Motor drive device

Abstract

The present invention relates to a motor drive device. A motor drive device capable of realizing a connection structure of a bus bar, a power element, and a printed circuit board with high strength, high vibration resistance, and low cost is provided. The motor drive device (1) includes: a bus bar (10) through which a current related to motor drive flows; a printed circuit board (20); and a conductive support base (30) that is mounted on the printed circuit board (20) and is interposed between the bus bar (10) and the printed circuit board (20). The conductive support base (30) has: at least one threaded member through-hole (31) for fastening the bus bar (10) and the conductive support base (30) by screw fastening; and a printed circuit board terminal portion (32) for electrically connecting the conductive support base (30) to an electrical wiring (21) provided on the printed circuit board (20).

Description

Technical Field

[0001] The present invention relates to a motor drive device having a bus bar. Background Art

[0002] Regarding a motor drive device that drives a motor in a machine tool, a forging machine, an injection molding machine, an industrial machine, or various robots, electric power supplied from an AC power source or a DC power source is converted into electric power for driving the motor (motor drive power) by a power conversion circuit. As the power conversion circuit, there are an inverter that converts the input DC power into AC power and outputs it, and a rectifier (also called a "converter") that converts the input AC power into DC power and outputs it. For example, after temporarily converting the AC power supplied from the AC power source into DC power by the rectifier, it is then converted into AC power by the inverter, and this AC power is supplied as the motor drive power.

[0003] A rectifier of a diode rectification method is formed by a full-bridge circuit of diodes. In addition, a rectifier and an inverter of a PWM control method and a 120-degree conduction method are formed by, for example, a full-bridge circuit having a large-power semiconductor switching element and a diode anti-parallel thereto. Hereinafter, the diodes and the large-power semiconductor switching elements provided in the rectifier and the inverter are simply referred to as "power elements". For a power conversion circuit including a rectifier and an inverter, a relatively large current flows through the power elements. Therefore, for the electrical connection to the electrode terminals of the power elements, a bus bar formed of a metal such as copper, brass, or aluminum is used. In addition, in the power conversion circuit, there are provided various circuits such as a main circuit formed by a full-bridge circuit of power elements, a control circuit for controlling power conversion, a detection circuit for detecting a current or a voltage used in various processes such as power conversion and abnormality detection, and a buffer circuit for protecting the circuit from a surge voltage generated when a large-power semiconductor switching element, which is one of the power elements, is turned on and off. These circuits include various components such as resistors, capacitors, inductors, diodes, FETs (field effect transistors), operational amplifiers, optocouplers, analog-to-digital conversion circuits (ADCs), digital-to-analog conversion circuits (DACs), or various integrated circuits. Thus, miniaturization and simplification of circuit wiring are mostly achieved by mounting these components together on a printed circuit board. For the motor drive device, a printed circuit board on which various components are mounted is arranged close to the power elements and is electrically and physically connected to the power elements. For example, a detection circuit for detecting a current flowing into or out of the power elements via the bus bar and a detection circuit for detecting the potential of the bus bar connected to the power elements are provided on the printed circuit board. In this case, the bus bar is not only electrically connected to the input / output terminals of the power elements but is also electrically connected to the electrical wiring communicating with the detection circuit on the printed circuit board.

[0004] For example, as described in Japanese Unexamined Patent Application Publication No. 6-302932, a printed wiring board is known, which includes: electrode terminals having threaded through-holes at predetermined positions and soldering claws for soldering to the printed wiring board, and the electrode terminals are formed of a highly conductive metal flat plate subjected to bending processing; and a printed wiring board having mounting holes that match the insertion of the claws of the electrode terminals and are wired to mounting components on the printed wiring board, and having through-holes at positions directly below the threaded through-holes in a state where the claws of the electrode terminals are inserted into the mounting holes. By inserting the claws into the mounting holes of the printed wiring board and performing soldering, the printed wiring board and the electrode terminals are fixed to form a printed wiring board.

[0005] For example, as described in Japanese Unexamined Patent Application Publication No. 2011-234488, a power conversion device is known, which is characterized in that the power conversion device has: a plurality of semiconductor components that form part of a power conversion circuit; a control circuit section that is electrically connected to the semiconductor components and controls the semiconductor components; a bus bar that is electrically connected to the semiconductor components and supplies power to and from the semiconductor components; a terminal block that mounts the bus bar and a high-voltage cable for power to enter and exit relative to the outside, and connects the bus bar and the high-voltage cable; and a housing that houses the semiconductor components, the bus bar, and the terminal block. The housing includes: a first through-hole and a second through-hole through which the high-voltage cable can pass; an operation hole formed opposite to the terminal block for performing the connection operation of the high-voltage cable and the terminal block; a through-hole cover that closes the hole in the first through-hole and the second through-hole through which the high-voltage cable does not pass; and an operation hole cover that closes the operation hole. The first through-hole and the second through-hole are formed at positions opposite to each other with the terminal block interposed therebetween, and the operation hole is formed in a direction orthogonal to the direction connecting the first through-hole and the second through-hole.

