Power Conversion Device

Abstract

To provide a power conversion device capable of preventing damage caused by oscillation of a substrate on which a smooth capacitor is mounted while suppressing lowering of assemblability of a device.SOLUTION: A power conversion device 100 comprises: a switching element 1; a smooth capacitor 2 that smooths a current flowing in the switching element 1; a substrate 4 on which the smooth capacitor 2 is mounted; and a die casting member 6 to which the substrate 4 is attached and which is provided so as to cover the smooth capacitor 2. The power conversion device 100 further comprises a sheet-like flexible deformation member 8 which is arranged while being deformed by deflection between the smooth capacitor 2 and the die casting member 6 so as to be in contact with an outer end surface 2a opposite a surface on the side it is arranged on the substrate 4 of the smooth capacitor 2.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a power conversion device, and more particularly to a power conversion device including a substrate on which a smoothing capacitor is mounted. [Background technology]

[0002] BACKGROUND ART Conventionally, a power conversion device including a substrate on which a smoothing capacitor is mounted is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a power conversion device including a substrate on which a smoothing capacitor is mounted, a power semiconductor, and a casing that covers a cooling fin that cools the power semiconductor. In this power conversion device, the substrate on which the smoothing capacitor is mounted is attached to the casing.

[0004] Here, in a conventional power conversion device such as that described in Patent Document 1, in order to prevent damage to the board when the device vibrates, it is necessary to suppress deformation of the board on which the smoothing capacitor is mounted due to stress caused by vibration (the weight of the smoothing capacitor) when the device vibrates. Therefore, although not explicitly stated in Patent Document 1, in a conventional power conversion device such as that described in Patent Document 1, in order to suppress deformation of the board due to stress caused by vibration (the weight of the smoothing capacitor), the smoothing capacitor may be fixed with potting resin, or the smoothing capacitor may be fitted into a plastic member attached to the board, thereby supporting the area around the smoothing capacitor on the board while fixing the smoothing capacitor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-165643 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a smoothing capacitor is fixed with potting resin, time is required for the potting resin to harden during assembly, which increases the time required to assemble the device. Furthermore, when the smoothing capacitor is fixed in place by fitting it into a plastic member attached to the board, and the area around the smoothing capacitor on the board is supported, the mounting position of the smoothing capacitor and the fitting position of the plastic member relative to the smoothing capacitor must be precisely aligned during assembly, making device assembly difficult. Therefore, there is a problem in that it is not possible to prevent damage caused by vibration of the board on which the smoothing capacitor is mounted while suppressing a decrease in device assembly ease.

[0007] 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 prevent damage caused by vibration of the board on which the smoothing capacitor is mounted, while suppressing a decrease in the ease of assembly of the device. [Means for solving the problem]

[0008] In order to achieve the above object, a power conversion device according to one aspect of the present invention includes a switching element, a smoothing capacitor for smoothing a current flowing through the switching element, and a power conversion device including a smoothing capacitor. circuit A substrate; circuit A cover member on which the substrate is attached and which is provided to cover the smoothing capacitor; circuit The device is provided with a sheet-like flexible deformation member that is disposed in a flexible deformation state between the smoothing capacitor and the cover member so as to abut against the outer end surface opposite the surface that is placed on the substrate.

[0009] As described above, the power conversion device according to the first aspect is provided with a smoothing capacitor. circuit A substrate; circuitThe substrate is attached to a cover member that is provided to cover the smoothing capacitor. The sheet-shaped flexible deformation member is circuit The flexible member is disposed between the smoothing capacitor and the cover member in a flexible state so as to abut against the outer end surface opposite to the surface on the side where the flexible member is disposed on the board. circuit Deformation of the board circuit Unlike when vibrations are suppressed only by fixing the board, vibrations of the smoothing capacitor when the device vibrates can be directly absorbed by the deflection deformation of the deflection deformation member. circuit Deformation due to vibration of the board can be effectively suppressed. Furthermore, since the flexible deformation member is a sheet-like member, it can be easily bent and placed between the smoothing capacitor and the cover member during assembly. Then, the smoothing capacitor can be mounted simply by placing the sheet-like flexible deformation member between the smoothing capacitor and the cover member during assembly. circuit Deformation caused by vibration of the substrate can be effectively suppressed, circuit Unlike when using potting resin to suppress deformation of the substrate, no time is required for the potting resin to harden. As a result, unlike when using hardened potting resin to fix the smoothing capacitor, the increase in the time required to assemble the device can be suppressed. Furthermore, during assembly, it is only necessary to place a sheet-like flexible member between the smoothing capacitor and the cover member, making it easier to assemble the device than when the smoothing capacitor is supported around the smoothing capacitor on the substrate while being fixed by fitting the smoothing capacitor into a plastic member attached to the substrate. As a result, damage caused by vibration of the substrate on which the smoothing capacitor is mounted can be prevented while suppressing a decrease in the ease of assembly of the device.

[0010] In the power conversion device according to the above aspect, the cover member preferably includes a recess within which the smoothing capacitor is disposed, and the flexible deformation member is disposed in a flexible state within the recess of the cover member between the smoothing capacitor and the cover member so as to abut against an outer end surface of the smoothing capacitor. With this configuration, since the flexible deformation member is disposed within the recess of the cover member, the position of the flexible deformation member can be aligned using the inner wall surface of the recess during assembly. As a result, assembly of the device can be facilitated.

