Headlight arrangement for vehicles

Abstract

Headlight assembly for vehicles, in particular motor vehicles, with the following features: - a headlight housing (1) comprising a rear housing wall (1a), a top housing cover (1b), a bottom housing base (1c), and side housing walls (1d, 1e) offset from one another; - with a front-facing disc (11) transparent to light rays; - the headlight housing (1) closed by the disc (11) comprises an interior housing space (7); - a reflector assembly (13) with at least one light source (29) in the form of an LED (29') is provided in the interior housing space (7); - with a cooling device for dissipating the heat generated in the headlight housing (1) during operation of the at least one light source (29); - the cooling device comprises a heat sink (111) defined by the disc (11).- the reflector arrangement (13) comprises a reflector housing (15) with a reflector housing rear wall (15a) and a reflector housing top (15b), whereby a reflector housing opening or an open reflector housing area is formed in the reflector housing (15) opposite the reflector housing rear wall (15a), - the reflector housing (15) is positioned and installed in the headlight housing (1) such that the reflector housing opening or the reflector housing area points towards the lens (11) of the headlight housing (1) and is adjacent to it, - the reflector housing (15) has at least one reflector housing chamber (23) in the interior (21) of the reflector housing, the inner wall surfaces of which are at least partially covered with a reflective material layer or have a reflective material layer,- wherein in the at least one reflector housing chamber (23) the at least one light source (29) is mounted on the reflector housing (15) and / or a circuit board on which the at least one light source (29) is mounted on the reflector housing (15),- the reflector housing (15) is installed in the headlight housing (1) such that the reflector housing (15) is spaced apart from the headlight housing (1) and is held and mounted relative to the headlight housing (1) by means of a holding and supporting device,- the reflector housing (15) or at least the reflector housing rear wall (15a) is made of a material having a thermal conductivity of at least 10 W / mK, and- the reflector housing rear wall (15a) is arranged at a distance opposite the disc (11) such thatthat during the operation of the at least one light source (29) and the resulting heating of the reflector housing rear wall (15a), a heat source is formed by the heated reflector housing rear wall (15a) and a heat sink (111) is formed by the disc (11), and the reflector housing rear wall (15a) and the disc (11) are arranged and / or equipped such that the heat source (211) and the heat sink (111) thereby formed generate an air circulation (43) in the reflector interior (21), in which the air heated by the at least one light source (29) rises within the at least one reflector housing chamber (23) adjacent to the reflector housing rear wall (15a), is cooled towards the disc (11) and thereby sinks, in order to then flow back towards the reflector housing rear wall (15a) and there be heated by the heat generated by the at least one light source (29). to rise again.

Description

The invention relates to a headlight arrangement for vehicles. As is well known, headlight assemblies for vehicles, i.e., especially for motor vehicles, typically comprise a headlight housing that surrounds an interior housing. At least one light module is arranged within this housing interior, which can emit light through a front-facing, translucent lens. The headlight housing itself can be made of a wide variety of materials, such as metal, die-cast aluminum, but also plastic. Inside the headlight housing is a reflector arrangement, in front of which at least one light source, for example in the form of one or more incandescent lamps, halogen lamps or light-emitting diodes (LEDs), is or are arranged. Of particular importance are the headlights, which are known to be located in the front part of a motor vehicle's engine compartment. These headlights are situated in close proximity to the engine compartment, and are therefore exposed to additional heating from the engine's waste heat, in addition to the heat generated by the bulbs themselves. Because of the overall warming and heating of the headlight assembly, for example according to DE 20 2014 004 057 U1, an additional cooling device for cooling the headlight housing when the motor vehicle's engine is running has already been proposed, which includes at least one cooling fan and an associated control system. According to EP 3 213 961 A1, a design-related solution is also proposed to reduce the disadvantages caused by the heating of the headlight housing. This preprint assumes that the headlight housing is made of plastic. Due to heat generation both within and around the headlight (from the engine's heat), changes in the light distribution emitted by the headlight can occur, affecting, for example, the cut-off line. Temperature-dependent deformation of the headlight housing can also result from the heating. Furthermore, the different coefficients of thermal expansion of the various materials used must be taken into account. In contrast, many headlight housings are not made of plastic, but of metal, particularly die-cast or injection-molded metal. When such materials are used, the headlight housing typically heats up even more due to its high thermal conductivity. The heat emitted from the engine compartment, in particular, further increases the temperature inside the headlight housing. Furthermore, the weight of the headlight housings increases considerably when metal housings are used. To dissipate heat from a headlight housing, particularly a motor vehicle headlight housing, the primary approach proposed so far has been to use housing designs preferably equipped with a plurality of externally projecting fins. These fins serve as cooling fins and are preferably also connected, for example, to cooling fins located inside the headlight housing to facilitate heat transfer from the lamp housing to the outside. Such proposals are known, for example, from DE 10 2006 001 711 A1 or US 8 562 174 B2. According to DE 10 2006 057 570 A1, it is proposed that the headlight housing, in a known manner, comprises a front-facing, light-transmitting disc connected to a rear heat-conducting wall, thus forming a chamber containing the light source, which is essentially sealed from the atmosphere. Optionally, the chamber may be equipped with a pair of pressure equalization openings. To achieve the desired cooling, a so-called heat-insulating wall is arranged offset from the rear heat-conducting wall and further offset from the front-facing, light-transmitting disc. Between this heat-insulating wall and the heat-conducting wall, a cooling channel is formed, running from bottom to top more or less across the entire width of the headlight housing. In other words, a heat sink is proposed on the rear of the lamp housing. JP 2011-222295 A discloses a headlight assembly with an LED as the light source. The LED is mounted on a heat sink within a headlight housing, and a separate reflector