Motor control device

Abstract

Provided is a motor control device which is easily minimized in size while securing an insulation distance of a bus bar to a substrate.　A motor control device according to the present invention comprises: a printed substrate (20) that has a surface on which a switching element (22) is mounted; a bus bar (31, 32) that is mounted on the surface of the printed substrate (20) and that is connected to the switching element (22); and an electrolytic capacitor (60) that is electrically connected to the switching element (22) with the bus bar (31, 32) therebetween. The bus bar (31, 32) has a main body (41, 51) that is connected to the printed substrate (20) and a bus bar terminal (42, 52) that is coupled to the main body (41, 51) and that is connected to the electrolytic capacitor (60). The bus bar terminal (42, 52) has a rising part that rises from the surface (20b) of the printed substrate (20) and a capacitor connection part (47, 57) that is bent and extended from an extreme end of the rising part toward the electrolytic capacitor (60) and that is connected to the electrolytic capacitor (60).

Description

Motor control device

[0001] The present invention relates to a motor control device.

[0002] Conventionally, motor control devices have been known that convert DC power supplied from a battery into AC power and drive an AC motor (hereinafter also referred to as a motor) with the converted AC power. The motor control device includes a substrate (switching module) on which switching elements are surface-mounted. In addition to the switching elements, electrolytic capacitors (hereinafter also referred to as capacitors) for smoothing the current flowing to the motor are surface-mounted (SMT: Surface Mount Technology) on the substrate. Here, if the inductance of the current path (current flow distance) is large, the ripple current flowing in the capacitor becomes large, which may cause thermal damage to the capacitor.

[0003] Known countermeasures include selecting a capacitor that can absorb ripple current or increasing the number of capacitors. However, from the perspective of miniaturizing and reducing the cost of motor control devices, it is preferable to implement countermeasures to reduce inductance. Effective methods for reducing inductance include shortening the current path and arranging the input and output terminals in parallel, facing each other over a wide area.

[0004] A known example of a motor control device that connects input and output terminals in parallel and facing each other over a wide area is one in which a bus bar connects a switching element, which is a heat-generating element, and a capacitor. The bus bar is integrally formed with a first terminal connected to the switching element, a second terminal connected to the capacitor, and a connecting portion connecting the first and second terminals. The first terminal is bent toward the capacitor. The bus bar has a positive electrode and a negative electrode, and the connecting portion for the positive electrode and the connecting portion for the negative electrode are arranged opposite each other. The bus bar is bent in an L shape so that the end of the first terminal facing the capacitor rises from the substrate. A second terminal is formed at the tip of the bent bus bar. This ensures an insulation distance between the substrate and the connection point (second terminal) of the bus bar to the capacitor (see, for example, Patent Document 1).

[0005] Japanese Patent Application Laid-Open No. 2003-319665

[0006] However, the bus bars in the motor control device described above are simply bent in an L shape so as to rise from the board, which limits the degree of freedom in capacitor layout, resulting in a problem that the motor control device tends to become large.

[0007] Therefore, the present invention provides a motor control device that can be easily downsized while ensuring the insulation distance between the bus bar and the circuit board.

[0008] In order to solve the above problems, in a first aspect of the present invention, a motor control device includes a substrate on which a heat-generating element is surface-mounted, a bus bar that is surface-mounted on the substrate and connected to the heat-generating element, and a capacitor that is arranged alongside the substrate in the extension direction of the substrate and is electrically connected to the heat-generating element via the bus bar, wherein the bus bar has a main body portion that is connected to the substrate, and a bus bar terminal that is coupled to the main body portion and connected to the capacitor, and the bus bar terminal has a rising portion that rises from the surface of the substrate, and a connection portion that is bent and extends from the end of the rising portion opposite the substrate towards the capacitor and is connected to the capacitor.

[0009] By configuring the bus bar terminals with rising portions and connecting portions in this way, the degree of freedom in the layout of the capacitors in the normal direction of the board can be increased, which makes it easier to miniaturize the motor control device while ensuring the insulation distance between the board and the connecting portion of the bus bar.

[0010] A second aspect of the present invention is a motor control device according to the first aspect, further comprising a plurality of the capacitors, each of the capacitors having a lead terminal connected to the connection portion, the lead terminals being arranged in a line in one direction, the bus bar having a plurality of the bus bar terminals connected to the plurality of capacitors, the connection portions being arranged in a line in the same direction as the arrangement of the lead terminals.

