Power conversion device

Abstract

To provide a power conversion device including a fixing plate capable of fixing a control board without scattering metal powder to a power conversion part.SOLUTION: The power conversion device includes a power conversion unit 101, a control board 50 on which a control unit 51 that controls the power conversion unit 101 is disposed, and a fixing plate 60 that is disposed between the power conversion unit 101 and the control board 50 and fixes the control board 50 by a screw N1, wherein the fixing plate 60 includes a metal caulking nut 1 and an insert nut 2 to which the screw N1 is fastened and which are closed without having an opening in a Z2 direction that is a side on which the power conversion unit 101 is disposed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a power converter, and more particularly to a power converter including a fixing plate disposed between a semiconductor module and a control board to which the control board is fixed. [Background technology]

[0002] BACKGROUND ART Conventionally, a power conversion device including a semiconductor module and a control board has been known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a power conversion device including a semiconductor module including a switching element, a control board that controls power conversion, and a metal storage case. The power conversion device of Patent Document 1 houses the semiconductor module and the control board inside the storage case. Furthermore, the power conversion device of Patent Document 1 includes a metal board plate provided between the semiconductor module and the control board inside the storage case. The control board is fixed to the board plate using fastening members. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-014730 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in Patent Document 1, a control board is fixed to a board plate using fastening members. When fastening members such as screws into screw holes, the screw holes and fastening members rub against each other, causing wear on the fastening members and the screw holes, which can generate metal powder. Although not explicitly stated in Patent Document 1, if the screw holes are through-holes, metal powder may escape from the through-holes and scatter onto and adhere to semiconductor modules and other devices arranged nearby. This can cause electrical conduction in unintended parts of the semiconductor modules due to the adhering metal powder, resulting in failure of the semiconductor modules (power conversion units). Therefore, there is a need for a power conversion device that includes a fixing plate that fixes the control board without scattering metal powder onto the power conversion units.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device equipped with a fixing plate that can fix a control board without scattering metal powder into the power conversion section. [Means for solving the problem]

[0007] In order to achieve the above object, a power conversion device according to one aspect of the present invention comprises a power conversion unit, a control board on which a control unit that controls the power conversion unit is arranged, and a fixing plate that is arranged between the power conversion unit and the control board and fixes the control board with a fastening screw member, and the fixing plate includes a metal nut member to which the fastening screw member is fastened and which is closed without an opening on the side on which the power conversion unit is arranged.

[0008] In the power conversion device according to the above aspect, as described above, the fixing plate includes a metal nut member to which the fastening screw member is fastened and which has a closed side on which the power conversion unit is disposed without having an opening. This prevents metal powder generated by friction between the fastening screw member and the metal nut member from escaping from the closed side on which the power conversion unit is disposed. As a result, it is possible to provide a power conversion device including a fixing plate that can fix the control board without scattering metal powder onto the power conversion unit.

[0009] In the power conversion device according to the above aspect, the fixing plate preferably includes a metal plate portion and an insulating cover portion having insulating properties and covering the metal plate portion. With this configuration, the fixing plate includes a metal plate portion having a relatively high rigidity, thereby suppressing distortion of the fixing plate. Furthermore, since the fixing plate includes an insulating cover portion having insulating properties and covering the metal plate portion, insulation can be easily achieved even when a control board, a power conversion unit, etc. are disposed near the fixing plate.

[0010] In this case, preferably, a first nut member, which is a separate part from the metal plate portion and serves as a nut member, is fixed to the metal plate portion of the fixing plate, and a second nut member, which is a separate part from the insulating cover portion and serves as a nut member, is fixed to the insulating cover portion of the fixing plate. This configuration allows the first nut member and the second nut member to be used appropriately depending on the material to be fixed. Furthermore, because the first nut member is a separate part from the metal plate portion and the second nut member is a separate part from the insulating cover portion, there is no need to process the nuts on the metal plate portion and the resin cover portion, making manufacturing easier.

[0011] In the power conversion device in which the first nut member and the second nut member are fixed to the fixing plate, preferably, the fixing plate has a first nut member with an exposed surface on the side where the power conversion unit is located arranged at a position where the distance between the fixing plate and the power conversion unit is equal to or greater than a predetermined value in the stacking direction in which the power conversion unit and the fixing plate overlap, and a second nut member with at least a portion of its surface on the side where the power conversion unit is located covered by an insulating cover arranged at a position where the distance between the fixing plate and the power conversion unit is less than the predetermined value in the stacking direction. With this configuration, the first nut member with an exposed surface on the side where the power conversion unit is located is arranged at a position where the distance between the fixing plate and the power conversion unit is equal to or greater than the predetermined value in the stacking direction, thereby reducing the amount of insulating material used. Furthermore, in the stacking direction, a second nut member having at least a portion of its surface on the side where the power conversion unit is located covered by an insulating cover member is positioned at a position where the distance between the fixing plate and the power conversion unit is less than a predetermined value.Therefore, since the distance between the second nut member and the power conversion unit is short, electrical conduction between the second nut member and the power conversion unit can be prevented.

