JP2014128133A - Shovel with electric power conversion system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shovel with electric power conversion system, capable of reducing an area to be ensured on a heat sink.SOLUTION: An upper rotating body is rotatably mounted on an undercarriage. An attachment is swingably mounted on the upper rotating body. A motor rotates the upper rotating body. An electric power conversion system supplies electric power to the motor. A power module is disposed in an enclosure of the electric power conversion system. A card plate is disposed at a different height from a surface on which the power module is disposed, and is supported on the enclosure. A CPU that transmits a control signal to the power module is mounted on the card plate.

Description

  The present invention relates to an excavator equipped with a power converter.

  In place of the conventional hydraulic excavator, a hybrid excavator that turns by an electric motor has attracted attention. A hybrid excavator is equipped with a power converter such as an inverter for driving an electric motor. This power converter is usually mounted on an upper swing body of an excavator. Since the engine, cabin, hydraulic circuit, turning electric motor, and the like are mounted on the upper swing body, it is difficult to secure a sufficient space for mounting the power conversion device. For this reason, size reduction of a power converter device is desired.

  Since a large current flows through the electric power converter for driving the electric motor, the wiring in the electric power converter must be thickened. The power conversion device is miniaturized because it accommodates electrical components such as an intelligent power module (IPM) including an insulated gate bipolar transistor (IGBT), a current sensor, a snubber capacitor, and a control processor (CPU). A sufficient space for arranging the wiring cannot be secured in the power conversion device. Since it is necessary to route thick wiring with high rigidity in a narrow space, the efficiency of assembly work is reduced. An inverter using a bus bar is known instead of wiring (Patent Documents 1 to 3).

JP 2003-319665 A JP 2008-245461 A JP 2012-110152 A

  Semiconductor elements such as IPM and CPU are mounted on a heat sink or the like for cooling. In order to mount these semiconductor elements on the heat sink, a large area must be secured on the heat sink. The objective of this invention is providing the shovel carrying the power converter device which can make the area | region which should be ensured on a heat sink small.

According to one aspect of the invention,
A lower traveling body,
An upper revolving unit attached to the lower traveling unit so as to be capable of swiveling; and
An attachment attached to the upper swing body so as to be swingable;
An electric motor for turning the upper turning body;
A power converter for supplying power to the electric motor,
The power converter is
A housing,
A power module disposed in the housing;
A card plate disposed at a height different from the surface on which the power module is disposed and supported by the housing;
An excavator having a CPU attached to the card plate and sending a control signal to the power module is provided.

  Since the power module and the CPU are arranged at different heights, the lateral expansion of the space in the housing can be suppressed.

FIG. 1 is a side view of an excavator according to the first embodiment. FIG. 2 is a block diagram of the shovel according to the first embodiment. FIG. 3 is a block diagram of a storage circuit and an equivalent circuit diagram of an inverter. FIG. 4 is an equivalent circuit diagram of the power storage circuit. FIG. 5 is a schematic front view inside the housing of the power conversion device. FIG. 6 is a plan view of the first layer of the power conversion device. 7A and 7B are a plan view and a front view of the bus bar, respectively. 8A is a cross-sectional view taken along one-dot chain line 8A-8A in FIG. 7A, and FIG. 8B is a cross-sectional view taken along one-dot chain line 8B-8B in FIG. 7A. FIG. 9 is a plan view of the second layer of the power conversion device. FIG. 10 is a plan view of a third layer of the power conversion device. 11 is a cross-sectional view taken along one-dot chain line 11-11 in FIG. 12A is a front view of a connection structure between a P-pole plate and a connection terminal and a connection structure between an N-pole plate and a connection terminal, and FIG. 12B is a connection structure between the P-pole plate and the connection terminal, and an N-pole. It is a side view of the connection structure of a plate and a connection terminal. FIG. 13 is a plan view of the fourth layer of the power conversion device. 14A is a plan view of a fifth layer of the power conversion device, and FIG. 14B is a cross-sectional view taken along one-dot chain line 14B-14B in FIG. 14A. 15A and 15B are cross-sectional views of other configuration examples taken along one-dot chain line 14B-14B in FIG. 14A. FIG. 16 is a cross-sectional plan view of the power converter according to the second embodiment. 17A and 17B are cross-sectional views taken along one-dot chain line 17A-17A in FIG. FIG. 18 is a plan sectional view of a power conversion device according to a modification of the second embodiment. 19 is a cross-sectional view taken along one-dot chain line 19-19 in FIG. FIG. 20 is a cross-sectional plan view of a power conversion device according to a second modification of the second embodiment. 21 is a cross-sectional view taken along one-dot chain line 21-21 in FIG.

[Example 1]
FIG. 1 shows a side view of a hybrid excavator according to the first embodiment. An upper turning body 21 is mounted on the lower traveling body 20 so as to be turnable. A boom 23 is connected to the upper swing body 21, an arm 25 is connected to the boom 23, and a bucket 27 is connected to the arm 25. Due to the expansion and contraction of the boom cylinder 24, the attachment including the boom 23, the arm 25, and the bucket 27 swings up and down with respect to the upper swing body 21. As the arm cylinder 26 expands and contracts, the posture of the arm 25 changes. Due to the expansion and contraction of the bucket cylinder 28, the posture of the bucket 27 changes. The boom cylinder 24, the arm cylinder 26, and the bucket cylinder 28 are hydraulically driven.

