Vehicle radome and method for manufacturing the same

Abstract

The vehicle radome comprises a front layer (1) and a rear layer (2), both of which are made of thermoplastic material, and the radome further comprises a heating element (3) arranged on a surface of the front layer (1) opposite to the rear layer (2). The method for manufacturing the radome comprises: forming a front layer (1), wherein the heating element (3) is arranged on a surface of the front layer (1); arranging a conductive element (5) on the heating element (3); forming a rear layer (2); assembling the front layer (1) and the rear layer (2) so that the heating element (3) is located on the surface of the front layer (1) opposite to the rear layer (2). The present invention provides a radome having a heating function and an excellent appearance.

Description

Technical Field

[0001] The invention relates to a vehicle radome, for example a decorative radome used as an emblem with a metallic image, in particular a radome in front of a radar arranged in a front grille of a vehicle, with an integrated heating function, and a method for manufacturing said radome. Background Art

[0002] Vehicles with sensors that can sense their surroundings are a key factor in reducing road fatalities. Through sensors, driver assistance features are implemented to minimize risk and increase the likelihood of avoiding collisions.

[0003] Vehicles are designed to provide an aesthetically pleasing impression. Therefore, the sensor must be integrated inside the vehicle behind a cover to perform its function, hiding it from public view and harmonizing with the vehicle's aesthetic design.

[0004] For radar sensors, this cover is called a radome. As mentioned above, the radome must minimize the effect of its presence on the radar's transmitted and received waves. This is especially important in adverse weather conditions, as driving becomes more dangerous due to reduced visibility, road conditions, etc. Obviously, water, ice and snow pose obvious dangers to the functioning of the radar, as they block radar waves and can settle on the radome surface.

[0005] Therefore, the radome must be able to remove such layers, for example, by melting them. Integrating heating functionality in a decorative radome is a challenging task, considering the complexity of the design, the different materials used and the decorative technology required to faithfully reproduce the brand identity.

[0006] Several inventions have disclosed the use of heating for automotive radomes.

[0007] DE 19724320A1 discloses arranging electrical conductor tracks in a curved dielectric body so that the conductive structure does not lie in one plane. This invention does not provide a solution for manufacturing a radome, but only presents a concept that needs to be produced.

[0008] DE 2017055182A1 discloses a flexible printed circuit board which is injection molded from thermoplastics. Circuit tracks are used instead of wires to transmit current. Electrical contact elements are present in the circuit board so that a plug-in basket can contact them.

[0009] The main limitation of this invention comes from the fact that circuit tracks are used, since the performance of the radome using this technology is significantly worse than using wires.

[0010] DE 10156699 A1 discloses a conductor path which is applied to the rear surface of a plastic component representing a brand logo, which in turn is attached to a second plastic component such that the conductor path is sandwiched between the two plastic materials.

[0011] The problem with this invention is the distance between the conductor path and the front surface, where ice or snow will settle and need to be removed.

[0012] US 20060086710A1 discloses a film embedded conductor strip placed in the inner surface of a polymer component. A control unit regulates the amount of current circulating through the conductor strip, thereby controlling the heating output. Again, a problem with this invention is the distance between the conductive element and the front surface, where ice or snow will deposit and will need to be removed.

[0013] DE102014002438A1 discloses a method for manufacturing a heatable radome, in which a thin foil with grooves for embedding wires is formed and insert molded. The electrical contact between the element and the wire is completed at the grooves of the film.

[0014] While this solution may allow the foil to be placed on the outermost radome surface, thereby optimizing heat transfer and efficiency, it lacks protection in the contact area. As a result, the metals in this location are exposed to the environment and are subject to corrosion and degradation over time.

[0015] DE 10 2013 207 482 A1 discloses a similar invention as DE 10 2014 002 438 A1 and is therefore subject to the same limitations.

[0016] The foregoing shows the design and manufacturing problems that affect heatable radome solutions. The present invention aims to address these problems while providing an aesthetically pleasing and functional solution that is easy to manufacture. Summary of the invention

[0017] By using the radome of the present invention, the above-mentioned disadvantages can be solved and the following other advantages can be provided.

[0018] The vehicle radome of the present invention comprises a front layer and a rear layer, both of which are made of thermoplastic material, and is characterized in that the radome further comprises a heating element, such as a foil with a wire, located on a surface of the front layer opposite to the rear layer.

[0019] Advantageously, the conductive wires are embedded in the foil.

[0020] Furthermore, the radome comprises a conductive element connected to each of the conductive lines of the foil, the conductive element preferably being arranged in a groove formed on the rear surface of the foil.

