Lighting device for a motor vehicle

Abstract

Lighting device (10) for a motor vehicle (11) comprising a first housing (12), a second housing (14), an elongated light source (16) and an elongated light guide (18) with optical fibers (20), wherein each housing (14) can be attached to the motor vehicle (11), wherein the light guide (18) has a section (26) encased by the light source (16), wherein the light source (16) is spaced apart from each housing (12, 14), wherein a first end section (22) of the optical fiber (18) extends from the sheathed section (26) to the first housing (12), wherein a second end section (24) of the optical fiber (18) extends from the sheathed section (26) into the second housing (14), wherein at least one light-emitting diode (32) and at least one coupling device (31) are arranged in each housing (14), wherein each coupling device (31) is provided for coupling the light (33) emitted by one of the light-emitting diodes (32) into the light guide (18), wherein the lighting device (10) has a first bellows (34) which is connected to the first housing (12) and the light source (16) and which defines a first internal volume (36) in which a partial section (28) of the first end section (22) is arranged, wherein the lighting device has a second bellows (38) which is connected to the second housing (14) and the light source (16) and defines a second internal volume (40) in which a partial section (30) of the second end section (24) is arranged, wherein the light source (16) lengthens when the light source (16) is heated and shortens when the light source (16) is cooled, so that when the first housing (12) and the second housing (14) are attached to the motor vehicle (11) each bellows (34, 38) is compressed when the light source (16) is heated and pulled apart when the light source (16) is cooled.

Description

Background of the invention

[0001] The present invention relates to a lighting device for a motor vehicle comprising a first housing, a second housing, an elongated light source and an elongated light guide with optical fibers.

[0002] Lighting devices of the type described above are increasingly used, particularly in passenger cars. These devices are designed to alter the visual appearance of the vehicle by means of the light source illuminated via the light guide. Therefore, these lighting devices are a popular means for many customers to visually enhance their vehicles.

[0003] The usually flexible light source is typically attached to the vehicle's radiator grille, following its contours. The two housings are usually mounted on parts of the vehicle or its body that are not visible from the outside. The light, usually white, is coupled into the light guide by at least one LED in each housing. This light guide is designed to direct the coupled light along the entire length of the light source—which acts as a casing around the light guide—to illuminate the entire length of the light source.

[0004] A technical challenge with these known lighting devices is the shortening or lengthening of the light source due to temperature changes or changes in the ambient temperature, compared to the length of the optical fibers of the light guide, which are very resistant to temperature changes and have a much smaller coefficient of thermal expansion.

[0005] This pronounced difference in expansion behavior results in the optical fiber becoming wavy, at least in sections, especially at ambient temperatures below 0 degrees Celsius. This occurs because the optical fibers are compressed as the luminaire housing shrinks or shortens in length due to the temperature drop. To avoid this wavy formation of the optical fibers, which is particularly detrimental to the lighting properties of the device, the luminaire housing, usually manufactured as an extruded body, is hot-stitched to the optical fiber after the fiber is threaded into its internal volume. This process shrinks the luminaire housing onto the optical fiber.This effectively suppresses, but does not prevent, the detrimental wave formation of the optical fibers in the section of the light guide encased by the light source, as it forms in another section of the light guide. Therefore, despite the suppression in the encased area, it is necessary to capture the wave formation, which would otherwise negatively affect the stability and functionality of the light guide and consequently the stability of the lighting device.

[0006] To prevent the wave formation described above from adversely affecting the lighting properties of the lamp during cooling, a known lamp incorporates two so-called compensation adapters made of a flexible yet very rigid plastic material. Each compensation adapter is positioned between one of the two housings and the lamp, with a section of the optical fiber being accommodated with some play within each adapter. The adverse wave formation of the optical fibers described above can develop unhindered within the designated play of each compensation adapter and be absorbed there. Alternatively, after being suppressed in the encased section, the wave formation can develop and be absorbed within the respective play of the compensation adapter.The function of known compensation adapters is therefore to counteract the described adverse wave formation in the optical fibers of the light guide. Furthermore, these adapters are also designed to accommodate the elongation of the light source caused by heating (e.g., due to intense sunlight). For this purpose, the adapters are usually pre-bent at room temperature and thus accommodate the change in length caused by the heating of the light source.

