Vehicular lighting fixture and manufacturing method of vehicular lighting fixture

Abstract

To provide a technology capable of reducing or eliminating generation of foreign objects inside a vehicular lighting fixture.SOLUTION: A vehicular lighting fixture includes: a first member having a thin wall part; a second member; and a tapping screw 24 for fastening the first member and the second member. At the thin wall part, a through-hole 22c and an annular protrusion part 22d protruding from an inner peripheral surface of the through-hole 22c are formed. The annular protrusion part 22d includes an inclined surface 22e positioned further outside toward a tip, at an inner peripheral edge part on the tip side. The tapping screw 24 is inserted in an insertion hole formed in the second member, and is screwed into an inner peripheral surface 22h of the annular protrusion part 22d of the first member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle lamp and a method for manufacturing the vehicle lamp. [Background technology]

[0002] Patent Document 1 discloses a vehicle lamp including a first member having a thin portion, a second member, and a tapping screw that fastens the first member to the second member. In this vehicle lamp, a through hole and an annular protrusion that protrudes from the inner circumferential surface of the through hole are formed in the thin portion of the first member, and a tapping screw is inserted into an insertion hole formed in the second member and screwed into the inner circumferential surface of the annular protrusion of the first member, thereby fastening the first member to the second member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 06-011205 Summary of the Invention [Problem to be solved by the invention]

[0004] FIG. 1 is a diagram illustrating a problem with a conventional vehicle lamp as described in Patent Document 1. In FIG. 1, a first member 100 and a second member 102, both of which are components of a vehicle lamp, are fastened together by a tapping screw 104. A thin-walled portion 100a of the first member 100 is formed with a through-hole 100b and an annular protrusion 100c protruding from the inner circumferential surface of the through-hole 100b. The tapping screw 104 is inserted into an insertion hole 102a formed in the second member 102 and screwed into an inner circumferential surface 100d of the annular protrusion 100c of the first member 100, thereby fastening the first member 100 and the second member 102 together. If the tip of this annular protrusion 100c, particularly the inner peripheral edge 100e at the tip, is sharp, when the tapping screw is passed through the annular protrusion 100c, the tapping screw may scrape off the sharp portion (see the area surrounded by the dotted line), generating spiral shavings. The spiral shavings may become entangled around the tapping screw and may not be removed by air blowing or suction. If the vehicle lamp is assembled in this state and then installed in a vehicle, the shavings will eventually fall off the tapping screw 104 due to vibration. In other words, foreign matter will be generated inside the vehicle lamp.

[0005] The present disclosure has been made in light of such a situation, and one of its exemplary purposes is to provide a technology that can reduce or eliminate the generation of foreign matter inside a vehicle lamp. [Means for solving the problem]

[0006] To solve the above problems, a vehicle lamp according to one embodiment of the present disclosure includes a first member having a thin-walled portion, a second member, and a tapping screw that fastens the first member to the second member. The thin-walled portion is formed with a through hole and an annular protrusion that protrudes from the inner circumferential surface of the through hole, and the annular protrusion has an inclined surface on the inner circumferential edge portion on the tip side that is positioned outward as it approaches the tip. The tapping screw is inserted into an insertion hole formed in the second member and threaded into the inner circumferential surface of the annular protrusion of the first member.

[0007] Another aspect of the present disclosure is a method for manufacturing a vehicle lamp, the method including: preparing a first member having a thin-walled portion; preparing a second member; and fastening the first member and the second member by inserting a tapping screw into an insertion hole formed in the second member and screwing it into an inner circumferential surface of an annular protrusion of the first member, wherein preparing the first member includes forming a pilot hole in the thin-walled portion, widening the edge of the pilot hole to form a raised portion, and tapping an inner circumferential edge of the raised portion on a tip side to form an inclined surface, thereby forming the annular protrusion. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a technology that can prevent foreign matter from remaining in a vehicle lamp. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are diagrams illustrating problems with a conventional vehicle lamp. [Figure 2] 1 is a schematic cross-sectional view of a lamp according to an embodiment. [Figure 3] FIG. 3 is an exploded perspective view of the lamp unit of FIG. 2. [Figure 4] 4 is a cross-sectional view of the heat dissipation member into which the tapping screw of FIG. 3 is screwed. [Figure 5] 5A to 5C are diagrams illustrating an example of a process for forming the annular protrusion in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0011] Fig. 2 is a schematic cross-sectional view of a vehicle lamp 1 according to an embodiment. Fig. 3 is an exploded perspective view of the lamp unit 10 of Fig. 2. The vehicle lamp 1 is, for example, a vehicle headlamp.

