JP5236433B2 - Hybrid construction machine - Google Patents

Description

  The present invention relates to a hybrid construction machine.

  Conventionally, a hybrid construction machine in which a part of a drive mechanism is electrically driven has been proposed. Such a construction machine includes a hydraulic pump for hydraulically driving movable parts such as a boom, an arm, and a bucket, and a motor generator is used as an internal combustion engine engine (engine) for driving the hydraulic pump. It connects, assists the driving force of the engine, and charges the storage battery (battery) with electric power obtained by power generation.

In addition to a hydraulic motor as a power source for turning the upper swing body, an electric motor is provided, assisting the drive of the hydraulic motor with an electric motor during acceleration turning, and performing a regenerative operation with the electric motor during deceleration turning, The battery is charged (for example, refer to Patent Document 1).
JP-A-10-103112

  In the hybrid construction machine described above, it is desirable to provide a DC voltage converter (buck-boost converter) between the motor generator and the storage battery in order to control charging / discharging of the storage battery. As a result, the voltage between the motor generator and the storage battery can be kept constant, and the turning motor and the like can be stably controlled.

  However, when the DC voltage converter includes a reactor, the reactor generates heat when charging and discharging of the storage battery are repeated. And if the temperature of a reactor becomes high too much, the resistivity of a reactor will increase and the conversion efficiency of a DC voltage converter will fall. For this reason, conventionally, the reactor has been air-cooled by bringing a heat sink or the like into contact therewith, but it is difficult to sufficiently cool the reactor in such a cooling method in a construction machine.

  In other words, work machines such as construction machines and haulage handling machines are used on land of various climates from tropical regions to cold regions, and are also used in places with a lot of dust. Therefore, it is preferable that electrical equipment such as a DC voltage converter is housed in a sealed container and is cut off from the outside air. However, when the DC voltage converter (particularly the reactor) is accommodated in the sealed container in this way, it becomes difficult to sufficiently cool the reactor by the conventional air cooling method.

  The present invention has been made in view of the above-described problems, and an object thereof is to effectively cool a DC voltage converter in a hybrid construction machine.

  In order to solve the above-described problem, a hybrid construction machine according to the present invention is a hybrid construction machine including a working electric motor driven by an operator's operation, and one end is connected to a terminal of the working electric motor. An inverter circuit and a reactor are included, a DC voltage converter having one end connected to the other end of the inverter circuit, a storage battery connected to the other end of the DC voltage converter, and a heat exchanger. And a coolant circulation system for cooling the reactor.

  The hybrid construction machine may further include a temperature sensor for detecting the temperature of the reactor.

  In the hybrid construction machine, the coolant circulation system may include a cooling pipe and a heat conduction plate, and the reactor may be disposed on the heat conduction plate.

  In the hybrid construction machine, the DC voltage converter may further include an intelligent power module that controls charging / discharging of the storage battery, and the intelligent power module may be disposed on the heat conduction plate.

  The hybrid construction machine may be characterized in that the DC voltage converter is formed in a sealed case, and the thermal conductive plate is disposed on one surface of the case.

  The hybrid construction machine is connected to the internal combustion engine motor and the internal combustion engine motor, generates electric power by the driving force of the internal combustion engine motor, and assists the driving force of the internal combustion engine motor by its own driving force. A motor generator may be further provided.

  The hybrid construction machine according to the present invention can effectively cool the DC voltage converter.

  Embodiments of a hybrid construction machine according to the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a perspective view showing an appearance of a lifting magnet vehicle 1 as an example of a hybrid construction machine according to the present invention. As shown in FIG. 1, the lifting magnet vehicle 1 includes a traveling mechanism 2 including an endless track, and a revolving body 4 that is rotatably mounted on an upper portion of the traveling mechanism 2 via a revolving mechanism 3. The revolving body 4 is attached with a boom 5, an arm 6 linked to the tip of the boom 5, and a lifting magnet 7 linked to the tip of the arm 6. The lifting magnet 7 is a facility for attracting and capturing the suspended load G such as a steel material by a magnetic force. The boom 5, the arm 6, and the lifting magnet 7 are hydraulically driven by a boom cylinder 8, an arm cylinder 9, and a bucket cylinder 10, respectively. Further, the revolving body 4 has power such as a driver's cab 4a for accommodating an operator who operates the position of the lifting magnet 7, the excitation operation and the release operation, and an engine (internal combustion engine engine) 11 for generating hydraulic pressure. A source is provided. The engine 11 is composed of, for example, a diesel engine.

