JP7069734B2 - Power converter - Google Patents

Description

The present invention relates to a power conversion device, and more particularly to a power conversion device including a heat sink.

Conventionally, a power conversion device including a heat sink is known (see, for example, Patent Document 1).

Patent Document 1 includes a power conversion circuit unit that includes a switching element and converts DC power into AC power, a housing that houses the power conversion circuit, and a heat sink that dissipates heat generated inside the housing to the outside of the housing. A power conversion device comprising the above is disclosed. In the power conversion device of Patent Document 1, the heat sink is arranged in contact with the switching element to dissipate the heat of the switching element, and the air inside the housing is cooled by the inner heat radiation fins provided toward the inside of the housing. It is configured as follows. Further, in the power conversion device of Patent Document 1, the heat sink is integrally provided with a portion corresponding to the switching element and a portion provided with the inner heat dissipation fins in close proximity to each other.

Japanese Unexamined Patent Publication No. 2016-146438

However, in the power conversion device described in Patent Document 1, since the heat sink is integrally provided with a portion corresponding to the switching element and a portion provided with the inner heat radiating fins in close proximity to each other, heat is generated. The heat generated from a large amount of switching elements is easily conducted to the inner heat dissipation fins. Therefore, there is a disadvantage that the temperature of the inner heat radiation fin tends to rise. As a result, the temperature difference between the inner heat radiating fins and the air inside the housing becomes smaller, so that the heat of the air inside the housing is suppressed from being transferred to the inner heat radiating fins. As a result, there is a problem that it is difficult to suppress an increase in the air temperature inside the housing.

The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a power conversion device capable of suppressing an increase in air temperature inside a housing. Is.

In order to achieve the above object, the power conversion device according to one aspect of the present invention includes a semiconductor switching element, a power conversion circuit that converts DC power into AC power, a housing that houses the power conversion circuit, and a housing. A heat sink that dissipates heat generated inside the body to the outside of the housing is provided, and the heat sink includes a first part that dissipates heat of a heat generating portion including a semiconductor switching element and a second part that cools the air inside the housing. A heat resistance portion is provided between the first portion and the second portion, and the second portion of the heat sink is provided integrally with the base portion and the base portion so as to extend to the outside of the housing. It includes a fin portion and an inner fin portion provided so as to be in direct contact with the inner surface of the housing of the base portion and extend toward the inside of the housing .

In the power conversion device according to the first aspect of the present invention, by configuring as described above, from the first part that dissipates heat of the semiconductor switching element by the thermal resistance part to the second part that cools the air in the housing. It is possible to suppress the transfer of heat. As a result, it is possible to suppress the temperature rise of the second portion, so that the temperature difference between the inside of the housing of the second portion and the air inside the housing can be increased. As a result, the heat of the air inside the housing can be efficiently transferred to the second portion, so that the rise in the air temperature inside the housing can be suppressed.

In the power conversion device according to the above one aspect, preferably, the first portion includes a first base plate and a first outer fin provided on the outside of the housing from the first base plate, and the second portion includes. The second base plate as the base portion, the second outer fin as the outer fin portion provided on the outside of the housing from the second base plate, and the inner fin provided on the inside of the housing from the second base plate. Includes inner fins as part . With this configuration, the heat generating portion including the semiconductor switching element can be brought into contact with the first base plate of the first portion, so that the semiconductor switching element can be provided via the first base plate and the first outer fin. The heat can be easily dissipated to the outside. Further, since the heat of the air inside the housing can be efficiently transferred to the second portion by the inner fins, the heat inside the housing can be efficiently discharged to the outside through the second outer fins.

In the power conversion device according to the above aspect, the thermal resistance portion preferably includes at least one of a member having a thermal conductivity smaller than that of the heat sink, a portion having a cross-sectional area smaller than that of the heat sink, and a bent portion. With this configuration, the first portion and the second portion can be easily thermally separated by using a member having a smaller heat conduction than the heat sink for the thermal resistance portion, so that the first portion to the second portion can be easily separated. The heat transfer to the portion can be easily suppressed. By using a portion or a bent portion having a smaller cross-sectional area than the heat sink for the thermal resistance portion, it is possible to integrally form the first portion and the second portion while thermally separating the first portion and the second portion. Therefore, it is possible to suppress an increase in the number of parts.