[0007] Although the compensation adapters described above can counteract the detrimental wave formation, significant mechanical stresses build up in the lighting device, particularly due to changes in the length of the light source, especially at large temperature differences. These stresses can negatively affect the device's functionality after a certain period of use. Particularly in very cold ambient temperatures, the resulting contraction of the light source and the compensation adapters can lead to leaks, resulting in the ingress of water, especially rainwater. Therefore, the connection between each housing and the compensation adapter must be sealed watertight.However, this seal often loses its effectiveness, especially during large temperature fluctuations, and rainwater can penetrate the housing in which the respective LED is located together with the electronics, resulting in a total failure of the lighting device. Underlying task

[0008] The present invention therefore aims to provide a lighting device of the above type which has a significantly higher reliability compared to known solutions. Inventive solution

[0009] This problem is solved according to the invention with a lighting device for a motor vehicle having the features of claim 1.

[0010] The lighting device according to the invention for a motor vehicle comprises a first housing, a second housing, an elongated light source and an elongated light guide with optical fibers.

[0011] Each housing can be attached to the motor vehicle.

[0012] The light guide has a section encased by the light source, and the light source is spaced away from each housing.

[0013] A first end section of the optical fiber extends from the sheathed section into the first housing. A second end section of the optical fiber extends from the sheathed section into the second housing.

[0014] Each housing contains at least one light-emitting diode (LED) and at least one coupling device, with each coupling device designed to couple the light emitted by one of the LEDs into the optical fiber. Thus, the coupling device in the first housing is designed to couple the light emitted by the LED in the first housing into the first end section of the optical fiber. And the coupling device in the second housing is designed to couple the light emitted by the LED in the second housing into the second end section of the optical fiber. In this way, light is coupled in at both ends of the optical fiber, resulting in very uniform illumination of the light source along its entire length.

[0015] The lighting device according to the invention is characterized in particular by the fact that it has a first bellows and a second bellows.

[0016] The first bellows is connected to the first housing and the light source. The first bellows encloses a first inner volume in which a section of the first end section is located.

[0017] The second bellows is connected to the second housing and the light source. The second bellows encloses a second inner volume in which a section of the second end section is located.

[0018] The light source expands when heated and contracts when cooled (i.e., the length of the light source increases when heated and decreases when cooled), so that, with the first and second housings attached to the vehicle, each bellows is compressed when the light source heats up and expanded when it cools down. Thus, each bellows is pulled apart by the light source as it cools and compressed by it as it heats up.

[0019] It is understood that this change in shape of the bellows, i.e. the compression and expansion during heating and cooling, should not necessarily be understood as a complete compression of the respective bellows or as a complete expansion of the bellows.In the manufacture of the lighting device according to the invention, the bellows are preferably connected to the light source and the respective housing in an unloaded state at a temperature of the light source within a range of 20 degrees to 30 degrees - i.e. at typical room temperature - and preferably have a design in which - starting from the unloaded state - within a predetermined temperature range of the light source temperature or the ambient temperature (which can in particular extend from -40 degrees Celsius to 90 degrees Celsius) they are neither completely pulled apart nor completely compressed by the light source.Or in other words: Within the specified temperature range, decompression to the decompression limit (i.e., the maximum possible decompression) of the bellows and compression to the compression limit (i.e., the maximum possible compression) of the bellows are particularly preferred. Compression or decompression of the bellows to these limits is thus advantageously avoided, resulting in a significant increase in the reliability of the bellows according to the invention.

