Lighting fixture unit

Abstract

To provide a novel heat sink that can make a lighting fixture unit compact.SOLUTION: A lighting fixture unit includes: a light-emitting device including a light-emitting surface that is directed forward of a vehicle; a substrate 32 including a circuit necessary for turning on and off of the light-emitting device and having a principal surface that is directed forward of the vehicle; and a heat sink 30 coming into contact with the substrate. The heat sink 30 includes a cylindrical part 30c extending in a vertical direction on an opposite side to the side coming into contact with the substrate 32.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lighting unit.

Background Art

[0002] Conventionally, vehicle lighting fixtures provided with a heat sink for dissipating the heat of an LED light source are known. For example, Patent Document 1 discloses a headlamp unit provided with a light source device of a type that reflects light emitted upward forward with a reflector.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The heat sink of the aforementioned light source device includes a shelf portion on which the LED light source is placed, a vertical wall portion that stands upright on the rear side of the shelf portion, and substantially L-shaped side plate portions that support the shelf portion and the vertical wall portion from both left and right sides, and is a very large component. Therefore, the depth in the front-rear direction and the height in the vertical direction of the light source device also increase, and the headlamp itself becomes larger.

[0005] The present invention has been made in view of such circumstances, and one of its exemplary purposes is to provide a new heat sink that makes the lighting unit compact.

Means for Solving the Problems

[0006] In order to solve the above problems, a lighting unit according to an aspect of the present invention includes a light-emitting element having a light-emitting surface facing the front of the vehicle, a substrate having a circuit necessary for turning on and off the light-emitting element and having a main surface facing the front of the vehicle, and a heat sink in contact with the substrate. The heat sink has a cylindrical portion that extends vertically on the side opposite to the side in contact with the substrate.

[0007] According to this aspect, the main surface of the substrate and the cylindrical portion of the heat sink extend in the vertical direction, and since the space occupied by the substrate and the cylindrical portion in the vehicle front-rear direction is small, the front-rear direction of the lamp unit becomes compact.

[0008] The cylindrical portion may be formed by bending a plate. Thereby, the assembly process and the number of parts can be reduced.

[0009] The cylindrical portion may have an opening facing the front of the vehicle formed at the lower part. Thereby, the air cooled at the front part of the vehicle lamp can be introduced to the back side of the substrate.

[0010] The cylindrical portion may be configured such that the size of the upper horizontal cross section is smaller than the size of the lower horizontal cross section. Thereby, it becomes easier to take in cold air from the lower part.

[0011] The cylindrical portion may be polygonal in top view, and one side surface facing the front of the vehicle among the plurality of side surfaces of the polygon may be the opening. Thereby, the substrate whose back surface is exposed from the opening can be directly cooled by the air passing through the cylindrical portion.

[0012] The heat sink may include a first plate-shaped member that is bent and a second plate-shaped member that is bent. The cylindrical portion may include a first fin that is at least a part of the first plate-shaped member and a second fin that is at least a part of the second plate-shaped member. Thereby, the cylindrical portion can be constituted by a plurality of members.

[0013] The cylindrical portion may have a gap formed in the vertical direction between the first fin and the second fin. Thereby, a cylindrical portion that satisfies the desired heat dissipation performance can be configured without increasing the dimensional accuracy of the first plate-shaped member and the second plate-shaped member and the assembly accuracy to the substrate too much.

[0014] The gap may be 3 mm or less. Due to the viscosity of air, it is difficult for air to move on the surfaces of the substrate and the heat sink. Therefore, by making the gap smaller to a certain extent, the air rising in the cylindrical portion of the heat sink is less likely to leak through the gap, and the heat dissipation performance can be maintained up to the upper portion of the cylindrical portion.

[0015] The heat sink may include a first fin and a second fin that form at least a part of the cylindrical portion and extend from the substrate toward the rear of the vehicle, a third fin that is arranged in parallel with a space from the first fin toward the peripheral edge side of the heat sink, and a fourth fin that is arranged in parallel with a space from the second fin toward the peripheral edge side of the heat sink. Thereby, the heat dissipation performance can be further improved.

