Power conversion device

Abstract

The present invention provides a power conversion device. The power conversion device (100) comprises a circuit substrate (4), a smoothing capacitor (3a), a housing (5), a first bus bar (6) and a second bus bar (7, 207). Furthermore, the housing (5) comprises a mounting portion (51, 251), the mounting portion (51, 251) having a bottom (51a), a first vertical wall (51b) and a second vertical wall (51c). In addition, the second bus bar (7, 207) comprises: a first leg portion (73) embedded between the first vertical wall (51b) and the second vertical wall (51c) to prevent the second bus bar (7, 207) from tipping over; and a second leg portion (74, 274) abutting against the bottom (51a) to prevent the second bus bar (7, 207) from tipping over.

Description

Technical Field

[0001] The present invention relates to a power conversion device, and more particularly to a power conversion device including a circuit board on which a semiconductor element for power conversion is mounted and a bus bar connected to the circuit board. Background Art

[0002] Conventionally, a circuit board unit including a circuit board on which a semiconductor element for power conversion is mounted and a bus bar connected to the circuit board is known. Such a circuit board unit is disclosed in, for example, Japanese Patent Application Publication No. 2018-133302.

[0003] The circuit substrate unit described in the above-mentioned Japanese Patent Publication No. 2018-133302 includes a circuit substrate equipped with a semiconductor element for power conversion and a bus bar connected to the circuit substrate. The circuit substrate unit is configured such that the bus bar is fastened to the terminal pattern of the circuit substrate using bolts and nuts to connect the bus bar to the circuit substrate. In addition, in the circuit substrate unit described in the above-mentioned Japanese Patent Publication No. 2018-133302, an operator places the circuit substrate on a jig, and while keeping the circuit substrate and the bus bar on the jig, the operator installs the bus bar relative to the circuit substrate.

[0004] Here, in the circuit substrate unit described in the above-mentioned Japanese Patent Publication No. 2018-133302, since a jig is used when installing the bus bar on the circuit substrate, when assembling products such as power conversion devices, after temporarily performing the installation operation of the bus bar relative to the circuit substrate outside the housing, it is necessary to store the circuit substrate with the bus bar installed in the housing. Therefore, the workability during the assembly of the product is reduced. On the other hand, although it is not clearly recorded in the above-mentioned Japanese Patent Publication No. 2018-133302, when the bus bar is installed relative to the circuit substrate in the housing without using a jig, in the previous circuit substrate unit described in the above-mentioned Japanese Patent Publication No. 2018-133302, the operator needs to hold the circuit substrate and the bus bar by hand while installing the bus bar on the circuit substrate. Therefore, there is a problem that the workability when installing the bus bar on the circuit substrate in the housing is reduced. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device capable of suppressing a decrease in workability when mounting a bus bar on a circuit board in a casing.

[0007] Solutions for solving problems

[0008] In order to achieve the above-mentioned purpose, a technical scheme of the present invention provides a power conversion device, wherein the power conversion device includes: a circuit substrate, which is equipped with a semiconductor element for power conversion; a smoothing capacitor; a housing, which accommodates the circuit substrate and the smoothing capacitor; a first bus bar, which is connected to the smoothing capacitor; and a second bus bar, which is connected to the circuit substrate and connected to the smoothing capacitor via the first bus bar, the housing includes a loading portion, the loading portion has: a bottom, which carries the second bus bar; and a first vertical wall and a second vertical wall, the first vertical wall and the second vertical wall are arranged opposite to each other in a manner of sandwiching the bottom, the second bus bar includes: a first leg, which is embedded between the first vertical wall and the second vertical wall of the loading portion, thereby preventing the second bus bar from tipping over to one side and the other side in a first direction opposite to the first vertical wall and the second vertical wall; and a second leg, which abuts against the bottom, thereby preventing the second bus bar from tipping over to one side in a second direction intersecting with the first direction in a horizontal plane.

[0009] In the power conversion device of the above-mentioned technical solution, as described above, the first leg of the second bus bar is embedded between the first vertical wall and the second vertical wall of the mounting portion, thereby preventing the second bus bar from tipping over to one side and the other side in the first direction opposite to the first vertical wall and the second vertical wall. In addition, the second leg of the second bus bar abuts against the bottom, thereby preventing the second bus bar from tipping over to one side in the second direction intersecting the first direction in the horizontal plane. As a result, when the second bus bar is installed on the circuit substrate, the second bus bar can be prevented from tipping over in three directions: one side in the first direction, the other side in the first direction, and one side in the second direction. As a result, even if the operator does not hold the second bus bar, the second bus bar can be easily installed relative to the circuit substrate in the housing, thereby suppressing the reduction in workability when the bus bar (second bus bar) is installed on the circuit substrate in the housing.