[0021] In the radome of the present invention, the rear layer preferably further comprises a housing for a connector, the housing comprising holes for placing conductive pins.

[0022] According to two alternative embodiments, the conductive element is a pad or a base.

[0023] Furthermore, in the radome of the invention, both the front layer and the rear layer have recesses and protrusions that are complementary to one another for optimizing the passage of radar waves through the radome and for defining the signature of the vehicle.

[0024] The front layer and / or the back layer may also comprise tracks arranged along the entire periphery of the front layer and / or tracks arranged around the recesses for the conductive elements.

[0025] According to a second aspect, the present invention also relates to a method for manufacturing the aforementioned vehicle radome, the method comprising the following steps:

[0026] - forming the front layer, wherein the heating element is arranged on a surface of the front layer, the heating element being, for example, a foil with a conductive wire;

[0027] - placing the conductive element on the heating element;

[0028] - forming the rear layer;

[0029] - Assembling the front layer and the back layer such that the foil is located on the surface of the front layer opposite to the back layer.

[0030] The method of the present invention may further comprise the following steps:

[0031] - arranging the conductive pins on the rear layer before assembling the front layer and the rear layer; and / or

[0032] - providing solderable tracks on said front layer and / or rear layer, the step of providing said conductive element on said front layer preferably being performed by soldering.

[0033] Furthermore, the forming of the front layer and the rear layer is preferably performed by injecting thermoplastic material in the first and second tools.

[0034] The present invention discloses a radome with heating function and excellent appearance. In addition, the present invention provides a method for simply and firmly connecting the heating element of the radome to an electrical connector, which is usually located on the innermost surface of the radome facing the vehicle engine.

[0035] For optimal heating performance, the heating element is positioned as close as possible to the outermost surface where water, ice or snow may accumulate.

[0036] In several of the inventions described above, the heating element is disposed on the rear surface of the front layer. The thermoplastic material acts as an insulator, so in these cases the heating element needs to consume more power to reach a certain temperature than in the present invention where the heating element is directly on the outermost surface.

[0037] The present invention also prevents corrosion of the electrical contact area accessible to the foil in which the heating wire is embedded by:

[0038] - providing grooves on the rear surface of the front layer,

[0039] - surrounding said groove with a thermoplastic material,

[0040] - fill the housing on the rear layer with conductive material,

[0041] - Eliminate direct ingress of air and water via weldable tracks around the area.

[0042] The present invention also optimizes the electrical contact between the heating wire and the connector pin by:

[0043] - adding a conductive element (e.g. a pad or a base) to the wire accessible through the groove so that the mechanical stress on the embedded thin wire is transferred to the more solid structure of the conductive element,

[0044] - filling the housing with conductive elements,

[0045] - All components are securely attached using laser welding (foils and front and back layer attachment). BRIEF DESCRIPTION OF THE DRAWINGS

[0046] For a better understanding of the above and for the purpose of providing examples only, some non-limiting drawings are presented which schematically depict practical embodiments.

[0047] Figure 1 and Figure 2 is a cross-sectional view showing a vehicle radome according to a first embodiment of the present invention; and

[0048] Figure 3 is a cross-sectional view of a vehicle radome in a second embodiment according to the present invention. DETAILED DESCRIPTION

[0049] exist Figure 1 and Figure 2 FIG. 4 shows a vehicle radome according to a first embodiment of the present invention.

[0050] The radome comprises a front layer 1 and a rear layer 2 assembled to each other. Both layers are made of thermoplastic material.

[0051] According to the invention, the heating element 3 is arranged on the front surface of the front layer 1 , ie on the outer surface of the radome.

[0052] According to a preferred embodiment, the heating element 3 is a foil with a plurality of conductive wires, which are preferably embedded in the foil.

[0053] The heating element 3 comprises a recess 4 for accommodating an electrically conductive element 5, which in the present embodiment is a pad.

[0054] The rear layer 2 includes a housing 6 for a connector (not shown) that is directly connected to the power supply of the vehicle. In addition, the housing 6 includes a conductive pin 7 located inside the housing, which passes through a hole in the housing and a portion of the rear layer 2.

[0055] Thus, a connection is made from the connector to the heating element 3 via the conductive pin 7 and the conductive element 5 , so that electricity is transferred from the connector to the respective wires of the heating element 3 .

[0056] It has to be pointed out that in the drawings, only one conducting element, housing and pin is shown for reasons of simplicity, but the radome according to the invention may comprise any suitable number of conducting elements, housings and pins.

