Construction machine with hybrid drive unit, regenerative device equipped in construction machine, and regenerative method
Provided is a method of controlling the regenerating condition by use of a construction machine having an upper revolving structure with a hybrid drive unit, and a lower traveling body, wherein when in a brake mode, the hydraulic motor is neutralized by the internal communication of an inlet port and an outlet port of the hydraulic motor via a communication valve, such that most of the kinetic (inertia) energy is efficiently transduced into electric energy by way of regenerative power generation for electric storage, and such that the switchover between driving and regenerative power generation is rendered in the optimal condition. The control unit determines the control mode of the control unit in accordance with the rotation direction of the hydraulic actuator, the operating direction of the hydraulic actuator controller, the actual rotational velocity of the hydraulic actuator, and the manipulated variable of the hydraulic actuator controller.
1. A construction machine having an upper revolving structure with a plurality of inertia objects each corresponding to each predetermined function, and a lower traveling body, the upper revolving structure comprising:
a hybrid drive unit;
a plurality of hydraulic actuators that drive each of the plurality of inertia objects;
a hydraulic pump that supplies pressure oil to the plurality of hydraulic actuators;
an engine that drives the hydraulic pump;
a controller that enters the operational intention of an operator;
a directional control valve unit that supplies the pressure oil supplied from the hydraulic pump to each of the hydraulic actuators in response to a pressure oil signal generated from the controller;
an electric motor/power generator that drives the upper revolving structure either in cooperation with at least a corresponding one of the plurality of hydraulic actuators or independent of the plurality of hydraulic actuators;
a servo driver that drives the electric motor/power generator;
an electrostatic capacitor that supplies/receives electrical power to/from the servo driver; and
a control unit that directs the generated torque to the servo driver in response to the pressure oil signal generated from the controller, and that switches over the control mode either to the power supply mode or to the regenerative power generation mode to direct the servo driver in accordance with the control mode,
wherein the control unit determines the control mode of the control unit in accordance with the rotation direction of the upper revolving structure, the operating direction of the controller, the actual rotational velocity of the upper revolving structure, and the manipulated variable of the controller.
2. The construction machine as claimed in claim 1 , wherein the control unit further comprises:
a rotation direction detector that is connected to the control unit to detect a rotation direction of the upper revolving structure;
an operating direction detector that is connected to the control unit to detect an operating direction of the controller;
an actual rotational velocity detector that is connected to the control unit to detect an actual rotational velocity of the upper revolving structure; and
a manipulated variable detector that is connected to the control unit to detect a manipulated variable of the controller.
3. A construction machine as claimed in claim 1 , wherein the control mode comprises:
a power supply mode in which power is supplied to the electric motor/power generator such that a torque is generated in the operating direction of the controller;
a regenerative power generation mode in which power supply to the electric motor/power generator is discontinued and in which power is supplied from the electric motor/power generator to the electrostatic capacitor; and
a zero mode in which power supply to the electric motor/power generator is discontinued.
4. A regenerative device that is equipped in a construction machine having an upper revolving structure with a plurality of inertia objects each corresponding to each predetermined function, and a lower traveling body, the upper revolving structure comprising:
a hybrid drive unit;
a plurality of hydraulic actuators that drive each of the plurality of inertia objects;
a hydraulic pump that supplies pressure oil to the plurality of hydraulic actuators;
an engine that drives the hydraulic pump;
a controller that enters the operational intention of an operator;
a directional control valve unit that supplies the pressure oil supplied from the hydraulic pump to each of the hydraulic actuators in response to a pressure oil signal generated from the controller;
an electric motor/power generator that drives the upper revolving structure either in cooperation with at least a corresponding one of the plurality of hydraulic actuators or independent of the plurality of hydraulic actuators;
a servo driver that drives the electric motor/power generator;
an electrostatic capacitor that supplies/receives electrical power to/from the servo driver;
a control unit that directs the generated torque to the servo driver in response to the pressure oil signal generated from the controller, and that switches over the control mode either to the power supply mode or to the regenerative power generation mode to direct the servo driver in accordance with the control mode,
wherein the control unit determines the control mode of the control unit in accordance with the rotation direction of the upper revolving structure, the operating direction of the controller, the actual rotational velocity of the upper revolving structure, and the manipulated variable of the controller.
5. A regenerative method by use of a regenerative device that is equipped in a construction machine having an upper revolving structure with a plurality of inertia objects each corresponding to each predetermined function, and a lower traveling body, the upper revolving structure comprising:
a hybrid drive unit;
a plurality of hydraulic actuators that drive each of the plurality of inertia objects;
a hydraulic pump that supplies pressure oil to the plurality of hydraulic actuators;
an engine that drives the hydraulic pump;
a controller that enters the operational intention of an operator;
a directional control valve unit that supplies the pressure oil supplied from the hydraulic pump to each of the hydraulic actuators in response to a signal generated from the controller;
an electric motor/power generator that drives one of the inertia objects either in cooperation with at least a corresponding one of the plurality of hydraulic actuators or independent of the plurality of hydraulic actuators;
a servo driver that drives the electric motor/power generator;
an electrostatic capacitor that supplies/receives electrical power to/from the servo driver;
a control unit that directs the generated torque to the servo driver in response to the pressure oil signal generated from the controller, and that switches over the control mode either to the power supply mode or to the regenerative power generation mode to direct the servo driver in accordance with the control mode,
wherein the control unit determines the control mode of the control unit in accordance with the rotation direction of the upper revolving structure, the operating direction of the controller, the actual rotational velocity of the upper revolving structure, and the manipulated variable of the controller.