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. 22, 2011
Filed:
Jun. 06, 2008
Kenji Katoh, Suntou-gun, JP;
Kenji Katoh, Suntou-gun, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
An internal combustion engine exhaust gas purification apparatus purifies exhaust gas using a NOx storage-reduction catalyst unit and a NOx selective reduction catalyst unit. The NOx selective reduction catalyst unit is provided downstream of the NOx storage-reduction catalyst unit in an exhaust gas passage. An urea injecting mechanism, for example an injection valve, injects urea into the exhaust gas passage. An urea injection controller prohibits urea injection from the urea injecting mechanism if at least one of the temperatures of the NOx storage-reduction catalyst unit and the NOx selective reduction catalyst unit is equal to or lower than a reference temperature. As such, production of cyanic acid is minimized, and therefore leaks of cyanic acid from the NOx storage-reduction catalyst unit and/or the NOx selective reduction catalyst unit can be suppressed.