Power conversion device

Abstract

The invention provides a power conversion device. This power conversion device is provided with: a first bus bar provided with a hole; a semiconductor module connected to the first bus bar; a second bus bar connected to the semiconductor module; and an insulating sheet that insulates the first bus bar from the second bus bar, the insulating sheet including a protruding portion, and the insulating sheet being fixed to the first bus bar by engaging the protruding portion with the hole portion of the first bus bar.

Description

Technical Field

[0001] The present invention relates to a power conversion device, in particular to a power conversion device with an insulating sheet and a bus bar fixed thereto. Background Art

[0002] Conventionally, there is known a power conversion device having a structure in which a plurality of bus bars and insulating sheets (insulating materials) are stacked on a semiconductor module. Such a power conversion device is disclosed in, for example, Japanese Patent No. 4474902.

[0003] The power conversion device described in Japanese Patent Gazette No. 4474902 is constructed as follows: for a laminated structure in which an insulating sheet larger than the two conductors is present between a positive-side conductor and a negative-side conductor arranged on a semiconductor module, through holes are respectively provided in the positive-side conductor, the negative-side conductor, and the insulating sheet, and when these positive-side conductor, negative-side conductor, and the insulating sheet are aligned, a resin clamping member is passed through the through holes to hold them.

[0004] However, the power conversion device described in Japanese Patent No. 4474902 is a structure in which the conductor and the insulating sheet are fixed by a clamping member, so the number of parts increases and the assembly man-hours increase. In addition, there is a problem that the clamping member may fall off due to vibration or the reaction force of the insulating sheet, and there is a possibility that the holding state is unstable. Summary of the invention

[0005] 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 that can stabilize the holding state between a plurality of bus bars and insulating sheets without increasing the number of parts.

[0006] In order to achieve the above-mentioned purpose, a power conversion device of a technical solution of the present invention comprises: a first bus bar, which is provided with a first locking portion; a semiconductor module for power conversion, which accommodates a semiconductor switching element and is connected to the first bus bar; a second bus bar, which is connected to the semiconductor module; and an insulating sheet, which insulates the first bus bar from the second bus bar, the insulating sheet including a second locking portion, and the insulating sheet is fixed to the first bus bar by locking the second locking portion with the first locking portion of the first bus bar.

[0007] In a power conversion device according to a technical solution of the present invention, as described above, the insulating sheet includes a second engaging portion, and the insulating sheet is fixed to the first bus bar by engaging the second engaging portion with the first engaging portion of the first bus bar. Thus, the position of the insulating sheet relative to the first bus bar can be fixed. As a result, the holding state between the plurality of bus bars and the insulating sheet can be stabilized without increasing the number of components.

[0008] In the power conversion device of the above-mentioned technical solution, it is preferred that one of the first engaging portion and the second engaging portion is a hole portion having a hole shape, and the other is a protrusion portion protruding relative to the first bus bar or the insulating sheet, and the first bus bar and the insulating sheet are fixed by inserting the protrusion portion into the hole portion. With such a configuration, the first bus bar and the insulating sheet can be fixed by a simple assembly operation such as inserting the protrusion portion into the hole portion. In addition, the first bus bar and the insulating sheet can be fixed without separately providing a fastening member for fixing, so that the first bus bar and the insulating sheet can be fixed with a simple structure with a reduced number of parts.

[0009] In this case, it is preferred that the first bus bar includes a side wall portion, the side wall portion protrudes in the first direction in which the first bus bar and the second bus bar are stacked, and extends in the second direction along a predetermined side of the first bus bar, the first engaging portion is a hole portion provided in the side wall portion of the first bus bar, and the second engaging portion is a protruding portion provided on the insulating sheet. With such a configuration, even if there is an obstacle in the first direction in which the first bus bar and the insulating sheet are stacked, the first bus bar and the insulating sheet can be fixed using the side wall portion extending in the second direction along the predetermined side of the first bus bar.

[0010] In the power conversion device in which the first bus bar includes a side wall portion, it is preferred that the side wall portions of the first bus bar are respectively provided at relative positions in a third direction orthogonal to the second direction as viewed from the first direction, the protrusions of the insulating sheet are respectively provided on both sides of the third direction as viewed from the first direction, the insulating sheet is provided on the inner side of the opposite side wall portions of the first bus bar as viewed from the first direction so as to extend in the third direction, and each of the protrusions provided on both sides of the insulating sheet is engaged with each of the hole portions provided on the opposite side wall portions, so that the insulating sheet is fixed to the first bus bar. With such a configuration, both sides of the insulating sheet provided on the inner side of the opposite side wall portions in the third direction are respectively fixed to the side wall portions, and therefore, the insulating sheet is more difficult to move in the third direction. As a result, the first bus bar and the insulating sheet can be fixed more firmly.

[0011] In this case, it is preferred that the second bus bar is provided inside the side wall portion opposite to the first bus bar so as to extend in the third direction and be separated from the side wall portion opposite to the first bus bar, and the length of the second bus bar extending in the third direction is shorter than the length of the insulating sheet extending in the third direction. With such a configuration, the first bus bar and the second bus bar are provided separately in the third direction and therefore do not contact each other in the third direction. In addition, the length of the second bus bar in the third direction is shorter than the length of the insulating sheet in the third direction and therefore the first bus bar and the second bus bar do not contact each other in the first direction. As a result, even if the side wall portion is provided on the first bus bar, insulation between the first bus bar and the second bus bar is ensured.