[0012] In the power conversion device in which the first nut member and the second nut member are fixed to the fixing plate, the first nut member is preferably fixed to the metal plate portion by crimping or press-fitting the metal plate portion. With this configuration, the first nut member, which is a separate part from the metal plate portion, can be reliably fixed to the metal plate portion without using a separate joining material such as an adhesive.

[0013] In the power converter in which the first nut member and the second nut member are fixed to the fixing plate, the second nut member is preferably fixed to the insulating cover portion by insert molding. With this configuration, the second nut member can be incorporated at the same time as the insulating cover portion of the fixing plate is manufactured (for example, during resin molding) without a separate process of combining the second nut member with the fixing plate including the insulating cover portion, thereby simplifying the manufacturing process of the fixing plate.

[0014] In the power conversion device in which the first nut member and the second nut member are fixed to the fixing plate, the second nut member preferably has a boss shape that functions as a spacer that separates the control board and the insulating cover portion by a predetermined distance. With this configuration, even if it is desired to insulate the control board from the metal plate portion included in the fixing plate at a portion other than the second nut member, the second nut member has a boss shape that functions as a spacer, so the control board and the insulating cover portion can be separated by a predetermined distance. As a result, the control board and the metal plate portion included in the fixing plate can be insulated. [Effects of the Invention]

[0015] According to the present invention, as described above, it is possible to provide a power conversion device including a fixing plate that can fix a control board without scattering metal powder onto a power conversion section. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a circuit configuration of a power conversion device according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating an entire power conversion device according to an embodiment. [Figure 3] FIG. 3 is a diagram illustrating a flow of a cooling liquid outside a power conversion device according to an embodiment. [Figure 4] 1 is a perspective view of a power converter according to an embodiment; [Figure 5] FIG. 2 is an exploded perspective view showing the power conversion device with a control board and a fixing plate removed. [Figure 6] FIG. 2 is a perspective view showing a metal plate portion and a crimp nut included in the fixing plate. [Figure 7] FIG. 10 is a perspective view showing a resin cover and an insert nut included in the fixing plate. [Figure 8] 8 is a cross-sectional view of the power converter taken along line VIII-VIII in FIG. 4. [Figure 9] 9 is a partially enlarged cross-sectional view of the power converter shown in FIG. 8. FIG. [Figure 10] 9 is a cross-sectional view of the power converter taken along line IX-IX in FIG. [Figure 11] 11 is a partially enlarged cross-sectional view of the power converter shown in FIG. 10. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0018] The configuration of a power conversion device 100 according to one embodiment of the present invention will be described with reference to Figures 1 to 9. The power conversion device 100 is mounted on a vehicle, for example.

[0019] (Overall configuration of power conversion device) The overall configuration of a power conversion device 100 according to one embodiment of the present invention will be described with reference to FIGS.

[0020] First, the circuit configuration of a power conversion device 100 will be described with reference to Fig. 1. The power conversion device 100 includes an inverter unit 10 and a converter unit 20. The inverter unit 10, the converter unit 20, and the wiring connecting these units together are referred to as a power conversion unit 101.

[0021] The inverter unit 10 converts the DC power transformed by the converter unit 20 into AC power and supplies it to a load 210. The load 210 is, for example, a motor. A switch 201 is provided between the power conversion device 100 and the DC power supply 200.

[0022] In the power conversion device 100, the inverter unit 10 includes a semiconductor module 11. The semiconductor module 11 includes semiconductor switching elements Q1 to Q6. The semiconductor module 11 includes a switching element module 111 and a switching element module 112 that convert DC power to AC power. Each of the switching element modules 111 and 112 includes semiconductor switching elements Q1, Q2, and Q3 that form an upper arm, and semiconductor switching elements Q4, Q5, and Q6 that form a lower arm.

[0023] The load 210 includes a load 210a and a load 210b. The switching element module 111 converts DC power input from the DC power supply 200 into AC power and supplies it to the load 210a. The switching element module 112 converts DC power input from the DC power supply 200 into AC power and supplies it to the load 210b.

[0024] The power conversion device 100 also includes a current sensor 30 that detects the value of a current supplied from the semiconductor module 11 to a load 210 external to the device. The current sensor 30 includes a current sensor 31 and a current sensor 32. The current sensors 31 and 32 are provided corresponding to the switching element modules 111 and 112, respectively. The current sensor 31 is provided between the switching element module 111 and the load 210a. The current sensor 32 is provided between the switching element module 112 and the load 210b.

[0025] The converter unit 20 transforms DC power input from the DC power supply 200. The converter unit 20 includes a boost converter unit 21 and a DC-DC converter unit 22.

[0026] The boost converter unit 21 is disposed on the input side of the inverter unit 10. The boost converter unit 21 boosts the DC power input from the DC power supply 200 and supplies the boosted power to the inverter unit 10. The boost converter unit 21 includes a boost switching element module 21a and a reactor 21b. The boost switching element module 21a includes boost switching elements Q11 and Q12. The boost switching elements Q11 and Q12 form an upper arm and a lower arm, respectively. The boost converter unit 21 also includes a capacitor C1. The reactor 21b is disposed between the positive side of the DC power supply 200 and the connection point between the boost switching element Q11 and the boost switching element Q12. The capacitor C1 is disposed in parallel with the boost switching element Q12.

