WO2018061193A1

WO2018061193A1 - Heat sink and power conversion device

Info

Publication number: WO2018061193A1
Application number: PCT/JP2016/079087
Authority: WO
Inventors: 哲平良; 加藤　真; 清志柴田
Original assignee: 三菱電機株式会社
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2018-04-05
Also published as: JPWO2018061193A1

Abstract

A heat sink (100) is characterized in being provided with the following: a fin base (1); two first fins (21) having bases (2d) that are attached to a bottom surface (1a) of the fin base (1); second fins (22) having bases (2d) that are attached to the bottom surface (1a) of the fin base (1), the second fins being disposed so as to be sandwiched between the two first fins (21); and a linking part (23) that is provided between each of the first fins (21) and a second fin (22) adjacent thereto, the linking part linking the first fin (21) and the second fin (22).

Description

Heat sink and power converter

The present invention relates to a heat sink and a power conversion device including a plurality of fins for radiating heat of a heating element.

The heat sink disclosed in Patent Document 1 includes a fin base to which a semiconductor module is attached on the upper surface, and a plurality of first fins and second fins on the lower surface of the fin base. Two first fins are provided so as to sandwich the plurality of second fins, and the thickness of the first fin is larger than the thickness of the second fin. With this configuration, the rigidity of the first fin is greater than the rigidity of the second fin, and the first when the object collides is greater than when the thickness of the first fin and the thickness of the second fin are equal. The deformation of the fins is suppressed. Here, the object includes not only structures such as walls and floors that may be hit by the heat sink during transportation of the heat sink, but also flying objects such as stone and wood. By the rigidity of the first fin being increased, the first fin is deformed so as to bend toward the second fin when an object collides, thereby forming between the first fin and the second fin. It can suppress that the 1st clearance gap currently performed is narrowed. In addition, the second gap formed between the second fins is also prevented from being narrowed by the first fin physically interfering with the second fin and the adjacent second fin being deformed. it can. As a result, a decrease in the flow rate of the refrigerant such as air flowing in the first and second gaps is suppressed, and a decrease in the heat dissipation performance of the heat sink is suppressed.

Japanese Patent Laying-Open No. 2015-27144

However, in the heat sink disclosed in Patent Document 1, since the thickness of the first fin is large, there is a problem that the amount of the material used for manufacturing the heat sink increases and the manufacturing cost of the heat sink increases.

The present invention has been made in view of the above, and an object of the present invention is to obtain a heat sink that can suppress a decrease in heat dissipation performance while suppressing an increase in manufacturing cost.

In order to solve the above-described problems and achieve the object, the heat sink of the present invention includes a fin base, two first fins having roots attached to the lower surface of the fin base, and a root on the lower surface of the fin base. A second fin that is attached and arranged to be sandwiched between the two first fins, the first fin, and a second fin adjacent to the first fin; And a connecting portion that connects the first fin and the second fin.

According to the present invention, it is possible to suppress a decrease in heat dissipation performance while suppressing an increase in manufacturing cost.

The perspective view of the power converter device which concerns on embodiment of this invention Front view of the heat sink shown in FIG. 1 viewed from the Z-axis direction Configuration diagram of heat sink according to first modification Configuration diagram of heat sink according to second modification Partial enlarged view of a heat sink according to a third modification The perspective view of the power converter device which concerns on a 4th modification The figure which shows the state before attaching a cover to the heat sink shown in FIG. The perspective view of the power converter device which concerns on a 5th modification Front view of the heat sink shown in FIG. 8 viewed from the Z-axis direction

Hereinafter, a heat sink and a power conversion device according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a perspective view of a power converter according to an embodiment of the present invention. FIG. 2 is a front view of the heat sink shown in FIG. 1 as viewed from the Z-axis direction. In FIG. 1, in the right-handed XYZ coordinates, the vertical direction of the heat sink 100 is the Y-axis direction, the direction orthogonal to the Y-axis direction is the X-axis direction, and the direction orthogonal to both the Y-axis direction and the X-axis direction is Z Axial direction. The X-axis direction is equal to the arrangement direction of first and

second fins

21 and 22 described later. The same applies to each figure after FIG.

