Heat sink, light-emitting module, and method for manufacturing heat sink

Abstract

To provide a new heat sink with devised bending.SOLUTION: A heat sink 24 is a heat sink formed by bending one metal plate, and has a plurality of bent surfaces 24a on which a substrate is mounted, and U-shaped fins 24b provided to connect the adjacent bent surfaces 24a to each other. The U-shaped fin 24b may be provided with vent holes 24d in a bottom face 24c of the U-shape. The bottom face 24c may be provided such that the perpendicular X1 of the bottom face and the perpendicular X2 of the bent surface 24a are in a twisted positional relationship.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a heat sink. [Background technology]

[0002] Conventionally, heat sinks for dissipating heat from a light source are known that are made by bending a single sheet of metal as a part or whole. For example, a heat sink has been devised that includes a heat source mounting plate on the surface of which a heat source is attached, and a corrugated heat dissipation plate that is formed continuously with the heat source mounting plate (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-234909 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned heat sink has a heat dissipation plate made up of multiple fins extending from one side of a rectangular heat source mounting plate, and the path for the heat generated by the heat source attached to the heat source mounting plate to dissipate to the fins of the heat dissipation plate is long, so it cannot necessarily be said that heat dissipation can be performed efficiently.

[0005] The present invention has been made in view of the above circumstances, and one of its objects is to provide a new heat sink with an improved bending process. [Means for solving the problem]

[0006] In order to solve the above problems, a heat sink according to one embodiment of the present invention is a heat sink constructed by bending a single metal plate, and has a number of folded surfaces on which substrates are placed, and U-shaped fins arranged to connect adjacent folded surfaces.

[0007] According to this embodiment, a heat sink can be realized on which a substrate can be placed and in which U-shaped fins are provided integrally with the bent surface.

[0008] The U-shaped fins may have ventilation holes on the bottom surface of the U. This allows air to flow in and out not only between the fins but also from the bottom surface, improving the heat dissipation effect.

[0009] The bottom surface may be provided such that a perpendicular line to the bottom surface and a perpendicular line to the folded surface are in a twisted positional relationship, which makes it easier for air to flow in a direction intersecting the perpendicular line to the substrate.

[0010] The bending surface may be a rectangular plane, and the U-shaped fin may have a first U-shaped fin connected to one side of the rectangle, and a second U-shaped fin connected to the other side opposite the one side.

[0011] The bottom surface of the U-shape of the first U-shaped fin and the bottom surface of the U-shape of the second U-shaped fin may be disposed on either side of a diagonal line of a rectangular plane, thereby realizing a heat sink having vents on both sides of the bent surface on which the substrate is placed.

[0012] Another aspect of the present invention is a light-emitting module. This light-emitting module includes a heat sink having a plurality of bent surfaces and U-shaped fins provided to connect adjacent bent surfaces and configured by bending a single metal plate, a substrate having one surface placed on the plurality of bent surfaces, and a light-emitting element mounted on the other surface of the substrate. The light-emitting element is disposed so as to overlap with the bent surfaces when the other surface of the substrate is viewed from the front.

[0013] According to this embodiment, since the bent surface of the heat sink is disposed on the rear surface side of the light emitting element, heat from the light emitting element can be easily transferred to the heat sink.

[0014] Yet another aspect of the present invention is a method for manufacturing a heat sink. This method includes the steps of preparing a metal plate from which a rectangular portion is punched out so that the metal plate can be folded multiple times, folding the metal plate in half in a predetermined direction to form multiple folded surfaces, and folding the metal plate multiple times in a direction different from the predetermined direction to form multiple U-shaped fins. The U-shaped fins are provided so as to connect adjacent folded surfaces to each other.

[0015] According to this embodiment, a heat sink having a plurality of U-shaped fins that contribute to heat dissipation can be manufactured by bending a single metal plate.

