| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the pressure loss buildup of exhaust gas and the incomplete burnout of PMs while securing a high PM trapping percentage. <P>SOLUTION: An outer periphery structural part 15 consisting of a straight cell 14 is provided on the outer peripheral portion of a DPF 1 with a catalyst, and a narrow part 16 having a communication hole whose total opening area is 10-90% of the opening area of the straight cell is formed in the downstream side opening of the straight cell 14. The passage resistance of the outer periphery structural part 15 is increased with the narrow part 16 to permit preferential flow of exhaust gas into the DPF 1 and to secure the PM trapping percentage because the PMs are also trapped in the narrow part 16. The narrow part 16 existing in the straight cell 14 has superior temperature retaining property and easy temperature rise to a combustion temperature and so the trapped PMs are easily burnt and less accumulated. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
