Vehicle lamp

Abstract

A vehicle lamp comprising a resin component (16) that is not required to have light transmittance, the resin component (16) having a three-layer structure including: a first skin layer (16a) including a first resin; a second skin layer (16b) including the first resin; and a core layer (16c) provided between the first skin layer (16a) and the second skin layer (16b) and including a second resin having a different flexural modulus from that of the first resin.

Description

Vehicle lighting fixtures

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

[0002] Patent Document 1 discloses a vehicle lighting component that includes a foamable resin in order to ensure the strength of the vehicle mounting portion while enabling weight reduction.

[0003] Patent Document 2 discloses a vehicle lamp in which the lamp body is formed from a resin composition containing a base resin and surface-treated vegetable fibers in order to reduce the environmental impact.

[0004] Japanese Patent Publication No. 2021-41625 International Publication No. 2013 / 187257

[0005] To reduce the environmental impact, the use of recycled materials in the resins that make up the lamp bodies of vehicle lamps has been considered. However, recycled materials tend to be less consistent in quality than virgin materials, which are made using only new materials, and there is a risk of reduced strength. Furthermore, the lack of consistent quality can result in poor appearance.

[0006] The object of the present invention is to provide a vehicle lamp that can ensure the required strength as a whole and has a good appearance even when low-strength resin such as recycled material is used in part.

[0007] In order to solve the above problem, a first aspect of the vehicle lamp of the present invention is a vehicle lamp including a resin part that does not require light transmittance, characterized in that the resin part has a three-layer structure including a first skin layer including a first resin, a second skin layer including the first resin, and a core layer disposed between the first skin layer and the second skin layer and including a second resin having a flexural modulus different from that of the first resin.

[0008] In order to solve the above problem, a second aspect of the present invention provides a vehicle lamp having an outer lens, a lamp body that forms a lamp chamber together with the outer lens, and a lamp unit that is housed within the lamp chamber, wherein at least a portion of the lamp body has a two-layer structure including a first layer made of a first resin and a second layer that includes a second resin that has a lower flexural modulus than the first resin, and the first layer faces the lamp chamber.

[0009] According to the present invention, even when a resin with low strength is partially used for resin parts that do not require optical transparency, the strength required for the entire vehicle lamp can be ensured. Furthermore, since the first skin layer and the second skin layer sandwiching the core layer form the appearance, the appearance of the vehicle lamp can be improved.

[0010] Furthermore, according to the present invention, even if a resin with low strength is used in part, the strength required for the entire vehicle lamp can be ensured.

[0011] 1 is a side cross-sectional view of a vehicle headlamp. FIG. 2 is a front view of the housing 30 as seen from the front. FIG. 3 is a schematic cross-sectional view showing a portion of the housing 30A of modified example 1. FIG. 4 is a schematic cross-sectional view showing a portion of the housing 30B of modified example 2. FIG. 5 is a schematic cross-sectional view showing a portion of the housing 30C of modified example 3. FIG. 6 is a schematic cross-sectional view showing a portion of the housing 30D of modified example 4. FIG. 7 is a schematic cross-sectional view showing a portion of the housing 30E of modified example 6. FIG. 8 is a schematic cross-sectional view showing a portion of the housing 30F of modified example 7. FIG. 9 is a schematic cross-sectional view showing a portion of the housing 30G of modified example 8. FIG. 10 is a side cross-sectional view of a vehicle headlamp. FIG. 11 is a front view of the housing 30 as seen from the front. FIG. 12 is a side cross-sectional view of a vehicle headlamp including the housing 30A of modified example 1. FIG. 13 is a front view of the housing 30A as seen from the front. FIG. 14 is a side cross-sectional view of a vehicle headlamp including the housing 30B of modified example 2. FIG. 15 is a side cross-sectional view of a vehicle headlamp including the housing 30C of modified example 3. FIG. 16 is a side cross-sectional view of a vehicle headlamp including the housing 30D of modified example 4. Fig. 10 is a side cross-sectional view of a vehicle headlamp including a housing 30E of modified example 5. Fig. 11 is a schematic cross-sectional view showing a portion of a housing 30F of modified example 6. Fig. 12 is a schematic cross-sectional view showing a portion of a housing 30G of modified example 7. Fig. 13 is a schematic cross-sectional view showing a portion of a housing 30H of modified example 8. Fig. 14 is a schematic cross-sectional view showing a portion of a housing 30I of modified example 9.

