Vehicular lighting fixture

Abstract

To provide a vehicular lighting fixture capable of being disassembled into a lamp body and an outer lens easily.SOLUTION: A vehicular lighting fixture includes: a lamp body having a mounting part on which a mounting groove is provided; and an outer lens having an insertion part which is inserted in the mounting groove in an outer peripheral edge part, and for forming a lamp chamber together with the lamp body. The mounting groove and the insertion part are adhered by an adhesive agent containing a photodegradable crosslinking agent which absorbs ultraviolet light having wavelengths of 250nm to 365nm and decomposes it.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle lamp. [Background technology]

[0002] Recycling is gaining attention due to the global movement toward carbon neutrality. With regard to vehicle lighting fixtures, there is a study being conducted on disassembling the lamp body and outer lens and recovering the respective resin materials for recycling.

[0003] Patent Document 1 discloses a vehicle lamp in which a front lens is attached to a lamp body via a sealant made of a gel-like low-adhesion hot melt. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-90724 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the lamp body and the outer lens are attached via hot melt, the hot melt can be softened by heating, making it possible to remove the outer lens from the lamp body. However, the molten hot melt adheres to the lamp body and the front lens, making separation difficult. For this reason, there is a risk that the hot melt will be mixed in as an impurity when the lamp body and the outer lens are recycled as resin materials.

[0006] An object of the present invention is to provide a vehicle lamp which can be easily disassembled into a lamp body and an outer lens. [Means for solving the problem]

[0007] In order to solve the above problems, the vehicle lamp of the present invention has a lamp body having an attachment portion in which an attachment groove is provided, and an outer lens having an insertion portion on its outer periphery that is inserted into the attachment groove and that forms a lamp chamber together with the lamp body, and the attachment groove and the insertion portion are bonded together with an adhesive that contains a photodegradable crosslinking agent that absorbs and decomposes ultraviolet light with a wavelength of 250 nm to 365 nm. It is characterized by: Effect of the Invention

[0008] According to the present invention, by irradiating the adhesive with ultraviolet light, the photodegradable crosslinking agent decomposes and the adhesive becomes brittle, so that the vehicle lamp can be easily disassembled into the lamp body and the outer lens. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a side cross-sectional view of a vehicle headlamp. [Diagram 2] FIG. 2 is a front view of the housing 30 as seen from the front. [Diagram 3] FIG. 3 is an enlarged perspective view of a portion III in FIG. 2. [Figure 4] 11 is a perspective view showing the outer lens attachment portion 31 after the detachable portion 50 has been removed. FIG. [Diagram 5] 11 is a perspective view showing the outer lens attachment portion 31 after the detachable portion 50 has been removed, according to the first modified example. FIG. [Figure 6] 13 is a cross-sectional view showing an adhesive portion between an outer lens 1 and an outer lens attachment portion 31A according to Modification 2. FIG. [Figure 7] 13 is a cross-sectional view showing an adhesive portion between an outer lens 1 and an outer lens attachment portion 31B according to Modification 3. FIG. [Figure 8] 13 is a cross-sectional view showing an adhesive portion between an outer lens 1A and an outer lens attachment portion 31 according to a fourth modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] A vehicle headlamp will be described as a vehicle lamp according to the present invention. Fig. 1 is a side cross-sectional view of the vehicle headlamp. As shown in Fig. 1, the vehicle headlamp has an outer lens 1, a lamp unit 10, an aiming mechanism 20, and a housing 30 (lamp body). In Fig. 1 and Figs. 3 to 8 below, arrow F indicates the forward direction, and arrow B indicates the rearward direction. Also, in Figs. 1 to 8, arrow U indicates the vertically upward direction, and arrow D indicates the vertically downward direction.

[0012] The outer lens 1 and the housing 30 form a lamp chamber. The lamp unit 10 is disposed inside the lamp chamber. The outer lens 1 is made of a transparent resin. The outer lens 1 transmits light emitted from the lamp unit 10.

[0013] The outer lens 1 has an insertion portion 1a on its outer circumferential edge. The insertion portion 1a is the rear edge of the outer lens 1, and is inserted into a mounting groove 32 (described later) of the housing 30. The insertion portion 1a is bonded to the mounting groove 32 with an adhesive 40 (described later), whereby the outer lens 1 and the housing 30 are integrally formed.

