JP2020145283A - Heat sink and lighting apparatus - Google Patents

Abstract

To provide a heat sink capable of efficiently discharging heat and being miniaturized and lightened, and to provide a light source device including the same.SOLUTION: A heat sink 100 includes: a base portion 110; and a first fin group 120 in which a plurality of fins 121 standing up from one surface 111 of the base portion 110 is disposed in an annular shape. Each fin 121 has a plate shape and stands independently without being connected to other fins. In the base portion 110, a light source portion 200 is disposed on the other surface 112, and a part of the one surface 111 on which an end of each fin 121 is disposed has a raised upper portion 119 raised to a convex shape 111A.SELECTED DRAWING: Figure 6

Description

The present invention relates to a heat sink and a lighting device using the heat sink.

The lighting device includes a lighting device provided with a heat sink in order to release heat generated by a light source (for example, Patent Document 1 and Patent Document 2).

Japanese Unexamined Patent Publication No. 2016-207368 Japanese Unexamined Patent Publication No. 2016-207369

However, in Patent Documents 1 and 2, as shown in FIGS. 1, 4, 5, and 6 of Patent Documents 1 and 2, a cylindrical portion is arranged in the central region, and air flows in from the side surface. Even so, it is difficult to get out to the opposite side. Therefore, it is considered that the heat dissipation effect is not sufficient.

An object of the present invention is to provide a heat sink that can efficiently dissipate heat and can be downsized and lightened.

The heat sink according to the present invention is
Plate-shaped base and
It includes a first fin group in which a plurality of fins rising from one surface of the base portion are arranged in an annular shape.
Each fin of the plurality of fins of the first fin group is
It is plate-shaped and stands alone without being connected to other fins so that a flow path through which gas can pass is formed between adjacent fins.
The base portion
The light source portion is arranged on the other surface, and a part of the one surface on which the end portion of each fin is arranged is raised in a convex shape along the direction in which the plurality of fins stand. Have.

According to the present invention, the heat of the light source unit can be efficiently discharged to the outside of the heat sink, and the heat sink can be made smaller and lighter.

FIG. 1 is a perspective view of the lighting device 10. Another perspective view showing the lighting device 10 in the figure of the first embodiment. FIG. 1 is an exploded perspective view of the lighting device 10. FIG. 6 is a sectional view of the lighting device 10 in the figure of the first embodiment. FIG. 1 is a plan view of the heat sink 100 in the first embodiment. FIG. 5 is a perspective view of a heat sink 100 in a state of being cut in half in the figure of the first embodiment. FIG. 5 is a plan view of the heat sink 100 showing the gas flow in the heat sink 100 in the figure of the first embodiment. FIG. 7A is a cross-sectional view taken along the line AA of FIG. 7 of the heat sink 100 showing the heat flow in the heat sink 100 in the figure of the first embodiment. FIG. 7 is a cross-sectional view taken along the line BB of FIG. 7 of the heat sink 100, showing the heat flow in the heat sink 100 in the figure of the first embodiment. The figure which shows the heat sink 100-1 of Embodiment 2. The figure which shows the heat sink 100-2 of Embodiment 2. The figure which shows the heat sink 100-3 of Embodiment 2. The figure which shows the heat sink 100-4 of Embodiment 2.

Embodiment 1.
The lighting device 10 of the first embodiment will be described with reference to FIGS. 1 to 9. The feature of the lighting device 10 is the heat sink 100. Specifically, the bulky portion 119 of the base portion 110 of the heat sink 100 and the arrangement of the fins of the heat sink 100 are characteristic. With these features, it is possible to provide a small and lightweight heat sink having good heat dissipation efficiency, and a lighting device including the heat sink. The heat sink 100 assumes that the base portion 110 and a plurality of fins are integrally formed by cold forging.

1 and 2 are perspective views of the lighting device 10.
FIG. 3 is an exploded perspective view of the lighting device 10.
FIG. 4 is a cross-sectional view of the lighting device 10.
FIG. 5 is a plan view of the lighting device 10.
FIG. 6 is a perspective view of one of the heat sinks 100 cut in two.

