| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an engine control device capable of performing the transfer of an engine operation mode from a low NOx mode to a high NOx mode further properly.SOLUTION: On condition that the catalyst temperature of a NOx reduction catalyst device 27 becomes equal to or higher than an activity determination value, an electronic control unit 50 shifts the engine operation mode from a low NOx mode, in which the NOx generation quantity of the engine becomes less, to a high NOx mode, in which the NOx generation quantity becomes more. On the basis of the detection results of the vehicle speed and the ambient temperature, moreover, the electronic control unit 50 sets that activity determination value at a higher value, if the vehicle speed is high or if the ambient temperature is low.</p> |