In this case, preferably, the thermal resistance portion includes a sealing member having a thermal conductivity lower than that of the heat sink, and the heat sink is attached to the housing via the sealing member. With this configuration, the heat sink can be attached to the housing via the sealing member, so that the inside of the housing can be sealed. As a result, the space inside the housing in which the parts including the semiconductor switching element are arranged can be sealed, so that the dustproof function and the waterproof function can be provided. Further, since the heat sink can be attached to the housing via a seal member having thermal resistance (low thermal conductivity), it is possible to suppress the heat of the heat sink from being transferred to the housing.

In the power conversion device according to the above one aspect, preferably, the heat sink has a first portion and a second portion formed by a separate body, and a thermal resistance is formed between the first portion and the second portion of the separate body. The part is arranged. With this configuration, the first portion and the second portion can be reliably thermally separated, so that heat transfer from the first portion to the second portion can be suppressed more effectively.

In the power conversion device according to the above one aspect, preferably, the heat sink is integrally formed with the first portion and the second portion, and the thermal resistance portion is provided between the first portion and the second portion. Includes the groove. With this configuration, the number of parts can be reduced and the inside of the housing can be easily sealed, as compared with the case where the first portion and the second portion are provided separately. Further, the groove portion can suppress heat transfer from the first portion to the second portion.

According to the present invention, as described above, it is possible to provide a power conversion device capable of suppressing an increase in the air temperature inside the housing.

It is a circuit diagram of the power conversion apparatus according to 1st Embodiment of this invention. It is an exploded perspective view of the power conversion apparatus according to 1st Embodiment of this invention. FIG. 3 is a plan sectional view of a power conversion device according to the first embodiment of the present invention. It is a front view of the power conversion apparatus according to 1st Embodiment of this invention. FIG. 3 is a plan sectional view of a power conversion device according to a second embodiment of the present invention. It is a front view of the power conversion apparatus according to 2nd Embodiment of this invention. FIG. 3 is a plan sectional view of a power conversion device according to a third embodiment of the present invention.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

The configuration of the power conversion device 100 according to the first embodiment will be described with reference to FIGS. 1 to 4.

[First Embodiment]
(Circuit configuration of power converter)
The circuit configuration of the power conversion device 100 will be described with reference to FIG. The power conversion device 100 is configured to convert the input DC or AC power into the set AC power and output the power. As shown in FIG. 1, the power conversion device 100 includes a power conversion circuit 101 that includes a semiconductor switching element and converts DC power into AC power, and a control circuit 42 for driving the semiconductor switching element. The power conversion device 100 is configured to convert DC power input from a DC power supply (not shown) via input terminals P and N into three-phase (U-phase, V-phase, and W-phase) AC power. ing. Further, the power conversion device 100 is configured to output the converted U-phase, V-phase, and W-phase AC power to the outside via the output terminals U, V, and W. The output terminals U, V, and W are connected to a motor (not shown) or the like.

The power conversion device 100 includes a capacitor C, semiconductor switching elements Sa, Sb, Sc, Sd, Se, Sf, and diodes Da, Db, Dc, Dd, De, Df. The capacitor C is connected between the input terminals P and N. Further, the capacitor C is provided for smoothing the ripple current and the like.

(Structure of power converter)
Next, the structural configuration of the power conversion device 100 will be described with reference to FIGS. 2 to 4. As shown in FIGS. 2 to 4, the power conversion device 100 includes a housing 10, sealing members 21, 22 and 23, fastening members 31, 32 and 33, a substrate 40, and a heat sink 50. .. The housing 10 includes a housing body 11 and a front cover 12. The housing body 11 is provided with openings 111 and 112. The substrate 40 is provided with a semiconductor switching element 41 and a control circuit 42. The heat sink 50 includes a first portion 51 and a second portion 52. The first portion 51 has a first base plate 511 and a first outer fin 512. The second portion 52 includes a second base plate 521, a second outer fin 522, and an inner fin 523. In FIGS. 2 to 4, electronic components other than the semiconductor switching element 41 of the power conversion device 100 and the control circuit 42 for driving the semiconductor switching element 41 are omitted for the sake of brevity.