[0012] The vehicle lamp 1 comprises a lamp body 2, a transparent outer cover 4 that covers the opening of the lamp body 2, and a lamp unit 10 that is arranged in a lamp chamber 6, which is the space between the lamp body 2 and the outer cover 4.

[0013] The lighting unit 10 includes a light source unit 12, a reflector 14, a shade 16, a lens holder 18, a lens 20, a heat dissipation member 22, and a tapping screw 24.

[0014] The light source unit 12 includes a light source 26 and a substrate 28. The light source 26 may be a semiconductor light-emitting element such as an LED (Light Emitting Diode), an LD (Laser Diode), or an EL (Electro Luminescence) element, or a light bulb, an incandescent lamp (halogen lamp), or a discharge lamp. A light-collecting member (not shown) may be provided between the light source 26 and the reflector 14. In the illustrated example, the light source unit 12 includes two light sources 26, but the number of light sources 26 included in the light source unit 12 is not particularly limited.

[0015] The light source 26 is mounted on a mounting surface 28a of a substrate 28. A circuit pattern for supplying power to the light source 26 is formed on the substrate 28.

[0016] The reflector 14 is disposed so that the reflecting surface 14a faces the light emitting surface of the light source 26, and reflects the light from the light source 26 forward of the lamp.

[0017] The shade 16 is provided on the front side of the light source 26. The shade 16 prevents light from the light source 26 from being emitted directly to the outside of the lamp.

[0018] The lens holder 18 holds the lens 20. More specifically, the lens holder 18 has a frame shape corresponding to the lens 20, and a flange portion 20a of the lens 20 is fixed to the front side of the lamp.

[0019] In the illustrated example, the reflector 14, shade 16, and lens holder 18 are all integrally molded as a lens holder unit 30, although this is not limited to this. In this case, the number of parts is reduced, which reduces manufacturing costs. Also, a decrease in light distribution accuracy due to assembly errors between the reflector 14, shade 16, and lens holder 18 can be avoided.

[0020] The reflector 14, shade 16, and lens holder 18 may be made of any suitable material, such as a resin material such as polycarbonate. The reflector 14 may have a surface that is coated with aluminum, for example, to form a reflective surface 14a that reflects light from the light source 26.

[0021] The lens 20 is a plano-convex aspherical lens with a convex surface on the front side of the lamp and a flat surface on the rear side of the lamp, and projects light from the light source 26 in front of the lamp. The lens 20 is made of a transparent resin such as polymethyl methacrylate (PMMA).

[0022] The heat dissipation member 22 includes a flat base portion 22a and a flat heat dissipation portion 22b extending downward from the periphery of the base portion 22a. The heat dissipation member 22 may be formed by pressing a metal plate such as an aluminum plate. In this case, the manufacturing cost of the heat dissipation member 22 can be reduced.

[0023] The base portion 22a is in surface contact with a surface 28b opposite to the mounting surface 28a of the substrate 28. In other words, the base portion 22a, i.e., the heat dissipation member 22, is in thermal contact with the light source unit 12. Therefore, heat generated by light emission from the light source 26 is dissipated to the surroundings through the heat dissipation member 22.

[0024] The heat dissipation member 22 may have a shape different from that shown in the figure. For example, the heat dissipation member 22 may have a disk-shaped base portion 22a.

[0025] The tapping screw 24 is inserted into the insertion hole 30a of the lens holder unit 30 and the insertion hole 28c of the substrate 28 of the light source unit 12, and the tapping screw 24 is screwed into the base portion 22a of the heat dissipation member 22, as will be described in detail later, thereby fastening the lens holder unit 30 and the light source unit 12 together to the heat dissipation member 22.

[0026] Fig. 4 is a cross-sectional view of the heat dissipation member 22 into which the tapping screw 24 is screwed. Fig. 4 can also be considered a cross-sectional view of the lamp unit 10, with everything omitted except for the heat dissipation member 22 and the tapping screw 24. Fig. 4 is a cross-section taken along a plane passing through the central axis C of the inner circumferential surface 22h of the annular protrusion 22d of the heat dissipation member 22.

