JP6526517B2 - Inverter device - Google Patents

Description

  The present invention relates to an inverter device provided with a switching element and a smoothing capacitor.

  An inverter device which converts a DC voltage into an AC voltage and supplies it to a load is used in various applications. For example, in a hybrid shovel, an inverter device converts a DC voltage generated by a DC battery into an AC voltage and supplies it to a generator motor that performs power assist of an engine that is a power source.

  The inverter device includes a switching element for converting a DC voltage to an AC voltage and a smoothing capacitor. Since these generate heat by the operation of the inverter device, it is desirable to attach a cooling mechanism to the inverter device. In particular, an inverter device mounted on a hybrid shovel is often disposed in an environment exposed to the heat generated by the engine, so efficient cooling of the inverter device is required. On the other hand, since the arrangement space is limited, miniaturization of the inverter device including the cooling mechanism is also required.

  Patent Document 1 discloses an inverter device in which a switching element is mounted on one surface of a plate having a refrigerant flow path and a smoothing capacitor is mounted on the other surface. The switching element and the smoothing capacitor are electrically connected by a bus bar drawn from one side of the plate to the other side. According to this inverter device, the switching element and the smoothing capacitor can be cooled and the demand for miniaturization can be satisfied.

JP, 2014-11926, A

  However, in the inverter device of Patent Document 1, the switching element as a heating element and the smoothing capacitor are respectively mounted on one surface and the other surface of the plates facing each other. For this reason, the heat which a switching element emits turns around to the other side, and there is a problem that cooling efficiency deteriorates. Further, the path length of the bus bar connecting the two becomes long because the wiring is required, and the inductance of the bus bar portion increases. This causes a large surge voltage and electrical loss during the operation of the inverter device, and causes inductive noise and radiation noise.

  An object of the present invention is to provide an inverter device capable of satisfying a demand for miniaturization and suppressing generation of noise while achieving good cooling of a switching element and a smoothing capacitor.

An inverter device according to one aspect of the present invention includes: a switching element that converts a DC voltage into an AC voltage; a capacitor that smoothes the DC voltage; a bus bar that electrically connects the switching element and the capacitor; And a cooler to which the switching element and the capacitor are attached, and a casing that covers the switching element and the capacitor attached to the cooler and is attached to another device. The cooler includes a first surface and a second surface adjacent to and intersecting the first surface, the switching element being attached to the first surface, and the capacitor being attached to the second surface. The bus bar connects the switching element and the capacitor in a path crossing the boundary between the first surface and the second surface. In it are inverter device, wherein the first surface and the second surface is a surface orthogonal to each other, the bus bar includes a first portion parallel to the first plane, the second parallel to the second plane It is characterized by having an L-shaped shape provided with a portion and a connection portion between the first portion and the second portion .

  According to this inverter device, since the switching element is attached to the first surface of the cooler and the capacitor is attached to the second surface adjacent to the first surface, it is difficult for the heat emitted by one to reach the other attachment surface. Cooling of the two can be performed efficiently. Further, since the first surface and the second surface intersect with each other, the cooler can be miniaturized as compared with the case where the first surface and the second surface are arranged in the same plane. . For this reason, even if the casing attached to another device is subject to dimensional limitations, this can be coped with. Furthermore, since the bus bar is wired in a route straddling the boundary between the first surface and the second surface, the path length of the bus bar can be shortened, and the inductance is not increased. Therefore, the generation of noise can be suppressed.

Further, wherein the first surface and the second surface is a surface orthogonal to each other, the bus bar includes a first portion parallel to the first surface, said second portion parallel to the second surface, wherein that having a L-shape and a connecting portion between the first portion and the second portion.

  According to this inverter device, since the first surface and the second surface are orthogonal to each other, further downsizing of the cooler can be achieved. In addition, since the bus bar can be disposed in the shortest path, the inductance can be minimized.

  In the above-mentioned inverter device, the cooler preferably has an exposed portion not covered by the casing.

  According to this inverter device, the exposed portion of the cooler is substantially used as a part of the casing. Therefore, the casing structure can be simplified, and the assembly process of the inverter device can be simplified.

