| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control system of internal combustion engines which can effectively treat and reduce an oxidized NOx adsorbent in the exhaust emission control system that has a NOx adsorbent therein. <P>SOLUTION: An exhaust emission control system comprises: an emission passage 14 wherein an emission from an internal combustion engine 10 flows; a bypass 20 diverged from the emission passage 14 at the upstream section connecting with the emission passage 14, the bypass 20 converging again with the emission passage 14 at the downstream connecting section below the upstream connecting section; a switching valve 22 switching over an emission flow destination between the emission passage 14 and the bypass 20; a prestage catalyst 16 disposed at the upstream of the upstream connecting section in the emission passage 14; and an NOx adsorbent 24 arranged in the bypass 20 and having a function to adsorb NOx included in the emission, wherein an exhaust air-oil ratio in the internal combustion engine 10 is controlled better than a theoretical air-oil ratio in terms of fuel enrichment when an adsorption capacity degradation due to oxidization of the NOx adsorbent 24 is identified. <P>COPYRIGHT: (C)2009,JPO&INPIT |