[0014] A flange 1b is provided on the outer peripheral edge of the outer lens 1. The flange 1b is provided so as to protrude further outward than an outer lens attachment portion 31, which will be described later. By providing the flange 1b, when attaching the outer lens 1 to the housing 30, the flange 1b can be abutted against the outer lens attachment portion 31 of the housing 30, and the insertion portion 1a can be positioned at a predetermined location within the attachment groove 32. In addition, since the flange 1b is positioned so as to close the opening of the attachment groove 32, it is possible to prevent ultraviolet rays from being irradiated onto the adhesive 40 within the attachment groove 32.

[0015] The lamp unit 10 includes a light source 11, a reflector 12, an inner lens 13, a cable 14, and a light source stand 15. Light emitted from the light source 11 is reflected by the reflector 12 and enters the inner lens 13. Light transmitted through the inner lens 13 passes through the outer lens 1 and is emitted forward of the vehicle headlamp. The light source 11 and the reflector 12 are attached to the light source stand 15. The inner lens 13 is attached to the light source stand 15 via a lens holder (not shown). The lamp unit 10 may include a shade (not shown) that blocks a portion of the light emitted from the light source 11 to form a specific light distribution pattern. The extension 16 is provided around the inner lens 13 inside the lamp chamber. The extension 16 is a member that hides the inner surface of the housing 30 inside the lamp chamber and the aiming mechanism 20 from the outside of the outer lens 1, and enhances the appearance design of the lamp. The design surface of the extension 16 may be subjected to a mirror finish or a texture finish.

[0016] The aiming mechanism 20 has a rectangular, plate-like holder 21, an adjuster screw 22, and an aiming actuator 23. Two upper corners of the rectangular holder 21 are attached to the housing 30 via support shafts (not shown) and the adjuster screws 22. One lower corner of the rectangular holder 21 is attached to the housing 30 via the aiming actuator 23.

[0017] The adjuster screw 22 is screwed into the upper part of the holder 21. The head of the adjuster screw 22 passes through the adjuster screw attachment portion 36 of the housing 30 and is exposed to the outside. The adjuster screw 22 can be rotated by rotating the head of the adjuster screw 22. When the adjuster screw 22 rotates, the upper part of the holder 21 can be moved in the front-rear direction. After the lamp unit 10 is mounted, the direction of the optical axis of the lamp unit 10 can be adjusted by operating the adjuster screw 22 before shipping or during vehicle inspection.

[0018] The aiming actuator 23 has a motor 24 and an aiming screw 25. The aiming screw 25 is screwed into the lower part of the holder 21. The motor 24 is attached to a motor attachment portion 37 of the housing 30. When the motor 24 is operated, the aiming screw 25 rotates, moving the lower part of the holder 21 in the front-rear direction. When the vehicle is traveling, if the center of gravity of the vehicle moves in the longitudinal direction and it becomes necessary to adjust the optical axis of the lamp unit 10, the aiming actuator 23 is operated to adjust the optical axis of the lamp unit 10.

[0019] Fig. 2 is a front view of the housing 30. As shown in Fig. 2, the housing 30 has an outer lens attachment portion 31, a cable insertion portion 33, a vehicle body attachment portion 35, an adjuster screw attachment portion 36, a motor attachment portion 37, and a support shaft attachment portion 38.

[0020] The outer lens attachment part 31 is provided on the front edge of the housing 30. A mounting groove 32 that opens forward is provided in the outer lens attachment part 31. An adhesive 40 is provided in the mounting groove 32, and the outer lens 1 is fixed to the housing 30 with the rear edge of the outer lens 1 inserted into the adhesive 40 in the mounting groove 32.

[0021] The cable insertion portion 33 has an insertion hole 34 through which the cable 14 is inserted. The cable insertion portion 33 is an example of a hole forming portion that forms a through hole for inserting electric wires extending from electronic devices such as the lamp unit 10 and the aiming actuator 23 arranged in the lamp chamber to the outside. The vehicle body mounting portion 35 is a portion for mounting the housing 30 to the vehicle body. The adjuster screw mounting portion 36 is a portion that mounts the adjuster screw 22 to the housing 30. The adjuster screw mounting portion 36 is an example of an internal support portion that supports an internal member. The motor attachment portion 37 is a portion where the motor 24 is attached to the housing 30 . The support shaft attachment portion 38 is a portion where the support shaft is attached.

