AUTOMOTIVE VEHICLE BODY PART.

Abstract

The invention relates to a motor vehicle body component, said component consisting of a box-shaped structural panel to which a skin panel is attached, said structural panel and skin panel being formed by plastic injection molding, wherein the structural panel and the skin panel are joined to each other by means of a bead of said plastic material, said bead being formed of at least one pair of ribs (66a, 66b, 68a, 68b), in particular arranged opposite each other, formed from the material of said structural panel and / or said skin panel, and welded to each other. Figure 19 is shown in the abstract.

Description

Title of the invention: AUTOMOBILE BODYWORK ELEMENT. Technical field of the invention

[0001] The invention relates to a motor vehicle bodywork component. Technical background

[0002] The production of automotive body parts increasingly relies on the use of plastic materials. These materials offer numerous advantages because they allow for a wide variety of shapes, are easy to mold, are resistant, and above all are lightweight, which, in the context of seeking weight reduction to optimize vehicle performance, is a definite advantage.

[0003] In order to obtain a bodywork element with a substantial extension, it is generally made in the form of a bodywork structure panel covered by one or more so-called "skin" panels, which form the externally visible part of said bodywork element. Both the structure panel and the skin panel are made by injection molding of a plastic material, such as a fiber-reinforced polypropylene material.

[0004] Conventionally, the assembly of the skin panel to the structural panel is carried out using glue.

[0005] For this purpose, at least a first bead of so-called "structuring" glue is used, for example a two-component polyurethane glue (PU2K) which is a slow-setting glue offering excellent bonding capabilities for these parts.

[0006] When the assembly of the skin panel to the structural panel requires a seal, this assembly is completed with a second bead of adhesive suitable for ensuring the seal. A non-structural, polypropylene (PP) hot melt adhesive is used for this purpose.

[0007] However, polyurethane adhesives contain carcinogenic, mutagenic, or toxic compounds, known as CMR agents. It is therefore important to develop alternative approaches to eliminate, replace, limit, or improve adhesives containing such compounds.

[0008] One known assembly technique that eliminates the need for glue is laser welding. One of the parts is transparent to the laser, while the other is not. The laser beam produces a fusion reaction at the interface of the parts, enabling their assembly.

[0009] However, this technique requires physical contact of the laser head with the transparent part and leaves a visible trace of the passage of the welding head on one of the parts without guaranteeing the seal between the parts.

[0010] There is therefore a real need for a structural panel in which the structural panel and the skin panel are joined together by reducing, or even eliminating, the amount of glue used in such an assembly while preserving the aesthetic appearance of the parts. Summary of the invention

[0011] The invention satisfies this need by proposing a motor vehicle bodywork element whose box-shaped structural panel and attached skin panel are assembled by a welding process.

[0012] To this end, the invention proposes a motor vehicle bodywork element, said element being made up of a box-shaped structural panel to which a skin panel attached to said structural panel is fixed, said structural panel and skin panel being formed by injection molding of plastic material,

[0013] in which the structural panel and the skin panel are joined to each other by means of a cord of said plastic material, said cord being formed of at least one pair of ribs, in particular arranged opposite each other, respectively made of material with said structural panel and / or with said skin panel, welded to each other.

[0014] The localized melting of the plastic ribs opposite each other to form a weld bead makes it possible to create an assembly using little or no glue, and free from the surface defects generated by laser welding, since it is sufficient to melt the ribs prior to their assembly using a heating method that does not come into direct contact with the parts. The resulting weld allows for assembly that is both fast and environmentally friendly.

[0015] According to various additional features of the bodywork element according to the invention, which may be taken together or separately and which constitute so many embodiments of the invention:

[0016] - one foot of each rib, at its junction with said structural panel or said skin panel, is of a width between one-third and one-quarter of the thickness of said structural panel or said skin panel,

[0017] - each rib made of material with said skin panel is of thickness lower than the corresponding rib of the structural panel,

[0018] - the structural panel and the skin panel are fixed to each other by means structural assembly and a sealing means are interposed between the structural panel and the skin panel,

[0019] - the first of said welded ribs constitute the means of assembly structural and in which the second of said welded ribs constitute said structural assembly means as well as the sealing means,

[0020] - said welded ribs constitute the structural assembly means and a joint The sealing method, achieved by applying a bead of adhesive between the structural panel and the skin panel, constitutes the means of sealing.

[0021] - said glue is a non-structuring, hot-melt polypropylene (PP) glue without CMR agents.

[0022] - said welded ribs constitute the sealing means and a bead of glue Two-component polyurethane (PU2K) applied between the structural panel and the skin panel constitutes the structural assembly method.

[0023] - wherein the structural panel and the skin panel are made of filled polypropylene of fibers, especially glass.

[0024] The invention also relates in particular to a door for a motor vehicle trunk, said door comprising a one-piece trunk door structure panel including:

[0025] - a lower part intended to be covered by an outer door panel,

[0026] - an intermediate part forming a rear window frame for the door,

[0027] - an upper part forming a box, covered with a skin panel of aerodynamic spoiler for the door,

[0028] wherein at least the upper part and the spoiler skin panel form a body structure element of the type described above.