[0020] As explained above, in a particularly preferred embodiment of the lighting device according to the invention, the first and second bellows are in an unloaded state when the lamp temperature is within a room temperature range of 20°C to 30°C. This can be achieved by connecting the bellows to the lamp and the respective housing in an unloaded state during the manufacture of the lighting device, either at the lamp temperature or at an ambient temperature within this room temperature range. It is understood that the unloaded state of the bellows is the state in which no compression or decompression force acts upon it.

[0021] Particularly preferably in the above particularly preferred embodiment, the first bellows and the second bellows have a design in which each bellows can be pulled apart from the unloaded state by a measure which corresponds to at least 50% of the reduction in length of the light source when the temperature of the light source is reduced from a temperature within the room temperature range to a temperature of -40 degrees Celsius.

[0022] Furthermore, in the above particularly preferred embodiment, the first bellows and the second bellows can have a design in which each bellows can be compressed from the unloaded state by an amount that corresponds to at least 50% of the increase in length or length enlargement of the light source when the temperature of the light source is increased from a temperature within the room temperature range to a temperature of 90 degrees Celsius.

[0023] It is understood that the two preferred configurations mentioned above can be present in combination in each bellows. These configurations of the bellows—which quantify the compressibility and decompression capacity of the bellows—make them suitable for use within an expected temperature range extending from room temperature up to 90 degrees Celsius and / or from room temperature down to minus 40 degrees Celsius. This design ensures a very high level of reliability for the lighting device according to the invention.

[0024] It is further understood that the above measurement is the difference in distance traveled along an axis of symmetry or center line penetrating the internal volume of the bellows when the bellows is compressed or extended.

[0025] The first bellows is connected to the first housing and the light source and encloses the first internal volume in which the partial section of the first end section is arranged. The second bellows is connected to the second housing and the light source and encloses the second internal volume in which the partial section of the first end section is arranged. It is understood that each bellows is connected to the respective housing by a first end section and to the light source by a second end section. The connection of each bellows to the respective housing and the light source can be a conventional connection known to those skilled in the art, wherein the first end section of each bellows is particularly preferably shrunk onto an end section of the respective housing and the second end section of each bellows is particularly preferably shrunk onto an end section of the light source.Alternatively, the first end section can also be injection-molded onto the respective housing, and the second end section can also alternatively be injection-molded onto the light source.

[0026] In a particularly practical embodiment of the lighting device according to the invention, an end section of the first bellows (or the second end section of the first bellows – see above) is shrunk onto an end section of the light source, and an end section of the second bellows (or the second end section of the second bellows – see above) is shrunk onto an end section of the light source. Alternatively, instead of shrinking, clipping can also be used, although this does not preclude other connection concepts. In this practical embodiment, each bellows is preferably made of polyamide, especially if the light source, which is designed as a casing, is preferably made of translucent polyamide. This material pairing advantageously creates a very stable shrink connection. However, other plastics can also be used as an alternative to polyamide.

[0027] By incorporating the two bellows, the adverse mechanical stresses known from the prior art on fixed and interconnected components, such as the housing and the known, flexible yet very rigid compensation adapter, resulting from shortening or lengthening of the light source while maintaining a nearly constant length of the optical fiber or optical fibers, can be effectively avoided. These adverse mechanical stresses in known solutions, caused by the heating / cooling of the light source, can lead to leaks and / or functional impairments.

[0028] Particularly advantageous is the lengthening or shortening of the light body due to heating or cooling being converted into a change in shape of the two bellows and not, as with known solutions, into adverse pressing or tensile forces that can lead to leaks between interconnected solid components (or components made of solid material), such as the housing and a flexible yet very rigid known compensation adapter, and / or adversely affect the functionality.

[0029] A further advantage of providing the bellows according to the invention is that they can advantageously reduce the installation space required on the respective motor vehicle considerably, since they can be designed to be significantly more space-saving than the known compensation adapters, which also have to be elaborately pre-bent in order to accommodate an extension of the light source due to heating or a required extension due to manufacturing tolerances of the usually purchased light guide.

