Method for manufacturing a sensor cover for a radar device, sensor cover and vehicle

Abstract

The invention relates to a method for manufacturing a sensor cover (100, 100A) for a radar device comprising the steps: a) Providing a decorative layer (130) with real wood veneer and b) Joining the decorative layer (130) to a plastic body (110). A sensor cover and a vehicle are also specified.

Description

[0001] The invention relates to a method for producing a sensor cover for a radar device, a sensor cover and a vehicle with a sensor cover.

[0002] Sensor covers are used, for example, in motor vehicles to cover radar devices on the visible side and to visually conceal them. These can be short-range or long-range radar systems that operate in the 76 / 77 GHz range and are hidden behind bumper fascias, radomes, or other visible components of the vehicle. The sensor cover should, on the one hand, ensure an appealing appearance for the customer, which, if possible, matches the rest of the vehicle's color and appearance, and, on the other hand, offer low effective transmission losses. To date, sensor covers have usually been made of plastics (PC, PC-ABS, ASA), as these offer good radar transparency and are easy to process using injection molding.

[0003] Vehicle designers are expressing a desire for particularly high-quality sensor covers with innovative designs. In particular, there is a desire to create the appearance of "natural" materials, as they occur in nature.

[0004] Against this background, the object of the invention is to provide a method for producing a sensor cover that creates a novel appearance with the impression of natural materials. In a further aspect, the sensor cover should have a high-quality appearance and feel.

[0005] A method for producing a sensor cover for a radar device is provided, comprising the steps: a) Providing a decorative layer with real wood veneer and b) Bonding the decorative layer to a plastic body. The bonding can be done, for example, in an injection molding process or by gluing.

[0006] Furthermore, a sensor cover for radar devices is specified with a layer structure comprising a decorative layer with real wood veneer and a plastic body which is connected to the decorative layer.

[0007] The use of real wood creates a particularly natural look that cannot be achieved with a purely plastic construction.

[0008] The decorative layer can be very thin, for example, film-like. The decorative layer can be composed of multiple layers. The decorative layer contains a real wood veneer. This can be glued to a plastic film, such as PC film. The decorative layer is visible in the finished sensor cover. The size of the decorative layer can be selected so that it extends over the entire visible side of the sensor cover or just over a portion.

[0009] The plastic body is, in particular, a support body for the decorative layer. The plastic body can, for example, define the external dimensions of the sensor assembly. Examples of plastics from which the plastic body is formed are PC, PC-ABS, and ASA. The plastic body is viewed from the visible side of the sensor cover, preferably arranged behind the decorative layer.

[0010] In a preferred embodiment, in a subsequent step c), the sensor cover is measured for its radar transparency and measurement results are recorded. Based on the measurement results, at least a partial surface area in a transmission range is laser treated to selectively remove material, thereby improving the transmission of the sensor cover. A sensor cover produced using this method has a surface structuring created by laser treatment in at least a partial surface area of ​​a transmission range.

[0011] The sensor cover has a transmission area through which the radiation from the radar device passes when installed. The transmission area of ​​the sensor cover is an area located within the sensor's reception area and through which the emitted or detected radar radiation passes. The transmission area can, for example, be a central area of ​​the sensor cover or be located in an edge area. At least the transmission area is preferably designed in terms of material, layer structure, and thickness so that radar radiation can pass through it to an extent that does not impair the evaluation of the received radar signals.

[0012] The transmission area is irradiated with laser radiation, at least in a partial surface area, so that material is locally vaporized and thus removed. By using laser radiation, the material removal can be finely controlled both in terms of the amount removed and the size of the removed structures. In particular, removal of a few micrometers is possible, both in terms of the removed layer thickness and the cross-section of the removed structure. Laser radiation can be used with high spatial resolution, which ensures the precision of the treatment. The laser treatment locally changes the layer thickness and / or surface structure of the sensor cover, thereby specifically altering the transmission.

[0013] The transmission properties of the sensor cover are determined, in particular, by the magnitude and phase of the attenuation, as well as the magnitude and phase of the reflection of the radar radiation. Wood is a natural material and therefore contains various inhomogeneities, such as knots and moisture levels. Furthermore, wood exhibits varying attenuation and reflection behavior depending on the orientation of the wood fibers. Using the process described above, phase inhomogeneities in the sensor cover can be reduced or even completely eliminated. This design has the advantage that the radar transparency of the transmission range can be individually optimized for each manufactured sensor cover. This allows the radar transparency of the sensor cover to be optimized, especially when using natural materials with non-homogeneous attenuation and reflection behavior.More areas of a real wood veneer can be used, finding suitable wood veneers is made easier, and radar transparency can be homogenized even with strong grain.