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] [First embodiment] A vehicle headlamp will be described as a vehicle lamp according to the present disclosure. Fig. 1 is a side cross-sectional view of the vehicle headlamp according to the first embodiment. 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).

[0014] 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 transparent resin. The outer lens 1 transmits light emitted from the lamp unit 10.

[0015] The lamp unit 10 includes a light source 11, a reflector 12, an inner lens 13, a cable 14, and a light source base 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 from the vehicle headlamp. The light source 11 and the reflector 12 are attached to the light source base 15. The inner lens 13 is attached to the light source base 15 via a lens holder (not shown). The lamp unit 10 may also include a shade (not shown) that blocks part 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 component that hides the inner surface of the housing 30 and the aiming mechanism 20 inside the lamp chamber from the outside of the outer lens 1, enhancing the appearance and design of the lamp. The decorative surface of the extension 16 may be subjected to a mirror finish or a texture finish.

[0016] The reflector 12, the extension 16, the lens holder, and the shade are examples of resin parts that do not require optical transparency.

[0017] 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. The holder 21 is an example of a resin part that does not require optical transparency.

[0018] 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 mounting 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-to-rear direction. After the lamp unit 10 is installed, 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.

[0019] 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 fore-and-aft direction. When the optical axis of the lamp unit 10 needs to be adjusted due to, for example, the center of gravity of the vehicle moving in the fore-and-aft direction while the vehicle is traveling, the aiming actuator 23 is operated to adjust the optical axis of the lamp unit 10.

[0020] 2 is a front view of the housing 30. As shown in FIG. 2, the housing 30 has an outer lens mounting portion 31, a cable insertion portion 33, a vehicle body mounting portion 35, an adjuster screw mounting portion 36, a motor mounting portion 37, and a support shaft mounting portion 38.

[0021] The outer lens attachment portion 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 portion 31. The outer lens 1 is fixed to the housing 30 with the rear edge of the outer lens 1 inserted into this mounting groove 32.

[0022] 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 that mounts 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 mounting portion 37 is a portion that mounts the motor 24 to the housing 30. The motor mounting portion 37 is an example of an internal support portion that supports an internal member. The support shaft mounting portion 38 is a portion that mounts a support shaft. The support shaft mounting portion 38 is an example of an internal support portion that supports an internal member.

[0023] The housing 30 is an example of a resin part that does not require optical transparency. In this embodiment, the resin part that does not require optical transparency has a three-layer structure including a first skin layer, a second skin layer, and a core layer. For example, as shown in FIG. 1 , the housing 30 has a three-layer structure including a first skin layer 30a, a second skin layer 30b, and a core layer 30c. The reflector 12 may also have a three-layer structure including a first skin layer 12a, a second skin layer 12b, and a core layer 12c. The extension 16 may also have a three-layer structure including a first skin layer 16a, a second skin layer 16b, and a core layer 16c. In the following description, the three-layer structure that constitutes the housing 30 will be described, but resin parts that do not require optical transparency may also have a similar three-layer structure.

[0024] The skin material constituting the first skin layer 30a and the second skin layer 30b includes a first resin, and the core material constituting the core layer 30c includes a second resin having a flexural modulus different from that of the first resin.