[0010] In the power conversion device of the above-mentioned technical solution, it is preferred that the loading portion of the housing has a third vertical wall formed along the first direction relative to the first vertical wall and the second vertical wall, and the first leg portion is configured to abut against the third vertical wall, thereby preventing the second bus bar from tipping over to the other side in the second direction. If so configured, when the second bus bar is installed on the circuit substrate, it is possible to prevent the second bus bar from tipping over in four directions: one side in the first direction, the other side in the first direction, one side in the second direction, and the other side in the second direction. As a result, even if the operator does not hold the second bus bar, it is possible to more easily install the second bus bar relative to the circuit substrate in the housing, thereby further suppressing the reduction in operability when installing the second bus bar on the circuit substrate in the housing.

[0011] In this case, it is preferred that the second leg portion is formed so as to extend in the direction along the bottom portion toward the side opposite to the side of the mounting portion where the third vertical wall is arranged, in such a manner that the distance from the third vertical wall of the mounting portion to the end of the second leg portion is greater than the distance from the third vertical wall of the mounting portion to the center of gravity of the second bus bar. If so configured, the end of the second leg portion can abut against the bottom of the mounting portion at a position farther from the first leg portion than the center of gravity of the second bus bar, so that the second bus bar can be placed more stably on the mounting portion (bottom portion). As a result, the second bus bar can be further prevented from tipping over.

[0012] In the power conversion device of the above-mentioned technical solution, it is preferred that the second busbar has a stepped shape including an upper step portion and a lower step portion, the first busbar is mounted on the upper step portion of the second busbar, the circuit substrate is mounted on the lower step portion of the second busbar, and the first leg and the second leg are arranged on the lower step portion side of the second busbar. If so configured, the first leg and the second leg arranged on the lower step portion side of the second busbar can prevent the second busbar from tipping over when the circuit substrate carrying semiconductor elements for power conversion is mounted on the lower step portion side of the second busbar. In addition, by accommodating the circuit substrate carrying semiconductor elements for power conversion in a housing and mounting it on the lower step portion of the second busbar, when the first busbar is mounted on the upper step portion of the second busbar, the first busbar can be mounted on the upper step portion of the second busbar while preventing the second busbar from tipping over. As a result, even when the first bus bar is arranged above the circuit board, the first bus bar can be easily attached to the second bus bar.

[0013] In this case, it is preferred that the lower step portion of the second bus bar is arranged below the circuit substrate and integrally includes a nut portion for threading the lower step portion to the circuit substrate. If so configured, the lower step portion of the second bus bar can be threadedly fixed to the circuit substrate using the nut portion of the lower step portion. As a result, even when threading is performed from the upper side of the circuit substrate, the operator does not need to maintain the nut independently provided relative to the second bus bar below the second bus bar, and thus the lower step portion of the second bus bar can be more easily mounted (threadedly fixed) to the circuit substrate.

[0014] In the structure in which the second bus bar has a stepped shape, it is preferred that the first leg portion is formed so as to extend downward from the lower step portion, and the second leg portion is formed so as to extend from the first leg portion along the bottom portion. With such a structure, the second leg portion extends along the bottom portion from the first leg portion extending downward from the lower step portion, thereby making it possible to make the second leg portion of the second bus bar contact the bottom portion of the mounting portion in a larger area. As a result, the second bus bar can be placed on the mounting portion (bottom portion) more stably.

[0015] In the power conversion device of the above-mentioned embodiment, the second leg is preferably formed to extend in a direction along the bottom and in a direction perpendicular to the first leg. With this configuration, the second bus bar can be prevented from falling in a direction perpendicular to the first leg.

[0016] In the power conversion device of the above-mentioned technical solution, it is preferred that the mounting portion of the housing further includes a fourth vertical wall, which is provided near the end of the second leg, and when the second bus bar is fastened to the circuit substrate, the fourth vertical wall abuts against the end of the second leg, and the second leg is formed in a manner extending along the bottom and extending from the first leg toward the fourth vertical wall. If so configured, when the second bus bar is fastened to the circuit substrate, the end of the second leg abuts against the fourth vertical wall of the mounting portion, so that the rotational torque can be suppressed from causing the second bus bar to shift relative to the circuit substrate. As a result, the lower step portion of the second bus bar can be more easily fastened to the circuit substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing an example of a circuit configuration of a power conversion device according to the first embodiment of the present invention.

[0018] Figure 2 It is an exploded perspective view for explaining the structure of the power conversion device according to the first embodiment.

[0019] Figure 3 It is a perspective view showing the structure of the second bus bar according to the first embodiment.

[0020] Figure 4 It is a side view showing the connection between the first bus bar and the second bus bar.

[0021] Figure 5 This is a diagram of the mounting portion of the housing as seen from above.

[0022] Figure 6 Yes Figure 5 An enlarged partial view of the mounting portion.

[0023] Figure 7 It is a perspective view showing the placement portion of the housing.

[0024] Figure 8 Yes Figure 7 An enlarged partial view of the mounting portion.

[0025] Fig. 9 It is a diagram showing the second bus bar mounted on the mounting portion.

[0026] Fig.10 Yes Fig. 9A partial enlarged view of the second bus bar mounted on the mounting portion.

