| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a remarkably durable DPF (diesel particulate filter) which prevents its dissolution loss or burnout by preventing local occurrence of high temperature therein in the case of removing, by oxidation and combustion, the PM (particulate matter) which is trapped and accumulated on the DPF at an idling operation low in exhaust gas temperature or low load operation. <P>SOLUTION: The DPF 10A, 10B and 10C for trapping PM in the exhaust gas from a diesel engine by using the catalysts 30a to 30d are composed such that the oxidation power of the catalysts 30a to 30d arranged in the filters 10A to 10C lowers stepwise or sequentially from the upstream of filters 10A and 10C toward the downstream thereof or from the outer periphery of filters 10B and 10C toward the center thereof. <P>COPYRIGHT: (C)2003,JPO |