[0027] The base portion 22a of the heat dissipation member 22 into which the tapping screw 24 is screwed is flat as described above, i.e., the entire base portion 22a is thin-walled. Note that it is sufficient that at least the portion of the base portion 22a into which the tapping screw 24 is screwed, i.e., the portion where the annular protrusion 22d described below is formed, is thin-walled.

[0028] The term "thin wall" may refer to a thickness that allows only three or fewer threads to engage when the tapping screw 24 is screwed in. Therefore, when the pitch of the tapping screw 24 is p [mm], the term "thin wall" may refer to a thickness of less than 3×p [mm].

[0029] Alternatively, thin-walled may mean a thickness of 3 mm or less.

[0030] The base portion (thin portion) 22a of the heat dissipation member 22 is formed with a through hole 22c and an annular protrusion 22d protruding from the inner peripheral surface of the through hole 22c. The annular protrusion 22d protrudes in a direction away from the substrate 28 (not shown in FIG. 4). The inner peripheral surface 22h of the annular protrusion 22d is cylindrical. The annular protrusion 22d may be formed by, but is not limited to, burring. The annular protrusion 22d is formed to provide a sufficient engagement for the tapping screw 24.

[0031] The tapping screw 24 penetrates the annular protrusion 22d. In other words, the tip of the tapping screw 24 protrudes from the tip of the annular protrusion 22d. The tapping screw 24 is screwed into the annular protrusion 22d while forming an internal thread on the inner circumferential surface 20h of the annular protrusion 22d.

[0032] The annular protrusion 22d has an outer diameter D2 that is larger than the outer diameter D1 of the male thread of the tapping screw 24 over the entire range in the axial direction, i.e., over the entire range in the direction parallel to the central axis C. This prevents the annular protrusion 22d from being cut off.

[0033] The annular protrusion 22d has an inclined surface 22e on its inner peripheral edge portion on the tip side, which is the side farthest from the through hole 22c. The inclined surface 22e is inclined so that it is positioned outward as it approaches the tip. In other words, the inclined surface 22e has an inner peripheral end 22f positioned closest to the through hole 22c and an outer peripheral end 22g positioned closest to the tip. By having such an inclined surface 22e on the inner peripheral edge portion on the tip side of the annular protrusion 22d, the inner peripheral edge portion on the tip side is less likely to be scraped by the tapping screw 24.

[0034] The inclination angle α of the inclined surface 22e may be equal to or greater than 30° and equal to or less than 60°. The inclination angle α is the angle of the inclined surface 22e with respect to the central axis C, and is an acute angle formed between the central axis C and the inclined surface 22e. When the inclination angle of the inclined surface 22e is within the above range, the inclined surface 22e becomes parallel or approximately parallel to the flank surface of the thread of the tapping screw 24 facing the through hole 22c, and therefore the inner peripheral edge of the annular protrusion 22d is less likely to be scraped.

[0035] In a cross section cut by a plane passing through the central axis C, the inclined surface 22e may be parallel to the flank surface facing the through hole 22c of the thread of the tapping screw 24 or may have a smaller inclination angle with respect to the central axis C than that.

[0036] Preferably, the outer peripheral end 22g of the inclined surface 22e has a diameter D3 larger than the outer diameter D1 of the male thread of the tapping screw 24. In other words, the inclined surface 22e extends radially, i.e., in a direction perpendicular to the central axis C, outward (farther from the central axis) than the threads of the tapping screw 24. In this case, the inner peripheral edge portion on the tip side of the annular protrusion 22d is even less likely to be scraped.

[0037] Next, a description will be given of a manufacturing method for the vehicle lamp 1 according to the embodiment. The manufacturing method for the vehicle lamp 1 according to the present embodiment includes a step of preparing components of the vehicle lamp 1, including the light source unit 12, the lens holder unit 30, and the heat dissipation member 22, a step of assembling the components, and an inspection step of inspecting the appearance, operation, function, etc. of the assembled vehicle lamp 1.

