Heat sink for a projection light module of a motor vehicle headlight

Abstract

A heat sink (12) for a projection light module of a motor vehicle headlight, comprising a semiconductor light source (2), the heat sink (12), a primary optic (14) and a secondary optic (16), and configured to focus a luminous flux emitted by the semiconductor light source (2) by means of the primary optic (14) and to illuminate with this focused luminous flux an aperture edge (18) of an aperture, the contour of which can be imaged by the secondary optic (16) as a light-dark boundary of a light distribution projected by the secondary optic (16), characterized in that the aperture, as an aperture rib (20), is a materially bonded component of the heat sink (12) and has a size, position and shape with which the contour of the aperture edge (18) can be defined for each of several different traffic types and / or legal areas.

Description

State of the art

[0001] The present invention relates to a heat sink for a projection light module of a motor vehicle headlight, which has a semiconductor light source, the heat sink, a primary optic and a secondary optic and which is designed to bundle a luminous flux radiated by the semiconductor light source by means of the primary optic and to illuminate with the bundled luminous flux a diaphragm edge of a diaphragm, the contour of which can be imaged by the secondary optic as a light-dark boundary of a low beam distribution projected by the secondary optic.

[0002] Such a heat sink is known per se. The applicant's low-beam modules are generally projection light modules that, for example, have a reflector as the primary optics for focused illumination of a mirror aperture having an aperture edge with light from a semiconductor light source. This creates an inner light distribution in the projection light module that is limited by the aperture edge. This light distribution is emitted as the outer light distribution by the projection lens, which is focused on this inner light distribution and serves as the secondary optics of the projection light module.

[0003] From WO 2022 / 025171, a projection light module is known with which a light-dark boundary of a low beam distribution is generated by imaging a (lower or rear) reflector edge.

[0004] Existing regulations for the various traffic types and legal jurisdictions (ECE RHT, ECE LHT, SAE) result in different shapes of permissible cut-off lines. The concept known from WO 2022 / 02571 of implementing the cut-off lines for different traffic types and legal jurisdictions using variations in the reflector geometry requires an undesirably high level of effort in terms of manufacturing tool design (interchangeable inserts or specific shapes).

[0005] In the applicant's known projection light modules mentioned above, the aperture is a separate sheet metal part, for which different variants must be kept and processed during the production process depending on the target legal area and traffic type. The known heat sink is designed and arranged to absorb heat emanating from the semiconductor light source and is not involved in generating the cut-off line. Disclosure of the invention

[0006] The present invention differs from the prior art mentioned at the outset in that the cover is a materially integral part of the heat sink and has a size, position and shape with which the contour of the cover edge can be determined for one of several different types of traffic and legal areas.

[0007] These features make it possible to avoid an additional sheet metal part in the form of the mirror cover and its variants for the different types of traffic and legal areas.

[0008] In contrast to the concept known from WO 2022 / 02571, which implements the cut-off lines for different traffic types and legal areas using variants of the reflector geometry, only a single reflector geometry is required. This can be adapted to the requirements of the different traffic types and legal areas through a milling process.

[0009] A preferred embodiment is characterized in that the heat sink is made of a light metal.

[0010] It is also preferred that the heat sink is made of aluminum or an aluminum alloy.

[0011] It is further preferred that the heat sink has cooling fins and / or other surface-enlarging structures such as cooling pins on its underside, which promote the dissipation of heat from the heat sink to its surrounding air.

[0012] A further preferred embodiment is characterized in that the heat sink has first fastening structures with which it can be fastened in the motor vehicle headlight.

[0013] It is also preferred that the first fastening structures have screw domes which, like the surface-enlarging structures, protrude downwards from the rest of the heat sink.

[0014] It is further preferred that further fastening structures are parts of threaded connections such as screw bosses, screws, studs and nuts and serve to fasten a circuit board and a reflector assembly on the top side of the heat sink.

[0015] A further preferred embodiment is characterized in that the reflector assembly has three concave reflector chambers and that the diaphragm partially covers all three reflector chambers and has an individual shape and position of its diaphragm edge for each reflector chamber, wherein the diaphragm edge is a length section of a rib extending over all three reflector chambers, which rib serves as a diaphragm.

[0016] It is also preferred that an upper side of the heat sink located in front of the aperture rib is covered with structures that diffusely scatter incident light.

