JP5178666B2 - Hybrid drilling machine - Google Patents

Description

  The present invention relates to a hybrid excavating machine that drives a drive system using power generated by an engine and stored electrical energy.

  In a construction machine such as a hydraulic excavator, regenerative power generated when the upper swing body is turned and decelerated and regenerative power generated when the boom is lowered are stored in one battery (see, for example, Patent Document 1). If the upper revolving body is decelerated and the boom is lowered at the same time, regenerative power from both is generated at a time, and a large current flows when the battery is charged, resulting in a large energy loss. The allowable current value of the battery charge / discharge circuit (converter) may be exceeded.

JP 2007-217992 A

  An object of the present invention is to provide a hybrid excavating machine with low energy loss.

  According to an aspect of the present invention, an engine that generates power, and a generator that is connected to the engine and that generates power using the rotational power of the engine so that the power generated by the engine can be transmitted. A power storage circuit to which electric power is supplied from the generator and an upper swing body are attached and driven by at least the power generated by the engine, and swings in the vertical direction with respect to the upper swing body A boom, a boom regenerative motor that converts mechanical energy of the boom into electrical energy and supplies regenerative power to the power storage circuit during a regenerative operation of lowering the boom relative to the upper swing body, and the upper part A turning electric motor for turning a turning body, performing at least a power running operation performed by supplying electric power from the power storage circuit, and a regenerative operation for generating electric power, A turning electric motor that supplies the electric power generated by the regenerative operation to the electric storage circuit; and a control device that controls the operation of the electric storage circuit, wherein the electric storage circuit includes the generator, the electric rotating motor, and the boom A DC bus line to which a regenerative motor is electrically connected, a first capacitor that is electrically connected to the DC bus line and stores electric power supplied from the turning motor, and an electric power to the DC bus line A second capacitor for storing electric power supplied from the boom regeneration motor, a first capacitor charge / discharge circuit for controlling a charge / discharge current of the first capacitor, and the second capacitor. There is provided a hybrid excavating machine including a second capacitor charging / discharging circuit for controlling the charging / discharging current.

  ADVANTAGE OF THE INVENTION According to this invention, a hybrid type excavation machine with little energy loss can be provided.

The side view of the hybrid type excavation machine (power shovel) by the 1st and 2nd Example is shown. The block diagram of the hybrid type excavation machine by the 1st and 2nd Example is shown. The structure of the electrical storage circuit 120 in the hybrid type excavation machine by a 1st Example is shown. An equivalent circuit diagram of converters 100a and 100b is shown. The structure of the electrical storage circuit 120 in the hybrid type excavation machine by a 2nd Example is shown. An equivalent circuit diagram of the converter 130 is shown.

  FIG. 1 shows a side view of a hybrid excavator (power shovel) according to the first and second embodiments. An upper swing body 3 is mounted on the lower traveling body (base body) 1 via a swing mechanism 2. The turning mechanism 2 includes an electric motor (motor), and turns the upper turning body 3 clockwise or counterclockwise. A boom 4 is attached to the upper swing body 3. The boom 4 swings up and down with respect to the upper swing body 3 by a hydraulically driven boom cylinder 7. An arm 5 is attached to the tip of the boom 4. The arm 5 swings in the front-rear direction with respect to the boom 4 by an arm cylinder 8 that is hydraulically driven. A bucket 6 is attached to the tip of the arm 5. The bucket 6 swings up and down with respect to the arm 5 by a hydraulically driven bucket cylinder 9. The upper swing body 3 further includes a cabin 10 that accommodates a driver.

  FIG. 2 is a block diagram of a hybrid excavating machine according to the first and second embodiments. In FIG. 2, the mechanical power system is represented by a double line, the high-pressure hydraulic line is represented by a thick solid line, the electric system is represented by a thin solid line, and the pilot line is represented by a broken line.

  The drive shaft of the engine 11 is connected to the input shaft of the transmission 13. As the engine 11, an engine that generates a driving force by a fuel other than electricity, for example, an internal combustion engine such as a diesel engine is used. The engine 11 is always driven during operation of the excavating machine.