[0016] Any combination of the above components, and any conversion of the expression of the present invention between a manufacturing method, a device such as a lamp or lighting, a light-emitting module, a light source, etc. are also valid as aspects of the present invention. Effect of the Invention

[0017] According to the present invention, a new heat sink with an improved bending process can be provided. [Brief description of the drawings]

[0018] [Figure 1] 1 is a vertical cross-sectional view showing an example of a vehicle lamp in which a lighting control module according to an embodiment of the present invention can be mounted; [Diagram 2] FIG. 1 is a perspective view of a heat sink according to an embodiment of the present invention. [Diagram 3] 3 is a front view of the heat sink shown in FIG. 2 as viewed from a direction A. [Figure 4] 3 is a top view of the heat sink shown in FIG. 2 as viewed from direction B. FIG. [Diagram 5] 1 is a top view of a metal plate before being bent into a heat sink according to an embodiment of the present invention; [Figure 6] FIG. 2 is a front view of the light-emitting module according to the present embodiment. [Figure 7] 1 is a perspective view of a light-emitting module according to an embodiment of the present invention; [Figure 8]8(a) to 8(c) are schematic views for explaining a method for manufacturing a heat sink according to this embodiment. [Figure 9] 9(a) and 9(b) are schematic views for explaining a method for manufacturing a heat sink according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0020] (Vehicle lighting fixtures) Fig. 1 is a vertical cross-sectional view showing an example of a vehicle lamp in which a lighting control module according to the present embodiment can be mounted. A headlamp 10 as a vehicle lamp shown in Fig. 1 shows one of a left or right headlamp. These headlamps 10 are attached to both sides in the vehicle width direction at the front of the vehicle, and these headlamps 10 illuminate the area ahead of the vehicle.

[0021] As shown in FIG. 1, the exterior of a headlamp 10 is formed by a lamp body 12 that is open at the front, and a front cover 14 that serves as a surface cover that covers the opening of the lamp body 12.

[0022] The lamp body 12 is composed of a rear wall portion 12a that stands up in the vertical direction and a peripheral wall portion 12b that protrudes forward (to the left in FIG. 1) from the peripheral edge of the rear wall portion 12a. The rear wall portion 12a extends in the horizontal direction (perpendicular to the paper surface in FIG. 1) while maintaining a constant height, and the peripheral wall portion 12b cooperates with the rear wall portion 12a to define a storage space 16, and the tip of the peripheral wall portion 12b forms a horizontally elongated opening 18 in the storage space 16.

[0023] The front cover 14 is detachably attached to the tip of the peripheral wall portion 12b of the lamp body 12. As a result, the front cover 14 and the lamp body 12 form a lamp housing, and a sealed lamp chamber 20 is formed therein. The front cover 14 is translucent, and light emitted in the lamp chamber 20 is irradiated to the outside through the front cover 14. A resin lens is used for the front cover 14 in this embodiment.

[0024] An LED unit 22 is disposed inside the lamp chamber 20. As shown in Fig. 1, the LED unit 22 includes a metal heat sink 24 serving as a conductive base. The heat sink 24 according to this embodiment integrally includes a plate-shaped metal support plate portion 26 attached to the LED unit 22 and a heat dissipation fin portion 28. The metal support plate portion 26 and the heat dissipation fin portion 28 may be formed as a single component.

[0025] The metal support plate 26 is supported by the rear wall 12a of the lamp body 12 via aiming screws 30 and the like, and the plate surface of the metal support plate 26 faces the front-rear direction and is disposed in a state spaced apart from the rear wall 12a toward the front side. The heat dissipation fins 28 are attached to the rear surface of the metal support plate 26, and the heat dissipation fins 28 are cooled by a heat dissipation fan 32 attached to the heat sink 24.

[0026] The LED unit 22 includes a cylindrical lens holder 34 and a projection lens 36 attached to the lens holder 34. The rear end of the lens holder 34 is attached to the front of the metal support plate portion 26, and the front end of the lens holder 34 extends forward. The projection lens 36 is attached to the front end of the lens holder 34, and thus the projection lens 36 is disposed on an optical axis L extending in the front-rear direction of the vehicle. A front cover 14 is disposed in front of the projection lens 36. An extension reflector 38 is disposed around the projection lens 36 and the lens holder 34.

[0027] The LED unit 22 includes a light emitting module 40. The light emitting module 40 includes a resin circuit board 42, a plurality of light emitting diodes (hereinafter referred to as LEDs) 44, and a power supply connector 46. The circuit board 42 is disposed within the lens holder 34 in a state where it is aligned with the front surface of the metal support plate portion 26, and a board surface 42a of the circuit board 42 faces forward. The circuit board 42 is disposed toward the lower side within the lens holder 34, and a power supply circuit (not shown) is formed on the board surface 42a.

[0028] The LEDs 44 are attached to an upper portion of the board surface 42a of the circuit board 42. The LEDs 44 are arranged as a planar light source that emits light, arranged side by side in the vehicle width direction with their light-emitting surfaces facing forward of the vehicle, and in this embodiment, each LED 44 is configured such that a fluorescent layer is provided on an LED chip so as to emit white light.