The housing 10 is arranged so as to cover the substrate 40 on which the semiconductor switching element 41 and the control circuit 42 are provided. That is, the housing 10 is configured to accommodate the power conversion circuit 101 (see FIG. 1) and the control circuit 42. Further, a heat sink 50 is attached to the housing 10. Further, the inside of the housing 10 is hermetically sealed. Specifically, the internal space is sealed by the housing 10 and the heat sink 50. That is, the semiconductor switching element 41 is arranged in a closed space inside the housing 10.

The housing 10 (housing body 11 and front cover 12) is formed of a metal plate member. The housing 10 is made of, for example, corrosion-resistant aluminum or an iron material. This makes it possible to easily secure the airtightness of the housing 10. Further, the housing 10 may be made of a resin material such as plastic as long as the airtightness can be ensured.

The front cover 12 is attached to the housing body 11 via the seal member 21. Further, the front cover 12 is fastened to the housing main body 11 by a plurality of fastening members 31. The first portion 51 of the heat sink 50 is attached to the housing body 11 via the sealing member 22. Further, the first portion 51 is attached to the housing body 11 so as to close the opening 111 of the housing body 11. Further, the first portion 51 is fastened to the housing body 11 by a plurality of fastening members 32. The second portion 52 of the heat sink 50 is attached to the housing body 11 via the sealing member 23. Further, the second portion 52 is attached to the housing body 11 so as to close the opening 112 of the housing body 11. Further, the second portion 52 is fastened to the housing body 11 by a plurality of fastening members 33.

The sealing members 21 to 23 are provided to maintain the airtightness inside the housing 10. The sealing members 21 to 23 are made of an elastic material such as rubber. The sealing members 21 to 23 are formed of, for example, a nitrile-based rubber material. The seal members 21 to 23 are formed in an annular shape along the opening of the housing 10.

Here, in the first embodiment, the seal members 22 and 23 function as thermal resistance portions. That is, seal members 22 and 23 having thermal resistance are provided between the first portion 51 and the second portion 52 of the heat sink 50.

That is, in the heat sink 50, the region to which the heat generating portion including the semiconductor switching element 41 is attached and the region to which the inner fin 523 is attached are thermally separated.

The sealing member 23 is made of a material having a lower thermal conductivity than the material of the heat sink 50. Further, the seal member 23 is made of a material having a lower thermal conductivity than the material of the housing 10. For example, the seal member 23 has a thermal conductivity of 1 W / (mK) or less. Further, the seal member 23 has a thermal conductivity of about one-thousandth to one-hundredth of that of the heat sink 50.

The components constituting the power conversion device 100 are mounted on the board 40. A semiconductor switching element 41 is mounted on the Y2 surface side (heat sink 50 side) of the substrate 40. Further, a control circuit 42 is provided on the Y1 surface side (opposite side of the heat sink 50) of the substrate 40. That is, the semiconductor switching element 41 and the control circuit 42 are provided on different surfaces with respect to the substrate 40. Further, the semiconductor switching element 41 is directly fastened to the first portion 51 of the heat sink 50. That is, as shown in FIG. 3, the semiconductor switching element 41 is in contact with the inside (Y1 direction side) of the first base plate 511 of the first portion 51. Further, the substrate 40 is fixed to the housing 10 or the first portion 51 of the heat sink 50 via a spacer or the like.

The semiconductor switching element 41 is composed of, for example, an isolated gate bipolar transistor (IGBT (Insulated Gate Bipolar Transistor)) or the like.

The heat sink 50 is configured to dissipate heat generated inside the housing 10 to the outside of the housing 10. Further, the heat sink 50 is arranged so as to be exposed to the outside of the housing 10. Further, the heat sink 50 is provided on the back surface (the surface on the Y2 direction side) of the power conversion device 100. The heat sink 50 is made of a material having high thermal conductivity. The heat sink 50 is made of, for example, an aluminum material, copper, or the like.