[0011] By configuring the motor control device in this manner, the motor control device can be made smaller, the work of connecting the lead terminals and the bus bar terminals can be simplified, and the productivity of the motor control device can be improved.

[0012] A third aspect of the present invention is a motor control device according to the first or second aspect, wherein the bus bars include a first bus bar and a second bus bar, each connected to one of the capacitors, and the main body portion includes a first main body portion provided on the first bus bar and a second main body portion provided on the second bus bar, and the first main body portion and the second main body portion are arranged opposite each other in the arrangement direction of the heat generating element and the capacitor, between the heat generating element and the capacitor.

[0013] In this way, by arranging the first body and the second body opposite each other in the alignment direction of the heating element and the capacitor, it is possible to reduce the size of the motor control device while shortening the current path between each bus bar terminal and the heating element, thereby reducing inductance and ensuring an insulation distance between the heating element and the capacitor via the bus bar.

[0014] In a fourth aspect of the present invention, in the motor control device of any one of the first to third aspects, the main body has a tongue portion extending from an end of the main body on the opposite side to the board.

[0015] With this configuration, for example, when assembling a motor control device, the bus bar can be easily moved to a desired position by gripping the tongue portion, thereby improving the assembly workability of the motor control device while miniaturizing the motor control device.

[0016] A fifth aspect of the present invention is the motor control device according to the fourth aspect, wherein the tongue portion extends in a direction parallel to the substrate.

[0017] With this configuration, for example, when transporting a bus bar, it is possible to lift it by suctioning the tongue portion while keeping the main body aligned in the normal direction of the board, further improving the ease of assembly of the motor control device.

[0018] In a sixth aspect of the present invention, in the motor control device according to any one of the first to fifth aspects, the main body has legs that protrude from side surfaces of the main body and come into contact with the board.

[0019] If the main body is positioned so that it is aligned normal to the board, the busbars will become unstable. In this state, the legs protrude from the sides of the main body and abut against the board. This allows the legs to function as a means of preventing the busbars from tipping over. This allows the motor control device to be made more compact while improving its reliability.

[0020] A seventh aspect of the present invention is the motor control device according to the sixth aspect, wherein the legs are connected to the substrate.

[0021] This configuration allows the bus bars to reliably maintain their position relative to the circuit board without increasing the size of the bus bars, thereby further improving the reliability of the motor control device.

[0022] According to the present invention, a motor control device is provided that can be easily downsized while ensuring the insulation distance between the bus bar and the substrate.

[0023] Fig. 1 is a perspective view showing a motor control device according to an embodiment of the present invention. Fig. 2 is a view taken along an arrow II in Fig. 1. Fig. 3 is a perspective view of the motor control device according to an embodiment of the present invention with the case removed. Fig. 4 is an exploded perspective view of the motor control device shown in Fig. 3. Fig. 5 is a view showing a connection state between bus bars and capacitors according to an embodiment of the present invention. Fig. 6 is a plan view of an electrolytic capacitor and its periphery in a view taken along an arrow VI in Fig. 3. Fig. 7 is a perspective view of the motor control device according to a modified embodiment of the present invention with the case removed.

[0024] Next, an embodiment of the present invention will be described with reference to the drawings.

[0025] <Motor Control Device> Fig. 1 is a perspective view showing a motor control device according to an embodiment. Fig. 2 is a side view showing the motor control device of Fig. 1. As shown in Figs. 1 and 2, the motor control device 1 has an inverter function that converts DC power supplied from a battery (not shown) into AC power and drives an AC motor (not shown) with the converted AC power. The motor control device 1 includes a case 10, a plate-shaped printed circuit board (substrate) 20 and a plurality of (e.g., eight in this embodiment) cylindrical electrolytic capacitors (capacitors) 60 housed in the case 10, and a bus bar 30 surface-mounted (SMT) on a surface 20b of the printed circuit board 20.

[0026] The electrolytic capacitors 60 are arranged in parallel in a direction perpendicular to the longitudinal direction (axial direction). Hereinafter, the longitudinal direction (axial direction) of the electrolytic capacitors 60 will be referred to as the X direction. The direction in which the electrolytic capacitors 60 are arranged in parallel will be referred to as the Y direction. The direction perpendicular to the surface 20b of the printed circuit board 20 (normal direction) will be referred to as the Z direction. The printed circuit board 20 and the electrolytic capacitors 60 are arranged side by side in the extension direction of the printed circuit board 20 and along the X direction. That is, the electrolytic capacitor 60 is arranged at one end 20a of the printed circuit board 20 in the X direction. Details of the electrolytic capacitor 60 will be described later.

