Thermally limited body panel

Abstract

The present invention relates to a panel (40) of a body part (10) of a vehicle (200), the panel comprising an external skin (50) made of plastic, the external skin (50) being glued to a structural inner lining (60) made of plastic over its entire periphery, characterized in that the inner lining (60) comprises, on at least a portion of its periphery, starting from the edge (70) of the panel (40), a fixed region (80) for being glued to the external skin (50), followed by a flexible region (90).

Description

Technical Field

[0001] This invention relates to the field of the motor vehicle industry, and more particularly to the field of vehicle body parts made of plastic.

[0002] The present invention particularly relates to an appearance panel constructed in a housing portion of a vehicle body part to limit appearance defects caused by differences in thermal expansion. Background Technology

[0003] Traditionally, the roof or canopy of a motor vehicle comprises a large external panel that covers the upper part of the vehicle's body structure. This canopy helps to provide rigidity and ensure the airtightness of the upper area of ​​the vehicle, while the panel provides the vehicle with its external appearance within that area. The panel is typically made of sheet metal and / or glass.

[0004] Motor vehicle manufacturers are increasingly looking to equip their vehicles with communication devices that allow them to receive and / or send information to communication networks or other vehicles. This is especially true for autonomous vehicles. This involves, for example, placing electromagnetic wave transmitting and receiving devices, such as 5G antennas, within the vehicle, preferably located in the upper part of the vehicle, particularly directly under the roof, for operational reasons.

[0005] However, the steel roof does not allow electromagnetic waves to pass through normally. Therefore, it is difficult to install such communication equipment.

[0006] One possible solution is to replace a portion of the steel roof panel with a plastic panel, as plastic is more transparent to this type of wave. To achieve the necessary rigidity for these panels, a double-thickness design consisting of an aesthetically pleasing outer skin fixed to a more rigid inner lining is known.

[0007] However, the plastic exterior panels embedded in the steel housing formed by the body structure and the rest of the roof are subject to differential expansion when exposed to light, causing inherent stress that results in visible deformation on the panels. The resulting gaps and flushing defects in the overall shape of the panels exceed the quality standards required by the technical specifications.

[0008] The problem of thermal expansion differences in embedded panels can also be encountered in other types of parts besides the roof, such as the tailgate or doors. Summary of the Invention

[0009] The object of the present invention is particularly to overcome the aforementioned deficiencies by providing a plastic body panel for embedding in a housing of a body part, particularly made of steel, which ensures that deformation is limited and that the peripheral gap and flush with the edge of its housing are controlled. This object is achieved by using a lining that includes a flexible region that allows for the management of deformation due to the thermal expansion of the panel.

[0010] Therefore, the subject of this invention is a vehicle body panel comprising an external skin made of plastic, the external skin being glued to a load-bearing internal lining made of plastic over its entire periphery, characterized in that the internal lining, on at least a portion of its periphery, sequentially includes a fixed region for being glued to the external skin, followed by a flexible region, the flexible region being a region with greater flexibility than the rest of the load-bearing internal lining.

[0011] This flexible area, invisible beneath the skin, allows for the concealed absorption of some of the deformation associated with the thermal expansion of the panel, particularly the skin, while ensuring better perimeter refinement in terms of gaps and flushing, thus providing an appearance that meets the expectations of automotive body component manufacturers.

[0012] Depending on other optional features of this panel, which may be used individually or in combination:

[0013] - The interior liner includes a shoulder on at least a portion of its periphery, the shoulder carrying the fixed area, followed by the flexible area, and then a second fixed area at the base of the shoulder, the second fixed area being designed to secure the interior liner to the body parts and / or the vehicle;

[0014] -The flexible region includes flexible elements, such as those with an accordion-like structure;

[0015] The accordion-shaped flexible element is specifically arranged in the extension of the edge of the inner lining, such that its contraction causes a shortening of the perimeter of the inner structure and a lowering of the edge of the outer skin toward the inner lining. The contraction of the accordion portion occurs during thermal expansion of the panel. This lowering follows an elliptical motion rather than a circular motion because the edge of the outer skin is pulled toward the inner lining by the shortening of the perimeter, rather than by rotation about a pivot point. Thus, the edge of the outer skin better conforms to the surface shape of the body parts and avoids excessive compression of the sealing gaskets fixed to the edge of the outer skin.