directs the LED's light forward through a lens that encloses the LED area. Air flows around the heat sink, heating it and cooling it at a front lens of the headlight assembly. The JP H10-12004 A shows a headlight assembly with a halogen bulb as the light source. The bulb is located in a reflector housing that is closed at the front, which in turn is located in a headlight housing. The reflector housing has ventilation openings to the rest of the headlight housing to allow air circulation. German patent DE 10 2013 001 287 A1 discloses a headlight arrangement with an LED as the light source. The LED is arranged on a heat sink, which is cooled from the rear by an airflow. EP 2 450 279 A1 discloses a headlight arrangement with an LED mounted on a component other than the reflector. JP 2004-253325 A shows a headlight arrangement with a light source mounted in a recess of a reflector. DE 3107420 A1 shows a headlight arrangement with light sources that are not LEDs. Against this background, the object of the present invention is to create an improved headlight arrangement for vehicles, specifically for headlight arrangements equipped with LED light sources. The problem is solved according to the invention in accordance with the features specified in claim 1. Advantageous embodiments of the invention are specified in the dependent claims. The invention offers a number of advantages over conventional solutions. The solution according to the invention achieves a lower heat load on the headlight housing using comparatively simple means. This reduced heat load on the headlight assembly can be achieved without the use of fans, both outside and inside the headlight housing. To minimize the heat load on the at least one light source in the form of at least one LED, the invention provides for a reflector arrangement within the headlight housing. This reflector arrangement is a separate component located within the headlight housing and is held relative to the headlight housing by a separate support and / or retaining device. This support and / or retaining device preferably has a relatively low thermal conductivity. The reflector arrangement is positioned at a distance from a rear wall section of the headlight housing within the housing interior in order to avoid heating via the rear wall arrangement of the headlight housing, which is usually additionally heated by the engine compartment when the engine is running. In the remaining interior space of the housing between the reflector assembly and the front lens intended for light emission, an additional cooling device is implemented as a result of the design of the headlight assembly. Within the scope of the invention, a heat sink is formed and defined in the form of the front, translucent lens. The invention provides that the wall of the reflector can be heated by the at least one light source in the form of an LED, as is known, but the overall arrangement ensures that the air in the housing interior can indeed heat up and rise via the at least one LED and the reflector assembly heated by it, while simultaneously being cooled again by the significantly cooler front lens (which, as explained, now forms the heat sink as a result of the design).In other words, convection causes air circulation within the headlight or reflector housing. In the area of ​​the light source, the air is heated and rises, then flows along the underside of the upper cover of the actual reflector housing in the form of at least one reflector chamber towards the front lens of the headlight assembly. There, it is cooled by the significantly cooler lens, which acts as a heat sink, causing it to sink. From there, the cooled air can flow back towards the rear in the area of ​​the light source, above the lower cover or the lower base of the actual reflector assembly, again in the form of at least one reflector chamber. To achieve the aforementioned cylindrical air circulation within the headlight or reflector housing, not only is the heat sink in the form of the front lens provided, but also, and perhaps more importantly, a rear reflector housing panel. Regardless of whether at least one light source is located on the rear reflector housing panel and / or also on the top of the reflector housing, the rear panel is designed to have the best possible, i.e., the highest possible, thermal conductivity. This thermal conductivity should be at least 10 W / mK. If even more thermally conductive plastics are used, this thermal conductivity can be, for example, at least 12.5, 15, 17.5, or even at least 20 W / mK. If metallic reflector housing back panels are preferably used, i.e., generally reflector back panels that consist of or comprise metal, preferably magnesium, the values ​​for thermal conductivity can also be significantly above 50 W / mK, for example, showing values ​​that are at least 65 or 70 W / mK. If other metals are used, the thermal conductivity for the reflector housing back wall can be even higher, for example at least 75, 80, 85, 90, 95 or 100 W / mK. The overall effect of generating a circulation of the air medium or, more generally, the gaseous medium in the reflector housing can be further improved if, in addition to the rear wall of the reflector housing, a reflector housing cover that is also highly thermally conductive is provided, preferably connected to it, which limits the reflector housing at the top. In a preferred embodiment of the invention, the reflector assembly, which accommodates at least one or preferably several light sources, preferably in the form of LEDs, is arranged as a separate unit at a distance from the inner surface of the actual headlight housing. Only retaining and fastening means are provided, by which the actual reflector housing is held within the interior of the headlight housing. This minimizes heat exchange and heat flow from the headlight housing towards the reflector housing. This improves the overall cooling effect, since the headlight housing, due to its proximity to the engine, is typically subject to considerable heating, particularly on its rear side in the engine compartment. Although the headlight housing can be made of any conceivable material or material composition, a variant made of plastic, for example thermoset or thermoplastic, is preferred. This results in a significant weight reduction. The reflector assembly itself can also be made of a wide variety of materials, such as metals or plastics. A reflector design made entirely or predominantly of magnesium is preferred. This results in very high dimensional stability. During the manufacturing process, this alloy can preferably be injection-molded into the desired shape. This allows for the production of very precise structures. To improve the reflector effect, the reflector surface on the side of the light source can be coated entirely or predominantly with aluminum. This oxide structure results in a very good reflectivity, even superior to that of chromium. A protective layer can also be applied to this aluminum oxide layer. Finally, the magnesium alloy used preferentially has a very high thermal conductivity, for example, approximately 100 watts per square meter. Finally, in a preferred embodiment of the