| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine capable of sufficiently suppressing NOx slippage quantity at a time of NOx reduction action. <P>SOLUTION: This exhaust emission control device for the internal combustion engine purifying exhaust gas discharged from the internal combustion engine 3 to an exhaust system 5 is provided with NOx trapping material 17 provided in the exhaust system 5 and trapping NOx in exhaust gas, a NOx trapped quantity calculation means calculating quantity of trapped NOx as NOx trapped quantity S_QNOx, a NOx reduction means (an injector 6, a throttle valve 12) reducing NOx when calculated NOx trapped quantity S_QNOx reaches a predetermined value S_QNOxREF, a NOx discharge state estimation means (step 20-23) estimating a discharge state of NOx discharged form the NOx trapping material 17 at a time of execution of NOx reduction, and a NOx reduction control means (step 24) controlling NOx reduction action according to the estimated discharge state of NOx. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