An inverter device according to another aspect of the present invention comprises a switching element for converting a DC voltage to an AC voltage, a capacitor for smoothing the DC voltage, and a bus bar for electrically connecting the switching element and the capacitor. A casing internally provided with a flow path for circulating a refrigerant, including a cooler to which the switching element and the capacitor are attached, a cover covering the switching element and the capacitor attached to the cooler, and a casing attached to another device And, the cooler includes a first surface and a second surface adjacent to and intersected with the first surface, the switching element on the first surface, and the capacitor on the second surface. Are respectively attached, and the bus bar is a path straddling the boundary between the first surface and the second surface, and the switching element and the capacitor In the inverter device which connects the capacitors, said cooler includes a first flat plate portion having a first surface and a second flat plate portion having the second surface, the first surface and the second surface And a side plate portion having a third surface which is adjacent to and orthogonal to these, and the casing includes at least one of the cover, the first flat plate portion, the second flat plate portion, and the back surface of the side plate portion. One and characterized in that it is constituted by.

  According to this inverter device, the first flat plate portion, the second flat plate portion, and the side plate portion can be used as a part of the casing. Therefore, the casing structure can be further simplified, the number of parts can be reduced, and the assembly process can be reduced.

  In the above-described inverter device, it is preferable that the flow passage of the cooler is formed of a single flow passage passing directly below the first surface and immediately below the second surface.

  According to this inverter device, since it is not necessary to provide an intermediate connection portion or the like of the flow path by integrating the flow path, it is possible to reduce the number of parts and the number of assembling steps.

  In this case, it is desirable that the upstream side of the refrigerant flow in the one flow passage is immediately below the second surface, and the downstream side is immediately below the first surface.

  In general, the switching element generates more heat than the smoothing capacitor. Therefore, when the first surface to which the switching element is attached is set to the upstream side, the refrigerant absorbs a large amount of heat, and there is a concern that sufficient heat exchange with the condenser can not be performed on the second surface downstream. According to the above configuration, this concern can be eliminated.

  In the above-mentioned inverter device, it is desirable that a supply destination of the alternating voltage generated by the switching element is a rotating electrical machine, and the other device to which the casing is attached is the rotating electrical machine.

  Since the inverter device according to the present invention can be miniaturized, the inverter device can be attached even when the mounting space is limited in the rotating electrical machine.

  In particular, the rotating electrical machine is a generator motor mounted on a hybrid construction machine, and the generator motor is arranged in series between an engine serving as a power source of the hybrid construction machine and a hydraulic pump operating a hydraulic system. Is desirable.

  As described above, in a hybrid construction machine, in a generator motor arranged in series between an engine and a hydraulic pump, the engine is exposed to the heat generated by the engine, and the arrangement space of the inverter device is greatly restricted. Be done. If the inverter device according to the present invention is applied to such a generator motor, the assembly can be easily performed, and the switching element and the smoothing capacitor can be efficiently cooled.

  According to the present invention, it is possible to provide an inverter device capable of satisfying the demand for downsizing and suppressing the generation of noise while achieving good cooling of the switching element and the smoothing capacitor.

It is a circuit diagram of an inverter device concerning an embodiment of the present invention. It is a sectional side view (II-II line sectional view of Drawing 3) of an inverter device concerning an embodiment of the present invention. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a cooler and a casing which are component parts of the said inverter apparatus. FIG. 5 is a perspective view of the cooler with the viewing direction changed. It is a see-through | perspective perspective view of the said cooler. It is a side sectional view showing an inverter device concerning a comparative example. It is a schematic side view of a hybrid shovel. It is a top view of the upper surface view of the said hybrid shovel. It is the schematic which shows the generator motor and inverter apparatus mounted in the said hybrid shovel. It is sectional drawing which shows the attachment state of the inverter apparatus to a generator motor. It is a top view of the mounting plate of an inverter apparatus. It is a top view which shows the mounting state to the generator motor housing of the said mounting board.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
[Circuit configuration of inverter device]
FIG. 1 is a circuit diagram of an inverter device 1 according to an embodiment of the present invention. The inverter device 1 is a device used to drive the AC motor M using a battery 10 generating a DC voltage. The inverter device 1 includes an inverter unit 2 and a capacitor 3.

  The battery 10 is a power supply that generates a predetermined DC voltage. For example, when the inverter device 1 is mounted on a construction machine such as a hybrid shovel, the battery 10 is a storage battery capable of charging and discharging which is included in the hybrid shovel. The first wiring 11 is drawn out from the positive electrode of the battery 10, and the second wiring 12 is drawn out from the negative electrode. The direct current voltage may be a direct current voltage generated by converting a commercial alternating current voltage by a converter.