  The drive shaft of the motor generator 12 is connected to the other input shaft of the transmission 13. The motor generator 12 can perform both the electric (assist) operation and the power generation operation. As the motor generator 12, for example, an interior permanent magnet (IPM) motor in which a magnet is embedded in a rotor is used. The transmission 13 has two input shafts and one output shaft. A drive shaft of the main pump 14 is connected to the output shaft.

  When the load applied to the engine 11 is large, the motor generator 12 performs an assist operation, and the driving force of the motor generator 12 is transmitted to the main pump 14 via the transmission 13. Thereby, the load applied to the engine 11 is reduced. On the other hand, when the load applied to the engine 11 is small, the driving force of the engine 11 is transmitted to the motor generator 12 via the transmission 13, so that the motor generator 12 is in a power generation operation. Switching between the assist operation and the power generation operation of the motor generator 12 is performed by an inverter 18 connected to the motor generator 12. The inverter 18 is controlled by the control device 30.

  The control device 30 includes a central processing unit (CPU) 30A and an internal memory 30B. The CPU 30A executes a drive control program stored in the internal memory 30B. The control device 30 alerts the driver by displaying the deterioration state of various devices on the display device 35.

  The main pump 14 supplies hydraulic pressure to the control valve 17 via the high pressure hydraulic line 16. The control valve 17 distributes hydraulic pressure to the hydraulic motors 1A, 1B, the boom cylinder 7, the arm cylinder 8, and the packet cylinder 9 in accordance with a command from the driver. The hydraulic motors 1A and 1B generate torques that cause the turning mechanism 2 shown in FIG. 1 to turn clockwise and counterclockwise, respectively.

  The input / output terminal of the electric system of the motor generator 12 is connected to the DC bus line of the storage circuit 120 via the inverter 18. Further, the DC bus line of the power storage circuit 120 is connected to the boom regeneration motor 131 via another inverter 132. Further, the turning electric motor 21 is connected to the DC bus line of the power storage circuit 120 via the inverter 20. The inverters 18, 20, and 132 can convert three-phase alternating current and direct current into each other. Inverters 18, 20, 132 are controlled by a control signal from control device 30.

  During the period in which the motor generator 12 is in the power generation operation, the motor generator 12 functions as a generator that performs a power generation operation by the rotational power of the engine 11, and the electric power generated by the motor generator 12 passes through the inverter 18. The electric storage circuit 120 is supplied, and the electric storage circuit 120 is charged. During the period in which the motor generator 12 is being assisted, necessary power is supplied from the power storage circuit 120 to the motor generator 12 via the inverter 18.

  The boom regenerative motor 131 is connected to the boom regenerative pump 130 and can generate power by the driving force of the boom regenerative pump 130 generated from the mechanical energy of the boom when the boom is lowered (during regenerative operation). . The electric power generated by the boom regeneration motor 131 is stored in the power storage circuit 120 via the inverter 132.

  Electric energy is transferred between the storage circuit 120 and the turning electric motor 21 through the inverter 20. For example, the electric power necessary for the turning drive of the upper swing body 3 is supplied from the power storage circuit 120 to the turning electric motor 21, and the electric power generated by the turning electric motor 21 when the upper swing body 3 is decelerated is stored in the power storage circuit 120. It is done.

  The turning electric motor 21 is AC driven by a pulse width modulation (PWM) control signal from the inverter 20 and can perform both a power running operation and a regenerative operation. For example, an IPM motor is used as the turning electric motor 21. An IPM motor generates a large induced electromotive force during regeneration.

  During the power running operation of the turning electric motor 21, the rotational force of the turning electric motor 21 is transmitted to the turning mechanism 2 shown in FIG. 1 through the transmission 24. At this time, the transmission 24 reduces the rotation speed. As a result, the rotational force generated by the turning electric motor 21 increases and is transmitted to the turning mechanism 2. Further, during the regenerative operation, the rotational motion of the upper swing body 3 is transmitted to the turning electric motor 21 via the transmission 24, so that the turning electric motor 21 generates regenerative electric power. At this time, the transmission 24 increases the rotational speed, contrary to the power running operation. Thereby, the rotation speed of the electric motor 21 for turning can be increased.

