Lighting unit

Abstract

To provide a lamp unit which achieves reduction of variations in the assembly position which affect light distribution accuracy at low costs.SOLUTION: A lamp unit 10 is mounted on a vehicle. The lamp unit 10 includes: a light source 14 mounted on a substrate 12; a reflector 16 which reflects light from the light source 14 forward; a projection lens 20 which is held by a lens holder 18 and disposed forward of the reflector 16; and a shade 22 for formation of a cutoff line CL which is disposed rearward of the projection lens 20. The lens holder 18, the reflector 16, and the shade 22 are integrally molded to form a lens holder unit 40.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a lamp unit, and more particularly to a lamp unit used in a vehicle headlamp. [Background technology]

[0002] Known examples of this type of lighting unit include a light source, a projection lens held by a lens holder, a reflector disposed behind the projection lens for reflecting light from the light source toward the projection lens, and a shade for blocking a portion of the light from the reflector to form a cutoff line, as disclosed in Patent Document 1. Conventionally, as in Patent Document 1, the lens holder, reflector, and shade are each separate parts, and the lighting unit is configured as an assembly. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-173096 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for smaller lighting units. In this situation, if the lens holder, reflector, and shade are configured as separate parts, as in Patent Document 1, there may be variations in the structure and assembly position of each, which may adversely affect the light distribution accuracy. In particular, there is a problem that the impact on the light distribution accuracy becomes greater when the unit is made smaller.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a lamp unit which is low-cost and reduces variations in assembly position that affect light distribution accuracy. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a lighting unit according to one embodiment of the present invention is a lighting unit mounted on a vehicle, and comprises a light source mounted on a substrate, a reflector that reflects light from the light source forward, a projection lens held by a lens holder and positioned in front of the reflector, and a shade for forming a cutoff line positioned behind the projection lens, wherein the lens holder, the reflector and the shade are all integrally molded as a lens holder unit.

[0007] According to the above aspect, by integrally molding the reflector, lens holder, and shade as a lens holder unit, the positional accuracy of the light source, the reflector, the lens, and the shade can be improved by simply aligning the lens holder unit with the substrate on which the light source is mounted, and the variation in light distribution caused by assembly errors can be reduced. This is also advantageous when the lighting unit is small. Furthermore, by integrally molding the reflector, the lens holder, and the shade, the number of parts can be reduced, and the materials can be shared, thereby reducing costs.

[0008] In the above aspect, it is also preferable that the lens holder unit is formed with a board attachment portion.

[0009] In the above aspect, it is also preferable that the lens holder unit has an opening formed in a position directly opposite the shade.

[0010] In addition, in the above-mentioned aspect, it is also preferable that the shade comprises a horizontal reflective surface that blocks a portion of the light reflected by the reflector to form a cutoff line, and an inclined reflective surface that inclines forward from the front end of the horizontal reflective surface, and a sub-reflector that reflects light from the light source onto the inclined reflective surface is formed in front of the opening of the lens holder unit, and the inclined reflective surface reflects light incident from the sub-reflector forward.

[0011] In addition, in the above-mentioned aspect, it is also preferable that a flange is formed on the outer periphery of the projection lens at its back surface which abuts against the front end surface of the lens holder unit, a positioning protrusion protruding rearward is formed on the back surface of the flange, and a recess that aligns with the positioning protrusion is formed on the front end surface of the lens holder unit. Effect of the Invention

[0012] According to the lamp unit according to the above aspect, it is possible to reduce variations in the assembly position that affect the light distribution accuracy at low cost. [Brief description of the drawings]

[0013] [Figure 1] 1 is a front view of a vehicle lamp including a lamp unit according to an embodiment of the present invention; [Diagram 2] 2 is a cross-sectional view of the vehicle lamp taken along line II-II in FIG. 1. [Diagram 3] FIG. 2 is an exploded perspective view of the lamp unit. [Figure 4] FIG. [Diagram 5] 4A and 4B are diagrams showing a low beam light distribution pattern formed by the vehicle lamp. [Figure 6] 4 is a diagram showing the layout of a mold used for injection molding a lens holder unit that constitutes the lamp unit. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A lamp unit 10 according to an embodiment of the present invention will be described below with reference to the drawings. The embodiment does not limit the invention but is merely an example, and all features and combinations thereof described in the embodiment are not necessarily essential to the invention.

