JP7236235B2 - Cooling system - Google Patents

Description

The present invention relates to cooling devices.

A power conversion device such as a converter includes electronic components that generate heat, such as semiconductors, capacitors, or coils, so heat sinks are attached to cool these components. On the other hand, in such a power conversion device, it is required to configure each circuit element and cooling structure with high density from the viewpoint of achieving high power and miniaturization.

However, as the density increases, the heat generation density in the power converter increases, so higher cooling performance is required. Here, the cooling performance of a heat sink generally depends on its volume (heat capacity), material (thermal conductivity), and surface area (heat transfer area) depending on its shape.

Therefore, in order to improve the cooling performance, it is required to increase the size of the heat sink itself, which leads to an increase in the size of the power converter as a whole. For this reason, improvements in the material and shape of the heat sink have been studied from the viewpoint of realizing an improvement in cooling performance while suppressing an increase in the size of the heat sink itself.

For example, Patent Document 1 proposes a heat sink provided with a plurality of fins. Then, the cooling air from the fan is circulated through the fins of the heat sink to cool the heating element provided on the heat sink.

JP 2009-290004 A

However, in the configuration of Patent Document 1, the plurality of fins disturb the flow of cooling air from the fan, resulting in increased pressure loss and reduced cooling efficiency.

In view of such circumstances, an object of the present invention is to provide a cooling device with higher cooling efficiency.

According to one aspect of the present invention, a heat sink having a first surface to which a heating element is joined, and an induced flow generator provided on a second surface of the heat sink facing the first surface and electrically generating an induced flow. is provided.

According to the present invention, it is possible to provide a cooling device with higher cooling efficiency.

FIG. 1 is a diagram illustrating the configuration of a cooling device according to a first embodiment of the present invention. 2 is a cross-sectional view taken along the line A-A' in FIG. 1. FIG. FIG. 3 is a cross-sectional view for explaining Modification 1-1 of the first embodiment. FIG. 4 is a cross-sectional view illustrating the configuration of the cooling device according to the second embodiment. 5 is a cross-sectional view taken along line B1-B1' in FIG. 4. FIG. 6 is a cross-sectional view taken along line B2-B2' in FIG. 4. FIG. FIG. 7 is a perspective view of the cooling device according to the second embodiment. FIG. 8 is a perspective view of a cooling device according to modification 2-1 of the second embodiment. FIG. 9 is a perspective view of a cooling device according to modification 2-2. FIG. 10 is a perspective view of a cooling device according to modification 2-3. FIG. 11 is a perspective view of a cooling device according to modification 2-4. FIG. 12 is a perspective view of a cooling device according to modification 2-5. FIG. 13 is a perspective view of a cooling device according to modification 2-6. FIG. 14 is a diagram illustrating the configuration of a cooling device having a fan according to a comparative example. FIG. 15 is a cross-sectional view illustrating the configuration of the cooling device according to the third embodiment. FIG. 16 is a cross-sectional view for explaining the configuration of a cooling device according to modification 3-1 of the third embodiment. FIG. 17 is a cross-sectional view illustrating the configuration of a cooling device according to modification 3-2. FIG. 18 is a perspective view illustrating the configuration of a cooling device according to modification 3-3. FIG. 19 is a perspective view illustrating the configuration of a cooling device according to modification 3-4. FIG. 20 is a cross-sectional view illustrating the configuration of a cooling device according to modification 3-5. FIG. 21 is a perspective view of a cooling device according to modification 3-5. FIG. 22 is a perspective view illustrating the configuration of a cooling device according to modification 3-6. FIG. 23 is a cross-sectional view for explaining the configuration of the plasma actuator according to the fourth embodiment. FIG. 24 is a cross-sectional view illustrating the configuration of a cooling device provided with plasma actuators. 25 is a cross-sectional view taken along line D-D' in FIG. 24. FIG.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings and the like. It should be noted that the drawings used for describing each embodiment and its modifications schematically show the essential parts of the configuration of each embodiment.

(First embodiment)
The first embodiment will be described below.

FIG. 1 is a flow direction cross-sectional view for explaining the configuration of a cooling device 10 according to the present embodiment. 2 is a cross-sectional view taken along line A-A' in FIG.

As illustrated, the cooling device 10 includes a heating element 1 , a heat sink main body 2 that constitutes the heat sink of the present embodiment, and an induced flow generator 3 . Heat generating elements 1 are various heat generating elements included in electronic devices such as motors, engines, and home appliances. In particular, as the heating element 1, electronic components such as semiconductors, semiconductor mold packages, capacitors, and coils are assumed.

The heat sink main body 2 is a structure that releases the heat generated by the heating element 1 into the surrounding atmosphere. In this embodiment, the heat sink main body 2 is formed as a plate-like member. The heating element 1 is bonded to the first surface 2a which is the surface on one side (Z-axis negative direction side) of the heat sink body 2 and functions as the first surface.

The heat sink body 2 is made of, for example, a metallic material with relatively high thermal conductivity such as copper or aluminum, or a non-metallic material with relatively high thermal conductivity such as FR4 (Flame Retardant Type 4) or ceramics. .

The induced flow generator 3 is provided on the second surface 2b functioning as the second surface of the heat sink main body 2 on the other side (the Z-axis positive direction side), that is, the second surface behind the first surface 2a. The induced flow generator 3 has an induced flow generator 3a on one side in the X-axis direction (the positive direction of the X-axis in the figure). Therefore, the induced flow generator 3 can generate the induced flow If in the positive direction of the X-axis in FIG.

More specifically, the induced flow generator 3 is electrically connected to molecules in the surrounding phase (gas phase such as an air atmosphere, an inert gas atmosphere such as a nitrogen atmosphere or an argon atmosphere, or a liquid phase such as water). It is a device that produces an induced flow If by giving a pressure difference by giving a bias to the charge distribution in the atmosphere. In the following description, for convenience of explanation, it is assumed that the surrounding phase is an air atmosphere (air layer 7). However, the following description is equally applicable to other gas or liquid phases.

The induced flow generator 3 has a length in the Y-axis direction substantially equal to that of the heat sink body 2 (see FIG. 1) and a length in the X-axis direction shorter than that of the heat sink body 2. The heat sink body 2 extends in the X-axis direction. Attached to a predetermined position within an area.

Further, the induced flow generator 3 of the present embodiment is arranged upstream of the heating element 1 in the direction of the induced flow If (X-axis direction).

More specifically, the induced flow generator 3 of the present embodiment is arranged at a peripheral position of the second surface 2b facing the heating element 1 joined to the first surface 2a (hereinafter also referred to as "heating element facing position P1"). 2 to the left side (X-axis negative direction side) of the heating element 1 so as to flow along the . In particular, the arrangement position of the induced flow generator 3 is adjusted so that a position a predetermined distance away from the induced flow generating section 3a where the flow velocity of the induced flow If is relatively high substantially coincides with the position P1 facing the heating element. is preferred. This further improves the efficiency of cooling by the induced flow If.

