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:
Sep. 07, 2010
Filed:
Jul. 21, 2005
Ichiro Tsumagari, Hino, JP;
Ichiro Tsumagari, Hino, JP;
Hino Motors, Ltd., Hino-shi, JP;
Abstract
Enabled is reliable detection of abnormality in a NOemission control system. Disclosed is a method for detecting abnormality in an exhaust emission control device with a reducing agent (urea water) being added to selective reduction catalystincorporated in an exhaust pipeso as to reduce and purify NO. Temperature of the catalyst during an operation period is monitored to record a cumulative time for each of temperature zones. On the basis of the recorded cumulative time for each of the temperature zones, a deterioration coefficient of NOreduction performance is determined for each of the temperature zones. A standard NOreduction ratio predetermined for each of the temperature zones is multiplied by the determined deterioration coefficient for each of the temperature zones to update the standard NOreduction ratio. The updated standard NOreduction ratio is used in a next operation to compare an actually measured NOreduction ratio with the standard NOreduction ratio on the measured temperature zone. It is determined that there is abnormality when deviation of the actually measured NOreduction ratio from the standard NOreduction ratio does not fall within a required range.