[0029] According to various additional features of the lake gate according to the invention, which may be taken together or separately and which constitute so many embodiments of the invention:

[0030] - the upper part comprises a concave portion equipped with longitudinal stiffeners of stiffening and a perimeter surrounding said concave part,

[0031] - a part of said stiffeners, the perimeter and the spoiler skin panel include said ribs welded opposite each other.

[0032] - the upper part receives a spoiler support extension, attached to the perimeter of the said upper part and extending vertically to the said rear window frame of the door, the said spoiler support extension and the said spoiler skin panel having at least one of the said ribs facing welded.

[0033] The invention also relates to a method for manufacturing a motor vehicle bodywork component of the type described above, said method comprising at least:

[0034] i) a step of forming the structural panel and said skin panel by injecting plastic material,

[0035] ii) a step of assembling said structural panel and said skin panel,

[0036] method in which:

[0037] - during the assembly step i) during plastic injection at least a projecting rib of the structural panel, and a projecting rib of said skin panel, said ribs being suitable for being positioned opposite each other,

[0038] - the assembly step ii) comprises at least one phase of securing said skin panel relative to the structural panel comprising a sub-phase ii.a) during which the ribs are arranged opposite each other, a sub-phase ii.b) during which the plastic material of the free edges of said ribs is melted, then a sub-phase ii.c) during which said edges of said ribs are brought into contact and finally a sub-phase ii.d) during which the structural panel and said skin panel are pressed against each other so as to form a bead of said molten plastic material.

[0039] According to various additional features of the method according to the invention, which may be taken together or separately and which constitute so many embodiments of the invention:

[0040] - during sub-phase ii.a) the structural panel and said skin panel in respective supports facing each other,

[0041] - during sub-phase ii.b) the edges of the ribs are melted by means of infrared wires, infrared lamps, or an ultrasonic welding device,

[0042] - the assembly step further comprises a structural assembly phase of said skin panel to structural panel and a phase of creating a seal between said skin panel and the structural panel,

[0043] - the structural assembly phase and the phase of creating a sealing joint are carried out through the solidarity phase,

[0044] - subphases ii.a), ii.b), ii.c) and ii.d) are applied to at least two pairs of ribs facing each other, at least two of the facing ribs assembled forming a structural assembly and at least two other facing ribs assembled forming a sealing joint,

[0045] - the structural assembly phase is carried out by the applied fastening phase to a pair of facing ribs, and the sealing joint phase is carried out by applying a bead of non-structural, CMR-free, polypropylene (PP) hot melt adhesive to one of the structural or skin panels prior to sub-step ii.b),

[0046] - according to a variant of the process: • Step ii.a) occurs before step ii.b), • during step ii.b) a two-sided infrared heating element is introduced between said skin panel and the structural panel,

[0047] - the sealing joint fabrication phase is carried out by the phase of bonding applied to a pair of facing ribs, and the structural assembly phase is carried out by applying a bead of two-component polyurethane adhesive (PU2K) to one of the structural or skin panels prior to sub-step ii.b),

[0048] - according to another variant of the process: • Step ii.a) occurs before step ii.b) • during step ii.b) a two-sided infrared heating element is introduced between the skin panel and the structural panel, with a thermally insulating mask interposed between said heating element and the bead of two-component polyurethane adhesive (PU2K) applied to one of the structural or skin panels. Brief description of the figures

[0049] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description that follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which:

[0050] Fig. 1 is an exploded perspective view of a rear door of a motor vehicle according to the invention;

[0051] [Fig.2] is a perspective view with removal of the door of [Fig.1] and of an element of the metal inserts of this door;

[0052] The [Fig.3] is a perspective ghost view of the door structure panel fitted with its metal insert elements;

[0053] Fig. 4 is a top detail view of the door structure panel fitted with its metal insert elements;

[0054] Fig. 5 is a schematic cross-sectional view of an intermediate part of the door structure panel;

[0055] Fig. 6 is a detailed perspective view of a metal insert according to the invention;

[0056] Fig. 7 is a perspective detail view of the door structure panel fitted with a metal insert element;

[0057] Fig. 8 is a cross-sectional detail view of the door structure panel equipped with a metal insert element;

[0058] Fig. 9 is a perspective view of the door structure panel fitted with its metal insert elements;

[0059] The [Fig. 10] is a perspective view of the door structure panel equipped with a spoiler support extension;

[0060] The [Fig. 11] is a perspective view of the spoiler support extension of the [Fig. 10];

[0061] The [Fig. 12] is a perspective ghost view of the door structure panel equipped with its spoiler support extension;

[0062] The [Fig. 13] is a side perspective view of the door structure panel equipped with its spoiler support extension;

[0063] The [Fig. 14] is a longitudinal sectional side view of the door structure panel equipped with its spoiler support extension;

[0064] Fig. 15 is a first detailed view of Fig. 14;

[0065] Fig. 16 is a second detailed view of Fig. 14;

[0066] Fig. 17 is a third detailed view of Fig. 14;

[0067] Fig. 18 is a fourth detailed view of Fig. 14;

[0068] Figure 19 is a perspective view representing connecting ribs of the structural panel and the spoiler support extension with the spoiler panel being peeled off;

[0069] Fig. 20 is a perspective view of a rib heating device, for joining the structural panel and the skin panel of the door;

