VEHICLE BODY PANEL WITH A TRANSPARENT PART

Description

[0001] The invention relates to motor vehicle body panels and more particularly to bumper skins.

[0002] Body panels may include a transparent portion visible from the exterior of the vehicle on which the panels are mounted. For example, a bumper skin may include, in an area comprising a vehicle emblem, a portion comprising a wall transparent to visible light. It could also be an area of a body panel forming a radome. By "transparent to visible light" is meant that it is at least transparent to any light radiation having a wavelength included in the visible spectrum, i.e. between approximately 380 and 780 nm. The use of a transparent wall makes it possible, for example, to obtain a good quality visual rendering.

[0003] However, the transparent wall, visible from the outside of the vehicle, can be exposed to climatic conditions and deteriorate, which poses a substantial problem for a part intended at least partly for aesthetic purposes. For example, certain available thermoplastic materials yellow through thermal oxidation, i.e. in contact with oxygen and in the presence of heat, for example that of the Sun. This is particularly the case for certain polyamides and polyvinyl chloride. It is then necessary to use particular plastic materials that are not subject to this phenomenon, which reduces the choice of materials and can generate additional production costs for body panels by having to design a transparent wall with a plastic material having a particular formulation.

[0004] These degradations not only lead to a potential loss of the desired aesthetic rendering but can also give the body panel an unacceptable appearance in the long term. Document US 2017 / 352938 A1 discloses a body panel corresponding to the preamble of claim 1.

[0005] The invention aims in particular to provide a body panel of the type mentioned above having an optimal and durable aesthetic appearance over the life of the vehicle on which it is mounted.

[0006] To this end, the invention relates to a motor vehicle body panel comprising: a main body, a wall made of plastic material transparent to visible light comprising a face intended to be visible from outside the vehicle, and a coating transparent to visible light covering at least the face of the wall transparent to visible light intended to be visible from outside the vehicle, the wall being encapsulated in a sealed manner between the main body and the coating.

[0007] This produces a motor vehicle body panel comprising an outer wall transparent to visible light that is not in contact with oxygen, which prevents thermal oxidation leading to the yellowing of certain plastic materials. This allows the aesthetics of the body panel to be preserved regardless of the plastic material used to form the wall transparent to visible light (plastic materials frequently used to design body panels can therefore be used without having to modify their formulation, in particular polyamides). The presence of an external coating allows the transparent wall to be protected from scratches and ultraviolet rays, but also allows for the integration, for example, of a decorative film or de-icing wires.This can protect the transparent wall (protection against scratches and ultraviolet rays), change the aesthetic appearance of the body panel (integration of a decorative film) or even integrate options on the vehicle (presence of defrosting wires).

[0008] The body panel according to the invention may further comprise at least one of the following characteristics: the visible light transparent wall is made of polyamide and the visible light transparent coating is a film made of polyurethane, the thickness of the visible light transparent coating is between 0.5 millimeters and 3 millimeters, at least one decorative element is positioned between the visible light transparent wall and the main body or between the visible light transparent wall and the visible light transparent coating, at least one body panel defrosting means is positioned between the visible light transparent wall and the main body or between the visible light transparent wall and the visible light transparent coating, at least one visible light emitting device is positioned between the visible light transparent wall and the main body or between the visible light transparent wall and the visible light transparent coating.

[0009] According to the invention, the main body covers all of the faces of the wall transparent to visible light with the exception of the face covered by the coating transparent to visible light.

[0010] Optionally, - the body panel forms a bumper skin, and the body panel forms at least part of a radome.

[0011] The invention also relates to a method of manufacturing a motor vehicle body panel according to any one of claims 1 - 8 in which a wall made of plastic material transparent to visible light is encapsulated in a sealed manner by molding between a coating transparent to visible light and a main body of the body panel.

[0012] This produces a body panel in which a part potentially sensitive to degradation, for example by thermal oxidation, is protected from the latter.

[0013] The method according to the invention may further comprise at least one of the following characteristics: the manufacturing method comprises the following steps: applying the visible light transparent coating in a mold, preferably by spraying, molding the visible light transparent wall on the coating, and sealingly encapsulating the visible light transparent wall between the visible light transparent coating and the main body of the body panel, the manufacturing method comprises the following steps: molding the visible light transparent wall, overmolding the visible light transparent coating on at least one face of the visible light transparent wall intended to be visible from the outside of a vehicle, and sealingly encapsulating the visible light transparent wall between the visible light transparent coating and the main body of the body panel,at least one decorative element, at least one means for defrosting the body panel and / or at least one visible light emitting device are placed between the main body and the wall transparent to visible light, at least one decorative element, at least one means for defrosting the body panel and / or at least one visible light emitting device are placed between the covering transparent to visible light and the wall transparent to visible light, and the wall transparent to visible light is made of polyamide and the covering transparent to visible light is a film made of polyurethane whose thickness is preferably between 0.5 millimeters and 3 millimeters. Brief description of the figures

[0014] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings in which: [ Fig. 1 ] there figure 1is an exploded view of a portion of a body panel according to the invention, and [ Fig. 2 ] there figure 2 is a sectional view of a portion of a body panel according to the invention. Detailed description

[0015] We now refer to the figure 1 illustrating in exploded form a portion 2 of a body panel according to the invention. It may for example be a body panel of the bumper skin type, this portion 2 then being able to correspond to an area comprising an emblem of the motor vehicle. For example, the presence of a decorative element 4 can be noted (which may have the form of a decorative sheet or even be painted). Of course, the portion 2 can also be placed at the level of a body panel other than a bumper.

[0016] In the following, we will describe section 2 of the body panel. Of course, everything described for section 2 (elements constituting it, manufacturing process) is also applicable to the body panel taken in its entirety.

[0017] The portion 2 of the body panel comprises a main body 6. The latter may be made in a conventional manner from a thermoplastic material of the type used to manufacture a thermoplastic body panel. The main body may also, as shown in the Figures 1 and 2 , be opaque to visible light. “Opaque to visible light” means that a material does not allow any light radiation with a wavelength in the visible spectrum, i.e. between approximately 380 and 780 nm, to pass through. The color of the main body 6 may vary.

[0018] The portion 2 also comprises a wall 8 made of plastic material transparent to visible light comprising a face 12 intended to be visible from the outside of the vehicle. This wall 8 is fixed on a face of the main body 6, more precisely the face visible from the outside of a motor vehicle on which the portion 2 is present.

[0019] The wall 8 can be made of polyamide or polyvinyl chloride. As explained above, these materials tend to degrade (yellowing) by thermal oxidation, that is to say in contact with oxygen (for example that of the ambient air) and in the presence of heat (for example that of the Sun).

[0020] To avoid this, a coating 10 transparent to visible light (according to the definition given above) is placed against the wall 8 so as to cover at least the face 12 of the wall transparent to visible light intended to be visible from outside the vehicle, the wall 8 being encapsulated in a sealed manner between the main body 6 and the coating 10 transparent to visible light.

[0021] In other words, the wall 8 cannot be in contact with oxygen. Therefore, even if the temperature of the wall increases, no yellowing of the wall 8 is observed because no thermal oxidation can take place.

[0022] In the examples shown, the main body 6 and the covering 10 are dimensioned so as to tightly encapsulate the wall 8 between them. No other element is necessary to encapsulate the wall 8. For example, we observe in the figure 2that the face 12 of the wall 8 is covered by the coating 10, all of the other faces, including the face 16 and the face 14, being covered by the main body 6 (therefore covering all of the faces of the wall 8 with the exception of the face 12 covered by the coating 10).

[0023] Alternatively, it would be possible to add at least one other element to encapsulate the latter. For example, the main body 6 and the covering 10 could each cover one face of the wall, for example the opposite faces 12 and 16. The other faces (including face 14) would then be covered by one or more other elements ensuring the sealing of the final structure.

[0024] The coating 10 may be made of a thermoplastic material. For example, it may be made of polyurethane. It is also advantageous to use a polyurethane coating 10 in combination with a polyamide wall 8 due to the good adhesion properties between the two materials. More particularly, and in particular in the case of production of the part by a process of depositing the coating in the mold (or " In Mold Coating » Or " BMI » in English"), a mixture of a resin and a polyurethane hardener is used.

[0025] In the case of using a polyurethane coating 10 (which can be in the form of a film), it is advantageous for the thickness of the latter to be between 0.5 and 3 millimeters. Indeed, this thickness range is interesting because: the coating 10 protects the wall 8 from ultraviolet radiation, the coating 10 protects the wall 8 from scratches. It is even possible to make scratches disappear by locally heating the coating 10, and a depth effect is obtained at the level of the portion 2, in particular if the latter has aesthetic aims.

[0026] As explained previously, it is possible for a decorative element 4 to be placed between the main body 6 and the wall 8 at the wall 16. It could also be placed between the wall 8 and the covering 10 at the wall 12. The wall 8 and the covering 10 being transparent to visible light, the decorative element 4 is visible from the outside of a motor vehicle on which the portion 2 is placed (it is noted here that, in the areas not comprising the decorative element 4, the main body 6 is visible due to the transparency to visible light of the wall 8 and the covering 10).

[0027] It is also possible to introduce at least one visible light emitting device between the main body 6 and the decorative element 4 (here opaque to visible light) to obtain backlighting of the area. Such devices, for example LEDs or even light guides (for example optical fibers diffusing light emitted by LEDs), are known to those skilled in the art.

[0028] In the same way, it is possible to place at least one means for defrosting the body panel between the wall 8 and the main body 6 or between the wall 8 and the covering 10. This is all the more relevant if the area is crossed by waves emitted by wave-emitting members of the distance sensor type in order to avoid disturbance of the wave propagation by a layer of frost. The defrosting means are chosen according to the wave-emitting member, for example metal wires for ACC-type radars capable of emitting between 75 and 81 GHz. Such means are known to those skilled in the art.

[0029] The invention also relates to a method of manufacturing a motor vehicle body panel of the type of the invention.

[0030] According to this method, a wall (the wall 8) made of plastic transparent to visible light is encapsulated in a sealed manner by molding between a covering (the covering 10) transparent to visible light and a main body (the main body 6) of the body panel (or the portion 2). Thus, the wall 8 cannot be in contact with the oxygen in the ambient air.

[0031] In the case of molding using an In Mold Coating process, the molding temperature is approximately 90°C, and the molding pressure is approximately 20 bars.

[0032] According to a first embodiment of the process, corresponding to an In Mold Coating process: the coating 10 transparent to visible light is applied in a mold, preferably by spraying. Thus, the bottom of the mold cavity is lined with material intended to form the coating 10; the wall 8 transparent to visible light is molded on the coating, for example by injection in the context of the use of a thermoplastic material; the wall 8 transparent to visible light is encapsulated in a sealed manner between the coating 10 transparent to visible light and the main body 6 of the body panel.

[0033] According to a second embodiment of the process, also corresponding to an In Mold Coating process: the wall 8 transparent to visible light is molded, for example by injection in the context of the use of a thermoplastic material; the coating 10 transparent to visible light is overmolded on at least one face (for example the face 12) of the wall 8 transparent to visible light intended to be visible from the outside of a vehicle, and the wall 8 transparent to visible light is encapsulated in a sealed manner between the coating 10 transparent to visible light and the main body 6 of the bodywork panel.

[0034] As regards the encapsulation of the wall 8, this can be done by overmolding the main body 6 onto the wall 8 / covering 10 assembly or by attaching the main body 6 previously molded onto this assembly.

[0035] Advantageously, at least one decorative element, at least one means for defrosting the body panel and / or at least one visible light emitting device can be placed between the main body 6 and the wall 8 transparent to visible light. These elements will make it possible to obtain the effects described above.

[0036] Alternatively, these elements can be placed between the coating 10 transparent to visible light and the wall 8 transparent to visible light.

[0037] The various placements mentioned take place before the step aimed at linking the two parts between which they are arranged. For example, and in the case of placement of a decorative element 4 between the main body 6 and the wall 8, this decorative element 4 is placed before encapsulating the main body 6 on the wall 8 / covering 10 assembly.

[0038] The invention is not limited to the embodiments presented and other embodiments will become apparent to those skilled in the art. Digital references

[0039] 2: portion of body panel 4: decorative element 6: main body 8: wall transparent to visible light 10: covering transparent to visible light 12, 14, 16: faces of the wall transparent to visible light

Claims

1. Motor vehicle bodywork panel, comprising: - a main body (6), - a wall (8) made of plastic material that is transparent to visible light, comprising a face (12) intended to be visible from the outside of the vehicle, and - a coating (10) that is transparent to visible light covering at least the face (12) of the wall (8) that is transparent to visible light intended to be visible from the outside of the vehicle, the wall (8) being encapsulated in a sealed manner between the main body (6) and the coating (10) that is transparent to visible light, characterized in that the main body (6) covers all the faces (14, 16) of the wall (8) transparent to visible light with the exception of the face (12) covered by the coating (10) transparent to visible light.

2. Bodywork panel according to claim 1, wherein the wall (8) transparent to visible light is made of polyamide and the coating (10) transparent to visible light is a film made of polyurethane.

3. Bodywork panel according to one of the preceding claims, wherein the thickness of the coating (10) transparent to visible light is between 0.5 millimeters and 3 millimeters.

4. Bodywork panel according to one of the preceding claims, wherein at least one decorative element (4) is positioned between the wall (8) transparent to visible light and the main body (6) or between the wall (8) transparent to visible light and the coating (10) transparent to visible light.

5. Bodywork panel according to one of the preceding claims, wherein at least one means for defrosting the bodywork panel is positioned between the wall (8) transparent to visible light and the main body (6) or between the wall (8) transparent to visible light and the coating (10) transparent to visible light.

6. Bodywork panel according to one of the preceding claims, wherein at least one visible light emitting device is positioned between the wall (8) transparent to visible light and the main body (6) or between the wall (8) transparent to visible light and the coating (10) transparent to visible light.

7. Bodywork panel according to one of the preceding claims, the bodywork panel forming a bumper skin.

8. Bodywork panel according to one of the preceding claims, the bodywork panel at least partially forming a radome.

9. Manufacturing method of the motor vehicle bodywork panel according to one of the preceding claims, characterized in that a wall (8) made of plastic material transparent to visible light is encapsulated in a sealed manner between a coating (10) transparent to visible light and a bodywork panel main body (6).

10. Manufacturing method according to claim 9, comprising the following steps: - the coating (10) transparent to visible light is applied in a mold, preferably by spraying, - the wall (8) transparent to visible light is molded on the coating, and - the wall (8) transparent to visible light is encapsulated in a sealed manner between the coating (10) transparent to visible light and the main body (6) of the bodywork panel.

11. Manufacturing method according to claim 9, comprising the following steps: - the wall (8) transparent to visible light is molded, - the coating (10) transparent to visible light is overmolded on at least one face (12) of the wall (8) transparent to visible light intended to be visible from outside a vehicle, and - the wall (8) transparent to visible light is encapsulated in a sealed manner between the coating (10) transparent to visible light and the main body (6) of the bodywork panel.

12. Manufacturing method according to one of claims 9 to 11, wherein at least one decorative element (4), at least one bodywork panel defrosting means and / or at least one visible light emitting device is placed between the main body (6) and the wall (8) transparent to visible light.

13. Manufacturing method according to one of claims 9 to 12, wherein at least one decorative element, at least one means for defrosting the bodywork panel and / or at least one device for emitting visible light is placed between the coating (10) transparent to visible light and the wall (8) transparent to visible light.

14. Manufacturing method according to one of claims 9 to 13, wherein the wall (8) transparent to visible light is made of polyamide and the coating (10) transparent to visible light is a film made of polyurethane, the thickness of which is preferably between 0.5 millimeters and 3 millimeters.