[0016] - The flexible element is configured to allow the edge of the outer skin to lower or move toward the inner lining when the panel thermally expands;

[0017] - The edge of the outer skin faces the edge of the inner lining;

[0018] - The flexible element is formed integrally with the liner, or the flexible element is added to the liner, particularly by overmolding. Adding the flexible element to the liner allows for simplified placement of the flexible area within the liner, as the flexible element does not have a specific shape to be presented. In the case of an accordion-shaped flexible element, it can be added to the surface of the liner opposite the outer skin to achieve the effect of lowering the edge of the outer skin. When the flexible element is added to the liner, the material of the flexible element can be, in particular, an injection-molded thermoplastic material (with or without reinforcing fibers) or an elastomer;

[0019] -The inner lining includes a stop between its edge and the flexible element, the stop being adapted to limit the reduction of the edge of the outer skin during thermal expansion of the panel;

[0020] -The stop portion is adapted to abut against the body part and / or the vehicle when the panel is mounted on the body part and the body part and the panel are subjected to thermal expansion;

[0021] - The inner lining is made of a thermosetting material such as SMC or a thermoplastic material such as one filled with glass fiber or talc.

[0022] - The outer skin is made of thermoplastic material;

[0023] - The outer skin and / or the inner lining include sealing gaskets adapted to absorb the difference in thermal expansion between the panel and the body part when the panel is mounted on the body part and the body part and the panel are subjected to thermal expansion.

[0024] In this invention, "reduction" refers to movement in the direction of the inner lining.

[0025] The subject of this invention also relates to a body part of a motor vehicle, comprising a main body having a receiving portion, characterized in that the receiving portion is sealed closed by a panel according to the invention.

[0026] Other optional features that can be used individually or in combination for this body part:

[0027] - The receiving portion enclosed by the panel forms a sealed compartment, the sealed compartment including at least one device for transmitting and / or receiving waves located below the panel.

[0028] - The main body is made of a material with a different coefficient of thermal expansion than the plastic that constitutes the panel.

[0029] - The body parts constitute the roof, tailgate, or doors. Attached Figure Description

[0030] The invention will be better understood by reading the following description, which is provided by way of example only and with reference to the accompanying drawings, in which:

[0031] Figure 1 An example of a vehicle body part according to the present invention is shown;

[0032] Figure 2 A panel in a resting (unexpanded) state is shown, embedded in a vehicle body part according to the invention;

[0033] Figure 3 This shows the effect when subjected to temperature conditions that cause thermal expansion of the panel. Figure 2 The panel;

[0034] Figure 4 Showing a body panel of a vehicle body according to the prior art in a resting (unexpanded) state;

[0035] Figure 5 This shows the effect when subjected to temperature conditions that cause thermal expansion of the panel. Figure 4 The panel. Detailed Implementation

[0036] Now, let's refer to an example of the body part 10 of vehicle 200. Figure 1 According to this example, the body part is the roof, and the vehicle is a motor vehicle. The roof includes a body 20, which has a receiving portion 30 that is sealed and closed by a panel 40. The receiving portion 30 includes electronic devices 14 that communicate via waves. The panel 40 is flush with the visible upper surface of the body 20, so that the roof has a surface with a continuous shape.

[0037] The body 20 and the panel 40 are made of different materials, and in particular, have different coefficients of thermal expansion. The body 20 may be made of a metal material such as aluminum or steel, while the panel 40 may be made of a different plastic.

[0038] Now refer to Figure 2 This illustrates one embodiment of a panel 40 embedded in a body part 10 of a vehicle 200 conforming to the present invention.

[0039] Panel 40 includes an exterior skin 50. This skin is made of plastic and includes a surface intended to be visible from the outside of the vehicle. To be securely held in place, the skin is glued to a load-bearing interior liner 60 made of plastic over its entire perimeter. This adhesive strip also allows it to act as a sealing gasket, sealing the volume between the skin 50 and the liner 60 to prevent any water (rain, wash, etc.) intrusion and retention during the vehicle's lifespan.

[0040] According to one embodiment, the load-bearing inner lining 60 is made of a thermosetting material such as SMC (Sheet Moulding Compound) or a thermoplastic material such as one filled with glass fiber or talc. The skin 50 may be made of a thermoplastic material.

[0041] The load-bearing interior lining 60 comprises, on at least a portion of its periphery, starting from the edge 70 of the panel 40, the following:

[0042] - Fixing area 80 for securing to the outer skin 50 by gluing;

[0043] - Flexible region 90, which is the region where the flexibility is greater than the rest of the lining 60;

[0044] - Second fixing area 110, which is designed to fix the interior lining 60 to the body part 10 and / or vehicle 200.

[0045] According to one embodiment shown in the accompanying drawings, the load-bearing inner lining 60 optionally includes a shoulder 100 on at least a portion of its periphery. The shoulder includes sloping walls and walls partially formed on a support surface of the lining 60 that supports the skin 50. The shoulder 100 carries a fixed region 80 and a flexible region 90 on its support surface. A second fixed region 110 is located at the base of the shoulder 100.

[0046] According to one embodiment, the entire periphery of the load-bearing liner 60 includes a flexible region 90. According to another embodiment, the liner 60 includes a flexible region 90 only on certain sides. For example, if the body part 10 is the roof, the liner 60 preferably includes a flexible region 90 on those sides with the largest dimensions: if the panel 40 is a rectangular part that extends through the roof in width (the length of the panel parallel to the Y-axis), then the liner 60 preferably includes a flexible region 90 on the side parallel to the Y-axis of the vehicle.

[0047] The fixing area 80 includes an adhesive strip 82 along the entire periphery of the panel 40. The lining 60 thus forms the frame on which the skin 50 is fixed.

[0048] The flexible region 90 includes a flexible element 120. The flexible element 120 may be formed as an integral part with the liner 60, or may be added to the liner 60, for example, by overmolding.

[0049] according to Figure 2 and 3 In one embodiment shown, the flexible element 120 forms an accordion-like structure, which thereby imparts flexibility to the liner 60 in the flexible region 90. The flexible element 120 may also be formed from a region thinned relative to the rest of the liner 60, or from a material that is more flexible than the material used for the rest of the liner 60.

[0050] According to an advantageous embodiment, the outer skin 50 and / or the inner lining 60 include sealing gaskets 140 on at least a portion of their periphery.

[0051] The gasket 140 allows for the absorption of thermal expansion differences between the panel 40 and the body part 10 on which the panel 40 is intended to be placed to enclose the body part 10. This not only ensures a tight seal between the panel and the part, but also improves the perceived appearance quality and reduces aerodynamic noise.

[0052] The fixing area 110 includes a second adhesive strip 112 adapted to fix the entire panel 40 to the body 20 of the vehicle body part 10 of the vehicle 200.

[0053] Now refer to Figure 3 , 4 Figures 5 and 6 illustrate the operation of the flexible element 120.

[0054] Figure 4 As shown Figure 2 Panel 40 but without flexible elements, according to the prior art panel 40'. Figure 5 Shown in Figure 4 The performance of the panel skin 50' and load-bearing lining 60' when subjected to thermal expansion.

[0055] The skin 50' and lining 60' expand, with their respective edges 74' and 72' moving closer to the body parts. The gasket 140' is then compressed, which allows the expansion while maintaining a seal between the body parts and the panel 40'.

[0056] The adhesive strip 82' maintains the skin 50' and lining 60' across their entire periphery. Consequently, all shear stresses resulting from the difference in thermal expansion between the skin 50' and lining 60' are located within and around the adhesive strip 82'. Therefore, there is a risk of skin 50' debonding.

[0057] Moreover, the skin 50' is free except at the adhesive strip 82' that holds it, so the central part of the skin 50', that is, the part surrounded by the adhesive strip 82', is lifted by expansion.

[0058] Finally, it can be observed that, under the influence of thermal expansion, the edge 74' of the skin 50' outside the adhesive strip 82' rises and separates from the lining 60'. This rise causes problems:

[0059] - The edge 74' of the skin 50' is no longer flush with the visible outer surface of the body parts; thus, a gap appears between the body and the edge 74' of the skin 50'. This is unacceptable for the vehicle;

[0060] - A shape defect 160 also appears along the adhesive strip 82', resulting in an unacceptable appearance defect for the vehicle.

