JP2005277193A - Heatsink with fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heatsink with fan that is excellent in heat radiating ability and is good in manufacturability. <P>SOLUTION: In the heatsink 1 with fan in which a plurality of sheet metal fins 3 is arranged at prescribed intervals and an axial fan 6 which blows air into the spaces 5 formed by the sheet metal fins 3 is arranged to face the spaces 5, a core 2 is provided on the central axial line of the fan 6 and the fins 3 are provided in the radial direction with respect to the core 2. At the same time, the upper ends 11 of the fins 3 on the side of the axial fan 6 are inclined with respect to the central axial line of the fan 6, so that the upper ends 11 may be positioned on the rear side than the lower ends 12 of the fins 11 on the opposite side of the upper ends 11 in the rotating direction of the fan 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat sink with a fan in which a fan for blowing air to a fin is integrally provided.

  Recently, with the rapid development of electronic devices, the speed and capacity of electronic components are increasing. For this reason, the amount of heat generated by the electronic components has increased, and accordingly, in order to avoid malfunctions or damage due to temperature rise, it has been required to more effectively dissipate and cool. .

  Therefore, conventionally, in order to cool the electronic component, a cooling device in which a heat sink is arranged is provided in the electronic device. In general, the heat sink has a function of expanding a substantial heat radiation area of the heat generating member or the high temperature part by contacting the heat generating member or the high temperature part.

  According to this kind of heat sink, since the heat radiation area is enlarged, a large amount of heat can be dissipated, but in order to further increase the heat radiation amount, it is preferable to perform forced cooling to blow air toward the fins. In that case, cooling air will be sent into the gaps between the heat sink fins, but considering the heat dissipation efficiency of the heat sink as a whole and the freedom of mounting the blower, A blower (fan) is disposed on the side opposite to the base portion. As an example of the heat sink, there is known a structure in which an axial flow type fan is attached to an end portion on the side opposite to the base portion in the heat sink having the above structure. Therefore, in this heat sink with a fan, air outside the heat sink is sucked by the axial flow fan and blown into the gaps between the thin plate fins to perform forced cooling. An example of such a heat sink is described in Patent Document 1.

In the heat sink having the above structure, the heat transmitted to the base portion is transmitted to the thin plate fins, and at the same time, the cooling air is blown into the gaps of the thin plate fins by the axial fan. Then, the high-temperature air in the vicinity of the thin-plate fin heated by the thin-plate fin and the cooling air are heat-exchanged or replaced, and then the high-temperature air is blown out of the heat sink. Therefore, in the heat sink having the above structure, since the cooling air is exchanged in the gap between the thin plate fins, the amount of heat released from the thin plate fins increases, and as a result, the temperature rise from the heat generating member can be suppressed.
JP 2001-319998 A

  By the way, in order to increase the heat radiation efficiency of the heat sink, as many fins as possible are provided to increase the heat radiation area. As a result, in the heat sink with a fan having the above-described structure, the interval between the fins is narrowed. Therefore, in order to increase the heat radiation area, if the fins are increased to make the gap between the fins too narrow, the air flow enters the heat sink due to the so-called throttling action even if the air is forced to cool. It will be difficult. As a result, the amount of air flowing between the fins is restricted, and the heat dissipation effect may be impaired, so there is a limit to increasing the heat dissipation area by increasing the fins.

  On the other hand, in order to increase the heat dissipation efficiency of the heat sink, it is conceivable to match the direction of the thin plate fins with the direction of the air flow supplied from the axial fan. However, in such a configuration, the manufacturability is remarkably deteriorated, and as a result, the manufacturing cost is increased.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a heat sink that has excellent heat dissipation capability and can be manufactured at low cost.

  In order to achieve the above object, the invention according to claim 1 is an axial flow type fan in which a plurality of thin plate-like fins are arranged at a predetermined interval and air is blown into a gap formed by the thin plate-like fins. In the heat sink with a fan disposed to face the gap, a core portion is provided on a central axis of the axial fan, and the thin fins are provided in a radial direction with respect to the core portion. The axial flow fan side end of the thin plate fin is located on the rear side in the rotation direction of the fan from the end opposite to the fan side end. A heat sink with a fan, which is inclined with respect to a central axis.