[0025] Such a three-layer resin part can be molded, for example, by injecting a skin material, a core material, and another skin material into a mold in that order. Alternatively, it can be manufactured by sandwich molding. Specifically, first, a sandwich molding machine starts injecting the skin material into the mold. Next, while continuing to inject the skin material, the core material starts to be injected from inside the skin material. After that, injection of the core material is completed, and then injection of the skin material is completed. As a result, a three-layer structure is formed in the mold, with the core layer 30c formed between the first skin layer 30a and the second skin layer 30b. Note that the first skin layer 30a may be formed integrally with the second skin layer 30b at its end.

[0026] The first resin contained in the skin material preferably has a higher flexural modulus than the second resin contained in the core material. Examples of thermoplastic resins that can be used include polyethylene, polypropylene, polyester, and polystyrene.

[0027] Here, the flexural modulus is the flexural modulus defined in JIS K7171. The flexural modulus can be measured, for example, as follows. A portion of the first portion 41 or the second portion 42 to be measured is cut out to prepare a test piece with a width b = 10 mm and a height h = 4 mm. This test piece is placed between supports with a distance L = 6.4 cm, and the load P and deflection w are measured when the center of the test piece is pressed with an indenter at a test speed = 5 mm / min in an environment of 25°C, and the stress σ and strain ε are calculated. Here, σ = 3PL / 2bh ２ and ε=6hw / L ２ Strain ε １ = 0.05% deflection w １ The load P applied to the measuring instrument when １ From stress σ １ =3P １ L / 2bh ２ Calculate the strain ε ２ = 0.25% deflection w ２ The load P applied to the measuring instrument when ２ From stress σ ２ =3P ２ L / 2bh ２The flexural modulus E can be calculated from the obtained value as follows: E = (σ ２ -σ １ ) / (ε ２ -ε １ )

[0028] As a method for making the flexural modulus of the first resin higher than that of the second resin, for example, the following method is available.

[0029] (1) The crystallinity of the first resin is made higher than that of the second resin. For example, by making the mold temperature higher during molding of the first part than during molding of the second part, the crystallinity of the first resin can be made higher than that of the second resin. For example, when manufacturing the housing 30 by two-color molding, the mold temperature T1 is set high when manufacturing the first part from the first resin, and then the mold temperature T2 is set lower than T1 when manufacturing the second part from the second resin, thereby making the crystallinity of the first resin higher than that of the second resin.

[0030] (2) Adding a reinforcing material to the first resin. For example, talc and / or reinforcing fibers can be added to the first resin. Examples of the reinforcing fibers include glass fibers and carbon fibers.

[0031] (3) A virgin material produced using only new materials is used as the first resin, and a recycled material is used as the second resin. Here, "recycled material" refers to, for example, a material obtained by crushing and melting waste plastic products. Generally, recycled materials made by crushing and melting waste plastic products for reuse tend to have lower strength, such as flexural modulus, compared to virgin materials.

[0032] In this embodiment, the first skin layer 30a and the second skin layer 30b of the housing 30 are formed from a first resin, so that the strength of the housing 30 can be ensured even if a second resin with lower strength is used for the core layer 30c.

[0033] Furthermore, the first skin layer 30a and the second skin layer 30b sandwiching the core layer 30c form the exterior of the housing 30, thereby improving the appearance of the vehicle lamp. Furthermore, when a virgin material manufactured using only uniform, new materials is used as the first resin, the surfaces of the first skin layer 30a and the second skin layer 30b can be made smooth, improving the appearance of the resin part. In particular, when the present invention is applied to the reflector 12 or the extension 16, a metal can be vapor-deposited on the first skin layer 30a or the second skin layer 30b to form a smooth reflective surface or a well-designed surface.

[0034] [Variation 1] The core material may contain 1% by mass of a first resin in addition to a second resin. When the core material contains the first resin, compatibility with the skin material containing the first resin is enhanced. FIG. 3 is a schematic cross-sectional view showing a portion of a housing 30A molded when the core material contains the first resin. As shown in FIG. 3, the core layer 30c of the housing 30A contains particles 30d made of the same first resin as contained in the first skin layer 30a and the second skin layer 30b. The particles 30d made of the first resin improve adhesion between the first skin layer 30a and the core layer 30c, and between the second skin layer 30b and the core layer 30c.