[0061] Figure 3 Shown in Figure 2 The performance of the panel 40, skin 50, and lining 60 when subjected to thermal expansion.

[0062] The skin 50 and lining 60 expand, with their respective edges 74, 72 moving closer to the body part 10. The gasket 140 is then compressed, which allows the expansion while maintaining a seal between the body part and the panel 40.

[0063] Similarly, the skin 50 is free except at the adhesive strip 82 that holds it in place, so the central portion of the skin 50 is lifted by expansion.

[0064] However, the flexible element 120 imparts flexibility to the edges 72 of the lining 60 in the area held by the adhesive. Thus, with Figure 5 In contrast, the edge 74 of the skin 50 undergoes the opposite movement: it does not rise, but rather lowers. Thus, the flexible element 120 allows the overall edge 70 to "follow" the shape imparted by the bulge and thus avoids (limits) shape discontinuities 160.

[0065] The reduction at edge 70 is more acceptable in terms of perceived quality than the increase. However, it is important that the flexible element 120 thereby allows for the release of stress in the adhesive strip 82 and, more generally, in region 80, thus minimizing appearance defects at the adhesive strip.

[0066] According to an advantageous embodiment, the inner lining 60 includes, for example, a stop 130 in the form of a partial rib between its edge 72 and the flexible element 120, the stop 130 being adapted to abut downward against the body part 10 and / or the vehicle 200 when the panel is mounted on the body part 10 and the body part 10 and the panel 40 are subjected to expansion.

[0067] Therefore, when the stop portion 130 abuts against the body part 10 and / or the vehicle 200, the lowering of the edge 74 of the skin 50 can be controlled and limited.

[0068] Arranging the flexible element 120 between the two adhesive strips 82 and 112 allows for uniform distribution of expansion and, in conjunction with the appropriately positioned fixed stops 130, effectively mitigates sag at the periphery and thus limits bulging at the center. This spring effect also limits the visual impact of defects along the adhesive trail.

[0069] The present invention also relates to a body part 10 of a motor vehicle 200. The body part according to the invention includes a body 20 having a receiving portion 30 sealed and closed by a panel 40 according to the invention.

[0070] The body 20 and the panel 40 are made of different materials, and in particular, have different coefficients of thermal expansion. The body 20 may be made of a metal material such as aluminum or steel, while the panel 40 may be made of a different plastic.

[0071] According to one embodiment, panel 40 includes a receiving portion 30 enclosed by panel 40, and the receiving portion 30 and panel 40 thus form a sealed compartment 12, the sealed compartment 12 including at least one device 14 for transmitting and / or receiving waves, such as a 5G antenna, located below panel 40.

[0072] According to another embodiment, the panel 40 includes a sealed compartment 12 located below the opening 30 and enclosed by the panel 40. The sealed compartment 12 includes at least one device 14 for transmitting and / or receiving waves, such as a 5G antenna, located below the panel 40.

[0073] This invention is not limited to the described embodiments, and other embodiments will be apparent to those skilled in the art. In particular, it is feasible for the body part 10 to not constitute a roof, but to constitute a tailgate or door.

[0074] List of reference numerals in the attached diagram:

[0075] 10: Body parts

[0076] 12: Sealed compartment

[0077] 14: Devices for transmitting and / or receiving waves located below panel 40, such as a 5G antenna; 20: The main body of vehicle body part 10.

[0078] 30: Reception area for body part 10

[0079] 40: Panel covering the receiving part 30

[0080] 50: External skin of panel 40

[0081] 60: Load-bearing internal lining of panel 40

[0082] 70: Edge of panel 40

[0083] 72: Lining edge 60

[0084] 74: Edge of skin 50

[0085] 80: Fixed area of ​​lining 60

[0086] 82: Adhesive strips for fixing area 80

[0087] 90: Flexible area of ​​lining 60

[0088] 100: 60 shoulder lining

[0089] 110: A second fixing area intended to secure the interior lining 60 to the body part 10 and / or the vehicle 200.