[0006] For example, as described in Japanese Utility Model Publication No. 7-29874, a connection structure of a high-current printed board is known, which is characterized in that a terminal portion is fixed so as to penetrate the high-current printed board from one side and protrude to both sides of the high-current printed board, and a threaded member passing through a hole in the terminal portion from one side is used to fasten and fix a conductor or a high-current element in contact with the other side of the terminal portion. Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] The shape of the bus bar is designed according to, for example, the configuration of the components of the motor drive device, as well as the size and shape of the motor drive device. Therefore, when manufacturing the motor drive device, it is necessary to ensure in advance the inventory of multiple types of bus bars with different shapes, and the manufacturing management is relatively complex. In addition, the bus bar is manufactured by performing sheet metal processing on a metal plate such as copper, brass, aluminum, etc. Therefore, the more complex the shape of the manufactured bus bar, the more waste (i.e., the part that will not become the bus bar product) is generated in the metal plate that is the raw material during sheet metal processing. The more waste there is, the higher the manufacturing cost of the motor drive device. In addition, it is necessary to prepare a mold corresponding to the shape of the manufactured bus bar. Therefore, the more types of bus bar shapes there are, the more molds need to be prepared in advance, and the manufacturing cost of the motor drive device increases. Furthermore, the more complex the shape of the bus bar, the weaker its strength and vibration resistance. Therefore, for the motor drive device, it is desirable to achieve a connection structure between the bus bar with high strength, high vibration resistance and low cost, the power element, and the printed circuit board.

[0009] Solution to the problem

[0010] According to one technical solution of the present disclosure, a motor drive device includes: a bus bar through which a current related to motor drive flows; a printed circuit board; and a conductive support table that is mounted on the printed circuit board and is interposed between the bus bar and the printed circuit board. The conductive support table has: at least one threaded member through hole for fastening the bus bar and the conductive support table by threaded fastening; and a printed circuit board terminal portion for electrically connecting the conductive support table to the electrical wiring provided on the printed circuit board.

[0011] For the above motor drive device, it may also be that a plurality of the bus bars are connected with respect to one of the threaded member through holes provided in the conductive support table.

[0012] For the above motor drive device, it may also be that a plurality of the bus bars are connected one by one with respect to each of the threaded member through holes provided in the conductive support table.

[0013] For the above motor drive device, it may also be that the conductive support table has: an upper plate portion; and side plate portions that are a pair of side plate portions extending from a pair of edges of the upper plate portion in a direction intersecting the upper plate portion and arranged at intervals from each other. The side plate portions are mounted on the printed circuit board by their ends, and the threaded member through holes are provided in the upper plate portion or the side plate portions.

[0014] For the above motor drive device, it may also be that the upper plate portion and the side plate portions form a drip-proof wall with respect to other mounting components of the printed circuit board.

[0015] Regarding the above-described motor drive device, alternatively, the upper plate portion and the side plate portion may form a ventilation path with respect to other mounting components of the printed circuit board.

[0016] Regarding the above-described motor drive device, alternatively, a plurality of the conductive support platforms may be provided on the printed circuit board.

[0017] Regarding the above-described motor drive device, alternatively, a plurality of the printed circuit boards may be connected to each other by means of the conductive support platforms.

[0018] Regarding the above-described motor drive device, alternatively, the bus bar may have ribs for ensuring the bending strength of the bus bar.

[0019] Regarding the above-described motor drive device, alternatively, the conductive support platform may have ribs for ensuring the bending strength of the conductive support platform.

[0020] Regarding the above-described motor drive device, alternatively, the bus bar may have a rectangular parallelepiped shape.

[0021] Effects of the Invention

[0022] By adopting a technical solution of the present disclosure, it is possible to realize a motor drive device having a connection structure of a bus bar, a power element, and a printed circuit board with high strength, high vibration resistance, and low cost. Description of the Drawings

[0023] The present invention will be more clearly understood by referring to the following drawings.

[0024] Figure 1 FIG. is a perspective view showing a connection structure of a bus bar, a printed circuit board, and a conductive support platform of a motor drive device according to a first embodiment of the present disclosure.

[0025] Figure 2 FIG. is a perspective view showing a conductive support platform of a motor drive device according to a first embodiment of the present disclosure.

[0026] Figure 3 FIG. is a perspective view illustrating the shape of a conventional bus bar having a bent portion.

[0027] Figure 4A FIG. is a view illustrating the shape of a conventional bus bar having a complex shape and is a top view showing the positional relationship between the bus bar and the printed circuit board.

[0028] Figure 4B FIG. is a view illustrating the shape of a conventional bus bar having a complex shape and is a top view showing the waste material generated when the bus bar is manufactured by sheet metal working of a metal plate.

[0029] Figure 5A FIG. 2 is a diagram illustrating the shape of a bus bar according to the first embodiment of the present disclosure, and is a top view showing the positional relationship between the bus bar and a printed circuit board.

[0030] Figure 5B FIG. 3 is a diagram illustrating the shape of a bus bar according to the first embodiment of the present disclosure, and is a top view showing waste generated when the bus bar is manufactured by sheet metal working of a metal plate.

[0031] Figure 6 FIG. 4 is a perspective view showing a conductive support table of a motor drive device according to the second embodiment of the present disclosure.

[0032] Figure 7 FIG. 5 is a perspective view showing a connection structure of a bus bar, a printed circuit board, and a conductive support table of a motor drive device according to the second embodiment of the present disclosure.

[0033] Figure 8 FIG. 6 is a perspective view showing a connection structure of a bus bar, a printed circuit board, and a conductive support table of a motor drive device according to a modified example of the second embodiment of the present disclosure.