[0012] In the power conversion device in which the first bus bar includes a side wall, it is preferred that the protrusion of the insulating sheet passes through the hole and protrudes outward from the first bus bar relative to the side wall. With such a configuration, the protrusion is unlikely to escape from the hole. As a result, the first bus bar and the insulating sheet can be more securely fixed.

[0013] In the power conversion device in which the first bus bar includes a side wall portion, it is preferred that the first bus bar further includes a flat plate portion extending on a plane orthogonal to the side wall portion, and the hole portion is provided near the boundary portion between the side wall portion and the flat plate portion. As long as it is configured in this way, the hole portion is arranged in such a manner that the position (height) of the hole portion in the first direction is at a height equal to the height of the flat plate portion. In the case where the hole portion is provided at a height position of the side wall portion that is a predetermined height greater than the height of the flat plate portion, the insulating sheet deflects by an amount corresponding to the difference between the height of the flat plate portion and the height of the hole portion. On the other hand, in the case where the position (height) of the hole portion in the first direction is at a height position equal to the height of the flat plate portion, the deflection of the insulating sheet can be reduced or eliminated. As a result, the protrusion of the insulating sheet can be inserted into the hole portion of the first bus bar while suppressing the deflection of the insulating sheet.

[0014] In this case, it is preferred that the second bus bar extends in the first direction, and the height of the portion of the second bus bar extending in the first direction relative to the flat plate portion is greater than the height of the side wall portion relative to the flat plate portion in the first direction. With such a configuration, when other components are stacked at the end of the portion of the second bus bar extending in the first direction, it is possible to prevent the other components from interfering with the end of the portion of the side wall portion extending in the first direction. As a result, it is easy to design a case where a plurality of components are stacked.

[0015] In the power conversion device of the above-mentioned technical solution, it is preferred that a plurality of second bus bars are provided, a plurality of insulating sheets are provided corresponding to the plurality of second bus bars, and a single first bus bar is provided which is common to the plurality of second bus bars and the plurality of insulating sheets. With such a configuration, there is no need to provide first bus bars corresponding to the second bus bars and the insulating sheets, respectively. As a result, the number of components constituting the power conversion device can be reduced, and the structure of the power conversion device can be simplified.

[0016] In the power conversion device of the above-mentioned technical solution, it is preferred that the second bus bar includes: a flat plate-shaped first portion connected to the semiconductor module; a flat plate-shaped second portion connected to the first portion and extending in the first direction in which the first bus bar and the second bus bar are stacked; and a flat plate-shaped third portion connected to the end of the second portion on the side opposite to the side where the semiconductor module is arranged, and orthogonal to the second portion. As long as it is configured in this way, the flat plate-shaped third portion is provided at a position of the second bus bar that is higher than the first portion connected to the semiconductor module by an amount corresponding to the length of the second portion. As a result, when another component is mounted to the second bus bar at a position different from the position of the semiconductor module, it can also be easily mounted using the third portion of the second bus bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing the structure of a power conversion device according to one embodiment of the present invention.

[0018] Figure 2 This is a diagram showing the structure of a power conversion circuit arranged inside a power conversion device according to one embodiment of the present invention.

[0019] Figure 3 It is a diagram showing the structure of stacked semiconductor modules, insulating sheets, first bus bars, and second bus bars according to one embodiment of the present invention.

[0020] Figure 4 This is a circuit diagram of a power conversion circuit according to one embodiment of the present invention.

[0021] Figure 5 It is a diagram showing the structure of a first bus bar according to one embodiment of the present invention.

[0022] Figure 6 It is a diagram showing the structure of the second bus bar according to one embodiment of the present invention.

[0023] Figure 7 It is a figure which shows the structure of the insulating sheet which concerns on one Embodiment of this invention.

[0024] Figure 8 It is a diagram showing the structure of a semiconductor module according to one embodiment of the present invention.

[0025] Fig. 9 It is a diagram showing the structure of stacked semiconductor modules and a first bus bar according to one embodiment of the present invention.

[0026] Fig.10 This is a diagram for explaining a state in which one side of a protruding portion of an insulating sheet is inserted into a hole provided in a side wall portion of a first bus bar according to one embodiment of the present invention.

[0027] Fig.11 This is a diagram for explaining that the insulating sheet is bent in a state where one side of a protruding portion of the insulating sheet is inserted into a hole provided in a side wall portion of a first bus bar according to one embodiment of the present invention.

[0028] Fig.12 This is a diagram for explaining a state in which the protrusions on both sides of the insulating sheet are completely inserted into the holes provided in the side wall portion of the first bus bar according to one embodiment of the present invention.

[0029] Fig.13 This is a diagram showing the structure of stacked semiconductor modules, insulating sheets, and a first bus bar according to one embodiment of the present invention.

[0030] Fig.14 It is a diagram for explaining the width and thickness of a hole portion and a protrusion portion according to one embodiment of the present invention.