[0027] <Case> The case 10 is formed in a box shape with one side open. The case 10 houses the printed circuit board 20, the bus bar 30, and a plurality of electrolytic capacitors 60 together with a cover (not shown) that closes the opening of the case 10. The case 10 is provided with a plurality of heat dissipation fins 12 on an outer surface 10a of the area where the printed circuit board 20 and the plurality of electrolytic capacitors 60 are housed. Hereinafter, the heat dissipation fins 12 may be referred to as "heat dissipation fins 12."

[0028] The multiple heat dissipation fins 12 are arranged, for example, at intervals in the Y direction on the outer surface 10a of the case 10. The multiple heat dissipation fins 12 extend in the X direction from the end 10b side where the electrolytic capacitors 60 are housed to the side where the printed circuit board 20 is housed. The multiple heat dissipation fins 12 protrude outward in the Z direction from the outer surface 10a of the case 10. The multiple heat dissipation fins 12 dissipate heat from the printed circuit board 20, the bus bar 30, and the multiple electrolytic capacitors 60 to the outside of the case 10.

[0029] <Printed Circuit Board> Figure 3 is a perspective view of the motor control device of Figure 1 with the case removed. Figure 4 is an exploded perspective view of the motor control device of Figure 3. As shown in Figures 3 and 4, the printed circuit board 20 is formed, for example, in a rectangular shape when viewed from the Z direction. The printed circuit board 20 is a PWB (Printed Wiring Board) on which a plurality of switching elements 22 are surface-mounted. The switching elements 22 are controlled by a switching control circuit (not shown) to turn on and off, thereby operating the motor control device 1 under optimal conditions according to the driving state of the AC motor.

[0030] The printed circuit board 20 has a plurality of first pattern terminals 23 and a plurality of second pattern terminals 24 provided at one end 20a on the side where the bus bar 30 is arranged. The plurality of first pattern terminals 23 and the plurality of second pattern terminals 24 are alternately arranged at intervals in the Y direction. The plurality of first pattern terminals 23 and the plurality of second pattern terminals 24 are exposed on the surface 20b of the printed circuit board 20.

[0031] The first pattern terminal 23 is electrically connected to the positive electrode of the switching element 22, for example, via a wiring pattern (not shown) formed on the printed circuit board 20. The second pattern terminal 24 is electrically connected to the negative electrode of the switching element 22, for example, via a wiring pattern (not shown) formed on the printed circuit board 20. In the embodiment, the first pattern terminal 23 is described as the positive electrode and the second pattern terminal 24 is the negative electrode, but this is not limiting. As another example, the first pattern terminal 23 may be the negative electrode and the second pattern terminal 24 may be the positive electrode.

[0032] <Busbar> FIG. 5 is a diagram showing the connection state between the busbar 30 and the electrolytic capacitor 60, and corresponds to FIG. 2 described above. As shown in FIGS. 3 to 5 , the busbar 30 is connected to the plurality of first pattern terminals 23 and the plurality of second pattern terminals 24 of the printed circuit board 20. The busbar 30 is surface-mounted on the front surface 20b of the printed circuit board 20 by being connected to the plurality of first pattern terminals 23 and the plurality of second pattern terminals 24. The busbar 30 electrically connects the plurality of electrolytic capacitors 60 and the plurality of switching elements 22. The busbar 30 includes a first busbar 31 and a second busbar 32. In the embodiment, for example, the first busbar 31 is described as a positive electrode and the second busbar 32 is described as a negative electrode, but this is not limited thereto. As another example, the first busbar 31 may be described as a negative electrode and the second busbar 32 as a positive electrode.

[0033] The first bus bar 31 is formed of a plate-shaped conductive material. The first bus bar 31 has a first main body portion 41 extending in the Y direction along the plurality of first pattern terminals 23 and the plurality of second pattern terminals 24 of the printed circuit board 20, and a plurality of first bus bar terminals 42 and first leg portions 43 connected to the first main body portion 41. For example, there are four of each pattern terminal 23, 24, for a total of eight. There are also eight first bus bar terminals 42. The total number of these pattern terminals 23, 24 and the number of first bus bar terminals 42 correspond to the number of electrolytic capacitors 60.