*** Explanation of the configuration of the lighting device ***
As shown in FIG. 3, the lighting device 10 includes a heat sink 100, a light source unit 200, a reflector 300, a diffuser plate 400, and a reflector frame 500. Further, the lighting device 10 includes a lighting device (not shown). The light source unit 200 is attached to the heat sink 100. The reflector 300 has a function of fixing the light source unit 200 to the heat sink 100. The diffuser plate 400 has a function of diffusing the light of the light source unit 200. The reflector frame 500 has a function of attaching the lighting device 10 to the ceiling hole.

The material of the heat sink 100 is preferably a metal having good heat dissipation because it dissipates heat generated by the light source unit 200, but the material is not limited to the metal as long as the heat dissipation is good. In the first embodiment, the material of the heat sink 100 is an aluminum alloy.

A plurality of LEDs (not shown) are mounted on the light source unit 200.

The exterior of the reflector 300 is made of plastic resin, and a conductive metal fitting is built in the reflector 300.

The diffuser plate 400 is made of a translucent material. The diffuser plate 400 diffuses and transmits the light directly emitted from the light source unit 200 and the light reflected by the reflector 300.

The reflector frame 500 has three mounting springs 501. The mounting spring 501 prevents the lighting device 10 from falling when the lighting device 10 is mounted in the ceiling hole. Note that FIG. 3 shows only the main members for forming the lighting device 10.

The light source unit 200 and the reflector 300 shown in FIGS. 3 and 4 are fastened to the heat sink 100 with screws. The diffuser plate 400 is attached to the reflector 300. The reflector frame 500 is attached to the reflector 300 or the heat sink 100.

*** Explanation of the configuration of the heat sink 100 ***
Next, the configuration of the heat sink 100 will be described. As shown in FIG. 6, the heat sink 100 includes a plate-shaped base portion 110 and a first fin group 120 in which a plurality of fins 121 rising from one surface 111 of the base portion 110 are arranged in an annular shape.

<1st fin group>
In FIG. 5, 18 fins 121 from fins 121-1 to fins 121-18 counterclockwise are the first fin group 120. When there is no particular need to distinguish, fins 121-1 and the like are referred to as fins 121. As shown in FIGS. 5 and 6, each fin 121 of the plurality of fins of the first fin group 120 has a plate shape, and a flow path through which gas can pass is formed between adjacent fins. , Stands alone without connecting to other fins 121.
The gas is assumed to be the atmosphere, that is, air, but the heat sink 100 can be used in an environment other than the atmosphere, so the term gas is used.

As shown in FIG. 5, a plurality of fins 121 and 121 are located in the central region 101 inside the first fin group 120. .. .. A space 102 is formed that is open in the direction in which the space stands.

As shown in FIG. 5, a plurality of fins 121, 121. .. .. The flow path 11 formed between any of the adjacent fins is another formed between any adjacent fins arranged between the spaces 102 formed in the central region 101. It is connected to the flow path 18 via the space 102. In FIG. 5, the flow path 11 formed between the fins 121-9 and the fins 121-10, which are adjacent fins, is arranged with the space 102 in between, and the fins 121-16 are different fins. It shows a state of being connected to another flow path 18 formed between the fins 121-17 and the fins 121-17 via a space 102. The flow path 11 and the flow path 18 are connected to form a stairwell path 103.

As shown in FIG. 5, a plurality of fins 121, 121. Of the first fin group 120. .. .. Are arranged in an annular shape so as to overlap the first virtual circumference 113 shown by the broken line of one surface 111 of the base portion 110. Each fin 121 of the plurality of fins of the first fin group 120 is arranged so that the plate surface 121F of each fin intersects the radial direction 115 of the first virtual circle 114 having the first virtual circumference 113. .. The plate surface 121F of the fin 121 is a surface of the plate width B of the fin 121, as shown in FIG. Further, the plate surface 111F of the fin 131, which will be described later, is a surface of the plate width B of the fin 131, as shown in FIG. In FIG. 5, taking fin 121-1 as an example, the width direction 124 of the plate surface 121F of fin 121-1 is arranged so as to intersect with respect to the radial direction 115 of the first virtual circle 114 at an angle θ. Has been done. The same applies to the fins 121 other than the fins 121-1. Specifically, as can be seen from the fins 121-1 in FIG. 5, each fin 121 of the plurality of fins 121 of the first fin group 120 has a plate surface 121F in the width direction 124 in the radial direction 115 in a plan view. On the other hand, they are arranged so as to intersect at an angle θ in the clockwise direction.

