POWER CONVERSION DEVICE

Abstract

According to the present invention, a current conversion device comprises at least one power module for current conversion, a plurality of busbars connected by welding to terminals of the power module, a current sensor that detects a current flowing through the plurality of busbars, a housing to which the power module and the current sensor are attached, and a busbar holder that causes the plurality of busbars to engage with the current sensor and enables the plurality of busbars to move at least in one direction of connection with the power module and in one arrangement direction of the current sensor.

Description

Technical field

[0001] The present invention relates to a current conversion device. State of the art

[0002] The following PTL 1, for example, discloses a power conversion device in which deviations are absorbed by positioning a power module and a control board in a housing of a connection circuit unit in which a DC bus, an AC bus and an AC sensor are integrated in a housing, thereby improving the arrangement accuracy of the AC bus connected to the outside or the like, improving the mountability and achieving a size reduction in an inverter, compared to a method for arranging components based on a power module. Citation list for patent literature

[0003] PTL 1: JP 7 005 732 B1 Summary of the invention: Technical problem

[0004] In the technique described in PTL 1, for example, if the AC busbar connected to a terminal on the power module side is fixed in a state where the connection varies, there is a possibility that an opening may occur between the connection terminals, resulting in a weld defect. In light of this, it is an object of the present invention to provide a current conversion device that aims to stabilize the weld quality and reduce the size. Solution to the problem.

[0005] According to the present invention, a current conversion device comprises at least one power module for current conversion, a plurality of busbars connected by welding to terminals of the power module, a current sensor that detects a current flowing through the plurality of busbars, a housing to which the power module and the current sensor are attached, and a busbar holder that causes the plurality of busbars to engage with the current sensor and enables the plurality of busbars to move at least in one direction of connection with the power module and in one arrangement direction of the current sensor. Advantageous effects of the invention

[0006] According to the present invention, it is possible to provide a current conversion device that aims to stabilize the welding quality and reduce the size. Brief description of the drawings Fig. Figure 1 shows a view to describe components of a current conversion device according to an embodiment of the present invention. Fig. Figure 2 shows a cross-sectional view of the current conversion device, which comprises the components of Fig. 1 records. Fig. Figure 3 shows a view to describe a subassembly consisting of a PMAC busbar and an AC sensor according to the embodiment of the present invention. Fig. Figure 4 shows a cross-sectional view of the subassembly consisting of the PMAC busbar and the AC sensor according to the embodiment of the present invention. Description of embodiments

[0007] An embodiment of the present invention is described below with reference to the drawings. The following description and the drawings are examples used to describe the present invention and may be omitted or simplified for clarity. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be present singly or in multiples.

[0008] The positions, sizes, shapes, areas, and the like of components shown in the drawings may not represent the actual positions, sizes, shapes, areas, and the like, for the sake of clarity and to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, areas, and the like disclosed in the drawings. (One embodiment and overall configuration)(FIG.1)

[0009] A power conversion device 100 comprises a power module 4 for power conversion, an EMC filter 8, a control board 12, a subassembly comprising a PMAC busbar 6a and an AC sensor 5, an HVAC busbar 6b ​​which is part of an AC line circuit, a DC mold busbar 9 which is part of a DC line circuit, and a housing 10. The housing 10 accommodates the above-mentioned components to form a flow path training element.

[0010] The PMAC busbar 6a is a series of busbars connected by welding to terminals of the power module 4. The AC sensor 5 detects a current flowing through the PMAC busbar 6a and is attached to the housing 10 by a screw or bolt. The AC sensor 5 is also combined with the PMAC busbar 6a to function as an integrated subassembly.

[0011] The HVAC busbar 6b ​​is attached to the housing 10 with a screw or bolt. The HVAC busbar 6b ​​and the PMAC busbar 6a are electrically connected by screwing the PMAC busbar 6a to it. A section of the HVAC busbar 6b, which is not connected to the PMAC busbar 6a and extends upwards in the drawing, is connected to a motor.

[0012] The control board 12 is a gate driver (GD) board that controls the power module 4 and is attached to the housing 10. The control board 12 also includes a GD board connector (not shown), and a signal pin of the AC sensor 5 and a connector of the power module 4 are electrically connected to the GD board connector.

[0013] The power module 4 is attached to the housing 10 by a bolt and mounted on an upper section of the control board 12. The power module 4 is also electrically connected to the GD board connector contained in the control board 12. Furthermore, the power module 4 is connected to the PMAC busbar 6a and the DC mold busbar 9 by welding.