[0015] In addition, for convenience of explanation and convenience of drawing, the drawings may be partially simplified except for essential parts of the invention. In addition, in this specification, directions such as front, rear, left and right mean directions when the vehicle lamp 1 equipped with the lamp unit 10 is viewed from the front unless otherwise specified. In each drawing, the arrow Up-Lo indicates the up-down direction, the arrow Le-Ri indicates the left-right direction, and the arrow Fr-Re indicates the front-rear direction.

[0016] (Embodiment) A lamp unit 10 according to the embodiment is a lamp unit constituting a vehicle lamp 1 that functions as a passing beam headlamp mounted in the front of a vehicle.

[0017] Fig. 1 is a front view of the vehicle lamp 1, Fig. 2 is a cross-sectional view of the vehicle lamp 1 taken along line II-II in Fig. 1. Fig. 3 is an exploded perspective view of the lamp unit 10, and Fig. 4 is an exploded rear perspective view showing the lens holder unit 40 and the projection lens 20 of the lamp unit 10.

[0018] As shown in Figures 1 and 2, a vehicle lamp 1 includes a lamp unit 10 for low beams, a box-shaped housing 2 with an opening at the front, and a plain outer lens 3. The housing 2 is made of an opaque resin such as polypropylene or polyethylene. The outer lens 3 is made of a transparent resin such as polycarbonate. The lamp unit 10 is provided in a lamp chamber S defined by attaching the outer lens 3 to the front surface of the housing 2 so as to close the opening of the housing 2.

[0019] Between the lamp unit 10 and the outer lens 3, there is disposed an extension member (PES cover) 4 for concealing the internal structure of the housing 2 from view from the outside, which has an opening 11 that matches the shape of a projection lens 20 of the lamp unit 10 described later. In Fig. 1, the rough dashed lines indicate members that are not visible due to an opaque member in front of them. The fine dashed lines indicate members that are visible through the projection lens 20 described later.

[0020] The lighting unit 10 includes a light source 14 mounted on a substrate 12, a reflector 16 arranged to cover the upper part of the substrate 12 and to reflect light from the light source 14 forward, a projection lens 20 arranged in front of the reflector 16 and held by a lens holder 18, and a shade 22 for forming a cutoff line arranged behind the projection lens 20.

[0021] The light source 14 is a white light-emitting diode (LED) having a rectangular light-emitting surface. The light source 14 is mounted on the substrate 12 with its light-emitting surface facing upward. A recess 17 that matches the shape of the substrate 12 is formed in the lower part of the reflector 16, and the substrate 12 is positioned and held between the recess 17 and the rear end of the shade 22. That is, the recess 17 formed in the reflector 16 and the rear end of the shade 22 define a substrate mounting part 19. The substrate 12 is positioned on the substrate mounting part 19, and is attached to the base member 24 via the reflector 16 by the screw 21 with the light-emitting surface of the light source 14 facing upward. The base member 24 is configured to also function as a heat sink.

[0022] The base member 24 is attached to the bracket 26 by a screw 27. The bracket 26 has a back plate portion 28 that is rectangular in shape and extends vertically in a front view similar to the vehicle lamp 1, and a shelf plate portion 30 that extends horizontally forward from the back plate portion 28. The base member 24 is fixed to the shelf plate portion 30. In addition, a ball joint 32 is attached to the upper left portion of the back plate portion 28, and an aiming screw 34 is attached to each of the upper right portion and the lower left portion, and the bracket 26 is attached to the housing 2 via the ball joint 32 and the aiming screw 34. This allows the optical axis of the lamp unit 10 to be adjusted in the vertical and horizontal directions.