  The inverter unit 2 includes a switching element that converts a DC voltage into an AC voltage, and supplies the motor M with an AC voltage for driving. In the present embodiment, the inverter unit 2 includes a power conversion module for each phase of three-phase alternating current, that is, a U-phase module 2U, a V-phase module 2V, and a W-phase module 2W. Each module includes, for example, a switching element made of a power semiconductor such as an insulated gate bipolar transistor (IGBT), and a free wheeling diode connected in antiparallel to the switching element.

  The capacitor 3 smoothes the DC voltage generated by the battery 10. The capacitor 3 has a P terminal A1 and an N terminal A2, and the P terminal A1 is connected to the first wiring 11, and the N terminal A2 is connected to the second wiring.

  The third wiring 13 connected to the P terminal of the inverter unit 2 is connected to the first wiring 11 like the P terminal A1, and the fourth wiring 14 connected to the N terminal is connected to the second wiring 12 like the N terminal A2. Each is connected. The U-phase, V-phase, W-phase modules 2U, 2V, 2W output wirings 15 of the inverter unit 2 are connected to the U-phase, V-phase, W-phase coils of the motor M, respectively.

  The motor M is a rotating electrical machine to which the three-phase AC voltage generated by the inverter unit 2 is supplied. For example, when the inverter device 1 according to the present embodiment is applied to a hybrid construction machine, the motor M is a generator motor that performs power assist of the drive unit while performing power generation with an excess engine output.

  In the circuit configuration of the inverter device 1 described above, it is required to shorten the length of the third wiring 13 and the fourth wiring 14 to reduce the inductance. In particular, it is desirable to make the fourth wiring 14 as short as possible. That is, the IGBT (switching element) included in the inverter unit 2 operates with the potential of the N terminal A2 as the reference potential for gate voltage application. For this reason, when the inductance of the fourth wiring 14 is increased, an appropriate voltage may not be applied to the switching element. Also, generally, the fourth wire 14 incorporates a shunt resistor for detecting the current flowing to the motor M. A noise voltage (surge voltage) is generated by the shunt resistance and the inductance of the fourth wiring 14 to give induction noise to the current detection circuit or generate radiation noise.

[Description of structure of inverter device]
2 is a side sectional view of the inverter device 1 according to the present embodiment, FIG. 3 is a sectional view taken along line III-III in FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 2 is a cross-sectional view taken along line II-II in FIG. The inverter device 1 includes a bus bar, a cooler 5 and a cover 6 in addition to the inverter unit 2 and the capacitor 3 described above.

  The inverter unit 2 includes three modules of U-phase, V-phase, and W-phase modules 2U, 2V, and 2W having a flat rectangular parallelepiped shape. Each module has two input terminals for electrical connection with the capacitor 3 and an output terminal for electrical connection with the motor M. The capacitor 3 consists of one smoothing capacitor, and an output terminal for electrical connection between the input terminal for electrical connection with the battery 10 and the U-phase, V-phase, W-phase modules 2U, 2V, 2W (FIG. 1 P terminal A1 and N terminal A2).

  The bus bar is a strip-like bare conductor made of copper or aluminum that electrically connects the input terminal of each module (switching element) of the inverter unit 2 and the output terminal of the capacitor 3. In the present embodiment, as the U-phase bus bar, the bus bar 41U connecting the first input terminal of the U-phase module 2U and the P terminal A1 of the capacitor 3 and the bus bar 42U connecting the second input terminal and the N terminal A2 And Similarly, bus bars 41V and 42V are provided as bus bars for the V-phase module 2V, and bus bars 41W and 42W are provided as bus bars for the W-phase module 2W. As other bus bars, bus bars 43U, 43V, 43W for connection of the motor M with respective U-phase, V-phase, W-phase modules 2U, 2V, 2W output terminals and the capacitor M and the battery 10 And a power supply bus bar 44 (FIG. 2) for connection.

  The above-described bus bars 41U, 41V, and 41W are bus bars corresponding to the third wiring 13 shown in FIG. 1, and the bus bars 42U, 42V, and 42W are bus bars corresponding to the fourth wiring 14. Further, the three-phase connection bus bars 43U, 43V, and 43W are bus bars corresponding to the output wiring 15 of FIG. 1, and the power bus bar 44 is a bus bar corresponding to the first wiring 11 and the second wiring 12.