The width of the heat generating element 1 and the induced flow generator 3 in the Y direction depends on the width of the heat generating element 1, the amount of heat, and the area where the heat spreads to the heat sink body 2, so that the induced flow If is effective for heat transfer. The width can be adjusted as appropriate.

In the cooling device 10 having the above configuration, the heat of the heating element 1 is first transferred to the heat sink main body 2 . Then, the heat transferred to the heat sink main body 2 is diffused in the heat sink main body 2 and conducted in the Z-axis negative direction (the direction of the induced flow generator 3).

On the other hand, the induced flow If generated by the induced flow generator 3 flows along the second surface 2b of the heat sink body 2 in the positive direction of the X axis, and the heat generated between the second surface 2b of the heat sink body 2 and the air layer 7 is Facilitate transmission. In particular, since the induced flow If can flow in the interface of the air layer 7 in contact with the heat sink main body 2 immediately below the heat generating element 1, excessive development of a boundary layer such as a heat insulating layer generated between solid fluids can be suppressed. can. As a result, it becomes possible to effectively perform cooling with a relatively small flow rate of the induced flow If.

According to this embodiment having the configuration described above, the following effects are obtained.

A cooling device 10 according to the present embodiment includes a heat sink body 2 as a heat sink that is joined to a heating element 1 on a first surface 2 a as a first surface, and a second surface (second surface) of the heat sink body 2 facing the first surface 2 a. and an induced flow generator 3 that is provided on the second surface 2b (the back surface of the first surface 2a) and electrically generates an induced flow If.

As a result, the induced flow If passes through the second surface 2b of the heat sink body 2, thereby promoting heat transfer from the second surface 2b to the air layer 7, thereby cooling the heat generating element 1 more efficiently. It can be carried out. In addition, since the induced flow If can generate a flow at the interface between the second surface 2b of the heat sink body 2 and the air layer 7, excessive development of the boundary layer (heat insulating layer) at the interface can be suppressed. be able to. As a result, the heating element 1 can be efficiently cooled with the induced flow If of a relatively small flow rate compared to cooling air that is physically generated using a fan or the like.

In particular, the induced flow generator 3 of this embodiment is arranged so as to generate the induced flow If in the direction along the second surface 2b of the heat sink body 2 . Thereby, the induced flow If can further promote the diffusion of heat on the second surface 2 b of the heat sink body 2 . As a result, the substantial heat transfer area between the second surface 2b of the heat sink body 2 and the air layer 7 can be further expanded, so that the cooling efficiency can be further improved.

Furthermore, in the present embodiment, the induced flow generator 3 generates the induced flow If toward the heating element facing position P1 as the position of the second surface 2b facing the heating element 1 joined to the first surface 2a. are arranged as follows.

As a result, the induced flow If can be preferably applied to a position on the heat sink main body 2 near the heating element 1 which is the heat source. In particular, by adjusting the area where the flow rate of the induced flow If generated by the induced flow generator 3 is relatively high to the position P1 facing the heating element, the induced flow If with a high flow rate can be applied to the portion where the amount of heat is relatively high. Therefore, heat transfer between the second surface 2b and the air layer 7 can be made more efficient. As a result, the cooling efficiency for the heating element 1 can be further improved.

Note that the heat generating element 1 of the present embodiment is assumed to be an electronic component provided in an electronic device such as a motor, an engine, or a household appliance. That is, the configuration of the cooling device 10 of the present embodiment can be applied by using an electronic component, such as a capacitor and a coil, which generates heat when energized, as the heating element 1 . Therefore, a suitable configuration for cooling electronic components is provided.

Next, Modification 1-1 of this embodiment will be described.

FIG. 3 is a diagram illustrating the configuration of the cooling device 10 according to Modification 1-1 of the present embodiment. As shown in FIG. 3, in Modification 1-1, the heating element 1 is attached to the heat sink main body 2 via the insulating material 11, which is different from the configuration of the cooling device 10 shown in FIG. 1 or FIG. . The insulating material 11 interrupts electrical continuity between the heating element 1 and the heat sink main body 2 . As a result, even when the heat sink body 2 is made of a conductive material such as copper or aluminum, the heating element 1 and the heat sink body 2 can be preferably insulated.

(Second embodiment)
A second embodiment will be described below. Elements similar to those of the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted.

FIG. 4 is a flow direction cross-sectional view for explaining the configuration of the cooling device 10 according to the present embodiment. 5 is a cross-sectional view taken along line B1-B1' in FIG. Furthermore, FIG. 6 is a cross-sectional view taken along line B2-B2' in FIG. 7 is a perspective view of the cooling device 10. FIG.

In the cooling device 10 according to this embodiment, the heat sink is composed of the heat sink main body 2 and the heat radiation fins 6 provided on the second surface 2 b of the heat sink main body 2 .

The radiating fins 6 are members that radiate heat transferred from the heating element 1 through the heat sink main body 2 to the air layer 7 from the surface 6a thereof. That is, the heat radiation fins 6 have a structure intended to increase the heat transfer area (surface area) between the heat sink and the air layer 7 .

The radiation fins 6 are formed in a substantially rectangular cross-sectional shape extending downward (positive direction of the Z-axis) in FIG. 4 from the second surface 2b of the heat sink body 2 . A plurality (four in FIG. 4) of the heat dissipating fins 6 of the present embodiment are provided at a substantially constant pitch along the Y-axis direction, and are configured in a comb shape as a whole. Below, among the surfaces 6a of the radiation fins 6, a surface along the Z-axis direction (a surface having a relatively large area) is referred to as a "wide surface 6a1". A surface along the Y-axis direction (a surface having a relatively small area) is referred to as a "narrow surface 6a2".

Moreover, the radiation fins 6 are made of the same material as or different from that of the heat sink main body 2 . That is, the radiation fins 6 are made of, for example, a metallic material with relatively high thermal conductivity such as copper or aluminum, or a non-metallic material with relatively high thermal conductivity such as FR4 or ceramics.

When the heat sink main body 2 is formed of a conductive material such as metal, the heat sink main body 2 and the heat dissipating fins 6 can be separated by forming the heat dissipating fins 6 of a non-conductive material having a relatively high thermal conductivity. It is possible to provide an insulating function while ensuring the heat conduction performance between the layers. On the other hand, if the heat sink main body 2 is made of an insulating material or otherwise has an insulating function from the heat generating element 1, the heat radiating fins 6 may be made of a material such as aluminum having relatively high thermal conductivity and low cost. It is preferably made of material.

Further, the induced flow generator 3 of the present embodiment is formed over the entire extension region in the Y-axis direction of the second surface 2b of the heat sink body 2 and the surface 6a of the radiation fin 6. As shown in FIG. That is, in the present embodiment, the “second surface of the heat sink” is composed of the second surface 2 b of the heat sink body 2 and the surface 6 a of the radiation fins 6 .

According to this embodiment having the configuration described above, the following effects are obtained.