[0070] Fig. 21 is a perspective view of one face of the rib heating device for securing Fig. 20;

[0071] Fig. 22 is a detailed top view of the structural panel and the location of its connecting ribs;

[0072] Fig. 23 is a cross-sectional view of a connecting rib;

[0073] Figure 24 is a schematic cross-sectional view of a first embodiment of the assembly of the structural panel to the skin panel of the door;

[0074] Fig. 25 is a schematic cross-sectional view of a second embodiment of the assembly of the structural panel to the skin panel of the door;

[0075] The [Fig.26] is a schematic cross-sectional view illustrating the realization of the second embodiment of the assembly of the [Fig.25];

[0076] Fig. 27 is a schematic cross-sectional view of a third embodiment of the assembly of the structural panel to the skin panel of the door;

[0077] The [Fig.28] is a schematic cross-sectional view illustrating the realization of the third embodiment of the assembly of the [Fig.27];

[0078] Figure 29 is a block diagram illustrating the steps of a manufacturing process for a motor vehicle body component according to the invention; and

[0079] Fig. 30 is a block diagram illustrating the steps of a manufacturing process for a structural panel according to the invention. Detailed description of the invention

[0080] Figures 1 and 2 show a motor vehicle body element 10, in particular, in this case, a door 10 for a motor vehicle trunk. The door 10 extends longitudinally along a direction X, transversely along a direction Y, and vertically along a direction Z. The body element 10 preferably has a length and width much greater than its thickness, in particular by at least a factor of ten.

[0081] The element or door 10 comprises a structural panel, here a trunk door structural panel 12. This door structure panel 12 includes, for example:

[0082] - a lower part 14 intended to be covered by an outer panel 16 of the door,

[0083] - an intermediate part 18 forming a frame 20 for a rear window, intended to be covered by a rear window (not shown) of the door, this intermediate part defining two arms 22 on either side of the frame 20, and / or

[0084] - an upper part 24, intended to be covered with a panel 26 of a skin aerodynamic spoiler of door 10. It should be noted that the upper part 24 could, alternatively, be covered by part of the rear window.

[0085] More specifically, the upper part 24 forms a box supporting the skin panel 26, which is fixed thereto. The upper part 24 includes, in particular, a concave portion 34 and a perimeter 36 surrounding said concave portion, as can be seen more clearly in Figures 3, 4, 9, 10, 12 and 22.

[0086] The skin panel 26 is preferably formed by injection of plastic material.

[0087] According to one aspect of the invention, as illustrated in [Fig.3], the structural panel 12 comprises a main extension portion, here divided into three zones 15, 17, 23 corresponding respectively to said lower portion 14, intermediate portion 16 and upper portion 24. The panel 12 further comprises a reinforcement element 28 defined by a rib 30 extending projecting over said main extension portion.

[0088] The reinforcing element 28 extends at least in the intermediate part 18 and in the upper part 24. Preferably, this reinforcing element 28 extends from the lower part 14 to the upper part 24 via the intermediate part 18. In this way, the reinforcing element 28 extends over each of the zones 15, 17, 23 of the main extension part. In the intermediate part 18, the element 24 comprises at least one part 29 with axis A, laterally bordering the rear window frame 20, as can be seen more particularly in [Fig. 3].

[0089] The main extension portion 15, 17, 23 and the rib 30 are monobloc and / or jointly produced in a single piece by injection molding of a plastic material such as polypropylene. This plastic material is reinforced with fibers, in particular glass fibers.

[0090] As schematically illustrated in [Fig. 5] and Figures 7 and 8, the reinforcing element 28 is hollow and is formed by injecting a fluid after the injection of the plastic material into the main extension portion of the structural panel 12 of the door 10, so as to define a vein 32 inside the rib 30. A vein is understood to be a shape whose cross-section has a closed contour. In [Fig. 5], the filler fibers 25 can be seen.

[0091] A problem may arise during the molding of the structural panel 12. The hollow vein, which extends throughout the entire reinforcement element 28, is created during the molding of the structural panel 12 by a process consisting of filling a mold corresponding to the shapes of the structural panel and the solid reinforcement element, then injecting the plastic material, and then, before this plastic material has completely solidified, hollowing out the reinforcement element 28 by injecting a pressurized fluid into it. Since the reinforcement element is solid, its periphery is already solidified while its core is still molten. It can thus be hollowed out by injecting a fluid into its molten core, which allows the unsolidified plastic material to be expelled. The result of this operation is a reinforcement element 28 that is both hollow and rigid.

[0092] However, it has been observed that the size of the vein and in particular its cross-section is significantly larger than the surrounding areas and concentrates more oriented fibers, thus creating a greater constriction phenomenon which generates deformations which take precedence over the deformations commonly observed.

[0093] This results, in the absence of specific provisions of the invention, in the cooling of the reinforcing element 28, in the shrinkage phenomena occurring in the reinforcing element 28 along a direction T, transverse to the direction of the reinforcing element. This phenomenon is further amplified in areas such as the intermediate zone 18, where the geometry of the panel itself causes the fibers 25 to be oriented in a direction parallel to that of said rib 30, i.e., along the axis A of the intermediate part 18. Upon cooling, the reinforcing element 28 deforms and no longer conforms to the desired dimensions.

[0094] This deformation is likely to propagate to any surrounding part of the structural panel 12, and in particular risks deforming in an unpredictable way the intermediate part 18 and a bottom wall 35 of the concave part 34 of the upper part 24.

[0095] The invention remedies these drawbacks by reinforcing these areas, in particular the intermediate part 18 and the upper part 24 to counteract this shrinkage phenomenon, as will be developed later.

[0096] With regard to the upper part 24, alternatively or cumulatively, parallel longitudinal stiffeners 38 extend from the bottom wall 35 of the concave part 34. These stiffeners 38 have been shown more particularly in Figures 4, 9, 10 and 12 to 18 and 22. They are advantageously made of the same material and molded with the structural panel 12.

[0097] As these figures illustrate in particular, the stiffeners are oriented substantially along the X direction of the door 10, and cross the entire concave part 34 from a front edge 36a to a rear edge 36b of the perimeter 36. As can be seen in particular on [Fig. 12], the longitudinal stiffeners 38 have longitudinal ends 38a, 38b respectively joined with the front edge 36a and rear edge 36b of the perimeter 36.

[0098] As can be seen in Figures 2 and 14, the spoiler skin panel 26 is fixed at least around its perimeter 36. Preferably, the spoiler skin panel 26 is also fixed to all or part of the longitudinal ends 38a, 38b of the longitudinal stiffeners. The details of the practical implementation of this fixing will be described later in this description.

[0099] Advantageously, the stiffeners 38 are at least locally of a determined height h which is less than a depth H of the cavity 34. In this way, as illustrated in [Fig. 13], the stiffeners 38 define in the cavity 34 a passage P, represented by dashed lines in [Fig. 13], allowing, for example, the passage of an electrical bundle (not shown) between the stiffeners 38 and the spoiler skin panel 26. Preferably, the stiffeners 38 have said height h, limited, over a part of their length and are flush with said cavity over another part, at least for some of said stiffeners.

[0100] Advantageously, as illustrated in Figures 9 and 10, transverse partitions 40 can pass through the cavity 34 to connect the stiffeners 38 so as to further stiffen the structural panel 12. These partitions 40 are also advantageously made from the same material and molded with the panel 12, and are particularly visible in Figures 10, 12 and 13.

[0101] As can be seen in Figures 2, 3, and 9, the upper part 24 has anchor points 42 for the hinges of the door 10 at its transverse ends 44. Preferably, the stiffeners 38 are distributed transversely in the cavity at a higher density near these anchor points, as can be seen in Figures 4, 9, and 22. As can be seen in these figures, the stiffeners 38 are less spaced near the anchor points 42. This configuration allows optimally support the stresses induced in the door material 10 by the hinge anchor points 42.

[0102] A particularly advantageous configuration of the door 10 is that it can accommodate spoiler skin panels 26 of varying lengths, and in particular long spoiler skin panels 26. To this end, the door 12 can include a spoiler support extension 46, which is attached to the rear edge 36b of the perimeter 36, and which extends vertically along the rear window frame 20 of the door 12, as shown in Figures 9 to 14, 19 and 22.

[0103] As can be seen in figures 10 and 11, 12 and 19, the spoiler support extension 46 preferably also includes longitudinal ribs 48, or even partitions 50 between these ribs, which make it possible to increase the rigidity of the spoiler support extension 46.

[0104] The spoiler support extension 46 does not necessarily occupy the entire width of the upper part 24. To provide sufficient support for the spoiler skin panel 26, it is sufficient for the spoiler support extension 46 to extend transversely along a portion of the width of the rear edge 36b of the perimeter 36, as can be seen in particular in Figures 9 and 12. As can be seen in particular in [Fig. 14], the spoiler skin panel 26 extends at least to a free end 52 of the spoiler support extension 46.

[0105] The spoiler support extension 46 is fixed to the upper part 24. For this purpose, as illustrated in Figures 11 to 13, the spoiler support extension comprises, from its end 52 towards the upper part 21:

[0106] - a first portion 54, in particular straight, which extends rearward from the rear edge 36b of the perimeter 36, extending from it

[0107] - at least one clamp 56 extending from said first portion 54, pinching the rear edge 36b of the perimeter 36,

[0108] - a second portion 58 which extends below the rear edge 36b of the perimeter 36 from of the first portion 54,

[0109] - at least one fixing tab 60 which extends under the upper part from of the said second portion 58 and which is fixed to the upper part in particular by screwing, stapling or welding. The two fixing tabs 60 shown here also allow the spoiler support extension 46 to be stopped against the structural panel 12 in the X direction.

[0110] The spoiler support extension 46 can thus be mounted simply and reliably at the end 36b of the perimeter 36, depending on the spoiler skin chosen. As seen in [Fig. 11], the spoiler will be closed under the spoiler skin extension by a trim piece 62, attached to the spoiler support extension 46.

[0111] Conventionally, the assembly of the spoiler skin panel 26 to the structure panel 12 is carried out by means of glue or by means of a screwed multi-component spoiler.

[0112] For this purpose, at least one first bead of so-called "structural" adhesive is used, for example a two-component polyurethane adhesive (PU2K), which is a slow-setting adhesive offering excellent bonding capabilities for these parts. This first bead of adhesive is, for example, located around the perimeter 36 of the structural panel.