The first portion 51 of the heat sink 50 is configured to dissipate heat from the heat generating portion including the semiconductor switching element 41. The heat generating portion includes, for example, a capacitor and a transformer in addition to the semiconductor switching element 41. The second portion 52 of the heat sink 50 is configured to cool the air inside the housing 10.

Further, the first portion 51 and the second portion 52 of the heat sink 50 are formed by separate bodies. Further, seal members 22 and 23 as thermal resistance portions are arranged between the first portion 51 and the second portion 52 of the separate body.

The first base plate 511 of the first portion 51 is provided substantially parallel to the XZ plane. The first outer fin 512 of the first portion 51 is provided on the outside of the housing 10 from the first base plate 511. Further, a plurality of first outer fins 512 are provided. Further, the first outer fin 512 is provided along a plane substantially orthogonal to the first base plate 511. Further, the plurality of first outer fins 512 are arranged substantially in parallel. Further, the first outer fin 512 is provided substantially parallel to the YZ plane. That is, the first outer fin 512 is arranged so as to extend in the vertical direction (Z direction).

The first portion 51 of the heat sink 50 conducts heat generated from the heat generating portion including the semiconductor switching element 41 from the first base plate 511 to the first outer fin 512. Then, the first portion 51 transfers heat from the first outer fin 512 to the air outside the housing 10, and releases the heat generated inside the housing 10 to the outside of the housing 10.

The second base plate 521 of the second portion 52 is provided substantially parallel to the XZ plane. The second outer fin 522 of the second portion 52 is provided on the outside of the housing 10 from the second base plate 521. Further, a plurality of second outer fins 522 are provided. Further, the second outer fin 522 is provided along a plane substantially orthogonal to the second base plate 521. Further, the plurality of second outer fins 522 are arranged substantially in parallel. Further, the second outer fin 522 is provided substantially parallel to the YZ plane. That is, the second outer fin 522 is arranged so as to extend in the vertical direction (Z direction).

As shown in FIGS. 3 and 4, the inner fin 523 of the second portion 52 is provided inside the housing 10 from the second base plate 521. Further, a plurality of inner fins 523 are provided. Further, the inner fin 523 is provided along a plane substantially orthogonal to the second base plate 521. Further, the plurality of inner fins 523 are arranged substantially in parallel. Further, the inner fin 523 is provided substantially parallel to the YZ plane. That is, the inner fin 523 is arranged so as to extend in the vertical direction (Z direction). Note that FIG. 4 is a view of the power conversion device 100 with the front cover 12 and the seal member 21 removed from the front (Y1 direction).

The inner fin 523 is configured to take heat from the air inside the housing 10 by coming into contact with the air inside the housing 10. The member including the plurality of inner fins 523 is formed separately from the member including the plurality of second outer fins 522. The member including the plurality of inner fins 523 is fixed to the member including the plurality of second outer fins 522 by a method such as fastening or welding.

The second portion 52 of the heat sink 50 conducts heat of the air inside the housing 10 from the inner fin 523 to the second base plate 521. The second portion 52 conducts heat from the second base plate 521 to the second outer fin 522. Then, the second portion 52 transfers heat from the second outer fin 522 to the air outside the housing 10, and releases the heat generated inside the housing 10 to the outside of the housing 10.

(Effect of the first embodiment)
In the first embodiment, the following effects can be obtained.

In the first embodiment, as described above, thermal resistance is generated between the first portion 51 that dissipates heat from the heat generating portion including the semiconductor switching element 41 and the second portion 52 that cools the air in the housing 10. The seal members 22 and 23 having the above are provided. As a result, the sealing members 22 and 23 having thermal resistance suppress the heat transfer from the first portion 51 that dissipates the heat of the semiconductor switching element 41 to the second portion 52 that cools the air in the housing 10. can do. As a result, it is possible to suppress the temperature rise of the second portion 52, so that the temperature difference between the inside of the housing 10 of the second portion 52 and the air inside the housing 10 can be increased. As a result, the heat of the air inside the housing 10 can be efficiently transferred to the second portion 52, so that the increase in the air temperature inside the housing 10 can be suppressed.

