Composite pane comprising a heating device

Abstract

The present invention relates to a heatable composite pane (10) acting as a roof window for a vehicle, said composite pane comprising: - an outer pane (1) having an outer surface (I) and an inner surface (II), and an inner pane (2) having an outer surface (III) and an inner surface (IV), the outer pane and inner pane being connected to one another by means of a thermoplastic interlayer (3), and - an infrared heating device (5) that emits infrared radiation for an interior space, wherein the infrared heating device (5) is arranged on the inner pane (2) in a planar manner as a structure (4) made of a printed, electrically conductive material and, when the composite pane (10) is installed, is designed to expose a vehicle occupant to heat, wherein the structure (4) can be connected to an electrical voltage via a strip-shaped first busbar (8) and a strip-shaped second busbar (8) in such a way that, after an electrical voltage has been applied to the busbars (8), a heating current flows via the structure (4).

Description

[0001] Composite pane with a heating device

[0002] The invention relates to a heatable composite pane and a vehicle with the heatable composite pane.

[0003] Vehicles with heated windshields are known from the prior art. This prevents icing or fogging of the windshield, which obstructs visibility. Heated composite windows are used in particular as heated windshields in motor vehicles and offer the possibility of conveniently removing icing or condensed moisture from the windshield by heating. They have transparent, electrically conductive coatings, in particular with silver layers. The coatings are electrically contacted so that a current can be passed through them. This heats up the coating, which is the basis for the heating effect. Reference is made to WO2013 / 104438A1, for example. One problem with such coatings is their frequently high sheet resistance, which requires a high operating voltage, especially for large-sized windshields to be heated.The heat and thus energy loss appears to be very high due to convection over the usually large disc surfaces.

[0004] Heating the interior of a vehicle and the windshield is typically achieved by heated air, which is blown into the interior or onto the windshield via intakes. Furthermore, electric heating systems have been used in vehicles for many years, including seat heaters and steering wheel heaters.

[0005] The thermal comfort of vehicle occupants and the goal of achieving a comfortable temperature play an important role in vehicle construction. Thermal comfort should be achieved as energy-efficiently as possible. Typically, maintaining a comfortable temperature at a comfortable temperature requires high energy consumption.

[0006] DE 10 2007 040008 A1 discloses a vehicle window with a temporarily transparent area, wherein the transparent area is heatable.

[0007] WO 2009 / 085741 A2 describes a sun protection film comprising a flexible carrier transparent to visible light, two metal layers, and a polymeric protective layer. The sun protection film is transparent to visible light and infrared-reflecting. The object of the present invention is to provide a composite pane that enables thermal comfort in the vehicle interior in an energy-efficient manner.

[0008] This object is achieved by a composite pane according to claim 1. Preferred embodiments emerge from the subclaims.

[0009] According to the invention, a heatable composite pane is provided as a roof pane for a vehicle, comprising an outer pane with an outer surface and an interior surface, and an inner pane with an outer surface and an interior surface, which are connected to one another via a thermoplastic intermediate layer, and at least one infrared heating device with infrared radiation for an interior, wherein the infrared heating device is arranged flatly as a structure made of a printed, electrically conductive material on the inner pane and is provided in the installed position of the composite pane for the effect of heat on a vehicle occupant, wherein the structure can be connected to an electrical voltage via a strip-shaped first bus conductor and a strip-shaped second bus conductor in such a way that after an electrical voltage is applied to the bus conductors, a heating current flows through the structure.In other words, the infrared heating device is designed in the form of an electrically conductive print. This allows thermal comfort and a pleasant temperature to be provided locally on the body of the vehicle occupant without, for example, having to raise the temperature throughout the entire vehicle interior. The use of a printed, electrically conductive material enables a particularly cost-effective technical implementation of an infrared emitter. The electrically conductive material conducts current via at least two connection points on the electrically conductive material, resulting in an energy conversion of heat in the form of infrared radiation.

[0010] The infrared heating device can generate infrared radiation in the wavelength range from A = 0.78 pm (micrometers) to 3.5 pm. The infrared heating device is preferably designed to generate infrared radiation in a wavelength range from 0.78 pm to 2.8 pm, i.e., in the long-wave part of the NIR (near infrared) range.

[0011] The structure can be formed as a printed, in particular imprinted, electrically conductive material. The printed, electrically conductive material preferably contains at least one metal compound, metal alloy, and / or carbon.

[0012] In a preferred embodiment, the printed, electrically conductive material comprises graphite. The structure can, in particular, comprise several, in particular 10 to 15, strip-shaped heating elements connected in parallel for emitting infrared radiation, wherein each strip-shaped heating element comprises the printed, electrically conductive material. The strip-shaped heating elements can be spaced apart from one another.

