JP2021175232A - Power conversion device - Google Patents

Abstract

To provide a power conversion device capable of suppressing distortion of a substrate although materials of a case and the substrate are different and linear expansion coefficients are different in general, such that there is the risk that the substrate is distorted by a difference generated between deformation amounts of the case and the substrate.SOLUTION: A power conversion device comprises a substrate, a power converter, and a case storing them. The case includes a substrate storage part in which the substrate is stored, a converter storage part in which the power converter is stored, and a partition part which separates these storage parts. When a direction in parallel with the substrate is defined as an X direction, the substrate storage part is wider in the X direction than the converter storage part. The power conversion device comprises a fastening part which fastens the substrate storage part and the substrate, outside of two opposed faces of the converter storage part in the X direction. Therefore, when the substrate is deformed, only the substrate storage part is deformed. Thus, the deformation of the case is easily responsible to the substrate, and distortion of the substrate is suppressed.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a power conversion device that performs power conversion.

Patent Document 1 describes a power conversion device mounted on a vehicle, which includes a control circuit board, a semiconductor unit, and a case for accommodating the control circuit board. The case has a partition portion that separates the first accommodating space and the second accommodating space. A control circuit board is arranged in the first accommodation space, and a semiconductor unit is arranged in the second accommodation space. The control circuit board is fastened to the partition.

Japanese Unexamined Patent Publication No. 2015-70682

Generally, since the case and the control circuit board are made of different materials, the coefficient of linear expansion is also different. Therefore, a difference in the amount of deformation between the case and the control circuit board may occur, and the control circuit board fastened to the partition portion may be distorted.

Based on this circumstance, an object of the present disclosure is to provide a power conversion device capable of suppressing distortion of a substrate.

A plate-shaped substrate, a power converter for performing power conversion, and a case for accommodating the substrate and the power converter are provided, and the case includes a substrate accommodating portion for accommodating the substrate and a converter accommodating portion for accommodating the power converter. , And a partition portion that separates the substrate accommodating portion and the converter accommodating portion, and when the direction parallel to the substrate is the X direction, the substrate accommodating portion has a wider width in the X direction than the converter accommodating portion and is in the X direction. , A power converter comprising a fastening portion for fastening a substrate accommodating portion and a substrate on the outside of two facing surfaces of the converter accommodating portion.

Contrary to the present disclosure, consider a case where the fastening portion is located inside the two opposing surfaces of the transducer accommodating portion in the X direction. In this case, for example, when the substrate is deformed, in order to deform the case in accordance with the deformation of the substrate, it is necessary to deform the converter accommodating portion in addition to the substrate accommodating portion. On the other hand, in the power conversion device of the present disclosure, the fastening portion is located outside the two opposing surfaces of the converter accommodating portion in the X direction. Therefore, when the substrate is deformed, only the substrate accommodating portion needs to be deformed. Therefore, even if the substrate and the case having different linear expansion coefficients are deformed, the deformation of the case easily conforms to the substrate, so that the distortion of the substrate can be suppressed.

It is sectional drawing which shows typically the positional relationship of the component part of the power conversion apparatus in 1st Embodiment. FIG. 1 is a sectional view taken along line II-II of FIG. FIG. 3 is a sectional view taken along line III-III of FIG. It is an enlarged view of the vicinity of the fastening portion 80 of FIG.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. By assigning the same reference numerals to the corresponding components in each embodiment, duplicate description may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. Further, not only the combination of the configurations specified in the description of each embodiment but also the configurations of a plurality of embodiments can be partially combined even if the combination is not specified. Further, an unspecified combination of the configurations described in the plurality of embodiments and modifications is also disclosed by the following description.

The power conversion device 1 will be described with reference to FIGS. 1 to 4. The power conversion device 1 is mounted on a vehicle such as a hybrid vehicle or an electric vehicle, and converts a DC current of an external DC power source (not shown) of the power conversion device 1 into a three-phase AC motor (not shown) as a traveling motor. Generates alternating current (U-phase, V-phase, W-phase) to be energized.