  The resolver 22 detects the position of the rotation shaft of the turning electric motor 21 in the rotation direction. The detection result is input to the control device 30. By detecting the position of the rotating shaft in the rotational direction before and after the operation of the turning electric motor 21, the turning angle and the turning direction are derived.

  A mechanical brake 23 is connected to the rotating shaft of the turning electric motor 21 and generates a mechanical braking force. The braking state and the released state of the mechanical brake 23 are controlled by the control device 30 and switched by an electromagnetic switch.

  The pilot pump 15 generates a pilot pressure necessary for the hydraulic operation system. The generated pilot pressure is supplied to the operating device 26 via the pilot line 25. The operating device 26 includes a lever and a pedal and is operated by a driver. The operating device 26 converts the primary side hydraulic pressure supplied from the pilot line 25 into a secondary side hydraulic pressure in accordance with the operation of the driver. The secondary side hydraulic pressure is transmitted to the control valve 17 via the hydraulic line 27 and to the pressure sensor 29 via the other hydraulic line 28.

  The detection result of the pressure detected by the pressure sensor 29 is input to the control device 30. Thereby, the control apparatus 30 can detect the operation state of the lower traveling body 1, the turning mechanism 2, the boom 4, the arm 5, and the bucket 6. In particular, in the hybrid excavating machine according to the embodiment, not only the hydraulic motors 1A and 1B but also the turning electric motor 21 drives the turning mechanism 2. For this reason, it is desirable to detect the operation amount of the lever for controlling the turning mechanism 2 with high accuracy. The control device 30 can detect the operation amount of the lever with high accuracy via the pressure sensor 29.

  FIG. 3 shows the configuration of the power storage circuit 120 in the hybrid excavating machine according to the first embodiment. The power storage circuit 120 includes a DC bus line 110, converters 100a and 100b, and capacitors 19a and 19b. Capacitors 19a and 19b are connected to portions of DC bus 110 that are connected to the same potential via converters 100a and 100b, respectively. Converters 100a and 100b control charge / discharge currents of capacitors 19a and 19b, respectively, according to a control signal from control device 30. The DC bus line 110 includes a smoothing capacitor 105. The voltage generated at both ends of the smoothing capacitor 105 is measured by the voltmeter 111, and the measurement result is input to the control device 30.

  The DC bus line 110 is connected to the motor generator 12, the turning electric motor 21, and the boom regeneration motor 131 via inverters 18, 20, and 132, respectively.

  During the period in which the motor generator 12 is generating, the electric power generated by the motor generator 12 is supplied to the capacitor 19a via the inverter 18 and the converter 100a, and the capacitor 19a is charged. During the period in which the motor generator 12 is assisted, electric power is supplied from the capacitor 19a to the motor generator 12 via the converter 100a and the inverter 18.

  Electric power is supplied to the turning electric motor 21 from the capacitor 19a through the converter 100a and the inverter 20. Further, the regenerative power generated by the turning electric motor 21 is stored in the capacitor 19a through the inverter 20 and the converter 100a.

  The regenerative power generated by the boom regeneration motor 131 is stored in the capacitor 19b via the inverter 132 and the converter 100b.

  Even when the regenerative power generated by the turning motor 21 is stored in the capacitor 19a and the regenerative power generated by the boom regenerative motor 131 is stored in the capacitor 19b, regenerative power from both is generated at a time. The currents flowing through converters 100a and 100b can be set within the allowable current value. Further, since the current value flowing through converters 100a and 100b can be reduced, energy loss can be reduced.

  FIG. 4 shows an equivalent circuit diagram of converters 100a and 100b.

  Capacitors 19a and 19b are connected to a pair of power supply connection terminals 103A and 103B of converters 100a and 100b, and a smoothing capacitor 105 of DC bus line 110 is connected to a pair of output terminals 104A and 104B. One power connection terminal 103B and one output terminal 104B are grounded.