  FIG. 2 is a block diagram showing an internal configuration such as an electric system and a hydraulic system of the lifting magnet vehicle 1 of the present embodiment. In FIG. 2, the mechanical power transmission system is indicated by a double line, the hydraulic system is indicated by a thick solid line, the steering system is indicated by a broken line, and the electrical system is indicated by a thin solid line.

  As shown in FIG. 2, the lifting magnet vehicle 1 includes a motor generator 12 and a speed reducer 13, and the rotation shafts of the engine 11 and the motor generator 12 are both connected to the input shaft of the speed reducer 13. Are connected to each other. When the load of the engine 11 is large, the motor generator 12 assists (assists) the driving force of the engine 11 with its own driving force, and the driving force of the motor generator 12 passes through the output shaft of the speed reducer 13 to the main pump 14. Communicated. On the other hand, when the load on the engine 11 is small, the driving force of the engine 11 is transmitted to the motor generator 12 via the speed reducer 13, so that the motor generator 12 generates power. The motor generator 12 is configured by, for example, an IPM (Interior Permanent Magnetic) motor in which a magnet is embedded in the rotor. Switching between driving and power generation of the motor generator 12 is performed according to the load of the engine 11 and the like by the controller 30 that controls driving of the electric system in the lifting magnet vehicle 1.

  A main pump 14 and a pilot pump 15 are connected to the output shaft of the speed reducer 13, and a control valve 17 is connected to the main pump 14 via a high pressure hydraulic line 16. The control valve 17 is a device that controls the hydraulic system in the lifting magnet vehicle 1. In addition to the hydraulic motors 2a and 2b for driving the traveling mechanism 2 shown in FIG. 1, the boom cylinder 8, the arm cylinder 9 and the bucket cylinder 10 are connected to the control valve 17 via a high pressure hydraulic line. The control valve 17 controls the hydraulic pressure supplied to them according to the operation input of the driver.

  One end of the inverter circuit 18 </ b> A is connected to the electrical terminal of the motor generator 12. The inverter circuit 18A is an example of a second inverter circuit in the present invention. The power storage means 110 is connected to the other end of the inverter circuit 18A. The inverter circuit 18 </ b> A controls the operation of the motor generator 12 based on a command from the controller 30. That is, when the inverter circuit 18 </ b> A causes the motor generator 12 to perform a power running operation, necessary power is supplied from the power storage unit 110 to the motor generator 12. Further, when the motor generator 12 is regeneratively operated, the electric power generated by the motor generator 12 is charged in the power storage means 110.

  A lifting magnet 7 is connected to the power storage means 110 via an inverter circuit 18B. The lifting magnet 7 includes an electromagnet that generates a magnetic force for magnetically attracting a metal object, and power is supplied from the power storage means 110 via the inverter circuit 18B. When the electromagnet is turned on based on a command from the controller 30, the inverter circuit 18 </ b> B supplies the requested power to the lifting magnet 7 from the power storage means 110. Further, when the electromagnet is turned off, the regenerated electric power is supplied to the power storage means 110.

  Further, a turning electric motor 21 as a working electric motor is connected to the power storage means 110 via an inverter circuit 20. The turning electric motor 21 is a power source of the turning mechanism 3 for turning the turning body 4. A resolver 22, a mechanical brake 23, and a turning speed reducer 24 are connected to the rotating shaft 21 </ b> A of the turning electric motor 21.

