Light module for a motor vehicle lighting device

Abstract

The present invention relates to a light module (100) for a motor vehicle lighting device, comprising at least one illuminant (1) on a printed circuit board (2) and a reflector (3) associated with the illuminant (1). According to the invention, the reflector (3) comprises a metallic sheet metal part.

Description

The present invention relates to a light module for a motor vehicle lighting device, and to a corresponding motor vehicle lighting device, wherein a signal light is formed by means of the light module.PRIOR ARTLight modules for motor vehicle lighting devices are known in the prior art, which use reflectors for beam shaping. For example, a lighting means is arranged at the focal point of a parabolic reflector, and a light beam emitted by the reflector is emitted via a subsequent optical unit, for example a projection optical unit or a scattering optical unit, into the operating environment of the associated motor vehicle lighting device. Customary reflectors are designed as injection-molded plastic components, the phototechnical surface being mirrored by means of a metal coating, typically made of aluminum. In many cases, the base body of the reflectors is designed as a composite component made of two different plastics, wherein one plastics material provides the necessary thermomechanical component properties, and the second plastics material serves for forming visible surfaces with decorative-aesthetic requirements or for forming the lighting surface. Furthermore, surface finishings, for example by means of painting or vapor deposition, are known for visible surfaces of the reflectors.From the aspect of sustainability, the recycling of such reflectors from the prior art is particularly difficult or impractical, since the material combinations used can only be separated from one another in the same way with disproportionate energy input. Furthermore, the material and energy expenditure for producing injection molding tools also plays a role in the material-energy overall balance, and the effort in surface finishing.DISCLOSURE OF THE INVENTIONThe object of the present invention is to propose an alternative embodiment of a generic light module for motor vehicle lighting devices, which in particular enables a more durable material use without this involving losses in technical functionality.This object is achieved by a light module according to claim 1 and a motor vehicle lighting device equipped therewith according to claim 10. Advantageous further developments of the invention are specified in the dependent claims.The technical teaching of the invention discloses that the light module comprises at least one lighting means on a printed circuit board and a reflector assigned to the lighting means, wherein the reflector has a metallic sheet metal part.The invention starts from the idea of replacing the combination of plastic(s) with functionalized surfaces that is common in the prior art by the use of metallic sheet metal, wherein the reflector is preferably formed entirely from a metallic sheet metal part. Metal sheets, in particular made of aluminum, on the one hand provide the necessary thermomechanical properties for forming a robust component under the operating conditions in a light module of a motor vehicle lighting device, and can also be provided with surfaces of sufficiently high degree of reflection for use as a reflector. An advantage compared with conventional plastics is, in addition, the high thermal conductivity of metallic sheet metal, so that efficient heat dissipation from the reflector is ensured during operation of the light module. In the event of damage or after the operating life has been reached, the reflector can be removed from the light module and is then available for further use as a preferably single-grade metallic material.The sheet metal part of the reflector is manufactured, for example, from metallic sheet metal, for example, from anodized aluminum sheet metal, by means of punching, bending, laser cutting and / or deep drawing. The sheet metal part is preferably provided with a lighting surface of sufficiently high reflectance, so that the reflector is formed completely, i.e. in one piece and in the same material, as a metallic sheet metal part. Alternatively, a lighting surface can have an additional mirror coating, for example comprising a silver layer, if a particularly high degree of reflection is desired. Preferably, the reflectance in the visible light spectrum is between 60% and 95%, in particular at least 75%.In an advantageous embodiment, the light module comprises a heat sink which is arranged on the rear side of the printed circuit board, wherein the heat sink has a metallic sheet metal part. In particular, the reflector is arranged on the front side of the printed circuit board and is connected to the printed circuit board and the heat sink by means of a rivet connection. The printed circuit board has at least one suitable bore for receiving a rivet, so that the printed circuit board is clamped between the rear-side heat sink and the front-side reflector by means of the rivet connection. The rivet connection contributes to the dissipation of the operating heat from the reflector into the cooling body, wherein the rivets used are preferably formed from a metallic material. By releasing the rivet connection in the course of a recycling measure, the reflector and the cooling body can be separated out without any circumstances as reusable sheet metal parts. In an alternative embodiment, the sheet metal part of the cooling body is already provided on the production side with rivets integrally formed thereon, as a result of which particularly efficient mounting of the printed circuit board and reflector is possible. After releasing rivet connections based thereon, the sheet metal part can be recycled at least in terms of material.In a further embodiment, the light module comprises at least one cooling element which is arranged on the cooling body and has a metallic sheet metal part. Such an additional cooling element may be expedient for increased requirements for heat dissipation, for example when using a powerful lighting means.In particular, the cooling element is connected on the rear side to the cooling body by means of a rivet connection.For example, the reflector comprises a lighting surface with light-diffusing surface structures such that the reflector has a scattering effect, which may be expedient, for example, for a light module for forming a signal light such as a direction indicator. Light-scattering surface structures, for example a small-particle pattern of concave curvatures, can be introduced into the lighting surface, for example by means of embossing. Furthermore, the reflector can comprise a lighting section with a free-form geometry, in particular