[0038] FIG. 5 is a diagram illustrating an example of a step of forming an annular protrusion 22d, which is included in the step of preparing the heat dissipation member 22. As shown in FIG. 5(a), a pilot hole 22j is formed in the base portion 22a of the heat dissipation member 22. The pilot hole 22j may be formed by any suitable means. As shown in FIG. 5(b), a raised portion 22k is formed. Specifically, a large punch (not shown) is pressed into the pilot hole 22j to widen the edge of the pilot hole 22j, thereby forming the raised portion 22k. As shown in FIG. 5(c), an inclined surface 22e is formed on the inner peripheral edge of the tip of the raised portion 22k. For example, the inclined surface 22e is formed by hitting the inner peripheral edge of the tip of the raised portion 22k with an appropriate tool or device. In this manner, the annular protrusion 22d is formed.

[0039] Next, the process of assembling the components includes a process of fastening the lens holder unit 30, the light source unit 12, and the heat dissipation member 22. This process includes a process of inserting a tapping screw 24 into an insertion hole 30a formed in the lens holder unit 30 and an insertion hole 28c in the substrate 28 of the light source unit 12 (see FIG. 3 ), and screwing the tapping screw 24 into the inner circumferential surface of the annular protrusion 22d of the base portion 22a of the heat dissipation member 22, thereby fastening the lens holder unit 30 and the light source unit 12 to the heat dissipation member 22 together, i.e., fastening them together.

[0040] The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention. These modifications will be described below.

[0041] In the embodiment, the lens holder unit 30, the light source unit 12, and the heat dissipation member 22 are fastened together using a tapping screw 24. However, this is not limiting. The technical concept of the embodiment can also be applied to fastening a first member and a second member, which are components of a vehicle lamp, using a tapping screw. In this case, the first member has a thin-walled portion, and the thin-walled portion is formed with a through-hole and an annular protrusion protruding from the inner circumferential surface of the through-hole. The annular protrusion has a peripheral edge without a tip end, with an inclined surface that is positioned more outward as it approaches the tip end. The first member and the second member are fastened together by inserting a tapping screw into an insertion hole formed in the second member and screwing it into the inner circumferential surface of the annular protrusion of the first member. This modification can achieve the same effects as the embodiment.

[0042] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. A new embodiment resulting from a combination will have the combined effects of the combined embodiments and modifications. It will also be understood by those skilled in the art that the functions to be performed by each constituent element recited in the claims can be realized by each constituent element shown in the embodiments and modifications, either alone or in combination. [Explanation of symbols]

[0043] 1 vehicle lamp, 10 lamp unit, 12 light source unit, 22 heat dissipation member, 22a base portion, 22c through hole, 22d annular protrusion portion, 22e inclined surface, 28 substrate, 28c insertion hole, 30 lens holder unit, 30a insertion hole.

Claims

1. a first member having a thin-walled portion; A second member; a tapping screw that fastens the first member and the second member together; Equipped with a through hole and an annular protrusion protruding from an inner circumferential surface of the through hole are formed in the thin-walled portion, The annular protrusion has an inclined surface on an inner peripheral edge portion on the tip side, the inclined surface being positioned outward as it approaches the tip, The tapping screw is inserted into an insertion hole formed in the second member and screwed into the inner circumferential surface of the annular protrusion of the first member.

2. 2. The vehicle lamp according to claim 1, wherein an inclination angle of the inclined surface with respect to a central axis of the annular protrusion is equal to or greater than 30 degrees and equal to or less than 60 degrees.

3. 2. The vehicle lamp according to claim 1, wherein in a cross section passing through the central axis of the through hole, the inclined surface is parallel to a flank of the thread of the tapping screw facing the through hole or has an inclination angle with respect to the central axis of the annular protrusion that is smaller than that of the flank.

4. the first member is a heat dissipation member that dissipates heat from a light source mounted on the second member, The vehicular lamp according to claim 1 , wherein the annular protrusion protrudes in a direction away from the second member.

5. A method for manufacturing a vehicle lamp according to any one of claims 1 to 4, comprising the steps of: preparing the first member having the thin-walled portion; providing the second member; fastening the first member and the second member by inserting the tapping screw into an insertion hole formed in the second member and screwing the tapping screw into an inner circumferential surface of the annular protrusion of the first member; Equipped with The method for manufacturing a vehicle lamp includes forming the annular protrusion by forming a pilot hole in the thin-walled portion, widening the edge of the pilot hole to form a raised portion, and hammering the inner peripheral edge portion on the tip side of the raised portion to form the inclined surface.

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