A swing motor 22, an engine 30, a motor generator 31, a power storage circuit 32, a power converter 33, and the like are mounted on the upper swing body 21. The motor generator 31 generates power with the power of the engine 30. The power storage circuit 32 is charged with the generated power. The turning electric motor 22 is driven by the electric power from the power storage circuit 32 to turn the upper turning body 21. The motor generator 31 also operates as an electric motor and assists the engine 30. The turning electric motor 22 also operates as a generator and generates regenerative power from the turning kinetic energy of the upper turning body 21.

  FIG. 2 is a block diagram of the hybrid excavator according to the first embodiment. 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 control system is represented by a thin solid line, and the pilot line is represented by a broken line.

  The drive shaft of the engine 30 is connected to the input shaft of the torque transmission mechanism 41. The engine 30 is an engine that generates a driving force by a fuel other than electricity, for example, an internal combustion engine such as a diesel engine. The engine 30 is always driven during operation of the work machine.

  The drive shaft of the motor generator 31 is connected to the other input shaft of the torque transmission mechanism 41. The motor generator 31 can perform both the electric (assist) operation and the power generation operation. For the motor generator 31, for example, an internal magnet embedded motor in which magnets are embedded in the rotor is used.

  The torque transmission mechanism 41 has two input shafts and one output shaft. A drive shaft of the main pump 42 is connected to the output shaft.

  When the load applied to the engine 30 is large, the motor generator 31 performs an assist operation, and the driving force of the motor generator 31 is transmitted to the main pump 42 via the torque transmission mechanism 41. Thereby, the load applied to the engine 30 is reduced. On the other hand, when the load applied to the engine 30 is small, the driving force of the engine 30 is transmitted to the motor generator 31 via the torque transmission mechanism 41, whereby the motor generator 31 is operated for power generation.

  The main pump 42 supplies hydraulic pressure to the control valve 44 via the high pressure hydraulic line 43. The control valve 44 distributes hydraulic pressure to the hydraulic motors 29 </ b> A and 29 </ b> B, the boom cylinder 24, the arm cylinder 26, and the bucket cylinder 28 according to a command from the driver. The hydraulic motors 29A and 29B drive the two left and right crawlers provided in the lower traveling body 20 shown in FIG.

  The motor generator 31 is connected to the storage circuit 32 via an inverter 33A. The turning electric motor 22 is connected to the storage circuit 32 via an inverter 33B. The inverters 33A and 33B and the power storage circuit 32 are controlled by the control device 55. Power conversion device 33 (FIG. 1) includes inverters 33A and 33B.

  The inverter 33A controls the operation of the motor generator 31 based on a command from the control device 55. Switching between the assist operation and the power generation operation of the motor generator 31 is performed by the inverter 33A.

  During the period in which the motor generator 31 is assisted, necessary power is supplied from the power storage circuit 32 to the motor generator 31 through the inverter 33A. During the period in which the motor generator 31 is generating, the electric power generated by the motor generator 31 is supplied to the power storage circuit 32 through the inverter 33A.

The swing electric motor 22 is AC driven by the inverter 33B and can perform both the power running operation and the regenerative operation. For the turning electric motor 22, for example, an internal magnet embedded motor is used. During the power running operation of the swing motor 22, electric power is supplied from the power storage circuit 32 to the swing motor 22 via the inverter 33B. The turning electric motor 22 turns the upper turning body 21 (FIG. 1) through the speed reducer 51. During the regenerative operation, the rotational motion of the upper swing body 21 is reduced by the speed reducer 5.
1 is transmitted to the turning electric motor 22 through the electric motor 1 so that the turning electric motor 22 generates regenerative electric power. The generated regenerative power is supplied to the power storage circuit 32 via the inverter 33B. Thereby, the power storage device in the power storage circuit 32 is charged.

  The resolver 52 detects the position of the rotating shaft of the turning electric motor 22 in the rotational direction. The detection result is input to the control device 55. By detecting the position of the rotating shaft in the rotational direction before and after the operation of the turning electric motor 22, the turning angle and the turning direction are derived.

  A mechanical brake 53 is connected to the rotating shaft of the turning electric motor 22 and generates a mechanical braking force. The braking state and release state of the mechanical brake 53 are controlled by the control device 55 and switched by an electromagnetic switch.

  The pilot pump 45 generates a pilot pressure necessary for the hydraulic operation system. The generated pilot pressure is supplied to the operating device 48 via the pilot line 46. The operating device 48 includes a lever and a pedal and is operated by a driver. The operating device 48 converts the primary side hydraulic pressure supplied from the pilot line 46 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 44 via the hydraulic line 49 and to the pressure sensor 47 via the other hydraulic line 50.

  The detection result of the pressure detected by the pressure sensor 47 is input to the control device 55. Thereby, the control apparatus 55 can detect the operation state of the lower traveling body 20, the boom 23, the arm 25, the bucket 27 (FIG. 1), and the turning electric motor 22.

