| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve exhaust gas emission control performance by preventing the degradation of a catalyst caused by the temperature rise of exhaust gas in an exhaust emission control device for an internal combustion engine. <P>SOLUTION: Regenerative filters 14, 15 are juxtaposed at an exhaust passage 11 through branch passages 12, 13. Selector valves 19, 20 are mounted to the branch passages 12, 13, while a selective reduction type catalyst 18 is connected through confluence passages 16, 17, and the selective reduction type catalyst 18 is provided with an injection nozzle 27 for supplying urea or ammonia. A control means 35 alternately operates the regenerative filters 14, 15 and changeover-controls the selector valves 19, 20 according to the collected amount of particulate matter, and carries out the regenerating function of the selected regenerative filter. <P>COPYRIGHT: (C)2004,JPO |