[0031] Fig.15 This is a diagram for explaining the positional relationship among laminated insulating sheets, a first bus bar, and a second bus bar according to one embodiment of the present invention. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0033] Reference Figures 1 to 8 , a structure of a power conversion device 100 according to an embodiment will be described.

[0034] (Device Structure of Power Converter 100)

[0035] In this embodiment, if Figure 1 As shown, the power conversion device 100 includes a housing 10, a power connection portion 20, and a cooling mechanism 30. In this embodiment, the height direction (vertical direction) of the power conversion device 100 installed on the ground is set as the Z direction, the direction in which the height increases (the direction away from the installed ground) is set as the Z1 direction, and the direction in which the height decreases (the direction close to the installed ground) is set as the Z2 direction. In this embodiment, the housing 10 has a short side and a long side, the direction along the short side is set as the X direction, and the direction along the long side is set as the Y direction. In addition, Figure 1 Set the direction from the front side to the back side as X1 direction and Y1 direction, and Figure 1 The direction from the inner side to the front side is set as the X2 direction and the Y2 direction. In addition, the X direction is an example of the "first direction" in the claims. In addition, the Z direction is an example of the "second direction" in the claims. In addition, the Y direction is an example of the "third direction" in the claims.

[0036] The power conversion device 100 converts the DC power supplied to the power connection unit 20 into AC power and outputs it, or converts the supplied AC power into DC power and outputs it from the power connection unit 20. In addition, the cooling mechanism 30 is, for example, a fan, which cools the inside of the housing 10 by exhausting the high-temperature air in the housing of the power conversion device 100 to the outside. Figure 2 As shown, the power conversion device 100 includes a power conversion circuit 40 inside a housing 10 .

[0037] like Figure 2 As shown, in this embodiment, the power conversion circuit 40 includes at least one first bus bar 1, three second bus bars 2, three insulating sheets 3, and a plurality of semiconductor modules 4. In addition, the power conversion circuit 40 in this embodiment is provided with a snubber capacitor CS and an output bus bar B for reducing noise. Figure 3 In this way, one first bus bar 1, three second bus bars 2, three insulating sheets 3, and a plurality of semiconductor modules 4 (4a to 41) are stacked and arranged.

[0038] Among them, use Figure 4 The configuration of the power conversion circuit 40 is described with reference to the circuit diagram shown in FIG. Figure 4As shown, a DC input terminal P and a DC input terminal N are provided, and a smoothing capacitor C is connected between the positive line and the negative line. A first bus bar 1 is connected to the positive line side, and is configured to supply DC power to a plurality of semiconductor modules 4a to 4l connected in parallel to the buffer capacitor CS. In addition, a negative bus bar not shown is connected to the negative line side. Inside the plurality of semiconductor modules 4a to 4l, two semiconductor switching elements Q are connected in series with each other. In addition, in the present embodiment, the semiconductor switching element Q is an IGBT (insulated gate bipolar transistor: Insulated Gate Bipolar Transistor) composed of, for example, a silicon (Si) semiconductor. The semiconductor switching elements Q contained in the plurality of semiconductor modules 4 and connected in series with each other are connected between the positive line and the negative line. Among them, the semiconductor switching elements Q contained in each of the four semiconductor modules 4a to 4d are respectively switched by a control unit not shown, thereby generating one-phase AC power. The power conversion circuit 40 generates three-phase AC power with different phases using semiconductor modules 4a to 4d, semiconductor modules 4e to 4h, and semiconductor modules 4i to 4l, which are four groups. The AC power generated by the plurality of semiconductor modules 4a to 4l is supplied to the load L via the second bus bar 2 and the output bus bar B connected to the semiconductor modules 4a to 4l.

[0039] Among them, Figure 5 As shown, the first bus bar 1 includes a side wall portion 1a, a side wall portion 1b, a connection portion 1c, a flat plate portion 1d, a connection hole 1e, an opening portion 1f, a hole portion 1g, and a boundary portion 1h, and is formed of a sheet of metal plate having a thickness t1. In this embodiment, the side wall portion 1a and the side wall portion 1b are formed by bending the end portion of the first bus bar 1 extending on the YZ plane in the Y direction so that the height becomes h1 in the X2 direction so as to face each other. The connection portion 1c is formed by bending the end portion of the first bus bar 1 extending on the YZ plane on the Z1 direction side in the X2 direction and further bending in the Z1 direction. The flat plate portion 1d is a flat plate that can carry three insulating sheets 3, and is provided with a connection hole 1e connected to the semiconductor module 4 and an opening portion 1f provided for connecting to the semiconductor module 4. In addition, the hole portion 1g is a through hole provided near the boundary portion 1h that is the boundary between the side wall portions 1a, 1b and the flat plate portion 1d. In the present embodiment, the hole portions 1g have a rectangular shape and are provided at three locations in the Z direction of the first bus bar 1. The hole portions 1g are an example of a "first engagement portion" in the claims.