  A series circuit in which a collector of a boosted insulated gate bipolar transistor (IGBT) 102A and an emitter of a step-down IGBT 102B are connected to each other is connected between output terminals 104A and 104B. . The emitter of the step-up IGBT 102A is grounded, and the collector of the step-down IGBT 102B is connected to the output terminal 104A on the high voltage side. An interconnection point between the step-up IGBT 102A and the step-down IGBT 102B is connected to the high-voltage side power supply connection terminal 103A via the reactor 101.

  Diodes 102a and 102b are connected in parallel to the step-up IGBT 102A and the step-down IGBT 102B, respectively, such that the direction from the emitter to the collector is the forward direction.

  A voltmeter 106 connected between the power connection terminals 103A and 103B measures the voltage between the terminals of the capacitors 19a and 19b. An ammeter 107 inserted in series with the reactor 101 measures charge / discharge currents of the capacitors 19a and 19b. The measurement results of voltage and current are input to the control device 30.

  The control device 30 applies a pulse width modulation (PWM) voltage for control to the gate electrodes of the step-up IGBT 102A and the step-down IGBT 102B.

  Hereinafter, the boosting operation (discharging operation) will be described. A PWM voltage is applied to the gate electrode of the boosting IGBT 102A. When the boosting IGBT 102A is turned off, an induced electromotive force is generated in the reactor 101 in a direction in which a current flows from the high-voltage side power supply connection terminal 103A toward the collector of the boosting IGBT 102A. This electromotive force is applied to the DC bus line 110 via the diode 102b. Thereby, the DC bus line 110 is boosted.

  Next, the step-down operation (charging operation) will be described. A PWM voltage is applied to the gate electrode of the step-down IGBT 102B. When the step-down IGBT 102B is turned off, an induced electromotive force is generated in the reactor 101 in a direction in which a current flows from the emitter of the step-down IGBT 102B toward the high-voltage side power supply connection terminal 103A. The capacitors 19a and 19b are charged by the induced electromotive force.

  In the first embodiment, independent and independent control is performed on converter 100a and converter 100b. For example, voltage control is performed on converter 100a. Specifically, electrical energy is transferred between the DC bus 110 and the capacitor 19a so that the voltage of the DC bus 110 is kept constant. By controlling the voltage of the converter 100a, the power generated by the motor generator 12 and the regenerative power generated by the turning motor 21 are stored in the capacitor 19a. Further, the electric power used for the assist operation of the motor generator 12 and the electric power supplied to the turning electric motor 21 can be discharged from the capacitor 19a.

  For converter 100b, for example, current control according to the regenerative current value is performed. With the current control, for example, a desired current can be flowed into and out of the capacitor 19b so that regenerative power generated by the boom regeneration motor 131 is stored in the capacitor 19b.

  The electrical energy of the capacitor 19b is controlled so that it is discharged by the operation of the converter 100b, for example, during a period in which the voltage across the capacitor 19b exceeds a predetermined value and the turning electric motor 21 performs a power running operation. Moreover, it controls so that it discharges at the time of boom raising request | requirement (at the time of power running operation). By the former discharge control, at least a part of the energy used for the power running operation of the turning electric motor 21 is provided by the electric energy of the capacitor 19b. By the latter discharge control, a part of energy necessary for the operation of raising the boom is supplied by the electric energy of the capacitor 19b through the assist operation of the motor generator 12. When the boom is raised using the energy of the capacitor 19b, the energy input / output balance of the capacitor 19b can be stabilized.

  In the first embodiment, the capacitor 19a stores the power generated by the motor generator 12 and the regenerative power generated by the turning motor 21, whereas the capacitor 19b stores the boom regeneration motor 131. Only the regenerative power generated in is stored. For this reason, the capacitance of the capacitor 19b may be smaller than that of the capacitor 19a.

  FIG. 5 shows the configuration of the storage circuit 120 in the hybrid excavating machine according to the second embodiment. The power storage circuit 120 in the second embodiment is different from that in the first embodiment in that it includes two DC bus lines 110a and 110b and a converter 130 disposed therebetween.

