Windshield including a protective plate
Integrating a transparent ceramic or monocrystalline protective plate into windshields addresses the high cost of sapphire by providing effective scratch and impact protection at a reduced cost, expanding its use beyond military and high-end applications.
Patent Information
- Application Number
- FR2023011530
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-10-24
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2043-10-24
AI Technical Summary
Existing scratch-resistant and projectile-resistant sapphire films or armor are expensive due to the high cost of synthesizing single-crystal sapphire, limiting their use to military applications or high-end products.
A windshield with a protective plate made of transparent ceramic or transparent monocrystalline material with a Vickers hardness greater than 10 GPa is integrated into sensitive areas, using various bonding methods to provide scratch and impact protection while reducing material costs.
The solution effectively protects sensitive areas of windshields from scratches and impacts at a lower cost, enabling wider application across various vehicles and devices.
Smart Images
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Abstract
Description
Title of the invention: Windshield comprising a protective plate. Field of the invention
[0001] The present invention relates to a windshield comprising a protective plate intended to protect a sensitive area of said windshield, in particular against scratches and / or impacts. The present invention also relates to a vehicle equipped with such a windshield. Previous art
[0002] Sapphire is the second hardest material on the Mohs scale, after diamond. This property makes it particularly interesting for creating scratch-resistant films or projectile-resistant armor.
[0003] By way of example, document WO 2006135832 describes armor incorporating sapphire. This armor is specifically designed to protect a military vehicle. This armor creates a shield that prevents projectile penetration.
[0004] Document WO2014078524 describes an electronic device, such as a mobile phone (or smartphone), whose screen is equipped with a sapphire film. This film protects the screen against scratches and impacts.
[0005] Disadvantages of the prior art
[0006] One drawback of such films or armor is that sapphire is an expensive material, as it must be synthesized as a single crystal from a molten bath. The melting temperature is above 2000 °C, which makes the growth process very costly.
[0007] Consequently, at present, the use of such films or armor is limited to military applications or high-end products.
[0008] There is therefore a need for a protective device which provides scratch and / or shock protection, and which has a reduced cost allowing it to be used on a wider range of products. Description of the invention
[0009] These objectives, as well as others which will become clearer later, are achieved using a windscreen, comprising a protective plate, arranged at the level of a sensitive area of the windscreen, the sensitive area representing an area less than 5% of the total surface of the windscreen, the protective plate being made of transparent ceramic or of a transparent monocrystalline material having a Vickers hardness greater than 10 GPa.
[0010] According to one embodiment of the invention, the protective plate is glued to the outer surface of the windshield, at the level of the sensitive area.
[0011] According to another embodiment, the protective plate is inserted and glued into a recess machined in the windshield or into an opening cut in the windshield.
[0012] According to a particular embodiment of the preceding embodiment, the windshield is machined to create a recess in the thickness of the windshield, at the level of the sensitive area, the protective plate being inserted and glued into the recess.
[0013] According to another particular embodiment, the windshield is cut to create an opening in the windshield, at the level of the sensitive area, the protective plate being inserted and glued into the opening.
[0014] According to another embodiment, the windshield is made of laminated glass. In this case, advantageously, the outer sheet of the windshield is cut out at the sensitive area, with the protective plate inserted and bonded into the cutout in the outer sheet. The inner sheet of the windshield can also be cut out at the sensitive area, with a second protective plate inserted and bonded into the cutout in the inner sheet.
[0015] The protective plate can be made of transparent ceramic based on aluminum oxynitride.
[0016] Alternatively, the protective plate can be made of a transparent single-crystal material chosen from magnesium aluminate spinel, single-crystal aluminum oxide, aluminum oxide or hydroxide, and zirconium silicate.
[0017] The invention also proposes a vehicle comprising: - a windshield as defined above, and - at least one data acquisition device disposed behind the windscreen, said at least one data acquisition device being arranged to capture, through the windscreen, data from outside the vehicle, the sensitive area of said windscreen being positioned in front of said at least one data acquisition device.