Further, in the first embodiment, as described above, the first portion 51 is provided with the first base plate 511 and the first outer fin 512 arranged outside the housing 10 from the first base plate 511. As a result, the heat generating portion including the semiconductor switching element 41 can be brought into contact with the first base plate 511 of the first portion 51, so that the semiconductor switching element can be brought into contact with the first base plate 511 and the first outer fin 512. The heat of 41 can be easily dissipated to the outside. Further, in the second portion 52, the second base plate 521, the second outer fin 522 arranged on the outside of the housing 10 from the second base plate 521, and the inside of the housing 10 from the second base plate 521 are arranged. An inner fin 523 is provided. As a result, the heat of the air inside the housing 10 can be efficiently transferred to the second portion 52 by the inner fin 523, so that the heat inside the housing 10 is efficiently released to the outside through the second outer fin 522. can do.

Further, in the first embodiment, as described above, a member having a thermal conductivity smaller than that of the heat sink 50 is provided as the thermal resistance portion. As a result, the first portion 51 and the second portion 52 can be easily thermally separated, so that heat transfer from the first portion 51 to the second portion 52 can be easily suppressed.

Further, in the first embodiment, as described above, the heat sink 50 is attached to the housing 10 via the seal members 22 and 23. As a result, the heat sink 50 can be attached to the housing 10 via the sealing members 22 and 23, so that the inside of the housing 10 can be sealed. As a result, the space inside the housing 10 in which the component including the semiconductor switching element 41 is arranged can be sealed, so that the dustproof function and the waterproof function can be provided. Further, since the heat sink 50 can be attached to the housing 10 via the sealing members 22 and 23 having thermal resistance (low thermal conductivity), it is possible to suppress the heat of the heat sink 50 from being transferred to the housing 10. can.

Further, in the first embodiment, as described above, the first portion 51 and the second portion 52 of the heat sink 50 are formed by separate bodies, and heat is generated between the first portion 51 and the second portion 52 of the separate bodies. The sealing members 22 and 23 having resistance are arranged. As a result, the first portion 51 and the second portion 52 can be reliably thermally separated, so that heat transfer from the first portion 51 to the second portion 52 can be suppressed more effectively.

Further, in the first embodiment, as described above, the inside of the housing 10 is sealed, and the semiconductor switching element 41 is arranged in the closed space inside the housing 10. As a result, the power conversion device 100 can be provided with a dustproof function and a waterproof function.

[Second Embodiment]
Next, the configuration of the power conversion device 200 according to the second embodiment will be described with reference to FIGS. 5 and 6. The power conversion device 200 in the second embodiment is different from the first embodiment in which the first portion 51 and the second portion 52 of the heat sink 50 are formed separately, and the power conversion device 200 is different from the first portion 61 of the heat sink 60. The second portion 62 is integrally formed. In the figure, the same reference numerals are given to the parts having the same configuration as that of the first embodiment, and the description thereof will be omitted.

(Structure of power converter)
The structural configuration of the power converter 200 will be described. As shown in FIGS. 5 and 6, the power conversion device 200 includes a housing 10, sealing members 21 and 24, fastening members 31 (see FIG. 2) and 34, a substrate 40, and a heat sink 60. There is. The housing 10 includes a housing body 13 and a front cover 12. The housing body 13 is provided with an opening 131. The substrate 40 is provided with a semiconductor switching element 41 and a control circuit 42. The heat sink 60 includes a first portion 61 and a second portion 62. The first portion 61 has a first base plate 611 and a first outer fin 612. The second portion 62 includes a second base plate 621, a second outer fin 622, and an inner fin 623. In FIGS. 5 and 6, electronic components other than the semiconductor switching element 41 of the power conversion device 200 and the control circuit 42 for driving the semiconductor switching element 41 are omitted for the sake of brevity.

Here, in the second embodiment, the first portion 61 and the second portion 62 of the heat sink 60 are integrally formed. Further, a bent portion 63 is provided as a thermal resistance portion between the first portion 61 and the second portion 62. The bent portion 63 includes a groove portion 631 formed so as to extend in the Z direction. Further, the bent portion 63 is provided between the first base plate 611 of the first portion 61 and the second base plate 621 of the second portion 62 so as to connect the first base plate 611 and the second base plate 621. It is configured in. The bent portion 63 is bent so as to project toward the outside (Y2 direction side). The bent portion 63 suppresses heat conduction from the first portion 61 to the second portion 62 by increasing the distance of the solid portion (heat conduction portion) between the first base plate 611 and the second base plate 621. It is configured as follows.