[0027] The operation of the semiconductor switching elements Q1, Q2, Q3, Q4, Q5, and Q6 is controlled by a control unit 51 mounted on a control board 50. At least one of the semiconductor switching elements Q1, Q2, Q3, Q4, Q5, and Q6 and the boost switching elements Q11 and Q12 is a wide bandgap semiconductor element.

[0028] The power conversion device 100 also includes a smoothing capacitor C2 and a resistor R. The smoothing capacitor C2 and the resistor R are provided between the boost converter unit 21 and the inverter unit 10. The smoothing capacitor C2 and the resistor R are provided in parallel with each other.

[0029] The DC-DC converter unit 22 converts the voltage of the DC power into a different voltage. Specifically, the DC-DC converter unit 22 steps down the voltage of the DC power input from the DC power supply 200 via the connector 20a. The DC-DC converter unit 22 also supplies the stepped-down voltage to the output terminal 20b.

[0030] Next, the structure of the power conversion device 100 will be described.

[0031] As shown in FIG. 2, the power conversion device 100 includes a base unit 40, a control board 50, and a fixing plate 60.

[0032] Herein, the direction in which the control board 50 and the fixed plate 60 are stacked is defined as the Z direction. One side and the other side in the Z direction are defined as the Z1 direction and the Z2 direction, respectively. The base unit 40, the control board 50, and the fixed plate 60 have a rectangular shape when viewed from the Z1 direction or the Z2 direction. The longitudinal direction of the base unit 40, the control board 50, and the fixed plate 60 when viewed from the Z1 direction or the Z2 direction is defined as the X direction. One side and the other side in the X direction are defined as the X1 direction and the X2 direction, respectively. The direction perpendicular to both the X direction and the Z direction (the short-side direction of the base unit 40, the control board 50, and the fixed plate 60) is defined as the Y direction. One side and the other side in the Y direction are defined as the Y1 direction and the Y2 direction, respectively. The Z direction is an example of a "stacking direction" in the claims.

[0033] The base unit 40 is disposed between the inverter unit 10 and the converter unit 20 in the Z direction. That is, the switching element module 111 and the switching element module 112 that constitute the inverter unit 10, and the boost converter unit 21 and the DC-DC converter unit 22 are disposed so as to sandwich the base unit 40 in the Z direction.

[0034] The switching element module 111 and the switching element module 112 are arranged on the Z1 direction side of the base part 40. Furthermore, the switching element module 111 and the switching element module 112 are arranged adjacent to each other along the longitudinal direction (X direction) of the base part 40.

[0035] The boost converter unit 21 and the DC-DC converter unit 22 are disposed on the Z2 direction side of the flat base unit 40. The boost converter unit 21 is disposed adjacent to the DC-DC converter unit 22 in the X direction. The boost converter unit 21 is disposed on the X2 direction side of the DC-DC converter unit 22.

[0036] The DC-DC converter unit 22 includes a DC-DC converter element 221 and a converter board 222. The DC-DC converter element 221 includes a converter switching element 22a, a transformer 22b, a resonant reactor 22c, a smoothing reactor 22d, and a diode element 22e. The power conversion device 100 is configured to convert the voltage of DC power input from the DC power supply 200 into a different voltage using the DC-DC converter element 221 included in the DC-CDC converter unit 22. The DC-DC converter element 221 is mounted on the converter board 222. The converter board 222 is formed in a flat plate shape. The converter board 222 is a printed circuit board (PCB) on which the DC-DC converter element 221 is mounted. The converter board 222 is disposed to face the base unit 40.

[0037] The control board 50 is disposed on the opposite side of the semiconductor module 11 from the side on which the base part 40 is disposed (the Z1 direction side of the semiconductor module 11). The control board 50 is formed in a flat plate shape. The control board 50 includes, for example, a CPU (Central Processing Unit) as a processor, a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and includes a control unit 51 (see FIG. 1) that controls power conversion by the semiconductor switching elements Q1 to Q6 by executing a program (software). The control board 50 is a printed circuit board to which a control terminal 11a (see FIG. 5) of the semiconductor module 11, which will be described later, is connected.

[0038] 2, the fixing plate 60 is disposed between the semiconductor module 11 and the control board 50 in the Z direction. The control board 50 is fixed to the fixing plate 60. Details of the fixing plate 60 will be described later.

[0039] (Configuration of cooling flow path) Here, the cooling configuration will be described. The base unit 40 has a cooling flow path 410 therein. In this embodiment, the cooling flow path 410 includes an inverter-side flow path 411, a connection flow path 412, and a converter-side flow path 413.

[0040] The inverter-side flow path 411 is provided on the inverter unit 10 side (Z1 direction side) of the base unit 40. The inverter unit 10 arranged on the Z1 direction side of the base unit 40 is cooled by the cooling liquid flowing through the inverter-side flow path 411. Specifically, the switching element modules 111 and 112 are cooled by the cooling liquid flowing through the inverter-side flow path 411. The inverter-side flow path 411 is connected to the converter-side flow path 413 via a connection flow path 412.