[0018] The vehicle may be an autonomous vehicle.
[0019] List of figures
[0020] The invention will be better understood upon reading the following description of preferred embodiments, given by way of simple figurative and non-limiting example, and accompanied by the figures, among which: - [Fig.l] is a perspective view of a vehicle; - [Fig.2] is a partial cross-sectional view of a windshield of the vehicle of the [Fig.1], according to a first embodiment of the invention; - [Fig.3] is a view similar to [Fig.2], the windshield being made of glass puff pastry; - [Fig. 4] is a partial cross-sectional view of a windshield of the vehicle of the [Fig.1], according to a second embodiment of the invention; - [Fig. 5] is a view similar to [Fig. 4], the windshield being made of glass puff pastry; - [Fig. 6] is a partial cross-sectional view of a windshield of the vehicle of the [Fig.1], according to a third embodiment of the invention; - [Fig.7] is a view similar to [Fig.6], the windshield being made of glass puff pastry; and - [Fig.8] is a partial cross-sectional view of a windshield of the vehicle of [Fig. 1], according to a fourth embodiment of the invention. Detailed description of embodiments of the invention 1. Vehicle
[0021] Figure 1 represents a vehicle 1. In this example, vehicle 1 is a motor vehicle. Generally, the invention can be applied to any type of vehicle, including road vehicles (cars, vans, trucks, public transport vehicles: buses, coaches, etc.) or railway vehicles (trains, subways, trams, etc.). The invention can also be applied to aircraft or industrial or military vehicles.
[0022] The vehicle 1 includes a passenger compartment 2, a front windscreen 3, and a rear windscreen 4, also called a rear window.
[0023] Vehicle 1 may be an autonomous, semi-autonomous or non-autonomous vehicle.
[0024] In the following description, the front windscreen 3 is described in more detail. The rear windscreen 4 of the vehicle 1 can be made in a similar way, and therefore will not be described in detail.
[0025] The windscreen 3 can be made of laminated glass.
[0026] A glass comprising at least an outer sheet 5 and an inner sheet 6, fixed together by a lamination interlayer 7, is called "laminated glass".
[0027] The lamination interlayer 7 can for example be made of polymer, polyvinyl butyral (PVB), polyurethane (PU), plasticizer-free thermoplastic such as ethylene / vinyl acetate copolymer (EVA), or ionomer resin.
[0028] In a known manner, the windscreen 3 can in this case be obtained by hot lamination of the different layers 5, 6, 7.
[0029] The windshield 3 may be curved. In the case of a motor vehicle, in the area of the data acquisition device, the windshield generally has a horizontal radius of curvature greater than or equal to 0.9 m and a vertical radius of curvature greater than or equal to 0.5 m. These values are given as an example and depend on the intended application for the windshield.
[0030] The vehicle 1 further comprises a data acquisition device 8. Alternatively, the vehicle 1 may comprise several data acquisition devices.
[0031] The data acquisition device 8 is fixed, for example via a plate, behind the windscreen 3, facing an area which is preferably located in the central and upper part of the windscreen 3.
[0032] The data acquisition device 8 can be a sensor configured to detect the presence of at least one object in an external environment of the vehicle 1. The sensor is then configured to scan the external environment of the vehicle 1, for example by means of the emission of radar waves.
[0033] The data acquisition device 8 can also be a camera, configured to capture images of the external environment of the vehicle 1. The camera can be a high-definition camera, known as an HD camera, an infrared or near-infrared camera, or a thermal camera.
[0034] Generally speaking, the data acquisition device 8 here refers to any device enabling the acquisition of data from outside the vehicle 1.
[0035] The use of several data acquisition devices 8, in particular the combination of at least one sensor and at least one camera, makes it possible to increase the level of security. 1. Protective plate
[0036] The windscreen 3 includes a protective plate 9. The thickness of the protective plate 9 is, for example, between 25 µm and 1 mm.
