WO2026012990A1 - Door for a motor vehicle luggage compartment - Google Patents

Abstract

The invention relates to a door for a motor vehicle luggage compartment, the door comprising an integral structural panel (12) of the luggage compartment door, made in one piece by injection of a plastic material, the structural panel (12) of the door including: - a lower portion (14) intended to be covered with an outer panel of the door; - an intermediate portion (18) forming a frame (20) of a rear window, intended to be covered by a rear window of the door; and - an upper portion (24), intended to be covered with a skin panel of an aerodynamic spoiler of the door, wherein the upper portion (24) includes a concave portion (34) and a peripheral portion (36) surrounding the concave portion (34), with parallel longitudinal stiffeners (38) extending from a bottom (35) of the concave portion (34).

Description

DESCRIPTION

TITLE: DOOR FOR A VEHICLE TRUNK

AUTOMOBILE.

Technical field of the invention

The invention relates to a door for a motor vehicle trunk.

Technical background

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

In order to benefit from a bodywork element with a substantial extension, it is generally made in the form of a bodywork structure panel covered with one or more so-called "skin" panels which form the externally visible part of said bodywork element.

A particular method for obtaining a lightweight yet rigid bodywork element involves designing the structural panel as a main extension part to which a reinforcing element is added during molding.

The applicant's document FR-3.083.484-B1 defines such a reinforcing element as consisting of a rib traversed by a hollow vein extending in projection on said extension part main. