Lid element with inner pane and outer pane

Abstract

Cover element of a vehicle roof, comprising an outer pane (16) and an inner pane (18, 18', 18"), which is connected around the perimeter to an inner surface (22) of the outer pane (16), so that a cover interior (28) is formed between the outer pane (16) and the inner pane (18, 18', 18"), characterized in that the cover interior (28) is provided with a pressure equalization device, wherein an electrically switchable shading element is formed on the inner pane (18, 18', 18") and the shading element comprises a liquid crystal cell (40).

Description

[0001] The invention relates to a cover element of a vehicle roof with the features of the preamble of claim 1.

[0002] Such a cover element is known in practice and is particularly well-suited as a sliding roof cover for a motor vehicle's roof opening system. The cover element can comprise a transparent outer pane, forming a roof skin element, and an inner pane, which is connected around its entire circumference to the inner or underside of the outer pane. A space within the cover is formed between the outer pane and the inner pane.

[0003] With lid elements of the type described above, a problem currently exists that condensation can occur inside the lid, causing the outer and / or inner pane to fog up on their respective inner surfaces facing the lid's interior. This is undesirable.

[0004] German patent application DE 102 03 846 A1 discloses a cover element for a vehicle roof, comprising an outer pane and an inner pane connected to the outer pane. A cover interior is formed between the outer pane and the inner pane.

[0005] From publication WO 2014 / 095 097 A1, an insulating glass arrangement with two glass panes is known, with an interior space formed between them. To compensate for pressure differences between the interior space and the environment, a pressure equalization element is arranged on a spacer.

[0006] An insulating glass arrangement with a pressure equalization valve is known from publication WO 02 / 42593 A1.

[0007] The invention is based on the objective of creating a lid element of the type mentioned in the introduction, in which the risk of the panes fogging up on their respective inner sides is reduced.

[0008] This problem is solved according to the invention by the lid element with the features of claim 1.

[0009] According to the invention, a double-pane cover element with a pressure equalization device is proposed, by means of which pressure differences between the interior of the cover and the environment can be counteracted. The pressure equalization device advantageously allows air exchange between the interior of the cover and the environment, in particular a vehicle interior. This reduces the risk of the panes of the double-pane cover element fogging up. The transparency properties of the cover element are thus essentially maintained even with changes in temperature or pressure.

[0010] In a preferred embodiment of the lid element according to the invention, the pressure equalization device is permeable to air and impermeable to water and water vapor. Thus, the pressure equalization device, which also acts as an air exchange device, effectively counteracts condensation effects in the interior of the lid.

[0011] For example, the pressure equalization device includes an air-permeable membrane that is specifically impermeable to water and water vapor. Such a membrane is comparable to waterproof membranes used in the clothing industry and sold, for example, under the Gore-Tex brand.

[0012] To simplify the installation of the pressure equalization device, the diaphragm can be part of an insert that is placed into a pressure equalization opening. Pressure equalization and air exchange between the interior of the lid and the surrounding environment, which is connected to the interior of the lid via the diaphragm, occur via the insert or the diaphragm.

[0013] The pressure equalization opening is formed, for example, in the inner pane itself, thus connecting the interior of the lid with an occupant compartment of the vehicle in question.

[0014] Alternatively, the pressure equalization opening can also extend through an inner cover plate, via which the inner disc is connected to the outer disc. In this context, it is essential that the flow path to the pressure equalization opening is not interrupted by any potentially interfering cover components.

[0015] The cover element according to the invention can be provided with one or more pressure equalization openings of the type described above. The number of pressure equalization openings is determined such that sufficient air circulation always takes place via the pressure equalization devices inserted into the pressure equalization openings and the pressure prevailing in the interior of the cover can be reliably adjusted to the ambient pressure.

[0016] To precisely align the outer and inner panes, at least one spacer can be placed between them. However, this spacer must not obstruct the flow path between the interior of the lid and the pressure equalization device.

