| 摘要 |
A target first air volume is calculated, using a first parameter, for achieving torque demand by way of operation of an intake characteristics variable actuator. Moreover, a target second air volume is calculated, using a second parameter, for achieving torque demand by way of operation of a supercharging characteristics variable actuator. The value of the first parameter changes to a value that reduces the conversion efficiency of the air volume to torque in response to the demand torque decreasing to below or equal to a first reference value. Moreover, the value of the second parameter starts to change so that the conversion efficiency is reduced in response to the torque demand decreasing to below or equal to a second reference value, which is larger than the first reference value, and then gradually changes so that the conversion efficiency is reduced to match the further decrease in the torque demand from the second reference value toward a first reference value. A target air-fuel ratio is set to a first air-fuel ratio while the torque demand is greater than the first reference value, and switches to a second air-fuel ratio that is leaner than the first air-fuel ratio in response to the torque demand dropping to or below the first reference value. |
