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. 11, 2012
Filed:
Feb. 23, 2011
Hiroaki Gotan, Aki-gun, JP;
Yoshiaki Tomita, Hiroshima, JP;
Masashi Naono, Hiroshima, JP;
Tamiharu Nakamura, Higashihiroshima, JP;
Hiroaki Ishida, Hatsukaichi, JP;
Hiroaki Gotan, Aki-gun, JP;
Yoshiaki Tomita, Hiroshima, JP;
Masashi Naono, Hiroshima, JP;
Tamiharu Nakamura, Higashihiroshima, JP;
Hiroaki Ishida, Hatsukaichi, JP;
Mazda Motor Corporation, Hiroshima, JP;
Abstract
A method is provided for purifying exhaust gas from an engine having an exhaust passage with a selective reducing catalyst and an oxidation catalyst upstream of the selective reducing catalyst. The method calculates an amount of NOx that flows into the selective reducing catalyst; sets an amount of an additive agent to be supplied to the selective reducing catalyst based on the calculated amount of NOx; determines a degradation degree of the oxidation catalyst; determines whether a correction to the amount of the additive agent is necessary based on the determined degradation degree of the oxidation catalyst; corrects the amount of the additive agent to be supplied when the correction is necessary; and supplies the additive agent to the selective reducing catalyst in the corrected amount if the amount is determined to be corrected and in the uncorrected amount if the amount is determined not to be corrected.