[0016] The first plate-like member or the second plate-like member may be configured such that the angle formed by adjacent surfaces is an obtuse angle. Thereby, the man-hour of bending processing can be reduced.

[0017] Any combination of the above components, and those obtained by converting the expression of the present invention among a manufacturing method, a device such as a lamp or lighting, a light-emitting module, a light source, etc. are also effective as aspects of the present invention.

Effects of the Invention

[0018] According to the present invention, the lamp unit can be made compact.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

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Figure 10

Figure 11

Mode for Carrying Out the Invention

[0020] Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. Further, the embodiments are illustrative and not restrictive of the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0021] FIG. 1 is a longitudinal sectional view schematically showing a vehicle lamp according to the present embodiment. The vehicle lamp 10 shown in FIG. 1 is a vehicle headlamp. The vehicle lamp 10 includes a lamp body 12 having a horizontally long opening formed in the front surface thereof, and an outer cover 14 attached to the peripheral edge of the opening of the lamp body 12 so as to cover the horizontally long opening. The outer cover 14 forms a lamp chamber 16 by covering the opening of the lamp body 12. Inside the lamp chamber 16, a lamp unit 18 is accommodated. The lamp unit 18 is configured such that light emitted from a semiconductor light emitting element 20, which is a light source, is irradiated to the outside through the outer cover 14.

[0022] Inside the lamp chamber 16, an extension 22 as a design member is further disposed. The extension 22 is disposed at a position where it can be visually recognized when the front portion 14a is viewed from the outside. The outer cover 14 has a front portion 14a through which light emitted from the semiconductor light emitting element 20 passes, and an extension portion 14b extending rearward from the upper portion of the front portion 14a. The outer cover 14 is a translucent resin member that transmits visible light, and is made of, for example, polycarbonate resin or acrylic resin. Polycarbonate resin and acrylic resin are materials having relatively high water absorption. Note that an anti-fogging coating may be applied to the inner surface on the lamp chamber side of the outer cover 14. The anti-fogging coating is a material having, for example, hydrophilicity or water absorption. Thereby, the inner surface of the outer cover 14 is less likely to fog up.

[0023] The vehicle lamp 10 further includes a heat radiating portion 26 that radiates heat H generated by the lamp unit 18. The heat radiating portion 26 is a heat sink having one or a plurality of cylindrical portions, and the lamp unit 18 is cooled by air A1 passing between the cylindrical portions.

[0024] The air A1 warmed by the heat dissipation of the lamp unit 18 reaches the inner surface of the front portion 14a of the outer cover 14. Since the outer cover 14 is cooled by the traveling wind W during vehicle travel, it takes heat from the air A1 passing through the inner surface and releases it to the outside. As a result, the cooled air A1 flows downward along the inner surface of the front portion 14a, passes through the lower part of the lamp chamber 16, reaches the heat dissipation portion 26, and contributes again to the heat dissipation at the heat dissipation portion 26.

[0025] FIG. 2(a) is a side view of the heat sink according to the first embodiment of the heat dissipation portion of the present embodiment, and FIG. 2(b) is a top view of the heat sink shown in FIG. 2(a). A semiconductor light-emitting element 20 having a light-emitting surface 20a facing the front of the vehicle is mounted on the main surface 32a of the substrate 32. Further, the substrate 32 has a circuit necessary for turning on and off the semiconductor light-emitting element 20.

[0026] The heat sink 30 according to the first embodiment has a plate-like portion 30a in contact with the back surface of the substrate 32 and a U-shaped semi-cylindrical portion 30b joined to the plate-like portion 30a. As a result, the heat sink 30 according to the first embodiment has a cylindrical portion 30c extending in the vertical direction on the side opposite to the side in contact with the substrate 32. Thereby, the main surface 32a of the substrate 32 and the cylindrical portion 30c of the heat sink 30 extend in the vertical direction, and since the space S occupied by the substrate 32 and the cylindrical portion 30c in the vehicle front-rear direction is small, the front-rear direction of the lamp unit 18 becomes compact.

