HYBRID VEHICLE SYSTEM

This system comprises an engine 1, a transmission device 4, a clutch 3 for engaging/disengaging the engine 1 with/from the transmission device 4, a rotational electric device 2, a power transmission mechanism 5 for inputting the rotation of the rotational electric device 2 to the transmission device, and an accumulator element 7 for accumulating electrical power supplied by the rotational electric device 2. A control unit 20 calculates the required driving force of the vehicle, and sets the ratio of output load allotted to the rotational electric device 2 and the ratio of output load allotted to the engine 1 in accordance with the accumulated charge in the accumulator element 7. The control unit 20 further controls the output of the rotational electric device 2 and the engine 1 in such a manner that these respective allotted output loads are achieved, and engages said clutch 3.