  Therefore, in the invention of claim 1, since the thin plate fins are arranged in a radial shape around the core portion, the thermal diffusion is efficiently performed from the core portion to the thin plate fin. Therefore, heat dissipation from each thin plate-like fin is promoted, and the cooling efficiency of the heat sink is improved. Further, the end of the thin plate fin on the axial flow fan side is positioned on a plane including the central axis of the axial flow fan so that the end on the axial flow fan rotation direction is located behind the opposite side portion. It is inclined with respect to. Therefore, the cooling air blown from the axial flow fan is guided by the end portion on the axial flow fan side and actively flows into the gap formed by the thin plate fins.

  In addition to the structure of claim 1, the invention of claim 2 is characterized in that an envelope surface formed by connecting upper end circles of the thin plate-like fins provided in the radial direction is recessed toward the center portion. This is a heat sink with a fan.

  Therefore, in the invention of claim 2, in addition to the action of claim 1, the envelope surface formed by connecting the upper end circles of the thin plate-like fins is a surface recessed toward the center portion. For this reason, when air is blown from the axial flow fan to the thin plate fins, cooling air is more likely to enter the gap.

  According to a third aspect of the present invention, in addition to the structure of the first or second aspect, the core portion is a heat sink with a fan, wherein the plug portion is fitted into the hollow portion.

  Therefore, in the invention of claim 3, since the core portion is formed by fitting the plug portion into the hollow portion, the structure of the heat sink is simplified.

  According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, a pedestal portion to which an electronic component is attached so as to be able to transfer heat is provided at one end portion of the core portion. It is a heat sink with a fan.

  Therefore, in the invention of claim 4, since the electronic component is attached to the core portion so as to be able to exchange heat, the core portion has two functions of a base portion and a heat diffusion plate in a conventional heat sink. Therefore, the number of parts of the heat sink with a fan is reduced.

  According to a fifth aspect of the present invention, in addition to the configuration of the third or fourth aspect, the plug portion is a heat pipe.

  Therefore, in the invention of claim 5, since the plug portion is a heat pipe, heat is efficiently transmitted to each thin plate fin.

  As described above, according to the first aspect of the present invention, when the air is blown from the axial fan to the thin fins, the heat transferred to the core portion is radially arranged. Can diffuse. Therefore, when air is blown from the axial flow fan to the fins, heat can be efficiently radiated from each flat fin. As a result, the heat dissipation efficiency of the heat sink with a fan can be improved. In addition, since the portion of the thin plate-like fin having a predetermined length on the axial flow fan side is inclined with respect to the central axis of the axial flow fan, the cooling air easily enters the gap formed by the plurality of fins. Become. Therefore, the flow rate of the cooling air flowing through the gap can be increased. As a result, heat exchange between the thin plate fins and the cooling air can be performed efficiently, so that the cooling performance of the heat sink can be improved.

  According to the invention of claim 2, the envelope surface formed by connecting the upper end circles of the thin plate fins is a surface that is recessed toward the center portion. Therefore, when air is blown from the fan to the fins, the cooling air can be more easily entered into the gap. As a result, the heat dissipation efficiency of the heat sink with a fan can be improved.

  According to the invention of claim 3, the structure of the heat sink can be simplified, and the manufacturing cost of the heat sink with a fan can be reduced.

  According to the invention of claim 4, since the electronic component is attached to the core portion so as to be able to exchange heat, the core portion has two functions of a base portion and a heat diffusion plate in a conventional heat sink. Therefore, the number of parts of the heat sink with a fan can be reduced. As a result, the manufacturing cost of the heat sink with a fan can be reduced.

  According to the invention of claim 5, heat can be efficiently transferred to the thin plate fin. Therefore, the cooling performance of the heat sink with a fan can be improved.

  The best mode for carrying out the present invention will be described below. The heat sink 1 includes a core portion 2, a plurality of thin plate fins 3, and a pedestal portion 4. The heat sink 1 has a structure in which an air flow is sent from a fan 6 to a gap 5 formed by thin plate-like fins 3 to dissipate heat. The fan 6 is a so-called axial fan that flows in the cooling air from the central axis direction of the blade 7 (blade) and flows out in the axial direction. The central axis of the core portion 2 is disposed on the central axis of the blade 7.

  As shown in FIG. 2, the core portion 2 is formed by fitting a plug portion 9 into a cylindrical hollow portion 8 formed at the center portion of the heat sink 1. The plug portion 9 is made of a metal having good thermal conductivity and is formed in a cylindrical shape. A pedestal portion 4 is formed at the lower end of the plug portion 9 in the axial direction, and the electronic component 10 is attached so as to be able to exchange heat. In addition, the core part 2 is not limited to column shape, You may form in other shapes.

