Motor vehicle with light-guiding outer skin, and method for collecting light or guiding light using such an outer skin

Abstract

The invention relates to a motor vehicle (10) comprising an outer skin (12), said outer skin (12) having a collector layer (14) with at least one coloring agent (16). The collector layer (14) is designed to absorb a defined spectral component (52) of sunlight (50) and guide same to a defined region (20) on the edge (22) of the collector layer (14) by means of the coloring agent (16) and / or an optical fiber (18) within the collector layer (14) such that the collected sunlight (30) can be used at a boundary surface (24) on the edge (22) of the collector layer (14). The invention additionally relates to an outer skin (12) for a motor vehicle and to a method for collecting light or guiding light using such an outer skin (12).

Description

[0001] Description

[0002] Motor vehicle with light-conducting outer skin and method for light collection or light conduction with such an outer skin

[0003] The invention relates to a motor vehicle with a light-conducting outer skin and to a method for light collection and / or light conduction with such an outer skin according to the preamble of the independent patent claims.

[0004] Hybrid vehicles or moving vehicles, in particular battery-electric motor vehicles, also known as Battery Electric Vehicles (BEVs), which are at least partially electric, have one or more energy storage devices that are discharged during operation or through self-discharge and must be recharged accordingly. For this purpose, in addition to the usual charging technology using a charging cable or inductive charging, solar cells can be provided on the vehicle's outer skin, for example on a glass roof, in particular a panoramic roof or a panoramic sliding roof. These solar cells are usually installed in glass components, such as the aforementioned glass roof or panoramic (sliding) roof. The structure of such a glass roof module consists of an upper and a lower glass layer, between which solar cells are inserted.In this sandwich construction, the solar cell layer is located in the center of the sandwich structure, with one or more carrier films inserted between the solar cell layer and the upper and lower glass layers. The entire structure is rigid, as the panoramic or panoramic sliding roof functions as a central, stable roof module and is firmly connected to a preferably self-supporting vehicle body.

[0005] The disadvantage of such solutions, however, is that solar modules in roofs are correspondingly heavy and inflexible and their application is limited to flat glass surfaces of the vehicle.

[0006] WO 2019 / 234105 A1 discloses a flexible and photovoltaically active laminate that can be applied to a motor vehicle outer skin, even if it is not flat but curved, such as in the case of a hood, tailgate, or doors. The laminate comprises a cover film forming the laminate's upper surface, which is transparent to incident light radiation, a solar film with photovoltaically active material, and a carrier layer made of a fiber composite material.

[0007] Although WO 2019 / 234 105 A1 solves the fundamental problem of making additional surfaces of motor vehicles usable for energy absorption, the efficiency of the energy yield from these surfaces is severely limited.

[0008] WO 2018 / 189394 A1 discloses a device for guiding light, which is particularly suitable for collecting diffuse light, and a manufacturing method for the device. The device enables a method for collecting light, which may be diffuse light, in particular sunlight, and emitting the light only parallel to one plane. Accordingly, the invention also relates to a method for concentrating light, in particular diffuse sunlight, wherein the emitted light is radiated in parallel planes. The emitted light is preferably directed onto a photovoltaic element.

[0009] The invention is based on the object of redirecting high-energy radiation, in particular sunlight, hitting the outer skin of a motor vehicle in such a way that this radiation can be used as efficiently as possible.

[0010] The object is achieved by a motor vehicle with an outer skin, wherein the outer skin has a collector layer with at least one colorant, wherein the collector layer is designed to absorb a predefined spectral component of the sunlight and to guide it by means of the colorant and / or an optical waveguide within the collector layer to a predefined region at an edge of the collector layer, so that the collected sunlight can be used at an interface at the edge of the collector layer.

[0011] The invention makes it possible to specifically collect sunlight that falls on the outer skin of a motor vehicle and is normally converted into unused heat or can lead to harmful UV degradation of the motor vehicle's components, particularly plastic components, and utilize it for the vehicle. This can, for example, reduce the vehicle's energy consumption and / or increase the durability of components.