<2nd fin group>
Further, the heat sink 100 includes a second fin group 130 as shown in FIGS. 5 and 6. In FIG. 5, 31 fins extending counterclockwise from fin 131-1 through fins 131-2, 131-7, 131-9, 131-10, 131-17, 131-18 to 131-31 are second fins. Group 130. When it is not necessary to distinguish between fins 131-1 and the like, they are referred to as fins 131. As described above, in the second fin group 130, a plurality of fins 131 rising from one surface 111 of the base portion 110 are arranged in an annular shape on the outside of the first fin group 120. Each fin 131 of the plurality of fins has a plate shape, and stands independently without being connected to other fins so that a flow path through which gas can pass is formed between adjacent fins.

As shown in FIG. 5, a plurality of fins 131, 131 of the second fin group 130. .. .. Are annularly arranged so as to overlap the second virtual circumference 116 of one surface 111 of the base portion 110. A plurality of fins 131, 131 of the second fin group 130. .. .. Each of the fins 131 is arranged so that the width direction 134 of the plate surface 131F (FIG. 6) of each fin 131 intersects the radial direction 118 of the second virtual circle 117 having the second virtual circumference 116. .. Specifically, as can be seen from the fins 131-7 in FIG. 5, each fin 131 of the second fin group 130 has a radial direction 118 and a plate surface 131F (FIG. 6) width direction 134 in a plan view. Are arranged so as to intersect at an angle φ in the clockwise direction.

<Structure of base>
As shown in FIGS. 3 and 4, the light source unit 200 is arranged on the other surface 112 of the base unit 110. As shown in FIG. 6, the base portion 110 has a plurality of fins 121, 121. .. .. Along the direction in which the fins 121 stand, a portion of one surface 111 on which the end portions of the fins 121 are arranged has a raised upper portion 119 that is raised in a convex shape. The bulky upper part 119 is raised like a disk. In FIG. 5, the upper circumference 119A and the lower circumference 119B of FIG. 6 are visible.

As shown in FIG. 6, in the base portion 110, the corresponding region 111B of one surface 111, which is the back surface of the light source portion arrangement region 112A in which the light source portion 200 is arranged, is the bulky upper portion of the convex shape 111A. It is 119.
The ratio of the thickness of the base portion 110 excluding the bulky portion 119 to the thickness of the bulky top 119 is, for example, in the range of 0.3 or more and 0.6 or less. FIG. 6 shows a case where the thickness of the base portion 110 is 4.7 mm and the thickness of the bulky portion 119 is 10.7 mm as an example.

As shown in FIG. 6, the space 102 is formed above the bulky portion 119. Since the space 102 forming the atrium path 103 exists above the bulky portion 119, there is an effect of improving the efficiency of heat dissipation.

<Specific composition of fins>
As shown in FIGS. 5 and 6, in the heat sink 100, at least a part of each fin 121 of the first fin group 120 stands up from the bulky portion 119. Therefore, at least a part of one fin 121 stands up from the bulky portion 119 that sucks heat from the light source unit 200, which has an effect of improving the efficiency of heat dissipation. In FIG. 6, a part of the lower end of the fin 121 stands up from the bulky top 119, but the entire lower end may stand up from the bulky top 119.

In the heat sink 100, the minimum distance Δh (FIG. 5) between adjacent fins is a dimension in the range of 3 mm or more and 5 mm or less. The adjacent fins include three cases of the fins 121 of the first fin group 120, the fins 131 of the second fin group 130, and the fins 121 and the fins 131. Each fin of the first fin group 120 and each fin 131 of the second fin group 130 stands independently without being connected to other fins. The “minimum distance Δh between adjacent fins” means that the minimum distance Δh between fins standing independently is in the range of 3 mm or more and 5 mm or less, and the minimum distance Δh Is a three-dimensional distance. In FIG. 5, the minimum distance Δh between the fins 121-17 and the fins 121-18 is indicated by double-headed arrows 105.