[0035] [Variation 2] A foaming agent may be mixed into the core material. Examples of foaming agents that can be used include water, sodium bicarbonate, ammonium carbonate, and hydrocarbon gas. Figure 4 is a schematic cross-sectional view showing a portion of a housing 30B molded when the core material contains a foaming agent. As shown in Figure 4, the use of a foaming agent causes bubbles 30e to form in the core layer 30c, thereby reducing the weight of the housing 30B.

[0036] [Variation 3] Reinforcing fibers such as glass fiber and carbon fiber may be added to the skin material. Fig. 5 is a schematic cross-sectional view showing a portion of a housing 30C molded when the skin material contains reinforcing fibers. As shown in Fig. 5, by using reinforcing fibers in the skin material, the flexural modulus of the first skin layer 30a and the second skin layer 30b can be increased by the reinforcing fibers 30f, thereby strengthening the housing 30C.

[0037] [Variation 4] Reinforcing fibers such as glass fiber and carbon fiber may be added to the core material. Fig. 6 is a schematic cross-sectional view showing a portion of a housing 30D formed when the core material contains reinforcing fibers. As shown in Fig. 6, by using reinforcing fibers in the core material, the flexural modulus of the core layer 30c can be increased by the reinforcing fibers 30f, thereby strengthening the housing 30D.

[0038] [Variation 5] In the above embodiment, the flexural modulus of the first resin contained in the skin material is higher than the flexural modulus of the second resin contained in the core material, but the present invention is not limited to this. For example, the flexural modulus of the second resin contained in the core material may be higher than the flexural modulus of the first resin contained in the skin material.

[0039] As a method for making the flexural modulus of the second resin higher than that of the first resin, for example, the following method is available.

[0040] (1) The crystallinity of the second resin is made higher than that of the first resin. For example, by making the mold temperature higher during molding of the first part than during molding of the second part, the crystallinity of the second resin can be made higher than that of the first resin. For example, when manufacturing the housing 30 by two-color molding, the mold temperature T1 is set high when manufacturing the first part from the second resin, and then the mold temperature T2 is set lower than T1 when manufacturing the second part from the first resin, thereby making the crystallinity of the second resin higher than that of the first resin.

[0041] (2) Adding a reinforcing material to the second resin, for example, adding talc as a reinforcing material to the second resin.

[0042] (3) The second resin is made of virgin material produced using only new materials, and the first resin is made of recycled material.

[0043] [Variation 6] The skin material may contain 1% by mass of a second resin in addition to the first resin. When the skin material contains the second resin, compatibility with the core material containing the second resin is enhanced. FIG. 7 is a schematic cross-sectional view showing a portion of a housing 30E molded when the skin material contains the second resin. As shown in FIG. 7, the first skin layer 30a and the second skin layer 30b of the housing 30E contain particles 30g made of the same second resin as contained in the core layer 30c. The particles 30g made of the second resin improve adhesion between the first skin layer 30a and the core layer 30c, and between the second skin layer 30b and the core layer 30c.

[0044] [Variation 7] A foaming agent may be mixed into the skin material. Examples of foaming agents that can be used include water, sodium bicarbonate, ammonium carbonate, and hydrocarbon gas. Figure 8 is a schematic cross-sectional view showing a portion of a housing 30F molded when the core material contains a foaming agent. As shown in Figure 8, the use of a foaming agent forms bubbles 30h in the first skin layer 30a and the second skin layer 30b, thereby reducing the weight of the housing 30F.

[0045] [Variation 8] Reinforcing fibers such as glass fiber and carbon fiber may be added to the skin material. Fig. 9 is a schematic cross-sectional view showing a portion of a housing 30G molded when the skin material contains reinforcing fibers. As shown in Fig. 9, by using reinforcing fibers 30f in the skin material, the flexural modulus of the first skin layer 30a and the second skin layer 30b can be increased by the reinforcing fibers 30f, thereby strengthening the housing 30G.