[0011] In the power conversion device according to the aforementioned aspect, preferably, the cover member is a metal housing, and the deflection deformation member is an insulating member; circuit Among the boards, the metal housing and circuit The switching element and the smoothing capacitor are arranged on the surface facing the internal space between the substrate, and the flexible deformation member is configured to insulate the metal housing from the smoothing capacitor when in a flexible deformation state. With this configuration, the insulating flexible deformation member insulates the metal housing from the smoothing capacitor, and the distance between the outer end face of the smoothing capacitor and the metal housing can be made closer than the insulation distance (air insulation distance) when insulation is achieved by air. As a result, circuit In the direction in which the substrate and the metal housing face each other, an increase in the size of the device can be suppressed.

[0012] In this case, it is preferable that cooling fins for cooling the switching elements are integrally provided on the outer surface of the metal housing. With this configuration, unlike when cooling fins are provided separately from the metal housing, the switching elements can be cooled by the cooling fins while suppressing an increase in the number of parts and assembly steps.

[0013] In the power converter according to the above aspect, preferably, the width of the inner bottom surface of the cover member facing the outer end surface of the smoothing capacitor is smaller than the width of the flexible member before being placed between the outer end surface of the smoothing capacitor and the inner bottom surface of the cover member. With this configuration, when the flexible member is placed between the outer end surface of the smoothing capacitor and the inner bottom surface of the cover member, the flexible member is bent to match the width of the inner bottom surface. As a result, the flexible member can be easily placed between the outer end surface of the smoothing capacitor and the inner bottom surface of the cover member in a bent state.

[0014] In this case, preferably, the device further includes an engaging portion that engages the flexural deformation member with the cover member, and the flexural deformation member is disposed between the cover member and the smoothing capacitor so as to abut against the outer end surface of the smoothing capacitor when engaged with the cover member by the engaging portion and in a flexed and deformed state. With this configuration, the flexural deformation member and the cover member can be engaged by the engaging portion, so that the flexural deformation member can be easily fixed between the cover member and the smoothing capacitor so as to abut against the outer end surface of the smoothing capacitor. As a result, the device can be easily assembled.

[0015] In the configuration including the engaging portion, preferably, the engaging portion includes a protrusion provided on either the flexible deformation member or the cover member so as to protrude toward the other of the flexible deformation member or the cover member, and a hole provided on either the flexible deformation member or the cover member into which the protrusion is fitted, the flexible deformation member being disposed in a flexible deformed state between the cover member and the smoothing capacitor so as to abut against the outer end surface of the smoothing capacitor by fitting the protrusion into the hole. With this configuration, the flexible deformation member and the cover member can be easily engaged by fitting the protrusion into the hole, and the flexible deformation member can be easily fixed between the cover member and the smoothing capacitor so as to abut against the outer end surface of the smoothing capacitor. As a result, the device can be easily assembled.

[0016] In the power conversion device according to the aforementioned aspect, preferably, the flexural deformation member is circuit At least one end of the substrate in the direction along the surface on which the smoothing capacitor is mounted includes a folded portion that is folded back toward the outer end face of the smoothing capacitor and abuts against the outer end face of the smoothing capacitor. With this configuration, the outer end face of the smoothing capacitor can be supported by the folded portion of the flexible deformation member that is disposed between the cover member and the smoothing capacitor. As a result, by the folded portion supporting the outer end face of the smoothing capacitor in a flexed and deformed state, circuit Deformation of the board circuit Unlike when suppressing vibrations by simply fixing the board, vibrations of the smoothing capacitor when the device vibrates can be directly absorbed by the bending deformation of the folded part. circuit Deformation caused by vibration of the substrate can be effectively suppressed.

[0017] In this case, preferably, the folded portion is circuit The smoothing capacitor is provided on each of both ends of the deflection deformation member in the direction along the surface of the substrate on which the smoothing capacitor is mounted. circuit Unlike the case where a folded portion is provided only at one end in the direction along the surface of the board on which the smoothing capacitor is mounted, circuit The outer end faces of the smoothing capacitors can be supported from both ends of the deflection deformation member in the direction along the surface of the substrate on which the smoothing capacitors are mounted. As a result, the smoothing capacitors can be supported in a balanced manner by the folded-back portions, and the smoothing capacitors mounted thereon can be supported in a balanced manner. circuit Deformation caused by vibration of the substrate can be effectively suppressed. [Effects of the Invention]

[0018] According to the present invention, as described above, it is possible to provide a power conversion device that can prevent damage caused by vibration of the substrate on which the smoothing capacitor is mounted, while suppressing an increase in the size of the device. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing an example of a circuit configuration of a power conversion device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view for explaining the configuration of the power conversion device. [Figure 3] FIG. 4 is a cross-sectional view taken along line 400-400 in FIG. 2. [Figure 4] FIG. 5 is a partial cross-sectional view taken along line 500-500 in FIG. 3. [Figure 5] 10A and 10B are diagrams illustrating recesses in a flexible deformation member and a die-cast member. [Figure 6] 6 is a partial cross-sectional view taken along line 600-600 in FIG. 5, showing a hole formed in the die-cast member. [Figure 7] 7 is a partial cross-sectional view taken along line 700-700 in FIG. 5, showing a hole formed in the die-cast member. [Figure 8] FIG. 10 is a diagram showing a recess in a state where a deflection deformation member is disposed. [Figure 9] 10A and 10B are diagrams showing a flexural deformation member in a second embodiment. [Figure 10] 8 is a cross-sectional view of the flexural deformation member in the second embodiment taken along line 800-800 in FIG. 9. [Figure 11] 10 is a view showing a flexural deformation member according to a second embodiment in a state where it is placed in a recess. FIG. [Figure 12] 12 is a cross-sectional view showing the flexural deformation member taken along line 900-900 in FIG. 11. [Figure 13] 10A and 10B are diagrams showing a cover member and a deflection deformation member according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0021] [First embodiment] (Overall configuration of power conversion device) The overall configuration of a power conversion device 100 according to the first embodiment will be described with reference to FIGS.

