Patent attributes
A self-propelled working machine, which performs work by using power of an internal combustion engine 10 and travels by using power of an electric motor 30, includes a mechanical governor 75 for maintaining the engine at a designated engine rotational speed Nf. A load control mechanism for the working machine has a maximum working output calculator that calculates a maximum working output Qf from the designated engine rotational speed, an actual working load calculator that calculates an actual working load Qr from the designated engine rotational speed Nf and a detected actual engine rotational speed Nr, and a limit speed calculator that calculates a limit speed Vc from the maximum working output Qf and the actual working load Qr. A travel controller operates and controls the electric motor 30 by setting a travel speed V to the limit speed Vc when the actual engine rotational speed Nr is decreased to be lower than the designated engine rotational speed Nf. The travel speed of the working machine is automatically controlled so that the working load is calculated from the driving condition of the internal combustion engine to ensure the working load to be appropriate. Thus excellent finish of the working is maintained and the operator is relieved from burden.