[0034] Figure 9 FIG. 7 is a perspective view showing a connection structure of a bus bar, a printed circuit board, and a conductive support table of a motor drive device according to an application example of the first and second embodiments of the present disclosure.

[0035] Figure 10 FIG. 8 is a perspective view of a case where ribs for ensuring bending strength are provided on a bus bar and a conductive support table of a motor drive device according to an embodiment of the present disclosure.

[0036] Figure 11A FIG. 9 is a perspective view showing a conductive support table provided with ribs of a motor drive device according to an embodiment of the present disclosure.

[0037] Figure 11B FIG. 10 is a diagram showing a conductive support table provided with ribs of a motor drive device according to an embodiment of the present disclosure, and is Figure 11A a cross-sectional view taken along line A-A'.

[0038] Figure 12 FIG. 11 is a front view of a printed circuit board in which a conductive support table of a motor drive device according to an embodiment of the present disclosure functions as a drip-proof wall and a wall constituting a ventilation path. DETAILED DESCRIPTION

[0039] The motor drive device having a bus bar will be described with reference to the following drawings. For ease of understanding, the scales of these drawings are appropriately changed. The forms shown in the drawings are examples for implementation and are not limited to the illustrated embodiments. Hereinafter, "electrically connected (i.e., connected in a manner capable of conducting electricity)" may sometimes be simply referred to as "connected".

[0040] The motor drive device according to an embodiment of the present disclosure includes: a bus bar through which a current related to motor drive flows; a printed circuit board; and a conductive support table that is mounted on the printed circuit board and is interposed between the bus bar and the printed circuit board. The conductive support table has: at least one threaded member through-hole for fastening the bus bar and the conductive support table by screw fastening; and a printed circuit board terminal portion for electrically connecting the electrical wiring provided on the printed circuit board to the conductive support table. The machine provided with the motor driven by the motor drive device includes, for example, a machine tool, a robot, a forging machine, an injection molding machine, an industrial machine, various electrical products, an electric train, an automobile, an aircraft, etc. Hereinafter, embodiments of the present disclosure will be listed.

[0041] First, the motor drive device according to the first embodiment of the present disclosure will be described.

[0042] Figure 1 It is a perspective view showing the connection structure of the bus bar, the printed circuit board, and the conductive support table of the motor drive device according to the first embodiment of the present disclosure. Figure 2 It is a perspective view showing the conductive support table of the motor drive device according to the first embodiment of the present disclosure.

[0043] The motor drive device 1 according to the first embodiment of the present disclosure includes: a bus bar 10, a printed circuit board 20, and a conductive support table 30.

[0044] The bus bar 10 is a conductor for conducting a relatively large current, is formed of a metal such as copper, brass, or aluminum, and is manufactured by, for example, sheet metal processing. The bus bar 10 is formed in a rectangular parallelepiped shape (linear plate shape). In the bus bar 10, there is provided a threaded member through-hole 11 for fastening the bus bar 10 and the conductive support table 30 by screw fastening.

[0045] Components directly or indirectly connected to the bus bar 10 include, for example: power elements in a power conversion circuit for generating motor drive power, power sources, large-capacity capacitors, and other devices related to motor drive. For example, the bus bar 10 is connected to the input terminals and output terminals of the power element. Examples of power conversion circuits include rectifiers and inverters. The rectifier converts the AC power input from an AC power source into DC power and outputs it to the DC link. The inverter converts the DC power of the DC link into AC power and outputs it as the drive power for the motor. Thus, a current related to motor drive flows through the bus bar 10. Examples of power elements connected to the bus bar 10 include diodes, unipolar transistors such as FETs, bipolar transistors, IGBTs, thyristors, and large-power semiconductor switching elements such as GTOs. A rectifier of the diode rectification method is formed by a full-bridge circuit of diodes. In addition, rectifiers and inverters of the PWM control method and the 120-degree conduction method are formed, for example, by a full-bridge circuit having large-power semiconductor switching elements and diodes anti-parallel thereto.

[0046] On the printed circuit board 20, there are provided various circuits such as a control circuit for controlling the power conversion of a power conversion circuit having a power element, a detection circuit for detecting current or voltage used in various processes such as power conversion and abnormality detection, and a buffer circuit for protecting the circuit from surge voltages generated when the power element is turned on and off. These circuits include various components such as resistors, capacitors, inductors, diodes, FETs (field effect transistors), operational amplifiers, optocouplers, analog-to-digital conversion circuits (ADCs), digital-to-analog conversion circuits (DACs), or various integrated circuits. These components are mounted on the printed circuit board 20, and the components are appropriately connected by electrical wiring according to the functions of the circuits having the components. Among the various circuits provided on the printed circuit board 20, a detection circuit for detecting the current flowing into or out of the power element via the bus bar 10 and for detecting the potential of the bus bar 10 connected to the power element, and a buffer circuit are electrically connected to the bus bar 10. Hereinafter, the electrical wiring on the printed circuit board 20 that is electrically connected to the bus bar 10 in the electrical wiring of the printed circuit board 20 is referred to as "electrical wiring 21". The electrical wiring 21 can be provided (i.e., embedded) inside the printed circuit board 20, can be provided on the first surface 20A of the printed circuit board 20, or can be provided on the second surface 20B of the printed circuit board 20. In the illustrated example, as an example, the electrical wiring 21 is provided inside the printed circuit board 20.