[0022] The power conversion device 100 includes a switching element 1 and a smoothing capacitor 2 that smooths the current flowing through the switching element 1. Specifically, as shown in Fig. 1, the power conversion device 100 is an inverter that includes an inverter unit 10 including the switching element 1, a smoothing unit 20 including the smoothing capacitor 2, and a rectifying unit 30 including a diode element 3. The switching element 1 of the inverter unit 10 and the diode element 3 of the rectifying unit 30 are electrically connected to the smoothing capacitor 2 of the smoothing unit 20.

[0023] As shown in FIG. 2, the power conversion device 100 also includes a substrate 4 on which a smoothing capacitor 2 is mounted. In the first embodiment, a plurality of (two) smoothing capacitors 2 are mounted. The smoothing capacitor 2 has a cylindrical shape. The substrate 4 is a printed circuit board (PCB) on which a wiring pattern is formed using conductors and on which electronic components are mounted. The substrate 4 is formed to extend along the X and Y directions (XY plane). In this specification, the vertical direction is defined as the Z direction, the direction perpendicular to the vertical direction (Z direction) is defined as the X direction, and the direction perpendicular to the Z and X directions is defined as the Y direction. The X direction is the direction of the short sides of the substrate 4, and the Y direction is the direction of the long sides of the substrate 4. The Z direction is the thickness direction of the substrate 4.

[0024] 2, a terminal block 5 to which wiring from outside the device is connected is provided above (on the Z1 direction side of) the substrate 4. The terminal block 5 is made of PBT (Polybutylene terephthalate) resin, and is provided with terminals for connecting to wiring outside the device.

[0025] The power conversion device 100 also includes a die-cast member 6 to which the substrate 4 is attached and which is provided so as to cover the smoothing capacitor 2. The substrate 4 is fastened to the die-cast member 6 by a plurality of screws B1.

[0026] The die-cast member 6 is a metal housing produced by die-cast molding. The die-cast member 6 contains aluminum. The die-cast member 6 is an example of a "cover member" in the claims.

[0027] 3, a semiconductor module 7 is mounted (implemented) on the lower side (Z2 direction side) of the substrate 4. The semiconductor module 7 is mounted on the substrate 4 by soldering. The semiconductor module 7 houses semiconductor elements for power conversion (switching elements 1 and diode elements 3). The substrate 4 is also provided with electrical components such as capacitors and relays (not shown).

[0028] 3, a semiconductor module 7 (switching element 1) and a smoothing capacitor 2 are disposed on a surface 4a of the substrate 4 on the side of the internal space S1 between the die-cast member 6 and the substrate 4. The smoothing capacitor 2 and the semiconductor module 7 are disposed adjacent to each other in the X direction (the direction of the short side of the substrate 4). The smoothing capacitor 2 is disposed closer to the X1 direction than the semiconductor module 7. The semiconductor module 7 is attached (screwed) to the die-cast member 6 with screws B2. This fixes the substrate 4 to the die-cast member 6 via the semiconductor module 7 mounted on the substrate 4. The distance D1 in the X direction between the center of the smoothing capacitor 2 and the end of the substrate 4 on the X1 direction side is shorter (smaller) than the distance D2 in the X direction between the center of the smoothing capacitor 2 and the end of the semiconductor module 7 on the X1 direction side.

[0029] Additionally, cooling fins 61 for cooling the switching elements 1 are integrally provided on the outer surface 6a of the die-cast member 6. A plurality of cooling fins 61 are provided so as to protrude in the Z2 direction (downward). The power conversion device 100 is configured so that the plurality of cooling fins 61 dissipate heat from the semiconductor module 7 that houses the switching elements 1 and the diode elements 3.

[0030] The die-cast member 6 includes a recess 62 in which the smoothing capacitor 2 is disposed. A plurality of (two) smoothing capacitors 2 are disposed inside the recess 62, as shown in FIG.

[0031] 4, the power conversion device 100 also includes a flexurally deformable member 8 that is disposed in a flexibly deformed state between the smoothing capacitor 2 and the die-cast member 6. The flexurally deformable member 8 is a sheet-like insulating member. The flexurally deformable member 8 abuts against an outer end surface 2a of the smoothing capacitor 2 that is opposite to the surface that is disposed on the substrate 4.

[0032] The flexural deformation member 8 is made of, for example, polycarbonate. Note that the flexural deformation member 8 may also be made of a flexibly deformable (elastically deformable) material other than polycarbonate, such as PET (Polyethylene Terephthalate).

[0033] The flexurally deformable member 8 is made by pressing a base with an embedded blade such as a Thomson die against a sheet of a flexible material (such as polycarbonate or PET) to cut out (cut out) the required shape (a shape that can be bent within the recess 62). Therefore, the flexurally deformable member 8 in the first embodiment can be made more easily than when a component (resin component) is formed using a mold, as in injection molding, and the cost of making the mold can be reduced.