  FIG. 3 shows a block diagram of the storage circuit 32 and an equivalent circuit diagram of the inverter 33B. The equivalent circuit diagram of the inverter 33A (FIG. 2) is also the same as the equivalent circuit diagram of the inverter 33B. The power storage circuit 32 includes a power storage device 34 and a step-up / down converter 35. A step-up / down converter 35 is connected to the DC bus line 36 of the inverter 33B. The step-up / down converter 35 boosts the output voltage of the power storage device 34 and applies it to the DC bus line 36. As a result, the power storage device 34 is discharged, and power is supplied to the DC bus line 36. The step-up / step-down converter 35 further charges the power storage device 34 by supplying power from the DC bus line 36 to the power storage device 34. The discharging operation and the charging operation of the step-up / step-down converter 35 are controlled by the control device 55.

  Between the DC bus lines 36, a U-phase power module 38U, a V-phase power module 38V, and a W-phase power module 38W are inserted in parallel. Each of these power modules 38U, 38V, and 38W includes two IGBTs connected in series, and a free wheel diode connected in parallel to each of the IGBTs. The interconnection points of the two IGBTs are connected to the U-phase, V-phase, and W-phase terminals of the swing electric motor 22, respectively. A control signal subjected to pulse width modulation (PWM) is applied from the control device 55 to the gate electrode of each IGBT.

  Further, a smoothing capacitor 37 is connected between the DC bus lines 36. As the smoothing capacitor 37, for example, a film capacitor is used.

FIG. 4 shows an equivalent circuit diagram of the storage circuit 32. Power storage circuit 32 includes a power storage device 34 and a step-up / down converter 35. A connector 203 for connecting to the DC bus line 36 and a connector 204 for connecting to the power storage device 34 are prepared in the step-up / step-down converter 35. Between the ground side terminal of the connector 203 and the high voltage side terminal, a series circuit of the IGBT 202A and the IGBT 202B is inserted. The free-wheeling diodes 202a and 202b are connected to the IGBT 202A on the ground side and the IGBT 202B on the high voltage side, respectively.
An interconnection point between the IGBTs 202 </ b> A and 202 </ b> B is connected to the high voltage side terminal of the connector 204 via the reactor 201. The ground side terminal of the connector 203 and the ground side terminal of the connector 204 are both grounded.

  The control device 55 applies a control pulse width modulation (PWM) signal to the gate electrodes of the two IGBTs. When a PWM signal is applied to the gate electrode of the IGBT 202A on the ground side, the voltage between the terminals of the power storage device 34 is boosted and a discharge current flows. When a PWM signal is applied to the gate electrode of the high-voltage-side IGBT 202B, a charging current flows from the DC bus line 36 to the power storage device 34.

  In FIG. 5, the schematic front view in the housing | casing of the power converter device 33 is shown. The power converter 33 shown in FIG. 5 corresponds to the inverter 33A or the inverter 33B (FIG. 2). In addition, you may accommodate the inverter 33A and the inverter 33B in one housing | casing.

  On the upper surface of the heat sink 60, a U-phase power module 38U, a V-phase power module 38V, and a W-phase power module 38W are mounted. Hereinafter, in order to facilitate the understanding of the relative positional relationship of each component, an xyz orthogonal coordinate system is defined. The x axis and the y axis are parallel to the mounting surface of the heat sink 60. The U-phase power module 38U, the V-phase power module 38V, and the W-phase power module 38W are arranged in this order in the x direction.

  A driver card 61 is fixed to the heat sink 60 by insulating columns 62. The driver card 61 is supported slightly above the upper surfaces of the three power modules 38U, 38V, and 38W. The driver card 61 incorporates a driver circuit for driving the power modules 38U, 38V, and 38W.

  Above the driver card 61, an N-pole plate 63 and a P-pole plate 65 are arranged. As an example, the N-pole plate 63 is disposed closer to the heat sink 60 than the P-pole plate 65. An insulating sheet 64 is inserted between the N-pole plate 63 and the P-pole plate 65 to ensure insulation between the two. The N-pole plate 63, the insulating sheet 64, and the P-pole plate 65 are supported on the heat sink 60 by insulating posts 66. The N pole plate 63 and the P pole plate 65 constitute a DC bus line 36 (FIG. 3). The three layers of the N-pole plate 63, the insulating sheet 64, and the P-pole plate 65 are referred to as “bus line plate 67”.

  A capacitor box 68 is mounted on the bus line plate 67. A smoothing capacitor 37 (FIG. 3) is accommodated in the capacitor box 68. A card plate 70 is attached on the capacitor box 68. A central processing unit (CPU) 71 is mounted on the card plate 70, and a control card 72 is mounted thereon. The control card 72 incorporates a control circuit for sending a control signal to a driver circuit incorporated in the driver card 61. A plurality of control lines 73 connect a control circuit incorporated in the control card 72 and a driver circuit incorporated in the driver card 61.

  A cover 75 is disposed on the heat sink 60. The heat sink 60 and the cover 75 constitute a housing 79 of the power conversion device 33. Components from the power modules 38U, 38V, 38W to the control card 72 are stored in a space surrounded by the heat sink 60 and the cover 75. A connector 76 is attached to the cover 75. Connector 76 includes a connection terminal for electrically connecting a component inside housing 79 and a component outside housing 79.