As shown in FIG. 1, the power converter 1 includes a power converter, a substrate 20, a capacitor unit 40, a reactor unit 50, and a case 60 for accommodating them. Further, the power conversion device 1 includes a fastening portion 80 for fastening the case 60 and the substrate 20.

The power converter includes an electronic component that performs power conversion of the power converter 1. In this embodiment, the power converter is the semiconductor unit 10. Therefore, in the following, the power converter will be referred to as the semiconductor unit 10.

The semiconductor unit 10 includes a semiconductor module 11 in which the switching element 13 is resin-sealed, a cooler 12 that cools the semiconductor module 11, and a terminal 14 that electrically connects the substrate 20 and the switching element 13. .. As shown in FIG. 2, the semiconductor unit 10 is formed by laminating a plurality of semiconductor modules 11 and a plurality of coolers 12. Here, the direction in which the plurality of semiconductor modules 11 and the plurality of coolers 12 are laminated is defined as the Y direction. The semiconductor module 11 is in contact with two coolers 12 in the Y direction. That is, the semiconductor module 11 is cooled by the cooler 12 from both sides of the two surfaces perpendicular to the Y direction.

The switching element 13 is switched on and off by passing an electric current. As a result, the semiconductor module 11 converts the direct current input from the direct current power source into an alternating current and outputs it to the three-phase alternating current motor. As the switching element 13, a semiconductor element such as an IGBT or MOSFET is used. Here, the IGBT is an abbreviation for Integrated Gate Bipolar Transistor. Further, MOSFET is an abbreviation for Metal-Oxide-Semiconductor Field-Effective Transistor.

The direction in which the terminal 14 extends is the Z direction. As shown in FIG. 1, the substrate 20 is a plate-shaped member perpendicular to the Z direction. The substrate 20 is electrically connected to the switching element 13 built in the semiconductor module 11 via the terminal 14. The substrate 20 is also electrically connected to an electronic control unit (ECU) arranged outside the power conversion device 1. That is, the substrate 20 outputs a drive signal to the switching element 13 based on the torque request input from the ECU and the signals detected by various sensors. The base material of the substrate 20 is made of resin.

The capacitor unit 40 has a filter capacitor, a smoothing capacitor, and a capacitor case (not shown). The filter capacitor and the smoothing capacitor are housed in a capacitor case. As these capacitors, a film capacitor in the shape of a wound film is used. The shape and number of capacitors are adjusted by adjusting the width of the film, the number of turns, and the quantity of film capacitors used. Then, by adjusting the arrangement of these capacitors, it is possible to make the capacitor case into a desired shape.

The filter capacitor smoothes the DC voltage input from the DC power supply. The smoothing capacitor smoothes the DC voltage boosted by using the semiconductor module 11. The capacitor unit 40 is arranged on the opposite side of the substrate 20 with respect to the semiconductor unit 10.

The reactor unit 50 has a reactor and a reactor case (not shown). The reactor is housed in a reactor case. The reactor boosts the DC voltage of the DC power supply as the switching element 13 switches. The reactor unit 50 is arranged on the opposite side of the substrate 20 with respect to the semiconductor unit 10.

The case 60 includes a substrate accommodating portion 61 accommodating the substrate 20, and a converter accommodating portion 62 accommodating a semiconductor unit 10, a capacitor unit 40, and a reactor unit 50. Further, the substrate accommodating portion 61 has a substrate side opening 64 that opens in the Z direction. Further, the converter accommodating portion 62 has a converter side opening 65 that opens in the Z direction. The substrate accommodating portion 61 and the converter accommodating portion 62 are arranged side by side in the Z direction.

As shown in FIG. 3, the substrate accommodating portion 61 and the converter accommodating portion 62 have a rectangular shape when viewed from the Z direction. Further, the converter accommodating portion 62 has a short side that extends in the X direction when viewed from the Z direction.