[0027] Fig.11 This is a first perspective view showing an assembly procedure of the power conversion device.

[0028] Fig.12 Yes Fig.11 An enlarged partial view of the mounting portion.

[0029] Fig.13 This is a second perspective view showing the assembly procedure of the power conversion device.

[0030] Fig.14 Yes Fig.13 An enlarged partial view of the mounting portion.

[0031] Fig.15 This is a third perspective view showing the assembly procedure of the power conversion device.

[0032] Fig.16 It is a perspective view showing the structure of the second bus bar according to the second embodiment.

[0033] Fig.17 It is a diagram showing the second bus bar according to the second embodiment mounted on the mounting portion.

[0034] Fig.18 Yes Fig.17 An enlarged partial view of the mounting portion. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0036] [First embodiment]

[0037] Reference Figure 1 and Figure 2 The overall structure of the power conversion device 100 according to the first embodiment of the present invention will be described. Figure 1 As shown, the power conversion device 100 is an inverter (Japanese: インバータ), which includes: a conversion circuit unit 1, which includes a switching element 1a; a rectifier circuit unit 2, which includes a diode element 2a; and a smoothing circuit unit 3, which includes a smoothing capacitor 3a. The switching element 1a of the conversion circuit unit 1 and the diode element 2a of the rectifier circuit unit 2 are electrically connected to the smoothing capacitor 3a of the smoothing circuit unit 3.

[0038] In addition, if Figure 2As shown, the power conversion device 100 includes: a smoothing capacitor 3a; a circuit board 4; and a housing 5 that accommodates the smoothing capacitor 3a and the circuit board 4. In addition, the power conversion device 100 includes: a first bus bar 6 that is connected to the smoothing capacitor 3a; and a second bus bar 7 that is connected to the circuit board 4 and connected to the smoothing capacitor 3a via the first bus bar 6.

[0039] In addition, in this specification, the vertical direction is referred to as the Z direction, the direction perpendicular to the vertical direction (Z direction) is referred to as the X direction, and the direction perpendicular to the Z direction and the X direction is referred to as the Y direction. In addition, the X direction is an example of the "second direction" in the claims, and the Y direction is an example of the "first direction" in the claims.

[0040] The first bus bar 6 and the second bus bar 7 are the current path N (see FIG. 1 ) between the rectifying circuit section 2 (diode element 2 a ) and the smoothing circuit section 3 (smoothing capacitor 3 a ). Figure 1 ) is provided on the bus bar. The first bus bar 6 and the second bus bar 7 are conductive plate-shaped members. For example, the first bus bar 6 and the second bus bar 7 are copper bars.

[0041] The circuit board 4 is a printed circuit board (PCB) on which electronic components are mounted in a wiring pattern formed by conductors. A semiconductor component 10 (see FIG. 1 ) including a semiconductor element for power conversion (a switching element 1a and a diode element 2a) is mounted (installed) on the circuit board 4. Figure 2 ). That is, a semiconductor element for power conversion is mounted on the circuit substrate 4. The circuit substrate 4 is formed in a manner extending along the X direction and the Y direction (XY plane). In addition, the XY plane is an example of a "horizontal plane" in the claims. The semiconductor component 10 is mounted on the back side (Z2 direction side) of the circuit substrate 4. In addition, on the circuit substrate 4, as shown Figure 2 As shown, connection terminals 41 for electrically connecting the first bus bar 6 and the wiring pattern of the circuit board 4 are provided.

[0042] In addition, the housing 5 includes a placement portion 51 for placing the second bus bar 7 (see Figure 2 The housing 5 is formed of a plastic resin. The detailed structure of the housing 5 will be described later.

[0043] (Structure of the second bus bar)

[0044] like Figure 3As shown, the second bus bar 7 has a stepped shape including an upper step portion 71 and a lower step portion 72. The upper step portion 71 of the second bus bar 7 integrally includes a nut portion 71a for screwing the upper step portion 71 to the first bus bar 6. In addition, the lower step portion 72 of the second bus bar 7 integrally includes a nut portion 72a for screwing the lower step portion 72 to the circuit board 4.

[0045] In addition, if Figure 3 As shown, the second bus bar 7 includes a first leg portion 73 and a second leg portion 74. The first leg portion 73 and the second leg portion 74 are provided on the lower step portion 72 side (Z2 direction side) of the second bus bar 7.

[0046] The first leg portion 73 is formed so as to extend downward (on the Z2 direction side) from the lower step portion 72. In addition, the second leg portion 74 is formed so as to extend from the first leg portion 73 in a direction (on the X1 direction side) perpendicular to the first leg portion 73. In addition, the second leg portion 74 is formed so as to extend from the end portion on the Y1 direction side of the first leg portion 73 to the X1 direction side.