[0057] Furthermore, in the radome according to the invention, both the front layer 1 and the rear layer 2 have recesses and protrusions that are complementary to one another for optimizing the passage of radar waves through the radome and for defining the identity of the vehicle.

[0058] The front layer 1 and / or the back layer 2 may also preferably comprise solderable tracks arranged along the entire periphery of the front layer and / or around the recesses for said conductive elements 5. These conductive tracks are not shown in the figures.

[0059] Figure 3 , which is very similar to the first embodiment. For reasons of simplicity, the same reference numerals are used to identify identical or equivalent elements.

[0060] The main difference from the first embodiment is that the conductive element 5 is a base, which serves as a base for the conductive pin 7 .

[0061] In order to obtain the best heating performance, the heating element 3 is preferably arranged as close as possible to the outermost surface, where water, ice or snow may accumulate.

[0062] As mentioned before, in order to arrange the heating element 3 on the outermost surface of the radome, it is preferred to use a plastic foil which embeds the wires in the sandwich structure.

[0063] It is also possible to place the conductors along one or more grooves 4 present in the front layer 1 and then over-injected with the back layer 2. This will produce a similar sandwich structure, but the thickness of the front layer 1 will be greater than the foil thickness due to the injection requirements.

[0064] The heating element 3 is supplied with power from a connector which is hidden by the badge body itself. The connector plugs into a cable coming from the vehicle's drive train and is responsible for providing the electrical energy that will circulate through the heating element 3.

[0065] Therefore, the electrical connection between the heating element 3 located on the outermost surface of the radome and the connector located on the innermost surface of the radome must be as simple and reliable as possible.

[0066] According to the method of the invention, the heating element 3 is inserted and molded in a first tool with a first thermoplastic material for forming the front layer 1 , the rear surface of the heating element 3 being in direct contact with the front surface of the thermoplastic front layer 1 .

[0067] The heating element 3 preferably partially covers the front surface of the front layer 1, even though it may be completely covered.

[0068] The front layer 1 has a plurality of holes from its front surface to its rear surface at the locations of the grooves 4 , so that the wires embedded in the heating element 3 are accessible from the rear surface of the front layer 1 .

[0069] Once the first part of the radome is molded, a conductive element 5 (such as, but not limited to, a gasket) is placed directly on the groove 4 and welded to the accessible part of the embedded wires by ultrasound, pressure, temperature or any other suitable means. Alternatively, the conductive element can be placed before the first injection.

[0070] Preferably, the number of the pads is two, and each number of parallel circuits implemented in the heating element 3 can be at most two pads.

[0071] Each pair of pads forms the positive and negative potential terminals required for current flow.

[0072] As mentioned above, the front layer 1 also has two protruding or serrated tracks on its rear surface, the first one being arranged along the entire periphery and the second one being arranged around the conductor groove in which the conductive pad is located.

[0073] These tracks are needed to assemble the front layer 1 and the back layer 2 together, for example by laser welding them together.

[0074] The rear layer 2 is injected in the second tool, its front surface having recesses and protrusions complementary to those present in the rear surface of the first thermoplastic injected part. This is done to optimize the transmission of radar waves through the radome.

[0075] As mentioned before, the rear layer 2 also comprises a housing 6 for embedding a pin 7. The pin 7 will make electrical contact with a connector coming from the vehicle and the pin 7 will make electrical contact with the heating element 3 on the outermost surface of the radome.

[0076] Through this connection, electrical energy will circulate from the vehicle drive train to the outermost surface of the radome.

[0077] The housing 6 contains a plurality of holes which will fix the position of the pin 7. The hole diameter is smaller than the diameter of the pin 7, but large enough to allow the edge of the pin 7 to be introduced through it.

[0078] The embedding of the pins 7 can be performed by a robot, which first places each pin 7 in each hole of the housing. The robot then applies sufficient pressure on the pins 7 to penetrate the rear layer 2 from the front surface to the rear surface. The pins 7 have a flat wide area on the portion protruding from the front surface of the rear layer 2.

[0079] As previously mentioned, the rear layer 2 also has two protruding or indented tracks on its front surface, complementary to the tracks present on the rear surface of the first injected part, the first being placed along the entire periphery and the second around the housing of the pin.

[0080] Once the front layer 1 and the rear layer 2 are manufactured as described above, the two parts are assembled. By welding the conductive element 5 with the pin 7, the electrical contact between the conductive element 5 and the pin 7 is more robust. The pin area located above the front surface of the rear layer 2 is dipped in a conductive UV curable resin or can be filled with elastic foam or any other suitable means of increasing the contact stability between the conductive element 5 and the pin 7. Thus, a longer life of the radome can be achieved.