[0017] Further advantages are evident from the description and the attached figures.

[0018] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention. Drawings

[0019] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show, in schematic form: Fig. 1 Parts of a light module of the applicant, which was assumed to be known at the outset and which has a separate mirror aperture; Fig. 2 a known projection light module that images a reflector edge as a light-dark boundary; Fig. 3 shows an example of a projection light module having an embodiment of a heat sink according to the invention; Fig. 4 examples of different aperture shapes, which differ in the position and shape of their aperture edges; and Fig. 5 an arrangement of a heat sink according to the invention and a reflector assembly from the front.

[0020] In detail, Fig. 1 shows a circuit board 1 on which various semiconductor light sources 2 are arranged, together with a reflector component 3 and a separate sheet metal part 4 designed as a mirror aperture. The circuit board 1 rests on the separate sheet metal part 4. A heat sink (not shown) would be arranged below the sheet metal part 4 in thermal contact with it, so that it could absorb heat from the semiconductor light sources 2 emanating from the circuit board 1 and flowing through the sheet metal part 4 and dissipate it to its surroundings. Each semiconductor light source 2 is assigned a concave reflector shell 3', which is illuminated by the semiconductor light source 2. Light from the semiconductor light sources 2 reflected by the reflector shells 3' illuminates an aperture edge 5, which is projected as a cut-off line by a secondary optic (not shown).

[0021] Fig. Figure 2 shows a known projection light module 6 in the form of an arrangement of a light source 7, a concave reflector 8 serving as the primary optics, and a projection lens 9 serving as the secondary optics in a sectional plane in which an optical axis of the arrangement and thus also a main radiation direction of the projection light module 6 lies. The lower edge of the reflector 8 is depicted as the cut-off line of a low-beam distribution.

[0022] Fig. 3 shows an example of another projection light module 10 of a motor vehicle headlight. The projection light module 10 comprises a circuit board 1 with a semiconductor light source 7, a heat sink 12, a primary optics 14, and a secondary optics 16. The projection light module 10 is configured to focus a luminous flux emitted by the semiconductor light source 2 by means of the primary optics 14 and to use this to illuminate a diaphragm edge 18 of a diaphragm rib 20 such that the diaphragm edge 18, serving as the contour of the diaphragm rib 20, can be imaged by the secondary optics 16 as the light-dark boundary of a light distribution projected by the secondary optics 16. The cover rib 20 is a materially integral component of the heat sink 12 and has a size, position and shape with which the contour of the cover edge 18 can be determined for one of several different traffic types (right-hand traffic, left-hand traffic) and legal areas (e.g. Europe (ECE), NAFTA (SAE), ...).

[0023] The primary optics 14 preferably has a concave reflector chamber. Furthermore, the primary optics 14 preferably has two focal points. One of the focal points is preferably located in the semiconductor light source 2. The other focal point preferably coincides with a focal point of the secondary optics 16. The aperture edge 18 preferably extends through an internal light distribution formed around the common focal point of the primary optics 14 and the secondary optics 16. The secondary optics 16 is preferably a projection lens. The structure protruding upward from the primary optics 14 is a ventilation opening 32, which improves heat dissipation from the primary optics.

[0024] Fig. Figure 4 shows, purely schematically and without claiming to be a true-to-life representation, examples of various aperture shapes that differ in the position and / or shape of their aperture edges 18 and can thus be used to create different cut-off line profiles of low-beam distributions for different traffic types and legal areas. The viewer's line of sight into the reflector assembly is directed toward a diaphragm rib of a reflector chamber or toward a portion of a diaphragm rib that partially covers and extends over several reflector chambers. The line of sight is thus opposite to the direction of the light emerging from the assembly.

[0025] The translucent regions 21 are each located above the aperture edge 18. The various aperture shapes are characterized in that they all have identical outlines 22 and can therefore all be produced from identical heat sinks 12, which initially have identical aperture ribs 20, by simply removing the desired translucent regions and leaving desired opaque regions 23 from the aperture rib 20. In other words: the aperture rib 20 is a materially integral component of the heat sink 12 and has a size, position, and shape with which the contour of the aperture edge 18 can be defined for one of several different traffic types and / or legal areas, in particular within the same outline.

[0026] The aperture edge 18, which has a predetermined shape and position and is to be determined depending on the type of traffic and / or legal area, can preferably be produced in the manufacturing process of the further projection light module 10 by a milling process in which the areas 21 of the aperture rib 20 which are to be translucent are milled away.