[0023] Further, the rear end of the extension member 4 is joined to the bracket 26, so that the lamp unit 10 and the extension member 4 can rotate together.

[0024] As can be seen from FIG. 1, the four light sources 14 are arranged on the substrate 12 at equal intervals in the left-right direction. The reflector 16 is divided into four sections in the left-right direction to correspond to the light sources 14. Each section of the reflector 16 is an ellipsoid of revolution arranged so that each light source 14 is a first focus, and a first reflecting surface 16a is formed on the inner surface. The first reflecting surface 16a is formed by, for example, sputtering or vacuum deposition of a metal such as aluminum. The shade 22 also has four shades arranged in parallel in the left-right direction. Therefore, the lamp unit 10 has a shape in which four lamp units having a cross-sectional shape shown in FIG. 2 are connected in the left-right direction.

[0025] The shade 22 has a horizontal surface 22b whose front end is located at the second focal point of the reflecting surface 16a of the reflector 16, and an inclined surface 22c that inclines forward from the front end of the horizontal surface 22b. Reflecting surfaces 22d and 22e are formed on the horizontal surface 22b and the area extending forward from the horizontal surface 22b by vacuum deposition of a metal such as aluminum. Hereinafter, the reflecting surface formed on the horizontal surface 22b of the shade 22 is referred to as the horizontal reflecting surface 22d, and the reflecting surface formed on the inclined surface 22c is referred to as the inclined reflecting surface 22e. The front end of the horizontal reflecting surface 22d, i.e., the boundary between the horizontal reflecting surface 22d and the inclined reflecting surface 22e, is referred to as the ridge line 22f.

[0026] Fig. 5(A) shows the shape of the shade 22 near the ridge line 22f as viewed from the front. In the figure, line VV indicates the reference line in the up-down direction, and line HH indicates the reference line in the left-right direction. The horizontal surface 22b of the shade 22 has a shape in which the left side of the line VV is higher than the line HH, and the right side of the line VV is aligned with the line HH, and the two horizontal surfaces are inclined and continuous at the line VV, and are configured to form a low beam light distribution pattern as shown in Fig. 5(B) described later.

[0027] The front end of the shade 22 constitutes the lower part of the lens holder 18 that holds the projection lens 20. The upper part of the lens holder 18 is connected to the front end of a sub-reflector 36, which will be described later.

[0028] As shown in FIG. 3, the lens holder 18, the reflector 16, and the shade 22 are all integrally molded to form a lens holder unit 40. Walls 42 are formed on both ends of the lens holder unit 40. An opening 44 is formed in the upper part of the lens holder unit 40 at a position directly opposite the ridge line 22f of the shade 22. The opening 44 functions as a heat dissipation port for dissipating heat generated by the substrate 12 to the outside of the lens holder unit 40 when the vehicle lamp 1 is turned on. In the conventional vehicle lamp, a heat dissipation port is sometimes provided, but it is provided forward of the ridge line 22f of the shade 22. In the lamp unit 10 of the present embodiment, the opening 44 is provided closer to the substrate 12, which is a heat source, so that the heat dissipation effect is improved. The inclined surface 22c of the shade 22 may have an opening in a portion other than the inclined reflecting surface 22e. If an opening is provided, the heat dissipation effect by the opening 44 is further improved.

[0029] A second reflecting surface 36a is formed on the inner surface of the sub-reflector 36, and as described below, is configured to reflect light from the light source 14 toward the inclined reflecting surface 22e of the shade 22. The second reflecting surface 36a is formed by depositing a metal such as aluminum by sputtering or vacuum deposition, similar to the first reflecting surface 16a.