[0046] In the first embodiment and modifications 1 to 8 described above, an example in which the housing of the vehicle lamp has a three-layer structure has been described, but the present invention is not limited to this and can be applied to other resin parts that do not require optical transparency. For example, the present invention may be applied to the reflector 12, extension 16, lens holder, shade, holder 21 of the aiming mechanism 22, etc. of the lamp unit 10.

[0047] [Second Embodiment] Fig. 10 is a side cross-sectional view of a vehicle headlamp according to a second embodiment of the present invention. As shown in Fig. 10, the vehicle headlamp according to the second embodiment includes an outer lens 101, a lamp unit 110, an aiming mechanism 120, and a housing 130 (lamp body). Fig. 11 is a front view of the housing 130 as viewed from the front. Note that components similar to those of the vehicle headlamp according to the first embodiment are designated by reference numerals with the same last two digits, and description thereof will be omitted.

[0048] The housing 130 is an example of a resin part that does not require optical transparency. In this embodiment, at least a portion of the lamp body has a two-layer structure including a first layer 130a and a second layer 130b. For example, as shown in FIG. 10 , the housing 130 has a two-layer structure including a first layer 130a and a second layer 130b.

[0049] The first layer 130a includes a first resin. The first layer 130a is an inner layer of the housing 130. In other words, the first layer 130a faces the lamp chamber. The second layer 130b is an outer layer of the housing 130 and includes a second resin having a lower flexural modulus than the first resin.

[0050] Such a two-layer resin part can be manufactured by two-color molding using a first resin and a second resin. For example, the first layer 130a, which is the inner layer of the housing 130, is molded first, and then the second layer 130b is molded. Alternatively, the second layer 130b may be molded first, and then the first layer 130a may be molded.

[0051] The resin parts may be made of thermoplastic resin such as polyethylene, polypropylene, polyester, or polystyrene.

[0052] Here, the flexural modulus is the flexural modulus defined in JIS K7171:2022.

[0053] Methods for making the flexural modulus of the first resin higher than that of the second resin include methods (1) to (3) described in the first embodiment.

[0054] In this embodiment, the first layer 130a of the housing 130 is formed from a first resin, thereby ensuring the strength of the housing 130 even when a second resin with lower strength is used for the second layer 130b. In particular, because the housing 130 has a container-like shape to house the lamp unit 110, aiming mechanism 120, etc., it has corners and other portions with small radii of curvature. In such a shape, stress can be concentrated at the corners. When stress acts on the corners, the inner (lamp chamber side) of the corners of the housing 130, which has a smaller radius of curvature, is more likely to break than the outer side. In this embodiment, the first layer 130a, which is made of a first resin with a higher flexural modulus than the second resin, faces the lamp chamber, thereby satisfying the rigidity required of the housing 130.

[0055] Furthermore, if a virgin material manufactured using only uniform new materials is used for the first resin, the surface of the first layer 130a can be made smooth, improving the appearance of the resin part. Note that when the present invention is applied to the reflector 112 or the extension 116, a metal can be vapor-deposited on the first layer to provide a smooth reflective surface or a good design surface.

[0056] If recycled material is used for the second layer 130b, impurities of unknown origin may be mixed into the recycled material, which may cause unexpected outgassing. If the outgassing remains within the lamp chamber, it can undesirably cause the outer lens 101 to cloud over. In this embodiment, the first layer 130a faces the lamp chamber, and therefore the second layer 130b is the outer layer of the housing 130. Therefore, even if outgassing occurs from the second layer 130b, the outgassing is discharged to the outside of the vehicular lamp, and therefore the outgassing does not remain within the lamp chamber.

[0057] [Variation 9] In the above embodiment, the case where the entire housing 130 has a two-layer structure including the first layer 130a and the second layer 130b has been described, but only a part of the housing 130 may have a two-layer structure.