[0047] In addition, if Figure 4 As shown, the first bus bar 6 has a stepped shape including an upper step portion 61 and a lower step portion 62. Furthermore, the upper step portion 61 and the lower step portion 62 of the first bus bar 6 are arranged above (Z1 direction side) the upper step portion 71 of the second bus bar 7. In addition, the upper step portion 61 and the lower step portion 62 of the first bus bar 6 are arranged above the circuit substrate 4 (connection terminal 41). In addition, the upper step portion 61 of the first bus bar 6 is arranged above the smoothing capacitor 3a.

[0048] like Figure 4 As shown, the upper step portion 71 of the second bus bar 7 is arranged above the circuit substrate 4 (Z1 direction side). In addition, the lower step portion 72 of the second bus bar 7 is arranged below the circuit substrate 4 (Z2 direction side). In addition, the first leg portion 73 and the second leg portion 74 are also arranged below the circuit substrate 4.

[0049] Furthermore, the first bus bar 6 is mounted on the upper step portion 71 of the second bus bar 7 , and the circuit board 4 is mounted on the lower step portion 72 of the second bus bar 7 .

[0050] On the upper side (Z1 direction side) of the upper step portion 71 of the second bus bar 7, as shown in FIG. Figure 4 As shown, the screw member 82 and the nut portion 71a (see Figure 3 ) The lower step portion 62 of the first bus bar 6 is screwed (fastened) from above. In addition, on the upper side of the lower step portion 72 of the second bus bar 7, as shown in FIG. Figure 4 As shown, the screw member 81 and the nut portion 72a (see Figure 3) The circuit board 4 is screwed and fixed (fastened) from above. Thus, the second bus bar 7 is connected to a terminal pattern (not shown) provided on the circuit board 4, and the first bus bar 6 and the second bus bar 7 are connected to the rectifier circuit unit 2 (see Figure 1 )Electrical connection.

[0051] In addition, if Figure 4 As shown, the lower step portion 62 of the first bus bar 6 is screwed (fastened) to the connection terminal 41 provided above the circuit substrate 4 (Z1 direction side) from above by means of a screw 83. Figure 4 As shown, the upper step portion 61 of the first bus bar 6 is screwed (fastened) to the smoothing capacitor 3 a from above using screws 84 .

[0052] (Structure of the mounting portion)

[0053] In addition, if Figure 5 and Figure 6 As shown, the housing 5 includes a component storage portion 52 for storing the semiconductor component 10 (for embedding the semiconductor component 10). In addition, the loading portion 51 is arranged adjacent to the component storage portion 52. The loading portion 51 is arranged on the Y2 direction side of the component storage portion 52. The loading portion 51 and the component storage portion 52 are formed integrally in the housing 5.

[0054] In addition, if Figure 5 and Figure 6 As shown, the housing 5 is provided with openings A1, A2, and A3. The openings A1 to A3 are located in the current path N (see Figure 1 ) is provided (added) with an EMC filter or other electronic component, and is used to expose the terminal portion of the installed electronic component (EMC filter, etc.) from the lower side (Z2 direction side) of the housing 5.

[0055] In addition, if Figure 6 As shown, the placement portion 51 includes a bottom portion 51 a on which the second bus bar 7 is placed, and a first standing wall 51 b and a second standing wall 51 c which are arranged to face each other with the bottom portion 51 a interposed therebetween.

[0056] like Figure 6 As shown in FIG. 1 , the bottom portion 51a has a rectangular shape when viewed from above (Z1 direction side). An opening A1 is provided on the Y2 direction side of the bottom portion 51a. In addition, a first vertical wall 51b is provided on the Y1 direction side of the bottom portion 51a.

[0057] In addition, if Figure 6 As shown, the placement portion 51 of the housing 5 has a third standing wall 51 d formed along the Y direction in which the first standing wall 51 b and the second standing wall 51 c face each other.

[0058] like Figure 6As shown, the third wall 51d is disposed between the first wall 51b and the second wall 51c and connects the first wall 51b and the second wall 51c. The bottom 51a is surrounded by the first wall 51b, the second wall 51c and the third wall 51d (see Figure 6 ). In addition, the mounting portion 51 (see Figure 7 ) is formed so as to extend from the bottom 51a in the Z1 direction (see Figure 8 ). In addition, the second vertical wall 51c is formed so as to extend in the Z direction along the first vertical wall 51b (substantially parallel to the first vertical wall 51b) (see Figure 8 ).

[0059] In addition, in a state where the second bus bar 7 is placed on the placement portion 51 (bottom portion 51a) (see Fig. 9 and Fig.10 ) is formed so as to extend in the Y1 direction along the third vertical wall 51d (see Fig.10 ). In addition, Fig.10 As shown in the figure, in a state where the second bus bar 7 is placed on the placement portion 51 (bottom portion 51a), the first vertical wall 51b is arranged on the Y1 direction side of the first leg portion 73, and the second vertical wall 51c is arranged on the Y2 direction side of the first leg portion 73. In addition, in a state where the second bus bar 7 is placed on the placement portion 51 (bottom portion 51a), the third vertical wall 51d is arranged on the X2 direction side of the first leg portion 73. In addition, a gap of about a few tenths of a millimeter is provided between the first leg portion 73 and the first vertical wall 51b and the second vertical wall 51c.