[0013] Furthermore, the structure can be connected via a strip-shaped first busbar and a strip-shaped second busbar such that, upon application of an electrical voltage to the busbars, a heating current flows through the structure. This creates a heating field formed by the structure.

[0014] The structure can have a material thickness of 1 μm to 500 μm. The material thickness (layer thickness) of the printed structure is preferably from 5 μm to 300 μm, more preferably from 10 μm to 100 μm, and most preferably from 12 μm to 50 μm. Structures with these thicknesses are technically simple to realize and exhibit advantageous electrical conductivity.

[0015] The composite pane is designed to separate the interior from the exterior in a window opening (particularly a window opening in a vehicle). For the purposes of the invention, the "inner pane" refers to the pane of the composite pane facing the interior. The "outer pane" refers to the pane facing the exterior.

[0016] The heatable composite pane is a roof pane, for example, designed as a window pane of a motor vehicle, rail vehicle, ship, or aircraft. The composite pane is preferably a roof pane of a passenger car or truck. In a particularly advantageous embodiment, the vehicle is an electric vehicle.

[0017] Furthermore, the heatable composite pane can comprise one or more photovoltaic modules. For this purpose, the structure can be arranged on the interior-side surface (IV) of the inner pane. The one or more photovoltaic modules can then be arranged on the exterior surface (III) of the inner pane or on the interior-side surface (II) of the outer pane or between the outer pane and the inner pane. In this case, the at least one or more photovoltaic modules and the structure can at least partially overlap in the direction of view through the composite pane. In other words, the structure lies spatially in front of a photovoltaic module in the direction of view through the composite pane from the inside, so that the heating foil is arranged in an orthogonal projection through the composite pane in coverage or overlap with the photovoltaic module.

[0018] Alternatively, the structure can be arranged on the outer surface (III) of the inner pane. The one or more photovoltaic modules can then be arranged on the interior surface (II) of the outer pane or between the outer pane and the inner pane, wherein at least one photovoltaic module and the structure can overlap in the viewing direction through the composite pane. In other words, the structure is located spatially in front of a photovoltaic module in the viewing direction through the composite pane from the inside, so that the heating foil is arranged in an orthogonal projection through the composite pane in overlap with the photovoltaic module.

[0019] The use of the printed structure offers great design freedom regarding the external shape of the printed structure in order to maintain the design freedom of the automobile manufacturers for different installation situations.

[0020] For example, the infrared heating device can have at least one separately controllable surface section with a rectangular basic shape with an edge length of 100 mm, 200 mm, 300 mm or 1500 mm. The heat radiated by the surface section warms an occupant sitting beneath the surface section. The infrared heating device can comprise multiple surface sections. The surface sections of the infrared heating device are each designed to distribute the heat as evenly as possible. This also enables local temperature adjustment. This allows efficient energy savings because the entire vehicle interior does not have to be heated. The infrared heating device can take up less than 20%, in particular less than 10%, of the outer surface (III) or the inner surface (IV) of the inner pane.

[0021] In an exemplary embodiment, the heatable composite pane can be opaque, particularly if the heatable composite pane is designed as a roof pane. In this case, the transmission of light of the visible spectrum through the composite pane is at most 15%, preferably at most 2%, particularly preferably at most 1%, in particular at most 0.1%.

[0022] In a further embodiment of the heatable composite window according to the invention, at least one surface section of the infrared heating device can be assigned to each seat or row of seats in a vehicle. Each surface section can be switched on and operated independently of other surface sections. The individually heated areas in the vehicle interior achieve a soothing effect and significantly increase the heat emitted by a surface section.

[0023] The thermoplastic intermediate layer is arranged between the outer pane and the inner pane. The intermediate layer connects the outer pane to the inner pane. The thermoplastic intermediate layer contains at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB) or polyurethane (PU) or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The thermoplastic intermediate layer is typically formed from a thermoplastic film (connecting film). The thickness of the thermoplastic intermediate layer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, for example 760 μm. The thermoplastic intermediate layer can be formed by a single film or by more than one film. The thermoplastic intermediate layer can also be a film with functional properties, for example a film with acoustically dampening properties.If the thermoplastic intermediate layer is formed from two foils and the infrared heating device is divided into at least two surface sections, the surface sections can be arranged in a plane between the two intermediate layers. If several surface sections are embedded in the composite pane, the heating output can be controlled much more precisely. One of the intermediate layers can, in particular, be an intermediate layer that is at least partially tinted.