[0030] The projection lens 20 is a projection lens that is rectangular when viewed from the front and is made of transparent resin such as polymethylmethacrylate (PMMA). A flange 46 is formed on the outer periphery of the projection lens 20. For convenience of drawing, the projection lens 20 is shown in FIG. 3 as a rectangular shape when viewed from the front, protruding in a kamaboko shape at the front and rear of the flange. In reality, however, the projection lens is a projection lens that is convex at the front and rear and is cut into the shape of a reduced flange, and has a shape that protrudes at the front and rear from a rectangular flange when viewed from the front.

[0031] The front end surface of the lens holder unit 40 forms the lens holder 18, which is connected to the front ends of the shade 22 and the sub-reflector 36. The lens holder 18 has a rectangular frame shape in a front view, which matches with the flange 46 of the projection lens 20.

[0032] A total of three positioning protrusions 48 that protrude rearward are formed on the back surface of the flange 46, two on the upper part and one on the lower part of the projection lens 20. The positioning protrusion 48 is formed in a rectangular shape when viewed from the front, similar to the shape of the projection lens when viewed from the front.

[0033] On the other hand, on the front end surface of the lens holder 18, i.e., the lens holder unit 40, recesses 52 having a shape that matches the positioning protrusion 48 are formed at positions corresponding to the positioning protrusion 48 of the flange 46, two at the top and one at the bottom.

[0034] Then, the positioning protrusions 48 are fitted into the corresponding recesses 52 to position them, and the back surface of the flange 46 of the projection lens 20 is abutted against the front end surface of the lens holder 18 (lens holder unit 40) by laser welding, whereby the projection lens 20 is attached to the lens holder unit 40.

[0035] In a conventional lamp unit using a rectangular projection lens, the lens holder is provided with a positioning protrusion, and the flange of the projection lens is provided with a recess with a shape that matches the protrusion, thereby positioning the projection lens and the lens holder. Therefore, when the lamp is viewed from the front, the colored positioning protrusion stands out among the transparent lens flange, which causes a problem of poor appearance.

[0036] In the lamp unit 10 according to this embodiment, the positioning protrusion 48 is formed on the back surface of the flange 46 of the projection lens 20, so that the positioning protrusion 48 is not directly visible. Even if the shape of the positioning protrusion is visible through the transparent flange 46 of the projection lens 20, it is not conspicuous, improving the appearance. In addition, in the lamp unit 10 according to this embodiment, the shape of the positioning protrusion 48 is rectangular when viewed from the front, so it is less conspicuous than other shapes such as a circle. Furthermore, the flange 46 of the projection lens 20, on which the positioning protrusion 48 is visible, can be arranged so that it is almost invisible from the front depending on the overlap with the extension member 4.

[0037] The number of positioning projections 48 is not particularly limited, but is preferably at least three, and three is advantageous since it provides the simplest configuration.

[0038] Also, as shown in Figures 3 and 4, it is preferable to provide a protrusion 54 on the back surface of the flange 46 in addition to the positioning protrusion 48, and to provide a recess 56 that matches the protrusion 54 on the front end surface of the corresponding lens holder 18, thereby preventing incorrect assembly of the lens holder unit 40 and the projection lens 20, which may vary slightly depending on the delivery destination, etc.

[0039] Here, the positioning protrusion 48 and the protrusion 54 have different shapes (sizes), but they may have the same shape. The positional relationship between the positioning protrusion 48 and the protrusion 54 can be set as appropriate. Also, instead of providing the protrusion 54 and the recess 56, the positional relationship between the multiple positioning protrusions 48 and the recesses 52 may be changed to provide a mechanism for preventing incorrect assembly.