[0012] The features listed in the further claims enable advantageous improvements, rather than further developments, of the motor vehicle specified in the independent claim. In a preferred embodiment of the invention, the motor vehicle comprises at least one photovoltaic device arranged in the predefined region such that light emerging from the collector layer is converted into electrical energy by the photovoltaic device. A photovoltaic device can utilize sunlight to supply electrical storage devices and / or consumers of the motor vehicle with power. In particular, in an electrically powered motor vehicle, the photovoltaic device can be used to charge a battery module of the electrically powered motor vehicle.An electrically powered motor vehicle includes both battery-electric vehicles, which are powered exclusively by an electric drive motor, and hybrid vehicles, which have both an electric drive motor and an internal combustion engine. Furthermore, the term electrically powered motor vehicle also includes vehicles that convert a fuel, in particular hydrogen, into electrical current and feed this electrical current to an electric drive motor, since such systems also generally contain a battery module for temporarily storing the electrical current, which can be charged by photovoltaics. The energy conversion by photovoltaics only takes place in limited areas at the respective edges of the collector layer, so that the visual appearance of the motor vehicle is only insignificantly affected.In addition, it is possible to arrange the photovoltaic devices at least partially in non-visible areas of the vehicle in order to avoid visual impairments or design restrictions.

[0013] It is particularly preferred if the photovoltaic device is designed as a high-efficiency photovoltaic material or comprises a high-efficiency photovoltaic material. A high-efficiency photovoltaic material in this context is understood to mean a material that has an efficiency of more than 25%, in particular more than 40%. A high-efficiency photovoltaic material is understood to mean, in particular, complex multi-junction solar cells in which each individual layer is further optimized. Such a multi-junction solar cell can, for example, comprise an upper tandem solar cell made of gallium indium phosphide (GalnP) and aluminum gallium arsenide (AlGaAs), and a lower tandem solar cell made of gallium indium arsenide phosphide (GalnAsP) and gallium indium arsenide (GalnAs). Such multi-junction solar cells already achieve efficiencies of 45–50% under laboratory conditions.Although such multi-junction solar cells are currently still extremely expensive in terms of price per square meter, the thin collector layer requires only very small photovoltaic areas, so that the use of a high-efficiency photovoltaic material is not only advantageous in terms of energy yield, but also economically viable due to the small area required.

[0014] In a further preferred embodiment of the invention, the outer skin of the motor vehicle is designed such that the light directed onto the predefined area exits the outer skin at the boundary surface. This prevents the interior of the motor vehicle from overheating. Furthermore, the collected sunlight can be used to specifically illuminate areas of the vehicle, so that, for example, daytime running lights can be formed, the light can be specifically coupled into the vehicle interior for lighting purposes, or a lighting effect can be created on a radiation surface of the outer skin.

[0015] According to an advantageous embodiment of the invention, the outer skin comprises a glass surface and / or a body surface of the motor vehicle. The outer skin of a motor vehicle, in particular a passenger car, typically has more or less curved surfaces, which complicates the installation of photovoltaic modules on the surface of the vehicle. The solution according to the invention makes it possible to apply a thin polymer layer, in particular a film, to the surface of the body in order to easily utilize the sunlight incident there.

[0016] In an advantageous embodiment of the invention, the at least one colorant comprises a dye and / or a pigment. The sunlight is absorbed by these colorants in the collector layer, which retains the sunlight within the collector layer and transmits it at different angles, so that at least a predefined spectral component of the sunlight is directed to a predefined region at an edge of the collector layer and utilized there.

[0017] The sunlight directed into the predefined area, in particular an end area of ​​the collector layer, can then be converted into electrical energy by means of a photovoltaic element or radiated as light with a correspondingly high intensity.

[0018] In a preferred embodiment of the invention, the predefined spectral component comprises a visible spectral component of sunlight. Visible sunlight accounts for approximately 64% of the energy of the entire sunlight spectrum, which is by far the largest component. Therefore, it is advantageous to absorb and utilize at least the visible spectral component of sunlight. Alternatively, by absorbing and deliberately deflecting the light through a radiating surface, energy input into the vehicle can be prevented, which can, in particular, reduce the heating of the interior. Furthermore, by selecting suitable dyes, a glass pane can be tinted by a corresponding collector layer, creating a privacy effect. With 100% adsorption, the pane would be completely black; with a realistic absorption of 60-65%, it would be correspondingly darkened.