[0058] Fig. 12 is a side cross-sectional view of a vehicle headlamp including a housing 130A having a two-layer structure only in a portion thereof, and Fig. 13 is a front view of the housing 130A as viewed from the front. As shown in Figs. 12 and 13, the housing 130A has a second layer 130b in a portion (hereinafter also referred to as an "enclosing portion") surrounding a portion 130e (hereinafter also referred to as an "opposing portion") that faces the lamp unit 110 and the aiming mechanism 120. Specifically, as shown in Fig. 13, the opposing portion 130e of the housing 130A is provided with a cable insertion portion 133, an adjuster screw mounting portion 136, a motor mounting portion 137, and a support shaft mounting portion 138. The second layer 130b, indicated by a dashed line, is provided in the surrounding portion that surrounds the opposing portion 130e. By providing the second layer 130b in this manner, which contains a second resin having a lower flexural modulus than the first resin, the strength of the surrounding portion surrounding the opposing portion 130e can be reduced compared to other portions.

[0059] 12, the surrounding portion provided with the second layer 130b can be easily destroyed. After that, the facing portion 130e surrounded by the destroyed surrounding portion can be easily removed, and the lamp unit 110 and the aiming mechanism 120 can be taken out from the lamp chamber. After the lamp unit 110 and the aiming mechanism 120 have been removed, the housing 130A can be easily recycled.

[0060] Note that, although Fig. 13 shows an example in which the second layer 130b is provided in a rectangular surrounding portion surrounding the facing portion 130e, the surrounding portion surrounding the facing portion 130e is not limited to a rectangular shape. For example, the second layer 130b may be provided in a circular surrounding portion surrounding the facing portion 130e. Also, although Fig. 13 shows the second layer 130b provided around the entire periphery of the surrounding portion, for example, the second layer 130b may not be provided in part of the surrounding portion, and a second layer 120b that is approximately C-shaped in front view may be provided. For example, the second layer 130b may be provided on only three of the four sides of the rectangular surrounding portion.

[0061] [Modification 10] Alternatively, a housing may be used that has a two-layer structure including a first layer 130a and a second layer 130b, and in which the thickness of one portion of the first layer 130a is thinner than the thickness of the other portion.

[0062] 14 is a side cross-sectional view of a vehicle headlamp including a housing 130B having a two-layer structure, in which a portion of a first layer 130a is thinner than the other portions. As shown in FIG. 14, the thickness of the first layer 130a in a surrounding portion 130c surrounding the facing portion 130e of the housing 130B is thinner than the thickness of the first layer 130a in the other portions of the housing 130B. Note that the thickness of the first layer 130a in the surrounding portion 130c is increased by the amount that the first layer 130a is thinner in the surrounding portion 130d of the second layer 130b corresponding to the surrounding portion 130c.

[0063] In this way, by making the thickness of the first layer 130a in the surrounding portion 130c that surrounds the opposing portion 130e of the housing 130B thinner than the thickness of the first layer 130a in other parts of the housing 130B, the strength of the surrounding portion 130c of the housing 130B can be reduced compared to other parts.

[0064] 14, the surrounding portions 130c and 130d of the housing 130B can be easily destroyed. After that, the facing portion 130e surrounded by the destroyed surrounding portions 130c and 130d can be easily removed, and the lamp unit 110 and the aiming mechanism 120 can be taken out from the lamp chamber. After the lamp unit 110 and the aiming mechanism 120 have been removed, the housing 130B can be easily recycled.

[0065] [Modification 11] Fig. 15 is a side cross-sectional view of a vehicle headlamp including a housing 130C of another embodiment. As shown in Fig. 15, the thickness of the first layer 130a at the facing portion 130e of the housing 130C is thinner than the thickness of the first layer 130a in other portions of the housing 130C.

[0066] In this way, by making the thickness of the first layer 130a at the opposing portion 130e of the housing 130C thinner than the thickness of the first layer 130a at other portions of the housing 130B, the strength of the opposing portion 130e of the housing 130B can be reduced compared to the other portions.