[0040] like Figure 6As shown, the second bus bar 2 includes: a first portion 2a, which is connected to the semiconductor module 4 and is in a flat plate shape with a width of w1; a second portion 2b in a flat plate shape, which is orthogonal to the first portion 2a and extends in the X2 direction to a height of h2; and a third portion 2c in a flat plate shape, which is orthogonal to the second portion 2b, is provided on the X2 direction side of the second portion 2b, and extends in the Z1 direction. The second bus bar 2 is a metal plate member with a thickness of t2. In addition, the second bus bar 2 is fixed to a position separated from the side wall portion 1a and the side wall portion 1b of the first bus bar 1 by connecting to the semiconductor module 4. The details related to the fixing of the second bus bar 2 will be discussed later.

[0041] like Figure 7 As shown in FIG. 1 , in this embodiment, the insulating sheet 3 includes a protrusion 3a and a notch 3b. The insulating sheet 3 is an insulating material for insulating the first bus bar 1 from the second bus bar 2, and for example, PET (polyethylene terephthalate) resin or PC (polycarbonate) resin is used. In addition, in this embodiment, the thickness t3 of the insulating sheet 3 is greater than t3. Figure 5 The thickness t1 of the first bus bar 1 is shown as Figure 6 The thickness t2 of the second bus bar 2 shown is thin and flexible. The protrusions 3a are provided on both sides of the insulating sheet 3 in the Y direction, are parts of the insulating sheet 3 that protrude relative to the insulating sheet 3 in the Y direction, and have a rectangular shape. In addition, the protrusions 3a are an example of the "second engaging portion" in the claims. In addition, the notch portions 3b are provided at four locations in a manner that avoids the first portion 2a of the second bus bar 2 in order to connect the first portion 2a of the second bus bar 2 and the terminal 5c of the semiconductor module 4.

[0042] like Figure 8 As shown, in this embodiment, the semiconductor module 4 includes a terminal 5a, a terminal 5b, and a terminal 5c. The terminal 5a is a collector terminal of the switching element, connected to the first bus bar 1, and supplies or outputs DC power. The terminal 5b is an emitter terminal of the switching element, connected to a bus bar not shown. The terminal 5c is an AC terminal (emitter-collector terminal) of the switching element, connected to the second bus bar 2, and outputs or supplies AC power.

[0043] Next, use Figures 9 to 15 Next, a structure in which the semiconductor modules 4 a to 4 l , the first bus bar 1 , the insulating sheet 3 , and the second bus bar 2 are stacked will be described.

[0044] In this embodiment, if Fig. 9 As shown in FIG. 1 , four semiconductor modules 4a to 41 are arranged in a row in the Y direction. Figure 3 The circuit shown in FIG. 1 is configured to include a semiconductor switching element Q inside, and thus, a bridge circuit is formed by four semiconductor modules 4a to 4l. Thus, the semiconductor modules 4a to 4l convert the DC power input via the first bus bar 1 into AC power. In addition, in this embodiment, Fig. 9 As shown, four semiconductor modules 4 are arranged in the Y direction and three sets are provided in the Z direction. Thus, each set of semiconductor modules 4 converts DC power input via the first bus bar 1 into three-phase AC power.

[0045] like Fig. 9 As shown, in this embodiment, the first bus bar 1 is fixed to the terminals 5a of the plurality of semiconductor modules 4 in a stacked manner in the X direction using fastening members such as screws (not shown) that pass through the connection holes 1e. Next, the first bus bar 1 and the insulating sheet 3 are fixed in a state where the semiconductor modules 4 and the first bus bar 1 are fixed.

[0046] Among them, Fig. 9 As shown in FIG. 1 , the distance from the inner side (Y1 side) surface of the side wall portion 1a of the first bus bar 1 to the inner side (Y2 side) surface of the side wall portion 1b is defined as the side wall distance d1. Figure 7 The length l1 between the protrusions 3a on both sides of the insulating sheet 3 shown is greater than the distance d1 between the side walls. In addition, the sheet length l2 connecting the portions of the side where the protrusions 3a are provided and where the protrusions 3a are not provided is less than the distance d1 between the side walls. In addition, in the present embodiment, the sheet length l2 is slightly smaller than the distance d1 between the side walls to the extent that the insulating sheet 3 cannot move in the Y direction when the insulating sheet 3 is attached to the inner side of the side walls 1a and 1b of the first bus bar 1.

[0047] Next, use Figure 10 to Figure 12 Next, the semiconductor module 4 and the first bus bar 1 are fixed to each other. Fig. 9 When the first bus bar 1 and the insulating sheet 3 are fixed, first, the protrusion 3a on one side of the insulating sheet 3 is inserted into the hole 1g on the side of the side wall 1a of the first bus bar 1. Fig.10 In this way, the length l1 of the protrusions 3a provided on both sides of the insulating sheet 3 is longer than the side wall distance d1 from the inner side (Y1 side) surface of the side wall portion 1a of the first bus bar 1 to the inner side (Y2 side) surface of the side wall portion 1b, and therefore, the insulating sheet 3 is not fixed parallel to the flat plate portion 1d of the first bus bar 1.