[0041] The converter-side flow path 413 is provided on the converter unit 20 side (Z2 direction side) of the base unit 40. The converter unit 20 (boost converter unit 21 and DC-DC converter unit 22) arranged on the Z2 direction side of the base unit 40 is cooled by the cooling liquid flowing through the converter-side flow path 413. Specifically, the boost switching element module 21a, the reactor 21b, and the DC-DC converter element 221 are cooled by the cooling liquid flowing through the converter-side flow path 413.

[0042] In the cooling flow path 410, the inverter side flow path 411 and the converter side flow path 413 are connected by a connection flow path 412 so that the cooling liquid passes through the inverter side flow path 411 and then through the converter side flow path 413. As a result, the inverter unit 10 is cooled by the cooling liquid flowing through the inverter side flow path 411, and then the converter unit 20 is cooled by the cooling liquid flowing through the converter side flow path 413.

[0043] The connection flow path 412 is disposed on one end side (X1 direction side) in the X direction along which the base unit 40 extends. The base unit 40 also has an inlet 410a through which the cooling liquid flows in and an outlet 410b through which the cooling liquid flows out. The inlet 410a and the outlet 410b are both provided on the other end side (X2 direction side) of the base unit 40 in the X direction. The cooling flow path 410 is connected in this order to the inlet 410a, the inverter-side flow path 411, the connection flow path 412, the converter-side flow path 413, and the outlet 410b. The cooling liquid flows into the inverter-side flow path 411 from the inlet 410a provided on the X2 direction side of the base unit 40, flows through the connection flow path 412 and the converter-side flow path 413 in this order, and then flows out from the outlet 410b provided on the X2 direction side of the base unit 40.

[0044] The cooling flow path 410 is formed so as to turn back at a connection flow path 412 arranged at one end side in the X direction (X1 direction side). In the power conversion device 100, the inverter side flow path 411 and the converter side flow path 413 are provided in a single base unit 40, and therefore the device configuration is more space-saving than when the inverter unit 10 and the converter unit 20 are arranged in separate cooling units and cooled by cooling flow paths provided in each cooling unit.

[0045] 3, the cooling liquid flowing out of the cooling flow path 410 of the base unit 40 is cooled by heat dissipation by the heat dissipation unit 110 outside the power conversion device 100. The cooling liquid cooled by the heat dissipation unit 110 is pumped by a pump 120 provided outside the power conversion device 100 and flows back into the cooling flow path 410 of the base unit 40. The heat dissipation unit 110 includes a heat exchanger and is cooled by external air. The heat dissipation unit 110 is, for example, a radiator. The pump 120 may be disposed between the outlet 410b and the heat dissipation unit 110, and the cooling liquid before heat dissipation by the heat dissipation unit 110 may be pumped by the pump 120. The cooling liquid may be, for example, water, antifreeze, or other liquid.

[0046] (Layout of various components in a power conversion device) Next, the arrangement of various components of the power converter 100 according to one embodiment of the present invention will be described in detail with reference to FIGS.

[0047] As shown in FIG. 4, the control board 50 is fastened to the fixing plate 60 by a plurality of screws N1. The fixing plate 60 is fastened to the base 40 by a plurality of screws N2. The screws N1 are an example of a "fastening screw member" in the claims. The power conversion device 100 also includes a capacitor module 70 including a smoothing capacitor C2 (see FIG. 1). The capacitor module 70 is disposed on the Y1 direction side of the control board 50 and the fixing plate 60.

[0048] 5, the control board 50 is disposed in the Z1 direction relative to the fixing plate 60 and the power conversion unit 101. The control board 50 is provided with a plurality of through holes 50a for passing screws N1 (see FIG. 4) for fixing the control board 50 to the fixing plate 60. The control board 50 also has a plurality of terminal holes 50b for passing control terminals 11a (described later) of the semiconductor module 11.

[0049] Furthermore, a fixed plate 60 is disposed in the Z2 direction of the control board 50. The fixed plate 60 includes a metal plate portion 61 and a resin cover portion 62 that covers the metal plate portion 61. The metal plate portion 61 is formed, for example, from a highly corrosion-resistant galvanized steel plate (ZAM steel plate). The resin cover portion 62 is formed, for example, from a PPS (Poly Phenylene Sulfide) resin. The metal plate portion 61 and the resin cover portion 62 of the fixed plate 60 are formed in a flat plate shape. The fixed plate 60 has the metal plate portion 61 insert-molded into the resin cover portion 62. The resin cover portion 62 is an example of an "insulating cover portion" in the claims.

[0050] Furthermore, a crimp nut 1 is disposed on and fixed to the metal plate portion 61 of the fixing plate 60. The crimp nut 1 is an example of the "nut member" and the "first nut member" in the claims. The crimp nut 1 is made of an iron-based metal and is a separate part from the metal plate portion 61.

[0051] An insert nut 2 is disposed and fixed to the resin cover portion 62 of the fixing plate 60. The insert nut 2 is an example of the "nut member" and "second nut member" in the claims. The insert nut 2 is formed from an iron-based metal and is a separate component from the resin cover portion 62. A detailed description of the arrangement of the crimp nut 1 disposed on the metal plate portion 61 and the insert nut 2 disposed on the resin cover portion 62 will be given later.

