Controller of hybrid construction machine

Abstract

Discharge energy of a rotation motor RM and a boom cylinder BC are used as an assist force for an electric motor MG. An assist motor AM and a sub pump SP driven by output of the electric motor MG are integrally rotated on the discharge side of main pumps MP1, MP2. The assist motor AM is rotated by the discharge energy of the rotation motor RM and the boom cylinder BC, and the driving force of the assist motor AM is used to assist the output of the electric motor MG.

1 . A controller of a hybrid construction machine, comprising:
 a variable displacement type of a main pump;   a regulator for controlling a tilt angle of the main pump;   an actuator activated by fluid discharged from the main pump;   a sensor detecting whether the actuator is activated or not;   a variable displacement type of a sub pump connected to a discharge side of the maim pump, a tilt angle of the sub pump being controlled by a tilt-angle control unit;   an electric motor for rotating the sub pump; and   a control unit for controlling the tilt-angle control unit and the electric motor,   wherein, when the control unit receives an output signal from the sensor and determines that the actuator is activated, the control unit puts the electric motor into operation and operates the tilt-angle control unit to control a tilt angle of the sub pump.   
     
     
         2 . The controller of the hybrid construction machine according to  claim 1 , comprising the electric motor, the sub pump, and a variable displacement type of an assist motor rotating coaxially with the electric motor and the sub pump, wherein the assist motor is activated by discharge energy of the actuator and comprises a tilt-angle control unit for controlling a tile angle, and the control unit controls the tilt-angle control unit to control a tilt angle of the assist motor. 
     
     
         3 . The controller of the hybrid construction machine according to  claim 1 , further comprising:
 a check valve that is provided in a passage connecting the sub pump to the main pump and permits only a flow from the sub pump to the main pump, and   a solenoid valve that is provided in a passage connecting the actuator to the assist motor and is kept in its normal position, which is a close position, by a spring force of a spring,   wherein the control unit controls the solenoid valve in accordance with an operation condition of the actuator.   
     
     
         4 . The controller of the hybrid construction machine according to  claim 1 , wherein the main pump is rotated by a driving force of an engine, further comprising
 a generator associated with the engine, and   a battery for accumulating electric power to be supplied to the electric motor, the battery being connected to a battery charger that is connected to the generator and is connectable to an independent power source, such as a household power source, other than the controller.   
     
     
         5 . The controller of the hybrid construction machine according to  claim 2 , further comprising:
 a check valve that is provided in a passage connecting the sub pump to the main pump and permits only a flow from the sub pump to the main pump, and   a solenoid valve that is provided in a passage connecting the actuator to the assist motor and is kept in its normal position, which is a close position, by a spring force of a spring,   wherein the control unit controls the solenoid valve in accordance with an operation condition of the actuator.   
     
     
         6 . The controller of the hybrid construction machine according to  claim 2 , wherein the main pump is rotated by a driving force of an engine, further comprising
 a generator associated with the engine, and   a battery for accumulating electric power to be supplied to the electric motor, the battery being connected to a battery charger that is connected to the generator and is connectable to an independent power source, such as a household power source, other than the controller.   
     
     
         7 . The controller of the hybrid construction machine according to  claim 3 , wherein the main pump is rotated by a driving force of an engine, further comprising
 a generator associated with the engine, and   a battery for accumulating electric power to be supplied to the electric motor, the battery being connected to a battery charger that is connected to the generator and is connectable to an independent power source, such as a household power source, other than the controller.   
     
     
         8 . The controller of the hybrid construction machine according to  claim 4 , wherein the main pump is rotated by a driving force of an engine, further comprising
 a generator associated with the engine, and   a battery for accumulating electric power to be supplied to the electric motor, the battery being connected to a battery charger that is connected to the generator and is connectable to an independent power source, such as a household power source, other than the controller.