[0024] The outer pane and the inner pane preferably contain or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, aluminosilicate glass, or clear plastics, preferably rigid clear plastics, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and / or mixtures thereof. The outer pane and the inner pane can be clear and colorless, but also tinted or colored. The outer pane and the inner pane can independently be untempered, partially tempered, or toughened. If at least one of the panes is to be tempered, this can be thermally or chemically tempered.

[0025] The outer pane and the inner pane may have suitable coatings known per se, for example anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings or sun protection coatings or low-E coatings.

[0026] The thickness of the outer pane and the inner pane can vary widely and thus be adapted to the requirements of the individual case. The outer pane and the inner pane preferably have thicknesses of 0.5 mm to 5 mm, particularly preferably of 1 mm to 3 mm, and most preferably of 1.6 mm to 2.1 mm. For example, the outer pane has a thickness of 2.1 mm and the inner pane a thickness of 1.6 mm. However, the outer pane or, in particular, the inner pane can also be thin glass with a thickness of, for example, 0.55 mm.

[0027] The invention also relates to a vehicle comprising a heatable composite pane according to the invention for heating an area in the vehicle interior, wherein at least one surface section of the infrared heating device is arranged in the head region of a vehicle occupant.

[0028] Furthermore, the invention relates to a heating system for heating a vehicle interior comprising the heatable composite pane according to the invention and at least one control unit and / or on-board electronics of a vehicle connected to the infrared heating device.

[0029] The invention is explained in more detail below with reference to figures and exemplary embodiments. The figures are schematic representations and not to scale. The figures do not limit the invention in any way. It should be noted that different aspects are described, each of which can be used individually or in combination. This means that any aspect can be used with different embodiments of the invention, unless explicitly presented as a mere alternative.

[0030] They show:

[0031] Figure 1 is a plan view of an embodiment of a composite pane according to the invention,

[0032] Figure 2 is a plan view of a further embodiment of the composite pane according to the invention,

[0033] Figure 3 is a cross-sectional view of an embodiment of the composite pane according to the invention, and

[0034] Figure 4 shows a cross-sectional view of another embodiment of the composite pane according to the invention. Numerical values ​​are generally not to be understood as exact values, but rather include a tolerance of + / - 1% to + / - 10%.

[0035] Figure 1 shows a first embodiment of a composite pane 10 according to the invention as a roof pane of a passenger car in a plan view. The composite pane 10 is intended to separate the interior 12 (Figure 3) of the car from the outside environment in a window opening of the car. Figures 3 and 4 show this embodiment in cross-section. For the sake of simplicity, the composite pane 10 is shown flat, although roof panes are typically curved in reality. The composite pane 10 has an infrared heating device 5. The infrared heating device 5 is designed as a structure 4 made of a printed, electrically conductive material. Each structure 4 can be connected to an electrical voltage via a strip-shaped first busbar 8 and a strip-shaped second busbar 8, so that after the electrical voltage is applied to the busbar 8, a heating current flows through the respective structure 4.Each structure 4 comprises several, in particular 10 to 15, strip-shaped heating elements 6 connected in parallel. The strip-shaped heating elements 6 are spaced apart from one another. By means of the infrared heating device 5, a passenger of the passenger car can be exposed to infrared radiation 9 (Figure 3). The infrared heating device 5 can generate infrared radiation in the wavelength range from λ = 1.5 pm (micrometers) to 3.5 pm.

[0036] The infrared heating device 5 is divided into four surface sections and one elongated surface section. Each surface section can be connected to an electrical voltage source via a busbar 8. When the composite pane 10 is installed, the infrared radiation 9 is directed at predetermined areas of the vehicle interior, in particular the head area of ​​a vehicle occupant. The surface sections can be electrically controlled separately. They each have a rectangular basic shape with an edge length of, for example, 100 mm, 200 mm, 300 mm, or 1500 mm. The surface sections of the infrared heating device 5 are preferably arranged in the edge region of the composite pane 100, which is typically opaque in the vehicle sector, for example, by photovoltaic modules 7 or by a black, usually enamel-like print (masking layer) on an interior-side surface 11 of the outer pane 1.The heat radiated by the surface section warms a passenger sitting beneath it. The surface sections are designed to distribute heat as evenly as possible. This allows for localized temperature adjustment while also efficiently saving energy, as the entire vehicle interior does not need to be heated.