[0014] The power module 4 comprises a terminal on one side connected to the PMAC busbar 6a and a weld terminal on a gate side, which is opposite the terminal on the side connected to the PMAC busbar 6a. The positioning of the component mounted on the housing 10 is adjusted with reference to the weld terminal on the gate side. In the present invention, the position of the PMAC busbar 6a in the housing 10 can be adjusted taking into account the weld connection with the power module 4 and the connection with the HVAC busbar 6b.

[0015] The positionally adjusted PMAC busbar 6a is attached to the HVAC busbar 6b ​​with a bolt in a state where there is no deviation in the connection with the power module 4. This improves the quality of the weld connection carried out in the subsequent step.

[0016] Although the drawing shows one power module 4 mounted on the power conversion device 100, two power modules 4 can also be mounted. (FIG. 2)

[0017] The control board 12 is attached to the housing 10. The control board 12 is electrically connected to a terminal of the power module 4 extending to the control board 12, an AC sensor terminal 5a, and a board power supply cable harness (not shown).

[0018] A power module connection 15 is electrically connected by welding to the connection of the PMAC busbar 6a. (FIG.3)

[0019] Fig. 3(a) is a view in which a busbar holder 19, having the PMAC busbar 6a, is attached to the AC sensor 5. Fig. 3(b) is an explanatory diagram of the PMAC busbar 6a and the busbar holder 19.

[0020] The PMAC busbar 6a includes a curved connector 24, which is connected to the power module 4 ( Fig. 1) is connected, and a core insertion port 21, which is opposite the bent port 24 and is inserted from the side of the power module 4 into a magnetic core 16 with a ring shape.

[0021] The busbar holder 19 guides the PMAC busbar 6a in an insertion direction 23 into a through-hole of the magnetic core 16 of the AC sensor 5. The AC sensor 5, which contains the magnetic core 16, has a structure for engaging with the busbar holder 19, and the PMAC busbar 6a is inserted into the magnetic core 16 to engage with the busbar holder 19. As a result, the AC sensor 5 and the PMAC busbar 6a become an integrated subassembly.

[0022] The PMAC busbar 6a is formed by integrating three-phase busbars for the U, V, and W phases with a molding resin. The magnetic core 16 is overmolded to prevent corrosion. Furthermore, the PMAC busbar 6a includes an extension section 18, which is inserted into the magnetic core 16 and overmolded. As described above, a molded sealing section of the extension section 18 makes it more difficult for the terminals of the respective phases of the PMAC busbar 6a to tilt or otherwise deform. This also helps to prevent the snap-fit ​​structure from coming loose.

[0023] The busbar holder 19 includes projecting sections 11 between the busbars of the PMAC busbar 6a. The projecting section 11 extends in one direction (upwards in the drawing) perpendicular to the direction of the connection with the power module 4 and to the arrangement direction of the AC sensors 5. The projecting section 11 is gripped by a device (not shown) to move the PMAC busbar 6a, which is inserted into the magnetic core 16, towards the side of the power module 4 and to adjust its position. This makes it possible to increase the positional accuracy of the connection on the side connected to the power module 4, thus improving the reliability of the welded connection.

[0024] It should be noted that such position adjustment can also be achieved by forming a section other than the projecting section 11. For example, the position can be adjusted by providing a folded section or a grooved section instead of the projecting section 11. This makes it possible to achieve both stress relief for the busbar holder 19 and to prevent sink marks during forming.

[0025] The busbar holder 19 includes a stress relief section 2. The stress relief section 2 relieves stress concentrations on the busbar holder 19 that occur when the AC sensor 5, which engages with the busbar holder 19, is attached to the housing 10. Furthermore, the stress relief section 2 also reduces thickness and prevents sink marks during the forming of the busbar holder 19, which is shaped to have a considerable thickness. This prevents deformation of the busbar holder 19 and the PMAC busbar 6a due to sink marks, thus also preventing deviations in the weld joint between the PMAC busbar 6a and the power module 4.

[0026] An AC busbar hole 7 of the PMAC busbar 6a is a connection mounting hole with the HVAC busbar 6b ​​and has a hole diameter larger than the size required for the connection. As a result, even if sink marks have occurred in the busbar holder 19, it is possible to absorb deviations in the connection positions of the PMAC busbar 6a and the HVAC busbar 6b ​​and improve the weld quality.