  The power conversion device 33 can be divided into a plurality of layers. Power modules 38U, 38V, and 38W are included in the first layer. The driver card 61 is included in the second layer. A bus line plate 67 is included in the third layer. A capacitor box 68 is included in the fourth layer. The fifth layer includes a card plate 70, a CPU 71, and a control card 72. Next, the structure of each layer will be described more specifically.

  In FIG. 6, the top view of the 1st layer of the power converter device 33 is shown. On the heat sink 60, a U-phase power module 38U, a V-phase power module 38V, and a W-phase power module 38W are mounted in this order in the x direction. The U-phase power module 38U has an output terminal 80U, a P-pole terminal 81U, and an N-pole terminal 82U on the upper surface thereof. The output terminal 80U, the P pole terminal 81U, and the N pole terminal 82U are arranged in this order in the y direction. Similarly, an output terminal 80V, a P-pole terminal 81V, and an N-pole terminal 82V are provided on the upper surface of the V-phase power module 38V, and an output terminal 80W and a P-pole terminal are provided on the upper surface of the W-phase power module 38W. 81W and an N pole terminal 82W are provided.

  The P pole terminals 81U, 81V, 81W are connected to the P pole of the DC bus line 36 (FIG. 3), and the N pole terminals 82U, 82V, 82W are connected to the N pole of the DC bus line 36 (FIG. 3). . The output terminals 80U, 80V, and 80W are connected to the U-phase, V-phase, and W-phase input terminals of the turning electric motor 22 (FIG. 3), respectively.

  Connectors 76A and 76B are arranged so as to intersect the edge of the heat sink 60 parallel to the y direction. The connectors 76A and 76B correspond to the connector 76 shown in FIG. The connector 76A includes connection terminals 90U, 90V, 90W arranged in the height direction (z direction). The U-phase power module 38U is disposed at a position farthest from the connector 76A, and the W-phase power module 38W is disposed at a position closest to the connector 76A.

  The output terminal 80U is connected to the connection terminal 90U via the output bus bar 83U, the intermediate conductive member 85U, and the connection bus bar 84U. The output terminal 80V is connected to the connection terminal 90V via the output bus bar 83V, the intermediate conductive member 85V, and the connection bus bar 84V. The output terminal 80W is connected to the connection terminal 90W via the output bus bar 83W, the intermediate conductive member 85W, and the connection bus bar 84W.

  The output bus bars 83U, 83V, 83W are arranged at the same position in the y direction. Output bus bar 83U and connection bus bar 84U are electrically connected to each other via intermediate conductive member 85U. The output bus bar 83U, the intermediate conductive member 85U, and the connection bus bar 84U are fastened together by a fastener 86 such as a bolt and a nut. Similarly, the output bus bar 83V and the connection bus bar 84V are electrically connected to each other via the intermediate conductive member 85V. The output bus bar 83W and the connection bus bar 84W are electrically connected to each other via the intermediate conductive member 85W. Connection portions of the output bus bars 83U, 83V, 83W and the connection bus bars 84U, 84V, 84W corresponding to each other are located on one virtual straight line parallel to the x direction.

  The three connection bus bars 84U, 84V, 84W are detoured in the height direction (z direction) or the width direction (y direction) so as not to contact each other.

  7A and 7B are a plan view and a front view of the bus bar, respectively. The plan view shown in FIG. 7A is the same as the bus bar portion of the plan view shown in FIG.

As shown in FIG. 7B, the output bus bars 83U, 83V, and 83W rise upward (in the z direction) from the U-phase power module 38U, the V-phase power module 38V, and the W-phase power module 38W, respectively. Yes. Each of output bus bars 83U, 83V, and 83W includes a plate-like portion parallel to the zx plane (first virtual plane) at the tip thereof. Each of the connection bus bars 84U, 84V, 84W also includes a plate-like portion parallel to the zx plane. The mutually corresponding output bus bars 83U, 83V, 83W and the connection bus bars 84U, 84V, 84W are coupled to each other at plate-like portions parallel to the zx plane. The fastener 86 passes through this plate-like portion in a direction (y direction) orthogonal to the zx plane. The joint portions of the output bus bars 83U, 83V, 83W and the connection bus bars 84U, 84V, 84W corresponding to each other are located at the same height with respect to the mounting surface of the heat sink 60.

  The connector 76A includes connection terminals 90U, 90V, and 90W. The connection terminals 90U, 90V, 90W are arranged in this order in the height direction (z direction) upward. Each of the connection terminals 90U, 90V, 90W includes a plate-like portion parallel to the zx plane. The connection terminals 90U, 90V, 90W are respectively coupled to the connection bus bars 84U, 84V, 84W at the plate-like portions.

  The connection bus bar 84W connects the output bus bar 83W and the connection terminal 90W. The connection terminal 90W is located at the same height as the joint between the output bus bar 83W and the connection bus bar 84W. For this reason, the connection bus bar 84W extends linearly in the x direction.

  The connection bus bar 84V connects the output bus bar 83V and the connection terminal 90V. The connection bus bar 84V extends in parallel with the x direction from the joint with the output bus bar 83V toward the connector 76A, and then descends to the same height as the connection terminal 90V before the output bus bar 83W. Extends linearly towards.

