| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of purifying various components included in the exhaust gas exhausted from a combustion chamber of an internal combustion engine as many as possible at a high purifying rate. <P>SOLUTION: This device is provided with an exhaust passage joining with a common exhaust passage 20 at a downstream side after branching to two exhaust branch passages 19a and 19b, NO<SB>x</SB>catalysts 21a and 21b arranged in the respective exhaust branch passages, a particulate filter 27 arranged in the common exhaust passage on the downstream of a joining part of the exhaust branch passages, and flow rate adjusting valves 25a and 25b for adjusting an amount of the exhaust gas flowing in the respective exhaust branch passages. When an air-fuel ratio of the exhaust gas flowing in the NO<SB>x</SB>catalyst is lean, NO<SB>x</SB>in the exhaust gas is maintained. When the air-fuel ratio of the exhaust gas flowing into is rich, NO<SB>x</SB>maintained is reduced and purified by a reducing agent. Fine particles in the exhaust gas are gathered by a particulate filter and the gathered fine particles are oxidized and removed. <P>COPYRIGHT: (C)2004,JPO |
