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:
Jan. 29, 2013
Filed:
Sep. 09, 2009
Yoichiro Goya, Susono, JP;
Keiichiro Aoki, Sunto-gun, JP;
Nao Murase, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A present exhaust purifying apparatus comprises a SCR catalyst, a urea-water injector, and a downstream air-fuel ratio sensor (an oxygen concentration sensor having a diffusion resistance layer) disposed at a position downstream of the SCR catalyst. The present apparatus, when a predetermined condition is satisfied, stops injecting the urea-water from the urea-water injector, and obtains an output value of the downstream air-fuel ratio sensor, as a first output value, in that state. The present apparatus obtains an output value of the downstream air-fuel ratio sensor when the urea-water is being injected from the urea-water injector, as a second output value. The present apparatus obtains a concentration of ammonia which flows out from the SCR catalyst based on the difference between the first output value and the second output value.