  When the turning electric motor 21 performs a power running operation, the rotational force of the rotational driving force of the turning electric motor 21 is amplified by the turning speed reducer 24, and the turning body 4 is subjected to acceleration / deceleration control to perform rotational motion. Further, due to the inertial rotation of the swing body 4, the rotation speed is increased by the swing speed reducer 24 and transmitted to the swing electric motor 21 to generate regenerative power. The electric motor 21 for turning is AC driven by the inverter circuit 20 by a PWM (Pulse Width Modulation) control signal. As the turning electric motor 21, for example, a magnet-embedded IPM motor is suitable.

  The resolver 22 is a sensor that detects the rotation position and rotation angle of the rotation shaft 21A of the turning electric motor 21, and mechanically connects to the turning electric motor 21 to detect the rotation angle and rotation direction of the rotation shaft 21A. When the resolver 22 detects the rotation angle of the rotation shaft 21A, the rotation angle and the rotation direction of the turning mechanism 3 are derived. The mechanical brake 23 is a braking device that generates a mechanical braking force, and mechanically stops the rotating shaft 21 </ b> A of the turning electric motor 21 according to a command from the controller 30. The turning speed reducer 24 is a speed reducer that reduces the rotational speed of the rotating shaft 21 </ b> A of the turning electric motor 21 and mechanically transmits it to the turning mechanism 3.

  Since the motor generator 12, the lifting magnet 7, and the turning motor 21 are connected to the power storage means 110 via the inverter circuits 18 </ b> A, 18 </ b> B, and 20, the electric power generated by the motor generator 12 is May be directly supplied to the lifting magnet 7 or the turning electric motor 21, and the electric power regenerated by the lifting magnet 7 may be supplied to the motor generator 12 or the turning electric motor 21. The electric power regenerated by the electric motor 21 may be supplied to the motor generator 12 or the lifting magnet 7.

  An operation device 26 is connected to the pilot pump 15 via a pilot line 25. The operating device 26 is an operating device for operating the turning electric motor 21, the traveling mechanism 2, the boom 5, the arm 6, and the lifting magnet 7, and is operated by an operator. A control valve 17 is connected to the operating device 26 via a hydraulic line 27, and a pressure sensor 29 is connected via a hydraulic line 28. The operating device 26 converts the hydraulic pressure (primary hydraulic pressure) supplied through the pilot line 25 into a hydraulic pressure (secondary hydraulic pressure) corresponding to the operation amount of the operator and outputs the hydraulic pressure. The secondary hydraulic pressure output from the operating device 26 is supplied to the control valve 17 through the hydraulic line 27 and detected by the pressure sensor 29. Here, although the turning electric motor 21 is cited as the working electric motor, the traveling mechanism 2 may be electrically driven as the working electric motor. Furthermore, when the present invention is applied to a forklift, the lifting device may be electrically driven as a working motor.

  When an operation for turning the turning mechanism 3 is input to the operating device 26, the pressure sensor 29 detects this operation amount as a change in the oil pressure in the hydraulic line 28. The pressure sensor 29 outputs an electrical signal indicating the hydraulic pressure in the hydraulic line 28. This electric signal is input to the controller 30 and used for driving control of the turning electric motor 21.

  The controller 30 includes a turning drive control unit 40 and a drive control unit 50, is configured by an arithmetic processing unit including a CPU (Central Processing Unit) and an internal memory, and the CPU executes a drive control program stored in the internal memory. It is realized by doing. The turning drive control unit 40 converts a signal representing an operation amount for turning the turning mechanism 3 among the signals input from the pressure sensor 29 into a speed command, and performs drive control of the turning electric motor 21. The drive control unit 50 is a battery by controlling the operation of the motor generator 12 (switching between assist operation and power generation operation), driving control of the lifting magnet 7 (switching between excitation and demagnetization), and driving control of the buck-boost converter 100. 19 charge / discharge control is performed.

  The configuration of the power storage unit 110 in this embodiment will be described in more detail. FIG. 3 is a diagram schematically showing a circuit configuration of the power storage means 110. The power storage means 110 includes a step-up / down converter (DC voltage converter) 100, a DC bus 111, and a battery 19.