[0060] And, if Fig.10 As shown, the first leg portion 73 is embedded between the first vertical wall 51b and the second vertical wall 51c of the mounting portion 51, thereby preventing the second bus bar 7 from falling over to the Y1 direction side and the Y2 direction side in the Y direction opposite to the first vertical wall 51b and the second vertical wall 51c. In addition, the Y1 direction side is an example of "one side in the first direction" in the claims, and the Y2 direction side is an example of "the other side in the first direction" in the claims.

[0061] In addition, if Fig.10 As shown, the first leg portion 73 is configured to prevent the second bus bar 7 from falling down toward the X2 direction side by abutting against the third upright wall 51d. The X2 direction side is an example of "the other side in the second direction" in the claims.

[0062] The second leg portion 74 is formed so as to extend (in a straight line) in the X1 direction along the first upright wall 51b (see Fig.10). In addition, the second leg portion 74 is formed so as to extend from the first leg portion 73 along the bottom portion 51a toward the X1 direction (see Figure 10 to Figure 12 ).

[0063] The second leg portion 74 is configured to prevent the second bus bar 7 from falling down toward the X1 direction side in the X direction by contacting the bottom portion 51a. The X1 direction side is an example of “one side in the second direction” in the claims.

[0064] like Fig.10 As shown, the second leg portion 74 is formed so that the distance D1 from the third upright wall 51d of the loading portion 51 to the end 74a of the second leg portion 74 is greater than (longer than) the distance D2 from the third upright wall 51d of the loading portion 51 to the center of gravity position P of the second bus bar 7, and extends in the direction along the bottom 51a (X direction) toward the side opposite to the side of the loading portion 51 on which the third upright wall 51d is arranged (X1 direction side).

[0065] (Assembly steps)

[0066] Next, refer to Figure 11 to Figure 15 , the installation operation of the power conversion device 100 having the second bus bar 7 is described. First, Fig.11 and Fig.12 As shown in FIG. 5 , the operator places the second bus bar 7 on the placement portion 51. Specifically, Fig.12 As shown, the operator fits the first leg portion 73 of the second bus bar 7 between the first upright wall 51 b and the second upright wall 51 c and places the second leg portion 74 on the bottom portion 51 a .

[0067] Next, if Fig.13 and Fig.14 As shown, the operator screws (fastens) the second bus bar 7 to the circuit board 4. Specifically, the operator places the circuit board 4 on the lower step portion 72 (see FIG. 1 ) of the second bus bar 7. Fig.12 ) (Z1 direction side), such as Fig.14 As shown, the second bus bar 7 is screwed (fastened) to the circuit board 4 from above using screws 81 .

[0068] Then, if Fig.15 As shown, the operator installs the first bus bar 6. Specifically, the first bus bar 6 is placed above the upper step portion 71 of the second bus bar 7 (Z1 direction side), and the first bus bar 6 is screwed (fastened) to the second bus bar 7, the connection terminal 41 and the smoothing capacitor 3a from above using screws 82, 83 and 84. By installing the first bus bar 6 and the second bus bar 7 in this way, the wiring pattern (conductor pattern) of the circuit board 4 and the smoothing capacitor 3a are electrically connected.

[0069] (Effects of the First Embodiment)

[0070] In the first embodiment, the following effects can be obtained.

[0071] In the first embodiment, the first leg portion 73 of the second bus bar 7 is embedded between the first vertical wall 51b and the second vertical wall 51c of the mounting portion 51, thereby preventing the second bus bar 7 from tipping over in the Y1 direction and the Y2 direction. In addition, the second leg portion 74 of the second bus bar 7 abuts against the bottom 51, thereby preventing the second bus bar 7 from tipping over in the X1 direction. Thus, when the second bus bar 7 is installed on the circuit substrate 4, the second bus bar 7 can be prevented from tipping over in three directions, namely, the Y1 direction, the Y2 direction, and the X1 direction. As a result, even if the operator does not hold the second bus bar 7, the second bus bar 7 can be easily installed relative to the circuit substrate 4 in the housing 5, thereby suppressing the reduction in workability when the second bus bar 7 is installed on the circuit substrate 4 in the housing 5. In addition, by configuring as described above, the first leg portion 73 of the second bus bar 7 is embedded between the first upright wall 51b and the second upright wall 51c of the mounting portion 51, so that the second bus bar 7 can be positioned relative to the housing 5. Furthermore, by housing the circuit board 4 on which the semiconductor component 10 is mounted (installed) in the housing 5 and installing it on the second bus bar 7, it is possible to prevent the second bus bar 7 from tipping over when the first bus bar 6 is installed on the second bus bar 7. Thus, the operator can install (screw-fasten) the first bus bar 6 connected to the smoothing capacitor 3a on the second bus bar 7 while the second bus bar 7 is stable. As a result, compared with the case where the first bus bar 6 is installed (screw-fastened) on the second bus bar 7 while the second bus bar 7 is unstable, the first bus bar 6 can be reliably installed (screw-fastened) on the second bus bar 7. This can prevent the quality degradation caused by poor installation (poor screw tightening) when the first bus bar 6 is installed (screwed) to the second bus bar 7. As a result, it is possible to prevent the quality degradation caused by poor installation (poor screw tightening) when the first bus bar 6 connected to the smoothing capacitor 3a is installed on the second bus bar 7 mounted on the circuit board 4.

