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:
Aug. 02, 2016
Filed:
May. 21, 2015
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, Aichi-ken, JP;
Kabushiki Kaisha Toyota Jidoshokki, Kariya-shi, Aichi-ken, JP;
Yoshitaka Nakamura, Nagoya, JP;
Satoshi Endo, Kariya, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, Aichi-ken, JP;
Kabushiki Kaisha Toyota Jidoshokki, Kariya-shi, Aichi-ken, JP;
Abstract
The present invention provides an abnormality diagnosis apparatus for an exhaust gas purification apparatus having an SCR catalyst, with which a misdiagnosis of an abnormality in the SCR catalyst even though the SCR catalyst is normal can be suppressed. In the present invention, a NOpurification ratio is determined using an estimated NOinflow amount as a parameter, and an abnormality in the SCR catalyst is diagnosed on the basis of the NOpurification ratio. According to the present invention, a minimum NHadsorption amount is determined as an NHadsorption amount of the SCR catalyst in a condition where an actual NOinflow amount reaches a maximum. When the minimum NHadsorption amount equals or exceeds a predetermined amount, a determination is made as to whether or not a NOpurification ability of the SCR catalyst has deteriorated from a normal condition by comparing the NOpurification ratio with a first threshold. When the minimum NHadsorption amount is smaller than the predetermined amount, a determination is made as to whether or not the NOpurification ability of the SCR catalyst has been completely lost by comparing the NOpurification ratio with a second threshold that is smaller than the first threshold.