[0047] The conductive support base 30 is installed on the printed circuit board 20, and is interposed between the bus bar 10 and the printed circuit board 20. The bus bar 10 is connected to the printed circuit board 20 by means of the conductive support base 30, so the vibration resistance is relatively high.

[0048] The conductive support base 30 has: an upper plate portion 33; and a pair of side plate portions 34 which extend from a pair of edges of the upper plate portion 33 in a direction intersecting the upper plate portion 33 and are arranged at intervals from each other, and the side plate portions 34 are mounted on the printed circuit board 20 by their ends.

[0049] In the first embodiment, a threaded member through hole 31 for fastening the bus bar 10 and the conductive support base 30 by screw fastening is provided in the upper plate portion 33 or the side plate portion 34 of the conductive support base 30. In Figure 1 and Figure 2 In the example shown, as an example, a threaded member through hole 31 is provided in the upper plate portion 33.

[0050] In addition, a printed circuit board terminal portion 32 for electrically connecting the electrical wiring 21 of the printed circuit board 20 and the conductive support base 30 by soldering is provided at the end of the side plate portion 34. The printed circuit board terminal portion 32 has, for example, a claw shape with spring properties (elasticity). The printed circuit board terminal portion 32 is firmly fixed to the first surface 20A or the second surface 20B of the printed circuit board 20 by fitting into a hole provided in the printed circuit board 20, and electrically connects the conductive support base 30 and the electrical wiring 21 provided inside the printed circuit board 20. In Figure 1 In the example shown, as an example, the conductive support base 30 is mounted on the first surface 20A of the printed circuit board 20 by means of the printed circuit board terminal portion 32. The shape of the printed circuit board terminal portion 32 may also be a shape other than the claw shape shown in the figure. Or for example, the electrical connection between the printed circuit board terminal portion 32 and the electrical wiring 21 provided inside the printed circuit board 20 may be by means of a pad provided in the printed circuit board 20.

[0051] In the first embodiment, a plurality of bus bars 10 (bus bars 10A and 10B in the example shown in Figure 1 ) are connected to one threaded member through hole 31 provided in the conductive support base 30. A plurality of conductive support bases 30 are provided on the printed circuit board 20, and a plurality of bus bars 10 are connected to one threaded member through hole 31 provided in the conductive support base 30 to connect the plurality of bus bars 10, so that current paths of various shapes and lengths can be formed. Here, the connection structure of the bus bar, the printed circuit board, and the conductive support base in the first embodiment will be described in more detail while comparing with the existing example.

[0052] Figure 3 2 is a perspective view showing the shape of a conventional bus bar with a bent portion. In the past, when a portion of the current path is not straight due to the arrangement of components of the motor drive device and the size and shape of the motor drive device, a bus bar 210 with a bent portion was used. In particular, the bent portion of the bus bar 210 has a problem of low strength and vibration resistance.

[0053] In contrast, in the first embodiment, in the case where a portion that is not a straight line, i.e., a bent portion, is generated in the current path due to the arrangement of components of the motor drive device and the size and shape of the motor drive device, a printed circuit board 20 directly below the bent portion (at Figure 1 In the example shown, a conductive support platform 30 is arranged on the first surface 20A. Then, the screw 40 is inserted into the screw insertion hole 11 of the busbars 10A and 10B formed into a rectangular parallelepiped shape (a straight plate shape) and the screw insertion hole 31 of the conductive support platform 30, and the busbars 10A, 10B and the conductive support platform 30 are electrically and physically connected by fastening with the screw 40. The busbars 10A and 10B form a bent portion at a predetermined angle on approximately the same plane. In this way, according to the first embodiment, in the portion of the bent portion that becomes the current path, the busbar 10 is physically fixed to the printed circuit board 20 by means of the printed circuit board terminal portion 32 of the conductive support platform 30, so that the strength and vibration resistance are high.

[0054] In addition, the bus bar 10 (at Figure 1 In the example shown, the busbars 10A and 10B are electrically connected to the electrical wiring 21 of the printed circuit board 20 via the printed circuit board terminal portion 32 of the conductive support 30. By making the impedance of the conductive support 30 larger than the impedance of the components connected to the busbars 10A and 10B (such as power elements, power supplies, large-capacity capacitors, and other devices related to motor drive), the current ( Figure 1 Solid arrow) small current ( Figure 1 The electric current flows from the busbar 10A to the electric wiring 21 of the printed circuit board 20 (the dotted arrow of the conductive support 30). That is, by appropriately adjusting the impedance of the conductive support 30, the current flowing in the busbar 10A can be divided into a large current flowing to the busbar 10B and a small current flowing to the electric wiring 21 of the printed circuit board 20. As examples of the connection object of the electric wiring 21, there are a control circuit for controlling the power conversion of a power conversion circuit having a power element, a detection circuit for detecting a current or voltage used in various processes such as power conversion and abnormality detection, and a buffer circuit for protecting the circuit from the surge voltage generated when the power element is turned on and off.

[0055] In addition, in Figure 1 as an example, two bus bars 10A and 10B are connected through a threaded member through-hole 31 provided in the conductive support table 30, thereby forming a current path having a bent portion. According to the first embodiment, if the number of bus bars 10 connected through a threaded member through-hole 31 provided in the conductive support table 30 is three or more, a current path having a branch portion can also be formed. For example, if the number of bus bars 10 connected through a threaded member through-hole 31 provided in the conductive support table 30 is three, a current path having a Y-shaped branch can be formed. For example, if the number of bus bars 10 connected through a threaded member through-hole 31 provided in the conductive support table 30 is four, a current path having an X-shaped branch can be formed.