[0027] Fig.5 shows an arrangement comprising a heat sink 12 according to the invention and a reflector assembly 24 from the front, so that the viewer's line of sight is directed into the reflector assembly 24 and thus opposite to the direction of the light emerging from the assembly. The heat sink 12 has cooling fins and / or other surface-enlarging structures 26 on its underside, such as cooling pins, which promote the dissipation of heat from the heat sink 12 to its surrounding air. In addition, the heat sink 12 has first fastening structures 28, with which it can be screwed into the motor vehicle headlight. The first fastening structures 28 are screw domes in the illustrated embodiment and, like the surface-enlarging structures 26, protrude downwards from the rest of the heat sink 12. In addition, the heat sink 12 has further fastening structures 30. The further fastening structures are, for example,Parts of threaded connections such as screw bosses, screws, studs and nuts and are used to secure a printed circuit board and a reflector assembly to the top of the heat sink 12.

[0028] In the illustrated embodiment, the reflector component 24 has three concave reflector chambers. The aperture rib 20, which preferably partially covers all three reflector chambers, has a unique shape and position of its aperture edge 18 for each reflector chamber. The aperture edge 18 is a length section of an aperture rib 20 extending across all three reflector chambers. To generate a regulation-compliant low-beam distribution, the reflector chambers are simultaneously illuminated with light from their respective assigned semiconductor light source, so that a regulation-compliant low-beam distribution results from overlapping light distributions of the reflector chambers.

[0029] The structures protruding upward from the reflector chambers are ventilation openings 32, which improve heat dissipation from the reflector chambers. The upper side of the heat sink 12, located in front of the diaphragm rib 20, can be covered with structures 34 that diffuse incident light to prevent specular reflections that would disrupt the desired low-beam distribution.

[0030] The heat sink 12 is preferably made of a material that is easy to mill and simultaneously provides good heat conduction. It is also preferred that the heat sink 12 be made of a light metal, for example, aluminum or an aluminum alloy. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 025171

[0003] WO 2022 / 02571 [0004, 0008]

Claims

[1] Heat sink (12) for a projection light module of a motor vehicle headlight, which has a semiconductor light source (2), the heat sink (12), a primary optic (14) and a secondary optic (16) and which is designed to bundle a luminous flux emitted by the semiconductor light source (2) by means of the primary optic (14) and to illuminate with this bundled luminous flux a diaphragm edge (18) of a diaphragm, the contour of which can be imaged by the secondary optic (16) as a light-dark boundary of a light distribution projected by the secondary optic (16), characterized by that the cover, as a cover rib (20), is a materially integral part of the heat sink (12) and has a size, position and shape with which the contour of the cover edge (18) can be determined for one of several different types of traffic and / or legal areas. [2] Heat sink (12) according to claim 1, characterized by that it is made of a light metal. [3] Heat sink (12) according to claim 2, characterized by that it is made of aluminum or an aluminum alloy. [4] Heat sink (12) according to one of the preceding claims, characterized by that it has cooling fins and / or other surface-enlarging structures (26) on its underside, such as cooling pins, which promote the dissipation of heat from the heat sink (12) to its surrounding air. [5] Heat sink (12) according to claim 4, characterized by that it has first fastening structures (28) with which it can be screwed into the motor vehicle headlight. [6] Heat sink (12) according to claim 5, characterized by that the first fastening structures (28) have screw domes which, like the surface-enlarging structures (26), protrude downwards from the rest of the heat sink (12). [7] Heat sink (12) according to one of the preceding claims, characterized bythat further fastening structures (30) are parts of threaded connections such as screw domes, screws, studs and nuts and serve to fasten a printed circuit board and a reflector assembly (24) on the top side of the heat sink (12). [8] Heat sink (12) according to claim 7, characterized by that the reflector assembly (24) has three concave reflector chambers and that the diaphragm rib (20) partially covers all three reflector chambers and has an individual shape and position of its diaphragm edge (18) for each reflector chamber, wherein the diaphragm edge (18) is in each case a length section of a diaphragm rib extending over all three reflector chambers. [9] Heat sink (12) according to one of the preceding claims, characterized by that an upper side of the heat sink (12) lying in front of the aperture rib (20) is covered with structures (34) which diffusely scatter incident light.

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