[0037] The protective plate 9 can have any shape, in particular circular, oval, ellipsoidal, rectangular, square or polygonal.
[0038] The protective plate 9 is positioned over a sensitive area of the windshield 3. A sensitive area of the windshield 3 is, for example, located directly above the data acquisition device 8. Such an area is particularly susceptible to scratches, as any optical defect in the field of vision of the data acquisition device 8 can impair its operation. The reliability of the data acquisition device 8 is important, especially in the case of a semi-autonomous or autonomous vehicle 1.
[0039] The area of the sensitive zone depends on the size of the data acquisition device(s) 8, but remains small in relation to the total area of the windscreen 3. The sensitive zone represents, for example, an area between 0.1% and 5% of the total area of the windscreen 3, preferably an area between 0.1% and 1% of the total area of the windscreen 3.
[0040] The protective plate 9 has a surface area enabling it to cover the sensitive area. This surface area is, for example, between 5 mm² and 3000 mm².
[0041] The sensitive area advantageously has a substantially flat surface. Indeed, a flat protective plate 9 is simpler and less expensive to produce, and the curvature of the sensitive area must then be sufficiently small to allow bonding.
[0042] Generally speaking, the smaller the protective plate 9, the greater the curvature of the sensitive area can be without hindering the bonding.
[0043] The maximum acceptable curvature Cmax of the sensitive area can, for example, be defined as Cmax = 0.5 mm / a², where a denotes the largest dimension of the protective plate 9. The corresponding minimum radius of curvature is then equal to 1 / Cmax. For a protective plate 9 whose largest dimension is 10 mm, this gives a radius of curvature of 0.2 m, and for a protective plate 9 whose largest dimension is 100 mm, this gives a radius of curvature of 20 mm.
[0044] The protective plate 9 can be made of transparent ceramic, for example of transparent ceramic based on aluminum oxynitride (ALON).
[0045] The protective plate can alternatively be made of a transparent single-crystal material having a Vickers hardness greater than 10 GPa.
[0046] A Vickers hardness measurement method is known per se and standardized, notably by standard EN 6507. It will therefore not be described in detail here.
[0047] The Vickers hardness measurement result can be expressed in kilogram-force per square millimeter (kgf / mm²), also known as the "HV number." The Vickers hardness measurement result can also be expressed in pascals. To convert the Vickers hardness number to pascals, the hardness number in kilogram-force per square millimeter (kgf / mm²) must be multiplied by the standard gravity (9.81) to obtain the hardness in MPa (N / mm²).
[0048] Such a transparent single-crystal material can, for example, be chosen from magnesium aluminate spinel (Spinel), single-crystal aluminum oxide (Sapphire), aluminum oxide or hydroxide (Alumina), or zirconium silicate (Zircon).
[0049] According to a first embodiment, shown in Figures 2 and 3, the protective plate 9 is glued to the outer surface of the windscreen 3, at the level of the sensitive area.
[0050] According to a second embodiment, shown in Figures 4 and 5, the windshield 3 is machined to create a recess 10 in the thickness of the windshield 3, at the level of the sensitive area. The protective plate 9 is then inserted and bonded into the recess 10.
[0051] The recess 10 is, for example, made with a milling cutter. Its depth is adapted so that the outer surface of the protective plate 9 is at the same level as the outer surface of the glass.
[0052] In the second embodiment, when the windshield 3 is made of laminated glass, the machining can be carried out by cutting the outer sheet 5 of the windshield 3 at the level of said sensitive area. The protective plate 9 is then inserted and bonded into the recess 10 formed by the cut in the outer sheet 5. This cut can be made before or after the assembly of the laminated glass.
[0053] According to a third embodiment, shown in Figures 6 and 7, the windshield 3 is cut to create an opening 11 in the windshield 3, at the level of the sensitive area. The protective plate 9 is then inserted and glued into said opening 11.