  The configuration of the buck-boost converter 100 in this embodiment will be described in more detail. FIG. 3 is a diagram schematically showing a circuit configuration of the buck-boost converter 100. The buck-boost converter 100 includes a reactor 101, transistors 102A and 102B, and a smoothing capacitor 107.

  One end of the step-up / down converter (DC voltage converter) 100 is connected to a DC wiring such as a DC bus 111. A battery 19 as a storage battery is connected to the other end of the step-up / down converter 100. For example, when the inverter circuit 18 </ b> A causes the motor generator 12 to perform a power running operation, necessary power is supplied to the motor generator 12 from the battery 19 and the buck-boost converter 100 via the DC bus 111. When the motor generator 12 is regeneratively operated, the power generated by the motor generator 12 is charged to the battery 19 via the DC bus 111 and the step-up / down converter 100. The switching control between the step-up / step-down operation of the step-up / step-down converter 100 is performed by the controller 30 based on the DC bus voltage value, the battery voltage value, and the battery current value. As a result, the DC bus 111 is maintained in a state of being stored at a predetermined constant voltage value. That is, the power storage unit 110 is configured by the DC bus 111, the battery 19, and the buck-boost converter 100.

  The buck-boost converter 100 includes a reactor 101, transistors 102A and 102B, and a smoothing capacitor 107. The transistors 102A and 102B are composed of, for example, an IGBT (Insulated Gate Bipolar Transistor) and are connected in series with each other. Specifically, the collector of the transistor 102A and the emitter of the transistor 102B are connected to each other, the emitter of the transistor 102A is connected to the negative side terminal of the battery 19 and the negative side wiring of the DC bus 111, and the collector of the transistor 102B is DC It is connected to the positive side wiring of the bus 111. Reactor 101 has one end connected to the collector of transistor 102 </ b> A and the emitter of transistor 102 </ b> B, and the other end connected to the positive terminal of battery 19. A PWM voltage is applied from the controller 30 to the gates of the transistors 102A and 102B. Note that a diode 102a, which is a rectifying element, is connected in the reverse direction between the collector and emitter of the transistor 102A. Similarly, a diode 102b is connected in the reverse direction between the collector and emitter of the transistor 102B. The smoothing capacitor 107 is connected between the collector of the transistor 102B and the emitter of the transistor 102A, and smoothes the output voltage from the buck-boost converter 100.

  In the buck-boost converter 100 having such a configuration, when supplying DC power from the battery 19 to the DC bus 111, a PWM voltage is applied to the gate of the transistor 102A, and the reactor 101 is turned on / off with the transistor 102A. The induced electromotive force generated in the capacitor is transmitted through the diode 102 b, and this power is smoothed by the capacitor 107. When supplying DC power from the DC bus 111 to the battery 19, a PWM voltage is applied to the gate of the transistor 102 </ b> B, and the current output from the transistor 102 </ b> B is smoothed by the reactor 101.

  Here, since the transistors 102A and 102B control high power, the amount of heat generation becomes extremely large. Further, the amount of heat generated in the reactor 101 also becomes great. Therefore, it is necessary to cool the transistors 102A and 102B and the reactor 101. In addition, since the inverter circuits 18A, 18B, and 20 also have high-power transistors like the buck-boost converter 100, they need to be cooled. Therefore, the lifting magnet vehicle 1 of this embodiment includes a coolant circulation system for cooling the step-up / down converter 100 and the inverter circuits 18A, 18B, and 20.

  The coolant circulation system in the present embodiment will be described in more detail. As shown in FIG. 2, the lifting magnet vehicle 1 includes a first coolant circulation system 60 for an internal combustion engine engine and a second coolant circulation system 70 for an electric system, which are independent from each other. The first coolant circulation system 60 is driven by a pump motor 61 to cool the engine 11. The second coolant circulation system 70 is driven by a pump motor 71 to cool the step-up / down converter 100, the inverter circuits 18A, 18B, and 20, and the controller 30. In addition, the second coolant circulation system 70 cools the motor generator 12, the speed reducer 13, and the turning electric motor 21.