[0014] In a preferred embodiment, step c) involves determining transmission parameters at a plurality of locations and creating a transmission map based on the transmission parameters. The laser treatment is then performed based on the transmission map.

[0015] When using a transmission characteristic map, the laser treatment specifically treats those areas with poorer transmission characteristics, e.g. those that deviate from the optimum of the component, and improves the transmission characteristics in these areas, e.g. by adjusting them to the optimum.

[0016] In a particularly preferred embodiment, transmission phase values ​​are determined as transmission characteristic values ​​and a transmission phase map is created as transmission characteristic value map.

[0017] The achieved optimization can be verified, for example, by remeasuring the transmission parameters and creating a new transmission parameter map. Using a transmission parameter map, it is advantageous to compensate for material inhomogeneities.

[0018] To avoid susceptibility to contamination and for aesthetic reasons, one design provides for the material removal to take place on the back of the sensor cover. The back refers to the side that faces the radar device when installed.

[0019] It can be provided that the material removal by means of laser radiation takes place only in individual previously defined areas or areas identified and locally limited based on the measurement results, or even only selectively.

[0020] In one embodiment, the material removal occurs across the entire surface of the transmission area. Such large-scale material removal can be used, for example, to correct tool changes, such as washouts, which can occur over the tool's service life. This enables longer tool use without compromising the quality of the sensor coverage.

[0021] In one embodiment of the method, a heating element is embedded in the sensor cover and / or the decorative layer is provided with a protective layer.

[0022] For example, the plastic body is manufactured as a pre-molded part with an embedded heating element, and the decorative layer and the pre-molded part are combined in a single injection molding process within an injection molding tool. This process allows the number of layers in the sensor cover to be reduced, which has a beneficial effect on radar transparency. The pre-molded part with an embedded heating element is manufactured, for example, in a preceding injection molding process. The pre-molded part is inserted into the injection molding tool on one side, for example. The decorative layer with real wood veneer is inserted on the other side. A third medium, preferably a plastic, in particular PC-PC-ABS / ASA, is then injected between the decorative layer and the pre-molded part.

[0023] In an alternative process, the decorative layer and the heating element are placed in an injection mold, and the decorative layer is back-injected in the closed injection mold with a plastic material, e.g., PC-PC-ABS / ASA-Luran, to form the plastic body and integrate the heating element into the plastic body. The decorative layer and heating element are bonded together by the plastic body in a single process step. The advantage of this process is that the heating element can be positioned closer to the visible side of the sensor array in the layered structure.

[0024] Accordingly, in one embodiment, the sensor cover has an integrated heating element, preferably integrated into the plastic body. The heating element can be formed, for example, by a wire or a conductor structure.

[0025] To reduce soiling or damage to the sensor cover, one embodiment provides a protective layer on the visible side. The protective layer is preferably applied to the decorative layer and, in particular, covers it completely. The protective layer is preferably made as thin as necessary to meet stone chip and environmental requirements. The protective layer is preferably made of a transparent material. The protective layer can, in particular, be a polyurethane layer or a bulletproof glass film. The protective layer can, for example, be glued on or applied to the sensor cover by PUR flooding. The protective layer is particularly preferably designed as a real glass layer. The use of a real glass layer reinforces the high-quality appearance of the real wood surface and improves the feel of the sensor cover. The combination creates a sensor cover with a particularly high-quality appearance.

[0026] Furthermore, a vehicle with a sensor cover as described above is specified.

[0027] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. Where the term "may" is used in this application, it refers to both the technical possibility and the actual technical implementation.

[0028] The following examples are explained with reference to the accompanying drawings, which show schematically: Fig. 1 and Fig. 2 exemplary procedures, Fig. 3 an example transmission characteristic map, Fig. 4 and Fig. 5 exemplary sensor covers and Fig. 6 an exemplary vehicle.

[0029] An exemplary method for manufacturing sensor covers for radar devices is described in Fig. 1. First, in step A, a decorative layer with real wood veneer is provided. In step B), the decorative layer is connected to a plastic body, e.g., in an injection molding process or by gluing. The sensor arrangement can also include an embedded heating element. For this purpose, for example, the plastic body can be produced as a pre-injected part with an embedded heating element, and the decorative layer and the pre-injected part can be connected to one another in an injection molding process in an injection molding tool. For example, the decorative layer and the heating element can be inserted into an injection molding tool, and the decorative layer can be back-injected with a plastic material in the closed injection molding tool to form the plastic body and integrate the heating element into the plastic body.

[0030] Fig. Figure 2 shows another exemplary method for manufacturing sensor covers. First, in steps A and B, as described in Fig. 1, a sensor cover with a transmission area is provided. I

[0031] In a subsequent step C, the sensor cover is laser treated. The laser treatment removes material from the back of the sensor cover, thereby improving the transmission of radar radiation in the transmission range.