  A plurality of thin plate-like fins 3 are arranged around the plug portion 9. In other words, the thin plate-like fins 3 are radially arranged around the core portion 2. The central axis of the core portion 2 is disposed on the central axis of the blade 7. A gap 5 between the thin plate fins 3 serves as a cooling air flow path.

  The thin plate-like fins 3 are formed by bending a metal plate material having good thermal conductivity such as aluminum. Further, among the thin plate-like fins 3, a fixing margin 3 </ b> A is formed at an end portion on the core portion 2 side, that is, an inner end portion. A fixing allowance 3B is formed at the lower end of the thin plate-like fin 3. In the core portion 2, the fixing margin 3 </ b> A of the thin plate-like fin 3 and the periphery of the plug portion 9 are joined by solder. Further, the fixing margin 3B of the thin plate fin 3 and the pedestal portion 4 are joined by solder. In addition, the joining method of this core part 2 and the thin-plate fin 3 can use an appropriate method.

  The upper end portion 11 of the thin fin 3 is inclined toward the central core portion 2 in the axial direction of the axial flow type fan 6. Therefore, the envelope surface formed by connecting the upper end portions 11 is a surface that is recessed toward the center portion. Further, the upper end portion 11 of the thin plate-like fin 3 is bent at a predetermined angle with respect to an axis parallel to the central axis of the blade 7. Therefore, the upper end portions 11 of the fins 3 are arranged so as to be inclined in the rotational direction of the airflow from the axial flow type fan 6. As a result, it is located rearward of the end on the axial flow fan 6 side in the rotational direction of the axial flow fan 6 relative to the lower end 12 positioned on the opposite side of the upper end portion 11 in the axial direction. ing.

  The gap 5 is opened at the upper end, the lower end, and the outer peripheral end of the fin portion 3. The upper end portion of the fin portion 3, in other words, the upper end portion 11 of the thin plate-like fin 3 disposed so as to face the discharge port of the axial fan 6 serves as an inflow port 13 for the gap 5. Further, the lower part of the thin plate-like fin 3 is an outlet 14 of the gap 5. Further, the end of the thin plate-like fin 3 disposed around the heat sink 1 is used as an outlet of the gap 5.

  The operation of the heat sink 1 with a fan will be described. First, heat generated in the electronic component 10 is transferred to the bottom of the core 2. The heat transferred to the core part 2 is conducted from the bottom of the core part 2 in the rising direction with a temperature difference. Then, heat moves from the core portion 2 to each thin plate-like fin 3. In the heat sink 1 with a fan, since the end portions of the plurality of thin plate fins 3 arranged radially around the core portion 2 and the core portion 2 are connected so as to be able to transfer heat, the efficiency from the core portion 2 is increased. Thermal diffusion is often performed on the thin plate-like fins 3. Therefore, heat dissipation from each thin plate-like fin 3 is promoted, and the cooling efficiency of the heat sink 1 with a fan is improved. Further, a portion of the thin plate fin 3 having a predetermined length on the axial flow fan 6 side is inclined with respect to the axis. Therefore, the cooling air blown from the axial flow type fan 6 is guided by the upper end portion 11 on the axial flow type fan side and positively flows into the gap formed by the thin plate fins 3.

  On the other hand, for forced cooling, air is blown from the axial fan 6 toward the heat sink 1 with a fan. The cooling air sent by the axial flow type fan 6 advances toward the inlet 13 formed by the end of the thin plate-like fin 3 of the heat sink 1 with the fan while rotating spirally. The upper end portion 11 of the thin plate fin 3 is disposed so as to be inclined with respect to the central axis of the axial fan 6. Therefore, the inlet 13 is also inclined with respect to the central axis of the axial flow fan 6. That is, the inlet 13 is inclined in the direction in which the cooling air flows. Therefore, the inflow port 13 functions as a guide for guiding the cooling air into the gap 5, and the flow rate of the cooling air blown into the gap 5 is increased.

  The cooling air that has entered the gap 5 moves along the thin plate-like fins 3 that are the walls of the gap 5. Heat generated from the core portion 2 to a heating element such as an electronic component is transmitted to the thin plate-like fin 3. Therefore, the temperature of the thin plate fin 3 is increased. As the cooling air flows along the thin plate-like fins 3 whose temperature has been increased, heat exchange is performed between the cooling air and the thin plate-like fins 3.