[0113] Since the assembly of the spoiler skin panel 26 to the structure panel 12 requires sealing when this spoiler skin panel is glued, this assembly is conventionally completed by a second bead of glue suitable for ensuring sealing.

[0114] However, polyurethane adhesives contain carcinogenic, mutagenic, or toxic compounds, known as CMR agents. According to a third aspect of the invention, which can be used alone or in combination with one or more of its preceding aspects, the invention aims to develop alternative approaches to eliminate, replace, limit, or improve adhesives containing such compounds.

[0115] To this end, as schematically shown in Figures 24, 25, and 27, the structural panel 12 and the spoiler skin panel 26 are joined to each other by means of at least one bead 64 of said plastic material. As schematically illustrated in Figures 26 and 28, this bead is formed of at least one pair of ribs 66, 68, in particular arranged opposite each other, which are respectively formed from said structural panel 12 and the skin panel 26, and which are welded to each other. In other words, the bead 34 is formed of welded portions of said ribs 66, 68.

[0116] It will be understood that such an assembly is applicable to the manufacture of any structural element comprising a structural panel 12 and a skin panel 26 in the general sense, and not limited to the door 10.

[0117] To do this, as illustrated in [Fig.29], the bodywork element, here the door 10, can be produced according to a process comprising at least one step i) of forming the structural panel 12 and said spoiler skin panel 26 by injection of plastic material, and one step ii) of assembling said structural panel 12 and said spoiler skin panel 26.

[0118] During the assembly step ii) at least the projecting rib 66 of the structural panel 12, and the projecting rib 68 of the spoiler skin panel 26 are formed during plastic injection. These ribs 66 and 68 are respectively formed from material with the structural panel 12 and the spoiler skin panel 26.

[0119] Ribs 66, 68 are suitable for being arranged opposite each other, as schematically illustrated in figures 26 and 28.

[0120] In the context of the invention, as illustrated in Figures 26, 28 and 29, the assembly step ii) comprises at least one phase PI for securing said spoiler skin panel 26 to the structural panel 12, comprising a sub-phase ii.a) in which the ribs 66, 68 are arranged opposite each other, a sub-phase ii.b) in which the plastic material of the free edges 70, 72 of said ribs 66, 68 is melted, then a sub-phase ii.c) (not shown) in which said edges 70, 72 of said ribs 66, 68 are brought into contact, and finally a sub-phase ii.d) (not shown) in which the structural panel 12 and the spoiler skin panel 26 are pressed together. the other so as to form the 34 cord of molten plastic material.

[0121] More particularly, during sub-phase ii.a) the structure panel 12 and the spoiler skin panel 26 are respectively placed in respective supports 74, 76 opposite each other.

[0122] [Fig.20] represents a fastening device 78 allowing the structural panel 12 of the aforementioned trunk door to be fastened to the spoiler skin panel 26. It includes the support 76, or lower support, on which the structural panel 12 rests, and the upper support 78, intended to carry the spoiler skin panel (not shown in [Fig.20]). The device 78 further includes a two-sided heating device 82 84, 86, each side of which is equipped with a heating means 88 suitable for melting the free edges 70, 72 of the ribs 66, 68. As illustrated in [Fig. 21], the heating means 88 can be infrared wires 90, but it could also be infrared lamps, or an ultrasonic welding means, suitable for melting the free edges 70, 72 of the ribs 66, 68 during sub-phase ii.b).

[0123] To ensure optimal weldability of the ribs 66, 68, as illustrated in [Fig.23], a foot 91 of each rib 66, 68, at its junction with the structural panel 12 or the skin panel 26, is of a width 1 which is between one third and one quarter of a thickness E of said structural panel 12 or of said skin panel 26.

[0124] The said rib(s) 66, 68 may have an inclined, non-perpendicular orientation with respect to the structural panel 12 or with respect to the spoiler skin panel 26 from which they originate. Advantageously, ribs joined to each other by welding have the same inclination and are substantially in the same plane.

[0125] Furthermore, in order to obtain a weld bead 64 of minimum thickness, it is not necessary for the ribs 66, 68 to be of the same thickness, based on the panels from which they originate. In this context, each rib 68 originating from the material with the skin panel 12 preferably has a thickness less than the opposite rib 66. corresponding to the structural panel 12. Advantageously, therefore, among one of the two ribs 66, 68 welded to the other, one penetrates into the other.

[0126] Another characteristic of the motor vehicle body element 10 according to this third aspect of the invention, and in particular of the door 10, is that the structural panel 12 and the spoiler skin panel 26 are on the one hand fixed to each other by a structural assembly means and that on the other hand, a sealing means is interposed between the structural panel 12 and the spoiler skin panel 26.

[0127] Thus, the assembly step ii) further comprises a phase P2 of structural assembly of the spoiler skin panel 26 to the structure panel and a phase P3 of making a sealing joint between the spoiler skin panel 26 and the structure panel 12.