[0032] The exemplary method may optionally include a step C1, which involves measuring the sensor coverage for its radar transparency and recording measurement results. The laser treatment in step C is then performed based on the measurement results.

[0033] In particular, in step C1, transmission parameters, here, for example, transmission phase values, are recorded at a variety of locations during the measurement. These are graphically represented in a spatially resolved transmission parameter map (TK) based on the transmission parameters. In the example shown, a transmission phase map is created. Based on this transmission phase map, the sensor cover is laser treated in step B. Steps A, B, and C correspond to steps a), b), and c) in the claims and the description, respectively.

[0034] Fig. Figure 3 shows an example of a transmission characteristic map TK. This shows the transmission range TB with different transmission phases on the surface of the sensor cover. Fig. For clarity, Figure 3 shows three areas: B0 - B2. In area B0, the transmission phase is 0°, in area B1, 1°, and in area B2, 2°. In reality, this transmission phase map can exhibit many more gradations in a much more delicate form due to the wood grain and the resulting phase inhomogeneities. The laser treatment removes material in such a way that the inhomogeneities in the phase distribution are compensated, and the transmission phase is ideally at 0° across the entire transmission range. The material removal can, for example, be in the range of 10 to 20 micrometers.

[0035] Fig. Figure 4 shows a cross-sectional view of an exemplary sensor cover 100. This includes a plastic body 110, on the front of which a decorative layer with real wood veneer is arranged. The sensor assembly has a front side 112 and a back side 114. On the back side 114, an (optional) laser treatment was performed locally in the transmission area TB in region B3, removing material and altering the surface of the back side 114.

[0036] Fig. Figure 5 shows another exemplary sensor cover 100A. The back side 114 of the plastic body was Fig. 4, treated with laser radiation and modified in the transmission range TB in the area B3. The transmission range TB is in Fig. 4 and Fig. 5 arranged between the dotted lines. In addition to the plastic body 110 on its front side 112, the sensor cover 100A further comprises a heating element 120 integrated into or glued to the plastic body, the decorative layer 130 with a real wood veneer, and a protective layer 140. The protective layer is formed as an adhesive-applied bulletproof glass layer or by PUR flow coating and forms the outer surface of the sensor cover 100A.

[0037] Fig. 6 shows a vehicle 1 in which a sensor cover 100 or 100A is provided in the area of ​​the front bumper fascia. List of reference symbols A, B, C, C1 process steps B0, B1, B2, B3 areas TB transmission range TK transmission characteristic card 1 vehicle 100, 100A sensor cover 110 plastic bodies 112 Front 114 Back 120 heating element 130 decorative layer with real wood veneer 140 protective layer

Claims

[1] A method for producing a sensor cover (100, 100A) for a radar device, comprising the steps of: a) providing a decorative layer (130) with real wood veneer and b) connecting the decorative layer (130) to a plastic body (110). [2] Method according to claim 1, wherein in a subsequent step c) the sensor cover (100, 100A) is measured with regard to its radar transparency and measurement results are recorded, wherein, based on the measurement results, a laser treatment of at least one surface portion in a transmission region (TB) is carried out for targeted material removal, whereby the transmission of the sensor cover (100, 100A) is improved. [3] Method according to claim 2, wherein step c) a determination of transmission parameters at a large number of locations and creation of a transmission map (TK) based on the transmission parameters, The laser treatment is carried out based on the transmission characteristic map (TK). [4] Method according to claim 3, wherein transmission phases are determined as transmission characteristics and a transmission phase map is created as transmission characteristic map (TK). [5] Method according to one of the preceding claims, further comprising a heating element (120) is embedded in the sensor cover and / or the decorative layer (130) is provided with a protective layer (140). [6] Method according to claim 5, wherein the plastic body (110) is produced as a pre-molded part with an embedded heating element (130) and the decorative layer (130) and the pre-molded part are joined together in an injection molding process in an injection molding tool. [7] Method according to claim 5, wherein the decorative layer (130) and the heating element (120) are inserted into an injection molding tool and the decorative layer (130) is back-injected in the closed injection molding tool with a plastic material to form the plastic body (110) and to integrate the heating element (120) into the plastic body (110). [8] Sensor cover for radar devices with a layer structure comprising a decorative layer (130) with real wood veneer and a plastic body (110) which is connected to the decorative layer (130). [9] Sensor cover according to claim 8, further comprising a heating element (120) embedded in the sensor cover and / or a protective layer (140) on the decorative layer (130), wherein the protective layer (140) is preferably formed as a real glass layer. [10] Sensor cover according to claim 8 or 9, wherein the sensor cover has a surface structuring produced by laser treatment at least in a partial area (B1, B2, B3) of a transmission area (TB). [11] Vehicle with a sensor cover according to one of claims 8 to 10.

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