The heat sink 100 includes a plate-shaped fin base 1 extending in the Z-axis direction, and a first fin 21 and a second fin 22 provided on the lower surface 1 a of the fin base 1. Examples of the method of attaching the first fin 21 and the second fin 22 to the fin base 1 may include attachment by welding, adhesion, welding, brazing, caulking, or fitting. Further, the first fin 21 and the second fin 22 may be formed integrally with the fin base 1. Hereinafter, the first fin 21 and the second fin 22 may be simply referred to as first and

second fins

21 and 22.

The roots 2 d of the first and

second fins

21 and 22 are attached to the lower surface 1 a of the fin base 1. The lower surface 1 a of the fin base 1 is a surface facing the upper surface 1 b of the fin base 1. The first and

second fins

21 and 22 are spaced apart from each other and arranged in the X-axis direction. The first fins 21 are provided outside the arrangement direction of the fin group composed of the plurality of second fins 22. That is, the first fins 21 are arranged at both ends of the fin group so that the two first fins 21 sandwich the second fin 22.

In the present embodiment, as shown in FIG. 2, the tips 2c of the first and

second fins

21 and 22 are released to form a comb-shaped heat sink. The first and

second fins

21 and 22 attached to the fin base 1 are collectively referred to as a fin group 2A.

The first thickness t1 of the first fin 21 in the X-axis direction and the second thickness t2 of the second fin 22 in the X-axis direction are equal to each other. Examples of the first and second thicknesses t1 and t2 include 0.6 mm to 1.2 mm. A first gap 3 a is formed between the adjacent first and

second fins

21 and 22. A second gap 3b is formed between the adjacent second fins 22.

Between the adjacent first and

second fins

21, 22, a connecting portion 23 that connects the first and

second fins

21, 22 is provided. The connecting portion 23 is provided near the tip 2c of the fin group 2A. That is, with reference to the lower surface 1a of the fin base 1, the position of the fin group 2A in the Y-axis direction in which the fin group 2A extends from the fin base 1, that is, the half of the length from the root 2d to the tip 2c of the fin group 2A Further, the connecting portion 23 is provided on the tip 2c side. That is, the connecting portion 23 is provided on the tip 2c side of the intermediate point between the root 2d and the tip 2c of the fin group 2A.

The connecting portion 23 has a rod shape extending from one end 2a to the other end 2b of the fin group 2A in the Z-axis direction. The width of the connecting portion 23 in the Y-axis direction is smaller than the width of the fin group 2A in the Y-axis direction. The width of the connecting portion 23 in the Z-axis direction is equal to the width of the fin group 2A in the Z-axis direction.

As shown in FIG. 1, the power converter 200 includes a housing 210 and a semiconductor module 220 that is a power module. The semiconductor module 220 is provided inside the housing 210. The semiconductor module 220 is mounted on a printed circuit board (not shown) that constitutes the power conversion apparatus 200. The semiconductor module 220 mounted on the printed circuit board is disposed on the upper surface 211 a side of the bottom wall 211 of the housing 210, and the upper surface 1 b of the fin base 1 is installed on the lower surface 211 b side of the bottom wall 211 of the housing 210. The semiconductor module 220 may be disposed directly on the upper surface 1b of the fin base 1 without being mounted on the printed circuit board.

Examples of the materials of the fin base 1, the fin group 2A, and the casing 210 include aluminum, aluminum alloy, austenitic stainless alloy, copper alloy, cast iron, steel, and iron alloy.

As shown in FIG. 1, the bottom wall 211 of the casing 210 is formed to extend from the box-shaped space in which the semiconductor module 220 is installed to the outside in the Z-axis direction, and the blower unit 300 is fixed to the extended portion. . The air blower 300 is provided to face the other end 2b of the fin group 2A in the Z-axis direction. The air blower 300 includes a fan and a fan drive motor (not shown).

