| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately diagnose the presence or absence of abnormality in a mechanism reversing the upstream and the downstream of a carrier carrying a fine grain oxidation remover. SOLUTION: An exhaust emission control device 50 is provided between the upstream 30u and the downstream 30d of an exhaust passage 30 in an engine 10. This exhaust emission control device 50 is provided with a switching part 51 and a carrier storage part 52. The upstream 30u and the downstream 30d of the exhaust passage 30 and a first and a second passage 52a, 52b of the carrier storage part 52 are respectively selectively connected by a valve 51d of the switching part 51. In this way, the upstream and the downstream of a DPR 60 stored in the carrier storage part 52 are reversed. When a differential pressure of an exhaust pressure detected by a pair of pressure sensors 55, 56 is an initial pressure loss or less which is a differential pressure under a condition with no exhaust gas component accumulated, presence of abnormality in the valve 51b is judged.</p> |
