| 摘要 |
The present invention is provided with: an NOx reduction catalyst 32; an MAF sensor 40; an SOx purge control unit 60 that combines air system control wherein intake air amount is feedback controlled on the basis of a target intake air amount and injection system control wherein a target injection increase amount is set on the basis of the target intake air amount and wherein fuel injection amount is feedback controlled on the basis of the target injection increase amount; an SOx purge prohibition processing unit 53 that prohibits SOx purge control; and a heat retention mode control unit 55 that, while SOx purge control is prohibited, performs open loop control on the air system, controls fuel injection amount, and maintains exhaust at a prescribed temperature. When starting SOx purge control after heat retention mode control has ended, the SOx purge control unit 60 switches the target intake air amount to an actual intake air amount and executes injection system control. |