[0019] It is particularly preferred if the outer skin comprises a glass surface of the motor vehicle and this glass surface is darkened at least in sections.

[0020] Alternatively, it is provided that the predefined spectral component is a non-visible spectral component of sunlight, in particular a UV radiation or infrared radiation of sunlight.

[0021] UV light accounts for approximately 6% of the total energy of sunlight. The outer skin according to the invention makes it possible to dispense with an additional UV filter, particularly for glass surfaces, and to direct the UV light to a predefined area via the collector layer. This allows the pane to be clear and without

[0022] Visibility may remain restricted, which can improve all-round visibility for a driver and thus increase safety.

[0023] Infrared radiation accounts for approximately 28% of the energy in the entire sunlight spectrum. Infrared radiation can be converted into electrical current by a germanium solar cell, for example, with efficiencies of up to 30%. Furthermore, heating of the vehicle interior can be minimized if the infrared radiation is absorbed in the collector layer and radiated at one edge of the collector layer.

[0024] In an advantageous embodiment of the outer skin, the colorants are enclosed by a polymer layer, an injection-molded component of the motor vehicle and / or a paint layer of the motor vehicle. Since the collector layers can be made very thin, in particular in the range of millimeters or tenths of a millimeter, the collector layer can be made flexible so that it adapts to any vehicle contour. The thin design makes it possible to design the outer skin either as a thin film that is subsequently applied to the body and / or glass surfaces, or to integrate it into a paint layer. Furthermore, it is possible to integrate the collector layer using an injection molding process into a component that forms part of the outer skin of a motor vehicle, for example into a headlight or exterior mirror housing.

[0025] Furthermore, the collector layer can be implemented, for example, as a film in a laminated glass pane. This can reduce typical losses during light transmission within the pane. Furthermore, no additional component is required; an existing component can be replaced with a film with a collector layer, thus reducing the additional cost.

[0026] In an advantageous embodiment of the invention, the collector layer is designed to convert UV radiation into a visible spectral component of sunlight, in particular into visible blue light. Alternatively, the collector layer can be designed to convert infrared radiation into visible light. This allows even non-visible components of the light to be converted into electrical current using simple photovoltaic devices, thus eliminating the need for special photovoltaic devices, such as germanium solar cells, which would be necessary for the direct utilization of infrared radiation.

[0027] It is particularly preferred if the collector layer comprises a compound for absorbing UV radiation and visible blue light. Such a compound can be, for example, 2-(2-ethylhexyl)-6,7-dimethyl-1H-benzo[de]isoquinoline-1,3(2H)-dione, which is suitable for collecting UV radiation and visible blue light in the collector layer and transmitting it from there to a radiation surface, where the UV radiation and visible blue light are converted into electrical energy.

[0028] In an advantageous embodiment of the colorant, the colorant comprises a dye for the absorption and emission of sunlight with a red shift. Such a dye is, for example, 6-(2,5-dicarboxyphenyl)-1,11-diethyl-2,2,4,8,10,10-hexamethyl-10,11-dihydro-2H-pyrano[3,2-g:5,6-g']diquinolin-1-ium.

[0029] A further aspect of the invention relates to an outer skin for a motor vehicle, wherein the outer skin comprises a collector layer with at least one colorant. The collector layer is designed to collect a predefined spectral component of the sunlight and, by means of the colorant and optical waveguide within the collector layer, to guide it to a predefined region at an edge of the collector layer, so that the collected sunlight can be used at an interface at the edge of the collector layer.

[0030] Such an outer skin allows only small areas of a vehicle to be coated with photovoltaic material, thus reducing costs. Furthermore, unlike rigid, inflexible photovoltaic modules, a flexible collector layer is able to adapt to any contour, allowing large areas of the vehicle's outer skin to be used for energy generation.