In the cooling device 10 according to the present embodiment, the heat sink is provided on the heat sink main body 2 and the second surface 2 b as the second surface facing the first surface 2 a which is the first surface configured in the heat sink main body 2. It further includes heat radiating fins 6 .

As a result, the heat transfer area between the heat sink and the air layer 7 can be increased with a simple configuration, and the cooling performance can be further improved.

In particular, in this embodiment, the induced current generator 3 is provided so as to cover at least a portion of the surface 6a of the radiation fin 6. As shown in FIG. Therefore, compared to the case where the radiation fins 6 are not provided, it is possible to substantially increase the area where the induced flow generator 3 is provided (the area that can function as the generation source of the induced flow If). . Therefore, the heat transfer between the air layer 7 and the second surface 2b and the surface 6a of the heat radiating fins 6 can be made more efficient. As a result, the cooling efficiency for the heating element 1 can be further improved.

Furthermore, in the present embodiment, a plurality of heat radiation fins 6 are provided in a comb shape.

As a result, a relatively wide area, such as the wide surface 6a1, for providing the induced flow generator 3 thereon can be secured. Furthermore, with this configuration, the flow path of the induced flow If can be defined between the radiating fins 6 arranged in a comb-teeth shape. By appropriately adjusting the length in the axial direction, etc., it is possible to form a channel for the induced flow If of a desired path on the second surface 2 b of the heat sink body 2 .

In this embodiment, as shown in FIG. 7, the heat sink main body 2 has comb-tooth-shaped heat radiation fins 6 formed at a predetermined pitch in the Y-axis direction, and the induced current generator 3 is formed on the surface of the heat radiation fins 6. 6a are arranged to extend along the Y-axis direction.

Thereby, the induced flow If can be generated in a wider width region in the Y-axis direction. Therefore, the heat transfer between the heat sink main body 2 and the heat radiation fins 6 and the air layer 7 can be further promoted, and the cooling efficiency can be further improved.

Modifications 2-1 to 2-6 of the second embodiment will be described below.

(Modification 2-1)
FIG. 8 is a perspective view of a cooling device 10 according to modification 2-1. As shown, the cooling device 10 according to Modification 2-1 differs from the cooling device 10 shown in FIG. 7 in that a heat spreader 8 is provided between the heating element 1 and the heat sink main body 2 .

The heat spreader 8 can be made of the same material as or different from that of the heat sink body 2 or the radiation fins 6 . Preferably, the heat spreader 8 is formed of relatively high thermal conductivity materials such as copper, aluminum and carbon structures (such as carbon black or diamond). In particular, it is preferably constructed of relatively low-cost materials such as copper.

As described above, the cooling device 10 of this modified example further includes the heat spreader 8 provided between the heat sink main body 2 and the heating element 1 .

As a result, the heat from the heating element 1 can be diffused over a wider range by the heat spreader 8 and transmitted to the heat sink main body 2 and the radiation fins 6 . Therefore, the heat from the heating element 1 can be transmitted more evenly without biasing the heat to a specific heat radiating fin 6 among the plurality of radiating fins 6 . As a result, the substantial heat transfer area between the surfaces 6a of the plurality of heat radiating fins 6 and the air layer 7 can be increased, and the heat transfer performance can be further improved.

In this modified example 2-1, an example in which the heat spreader 8 is provided in the heat sink in which the heat sink main body 2 is provided with the radiation fins 6 has been described. However, the present invention is not limited to this, and the heat spreader 8 may be provided between the heating element 1 and the heat sink main body 2 in the cooling device 10 related to the heat sink main body 2 without the heat radiation fins 6 shown in FIG. .

(Modification 2-2)
FIG. 9 is a perspective view of a cooling device 10 according to modification 2-2. As shown, the cooling device 10 according to this modified example differs from the cooling device 10 shown in FIG.

More specifically, in the cooling device 10 of this modified example, the induced flow generator 3 extends over a predetermined length to the tip of the wide surface 6a1 on one side (upper region of the radiation fins 6 in FIG. 9). there is In particular, in FIG. 9, it extends from the tip of the radiating fin 6 to a position of about 1/3 of the total length in the Z-axis direction of the wide surface 6a1 on one side. In addition, the induced flow generator 3 is provided so as to cover substantially the entire length region of the wide surface 6a1 on one side of the radiation fin 6 in the X-axis direction.

Further, the induced flow generator 3 is arranged such that the induced flow generator 3a faces in the negative Z-axis direction (vertical direction in the drawing) so that the induced flow If flows toward the second surface 2b of the heat sink body 2. there is As a result, in the present embodiment, the induced flow If from the induced flow generating portion 3a flows along the wide surface 6a1 on one side of the heat radiating fin 6, collides with the second surface 2b of the heat sink main body 2, and radiates adjacent to the second surface 2b. It goes in the direction of the fin 6 (the positive direction of the Y-axis). Then, the induced flow If collides with the wide surface 6a1 of the adjacent radiation fin 6 and is guided upward in the Z-axis direction. As a result, the induced flow If flows like a whirlpool between the adjacent radiation fins 6 .

According to this modification, the induced flow generating device 3 is configured such that the induced flow generating portion 3a is directed toward the second surface 2b of the heat sink main body 2, and the induced flow generating device 3 extends along the wide surface 6a1 on one side of the heat radiating fin 6 in the X-axis direction. It is stretched and arranged. Therefore, the path along which the induced flow If generated by the induced flow generator 3 collides with the second surface 2b of the heat sink body 2 can be adjusted appropriately. Therefore, the heat dissipation effect of the second surface 2b of the heat sink body 2 and the surface 6a of the heat dissipation fins 6 can be further enhanced by the induced flow If.

In particular, in this modification, the induced flow generator 3 extends over substantially the entire length region of the wide surface 6a1 of the radiation fin 6 in the X-axis direction, so that the induced flow If is generated on the surface of the radiation fin 6. The area of contact between 6a and the second surface 2b of the heatsink body 2 can be larger. As a result, the heat dissipation effect can be exhibited more favorably.

Furthermore, in this modification, the induced flow generator 3 is arranged only on one wide surface 6 a 1 of the radiation fin 6 . Therefore, the induced flow If flows in a spiral path along the wide surface 6 a 1 on one side, the second surface 2 b of the heat sink body 2 , and the adjacent wide surface 6 a 1 of the radiation fin 6 . Therefore, the heat dissipation effect from the wide surface 6a1 of the heat dissipation fin 6 and the second surface 2b of the heat sink body 2 by the induced flow If can be further enhanced.

(Modification 2-3)
FIG. 10 is a perspective view of a cooling device 10 according to modification 2-3. As shown in the figure, in the cooling device 10 according to this modified example, induced flow generators 3 having the same configuration as the induced flow generator 3 described with reference to FIG. there is

In the cooling device 10 of this modified example, the induced flow If flows downward in the Z-axis direction toward the second surface 2b of the heat sink main body 2 between the two opposing wide surfaces 6a1 of the adjacent heat radiating fins 6. flow. Then, each induced flow If collides with the second surface 2b of the heat sink body 2, reflects, joins, and flows away from the second surface 2b.

