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:
Dec. 11, 2001
Filed:
Apr. 28, 2000
Kenji Sugiura, Saitama, JP;
Hiroshi Ohno, Saitama, JP;
Masahiro Sakanushi, Saitama, JP;
Keiichi Yagisawa, Saitama, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
When deterioration of a NOx purifying device due to sulfur contamination is detected, a specific operating state flag FHL is set to “1,” and, at intervals equal to or shorter than, for example, three seconds, the air-fuel ratio of an air-fuel mixture to be supplied to an engine is varied so that it is alternately leaner and richer than the stoichiometric air-fuel ratio. When the temperature TCAT of the NOx purifying device exceeds a deterioration recovery temperature STCAT2 while the air-fuel ratio variation control is being executed, the SOx removing flag FHLSOx is set to “1,” and for a period equivalent to the deterioration recovery time TRSOx, the air-fuel ratio is maintained richer than the stoichiometric air-fuel ratio.