[0052] The fixing plate 60 is also provided with openings 60a, 60b, 60c, and 60d. The openings 60a are provided corresponding to the position of the capacitor wiring portion 70a (see FIG. 8, etc.) that fixes the smoothing capacitor C2 (see FIG. 1), and a total of six openings 60b are provided overlapping in the Y direction. The openings 60b are provided corresponding to the position of the control terminal 11a of the semiconductor module 11 so that the control terminal 11a can protrude from the Z2 direction to the Z1 direction, and a total of six openings 60b are provided overlapping in the Y direction. Two openings 60c are provided on the Y2-direction surface of the fixing plate 60 corresponding to the position of the terminal 30a of the current sensor 30 so that the terminal 30a can protrude from the Z2 direction to the Z1 direction. The openings 60d are provided to reduce the amount of raw material used in manufacturing the metal plate portion 61 and the resin cover portion 62 included in the fixing plate 60 and to reduce the weight of the fixing plate 60, and a total of seven openings 60d are provided overlapping in the Y direction.

[0053] A switching element module 111 and a switching element module 112 are arranged on the Z1 direction side of the base unit 40. The base unit 40 also includes a boss portion 40a for fixing a fixing plate 60. A metal plate portion 61 included in the fixing plate 60 is fastened to the base unit 40 by a screw N2. The control board 50 is electrically connected to the base unit 40 via the metal plate portion 61. Specifically, the control board 50 is electrically connected to the base unit 40 via the screw N1, the metal plate portion 61, and the screw N2.

[0054] The base portion 40 also includes a protrusion 40b that engages with the metal plate portion 61 to determine positioning with respect to the metal plate portion 61. The protrusion 40b is provided on the base portion 40. The protrusion 40b is formed in a truncated cone shape so as to protrude toward the fixed plate 60 side (Z1 direction side).

[0055] The semiconductor module 11 also has a control terminal 11a for transmitting a signal for controlling switching by a control unit 51 included in the control board 50. The semiconductor module 11 (switching element modules 111 and 112) is fixed to the base unit 40 with screws N3. The power conversion device 100 also includes a plurality of (six) conductor wirings 90 connected to the semiconductor module 11.

[0056] A current sensor 30 consisting of a current sensor 31 and a current sensor 32 is arranged on the Y2 direction side of the switching element module 111. The current sensor 31 detects the value of a current flowing through a plurality (three) of conductor wirings 90 connected to the switching element module 111. Furthermore, a current sensor 32 is arranged on the Y2 direction side of the switching element module 112. The current sensor 32 detects the value of a current flowing through a plurality (three) of conductor wirings 90 connected to the switching element module 112. A terminal 30a of the current sensor 30 extends in the Z1 direction through the opening 60c and is connected to the control board 50.

[0057] Furthermore, the conductor wiring 90 is fastened and fixed to the terminal 11b (see FIG. 8, etc.) of the semiconductor module 11 by a screw N4. The terminal 11b is an output-side terminal. Furthermore, the capacitor wiring portion 70a (see FIG. 8, etc.) of the capacitor module 70 is fastened and fixed to the terminal 11c (see FIG. 8, etc.) of the semiconductor module 11 by a screw N5. The terminal 11c is an input-side terminal.

[0058] Here, the metal plate portion 61 will be described with reference to Fig. 6. As shown in Fig. 6, the metal plate portion 61 is provided with base fixing holes 61a for fixing the fixing plate 60 to the base portion 40 with screws N2 (see Fig. 4). The metal plate portion 61 also includes positioning holes 61b that engage with the protrusions 40b of the base portion 40. The positioning holes 61b are provided in the metal plate portion 61 so as to correspond to the positions of the protrusions 40b (see Fig. 5).

[0059] The metal plate portion 61 is also provided with nut openings 61c, 61d, 61e, 61f, and 61g. Nut opening 61c is an opening through which the crimp nut 1 is inserted from the Z2 direction and crimped. Opening 61d corresponds to opening 60a (see FIG. 5) of the fixing plate 60 (see FIG. 5), opening 61e corresponds to opening 60d (see FIG. 5) of the fixing plate 60, opening 61f corresponds to opening 60b (see FIG. 5) of the fixing plate 60, and opening 61g corresponds to opening 60c (see FIG. 5) of the fixing plate 60.

[0060] 7, the resin cover portion 62 is provided with a nut opening 62a, an opening 62b, an opening 62c, an opening 62d, and an opening 62e. The nut opening 62a is an opening provided for insert molding so as to embed the insert nut 2 during the manufacturing of the resin cover portion 62. The opening 62d is an opening corresponding to the position of the crimp nut 1 fixed to and integrated with the metal plate portion 61. The opening 62c is an opening corresponding to the opening 60a (see FIG. 5) of the fixing plate 60 (see FIG. 5), the opening 62d is an opening corresponding to the opening 60b (see FIG. 5) of the fixing plate 60, and the opening 62e is an opening corresponding to the opening 60d (see FIG. 5) of the fixing plate 60.

[0061] (Fixing structure between control board and fixing plate) Next, with reference to FIGS. 8 to 11, a detailed description will be given of the structure for fixing the control board 50 and the fixing plate 60 of the power converter 100 according to one embodiment of the present invention.

