| 摘要 |
PROBLEM TO BE SOLVED: To enable regeneration of a catalyst while preventing degradation of smoke. SOLUTION: In this exhaust emission control device, determining means 73 determines whether this device is in an EGR region or not, and based on this result, control means 74 controls displacement circulated in an EGR region in an air-intake An NOx absorbed amount in an HC fluctuation type catalyst 72 is saturated, fluctuation means 75 fluctuates concentration of HC in exhaust gas flowing in the HC fluctuation type catalyst 72 in the EGR region. When the NOx absorbed amount of λ fluctuation type catalyst 71 reaches saturation, rich means 76 enriches air-fuel ratio of the exhaust gas flowing in the λ fluctuation type catalyst 71 in a region other than the EGR region. |
