| 摘要 |
<P>PROBLEM TO BE SOLVED: To distinguish the deterioration of a selective reduction type NOx catalyst and an abnormality of a reducing agent supply device. <P>SOLUTION: A failure detecting device of an exhaust gas purification device includes: a calculation means that calculates the purification rate of NOx based on the NOx concentration of the selective reduction type NOx catalyst on an upstream side and a downstream side; an adjusting means that adjusts an amount of a reducing agent supplied according to the NOx concentration; and a determination means that determines the reducing agent supply device is out of order if the purification rate of the NOx returns after decreasing once when the NOx concentration entering the NOx catalyst increases in the case that the purification rate of NOx is a value showing the deterioration of the NOx catalyst or the short supply of the reducing agent. <P>COPYRIGHT: (C)2012,JPO&INPIT |