[0022] In this embodiment, the adhesive 40 is preferably a crosslinking adhesive containing a photodecomposable crosslinking agent that absorbs ultraviolet light with a wavelength of 250 nm to 365 nm and decomposes. Specifically, a thermosetting adhesive, a chemically curing adhesive, or a photocuring adhesive can be used. For example, an acrylic resin curing agent, a urethane resin curing agent, a phenolic resin curing agent, an epoxy resin curing agent, a bismaleimide curing agent, etc. can be used as such an adhesive.

[0023] The photodegradable crosslinking agent has a structure having a photodegradable group between a plurality of reactive groups. The reactive groups react and bond with other polymer molecules when exposed to heat, pressure, changes in pH, or radiation such as electron beams and gamma rays (excluding ultraviolet rays with wavelengths of 250 nm to 365 nm). When the reactive groups bond with each other, the photodegradable crosslinking agent crosslinks the polymer molecules together, and the adhesive hardens. The photodegradable group is decomposed by irradiation with ultraviolet light having a wavelength of 250 nm to 365 nm. As the photodegradable group is decomposed, the polymer molecules crosslinked by the photodegradable crosslinking agent are separated, and the hardened adhesive 40 is decomposed. Therefore, the outer lens 1 and the housing 30 can be easily separated.

[0024] Examples of photodegradable crosslinking agents that absorb ultraviolet light with a wavelength of 250 nm to 365 nm and decompose include 1,4-diacetylbenzene=1,4-bis(O-methacryloyl)dioxime (DBzM) and 1,3,5-triacetylbenzene=1,3,5-tris(O-methacryloyl)trioxime (TBzM). [ka]

[0025] For example, when acrylic ester and TBzM are polymerized by light or heat, they are crosslinked and hardened as shown below. [ka]

[0026] When the cured product is to be decomposed, the crosslinked portion is decomposed by irradiating it with ultraviolet light as shown below. [ka]

[0027] In this embodiment, as shown in Fig. 2, a detachable portion 50 is provided in a part of the outer lens mounting portion 31. In Fig. 2, the detachable portion 50 is provided in a portion below the outer lens mounting portion 31 (in the direction of arrow D). Fig. 3 is an enlarged perspective view of part III in Fig. 2. In Fig. 3, adhesive 40 is indicated by a dashed line. As shown in Fig. 3, outer lens mounting part 31 is provided with detachment part 50 surrounded by first thin-walled parts 51a, 51b which are thinner than the plate thickness of other parts of outer lens mounting part 31. First thin-walled part 51a is provided inside mounting groove 32, and first thin-walled part 51b is provided on the outside of outer lens mounting part 31. When forming a housing 30 having such a shape of the outer lens mounting portion 31 by injection molding, the molding can be performed, for example, by forming a separate part for forming the first thin-walled portion 51b in a mother mold in a nested structure.

[0028] When disassembling the vehicle headlamp, pressing the detachable portion 50 from the outside toward the inside of the housing 30 (in the direction of arrow A in Figure 3) destroys the first thin-walled portions 51a, 51b, allowing the detachable portion 50 to be removed from the outer lens mounting portion 31. The thickness of the first thin portions 51a, 51b is preferably 2 mm or less. When the thickness of the first thin portions 51a, 51b is 2 mm or less, the first thin portions 51a, 51b can be easily broken.

[0029] 3, it is preferable that no adhesive 40 is provided in the portions of the mounting groove 32 corresponding to the first thin-walled portions 51a, 51b and the detachable portion 50. Since no adhesive 40 is provided in the portions corresponding to the first thin-walled portion 51a and the detachable portion 50, the first thin-walled portions 51a, 51b can be easily destroyed when the detachable portion 50 is pressed inwardly of the housing 30, and the detachable portion 50 can be removed from the outer lens mounting portion 31.