  Thereafter, the cooling air travels along the thin plate-like fin 3 into the gap 5 and is discharged from the outer peripheral end of the thin plate-like fin 3 and the outlet 14. Since the outflow port 14 is an opening disposed at the lower end of the gap 5, a part of the cooling air advances straight through the gap 5 and is discharged. As a result, the resistance in the gap 5 is reduced and the flow of cooling air is promoted. On the other hand, the remaining cooling air collides with the surface of the core portion 2, proceeds along the thin plate fins 3 into the gap 5, and is discharged from the outlet 14.

  Further, the thin plate-like fins 3 are arranged radially around the core portion 2, and one end portion of the thin plate-like fin 3 is connected to the periphery of the core portion 2. Therefore, the heat transmitted to the core part 2 is diffused to the thin plate-like fins 3 arranged radially. Since the thin plate-like fins 3 are directly exposed to the air flow, forced air cooling of the heat sink 1 is promoted, and the cooling efficiency is improved. Therefore, the heat of the electronic component 10 is efficiently transmitted to the thin plate-like fin 3 by the core portion 2 and radiated.

  In addition, a portion of the core portion 2 that is not exposed to the airflow is generated in a very narrow region facing the center of the axial flow fan 6. The core portion 2 is disposed in this portion and connected to the thin plate fin 3. . Therefore, since the other part is directly exposed to the air flow, forced air cooling of the core part 2 is promoted, and the cooling efficiency is improved. Further, the heat of the electronic component 10 is efficiently transmitted to the thin plate-like fins 3 by the core portion 2 which is a heat conducting member, and is radiated.

  Further, the thin plate-like fins 3 are arranged radially around the core portion 2, and one end portion of the thin plate-like fin 3 is connected to the periphery of the core portion 2. Therefore, heat is transmitted to the core portion 2 when the air is blown from the axial flow type fan 6 to the gap 5. The heat transferred to the core portion 2 is diffused to the thin plate-like fins 3 arranged radially. Since the thin fins 3 are directly exposed to the air flow, forced air cooling of the core portion 2 is promoted, and the cooling efficiency is improved. Therefore, the heat of the core part 2 is efficiently transmitted to the thin fins 3 by the heat conducting member and radiated.

  Further, the envelope surface formed by connecting the upper end portions 11 of the thin plate-like fins 3 is a surface that is recessed toward the center portion. Therefore, it becomes easier for cooling air to enter the gap 5.

  According to the heat sink 1 described above, the ends of the plurality of thin plate-like fins 3 arranged radially around the core portion 2 and the core portion 2 are connected so as to be able to transfer heat. Thermal diffusion is efficiently performed from the portion 2 to the thin plate-like fin 3. Therefore, heat dissipation from each thin plate-like fin 3 is promoted, and the cooling efficiency of the heat sink 1 with a fan is improved. In addition, since a portion of the thin plate fin 3 having a predetermined length on the axial flow fan 6 side is inclined with respect to the axis, the cooling air easily enters a gap formed by the plurality of fins 3. Become. Therefore, the flow rate of the cooling air flowing through the gap can be increased. As a result, the heat exchange between each thin plate-like fin 3 and the cooling air can be performed efficiently, so that the cooling performance of the heat sink 1 with a fan can be improved.

  Moreover, the core part 2 and the thin plate-shaped fin 3 can be easily connected so that heat transfer is possible. As a result, the manufacturability of the heat sink 1 with a fan can be improved.

  Further, the base portion that has been conventionally provided is omitted by the core portion 2. Therefore, the thermal resistance can be reduced. In addition, since the number of parts can be reduced, the manufacturing cost can be reduced.

  Moreover, the base part 4 and the thin plate-like fin 3 can be easily connected so as to be able to transfer heat. As a result, the cooling performance of the heat sink 1 with a fan can be improved, and at the same time, the manufacturability of the heat sink 1 with a fan can be improved.

  Further, since the fixing allowance 3A and the fixing allowance 3B are formed on the thin plate-like fin 3, the plug portion 9 and the fin 3 are easily joined. Therefore, the manufacturability of the heat sink 1 with a fan can be further improved.

  Moreover, since the core part 2 is formed of a material having a good heat transfer efficiency, the heat of the electronic component 10 can be efficiently transferred to the thin plate-like fins 3. As a result, the heat dissipation efficiency of the heat sink 1 can be improved.

  In addition to the outer peripheral end of the thin plate-like fin 3, the air flow can be discharged from the outlet 14. Therefore, since the flow rate of the air passing through the gap 5 can be increased, heat exchange can be performed efficiently. As a result, the cooling performance of the heat sink 1 can be improved.

  The envelope surface formed by connecting the upper end portions 11 of the fins 3 is a surface that is recessed toward the center portion. Therefore, when the air is blown from the axial flow type fan 6 to the fins 3, the cooling air can be further easily entered into the gap 5. As a result, the heat dissipation efficiency of the heat sink 1 with a fan can be improved.

  In the above specific example, the thin plate-like fins 3 are made of aluminum, but the material of the thin plate-like fins is not limited to the above-mentioned aluminum. For example, the thin plate-like fins 3 may be made of copper.

  In the above-described specific example, the plug portion 9 is a copper member and has a solid structure, but the plug portion of the present invention is not limited to the above-described structure. For example, the plug part may be formed of a heat pipe. In the heat sink 15 shown in FIG. 6, a columnar heat pipe 16 corresponding to the plug portion of the present invention is fitted in the hollow portion 8, and the electronic component 10 is attached to the bottom surface of the heat pipe 16 so as to be able to transfer heat. It is supposed to be.

  FIG. 7 shows the heat pipe 16. This heat pipe 16 encloses a condensable fluid such as water as a working fluid 18 in a state where a non-condensable gas such as air is deaerated inside a container (hollow sealed container) 17 sealed in an airtight state. Further, the heat conduction device is configured by providing a wick or the like (not shown) inside. The container 17 of the heat pipe 16 is formed in a cylindrical shape. A pedestal portion 4 is formed at a lower end portion of the container 17, and an electronic component 10 is attached to the pedestal portion 4 so as to be able to transfer heat.

  In the heat sink 15, heat generated in the electronic component 10 is transmitted to the heat pipe 16. A portion where heat is transmitted to the heat pipe 16 is a heat input portion of the heat pipe 16. When heat is transferred to the heat input section, the working fluid 18 inside the container 17 evaporates, and the vapor moves above the heat pipe 16 having a low temperature and pressure. Therefore, the upper part of the heat pipe 16 is a heat radiating part. Since the upper part of the heat pipe 16 is connected to the end of each thin plate-like fin 3, heat is transmitted from the heat pipe 16 to each thin plate-like fin 3. Then, heat exchange between each thin plate-like fin 3 and the cooling air from the fan 6 is performed. On the other hand, the heat of the working fluid 18 is dissipated inside the heat radiating part to which heat has been transmitted, and the working fluid 18 is condensed and liquefied. Thereafter, the working fluid is refluxed to the heat input portion side by capillary action or gravity, and is evaporated again by the heat of the electronic component 10.

  Therefore, in the heat sink 15, heat can be efficiently transferred to the thin plate-like fin 3 by the heat pipe 16. Therefore, the cooling performance of the heat sink 15 can be improved.

It is a perspective view which shows one specific example of the heat sink of this invention. It is a front view which shows the heat sink of FIG. It is a longitudinal cross-sectional view of the heat sink of FIG. It is a perspective view which shows the fin of FIG. FIG. 2 is a simplified diagram showing the air flow by the fins of FIG. 1. It is a longitudinal cross-sectional view which shows the other specific example of the heat sink of this invention. It is a longitudinal cross-sectional view which shows one specific example of the plug part of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat sink with a fan, 2 ... Core part, 3 ... Thin-plate fin, 4 ... Base part, 5 ... Gap, 6 ... Axial fan, 7 ... Blade, 8 ... Hollow part, 9 ... Plug part, 10 ... Electronics Components: 11 ... upper end, 12 ... lower end, 16 ... heat pipe.

Claims (5)

A heat sink with a fan in which a plurality of thin plate-like fins are arranged at predetermined intervals, and an axial flow fan that blows air into a gap formed by the thin plate-like fins is disposed opposite to the gap.
A core portion is provided on a central axis of the axial flow fan, the thin fins are provided in a radial direction with respect to the core portion, and an end of the thin fins on the axial flow fan side is A fan that is inclined with respect to the central axis of the axial-flow fan so as to be located on the rear side in the rotational direction of the fan with respect to the end opposite to the end on the fan side With heat sink.   The heat sink with a fan according to claim 1, wherein an envelope surface formed by connecting upper end circles of the thin plate-like fins provided in the radial direction is a surface recessed toward a central portion.   The heat sink with a fan according to claim 1 or 2, wherein the core portion is formed by fitting a plug portion into a hollow portion.   The heat sink with a fan according to any one of claims 1 to 3, wherein a pedestal portion to which an electronic component is attached so as to be capable of transferring heat is provided at one end portion of the core portion.   The heat sink with a fan according to claim 3 or 4, wherein the plug portion is a heat pipe.

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