[0056] Next, the strength of the bus bar and the manufacturing method of the bus bar of the motor drive device according to the first embodiment will be described while comparing with the existing example.

[0057] Figure 4A is a diagram illustrating the shape of an existing bus bar having a complex shape and is a top view showing the positional relationship between the bus bar and the printed circuit board. Figure 4B is a diagram illustrating the shape of an existing bus bar having a complex shape and is a top view showing the waste material generated when the bus bar is manufactured by sheet metal processing of a metal plate.

[0058] Conventionally, as Figure 4A shown, even for a bus bar 210 having a complex shape, there is no support table for supporting the bus bar 210 provided on the printed circuit board 220, but it depends on the support of components such as power elements connected to the bus bar 210. Therefore, vibration is likely to occur in the bus bar 210 and the strength is also weak. In addition, since the shape of the bus bar 210 varies depending on the configuration of the components of the motor drive device, the size and shape of the motor drive device, etc., it is necessary to pre-ensure the inventory of multiple types of bus bars having different shapes during the manufacture of the motor drive device, and there is a problem that the manufacturing management is complicated. In addition, it is necessary to prepare in advance a mold for forming the complex shape of the bus bar 210, and there is a problem that the manufacturing cost of the motor drive device increases. In addition, as Figure 4B shown, for the metal plate 200 that is the raw material, by using a mold for forming the complex shape of the bus bar 210 for sheet metal processing, the area of the waste material 201 becomes large, so there is a problem that the manufacturing cost of the motor drive device increases.

[0059] Figure 5A is a diagram illustrating the shape of the bus bar according to the first embodiment of the present disclosure and is a top view showing the positional relationship between the bus bar and the printed circuit board.Figure 5B FIG. Figure 5B is a view showing the shape of a bus bar according to the first embodiment of the present disclosure, and is a top view showing waste material generated when the bus bar is manufactured by sheet metal working of a metal plate. Figure 5A and Figure 5B The shape of the current path shown in FIG. Figure 5B is an example, and other shapes may also be possible.

[0060] In the case of forming a current path having a complex shape as shown in FIG. Figure 5A , a conductive support base 30 is disposed on the printed circuit board 20 at the bent portion of the current path. Then, threaded members 40 (threaded members 40A, 40B, 40C in the examples shown in FIGS. Figure 5A and Figure 5B ) are inserted through the threaded member through holes 11 of the bus bar 10 formed in a rectangular parallelepiped shape (linear plate shape) (bus bars 10A, 10B, 10C, 10D in the examples shown in FIGS. Figure 5A and Figure 5B ) and the threaded member through holes 31 of the conductive support base 30. By tightening with the threaded tightening by the threaded member 40A, the bus bar 10A, the bus bar 10B, and the conductive support base 30 are electrically and physically connected. By tightening with the threaded tightening by the threaded member 40B, the bus bar 10B, the bus bar 10C, and the conductive support base 30 are electrically and physically connected. By tightening with the threaded tightening by the threaded member 40C, the bus bar 10C, the bus bar 10D, and the conductive support base 30 are electrically and physically connected. A plurality of conductive support bases 30 are provided on the printed circuit board 20, and bus bars 10 are connected to each of the conductive support bases 30 to connect the plurality of bus bars 10, thereby enabling current paths of various shapes and lengths to be formed. Thus, according to the first embodiment, at the portion that becomes the bent portion of the current path, the bus bars 10A, 10B, 10C, 10D are physically fixed to the printed circuit board 20 by the printed circuit board terminal portions 32 of the conductive support base 30, and thus the strength and vibration resistance are high.

[0061] In addition, since the bus bar 10 has a rectangular parallelepiped shape (linear plate shape), the mold for manufacturing the bus bar 10 has a simple shape and thus a low cost, and the motor drive device can be manufactured at low cost. Regardless of the shape of the current path, it is possible to cope with a combination of a plurality of bus bars 10 having different dimensions, and thus the manufacturing management of the motor drive device can be simplified. Further, as shown in FIG. Figure 5B , for the metal plate 100 that is a raw material, sheet metal working is performed using a mold for manufacturing a simple rectangular parallelepiped shape, and thus the metal plate 100 can be effectively utilized, and the area of the waste material 101 can be reduced. As a result, the motor drive device can be manufactured at low cost.

[0062] ​​​​​​​​​​​​In addition, in Figure 5A and Figure 5B the electrical wiring 21 provided on the printed circuit board 20 is not illustrated, but the bus bars 10 (i.e., bus bars 10A, 10B, 10C, 10D) can also be electrically connected to the electrical wiring 21 provided on the printed circuit board 20 through the printed circuit board terminal portions 32 of the conductive support base 30.

[0063] Next, a motor drive device according to a second embodiment of the present disclosure will be described.

[0064] Figure 6 is a perspective view of a conductive support base of a motor drive device according to a second embodiment of the present disclosure. Figure 7 is a perspective view of a connection structure of a bus bar, a printed circuit board, and a conductive support base of a motor drive device according to a second embodiment of the present disclosure.