[0128] As seen above, conventionally, during the assembly step ii) the fixing of the structural panel 12 to the spoiler skin panel 26 is ensured by a first bead of so-called "structural" glue, for example a two-component polyurethane glue (PU2K), while the sealing between these panels 12, 26 is ensured by a second bead of non-structural, hot-melt polypropylene (PP) glue.

[0129] The weld bead 66 produced during the bonding phase occurring during step ii) can advantageously perform one, the other, or all of these functions in accordance with the third aspect of the invention.

[0130] Thus, according to a first embodiment of the assembly, the first of said welded ribs 66a, 68a constitute the structural assembly means, and the second of said welded ribs 66b, 68b constitute the sealing means.

[0131] In this case, each phase P2 of structural assembly of the skin panel 26 to the structure panel 12 and each phase P3 of making a sealing joint correspond to the phase PI, mentioned above, of securing said spoiler skin panel 26 to the structure panel 12.

[0132] Sub-phases ii.a), ii.b), ii.c) and ii.d) are therefore applied to at least two pairs 66a, 68a and 66b, 68b of facing ribs, at least two of the facing ribs 66a, 68a assembled forming a structural assembly, and at least two other of the facing ribs 66b, 68b assembled forming a sealing joint.

[0133] This configuration is shown in Figures 19 and 22. In [Fig. 19], the locations of the structural assembly ribs 66a of the structural panel 12 and the sealing ribs 66b of the structural panel 12 are visible, with the locations of the structural assembly ribs 68a of the skin panel 26 and the sealing ribs 68b of the spoiler skin panel 26 opposite each other. It should be noted that the structural assembly ribs 66a of the structural panel 12 are essentially formed from an upper portion of all or part of the stiffeners 38 and the partition 40. They are placed here on some of the stiffeners 38 and on parts of the partition 40 in a U shape, and / or also on the spoiler support extension 46. The sealing ribs 66b of the structural panel 12, meanwhile, run around the entire perimeter 36.

[0134] On [Fig.22], only the locations of the structural assembly ribs 66a of the structural panel 12 and the sealing ribs 66b of the structural panel 12 can be seen.

[0135] Figures 15 to 18 illustrate more particularly the locations of the structural assembly ribs 68a of the skin panel 26 on the stiffeners 38.

[0136] As can be seen in [Fig. 15], the front edge 36a of the perimeter 36 has a sealing rib 66b and the front end 38a of the stiffener 38 has a structural assembly rib 66a. In [Fig. 16], the sealing rib 66b of the rear edge 36b of the perimeter 36 is seen above the spoiler support extension 46. In [Fig. 17], the structural assembly rib 66a of the rear end 38b of the stiffener 38 is seen. Finally, in [Fig. 18], the structural assembly rib 66a of the spoiler support extension 46 is seen.

[0137] According to second and third embodiments of the assembly, as illustrated in figures 25 to 28, the weld bead 66 produced during the bonding phase occurring during step ii) may only ensure structural fixing or sealing.

[0138] Thus, in the case of the assembly of [Fig.25], in the second embodiment of the assembly, the welded ribs forming the bead 34 constitute the sealing means and a bead of two-component polyurethane adhesive 92 (PU2K) is applied between the structural panel 12 and the skin panel 26 to constitute the structural assembly means.

[0139] In this case, only phase P3 of the creation of a sealing joint corresponds to phase PL

[0140] The sealing joint P3 phase is therefore carried out by the bonding phase PI applied to a pair of ribs 66b, 68b opposite, and the structural assembly phase PI is carried out by applying the bead of two-component polyurethane adhesive 92 (PU2K) to one of the structural panels 12 or skin panel 26 prior to substep ii.b), in this case the structural panel 12, as shown in [Fig.26].

[0141] Preferably, sub-phase ii.a), in which the ribs 66b, 68b are arranged opposite each other, occurs before sub-phase ii.b), in which the plastic material of the free edges 70, 72 of said ribs 66b, 68b is melted. During sub-phase ii.b), the two-sided heating device 82 84, 86 is introduced between the skin panel 26 and the structural panel 12, with a mask thermally insulating interposed between the heating device 82 and the two-component polyurethane (PU2K) adhesive bead 92 applied to the structural panel 12. The purpose of this mask is to prevent the heating device from causing the adhesive bead 92 to harden before the ribs 66b, 68b are melted and assembled.

[0142] Thus, in the case of the assembly of [Fig.27], in the third embodiment of the assembly, the welded ribs 66a, 68a forming the bead 34 constitute the structural assembly means and a bead of non-structural, hot-melt polypropylene (PP) glue 94 without CMR agents is applied between the structural panel 12 and the skin panel 26 to constitute the sealing means.

[0143] In this case, the structural assembly phase P2 is carried out by the bonding phase PI applied to a pair of facing ribs 68a, 68b, and the sealing joint phase P3 is carried out by applying the hot melt adhesive bead 94, polypropylene (PP), non-structural, without CMR agents, to one of the structural panels 12 or skin panel 26 prior to sub-phase ii.b), in this case the skin panel 12.

[0144] In the same way as before, preferably sub-phase ii.a), during which the ribs 66a, 68a are arranged opposite each other, occurs before sub-phase ii.b).