[0037] The surface sections of the infrared heating device 5 are expediently connected to a power supply via supply lines, so that upon application of an electrical voltage, a heating current flows through a heating field formed by a structure 4 (Figure 3). Furthermore, the surface sections of the infrared heating device 5 can be functionally connected to a control and / or regulating unit, for example, to the on-board electronics of a vehicle. This makes it possible to selectively achieve the desired heating effect in an energy-efficient manner, for example, to heat only the rear seat to warm a passenger or only the front seat to warm a driver. It is also possible to control and operate individual or multiple surface sections of the heating device 5. This enables optimal adaptation of the applied infrared radiation to the required or desired heating effect.

[0038] Figure 2 shows a second embodiment of the composite pane 10 in a plan view of an interior-side surface of the composite pane 10. The difference from the embodiment described in Figure 1 is that the composite pane 10 has three surface sections of the infrared heating device 5. In addition, the surface sections of Figure 2 differ in shape from the surface sections of Figure 1. The three surface sections of the infrared heating device 5 are strip-shaped and extend from one side edge to an opposite side edge of the composite pane 10, preferably in each case above a row of seats of a car. The infrared heating device 5 is designed as a structure 4. The structure 4 is connected via a strip-shaped first bus conductor 8 and a strip-shaped second bus conductor 8 in such a way that after an electrical voltage is applied to the bus conductors 8, a heating current flows through the structure 4.

[0039] Figure 3 shows the composite pane according to the invention from Figure 1 in cross section XX'. The composite pane 10 comprises an outer pane 1 and the inner pane 2, which are connected to one another via an intermediate layer 3. The outer pane 1 comprises an outer surface I and the inner space surface II. The inner pane 2 comprises an outer surface III and an inner space surface IV. The outer surface refers to the main surface which is intended to face the outside environment in the installed position. The inner space surface refers to the main surface which is intended to face the interior 12 in the installed position. The outer pane 1 and the inner pane 2 are made of soda-lime glass. The outer pane 1 has, for example, a thickness of 2.1 mm, the inner pane 2 a thickness of 1.6 mm.The intermediate layer 3 is formed, for example, from a PVB film with a thickness of 0.76 mm. The interior-facing surface II of the outer pane 1 and the exterior-facing surface III of the inner pane 2 face each other and are connected by the thermoplastic intermediate layer 3.

[0040] The heatable composite pane 10 comprises the infrared heating device 5, which is formed from the structure 4. Structure 4 emits infrared radiation 9 for the interior 12 of the car, wherein the infrared heating device 5 is intended to apply heat to a vehicle occupant. Analogous to Figure 1, the structure 4 comprises several, in particular 10 to 15, strip-shaped, parallel-connected heating elements 6 for emitting infrared radiation, wherein each strip-shaped heating element 6 comprises the printed, electrically conductive material. The strip-shaped heating elements 6 are spaced apart from one another. Furthermore, the structure 4 is connected via a strip-shaped first busbar 8 and a strip-shaped second busbar 8 such that, upon application of an electrical voltage to the busbar 8, a heating current flows through the structure 4. This creates a heating field formed by the structure.

[0041] The structure 4 is divided into several surface sections. Preferably, the entire structure is applied by screen printing a baking paste and baked. Techniques other than screen printing can also be used to create the printed structure 4, for example inkjet printing or extrusion. The surface sections of the structure 4 occupy less than 50%, 20%, or less than 10% of the interior-side surface IV of the inner pane 2. This allows thermal comfort and a pleasant temperature to be provided locally on the body of the vehicle occupant without having to increase the temperature in the entire vehicle interior. The use of a structure 4 as an infrared emitter enables particularly simple technical production of the composite pane. Furthermore, the use of the structure 4 does not require a great deal of additional installation space. In addition, a protective sheath can envelop the structure 4 or cover it on one side.

[0042] The composite pane 10 also comprises a plurality of photovoltaic modules 7. The photovoltaic modules 7 are arranged on the interior-side surface II of the outer pane 1. Alternatively, the photovoltaic modules 7 can be arranged on the exterior surface III of the inner pane 2 or between the outer pane 1 and the inner pane 2. The photovoltaic modules 7 and the structure 4 overlap in the viewing direction through the composite pane 10. The photovoltaic modules 7 conceal the view of the structure 4 from the outside. The structure 4 is thereby unobtrusively concealed for the observer. As a result, the structure 4 is particularly advantageously not visible from the outside when the composite pane is installed as a roof pane of a vehicle, so that the optical-aesthetic appearance of the composite pane 10 is not impaired.

[0043] Figure 4 shows a second embodiment of cross-section XX'. The difference from the embodiment described in Figure 3 is that the printed structure 4 is arranged on the outer surface III of the inner pane 2.