[0062] FIG. 8, which is a cross section taken along line VIII-VIII in FIG. 4, illustrates an example of a position where the control board 50 and the fixing plate 60 are fixed together using the crimp nut 1. As shown in FIG. 8, in this embodiment, the control board 50 and the fixing plate 60 are fixed together using the crimp nut 1, for example, near the center of the control board 50 in the Y direction. Here, as shown in FIG. 9, at a position where the nut opening 61c of the metal plate portion 61 is provided, a distance d1 is provided between the Z2-direction surface of the fixing plate 60 (resin cover portion 62) and the Z1-direction surface of the semiconductor module 11 included in the power conversion unit 101 (see FIG. 1). In this embodiment, this distance d1 is equal to or greater than a threshold distance d that ensures sufficient insulation between the metal plate portion 61 of the fixing plate 60 and the semiconductor module 11 serving as the power conversion unit 101. The threshold distance d is an example of a "predetermined value" in the claims.

[0063] Here, when the metal crimp nut 1 is crimped and fixed to the metal plate portion 61, the Z2 direction surface of the crimp nut 1 is positioned at a position substantially equal to the Z2 direction surface of the resin cover portion 62 of the fixing plate 60. However, even if the crimp nut 1 is positioned in the nut opening 61c, the crimp nut 1 and the semiconductor module 11 are separated by a distance d1, ensuring insulation. Therefore, in this position, the crimp nut 1 is crimped and fixed to the nut opening 61c of the metal plate portion 61.

[0064] Furthermore, the crimp nut 1 has a boss shape extending in the Z direction and having a pre-designed size, and therefore functions as a spacer. Therefore, the Z1-direction surface of the fixing plate 60 (resin cover portion 62) is spaced a distance d2 from the Z2-direction surface of the control board 50, which is a pre-designed desired size. That is, the control board 50 is fixed to the fixing plate 60 by the screw N1 and the crimp nut 1, spaced a distance d2 apart.

[0065] The crimp nut 1 has a bottom 1a and is closed without an opening in the Z2 direction, which is the side where the semiconductor module 11 included in the power conversion unit 101 is arranged. That is, the crimp nut 1 is a so-called cap nut. Therefore, in this embodiment, when the screw N1 is fastened to the crimp nut 1, the screw N1 and the crimp nut 1 rub against each other, causing wear and tear. This metal powder is scattered on the bottom 1a, but is not scattered around the crimp nut 1.

[0066] FIG. 10 , which is a cross section taken along line IX-IX in FIG. 4 , illustrates an example of a position where the control board 50 and the fixing plate 60 are fixed using the insert nut 2. As shown in FIG. 10 , in this embodiment, the control board 50 and the fixing plate 60 are fixed using the insert nut 2, for example, at a position near the Y1 end of the control board 50 in the Y direction. As shown in FIG. 11 , at a position where the nut opening 62a of the resin cover 62 is provided, a distance d3 is provided between the Z2-direction surface of the fixing plate 60 (resin cover 62) and the Z1-direction surface of the capacitor wiring 70a included in the power conversion unit 101 (see FIG. 1 ). In this embodiment, this distance d3 is less than the threshold distance d, which ensures sufficient insulation between the metal plate 61 of the fixing plate 60 and the capacitor wiring 70a of the power conversion unit 101 (see FIG. 1 ).

[0067] Here, for example, if the crimp nut 1 is placed in this position, the Z2 direction surface of the crimp nut 1 will be placed on the Z2 direction surface of the fixing plate 60 (resin cover portion 62), which may cause a short circuit between the metallic crimp nut 1 and the capacitor wiring portion 70a. Therefore, to prevent a short circuit between the nut member and the capacitor wiring portion 70a, an insert nut 2, at least a portion of whose Z2 direction surface is covered by the resin cover portion 62, is fixed to the nut opening 62a.

[0068] The insert nut 2 has a boss shape that extends in the Z direction and has a pre-designed size, and therefore functions as a spacer. Therefore, the metal plate portion 61 is spaced a distance d2 from the control board 50, which is a pre-designed desired size. That is, the control board 50 is fixed to the fixing plate 60 by the screw N1 and the insert nut 2, spaced a distance d2 from the metal plate portion 61.

[0069] The insert nut 2 has a bottom 2a and is closed without an opening in the Z2 direction, which is the side where the capacitor wiring unit 70a included in the power conversion unit 101 is arranged. That is, the insert nut 2 is a so-called cap nut. Therefore, in this embodiment, when the screw N1 is fastened to the insert nut 2, the screw N1 and the insert nut 2 rub against each other, causing wear and tear. This causes metal powder to scatter to the bottom 2a, but is not scattered around the insert nut 2.