[0034] A sheet-like flexible member 8 is arranged in a flexible and deformed state between the smoothing capacitor 2 and the die-cast member 6 within the recess 62 of the die-cast member 6 so as to abut against the outer end surface 2a of the smoothing capacitor 2.

[0035] 4, the thickness T of the flexural deformation member 8 is smaller than the distance D3 in the Z direction between the outer end surface 2a of the smoothing capacitor 2 and the die-cast member 6 (inner bottom surface 62a). The flexural deformation member 8 is flexibly deformed within the recess 62 of the die-cast member 6 so as to be convex toward the outer end surface 2a of the smoothing capacitor 2 (Z1 direction side). As a result, a gap S2 (see FIG. 4) is formed between the die-cast member 6 (inner bottom surface 62a) and the flexural deformation member 8 below the outer end surface 2a of the smoothing capacitor 2 (Z2 direction side).

[0036] When the power conversion device 100 vibrates, the flexural deformation member 8 flexes and deforms while supporting the smoothing capacitor 2 (outer end surface 2 a), thereby suppressing deformation of the substrate 4 on which the smoothing capacitor 2 is mounted. In the first embodiment, when assembling the device, the sheet-like flexural deformation member 8 is disposed between the smoothing capacitor 2 and the die-cast member 6 so as to abut against the outer end surface 2 a of the smoothing capacitor 2. This allows the vibration of the smoothing capacitor 2 when the device vibrates to be directly absorbed by the flexural deformation of the sheet-like flexural deformation member 8, thereby effectively suppressing deformation of the substrate 4 on which the smoothing capacitor 2 is mounted. Therefore, unlike when a resin such as potting resin is filled between the smoothing capacitor 2 and the die-cast member 6, no time is required for the resin to harden, thereby suppressing an increase in the time required to assemble the device.

[0037] Furthermore, because the potting resin is liquid before hardening, using potting resin imposes restrictions on the direction of gravity. Furthermore, when using potting resin, when injecting the potting resin from a container filled with the potting resin around the smoothing capacitor 2, the container may interfere with components surrounding the smoothing capacitor 2, making it difficult to inject the potting resin into the desired location. In contrast, in the power conversion device 100 according to the first embodiment, during assembly, the sheet-like flexible deformation member 8 is simply placed (attached) between the smoothing capacitor 2 and the die-cast member 6 (in the recess 62) so as to abut against the outer end surface 2 a of the smoothing capacitor 2. Therefore, in the power conversion device 100 according to the first embodiment, as described above, restrictions on the direction of gravity that would occur when using potting resin and interference of the container filled with the potting resin with components surrounding the smoothing capacitor 2 do not occur. Therefore, in the power conversion device 100 according to the first embodiment, which uses a sheet-shaped flexible deformation member 8, unlike the case where potting resin is used, it is possible to suppress the deterioration in the ease of assembling the device caused by the constraints on the direction of gravity that occur when potting resin is used, and the interference of the container filled with potting resin with the components surrounding the smoothing capacitor 2.

[0038] Furthermore, unlike the power converter 100 according to the first embodiment, when a plastic member is attached to the substrate 4 and the smoothing capacitor 2 is fitted into the plastic member attached to the substrate 4 to support the periphery of the smoothing capacitor 2 while fixing the smoothing capacitor 2, high precision is required in the manufacture of each component and the mounting of the smoothing capacitor 2. For example, it is necessary to minimize misalignment of the holes (through holes) formed in the substrate 4 for mounting the smoothing capacitor 2, misalignment of the pins that occurs during the manufacture of the smoothing capacitor 2, misalignment (misalignment of the soldering) when the smoothing capacitor 2 is mounted on the substrate 4, and misalignment of the shape of the part of the plastic member into which the smoothing capacitor 2 is fitted (the fitting position of the smoothing capacitor 2). This increases the difficulty of manufacturing and assembling each component. In contrast, in the power converter 100 according to the first embodiment, during assembly, the sheet-like flexible member 8 is simply placed (mounted) between the smoothing capacitor 2 and the die-cast member 6 (in the recess 62) so as to abut against the outer end surface 2a of the smoothing capacitor 2. Therefore, in the power conversion device 100 according to the first embodiment, which uses a sheet-shaped flexible deformation member 8, a plastic member is attached to the substrate 4, and the smoothing capacitor 2 is fitted into the plastic member attached to the substrate 4, which makes it easier to assemble the device compared to the case where the smoothing capacitor 2 is fixed while the periphery of the smoothing capacitor 2 on the substrate 4 is supported.

[0039] Furthermore, in the power conversion device 100, the flexural deformation member 8 is configured to insulate the die-cast member 6 from the smoothing capacitor 2 in a flexurally deformed state.

[0040] Also, as shown in Figure 5, the width W1 in the Y direction of the inner bottom surface 62a of the die-cast member 6 facing the outer end surface 2a of the smoothing capacitor 2 is smaller (narrower) than the width W2 in the Y direction of the flexible deformation member 8 before it is placed between the outer end surface 2a of the smoothing capacitor 2 and the inner bottom surface 62a of the die-cast member 6 (before it bends).

[0041] The power conversion device 100 also includes an engagement portion A that engages the flexural deformation member 8 with the die-cast member 6. The engagement portion A includes protrusions 8a and 8b that are provided on the flexural deformation member 8 so as to protrude toward the die-cast member 6, and holes 9a and 9b that are provided in the die-cast member 6. The protrusions 8a and 8b are fitted into the holes 9a and 9b, respectively.