[0072] In addition, in the first embodiment, as described above, the placement portion 51 of the housing 5 has a third vertical wall 51d formed along the Y direction. And, the first leg portion 73 is configured to abut against the third vertical wall 51d, thereby preventing the second bus bar 7 from tipping over to the X2 direction side. Thus, when the second bus bar 7 is installed on the circuit substrate 4, it is possible to prevent the second bus bar 7 from tipping over to the four directions of the Y1 direction side, the Y2 direction side, the X1 direction side, and the X2 direction side. As a result, even if the operator does not hold the second bus bar 7, it is possible to more easily install the second bus bar 7 relative to the circuit substrate 4 in the housing 5, thereby further suppressing the reduction in operability when installing the second bus bar 7 on the circuit substrate 4 in the housing 5. In addition, by configuring as described above, the first leg portion 73 of the second bus bar 7 is inserted between the first upright wall 51b and the second upright wall 51c of the mounting portion 51 and the first leg portion 73 abuts against the third upright wall 51d, thereby enabling the second bus bar 7 to be positioned relative to the housing 5 in three directions, namely, the Y1 direction side, the Y2 direction side, and the X2 direction side. Furthermore, by housing the circuit substrate 4 on which the semiconductor component 1 is mounted (mounted) in the housing 5 and mounting it on the second bus bar 7, it is possible to prevent the second bus bar 7 from tipping over when the first bus bar 6 is mounted on the second bus bar 7. As a result, the operator can mount (screw-fasten) the first bus bar 6 connected to the smoothing capacitor 3a on the second bus bar 7 in a more stable state. As a result, the first bus bar 6 can be more reliably mounted (threadedly fastened) to the second bus bar 7 than when the first bus bar 6 is mounted (threadedly fastened) to the second bus bar 7 in an unstable state. Thus, it is possible to further prevent the degradation of quality due to poor mounting (poor threading) when the first bus bar 6 is mounted (threadedly fastened) to the second bus bar 7. As a result, it is possible to further prevent the degradation of quality due to poor mounting (poor threading) when the first bus bar 6 connected to the smoothing capacitor 3a is mounted on the second bus bar 7 mounted on the circuit board 4.

[0073] In the first embodiment, as described above, the second leg portion 74 is formed so as to extend toward the side (X1 direction side) opposite to the side where the third vertical wall 51d of the mounting portion 51 is arranged in the direction along the bottom 51a (X direction) in such a manner that the distance D1 from the third vertical wall 51d of the mounting portion 51 to the end portion 74a of the second leg portion 74 is greater than the distance D2 from the third vertical wall 51d of the mounting portion 51 to the center of gravity position P of the second bus bar 7. As a result, the end portion 74a of the second leg portion 74 can be brought into contact with the bottom 51a of the mounting portion 51 at a position of the mounting portion 51 that is farther from the first leg portion 73 than the center of gravity position P of the second bus bar 7, so that the second bus bar 7 can be placed on the mounting portion 51 (bottom 51a) more stably. As a result, the second bus bar 7 can be further prevented from falling over.

[0074] In the first embodiment, as described above, the first bus bar 6 is mounted on the upper step portion 71 of the second bus bar 7, and the circuit substrate 4 is mounted on the lower step portion 72 of the second bus bar 7. Furthermore, the first leg portion 73 and the second leg portion 74 are provided on the lower step portion 72 side (Z2 direction side) of the second bus bar 7. Thus, by using the first leg portion 73 and the second leg portion 74 provided on the lower step portion 72 side of the second bus bar 7, when the circuit substrate 4 on which the semiconductor component 10 is mounted (mounted) is mounted on the lower step portion 72 side of the second bus bar 7, it is possible to prevent the second bus bar 7 from falling over. In addition, by housing the circuit substrate 4 on which the semiconductor component 10 is mounted (installed) in the housing 5 and installing it on the lower step portion 72 of the second bus bar 7, when the first bus bar 6 is installed on the upper step portion 71 of the second bus bar 7, the first bus bar 6 can be installed on the upper step portion 71 of the second bus bar 7 while preventing the second bus bar 7 from falling over. As a result, even when the first bus bar 6 is arranged above the circuit substrate 4 (on the Z1 direction side), the first bus bar 6 can be easily installed on the second bus bar 7.