The groove portion 631 may be formed deeper than the first base plate 611 and the second base plate 621, or may be shallower than the first base plate 611 and the second base plate 621 so that the width of the groove (X direction). Length) may be increased. This makes it possible to increase the distance of heat conduction. Further, the bent portion 63 may be bent a plurality of times.

The heat sink 60 is attached to the housing body 13 via the seal member 24. Further, the heat sink 60 is attached to the housing body 13 so as to close the opening 131 of the housing body 13. Further, the heat sink 60 is fastened to the housing body 13 by a plurality of fastening members 34. The first base plate 611 and the first outer fin 612 of the first portion 61 correspond to the first base plate 511 and the first outer fin 512 of the first embodiment, respectively, and have the same configuration. .. Further, the second base plate 621, the second outer fin 622, and the inner fin 623 of the second portion 62 correspond to the second base plate 521, the second outer fin 522, and the inner fin 523 of the first embodiment, respectively. It has a similar configuration.

The other configurations of the second embodiment are the same as those of the first embodiment.

(Effect of the second embodiment)
In the second embodiment, the following effects can be obtained.

In the second embodiment, as described above, thermal resistance is generated between the first portion 61 that dissipates heat from the heat generating portion including the semiconductor switching element 41 and the second portion 62 that cools the air in the housing 10. A bent portion 63 is provided as a portion. As a result, the bent portion 63 as the thermal resistance portion suppresses heat transfer from the first portion 61 that dissipates heat of the semiconductor switching element 41 to the second portion 62 that cools the air in the housing 10. be able to. As a result, it is possible to suppress an increase in the air temperature inside the housing 10 as in the first embodiment.

Further, in the second embodiment, as described above, the bent portion 63 is provided as the thermal resistance portion. As a result, the first portion 61 and the second portion 62 can be integrally formed while thermally separating the first portion 61 and the second portion 62, so that the increase in the number of parts can be suppressed. Can be done.

Further, in the second embodiment, as described above, the first portion 61 and the second portion 62 of the heat sink 60 are integrally formed, and as a thermal resistance portion, between the first portion 61 and the second portion 62. A groove 631 is provided in the groove. As a result, the number of parts can be reduced and the inside of the housing 10 can be easily sealed as compared with the case where the first portion 61 and the second portion 62 are provided separately. Further, the groove portion 631 can suppress the transfer of heat from the first portion 61 to the second portion 62.

The other effects of the second embodiment are the same as those of the first embodiment.

[Third Embodiment]
Next, the configuration of the power conversion device 300 according to the third embodiment will be described with reference to FIG. 7. The power conversion device 300 in the third embodiment is different from the first embodiment in which the first portion 51 and the second portion 52 of the heat sink 50 are formed separately, and the power conversion device 300 is different from the first portion 71 of the heat sink 70. The second portion 72 is integrally formed. Further, the power conversion device 300 in the third embodiment is different from the second embodiment in which the bent portion 63 is provided between the first portion 61 and the second portion 62 of the heat sink 60, and the heat sink 70 is the first. A portion having a cross-sectional area smaller than that of the heat sink 70 is formed between the first portion 71 and the second portion 72. In the figure, the same reference numerals are given to the parts having the same configuration as that of the first embodiment or the second embodiment, and the description thereof will be omitted.

(Structure of power converter)
The structural configuration of the power conversion device 300 will be described. As shown in FIG. 7, the power conversion device 300 includes a housing 10, sealing members 21 and 24, fastening members 31 (see FIG. 2) and 34, a substrate 40, and a heat sink 70. The housing 10 includes a housing body 13 and a front cover 12. The housing body 13 is provided with an opening 131. The substrate 40 is provided with a semiconductor switching element 41 and a control circuit 42. The heat sink 70 includes a first portion 71 and a second portion 72. The first portion 71 has a first base plate 711 and a first outer fin 712. The second portion 72 includes a second base plate 721, a second outer fin 722, and an inner fin 723. In FIG. 7, electronic components other than the semiconductor switching element 41 of the power conversion device 300 and the control circuit 42 for driving the semiconductor switching element 41 are omitted for simplification of description.

