| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress development of SOx poisoning in a NOx catalyst even if SOx slips through a SOx absorbent, in an exhaust emission control device for an internal combustion engine. <P>SOLUTION: This exhaust emission control device for the internal combustion engine includes: the SOx absorbent 5 provided in the exhaust passage of the internal combustion engine 1 and absorbing SOx in exhaust gas; branch passages 31, 32 branched into a plurality of portions in the exhaust passage 3 downstream of the SOx absorbent 5; storage reduction type NOx catalysts 61, 62 respectively provided in the branch passages 31, 32 and occluding NOx in exhaust gas; a switching device 7 switching the branch passages 31, 32 for allowing exhaust gas to flow; an absorption estimation means 10 estimating a SOx absorption as a ratio of the amount of SOx absorbed into the SOx absorbent to the amount of SOx led to flow into the SOx absorbent; and a reduction means 10 reducing the number of the branch passages 31, 32 allowing exhaust gas to flow in comparison with a higher SOx absorption when the SOx absorption estimated by the absorption estimation means 10 is lower than a specified value. <P>COPYRIGHT: (C)2011,JPO&INPIT |
