Patent ID: 8667782
Filing Date: 2014-03-11
Classification: F01N,Y02T

Abstract:
1. An exhaust gas purifying apparatus for an internal combustion engine, comprising: a selective reduction catalyst disposed in an exhaust passage of said engine for reducing NOx in exhaust gases from said engine under existence of a reducing agent; reducing-agent supply means for supplying the reducing agent or a reactant for generating the reducing agent to the upstream side of said selective reduction catalyst; reducing-agent slip determining means for determining occurrence of a reducing-agent slip in which the reducing agent is discharged to the downstream side of said selective reduction catalyst; storage amount changing means for temporarily decreasing a storage amount indicative of an amount of the reducing agent stored in said selective reduction catalyst, from the state where the storage amount is at the maximum, and thereafter increasing the storage amount until the occurrence of the reducing-agent slip is detected; and accuracy determining means for determining an accuracy of the reducing agent supply by said reducing agent supply means, according to an occurrence state of the reducing agent slip when said storage amount change means changes the storage amount.