[0027] As a connection to be welded to power module 4, the PMAC busbar 6a includes a bent terminal 24. In power module 4, terminal 15 (see Fig. 2), which is connected to the PMAC busbar 6a by welding, is bent in the same direction as the bent terminal 24. Therefore, the terminals can be joined together by welding, causing the tips of the bent terminals to butt against each other. The welded connection between the bent terminal 24 and the power module terminal 15 is, for example, achieved by TIG welding.

[0028] Regarding the size of the through-hole of the magnetic core 16, when the PMAC busbar 6a is inserted, it is not necessary to insert the bent terminal 24 of the PMAC busbar 6a, thus eliminating an unnecessary enlargement of the through-hole of the magnetic core 16. Furthermore, it is therefore possible to reduce the size of a mounting section of the magnetic core 16, which is contained in the AC sensor 5 combined with the magnetic core 16, thereby contributing to cost reduction. (FIG.4)

[0029] Fig. 4(a) is a top view of the subassembly consisting of the PMAC busbar 6a and the AC sensor 5, and Fig. 4(b) is a cross-sectional view along line BB of Fig. 4(a). The AC sensor 5 is provided with a hole section 14, and the busbar holder 19 is provided with a claw section 13. By engaging the claw section 13 and the hole section 14, the PMAC busbar 6a and the AC sensor 5 become an integrated subassembly.

[0030] The claw section 13 must pass over a crossing section 14a once when it engages with the hole section 14, but the voltage is only applied to the claw section 13 this one time, and since a clearance is provided as a range of motion in the engagement section, no voltage is applied to the claw section 13 after engagement. Since the AC sensor 5 is attached to the housing 10, the PMAC busbar 6a can use this clearance to adjust its position in the weld joint with the power module 4 by pushing the projecting section 11 from a direction opposite to the side where the PMAC busbar 6a is inserted into the magnetic core 16 (see Fig. 3).

[0031] As described above, even when positional / dimensional deviations are taken into account, the busbar holder 19 does not come into contact with the inner wall of the hole section 14 of the AC sensor 5 at an engagement section between the claw section 13 and the hole section 14. Therefore, the busbar holder 19 can move the PMAC busbar 6a at least in the direction of the connection with the power module 4 and in the arrangement direction of the AC sensor 5 (magnetic core 16).

[0032] The busbar holder 19 has a gap 17 to the magnetic core 16 in the direction in which the core insertion port 21 is inserted into the magnetic core 16 when the PMAC busbar 6a is combined with the AC sensor 5. This gap 17 is created by adjusting the PMAC busbar 6a at the terminal 15 of the power module 4, and it is possible to optimize the movable distance together with the clearance structure provided in the claw section 13 and the hole section 14, as described above. Furthermore, by moving the PMAC busbar 6a to the side of the power module 4 to create the gap 17, it is possible to adjust the busbar so that the end of the PMAC busbar 6a does not abut the busbar wall of the HVAC busbar 6b.

[0033] The busbar holder 19 is provided with a round shape at the root of the claw section 13 in order to make the length of the claw section 13 as long as possible and to relieve tension.

[0034] As described above, the present invention absorbs the tolerance between the PMAC busbar 6a, the power module 4, and the HVAC busbar 6b, and improves the arrangement accuracy of the parts, thus making it possible to achieve a reduction in size. Since the power conversion device 100 can be used on an automated assembly line, the assembly efficiency and welding accuracy of the power conversion device 100 are also improved. Furthermore, even without a mounting point on the PMAC busbar 6a, it is possible to achieve a stable welded connection and reduce costs.

[0035] According to the embodiment of the present invention described above, the following operational effects are achieved.

[0036] (1) The current conversion device 100 according to the present invention comprises at least one power module 4 for current conversion, a plurality of busbars 6a connected by welding to terminals 15 of the power module 4, a current sensor 5 that detects a current flowing through the plurality of busbars 6a, a housing 10 to which the power module 4 and the current sensor 5 are attached, and a busbar holder 19 that causes the plurality of busbars 6a to engage with the current sensor 5 and allows the plurality of busbars 6a to move at least in one direction of connection with the power module 4 and in one arrangement direction of the current sensor 5. With this configuration, it is possible to provide a current conversion device 100 that aims to stabilize weld quality and reduce size.

[0037] (2) The busbar holder 19 includes a projection section 11 that extends between the multiple busbars 6a in a direction perpendicular to the direction of the connection with the power module 4 and the arrangement direction of the current sensor 5. This configuration allows the position of the PMAC busbar 6a relative to the power module 4 to be adjusted.