[0030] Overall, the lighting device according to the invention therefore exhibits a significantly higher reliability compared to known solutions.

[0031] The optical fiber according to the invention can have a structure known to those skilled in the art and is designed to radiate the light coupled into the optical fibers of the optical fiber into the light source to illuminate it. This radiation occurs along the entire length of the light source, or substantially along the entire length of the light source (which is designed as a sheath around the optical fiber), in order to illuminate it along its entire length, or to illuminate it completely. In a typical known design, the optical fiber has a plurality of optical fibers arranged in the form of a fiber bundle, wherein the fiber bundle is encased by a polyolefin sheath into which defects are introduced for coupling the light transmitted by the optical fibers into the light source. The defects can, in particular, be in the form of cavities.Any lengthening or shortening of the polyolefin sheathing caused by heating or cooling of the light source can be accommodated, for example, by a receptacle provided in each housing that allows movement of the polyolefin sheathing within the housings, in order to avoid any complications that may arise as a result.

[0032] The luminaire according to the invention is designed in the form of a sheath that encloses a section of the light guide. The luminaire preferably consists of a translucent polyamide. As with known solutions, the luminaire according to the invention is also preferably designed as an extrudate or as an extruded body, which, after the light guide has been threaded into the inner volume of the luminaire, is connected to the light guide by hot crimping, thereby shrinking the luminaire onto the light guide. This very effectively suppresses the known adverse wave formation of the optical fibers in the area of ​​the light guide section encased by the luminaire.This wave formation can advantageously propagate both into the first end section of the optical fiber and into the second end section, developing unhindered within the first and second inner volumes enclosed by the first and second bellows. The wave formation is thus advantageously contained within the two inner volumes, where it has no adverse effect on the stability and functionality of the optical fiber.

[0033] It is understood that the compression of each bellows when the light source is heated, as well as the expansion of each bellows when the light source is cooled, is only possible if the two housings are attached to the motor vehicle, i.e., only if the two housings are attached to the motor vehicle.

[0034] Each housing can be attached to the motor vehicle using means familiar to a person skilled in the art. For example, each housing can be attached to the motor vehicle or its body by means of a screw connection or a snap-fit ​​connection. Each housing can have a design familiar to a person skilled in the art; in particular, each housing can have a design typical for lighting devices of this type. In particular, each housing can be made at least partially of a plastic material.

[0035] Each of the light-emitting diodes (LEDs) can be a standard LED capable of producing white light. However, each LED can also be capable of producing red, blue, green, or yellow light.

[0036] It is understood that a heating of the light source can be caused, for example, by an increase in the ambient temperature (e.g., due to increased solar radiation). It is also understood that a cooling of the light source can be caused, for example, by a decrease in the ambient temperature (e.g., due to a change in the weather).

[0037] In each housing of the lighting device according to the invention, at least one light-emitting diode (LED) and at least one coupling element are arranged and preferably attached therein, each coupling element being designed to couple the light emitted by one of the LEDs into the light guide. The first end section of the light guide extends from the section encased with the light source to the first housing. The second end section of the light guide extends from the section encased with the light source to the second housing. The housing, the coupling element, and the LED may be devices or arrangements known to those skilled in the art. The first end section and the second end section are particularly preferably attached to the housing itself or to another structure or device, such as, for example, a housing.a circuit board, attached in the respective housing to enable a stable construction.

[0038] Coupling devices for coupling light into an optical fiber, which couple the light into the optical fibers of the optical fiber, are known to those skilled in the art and are used in particular for lighting devices according to the invention. In particular, the respective coupling device of the lighting device according to the invention can therefore also have a design known to those skilled in the art. In particular, the coupling device can have a so-called ferrule known to those skilled in the art. It is understood that conventional optical fibers, and also the optical fiber provided according to the invention, can have a conventional known design at each of its two ends, such as, in particular, a material-bonded connection of the end sections of the optical fiber bundle in a suitable transmission material, which is necessary, depending on the design of the coupling device, to achieve the coupling into the optical fibers.