[0029] The power supply connector 46 is attached to the lower portion of the board surface 42a. A power source (not shown) is connected to the power supply connector 46 via an LED driver module (LDM) 50 by using a wire harness 48, and each LED 44 is connected via a power supply circuit (not shown) on the board surface 42a. The LED driver module 50 is disposed in the lower portion of the lamp body 12, and includes a metal case 52 as a conductive case and a lighting control circuit board 54 housed in the metal case 52. The power supply connector 46 and the power source (not shown) are connected via the lighting control circuit board 54 in the metal case 52, and the lighting control circuit board 54 controls the turning on and off of the multiple LEDs 44.

[0030] (heat sink) Fig. 2 is a perspective view of the heat sink according to the present embodiment. Fig. 3 is a front view of the heat sink shown in Fig. 2, seen from direction A. Fig. 4 is a top view of the heat sink shown in Fig. 2, seen from direction B. Fig. 5 is a top view of a metal plate before bending into the heat sink according to the present embodiment.

[0031] When manufacturing the heat sink 24, as shown in Fig. 5, a rectangular metal plate 56 is prepared with predetermined areas (slits 56a, corners 56b, and round holes 56c) punched out so that the heat sink 24 can be folded multiple times. The material of the metal plate 56 is, for example, aluminum. The thickness of the metal plate 56 is, for example, about 1 to 3 mm, and may be in the range of 1.5 to 2.5 mm in consideration of strength and workability.

[0032] The method of bending will be described later, but the heat sink 24 shown in Figs. 2 to 4 is formed by bending a single metal plate 56. The heat sink 24 has a plurality of bent surfaces 24a on which a substrate is placed, and U-shaped fins 24b provided to connect adjacent bent surfaces 24a. The bent surfaces 24a may be bent on both sides, such as the three central surfaces out of the five, or may be surfaces at both ends that are bent on only one side. The five bent surfaces 24a form part of the same plane, allowing a substrate to be stably placed thereon, and realizing a heat sink 24 in which the U-shaped fins 24b are provided integrally with the bent surfaces 24a.

[0033] The U-shaped fins 24b are provided with ventilation holes 24d on a bottom surface 24c of the U. This allows air to flow in and out not only through gaps 24e between the fins 24b but also through the bottom surface 24c, improving the heat dissipation effect.

[0034] The bottom surface 24c is provided such that a perpendicular line X1 to the bottom surface 24c and a perpendicular line X2 to the bent surface 24a are in a twisted positional relationship, which makes it easier for air to flow in a direction intersecting the perpendicular line of the substrate placed on the bent surface 24a (the direction of the perpendicular line X1).

[0035] The bent surface 24a may be a rectangular plane, and the U-shaped fin 24b may have a first U-shaped fin 24b1 connected to one side of the rectangle, and a second U-shaped fin 24b2 connected to the other side opposite the one side (see FIG. 3).

[0036] The bottom surface 24c1 of the U-shape of the first U-shaped fin 24b1 and the bottom surface 24c2 of the U-shape of the second U-shaped fin 24b2 are disposed across the diagonal line of a commonly connected rectangular plane (bent surface 24a). This makes it possible to realize a heat sink 24 in which vent holes 24d are disposed on both sides of the bent surface 24a on which a substrate is placed.

[0037] The U-shaped fin 24b has two flat surfaces 24f bent from a specific side of a rectangular flat surface (bottom surface 24c) toward the back of the page (see FIG. 4). In other words, the two opposing flat surfaces 24f are connected by the bottom surface 24c to form the fin 24b having a U-shaped cross section. In this embodiment, at least a part of the bottom surface 24c connecting the two flat surfaces 24f includes a flat shape, but the part of the bottom surface 24c may be formed of a curved surface without including a flat surface.

[0038] (Light Emitting Module) FIG. 6 is a front view of the light emitting module according to the present embodiment. FIG. 7 is a perspective view of the light emitting module according to the present embodiment. The light emitting module 40 according to the present embodiment includes a heat sink 24, a circuit board 42 having a back surface 42b placed on a plurality of bent surfaces, and a plurality of light emitting elements mounted on a board surface 42a of the circuit board 42. The light emitting element according to the present embodiment is an LED 44. As shown in FIG. 6, the LED 44 is arranged so as to overlap with the bent surface 24a when the board surface 42a of the circuit board 42 is viewed from the front. As a result, the bent surface 24a of the heat sink 24 is arranged on the back surface side of each of the LEDs 44, so that heat from the LED 44 is easily transferred to the heat sink 24.