[0034] The first main body portion 41 is formed in a plate shape that is long in the Y direction. That is, the first main body portion 41 is formed in a rectangular shape by extending at a constant height from one side edge 20c to the other side edge 20d in the Y direction of the printed circuit board 20. The first main body portion 41 is disposed so as to be perpendicular to the surface 20b of the printed circuit board 20. That is, the thickness direction of the first main body portion 41 coincides with the X direction. Therefore, the first main body portion 41 is formed to have as large an area as possible in terms of its width dimension in the Y direction and its height dimension in the Z direction.

[0035] In the embodiment, an example in which the first body portion 41 is orthogonal to the printed circuit board 20 will be described, but this is not limiting. As another example, the first body portion 41 may be intersecting the printed circuit board 20. That is, the first body portion 41 only needs to be arranged along the normal direction (Z direction) of the surface 20b of the printed circuit board 20. The first body portion 41 is arranged between one end portion 20a of the printed circuit board 20 and the multiple switching elements 22. The first body portion 41 is arranged close to the multiple switching elements 22.

[0036] The multiple first bus bar terminals 42 are bent and extended from an edge 41 a of the first body portion 41 on the printed circuit board 20 side toward the electrolytic capacitor 60. In other words, the multiple first bus bar terminals 42 are bent and extended from the edge 41 a of the first body portion 41 toward the opposite side to the switching elements 22. The multiple first bus bar terminals 42 are arranged at equal intervals in the Y direction.

[0037] The first bus bar terminal 42 has a first pattern connecting portion 45 bent and extended from the first main body portion 41, a first rising portion 46 extending from a tip of the first pattern connecting portion 45 (the end opposite the first main body portion 41), and a first capacitor connecting portion 47 extending from a tip of the first rising portion 46 (the end opposite the first pattern connecting portion 45). The first pattern connecting portion 45 extends along the first pattern terminal 23. The first pattern connecting portion 45 is connected to the first pattern terminal 23 of the printed circuit board 20 by soldering through surface mounting.

[0038] The first pattern connection portion 45 is electrically connected to the positive electrode of the switching element 22 via the first pattern terminal 23 and a wiring pattern (not shown). That is, the first body portion 41 is electrically connected to the positive electrode of the switching element 22 via the first pattern connection portion 45, the first pattern terminal 23, and the wiring pattern.

[0039] The first rising portion 46 is bent and extends from the tip of the first pattern connecting portion 45 so as to be spaced apart in the Z direction relative to the printed circuit board 20. In other words, the first rising portion 46 rises from the surface 20b of the printed circuit board 20. The first capacitor connecting portion 47 is bent and extends from the tip of the first rising portion 46 in parallel to the first pattern connecting portion 45 toward the electrolytic capacitor 60. In other words, the first capacitor connecting portion 47 is disposed at a distance in the Z direction relative to the printed circuit board 20. A recess 48 is formed at the tip of the first capacitor connecting portion 47. A first lead terminal 61 (described later) of the electrolytic capacitor 60 is fitted into the recess 48.

[0040] The first leg 43 is bent and extends from an end 41b of the first body 41 on one side 20c of the printed circuit board 20 toward the switching element 22. That is, the first leg 43 protrudes from the side surface 41c of the first body 41 on the switching element 22 side. A protruding piece 43a that protrudes toward the printed circuit board 20 is integrally formed at the end of the first leg 43 on the printed circuit board 20 side. The protruding piece 43a is connected to the surface 20b of the printed circuit board 20. In other words, the first leg 43 abuts against the surface 20b of the printed circuit board 20.

[0041] The basic configuration of the second bus bar 32 is the same as that of the first bus bar 31. Therefore, in the following description of each part of the second bus bar 32, the names of each part of the first bus bar 31 will be changed from "first" to "second" and the reference numerals will be changed, and the description will be omitted. Only the differences in the configuration of the second bus bar 32 from the first bus bar 31 will be described.

[0042] The second bus bar 32 is formed from a plate-shaped conductive material and has a second body portion 51, a plurality of second bus bar terminals 52, and second legs 53. The second body portion 51 is disposed between one end portion 20a of the printed circuit board 20 and the plurality of switching elements 22. The second body portion 51 is disposed closer to the one end portion 20a of the printed circuit board 20 than the first body portion 41. The second body portion 51 faces the first body portion 41 in the X direction.

[0043] The plurality of second bus bar terminals 52 have second pattern connection portions 55, second rising portions 56, and second capacitor connection portions 57. The second pattern connection portions 55 are connected to the second pattern terminals 24 of the printed circuit board 20 by surface mounting with solder. The second pattern connection portions 55 are electrically connected to the negative electrodes of the switching elements 22 via the second pattern terminals 24 and a wiring pattern (not shown). In other words, the second body portion 51 is electrically connected to the negative electrodes of the switching elements 22 via the second pattern connection portions 55, the second pattern terminals 24, and the wiring pattern.

