Patent ID: 7100312

Claim:
A working machine comprising: a driving part comprised of an engine, a battery, a generator driven by the engine for supplying electrical power to the battery to charge the battery, and an electric motor driven by the generator and the battery; a working part driven by the engine for performing a predetermined work operation; a work ON/OFF switch for switching between a working state and a non-operating state of the working part; a transporting part driven by the electric motor; and a control part for controlling rotation of the electric motor in accordance with a comparison of an actual travel speed of the transporting part and a target travel speed of the transporting part, the control part comprising reference speed setting means for setting the speed of the engine to a reference speed at a time at which the working part is placed in the working state when the ON/OFF switch is switched ON, correction coefficient determining means for determining a correction coefficient corresponding to a present speed of the engine from a correction characteristic having a correction coefficient corresponding to the reference speed as an upper limit value and approaching zero as the speed of the engine decreases, required acceleration determining means for determining a required acceleration of the transporting part in accordance with the actual travel speed of the transporting part, means for obtaining a corrected required acceleration by multiplying the required acceleration by the correction coefficient determined by the correction coefficient determining means, and means for accelerating the speed of the electric motor in accordance with the obtained corrected required acceleration.