invention, it is also possible to attach a corresponding circuit board with light sources mounted on it, preferably in the form of one or more LEDs, to the corresponding locations of the reflector housing, or alternatively, to provide the circuit board, i.e., a corresponding circuit board, preferably on the underside of an intermediate floor of the reflector arrangement, whereas the light sources are preferably arranged in the form of LEDs above this intermediate floor in the actual reflector housing chamber. The reflector housing can preferably be divided into several chambers situated side by side, each formed by a bottom section, a ceiling section and two opposing side wall sections, and open towards the front in the direction of the disc arrangement of the headlight arrangement. Each of these reflector chambers can house one or more separate light sources, for example, for the parking lights, high beams, daytime running lights, cornering lights (activated when driving around curves), turn signals, etc. For example, the various lights, such as the high beams, may use only one light source or several, such as two, preferably LED lights. Similarly, other lights, such as the normal low beams, may use one or more, preferably two, LEDs. Finally, the invention also allows the entire reflector assembly to be moved or adjusted, preferably electrically. This enables different height or angle and / or lateral adjustments, so that the lights can be set at different angles to the horizontal and / or at different lateral angles, for example, to be directed more or less towards the ground. This allows for optimal illumination of the road. In summary, the invention provides a simple headlight assembly characterized by low weight, optimal thermal conductivity, and an optimized integrated cooling system, without requiring active cooling components such as electrically driven fans. Furthermore, no heat sinks are necessary, which would otherwise be required, for example, between the reflector assembly and the rear housing wall of the headlight assembly. The invention is explained in more detail below with reference to exemplary embodiments. Specifically, the following are shown: Fig. 1a: a basic simplified representation of a headlight arrangement according to the invention with a front glass cover; Fig. 1b: a schematic three-dimensional front view of the headlight arrangement according to the invention; Fig. 1c: a corresponding representation to Fig. 1a, but without the headlight housing, so that the reflector housing contained therein is visible; Fig. 2a: a corresponding perspective view of the headlight housing showing the lower housing wall; Fig. 2b: a corresponding representation of Fig. 1a, but omitting the headlight housing, so that only the reflector housing is visible; Fig. 3a: a front view of the headlight housing; Fig. 3b: a corresponding representation to Fig.3a, however omitting the headlight housing, so that only the reflector housing is visible; Fig. 4a: a corresponding representation of the headlight housing predominantly in top view; Fig. 4b: a corresponding representation to Fig. 4a, however omitting the headlight housing, so that only the reflector housing is visible; Fig. 5a: a corresponding representation of the headlight housing predominantly from the underside or bottom; Fig. 5b: a corresponding representation to Fig. 5a, however omitting the headlight housing, so that only the reflector housing is visible; Fig. 6: a schematic front view of the headlight housing according to the invention, explaining various sectional views shown below; Fig. 7: a horizontal sectional view through the headlight housing with the reflector housing located therein along line VII-VII in Fig. 6; Fig.Fig. 8a: a schematic vertical section through the headlight housing according to the invention with the front disc serving as a heat sink; Fig. 8b: a corresponding representation to Fig. 8a, in which, however, the heat source generated by the light source and the heat sink defined by the disc, and the circulation of the gaseous medium / air inside the reflector housing are shown; Figs. 9a to 9c: further schematic representations along the section lines IXa-IXa, IXb-IXb, and IXc-IXc in Fig. 6. Figures 1a to 5b show different views of the headlight arrangement according to the invention, as it is used particularly for vehicles, i.e. especially for motor vehicles. This headlight arrangement therefore comprises a headlight housing 1, which, in particular, has a preferably adapted housing shape with a corresponding housing back wall 1a, adapted to certain types of motor vehicles. In front of a rear housing panel 1a, a housing top 1b and a housing bottom 1c are provided, one above the other and spaced apart from each other. In the front view, a housing side panel 1d and 1e are provided externally between the housing top 1b and the housing bottom 1c. This defines and delimits an interior housing 7 (Fig. 1b and Fig. 8a), which is bounded at the front by the disc 11 (i.e., the translucent disc 11, which may also be designed as a lens or diverging lens), through which the interior housing 7 is usually sealed to be moisture-proof or at least splash-proof. Since the disc 11 itself is translucent, it is not shown in detail in the drawings except in Fig. 1a. The circumferential edge 11a of the disc 11 then abuts the circumferential edge 1f of the headlight housing 1 (Fig. 8a). The individual housing walls can have different shapes. For example, the housing top 1b and the housing bottom 1c do not necessarily have to be exactly parallel to each other, as the housing top 1b and the housing bottom 1c can also, if necessary, run slightly towards or away from each other in sections from the front 9 to the rear 10 (Fig. 8a). As can also be seen from the drawings, the housing rear wall 1a can also be provided with wall sections oriented differently relative to each other to adapt to the vehicle requirements. There are no restrictions in this respect. Therefore, in some cases, and deviating from the described rear housing wall 1a, the housing top 1b, the housing bottom 1c and the housing side walls 1d and 1e, reference is also made to a rear housing wall section 1'a, an upper housing wall section 1'b, a lower housing wall section 1'c and to the two lateral housing wall sections 1'd and 1'e, which are offset laterally from each other and define the housing interior 7 towards the outside. Within the housing interior 7 thus formed, a so-called reflector arrangement 13 is provided according to the invention, which preferably consists of a reflector housing 15. While Fig. 1b shows a corresponding representation of the headlight arrangement with the outer headlight housing 1, Fig. 1c shows a corresponding representation of the reflector housing 15, omitting the headlight housing 1 that receives the reflector housing 15. It can be seen from this that this reflector housing 15 preferably comprises a reflector housing rear wall 15a, a reflector housing top 15b, a reflector housing bottom 15c, and two lateral reflector housing side walls 15d and 15e (Fig. 1b), spaced apart from each other.In this respect, some also refer to a rear reflector housing wall section 15'a, an