[0039] (Heat sink manufacturing method) Figures 8(a) to 8(c) are schematic diagrams for explaining a method for manufacturing a heat sink according to this embodiment. Figures 9(a) to 9(b) are schematic diagrams for explaining a method for manufacturing a heat sink according to this embodiment. Note that the ventilation holes 24d are omitted from each drawing.

[0040] As described above, the metal plate 56 shown in FIG. 5 is prepared, and as shown in FIG. 8(a), the portions that will become the bending surfaces 24a are sandwiched between the portions on both sides and bent 90 degrees to fold the plate in half. Next, as shown in FIG. 8(b), the bending surfaces 24a at both ends are bent outward by 90 degrees. Next, as shown in FIG. 8(c), the second and fourth bending surfaces 24a are bent outward by 90 degrees. Furthermore, as shown in FIG. 9(a), the bending surfaces 24a at both ends are bent inward by 90 degrees. Finally, as shown in FIG. 9(b), the second and fourth bending surfaces 24a are bent inward by 90 degrees.

[0041] In this way, multiple U-shaped fins 24b are formed by bending the metal plate 56 multiple times in directions different from the predetermined direction. The U-shaped fins 24b are provided so as to connect adjacent bent surfaces 24a. In this way, by bending one metal plate 56, a heat sink 24 having multiple U-shaped fins 24b that contribute to heat dissipation can be manufactured.

[0042] The heat sink 24 described above is easier to manufacture and requires less material costs than cast parts such as aluminum die casting. In addition, by devising the punching and bending methods, a three-dimensional heat sink 24 with a large heat dissipation area can be manufactured from a rectangular aluminum plate, so that a large number of aluminum plates can be cut out from a large aluminum plate.

[0043] Although the present invention has been described above with reference to the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment, and suitable combinations or substitutions of the configurations of the embodiment are also included in the present invention. In addition, it is possible to suitably rearrange the combinations and processing order in the embodiment based on the knowledge of a person skilled in the art, and to make modifications such as various design changes to the embodiment, and the embodiment to which such modifications have been made is also included in the scope of the present invention. [Explanation of symbols]

[0044] 10 headlamp, 22 LED unit, 24 heat sink, 24a bent surface, 24b fin, 24c bottom surface, 24d ventilation hole, 40 light-emitting module, 42 circuit board, 42a board surface, 42b back surface, 44 LED, 46 power supply connector, 56 metal plate, 56a slit.

Claims

1. A heat sink constructed by bending a single metal plate, a plurality of folding surfaces on which the substrate is placed; and U-shaped fins provided so as to connect adjacent bent surfaces to each other.

2. 2. The heat sink according to claim 1, wherein the U-shaped fin has a vent hole on a bottom surface of the U-shape.

3. 3. The heat sink according to claim 2, wherein the bottom surface is provided such that a perpendicular line to the bottom surface and a perpendicular line to the bent surface are in a twisted positional relationship.

4. The bending surface is a rectangular plane, 4. The heat sink according to claim 1, wherein the U-shaped fin comprises a first U-shaped fin connected to one side of the rectangle and a second U-shaped fin connected to the other side opposite the one side.

5. 5. The heat sink according to claim 4, wherein the bottom surface of the U-shape of the first U-shaped fin and the bottom surface of the U-shape of the second U-shaped fin are arranged on either side of a diagonal line of the rectangular plane.

6. A heat sink having a plurality of bent surfaces and U-shaped fins provided so as to connect adjacent bent surfaces, the heat sink being constructed by bending a single metal plate; a substrate having one surface placed on the plurality of bending surfaces; a light emitting element mounted on the other surface of the substrate, The light emitting module is characterized in that the light emitting element is arranged so that the other surface of the substrate overlaps with the bent surface when viewed from the front.

7. A step of preparing a metal plate having a rectangular portion punched out therefrom so that the metal plate can be folded multiple times; A step of forming a plurality of folded surfaces by folding the metal plate in two in a predetermined direction; and forming a plurality of U-shaped fins by folding the fin a plurality of times in a direction different from the predetermined direction, A method for manufacturing a heat sink, characterized in that the U-shaped fins are arranged to connect adjacent bent surfaces to each other.

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