  A capacitor 19a is connected to the DC bus line 110a via a converter 100a. A motor generator 12 and a turning electric motor 21 are connected via inverters 18 and 20. The DC bus line 110 a includes a smoothing capacitor 105 a, the voltage generated at both ends thereof is measured by the voltmeter 111 a, and the measurement result is input to the control device 30.

  A capacitor 19b is connected to the DC bus line 110b via a converter 100b. Further, a boom regeneration motor 131 is connected via an inverter 132. The DC bus line 110b includes a smoothing capacitor 105b, the voltage generated at both ends thereof is measured by the voltmeter 111b, and the measurement result is input to the control device 30.

  Converters 100a and 100b are converters whose equivalent circuit diagram is shown in FIG. The charge / discharge currents of the capacitors 19a and 19b are controlled by control signals from the control device 30, respectively.

  FIG. 6 shows an equivalent circuit diagram of the converter 130. For example, converter 130 has a configuration in which relay switch 108 is provided between terminal 104A, step-down IGBT 102B, and diode 102b in converters 100a and 100b shown in FIG. The terminals 103A and 103B are connected to the DC bus line 110b (between the terminals of the smoothing capacitor 105b), and the terminals 104A and 104B are connected to the DC bus line 110a (between the terminals of the smoothing capacitor 105a).

  Converter 130 can electrically disconnect both DC bus lines 110a and 110b by turning off relay switch 108. Further, by turning on the relay switch 108 and not performing other operations such as step-up operation and step-down operation, when the voltage of the DC bus line 110b is higher than the voltage of the DC bus line 110a, the DC bus line 110b is connected to the DC bus. A current can be passed through the line 110a (power can be supplied).

  Furthermore, when the voltage of the DC bus line 110b is lower than the voltage of the DC bus line 110a, the boosting operation of the DC bus line 110a is performed with the relay switch 108 turned on, so that the DC bus line 110b is switched to the DC bus line. An electric current can be passed through 110a (power can be supplied).

  Further, when the voltage of the DC bus line 110b is lower than the voltage of the DC bus line 110a, the relay switch 108 is turned on, the PWM voltage is applied to the gate electrode of the step-down IGBT 102B, and the DC bus line 110a is stepped down. A current can be supplied (power can be supplied) from the DC bus line 110a to the DC bus line 110b.

  During normal operation of the hybrid excavator according to the second embodiment, the relay switch 108 is turned off to electrically disconnect the DC bus lines 110a and 110b.

  During the period in which the motor generator 12 is generating, the electric power generated by the motor generator 12 is supplied to the capacitor 19a via the inverter 18 and the converter 100a, and the capacitor 19a is charged. During the period in which the motor generator 12 is assisted, electric power is supplied from the capacitor 19a to the motor generator 12 via the converter 100a and the inverter 18.

  Electric power is supplied to the turning electric motor 21 from the capacitor 19a through the converter 100a and the inverter 20. Further, the regenerative power generated by the turning electric motor 21 is stored in the capacitor 19a through the inverter 20 and the converter 100a.

  The regenerative power generated by the boom regeneration motor 131 is stored in the capacitor 19b via the inverter 132 and the converter 100b.

  For example, voltage control is performed on both converters 100a and 100b. Electric energy is exchanged between the DC buses 110a and 110b and the capacitors 19a and 19b so that the voltages of the DC buses 110a and 110b are kept constant.

  Since the regenerative power generated by the turning electric motor 21 is stored in the capacitor 19a and the regenerative power generated by the boom regenerative motor 131 is stored in the capacitor 19b, even if both regenerative powers are generated at a time, The current flowing through converters 100a and 100b can be set within an allowable current value. Further, since the current value flowing through converters 100a and 100b can be reduced, energy loss can be reduced.

  Also in the second embodiment, the capacitor 19a stores the power generated by the motor generator 12 and the regenerative power generated by the turning motor 21, whereas the capacitor 19b stores the power for boom regeneration. Only regenerative power generated by the motor 131 is stored. For this reason, the capacitance of the capacitor 19b may be smaller than that of the capacitor 19a.