[0067] 15, the opposing portion 130e of the housing 130C can be easily destroyed and removed, and then the lamp unit 110 and the aiming mechanism 120 can be removed from the lamp chamber. After the lamp unit 110 and the aiming mechanism 120 have been removed, the housing 130C can be easily recycled.

[0068] [Modification 12] A two-layer structure including a first layer 130a and a second layer 130b may be provided, with a notch formed in a portion of the surface of the first layer 130a. Fig. 16 is a side cross-sectional view of a vehicle headlamp including a housing 130D having a two-layer structure and having a notch 130f in a portion of the surface of the first layer 130a. As shown in Fig. 16, the notch 130f is provided in the surface of the first layer 130a in the surrounding portion that surrounds the facing portion 130e of the housing 130D.

[0069] In this way, by providing notches 130f on the surface of first layer 130a in the surrounding portion of housing 130D, the strength of the surrounding portion of housing 130D can be reduced compared to other portions.

[0070] 16, the housing 130D can be easily broken from the notch 130f. After that, the facing portion 130e of the housing 130A, which is surrounded by the broken surrounding portion, can be easily removed, and the lamp unit 110 and the aiming mechanism 120 can be taken out from the lamp chamber. After the lamp unit 110 and the aiming mechanism 120 have been removed, the housing 130D can be easily recycled.

[0071] [Variation 13] Alternatively, the housing may have a two-layer structure including a first layer 130a and a second layer 130b, in which the thickness of a portion of the first layer 130a is thinner than the thickness of the other portion, and the first layer 130a has a notch in a portion of its surface.

[0072] 17 is a side cross-sectional view of a vehicle headlamp including a housing 130E having a two-layer structure, in which a portion of a first layer 130a is thinner than the other portions, and a notch 130f is formed in a portion of the surface of the first layer 130a. As shown in FIG. 17, the thickness of the first layer 130a at the facing portion 130e of the housing 130E is thinner than the thickness of the first layer 130a in the other portions of the housing 130E. Furthermore, a notch 130f is formed in the surface of the first layer 130a at the outer periphery of the facing portion 130e of the housing 130E.

[0073] In this way, by making the thickness of the first layer 130a at the facing portion 130e of the housing 130E thinner than the thickness of the first layer 130a in other portions of the housing 130E, it is possible to reduce the strength of the facing portion 130e of the housing 130E compared to other portions. Furthermore, by providing notches 130f in the surface of the first layer 130a at the outer periphery of the facing portion 130e of the housing 130E, it is possible to further reduce the strength of the outer periphery of the facing portion 130e of the housing 130E.

[0074] Therefore, when recycling the vehicle headlamp shown in Figure 17, the opposing portion 130e of the housing 130E can be easily destroyed and removed. The lamp unit 110 and the aiming mechanism 120 can then be removed from the lamp chamber. After the lamp unit 110 and the aiming mechanism 120 have been removed, the housing 130E can be easily recycled.

[0075] [Variation 14] The second layer 130b may contain 1% by mass of a first resin in addition to the second resin. When the second layer 130b contains the first resin, compatibility with the first layer 130a containing the first resin is enhanced. FIG. 18 is a schematic cross-sectional view showing a portion of a housing 130F molded when the second layer 130b contains the first resin. As shown in FIG. 18, the second layer 130b of the housing 130F contains particles 130g made of the same first resin as the first layer 130a. The particles 30g made of the first resin improve adhesion between the first layer 130a and the second layer 130b.

[0076] [Variation 15] A foaming agent may be mixed into the second layer 130b. Examples of foaming agents that can be used include water, sodium bicarbonate, ammonium carbonate, and hydrocarbon gas. Figure 19 is a schematic cross-sectional view showing a portion of a housing 130G molded when the second layer 130b contains a foaming agent. As shown in Figure 19, the use of a foaming agent causes bubbles 130h to form in the second layer 130b, thereby reducing the weight of the housing 130G.