Here, in the third embodiment, the first portion 71 and the second portion 72 of the heat sink 70 are integrally formed. Further, a thermal resistance portion 73 is provided between the first portion 71 and the second portion 72. The thermal resistance portion 73 includes a thin-walled portion 731 having a smaller cross-sectional area (cross-sectional area cut in parallel with the YZ plane) than the first base plate 711 and the second base plate 721 of the heat sink 70. Further, the thermal resistance portion 73 includes a groove portion 732 formed so as to extend in the Z direction. Further, the thermal resistance portion 73 is provided between the first base plate 711 of the first portion 71 and the second base plate 721 of the second portion 72, and connects the first base plate 711 and the second base plate 721. It is configured as follows. That is, the thermal resistance portion 73 has a cross-sectional area smaller than the cross-sectional area of the connecting portions of the first portion 71 and the second portion 72. The groove portion 732 is formed so as to be recessed toward the inside (Y1 direction side). By arranging the groove portion 732 on the outside, it is possible to easily secure the airtightness inside the housing 10. The thin-walled portion 731 is configured to increase the thermal resistance by reducing the cross-sectional area and suppress heat conduction from the first portion 71 to the second portion 72.

The first base plate 711 and the first outer fin 712 of the first portion 71 correspond to the first base plate 511 and the first outer fin 512 of the first embodiment, respectively, and have the same configuration. .. Further, the second base plate 721, the second outer fin 722, and the inner fin 723 of the second portion 72 correspond to the second base plate 521, the second outer fin 522, and the inner fin 523 of the first embodiment, respectively. It has a similar configuration.

The other configurations of the third embodiment are the same as those of the first embodiment.

(Effect of the third embodiment)
In the third embodiment, the following effects can be obtained.

In the third embodiment, as described above, thermal resistance is generated between the first portion 71 that dissipates heat from the heat generating portion including the semiconductor switching element 41 and the second portion 72 that cools the air in the housing 10. A unit 73 is provided. As a result, the thermal resistance portion 73 can suppress heat transfer from the first portion 71, which dissipates heat from the semiconductor switching element 41, to the second portion 72, which cools the air inside the housing 10. As a result, it is possible to suppress an increase in the air temperature inside the housing 10 as in the first embodiment.

Further, in the third embodiment, as described above, the thermal resistance portion includes a portion having a cross section smaller than that of the heat sink 70. As a result, the first portion 71 and the second portion 72 can be integrally formed while thermally separating the first portion 71 and the second portion 72, so that the increase in the number of parts can be suppressed. Can be done.

The other effects of the third embodiment are the same as those of the first embodiment.

(Modification example)
It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims.

For example, in the first to third embodiments described above, an example of a configuration in which a heat sink is provided on the back surface (rear surface) of the power conversion device is shown, but the present invention is not limited to this. In the present invention, the heat sink may be provided on any surface of the power conversion device. For example, a heat sink may be provided on the side surface or the front surface of the power converter. Further, the installation posture of the power conversion device may be arbitrarily determined and arranged.

Further, in the first to third embodiments, an example of a configuration in which a control circuit is provided in the power conversion device is shown, but the present invention is not limited to this. In the present invention, the control circuit may be provided externally to the power conversion device.

Further, in the first to third embodiments, an example of the configuration in which the front cover is provided on the housing is shown, but the present invention is not limited to this. In the present invention, the front surface may be covered with the housing body without providing the front cover on the housing.

Further, in the first to third embodiments, the example of the configuration in which the power conversion device converts electric power into three-phase alternating current is shown, but the present invention is not limited to this. In the present invention, for example, the power conversion device may be configured to convert electric power into single-phase alternating current. Further, the circuit configuration of the power conversion device is not limited to the circuit configuration of the embodiment.