As a result, the heat flows in a spiral path along the wide surfaces 6 a 1 on both sides of the radiation fins 6 and the second surface 2 b of the heat sink body 2 . Therefore, the effect of promoting heat dissipation from the surface 6a of the heat radiating fin 6 and the second surface 2b of the heat sink body 2 by the induced flow If can be further enhanced.

In Modifications 2-1 to 2-3, the induced flow If flows along the second surface 2b of the heat sink body 2, or is reflected by the second surface 2b and flows in a direction away from the induced flow. An example of arranging the generator 3 has been described. However, instead of these examples, the arrangement position of the induced flow generator 3 (induced flow generation section 3a position) may be adjusted.

That is, the arrangement position of the induced flow generator 3 is appropriately adjusted from the viewpoint of realizing a desired flow direction of the induced flow If according to the distribution of heat transferred from the heating element 1 to the heat sink main body 2 or the radiation fins 6. It is possible to

(Modification 2-4)
FIG. 11 is a perspective view of the cooling device 10 according to modification 2-4. As shown in the figure, in the cooling device 10 according to this modified example, instead of the comb-shaped heat radiation fins 6 described in FIG. 2b.

In particular, on the second surface 2b of the heat sink body 2, the radiation fins 6 of this modification are arranged in two rows at equal intervals along the X-axis direction, and arranged in three rows at equal intervals along the Y-axis direction. . That is, six of the plurality of radiation fins 6 are arranged on the second surface 2 b of the heat sink body 2 .

Furthermore, the induced flow generator 3 is provided on the second surface 2b of the heat sink main body 2 between the two rows of radiation fins 6 in the X-axis direction. In particular, the induced flow generator 3 is provided so as to extend over the entire area of the second surface 2b in the Y-axis direction, with the induced flow generation section 3a directed in the positive direction of the X-axis.

According to the cooling device 10 according to this modified example described above, the radiation fins 6 are formed in a projecting shape (pin shape). As a result, the induced flow If flowing on the second surface 2b of the heat sink body 2 is changed while colliding with the surface 6a of the heat radiating fin 6. As shown in FIG.

Therefore, by arranging the radiation fins 6 at appropriate positions on the second surface 2b of the heat sink body 2, the flow direction of the induced flow If can be appropriately adjusted. As a result, heat transfer between the heat sink main body 2 or the heat radiation fins 6 and the surrounding air layer 7 can be promoted more.

In particular, if the radiating fins 6 are projecting, the induced flow generating device 3 can be arranged in various ways, such as arranging the induced flow generating device 3 so as to weave between the radiating fins 6 . Therefore, the direction of the induced flow If can be adjusted on the second surface 2b of the heat sink body 2 with a higher degree of freedom.

Furthermore, according to the configuration of this modification, the induced flow If generated by the induced flow generator 3 first flows through the second surface 2b of the heat sink body 2 near the heating element 1, and then flows through the second surface 2b. It will flow along the surface 6a of the heat radiation fin 6 later. That is, since the induced flow If can be brought into contact with the second surface 2b of the heat sink main body 2 having a higher heat quantity first, the heat dissipation effect of the induced flow If can be exhibited more efficiently.

In this embodiment, the induced flow generator 3 is provided on the second surface 2b of the heat sink main body 2 between the two rows of radiation fins 6 in the X-axis direction, and generates an induced flow If along the X-axis direction. It is configured to let For this reason, the induced flow If that collides with the radiation fins 6 and changes its direction and the induced flow If that passes through the adjacent radiation fins 6 in the Y-axis direction merge. flow is generated. Therefore, the heat dissipation performance of the heat sink main body 2 or the heat dissipation fins 6 can be further improved by the action of the induced flow If.

(Modification 2-5)
FIG. 12 is a perspective view of the cooling device 10 according to modification 2-5. As illustrated, in the cooling device 10 according to the present modification, the induced flow generator 3 is arranged in the X-axis direction or the Y-axis direction so as to weave between the plurality of heat radiation fins 6 installed on the second surface 2b. It is provided so as to form a predetermined angle and extend obliquely.

With the configuration of this modified example as well, it is possible to form a three-dimensional flow of the induced flow If that can improve the heat dissipation performance of the heat sink main body 2 or the heat dissipation fins 6 .

(Modification 2-6)
FIG. 13 is a perspective view of the cooling device 10 according to modification 2-6. As shown in the figure, the cooling device 10 according to this modified example differs from the configuration described with reference to FIG. 11 in that the radiation fins 6 are formed in a substantially quadrangular prism shape.

In particular, the induced flow generator 3 of this modified example extends over substantially the entire Y-axis direction of the second surface 2b of the heat sink body 2 while covering the surface 6a of the radiation fins 6 perpendicular to the Y-axis or Z-axis. It is designed to

According to the configuration of this modified example, the induced flow If around the heat dissipating fins 6 forms a three-dimensional flow that is different from the case of the heat dissipating fins 6 formed in a substantially cylindrical shape described with reference to FIG. 12 . It will happen.

With the configuration of this modified example as well, it is possible to form a three-dimensional flow of the induced flow If that can improve the heat dissipation performance of the heat sink main body 2 or the heat dissipation fins 6 .

Note that the number, installation position, and shape of the radiation fins 6 and the configuration of the induced flow generator 3 are not limited to the examples described in Modifications 2-5 and 2-6. That is, these configurations can be changed as appropriate from the viewpoint of achieving a suitable flow velocity, flow rate, or flow direction of the induced flow If according to the heat distribution in the heat sink main body 2 or the radiation fins 6 .

For example, the induced flow generator 3 is arranged on the first surface 2a of the heat sink main body 2 so as to surround the area on the second surface 2b facing the area of the heat generating element 1 (heat generating element facing position P1). Alternatively, the induced flow If may be generated in a specific manner. Moreover, from the viewpoint of enhancing the cooling effect of the induced flow If, a plurality of induced flow generators 3 may be provided.

Moreover, the radiation fins 6 may be formed in any shape (polygonal prism shape, conical shape, polygonal pyramid shape, etc.) other than the above-described substantially cylindrical shape and substantially quadrangular prism shape.

According to the configurations of the above-described second embodiment and modifications 2-1 to 2-6, the induced flow If is generated on the second surface 2b of the heat sink main body 2 or the surface 6a of the heat radiating fin 6, thereby induced The heat transfer performance can be further improved without greatly increasing the pressure loss of the flow If. As a result, the action of the induced flow If can suppress the development of a boundary layer generated between the air layer 7 and the second surfaces 2b and 6a. That is, without changing the size and shape of the heat sink main body 2, the cooling performance can be improved by the action of the induced flow If.

(Third embodiment)
A third embodiment will be described below. Elements similar to those of the first embodiment or the second embodiment are assigned the same reference numerals, and descriptions thereof are omitted.

