| 摘要 |
<P>PROBLEM TO BE SOLVED: To define sulfur deposition quantity on a storage-reduction type NOx catalyst based on fuel consumption quantity of an internal combustion engine and sulfur concentration of fuel, and improve accuracy of catalyst deterioration judgment in catalyst deterioration judgment based on the sulfur deposition quantity. <P>SOLUTION: This exhaust emission control device is provided with a first estimation means estimating sulfur deposition quantity of the NOx catalyst 32 based on quantity of fuel consumed for reduction during rich purge control, and a second estimation means estimating sulfur deposition quantity of the NOx catalyst 32 based on fuel consumption quantity of the internal combustion engine 1 and sulfur concentration of fuel, and corrects sulfur deposition quantity estimated by the second estimation means based on accurate sulfur deposition quantity estimated by the first estimation means. <P>COPYRIGHT: (C)2008,JPO&INPIT |