[0027] FIG. 3(a) is a side view of the heat sink according to the second embodiment, and FIG. 3(b) is a top view of the heat sink shown in FIG. 3(a). FIG. 4 is a schematic diagram for explaining a method of processing the cylindrical portion of the heat sink shown in FIG. 3(a). Note that FIG. 4 is a schematic diagram of the heat sink 34 shown in FIG. 3(a) viewed from the direction of arrow X1.

[0028] The heat sink 34 according to the second embodiment has a plate-like portion 34a in contact with the back surface of the substrate 32 and a rectangular tube-shaped cylindrical portion 34b joined to the plate-like portion 34a. The cylindrical portion 34b is formed by bending both sides of a rectangular flat plate 35 inward twice. Thereby, the assembly process and the number of parts can be reduced.

[0029] FIG. 5 is a top view of the heat sink according to the modified example of Example 2. The heat sink 36 shown in FIG. 5 includes a bent portion 36b having two U-shaped semi-cylindrical portions 36a. The bent portion 36b is formed by bending both sides of the flat plate 35 shown in FIG. 4 inward once and then bending them outward twice. Then, two cylindrical portions 36c are formed by the plate-like portion 34a and the bent portion 36b.

[0030] FIG. 6 is a longitudinal sectional view of the heat sink according to Example 3. As shown in FIG. 1, the air A1 passing through the inner surface of the outer cover 14 reaches the heat dissipation portion 26 after passing through the lower part of the lamp chamber 16. Therefore, the cylindrical portion 38a of the heat sink 38 according to Example 3 has an opening 38b formed at the lower part facing the front of the vehicle. Thereby, the air A1 cooled at the front part of the vehicle lamp can be efficiently introduced to the back side of the substrate 32.

[0031] FIG. 7(a) is a rear view of the heat sink according to Example 4, and FIG. 7(b) is a top view of the heat sink shown in FIG. 7(a). The cylindrical portion 40a of the heat sink 40 according to Example 4 is configured such that the size of the upper horizontal section H2 is smaller than the size of the lower horizontal section H1. Thereby, it is possible to easily take in the cold air A1 from the lower part.

[0032] FIG. 8(a) is a rear view of the heat sink according to Example 5, and FIG. 8(b) is a top view of the heat sink shown in FIG. 8(a). The plurality of cylindrical portions 42a, 42b of the heat sink 42 according to Example 5 are triangular (polygonal) in top view, and one side facing the front of the vehicle among the plurality of sides of the triangle is the opening 42c, 42d. Thereby, the surface area can be increased compared to the case of the flat plate-like portion 34a, and the heat dissipation performance can be improved. In addition, the substrate 32 whose back surface is exposed from the openings 42c, 42d can be directly cooled by the air A1 passing through the cylindrical portions 42a, 42b. Each cylindrical portion is formed by processing such as deep drawing.

[0033] Further, the plurality of cylindrical portions 42a and 42b are formed so as to surround the central region R1 on the back surface of the plate-like portion 34a. The three cylindrical portions 42a with short flow paths are provided above the central region R1, and the two cylindrical portions 42b with long flow paths are provided on the left and right of the central region R1. In this way, the heat sink 42 can increase the surface area by simple processing of the plate-like portion 34a, and since the plurality of cylindrical portions are formed at desired positions, heat dissipation performance according to the heat generation amount of the light source and the layout of the vehicle lamp can be obtained.

[0034] FIG. 9(a) is a rear view of the heat sink according to Example 6, and FIG. 9(b) is a top view of the heat sink shown in FIG. 9(a). The heat sink 44 according to Example 6 has a plate-like portion 34a in contact with the back surface of the substrate 32, a bent first plate-like member 44a, and a bent second plate-like member 44b. The first plate-like member 44a and the second plate-like member 44b are fixed to the back surface of the plate-like portion 34a. Examples of the fixing method include fastening with a fastening member such as a screw or a bolt, welding with solder, and adhesion with an adhesive tape.