upper reflector housing wall section 15'b, a lower reflector housing wall section 15'c and two lateral reflector housing wall sections 15'd and 15'e. Figure 6 shows another schematic front view of the headlight arrangement according to the invention, i.e., of the front glass. The individual reflector housing chambers 23 are at least partially visible. Figure 7 shows a horizontal section along line VII-VII in Figure 6. As can be seen from the drawings and in particular from the longitudinal section shown in Fig. 7, which runs approximately midway between the upper and lower housing walls 1b, 1c, the interior of the reflector housing 21 is divided into several reflector housing chambers 23. In the illustrated embodiment, the interior of the reflector housing 21 is divided into five reflector housing chambers 23a, 23b, 23c, 23d and 23e. For this purpose, a reflector housing chamber partition or partition section 25 is provided in the interior of the reflector housing 21 between two adjacent reflector housing chambers 23, which extends forward from the rear reflector housing wall section 15a or 15'a and ends there near the front disk 11, preferably at a smaller distance from the inside of the front disk 11. In the longitudinal section shown in Fig. 7, the reflector housing partition sections 25 converge towards each other from the rear side 15a to the front side 9, preferably with partitions or partition surfaces 25a that are partly concave and partly straight or flat. According to the sectional view in Fig. 7, these partition surfaces 25a extend from their front edge or border 25b, which is directly adjacent to the inside of the disc 11 and more or less parallel or vertical to it, in a rearward direction. The partition surfaces 25a are preferably formed on one side of the partition edge 25b with a concave reflector section 25' and on the opposite side to the partition edge 25b with a flat reflector section 25" over at least a portion of its length.This allows for a stepped arrangement of the individual reflector housing chambers 23 in the direction of travel, from front to rear. Furthermore, this results in a top view showing at least an approximately C-shaped shape for the chamber walls of the respective reflector housing chambers 23. The upper reflector housing chamber wall 15b, offset from this, and the lower reflector housing chamber wall 15c, also called the reflector housing base 15c, can, for example, run at least approximately parallel to each other. Therefore, the reflector housing chambers 23a, 23b and 23c are, for example, designed in a U- or C-shape according to the horizontal or longitudinal section according to Fig. 6, or at least approximately so. Since the individual reflector chambers 23 do not have to be positioned side by side in the same location, i.e., in the same position between the front of the lens 11 and the rear 10 of the headlight assembly, but can also be offset from each other in the longitudinal direction of a vehicle, the individual reflector housing chambers 23 are arranged offset from each other in the longitudinal direction L of the vehicle, as can be seen from the drawings. The individual reflector surfaces, which are at least predominantly concave in horizontal section according to Fig. 6, extend over a more or less straight or flat wall section 25'a to the partition wall end edge 25b facing the lens, and then a next reflector chamber follows, which is further offset in the direction L. From the aforementioned partition wall end edge 25b, the reflector wall then again generally extends at least predominantly concave in horizontal section. The headlight housing arrangement 1 is usually designed symmetrically with respect to a vertical central plane of symmetry S through a vehicle, i.e., the headlight housing 1 located on the right in the vehicle is designed symmetrically to the headlight housing 1 located on the left in the vehicle, i.e., with respect to a vertical central longitudinal plane running approximately in the middle through the vehicle, which is only schematically indicated in Fig. 6, since in reality the headlight is located further away from the central plane of symmetry S. The headlight housing 1 shown in the figures is preferably designed for a headlight arrangement located on the right side of the motor vehicle, wherein the headlight arrangement 1 intended for the left side of the motor vehicle is then designed symmetrically, as expressed. In the illustrated embodiment, the chamber arrangement adjoining the reflector housing chamber 23c is arranged vertically one above the other (and not only additionally side by side horizontally like the other reflector housing chambers 23a to 23c), with an additional reflector housing partition or partition section 25c running between the upper and lower reflector housing walls 15b, 15c. This forms two reflector housing chambers 23d and 23e, arranged one above the other relative to the other reflector housing chambers 23. The drawings (including Fig. 8a) also show that the reflector housing top 15b, in the form of the upper reflector housing wall 15'b, is spaced apart from and located below the corresponding housing top 1b of the headlight housing 1. Similarly, the reflector housing bottom 15c, in the form of the lower reflector housing wall section 15'c, is arranged above the headlight housing bottom 1c, at a distance from it. Likewise, the reflector housing side walls 15d and 15e are preferably arranged at a distance from the headlight housing side walls 1d and 1e. This results in an overall design in which the reflector housing 15 is preferably located without contact within the housing interior 7 of the headlight housing 1, i.e., it has no full-surface wall sections that are in contact with corresponding wall sections of the headlight housing 1. This serves as thermal insulation, thereby preventing or reducing as much as possible any heat flow from the engine compartment via the headlight housing 1 towards the reflector housing 15. Preferably, the reflector housing 15 is installed in the headlight housing 1 without contact, or as far as possible without contact. Only appropriate mounting and / or retaining brackets or devices 27 or bridges, etc., are provided to arrange and hold the reflector housing 15 in the interior space 7 of the headlight housing 1 as far as possible without contact (Fig. 8a). Preferably, an adjustment device 27a, not shown in detail in the drawings (Fig. 8a), is also provided. This device is preferably mounted inside the housing of the headlight housing 1, and the reflector assembly, in the form of the reflector housing 15, is then held and fixed on it. Using this adjustment device 27a, preferably an electrically actuated actuator, the entire reflector housing 15 can be adjusted to different angular positions in order to adjust the headlight alignment in different ways. The aforementioned adjustment device 27a can be designed in such a way that the reflector housing and thus the generated light rays can not only be adjusted differently in the vertical direction, but can also be pivoted, for example, from left to right and vice versa within a certain angular range, which can have advantages when cornering. To