[0038] (3) The busbar holder 19 includes a stress relief section 2 at each of the positions between the multiple busbars and the projection section. With this configuration, the busbar holder 19 can prevent sink marks during forming and suppress the occurrence of deformation.

[0039] (4) A control board 12, which controls the power module 4, is further provided, and the control board 12 is attached to the housing 10. With this configuration, the current conversion device 100, which aims to stabilize the weld quality and reduce the size in the present invention, can be realized based on the prerequisite that the control board 12 is attached to the housing 10.

[0040] (5) The busbar holder 19 includes a claw section 13, the current sensor 5 includes a hole section 14 with which the claw section 13 engages, and the claw section 13 does not come into contact with an inner wall of the hole section 14 when engaged with the hole section 14. With this configuration, the position of the PMAC busbar 6a can be adjusted relative to the power module 4 without being affected by the voltage.

[0041] (6) The current sensor 5 comprises a ring-shaped magnetic core 16, the plurality of busbars 6a comprises a bent terminal 24, which is welded to a terminal of the power module 4, and a core insertion terminal 21, which is opposite the bent terminal 24 and is inserted into the magnetic core 16 from the side of the power module 4, and the terminal 15 of the power module 4 and the bent terminal 24 abut each other and are welded together. This configuration makes it possible to reduce size and cost.

[0042] (7) The busbar holder 19 has a gap 17 to the magnetic core 16 in the direction in which the core insertion port 21 is inserted into the magnetic core 16. This configuration makes it possible to improve ease of assembly and welding accuracy.

[0043] (8) A section of the multiple busbars 6a, which is inserted into the magnetic core 16, is overmolded. With this configuration, it is possible to prevent the tilting of the PMAC busbar 6a and to prevent the engagement section from loosening, thus improving welding accuracy.

[0044] It should be noted that the present invention is not limited to the embodiment described above and that various modifications and other configurations can be combined without departing from the essence of the present invention. Furthermore, the present invention is not limited to an embodiment containing all the configurations described above and includes an embodiment in which part of the configuration is deleted. Reference symbol list 2. Stress relief section 4 Power module 5 AC sensor 5a AC sensor connection 6 busbar 6a PMAC busbar 6b HVAC busbar 7 AC busbar holes 8 EMC filters 9 DC-Mold power rail 10 cases 11th lead section 12 Control board 13 Claw section 14-hole section 14a Crossing section 15 Power module connection 16 magnetic cores 17 gaps 18 Extension section 19 busbar holders 21 Core entry port 23 Introduction direction 24 curved connector 100 Power conversion device QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 7 005 732 B1

[0003]

Claims

[1] Power conversion device comprising: at least one power module for power conversion; a multitude of busbars connected to the power module's terminals by welding; a current sensor that detects a current flowing through the multitude of busbars; a housing to which the power module and current sensor are attached; and a busbar holder that causes the multitude of busbars to engage with the current sensor, and allows the multitude of busbars to move at least in one direction of connection with the power module and in one arrangement direction of the current sensor. [2] Current conversion device according to claim 1, wherein the busbar holder includes a projection section that extends between the plurality of busbars in a direction perpendicular to the direction of the connection with the power module and the arrangement direction of the current sensor. [3] Current conversion device according to claim 2, wherein the busbar holder includes a stress relief section at each of the positions between the plurality of busbars and the projection section. [4] Power conversion device according to claim 1, further comprising: a control board that controls the power module, with the control board being attached to the housing. [5] Power conversion device according to claim 1, wherein the busbar holder contains a claw section, the current sensor contains a hole section with which the claw section engages, and the claw section does not come into contact with an inner wall of the hole section when it is engaged with the hole section. [6] Current conversion device according to claim 5, wherein the current sensor includes a magnetic core with a ring-shaped form, The multiple busbars include a curved terminal that is connected by welding to a terminal of the power module, and a core insertion terminal that is opposite the curved terminal and is inserted into the magnetic core from the power module side, and The connection of the power module and the curved connection abut each other and are joined by welding. [7] Current conversion device according to claim 6, wherein the busbar holder has a gap to the magnetic core in a direction in which the core insertion port is inserted into the magnetic core. [8] Current conversion device according to claim 7, wherein a section of the plurality of busbars which is inserted into the magnetic core is overmolded.

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