[0070] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0071] In this embodiment, the power converter 101 includes a control board 50 on which a control unit 51 that controls the power converter 101 is disposed, a fixing plate 60 that is disposed between the power converter 101 and the control board 50 and that fixes the control board 50 with a screw N1. The fixing plate 60 includes a metal crimp nut 1 and an insert nut 2 to which the screw N1 is fastened and that are closed on the Z2 side, i.e., on the side on which the power converter 101 is disposed, without any opening. This prevents metal powder generated by friction between the screw N1 and the metal crimp nut 1 and insert nut 2 from escaping from the crimp nut 1 and insert nut 2, which are closed on the Z2 side, i.e., on the side on which the power converter 101 is disposed. As a result, a power converter 100 can be provided that includes a fixing plate 60 that can fix the control board 50 without scattering metal powder onto the power converter 101.

[0072] Furthermore, in this embodiment, as described above, the fixed plate 60 includes the metal plate portion 61 and the insulating resin cover portion 62 that covers the metal plate portion 61. As a result, the fixed plate 60 includes the metal plate portion 61, which has a relatively high rigidity, and therefore, it is possible to suppress the occurrence of distortion of the fixed plate 60. Furthermore, since the fixed plate 60 includes the insulating resin cover portion 62 that covers the metal plate portion 61, insulation can be easily achieved even when the control board 50, the power conversion unit 101, and the like are arranged near the fixed plate 60.

[0073] Furthermore, in this embodiment, as described above, the crimp nut 1, which is a separate component from the metal plate portion 61 and serves as a nut member, is fixed to the metal plate portion 61 of the fixing plate 60, and the insert nut 2, which is a separate component from the resin cover portion 62 and serves as a nut member, is fixed to the resin cover portion 62 of the fixing plate 60. This allows the crimp nut 1 and the insert nut 2 to be used appropriately depending on the material to be fixed. Furthermore, because the crimp nut 1 is a separate component from the metal plate portion 61 and the insert nut 2 is a separate component from the resin cover portion 62, there is no need to process the metal plate portion 61 and the resin cover portion 62 into nuts, making manufacturing easier.

[0074] Furthermore, in the present embodiment, as described above, the fixing plate 60 has a crimp nut 1 with its surface facing the Z2 direction, on the side where the power conversion unit 101 is disposed, exposed at a position where the distance d1 between the fixing plate 60 and the power conversion unit 101 is equal to or greater than the predetermined threshold distance d in the Z direction where the power conversion unit 101 overlaps with the fixing plate 60, and an insert nut 2 with at least a portion of its surface facing the Z2 direction, on the side where the power conversion unit 101 is disposed, covered with a resin cover 62, is disposed at a position where the distance d3 between the fixing plate 60 and the power conversion unit 101 is less than the predetermined threshold distance d in the Z direction. As a result, the crimp nut 1 with its surface facing the Z2 direction, on the side where the power conversion unit 101 is disposed, exposed is disposed at a position where the distance d1 between the fixing plate 60 and the power conversion unit 101 is equal to or greater than the predetermined threshold distance d in the Z direction, thereby reducing the amount of insulating material used. Furthermore, in the Z direction, at a position where the distance d3 between the fixing plate 60 and the power conversion unit 101 is less than a predetermined threshold distance d, an insert nut 2 is arranged, and at least a portion of its surface in the Z2 direction, on the side where the power conversion unit 101 is arranged, is covered with a resin cover portion 62.Therefore, since the distance d2 between the insert nut 2 and the power conversion unit 101 is close, electrical conduction between the insert nut 2 and the power conversion unit 101 can be prevented.

[0075] In this embodiment, as described above, the crimp nut 1 is fixed to the metal plate portion 61 by being crimped to the metal plate portion 61. This allows the crimp nut 1, which is a separate part from the metal plate portion 61, to be reliably fixed to the metal plate portion 61 without using a separate joining material such as an adhesive.

[0076] Furthermore, in this embodiment, as described above, the insert nut 2 is fixed to the resin cover portion 62 by insert molding with respect to the resin cover portion 62. This allows the insert nut 2 to be incorporated simultaneously when the resin cover portion 62 of the fixing plate 60 is manufactured (for example, during resin molding) without the need for a separate process of combining the insert nut 2 with the fixing plate 60 including the resin cover portion 62, thereby simplifying the manufacturing process of the fixing plate 60.

[0077] Furthermore, in this embodiment, as described above, the insert nut 2 has a boss shape that functions as a spacer that separates the control board 50 and the resin cover portion 62 by a predetermined distance d2. As a result, even when it is desired to insulate the control board 50 from the metal plate portion 61 included in the fixing plate 60 in a portion other than the insert nut 2, the insert nut 2 has a boss shape that functions as a spacer, so that the control board 50 and the resin cover portion 62 can be separated by the predetermined distance d2. As a result, the control board 50 and the metal plate portion 61 included in the fixing plate 60 can be insulated from each other.

[0078] [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.

[0079] For example, in the above embodiment, the fixing plate 60 includes the metal plate portion 61 and the insulating resin cover portion 62 that covers the metal plate portion 61, but the present invention is not limited to this. The fixing plate 60 may be composed only of the metal plate portion 61, for example, when a sufficient distance can be secured between the control board 50 and the power conversion unit 101.