[0030] If the adhesive 40 is not provided in the portion corresponding to the first thin-walled portions 51a, 51b and the detachable portion 50, a gap may be generated between the insertion portion 1a of the outer lens 1 and the mounting groove 32, and water or the like may enter the lamp chamber through this gap. For this reason, if the adhesive 40 is not provided in the portion corresponding to the first thin-walled portions 51a, 51b and the detachable portion 50, it is preferable to provide the first thin-walled portions 51a, 51b and the detachable portion 50 in the vertically lower portion of the outer lens mounting portion 31 (the portion on the side of the arrow B in FIG. 2). If the first thin-walled portions 51a, 51b and the detachable portion 50 are provided in the vertically lower portion of the outer lens mounting portion 31, it is possible to prevent water or the like from entering the lamp chamber through the gap between the insertion portion 1a and the mounting groove 32. Even if water or the like enters the lamp chamber, the water or the like is discharged from the gap by gravity.

[0031] Fig. 4 is a perspective view showing the outer lens attachment portion 31 after the detachable portion 50 has been removed. As shown in Fig. 4, when the detachable portion 50 is removed, an end face 40a of the adhesive 40 in the attachment groove 32 is exposed. By irradiating the end face 40a of the adhesive 40 with ultraviolet light having a wavelength of 250 nm to 365 nm, the photodegradable crosslinking agent contained in the adhesive 40 is decomposed, and the hardened adhesive 40 is decomposed. This allows the insertion portion 1a of the outer lens 1 to be easily separated from the attachment groove 32.

[0032] An ultraviolet reflective film may be provided on the inner wall surface 32a of the mounting groove 32. When an ultraviolet reflective film is provided on the inner wall surface 32a of the mounting groove 32, ultraviolet light irradiated onto the end face of the adhesive 40 is reflected by the ultraviolet reflective film, and the ultraviolet light can be irradiated onto the entire adhesive 40 along the mounting groove 32.

[0033] <Variation 1> FIG. 5 is a perspective view showing the outer lens attachment part 31 after removing the detachable part 50 according to the first modification. As shown in FIG. 5, the light guide 60 may be provided inside the adhesive 40A along the attachment groove 32, and the light guide 60 may be embedded in the adhesive 40A. When the detachable part 50 is removed, the end face of the light guide 60 is exposed together with the end face of the adhesive 40A in the attachment groove 32. When the end face of the light guide 60 is irradiated with ultraviolet light having a wavelength of 250 nm to 365 nm, the entire adhesive 40A can be irradiated with ultraviolet light along the light guide 60. The light guide 60 is a member that totally reflects guided light on its outer peripheral surface, and gradually leaks light from the outer peripheral surface to the outside along the light guiding direction. In this modified example, the inner wall surface 32a of the mounting groove 32 may also be provided with an ultraviolet reflective film.

[0034] <Variation 2> FIG. 6 is a cross-sectional view showing the adhesive portion between the outer lens 1 and the outer lens attachment portion 31A according to the second modification. In the second modification, a detachable portion 50A is provided at a portion of the outer lens mounting part 31A that becomes the bottom of the mounting groove 32. As shown in Fig. 5, a first thin-walled portion 51A that is thinner than the plate thickness of other portions is provided at a portion of the outer lens mounting part 31A that becomes the bottom of the mounting groove 32, and the detachable portion 50A is surrounded by the first thin-walled portion 51A.

[0035] In this modification, the first thin portion 51A is broken and the detachable portion 50A can be removed by pressing the detachable portion 50A toward the mounting groove 32. When the detachable portion 50A is removed, the adhesive 40 is exposed. By irradiating the end face of this adhesive 40 with ultraviolet light having a wavelength of 250 nm to 365 nm, the photodegradable crosslinking agent contained in the adhesive 40 is decomposed, and the hardened adhesive 40 is decomposed. Therefore, the insertion portion 1a of the outer lens 1 can be easily separated from the mounting groove 32A. The thickness of the first thin portion 51A is preferably 2 mm or less. When the thickness of the first thin portion 51A is 2 mm or less, the first thin portion 51A can be easily broken. In this modification, it is also preferable not to provide adhesive 40 in the portion corresponding to first thin portion 51A and detachable portion 50. An ultraviolet reflective film may be provided on the inner wall surface of mounting groove 32. A light guide 60 may be provided inside adhesive 40 along mounting groove 32A.

[0036] <Variation 3> FIG. 7 is a cross-sectional view showing the adhesive portion between the outer lens 1 and the outer lens attachment portion 31B according to the third modification. In the third modification, a hole 52 is provided in a portion that becomes the bottom of the mounting groove 32 of the outer lens mounting portion 31B.

