| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology improving purification rate of NOx and HC in an exhaust emission control device for an internal combustion engine. <P>SOLUTION: This device is provided with a fuel adding means adding fuel into exhaust gas, a storage reduction type NOx catalyst reducing stored NOx by fuel added by the fuel adding means. Intake air quantity to the internal combustion engine, fuel supply quantity to the internal combustion engine, target air fuel ratio during NOx reduction and fuel addition quantity added during continuous rich period based on the continuous rich period during which target air fuel ratio continues are calculated, and calculated fuel addition quantity is added dispersingly over the continuous rich period. <P>COPYRIGHT: (C)2007,JPO&INPIT |