  FIG. 4 is a block diagram for explaining a coolant circulation system in the lifting magnet vehicle 1. As shown in FIG. 4A, the first coolant circulation system 60 includes a pump 62 driven by the pump motor 61 and a radiator 63, and the coolant circulated by the pump 62 is supplied to the radiator. The heat is dissipated by 63 and supplied to the cooling pipe of the engine 11.

  As shown in FIG. 4B, the second coolant circulation system 70 includes a pump 72 driven by the pump motor 71 described above, a radiator 73, and a driver unit 74. The coolant circulated by the pump 72 is radiated by the radiator 73 and sent to the driver unit 74. The driver unit 74 is a structure having a plurality of modules that respectively constitute the buck-boost converter 100, the inverter circuits 18A, 18B, and 20, and the controller 30, and piping that cools these modules. The coolant that has passed through the piping of the driver unit 74 cools the turning electric motor 21, the motor generator 12, and the speed reducer 13 in this order, and then is returned from the pump 72 to the radiator 73. The radiator 73 is an example of a heat exchanger in the present invention. A temperature sensor 77 for detecting the temperature of the coolant is preferably provided at the inlet of the driver unit 74. Furthermore, it is preferable to provide a display device that displays the detected temperature. Thereby, when the radiator 73 is clogged and the cooling performance is lowered, the control device in the control box may limit the output of at least one of the turning electric motor 21 or the motor generator 12 based on the detected value. it can. As a result, continuous operation can be performed, and continuous work can be performed without stopping the hybrid construction machine.

  FIG. 5 is a perspective view showing the external appearance of the driver unit 74. The driver unit 74 has a substantially rectangular parallelepiped appearance, and houses a control box 81 that houses the controller 30, a buck-boost converter unit 82 that houses the buck-boost converter 100, and inverter circuits 18A, 18B, and 20. Inverter units 83 to 85 and a riff mug cooling fan unit 86 are provided. The step-up / down converter unit 82, the inverter units 83 to 85, and the riff mug cooling fan unit 86 each have a rectangular parallelepiped appearance that is long in the depth direction, and are installed side by side on a metal plate-like base 87. Has been. A control box 81 is placed on these units 82 to 86, and a heat sink 88 for air cooling is attached to the upper surface of the control box 81.

  The control box 81 includes a cooling pipe 81a. Similarly, the step-up / down converter unit 82 includes a cooling pipe 82a, the inverter units 83 to 85 include cooling pipes 83a to 85a, and the riff mug cooling fan unit 86 includes a cooling pipe 86a.

  FIG. 6 is a perspective view showing a state in which the cooling pipes 81 a to 86 a are connected to the second coolant circulation system 70. As shown in FIG. 6, the pipe 90A extending from the radiator 73 (see FIG. 4) is branched into three pipes 90B to 90D. Among these pipes, the pipe 90B is connected to one end of the cooling pipe 81a of the control box 81, and the other end of the cooling pipe 81a is further connected to one end of the cooling pipe 85a of the inverter unit 85 via another pipe 90E. Connected to The pipe 90C is connected to one end of the cooling pipe 82a of the step-up / down converter unit 82, and the other end of the cooling pipe 82a is connected to one end of the cooling pipe 83a of the inverter unit 83 via the pipe 90F. The pipe 90D is connected to one end of the cooling pipe 86a of the riffmag cooling fan unit 86, and the other end of the cooling pipe 86a is connected to one end of the cooling pipe 84a of the inverter unit 84 through the pipe 90G.

  Pipes 90H, 90I and 90J are connected to the other ends of the cooling pipes 83a to 85a of the inverter units 83 to 85, respectively. The pipes 90H, 90I and 90J are connected to a single pipe 90K, and the pipe 90K extends to the turning electric motor 21.

  FIG. 7A is a plan view showing the internal configuration of the buck-boost converter unit 82. FIG. FIG. 7B is a side view showing the internal configuration of the buck-boost converter unit 82. In these drawings, the top plate and the side plate of the case are removed so that the internal configuration of the buck-boost converter unit 82 can be seen.