  For example, during the period in which the voltage between the terminals of the capacitor 19b exceeds a predetermined value and the turning electric motor 21 performs the power running operation and when the boom is requested (during the power running operation), the electrical energy of the capacitor 19b is discharged by the operation of the converter 100b. As described above, the converter 100b and the converter 130 are controlled, the relay switch 108 is turned on, and the DC bus line 110a is boosted. By doing so, the electrical energy of the capacitor 19b is transferred from the DC bus line 110b to the DC bus line 110a. If it is the period when the electric motor 21 for turning is performing a power running operation, at least a part of the energy used for it is provided by the electric energy of the capacitor 19b. When the boom is raised (during a power running operation), part of the energy necessary for the operation of raising the boom is supplied by the electric energy of the capacitor 19b through the assist operation of the motor generator 12. When the boom is raised using the energy of the capacitor 19b, the energy input / output balance of the capacitor 19b can be stabilized.

  On the other hand, the electric energy is transferred from the DC bus line 110a to the DC bus line 110b, for example, when the hybrid excavating machine according to the embodiment is started up. When the excavating machine is started up, the capacitors 19a and 19b are charged. When charging the capacitor 19b, the voltage of the DC bus line 110a is set higher than that of the DC bus line 110b, the relay switch 108 is turned on, and the converter 130 is controlled to step down the DC bus line 110a. Together with or after that, the converter 100b is controlled so that the capacitor 19b is charged by the operation of the converter 100b.

  The reason is that if the regenerative power generated by the boom regeneration motor 131 is stored in the uncharged capacitor 19b, the current flowing through the converter 100b may become extremely large. By charging the capacitor 19b when starting the excavating machine, the current flowing through the converter 100b during regenerative power storage can be reduced.

  As mentioned above, although this invention was demonstrated along the 1st and 2nd Example, this invention is not restrict | limited to these.

  For example, in the first and second embodiments, the electrical energy of the capacitor 19b is, for example, a period during which the voltage between the terminals of the capacitor 19b exceeds a predetermined value and the turning electric motor 21 performs a power running operation, and when a boom raising request is made. It was controlled to be discharged during powering operation. When the condition that the voltage between the terminals of the capacitor 19b exceeds a predetermined value is satisfied, the capacitor 19b may be discharged. In this case, for example, converters 100a, 100b, and 130 are controlled so that energy discharged from capacitor 19b is stored in capacitor 19a.

  In the first embodiment, the voltage control is performed on the converter 100a. However, the voltage control is performed on the converter 100b. For the converter 100a, for example, the turning electric motor 21 and the motor generator 12 are used. A desired current may be flowed into and out of the capacitor 19a so that the generated power is charged and discharged to the capacitor 19a. Current control corresponding to the regenerative current value can be performed on at least one of converters 100a and 100b.

  Furthermore, in the second embodiment, the motor generator 12 is connected to the DC bus line 110a via the inverter 18, but it can also be connected to the DC bus line 110b. In this case, the capacitance of the capacitor 19b is preferably larger than that of the capacitor 19a.

  In the embodiment, a parallel type hybrid excavating machine in which the motor generator 12 and the main pump 14 are connected to the engine 11 is shown. However, only the motor generator 12 as a generator is connected to the engine 11, and the engine It is also possible to apply to a series type hybrid excavating machine that converts all of the 11 rotational powers into electric energy. In this case, the motor generator 12 functions only as a generator, and further includes a main pump motor that drives the main pump 14. The main pump 14 is driven based on the electric power obtained by the power generation operation of the motor generator 12.

  It will be apparent to those skilled in the art that other various modifications, improvements, combinations, and the like can be made.