[0081] Furthermore, the resin or elastic foam fills the housing space in which the conductive element 5 and the pin 7 will be located, thereby removing air and greatly reducing the possibility of water entering the housing. Thus, the corrosion resistance is significantly improved, which would ultimately prevent the current from optimally circulating from the vehicle connector to the surface to be heated by attacking the conductive area. Thus, a longer life of the heated radome can be achieved.

[0082] Then, the front layer 1 and the back layer 2 are aligned according to their depressions and protrusions. At the same time, the groove 4 is aligned with the pin area.

[0083] Laser welding is then applied along the tracks on the perimeter, bringing the rear surface of the front layer 1 into contact with the front surface of the rear layer 2. The laser welding melts the material from both components, and a single solid radome block is then obtained. Laser welding is also applied on the welding tracks around the shell 6, thus ensuring the waterproofness of the electrical contact area.

[0084] The front layer 1 and the rear layer 2 are then attached. This will also result in a certain amount of pressure between the pins 7 and the heating element wires accessible through the grooves 4. Furthermore, the robustness of the electrical contact is greatly improved by the conductive element 5 filling the plurality of holes in the front layer 1 and the rear layer 2 as well as the grooves 4. Thus, a reliable electrical contact between the pins 7 and the heating element 3 is obtained.

[0085] In the second embodiment, the method is very similar.

[0086] In this case, the conductive element 5 is formed of a flat base and a protruding member, and they are placed and fixed on the heating element 3 by ultrasonic welding or any other suitable means. The wire is wound on the protruding member over the base so that the electrical contact is reliably ensured.

[0087] Although specific embodiments of the invention have been described, it is obvious to a person skilled in the art that the radome described in the invention is susceptible to various changes and modifications and that all the details mentioned may be replaced by other technically equivalent details without departing from the scope of protection defined in the claims.

Claims

1. A vehicle radome, comprising a front layer (1) and a rear layer (2), both of which are made of thermoplastic material, the radome further comprising a heating element (3) located on a surface of the front layer (1) facing away from the rear layer (2), wherein: Water, ice or snow can accumulate on the surface of the front layer (1) facing away from the rear layer (2); the heating element (3) is a foil with conductive wires; Characterized in that the radome comprises at least one conductive element (5) connected to the conductive wire of the foil, and wherein the conductive element (5) is placed in a groove (4) formed on the rear surface of the foil; Wherein, the front layer (1) and the rear layer (2) are both provided with recesses and protrusions which complement each other.

2. The vehicle radar cover according to claim 1, characterized in that The conductive wires are embedded in the foil.

3. The vehicle radar cover according to claim 1, characterized in that The rear layer (2) comprises a housing (6) for a connector.

4. The vehicle radar cover according to claim 3, characterized in that The housing (6) comprises a hole for placing a conductive pin (7).

5. The vehicle radar cover according to claim 1, characterized in that The conductive element (5) is a pad or a base.

6. The vehicle radar cover according to claim 1, characterized in that The front layer (1) and / or the rear layer (2) further comprises a weldable track arranged along the entire periphery of the front layer.

7. The vehicle radome according to claim 1, characterized in that The front layer (1) and / or the back layer (2) further comprises a solderable track arranged around the recess (4) for the conductive element (5).

8. A method for manufacturing a vehicle radome according to any one of the preceding claims, the method comprising the following steps: - forming the front layer (1), wherein the heating element (3) is arranged on a surface of the front layer (1); - arranging the conductive element (5) on the heating element (3); - forming the rear layer (2); - assembling the front layer (1) and the rear layer (2) so that the heating element (3) is located on the surface of the front layer (1) facing away from the rear layer (2), wherein water, ice or snow can accumulate on the surface of the front layer (1) facing away from the rear layer (2); Characterized in that the heating element (3) is a foil with a conductive wire; wherein the radome comprises at least one conductive element (5) connected to the conductive wire of the foil, and wherein the conductive element (5) is placed in a groove (4) formed on the rear surface of the foil; Wherein, the front layer (1) and the rear layer (2) are both provided with recesses and protrusions which complement each other.

9. The method according to claim 8, characterized in that The method further comprises the step of arranging the conductive pins (7) on the rear layer (2) before assembling the front layer (1) and the rear layer (2).

10. The method according to claim 8, characterized in that The method further comprises the step of providing weldable tracks on the front layer (1) and / or the rear layer (2).

11. The method according to claim 8, characterized in that The step of arranging the conductive element (5) on the front layer (1) is performed by welding.

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