The heat generated in the semiconductor module 220 is transmitted to the heat sink 100. When a fan (not shown) provided in the air blowing unit 300 rotates, negative pressure is generated in the first and

second gaps

3a and 3b, and the first and second gaps 2A cause a pressure difference between the inside and outside of the fin group 2A. In addition, air is taken into the

second gaps

3a and 3b. When air flows in the first and

second gaps

3a and 3b in the direction of arrow A in FIG. 1, high-temperature air near the surface of the fin group 2A and low-temperature air flowing away from the fin group 2A Are mixed. Thereby, the development of the temperature boundary layer formed on the surface of the fin group 2A is suppressed, the amount of heat exchange between the air and the fin group 2A is improved, the cooling efficiency of the fin group 2A is improved, and the semiconductor module 220 Is effectively cooled.

In the power conversion device 200 according to the present embodiment, the example in which the air blowing unit 300 is disposed on the downstream side of the fin group 2A has been described. However, the air blowing unit 300 is disposed on the upstream side, You may comprise so that a refrigerant | coolant may be sent into the fin group 2A from the ventilation part 300. FIG. Moreover, it cannot be overemphasized that the power converter device 200 may omit the ventilation part 300, and may perform natural cooling.

In order to improve the cooling efficiency of the semiconductor module 220, it is effective to increase the surface areas of the first and

second fins

21 and 22 that exchange heat with the refrigerant. Here, in order to increase the surface area of the fin group 2A while keeping the volume of the heat sink 100, that is, the width from one end to the other end of each fin group 2A in the X-axis direction, Y-axis direction, and Z-axis direction constant. Is a method of increasing the number of the second fins 22 by reducing the thickness of the fin group 2A in the X-axis direction.

In addition, there is a method of improving the cooling efficiency by reducing the thickness of the first and

second fins

21 and 22 to increase the first and

second gaps

3a and 3b and increasing the amount of refrigerant for heat exchange. .

However, as the thickness of the fin group 2A is reduced, the rigidity of the fin group 2A is reduced, and the fin group 2A is easily deformed when an object collides with the fin group 2A. In particular, the first fin 21 disposed on the outermost side of the fin group 2A is most susceptible to an object collision, and thus is likely to be deformed.

On the other hand, in order to increase the thickness of the first fin 21 in order to improve the rigidity of the fin group 2A, in particular, the rigidity of the first fin 21 that is likely to be deformed because an object easily collides, the volume of the heat sink 100 is reduced. If it does not increase, it is necessary to narrow the first gap 3a or the second gap 3b, and the cooling efficiency is lowered.

Thus, the improvement of the cooling efficiency of the fin group 2A and the improvement of the rigidity of the fin group 2A are in a trade-off relationship.

Further, in order to improve the rigidity of the fin group 2A while maintaining the cooling efficiency, if the narrowing of the first gap 3a and the second gap 3b is suppressed, the heat sink 100 is increased in size.

In the heat sink 100 according to the present embodiment, since the first and

second fins

21 and 22 are connected by the connecting portion 23, the first fin 21, the second fin 22, and the connecting portion 23 are integrally formed. And configured as one structure. Compared with the case where the first and

second fins

21 and 22 are not connected by the connecting portion 23, the first and

second fins

21 and 22 that are connected have a higher rigidity, so that the first and

second fins

21 and 22 are less affected when the object collides. The deformation of one fin 21 is suppressed. That is, since the first fin 21 is physically supported by the second fin 22 through the connecting portion 23, the rigidity is improved, and deformation is suppressed when an object collides with the first fin 21. . Further, since the deformation of the first fin 21 is suppressed, the deformation of the second fin 22 due to the physical interference of the deformed first fin 21 with the second fin 22 is suppressed. Therefore, the first and

second gaps

3a and 3b are not blocked, and a decrease in the flow rate of the air flowing through the first and

second gaps

3a and 3b is suppressed.