[0042] The protrusions 8a and 8b are provided so as to protrude from the Y1-direction end and the Y2-direction end, respectively, of a main body 8c (see FIG. 5) of the flexural deformation member 8. The protrusions 8a and 8b are formed integrally with the main body 8c.

[0043] Furthermore, on the X2-direction side of inner wall surface 62b of recess 62, inner wall surface 62c (see FIG. 5) adjacent to inner wall surface 62b is formed in an arc shape when viewed from the Z1-direction side. Furthermore, inner wall surfaces 62b and 62e (see FIG. 5) of recess 62 are formed linearly along the X-direction and are disposed so as to sandwich inner bottom surface 62a in the Y-direction. Furthermore, inner wall surfaces 62d and 62f (see FIG. 5) of recess 62 are formed linearly along the Y-direction and are disposed so as to sandwich inner bottom surface 62a in the X-direction. Furthermore, main body 8c of flexural deformation member 8 is formed along inner wall surfaces 62b to 62f of recess 62.

[0044] 5, the width W3 in the Y direction of the inner bottom surface 62a of the recess 62 on the semiconductor module 7 side (X2 direction side) (the distance between the inner wall surface 62b and the inner wall surface 62e of the recess 62) is smaller (narrower) than the width W4 in the Y direction of the main body 8c of the flexural deformation member 8 (the portion of the flexural deformation member 8 excluding the protrusions 8a and 8b) before being placed (before deflection) between the outer end surface 2a of the smoothing capacitor 2 and the inner bottom surface 62a of the die-cast member 6. The amount of deflection of the flexural deformation member 8 is determined by the dimensions of the widths W3 and W4. The amount of deflection of the flexural deformation member 8 is related to the force supporting the smoothing capacitor 2 from below (the Z2 direction side). The amount of deflection of the flexural deformation member 8 (the dimensions of widths W3 and W4) is determined so as to achieve a balance between the predetermined stress acting on the smoothing capacitor 2, taking into account the load on the substrate 4, and the repulsive force generated according to the amount of deflection of the flexural deformation member 8.

[0045] 6, the hole 9a is provided on the inner bottom surface 62a side (Z2 direction side) of the recess 62 so as to penetrate an inner wall surface 62b on the Y1 direction side corresponding to the protrusion 8a. The hole 9a is provided below the smoothing capacitor 2 (Z2 direction side).

[0046] 7, hole 9b is provided on the inner bottom surface 62a side (Z2 direction side) of recess 62 so as to penetrate an inner wall surface 62e on the Y2 direction side corresponding to protrusion 8b. Hole 9b is provided below smoothing capacitor 2 (Z2 direction side). Also, as shown in FIG. 8, inner wall surface 62c is provided along the outer diameter shape of smoothing capacitor 2, which has a cylindrical shape.

[0047] The flexural deformation member 8 is disposed between the die-cast member 6 and the smoothing capacitor 2 so as to be engaged with the die-cast member 6 by the engagement portion A (see FIG. 8) and to be in a flexibly deformed state (see FIG. 4) and to be in contact with the outer end surface 2a of the smoothing capacitor 2. That is, the flexural deformation member 8 is disposed between the die-cast member 6 and the smoothing capacitor 2 in a flexibly deformed state (see FIG. 4) so ​​as to be in contact with the outer end surface 2a of the smoothing capacitor 2 by fitting the protrusions 8a and 8b into the holes 9a and 9b, respectively.

[0048] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0049] The first embodiment includes a substrate 4 on which a smoothing capacitor 2 is mounted, and a die-cast member 6 to which the substrate 4 is attached and which is provided so as to cover the smoothing capacitor 2. A sheet-like flexible member 8 is disposed between the smoothing capacitor 2 and the die-cast member 6 in a flexible state so as to abut against an outer end surface 2a of the smoothing capacitor 2 opposite the surface on which the substrate 4 is mounted. This allows the flexible member 8 to support the smoothing capacitor 2 in a flexible state, which, unlike a case in which deformation of the substrate 4 is suppressed only by fixing the substrate 4, directly absorbs vibrations of the smoothing capacitor 2 when the device vibrates. As a result, deformation caused by vibrations of the substrate 4 on which the smoothing capacitor 2 is mounted can be effectively suppressed. Furthermore, because the flexible member 8 is a sheet-like member, it can be easily bent and disposed between the smoothing capacitor 2 and the die-cast member 6 during assembly. Furthermore, simply placing the sheet-like flexible member 8 between the smoothing capacitor 2 and the die-cast member 6 during assembly effectively suppresses deformation caused by vibration of the substrate 4 on which the smoothing capacitor 2 is mounted. Therefore, unlike when potting resin is used to suppress deformation of the substrate 4, no time is required for the potting resin to harden. As a result, unlike when the smoothing capacitor 2 is fixed using hardened potting resin, an increase in the time required to assemble the device can be suppressed. Furthermore, since only the sheet-like flexible member 8 needs to be placed between the smoothing capacitor 2 and the die-cast member 6 during assembly, device assembly can be simplified compared to when the periphery of the smoothing capacitor 2 on the substrate 4 is supported while the smoothing capacitor 2 is fixed by fitting the smoothing capacitor 2 into a plastic member attached to the substrate 4. As a result, damage caused by vibration of the substrate 4 on which the smoothing capacitor 2 is mounted can be prevented while suppressing deterioration in device assembly.