[0017] In the cover element according to the invention, the inner pane serves as a carrier for a functional element or is itself a functional element of the cover element. The inner pane serves to influence the transparency properties of the cover element. An electrically switchable shading element is formed on the inner pane, which can be switched between an enable state and a shading or partial shading state by applying a corresponding voltage.

[0018] In the lid element according to the invention, the shading element comprises a liquid crystal cell (LC cell).

[0019] The electrically switchable shading element can be implemented on the inner pane in various ways. For example, the electrically switchable shading element can be part of a film or a glass laminate that is applied to the inner surface of the inner pane.

[0020] In a special embodiment of the lid element according to the invention, the inner disc itself is designed as a liquid crystal cell. In this case, the inner disc consists of a composite of two thin glass plates with a liquid crystal layer arranged between them.

[0021] To give the lid element additional functionality and, in particular, to enable its use as an ambient lighting element, a special embodiment of the lid element according to the invention has a light source on its circumference, preferably comprising LEDs. In this case, it is advantageous if the inner pane has light-guiding properties. Particularly good light-guiding properties can be achieved if the inner pane is made of glass or plastic, especially PMMA.

[0022] To improve light transmission from the inner pane towards the vehicle interior, the inner pane can have a structured surface, contain nanoparticles, and / or be printed accordingly. The inner pane can also be equipped with an additional diffusing layer that acts like a diffuser to scatter light.

[0023] In order to apply a film designed as a liquid crystal cell, i.e., an LC film, to the inner disk, the inner disk, in a preferred embodiment, has at least one flat inner or upper surface. In particular, the disk body of the inner disk itself is flat.

[0024] Alternatively, it is conceivable that the inner disk follows a cylindrical curvature, that is, that the inner disk is curved only around one axis of curvature, so that it follows a cylindrical surface.

[0025] The outer pane, on the other hand, can have a three-dimensional curvature that is adapted to the shape of the vehicle roof in question.

[0026] The flat or simply curved or cylindrical shape of the inner disc makes it possible to laminate LC films, which are very pressure-sensitive, onto the inner disc without any delamination or optical defects within the film.

[0027] To protect vehicle occupants, it can be advantageous for the inner pane to be fitted with a shatterproof device, in particular a shatterproof film, on its outer surface facing away from the interior of the cover. The shatterproof film retains a broken or shattered inner pane, preventing shards or splinters from falling into the vehicle's interior.

[0028] The cover element according to the invention is, for example, a sliding roof cover of a roof opening system of a passenger car. However, it is also conceivable that the cover element according to the invention is designed to be fixed to the vehicle, that is, a fixed roof element that is immovably connected to a vehicle body.

[0029] Further advantages and advantageous embodiments of the subject matter of the invention will become apparent from the description, the drawing and the patent claims.

[0030] Exemplary embodiments of a cover element according to the invention are shown schematically simplified in the drawing and are explained in more detail in the following description. It shows: Fig. 1 a perspective top view of a vehicle roof with a cover element of a roof opening system; Fig. 2 a section through a first embodiment of a lid element; Fig. 3 a section through a second embodiment of a cover element; and Fig. 4 a section through a third embodiment of a lid element.

[0031] In Fig. Figure 1 shows the roof 10 of a passenger car, which is provided with a roof opening 12 that is bounded by a fixed roof section 13. The roof opening 12 can be selectively opened or closed by means of a cover element 14, which is part of a roof opening system designed as a sliding roof.

[0032] The cover element 14, whose cross-section is in Fig. 2, comprises an outer pane 16, which consists of a three-dimensionally curved glass or plastic sheet (PC or PMMA) and whose shape is aligned with a fixed roof section 13 when the lid element 14 is in the closed position, and an inner pane 18, which is completely connected around the perimeter to an underside or inner surface 22 of the outer pane 16 via an adhesive bead 20 that follows the edge of the inner pane 18.