  The cooler 5 is a member that serves as a mounting base for the inverter unit 2 and the capacitor 3 and is a member that functions to cool them. The cooler 5 is a member made of a cast product of a metal having good heat conductivity, such as aluminum, and as shown in FIG. Inside the cooler 5, a flow path 54 for circulating a refrigerant such as water is provided. The cover 6 is a member that covers the opening of the cooler 5 so as to cover the inverter unit 2 and the capacitor 3 attached to the cooler 5. In the present embodiment, a casing is configured by a part of the cooler 5 and the cover 6. The inverter device 1 is attached to another device in units of the casing.

  The cooler 5 includes a flat first surface 51A and a flat second surface 52A adjacent to and intersecting the first surface 51A. The inverter unit 2 (switching element) is attached to the first surface 51A, and the capacitor 3 is attached to the second surface 52A. In the present embodiment, as shown in FIG. 2, the first surface 51A and the second surface 52A are surfaces orthogonal to each other. The first surface 51A and the second surface 52A may be surfaces adjacent to and intersect with each other, and the surfaces do not necessarily have to be orthogonal to each other. For example, the angle formed by the two surfaces may be greater than or equal to a right angle (approximately 90 ° to 150 °) or less than or equal to a right angle (approximately 90 ° to 30 °). However, in the former, there is a tendency that the size in the horizontal direction of the cooler 5 becomes large and it becomes difficult to meet the request for miniaturization, and in the latter, the first surface 51A and the second surface 52A face each other, And the heat tends to become hot. Therefore, it is desirable that the first surface 51A and the second surface 52A be surfaces orthogonal to each other.

[Detailed explanation of the cooler]
The structure of the cooler 5 will be described in more detail. FIG. 5 is a perspective view of the cooler 5 and the cover 6, FIG. 6 is a perspective view of the cooler 5 whose viewing direction is different from that of FIG. 5, and FIG. 7 is a transparent perspective view of the cooler 5. Note that FIG. 5 shows direction display using XYZ coordinates, and this direction display is used in the following description. The cooler 5 includes a first flat plate portion 51 having a first surface 51A which is an XY plane, a second flat plate portion 52 having a second surface 52A which is an XZ plane, and a first surface 51A and a second surface 52A. And a pair of side plate portions 53 having a third surface 53A (YZ plane) which is adjacent and orthogonal to these.

  The first flat plate portion 51 is a plate having a substantially square shape in a Z direction view and having a predetermined thickness in the Z direction. The first surface 51A has an area sufficient to mount three modules of U-phase, V-phase, and W-phase modules 2U, 2V, and 2W. The second flat plate portion 52 is a plate having a substantially square shape in a Y direction view and having a predetermined thickness in the Y direction. The second surface 52A has a size in the X direction and the Z direction in which the capacitor 3 can be mounted. The first flat plate portion 51 and the second flat plate portion 52 are integrated in an orthogonal state at the -Y end portion of the first flat plate portion 51 and the -Z end portion of the second flat plate portion 52.

  The pair of side plate portions 53 are integrated with each other along the side portion on the -X side and the side portion on the + X side of the L-shaped continuous arrangement of the first flat plate portion 51 and the second flat plate portion 52. It is a substantially triangular flat plate member. Side plate portion 53 includes + Y side vertical side 531, + Z side horizontal side 532, oblique side 533 connecting vertical side 531 and horizontal piece 532, and −Z side horizontal side 534. The first flat plate portion 51 is continuously provided to the side plate portion 53 at a position separated from the −Z side horizontal side 534 by a predetermined distance on the + Z side. The second flat plate portion 52 is continuously provided on the vertical side on the −Y side of the side plate portion 53. Accordingly, the cooler 5 includes the first accommodation space S1 on the + Z side and the second accommodation space S2 on the −Z side with the first flat plate portion 51 as a partition in the Z direction. The first accommodation space S1 is a substantially triangular prism space, and the second accommodation space S2 is a flat rectangular prism space.

  The + Y side vertical side 531 is the portion which protrudes most in the + Y direction in the cooler 5, and the + Y side end surface 511 of the first flat plate portion 51 is at a position retracted to the −Y side by a predetermined distance than the + Y side vertical side 531. is there. The space formed by the retraction is a space for drawing the three-phase connection bus bars 43U, 43V, and 43W from the first surface 51A of the first flat plate portion 51 to the back surface 51B. The + Z end surface 521 of the second flat plate portion 52 is flush with the + Z side horizontal side 532 of the side plate portion 53. Further, the −Z end surface 522 is flush with the −Z side horizontal side 534.

