| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control catalytic device effectively maintaining exhaust gas cleaning performance of a NO<SB>X</SB>trap reduction catalyst, while the NO<SB>X</SB>trap reduction catalyst including NO<SB>X</SB>adsorbent and NH<SB>3</SB>adsorbent is disposed downstream a particulate filter. <P>SOLUTION: In the exhaust emission control catalytic device, an engine exhaust gas passage includes the particulate filter, and an exhaust gas cleaning catalyst which is disposed downstream of the filter and of which the catalyst layers contain the NO<SB>X</SB>adsorbent and NH<SB>3</SB>adsorbent. The exhaust emission control catalytic device includes a catalyst cooling means cooling the exhaust gas cleaning catalyst. When the filter is regenerated or an exhaust gas temperature reaches a predetermined temperature, the catalyst cooling means is driven. The catalyst cooling means is at least any one of: a means for cooling the exhaust gas passage between the filter and the exhaust gas cleaning catalyst and/or a converter housing the exhaust gas cleaning catalyst, by cooling water; and a means for cooling by air supply to the exhaust gas passage. <P>COPYRIGHT: (C)2008,JPO&INPIT |