[0039] It is understood that any bellows can be a typical bellows, which can be made from a typical known bellows material.

[0040] The luminaire according to the invention can have a length of approximately 1000 millimeters in its straight state. Typically, the luminaire can have a length between 800 and 3000 millimeters, for example, and in particular between 800 and 1200 millimeters. The light guide is correspondingly longer to provide the first and second end sections.

[0041] It goes without saying that the light guide and the light source can be curved rather than necessarily straight, in order to meet specific requirements.

[0042] The invention also relates to a motor vehicle with a lighting device according to the invention for a motor vehicle, wherein the first housing and the second housing are attached to the motor vehicle. Brief description of the characters

[0043] A lighting device for a motor vehicle known from the prior art and an embodiment of the invention are explained in more detail below with reference to the accompanying figures. The figures show: Fig. 1 a schematic, partially cutaway representation of a lighting device for a motor vehicle of the prior art, Fig. 2 a schematic partially cutaway representation of an embodiment of a lighting device according to the invention for a motor vehicle, Fig. 3A, Fig. 3B, Fig. 3C each one lighting device according to Fig. 2 with different light source lengths, Fig. 4. A very schematic representation to illustrate the functioning of an optical fiber, Fig. 5 a very schematic cross-sectional view through a light guide and through a light source that is designed as a sheath around the light guide, and Fig. 6 a schematic sketch to illustrate the position of a light source according to the invention on the radiator grille of a motor vehicle.

[0044] The lighting device 100, known from the prior art, comprises a light guide 114 encased by a light source 116, two housings 112, and two compensation adapters 118 made of a flexible yet very strong plastic material. The compensation adapters 118 are connected to their respective housings 112 via a snap-fit ​​connection 120. Furthermore, the light guide 114 is sealed to each housing 112 by a gasket 122 to prevent water ingress into the housings 112, each of which contains, among other things, a light-emitting diode 124 and a light coupling device 126.

[0045] To accommodate the adverse fiber optic wave formation 128, each compensation adapter 118 has a clearance 130. It is immediately apparent that, particularly in the case of significant shortening of the light source 116 due to strong cooling, while the length of the light guide 114 remains almost constant, leaks can occur, especially in the vicinity of the seal 122, when the housings 112 are attached to the motor vehicle.

[0046] The in Fig. Figure 2, a very schematically illustrated lighting device 10 according to the invention for a motor vehicle, comprises a first housing 12, a second housing 14, an elongated light source 16 and an elongated light guide 18 with optical fibers (in Fig. (1 not illustrated) on.

[0047] Each housing 12 and 14 can be attached to a motor vehicle.

[0048] The luminaire 16 is designed as a casing 16 (or as a casing body or as a casing layer) and encases the section 26, which is therefore a encased section 26.

[0049] The light source 16 is spaced apart from each housing 12 and 14.

[0050] A first end section 22 of the optical fiber 18 extends from the sheathed section 26 to the first housing 12. A second end section 24 of the optical fiber 18 extends from the sheathed section 26 to the second housing 14.

[0051] Each housing 12 and 14 contains a light-emitting diode 32 and a coupling device 31, which are arranged and mounted there (not shown in detail). Each light-emitting diode 32 is mounted on a circuit board 48 with electronic components 47 (shown only very schematically) for powering and controlling the light-emitting diode 32. Each coupling device 31, shown only very schematically, is designed to couple the light 33 emitted by the respective light-emitting diode 32 into the light guide 18 (see also the very schematic sketch in Fig. 2 below the light device 10).

[0052] The lighting device 10 after Fig. 2 has a first bellows 34 which is connected to the first housing 12 and the light source 16. The bellows 34 encloses a first inner volume 36 in which a partial section 28 of the first end section 22 is arranged.

[0053] Furthermore, the lighting device 10 indicates Fig. 2 a second bellows 38, which is connected to the second housing 14 and the light source 16. The bellows 38 encloses a second inner volume 40 in which a partial section 30 of the second end section 24 is arranged.

