoichiometric conversion time threshold value tm: LMT heat deterioration, and shorter than the sulfur poisoning stoichiometric conversion time threshold value tm: LMT-S deterioration, it is judged that there is sulfur poisoning.