| 摘要 |
<P>PROBLEM TO BE SOLVED: To inhibit discharge of a reducing agent into an exhaust-gas passage in an engine without being oxidized. <P>SOLUTION: A circular exhaust pipe 67 extends circularly between inlet and outlet ports 65, 66 respectively of a direction-control valve 61 of a catalytic converter 22. A particulate filter 69 carrying a NOX-catalyst 81 is placed in the exhaust pipe 67. Catalysts 79, 80 having oxidative function are placed respectively in the exhaust pipe 67 between the inlet-outlet port 65 and the particulate filter 69, and the exhaust pipe 67 between the port 66 and the filter 69. A reducing agent-supply valve 77 for supplying the reducing agent to the NOX-catalyst 81 is placed in the exhaust pipe 67 between the port 65 and the catalyst 79. <P>COPYRIGHT: (C)2004,JPO |