achieve all this, it is preferably provided that the fastening and holding device for the reflector housing 15 is implemented, for example, via ball joint bearings in the headlight housing 1, whereby these ball joint bearings can already be molded on, whereby the reflector housing 15 can then ultimately be held, fastened and adjusted on or in the headlight housing 1. The reflector surfaces, at least on the side facing the disk 11, are coated with a surface layer that increases the reflection effect for the light, unless the reflector housing 15 is already made of a material with a sufficiently high reflecting property. The headlight housing 1 can be made of or comprise any suitable material, for example, metal or metal alloys. The headlight housing 1 can also be made of or comprise any conceivable plastic or plastic compound, for example, thermoplastics or thermosets. For example, a headlight housing 1 can be used that is made of a thermoset plastic or, when using composite materials and / or layers, predominantly comprises thermoset plastic, i.e., more than 50%, in particular more than 60%, 70%, 80%, or 95% of the total weight of the headlight housing 1. Preferably, the reflector housing 15, including the reflector chambers and the reflector housing partitions 25 for forming the reflector housing chambers 23, is made of magnesium or a magnesium alloy or comprises at least predominantly, i.e. preferably to more than 60 wt%, in particular to more than 70, 80, 90 or 95 wt% magnesium or a magnesium alloy, for example AZ91D-NG. This results in very high dimensional stability. In the manufacturing process, this alloy can be shaped using injection molding. The material has a melting point of 600°C, with injection taking place, for example, at 590°C. In this case, the material is very viscous, with only minimal formation of voids (air bubbles). Very precise structures can be manufactured. The inside of such a reflector, i.e., the side onto which the light strikes and is reflected, is preferably coated with aluminum. Due to the oxide structure, this results in a very good reflective effect, even superior to that of chromium. A protective layer is then applied to this aluminum oxide layer. This magnesium alloy has a very high thermal conductivity of approximately 100 watts per square meter (please verify units). In principle, the reflector could also be made from another material, e.g.,made from a plastic that is coated accordingly. The use of magnesium or a magnesium alloy for the reflector housing offers the advantage that the housing can be manufactured using a magnesium injection molding process. The tooling required for this process is more durable than that used for conventional aluminum die casting. For example, the tooling for magnesium injection molding is four to five times more durable than that used for aluminum die casting. Furthermore, a magnesium alloy exhibits isotropic behavior. This means that the magnesium or magnesium alloy has the same thermal conductivity in all directions. In contrast, plastics exhibit anisotropic behavior. When injected, the molten plastic cools from the bottom up, whereas in a die-casting process, cooling occurs from the outside in, which can lead to the formation of voids in such processes. However, manufacturing a reflector housing from magnesium or a magnesium alloy is comparatively inexpensive, and the housing can be produced with an accuracy of up to 0.4 mm using injection molding. To create the aforementioned high reflective layer for the reflector housing and reflector chambers, a layer of lacquer is preferably first applied to the material of the reflector housing and reflector chambers, which is preferably made of magnesium or a magnesium alloy. An aluminum layer is then applied to this lacquer to create the reflective layer. The aluminum itself can then be covered with a protective coating. Furthermore, the rear surface, i.e. the back or rear side of the reflector or reflector housing, can be provided with insulation or an insulating layer, as can be seen in particular from the schematic cross-sectional representation according to Fig. 8a ff. discussed below. The following section discusses the electrical and electronic aspects of the headlight assembly. In some of the drawings mentioned (Fig. 8a) corresponding light sources 29 are shown, wherein LEDs 29' are preferably used for the light sources 29. The light sources 29 or the LEDs 29' are installed in the interior of the reflector housing 21 in the reflector housing 15, preferably in the individual reflector housing chambers 23a to 23e. At least one light source in the form of an LED is housed in the reflector housing 15, even in the simplest embodiment. Preferably, however, several reflector housing chambers 23 are provided, so that each chamber 23 can house at least one light source, preferably in the form of an LED, or at least partially two or more LEDs. The individual light sources 29 / LEDs 29' are preferably positioned and mounted in the upper area of ​​the reflector housing rear wall 15a or in the respective reflector housing chamber 23, optionally also at the transition to the reflector housing top 15b, preferably in the form of the reflector housing chamber top 15'b, so that at the usual mounting height of such headlight arrangements in motor vehicles, the actual light sources / LEDs cannot be directly seen from the outside. In principle, however, the light sources / LEDs could also be located at any other point in the individual reflector housing chambers 23 if this allows the desired light emission to be produced, whereby the lens itself can also be provided with lens structures to ensure that the light emitted by the light sources can exit in the desired direction with the desired width and height distribution, i.e., with the desired intensity distribution. For example, in the schematic cross-sectional views in Figs. 7 and 8a, light sources 29, for example in the form of LEDs 29', are shown, arranged once on the front of the rear reflector housing wall 15a and once on the underside of the upper reflector housing wall 15b. Thus, as mentioned above, two such light sources 29 can be provided in a reflector chamber, or one or more light sources can be arranged only on the rear reflector wall or only on the underside of the reflector ceiling. The individual LEDs 29' can also be mounted on printed circuit boards 31 (Fig. 8a). The printed circuit boards 31 themselves can preferably be provided with an aluminum layer and with a layer that is also as thermally conductive as possible, namely on the side of the printed circuit board 31 that accommodates the light sources 29 and in particular the LEDs 29' or the respective LED 29'. A thermal interface material (TIM) can also be arranged between this printed circuit board 31 with the at least one LED mounted on it and the actual support arrangement of the printed circuit board, preferably in the form of part of the reflector housing 15. This TIM can be, for example, a thermal paste or a corresponding adhesive. This thermal paste or the aforementioned highly conductive adhesive can be provided on the back side of the printed circuit board 31 in addition to, or instead