[0080] In the above embodiment, an example is shown in which the crimp nut 1, which is a separate component from the metal plate portion 61 and serves as a nut member, is fixed to the metal plate portion 61 of the fixing plate 60, and the insert nut 2, which is a separate component from the resin cover portion 62 and serves as a nut member, is fixed to the resin cover portion 62 of the fixing plate 60, but the present invention is not limited to this. In the present invention, for example, either the crimp nut 1 alone or the insert nut 2 may be arranged on both the metal plate portion 61 and the resin cover portion 62.

[0081] In the above embodiment, the fixing plate 60 has a caulking nut 1 with an exposed surface facing the Z2 direction, where the power conversion unit 101 is located, at a position where the distance d1 between the fixing plate 60 and the power conversion unit 101 is equal to or greater than the predetermined threshold distance d in the Z direction where the power conversion unit 101 and the fixing plate 60 overlap, and an insert nut 2 with at least a portion of its surface facing the Z2 direction, where the power conversion unit 101 is located, covered with a resin cover 62, at a position where the distance d3 between the fixing plate 60 and the power conversion unit 101 is less than the predetermined threshold distance d. However, the present invention is not limited to this. In the present invention, to ensure more reliable insulation, the insert nut 2 may have at least a portion of its surface facing the Z2 direction, where the power conversion unit 101 is located, covered with a resin cover 62, at any position.

[0082] In the above embodiment, the crimp nut 1 is fixed to the metal plate portion 61 by being crimped to the metal plate portion 61, but the present invention is not limited to this. In the present invention, the crimp nut 1 may be fixed to the metal plate portion 61 by being press-fitted into the metal plate portion 61, or may be fixed to the metal plate portion 61 using a joining member such as an adhesive.

[0083] In the above embodiment, the insert nut 2 is fixed to the resin cover portion 62 by insert molding, but the present invention is not limited to this. In the present invention, the insert nut 2 may be fixed to the resin cover portion 62 using a joining member such as an adhesive after the resin cover portion 62 is manufactured.

[0084] In the above embodiment, the insert nut 2 has a boss shape that functions as a spacer that separates the control board 50 and the resin cover portion 62 by the predetermined distance d2, but the present invention is not limited to this. In the present invention, for example, in cases where the crimp nuts 1 have a boss shape that functions as a spacer in a portion fastened by multiple crimp nuts 1, or when the control board 50 is fixed using a separate spacer member, the insert nut 2 does not need to have a boss shape.

[0085] In the above embodiment, the metal plate portion 61 is made of ZAM steel plate and the resin cover portion 62 is made of PPS resin, but the present invention is not limited to this. In the present invention, the metal plate portion 61 may be made of any material as long as it is conductive and has the required strength. The resin cover portion 62 may be made of, for example, PBT (Poly Butylene Terephthalate), or may be made of an insulating material other than resin.

[0086] In the above embodiment, the fixing plate 60 is provided with the openings 60a and 60b for passing fastening members for fastening the wiring, such as the screws N4 and N5, but the present invention is not limited to this. In the present invention, for example, the fixing plate 60 may be configured not to have the openings 60a, but to allow the wiring to be detoured and fastened at a different position. [Explanation of symbols]

[0087] Crimp nut 1 (nut component, first nut component) Insert nut 2 (nut member, second nut member) 11 Semiconductor module (power conversion section) 40 Base 50 control board 51 Control section 60 Fixed plate 61 Metal plate part 62 Resin cover part 70 Capacitor module (power conversion section) 70a Capacitor terminal (power conversion section) 90 Conductor wiring (power conversion section) 100 Power conversion device 101 Power conversion unit C2 smoothing capacitor N1 Screw (fastening screw component)

Claims

1. a power conversion unit; a control board on which a control unit that controls the power conversion unit is disposed; a fixing plate disposed between the power conversion unit and the control board and configured to fix the control board with a fastening screw member; The fixing plate includes a metal nut member to which the fastening screw member is fastened, the metal nut member having a closed side without an opening on which the power conversion unit is disposed.

2. The power conversion device according to claim 1 , wherein the fixing plate includes a metal plate portion and an insulating cover portion having insulating properties and covering the metal plate portion.

3. a first nut member, which is a separate part from the metal plate portion and serves as the nut member, fixed to the metal plate portion of the fixing plate; The power conversion device according to claim 2 , wherein a second nut member, which is a separate component from the insulating cover portion and serves as the nut member, is fixed to the insulating cover portion of the fixing plate.

4. The fixing plate is the first nut member, the surface of which is exposed on the side where the power conversion unit is disposed, is disposed at a position where a distance between the fixing plate and the power conversion unit is equal to or greater than a predetermined value in a stacking direction in which the power conversion unit and the fixing plate overlap, 4. The power conversion device according to claim 3, wherein the second nut member is arranged at a position in the stacking direction where the distance between the fixing plate and the power conversion unit is less than a predetermined value, and at least a portion of the surface on the side where the power conversion unit is arranged is covered by the insulating cover portion.

5. The power conversion device according to claim 3 , wherein the first nut member is fixed to the metal plate portion by being crimped or press-fitted to the metal plate portion.

6. The power conversion device according to claim 3 , wherein the second nut member is fixed to the insulating cover portion by insert molding.

7. The power conversion device according to claim 3 , wherein the second nut member has a boss shape that functions as a spacer that separates the control board and the insulating cover portion by a predetermined distance.

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