  The cover 6 is formed of a heat-resistant resin, and the + Z-side horizontal surface 61, the + Y-side vertical surface 62, the slope 63 connecting the + Z-side horizontal surface 61 and the + Y-side vertical surface 62, and the -Z end of the + Y-side vertical surface 62 It comprises a -Z side horizontal surface 64 extending in the -Y direction from the edge. The inner surface of the + Z-side horizontal surface 61 is in contact with the + Z end surface 521 and the Z-side horizontal side 532 when the cover 6 is mounted on the cooler 5. The slope 63 is in contact with the oblique side 533. As a result, the first accommodation space S1 becomes a substantially sealed space. Furthermore, the + Y side vertical surface 62 is in contact with the vertical side 531 of the cooler 5, and the -Z side horizontal surface 64 is in contact with the -Z end surface 522 and the -Z side horizontal side 534. Thus, the second accommodation space S2 also becomes a substantially sealed space.

  In the present embodiment, the cooler 5 has an exposed portion not covered by the cover 6 (casing). That is, the cooler 5 itself is substantially used as a part of the casing. The exposed portion is a back surface (not shown in the figure) on the opposite side to the second surface 52A in the second flat plate portion 52 and each back surface 53B of the pair of side plate portions 53. By using a part of the cooler 5 as the exterior member, the casing structure can be further simplified, the number of parts can be reduced, and the assembly process of the inverter device 1 can be simplified. Note that the back surface 51B of the first flat plate portion 51 may be used as a part of the casing. Further, without providing the pair of side plate portions 53 in the cooler 5, the cover 6 may have a side surface corresponding to the side plate portion 53.

[Detailed description of the bus bar]
The bus bars 41U, 41V, 41W and the bus bars 42U, 42V, 42W electrically connect the inverter unit 2 and the capacitor 3 in a path that linearly straddles the boundary Bo between the first surface 51A and the second surface 52A, that is, the shortest path. Connected to A specific description will be given based on the bus bar 42V depicted in FIG. The bus bar 42V is L-shaped including a first portion 401 parallel to the first surface 51A, a second portion 402 parallel to the second surface 52A, and a connecting portion 403 between the first portion 401 and the second portion 402. It has a shape. The bus bar 42V is not limited to the L-shaped shape, and may have various shapes as long as it has a linear path in the arrow direction (FIG. 3) in the Z direction (FIG. 3) and the arrow direction (FIG. 4) in the Y direction of FIG. Can be adopted. For example, instead of the connection portion 403 bent at a right angle, a curved connection portion or an obliquely extending connection portion may be used.

  The first portion 401 is separated from the first surface 51A, and the second portion 402 is separated from the second surface 52A. The connection portion 403 is also separated from the boundary Bo. The tip of the first portion 401 is connected to the input terminal 21 of the V-phase module 2V using a screw or the like. Further, the tip of the second portion 402 is connected to the N terminal A2 of the capacitor 3 using a screw or the like. The vicinity of the connection portion 403 is a portion that crosses the boundary Bo. The same applies to the other bus bars.

  In this embodiment, the inverter unit 2 and the capacitor 3 are mounted on the first surface 51A and the second surface 52A adjacent to each other and orthogonal to each other, and the input terminal 21 and the N terminal A2 are arranged in the direction toward the boundary Bo It is set up. Then, these terminals are connected by the L-shaped bus bar 42V. Therefore, the path length of the bus bar 42V can be shortened, and an increase in line inductance can be suppressed. Therefore, it is possible to suppress the occurrence of electrical loss and the occurrence of noise in the bus bar 42V.

[Distribution route of refrigerant]
Subsequently, the flow path 54 of the refrigerant that the cooler 5 has inside will be described. As shown in FIG. 7, the flow passage 54 of the cooler 5 is formed of a single flow passage passing directly below the first surface 51 </ b> A and immediately below the second surface 52 </ b> A. More specifically, in the flow path 54, a meandering portion 54B which meanders and advances inside the first flat plate portion 51 and a meandering portion 54A which meanders and advances inside the second flat plate portion 52 are connected in one. Flow path.