In the heat sink 100, each fin of the plurality of fins has a plate thickness t (FIG. 6) of 1 mm or more and 2 mm or less, and a maximum width Bmax along the plate surface of 30 mm or less. The plurality of fins are both the fin 121 of the first fin group 120 and the fin 131 of the second fin group 130. The width along the plate surface is the plate width B of the fins in the lateral direction when the fins are manufactured in a straight shape upward from the root to the tip. FIG. 6 shows the plate widths B of the fins 121 and 131. Further, FIG. 6 shows the plate thickness t using the fin 131 as an example.
Since the maximum width Bmax of the fin plate width is 30 mm or less, the heat sink 100 can be manufactured without providing a draft in the fin mold when the cold forging method is used. Further, since the maximum width Bmax is 30 mm or less, there is an effect of preventing the fins from being deformed or falling when the heat sink 100 is removed from the mold. If the plate width of the fins exceeds 30 mm, there is a high possibility that the fins will be deformed when the fins are removed from the mold. Further, when the fin has no draft in the mold, the shape of the fin can be straight from the root to the tip, which is effective in reducing the weight. That is, each fin of the plurality of fins has a constant length along the plate surface, that is, a plate width B in a plan view.
Regarding the plate thickness t of the fins, if the plate thickness t is 1 mm or more and 2 mm or less, when the cold forging method is used as the method for producing the heat sink 100, the heat sink 100 can be manufactured without providing a draft in the fin mold. Therefore, when the cold forging method is used, the fin shape can be manufactured in a straight shape from the root to the tip, which has the effect of reducing the weight as described above. The fins are both the fin 121 of the first fin group 120 and the fin 131 of the second fin group 130.

In the heat sink 100, each fin of the plurality of fins has a height H from one surface 111 of 80 mm or less. By setting the height H to 80 mm or less, a compact and lightweight heat sink 100 can be provided. The fins of the plurality of fins are both the fin 121 of the first fin group 120 and the fin 131 of the second fin group 130. Since it is "height H from one surface 111", as shown in FIG. 6, when the fin stands up from one surface 111 other than the bulky portion 119, the height H1 ≤ 80 mm from one surface 111. Yes,
When the fins stand up from one surface 111 corresponding to the upper surface of the bulky portion 119,
The height H2 ≦ 80 mm from one surface 111.

<Explanation of gas flow>
FIG. 7 shows the flow of gas in the heat sink 100. FIG. 7 is a plan view of the heat sink 100, which is the same as that of FIG. In FIG. 7, the broken line arrow 106A indicates the traveling direction of the gas. The solid line arrow 106B indicates the traveling direction in which the traveling direction of the gas flowing into the flow path of the heat sink 100 along the broken line arrow 106A is gradually changed by the second fin group 130. The broken line arrow 106A, the solid line arrow 106B, and the arrow 107 described later are for explanation purposes only and do not indicate the actual flow. The ten thick arrows 107 in the center indicate that the first fin group 120 causes a spiral flow in the corresponding region 111B of one surface 111.
That is, the fins of the heat sink 100 are installed so as to pass through a position offset from the center of the heat sink 100 without passing through the center of the heat sink 100 when an imaginary line is drawn toward the center. Therefore, the flow of the gas flowing in from the outer circumference is changed in a spiral shape so as not to stay, and the convection of the gas passing through the heat sink 100 is promoted.
Specifically, the width direction 124 of each fin 121 is inclined to the right by an angle θ with respect to the radial direction 115, and the width direction 134 of each fin 131 is angled to the right with respect to the radial direction 118. φ is tilted. With this configuration, a spiral gas flow is created in the corresponding region 111B without retaining the gas flow, thereby creating a gas flow that smoothly progresses toward the space 102 above the corresponding region 111B. Can be done. The cooling efficiency can be improved by this spiral gas flow.

<Explanation of heat flow>
FIG. 8 is a cross-sectional view taken along the line AA of FIG.
FIG. 9 is a cross-sectional view taken along the line BB of FIG. The heat flow in the heat sink 100 will be described with reference to FIGS. 8 and 9. Arrow 108 indicates the flow of heat. As shown in FIGS. 8 and 9, the heat generated in the light source unit 200 is mainly pulled up by the bulky portion 119. The heat pulled up by the bulky portion 119 is radiated into the atmosphere from the fins 121 of the first fin group 120 and radiated from the fins 131 of the second fin group 130.