FIG. 14 is a diagram illustrating the configuration of a cooling device 100 according to a comparative example. As illustrated, the cooling device 100 includes a heat sink body 2 and a fan 4 similar to the cooling device 10 described with reference to FIG.

In the cooling device 100 as well, the heat from the heating element 1 on the first surface 2a of the heat sink body 2 is transferred to the heat sink body 2 and released to the air layer 7 from the second surface 2b. The fan 4 is appropriately composed of a DC/AC axial fan or a blower fan in consideration of factors such as the flow rate and flow velocity required according to the form of the component or equipment assumed as the heating element 1 and the installation space. When the heat sink main body 2 is provided with the heat radiation fins 6 , it is preferable to construct the fan 4 of a type corresponding to the shape of the heat radiation fins 6 .

In addition, in the example of FIG. 14, the fan 4 is arranged so that the cooling air (hereinafter also referred to as "main stream Mf") flows in the direction along the second surface 2b of the heat sink body 2 (positive direction of the X axis). is provided near one end in the X-axis direction.

With this configuration, the main flow Mf flows along the second surface 2 b of the heat sink body 2 by driving the fan 4 . At this time, friction between the second surface 2 b of the heat sink body 2 and the main flow Mf reduces the flow velocity of the main flow Mf, and a boundary layer 18 is generated between the second surface 2 b and the air layer 7 . The boundary layer 18 develops and increases in thickness as the main flow Mf advances from the position of the fan 4 in the positive direction of the X axis. Due to the development of this boundary layer 18, the flow velocity at the interface between the second surface 2b and the air layer 7 is reduced and the heat transfer from the second surface 2b to the air layer 7 is impeded. As a result, the cooling efficiency of the heating element 1 is lowered. According to the cooling device 10 according to this embodiment, which will be described in detail below, the development of such a boundary layer 18 can be suppressed.

FIG. 15 is a cross-sectional view illustrating the configuration of the cooling device 10 according to this embodiment. A cooling device 10 shown in FIG. 15 is provided with an induced flow generator 3 on the second surface 2 b of the heat sink body 2 in addition to the configuration of the cooling device 100 described with reference to FIG. 14 .

In particular, the induced flow generator 3 is provided on the second surface 2 b of the heat sink body 2 at a position substantially directly below the heating element 1 .

According to this configuration, the induced flow If generated by the induced flow generator 3 generates a flow directly below the heating element 1 on the second surface 2b of the heat sink body 2, thereby causing friction between the second surface 2b and the main flow Mf. can be reduced to make the boundary layer 18 thinner.

Furthermore, in the cooling device 10 according to the present embodiment, the thickness T1 (the length in the Z-axis direction) of the induced flow generator 3 is configured to be thinner than the thickness D1 (the maximum thickness in the X-axis direction) of the boundary layer 18. . With this configuration, the induced flow generator 3 itself provided on the second surface 2 b of the heat sink body 2 can more preferably suppress the flow of the main flow Mf of the fan 4 .

According to this embodiment having the configuration described above, the following effects are obtained.

The cooling device 10 of the present embodiment includes a fan 4 as a main stream generating device that generates the main stream Mf to be supplied to the heat sink main body 2 .

As a result, the flow rate of the induced flow If from the induced flow generator 3 can be supplemented by the main flow from the fan 4, so that the cooling performance for the heating element 1 can be further enhanced.

In particular, when the induced flow generator 3 is formed relatively thin in consideration of the layout, the flow rate of the induced flow If is not always sufficient from the viewpoint of the desired cooling performance depending on the amount of heat generated by the heating element 1. It is also envisioned that a scene will occur. Even in such a scene, with the configuration of the cooling device 10 of the present embodiment, the flow rate for cooling can be suitably supplemented by the main stream Mf of the fan 4 .

Furthermore, the induced flow If from the induced flow generator 3 can act to accelerate the velocity of the main flow Mf in the vicinity of the second surface 2b of the heat sink body 2 . Therefore, with the cooling device 10 of the present embodiment, in addition to the action of increasing the flow rate due to the combined use of the induced flow generator 3 and the fan 4, the development of the boundary layer 18, which is a factor that lowers the cooling performance, is suppressed. and the cooling performance for the heating element 1 can be further enhanced.

In particular, in the cooling device 10 shown in FIG. 15, the induced flow generator 3 is provided near the position P1 facing the heating element.

Therefore, the induced flow If from the induced flow generator 3 can generate a flow around the position P1 facing the heating element. The fan 4 is provided near one end of the heat sink main body 2 in the X-axis direction so that the main stream flows in the direction along the second surface 2b. Therefore, at least part of the main stream Mf of the fan 4 flowing in the direction along the second surface 2b passes through the interface between the second surface 2b and the air layer 7 at the position P1 facing the heating element together with the induced flow If. Thereby, the heat transfer from the second surface 2b of the heat sink body 2 to the air layer 7 can be further promoted, and as a result, the cooling performance of the cooling device 10 can be further improved.

Further, in this embodiment, the induced flow generator 3 is configured to be thinner than the thickness D1 of the boundary layer 18 generated between the main flow Mf and the heat sink body 2 .

As a result, the induced flow generator 3 itself provided on the second surface 2 b of the heat sink body 2 is more reliably prevented from obstructing the flow of the main flow Mf of the fan 4 . As a result, the effect of suppressing the development of the boundary layer 18 is further improved, which contributes to further improvement of the cooling performance.

Furthermore, in the present embodiment, the induced flow generator 3 and the fan 4 are arranged at positions where the main flow Mf and the induced flow If respectively generated by them are substantially parallel to each other.

As a result, the main flow Mf accelerates the induced flow If flowing in the same direction as the main flow Mf, so that the effect of suppressing the development of the boundary layer 18 can be exhibited more favorably.

Modifications 3-1 to 3-4 of the third embodiment will be described below.

(Modification 3-1)
FIG. 16 is a cross-sectional view illustrating the configuration of the cooling device 10 according to Modification 3-1. As shown, the cooling device 10 according to this modified example has a form in which the heat sink main body 2, the induced flow generator 3, and the fan 4 shown in FIG.

The housing 5 is made of a metal material or a resin material. In particular, when the heating element 1 is an electronic component and the housing 5 is made of a metal material such as aluminum, the surface of the housing 5 is preferably subjected to insulation treatment such as alumite treatment.

As described above, in the cooling device 10 of this modified example, the heat sink main body 2 is housed in the housing 5 having the inlet 5a and the outlet 5b as vents. Therefore, when the fan 4 is operated, the main stream Mf is taken in from the inlet 5a of the housing 5 on the left side in the figure. The main flow Mf taken in is used for cooling the heat sink main body 2 in the housing 5 and is discharged from the outlet 5 b of the housing 5 .

Therefore, the main flow Mf and the induced flow If from the fan 4 can flow along the second surface 2b of the heat sink body 2 without being maintained inside the housing 5 and diffused. Therefore, heat transfer between the heat sink and the air layer 7 can be performed more efficiently, and the cooling performance is further improved. In addition, the housing 5 can more reliably prevent external exposure, electric shock, and the like.

