Patent ID: 7554213

Claim:
A load control mechanism for a self-propelled working machine that performs work by using power of an internal combustion engine, travels by using power of an electric motor, and includes a governor for maintaining the internal combustion engine at a designated engine rotational speed, wherein: the governor is a mechanical governor that mechanically controls a throttle opening of the internal combustion engine; and the load control mechanism comprises: a maximum working output calculating means that calculates a maximum working output from the designated engine rotational speed; an actual working load calculating means that calculates an actual working load from the designated engine rotational speed and a detected actual engine rotational speed; a limit speed calculating means that calculates a limit speed from the maximum working output and the actual working load; and a travel controller that operates and controls the electric motor by setting a travel speed to the limit speed when the actual engine rotational speed is decreased to be lower than the designated engine rotational speed.