As shown in FIG. 1, the case 60 has a substrate side lid 66 attached to the opening of the substrate side opening 64 and a transducer side lid 67 attached to the transducer side opening 65. The substrate accommodating portion 61 and the substrate side lid portion 66 are fastened by bolts (not shown). Similarly, the transducer accommodating portion 62 and the transducer side lid portion 67 are fastened by bolts (not shown).

Further, the case 60 has a partition portion 63 for partitioning the substrate accommodating portion 61 and the converter accommodating portion 62. The partition portion 63 is a plate-shaped member and has a surface perpendicular to the Z direction. The partition portion 63 and the substrate 20 are arranged in parallel so as to face each other in the Z direction. In this embodiment, the case 60 is made of metal. Specifically, it is formed by aluminum die casting. The partition portion 63 has a hole for passing the terminal 14 (not shown). The plate thickness of the substrate accommodating portion 61 is smaller than the plate thickness of the converter accommodating portion 62.

The substrate accommodating portion 61 has a substrate accommodating bottom portion 612 arranged on the same plane as the partition portion 63. The substrate accommodating bottom 612 has a surface parallel to the partition 63. Further, the substrate accommodating bottom portion 612 is adjacent to the partition portion 63. The plate thickness of the partition portion 63 is smaller than the plate thickness of the substrate accommodating bottom portion 612. The substrate accommodating portion 61 has a first substrate accommodating side surface 613 and a second substrate accommodating side surface 614, which are inner wall surfaces perpendicular to the X direction and facing the substrate 20 in the X direction.

The capacitor unit 40 and the reactor unit 50, including the semiconductor unit 10, convert electric power. Therefore, heat is generated in the process of converting electric power. A partition 63 is arranged to prevent this heat from being transferred to the substrate 20 via the air convected in the case 60. By arranging the partition portion 63, it is possible to prevent the air in the converter accommodating portion 62 from convection into the substrate accommodating portion 61. Further, by arranging the partition portion 63, it is possible to increase the number of fixing points (not shown) for fixing the semiconductor unit 10, the capacitor unit 40, and the reactor unit 50, and these are stably fixed in the case 60. be able to.

As shown in FIG. 2, a semiconductor unit 10, a reactor unit 50, and a capacitor unit 40 are arranged in the converter accommodating portion 62. Here, the direction perpendicular to the Y direction and the Z direction is defined as the X direction. The reactor unit 50 and the condenser unit 40 are arranged side by side in the X direction. Further, as shown in FIG. 1, the semiconductor unit 10 and the reactor unit 50 are arranged side by side in the Z direction. The semiconductor unit 10 and the capacitor unit 40 are arranged side by side in the Z direction. The converter accommodating portion 62 has a reactor side surface 621 which is an inner wall surface arranged at a position perpendicular to the X direction and closer to the reactor unit 50 than the capacitor unit 40 in the X direction. Further, the converter accommodating portion 62 has a capacitor side surface 622 which is an inner wall surface perpendicular to the X direction and facing the capacitor unit 40 in the X direction. The reactor side surface 621 and the capacitor side surface 622 are parallel to each other and are arranged so as to face each other in the X direction. In other words, the reactor side surface 621 and the capacitor side surface 622 are parallel to the Y direction and the Z direction, and are arranged side by side in the X direction.

The fastening portion 80 has a fastening base 81 and bolts 82. The fastening base 81 is formed as a protruding member extending in the Z direction, which is integrated with the substrate accommodating bottom portion 612. Specifically, it is integrally formed with the substrate accommodating bottom 612 by aluminum die casting. A screw hole is formed in the fastening base 81, and the bolt 82 is inserted into the fastening base 81 to fasten the substrate accommodating bottom portion 612 and the substrate 20. The bolt 82 is inserted in the Z direction with respect to the fastening base 81. As shown in FIG. 3, all of the plurality of fastening portions 80 are arranged outside the range in which the converter accommodating portion 62 is projected in the Z direction. In the present embodiment, the power conversion device 1 includes four fastening portions 80.