in the form of an expedient deviation from a paraboloid for generating a scattering effect.Advantageously, the reflector is folded at the edge in order to increase the mechanical stability, and in particular has a standing fold, i.e. a edge bent over by substantially 90°. In addition, the natural frequency spectrum of the reflector can be specifically influenced by introduced folds in order to prevent the vibrations occurring during the vehicle driving operation from leading to undesired resonances.In a further embodiment, the light module comprises a plurality of lighting means and reflectors which are arranged side by side in pairs on the printed circuit board transversely to a main reflection direction. The reflectors, in particular designed as reflector blades, are provided as individual elements in order to generate an elongate signal function as a narrow light signature equidistant from a curved outer contour. Such a light module is configured in particular for a signal light function, for example as a daytime running light, tail light, turn signal indicator or stop light.The invention also relates to a motor vehicle lighting device, which comprises at least one light module according to one of the aforementioned embodiments, wherein a signal light is formed by means of the light module, in particular a daytime running light, a tail light, a direction indicator or a stop light.PREFERRED EMBODIMENTS OF THE INVENTIONFurther measures which improve the invention are illustrated below together with the description of preferred exemplary embodiments of the invention on the basis of the figures. They show in schematic form: FIGS. 1 a- 1 f : a first exemplary embodiment of the light module according to the invention, FIGS. 2a-2c show a second embodiment; and FIGS. 3-5 show embodiments with special reflectors.FIGS. 1 a- 1 f show a first exemplary embodiment of the light module 100 according to the invention in perspective views (FIGS. 1 a- 1 c ), as an exploded illustration (FIG. 1 d ) and in detailed views (FIGS. 1 e- 1 f ). The representations comprise in each case only the components of the light module 100 relevant within the scope of the invention, whereas further optional components such as a module housing, fastening means or further optical elements are not shown.The light module 100 comprises a plurality of lighting means 1 in the form of light-emitting diodes and reflectors 3 assigned thereto, which are arranged side by side in pairs on the printed circuit board 2 transversely to a main reflection direction. The reflectors 3 are each formed entirely as metal sheet metal parts, for example as stamped and bent parts made of anodized aluminum sheet. The reflectors 3 have a blade-like shape with parabolic curvatures, and the associated lighting means 1 are each arranged at the focal point of the reflectors 3. The reflectors 3 are arranged offset to one another in such a way that their lighting surfaces overlap in the front view and can generate the light impression of a continuously illuminated surface in the main reflection direction. The light module 100 is thus suitable in a motor vehicle lighting device in particular for forming a signal light, in particular a daytime running light, a tail light, a direction indicator or a stop light.The light module 100 further comprises the cooling body 4, on which the printed circuit board 2 is arranged on the rear side, wherein the cooling body 4 has a metallic sheet metal part. The heat sink 4 is preferably likewise designed as a one-piece stamped and bent part of uniform material and can be recycled after the service life of the light module 100 has been reached. The reflectors 3 arranged on the front side of the printed circuit board 2 are connected to the printed circuit board 2 and the cooling body 4 by means of the rivet connections 5. For this purpose, the printed circuit board 2 has the bores 52 for receiving the rivets 51, and the printed circuit board 2 is clamped between the cooling body 4 and the reflectors 3 by means of the rivet connections 5. The rivets 51 formed on the cooling body 4 additionally function on the mounting side as common referencing elements for the printed circuit board 2 and the reflectors 3. The heat sink 4 can be designed in such a way that it acts as an interface for integrating the light module 100 into an associated motor vehicle lighting device.A second exemplary embodiment of the light module 100 according to the invention is shown in a perspective view in FIGS. 2 aand 2 c, and as an exploded illustration in FIG. 2 b. In contrast to the first exemplary embodiment, the light module 100 comprises the cooling elements 6, which are arranged on the rear side of the cooling body 4 and which are likewise designed as metallic sheet metal parts. As a result, the cooling capacity for the operation of powerful lighting means is increased, so that the light module 100 is suitable, for example, for the formation of a daytime running light. The cooling elements 6 can preferably be integrated into the rivet connections between the reflectors 3, the printed circuit board 2 and the cooling body 4.FIG. 2 cshows a perspective detailed view of the light module 100 behind a cover pane 7 of a motor vehicle lighting device, which serves for light scattering. For this purpose, the cover plate 7 has a multiplicity of small-part cushion optics as scattering structures.FIG. 3 shows a perspective view of an exemplary embodiment of the light module 100 with reflectors 3, which are each formed folded along the edges to form a standing fold 33, whereby the mechanical rigidity of the reflectors 3 is increased. The reflectors 3 can thereby advantageously be made of sheet metal of smaller wall thickness.FIGS. 4 and 5 show detailed views of embodiments of the reflectors 3 with a scattering effect, for which purpose the lighting surface comprises light-scattering surface structures 31, 32 in each case, which have been introduced into the sheet metal parts in particular by means of embossing. In the exemplary embodiment of FIG. 4, the surface structures 31 are designed as pad-shaped concave indentations of the light-technology surface, which generate a substantially homogeneous scattering of incident light.In the exemplary embodiment of FIG. 5, the surface structures 32 are designed as trough-shaped concave indentations of the light-technology surface, which thus generate a scattering in the transverse direction. In order to generate an additional scattering effect in the longitudinal direction, the reflector 3 can have a free-form geometry in the lighting section, i.e. a curvature deviating from a parabolic shape.List of reference characters100 Light module 1 Lighting means 2 Circuit board 3 Reflector 31, 32 Surface structure 33 Standing seam 4 Cooling body 5 Rivet connection 51 Rivet 52 Bore 6 Cooling element 7 Cover pane