[0048] In this embodiment, the insulating sheet 3 has flexibility. Therefore, when the protrusion 3a is inserted into the hole 1g on the side of the side wall 1a of the first bus bar 1, the insulating sheet 3 can be made to be flexible. Fig.11 Thus, the insulating sheet 3 is bent in the X2 direction. Therefore, the other protrusion 3a of the insulating sheet 3 can be inserted into the hole 1g on the side of the side wall 1b of the first bus bar 1 by bending the insulating sheet 3. Thus, the insulating sheet 3 is fixed so as not to move relative to the first bus bar 1 in the Y direction. In addition, in the present embodiment, the hole 1g of the first bus bar 1 is provided near the boundary 1h which is the boundary between the side wall 1a, 1b and the flat plate 1d. Therefore, as Fig.12 As shown, when the first bus bar 1 and the insulating sheet 3 are fixed, the surface of the insulating sheet 3 is provided parallel to the flat plate portion 1 d of the first bus bar 1 without being bent.

[0049] Among them, Fig.13 As shown, the protrusion 3a on one side of the insulating sheet 3 protrudes outward (toward the Y2 side) relative to the side wall portion 1a of the first bus bar 1. In addition, the protrusion 3a on the other side of the insulating sheet 3 protrudes outward (toward the Y1 side) relative to the side wall portion 1b of the first bus bar 1. In the present embodiment, the protrusion 3a protrudes in such a manner that the distance d2 from the protrusion 3a to the outside (toward the Y2 side) of the side wall portion 1a of the first bus bar 1 and the distance d3 from the protrusion 3a to the outside (toward the Y1 side) of the side wall portion 1b of the first bus bar 1 become the lengths that are at least twice the thickness t1 of the first bus bar 1.

[0050] In addition, if Fig.14 As shown in FIG. 1 , the width wg of the hole 1g of the first bus bar 1 in the Z direction is slightly larger than the width w3 of the protrusion 3a of the insulating sheet 3 in the Z direction. Thus, the insulating sheet 3 is fixed so as to be almost unable to move relative to the first bus bar 1 in the Z direction. On the other hand, in the present embodiment, the height hg of the hole 1g of the first bus bar 1 in the X direction is sufficiently larger than the height (thickness t3) of the protrusion 3a of the insulating sheet 3 in the X direction. Thus, when the insulating sheet 3 is made as Fig.10 In such an inclined state, the protrusion 3 a can be easily inserted into the hole 1 g , and the insulating sheet 3 can be slightly moved or bent in the X direction relative to the first bus bar 1 .

[0051] After the three insulating sheets 3 are attached to the first bus bar 1 as described above, the second bus bar 2 is connected to the semiconductor module 4. Figure 6 The busbar length l3 shown as the length of the second busbar 2 in the Y direction is shorter than the sheet length l2 of the insulating sheet 3. In addition, the busbar width w1 of the second busbar 2 in the Z direction is shorter than the sheet width w2 of the insulating sheet 3 in the Z direction. In addition, the height h2 of the second busbar 2 in the X direction is shorter than the sheet width w2 of the insulating sheet 3 in the Z direction. Figure 5 The side walls 1 a and 1 b of the first bus bar 1 shown in the figure have a high height h1.

[0052] Among them, Figure 2 As shown, the second bus bar 2 is fixed to the terminal 5c of the semiconductor module 4 by passing through the first portion 2a using a fastening member (not shown). At this time, in the present embodiment, a notch portion 3b is provided in the insulating sheet 3, so that the first portion 2a of the second bus bar 2 is fixed to the terminal 5c of the semiconductor module 4 without contacting the insulating sheet 3. In addition, at this time, the second bus bar 2 and the semiconductor modules 4a to 41 are fixed in such a manner that the end portion of the second bus bar 2 extending in the Y2 direction is located at a position separated from the side wall portion 1a of the first bus bar 1. Similarly, the second bus bar 2 and the semiconductor module 4 are fixed in such a manner that the end portion of the second bus bar 2 extending in the Y1 direction is located at a position separated from the side wall portion 1b of the first bus bar 1. In addition, the height ratio of the second bus bar 2 in the X2 direction relative to the flat plate portion 1d of the first bus bar 1 is Figure 5 The side walls 1 a and 1 b of the first bus bar 1 shown in the figure have a high height h1.

[0053] At this time, if Fig.15 As shown, the insulating sheet 3 is sandwiched between the first bus bar 1 and the second bus bar 2. In the present embodiment, although the gap between the first bus bar 1 and the second bus bar 2 is larger than the thickness t3 of the insulating sheet 3, it is not large enough to achieve the bending amount required for the protrusion 3a to come out of the hole 1g of the insulating sheet 3. Therefore, the fixing between the insulating sheet 3 and the first bus bar 1 cannot be released without releasing the engagement state between the protrusion 3a and the hole 1g.

[0054] (Effects of this embodiment)

[0055] Next, the effects of this embodiment will be described.

[0056] The power conversion device 100 of the present embodiment includes: a first bus bar 1 provided with a hole 1g; a semiconductor module 4 for power conversion, which houses a semiconductor switch element Q and is connected to the first bus bar 1; a second bus bar 2 connected to the semiconductor module 4; and an insulating sheet 3, which insulates the first bus bar 1 from the second bus bar 2, the insulating sheet 3 including a protrusion 3a, and the insulating sheet 3 is fixed relative to the first bus bar 1 by engaging the protrusion 3a with the hole 1g of the first bus bar 1. Thus, the position of the insulating sheet 3 relative to the first bus bar 1 can be fixed. As a result, a plurality of bus bars and the insulating sheet 3 can be stably held without increasing the number of parts and the number of assembly man-hours.