[0065] The motor drive device 1 according to the second embodiment of the present disclosure includes a bus bar 10, a printed circuit board 20, and a conductive support base 30, similar to the first embodiment. However, the second embodiment is different from the first embodiment in that the conductive support base 30 includes a plurality of threaded member through holes 31, and the plurality of bus bars 10 are connected to each of the plurality of threaded member through holes 31 one by one. The bus bar 10 and the printed circuit board 20 of the second embodiment are the same as those of the first embodiment, and thus the description thereof is omitted.

[0066] The conductive support base 30 of the second embodiment is mounted on the printed circuit board 20 and is interposed between the bus bar 10 and the printed circuit board 20, similar to the first embodiment. The conductive support base 30 has: an upper plate portion 33; and a pair of side plate portions 34 that extend from a pair of edges of the upper plate portion 33 in a direction intersecting the upper plate portion 33 and are arranged at intervals from each other, and the side plate portions 34 are mounted on the printed circuit board 20 using their ends. In addition, at the ends of the side plate portions 34, there are provided printed circuit board terminal portions 32 for electrically connecting the electrical wiring 21 of the printed circuit board 20 to the conductive support base 30 by soldering. The printed circuit board terminal portions 32 have, for example, a claw shape having a spring property (elasticity). The printed circuit board terminal portions 32 are firmly fixed to the first surface 20A or the second surface 20B of the printed circuit board 20 by fitting into holes provided in the printed circuit board 20, and electrically connect the conductive support base 30 to the electrical wiring 21 provided inside the printed circuit board 20. In Figure 7In the example shown, as an example, the conductive support 30 is mounted on the first surface 20A of the printed circuit board 20 via the printed circuit board terminal portion 32. The shape of the printed circuit board terminal portion 32 may be a shape other than the claw shape shown in the figure. Alternatively, for example, the electrical connection between the printed circuit board terminal portion 32 and the electrical wiring 21 provided inside the printed circuit board 20 may be via a pad provided on the printed circuit board 20.

[0067] In the second embodiment, a plurality of screw insertion holes 31 for fastening the bus bar 10 to the conductive support base 30 by screw fastening are provided in the upper plate portion 33 or the side plate portion 34 of the conductive support base 30. A plurality of conductive support bases 30 are provided on the printed circuit board 20, and at least one bus bar 10 is connected to each of the plurality of screw insertion holes 31 provided on the conductive support base 30, so that the plurality of bus bars 10 are connected, thereby being able to form current paths of various shapes and lengths.

[0068] exist Figure 6 and Figure 7 In the example shown, two screw insertion holes 31A and 31B are provided in the upper plate portion 33. In the case where a portion that is not a straight line, i.e., a bent portion, is generated in the current path due to the arrangement of the components of the motor drive device and the size and shape of the motor drive device, a printed circuit board 20 directly below the bent portion (at Figure 7 In the example shown, the conductive support 30 is arranged on the first surface 20A. Then, the screw 40 is inserted into the screw insertion hole 11 of the busbars 10A and 10B formed into a rectangular parallelepiped shape (a straight plate shape) and the screw insertion hole 31 of the conductive support 30, and the busbars 10A and 10B are electrically and physically connected to the conductive support 30 by fastening by screws of the screw 40. In this way, according to the second embodiment, the busbar 10 is physically fixed to the printed circuit board 20 by the printed circuit board terminal portion 32 of the conductive support 30 at the portion that becomes the bending portion of the current path, so that the strength and vibration resistance are high. In addition, according to the second embodiment, compared with the first embodiment in which a plurality of busbars 10 are connected to one screw insertion hole 31, the heat generated by the current flowing through the busbar 10 is less.

[0069] According to the second embodiment, the positions for setting the screw insertion holes 31A and 31B are appropriately selected from the upper plate portion 33 and the two side plate portions 34, and the bus bars 10A and 10B formed into a rectangular shape (straight plate shape) are respectively connected to the screw insertion holes 31A and 31B, thereby forming a current path bent in various directions.

[0070] In addition, according to the second embodiment, if the number of screw member through-holes 31 provided in the conductive support base 30 is three or more, a current path having a branch portion can also be formed. For example, if three bus bars 10 are respectively connected to each of the three screw member through-holes 31 provided in the conductive support base 30, a current path having a Y-shaped branch can be formed. For example, if four bus bars 10 are respectively connected to each of the four screw member through-holes 31 provided in the conductive support base 30, a current path having an X-shaped branch can be formed.

[0071] In addition, also in the second embodiment, by making the impedance ratio of the conductive support base 30 larger than the impedance of the members (such as power elements, power supplies, large-capacity capacitors, and other devices related to motor drive) to which the bus bars 10A and 10B are connected, a current ( Figure 7 the solid arrow) smaller than the current flowing from the bus bar 10A to the bus bar 10B can flow from the bus bar 10A to the electrical wiring 21 of the printed circuit board 20. Figure 7 the dotted arrow)

[0072] In addition, the above-described bus bar 10 has a rectangular parallelepiped shape. However, as a modified example thereof, a bus bar 10 having a bent portion may be connected to the conductive support base 30. Figure 8 FIG. is a perspective view showing a connection structure of a bus bar, a printed circuit board, and a conductive support base of a motor drive device according to a modified example of the second embodiment of the present disclosure. In this modified example, as an example, the case where bus bars 10E and 10F having bent portions are connected to the conductive support base 30 of the second embodiment will be described. However, the same description also holds for the case of connecting to the conductive support base 30 of the first embodiment. By making the bus bars 10E and 10F connected to the conductive support base 30 have bent portions, the degree of freedom of wiring of the current path in the motor drive device 1 increases. However, the bus bars 10E and 10F having bent portions cannot be manufactured by simple sheet metal processing like the bus bar having a rectangular parallelepiped shape, so the manufacturing cost increases.

