| 摘要 |
<P>PROBLEM TO BE SOLVED: To excellently treat NOx exhausted from an SOx collecting material, when restoring SOx collecting capacity of the SOx collecting material. <P>SOLUTION: This exhaust emission control device has in an engine exhaust passage the SOx collecting material 25 for collecting SOx in exhaust gas, that is, the SOx collecting material for collecting SOx when an inside atmosphere of the SOx collecting material is a lean atmosphere and the temperature of the SOx collecting material is relatively low, and restoring the SOx collecting capacity when the temperature of the SOx collecting material becomes relatively high while maintaining the inside atmosphere of the SOx collecting material in the lean atmosphere; and has in the engine exhaust passage on the downstream side of the SOx collecting material, an NOx catalyst 37 for collecting and holding NOx when the inside atmosphere is the lean atmosphere and reducing and purifying the holding NOx when the inside atmosphere becomes a rich atmosphere. Control for restoring NOx collecting capacity of the NOx catalyst is started before starting control for restoring the SOx collecting capacity of the SOx collecting material when restoring the SOx collecting capacity of the SOx collecting material. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