[0075] In addition, in the first embodiment, as described above, the lower step portion 72 of the second bus bar 7 is arranged below the circuit substrate 4 (Z2 direction side), and integrally includes the nut portion 72a for screwing the lower step portion 72 to the circuit substrate 4. Thus, the lower step portion 72 of the second bus bar 7 can be screwed to the circuit substrate 4 using the nut portion 72a of the lower step portion 72. As a result, even when screwing is performed from the upper side (Z1 direction side) of the circuit substrate 4, the operator does not need to hold the nut independently provided with respect to the second bus bar 7 below the second bus bar 7, so that the lower step portion 72 of the second bus bar 7 can be more easily mounted (screwed) to the circuit substrate 4.

[0076] In the first embodiment, as described above, the first leg portion 73 is formed to extend downward (Z1 direction side) from the lower step portion 72, and the second leg portion 74 is formed to extend along the bottom portion 51a from the first leg portion 73. Thus, the second leg portion 74 of the second bus bar 7 can be brought into contact with the bottom portion 51a of the mounting portion 51 in a wider area by extending along the bottom portion 51a from the first leg portion 73 extending downward from the lower step portion 72. As a result, the second bus bar 7 can be placed more stably on the mounting portion 51 (bottom portion 51a).

[0077] In the first embodiment, as described above, the second leg 74 is formed to extend in the direction along the bottom 51a and in the direction perpendicular to the first leg 73. This prevents the second bus bar 7 from falling in the direction perpendicular to the first leg 73 (X direction).

[0078] [Second embodiment]

[0079] Reference Figure 16 to Figure 18 The configurations of the second bus bar 207 and the mounting portion 251 according to the second embodiment of the present invention will be described. The same reference numerals are used for the same configurations as those in the second embodiment, and description thereof will be omitted.

[0080] The second bus bar 207 includes a second leg portion 274 (see FIG. 2 ) formed so as to extend (in a straight line) from the first leg portion 73. Fig.16 ). And, if Fig.18 As shown, the mounting portion 251 of the housing 5 (see Fig.17 and Fig.18 ) includes a fourth wall 251e in addition to the bottom 51a, the first wall 51b, the second wall 51c, and the third wall 51d. The fourth wall 251e is configured to be provided near the end 274a (near the top end) of the second leg 274, and to abut against the end 274a (top end) of the second leg 274 when the second bus bar 207 is fastened to the circuit board 4. In addition, the fourth wall 251e is provided on the side opposite to the side where the third wall 51d is provided with respect to the second bus bar 207 (the X1 direction side).

[0081] The second leg portion 274 is formed so as to extend along the bottom portion 51a and extend from the first leg portion 73 toward the fourth upright wall 251e (in a straight line) (see Fig.18 ). In addition, the second leg portion 274 is formed so as to be separated from the first upright wall 51b as it goes toward the fourth upright wall 251e side (X1 direction side). That is, the second leg portion 274 is formed so as to extend from the first leg portion 73 in the oblique direction.

[0082] The other structures of the second embodiment are the same as those of the above-mentioned first embodiment.

[0083] (Effects of the Second Embodiment)

[0084] In the second embodiment, the following effects can be obtained.

[0085] In the second embodiment, similarly to the above-described first embodiment, it is possible to suppress a decrease in workability when mounting the second bus bar 20 on the circuit board 4 in the case 5 .

[0086] In addition, in the second embodiment, as described above, the mounting portion 51 of the housing 5 includes a fourth vertical wall 251e, and the fourth vertical wall 251e is provided near the end 274a of the second leg 274. When the second bus bar 207 is fastened to the circuit substrate 4, the fourth vertical wall 251e abuts against the end 274a of the second leg 274. Furthermore, the second leg 274 is formed in a manner extending along the bottom 51a and extending from the first leg 73 toward the fourth vertical wall 251e. Thus, when the second bus bar 207 is fastened to the circuit substrate 4, the end 274a of the second leg 274 abuts against the fourth vertical wall 251e of the mounting portion 251, thereby suppressing the rotational torque from causing the second bus bar 207 to move relative to the circuit substrate 4 (see Figure 2 As a result, the lower step portion 72 of the second bus bar 207 can be more easily fastened and fixed to the circuit board 4.

[0087] The other effects of the second embodiment are the same as those of the above-mentioned first embodiment.

[0088] [Modifications]

[0089] The embodiments of the present application are to be considered as illustrative and non-limiting in all respects. The scope of the present invention is indicated not by the description of the above embodiments but by the claims, and includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0090] For example, in the first and second embodiments described above, the placement portion 51 (placement portion 251) of the housing 5 has a third wall 51d formed along the Y direction in addition to the bottom 51a, the first wall 51b, and the second wall 51c. In addition, an example is shown in which the first leg 73 and the second leg 74 (second leg 274) of the second bus bar 7 (second bus bar 207) are used to prevent the second bus bar 7 (second bus bar 207) from tipping over in four directions: the Y1 direction side (one side in the first direction), the Y2 direction side (the other side in the first direction), the X1 direction side (one side in the second direction), and the X2 direction side (the other side in the second direction), but the present invention is not limited thereto. For example, the first leg and the second leg of the second bus bar may be used to prevent the second bus bar from tipping over in only three directions: one side in the first direction, the other side in the first direction, and one side in the second direction.