  The connection bus bar 84U connects the output bus bar 83U and the connection terminal 90U. The connection bus bar 84U extends in parallel with the x direction from the joint with the output bus bar 83U toward the connector 76A, and bypasses the y direction in front of the output bus bar 83V as shown in FIG. 7A. Thereafter, as shown in FIG. 7B, after descending to the same height as the connection terminal 90V, it extends toward the connection terminal 90V. After the connection bus bar 84U intersects the output bus bar 83W in the zx plane, the connection bus bar 84U once rises to the same height as the connection terminal 90W, and then extends toward the connection terminal 90W. Then, after descending to the same height as the connection terminal 90U, as shown in FIG. 7A, it returns to the original position in the y direction and extends linearly toward the connection terminal 90U.

  As described above, an image obtained by vertically projecting each of the plurality of connection bus bars 84U, 84V, and 84W on the zx plane (first virtual plane) is a vertical projection of the connection point between the other connection bus bars and the output bus bar on the zx plane. Connection bus bars 84U, 84V, 84W are arranged so as not to overlap with the image. For this reason, a work space is ensured at the side of the joint between the output bus bars 83U, 83V, 83W and the connection bus bars 84U, 84V, 84W corresponding to each other. Since the work space is secured, the fastening operation of the fastener 86 can be easily performed.

  7B, a part of the connection bus bar 84U is arranged at the same height as the connection terminal 90W between the output bus bar 83W and the connector 76A. A current sensor 87 can be attached to this portion.

  8A shows a cross-sectional view taken along one-dot chain line 7A-7A in FIG. 7A, and FIG. 8B shows a cross-sectional view taken along one-dot chain line 7B-7B in FIG. 7A.

As shown in FIG. 8A, an output bus bar 83W is connected to the output terminal 80W of the W-phase power module 38W. The connection bus bar 84 </ b> W, the intermediate conductive member 85 </ b> W, and the output bus bar 83 </ b> W are fastened together by a fastener 86. The connection bus bar 84V passes below the connection bus bar 84W. The connection bus bar 84U passes the side of the connection bus bar 84V. An insulating support plate 88 is disposed between the output bus bar 83W and the connection bus bar 84W. The insulating support plate 88 is fixed to the heat sink 60.

  As shown in FIG. 8B, the insulating support plate 88 is continuously arranged from the intermediate conductive member 85U at one end to the intermediate conductive member 85W at the other end in the x direction. A plurality of U-shaped notches 89 are provided on the upper edge of the insulating support plate 88. The intermediate conductive members 85U, 85V, and 85W are mechanically supported by the insulating support plate 88 by being inserted into the notch 89. Since the insulating support plate 88 having a larger area than the output bus bars 83U, 83V, 83W supports the intermediate conductive members 85U, 85V, 85W, the output bus bars 83U, 83V, 83W and the connection bus bars 84U, 84V, 84W Impact resistance can be increased.

  In FIG. 9, the top view of the 2nd layer of the power converter device 33 is shown. The driver card 61 is arranged so as to overlap with the U-phase power module 38U, the V-phase power module 38V, and the W-phase power module 38W. Three openings 69 are formed in the driver card 61. One opening 69 includes the output terminal 80U, the P-pole terminal 81U, and the N-pole terminal 82U in plan view. Similarly, the other opening 69 includes the output terminal 80V, the P-pole terminal 81V, and the N-pole terminal 82V in a plan view, and the other opening 69 has an output terminal 80W, a P-pole terminal 81W, and N pole terminal 82W is included.

  The output bus bars 83U, 83V, 83W (FIG. 7B) extend upward through the opening 69. The P-pole terminals 81U, 81V, 81W and the N-pole terminals 82U, 82V, 82W are electrically connected to the components of the upper layer through the opening 69.

  In FIG. 10, the top view of the 3rd layer of the power converter device 33 is shown. A bus line plate 67 is arranged so as to overlap the U-phase power module 38U, the V-phase power module 38V, and the W-phase power module 38W. Connectors 76A and 76B are arranged so as to overlap the edge of the heat sink 60 parallel to the y direction. The connector 76B includes connection terminals 90N and 90P.

  Openings 92 are formed in the bus line plate 67 at positions corresponding to the output terminals 80U, 80V, and 80W, respectively. Output bus bars 83U, 83V, 83W (FIG. 7B) pass through the opening 92.

  As shown in FIG. 5, the bus line plate 67 has a structure in which an N-pole plate 63, an insulating sheet 64, and a P-pole plate 65 are laminated. Openings 93 are formed in the N-pole plate 63 at positions corresponding to the P-pole terminals 81U, 81V, and 81W. Openings 94 are formed in the P-pole plate 65 at positions corresponding to the N-pole terminals 82U, 82V, and 82W, respectively.

  A connection point 95N of the N-pole plate 63 is connected to the connection terminal 90N via an N-pole connection bus bar 96N. A connection point 95P of the P-pole plate 65 is connected to the connection terminal 90P via a P-pole connection bus bar 96P.

  FIG. 11 is a cross-sectional view taken along one-dot chain line 10-10 in FIG. A bus line plate 67 is supported above the U-phase power module 38U. The bus line plate 67 includes an N-pole plate 63, an insulating sheet 64, and a P-pole plate 65. An insulating sheet 64 is sandwiched between the N-pole plate 63 and the P-pole plate 65. The N pole plate 63 is disposed below the P pole plate 65.

