| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine capable of stably providing the effect of sufficiently elevating the temperature of an NOx catalyst in the exhaust system of the engine while reducing smoke, and optimizing energy efficiency regardless of the operating condition of the engine. SOLUTION: A CPU 80 which controls the overall operating condition of the engine 1 indirectly determines the combustion state of the engine according to the quantity of fuel injection and the engine speed and presets four operating regions related to the combustion state. A control mode, in which a plurality of doubly applicable control items (pilot injection, post injection, low-temperature combustion based on EGR control, and refueling to the exhaust system through a refueling value) are used in combination, is effected as a control mode corresponding to each of the four regions. |