[0035] The cylindrical portion 44c is a triangular prism region surrounded by a fin 46a which is a part of the first plate-like member 44a and a fin 46b which is a part of the second plate-like member 44b. Thereby, the cylindrical portion 44c can be constituted by a plurality of members. Further, the cylindrical portion 44c has an elongated gap 48 formed in the vertical direction between the fin 46a and the fin 46b. In other words, the fin 46a and the fin 46b are not in contact. Thereby, even if the dimensional accuracy of the first plate-like member 44a and the second plate-like member 44b and the assembling accuracy to the substrate are not increased so much, the cylindrical portion 44c satisfying the desired heat dissipation can be constituted. Note that the substrate according to this embodiment including Example 6 may include not only the substrate 32 but also the plate-like portion 34a, or the plate-like portion 34a itself may be regarded as the substrate. Further, the heat sink according to this embodiment may include the plate-like portion 34a, or may be other plate-like members excluding the plate-like portion 34a.

[0036] The gap 48 preferably has a width of 3 mm or less. Due to the viscosity of air, it is difficult for air to move on the surfaces of the substrate and the heat sink. Therefore, by making the gap 48 smaller to some extent, the air rising in the cylindrical portion of the heat sink is less likely to leak from the gap 48, and the heat dissipation performance can be maintained up to the upper part of the cylindrical portion 44c.

[0037] The heat sink 44 has fins 46c arranged in parallel with a space on the peripheral edge side of the heat sink (plate-like portion 34a) with respect to the fin 46a, and fins 46d arranged in parallel with a space on the peripheral edge side of the heat sink (plate-like portion 34a) with respect to the fin 46b. Thereby, the heat dissipation performance can be further improved as compared with the case where there are two fins. Further, the first plate-like member 44a and the second plate-like member 44b are configured such that the angles φ and θ formed by the adjacent surfaces are obtuse angles (angles greater than 90°). Thereby, the man-hours for bending processing can be reduced.

[0038] The ranges of the lengths and widths of the respective parts of the heat sink 44 are set in consideration of the desired heat dissipation performance and the miniaturization of the lamp unit. For example, the length N in the height direction of each plate-like member may be in the range of 50 to 105 mm. The fins 46c of the first plate-like member 44a and the fins 46d of the second plate-like member 44b may have a length L in the depth direction in the range of 30 to 40 mm. The fins 46a of the first plate-like member 44a and the fins 46b of the second plate-like member 44b may have a length M in the depth direction in the range of 30 to 40 mm. The angles φ and θ formed by the adjacent surfaces of each plate-like member may be 95.5° or more. Further, the width W1 of the portion where the first plate-like member 44a contacts the plate-like portion 34a may be in the range of 10 to 20 mm. Further, the width W3 of the portion where the second plate-like member 44b contacts the plate-like portion 34a may be in the range of 10 to 20 mm. Further, the width W2 of the cylindrical portion 44c may be in the range of 5 to 20 mm. Note that if φ = θ and L = M, the first plate-like member 44a and the second plate-like member 44b can be assembled without distinction, so that misassembly can be prevented.

[0039] FIG. 10(a) is a rear view of the heat sink according to Example 7, and FIG. 10(b) is a top view of the heat sink shown in FIG. 10(a). The heat sink 50 according to Example 7 has a plate-shaped portion 34a in contact with the back surface of the substrate 32 and a bent plate-shaped member 52. The plate-shaped member 52 is fixed to the back surface of the plate-shaped portion 34a.

[0040] The cylindrical portion 50a is a rectangular (trapezoidal) region surrounded by a plurality of surfaces of the bent plate-shaped member 52. Also, since the heat sink 50 has at least four or more fins in the plate-shaped member 52, the heat dissipation performance can be improved as compared with the heat sink 30 according to Example 1. Also, the preferable ranges of the length, width, and angle of each part of the heat sink 50 are the same as those of the heat sink 44 according to Example 6.

[0041] FIG. 11 is a top view of the heat sink according to Example 8. The heat sink 54 according to Example 8 has a plate-shaped portion 34a, a bent first plate-shaped member 54a, a bent second plate-shaped member 54b, and a bent third plate-shaped member 54c. The first plate-shaped member 54a, the second plate-shaped member 54b, and the third plate-shaped member 54c are fixed to the back surface of the plate-shaped portion 34a.