  Inside the step-up / down converter unit 82 is an intelligent power module (IPM) 103 incorporating the transistors 102A and 102B of the step-up / down converter 100, a reactor 101 (see FIG. 3), and a cooling pipe 82a. Built in. The IPM 103 is mounted on the wiring board 104. The cooling pipe 82 a is two-dimensionally arranged along the side surface of the step-up / down converter unit 82. Specifically, the cooling pipe 82a is accommodated in a metal container 82b having a rectangular cross section in a bent state so as to be disposed as long as possible inside the step-up / down converter unit 82, and serves as a heat conduction plate. In contact with the inner surface of the aluminum metal container 82b. As shown in FIG. 7A, the reactor 101 and the IPM 103 are disposed in contact with the outer surface of the metal container 82b, and the metal container 82b transmits heat from the reactor 101 and the IPM 103 to the cooling pipe 82a. Thereby, reactor 101 and IPM 103 are cooled. Here, the metal container 82 b has a larger area than the reactor 101. In addition, the IPM 103 has a large area. Thus, since the metal container 82b has a sufficiently large contact area with respect to the reactor 101 and the IPM 103, the heat generated in the reactor 101 and the IPM 103 can be sufficiently transferred.

  Further, the reactor 101 is preferably provided with a temperature sensor 107 for detecting the temperature of the reactor 101. Thereby, the temperature abnormality of the reactor 101 can be monitored. Thereby, when reactor 101 is generating heat excessively, charging / discharging of battery 19 can be restricted. As a result, by preventing the reactor 101 from being short-circuited, continuous operation can be performed, and continuous work can be performed without stopping the hybrid construction machine.

  FIG. 8A is a plan view showing the internal configuration of the inverter unit 83. FIG. 8B is a side view showing the internal configuration of the inverter unit 83. In these drawings, as in FIG. 7, the top plate and the side plate of the case are removed so that the internal configuration of the inverter unit 83 can be understood. Further, the internal configuration of the inverter units 84 and 85 is the same as the internal configuration of the inverter unit 83 shown in FIG. 8 except for the configuration of the built-in inverter circuit.

  Inside the inverter unit 83, an IPM 105 incorporating a transistor of the inverter circuit 18A and a cooling pipe 83a are incorporated. The IPM 105 is mounted on the wiring board 106. The cooling pipe 83 a is arranged in the same form as the cooling pipe 82 a in the buck-boost converter unit 82. The cooling pipe 83a is accommodated in a metal container 83b having a rectangular cross section, and is in contact with the inner surface of the metal container 83b. As shown in FIG. 8A, the IPM 105 is disposed in contact with the outer surface of the metal container 83b, and the metal container 83b transmits heat from the IPM 105 to the cooling pipe 83a.

  FIG. 9 is a diagram for explaining a cooling method of the turning electric motor 21 by the second coolant circulation system 70. Since the cooling method in the motor generator 12 is the same as that in the turning electric motor 21, only the turning electric motor 21 will be described as a representative here.

  As shown in FIG. 9, the turning electric motor 21 includes a drive unit case 201, a stator 202 attached to the drive unit case 201, and a rotor 203 that is rotatably arranged radially inward of the stator 202, An output shaft 206 that extends through the rotor 203 and is rotatably arranged by bearings 204 and 205 with respect to the drive unit case 201 is provided. The drive unit case 201 includes a side plate 207 and 208, and a cylindrical motor frame 209 that is attached between the side plates 207 and 208 and extends in the axial direction. The bearing 204 is on the side plate 207, and the bearing 205 is on the side plate 208. The stator 202 is attached to the motor frame 209.

  The stator 202 includes a coil (not shown). When a predetermined current is supplied to the coil, the turning electric motor 21 is driven, and the rotor 203 rotates at a rotation speed corresponding to the magnitude of the current. The rotation of the rotor 203 is transmitted to the output shaft 206 to which the rotor 203 is attached.