  An inlet 541 serving as an inlet of the refrigerant to the flow path 54 and an outlet 542 serving as an outlet of the refrigerant are bored on the back surface 53B of one side plate portion 53. The inlet 541 is an end of the meandering portion 54A, and the outlet 542 is an end of the meandering portion 54B. The flow channel 54 may not be a single flow channel. For example, separate refrigerant flow channels may be formed in the first flat plate portion 51 and the second flat plate portion 52. However, there is an advantage that the number of parts can be reduced and the number of assembling steps can be reduced by providing one flow path 54 without providing an intermediate connection portion or the like of the flow path.

  A refrigerant circulation system (not shown) is connected to the inlet 541 and the outlet 542. When the refrigerant passes through the flow path 54, the refrigerant exchanges heat with the first flat plate portion 51 and the second flat plate portion 52 heated by the heat generation of the inverter portion 2 and the capacitor 3. Thus, the inverter unit 2 and the capacitor 3 are cooled.

  As can be seen from the arrangement of the inlet 541 and the outlet 542, the upstream side of the refrigerant flow in one flow passage 54 is directly below the second surface 52A (inside the second flat plate portion 52), and the downstream side is directly below the first surface 51A ( Inside the first flat plate portion 51). That is, the mounting surface of the capacitor 3 is upstream of the mounting surface of the inverter unit 2. In general, the inverter unit 2 having a switching element generates larger heat than the smoothing capacitor 3. Therefore, if the first surface 51A to which the inverter unit 2 is attached is set on the upstream side of the refrigerant flow, the refrigerant absorbs a large amount of heat, and sufficient heat exchange with the condenser 3 can not be performed at the downstream second surface 52A. I have a concern. According to the present embodiment, this concern can be eliminated.

[Operation effect of inverter device]
The operation and effect of the inverter device 1 described above will be described in comparison with the inverter device 100 according to the comparative example shown in FIG. The inverter device 100 of the comparative example includes a flat plate-shaped cooler 50 provided with a refrigerant flow path 540 inside. The inverter unit 20 is mounted on one surface 501 of the cooler 50, and the smoothing capacitor 30 is mounted on the other surface 502 opposite to the surface 501. The inverter unit 20 and the capacitor 30 are electrically connected by the bus bar 40 drawn from one surface 501 of the cooler 50 to the other surface 502. According to this inverter device 100, it is possible to cool the inverter unit 20 and the capacitor 30, and to meet the demand for downsizing.

  However, in the inverter device 100 of the comparative example, the inverter unit 20 as a heating element and the capacitor 30 are respectively mounted on the one surface 501 and the other surface 502 opposed to each other. For this reason, relatively large heat h emitted from the inverter unit 20 goes around to the other surface 502 as indicated by an arrow in the drawing, and there is a problem that the cooling efficiency of the capacitor 30 is deteriorated. On the other hand, according to the inverter device 1 of the present embodiment, as shown in FIG. 2, the inverter unit 2 is on the first surface 51A of the cooler 5 and the capacitor 3 is on the second surface 52A adjacent to the first surface 51A. Since it is attached, the heat emitted at one attachment surface is less likely to reach the other attachment surface. Accordingly, the cooling of the inverter unit 2 and the capacitor 3 by the cooler 5 can be efficiently performed.

  In addition, since the first surface 51A and the second surface 52A are surfaces orthogonal to each other (intersecting surfaces), the size of the cooler 5 is smaller than when the first surface 51A and the second surface 52A are arranged in the same plane. Can be implemented. For this reason, even in the case where the casing (in the present embodiment, consisting of a part of the cooler 5 and the cover 6) attached to another device is subject to dimensional limitations due to the influence of the installation destination space, It can correspond.

  Furthermore, in the inverter device 100 of the comparative example, the path length of the bus bar 40 connecting the inverter unit 20 and the capacitor 30 is routed from one surface 501 to the other surface 502 through the distance of the thickness D of the cooler 50. It takes a long time to do it. Therefore, the inductance of the bus bar 40 is increased. On the other hand, in the inverter device 1 of the present embodiment, the inverter unit 2 and the capacitor 3 are mounted on the first surface 51A and the second surface 52A adjacent to each other, and the bus bar has the first surface 51A and the second surface 52A. Since the wiring is performed by the path straddling the boundary Bo, the path length of the bus bar can be shortened. Therefore, the inductance is not increased in the bus bar portion, and the generation of power loss and the generation of noise can be suppressed.

