Patent ID: 8639404
Filing Date: 2014-01-28
Classification: B60K,B60L,B66C,E02F,Y02T,Y10S

Abstract:
1. A working machine comprising: a running mechanism; an engine configured to generate a hydraulic pressure; an electrical generator configured to assist the engine; a working motor which is driven by an operator's operation; a DC busbar which is connected to the working motor via a first inverter circuit; a storage battery which is connected to the DC busbar via a DC voltage converter and a switch; a control unit which controls the first inverter circuit, the DC voltage converter, and the switch; a second motor; a rotation body which mounts the working motor, the engine, the electrical generator, and the second motor; a boom and an arm which attach to the rotation body; a hydraulic pump configured to be driven by the electrical generator or the engine; and a motor driving circuit which is connected between the second motor and the DC busbar and is controlled by the control unit to drive the second motor, wherein the control unit includes a busbar voltage lowering mode decreasing a voltage of the DC busbar when the operation of the working machine is stopped, and decreases the voltage of the DC busbar in a manner such that the motor driving circuit is operated after the switch enters a disconnection state to consume electricity in the second motor in the busbar voltage lowering mode.