[0044] The first bus bar 31 and the second bus bar 32 are arranged such that the first body portion 41 and the second body portion 51 are slightly offset in the Y direction. In this state, the plurality of second bus bar terminals 52 are arranged between the plurality of first bus bar terminals 42 in the Y direction. The arrangement of these first bus bar terminals 42 and second bus bar terminals 52 will be described in detail below. A recess 58 is formed at the tip of the second capacitor connection portion 57. The recess 58 is fitted into a second lead terminal 62 (described below) of the electrolytic capacitor 60. The second leg portion 53 is bent and extends from an end portion 51b of the second body portion 51 on the other side edge 20d of the printed circuit board 20 toward the switching element 22. That is, the second leg portion 53 protrudes from a side surface 51c of the second body portion 51 facing the switching element 22. The protruding piece 53a of the second leg portion 53 is connected to the surface 20b of the printed circuit board 20. In other words, the second leg portion 53 abuts against the surface 20 b of the printed circuit board 20 .

[0045] 6 is a plan view showing the electrolytic capacitor 60 and its periphery in the view seen from the arrow VI in FIG. 3 . As shown in FIGS. 5 and 6 , the first capacitor connection portions 47 of the first bus bar terminals 42 and the second capacitor connection portions 57 of the second bus bar terminals 52 are alternately arranged in a row in the Y direction. In other words, the first capacitor connection portions 47 and the second capacitor connection portions 57 are linearly arranged along a straight line L extending in the Y direction. In particular, the recesses 48 of the first capacitor connection portions 47 and the recesses 58 of the second capacitor connection portions 57 are linearly arranged along the straight line L extending in the Y direction. Furthermore, the first capacitor connection portions 47 and the second capacitor connection portions 57 are arranged at the same height H in the direction away from the printed circuit board 20.

[0046] <Electrolytic Capacitor> The electrolytic capacitor 60 is disposed so that the end face 60a facing the bus bar 30 is the same distance D from the first capacitor connection portion 47 and the second capacitor connection portion 57. As shown in Figures 3, 5, and 6, the electrolytic capacitor 60 has a first lead terminal 61 protruding from the end face 60a and a second lead terminal 62 protruding from the end face 60a. The first lead terminal 61 and the second lead terminal 62 protrude from the end face 60a of the electrolytic capacitor 60 toward the printed circuit board 20, with a gap between them in the Y direction.

[0047] The first lead terminal 61 and the second lead terminal 62 protrude from the end face 60a and are bent partway out to the opposite side of the case 10 (see FIG. 1). The first lead terminals 61 and the second lead terminals 62 are arranged alternately in a line in the Y direction. In other words, the first lead terminals 61 and the second lead terminals 62 are arranged linearly along a straight line L extending in the Y direction. The height of the tip of each lead terminal 61, 62 is the same.

[0048] With this configuration, the first capacitor connection portion 47 provided on the first bus bar 31 and the second capacitor connection portion 57 provided on the second bus bar 32 are disposed near the tips of the respective lead terminals 61, 62. As a result, the first lead terminal 61 is inserted into the recess 48 of the first capacitor connection portion 47. In this state, the first lead terminal 61 is directly connected to the first capacitor connection portion 47 by soldering. The second lead terminal 62 is inserted into the recess 58 of the second capacitor connection portion 57. In this state, the second lead terminal 62 is directly connected to the second capacitor connection portion 57 by soldering.

[0049] As a result, the electrolytic capacitor 60 is electrically connected to the switching element 22 via the bus bar 30. The electrolytic capacitor 60 has a function of suppressing fluctuations in DC voltage due to the switching operation of the switching element 22. In the embodiment, the electrolytic capacitor 60 is described as an example of the capacitor, but the capacitor is not limited to the electrolytic capacitor 60. As another example, for example, a capacitor having a sufficiently large capacitance that can suppress fluctuations in DC voltage to within a target value may be used.