[0050] Furthermore, in the first embodiment, as described above, the die-cast member 6 includes the recess 62 inside which the smoothing capacitor 2 is disposed. The flexurally deformable member 8 is disposed in a flexibly deformed state between the smoothing capacitor 2 and the die-cast member 6 within the recess 62 of the die-cast member 6 so as to abut against the outer end surface 2a of the smoothing capacitor 2. As a result, the flexurally deformable member 8 is disposed within the recess 62 of the die-cast member 6, and therefore, during assembly, the position of the flexurally deformable member 8 can be aligned using the inner wall surface (inner wall surfaces 62b to 62f) of the recess 62. As a result, the device can be easily assembled.

[0051] In the first embodiment, as described above, the die-cast member 6 is a metal housing, and the flexurally deformable member 8 is an insulating member. The substrate 4 is configured so that the switching element 1 and the smoothing capacitor 2 are disposed on the surface 4a of the substrate 4 that faces the internal space S1 between the die-cast member 6 and the substrate 4. The flexurally deformable member 8 is configured to insulate the die-cast member 6 from the smoothing capacitor 2 in a flexibly deformed state. This allows the die-cast member 6 and the smoothing capacitor 2 to be insulated from each other by the insulating flexurally deformable member 8, thereby making the distance between the outer end surface 2a of the smoothing capacitor 2 and the die-cast member 6 shorter than the insulation distance (air insulation distance) when insulation is achieved by air. As a result, an increase in the device size can be suppressed in the Z direction in which the substrate 4 and the die-cast member 6 face each other.

[0052] Furthermore, in the first embodiment, as described above, the cooling fins 61 for cooling the switching elements 1 are integrally provided on the outer surface 6a of the die-cast member 6. This makes it possible to cool the switching elements 1 (semiconductor modules 7) by the cooling fins 61 while suppressing an increase in the number of parts and assembly steps, unlike when the cooling fins 61 are configured separately from the die-cast member 6.

[0053] Furthermore, in the first embodiment, as described above, the widths W1 and W3 in the Y direction of the inner bottom surface 62a of the die-cast member 6 facing the outer end surface 2a of the smoothing capacitor 2 are smaller than the widths W2 and W4 in the Y direction of the flexural member 8 before being placed (before being deflected) between the outer end surface 2a of the smoothing capacitor 2 and the inner bottom surface 62a of the die-cast member 6. As a result, when the flexural member 8 is placed between the outer end surface 2a of the smoothing capacitor 2 and the inner bottom surface 62a of the die-cast member 6, the flexural member 8 is deflected to match the widths W1 and W3 in the Y direction of the inner bottom surface 62a. As a result, the flexural member 8 can be easily placed between the outer end surface 2a of the smoothing capacitor 2 and the inner bottom surface 62a of the die-cast member 6 in a deflected state.

[0054] Furthermore, in the first embodiment, as described above, the power conversion device 100 includes an engagement portion A that engages the flexural deformation member 8 with the die-cast member 6. The flexural deformation member 8 is disposed between the die-cast member 6 and the smoothing capacitor 2 so as to abut against the outer end surface 2a of the smoothing capacitor 2 while engaged with the die-cast member 6 by the engagement portion A and while in a flexibly deformed state. This allows the flexural deformation member 8 and the die-cast member 6 to be engaged with each other by the engagement portion A, so that the flexural deformation member 8 can be easily fixed between the die-cast member 6 and the smoothing capacitor 2 so as to abut against the outer end surface 2a of the smoothing capacitor 2. As a result, the power conversion device 100 can be easily assembled.

[0055] Furthermore, in the first embodiment, as described above, the engaging portion A includes protrusions 8a and 8b provided on the flexurally deformable member 8 and holes 9a and 9b provided in the die-cast member 6. The flexurally deformable member 8 is disposed in a flexibly deformed state between the die-cast member 6 and the smoothing capacitor 2 so as to abut against the outer end surface 2a of the smoothing capacitor 2 by fitting the protrusions 8a and 8b into the holes 9a and 9b, respectively. This allows the flexurally deformable member 8 and the die-cast member 6 to be easily engaged with each other by fitting the protrusions 8a and 8b into the holes 9a and 9b, respectively. Therefore, the flexurally deformable member 8 can be easily fixed between the die-cast member 6 and the smoothing capacitor 2 so as to abut against the outer end surface 2a of the smoothing capacitor 2. As a result, the power conversion device 100 can be easily assembled.

[0056] [Second embodiment] Next, a configuration according to a second embodiment of the present invention will be described with reference to FIGS.

[0057] Unlike the first embodiment, which includes an engagement portion A that engages the die-cast member 6 and the flexural deformation member 8, the second embodiment does not include an engagement portion A, and instead, a flexural deformation member 208 (see FIGS. 9 and 10) is disposed between a die-cast member 206 (see FIGS. 11 and 12) and the outer end surface 2a of the smoothing capacitor 2. That is, in the second embodiment, the die-cast member 206 and the flexural deformation member 208 are not engaged with each other.