  It can be used for hybrid excavation machines in general.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 1A, 1B Hydraulic motor 2 Turning mechanism 3 Upper turning body 4 Boom 5 Arm 6 Bucket 7 Boom cylinder 8 Arm cylinder 9 Bucket cylinder 10 Cabin 11 Engine 12 Motor generator 13 Transmission 14 Main pump 15 Pilot pump 16 High pressure Hydraulic line 17 Control valve 18 Inverter 19, 19a, 19b Capacitor 20 Inverter 21 Turning motor 22 Resolver 23 Mechanical brake 24 Transmission 25 Pilot line 26 Operating device 27, 28 Hydraulic line 29 Pressure sensor 30 Control device 30A CPU
30B Internal memory 35 Display device 100, 100a, 100b Converter (capacitor charge / discharge circuit)
101 Reactor 102A Boost IGBT
102B IGBT for step-down
102a, 102b Diodes 103A, 103B Power connection terminals 104A, 104B Output terminals 105, 105a, 105b Smoothing capacitor 106 Voltmeter 107 Ammeter 108 Relay switches 110, 110a, 110b DC bus lines 111, 111a, 111b Voltmeter 120 Storage circuit 130 Converter (intermediate electrical circuit)
131 Boom regeneration motor

Claims (6)

An engine that generates power,
A generator that is connected to the engine and performs a power generation operation by the rotational power of the engine so that the power generated by the engine can be transmitted;
A power storage circuit to which power is supplied from the generator;
A boom attached to the upper swing body, driven by at least the power generated by the engine being supplied, and swinging up and down with respect to the upper swing body;
A boom regenerative motor that converts mechanical energy of the boom into electrical energy and supplies regenerative power to the power storage circuit during a regenerative operation of lowering the boom relative to the upper swing body;
A turning electric motor for turning the upper-part turning body, wherein at least a power running operation performed by supplying power from the power storage circuit and a regenerative operation for generating power are performed, and the power generated by the regenerative operation is supplied to the power storage circuit A turning electric motor to be supplied;
A control device for controlling the operation of the power storage circuit,
The storage circuit is
A DC bus line to which the generator, the turning electric motor, and the boom regeneration motor are electrically connected;
A first capacitor that is electrically connected to the DC bus line and stores electric power supplied from the turning electric motor;
A second capacitor that is electrically connected to the DC bus line and stores electric power supplied from the boom regeneration motor;
A first capacitor charge / discharge circuit for controlling a charge / discharge current of the first capacitor;
A hybrid excavating machine comprising: a second capacitor charging / discharging circuit that controls a charging / discharging current of the second capacitor. The DC bus line includes a first portion and a second portion that are continuous at the same potential,
The first capacitor is electrically connected to the first portion of the DC bus line;
The second capacitor is electrically connected to the second portion of the DC bus line;
In the control device, the electric power generated by the turning electric motor or the electric power generated by the boom regeneration motor is supplied to the first or second capacitor charging / discharging circuit by the first or second capacitor charging / discharging circuit. The hybrid excavation machine according to claim 1, wherein control is performed so that a current flows into the first or second capacitor so that the current is stored in the second capacitor.   In the control device, for one of the first and second capacitor charge / discharge circuits, the electric power generated by the turning electric motor or the electric power generated by the boom regeneration motor is changed to the first or second electric power. 3. The control according to claim 2, wherein control is performed so that a current flows into the first or second capacitor so as to be stored in the capacitor, and control is performed so that the voltage of the DC bus line is constant. Hybrid drilling machine. The first capacitor is electrically connected to a third portion of the DC bus line;
The second capacitor is electrically connected to a fourth portion of the DC bus line;
(I) electrical disconnection between the third portion and the fourth portion between the third portion and the fourth portion of the DC bus line; and (ii) from the third portion. The hybrid of claim 1, further comprising an intermediate electrical circuit that selectively enables power transfer to the fourth portion, (iii) power transfer from the fourth portion to the third portion. Type drilling machine.   5. The hybrid type according to claim 4, wherein the control device controls the first and second capacitor charge / discharge circuits so that voltages of the third and fourth portions of the DC bus line are constant, respectively. Drilling machine.   The control device is configured such that the electric power of the second capacitor is such that the voltage between the terminals of the second capacitor exceeds a predetermined value and the electric motor for turning performs a power running operation, or the boom is used as the upper rotating body. The hybrid excavation machine according to any one of claims 1 to 5, wherein the operation of the power storage circuit is controlled so as to be released during a powering operation to be raised.

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