Patent attributes
Since a maximum rotation speed is set to a lower value when a supercharging pressure from a supercharger is high than when the supercharging pressure is low, an engine torque is decreased at a relatively low engine rotation speed and the engine rotation speed is less likely to fall into a high-rotation state. Since the maximum rotation speed is set to a relatively high value when the supercharging pressure is relatively low and the engine rotation speed is less likely to fall into a high-rotation state, the engine torque is not decreased at a relatively high engine rotation speed and power performance can be easily secured. Accordingly, it is possible to curb a decrease in power performance due to a decrease in the engine torque and to prevent the engine rotation speed from falling into a high-rotation state.