[0073] The above-described first embodiment and second embodiment may also be combined and implemented. That is, by connecting two or more bus bars to one of the plurality of screw member through-holes 31 provided in the conductive support base 30, branches of a larger number of current paths than the number of screw member through-holes 31 can also be formed.

[0074] Next, application examples of the first embodiment and the second embodiment will be described. In this application example, the above-described conductive support base 30 and bus bar 10 are used to connect a plurality of printed circuit boards 20 to each other, so that the plurality of printed circuit boards 20 are firmly fixed.

[0075] Figure 9 This is a perspective view of the connection structure of a bus bar, a printed circuit board, and a conductive support base of a motor drive device showing application examples of the first and second embodiments of the present disclosure. In Figure 9 As an example, a case where two printed circuit boards 20-1 and 20-2 are fixed by means of the conductive support base 30-2 of the second embodiment will be described.

[0076] The printed circuit board terminal portion 32 of the conductive support base 30-1 of the first embodiment is mounted on the printed circuit board 20-1 having a normal line in the Y-axis direction, so that the conductive support base 30-1 is mounted on the printed circuit board 20-1. By tightening with a threaded fastener 40A, one end of the bus bar 10A is electrically and physically connected to the upper plate portion 33 of the conductive support base 30-1. In addition, an integrated circuit 61 is mounted on the printed circuit board 20-1. For example, by means of electrical wiring 21 (not shown in Figure 9 ), the bus bar 10A is electrically connected to the integrated circuit 61.

[0077] The printed circuit board terminal portion 32 of the conductive support base 30-2 of the second embodiment is mounted on the printed circuit board 20-2 having a normal line in the Z-axis direction, so that the conductive support base 30-2 is mounted on the printed circuit board 20-2. By tightening with a threaded fastener 40B, one end of the bus bar 10A is electrically and physically connected to the side plate portion 34 of the conductive support base 30-2. In this way, the printed circuit board terminal portion 32 of the conductive support base 30-2 is fixed to the printed circuit board 20-2, and the side plate portion 34 of the conductive support base 30-2 is fixed relative to the printed circuit board 20-1 by means of the bus bar 10A and the conductive support base 30-1, so that the printed circuit board 20-1 having a normal line in the Y-axis direction and the printed circuit board 20-2 having a normal line in the Z-axis direction form an angle of about 90 degrees and are firmly fixed.

[0078] Figure 9 The example shown is merely an example. For the type of the conductive support base 30 (the first embodiment and / or the second embodiment), the number of threaded fastener through holes 31 provided, the position of the threaded fastener through holes 31 provided (the upper plate portion 33 and / or the side plate portion 34), and the fixing method of the bus bar 10 to the conductive support base 30 (the first embodiment and / or the second embodiment), they can be appropriately selected according to the number of printed circuit boards 20 to be fixed and the fixing angle between the printed circuit boards 20. According to this application example, by means of the conductive support base 30 and the bus bar 10, a plurality of printed circuit boards 20 can be firmly fixed at various angles, and the vibration resistance is improved.

[0079] Next, a modified example of the bus bar 10 and the conductive support base 30 will be described. In this modified example, ribs are provided on the bus bar 10 and the conductive support base 30, thereby improving their bending strength.

[0080] Figure 10 It is a perspective view of a case where ribs for ensuring bending strength are provided on the bus bar and the conductive support base of the motor drive device according to an embodiment of the present disclosure. In addition, Figure 11A It is a perspective view of the conductive support base provided with ribs of the motor drive device according to an embodiment of the present disclosure. In addition, Figure 11B It is a view showing the conductive support base provided with ribs of the motor drive device according to an embodiment of the present disclosure, and is Figure 11A A - A' cross - sectional view. The rib 51 provided on the bus bar 10 and the rib 52 provided on the conductive support base 30 have convex portions and concave portions obtained by stamping a flat - plate - shaped metal member. For example, as Figure 11A and Figure 11B shown, for the conductive support base 30, the rib 52 has a convex portion 52A and a concave portion 52B. The ribs 51 and 52 may be provided at any portion of the bus bar 10 and the conductive support base 30 where bending strength is desired to be ensured. In the examples shown in Figure 11A and Figure 11B as an example, it shows a case where the rib 52 is provided on the side plate portion 34 of the conductive support base 30 of the first embodiment, but the rib 52 may also be provided on the upper plate portion 33, or the rib 52 may also be provided on the upper plate portion 33 and / or the side plate portion 34 of the conductive support base 30 of the second embodiment. Thus, by providing ribs on the bus bar 10 and the conductive support base 30, the strength (folding resistance) and vibration resistance are increased.

[0081] Next, with reference to Figure 12 , another application example of the motor drive device 1 having the above - described connection structure will be described. Since the pair of side plate portions 34 of the conductive support base 30 have relatively large sizes, in this application example, the side plate portion 34 of the conductive support base 30 mounted on the printed circuit board 20 functions as a drip - proof wall with respect to other mounting components on the printed circuit board 20, or functions as a wall for forming a ventilation path with respect to other mounting components on the printed circuit board 20.