In addition, in the cooling device 10 of this modified example, the heat sink main body 2 may be provided with the heat radiation fins 6 having the configuration described with reference to FIGS. 7 to 13 . With this configuration, the main flow Mf and the induced flow If flow along the second surface 2b of the heat sink body 2 and the surfaces 6a of the heat radiation fins 6, so that heat transfer to the air layer 7 on the second surfaces 2b and the surfaces 6a is suppressed. can be promoted.

(Modification 3-2)
FIG. 17 is a cross-sectional view illustrating the configuration of the cooling device 10 according to modification 3-2. As illustrated, in the cooling device 10 according to this modified example, a heat sink main body 2 is provided with a plurality of heat generators 1 and induced flow generators 3 (two each in FIG. 17).

According to this modification, even if a plurality of heat generating elements 1 to be cooled are provided, the heat sink main body 2 is cooled by the induced flow If by providing the induced flow generator 3 for each of them. The effect of promoting heat transfer between the second surface 2b and the air layer 7 and the effect of suppressing the development of the boundary layer 18 can be exhibited favorably.

(Modification 3-3)
FIG. 18 is a perspective view illustrating the configuration of the cooling device 10 according to modification 3-3. As shown in the figure, the cooling device 10 according to this modified example is configured in such a manner that the fan 4 described in FIG.

According to the configuration of this modified example, the boundary layer 18 between the second surface 2b and the air layer 7 is thinned by the induced flow If as described above, so that the main stream Mf of the fan 4 flows between the adjacent radiating fins 6. It flows like being sucked in. Therefore, the main flow Mf will flow along the second surface 2b of the heat sink main body 2 and the surface 6a of the radiation fin 6 together with the induced flow If.

Therefore, the effect of assisting the air volume of the induced flow If from the induced flow generator 3 by the main stream of the fan 4 is obtained not only in the region along the second surface 2b of the heat sink main body 2 but also in the region along the surface 6a of the heat radiating fins 6. will also be exhibited. Therefore, the heat transfer from the surface 6a of the radiation fin 6 to the air layer 7 is also promoted.

Furthermore, since the main flow Mf of the fan 4 flows along the surface 6a of the heat radiation fin 6, friction occurs between the surface 6a and the main flow Mf, as in the case of the second surface 2b of the heat sink body 2, and the main flow Mf It is assumed that the flow velocity of is reduced and a boundary layer 18 is formed. On the other hand, in the configuration of this modified example, since the induced flow If flows along the surface 6a of the radiation fin 6 along with the main flow, the boundary layer 18 formed at the interface between the surface 6a of the radiation fin 6 and the air layer 7 is formed. Development can also be suppressed. As a result, the cooling effect on the heating element 1 can be further improved.

(Modification 3-4)
FIG. 19 is a perspective view illustrating the configuration of the cooling device 10 according to modification 3-4. As shown in the figure, in the cooling device 10 according to this modified example, the cooling device 10 having the configuration described in FIG. The fan 4 described in 1 is provided.

According to the configuration of this modification, the direction of the induced flow If flowing toward the second surface 2b of the heat sink body 2 and the direction of the main flow Mf are substantially orthogonal. Therefore, the combination of the induced flow If and the main flow Mf produces a combined flow W1 that flows obliquely toward the second surface 2b of the heat sink body 2 .

Therefore, by generating a combined flow W1 that is different in direction from the induced flow If and the main flow Mf, the flow around the second surface 2b of the heat sink body 2 and the surface 6a of the heat radiating fins 6 can be disturbed. As a result, the heat transfer between the air layer 7 and the second surface 2b of the heat sink body 2 and the surface 6a of the radiation fins 6 can be promoted.

In both of Modifications 3-3 and 3-4, the thickness T1 of the induced flow generator 3 is equal to the thickness D1 of the boundary layer 18 and the thickness of the radiation fins 6 (the thickness of the substantially quadrangular prism in FIG. 19). It is preferably formed thinner than the length of the radiation fins 6 in the Y-axis direction). As a result, the induced flow generator 3 itself provided on the surface 6 a of the heat radiating fin 6 is more reliably prevented from obstructing the flow of the main stream of the fan 4 . As a result, the effect of suppressing the development of the boundary layer 18 is further improved, which contributes to further improvement of the cooling performance.

(Modification 3-5)
FIG. 20 is a cross-sectional view for explaining the configuration of a cooling device 10 according to modification 3-5. FIG. 21 is a perspective view illustrating the configuration of the cooling device 10 according to modification 3-5. As shown in the figure, in the cooling device 10 according to this modified example, in the cooling device 10 provided with the comb-shaped heat radiation fins 6 described with reference to FIG. 4 is provided.

A plurality of induced flow generators 3 are provided on the heat sink main body 2 and the radiation fins 6 along predetermined intervals in the X-axis direction. In particular, FIG. 21 shows two induced flow generators 3-1 and 3-2. The induced flow generator 3-1 is configured to generate an induced flow If directed in the positive direction of the X-axis. Also, the induced flow generator 3-2 is configured to generate an induced flow If directed in the negative direction of the X axis.

Due to the configuration of the cooling device 10 according to this modified example, the main flow Mf from the fan 4 flows between the adjacent radiation fins 6 along the surface 6a toward the second surface 2b of the heat sink main body 2 . The main stream Mf that collides with the second surface 2b has a component directed in the positive direction of the X axis due to the action of the induced flow If generated by the induced flow generator 3-1, and an induced flow generated by the induced flow generator 3-2. and a component in the negative direction of the X-axis due to the action of If.

Therefore, according to the cooling device 10 according to this modified example, since the cooling air can be generated on the surface layer of the surface 6a of the radiation fin 6 and the surface layer of the second surface 2b of the heat sink body 2, the surface 6a and the second surface Heat transfer between 2b and air layer 7 can be promoted more.

(Modification 3-6)
FIG. 22 is a perspective view illustrating the configuration of the cooling device 10 according to modification 3-6. As shown in the figure, in the cooling device 10 according to this modified example, in the cooling device 10 provided with the projecting radiation fins 6 described with reference to FIG. is provided.

Further, at both edges of the second surface 2b of the heat sink body 2 in the X-axis direction, induced flow generators 3-1 and 3-2 are provided over the entire length of the second surface 2b in the Y-axis direction. is provided.

The induced flow generating device 3-1 is arranged such that the induced flow generating portion 3a-1 faces in the positive direction of the X-axis so as to generate the induced flow If in the positive direction of the X-axis. Further, the induced flow generator 3-2 is arranged such that the induced flow generating portion 3a-2 faces in the negative direction of the X-axis so as to generate the induced flow If in the negative direction of the X-axis.