[0057] Furthermore, in the present embodiment, one of the first engaging portion and the second engaging portion is a hole portion 1g having a hole shape, and the other is a protrusion 3a protruding relative to the first bus bar 1 or the insulating sheet 3, and the first bus bar 1 and the insulating sheet 3 are fixed by inserting the protrusion 3a into the hole portion 1g. Thus, the first bus bar 1 and the insulating sheet 3 can be fixed by a simple assembly operation such as inserting the protrusion 3a into the hole portion 1g. In addition, the first bus bar 1 and the insulating sheet 3 can be fixed without separately providing a fastening member for fixing, so that the first bus bar 1 and the insulating sheet 3 can be fixed with a simple structure with a reduced number of parts.

[0058] In addition, in the present embodiment, the first bus bar 1 includes side wall portions 1a and 1b that protrude in the X direction in which the first bus bar 1 and the second bus bar 2 are stacked and extend in the Z direction along a predetermined side of the first bus bar 1, the first engaging portion is a hole portion 1g provided in the side wall portions 1a and 1b of the first bus bar 1, and the second engaging portion is a protrusion 3a provided in the insulating sheet 3. Thus, even when there is an obstacle in the X direction in which the first bus bar 1 and the insulating sheet 3 are stacked, the first bus bar 1 and the insulating sheet 3 can be fixed using the side wall portions 1a and 1b that extend in the Z direction along the predetermined side of the first bus bar 1.

[0059] In addition, in the present embodiment, the side walls 1a and 1b of the first bus bar 1 are respectively provided at opposite positions in the Y direction orthogonal to the Z direction when viewed from the X direction, and the protrusions 3a of the insulating sheet 3 are respectively provided on both sides in the Y direction. The insulating sheet 3 is provided inside the opposite side walls 1a and 1b of the first bus bar 1 in a manner extending in the Y direction, and each of the protrusions 3a provided on both sides of the insulating sheet 3 is engaged with each of the holes 1g provided on the opposite side walls 1a and 1b, so that the insulating sheet 3 is fixed to the first bus bar 1. As a result, the two sides of the insulating sheet 3 provided inside the opposite side walls 1a and 1b in the Y direction are respectively fixed to the side walls 1a and 1b, so that the insulating sheet 3 is more difficult to move in the Y direction. As a result, the first bus bar 1 and the insulating sheet 3 can be fixed more firmly.

[0060] In addition, in the present embodiment, the second bus bar 2 is provided inside the opposite side wall portions 1a, 1b of the first bus bar 1 in a manner extending in the Y direction and being separated from the opposite side wall portions 1a, 1b, respectively, and the length of the second bus bar 2 extending in the Y direction is shorter than the length of the insulating sheet 3 extending in the Y direction. Thus, the first bus bar 1 and the second bus bar 2 are provided separately in the Y direction, and therefore, they are not in contact with each other in the Y direction. In addition, the length of the second bus bar 2 in the Y direction is shorter than the length of the insulating sheet 3 in the Y direction, and therefore, the first bus bar 1 and the second bus bar 2 are not in contact with each other in the X direction. As a result, even if the side wall portions 1a, 1b are provided on the first bus bar 1, insulation between the first bus bar 1 and the second bus bar 2 is ensured.

[0061] In addition, in the present embodiment, the protrusion 3a of the insulating sheet 3 passes through the hole 1g and protrudes toward the outside of the first bus bar 1 relative to the side walls 1a and 1b. As a result, the protrusion 3a is unlikely to escape from the hole 1g. As a result, the first bus bar 1 and the insulating sheet 3 can be more firmly fixed.

[0062] In addition, in the present embodiment, the first bus bar 1 further includes a flat plate portion 1d extending on a plane perpendicular to the side walls 1a and 1b, and the hole portion 1g is provided near the boundary portion 1h between the side walls 1a and 1b and the flat plate portion 1d. Thus, the hole portion 1g is arranged so that the position (height) of the hole portion 1g in the X direction becomes the same height as the height of the flat plate portion 1d. However, when the hole portion 1g is provided at a height position greater than the flat plate portion 1d in the side walls 1a and 1b by a predetermined amount, the insulating sheet 3 is bent by an amount corresponding to the difference between the height of the flat plate portion 1d and the height of the hole portion 1g. On the other hand, when the position (height) of the hole portion 1g in the X direction is the same height position as the height of the flat plate portion 1d, the bending of the insulating sheet 3 can be reduced or eliminated. As a result, the protrusion 3a of the insulating sheet 3 can be inserted into the hole portion 1g of the first bus bar 1 while suppressing the bending of the insulating sheet 3.

[0063] In addition, in the present embodiment, the second bus bar 2 extends in the X direction, and the height of the portion of the second bus bar 2 extending in the X direction relative to the flat plate portion 1d is greater than the height h1 of the side walls 1a and 1b relative to the flat plate portion 1d in the X direction. Thus, when other components are arranged in a stacked manner at the end of the portion of the second bus bar 2 extending in the X direction, it is possible to prevent the other components from interfering with the end of the portion of the side walls 1a and 1b extending in the X direction. As a result, the design of a case where a plurality of components are stacked becomes easy.

