CONSTRUCTION MACHINE AND INDUSTRIAL VEHICLE PROVIDED WITH POWER SUPPLY SYSTEM

[Problem] To recover regenerative energy with high efficiency and control the voltage of a battery or capacitor optimally. [Solution] A construction machine or industrial vehicle having a power supply system which includes a chargeable and dischargeable capacitor and a feeder circuit connecting a chargeable and dischargeable battery and the capacitor to a load capable of power running and regeneration, feeds the energy stored in the capacitor through an inverter to the load and feeds regenerative energy of the load through the inverter to the capacitor, in which the load is an electric motor, the capacitor is connected through a DC/DC converter to the load, the DC/DC converter includes control means that controls the energy charged or discharged by the capacitor through the DC/DC converter; and the control means includes power running/regeneration operation estimating means 19 that estimates an operation pattern including a point of change between power running and regeneration modes of the motor according to the revolution speed and torque of the motor, or DC current supplied to the inverter, or control lever information and previously stored operation pattern information including a point of change between power running and regeneration in repetitive work and capacitor target voltage calculating means 18 that controls an output command value of the DC/DC converter according to the point of change and operation pattern estimated by the power running/regeneration operation estimating means so that a capacitor target voltage gradually decreases in power running and gradually decreases in regeneration.