According to the configuration of the cooling device 10 according to this modified example, the main flow Mf from the fan 4 flows toward the second surface 2 b of the heat sink body 2 . Then, the main stream Mf collides with the second surface 2b, and the component directed in the positive direction of the X axis by the action of the induced flow If generated by the induced flow generator 3-1 and the induced flow generated by the induced flow generator 3-2 A component directed in the negative direction of the X-axis due to the action of the flow If. Thus, the induced flow If can suitably guide the main flow Mf to flow along the second surface 2b while passing through the surfaces 6a of the projecting heat radiation fins 6 . As a result, the heat transfer between the air layer 7 and the surface 6a of the heat radiating fins 6 and the second surface 2b of the heat sink body 2 can be further promoted.

(Fourth embodiment)
A fourth embodiment will be described below. Elements similar to those in the first to third embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. In this embodiment, an example in which a plasma actuator 17 is employed as one aspect of the induced current generator 3 described in each of the above embodiments will be described.

FIG. 23 is a cross-sectional view for explaining the configuration of the plasma actuator 17 according to the fourth embodiment.

As illustrated, the plasma actuator 17 is constructed by sandwiching a dielectric 14 between a first electrode 12 and a grounded second electrode 13 . The plasma actuator 17 is connected to the power supply 15 . Predetermined insulating layers are applied to the upper and lower portions of the plasma actuator 17 .

The first electrode 12 and the second electrode 13 are provided at positions displaced from each other in the Z-axis direction. Also, the first electrode 12 and the second electrode 13 are made of a metal material such as copper, aluminum, or iron. The first electrode 12 and the second electrode 13 are made of, for example, a copper tape with a thickness on the order of several hundreds of micrometers.

Dielectric 14 is made of a predetermined insulating material. In particular, polytetrafluoroethylene, polyimide, or nylon is preferably used as the insulating material from the viewpoint of resistance to high voltage and high insulation. With these insulating materials, even if the thickness is on the order of hundreds of micrometers, it is possible to maintain resistance to a high voltage of about several kV.

In addition, the second electrode 13 and the dielectric 14 are provided so as to be displaced in the Y-axis direction (perpendicular to the paper surface of FIG. 23). That is, the second electrode 13 and the dielectric 14 are provided so as not to overlap each other in the Z-axis direction.

The plasma actuator 17 of this embodiment is configured so that the overall thickness in the Z-axis direction is, for example, about 1 mm or less.

The power supply device 15 is composed of an AC power supply and is connected to the first electrode 12 and the second electrode 13 of the plasma actuator 17, respectively. That is, the power supply device 15 applies an AC voltage to the plasma actuator 17 to generate the plasma atmosphere 16 from the first electrode 12 toward the positive direction of the X axis. The ions in the plasma atmosphere 16 electrically act on the air molecules to move them, thereby generating an induced flow If that flows along the positive direction of the X-axis. That is, the first electrode 12 functions as the induced current generating portion 3a.

Here, although the induced flow If generated by the plasma actuator 17 is generated from the first electrode 12 in the positive direction of the X-axis, the flow velocity is maximum at a position P2, which is a predetermined distance away from the plasma atmosphere 16 in the positive direction of the X-axis. becomes. This is because the charged particles in the plasma atmosphere 16 generate body force due to the Coulomb force, start accelerating, and reach a constant speed at the position separated by the predetermined distance.

The predetermined distance from the plasma atmosphere 16 where the above-described induced flow is generated varies depending on the frequency of the AC voltage applied to the power supply 15, the electrode material, and the material of the dielectric 14, but is, for example, several mm to several cm.

FIG. 24 is a cross-sectional view for explaining the configuration of the cooling device 10 having the plasma actuator 17. As shown in FIG. 25 is a cross-sectional view taken along line DD' of FIG.

As illustrated, the cooling device 10 of this embodiment employs a plasma actuator 17 as the induced flow generating device 3 of the cooling device 10 described with reference to FIG. More specifically, the second electrode 13 and the dielectric 14 are connected to the second surface 2b of the heatsink body 2. As shown in FIG. An insulating material may be appropriately provided between the plasma actuator 17 and the second surface 2 b of the heat sink body 2 .

By employing the plasma actuator 17 in the induced flow generator 3 of the cooling device 10 in this manner, the induced flow generator 3 can be formed thinner than the thickness D1 of the boundary layer 18 . Even if the heat sink main body 2 is provided with the radiating fins 6 , the thickness of the radiating fins 6 can be reduced. As a result, it is possible to more preferably prevent the plasma actuator 17 itself from blocking the flow of fluid along the second surface 2 b of the heat sink body 2 or the surface 6 a of the radiation fins 6 .

In particular, in a cooling device 10 provided with a plurality of induced flow generators 3 (for example, the cooling device 10 shown in FIG. 13) and a cooling device 10 provided with a fan 4 (for example, the cooling device 10 shown in FIG. 15), the induced flow generation Adoption of the plasma actuator 17 in the device 3 allows more favorable cooling performance to be exhibited.

Also, the plasma actuator 17 can electrically control the induced flow If. More specifically, by switching on/off the power supply from the power supply device 15, it is possible to switch between a state in which the induced current If is generated and a state in which it is not generated. This on/off switching of the power supply disturbs the flow of the main stream Mf to promote turbulence and improve heat transfer. Furthermore, in situations where it is not necessary to generate the induced flow If, it is possible to suppress the occurrence of pressure loss due to the action of the induced flow If by turning off the power supply. Furthermore, by appropriately adjusting the magnitude of the voltage applied by the power supply device 15, the velocity and flow rate of the induced flow If can be adjusted.

In addition, in the cooling device 10 of the present embodiment, heat generation due to power loss is assumed due to the operation of the plasma actuator 17 . However, as described above, there is a predetermined distance from the plasma atmosphere 16 to the position P2 where the flow velocity of the induced flow If is maximum. Therefore, it is preferable that the distance between the center position C1 of the heating element 1 and the center position C2 of the plasma actuator 17 exceeds the distance between the center position C2 and the position P2. As a result, while reducing thermal interference between the heating element 1 and the plasma actuator 17, the cooling efficiency for the heating element 1 can be increased.

For example, when the applied voltage (effective value of the applied AC voltage) of the power supply 15 is about several kV and the AC frequency is about 20 kHz or less, the position P2 is about 2 cm away from the plasma atmosphere 16 . Therefore, in this case, by setting the distance between the center position C1 of the heating element 1 and the center position C2 of the plasma actuator 17 to be 2 cm or more, the induced flow with the maximum flow velocity can flow at the heating element facing position P1. , the heat transfer can be more promoted. That is, it is preferable that the distance between the center position C1 of the heating element 1 and the center position C2 of the plasma actuator 17 from the plasma atmosphere 16 to the position where the induced flow is generated is greater than or equal to a predetermined distance.

According to the cooling device 10 of this embodiment having the configuration described above, the following effects are obtained.

In the cooling device 10 of this embodiment, the induced current generator 3 includes a plasma actuator 17 having a dielectric 14 interposed between the first electrode 12 and the second electrode 13 .