[0040] In the lamp unit 10 according to the present embodiment, the reflector 16, the lens holder 18, and the shade 22 are integrally molded as the lens holder unit 40. As a result, simply by aligning the lens holder unit 40 with the substrate 12 on which the light source 14 is mounted, the positional accuracy of the light source 14, the reflector 16, the projection lens 20, and the shade 22 is improved, and the variation in light distribution caused by assembly errors is reduced. In particular, when the lamp unit 10 is made compact, the influence of assembly errors of the components becomes relatively large. However, if the lens holder unit 40 is integrally molded as in the present embodiment, the influence of such assembly variations between the components does not occur. Furthermore, by integrally molding the reflector 16, the lens holder 18, and the shade 22 (one-color molding), the number of parts is reduced, and the materials can be shared, thereby reducing costs.

[0041] In this case, the substrate 12 on which the light source 14 is mounted may be configured to be positioned and fixed to, for example, a base member 24, and the lens holder unit 40 may be attached to this base member 24. However, as in the above embodiment, forming a substrate mounting portion 19 for directly positioning and holding the substrate 12 on which the light source 14 is mounted on the lens holder unit 40 is particularly advantageous because it improves the positional accuracy of the light source 14, the reflector 16, the lens holder 18, and the shade 22.

[0042] Next, the function of the vehicle lamp 1 equipped with the lamp unit 10 will be described with reference to FIG. 2 and FIG. 5(A).

[0043] The light emitted from the light source 14 is reflected by the first reflecting surface 16a of the reflector 16 and collected in the vicinity of the ridge line 22f of the shade 22. The light collected in the vicinity of the ridge line 22f is irradiated forward of the lamp as parallel light L1 while being inverted vertically and horizontally by the projection lens 20. In the light distribution pattern formed at this time, a dark area caused by the shade 22 is formed.

[0044] FIG. 5(B) is a diagram showing a schematic diagram of a light distribution pattern of a low beam formed by the vehicle lamp 1, projected onto a virtual screen provided in front of the lamp. As can be seen from FIG. 5(B), the vehicle lamp 1 forms a light distribution pattern of a low beam having a cutoff line CL on the upper side. This cutoff line CL is formed so as not to give glare to oncoming vehicles. Therefore, the position of the cutoff line, that is, the shape of the ridge of the shade, is designed depending on whether the vehicle is driving on the right side or the left side. The vehicle lamp 1 is a vehicle lamp for driving on the right side.

[0045] A part of the light emitted from the light source 14 is reflected by the reflecting surface of the sub-reflector, and is further reflected by the inclined reflecting surface of the shade 22 to become parallel light and enter the projection lens 20, forming overhead sign illumination light L2. An overhead sign refers to a road sign or the like that is located above and in front of the vehicle and passes over the driver's head as the vehicle travels.

[0046] Next, a description will be given of a mold for forming the lens holder unit 40 of the lamp unit 10 according to the embodiment. The lens holder unit 40 is formed by one-piece molding using one-color molding of an opaque resin such as polyethylene or polypropylene.

[0047] 6 is a diagram showing a cross section of a mold 200 for injection molding the lens holder unit 40 of the lamp unit 10 according to the embodiment. The mold 200 includes a cavity side mold 210, a core side mold 220, and a slide mold 230. A cavity C1 that defines a portion of the reflector 16 having the substrate attachment portion 19 is formed on a parting surface PL of the cavity side mold 210 and the core side mold 220.

[0048] Furthermore, the cavity side mold 210 protrudes from the core side mold 220 at a portion corresponding to the opening 44 of the lens holder unit 40, and cooperates with the core side mold 220 and the slide mold 230 to form the lower part of the lens holder 18 and a cavity C2 that defines the shade 22. The cavity side mold 210 defines the horizontal surface 22b of the shade 22 and the portion of the inclined reflecting surface 22e of the inclined surface 22c, while the slide mold 230 defines the lens holder 18 and the portion of the inclined surface 22c of the shade 22 other than the inclined reflecting surface 22e.

[0049] Moreover, the cavity side mold 210 and the slide mold 230 cooperate to form a cavity C3 that defines the sub-reflector 36 and the upper part of the lens holder 18.