[0058] 9 and 10, the flexural deformation member 208 includes folded portions 208a and 208b that are folded back from an end in the X direction along the surface (front surface 4a) of the substrate 4 on which the smoothing capacitor 2 is mounted toward the outer end surface 2a (see FIG. 12) of the smoothing capacitor 2. The folded portions 208a and 208b are provided at both ends of the flexural deformation member 208 in the X direction. Specifically, the folded portion 208a is provided at the end of the flexural deformation member 208 on the X1 direction side, and the folded portion 208b is provided at the end of the flexural deformation member 208 on the X2 direction side. The folded portion 208a is formed at the end of the flexural deformation member 208 on the X1 direction side so as to extend upward (toward the Z1 direction) and spread outward (toward the X1 direction), and then bends inward (toward the X2 direction) at a corner C1 (see FIG. 10). Furthermore, the folded portion 208b is formed so as to extend upward (toward the Z1 direction) at the end of the bending deformation member 208 on the X2 direction side so as to spread outward (toward the X2 direction), and then bend inward (toward the X1 direction) at the corner C2 (see Figure 10).

[0059] 11, end E1 of folded portion 208a and end E2 of folded portion 208b are spaced apart from each other. Distance D4 between end E1 of folded portion 208a and end E2 of folded portion 208b is smaller than width W5 of smoothing capacitor 2 in the X direction. Folded portions 208a and 208b are provided at positions corresponding to smoothing capacitor 2. As shown in FIGS. 11 and 12, folded portions 208a and 208b are provided so as to overlap with smoothing capacitor 2 when viewed from the Z1 direction or the Z2 direction. When smoothing capacitor 2 presses on flexural deformation member 208 from above (Z1 direction), the position of flexural deformation member 208 is fixed within recess 262.

[0060] 12, the folded portions 208a and 208b abut against the outer end surface 2a of the smoothing capacitor 2. When the folded portions 208a and 208b abut against the outer end surface 2a of the smoothing capacitor 2, the folded portions 208a and 208b are bent downward (toward the Z2 direction) with the corners C1 and C2 abutting against the inner wall surfaces 262f and 262d of the recess 262, respectively.

[0061] Furthermore, in the second embodiment, unlike the first embodiment, no through holes (holes 9a and 9b) are provided in the die-cast member 206, so that it is possible to prevent foreign matter such as water from entering from the outer surface 206a side of the die-cast member 206.

[0062] The other configurations are the same as those of the first embodiment.

[0063] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0064] In the second embodiment, similarly to the first embodiment, it is possible to prevent damage caused by vibrations to the substrate 4 on which the smoothing capacitor 2 is mounted, while suppressing a decrease in the ease of assembly of the device.

[0065] Furthermore, in the second embodiment, as described above, the flexural deformation member 208 is folded back toward the outer end surface 2a of the smoothing capacitor 2 at its end in the X direction along the surface (front surface 4a) of the substrate 4 on which the smoothing capacitor 2 is mounted, and includes folded-back portions 208a and 208b that abut against the outer end surface 2a of the smoothing capacitor 2. This allows the folded-back portions 208a and 208b of the flexural deformation member 208, which are disposed between the die-cast member 6 and the smoothing capacitor 2, to support the outer end surface 2a of the smoothing capacitor 2. As a result, since the folded-back portions 208a and 208b support the outer end surface 2a of the smoothing capacitor 2 in a flexibly deformed state, vibrations of the smoothing capacitor 2 caused by device vibrations can be directly absorbed by the flexural deformation of the folded-back portions 208a and 208b, unlike when deformation of the substrate 4 is suppressed only by fixing the substrate 4. This effectively suppresses deformation of the substrate 4 on which the smoothing capacitor 2 is mounted due to vibration.

[0066] Furthermore, in the second embodiment, as described above, folded portions 208a and 208b are provided on both ends of flexural deformation member 8 in the X direction along the surface (front surface 4a) of substrate 4 on which smoothing capacitor 2 is mounted. This makes it possible to support outer end surface 2a of smoothing capacitor 2 from both ends of flexural deformation member 8 in the X direction along the surface of substrate 4 on which smoothing capacitor 2 is mounted, unlike when folded portions are provided only on one end in the X direction along the surface of substrate 4 on which smoothing capacitor 2 is mounted (front surface 4a). As a result, smoothing capacitor 2 can be supported in a balanced manner by folded portions 208a and 208b, and deformation due to vibration of substrate 4 on which smoothing capacitor 2 is mounted can be effectively suppressed.

[0067] Other effects are the same as those of the first embodiment.

[0068] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0069] For example, in the first embodiment, the die-cast member 6 (cover member) is a metal housing, but the present invention is not limited to this. For example, the cover member may be formed of a non-metallic member, and the non-metallic cover member may be covered by a metal housing.

[0070] Furthermore, in the first embodiment, an example was shown in which the insulating flexural deformation member 8 insulates the die-cast member 6 (cover member) and the smoothing capacitor 2 in a flexibly deformed state, but the present invention is not limited to this. In the present invention, the flexural deformation member does not have to be an insulating member. In addition, in the present invention, an insulating member may be disposed between the non-insulating flexural deformation member and the cover member, or an insulating member may be disposed between the non-insulating flexural deformation member and the smoothing capacitor.

[0071] In the first embodiment, the cooling fins 61 for cooling the switching elements 1 are integrally provided on the outer surface 6a of the die-cast member 6 (cover member), but the present invention is not limited to this. In the present invention, the cooling fins may be provided separately from the cover member.

[0072] Furthermore, in the above first embodiment, an example was shown in which the width W1 in the Y direction of the inner bottom surface 62a of the die-cast member 6 (cover member) facing the outer end surface 2a of the smoothing capacitor 2 is smaller than the width W2 in the Y direction of the flexural deformation member 8 before (before bending) being placed between the outer end surface 2a of the smoothing capacitor 2 and the inner bottom surface 62a of the die-cast member 6, but the present invention is not limited to this. In the present invention, the width of the inner bottom surface of the cover member facing the outer end surface of the smoothing capacitor may be larger than the width of the flexural deformation member before being placed between the outer end surface of the smoothing capacitor and the inner bottom surface of the cover member, or may be approximately the same as the width of the flexural deformation member before being placed between the outer end surface of the smoothing capacitor and the inner bottom surface of the cover member.