  A jacket 211 is attached to the outer periphery of the drive unit case 201 in order to dissipate heat generated by driving the turning electric motor 21 and cool the turning electric motor 21. The jacket 211 has a cooling liquid supply port 212 to which the cooling liquid is supplied, a cooling liquid discharge port 213 that discharges the cooling liquid whose temperature has increased after cooling the turning electric motor 21, and the cooling liquid supply port 212 and the cooling. The liquid discharge port 213 is connected to the liquid discharge port 213 and has a single coolant flow path 214 extending spirally or meandering. The coolant supplied from the pump 72 through the radiator 73 and the driver unit 74 to the coolant supply port 212 flows in a meandering manner in the coolant flow path 214, and cools the turning electric motor 21 while cooling the cooling motor 21. The liquid is discharged from the liquid discharge port 213.

  The second coolant circulation system 70 is preferably provided with an auxiliary tank 75 for replenishing the coolant as shown in FIG.

  The lifting magnet vehicle 1 of the present embodiment described above includes the coolant circulation system 70 for cooling the reactor 101 of the step-up / down converter 100. As a result, even when the reactor 101 is housed in a sealed case of the step-up / down converter unit 82, the reactor 101 can be effectively cooled, and the rise in the resistivity of the reactor 101 can be suppressed while moving up and down. The conversion efficiency of the pressure converter 100 can be maintained.

  Further, the lifting magnet vehicle 1 of the present embodiment includes a coolant circulation system 70 for cooling the reactor 101 of the step-up / down converter 100, separately from the coolant circulation system 60 for cooling the engine 11. Therefore, sufficient cooling performance can be ensured, and the coolant can be cooled to a lower temperature than the coolant for cooling the engine, so that the reactor 101 can be effectively cooled. Even when the engine 11 is stopped, the reactor 101 can be continuously cooled as long as the pump motor 71 and the radiator 73 operate.

In the present embodiment, the coolant circulation system 70 further cools not only the reactor 101 but also the motor generator 12 and the turning electric motor 21. In the present invention, such a form is more suitable, whereby the motor generator 12 and the turning electric motor 21 can be effectively cooled. In the present embodiment, in the coolant circulation system 70, after the coolant is sent from the radiator 73, the coolant passes through the driver unit 74 that houses the step-up / down converter 100 and then the motor generator 12 and the turning motor 21. Is going through. Thus, the cooling efficiency of the coolant circulation system 70 is further increased by cooling the relatively low temperature buck-boost converter 100 first and then cooling the relatively high temperature motor generator 12 and the turning motor 21. be able to.
(Modification)

  FIG. 10 is a view showing a modification of the coolant circulation system according to the embodiment. As shown in FIG. 10, in this modification, the lifting magnet vehicle has a second coolant circulation system 70A and a third coolant circulation system 120 in addition to the first coolant circulation system 60 shown in FIG. It has. The second coolant circulation system 70A is obtained by omitting the turning electric motor 21, the motor generator 12, and the speed reducer 13 from the second coolant circulation system 70 of the above embodiment, and is similar to the above embodiment. A pump 72 having a configuration, a radiator 73, and a driver unit 74 are provided.

  The third coolant circulation system 120 is a coolant circulation system provided separately from the first and second coolant circulation systems 60 and 70 </ b> A in order to cool the motor generator 12 and the turning electric motor 21.

  The third coolant circulation system 120 includes a pump 122 driven by a pump motor (not shown) and a radiator 123. The coolant circulated by the pump 122 is radiated by the radiator 123 and sent to the turning electric motor 21. In the turning electric motor 21, as described in FIG. 9, the cooling liquid flows through the cooling liquid flow path 214, and then the motor generator 12 and the speed reducer 13 are cooled in this order and returned to the pump 122.

  The second and third coolant circulation systems 70A and 120 are preferably provided with a common auxiliary tank 76 for replenishing coolant as shown in FIG.

  As in the present embodiment, in order to cool the motor generator 12 and the turning electric motor 21, a coolant circulation system 120 different from the first and second coolant circulation systems 60 and 70A may be provided. . In this way, the cooling efficiency can be further increased by independently cooling the relatively low temperature driver unit 74 (particularly the reactor 101), the relatively high temperature motor generator 12 and the turning electric motor 21. .