of, the aluminum plate or aluminum layer.It is particularly advantageous to place the individual circuit boards 31 on the underside of the reflector housing top 15b, on which the light source, preferably in the form of an LED 29', is then mounted. This LED is then not directly visible from the outside, with the light from the LED shining onto the rear reflective wall in the respective reflector chamber and being deflected from there towards the disc 11. It is noted, however, that it would also be possible in principle for the light source 29 / LED 29' to be arranged directly on the support section of the reflector assembly, i.e., a part of the corresponding reflector housing 15 or the reflector housing chamber 23. In addition to the aforementioned LED 29', one of the aforementioned circuit boards 31 can also be arranged at the corresponding location, specifically next to the LED, with the corresponding connections of the LED being connected to the connections on the circuit board 31, for example, via a bonding process. This also allows for optimal heat transfer. The electronics and / or control electronics and / or electronics for the power supply of the light sources 29 or the LEDs 29' need not be located in the respective reflector housing chamber 23 with the LED mounted on or positioned next to it, but can also be arranged above the reflector housing top 15b or below the reflector housing bottom 15c, i.e., above the reflector housing wall section 15'b and below the reflector housing wall section 15'c. The latter variant is shown, for example, in the drawings according to Fig. 2a and Fig. 2b, where the electronics 32 with the corresponding circuit board are housed in the space 33b between the reflector housing bottom 15c and the headlight housing bottom 1c.The aforementioned electronics 32, usually with an associated circuit board, located below the lower reflector housing base 15c, can also be used, for example, to operate one or more light sources. This can also be a driver circuit for the LED array, which may be provided multiple times below the reflector base for the individual LEDs. The drawings also show that, adjacent to the outer surface facing the vehicle, an additional wall section 25d is provided on the outermost reflector housing chamber 23a, which may, for example, be in the form of a circuit board. Here, for example, an outward-facing light source 29, preferably also in the form of an LED 29', may be provided, which may serve, for example, as a turn signal and be controlled accordingly. This outermost wall section 25d is also housed within the headlight housing 1. The corresponding wall section, preferably in the form of a circuit board, may also be held by the reflector housing 15. Reference is made below again to Fig. 8a, which shows a schematic vertical cross-sectional view through the headlight housing arrangement 1 according to the invention with the reflector housing 15 arranged inside the headlight housing 1, in order to illustrate the cooling mechanism. From this schematic cross-sectional view, which runs more or less in the direction of light emission from the LEDs and thus from the rear side 10 to the front side 9 of the headlight housing 1, it can be seen that the entire reflector housing 15 is arranged within the housing interior 7 of the headlight housing 1 with as much spacing as possible on all sides and without contact, with the exception of specific retaining or fixing elements, for example, in the form of the aforementioned adjustment device 27, 27a. As already mentioned, the reflector housing 15 can be adjusted to different angular positions, primarily from top to bottom, using such an adjustment device in order to direct the beam angle more or less strongly onto the road. This adjustment device is also designed and implemented in such a way as to minimize heat flow from the bottom of the headlight housing 1 towards the reflector housing 15. The cross-sectional view according to Fig. 8a also shows that the reflector housing base 15c extends to just before the inner surface of the disc 11, resulting in only a small gap 33c between the front edge of the reflector housing base 15c and the inner surface of the translucent disc 11. This reflector housing base 15c can even project beyond the rear reflector housing wall 15a in the rear direction, at least from a point or edge 37 where the reflector housing wall 15a transitions into the reflector housing base 15c. This thus forms a rearwardly projecting reflector housing base section 115c. The same applies to the reflector housing cover 15b, which also projects beyond the reflector housing rear wall 15a towards the headlight housing rear wall 1a, at least at a point or edge 37b where the reflector housing rear wall 15a transitions into the reflector housing top 15b. This forms a rearwardly projecting reflector housing top section 115b. The rear end of the projecting reflector housing top section 115b also terminates at a distance in front of the headlight housing rear wall 1a, thus creating a gap 33d to prevent direct thermal bridges between the headlight housing and the reflector housing. Finally, it should be mentioned that the reflector housing top 15b, with its projecting edge, also terminates at a distance from the front lens 11, thus creating a gap 33e between the reflector housing top 15b and the front lens 11. The lower, rearwardly projecting section 115c of the reflector housing bottom also terminates in front of the headlight housing wall 1a, creating a further gap 33f. As mentioned, the schematic vertical cross-sectional view according to Fig. 8a also shows that, for example, additional light sources 29 can be located in a respective reflector housing chamber 23 or, alternatively to the light source 29 located above, also on the rear reflector housing wall 15a. In operation, the light sources 29, preferably in the form of LEDs 29', and optionally the reflector back wall 15a illuminated by them, generate a corresponding heat, which heats the air located in the interior of the reflector housing 21. The correspondingly heated air rises upwards towards the reflector housing ceiling 15b and is moved further towards the disc by the air heated by the LEDs, as shown in Fig. 8b according to the flow lines 39 inside the reflector housing interior 21. When the heated air reaches the front pane 11, which is cooled to ambient temperature from the outside, the heated air cools down on the inside of the pane 11 and then sinks downwards due to its greater weight, before flowing again towards the rear wall 15e of the reflector housing next to the bottom 15c of the reflector housing. In other words, in the solution according to the invention, the front-facing light-flooded disc 11 represents a heat sink 111, whereas the inner areas of the reflector housing, especially in the area of ​​the light sources 29, i.e., especially also in the area of ​​the rear reflector housing wall 15a and / or adjacent thereto on the underside of the upper reflector housing ceiling 15b, define a heat source, so that the circulation described above is generated between the heat source 211 and the heat sink 111 according to the flow lines 45 in Fig. 8b. Therefore, a