[0044] The first and second configurations of the cross-section can be used both in the embodiment according to Figure 1 and in the embodiment according to Figure 2. For the embodiment according to Figure 2, the shape of the surface sections of the structure 4 is adapted.

[0045] Particular advantages of the invention are that it enables local heating of a vehicle interior and that the heating effect can be achieved in a particularly energy-efficient manner. Energy efficiency is an extremely important criterion for future product developments. Advantageously, the heating effect according to the invention does not depend on the heating of the laminated pane itself, but is achieved selectively by controlling a specific surface section of the infrared heating device. The heating effect therefore occurs much more quickly than with previously used heating devices and can offer a very effective solution, especially when used in conjunction with child car seats.

[0046] List of reference symbols:

[0047] 1 outer pane

[0048] 2 inner pane

[0049] 3 Intermediate layer

[0050] 4 Structure

[0051] 5 Infrared heating device

[0052] 6 Heating element

[0053] 7 Photovoltaic module

[0054] 8 collection managers

[0055] 9 Infrared radiation

[0056] 10 Composite pane

[0057] 12 Interior of a vehicle

[0058] I outside surface of the outer pane 1

[0059] II Interior surface of the outer pane 1

[0060] III outer surface of the inner pane 2

[0061] IV Interior surface of the inner pane 2

Claims

Patent claims 1. Heatable composite pane (10) as a roof pane for a vehicle, comprising an outer pane (1) with an outer surface (I) and an interior surface (II), and an inner pane (2) with an outer surface (III) and an interior surface (IV), which are connected to one another via a thermoplastic intermediate layer (3), and an infrared heating device (5) with infrared radiation for an interior, wherein the infrared heating device (5) is arranged as a structure (4) made of a printed, electrically conductive material on the inner pane (2) and is provided in the installed position of the composite pane (10) for the heat effect on a vehicle occupant, wherein the structure (4) can be connected to an electrical voltage via a strip-shaped first busbar (8) and a strip-shaped second busbar (8) in such a way thatthat after applying the electrical voltage to the bus bars (8) a heating current flows through the structure (4).

2. Heatable composite pane (10) according to claim 1, wherein the printed, electrically conductive material comprises graphite.

3. Heatable composite pane (10) according to claim 1 or 2, wherein the structure (4) comprises several, in particular 10 to 15, strip-shaped, parallel-connected heating elements (6) for emitting infrared radiation (9).

4. Heatable composite pane (10) according to one of claims 1 to 3, wherein the printed structure (4) has a material thickness of 1 pm to 500 pm.

5. Heatable composite pane (10) according to one of claims 1 to 4, wherein the heatable composite pane (10) comprises one or more photovoltaic modules (7).

6. Heatable composite pane (10) according to one of claims 1 to 5, wherein the heatable composite pane (10) is opaque.

7. Heatable composite pane (10) according to one of claims 1 to 6, wherein the infrared heating device (5) occupies less than 20%, in particular less than 10% of the outside surface (III) or the inside surface (IV) of the inner pane (2).

8. Heatable composite pane (10) according to one of claims 1 to 7, wherein the infrared heating device (5) has at least one separately controllable surface section with a rectangular basic shape with an edge length of 100 mm, 200 mm, 300 mm or 1500 mm.

9. Heatable composite pane (10) according to one of claims 1 to 8, wherein at least one surface section of the infrared heating device (5) is assigned to each vehicle seat or row of vehicle seats and the surface section can be switched and operated independently of other surface sections.

10. Heatable composite pane (10) according to one of claims 1 to 9, wherein the thermoplastic intermediate layer (3) is formed by more than one film and the infrared heating device (5) comprises at least two surface sections which are arranged in a plane between at least two films of the intermediate layer (3).

11. Heatable composite pane (10) according to one of claims 1 to 10, wherein the infrared heating device (5) is provided for generating infrared radiation in a wavelength range from 0.78 pm to 2.8 pm.

12. Heatable composite pane (10) according to one of claims 1 to 11, wherein in the installed position of the composite pane (10) the infrared radiation (9) is directed onto an area of ​​a vehicle interior, in particular the head area of ​​a vehicle occupant.

13. Heating system for heating a vehicle interior, comprising a heatable composite pane (10) according to one of claims 1 to 12 and at least one control unit and / or on-board electronics of a vehicle connected to the infrared heating device (5).

14. Vehicle comprising a heatable composite window (10) according to one of the claims 1 to 12 for heating an area in the vehicle interior, wherein at least one surface section of the infrared heating device (5) is in the head region of a vehicle occupants.

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