[0042] The first cylindrical portion 54d is a triangular prism region surrounded by a fin 56a that is a part of the first plate-shaped member 54a and a fin 56b that is a part of the second plate-shaped member 54b. Also, the second cylindrical portion 54e is a triangular prism region surrounded by a fin 56c that is a part of the third plate-shaped member 54c and a fin 56d that is a part of the second plate-shaped member 54b. Thereby, a plurality of cylindrical portions can be formed by a plurality of members. Also, the first cylindrical portion 54d has a gap 58 formed in the vertical direction between the fin 56a and the fin 56b. The second cylindrical portion 54e has a gap 58 formed in the vertical direction between the fin 56c and the fin 56d. Thereby, even if the dimensional accuracy of the first plate-shaped member 54a, the second plate-shaped member 54b, and the third plate-shaped member 54c and the assembling accuracy to the substrate are not increased too much, the cylindrical portions 54d and 54e that satisfy the desired heat dissipation performance can be configured.

[0043] As described above, the present invention has been described with reference to the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and the present invention also includes those obtained by appropriately combining or substituting the configurations of the embodiments. In addition, it is possible to appropriately rearrange the combinations and processing orders in the embodiments based on the knowledge of those skilled in the art, and to add various design changes and other modifications to the embodiments. Embodiments with such modifications can also be included in the scope of the present invention.

Description of Reference Numerals

[0044] 10 Vehicle lamp, 12 Lamp body, 14 Outer cover, 16 Lamp chamber, 18 Lamp unit, 20 Semiconductor light-emitting element, 20a Light-emitting surface, 22 Extension, 26 Heat dissipation part, 30 Heat sink, 30a Plate-like part, 30b Semi-cylindrical part, 30c Cylindrical part, 32 Substrate, 32a Main surface, 34 Heat sink, 34a Plate-like part, 34b Cylindrical part, 35 Flat plate, 36 Heat sink, 36a Semi-cylindrical part, 36b Bent part, 36c Cylindrical part, 38 Heat sink, 38a Cylindrical part, 38b Opening, 40 Heat sink, 40a Cylindrical part, 42 Heat sink, 42a Cylindrical part, 42b Cylindrical part, 42c Opening, A1 Air.

Claims

1. A light emitting element having a light emitting surface facing forward of the vehicle; A substrate having a circuit necessary for turning on and off the light emitting element and having a main surface facing the front of the vehicle; a heat sink in contact with the substrate; The heat sink has a cylindrical portion extending in a vertical direction on a side opposite to a side in contact with a substrate.

2. 2. The lamp unit according to claim 1, wherein the cylindrical portion is formed by bending a plate.

3. 3. The lamp unit according to claim 1, wherein the cylindrical portion has an opening formed at a lower portion thereof, the opening facing toward the front of the vehicle.

4. 3. The lamp unit according to claim 1, wherein the cylindrical portion is configured so that a horizontal cross-section of an upper portion is smaller than a horizontal cross-section of a lower portion.

5. 3. The lamp unit according to claim 1, wherein the cylindrical portion is polygonal in top view, and one of a plurality of side surfaces of the polygon that faces forward of the vehicle is an opening.

6. The heat sink includes a first plate-shaped member that is bent and a second plate-shaped member that is bent, The lamp unit according to claim 1 , wherein the cylindrical portion has a first fin that is at least a part of the first plate-like member, and a second fin that is at least a part of the second plate-like member.

7. The lamp unit according to claim 6 , wherein the cylindrical portion has a gap formed between the first fin and the second fin in the up-down direction.

8. 8. The lamp unit according to claim 7, wherein the gap is 3 mm or less.

9. The heat sink is a first fin and a second fin that configure at least a part of the cylindrical portion and extend from the base plate toward the rear of the vehicle; a third fin disposed in parallel with the first fin on a peripheral edge side of the heat sink at a distance from the first fin; a fourth fin arranged in parallel with the second fin on a peripheral edge side of the heat sink at a distance from the second fin; 7. The lamp unit according to claim 6, further comprising:

10. 7. The lamp unit according to claim 6, wherein the first plate-like member or the second plate-like member is configured such that an angle formed between adjacent faces is an obtuse angle.

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