Further, in the heat sink 100 according to the present embodiment, since the first fin 21 is connected to the second fin 22 by the connecting portion 23, the first thickness t1 of the first fin 21 in the X-axis direction is increased. The rigidity of the first fin 21 can be improved without doing so. In the heat sink 100, the amount of the material used is increased by the amount of the connecting portion 23 compared to the case where the connecting portion 23 is not provided, but the amount of the material used for the connecting portion 23 is the first to obtain the rigidity described above. It is less than the amount of material used when the thickness t1 is increased. Therefore, an increase in manufacturing cost of the heat sink 100 is suppressed.

Although the first fin 21 has the same thickness as the second fin 22 in the present embodiment, the thickness of the first fin 21 and the second fin 22 may not be completely the same. When the first fin 21 and the second fin 22 are independent from each other without being connected by the connecting portion 23, the thickness of the first fin 21 is increased in order to improve the rigidity of the first fin 21. Can be considered. In order to obtain sufficient rigidity only by increasing the thickness of the first fin 21, it is necessary to increase the thickness of the first fin 21 sufficiently. This leads to narrowing and an increase in the size of the heat sink 100.

Since the heat sink 100 according to the present embodiment uses the connecting portion 23, the effect of improving the rigidity of the fin can be obtained while suppressing the amount of material used compared to the case of improving the rigidity only by the thickness of the fin. Furthermore, it is possible to suppress a decrease in cooling efficiency and an increase in the size of the heat sink.

Further, in the heat sink 100 according to the present embodiment, since it is not necessary to increase the first thickness t1 of the first fin 21 in the X-axis direction more than necessary, the other end to the other end of the fin group 2A in the X-axis direction. The first gap 3a between the first and

second fins

21 and 22 is larger than the case where the first thickness t1 of the first fin 21 is increased with the width up to the portion, that is, the size of the heat sink 100 being constant. Is increased, and a decrease in heat dissipation performance of the heat sink 100 is suppressed.

FIG. 3 is a configuration diagram of a heat sink according to the first modification. FIG. 4 is a configuration diagram of a heat sink according to a second modification. In the heat sink 100A shown in FIG. 3, the connecting portion 23 is provided near the root 2d of the fin group 2A in the Y-axis direction. That is, with the lower surface 1a of the fin base 1 as a reference, the connecting portion 23 is provided on the root 2d side from a position that is half the length of the fin group 2A in the Y-axis direction in which the fin group 2A extends from the fin base 1. That is, the connecting portion 23 is provided closer to the root 2d than the center point between the root 2d and the tip 2c. In the heat sink 100 </ b> B shown in FIG. 4, the connecting portion 23 is provided at the front end 2 c of the first fin 21 and the second fin 22. In the heat sink 100A and the heat sink 100B, since the first and

second fins

21 and 22 are connected by the connecting portion 23, similarly to the heat sink 100 shown in FIG. The deformation of the first fin 21 at the time of collision is suppressed. Therefore, an increase in the amount of material used for the heat sink 100A and the heat sink 100B is suppressed, and a decrease in the heat dissipation performance of the heat sink 100A and the heat sink 100B is suppressed.

FIG. 5 is a partially enlarged view of a heat sink according to a third modification. In the heat sink 100 shown in FIGS. 1 and 2, the fin group 2A is attached to the fin base 1 by welding or bonding. However, in the heat sink 100C shown in FIG. 5, the fin group 2A is fixed to the fin base 1 by a fitting structure. ing.

As shown in FIG. 5, an ant tenon-shaped ant tenon portion 2e is formed on the root 2d of the fin group 2A in the Y-axis direction. The root 2d of the fin group 2A is the end of the fin group 2A on the fin base 1 side. The ant tenon 2e extends from one end 2a of the fin group 2A to the other end 2b in the Z-axis direction.

A plurality of slide guides 1 a 1 are formed on the lower surface 1 a of the fin base 1. The slide guide 1a1 has a dovetail shape that extends from one end 1c of the fin base 1 to the other end 1d in the Z-axis direction and into which the dovetail part 2e is fitted.

When attaching the fin group 2A to the fin base 1, the dovetail part 2e is inserted into the slide guide 1a1 and guided toward the other end 1d of the fin base 1 in the Z-axis direction. Thereby, the ant tenon portion 2e and the slide guide 1a1 are fitted to each other, and the fin group 2A is fixed to the fin base 1. When removing the fin group 2A from the fin base 1, the fin group 2A may be slid in the Z-axis direction.