*** Effect of Embodiment 1 ***
(1) The heat sink 100 has a bulky portion 119 having a convex shape 111A in a corresponding region 111B corresponding to the back surface of the light source portion arrangement region 112A in which the light source portion 200 is arranged. Since the bulky portion 119 can pull up the heat from the light source unit 200, the heat generated by the light source unit 200 can be efficiently transferred to each fin of the first fin group 120.
(2) As described with reference to FIG. 5, in the central region 101 of the heat sink 100, there is no structure that obstructs the flow of gas, and a stairwell path 103 is formed. Therefore, the gas can blow through the blow-through path 103. Since the fins are formed at intervals of 3 mm or more and 5 mm or less, the fins do not block the inflow of gas. Therefore, the heat transferred from the light source unit 200 can be efficiently discharged to the outside of the heat sink 100.
(3) As described above, the fins 121 and 131 of the heat sink 100 are installed at positions where the plate thickness holding direction is offset by an angle θ and an angle φ with respect to the center direction of the virtual circle. Therefore, the flow of the gas flowing in from the outer circumference can be spiraled and easily convected toward the space 102 above the corresponding region 111B without staying. Therefore, the heat dissipation efficiency can be improved.

Embodiment 2.
The heat sinks 100-1, 100-2, 100-3, and 100-4 of the second embodiment will be described with reference to FIGS. 10 to 13. Each heat sink of the second embodiment has a different fin shape from the heat sink 100 of the first embodiment. In the second embodiment, the same parts as those in the first embodiment will be omitted.

FIG. 10 shows the heat sink 100-1.
FIG. 11 shows the heat sink 100-2.
FIG. 12 shows the heat sink 100-3.
FIG. 13 shows the heat sink 100-4.

The heat sink 100-1 will be described with reference to FIG.
(1) In the heat sink 100-1, all the fins arranged outside the first fin group 120 form the second fin group 130. As shown in FIG. 5, in the case of the heat sink 100, there are fins between the fins 131-9 and the fins 131-10, but these are not included in the second fin group 130. In the heat sink 100-1, all the fins arranged around the first fin group 120 form the second fin group 130 as fins 131.

The heat sink 100-2 will be described with reference to FIG.
(1) In the heat sink 100-2, the first fin group 120 stands up from the upper surface of the bulky portion 119. This can be seen from the fact that a part of the lower bottom side of the fin 131 of the second fin group 130 is in a contact state as shown in the broken line range 119C.
(2) In the heat sink 100-2, each fin 131 of the second fin group 130 is not flat and has a curvature.
(3) In the heat sink 100-2, there is a third fin group 140 surrounding the second fin group 130. The third fin group 140 is composed of a plurality of fins 141. The fin 141 has a curvature like the fin 131. The radius of curvature R is shown on the fins 141-1. The fin 131 also has the same radius of curvature as the fin 141.

The heat sink 100-3 will be described with reference to FIG.
(1) In the heat sink 100, the second fin group 130 does not exist. The first fin group 120 exists.
(2) In the space surrounded by the fins 121 of the first fin group 120, there are four pillar-shaped columnar portions 150. The four columnar portions 150 stand up from the upper surface of the bulky portion 119.

The heat sink 100-4 will be described with reference to FIG.
(1) The heat sink 100-4 has a first fin group 120, a second fin group 130, a third fin group 140, and a fourth fin group 160. The first fin group 120 is composed of a plurality of fins 121, the second fin group 130 is composed of a plurality of fins 131, the third fin group 140 is composed of a plurality of fins 141, and the fourth fin group 160 is composed of a plurality of fins 161. Become.
(2) Each of the fins of the second fin group 130, the third fin group 140, and the fourth fin group 160 is arranged along the virtual circumference so that the plate thickness of the fins is along the virtual circumference.

The effect of the heat sink 100 of the first embodiment can also be obtained for the heat sinks 100-1 to 100-2 of the second embodiment.

Although the first and second embodiments of the present invention have been described above, the first and second embodiments may be combined and implemented. Alternatively, the first embodiment or the second embodiment may be partially implemented. Alternatively, the first and second embodiments may be partially combined. The present invention is not limited to these embodiments, and various modifications can be made as needed.