  The hybrid construction machine according to the present invention is not limited to the above-described embodiment, and various other modifications are possible. For example, in the above-described embodiment, the case of a lifting magnet vehicle is described as an example of a hybrid construction machine. However, the present invention may be applied to other hybrid construction machines (for example, an excavator, a wheel loader, and a crane).

1 is a perspective view showing an appearance of a lifting magnet vehicle 1 as an example of a hybrid construction machine according to the present invention. 2 is a block diagram showing an internal configuration of the lifting magnet vehicle 1 such as an electric system and a hydraulic system. FIG. 2 is a diagram schematically showing a circuit configuration of a buck-boost converter 100. FIG. It is a block diagram for demonstrating the cooling fluid circulation system in the lifting magnet vehicle 1, Comprising: (a) The 1st cooling fluid circulation system 60, (b) The 2nd cooling fluid circulation system 70 is each shown. FIG. 4 is a perspective view showing an appearance of a driver unit 74. It is a perspective view which shows the state which connected each piping 81a-86a for cooling to the 2nd coolant circulation system 70. FIG. (A) It is a top view which shows the internal structure of the buck-boost converter unit 82. FIG. (B) It is a side view which shows the internal structure of the buck-boost converter unit 82. FIG. 4A is a plan view showing an internal configuration of an inverter unit 83. FIG. (B) It is a side view which shows the internal structure of the inverter unit 83. FIG. It is a figure for demonstrating the cooling system of the electric motor 21 for rotation by the 2nd coolant circulation system. It is a figure which shows the modification of a cooling fluid circulation system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lifting magnet vehicle, 7 ... Lifting magnet, 11 ... Engine, 12 ... Motor generator, 13 ... Reduction gear, 14 ... Main pump, 16 ... High pressure hydraulic line, 17 ... Control valve, 18A, 18B, 20 ... Inverter circuit , 19 ... battery, 21 ... electric motor for turning, 30 ... controller, 40 ... turning drive control unit, 50 ... drive control unit, 60 ... first coolant circulation system, 61, 71 ... pump motor, 62, 72, 122 ... Pump, 63, 73, 123 ... Radiator, 70, 70A ... Second coolant circulation system, 74 ... Driver unit, 75, 76 ... Auxiliary tank, 81 ... Control box, 81a-86a ... Cooling piping, 82 ... Buck-boost converter unit, 82b, 83b ... metal container, 83-85 ... inverter unit, 86 Rifmag cooling fan unit, 87 ... plate-shaped base, 88 ... heat sink, 90A to 90K ... piping, 100 ... buck-boost converter, 101 ... reactor, 103 ... IPM, 110 ... power storage means, 111 ... DC bus, 120 ... third Coolant circulation system.

Claims (6)

A hybrid construction machine including a working electric motor driven by an operator's operation,
An inverter circuit having one end connected to a terminal of the working electric motor;
A DC voltage converter comprising a reactor and having one end connected to the other end of the inverter circuit;
A storage battery connected to the other end of the DC voltage converter;
A hybrid construction machine comprising a heat exchanger and a coolant circulation system for cooling the reactor.   The hybrid construction machine according to claim 1, further comprising a temperature sensor for detecting a temperature of the reactor. The coolant circulation system includes a cooling pipe and a heat conduction plate,
The hybrid construction machine according to claim 1, wherein the reactor is disposed on the heat conducting plate. The DC voltage converter further includes an intelligent power module that controls charging and discharging of the storage battery,
The hybrid construction machine according to claim 3, wherein the intelligent power module is disposed on the heat conducting plate. The DC voltage converter is formed in a sealed case,
The hybrid construction machine according to claim 3 or 4, wherein the thermal conductive plate is disposed on one surface of the case. An internal combustion engine motor;
A motor generator connected to the internal combustion engine engine, generating electric power with the driving force of the internal combustion engine engine, and assisting the driving force of the internal combustion engine engine with its own driving force. The hybrid construction machine according to any one of claims 2 to 5.

Images