[0082] Figure 12The main view of a printed circuit board in which a conductive support table of a motor drive device illustrating an embodiment of the present disclosure functions as a drip-proof wall and a wall constituting a ventilation path. Here, as an example, an example in which the printed circuit board 20 is provided in a vertically erected state in the motor drive device 1 will be described. In the illustrated example, on the first surface 20A of the printed circuit board 20, there are mounted: a conductive support table 30 for supporting bus bars 10A and 10B, components 71 to 75 such as chip resistors, and an electrolytic capacitor 76. In addition, a cooling fan 80 for cooling the mounted components on the printed circuit board 20 is provided above the printed circuit board 20. Figure 12 The types, numbers, and positional relationships of the illustrated components are merely examples.

[0083] For example, when the motor drive device 1 is used as a drive source for driving a motor in a machine tool, cutting fluid may sometimes drip from above the printed circuit board 20. When the components 71 to 75 that want to avoid the attachment of the cutting fluid 91 are located below the conductive support table 30, as Figure 12 shown, the conductive support table 30 is mounted on the printed circuit board 20 in such a manner that the outflow source of the cutting fluid and the components 71 to 75 are located on opposite sides of each other across the side plate portion 34 of the conductive support table 30. Thereby, the cutting fluid dripping from above collides with the side plate portion 34 of the conductive support table 30, and thus the flow of the cutting fluid becomes along the orientation of the side plate portion 34, and the cutting fluid does not adhere to the components 71 to 75. In this way, the side plate portion 34 of the conductive support table 30 can function as a drip-proof wall with respect to other mounted components on the printed circuit board 20.

[0084] In addition, for heat-generating components such as the electrolytic capacitor 76, cooling is performed using the air flowing due to the cooling fan 80. In the illustrated example, the cooling fan 80 causes the air to flow in the upward direction from the lower side of the printed circuit board 20 (the orientation of the arrow 92), but if the conductive support table 30 is mounted on the printed circuit board 20 in such a manner that the length direction of the side plate portion 34 of the conductive support table 30 becomes the orientation of the arrow 94, the air sucked up by the cooling fan 80 collides with the electrolytic capacitor 76. Thereby, the electrolytic capacitor 76 can be cooled. In this way, the side plate portion 34 of the conductive support table 30 can function as a wall constituting a ventilation path with respect to other mounted components on the printed circuit board 20. In addition, since the bus bars 10A and 10B are supported by the conductive support table 30 at positions separated from the printed circuit board 20, they do not have a great influence on the above ventilation path.

[0085] The conductive support table 30 only needs to be able to support the busbars 10A and 10B. Since the orientation of the side plate portion 34 of the conductive support table 30 is relatively free, according to the positional relationship between the outflow source of the cutting fluid and the mounting component where the attachment of the cutting fluid is to be avoided, and the positional relationship between the cooling fan 80 and the mounting component to be cooled, it is only necessary to appropriately design the angle formed by the direction 94 along the side plate portion 34 of the conductive support table 30, the extending direction 93 of the busbar 10A, and the extending direction 95 of the busbar 10B.

Claims

1. A motor drive device, characterized in that, The motor drive device includes: A bus bar through which current related to motor drive flows; A printed circuit board; and A conductive support base that is mounted on the printed circuit board and is interposed between the bus bar and the printed circuit board, The conductive support base has: At least one threaded member through hole for fastening the bus bar and the conductive support base by threaded fastening; and A printed circuit board terminal portion for electrically connecting the conductive support base to electrical wiring provided on the printed circuit board, Wherein the bus bar is connected to the printed circuit board via the conductive support base, The conductive support base further has: An upper plate portion; and Side plate portions which are a pair of side plate portions that extend from a pair of edges of the upper plate portion in a direction crossing the upper plate portion and are arranged at intervals from each other, and the side plate portions are mounted on the printed circuit board by their ends, The threaded member through hole is provided in the upper plate portion or the side plate portion.

2. The motor drive device according to claim 1, characterized in that, A plurality of the bus bars are connected to one of the threaded member through holes provided in the conductive support base.

3. The motor drive device according to claim 1, characterized in that, A plurality of the bus bars are connected one by one to each of the plurality of threaded member through holes provided in the conductive support base.

4. The motor drive device according to claim 1, characterized in that, The upper plate portion and the side plate portions form a drip-proof wall with respect to other mounting components of the printed circuit board.

5. The motor drive device according to claim 1, characterized in that, The upper plate portion and the side plate portions form a ventilation path with respect to other mounting components of the printed circuit board.

6. The motor drive device according to any one of claims 1 to 5, characterized in that, A plurality of the conductive support bases are provided on the printed circuit board.

7. The motor drive device according to any one of claims 1 to 5, characterized in that, A plurality of the printed circuit boards are connected to each other via the conductive support bases.

8. The motor drive device according to any one of claims 1 to 5, characterized in that, The bus bar has ribs for ensuring the bending strength of the bus bar.

9. The motor drive device according to any one of claims 1 to 5, characterized in that, The conductive support base has ribs for ensuring the bending strength of the conductive support base.

10. The motor drive device according to any one of claims 1 to 5, characterized in that, The bus bar has a rectangular parallelepiped shape.

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