Hydraulic system of energy saving type

PURPOSE: An energy saving type hydraulic circuit is provided to minimize energy loss by supplying working oil to a hydraulic cylinder using an electric motor. CONSTITUTION: A hydraulic cylinder(1) is installed in a flow channel of a hydraulic pump and operated with working fluid of the hydraulic pump. The hydraulic pump is driven according to the rotational direction or speed of an electric motor(10). A branch valve(3) is installed in the flow channel between the hydraulic cylinder and the hydraulic pump and converts a spool according to a control signal from the outside. A generator(16) is axis-connected in a hydraulic motor(17). The hydraulic motor is driven by the working fluid. An electronic control unit(12) drives the branch valve or the electric motor by outputting the control signal.