[0145] During sub-phase ii.b) the plastic material of free edges 70, 72 of said ribs 66a, 68a is melted. The two-sided heating device 82 84, 86 is introduced between the skin panel 12 and the structural panel 26, with or without a thermally insulating mask, because the setting time of the hot melt, polypropylene (PP), non-structural adhesive bead 94 is much longer and the adhesive bead is not likely to be affected by the heating device 82.

[0146] As previously seen, the invention, in particular according to its first aspect, aims to remedy the disadvantages of the shrinkage phenomenon caused by the orientation of the fibers during the production of the hollow reinforcement element 28, defined by the rib 30 traversed by the hollow vein 32, extending, in the illustrated embodiment, over the zones 15, 17 and 23 of the main extension part at the level of the lower 14, intermediate 18 and upper 24 parts of the door 10.

[0147] Since the reinforcing element 28 and the main extension portion are, as already stated, produced jointly by injection molding of the fiber-reinforced plastic material, the invention proposes to remedy the transverse shrinkage phenomenon caused by the orientation of the fibers 25 during the molding of the reinforcing element 28 by reinforcing it, particularly during the solidification of the plastic material. To this end, as illustrated in Figures 1 to 5 and 7 to 9, the structural panel 12 comprises a metal insert element 98 which is overmolded by the plastic material at least along a part of said rib 30.

[0148] By "overmolded", it is understood that the plastic material is present around the insert element, following a molding, without necessarily covering the entire surface of the metal insert element 98. In this way, by observing said panel, it is possible to see locally the metal insert element 98 in areas where it is not covered with plastic material, while remaining within the scope of the first aspect of the invention.

[0149] More particularly, the metal insert element 98 has at least a first part 100 which is overmolded between the main extension part, in particular at the level of the zone 17 of the intermediate part 18, and the reinforcing element 28.

[0150] As illustrated more particularly in figures 7 and 8, the first part 100 extends opposite one side of the rib 30. The first part 100 is thus able to oppose the phenomenon of shrinkage during the solidification of the plastic material.

[0151] Preferably, the rib 30 has a rectangular or square cross-section. The first portion 100 extends along one side of the rectangular or square cross-section, as schematically shown in [Fig. 7]. Thus, the first portion of the metal insert element comprises at least one substantially flat wall 102, extending opposite one side of said rib 30.

[0152] Moreover, as can be seen in [Fig.6], the first part 100 of the metal insert element 98 has at least one hole 104 through which the plastic material from the reinforcing element 28 passes.

[0153] Furthermore, the first portion 100 of the metal insert element 98 is covered, in whole or in part, with plastic material from the main extension portion 17, in particular by a network of intersecting plastic ribs 106. The material of these ribs 106 communicates, for example, with the material of the rib 30 through the holes 104. In other words, the holes 104 allow the passage of plastic material to facilitate the filling of the ribs 106. It will therefore be understood that an injection mold for the panel 12 will have grooves suitable for forming the ribs 106. The ribs 106 can take any useful shape and are, for example, intersecting.

[0154] In other words, the rib network 106 is located on one face of the metal insert element 98 and, on the opposite face, in continuity of material through the holes 104, the remainder of said main extension portion of the panel 12 extends continuously. Put another way, on the side of the rib network 106, the metal insert element 98 is visible between the ribs of the network of ribs 106 while on the opposite side it is embedded in the plastic material of panel 12.

[0155] In the context of the door 10 according to the invention, the first part 100 of the metal insert element 98 is located substantially on the intermediate part 18 of axis A.

[0156] As can be seen in Figures 6 to 8, the metal insert element 98 also includes a second part 108, adjacent to the first part 100, which extends into the intermediate part 18 of the structural panel 12 opposite the rear window frame 20, specifically from one of its lateral sides, which is locally shortened. This second part 108 is shaped into a wing extending parallel to the axis A. One end 107 of this second part 108 has a hole 110, suitable for receiving a fixing element 112 of a door cylinder ball joint 114, as shown in [Fig. 8].

[0157] As illustrated in Figures 2 to 4, the metal insert element 98 further comprises a third part 116, adjacent to the first part 100, which extends into the upper part 24 of the structural panel 12 and, which extends transversely with respect to the axis A. The metal insert element 98 locally defines at this level an L-shaped tab having at least one hole 118 suitable for being passed through by a screw (not shown) for fixing a hinge of the door, visible in [Fig.2].

[0158] As can be seen in Figures 6 to 9, the overmolded metal insert element 98 further comprises a fourth part 120, adjacent to the first part 100, which extends in the intermediate part 18 of the structural panel 12 towards the rear window frame 20 and which has a vertical wing shape.

[0159] In this way, the first, second and fourth parts 100, 108 and 120 of the metal insert element 98 define a gutter with a substantially U-shaped cross-section.

[0160] In other words, on either side of said rib 30, said insert element 98 extends by lateral sides so as to present a substantially U-shaped profile, a bottom wall of the profile forming the part of the insert element located opposite the rib 30.

[0161] Here, the rib network 106 extends at the level of the said lateral flank(s), at the level of the said first face of the insert element 98. The remainder of the said main extension part extends, for example, over the entire opposite face of the metal insert element 98.