The fitting structure of the fin base 1 and the fin group 2A is not limited to the dovetail and dovetail groove, and at least one of the first and

second fins

21 and 22 is slid in the Z-axis direction on the fin base 1. Any structure that fits into the fin base 1 may be used. By using the fitting structure, even when one first fin 21 is deformed, it is not necessary to replace the remaining plurality of fins. Therefore, compared to the case where the entire heat sink 100C is replaced, the maintainability is improved. Work time associated with fin replacement can be reduced.

Note that, as described above, a caulking method may be used as a method of fixing the fin group 2A to the fin base 1. In this case, a fin insertion claw (not shown) is provided in advance in the fin base 1, and the fin group 2A is inserted into the claw and fixed by caulking.

In addition, the length of the connecting portion 23 in the Z-axis direction is such that the first and

second fins

21 and 22 in the Z-axis direction have a sufficient mechanical strength to connect the first and

second fins

21 and 22. It may be smaller than the width. The number of connecting portions 23 provided in the first gap 3a may be plural. Specifically, a plurality of connecting portions that are shorter in the Z-axis direction than the connecting portion 23 shown in FIG. 1 may be arranged along the Z-axis direction, or the connecting portions 23 shown in FIG. A plurality may be arranged along the axial direction.

FIG. 6 is a perspective view of a power converter according to a fourth modification. FIG. 7 is a view showing a state before the cover is attached to the heat sink shown in FIG. As shown in FIGS. 6 and 7, the heat sink 100D according to the fourth modification includes a cover 400 that covers the tip 2c of the fin group 2A. As shown in FIG. 7, in the heat sink 100D, the connecting portion 23 is provided near the tip 2c of the fin group 2A in the Y-axis direction. The connecting portion 23 has a female screw portion (not shown) penetrating in the Y-axis direction, and the cover 400 is fixed to the connecting portion 23 by screwing the fastening member 401 into the female screw portion. The fixing place of the cover 400 is not limited to the connecting portion 23, and the cover 400 may be fixed to the first fin 21 using a fastening member (not shown) screwed into the first fin 21 from the X-axis direction. Good.

By providing the cover 400, it is possible to prevent an object from colliding with the tip 2c of the fin group 2A and deforming. Further, since the two first fins 21 sandwiching the second fin 22 on both sides are fixed to the cover 400, the rigidity of the first fin 21 is further improved. As a result, the deformation of the first fin 21 and the second fin 22 is further suppressed.

FIG. 8 is a perspective view of a power converter according to a fifth modification. FIG. 9 is a front view of the heat sink shown in FIG. 8 as viewed from the Z-axis direction. As shown in FIGS. 8 and 9, the heat sink 100E according to the fifth modification includes a cover 500 that covers the tip 2c of the fin group 2A and covers the outside of the first fin 21 in the X-axis direction. A female screw portion (not shown) is formed on the lower surface 1a of the fin base 1 in the Y-axis direction, and the cover 500 is fixed to the fin base 1 by screwing the fastening member 501 into the female screw portion.

By providing the cover 500, it is possible to prevent an object from colliding with the fin group 2A, so that the deformation of the first and

second fins

21 and 22 is further suppressed.

In the heat sink according to the present embodiment, the first thickness t1 of the first fin 21 in the X-axis direction and the second thickness t2 of the second fin 22 in the X-axis direction may not be equal to each other. When the thicknesses are equal, the yield of the fins is improved and an increase in the manufacturing cost of the fins can be suppressed as compared with the case of manufacturing two types of fins having different thicknesses.

Further, in the

heat sinks

100 and 100B shown in FIGS. 1 and 4 according to the present embodiment, the first fin 21 includes a root 2d attached to the fin base 1, a root 2d of the first fin 21, and a tip 2c. It is supported by the connecting portion 23 provided on the tip 2c side from the center point in between. In the heat sink 100A shown in FIG. 3, which is a modification of the present embodiment, the first fin 21 is provided on the root 2d side from the root 2d and the center point between the root 2d and the tip 2c of the first fin 21. The connecting portion 23 is supported. In the former case, the rigidity on the tip 2c side of the first fin 21 is larger than that in the latter, and deformation of the first fin 21 at the time of an object collision is suppressed. That is, the rigidity of the first fins 21 can be effectively improved by the arrangement of the connecting portions 23.