[0033] The outer pane 16, which forms a roof skin element, is provided with a plastic foam covering 24 made of a polyurethane material at its surrounding edge, through which the cover element 14 can be sealed in the roof opening 12 of the vehicle roof 10 and which serves to fix an inner cover sheet 26, through which the cover element 14 can be connected to an adjustment kinematic of the roof opening system not shown in detail.

[0034] Between the outer disc 16 and the planar or cylindrically curved inner disc 18, a cover interior 28 is formed, which is bounded all around by the adhesive bead 20.

[0035] To equalize pressure and prevent condensation within the lid interior 28, and thus prevent fogging of the inner pane 18 and / or the outer pane 16, the lid interior 28 is connected to the environment via a pressure equalization opening 30 that extends through the inner pane 18. An insert 32 is arranged in the pressure equalization opening 30, which includes an air-permeable membrane 34 that is impermeable to water and water vapor. This allows air exchange between the lid interior 28 and the environment, but prevents the transport of moisture.

[0036] On its upper surface 35, the inner pane 18, which consists of glass, polycarbonate (PC) or PMMA, is laminated with a liquid crystal (LC) film 36, which forms an electrically switchable shading element of the cover element 14. By appropriate wiring or by applying an electrical voltage to the liquid crystal film 36, it can be switched between a light-transmitting switching state and a light-opaque or light-transmitting switching state.

[0037] To enable the inner pane 18 to also be used as a lighting element for the interior of the vehicle in question, LED light sources 38 are arranged at the edge of the inner pane 18, by means of which the light-guiding inner pane 18 can be flooded with light. For the light to be directed towards the vehicle interior, the inner pane 18 can have a structured surface, contain nanoparticles within its volume, or be coated with nanoparticles on its surface.

[0038] In Fig. Figure 3 shows a cover element 14', which is also designed as a sliding roof cover and largely corresponds to the one shown in Fig. The lid element shown in section 2 corresponds to this. However, lid element 14' differs from the lid element shown in section 2. Fig. 2. The liquid crystal cell 40 is characterized by the fact that its upper surface 35 of an inner disk 18' does not have a liquid crystal film, but is instead provided with a conventional liquid crystal cell 40, which consists of two thin glass plates 42 and 44 that can be planar or cylindrically curved, depending on the design of the inner disk 18'. The two glass plates 42 and 44, each with a maximum thickness of 1 mm, hold a liquid crystal layer 46 between them, the light transmittance of which depends on the applied electrical voltage. The liquid crystal cell 40, which forms a glass composite consisting of the two glass plates 42 and 44 and the liquid crystal layer 46, is applied to the upper surface 35 of the inner disk 18' via a bonding layer 48. The bonding layer 48 is produced using a so-called optical bonding process.

[0039] Furthermore, the cover element 14' corresponds to the cover element according to Fig. 2.

[0040] In Fig. Figure 4 shows a further embodiment of a cover element 14", which also has a three-dimensionally curved outer disc 16, the circumference of which is provided with a circumferential plastic foam covering 24, via which an inner cover plate 26 is connected to the outer disc 16. The inner cover plate 26 serves as a support for an inner disc 18", which is fixed to the inner cover plate 26 by means of a circumferential adhesive bead 50. The inner cover plate 26 thus also serves to connect the inner disc 18" to the outer disc 16.

[0041] The inner pane 18" is designed as a liquid crystal cell and consists of two thin glass plates 42 and 44, between which a liquid crystal layer 46 is embedded. The inner pane 18", which thus represents a glass composite, can be flat or cylindrically curved.

[0042] For occupant protection, the inner pane 18" is provided on its underside, i.e. on the side facing away from the outer pane 16, with a shatterproof film 52, which is undercut at its edges by the circumferential adhesive bead 50.

[0043] For the exact positioning of the inner pane 18" relative to the outer pane 16, spacers 54 can be arranged between the inner or top surface 35 of the inner pane 18" and the bottom or inside surface 22 of the outer pane 16.