cooling effect is created by a circulation 43 of the air in the interior of the reflector housing 21, which is so strong that the cooling of the air caused by the disc 11 is ultimately sufficient to cool the entire headlight assembly, preferably in the form of the LEDs, and thus to cool the entire headlight housing 1. The circulation of air according to the invention, generating the desired cooling effect, can only be achieved if, in addition to the predominantly vertically oriented front window 11 (whose vertical extent is greater than its horizontal extent even when inclined), the rear reflector housing wall 15a, 15'a opposite this front window is also made of or comprises a material that is thermally conductive to very thermally conductive. If the reflector housing, and in particular the reflector housing back wall 15a, is made of a plastic, then this plastic-made or plastic-encompassing reflector housing back wall should have a thermal conductivity of at least 10, 11, 12, 13, 14, or 15 W / mK. This is significantly higher than the thermal conductivity of conventional plastics, which is, for example, between 0.2 and 0.5 W / mK. Within the scope of the invention, particularly thermally conductive plastics could also be used, which, for example, have a thermal conductivity of 15 to 20 W / mK. The cooling effect is enhanced by the higher the thermal conductivity. Therefore, preferably at least one reflector rear wall, i.e., the reflector housing rear wall 15a, 15'a, and an optionally provided reflector housing top 15b, 15'b, which is generally connected to the reflector housing rear wall, are used. These reflector housing tops are made of metal or comprise metal to a sufficient extent. In the invention, magnesium is most preferably used for the reflector housing rear wall and optionally for the additionally provided reflector housing top. When using magnesium, thermal conductivities of over 50 W / mK, in particular over 55, 60, 65, or even 70 W / mK, can be achieved. With other materials, this value can be even higher, for example, over 75, 80, 85, 90, 95, or 100 W / mK. The thermal conductivity of aluminum, for example, is between 100 and 120 W / mK.By using such a material on the rear wall of the reflector housing space 21, strong heating is achieved by the light sources 29, 29', which causes strong heating to occur on this rear wall, which has a sufficient vertical component (with a slope of at least 30°, in particular at least 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85° or even 90° relative to the horizontal), causing the heated air to rise in the area of ​​the reflector housing rear wall 15a and then flow along the underside of the ceiling towards the lamp glass 11, where it is cooled by the heat sink formed there and sinks. In other words, the reflector housing rear wall, which is usually horizontally spaced and equipped with a vertical component, and the glass pane primarily act as the "engines," forming both a heat source and a heat sink, thereby generating the air circulation within the reflector housing chamber 21. This eliminates the need for additional cooling measures. Due to the design according to the invention, it is ensured that the heat generated by the light sources can be optimally dissipated. According to the invention, cooling is achieved solely by the front lens 11, i.e., the headlight lens. The engine compartment with the engine is typically located in the rear area of ​​the headlight housing, which can cause the housing 1 to heat up additionally. The rear part of the headlight housing 1, facing the engine compartment, can reach temperatures of up to 100°C. In contrast, the part in the area of ​​the front lens only reaches temperatures of, for example, 50°C.This temperature difference can therefore be used for cooling according to the invention. The inventive design of the headlight housing with the reflector housing placed therein generates the described circulating airflow, which transports the heat from the heat source (LEDs) towards the front lens 11 for cooling. The air circulation generated by the design thus achieves the desired cooling of the lighting assembly, including the electrical / electronic components, without the need for additional active cooling components such as electrically driven fans. Furthermore, no additional heat sinks are required, which are often arranged between the reflector assembly and the preferably rear housing wall of the headlight assembly to dissipate heat.In contrast, in the solution according to the invention, a space is formed between the reflector housing rear wall and the headlight housing rear wall, in which no further components are usually housed. The cross-sectional figure 8a, 8b (vertical section through the headlight arrangement) shows a representation as it is drawn along line VIII-VIII in Fig. 6. In contrast to the cross-sectional views described in Figs. 8a and 8b, reference is also made to Figs. 9a, 9b, and 9c, which likewise show schematic vertical cross-sectional views through the headlight housing arrangement according to the invention with an internal reflector housing 15. However, these figures differ from one another in the dimensions, design, and guidance of the individual walls and wall sections. The view in Fig. 9a corresponds to the section along line IXa-IXa in Fig. 6, the view in Fig. 9b corresponds to the section along line IXb-IXb in Fig. 6, and the vertical cross-sectional view in Fig. 9c corresponds to section IXc-IXc in Fig. 6. This is only intended to illustrate that a wide variety of housing shapes for the headlight housing 1 and / or the reflector housing 15 can not only be used, but that the corresponding headlight arrangement can have a different geometry for each of the individual headlight chambers. Fig. 9c shows a variant with two superimposed reflector housing chambers 23d and 23e, which are separated from each other by a partition section 25c that runs more or less horizontally or with a horizontal component. The described embodiments show a variant in which a one-piece reflector housing is used, preferably forming several reflector housing chambers, which can preferably be manufactured as a single and / or integral piece, at least in its basic function. It is subsequently installed in the housing interior 7 of the headlight housing 1 and thus represents a separate component. However, it is also possible that not just one, but several reflector housings, in particular separate reflector housings, are provided, each comprising at least one, two, or more reflector housing chambers 23. In the extreme case, it would even be possible to provide several reflector housings, each with one reflector housing chamber. These would then have to be mounted separately in the housing interior 7 of the headlight housing 1. All these separate reflector housings 15 or reflector housing chambers 23 could be arranged on a common support or on separate supports, which can also be adjusted individually and independently of each other. There are no technical limitations in this respect. By such measures, individual light sources 29 / LEDs 29' with their associated reflector housing chamber 23 could thus be individually aligned.