Since the root 2d of the first fin 21 is attached to the fin base 1, in order to effectively improve the rigidity from the root 2d to the tip 2c of the first fin 21, the connecting portion 23 is connected to the tip 2c. The closer to the side, the greater the effect, and it is most desirable to provide the connecting portion 23 at the tip 2c.

On the other hand, when the width from the root 2d to the tip 2c of the first fin 21 is long, it is preferable to provide the connecting portion 23 at two points, that is, the tip 2c and an intermediate point between the root 2d and the tip 2c.

As described above, a plurality of connecting portions 23 may be provided between the root 2d and the tip 2c in the first gap 3a. In order to effectively improve the rigidity of the first fin 21, it is preferable to arrange the plurality of connecting portions 23 so that the first gap 3a from the root 2d to the tip 2c is divided at equal intervals. Or you may concentrate the connection part 23 in the location which an object collides easily.

In the present embodiment, the connecting portion 23 has an example of a rod shape from the upstream side to the downstream side in the Z-axis direction, that is, from the upstream side through which the refrigerant passes, but has a zigzag shape from the upstream side to the downstream side. Alternatively, it may be wavy or uneven.

Moreover, although the connection part 23 was provided in the 1st clearance gap 3a in this Embodiment, it cannot be overemphasized that the connection part which connects two adjacent 2nd fins 22 may be provided further. .

In addition, the heat sink according to the present embodiment is installed in the casing 210 of the power conversion device 200 including the semiconductor module 220, but the installation location of the heat sink according to the present embodiment is not limited to this, and the present embodiment The heat sink according to the embodiment may be installed on the outer peripheral surface of the stator of the rotating electric machine, and may be installed in the housing of the instrument transformer having a built-in current transformer or instrument transformer.

The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

1 fin base, 1a, 2c, 211b bottom surface, 1a1 slide guide, 1b, 211a top surface, 1d, 2b other end, 1c, 2a one end, 2d root, 2A fin group, 2e ant tenon, 3a first gap 3b, 2nd gap, 21 1st fin, 22 2nd fin, 23 connecting part, 100, 100A, 100B, 100C, 100D, 100E heat sink, 200 power converter, 210 housing, 211 bottom wall, 220 Semiconductor module, 300 blower, 400,500 cover, 401,501 fastening member.

Claims

The fin base,
Two first fins having roots attached to the lower surface of the fin base;
A second fin disposed on a lower surface of the fin base and disposed so as to be sandwiched between the two first fins;
A connecting portion that is provided between the first fin and the second fin adjacent to the first fin and connects the first fin and the second fin;
A heat sink characterized by comprising:
The heat sink according to claim 1, wherein the thicknesses of the first fin and the second fin are equal to each other.
The heat sink according to claim 1 or 2, wherein the connecting portion is provided on a tip side of a root and a center point of the tip of the first fin.
The heat sink according to claim 1 or 2, wherein the connecting portion is provided at a plurality of locations from the base to the tip of the first fin.
The heat sink according to claim 1 or 4, wherein the connecting portion is provided at a position that divides a gap between the first fin and the second fin at equal intervals.
The heat sink according to any one of claims 1 to 5, wherein the heat sink has a fitting structure in which the first fin is slid and fitted into the fin base.
The heat sink according to any one of claims 1 to 6, further comprising an air blowing unit that generates an air flow in a gap between the first fin and the second fin.
The heat sink according to any one of claims 1 to 7, further comprising a cover that covers tips of the first fin and the second fin.
The heat sink according to claim 8, wherein the cover is fixed to the connecting portion.
A heat sink according to any one of claims 1 to 9,
A power module provided on the upper surface of the fin base;
A power conversion device comprising: