JP2003060135A - Radiation fin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small radiation fin of high efficiency, provided with a substrate and a plurality of vertical fins held by the substrate, which couses less pressure loss of a cooling fluid, sufficient cooling fluid is introduced into even deep part of the fin, and uniform cooling effect is obtained for the entire radiation fin. SOLUTION: Vertical fins are placed so that tip positions of vertical fins are shifted back and forth in the circulating direction of a cooling fluid. When a tapered part is provided to the tip of the vertical fin, a higher effect is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiating fin, and more particularly to a heat radiating fin for forcibly cooling a heat generating portion with a cooling fluid such as air flowing by a fan or the like.

[0002]

2. Description of the Related Art Conventionally, heat radiating fins called heat sinks have been provided at various heat generating parts of inverters, machine tools, etc. It is known to do so.

An example of this type of conventional radiation fin will be described below. FIG. 9 is a perspective view showing a main part of a conventional heat radiation fin. As shown in FIG. 9, the conventional radiation fin 1
Are electronic components such as thyristors and transistors (not shown)
It is composed of a substrate 2 having a substantially rectangular shape to which the above are fixed, and a fin body 3 having a large number of flat plate-shaped vertical fin bodies 3a standing on the substrate 2. The vertical fin bodies 3a are forced to be blown by a fan (not shown) or the like so that their side surfaces face each other, and the desired cooling fluid such as air flows in the direction (arrow A in the figure). On the other hand, they are aligned in parallel with each other with an appropriate gap G maintained.

By the way, in recent years, various products have been reduced in size and improved in performance, so that the radiation fins are required to be further reduced in size and improved in performance. In order to reduce the size and improve the performance of the radiation fins, the surface area of the vertical fin bodies 3a is increased, or the interval G between the vertical fin bodies 3a is narrowed to increase the number of the vertical fin bodies 3a. A method of arranging the fin bodies 3a at a high density can be considered. Furthermore, there has been proposed a method of providing horizontal fins made of metal flakes having good thermal conductivity between the vertical fin bodies 3a. Even with a structure in which the vertical fin bodies 3a are arranged at a high density, there is a limit to increasing the number of the vertical fin bodies 3a, and if the interval G between the vertical fin bodies 3a is narrowed, the gap between the vertical fin bodies 3a is reduced. There is a problem that ventilation resistance (pressure loss) of a cooling fluid such as air passing through G is increased, resulting in a decrease in air volume, which makes it impossible to improve cooling efficiency.

As a method for ensuring the air volume by making the arrangement of the vertical fins 3a high density and reducing the ventilation resistance (pressure loss) of the cooling fluid such as air passing between the vertical fins 3a to secure the air volume. As shown in FIG. 10, a person arranges the fin body 3 substantially parallel to the flowing direction of the cooling fluid, and forms the tapered portion 7 at the end of the fin body 3 facing the cooling fluid. (Japanese Patent Laid-Open No. 7-
218174).

[0006]

However, if the tapered portion 7 is simply formed at the end of the vertical fin body 3a facing the cooling fluid, turbulent flow is generated at the portion where the cooling fluid hits the fin body. However, it has been found that it is difficult to secure a sufficient air volume because the ventilation resistance cannot be reduced. An object of the present invention is to suppress the generation of turbulent flow when a cooling fluid hits the fin body in a radiating fin having a substrate and vertical fins held by the substrate, and to provide ventilation resistance (pressure) even in a deep portion of the fin body. The purpose of the present invention is to suppress an increase in (loss) and secure a sufficient amount of air flow, and as a result, to enhance the heat dissipation function of the entire heat dissipation fin and improve the cooling efficiency.

[0007]

In order to solve the above-mentioned problems, in a radiation fin having a substrate and a plurality of vertical fins held by the substrate, the tip positions of the vertical fins are arranged with respect to the flow direction of the cooling fluid. The heat radiation fins are arranged in a staggered manner. By using a heat radiation fin with such a structure, turbulence is suppressed from occurring when the cooling fluid hits the fin body, and ventilation resistance (pressure loss) in the fin body is suppressed from increasing, It is possible to improve the cooling efficiency by drawing in such a cooling fluid into the radiation fin body. The vertical fins that are offset from each other in the front and rear are provided in the front (windward) and in the rear (windward) with respect to the flow direction of the cooling fluid.

In the radiating fin of the present invention, as shown in the external view of FIG. 1 and the plan view of FIG. 2, the tip positions of the vertical fins are alternately arranged in the front-back direction with respect to the flow direction of the cooling fluid. It is preferable to arrange them in a staggered manner. When the cooling fluid enters the fin body 13, the two vertical fin bodies 13a in front of
Plays a role of a wall and enters the fin main body 13 while maintaining the rectified state, and thus exerts an effect of suppressing an increase in pressure loss. Further, in the heat dissipating fin of the present invention, as shown in the plan view of FIG. 5, the tip positions of the respective vertical fin bodies may be arranged so as to be shifted forward every two in the flowing direction of the cooling fluid. This is because the effect of keeping the rectified state can be maintained even if the number is set to two.

The distance (D) by which the vertical fin body is displaced back and forth with respect to the flow direction of the cooling fluid is 20 mm to 50 mm.
Is preferred. The vertical fin body protruding 20 mm to 50 mm forward in the flow direction serves as a wall for the cooling fluid, and can suppress the occurrence of turbulent flow.

In the radiating fin of the present invention, it is preferable to provide tapered portions 24a, 24b, 25a, 25b at the tips of the vertical fin bodies as shown in the plan views of FIGS. If a taper is provided at the tip of the vertical fin body, it reduces the ventilation resistance of the cooling fluid that hits the vertical fin body.
This is because it is possible to suppress an increase in pressure loss. The tapered portions 24a, 24b, 25a, 25b are provided on both front and rear ends of the vertical fin bodies 23a, 23b, but only on the vertical fin bodies 23a which are arranged to be shifted forward in the flowing direction A of the cooling fluid. But it works. This is because if there is a wall, even if the cooling fluid collides with a flat surface, the flow direction is prevented from being disturbed. Further, it is particularly effective to provide it on the windward side of the vertical fin body.

Further, in the radiation fin of the present invention, horizontal fins can be arranged between the vertical fins. By arranging the horizontal fins made of a thin plate of a metal having a high thermal conductivity such as aluminum or copper, the area for contacting with the cooling fluid and exchanging heat is increased, and the cooling effect of the radiation fins can be further enhanced. The present invention will be described in more detail below with reference to the drawings.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 and 2
Shows a first embodiment of the heat dissipation fin of the present invention, FIG. 1 is an external perspective view thereof, and FIG. 2 is a plan view thereof. In the following figures, the scale is not necessarily accurate in order to make the structure easy to understand. As shown in FIGS. 1 and 2, the radiation fin 11 of the present embodiment has electronic components (not shown) such as thyristors and transistors fixed thereto, for example, a vertical dimension L and a horizontal dimension W are 270, respectively.
A square substrate 12 having a size of about mm, and a large number of vertical fin bodies 1 erected on one surface (upper surface in FIG. 1) of the substrate 12.
And a fin body 13 having 3a and 13b. The shape of the substrate 12 is not limited to a square flat plate,
A plane rectangular shape, a plane elliptical shape, a plane circular shape, etc. can be used. As the material of the substrate 12, a metal having a high thermal conductivity such as aluminum or copper is used.

The vertical fin bodies 13a and 13b are provided on one upper surface of the substrate 12 as shown in FIG. 1 so as to be substantially parallel to the flow direction A of the cooling fluid, and one vertical fin body. A large number of bodies 13a are arranged in a line with being shifted to the windward side of the other vertical fin body 13b. Vertical fin bodies 13a, 1
The size of 3b is, for example, about 180 mm in height, about 250 mm in length or slightly shorter than the substrate 12, and about 1.0 mm to 6.0 mm in thickness. In the example of FIG. 1, the vertical fin body 13a is slightly longer than the vertical fin body 13b. When the arrangement of the vertical fin bodies 13a and 13b is seen in a plan view, as shown in FIG.
With respect to the flow path direction A of the cooling fluid that vertically strikes the sheet, the sheets are arranged so as to be shifted front and back for each sheet by a distance (D). The shifting distance (D) is 20 mm to 50 mm, more preferably 30
mm to 40 mm is suitable. Vertical fin body 1
By arranging 3a and 13b so as to be shifted in the front-back direction with respect to the flow direction A of the cooling fluid, the cooling fluid is transferred to the fin body 13
A space V sandwiched by the vertical fin bodies 13 a is formed in the portion that hits the fins, and when the cooling fluid hits the fin body 13, it can be prevented from laterally escaping and the occurrence of turbulence can be suppressed. Therefore, it is possible to suppress an increase in pressure loss even to a deep portion of the fin body 13, to secure a sufficient flow rate of the cooling fluid, and to improve the cooling efficiency of the radiation fin.

(Second Embodiment) FIG. 3 is a plan view showing a second embodiment of the radiation fin of the present invention. The radiating fin of the second embodiment is different from that of the first embodiment shown in FIG. 2 in that tapered portions 24a, 24b, 25a, 25b are provided at the tips of the vertical fin bodies 23a, 23b. . By providing the tapered portion at the tip of the vertical fin body, it is possible to reduce the pressure loss of the cooling fluid by the vertical fin body and improve the cooling efficiency.

Vertical fin bodies 23a, 2 having tapered portions
FIG. 4 is an enlarged view of the tip of 3b. Figure 4
As shown in, the taper portions 24a, 24b, 25a, 2
5b is the windward side 24a, 2 with respect to the flow direction A of the cooling fluid.
4b and the leeward side 25a, 25b is more effective. Especially, taper portions 24a and 24b provided on the windward side
Has a large effect of reducing the pressure loss of the cooling fluid. The tapered portions 24a, 24b, 25a, 25b are the vertical fin bodies 23a,
The taper portions 24a and 24b provided on the windward side have a width T with respect to the flow path direction A of the cooling fluid, and are formed substantially symmetrically with respect to the center plane in the length (L) direction of 23b. Gradually increases, and the taper portion 25 provided on the leeward side
The widths T of the a and 25b are formed so as to gradually decrease in the flow direction A of the cooling fluid. Further, each tapered portion is formed in plane symmetry with the center plane in the width T direction of the vertical fin bodies 24a, 24b as a plane of symmetry, and each inclination angle θ of the tapered portion is 5 to 60 degrees, more preferably 15 degrees. A range of degrees to 45 degrees is suitable. It should be noted that the inclination angles θ of the taper portions of the windward side 23c and the leeward side 23d may be different from each other with respect to the flow passage direction A of the cooling fluid. In this case, it is effective to reduce the inclination angle on the windward side within the above range of angles.

(Third Embodiment) FIG. 5 is a plan view showing a third embodiment of the radiation fin of the present invention. The radiating fins of the third embodiment differ from the first and second embodiments in that one vertical fin body 33a and two vertical fin bodies 33b are alternately and repeatedly arranged. That is, the tip positions of the respective vertical fin bodies are arranged so as to be shifted forward every two in the flowing direction A of the cooling fluid. Although a space having an appropriate width is formed, it is possible to suppress the occurrence of turbulence, although it depends on the arrangement interval of the vertical fin bodies. Therefore, the increase of the pressure loss is suppressed even in the deep portion of the fin body, a sufficient flow rate of the cooling fluid can be secured, and the cooling efficiency of the radiation fins can be improved. In FIG. 5, each vertical fin body 33a, 33
An example is shown in which tapered portions 34a and 34b are provided at the tip of b.

(Fourth Embodiment) FIG. 6 is a plan view showing a fourth embodiment of the radiation fin of the present invention. The radiating fins of the fourth embodiment differ from the first to third embodiments in that the taper portion is provided only at the tip end portion of the vertical fin body 43a which is arranged so as to project forward in the cooling fluid flow direction A. 44 is provided, and the vertical fin body 43b arranged rearward is not provided with a taper portion. This is because if the tapered portion 44 is provided only on the tip end portion to prevent the pressure loss of the cooling fluid from increasing, the turbulent flow can be suppressed by the effect of the space. The vertical fin bodies 43a protruding forward and the vertical fin bodies 43b arranged rearward are alternately arranged.

In the heat dissipating fins of the present invention shown in the first to fourth embodiments, horizontal fins may be arranged between each vertical fin body. The horizontal fin is formed by corrugating a thin plate or foil of a metal having good thermal conductivity, such as aluminum or copper, and joined to the vertical fin body by a joining method such as brazing. The size of the horizontal fins is not particularly limited, and the vertical fins may be mounted to fill the area as much as possible.

The radiation fin used in the present invention is a vertical fin.
It is preferable to use aluminum, copper, or an alloy thereof, which has a high horizontal fin co-thermal conductivity. For example, when an aluminum alloy is used, the vertical fins can be formed by performing various necessary mechanical processing (cutting, grinding, etc.) such as taper processing on an intermediate material formed by well-known plastic processing such as extrusion or forging. It is formed by subjecting the intermediate material formed by the plastic working of the cast to various necessary mechanical workings. Further, the substrate and the fin body may be integrally formed, or may be formed separately and then fixed by an appropriate method such as welding. Further, the horizontal fins may be constructed by brazing brazing sheets made of ultra-thin plates or foils whose surfaces are coated with a brazing material and corrugated to a predetermined size, and brazing the brazing sheets to predetermined positions.

(Experimental example) Next, an experimental result is shown in which the cooling performances of the radiation fin of the present invention having the above-mentioned structure and the radiation fin having a radiation area of the same size as the radiation fin of the present invention are compared. The external structure and dimensions of the radiation fin used in the experiment are shown in FIGS. 7 and 8. 7 is an external perspective view, and FIG. 8 is a sectional view taken along the line AA ′ in FIG. 7. As shown in FIG. 7, the radiation fin 51 has a length L, a width of 270 mm, and a thickness of 30.
On one side of the substrate 52 made of pure aluminum of mm, there are 14 vertical fin bodies 53a made of aluminum and having a length L1, a height of 180 mm, and a thickness of 2 mm.
2. A total of 27 vertical fin bodies, that is, 13 vertical fin bodies 53b made of aluminum having a height of 180 mm and a thickness of 2 mm, were arranged at a distance of 3 mm. Here, the length L1 of the vertical fin body 53a is 210 mm to 610 mm.
Set between. The length L of the substrate 52 is 250 m
It was set in the range of m to 650 mm. The length L2 of the vertical fin body 53b is set to be shorter than the length L1 of the vertical fin body 53a by 30 mm or 40 mm. Then, the taper portion 54a is provided only at the tip of the vertical fin body 53a which is arranged so as to be shifted forward and backward. The angle θ of the tapered portion was 30 degrees. Further, between the vertical fin bodies 53a and 53b, an aluminum foil having a thickness of 0.16 mm is formed with a width of 3 mm and a height of 3 m.
The horizontal fin body 56 corrugated to m was brazed and attached. The length L3 of the horizontal fin body 56 is set shorter than the length L2 of the vertical fin body 53.

Cooling air at 20 ° C. is blown from one end of the radiation fin 51 thus constructed at a speed of 8.8 m / s, and the static pressure at the inlet side and the outlet side of the cooling air is measured by a manometer to radiate heat. The pressure loss inside the fin 51 was measured. The results are shown in Table 1.

[0022]

[Table 1]

[0023]

According to the present invention, in a radiation fin having a substrate and a plurality of vertical fins held by the substrate, the tip positions of the respective vertical fins are arranged so as to be shifted forward and backward with respect to the flow direction of the cooling fluid. As a result, turbulent flow is suppressed when the cooling fluid hits the fin body, and the ventilation resistance (pressure loss) in the fin body is prevented from rising, and sufficient cooling fluid is drawn into the heat radiation fin body. It is intended to improve the cooling efficiency.

[0024]

According to the present invention, turbulent flow is prevented from occurring when the cooling fluid hits the fin body, and the ventilation resistance (pressure loss) in the fin body is prevented from increasing.
Since sufficient cooling fluid can be drawn into the radiating fin body to improve cooling efficiency, it can be made smaller than before.
It is possible to provide a high-performance radiating fin.

[Brief description of drawings]

FIG. 1 is an external view illustrating a structure of a heat dissipation fin according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a planar arrangement of heat radiation fins according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a planar arrangement of heat dissipation fins according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing in detail the shape of the tapered portion of the tip end portion of the heat dissipation fin according to the second embodiment of the present invention.

FIG. 5 is a diagram showing a planar arrangement of heat dissipation fins according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a planar arrangement of heat dissipation fins according to a fourth embodiment of the present invention.

FIG. 7 is an external view illustrating the structure of a radiation fin used in an experiment of the present invention.

FIG. 8 is a view showing a side structure of a heat dissipation fin used in an experiment of the present invention.

FIG. 9 is an external view showing an example of the structure of a conventional radiation fin.

FIG. 10 is an external view showing another example of the structure of a conventional radiation fin. It is an external view explaining the structure of the radiation fin concerning 1st Embodiment of this invention.

[Explanation of symbols]

1, 11, 21, 31, 41, 51 ... Radiating fins 2, 12, 22, 32, 42, 52 ... Substrate 3, 13 ... Fin body 3a 13a, 13b, 23a, 23b, 33a, 33
b, 43a, 43b, 53a, 53b ... Vertical fin bodies 7, 24a, 24b, 34a, 34b, 44a, 54a
・ ・ ・ ・ ・ Tapered part 56 ・ ・ ・ ・ ・ Horizontal fin

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masakazu Nakanishi             194 Senfuku, Susono City, Shizuoka Prefecture M Co., Ltd.             A Fab Tech Senfuku Factory (72) Inventor Yasuhito Sueki             194 Senfuku, Susono City, Shizuoka Prefecture M Co., Ltd.             A Fab Tech Senfuku Factory F-term (reference) 5F036 AA01 BA04 BA24 BB05 BD03

Claims (7)

[Claims] 1. A radiating fin having a substrate and a plurality of vertical fins held by the substrate, wherein the tip positions of the respective vertical fins are arranged so as to be shifted forward and backward with respect to the flow direction of the cooling fluid. A heat dissipation fin. 2. The radiating fin according to claim 1, wherein the tip positions of the respective vertical fins are arranged so as to be alternately shifted back and forth with respect to the flow direction of the cooling fluid. 3. The radiating fin according to claim 1, wherein the vertical fins are arranged such that every two vertical fins are offset from each other in the front-back direction in the flowing direction of the cooling fluid. 4. The distance from which the vertical fins are displaced forward and backward with respect to the flow direction of the cooling fluid is 20 mm or more and 50 mm or less, according to any one of claims 1 to 3.
The radiation fin according to item. 5. The radiating fin according to claim 1, wherein a taper portion is provided at a tip end portion of each of the vertical fins. 6. The heat dissipating fin according to claim 5, wherein the tapered portion is provided only on a vertical fin that is arranged so as to project forward in the flowing direction of the cooling fluid. 7. The radiating fin according to claim 1, wherein a horizontal fin is arranged between the vertical fins.