  A P-pole terminal 81U and an N-pole terminal 82U are defined on the upper surface of the U-phase power module 38U. An opening 93 is formed in the N-pole plate 63 at a position corresponding to the P-pole terminal 81U. An opening is also formed in the insulating sheet 64 at the same position. As a result, the bottom surface of the P-pole plate 65 is exposed at a position facing the P-pole terminal 81U. A P pole bus bar 97P whose upper end and lower end are bent in an L shape in the same direction connects the exposed bottom surface of the P pole plate 65 to the P pole terminal 81U. The P pole bus bar 97P and the P pole plate 65 are connected to each other by a fastener 100 such as a bolt and a nut. P pole bus bar 97P and P pole terminal 81U are connected to each other by a fastener 101 such as a bolt.

  An N pole bus bar 97N whose upper end and lower end are bent in an L shape in the same direction connects the N pole terminal 82U and the N pole plate 63. An opening 94 is formed at a position of the P-pole plate 65 corresponding to the N-pole terminal 82U. An opening is also formed in the insulating sheet 64 at the same position as the opening 94. The N pole bus bar 97N and the N pole plate 63 are connected to each other by a fastener 102 such as a bolt and a nut. The opening 94 secures an accommodation space for the fastener 102. The N pole bus bar 97N and the N pole terminal 82U are connected to each other by a fastener 103 such as a bolt.

  The P-pole bus bar 97P and the N-pole bus bar 97N ensure electrical connection between the P-pole terminal 81U and the P-pole plate 65 and between the N-pole terminal 82U and the N-pole plate 63, respectively. 67 is mechanically supported.

  With reference to FIGS. 12A and 12B, a connection structure between the P-pole plate 65 and the connection terminal 90P and a connection structure between the N-pole plate 63 and the connection terminal 90N will be described. 12A shows a front view of the connection structure when viewed from a direction parallel to the y direction, and FIG. 12B shows a side view of the connection structure when viewed from a direction parallel to the x direction.

  The connection terminal 90 </ b> P and the connection terminal 90 </ b> N are arranged in the height direction (z direction), that is, in the direction perpendicular to the bus line plate 67. The connection terminal 90P is disposed above the connection terminal 90N. The connection terminals 90P and 90N include a plate-like portion parallel to the zx plane.

  A P-pole connection bus bar 96P connects the P-pole plate 65 and the connection terminal 90P. The P-pole bus bar 96P includes a plate-side bus bar 99P and a terminal-side bus bar 98P. The lower end and the upper end of the plate-side bus bar 99P are bent in an L shape in opposite directions. The lower end of the plate-side bus bar 99P is connected to the P-pole plate 65. The upper end of the plate side bus bar 99P is connected to the terminal side bus bar 98P.

  One end of the terminal-side bus bar 98P is constituted by a plate-like portion parallel to the xy plane, and the other end is constituted by a plate-like portion parallel to the zx plane. A plate-like portion parallel to the xy plane of the terminal-side bus bar 98P is connected to the upper end of the plate-side bus bar 99P, and a plate-like portion parallel to the zx plane is connected to the connection terminal 90P. An opening 105 penetrating the N-pole plate 63 and the insulating sheet 64 is formed at a connection portion between the plate-side bus bar 99P and the P-pole plate 65. The opening 105 secures a storage space for the fastener 107 for fastening the P-pole plate 65 and the plate-side bus bar 99P.

An N pole connection bus bar 96N connects the N pole plate 63 and the connection terminal 90N. The N pole connection bus bar 96N includes a plate side bus bar 99N and a terminal side bus bar 98N. The lower end and the upper end of the plate-side bus bar 99N are bent in an L shape in opposite directions. The lower end of the plate-side bus bar 99N is connected to the N-pole plate 63 through the opening 106 formed in the P-pole plate 65. The upper end of the plate-side bus bar 99N is connected to the terminal-side bus bar 98N.

  One end of the terminal-side bus bar 98N is constituted by a plate-like portion parallel to the xy plane, and the other end is constituted by a plate-like portion parallel to the zx plane. A plate-like portion parallel to the xy plane of the terminal-side bus bar 98N is connected to the upper end of the plate-side bus bar 99N, and a plate-like portion parallel to the zx plane is connected to the connection terminal 90N.

  In FIG. 13, the top view of the 4th layer of the power converter device 33 is shown. A capacitor box 68 is mounted on the bus line plate 67. A P-pole terminal 110P and an N-pole terminal 110N protrude from the capacitor box 68. The P-pole terminal 110P is electrically connected to the P-pole plate 65 (FIG. 5) of the bus line plate 67 and is mechanically fixed. The N pole terminal 110N is electrically connected to the N pole plate 63 (FIG. 5) of the bus line plate 67 and is mechanically fixed.

  FIG. 14A shows a plan view of the fifth layer of the power conversion device 33. FIG. 14B is a cross-sectional view taken along one-dot chain line 13B-13B in FIG. 14A. A card plate 70 is disposed on the capacitor box 68. The card plate 70 extends from one wall surface of the cover 75 to the other wall surface (from one side surface of the housing 79 to the side surface facing it) in the width direction (y direction). An edge of the card plate 70 parallel to the x direction is bent downward in an L shape. The tip of the card plate 70 from the bent portion is fixed to the cover 75 by a fastener 113.