[0050] As described above, the motor control device 1 includes the printed circuit board 20 on which the switching elements 22 are surface-mounted, the bus bars 30 that are surface-mounted on the printed circuit board 20 and connected to the switching elements 22, and the electrolytic capacitors 60 that are arranged alongside the printed circuit board 20 along the extension direction of the printed circuit board 20. Each bus bar 31, 32 of the bus bar 30 includes a main body portion 41, 51 and a plurality of bus bar terminals 42, 52 that are connected to the main body portion 41, 51. Each bus bar terminal 42, 52 has a pattern connection portion 45, 55, a rising portion 46, 56, and a capacitor connection portion 47, 57. Each rising portion 46, 56 rises from the surface 20b of the printed circuit board 20. Each capacitor connection portion 47, 57 is bent and extends from the tip of each rising portion 46, 56 toward the electrolytic capacitor 60 in parallel with the pattern connection portion 45, 55.

[0051] As described above, because each bus bar terminal 42, 52 has a rising portion 46, 56 and a capacitor connection portion 47, 57, the degree of freedom in the layout of the electrolytic capacitor 60 in the normal direction of the printed circuit board 20 can be increased. This makes it easier to miniaturize the motor control device 1 while ensuring an insulation distance between the printed circuit board 20 and the capacitor connection portions 47, 57. For example, if it is desired to increase the fin height of the heat dissipation fins 12 (see FIGS. 1 and 2 ) formed along the electrolytic capacitor 60, the electrolytic capacitor 60 can be moved in the Z direction intersecting the printed circuit board 20, thereby ensuring a large fin height.

[0052] The first capacitor connection portions 47 of the first bus bar terminals 42 and the second capacitor connection portions 57 of the second bus bar terminals 52 are alternately arranged in a line in the Y direction. In other words, the first capacitor connection portions 47 and the second capacitor connection portions 57 are linearly arranged along a straight line L extending in the Y direction. In particular, the recesses 48 of the first capacitor connection portions 47 and the recesses 58 of the second capacitor connection portions 57 are linearly arranged along the straight line L extending in the Y direction. In particular, the recesses 48 of the first capacitor connection portions 47 and the recesses 58 of the second capacitor connection portions 57 are linearly arranged along the straight line L. The recesses 48 are fitted into the first lead terminals 61 of the electrolytic capacitors 60. The recesses 58 are fitted into the second lead terminals 62 of the electrolytic capacitors 60. In this way, the first lead terminals 61 and the second lead terminals 62 are linearly arranged along the straight line L.

[0053] This improves the ease of soldering when connecting the capacitor connecting portions 47, 57 corresponding to the lead terminals 61, 62 with solder. This facilitates the soldering process. For example, the soldering process can be performed by an automated machine such as a robot, thereby improving productivity. Additionally, the first capacitor connecting portion 47 and the second capacitor connecting portion 57 are positioned at the same height H relative to the printed circuit board 20. This allows the soldering process to be more easily performed by an automated machine such as a robot.

[0054] Each end face 60a of the electrolytic capacitor 60 is disposed at an equal distance D from the first capacitor connection portion 47 of the first bus bar terminal 42 and the second capacitor connection portion 57 of the second bus bar terminal 52. This makes it possible to make the charge / discharge distance of the electrolytic capacitor 60 uniform, thereby achieving a uniform usage rate for the electrolytic capacitor 60.

[0055] The main body portions 41, 51 of the bus bars 31, 32 are arranged opposite each other in the X direction (the direction in which the switching elements 22 and the electrolytic capacitors 60 are arranged). This allows the area required to mount the bus bars 31, 32 on the printed circuit board 20 to be minimized, thereby enabling the motor control device 1 to be miniaturized. The current paths between the bus bar terminals 42, 52 and the switching elements 22 can be shortened, thereby reducing inductance. In addition, the switching elements 22 and the electrolytic capacitors 60 are connected via the bus bar 30. The bus bar 30 is arranged at one end 20a in the X direction of the printed circuit board 20 on which the switching elements 22 are surface-mounted. This allows an insulation distance to be secured between the switching elements 22 and the electrolytic capacitors 60.

[0056] The main body portions 41, 51 of the bus bars 31, 32 are arranged opposite each other in the X direction, and each main body portion 41, 51 is formed with as large an area as possible. The pattern connection portions 45, 55 of the bus bars 31, 32 are connected by soldering to the pattern terminals 23, 24 surface-mounted on the front surface 20b of the printed circuit board 20. This minimizes the area required to surface-mount the bus bars 31, 32 on the printed circuit board 20. This also shortens the current path from the switching element 22 to the bus bars 31, 32 (first pattern connection portion 45, second pattern connection portion 55).

