A control device (24, 40, 70) is configured to, during acceleration, set a first operation point on a basis of an engine output power and a high torque constraint, set a second operation point on a basis of the engine output power and a high efficiency constraint, set a target operation point so that a target rotation speed of the engine (22) is varied from a first operation rotation speed toward a second operation rotation speed and the engine output power is output from the engine, set a third operation point on a basis of a travel required power and the high efficiency constraint after that, and vary the target rotation speed from the second operation rotation speed toward a third operation rotation speed and set the target operation point so that the engine is operated at the target operation point to operate the engine in accordance with the high efficiency constraint.