[0031] A further aspect of the invention relates to a method for light collection and / or light guidance with such an outer skin, the method comprising the following steps:

[0032] Collecting sunlight through a collector layer with at least one colorant, directing the sunlight to a predefined area at an edge of the collector layer,

[0033] Utilization of the collected sunlight at an interface at the edge of the collector layer. In a preferred embodiment of the method, the collected sunlight is fed to a photovoltaic device at the interface and the collected sunlight is converted into electrical energy.

[0034] Alternatively or additionally, in a further advantageous embodiment of the method, the collected sunlight exits at the interface and illuminates the interface or a component optically connected to the interface.

[0035] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0036] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show:

[0037] Figure 1 shows a motor vehicle according to the invention with a light-conducting outer skin in a side view;

[0038] Figure 2 shows a motor vehicle according to the invention with a light-conducting outer skin in a plan view;

[0039] Figure 3 shows a preferred embodiment of an outer skin according to the invention for a motor vehicle; and

[0040] Figure 4 shows a further preferred embodiment of an inventive

[0041] Outer skin for a motor vehicle.

[0042] Figure 1 shows a side view of a motor vehicle 10 according to the invention. The motor vehicle 10 comprises a body 40 with a hood 42, a plurality of doors 44, an exterior mirror 46, and a roof 48. The body 40 further comprises a front bumper 74, a rear bumper 76, and a fender 78. For this purpose, glass surfaces 60 in the form of a windshield 62, a rear window 64, and a plurality of side windows 66 are formed on the motor vehicle 10. In addition, the motor vehicle 10 can have a glass roof 68. The motor vehicle 10 comprises an outer skin 12, which is arranged or formed on or in the body surface 28 or a glass surface 60 of the motor vehicle 10.The outer skin 12 comprises a collector layer 14 which absorbs the sunlight 50 and directs it to a predefined area 20 at an edge 22 of the collector layer 14 so that the collected sunlight 50 can be used at an interface 24 at the edge 22 of the collector layer 14.

[0043] If the motor vehicle 10 is exposed to sunlight 50, the sun's rays and thus the visible spectrum 54 of the sunlight 50, infrared radiation 56 and UV radiation 58 strike the outer skin 12 of the motor vehicle 10.

[0044] Figure 2 shows a further illustration of a motor vehicle 10 according to the invention. The motor vehicle 10 is shown in a plan view of the roof 48 of the motor vehicle 10.

[0045] Figure 3 shows an outer skin 12 of a motor vehicle 10 according to the invention. The outer skin 12 comprises a collector layer 14, which comprises colorants 16, in particular dyes 30 and pigments 32, which are designed to transmit a predefined spectral component 52 of the sunlight 50 within the collector layer 14 to a predefined region 20. The outer skin 14 is designed as a polymer layer 34, preferably as a film 72, which can be easily applied to a glass surface 60 or a body surface 28. The collector layer 14 can additionally have an optical fiber 18, which supports the transport of the predefined spectral component 52 of the sunlight 50 to the predefined region 20.As an alternative to a polymer layer, the collector layer 14 can also be integrated into a paint layer 38 of the motor vehicle 10 or formed by injection molding in a component, for example a headlight or an exterior mirror 46, in particular an exterior mirror housing, which forms part of the outer skin 12 of the motor vehicle 10.

[0046] In the predefined region 20, the collector layer 14 has an edge 22 at which the collected sunlight 50 can be utilized at an interface 24. The interface 24 is, in particular, a radiation surface at which the collected sunlight 50 is re-emitted or a transition surface to a photovoltaic means 26 at which the collected sunlight 50 is converted into electrical energy. The photovoltaic means 26 can, in particular, comprise a high-efficiency photovoltaic material 70, since the surface area of ​​the photovoltaic means 26 is correspondingly small due to the small thickness of the collector layer 14, so that the additional costs for an expensive high-efficiency photovoltaic material 70 are justifiable.