[0057] Furthermore, the first pattern connection portion 45 and the second pattern connection portion 55, which are surface-mounted on the front surface 20b of the printed circuit board 20, are connected to the electrolytic capacitor 60. This shortens the current path from the switching element 22 to the electrolytic capacitor 60. By arranging the first body portion 41 and the second body portion 51, each of which has a large area, facing each other and further shortening the current path, the inductance of the motor control device 1 can be reduced.

[0058] The first pattern connection portion 45 of the first bus bar 31 and the second pattern connection portion 55 of the second bus bar 32 are surface-mounted on the front surface 20b of the printed circuit board 20. Furthermore, the first pattern connection portion 45 and the second pattern connection portion 45 surface-mounted on the front surface 20b of the printed circuit board 20 are connected to the electrolytic capacitor 60, thereby shortening the current path. This allows the motor control device 1 to be made more compact.

[0059] A first leg 43 protrudes from the side surface 41c of the first main body 41, and a second leg 53 protrudes from the side surface 51c of the second main body 51. These legs 43, 53 are connected to (contact) the surface 20b of the printed circuit board 20 via protruding pieces 43a, 53a, respectively. Each main body 41, 51 is arranged perpendicular to the surface 20b of the printed circuit board 20. Therefore, if each main body 41, 51 were to stand alone, its posture would be unstable. In this posture, each leg 43, 53 functions to prevent each main body 41, 52 from tipping over. This improves the reliability of the motor control device 1.

[0060] [Modification] Next, a modification of the motor control device 1 will be described with reference to Fig. 6. Fig. 6 is a perspective view of the motor control device 1 according to the modification with the case 10 removed. Fig. 6 corresponds to Fig. 3 described above. As shown in Fig. 6, a first tongue portion 44 may be integrally formed with the first main body portion 41 of the first bus bar 31. A second tongue portion 54 may be integrally formed with the second main body portion 51 of the second bus bar 32.

[0061] The first tongue portion 44 is disposed in the center in the Y direction of an edge 41d of the first main body portion 41 on the side opposite to the printed circuit board 20. The first tongue portion 44 is bent and extends from the edge 41d of the first main body portion 41 toward the switching element 22. That is, the first tongue portion 44 extends in a direction perpendicular to the first main body portion 41. In other words, the first tongue portion 44 extends in a direction parallel to the surface 20b of the printed circuit board 20.

[0062] The second tongue portion 54 is disposed in the center in the Y direction of an edge 51d of the second main body portion 51 on the side opposite to the printed circuit board 20. The second tongue portion 54 is bent and extends from the edge 51d of the second main body portion 51 toward the switching element 22. That is, the second tongue portion 54 extends in a direction perpendicular to the second main body portion 51. In other words, the second tongue portion 54 extends in a direction parallel to the surface 20b of the printed circuit board 20.

[0063] The second tongue portion 54 is arranged to overlap the first tongue portion 44. Here, the first bus bar 31 and the second bus bar 32 are arranged such that the first main body portion 41 and the second main body portion 51 are slightly misaligned in the Y direction. Therefore, a portion of the first tongue portion 44 is exposed from the second tongue portion 54 when viewed from the Z direction.

[0064] With this configuration, when placing each bus bar 31, 32 on the printed circuit board 20 in assembling the motor control device 1, an industrial robot (not shown) or the like sucks and transfers each bus bar 31, 32 by sucking each tongue portion 44, 54. When sucking, the upper surfaces 44 a, 54 a of each tongue portion 44, 54, which are the surfaces opposite to the printed circuit board 20, are sucked.

[0065] Here, each of the tongue portions 44, 54 is bent 90 degrees relative to the corresponding main body portion 41, 52. Therefore, when each of the tongue portions 44, 54 is sucked and transported onto the printed circuit board 20, the main body portions 41, 51 are transported in an orientation in which they are perpendicular to the surface 20b of the printed circuit board 20. In this orientation, the protruding pieces 43a, 53a of each of the legs 43, 53 are inserted into and connected to the printed circuit board 20. This completes the assembly of the bus bars 31, 32 to the printed circuit board 20. Therefore, according to the above-described modified example, the assembly workability of the motor control device 1 can be improved.

[0066] The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention. For example, in the above-described embodiment, the number of electrolytic capacitors 60 is eight, and the total number of pattern terminals 23, 24 and the number of each bus bar terminal 42, 52 correspond to the number of electrolytic capacitors 60. However, the present invention is not limited to this, and the number of electrolytic capacitors 60 can be any number. The total number of pattern terminals 23, 24 and the number of each bus bar terminal 42, 52 can be determined accordingly.

