| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the durability of an NOx absorbent or a particulate filter while effectively utilizing a fuel for releasing SOx or oxidizing and removing particulate matters. <P>SOLUTION: This exhaust emission control device comprises a first exhaust passage 22a and a second exhaust passage 22b branched from the exhaust passage 21 of an internal combustion engine. The NOx absorbent 67 is disposed in each of the exhaust passages 22a, 22b. When SOx must be released from the NOx absorbent 67, a fuel adding period F for adding a fuel from a fuel adding valve 32 and a fuel adding suspension period R are alternately performed repeatedly. In each fuel adding period F, either of a first exhaust control valve 26a and a second exhaust control valve 26b is closed, and kept closed continuously during the fuel adding suspension period R. When a load on the engine becomes larger than a predetermined set value when the first exhaust control valve 26a or the second exhaust control valve 26b is closed, the first exhaust control valve 26a or the second exhaust control valve 26b closed is opened while being delayed. <P>COPYRIGHT: (C)2008,JPO&INPIT |