In the X direction, the fastening portion 80 is arranged outside the reactor side surface 621 and the capacitor side surface 622. That is, when the power converter 1 is viewed from the Z direction, the partition portion 63 and the converter accommodating portion 62 are arranged between two of the plurality of fastening portions 80 arranged in the X direction. Further, the fastening portions 80 are arranged at the four corners of the substrate accommodating portion 61.

Further, the substrate accommodating bottom portion 612 has a recess 611 recessed in the Z direction. In the present embodiment, four recesses 611 are formed in the substrate accommodating bottom 612. Each of the four recesses 611 is arranged in pairs with each of the four fastening portions 80. In the X direction, the recess 611 is arranged closer to the partition 63 than the fastening 80. Further, in the X direction, all of the plurality of recesses 611 are arranged between the two fastening portions 80 arranged in the X direction and outside the partition portion 63. As shown in FIG. 1, the recess 611 is formed in a substantially V shape on the substrate accommodating bottom portion 612. Further, the plate thickness in the Z direction of the substrate accommodating bottom 612 at the position where the recess 611 is formed is smaller than the plate thickness in the Z direction at the position where the recess 611 is not formed. The depth of the recess 611 in the Z direction may be larger or smaller than half the thickness of the substrate accommodating bottom 612 in the Z direction.

As shown in FIG. 3, the width of the substrate accommodating portion 61 in the X direction is larger than the width of the converter accommodating portion 62 in the X direction. Specifically, the width of the converter accommodating portion 62 in the X direction is smaller than the distance between the two recesses 611 arranged in the X direction. Here, the width of the substrate accommodating portion 61 in the X direction is the distance between the first substrate accommodating side surface 613 and the second substrate accommodating side surface 614 in the X direction. The width of the converter accommodating portion 62 in the X direction is the distance between the reactor side surface 621 and the capacitor side surface 622 in the X direction. Further, the width of the substrate accommodating portion 61 in the Y direction is the same as the width of the converter accommodating portion 62 in the Y direction. Here, the width of the substrate accommodating portion 61 in the Y direction is the distance in the Y direction between the two inner wall surfaces of the substrate accommodating portion 61 that are perpendicular to the Y direction and face the substrate 20 in the Y direction. The width of the converter accommodating portion 62 in the Y direction is the distance between the two inner wall surfaces of the converter accommodating portion 62 that are perpendicular to the Y direction and face the substrate 20 in the Y direction in the Y direction.

FIG. 4 is an enlarged view of the vicinity of the fastening portion 80 in FIG. 1. As shown in FIG. 4, the distance between the recess 611 and the bolt center 822 of the bolt 82 in the X direction is defined as the bolt distance 91, and the distance between the recess 611 and the partition portion 63 in the X direction is defined as the partition portion distance 92. Specifically, the bolt distance 91 is the distance between the most recessed position in the Z direction and the bolt center 822 among the recesses 611. Further, the partition portion distance 92 is a distance between the position of the partition portion 63 closest to the recess 611 in the X direction and the position of the recess 611 that is closest to the recess in the Z direction. The bolt distance 91 is larger than the partition distance 92.

Since the power conversion device 1 is mounted on the vehicle, it is affected by the temperature change in the vehicle. Here, as described above, since the materials of the substrate 20 and the case 60 are different, the coefficient of linear expansion is also different. Therefore, for example, when the heat generated from the engine in the vehicle is transferred to the power conversion device 1 via the convected air, the amount of deformation may differ between the substrate 20 and the case 60, and the substrate 20 may be distorted. be. If the substrate 20 is distorted, the solder on the substrate 20 may crack. Therefore, it is necessary to suppress the distortion of the substrate 20.