[0064] In addition, in the present embodiment, a plurality of second bus bars 2 are provided, a plurality of insulating sheets 3 are provided corresponding to the plurality of second bus bars 2, and a single first bus bar 1 is provided that is common to the plurality of second bus bars 2 and the plurality of insulating sheets 3. Thus, there is no need to provide the first bus bars 1 corresponding to the second bus bars 2 and the insulating sheets 3, respectively. As a result, the number of components constituting the power conversion device 100 can be reduced, and the structure of the power conversion device 100 can be simplified.

[0065] In addition, in the present embodiment, the second bus bar 2 includes: a flat plate-shaped first portion 2a connected to the semiconductor module 4; a flat plate-shaped second portion 2b connected to the first portion 2a and extending in the X direction in which the first bus bar 1 and the second bus bar 2 are stacked; and a flat plate-shaped third portion 2c connected to the end of the second portion 2b on the side opposite to the side where the semiconductor module 4 is arranged, and orthogonal to the second portion 2b. Thus, the flat plate-shaped third portion 2c is provided at a position of the second bus bar 2 that is higher than the first portion 2a connected to the semiconductor module 4 by an amount corresponding to the length of the second portion 2b. As a result, when another component is mounted to the second bus bar 2 at a position different from the semiconductor module 4, it can be easily mounted using the third portion 2c of the second bus bar 2.

[0066] [Modifications]

[0067] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments described above, and includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0068] For example, in the present embodiment, the first engaging portion is a hole portion 1g and the second engaging portion is a protrusion 3a, but the present invention is not limited thereto. In the present invention, for example, the first engaging portion and the second engaging portion may both be claw-shaped protrusions, and the first bus bar 1 and the second bus bar 2 may be fixed by engaging the protrusions of the two.

[0069] In the present embodiment, the first bus bar 1 has a hole 1g for inserting the protrusion 3a of the insulating sheet 3, but the present invention is not limited thereto. In the present invention, the insulating sheet 3 may have a hole and the first bus bar 1 may have a protrusion.

[0070] In the present embodiment, the hole 1g is provided in the side wall portions 1a and 1b of the first bus bar 1, but the present invention is not limited thereto. In the present invention, the first bus bar 1 may not have the side wall portions 1a and 1b, and the hole 1g may be provided in the flat plate portion 1d, for example.

[0071] In addition, the following example is shown in the present embodiment: the first bus bar 1 is provided in such a manner that the side wall portion 1a and the side wall portion 1b are opposite to each other, and the protrusions 3a on both sides of the insulating sheet 3 are inserted, but the present invention is not limited to this. In the present invention, the first bus bar 1 may be configured in such a manner that only the side wall portion 1a is provided, and the side wall portions 1a and 1b may be provided at non-opposite positions. In addition, the first bus bar 1 may also include other wall portions in addition to the side wall portions 1a and 1b. In addition, in the above case, the insulating sheet 3 may be provided with the protrusion 3a in such a manner that it corresponds to the position of the hole portion 1g of the first bus bar 1.

[0072] In addition, in the present embodiment, an example is shown in which the second bus bar 2 is provided inside the side wall portions 1a and 1b in a manner separated from the side wall portions 1a and 1b and insulated from the first bus bar 1, but the present invention is not limited thereto. In the present invention, for example, the second bus bar 2 may be provided in a manner separated from the first bus bar 1 so as to protrude in the X2 direction and insulated from the first bus bar 1.

[0073] In addition, in the present embodiment, an example is shown in which the protrusion 3a passes through the hole 1g and protrudes outward relative to the side wall portions 1a and 1b, but the present invention is not limited to this. In the present invention, the protrusion 3a may also be configured in a manner that it passes through the hole 1g and is aligned with the outer surface of the side wall portions 1a and 1b, or is slightly inside the outer surface of the side wall portions 1a and 1b.

[0074] In the present embodiment, the hole 1g is provided near the boundary 1h between the side walls 1a and 1b and the flat plate 1d, but the present invention is not limited thereto. In the present invention, the hole 1g may be provided above the side walls 1a and 1b (on the X2 direction side).

[0075] In addition, in the present embodiment, there is shown an example in which the second bus bar 2 extends in the X2 direction, and the height h2 of the portion of the second bus bar 2 extending in the X2 direction relative to the flat plate portion 1d is greater than the height h1 of the side wall portions 1a and 1b relative to the flat plate portion 1d in the X2 direction, but the present invention is not limited to this. In the present invention, the height h2 of the portion of the second bus bar 2 extending in the X2 direction relative to the flat plate portion 1d may be smaller than the height h1 of the side wall portions 1a and 1b relative to the flat plate portion 1d in the X2 direction. In this case, the output bus bar B connected to the second bus bar 2 may be provided in accordance with the height h2 of the second bus bar 2.