  Further, the card plate 70 is fixed to the capacitor box 68 by a fastener 115 in the inner back portion of the card plate 70. A CPU 71 is mounted on the card plate 70. A control card 72 is attached on the CPU 71.

  The capacitor box 68 is fixed to the bus line plate 67 by an N pole terminal 110N and a P pole terminal 110P (FIG. 13). The bus line plate 67 is fixed to the heat sink 60 by insulating posts 66, and is connected to the heat sink 60 via the N pole bus bar 97N, the P pole bus bar 97P (FIG. 11), and the power modules 38U, 38V, and 38W (FIG. 5). It is supported. For this reason, the capacitor box 68 is firmly fixed to the heat sink 60. Since the card plate 70 is fixed to the capacitor box 68 at the inner back thereof, the vibration of the card plate 70 can be suppressed. Thereby, the impact applied to CPU71 can be reduced.

  FIG. 15A is a cross-sectional view of another configuration example taken along one-dot chain line 13B-13B in FIG. 14A. Hereinafter, differences from the cross-sectional view illustrated in FIG. 14B will be described. A cooling medium channel 77 is formed in the heat sink 60. The cover 75 includes a bottom surface and a side surface. The outer surface of the bottom surface of the cover 75 is in close contact with the heat sink 60. The V-phase power module 38 </ b> V is attached to the bottom surface of the cover 75. Similarly, the U-phase power module 38U and the W-phase power module 38W (FIG. 5) are also attached to the bottom surface of the cover 75. Heat generated in the U-phase power module 38U, the V-phase power module 38V, and the W-phase power module 38W is transmitted to the heat sink 60 via the bottom surface of the cover 75.

Since the cover 75 is in close contact with the heat sink 60 on the bottom surface, good heat transfer between the cover 75 and the heat sink 60 can be ensured. Thereby, the CPU 71 can be efficiently cooled from the heat sink 60 through the cover 75 and the card plate 70. Similarly to the U-phase power module 38U and the like, the CPU 71 covers the cover 75.
In the case of adopting a configuration arranged on the bottom surface of the cover 75, the bottom surface of the cover 75 must be widened. In the first embodiment, the CPU 71, the U-phase power module 38U, and the like are arranged in different layers. For this reason, the increase in the dimension in the planar view of the power converter device 33 can be suppressed. Although the CPU 71 is arranged in a layer different from the U-phase power module 38U and the like, the CPU 71 can be efficiently cooled via the cover 75 and the card plate 70.

  As shown in FIG. 15B, a cooling medium channel 78 may be formed in the side surface of the cover 75. Alternatively, the flow path may be thermally coupled to the outer surface of the cover 75. By forming the cooling medium channel 78 on the side surface of the cover 75, the CPU 71 can be cooled more efficiently.

  15A and 15B, the cooling medium channels 77 and 78 incorporated in the housing 79 are used as a cooling mechanism for cooling the housing 79 including the heat sink 60 and the cover 75. As a cooling mechanism, an air cooling mechanism, a Peltier element, or the like may be used instead of the cooling medium channels 77 and 78.

[Example 2]
In FIG. 16, the plane sectional view of the power converter device 33 mounted in the shovel by Example 2 is shown. Hereinafter, differences from the first embodiment will be described, and description of the same configuration will be omitted. In FIG. 16, a first layer component, for example, a U-phase power module 38 </ b> U or the like is shown inside the housing 79. The insulating member 120 is disposed between the connection bus bars 84U, 84V, 84W and the side surface of the housing 79. For the insulating member 120, for example, a thermosetting resin, insulating paper, or the like is used.

  FIG. 17A is a cross-sectional view taken along one-dot chain line 16A-16A in FIG. The housing 79 includes a heat sink 60, a container 75A having an opening above it, and a lid 75B that closes the opening of the container 75A. The insulating member 120 is disposed between the connection bus bars 84U, 84V, 84W and the side surface of the housing 79. The insulating member 120 prevents an electrical short circuit between the connection bus bars 84U, 84V, 84W and the side surface of the housing 79. When the output bus bars 83U, 83V, 83W are arranged closer to the side surface of the housing 79 than the connection bus bars 84U, 84V, 84W, the output bus bars 83U, 83V, 83W, The insulating member 120 may be disposed between the two.

  As shown in FIG. 17B, the insulating member 120 may be attached to the inner surface of the side surface of the housing 79 with an adhesive or the like. With the configuration shown in FIG. 17B, even when an impact or vibration occurs in the power conversion device 33, it is possible to prevent the short-circuit prevention function from being lowered due to the displacement of the insulating member 120 or the like.

[Modification 1 of Embodiment 2]
In FIG. 18, the plane sectional view of the power converter device 33 by the modification 1 of Example 2 is shown. In the first modification of the second embodiment, the insulating member 120 has a cylindrical shape that surrounds the electrical component disposed inside the housing 79 in plan view. The height of the insulating member 120 is substantially equal to the height from the bottom surface of the container 75A to the card plate 70. The connection bus bars 84U, 84V, 84W are led out to the outside of the insulating member 120 through the slit 121 formed in the insulating member 120, and are connected to the connection terminals 90U, 90V, 90W.