[0044] In order to ensure pressure equalization between a lid interior 28, which is arranged between the outer disc 16 and the inner disc 18", and to prevent condensation in the lid interior 28, the lid inner plate 26 is provided with at least a pressure equalization opening 30, into which an insert 32 is inserted, which has a membrane 34 that is permeable to air but impermeable to water and water vapor.

[0045] According to the embodiments as described above. Fig. 2 and Fig. The cover element 14" is also provided with LED light sources 38 on the circumference of the inner pane 18", so that the inner pane 18" can be used as a lighting device for the vehicle interior via the light-guiding properties of the glass plates 42 and 44. For light transmission, the inner pane 18" can be printed and / or structured in a suitable manner. The LED light sources 38 are fixed to the edges of the glass plates 42 and 44. Reference symbol list 10 Vehicle roof 12 Roof opening 13 Fixed roof section 14 Cover element 16 Outer pane 18 inner disc 20 glue caterpillars 22 Inside 24 Plastic foaming 26 Inner lid sheet 28 Lid interior 30 Pressure equalization opening 32 deployment 34 Membran 35 Top 36 Liquid crystal film 38 LED light source 40 liquid crystal cells 42 glass plate 44 glass plate 46 Liquid crystal layer 48 Compound layer 50 glue caterpillars 52 shatterproof film 54 spacers

Claims

[1] Cover element of a vehicle roof, comprising an outer pane (16) and an inner pane (18, 18', 18"), which is connected around its circumference to an inner surface (22) of the outer pane (16), so that a cover interior (28) is formed between the outer pane (16) and the inner pane (18, 18', 18"), characterized by , that the interior of the lid (28) is provided with a pressure equalization device, wherein an electrically switchable shading element is formed on the inner disc (18, 18', 18") and the shading element comprises a liquid crystal cell (40). [2] Lid element according to claim 1, characterized by that the pressure equalization device is permeable to air and impermeable to water and water vapor. [3] Lid element according to claim 1 or 2, characterized by , that the pressure equalization device comprises an air-permeable membrane (34). [4] Lid element according to claim 3, characterized by, that the membrane (34) is part of an insert (32) which is inserted into a pressure equalization opening (30). [5] Lid element according to claim 4, characterized by , that the pressure equalization opening (30) extends through the inner disk (18, 18'). [6] Lid element according to claim 4, characterized by , that the pressure equalization opening (30) extends through an inner cover plate (26) via which the inner disc (18") is connected to the outer disc (16). [7] Lid element according to any one of claims 1 to 6, characterized by , that at least one spacer (54) is arranged between the outer pane (16) and the inner pane (18"). [8] Lid element according to any one of claims 1 to 7, characterized by , that the electrically switchable shading element is part of a film (36) or a glass laminate which is applied to an inside of the inner pane (18, 18'). [9] Lid element according to any one of claims 1 to 7, characterized by , that the inner disk (18") is formed as a liquid crystal cell. [10] Lid element according to any one of claims 1 to 9, characterized by , that the inner disk (18, 18', 18") is provided on its periphery with a light source (38) which preferably comprises LEDs. [11] Lid element according to any one of claims 1 to 10, characterized by , that the inner pane (18, 18', 18") is made of glass or of plastic, in particular of PMMA. [12] Lid element according to any one of claims 1 to 11, characterized by , that the inner disk (18, 18', 18") is planar. [13] Lid element according to any one of claims 1 to 11, characterized by , that the inner disk (18, 18', 18") is curved about an axis of curvature so that it follows a cylindrical surface. [14] Lid element according to any one of claims 1 to 13, characterized by, that the inner pane (18") is provided on its outer side facing away from the interior of the cover (28) with a splinter protection device, in particular with a splinter protection film (52). [15] Lid element according to any one of claims 1 to 14, characterized by that it is a sunroof cover. [16] Cover element according to any one of claims 1 to 15, characterized by that it is a vehicle-mounted fixed roof element.

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