[0050] Here, in the lens holder unit 40, the rear end 22a of the horizontal surface 22b of the shade 22 is designed to be located forward of the front end of the reflector 16 in the front-rear cross section. Also, among the inclined surfaces 22c of the shade 22, the front end of the inclined reflective surface 22e is designed to be located rearward of the rear end of the sub-reflector 36. Also, the inclination of the inclined surface 22c of the shade 22 with respect to the horizontal line is designed to be larger than the inclination of the reflective surface 36a of the sub-reflector 36 with respect to the horizontal line.

[0051] By designing the lens holder unit 40 in this manner, it becomes possible to avoid undercuts and demold the molded product, the lens holder unit 40, by opening the cavity side mold 210, the core side mold 220, and the slide mold 230 in the directions of arrows A1, A2, and A3, respectively.

[0052] A lamp unit for low beam needs to have a shade for forming a cutoff line CL. When a shade is provided, if the lens holder, the reflector, and the shade are integrally molded as a lens holder unit, the shade portion may be undercut and the mold may not be completed. In the lamp unit 10 according to the present embodiment, an opening 44 is provided at the upper part of the lens holder unit 40 directly facing the shade 22, so that the opening 44 can be used to define the reflective surfaces 22d and 22e of the shade with the cavity side mold 210, the core side mold 220, and the slide mold 230, and integral molding is possible.

[0053] When the lens holder, the reflector, and the shade are integrally molded, it is not necessarily necessary to provide an opening on the upper surface facing the shade. However, in a configuration in which the sub-reflector 36 and the shade 22 having the horizontal surface 22b and the inclined reflective surface 22e are provided and the illumination light for an overhead sign is irradiated, as in the lighting unit 10 according to the embodiment, the horizontal surface 22b and the inclined surface 22c are necessarily undercut when the lighting unit is integrally molded. If an opening 44 is provided on the upper surface facing the shade 22 (the reflective surfaces 22d, 22e) as in the present embodiment, the reflector 16, the shade 22, and the lens holder 18 can be integrally molded even in the case of the configuration in which the illumination light for an overhead sign is irradiated. [Explanation of symbols]

[0054] 10: Lighting unit 11:Aperture 12: Substrate 14:Light source 16: Reflector 16a: First reflecting surface (reflecting surface of reflector) 17: Recess 18: Lens holder 19: Circuit board mounting section 20: Projection lens 22:Shade 22d: Reflective surface 22d: Horizontal reflective surface 22e: Reflective surface 22e: Inclined reflective surface 36: Subreflector 36a: Second reflecting surface (reflecting surface of the sub-reflector) 40: Lens holder unit 44 :Aperture 46: Flange 48: Positioning protrusion 52: Recess 54: Protrusion 56: Recess CL: Cutoff line

Claims

1. A lighting unit mounted on a vehicle, A light source mounted on the substrate; A reflector that reflects light from the light source forward; a projection lens held by a lens holder and disposed in front of the reflector; a shade for forming a cutoff line disposed behind the projection lens; the lens holder, the reflector, and the shade are all integrally molded as a lens holder unit; The lens holder unit has an opening formed at a position directly opposite the shade, The shade is a horizontal reflecting surface that blocks a portion of the light reflected by the reflector to form a cutoff line; a slanted reflecting surface inclined forward from a front end of the horizontal reflecting surface, a sub-reflector that reflects light from the light source to the inclined reflecting surface is formed in front of the opening of the lens holder unit; The inclined reflecting surface reflects light incident from the sub-reflector forward.

2. 2. The lamp unit according to claim 1, wherein the lens holder unit is formed with a board mounting portion.

3. a flange is formed on the outer periphery of the projection lens, the flange abutting on the front end surface of the lens holder unit at the rear surface of the projection lens; The lamp unit according to claim 1 or 2, characterized in that a positioning protrusion protruding rearward is formed on the rear surface of the flange, and a recess that aligns with the positioning protrusion is formed on the front end surface of the lens holder unit.

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