[0077] [Variation 16] Reinforcing fibers such as glass fiber and carbon fiber may be added to the first layer 130a. Fig. 20 is a schematic cross-sectional view showing a portion of a housing 130H formed when the first layer 130a contains reinforcing fibers. As shown in Fig. 20, by using reinforcing fibers 130i in the first layer 130a, the flexural modulus of the first layer 130a can be increased by the reinforcing fibers 130i, and the housing 130H can be strengthened.

[0078] [Variation 17] Reinforcing fibers such as glass fiber and carbon fiber may be added to the second layer 30b. Fig. 21 is a schematic cross-sectional view showing a portion of a housing 130I formed when the second layer 30b contains reinforcing fibers. As shown in Fig. 21, by using reinforcing fibers in the second layer 130b, the flexural modulus of the second layer 130b can be increased by the reinforcing fibers 30i, thereby strengthening the housing 130I.

[0079] Furthermore, in the above first and second embodiments and modifications 1 to 17, a vehicle headlamp has been described as a vehicle lamp, but the present invention is not limited to this. The present invention can also be applied to a rear combination lamp, a turn signal lamp, a fog lamp, and the like as a vehicle lamp.

[0080] This application claims priority based on Japanese Patent Application No. 2023-137142 filed on August 25, 2023 and Japanese Patent Application No. 2023-137143 filed on August 25, 2023.

Claims

1. A vehicle lamp including a resin part that does not require light transmission, the resin part having a three-layer structure including: a first skin layer including a first resin; a second skin layer including the first resin; and a core layer provided between the first skin layer and the second skin layer, the core layer including a second resin having a flexural modulus different from that of the first resin.

2. The vehicular lamp according to claim 1, wherein the second resin is a material obtained by crushing and melting waste plastic products.

3. The vehicular lamp according to claim 1 or 2, wherein the core layer contains 1 mass % of the first resin.

4. The vehicular lamp according to claim 1 or 2, wherein the core layer has air bubbles.

5. The vehicular lamp according to claim 1 or 2, wherein the first skin layer or the second skin layer contains reinforcing fibers.

6. The vehicular lamp according to claim 1, wherein the first resin is a material obtained by crushing and melting waste plastic products.

7. The vehicular lamp according to claim 1 or 6, wherein the first skin layer or the second skin layer contains 1 mass % of the second resin.

8. The vehicular lamp according to claim 1 or 6, wherein the first skin layer or the second skin layer has air bubbles.

9. The vehicular lamp according to claim 1 or 6, wherein the core layer includes reinforcing fibers.

10. A vehicular lamp comprising: an outer lens; a lamp body forming a lamp chamber together with the outer lens; and a lamp unit housed within the lamp chamber, wherein at least a portion of the lamp body has a two-layer structure including a first layer made of a first resin and a second layer including a second resin having a flexural modulus lower than that of the first resin, and the first layer faces the lamp chamber.

11. The vehicular lamp according to claim 10, wherein the two-layer structure is provided in a portion surrounding a portion of the lamp body facing the lamp unit.

12. The vehicular lamp according to claim 10, wherein a thickness of the first layer in a portion of the lamp body facing the lamp unit is thinner than a thickness of the first layer in other portions of the lamp body.

13. The vehicular lamp according to claim 12, wherein a portion of the lamp body surrounding the portion facing the lamp unit has a notch in a surface of the first layer.

14. The vehicular lamp according to any one of claims 10 to 13, wherein the second resin is a material obtained by crushing and melting waste plastic products.

15. The vehicular lamp according to any one of claims 10 to 13, wherein the second layer contains 1 mass % of the first resin.

16. The vehicular lamp according to any one of claims 10 to 13, wherein the second layer has air bubbles.

17. A vehicle lamp according to any one of claims 10 to 13, wherein the first layer includes reinforcing fibers.

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