[Example of application of inverter device to hybrid construction machine]
Subsequently, as an example of mounting the above-described inverter device 1 to another device, an example of application to a hybrid construction machine will be described. Here, a hybrid shovel 7 shown in FIG. 9 is illustrated as a hybrid construction machine. Of course, the inverter device 1 can be applied to other hybrid construction machines such as a hybrid dismantling machine and a crusher.

  The hybrid shovel 7 has a configuration in which the upper swing body 72 is mounted on a crawler type lower traveling body 71. The upper swing body 72 is mounted on the lower traveling body 71 so as to be pivotable about an axis perpendicular to the ground. On an upper frame 73 which is a base of the upper revolving superstructure 72, various equipment such as a cabin 74 and the like are mounted, and a work attachment 75 is mounted. The work attachment 75 includes a boom 751, an arm 752, and a bucket 753.

  FIG. 10 is a plan view of the hybrid shovel 7 as viewed from above. The upper frame 73 is constituted by a center section 731 having a pair of left and right vertical plates 76 serving both as a reinforcing function and a holding function of the work attachment 75, and side decks 732 and 733 provided on the left and right sides of the center section 731. It is done. At the rear of the center section 731, an engine 81 serving as a power source of the hybrid shovel 7 is installed. A radiator 84 for engine cooling and a cooling fan 85 are attached to the engine 81.

  The engine 81 powers a hydraulic pump 82 that operates the hydraulic system of the hybrid shovel 7. In addition to this, between the engine 81 and the hydraulic pump 82, a generator motor 9 (rotary electric machine) for assisting the engine 81 when the hydraulic pump 82 is heavily loaded is arranged in series. Further, near the middle of the center section 731, a swing motor 83 as a swing drive source is installed. On the side deck 733, a fuel tank 86 for the engine 81, and a power storage device 87 (corresponding to the battery 10 in FIG. 1) serving as a drive power supply for the generator motor 9 and the swing motor 83 are mounted.

  The operation of the hybrid shovel 7 will be schematically described. When the hydraulic pump 82 is not loaded or lightly loaded, the generator motor 9 is driven by the engine 81 to function as a generator, and the generated power is stored in the storage device 87. On the other hand, when the hydraulic pump 82 is heavily loaded, the generator motor 9 receives supply of electric power from the storage device 87 to function as an electric motor, and assists the engine 81 for driving the hydraulic pump 82. The swing motor 83 receives supply of power from the power storage device 87 at the time of swing operation, and stores regenerative power in the power storage device 87 at the time of swing braking.

  The inverter device 1 is attached to the above-described generator motor 9. FIG. 11 (A) is a side view schematically showing the layout of the generator motor 9 and the inverter device 1, and FIG. 11 (B) is a front view thereof. The generator motor 9 includes a housing 91 accommodating the rotor and the stator, a flange 92 disposed on one end surface of the housing 91, and a rotation shaft 93 integrated with the rotor.

  The inverter device 1 is attached to the lower surface of the housing 91. In FIG. 11 (A), the engine 81 and the hydraulic pump 82 which are disposed in front and rear in the axial direction of the generator motor 9 are schematically illustrated. Since the generator motor 9 has such a layout to be sandwiched between the engine 81 and the hydraulic pump 82, the space to which the inverter device 1 can be attached is substantially only the space on the lower surface of the housing 91. Moreover, since the engine 81 and the hydraulic pump 82 are present at the front and rear, the inverter device 1 can not be configured to be bulky in the axial direction.

  FIG. 12 is a cross-sectional view showing how the inverter device 1 is attached to the generator motor 9. As shown in FIG. In the inverter device 1 of the present embodiment, since the cooler 5 as a mounting base for the inverter unit 2 and the capacitor 3 has a structure bent in an L shape, the size in the axial direction can be suppressed. The inverter device 1 is attached to the lower surface of the housing 91 using a mounting plate 94 in a mode in which the state shown in FIG. 2 is inverted by 180 °.