Further, in the first to third embodiments, an example of the configuration in which the inner fin and the second outer fin of the second portion are formed by different members is shown, but the present invention is not limited to this. In the present invention, the inner fin and the second outer fin of the second portion may be formed by an integral member.

Further, in the first to third embodiments, an example of a configuration in which fins are provided on the heat sink is shown, but the present invention is not limited to this. In the present invention, the heat sink may not be provided with fins. Further, when the fins are provided, at least one of the first outer fin, the second outer fin and the inner fin may be provided.

Further, in the first to third embodiments, the example of the configuration in which the semiconductor switching element and the control circuit are mounted on the surfaces opposite to each other with respect to the substrate is shown, but the present invention is limited to this. not. In the present invention, the semiconductor switching element and the control circuit may be mounted on the same side surface of the substrate.

Further, in the first embodiment, an example in which a member having a thermal conductivity smaller than that of a heat sink is provided as a thermal resistance portion is shown, and in the second embodiment, an example in which a bent portion is provided as a thermal resistance portion is shown. In the embodiment, an example in which a portion having a cross-sectional area smaller than that of the heat sink is provided as the thermal resistance portion is shown, but the present invention is not limited to this. In the present invention, the thermal resistance portion may include at least one of a member having a thermal conductivity smaller than that of the heat sink, a portion having a cross-sectional area smaller than that of the heat sink, and a bent portion.

Further, in the second embodiment, an example of a configuration in which the bent portion as the thermal resistance portion is bent outward is shown, but the present invention is not limited to this. In the present invention, the bent portion as the thermal resistance portion may be bent inward.

Further, in the first to third embodiments, examples of the configuration in which the inner fins are arranged at positions in the horizontal direction with respect to the semiconductor switching element are shown, but the present invention is not limited to this. In the present invention, the inner fins may be arranged at positions in the vertical direction with respect to the semiconductor switching element.

10 Housing 22, 23, 24 Seal member (heat resistance part)
41 Semiconductor switching element 50, 60, 70 Heat sink 51, 61, 71 First part 52, 62, 72 Second part 63 Bending part (heat resistance part)
73 Thermal resistance unit 100, 200, 300 Power conversion device 101 Power conversion circuit 511, 611, 711 First base plate 512, 612, 712 First outer fin 521, 621, 721 Second base plate 522, 622, 722 Second Outer fins 523, 623, 723 Inner fins 631, 732 Grooves

Claims (6)

A power conversion circuit that includes a semiconductor switching element and converts DC power to AC power,
A housing for accommodating the power conversion circuit and
A heat sink that dissipates heat generated inside the housing to the outside of the housing is provided.
The heat sink includes a first portion that dissipates heat from a heat generating portion including the semiconductor switching element, and a second portion that cools air in the housing.
A thermal resistance portion is provided between the first portion and the second portion .
The second portion of the heat sink directly contacts the base portion, the outer fin portion provided integrally with the base portion so as to extend to the outside of the housing, and the inner surface of the housing of the base portion. A power conversion device including an inner fin portion provided so as to extend toward the inside of the housing . The first portion includes a first base plate and a first outer fin provided on the outer side of the housing from the first base plate.
The second portion includes a second base plate as the base portion, a second outer fin as the outer fin portion provided on the outer side of the housing from the second base plate, and the second base plate to the above. The power conversion device according to claim 1, further comprising an inner fin as the inner fin portion provided inside the housing. The power conversion device according to claim 1 or 2, wherein the thermal resistance portion includes a member having a thermal conductivity smaller than that of the heat sink, a portion having a cross-sectional area smaller than that of the heat sink, and at least one of a bent portion. .. The thermal resistance portion includes a sealing member having a thermal conductivity lower than that of the heat sink.
The power conversion device according to claim 3, wherein the heat sink is attached to the housing via the seal member. The heat sink is formed by a separate body of the first portion and the second portion.
The power conversion device according to any one of claims 1 to 4, wherein the thermal resistance portion is arranged between the first portion and the second portion of the separate body. The heat sink is integrally formed with the first portion and the second portion.
The power conversion device according to any one of claims 1 to 5, wherein the thermal resistance portion includes a groove portion provided between the first portion and the second portion.

Images