[0047] Figure 4 shows a further exemplary embodiment of an outer skin 12 of a motor vehicle 10 according to the invention. With essentially the same structure as shown in Figure 3, the collector layer 14 in this exemplary embodiment has a glass surface 60 which reflects at least a defined spectral component 52 of the sunlight 50. As an alternative to a glass surface 60, a paint layer, in particular a chrome paint layer, can also be provided, which also reflects at least a defined spectral component 52 of the sunlight 50. The sunlight 50 absorbed in the collector layer 14 is guided to the defined area 20 by reflection from the colorant 16 and / or by light conduction, where it can be converted into electrical current by photovoltaic means 26 or emitted as visible light at an interface 24 in order to illuminate the outer skin 12 of the motor vehicle 10 at least in sections.

[0048] List of reference symbols

[0049] 10 motor vehicle

[0050] 12 Outer skin

[0051] 14 Collector layer

[0052] 16 colorants

[0053] 18 optical fibers

[0054] 20 predefined range

[0055] 22 edges

[0056] 24 Interface

[0057] 26 photovoltaic funds

[0058] 28 Body surface

[0059] 30 dye

[0060] 32 pigments

[0061] 34 polymer layer

[0062] 36 injection-molded component

[0063] 38 coats of paint

[0064] 40 Body

[0065] 42 Bonnet

[0066] 44 Door

[0067] 46 exterior mirrors

[0068] 48 roof

[0069] 50 sunlight

[0070] 52 predefined spectral components

[0071] 54 visible light / visible spectral component

[0072] 56 UV radiation

[0073] 58 infrared radiation 60 glass surface

[0074] 62 Windscreen

[0075] 64 Rear window

[0076] 66 side window

[0077] 68 glass roof

[0078] 70 high-efficiency photovoltaic material

[0079] 72 Slide

[0080] 74 front bumper

[0081] 76 rear bumper 78 fender

Claims

Patent claims 1. Motor vehicle (10) with an outer skin (12), wherein the outer skin (12) has a collector layer (14) with at least one colorant (16), wherein the collector layer (14) is designed to absorb a predefined spectral component (52) of the sunlight (50) and to guide it by means of the colorant (16) and / or an optical fiber (18) within the collector layer (14) to a predefined region (20) at an edge (22) of the collector layer (14), such that the collected sunlight (50) can be used at an interface (24) at the edge (22) of the collector layer (14).

2. Motor vehicle (10) according to claim 1, wherein the motor vehicle (10) comprises at least one photovoltaic means (26) which is arranged in the predefined region (20) in such a way that light emerging from the collector layer (14) is converted into electrical energy by means of the photovoltaic means (26).

3. Motor vehicle (10) according to claim 1 or 2, wherein the outer skin (12) is designed such that the light directed onto the predefined area (20) exits from the outer skin (12).

4. Motor vehicle (10) according to one of claims 1 to 3, wherein the outer skin (12) comprises a glass surface (60) and / or a body surface (28).

5. Motor vehicle (10) according to one of claims 1 to 4, wherein the at least one colorant (16) comprises a dye (30) and / or pigments (32).

6. Motor vehicle (10) according to one of claims 1 to 5, wherein the predefined spectral component (52) comprises a visible spectral component (54) such that the glass surface (26) is partially darkened.

7. Motor vehicle (10) according to one of claims 1 to 6, wherein the predefined spectral component (52) of the sunlight (50) is a non-visible spectral component (56, 58).

8. Motor vehicle (10) according to one of claims 1 to 7, wherein the colorants (16) are comprised by a polymer layer (34), an injection-molded component (36) of the motor vehicle (10) and / or a paint layer (38) of the motor vehicle (10).

9. Outer skin (12) for a motor vehicle (10), wherein the outer skin (12) has a collector layer (14) with at least one colorant (16), wherein the collector layer (14) is designed to absorb a predefined spectral component (52) of the sunlight (50) and to guide it by means of the colorant (16) and / or an optical fiber (18) within the collector layer (14) to a predefined region (20) at an edge (22) of the collector layer (14), such that the collected sunlight (30) can be used at an interface (24) at the edge (22) of the collector layer (14).

10. A method for light collection and / or light guidance with an outer skin (12) according to claim 9, comprising the following steps: Collecting sunlight (50) through the collector layer (14), Directing the sunlight (50) onto a predefined area (20) at an edge (22) of the collector layer (14), Use of the collected sunlight (30) at an interface (24) at an edge (22) of the collector layer (14).

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