[0054] The light source 16 extends when heated and contracts when cooled, so that, with the first housing 12 and the second housing 14 attached to the vehicle, each bellows 34 and 38 is compressed when the light source 16 heats up and extended when it cools down. This is illustrated by the Fig. 3A to 3C, which - starting from a state with a luminaire temperature of 25 degrees Celsius (cf. Fig. 3A) - the states of the bellows 34 and 38 and the light source 16 after cooling the light source 16 to a temperature below 25 degrees Celsius (cf. Fig. 3B) and after heating the luminaire 16 to a temperature above 25 degrees Celsius (see Fig. 3C) illustrate.

[0055] The Fig. Figure 3A illustrates the state of the lighting device 10 at a temperature of the light source 16 of 25 degrees Celsius, which corresponds to the prevailing room temperature. Both bellows 34 and 38 are in an unloaded state, or essentially in an unloaded state, at this temperature. This was achieved by connecting the bellows 34 and 38 to their respective housings 12 and 14, respectively, and to the light source 16 during the manufacturing of the lighting device 10 at a room temperature of 25 degrees Celsius – which corresponded to the temperature of the light source 16. In this embodiment, the light source 16 has a length of approximately 1000 millimeters at a temperature of 25 degrees Celsius. This length can increase by approximately 10 millimeters at high ambient temperatures and decrease by approximately 10 millimeters at low ambient temperatures.

[0056] The Fig. Figure 5 shows a highly schematic cross-sectional view through the optical fiber 18 and the light source 16, which is formed as a sheath around the optical fiber 18. The light source 16 consists of a translucent polymer, preferably polyamide. The optical fiber 18 comprises a plurality of optical fibers 20 arranged in the form of a fiber bundle, the fiber bundle being encased by a polyolefin sheath 52. Imperfections 50 are introduced into this sheath to couple the light transmitted by the optical fibers 20 into the light source 16. The imperfections 50, shown only symbolically, are formed in the form of small cavities that cause the light to be coupled out or escape from the optical fibers 20 (see also Figure 5). Fig. 4) and thus illuminate the light source 16 with light from the respective light-emitting diode 32.

[0057] The light source 16, formed as an extrudate or extruded body 16, was connected to the light guide 18 by hot crimping after the light guide 18 had been threaded into its inner volume. This shrinking process effectively shrinks the light source 16 onto the light guide 18. This very effectively suppresses the known adverse wave formation of the optical fibers 20 in the area of ​​the light guide section 26 encased by the light source 16. This wave formation 54 (in Fig. (Figure 3B, illustrated only very schematically) can advantageously shift both into the subsection 28 of the first end section 22 of the optical fiber 18 and into the subsection 30 of the second end section 24 of the optical fiber 18, and develop unhindered in the first inner volume 36 and the second inner volume 40, which are bounded by the first bellows 34 and the second bellows 38. The wave formation 54 is thus advantageously contained in the two inner volumes 36 and 40, where it has no adverse effect on the stability and functioning of the optical fiber 18.

[0058] In the case of the lighting device 10 (see Fig. 2) An end section 44 of the first bellows 34 is shrunk onto a first end section 42 of the light source 16, and an end section 44 of the second bellows 38 is shrunk onto a second end section 46 of the light source 16. Each bellows 34 and 38 is partially made of polyamide.