[0162] As illustrated in [Fig. 30], the structural panel 12 can be manufactured according to a process comprising firstly a step I) in which a plastic injection mold is prepared, consisting of two shells (not shown) defining between them an overall shape of the structural panel 12. The shells further define between them a cavity constituting a counter-form of the reinforcing element 24 of said structural panel and two ends of said cavity opening to the outside said mold. Then, in step II), the insert element 98 is placed in the mold, between the two shells. It should be noted that preferably, the mold advantageously includes means for positioning the insert element 98 relative to the cavity, so as to define a unique position for the insert element 98.

[0163] Then, in a step III), a plastic material is injected into the mold, which allows the element 28 to be overmolded. Finally, in a step IV), before complete polymerization of the plastic material, a fluid is injected at one end of the cavity to hollow out the reinforcing element 24 by forming the hollow vein 32 in the rib 30. Thanks to the insert element 98, the phenomenon of fiber orientation which may occur during the creation of the vein is limited.

[0164] The invention is particularly applicable to a vehicle door 10, thus offering high rigidity characteristics and reduced weight.

Claims

Demands

1. Motor vehicle bodywork element, said element being made up of a box-shaped structural panel (12) to which a skin panel (26) attached to said structural panel (12) is attached, said structural panel (12) and skin panel (26) being formed by injection of plastic material, in which the structural panel (12) and the skin panel (26) are joined to each other by means of a bead (64) of said plastic material, said bead being formed of at least one pair of ribs (66, 66a, 66b, 68, 68a, 68b), in particular arranged opposite each other, respectively formed from material with said structural panel (12) and / or with said skin panel (26), welded to each other.

2. Motor vehicle body element according to the preceding claim, wherein a foot 91 of each rib (66, 68), at its junction with said structural panel (12) or said skin panel (26), is of a width (1) between one third and one quarter of a thickness (E) of said structural panel (12) or said skin panel (26).

3. Motor vehicle bodywork element according to any one of the preceding claims, wherein each rib (68, 68a, 68b) made of material with said skin panel (26) is of less thickness than the corresponding opposite rib (66, 66a, 66b) of the structural panel (12).

4. Motor vehicle bodywork element according to any one of the preceding claims, wherein the structural panel (12) and the skin panel (26) are fixed to each other by a structural assembly means and wherein a sealing means is interposed between the structural panel (12) and the skin panel (26).

5. Bodywork element according to the preceding claim, wherein first of said welded ribs (66a, 68a) constitute the structural assembly means and wherein second of said welded ribs (66b, 68b) constitute said structural assembly means as well as the sealing means.

6. Bodywork element according to claim 4, wherein said welded ribs (66a, 68a) constitute the assembly means structural and in which a sealing joint, made by application of a bead of glue (94) applied between the structural panel (12) and the skin panel (26), constitutes the means of sealing.

7. Bodywork element according to claim 4, wherein said welded ribs (66b, 68b) constitute the sealing means and wherein a bead of two-component polyurethane (PU2K) adhesive (92) applied between the structural panel (12) and the skin panel (26) constitutes the structural assembly means.

8. Door (10) for a motor vehicle trunk, said door (10) comprising a one-piece trunk door structure panel (12) having: - a lower part (14) intended to be covered by an outer panel (16) of the door (10), - an intermediate part (18) forming a rear window frame (20) of the door, - an upper part (24) forming a box, covered by a skin panel (26) of an aerodynamic spoiler of the door (10), in which at least the upper part (24) and the spoiler skin panel (26) form a bodywork element according to any one of claims 1 to 7.

9. Door (10) according to the preceding claim, wherein the upper part (24) comprises a concave portion (34) provided with longitudinal stiffeners (38) for stiffening and a perimeter (36) surrounding said concave portion (34).

10. Door (10) according to the preceding claim, wherein a portion of said stiffeners (38), the perimeter (36) and the spoiler skin panel (26) comprise said ribs (66a, 68a; 66b, 68b) welded opposite each other.

11. Door (10) according to any one of claims 9 to 10, wherein the upper part (24) receives a spoiler support extension (46), attached to the periphery (36) of said upper part (24) and extending vertically below said rear window frame (20) of the door, said spoiler support extension (46) and said spoiler skin panel (26) having at least one of said ribs (66a, 68a; 66b, 68b) welded opposite each other.

12. A method for manufacturing a motor vehicle body component according to claim 1, said method comprising at least: (i) a step of forming the structural panel (12) and said skin panel (26) by injection of plastic material, (ii) a step of assembling said structural panel and said skin panel, process in which: - during the assembly step ii) at least one rib (66a, 66b) projecting from the structural panel (12), and one rib projecting from said skin panel (26) are formed during plastic injection, said ribs being (66a, 68a; 66b, 68b) capable of being positioned opposite each other, - the assembly step ii) comprises at least one bonding phase PI of said skin panel to the structural panel (12) comprising a sub-phase ii.a) during which the ribs (66a, 68a; 66b, 68b) are arranged opposite each other, a sub-phase ii.b) during which the plastic material of the free edges (70, 72) of said ribs (66a, 68a; 66b, 68b) is melted, then a sub-phase ii.c) during which said edges (70, 72) of said ribs (66a, 68a; 66b, 68b) are brought into contact, and finally a sub-phase ii.d) during which the structural panel (12) and said skin panel (26) are pressed together so as to form a bead (64) of said melted plastic material.

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