| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably and effectively recover from sulfur poisoning of a NOx storage catalyst over substantially whole the region of an engine operation without causing excessive temperature rise of the NOx storage catalyst. <P>SOLUTION: The device is equipped with a NOx storage catalyst (40), an HC supply means (52) for supplying HC into exhaust flowing into the NOx storage catalyst (40) and an EGR adjusting means (22) for adjusting an exhaust reflux amount to an intake side of an engine. When an engine is in a prescribed high speed/high load operating region, besides executing the exhaust reflux to the intake side by the EGR adjusting means (22), an S purge of the NOx storage catalyst (40) is performed by supplying HC into exhaust by the HC supply means (52). When an engine is not in a prescribed high speed/high load operating region, on the other hand, besides stopping the exhaust reflux to the intake side by the EGR adjusting means (22), the S purge of the NOx storage catalyst (40) is performed by supplying HC into exhaust by the HC supply means (52). <P>COPYRIGHT: (C)2007,JPO&INPIT |