The effects of this embodiment are shown below. Here, contrary to the present embodiment, consider a case where the fastening portion 80 is located inside the reactor side surface 621 and the capacitor side surface 622 in the X direction. In this case, for example, when the substrate 20 is deformed, in order for the case 60 to be deformed in accordance with the deformation of the substrate 20, it is necessary to deform the converter accommodating portion 62 in addition to the substrate accommodating portion 61. On the other hand, in the power conversion device 1 of the present embodiment, the fastening portion 80 is located outside the reactor side surface 621 and the capacitor side surface 622 in the X direction. Therefore, when the substrate 20 is deformed, only the substrate accommodating portion 61 needs to be deformed. Therefore, even if the substrate 20 and the case 60 having different linear expansion coefficients are deformed, the deformation of the case 60 is likely to conform to the substrate 20, and the distortion of the substrate 20 can be suppressed.

The board accommodating portion 61 is connected to the substrate 20 via the fastening portion 80. Therefore, in order to suppress the distortion of the substrate 20, the substrate accommodating portion 61 needs to be deformed in accordance with the shrinkage of the substrate 20. In the present embodiment, the recess 611 is provided between the two fastening portions 80 and outside the partition portion 63 in the X direction of the substrate accommodating bottom portion 612. Since the recess 611 is recessed in the Z direction, the thickness in the Z direction is smaller than that of the portion of the substrate accommodating bottom 612 other than the recess 611. Therefore, the rigidity of the substrate accommodating portion 61 is smaller than that in the case where the recess 611 is not provided. Therefore, the deformation of the substrate accommodating portion 61 is adjusted to the shrinkage of the substrate 20, and the distortion of the substrate 20 can be further suppressed.

The board accommodating portion 61 is connected to the board 20 by inserting bolts 82 into the fastening base 81. Therefore, in order to suppress the distortion of the substrate 20, the substrate accommodating portion 61 needs to be deformed in accordance with the shrinkage of the substrate 20. Here, consider the bending moment of the recess 611 around the Y direction when the substrate 20 contracts. The bolt 82 is inserted in the direction perpendicular to the substrate 20. Therefore, the bending moment of the recess 611 around the Y direction increases as the bolt distance 91 increases. Therefore, in the present embodiment, the bolt distance 91 is larger than the partition distance 92 in the X direction. Therefore, the deformation of the substrate accommodating portion 61 is adjusted to the shrinkage of the substrate 20, and the distortion of the substrate 20 can be further suppressed. The above-mentioned effect is improved as the bolt distance 91 is larger.

(Other embodiments)
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following embodiments are also included in the technical scope of the present disclosure. Various changes can be made within the range that does not deviate.

Although the semiconductor unit 10 is described as the power converter in the first embodiment, the present disclosure is not limited to this. The power converter may be the reactor unit 50 or the capacitor unit 40.

In the first embodiment, a recess 611 is formed in the substrate accommodating bottom 612, but the present disclosure is not limited to this. The recess 611 may not be formed in the substrate accommodating bottom 612. Further, a recess 611 may be formed in a portion of the substrate accommodating portion 61 other than the substrate accommodating bottom portion 612.

In the first embodiment, the bolt distance 91 is larger than the partition distance 92, but the present disclosure is not limited to this. The bolt distance 91 may be smaller than the partition distance 92.

In the first embodiment, the fastening base 81 is a protruding member, but the present disclosure is not limited to this. For example, the step formed in the substrate accommodating portion 61 may be used as the fastening base 81.

In the first embodiment, four fastening portions 80 are arranged, but the present disclosure is not limited to this, and the number of fastening portions 80 may be a plurality.

In the first embodiment, the fastening base 81 is integrally formed by the substrate accommodating bottom portion 612 and the aluminum die casting, but the present disclosure is not limited to this. The fastening base 81 may be formed separately from the substrate accommodating bottom portion 612. Specifically, the fastening base 81 and the substrate accommodating bottom 612 may be fixed by welding or may be fastened by bolts.

In the first embodiment, the fastening base 81 is arranged on the substrate accommodating bottom 612, but the present disclosure is not limited to this. The fastening base 81 may be arranged in a portion of the substrate accommodating portion 61 other than the substrate accommodating bottom portion 612.

In the first embodiment, the fastening portion 80 has a bolt 82, but the present disclosure is not limited to this. It is not necessary to use the bolts 82 when fixing the substrate 20 to the fastening base 81.

