| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a degrading judging apparatus of an exhaust emission control device which is higher in response than an NOx sensor without using an expensive NOx sensor. <P>SOLUTION: The degrading judging apparatus, in which nitrogen oxide is absorbed when air-fuel ratio is lean, and the nitrogen oxide absorbed is reduced when the air-fuel ratio is rich, comprises: an air-fuel ratio detecting means for detecting the air-fuel ratio of exhaust gas supplied to the above-mentioned exhaust emission control device; an estimating means for finding an estimation amount of the nitrogen oxide absorbed by the above-mentioned exhaust emission control device; a temperature detecting means for detecting a temperature of the above-mentioned exhaust emission control device; a calculating means for finding a calorific power of the above-mentioned exhaust emission control device on the basis of the above-mentioned air-fuel ratio when the above-mentioned exhaust gas is rich, and the estimation amount of the above-mentioned nitrogen oxide absorbed; and a judging means for judging a degrading of the above-mentioned exhaust emission control device on the basis of the above-mentioned calorific power found and the above-mentioned temperature detected. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
