| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform a NOx regeneration control or a SOx regeneration control of a NOx trap catalyst in a good manner, without causing excessive deposition of PM in a DPF. <P>SOLUTION: The DPF 14 collecting PM in exhaust flowing therein, and the NOx trap catalyst 13 trapping NOx in the exhaust flowing therein when an exhaust air-fuel ratio is lean and desorbing and cleaning the trapped NOx when the exhaust air-fuel radio is rich, are disposed in an exhaust passage 10 of an engine 1. A PM deposition amount accumulated in the DPF 14 is detected, and a target excess air ratio is adjusted according to the PM deposition amount in the NOx regeneration control or SOx regeneration control of the NOx trap catalyst 13. <P>COPYRIGHT: (C)2010,JPO&INPIT |