[0090] 112: Adhesive strip in the second fixed area 110

[0091] 120: 60% flexible area of ​​lining and 90% flexible element

[0092] 130: Lining 60 stop section

[0093] 140: Sealing gasket

[0094] 160: Shape defect

[0095] 200: Vehicles

[0096] The reference numerals 40', 50', 60', 72', 74' and 140' for panels excluding the flexible region 90 correspond to reference numerals 40, 50, 60, 72, 74 and 140, respectively.

Claims

1. A panel (40) of a body part (10) of a vehicle (200), said panel comprising an aesthetically pleasing outer skin (50) made of plastic, said outer skin (50) being glued to a load-bearing inner lining (60) made of plastic over its entire periphery, characterized in that, The inner lining (60) includes, on at least a portion of its periphery, a fixing region (80) for securing to the outer skin (50) by gluing, followed by a flexible region (90); and the inner lining (60) includes, on at least a portion of its periphery, a shoulder (100) that carries the fixing region (80), followed by the flexible region (90), followed by a second fixing region (110) at the base of the shoulder (100), the second fixing region (110) being intended to secure the inner lining (60) to the vehicle (200).

2. The panel (40) as claimed in claim 1, wherein, The second fixing area (110) is intended to fix the inner lining (60) to the body part (10).

3. The panel (40) as claimed in claim 1, wherein, The flexible region (90) includes a flexible element (120).

4. The panel (40) as claimed in claim 3, wherein, The flexible element (120) has an accordion-like structure.

5. The panel (40) as claimed in claim 3, wherein, The flexible element (120) is configured to allow the edge (74) of the outer skin (50) to move toward the inner lining when the panel (40) thermally expands.

6. The panel (40) as claimed in claim 5, wherein, The flexible element (120) is formed as an integral part with the inner lining (60), or the flexible element (120) is added to the inner lining (60).

7. The panel (40) as claimed in claim 6, wherein, The flexible element (120) is added to the inner lining (60) by overmolding.

8. The panel (40) as claimed in claim 6, wherein, The inner lining (60) includes a stop (130) between its edge (72) and the flexible element (120), the stop (130) being adapted to restrict the movement of the edge (74) of the outer skin (50) toward the inner lining when the panel (40) thermally expands.

9. The panel (40) as claimed in claim 8, wherein, The stop (130) is adapted to abut against the vehicle (200) when the panel (40) is mounted on the body part (10) and the body part (10) and the panel (40) are subjected to thermal expansion.

10. The panel (40) as claimed in claim 9, wherein, The stop (130) is adapted to abut against the body part (10) when the panel (40) is mounted on the body part (10) and the body part (10) and the panel (40) are subjected to thermal expansion.

11. The panel (40) as claimed in any one of claims 1 to 10, wherein, The inner lining (60) is made of thermosetting material or thermoplastic material.

12. The panel (40) as claimed in claim 11, wherein, The thermosetting material is SMC.

13. The panel (40) as claimed in claim 11, wherein, The thermoplastic material is filled with glass fiber or talc.

14. The panel (40) as claimed in any one of claims 1 to 10, wherein, The outer skin (50) is made of thermoplastic material.

15. The panel (40) as claimed in any one of claims 1 to 10, wherein, The outer skin (50) and / or the inner lining (60) include a sealing gasket (140) adapted to absorb the difference in thermal expansion between the panel (40) and the body part (10) when the panel (40) is mounted on the body part (10) and the body part (10) and the panel (40) are subjected to thermal expansion.

16. A body part (10) of a motor vehicle (200), said body part comprising a main body (20) having a receiving portion (30), characterized in that, The receiving portion (30) is sealed by the panel (40) as claimed in any one of claims 1 to 15.

17. The vehicle body part (10) as claimed in claim 16, wherein, The receiving portion (30) enclosed by the panel (40) forms a sealed compartment (12), the sealed compartment (12) including at least one device (14) for transmitting and / or receiving waves located below the panel (40).

18. The body part (10) as claimed in any one of claims 16 and 17, wherein, The main body (20) is made of a material with a different coefficient of thermal expansion than the plastic constituting the panel (40).

19. The body part (10) as claimed in any one of claims 16 to 17, wherein the body part constitutes a roof, tailgate or door.

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