[0037] In this modification, the adhesive 40 is exposed from the hole 52. By irradiating the end face of this adhesive 40 with ultraviolet light having a wavelength of 250 nm to 365 nm, the photodegradable cross-linking agent contained in the adhesive 40 is decomposed, and the hardened adhesive 40 is decomposed. Therefore, the insertion portion 1a of the outer lens 1 can be easily separated from the mounting groove 32B. In this modification, an ultraviolet reflective film may be provided on the inner wall surface of the mounting groove 32B. Also, a light guide 60 may be provided inside the adhesive 40 along the mounting groove 32B.

[0038] <Variation 4> FIG. 8 is a cross-sectional view showing the adhesive portion between the outer lens 1A and the outer lens attachment portion 31 according to the fourth modification. In the second modification, a second thin portion 1c that is thinner than the other portion of the flange 1b is provided at the base of the flange 1b of the outer lens 1A. By pressing the flange 1b toward the outer lens attachment portion 31, the second thin portion 1c is destroyed and the flange 1b can be removed.

[0039] By removing the flange 1b, the adhesive 40 in the mounting groove 32 is exposed. By irradiating the adhesive 40 with ultraviolet light having a wavelength of 250 nm to 365 nm, the photodegradable crosslinking agent contained in the adhesive 40 is decomposed, and the hardened adhesive 40 is decomposed. Therefore, the insertion portion 1a of the outer lens 1A can be easily separated from the mounting groove 32.

[0040] The thickness of the second thin portion 1c is preferably 2 mm or less. If the thickness of the second thin portion 1c is 2 mm or less, the second thin portion 1c can be easily broken.

[0041] In this modified example, an ultraviolet reflective film may also be provided on the inner wall surface of the mounting groove 32. Furthermore, a light guide 60 may be provided inside the adhesive 40 along the mounting groove 32B.

[0042] In the above embodiment and modifications 1 to 4, the vehicle lamp is a vehicle headlamp, but the present invention is not limited to this. The present invention can be applied to vehicle lamps such as rear combination lamps, turn signal lamps, and fog lamps. [Explanation of symbols]

[0043] 1, 1A Outer lens 1a Insertion section 1b Flange 1c Second thin section 10 Lamp unit 11 Light source 12 Reflector 13 Inner Lens 14 Cable 15 Light source stand 16 Extension 20 Aiming mechanism 21 Holder 22 Adjuster screw 23 Aiming Actuator 24 Motor 25 Aiming Screw 30 Housing (lamp body) 31, 31A, 31B Outer lens attachment part 32, 32A, 32B mounting groove 33 Cable insertion part 35 Vehicle mounting part 36 Adjuster screw mounting part 37 Motor mounting part 38 Support shaft attachment part 40, 40A Adhesive 50, 50A Detachment part 51, 51A First thin section 52 holes 60 Light guide

Claims

1. a lamp body having a mounting portion in which a mounting groove is provided; an outer lens having an insertion portion at an outer periphery thereof that is inserted into the mounting groove and that forms a lamp chamber together with the lamp body; The mounting groove and the insertion portion are bonded to each other by an adhesive containing a photodegradable crosslinking agent that absorbs ultraviolet light having a wavelength of 250 nm to 365 nm and decomposes therewith.

2. 2. The vehicular lamp according to claim 1, wherein the mounting portion is provided with a detachable portion surrounded by a first thin portion that is thinner than a plate thickness of the remaining portion of the mounting portion.

3. The vehicular lamp according to claim 2 , wherein the adhesive is not provided on the detachable portion.

4. The vehicular lamp according to claim 2 , wherein the detachable portion is a bottom portion of the mounting groove.

5. The vehicular lamp according to claim 1 , wherein a hole is provided in a bottom portion of the mounting groove.

6. the outer lens has a flange that protrudes from the outer circumferential edge portion toward an outer periphery beyond the attachment portion, 2. The vehicular lamp according to claim 1, wherein the flange is provided with a second thin portion that is thinner than the other portion of the outer lens.

7. The vehicular lamp according to claim 1 , further comprising a light guide embedded in the adhesive along the mounting groove.

8. 2. The vehicle lamp according to claim 1, wherein an ultraviolet ray reflective film that reflects ultraviolet rays is provided on an inner wall surface of the mounting groove.

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