| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of torque shock at the time of recovering purifying performance of an exhaust emission control device. SOLUTION: In order to reactivate an NOx catalyst housed in a catalytic converter 22 of an exhaust emission control device, an opening of an exhaust throttle valve 20 is throttled for reducing a flow amount of exhaust gas. Reduction agent is added thereto from an addition nozzle 21. When the state is left, pumping loss is increased by the execution of exhaust throttling, and an output of an engine 1 is reduced. Torque shock may be caused. To cope with it, an opening of an EGR valve 29 is increased so as to obtain an engine output same as that prior to execution of exhaust throttling. In addition, a main fuel injection amount to be supplied to a combustion chamber of the engine 1 is increased. |