Claims

Light module (100) for a motor vehicle lighting device, at least comprising a lighting means (1) on a printed circuit board (2) and a reflector (3) assigned to the lighting means (1), characterized in that the reflector (3) has a metallic sheet metal part.Light module (100) according to Claim 1, characterized in that the reflector (3) is formed entirely as a metallic sheet metal part.Light module (100) according to Claim 1 or 2, characterized in that the light module (100) comprises a heat sink (4) which is arranged on the rear side of the printed circuit board (2), wherein the heat sink (4) has a metallic sheet metal part.Light module (100) according to Claim 3, characterized in that the reflector (3) is arranged on the front side of the printed circuit board (2), wherein the reflector (3) is connected to the printed circuit board (2) and the heat sink (4) by means of a rivet connection (5).Light module (100) according to either of Claims 3 and 4, characterized in that the light module (100) comprises at least one cooling element (6) which is arranged on the cooling body (4), wherein the cooling element (6) has a metallic sheet metal part.Light module (100) according to one of the preceding claims, characterized in that the reflector (3) comprises a lighting surface with light-scattering surface structures (31, 32), such that the reflector (3) has a scattering effect.Light module (100) according to one of the preceding claims, characterized in that the reflector (3) comprises a lighting section with a parabolic geometry or a free-form geometry.Light module (100) according to one of the preceding claims, characterized in that the reflector (3) is folded on the edge side, in particular has a standing fold (33).Light module (100) according to one of the preceding claims, characterized in that the light module (100) comprises a plurality of lighting means (1) and reflectors (3) which are arranged side by side in pairs on the printed circuit board (2) transversely to a main reflection direction.Motor vehicle lighting device, at least comprising a light module (100) according to one of the preceding claims, wherein a signal light is formed by means of the light module (100), in particular a daytime running light, a tail light, a direction indicator or a stop light.

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