[0091] In addition, in the above-mentioned first and second embodiments, an example in which only one second leg portion 74 (second leg portion 274) is provided is shown, but the present invention is not limited to this. In the present invention, a plurality of (two or more) second leg portions may be provided.

[0092] In addition, in the above-mentioned first and second embodiments, an example is shown in which the second leg portion 74 (second leg portion 274) is formed in a manner extending from the Y1 direction side (one side in the first direction) of the first leg portion 73 to the X1 direction side (one side in the second direction), but the present invention is not limited to this. In the present invention, the second leg portion may also be formed in a manner extending from the end portion of the other side (Y2 direction side) of the first leg portion in the first direction to the one side (X1 direction side) in the second direction. In this case, the bottom of the placement portion is also provided on the other side in the first direction.

[0093] In addition, in the above-mentioned first and second embodiments, an example is shown in which the second bus bar 7 has a stepped shape including an upper step portion 71 and a lower step portion 72, and the first bus bar 6 is mounted on the upper step portion 71 of the second bus bar 7 and the circuit substrate 4 is mounted on the lower step portion 72 of the second bus bar 7, but the present invention is not limited to this. In the present invention, both the first bus bar and the circuit substrate may be mounted on either the upper step portion or the lower step portion of the second bus bar. That is, the first bus bar and the circuit substrate may also be mounted on the second bus bar at the same height position. In addition, the second bus bar may not have a stepped shape and both the first bus bar and the circuit substrate may be mounted.

[0094] In addition, in the above-mentioned first and second embodiments, the lower step portion 72 of the second bus bar 7 (second bus bar 207) is arranged below the circuit substrate 4 (Z2 direction side), and an example is shown in which the lower step portion 72 is integrally included with the nut portion 72a for screwing the lower step portion 72 to the circuit substrate 4, but the present invention is not limited to this. In the present invention, a nut for screwing the second bus bar may also be provided independently of the second bus bar.

[0095] In the first and second embodiments, the second leg 74 (second leg 274) is formed to extend from the first leg 73 along the bottom 51a, but the present invention is not limited thereto. In the present invention, the second leg may also be formed to extend from the upper step portion.

Claims

1. A power conversion device, wherein: The power conversion device has: A circuit board having a semiconductor element for power conversion mounted thereon; Smoothing capacitors; a housing that accommodates the circuit substrate and the smoothing capacitor; a first bus bar connected to the smoothing capacitor; and a second bus bar connected to the circuit substrate and connected to the smoothing capacitor via the first bus bar, The housing includes a placement portion having: a bottom portion on which the second bus bar is placed; and a first upright wall and a second upright wall, the first upright wall and the second upright wall being arranged opposite to each other with the bottom portion interposed therebetween. The second bus bar comprises: a first leg portion embedded between the first upright wall and the second upright wall of the mounting portion, thereby preventing the second bus bar from falling to one side and the other side in a first direction in which the first upright wall and the second upright wall are opposite to each other; as well as The second leg portion contacts the bottom portion to prevent the second bus bar from falling to one side in a second direction intersecting the first direction in a horizontal plane.

2. The power conversion device according to claim 1, wherein: The placement portion of the housing has a third standing wall formed along the first direction in which the first standing wall and the second standing wall are opposite to each other. The first leg portion is configured to abut against the third standing wall, thereby preventing the second bus bar from falling to the other side in the second direction.

3. The power conversion device according to claim 2, wherein: The second leg portion is formed so as to extend in the direction along the bottom toward the side opposite to the side of the mounting portion on which the third upright wall is arranged, in such a manner that the distance from the third upright wall of the mounting portion to the end of the second leg portion is greater than the distance from the third upright wall of the mounting portion to the center of gravity of the second bus bar.

4. The power conversion device according to any one of claims 1 to 3, wherein: The second bus bar has a stepped shape including an upper step portion and a lower step portion, The first bus bar is mounted on the upper step portion of the second bus bar, The circuit substrate is mounted on the lower step portion of the second bus bar. The first leg portion and the second leg portion are provided on the lower step portion side of the second bus bar.

5. The power conversion device according to claim 4, wherein: The lower step portion of the second bus bar is disposed below the circuit board and integrally includes a nut portion for screwing the lower step portion to the circuit board.

6. The power conversion device according to claim 4, wherein: The first leg portion is formed so as to extend downward from the lower step portion. The second leg portion is formed to extend from the first leg portion along the bottom portion.

7. The power conversion device according to any one of claims 1 to 3, wherein: The second leg portion is formed so as to extend in a direction along the bottom portion and in a direction orthogonal to the first leg portion.

8. The power conversion device according to any one of claims 1 to 3, wherein: The mounting portion of the housing further includes a fourth wall, which is provided near the end of the second leg, and when the second bus bar is fastened to the circuit board, the fourth wall abuts against the end of the second leg. The second leg portion is formed to extend along the bottom portion and to extend from the first leg portion toward the fourth standing wall.

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