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:
Feb. 07, 2012
Filed:
Apr. 16, 2008
Masashi Gabe, Fujisawa, JP;
Daiji Nagaoka, Fujisawa, JP;
Masashi Gabe, Fujisawa, JP;
Daiji Nagaoka, Fujisawa, JP;
Isuzu Motors Limited, Tokyo, JP;
Abstract
In a NOx purification systemprovided with a NOx occlusion reduction catalystand a control unitwhich executes a NOx regeneration control and a sulfur poisoning regeneration control, a binary λ sensorand a reducing agent concentration sensorfor detecting a concentration of the reducing agent are disposed downstream of the NOx occlusion reduction catalyst. The level of deterioration of the NOx occlusion reduction catalystcaused by sulfur poisoning is estimated on the basis of a time period Ta from a time point Tat which a marked decrease of oxygen concentration is detected by the binary λ sensorto the time point Tat which the marked increase of the oxygen concentration is detected by the reducing agent concentration sensorunder the NOx regeneration control. Accordingly, the sulfur poisoning amount is accurately estimated and by performing the sulfur poisoning regeneration at an appropriate frequency, any excessive sulfur poisoning regeneration can be avoided, thereby preventing deterioration of mileage.