FIG. 19 is a cross-sectional view taken along one-dot chain line 18-18 in FIG. In this cross section, the insulating members 120 are arranged on both sides of the electrical component such as the V-phase power module 38V. The insulating member 120 has a form retentivity capable of retaining its form only with the insulating member 120. That is, when the cylindrical insulating member 120 is erected on the horizontal plane, the insulating member 120 is self-supporting while maintaining its form. For this reason, the insulating member 120 can be easily positioned and mounted in the container 75A with the lid 75B and the card plate 70 removed.

  In the first modification of the second embodiment, the insulating member 120 has a cylindrical shape, and its height is substantially equal to the height from the bottom surface of the container 75A to the card plate 70. Therefore, even if the power conversion device 33 vibrates. The insulating member 120 is difficult to move from the initial position. For this reason, the short-circuit preventing function between the connection bus bars 84U, 84V, 84W and the side surface of the housing 79 can be stably maintained. The height of the insulating member 120 is preferably 90% or more of the height from the bottom surface of the container 75A to the card plate 70.

[Modification 2 of Embodiment 2]
In FIG. 20, the plane sectional view of the power converter device 33 by the modification 2 of Example 2 is shown. FIG. 21 is a cross-sectional view taken along one-dot chain line 21-21 in FIG. In the second modification of the second embodiment, the insulating member 120 is bonded to the inner surface of the side surface of the housing 79 with an adhesive. Other configurations are the same as those of the first modification of the second embodiment.

  In the second modification of the second embodiment, since the insulating member 120 is bonded to the housing 79, the vibration resistance of the power conversion device can be further improved.

  5 to 21, the inverters 33 </ b> A and 33 </ b> B have been described as examples of the power converter. The buck-boost converter 35 shown in FIG. 4 can also have the same configuration as that of the power converter shown in FIGS. For example, the IGBTs 202A and 202B and the reactor 201 are mounted on the heat sink 60 (FIG. 5). Connector 203 and IGBTs 202A and 202B are connected by a bus bar. Connector 204 and reactor 201 are connected by a bus bar.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 20 Lower traveling body 21 Upper turning body 22 Turning electric motor 23 Boom 24 Boom cylinder 25 Arm 26 Arm cylinder 27 Bucket 28 Bucket cylinder 29A, 29B Hydraulic motor 30 Engine 31 Motor generator 32 Power storage circuit 33 Power converters 33A, 33B Inverter 34 Power storage Device 35 Step-up / down converter 36 DC bus line 37 Smoothing capacitor 38U U-phase power module 38V V-phase power module 38W W-phase power module 41 Torque transmission mechanism 42 Main pump 43 High-pressure hydraulic line 44 Control valve 45 Pilot pump 46 Pilot line 47 Pressure sensor 48 Operating device 49, 50 Hydraulic line 51 Reducer 52 Resolver 53 Mechanical brake 55 Control device 60 Heat sink 61 Driver card 62 Strut 63 N-pole plate 64 insulating sheet 65 P electrode plate 66 insulating posts 67 bus line plate 68 capacitor box 69 opening 70 card plate 71 central processing unit (CPU)
72 Control card 73 Control line 75 Cover 76, 76A, 76B Connector 77, 78 Coolant flow path 79 Housing 80U, 80V, 80W Output terminal 81U, 81V, 81W P-pole terminal 82U, 82V, 82W N-pole terminal 83U, 83V, 83W Output bus bar 84U, 84V, 84W Connection bus bar 85U, 85V, 85W Intermediate conductive member 86 Fastener 87 Current sensor 88 Insulation support plate 89 Cut 90U, 90V, 90W, 90N, 90P Connection terminal 92, 93, 94 Opening 95N , 95P Connection point 96N N pole connection bus bar 96P P pole connection bus bar 97N N pole bus bar 97P P pole bus bar 98N, 98P Terminal side bus bar 99N, 99P Plate side bus bar 100, 101, 102, 103 Fastener 105, 106 Opening 107 Fastener 110P Terminal 110N N terminal 113,115 fastener 120 insulating member 121 slit 201 reactor 202A, 202B IGBT
202a, 202b Freewheeling diode 203, 204 Connector

Claims (4)

A lower traveling body,
An upper revolving unit attached to the lower traveling unit so as to be capable of swiveling; and
An attachment attached to the upper swing body so as to be swingable;
An electric motor for turning the upper turning body;
A power converter for supplying power to the electric motor,
The power converter is
A housing,
A power module disposed in the housing;
A card plate disposed at a height different from the surface on which the power module is disposed and supported by the housing;
A shovel having a CPU attached to the card plate and sending a control signal to the power module. The card plate is supported by the housing at both ends thereof,
further,
A capacitor electrically connected to the power module;
A capacitor box that houses the capacitor and is fixed to the housing;
The shovel according to claim 1, wherein the card plate is fixed to the capacitor box at an inner back portion thereof.   The shovel according to claim 2, wherein the capacitor is a film capacitor.   The shovel according to any one of claims 1 to 3, further comprising a cooling mechanism that cools the casing.

Images