[0076] In addition, in the present embodiment, the following example is shown: three second bus bars 2 are provided, three insulating sheets 3 are provided corresponding to the three second bus bars 2, and one first bus bar 1 is provided for the three second bus bars 2 and the three insulating sheets 3, but the present invention is not limited thereto. In the present invention, one insulating sheet 3 may be provided for the three second bus bars 2, or the first bus bar 1 may be provided corresponding to the three second bus bars 2 and the three insulating sheets 3, respectively.

[0077] In addition, in the present embodiment, the following example is shown, in which the second bus bar 2 includes: a flat plate-shaped first portion 2a, which is connected to the semiconductor module 4; a flat plate-shaped second portion 2b, which is connected to the first portion 2a and extends in the X2 direction where the first bus bar 1 and the second bus bar 2 are stacked; and a flat plate-shaped third portion 2c, which is connected to the end of the second portion 2b on the side opposite to the side where the semiconductor module 4 is arranged, and is orthogonal to the second portion 2b, but the present invention is not limited to this. In the present invention, the second bus bar 2 may also be, for example, simply in the form of a flat plate.

[0078] In addition, in this embodiment, the insulating sheet 3 is shown as an example of PET resin or PC resin, but the present invention is not limited thereto. In the present invention, the insulating sheet 3 can be a material that can insulate the first bus bar 1 from the second bus bar 2, and a resin material different from PET resin and PC resin, or a rubber material such as silicone rubber can also be used.

[0079] In addition, in the present embodiment, an example is shown in which the insulating sheet 3 and the second bus bar 2 are provided with a gap therebetween, but the present invention is not limited thereto. In the present invention, the insulating sheet 3 and the second bus bar 2 may be provided in contact with each other.

[0080] In addition, in this embodiment, an example of a three-phase circuit in which four semiconductor modules 4 are connected in parallel for each phase is shown, but the present invention is not limited to this. In the present invention, for each phase, the number of semiconductor modules 4 may be one, or the number of parallel connections other than four (for example, two, three, and five or more parallel connections) may be used. In addition, a three-phase circuit is not essential, and a single-phase circuit may be used, for example.

Claims

1. A power conversion device comprising: a first bus bar provided with a first engaging portion; a semiconductor module for power conversion, which houses a semiconductor switch element and is connected to the first bus bar; a second bus bar connected to the semiconductor module; and an insulating sheet that insulates the first bus bar from the second bus bar, The insulating sheet includes a second engaging portion, and the insulating sheet is fixed to the first bus bar by the second engaging portion engaging with the first engaging portion of the first bus bar.

2. The power conversion device according to claim 1, wherein: One of the first engaging portion and the second engaging portion is a hole portion having a hole shape, and the other is a protruding portion protruding relative to the first bus bar or the insulating sheet. The first bus bar and the insulating sheet are fixed to each other by inserting the protrusion into the hole.

3. The power conversion device according to claim 2, wherein: The first bus bar includes a side wall portion, the side wall portion protruding in a first direction in which the first bus bar and the second bus bar are stacked, and extending in a second direction along a predetermined side of the first bus bar, The first engaging portion is the hole portion provided in the side wall portion of the first bus bar, The second engagement portion is the protruding portion provided on the insulating sheet.

4. The power conversion device according to claim 3, wherein: The side wall portions of the first bus bar are respectively provided at opposite positions in a third direction orthogonal to the second direction when viewed from the first direction. The protruding portions of the insulating sheet are respectively arranged on both sides of the third direction when viewed from the first direction, The insulating sheet is arranged on the inner side of the opposite side wall portion of the first bus bar in a manner extending in the third direction when viewed from the first direction, and each of the protrusions provided on both sides of the insulating sheet is engaged with each of the hole portions respectively provided on the opposite side wall portions, so that the insulating sheet is fixed to the first bus bar.

5. The power conversion device according to claim 4, wherein: The second bus bar is provided inside the opposing side wall portions of the first bus bar so as to extend in the third direction and be separated from the opposing side wall portions. A length of the second bus bar extending in the third direction is shorter than a length of the insulating sheet extending in the third direction.

6. The power conversion device according to claim 3, wherein: The protruding portion of the insulating sheet passes through the hole and protrudes toward the outside of the first bus bar relative to the side wall.

7. The power conversion device according to claim 3, wherein: The first bus bar further includes a flat plate portion extending on a surface perpendicular to the side wall portion. The hole portion is provided near a boundary portion between the side wall portion and the flat plate portion.

8. The power conversion device according to claim 7, wherein: The second bus bar extends in the first direction, A portion of the second bus bar extending in the first direction has a height relative to the flat plate portion greater than a height of the side wall portion relative to the flat plate portion in the first direction.

9. The power conversion device according to claim 1, wherein: The second bus bar is provided in plurality. The insulating sheet is provided in plurality corresponding to the plurality of second bus bars, The first bus bar is provided in one piece and is commonly used for the plurality of second bus bars and the plurality of insulating sheets.

10. The power conversion device according to claim 1, wherein: The second bus bar includes: a flat-plate-shaped first portion connected to the semiconductor module; a flat-plate-shaped second portion connected to the first portion and extending in a first direction in which the first bus bar and the second bus bar are stacked; and a flat-plate-shaped third portion connected to an end portion of the second portion on a side opposite to a side on which the semiconductor module is disposed and orthogonal to the second portion.

Images