In the first embodiment, all of the plurality of fastening portions 80 are arranged outside the range in which the converter accommodating portion 62 is projected in the Z direction, but the present disclosure is not limited to this. At least two of the plurality of fastening portions 80 may be arranged outside the range in which the converter accommodating portion 62 is projected in the Z direction. Similarly, at least two of the plurality of recesses 611 may be arranged outside the range in which the transducer accommodating portion 62 is projected in the Z direction.

In the first embodiment, the width of the substrate accommodating portion 61 in the X direction is larger than the width of the transducer accommodating portion 62 in the X direction, but the present disclosure is not limited to this. Even if the width of the substrate accommodating portion 61 in the X direction is smaller than the width of the converter accommodating portion 62 in the X direction, the width of the substrate accommodating portion 61 in the Y direction should be larger than the width of the converter accommodating portion 62 in the Y direction. Just do it.

In the first embodiment, the substrate accommodating portion 61 is larger than the transducer accommodating portion 62 only in the X direction, but the present disclosure is not limited to this. The substrate accommodating portion 61 may be larger than the transducer accommodating portion 62 in both the X direction and the Y direction. At this time, if the fastening portion 80 and the recess 611 are arranged outside the range in which the converter accommodating portion 62 is projected in the Z direction, the effect of suppressing the distortion of the substrate 20 described above in the first embodiment is further improved.

In the first embodiment, the width of the converter accommodating portion 62 in the X direction is smaller than the distance between the two recesses 611 arranged in the X direction, but the present disclosure is not limited to this. Even if the width of the converter accommodating portion 62 in the X direction is larger than the distance between two of the plurality of dents 611 arranged in the X direction, the conversion is performed more than the distance between the two dents 611 arranged in the Y direction. The width of the vessel accommodating portion 62 in the Y direction may be smaller.

In the first embodiment, at any position of the substrate accommodating portion 61, the width in the X direction is larger than the width of the converter accommodating portion 62 in the X direction. However, this disclosure is not limited to this. It is sufficient that there is a part where the width of the substrate accommodating portion 61 in the X direction is larger than the width of the converter accommodating portion 62 in the X direction.

1 ... Power converter 10 Power converter, 20 boards, 60 cases, 61 board housing, 611 recesses, 612 board housing bottom, 62 converter housing, 63 dividers, 80 fastenings, 81 fastening bases, 82 volts.

Claims (3)

A plate-shaped substrate (20), a power converter (10) for performing power conversion, and a case (60) for accommodating the substrate and the power converter are provided.
The case includes a substrate accommodating portion (61) for accommodating the substrate, a converter accommodating portion (62) accommodating the power converter, and a partition portion (63) for partitioning the substrate accommodating portion and the converter accommodating portion. Have,
When the direction parallel to the substrate is the X direction,
The substrate accommodating portion has a larger width in the X direction than the converter accommodating portion.
A power conversion device comprising a fastening portion (80) for fastening the substrate accommodating portion and the substrate on the outer side of two facing surfaces of the converter accommodating portion in the X direction. The partition portion is a plate-shaped member arranged in parallel with the substrate, and is a plate-shaped member.
The substrate accommodating portion has a substrate accommodating bottom portion (612) arranged on the same plane as the partition portion.
Assuming that the direction perpendicular to the substrate is the Z direction,
The substrate accommodating bottom has a recess (611) recessed in the Z direction.
The power conversion device according to claim 1, wherein the recess is provided between two of the plurality of fastening portions and outside the partition portion in the X direction. The fastening portion has a fastening base (81) formed integrally with the substrate accommodating portion, and a bolt (82) for fastening the substrate accommodating portion and the substrate by being inserted into the fastening base. ,
The bolt is inserted in the Z direction with respect to the substrate, and the bolt is inserted in the Z direction.
The power conversion device according to claim 2, wherein in the X direction, the distance between the recess and the center of the bolt is larger than the distance between the recess and the partition.

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