[0054] Figure 8 represents a fourth embodiment, in which the windshield 3 is made of laminated glass. Here, the outer sheet 5 of the windshield 3 is cut out at the sensitive area. A first protective plate 9A is then inserted and bonded into the cutout 10A in the outer sheet 5.
[0055] Furthermore, in the fourth embodiment, the inner sheet 6 of the windshield 3 is also cut out at the sensitive area. A second protective plate 9B is then inserted and glued into the cutout 10B of the inner sheet 6.
[0056] In the various embodiments described above, the protective plate 9 can be bonded using a variety of mechanical or chemical means. These include, in particular, heat-cured adhesives, radiation-cured adhesives, time-cured adhesives, chemically cured adhesives, and / or catalyst-cured adhesives, for example, polyurethanes, thermoplastic polyurethanes, epoxies, silicones, polyvinyl butyral, cyanoacrylate, and metal-based adhesives. Molten glass or other materials can also be used as adhesives. A selection criterion is to ensure that the glass and the protective plate 9 are optically matched so as to minimize optical distortions.
[0057] Alternatively, the bonding can be carried out during the bending of the glass, while hot, without any addition of glue.
[0058] In the case of laminated glass, the lamination interlayer 7 can be used to bond the protective plate 9.
[0059] The windscreen 3 may include several protective plates 9, to protect several sensitive areas.
[0060] Organic and / or inorganic coatings can be deposited on the glazing and / or on the protective plate(s) 9, to further increase the anti-scratch function.
[0061] The use of one or more protective plate(s) 9 on targeted reduced areas thus makes it possible to effectively protect the windscreen 3, 4, while limiting the impact on its price, therefore on the price of the vehicle 1.
[0062] Of course, the present invention is not limited to the embodiments described above by way of example; it extends to other variants.
Claims
Demands
1. Windscreen (3,4), characterized in that it comprises a protective plate (9, 9A, 9B), arranged at the level of a sensitive area of said windscreen, the sensitive area representing an area less than 5% of the total area of said windscreen (3, 4), said protective plate being made of transparent ceramic or of a transparent monocrystalline material having a Vickers hardness greater than 10 GPa, and in which said protective plate (9, 9A, 9B) is inserted and bonded into a recess (10) machined in said windscreen (3, 4) or into an opening (11) cut in said windscreen (3, 4).
2. Windscreen according to claim 1, wherein said windscreen (3, 4) is machined to create a recess (10) in the thickness of said windscreen, at the level of said sensitive area, said protective plate (9) being inserted and glued into said recess.
3. Windscreen according to claim 1, wherein said windscreen (3, 4) is cut to create an opening (11) in said windscreen, at the level of said sensitive area, said protective plate (9) being inserted and glued into said opening.
4. Windscreen according to any one of claims 1 to 3, wherein said windscreen (3, 4) is made of laminated glass.
5. Windscreen according to claim 4, wherein the outer sheet (5) of said windscreen is cut out at said sensitive area, said protective plate (9A) being inserted and glued into said cutout (10A) of the outer sheet.
6. Windscreen according to claim 5, wherein the inner sheet (6) of said windscreen (3, 4) is cut out at said sensitive area, a second protective plate (9B) being inserted and glued into said cutout (10B) of the inner sheet.
7. Windscreen according to any one of claims 1 to 6, wherein said protective plate (9, 9A, 9B) is made of transparent ceramic based on aluminum oxynitride.
8. Windscreen according to any one of claims 1 to 6, wherein said protective plate (9, 9A, 9B) is made of a transparent single-crystal material selected from magnesium aluminate spinel, single-crystal aluminum oxide, aluminum oxide or hydroxide, and zirconium silicate.
9. Vehicle (1), in particular autonomous, characterized in that it comprises: - a windscreen (3, 4) according to any one of claims 1 to 8, and - at least one data acquisition device (8) disposed behind said windscreen, said at least one data acquisition device being arranged to capture, through the windscreen, data from outside the vehicle, the sensitive area of said windscreen being disposed in front of said at least one data acquisition device.