POWER CONTROL DEVICE AND CONSTRUCTION MACHINE WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a power control device in which cost reduction and downsizing of a regenerative motor and a dynamo can be achieved, and to provide a construction machine with the power control device.SOLUTION: A power control device 5 includes: a controller 25 that controls a none-regenerative side control valve 20 in such a way that when the flow rate of return oil from a boom cylinder 9 exceeds the allowable flow rate preset in a regenerative motor 18, excess hydraulic fluid is allowed to flow through a none-regenerative oil passage R4; and a regenerative side control valve 19 provided in a regenerative oil passage R3 and for controlling the pressure of the hydraulic fluid in the regenerative oil passage R3. The controller 25 controls the regenerative side control valve 19 in such a way that when a virtual torque for driving a dynamo 21 at the target speed specified by the flow rate of the hydraulic fluid passing through the regenerative motor 18 exceeds the allowable torque preset in the dynamo 21, the differential pressure between the upstream and the downstream of the regenerative motor 18 is reduced to be small so as to reduce the virtual torque to the allowable torque or less.