Claims

Headlight assembly for vehicles, in particular motor vehicles, with the following features: - a headlight housing (1) comprising a rear housing wall (1a), a top housing cover (1b), a bottom housing base (1c), and side housing walls (1d, 1e) offset from one another; - with a front-facing disc (11) transparent to light rays; - the headlight housing (1) closed by the disc (11) comprises an interior housing space (7); - a reflector assembly (13) with at least one light source (29) in the form of an LED (29') is provided in the interior housing space (7); - with a cooling device for dissipating the heat generated in the headlight housing (1) during operation of the at least one light source (29); - the cooling device comprises a heat sink (111) defined by the disc (11).- the reflector arrangement (13) comprises a reflector housing (15) with a reflector housing rear wall (15a) and a reflector housing top (15b), whereby a reflector housing opening or an open reflector housing area is formed in the reflector housing (15) opposite the reflector housing rear wall (15a), - the reflector housing (15) is positioned and installed in the headlight housing (1) such that the reflector housing opening or the reflector housing area points towards the lens (11) of the headlight housing (1) and is adjacent to it, - the reflector housing (15) has at least one reflector housing chamber (23) in the interior (21) of the reflector housing, the inner wall surfaces of which are at least partially covered with a reflective material layer or have a reflective material layer,- wherein in the at least one reflector housing chamber (23) the at least one light source (29) is mounted on the reflector housing (15) and / or a circuit board on which the at least one light source (29) is mounted on the reflector housing (15),- the reflector housing (15) is installed in the headlight housing (1) such that the reflector housing (15) is spaced apart from the headlight housing (1) and is held and mounted relative to the headlight housing (1) by means of a holding and supporting device,- the reflector housing (15) or at least the reflector housing rear wall (15a) is made of a material having a thermal conductivity of at least 10 W / mK, and- the reflector housing rear wall (15a) is arranged at a distance opposite the disc (11) such thatthat during the operation of the at least one light source (29) and the resulting heating of the reflector housing rear wall (15a), a heat source is formed by the heated reflector housing rear wall (15a) and a heat sink (111) is formed by the disc (11), and the reflector housing rear wall (15a) and the disc (11) are arranged and / or equipped such that the heat source (211) and the heat sink (111) thereby formed generate an air circulation (43) in the reflector interior (21), in which the air heated by the at least one light source (29) rises within the at least one reflector housing chamber (23) adjacent to the reflector housing rear wall (15a), is cooled towards the disc (11) and thereby sinks, in order to then flow back towards the reflector housing rear wall (15a) and there be heated by the heat generated by the at least one light source (29). to rise again. Headlight arrangement according to claim 1, characterized in that the reflector housing (15) is held, mounted and / or supported in the headlight housing (1) only by means of mounting and / or retaining ribs or devices (27). Headlight arrangement according to claim 2, characterized in that the mounting and / or holding device (27) comprises a control device by means of which the reflector housing (15) in the headlight housing (1) is adjustable in the vertical direction or with a vertical component and / or in the horizontal direction or with a horizontal component at least in a certain angular range. Headlight arrangement according to one of claims 1 to 3, characterized in that the reflector housing (15) is formed in one piece and preferably comprises several reflector housing chambers (23) in each of which at least one of the at least one light source (29) is housed. Headlight arrangement according to one of claims 1 to 3, characterized in that the reflector housing (15) is formed in multiple parts and the multiple reflector housing parts each comprise at least one reflector housing chamber (23) in which at least one of the at least one light source (29) is positioned. Headlight arrangement according to one of claims 1 to 5, characterized in that the reflector housing (15) comprises a reflector housing base (15c). Headlight arrangement according to one of claims 1 to 6, characterized in that the reflector housing (15) is made of plastic, thermoplastics or thermosets or metal or comprises one of these materials, preferably made of magnesium or comprising magnesium. Headlight arrangement according to one of claims 1 to 7, characterized in that the reflector housing (15) or at least the reflector housing rear wall (15a) has a thermal conductivity of at least 12.5, 15, 17.5 or at least 20 W / mK and is preferably made of or comprises plastic. Headlight arrangement according to claim 7, characterized in that the reflector housing (15) or at least the reflector housing rear wall (15a) has a thermal conductivity of at least 30 W / mK, in particular at least 40, 50, 60, 70, 80, 90 or at least 100 W / mK, and is preferably made of metal or comprises metal, in particular magnesium or is made of magnesium. Headlight arrangement according to claim 7, characterized in that the reflector housing (15) or at least the reflector housing rear wall (15a) has or comprises a metal or a metallic alloy whose thermal conductivity is at least 100 W / mK, preferably 105, 110, 115 or 120 W / mK, and is preferably made of or comprises aluminium. Headlight arrangement according to one of claims 7 or 10, characterized in that the reflector housing (15) is manufactured as a magnesium injection molded part. Headlight arrangement according to one of the preceding claims, characterized in that for the operation of the at least one light source (29) circuit boards (31) optionally with driver circuits are assigned which are positioned on the top of the underside of the reflector housing top (15b) or on the back or front of the reflector housing rear wall (15a) or on the underside of the reflector housing bottom (15c). Headlight arrangement according to one of the preceding claims, characterized in that the at least one light source (29) is arranged adjacent to a circuit board (31) and is preferably connected to it via bond wires, or that the LED or LEDs (29') are located on a circuit board (31) associated with them.

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