As a result, it is possible to realize a configuration for generating an induced flow If that promotes cooling of the heating element 1 without significantly increasing the overall size and volume of the cooling device 10 . In particular, since the plasma actuator 17 can be formed in a relatively small size, the induced flow generator 3 itself prevents the flow along the second surface 2b of the heat sink body 2 or the surface 6a of the radiation fins 6 from being obstructed. It can be suitably suppressed.

In addition, the area where the induced flow If is generated can be made relatively small by electrical control of the plasma actuator 17 or selection of constituent materials. Therefore, a configuration is realized that generates a flow for cooling while reducing the influence on the overall pressure loss of the cooling device 10 . In particular, since it is possible to electrically control the plasma actuator 17 using the power supply device 15 as a control device, compared to passive components (such as the structure of the flow path) that adjust the flow rate and flow velocity of the flow for cooling Therefore, it is possible to provide the flow rate, flow velocity, and the like with high-speed responsiveness to the adjustment.

Furthermore, in the present embodiment, the plasma actuator 17 is connected to the heat generating element 1 at the position of the second surface 2b facing the heat generating element 1 joined to the first surface 2a of the heat sink body 2 (heat generating element facing position P1). are placed at a predetermined distance from each other.

As a result, the induced flow If having a high flow velocity can be applied to the portion of the heat sink main body 2 having a relatively large amount of heat, so that cooling can be performed more efficiently. In particular, in the present embodiment, the central position C1 of the heating element 1 is arranged at the position P2 where the velocity of the induced flow If generated by the plasma actuator 17 is maximum, so the cooling efficiency is further enhanced. Further, by arranging the plasma actuator 17 and the heating element 1 apart from each other, thermal interference with the heating element 1 due to the heat generated by the plasma actuator 17 can be suppressed.

In this embodiment, an example in which the plasma actuator 17 is employed in the induced flow generating device 3 of the cooling device 10 (cooling device 10 of the first embodiment) configured as described in FIG. 1 has been described. However, not limited to this, the cooling device 10 of the second embodiment (cooling device 10 shown in FIGS. 4 to 7), the cooling device 10 of any of modifications 2-1 to 2-6 (FIGS. 8 to 13), the cooling device 10 of the third embodiment (the cooling device 10 shown in FIG. 15), and the cooling device 10 of any of Modifications 3-1 to 3-6 ( A plasma actuator 17 may be employed in the induced flow generating device 3 of the cooling device 10) shown in any one of FIGS. 16 to 20 or FIGS.

Although the embodiments of the present invention have been described above, the above-described embodiments and modifications merely show a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above-described embodiments. It is not intended to be limited to

For example, in the cooling device 10 described with reference to FIGS. 16 and 17 (the cooling devices 10 of Modifications 3-1 and 3-2), an example in which the fan 4 is arranged at the inlet 5a of the housing 5 has been described. However, instead of this configuration, the fan 4 may be arranged at the outlet 5b of the housing 5 so that the operation of the fan 4 sucks air from the outlet 5b.

Further, in the drawings for explaining each of the above-described embodiments, the heating element 1 is shown in a rectangular shape. However, the heating element 1 having a shape corresponding to the shape of electronic components such as coils and capacitors assumed as the heating element 1, or other devices that require cooling can also be applied to each of the above-described embodiments. .

Furthermore, in each of the above-described embodiments, an example in which one induced flow generator 3 is provided for one heating element 1 has been described. However, the configuration is not limited to this, and a plurality of induced flow generators 3 may be provided for one heating element 1, or a configuration in which one induced flow generating device 3 is provided for a plurality of heating elements 1 may be employed. .

Further, as the induced current generator 3, a device other than the plasma actuator 17 described in the fourth embodiment can be used. For example, the induced flow generator 3 may be configured by other devices that generate airflow by electrical action, such as piezoelectric elements.

Furthermore, in each of the above-described embodiments, a mode in which the induced flow If is generated in a direction substantially orthogonal to or substantially parallel to the main flow Mf has been described. However, the direction of the generated induced flow If is not limited to this aspect, and the induced flow If may be generated so as to form a predetermined angle with respect to the main flow Mf. In particular, if the induced flow If is generated from the viewpoint of suppressing the boundary layer 18, it is possible to appropriately adjust the direction, flow rate, or flow velocity of the induced flow If.

Further, in each of the above-described embodiments, examples of using the blower type fan 4 or the suction type fan as the mainstream generating device have been described. However, other types of mainstream generators may be employed as long as they function to promote heat dissipation from the heat sink to the air layer 7 . For example, instead of the fan 4 or a suction type fan, a device that generates an air flow around the heat sink by natural retention may be employed.

REFERENCE SIGNS LIST 1 heating element 2 heat sink 2a first surface 2b second surface 3 induced current generator 4 fan 5 housing 5a inlet 5b outlet 6 heat dissipation fin 6a surface 7 air layer 8 heat spreader 10 cooling device 17 plasma actuator 18 boundary layer

Claims (12)

a heating element that generates heat;
a heat sink having the heating element bonded to the first surface;
an induced current generator provided on a second surface of the heat sink, which is the back surface of the heat sink with respect to the first surface, for electrically generating an induced current in a direction along the second surface ;
a main flow generating device for generating a main flow for cooling the heat sink on the second surface in a direction along the flow of the induced flow;
The induced flow generator is arranged offset from the heating element on the first surface on the second surface,
Cooling system. A cooling device according to claim 1 ,
The induced flow generator is arranged to generate the induced flow toward a position of the second surface facing the heating element joined to the first surface,
Cooling system. The cooling device according to claim 1 or 2 ,
The induced current generator includes a plasma actuator having a dielectric interposed between a first electrode and a second electrode,
Cooling system. A cooling device according to claim 3 ,
The plasma actuator is arranged at a position on the second surface facing the heat generating element joined to the first surface, at a position separated from the heat generating element by a predetermined distance,
Cooling system. The cooling device according to any one of claims 1 to 4 ,
The heat sink includes a heat sink body and heat radiation fins provided on the back surface of the first surface configured in the heat sink body,
The second surface is configured as a surface of the heat dissipation fins,
Cooling system. A cooling device according to claim 5 ,
The heat radiation fins are provided in a plurality in a comb shape,
Cooling system. A cooling device according to claim 5 ,
The heat radiation fin is formed in a projecting shape,
Cooling system. The cooling device according to any one of claims 1 to 7 ,
The induced flow generating device and the main flow generating device are arranged at positions where the main flow and the induced flow respectively generated by them are parallel to each other.
Cooling system. The cooling device according to any one of claims 1 to 8 ,
The induced flow generator is
configured to be thinner than the thickness of a boundary layer generated between the main stream and the heat sink;
Cooling system. The cooling device according to any one of claims 1 to 9 ,
the heat sink is housed in a housing with a vent;
Cooling system. The cooling device according to any one of claims 1 to 10 ,
The heating element is an electronic component provided in an electronic device,
Cooling system. The cooling device according to any one of claims 1 to 11 ,
The heat sink
further comprising a heat spreader provided between the first surface and the heating element;
Cooling system.

Images