[0073] In the first embodiment, the engaging portion A includes the holes 9a and 9b that penetrate the inner wall surfaces 62b and 62c of the die-cast member 6 (cover member), respectively, but the present invention is not limited to this. In the present invention, the engaging portion may be a recess that does not penetrate the cover member, instead of a hole that penetrates the inner wall surface of the cover member, and may be provided in correspondence with the protrusion.

[0074] Furthermore, in the first embodiment described above, an example was shown in which engagement portion A includes protrusions 8a and 8b provided on flexural deformation member 8 and holes 9a and 9b provided on die-cast member 6 (cover member), but the present invention is not limited to this. In the present invention, as in die-cast member 306 shown in a modified example in FIG. 13 , support portions 363 that protrude toward smoothing capacitor 2 may be provided on each of the inner walls (inner wall surfaces 362f and 362d) on the X1 and X2 direction sides of recess 362 of die-cast member 306. The edges of flexural deformation member 308 may be configured to be supported by support portions 363.

[0075] In the first embodiment, the engaging portion A includes the protrusions 8a and 8b provided on the flexural deformation member 8 and the holes 9a and 9b provided on the die-cast member 6 (cover member), but the present invention is not limited to this. In the present invention, holes may be provided on the flexural deformation member, and protrusions may be provided on the cover member that protrude into the holes in the flexural deformation member.

[0076] In the second embodiment, the folded portions 208a and 208b are provided at both ends (the ends in the X1 direction and the X2 direction) of the bending deformation member 8, but the present invention is not limited to this. In the present invention, the folded portions may be provided only at the end on one side (the X1 direction or the X2 direction) in the direction along the surface of the substrate on which the smoothing capacitor is mounted. [Explanation of symbols]

[0077] 1 Switching element 2 smoothing capacitors 2a (Smoothing capacitor) outer end face 4 boards 4a (substrate) surface 6, 206, 306 Die-cast parts (cover parts) 6a, 206a (of die-cast parts) outer surface 8, 208, 308 Flexural deformation members 8a, 8b protrusion 9a, 9b holes 61 Cooling fin 62, 262, 362 recesses 62a inner bottom 100 Power conversion device 208a, 208b Folded portion A Engagement part S1 interior space W1, W3 (inner bottom) width W2, W4 (flexural member) width

Claims

1. A switching element; a smoothing capacitor that smoothes the current flowing through the switching element; a circuit board on which the smoothing capacitor is mounted; a cover member to which the circuit board is attached and which is provided so as to cover the smoothing capacitor; A power conversion device comprising: a sheet-shaped flexible deformation member that is arranged in a flexible and deformed state between the smoothing capacitor and the cover member so as to abut against an outer end surface of the smoothing capacitor opposite to the surface that is placed on the circuit board.

2. the cover member includes a recess in which the smoothing capacitor is disposed, 2. The power conversion device according to claim 1, wherein the flexible deformation member is disposed in a flexible and deformed state between the smoothing capacitor and the cover member within the recess of the cover member so as to abut against the outer end surface of the smoothing capacitor.

3. the cover member is a metal housing, the flexible deformation member is an insulating member, the switching element and the smoothing capacitor are arranged on a surface of the circuit board facing an internal space between the metal housing and the circuit board, The power conversion device according to claim 1 , wherein the flexural deformation member is configured to insulate the metal housing from the smoothing capacitor in a flexurally deformed state.

4. The power conversion device according to claim 3 , wherein cooling fins for cooling the switching elements are integrally provided on an outer surface of the metal housing.

5. A power conversion device as described in any one of claims 1 to 4, wherein the width of the inner bottom surface of the cover member facing the outer end surface of the smoothing capacitor is smaller than the width of the flexible deformation member before being placed between the outer end surface of the smoothing capacitor and the inner bottom surface of the cover member.

6. an engaging portion that engages the deflection member with the cover member; 6. The power conversion device according to claim 5, wherein the flexible deformation member is disposed between the cover member and the smoothing capacitor so as to abut the outer end surface of the smoothing capacitor when engaged with the cover member by the engaging portion and when in a flexible deformation state.

7. the engaging portion includes a protruding portion provided on one of the flexible deformation member or the cover member so as to protrude toward the other of the flexible deformation member or the cover member, and a hole portion provided on one of the flexible deformation member or the cover member and into which the protruding portion is fitted, 7. The power conversion device according to claim 6, wherein the flexible deformation member is arranged in a flexible and deformed state between the cover member and the smoothing capacitor so as to abut against the outer end surface of the smoothing capacitor by fitting the protrusion into the hole.

8. The power conversion device according to any one of claims 1 to 4, wherein the flexible deformation member is folded back toward the outer end surface of the smoothing capacitor at at least one end in a direction along the surface of the circuit board on which the smoothing capacitor is mounted, and includes a folded back portion that abuts against the outer end surface of the smoothing capacitor.

9. The power conversion device according to claim 8 , wherein the folded portion is provided on each of both ends of the deformation member in a direction along a surface of the circuit board on which the smoothing capacitor is mounted.

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