B plate width, Bmax maximum plate width, H height, hmin minimum interval, t plate thickness, 10 lighting device, 11,18 flow path, 100 heat source, 101 central area, 102 space, 103 stairwell path, 104 gas, 105 cars Arrow, 106A dashed arrow, 106B solid arrow, 107,108 arrow, 110 base, 111 one side, 111A convex, 111B corresponding area, 112 other side, 112A light source placement area, 113 first virtual circumference , 114 1st virtual circle, 115 radial direction, 116 2nd virtual circumference, 117 2nd virtual circle, 118 radial direction, 119 bulk upper part, 119A upper circumference, 119B lower circumference, 119C broken line range 120 1st fin group, 121 fin, 121F plate surface, 124 width direction, 130 2nd fin group, 131 fin, 131F plate surface, 134 width direction, 140 3rd fin group, 141 fin, 150 columnar part, 160 4th Fins, 161 fins, 200 light source, 300 reflector, 400 diffuser, 500 reflector frame, 501 mounting spring.

Claims (13)

Plate-shaped base and
It includes a first fin group in which a plurality of fins rising from one surface of the base portion are arranged in an annular shape.
Each fin of the plurality of fins of the first fin group is
It is plate-shaped and stands alone without being connected to other fins so that a flow path through which gas can pass is formed between adjacent fins.
The base portion
The light source portion is arranged on the other surface, and a part of the one surface on which the end portion of each fin is arranged is raised in a convex shape along the direction in which the plurality of fins stand. Heat sink to have. The base portion
The heat sink according to claim 1, wherein the corresponding region of the other surface, which is the back surface of the light source portion arrangement region in which the light source portion is arranged, is the bulky upper portion. In the central region inside the first fin group,
An open space is formed in the direction in which the plurality of fins stand.
The flow path formed between any of the adjacent fins among the plurality of fins
It is connected via the space to another flow path formed between any other adjacent fins arranged between the spaces formed in the central region.
The space is
The heat sink according to claim 1 or 2, which is formed above the bulky portion. Each fin of multiple fins
The heat sink according to any one of claims 1 to 3, wherein at least a part thereof stands up from the bulky portion. The plurality of fins of the first fin group are
Arranged in a ring so as to overlap the first virtual circumference of the one surface of the base portion.
Each fin of the plurality of fins of the first fin group is
The heat sink according to any one of claims 1 to 4, wherein the plate surface of each fin is arranged so as to intersect the radial direction of the first virtual circle having the first virtual circumference. Each fin of the plurality of fins of the first fin group is
The heat sink according to claim 5, wherein the plate surfaces are arranged so as to intersect with each other at an angle in a clockwise direction with respect to the radial direction in a plan view. The heat sink is
A plurality of fins rising from the one surface of the base portion include a second fin group arranged in an annular shape on the outside of the first fin group.
Each fin of the plurality of fins of the second fin group
Any of claims 1 to 6, which are plate-shaped and stand alone without being connected to other fins so that a flow path through which gas can pass is formed between adjacent fins. The heat sink according to item 1. The plurality of fins of the second fin group are
Arranged in a ring so as to overlap the second virtual circumference of the one surface of the base portion.
Each fin of the plurality of fins of the second fin group
The heat sink according to claim 7, wherein the plate surface of each fin is arranged so as to intersect the radial direction of the second virtual circle having the second virtual circumference. The base portion and the plurality of fins
It is integrally molded by cold forging,
Each fin of the plurality of fins
The heat sink according to any one of claims 1 to 8, wherein the length along the plate surface is constant in a plan view. The minimum spacing between adjacent fins is
The heat sink according to any one of claims 1 to 9, which has a size in the range of 3 mm or more and 5 mm or less. Each fin of the plurality of fins
The heat sink according to any one of claims 1 to 10, wherein the plate thickness is 1 mm or more and 2 mm or less, and the maximum width along the plate surface is 30 mm or less. Each fin of the plurality of fins
The heat sink according to any one of claims 1 to 11, wherein the height from one of the surfaces is 80 mm or less. The lighting device provided with the heat sink according to any one of claims 1 to 12.

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