[0067] In the above embodiment, the first leg 43 is bent and extends from the end 41 b of the first body 41 on one side 20 c of the printed circuit board 20 toward the switching element 22. The second leg 53 is bent and extends from the end 51 b of the second body 51 on the other side 20 d of the printed circuit board 20 toward the switching element 22. The protruding pieces 43 a, 53 a of each leg 43, 53 are connected to the surface 20 b of the printed circuit board 20. However, this is not limited thereto, and each leg 43, 53 may protrude from the side of the main body 41, 51 and abut against the surface 20 b of the printed circuit board 20. This configuration allows the legs 43, 53 to function as a means for preventing the bus bars 31, 32 from tipping over.

[0068] In the above-described modified example, the first tongue portion 44 is bent and extends from the center in the Y direction of the edge 41 d of the first main body portion 41 toward the switching element 22. The second tongue portion 54 is bent and extends from the center in the Y direction of the edge 51 d of the second main body portion 51 toward the switching element 22. However, this is not limited to this, and each tongue portion 44, 54 may extend from the edge 41 d, 51 d of each main body portion 41, 51. The tongue portions 44, 54 may not be bent and extend from each main body portion 41, 51. It is only necessary that each tongue portion 44, 54 can be transported by being grasped or sucked by an industrial robot (not shown).

[0069] In addition, within the scope of the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate.

[0070] REFERENCE SIGNS LIST 1...motor control device, 10...case, 10a...outer surface, 10b...end, 12...heat dissipation fin (fin), 20...printed circuit board (circuit board), 20a...one end, 20b...surface, 20c...side edge, 20d...side edge, 22...switching element (heat generating element), 23...first pattern terminal, 24...second pattern terminal, 30...bus bar, 31...first bus bar, 32...second bus bar, 41...first main body portion (main body portion), 41a...edge, 41b...end, 41c...side surface, 41d...edge, 42...first bus bar terminal (bus bar terminal), 43...first leg portion, 43a...projecting piece, 44...first tongue portion, 44a...upper surface, 45...first pattern Turn connection portion, 46...first rising portion (rising portion), 47...first capacitor connection portion (connection portion), 48...recess, 51...second main body portion (main body portion), 51b...end portion, 51c...side surface, 51d...edge, 52...second bus bar terminal (bus bar terminal), 53...second leg portion, 53a...projecting piece, 54...second tongue portion, 54a...top surface, 55...second pattern connection portion, 56...second rising portion (rising portion), 57...second capacitor connection portion (connection portion), 58...recess, 60...electrolytic capacitor (capacitor), 60a...end surface, 61...first lead terminal (lead terminal), 62...second lead terminal (lead terminal), D...distance, H...height, L...straight line

Claims

1. A motor control device comprising: a substrate having a heat-generating element surface-mounted thereon; a busbar surface-mounted on the substrate and connected to the heat-generating element; and a capacitor arranged alongside the substrate in the extension direction of the substrate and electrically connected to the heat-generating element via the busbar, wherein the busbar has a main body portion connected to the substrate, and a busbar terminal coupled to the main body portion and connected to the capacitor, and the busbar terminal has a rising portion rising from a surface of the substrate, and a connection portion bent and extended from an end of the rising portion opposite the substrate towards the capacitor and connected to the capacitor.

2. A motor control device as described in claim 1, characterized in that it has a plurality of the capacitors, each of the capacitors having a lead terminal connected to the connection portion, and the lead terminals are arranged to be lined up in one direction, the bus bar has a plurality of the bus bar terminals connected to the plurality of the capacitors, and the connection portions are arranged to be lined up in the same direction as the arrangement of the lead terminals.

3. A motor control device as described in claim 1 or 2, characterized in that: the bus bars include a first bus bar and a second bus bar, each connected to one of the capacitors; the main body portion includes a first body portion provided on the first bus bar and a second body portion provided on the second bus bar; and the first body portion and the second body portion are arranged opposite each other in the arrangement direction of the heat generating element and the capacitor, between the heat generating element and the capacitor.

4. The motor control device according to claim 1, characterized in that the main body has a tongue portion extending from an end of the main body opposite the substrate.

5. The motor control device according to claim 4, wherein the tongue portion extends in a direction parallel to the substrate.

6. The motor control device according to claim 1, characterized in that the main body has legs that protrude from the side surfaces of the main body and come into contact with the board.

7. The motor control device according to claim 6, wherein the legs are connected to the substrate.

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