[0059] The Fig. Figure 6 shows a very schematic embodiment of a motor vehicle 11 according to the invention with a lighting device according to the invention, in which the housings are attached to the motor vehicle. Fig. Figure 6 schematically illustrates a possible attachment of a lighting device according to the invention to the motor vehicle 11 in the form of a passenger car, in which the housings are not visible from outside the car and are attached to the body, while the light source 16 is arranged on the radiator grille 56 and extends along an edge region of the radiator grille 56. It is also evident from this that the light source and the light guide themselves are not necessarily designed to be straight, as, for example, in the Fig. 2 can be seen. Of course, both the light guide and the light source can be flexible or bent. Reference symbol list 10 Lighting device 11 Motor vehicle 12 first case 14 second case 16 light sources 18 fiber optic cables 20 fiber optic cables 22 first final section 24 second final section 26 encased section 28 Subsection 30 Subsection 31 Coupling device 32 LEDs 33 light 34 first bellows 36 first internal volume 38 second bellows 40 second internal volume 42 End section light source 44 End section bellows 46 End section luminaire 47 electronic components 48 circuit boards 50 fault location 52 Polyolefin coating 54 Wave formation in optical fibers 56 Radiator grille 100 lighting devices 112 cases 114 fiber optic cables 116 light sources 118 compensation adapters 120 Snap connection 122 Seal 124 light-emitting diodes 126 Coupling device 128 Wave formation in optical fibers 130 game

Claims

[1] Lighting device (10) for a motor vehicle (11) comprising a first housing (12), a second housing (14), an elongated light source (16) and an elongated light guide (18) with optical fibers (20), wherein each housing (14) can be attached to the motor vehicle (11), wherein the light guide (18) has a section (26) encased by the light source (16), wherein the light source (16) is spaced apart from each housing (12, 14), wherein a first end section (22) of the optical fiber (18) extends from the sheathed section (26) to the first housing (12), wherein a second end section (24) of the optical fiber (18) extends from the sheathed section (26) into the second housing (14), wherein at least one light-emitting diode (32) and at least one coupling device (31) are arranged in each housing (14), wherein each coupling device (31) is provided for coupling the light (33) emitted by one of the light-emitting diodes (32) into the light guide (18), wherein the lighting device (10) has a first bellows (34) which is connected to the first housing (12) and the light source (16) and which defines a first internal volume (36) in which a partial section (28) of the first end section (22) is arranged, wherein the lighting device has a second bellows (38) which is connected to the second housing (14) and the light source (16) and defines a second internal volume (40) in which a partial section (30) of the second end section (24) is arranged, wherein the light source (16) lengthens when the light source (16) is heated and shortens when the light source (16) is cooled, so that when the first housing (12) and the second housing (14) are attached to the motor vehicle (11) each bellows (34, 38) is compressed when the light source (16) is heated and pulled apart when the light source (16) is cooled. [2] Lighting device (10) according to claim 1, characterized by , that the first bellows (34) and the second bellows (38) are in an unloaded state when the temperature of the light source (16) is within a room temperature range of 20 degrees to 30 degrees. [3] Lighting device (10) according to claim 2, characterized by, that the first bellows (34) and the second bellows (38) have a design in which each bellows (34, 38) can be pulled apart from the unloaded state by a measure which corresponds to at least 50% of the reduction in length of the light source (16) when the temperature of the light source (16) is reduced from a temperature within the room temperature range to -40 degrees. [4] Lighting device (10) according to claim 2 or 3, characterized by , that the first bellows (34) and the second bellows (38) have a design in which each bellows (34, 38) can be compressed from the unloaded state by a measure which corresponds to at least 50% of the increase in length of the light source (16) when the temperature of the light source (16) is increased from a temperature within the room temperature range to 90 degrees. [5] Lighting device (10) according to any one of the preceding claims, characterized by, that an end section (44) of the first bellows (34) is shrunk onto a first end section (42) of the light body (16), and that an end section (44) of the second bellows (38) is shrunk onto a second end section (46) of the light body (16). [6] Lighting device (10) according to any one of the preceding claims, characterized by , that the luminaire body (16) designed as a casing is made of translucent polyamide. [7] Lighting device according to claims 5 and 6, characterized by , that each bellows (34, 38) consists at least partially of polyamide. [8] Motor vehicle (11) with a lighting device (10) according to one of claims 1 to 7, wherein the first housing (12) and the second housing (14) are attached to the motor vehicle (11).

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