  FIG. 13 is a plan view of the mounting plate 94, and FIG. 14 is a plan view showing the mounting plate 94 attached to the housing 91. As shown in FIG. The mounting plate 94 is a rigid plate having a plurality of screw holes 941 through which fixing screws are inserted and a passage hole 942 of the motor cable 9EW. The mounting plate 94 may be a surface to which the −Z side horizontal surface 64 of the cover 6 shown in FIG. 5 is attached (in this case, holes corresponding to the screw holes 941 and the passing holes 942 are bored in the horizontal surface 64) The cover wall surface may be substituted for the horizontal surface 64.

  The three-phase connection bus bar 43V (43U, 43W) is routed from the first accommodation space S1 in which the inverter unit 2 and the capacitor 3 are accommodated to the second accommodation space S2, and the terminal end thereof is attached to the terminal block 55 It is done. The second accommodation space S2 is used as a routing space for the motor cable 9EW. The end of the motor cable 9EW is connected to the end of the three-phase connection bus bar 43V.

  As described above, in the hybrid shovel 7, in the generator motor 9 arranged in series between the engine 81 and the hydraulic pump 82, it is in an environment exposed to the heat generated by the engine 81, and the arrangement space of the inverter device Is greatly limited. If the inverter device 1 of the present embodiment is applied to such a generator motor 9, the miniaturization can be achieved, so that the assembly can be easily performed, and the inverter portion 2 and the capacitor 3 can be sufficiently cooled. be able to.

1 inverter device 2 inverter unit (switching element)
Reference Signs List 3 capacitor 41U, 41V, 41W bus bar 42U, 42V, 42W bus bar 5 cooler 51 first flat plate portion 51A first surface 52 second flat plate portion 52A second surface 53 side plate portion 53A third surface 53B rear surface (exposed portion)
54 flow path 6 cover (casing)
7 Hybrid excavator (Hybrid construction machine)
81 Engine 82 Hydraulic pump 9 Generator motor (Other equipment: Rotating electrical machine)

Claims (6)

A switching element that converts a DC voltage into an AC voltage;
A capacitor for smoothing the DC voltage;
A bus bar electrically connecting the switching element and the capacitor;
A cooler internally provided with a flow path for circulating a refrigerant, and the switching element and the condenser are attached;
And a casing that covers the switching element and the capacitor attached to the cooler and is attached to another device.
The cooler includes a first surface and a second surface adjacent to and intersecting the first surface, the switching element being attached to the first surface, and the capacitor being attached to the second surface, respectively.
In the inverter device, in which the bus bar connects the switching element and the capacitor in a path crossing a boundary between the first surface and the second surface .
The first surface and the second surface are surfaces orthogonal to each other,
The bus bar has an L-shape including a first portion parallel to the first surface, a second portion parallel to the second surface, and a connection portion between the first portion and the second portion. , Inverter device. A switching element that converts a DC voltage into an AC voltage;
A capacitor for smoothing the DC voltage;
A bus bar electrically connecting the switching element and the capacitor;
A cooler internally provided with a flow path for circulating a refrigerant, and the switching element and the condenser are attached;
A casing including the switching element attached to the cooler and a cover covering the capacitor and attached to another device;
The cooler includes a first surface and a second surface adjacent to and intersecting the first surface, the switching element being attached to the first surface, and the capacitor being attached to the second surface, respectively.
In the inverter device, in which the bus bar connects the switching element and the capacitor in a path crossing a boundary between the first surface and the second surface.
The cooler is a third surface adjacent to and orthogonal to a first flat plate portion having the first surface, a second flat plate portion having the second surface, and the first surface and the second surface. Side plates having
Said casing, said cover, said first flat portion is constituted by at least one of the rear surface of the second flat plate portion and the side plate portion, the inverter device. In the inverter device according to claim 1 or 2 ,
The inverter device according to claim 1, wherein the flow passage of the cooler includes a flow passage directly below the first surface and directly below the second surface. In the inverter device according to claim 3 ,
The inverter apparatus whose upstream of the refrigerant | coolant circulation in said one flow path is right under the said 2nd surface, and whose downstream is right under the said 1st surface. In the inverter device according to any one of claims 1 to 4 ,
The supply destination of the alternating voltage generated by the switching element is a rotating electric machine,
The inverter device in which the other apparatus to which the casing is attached is the rotating electric machine. In the inverter device according to claim 5 ,
The rotating electrical machine is a generator motor mounted on a hybrid construction machine,
The inverter device, wherein the generator motor is disposed in series between an engine serving as a power source of the hybrid construction machine and a hydraulic pump that operates a hydraulic system.

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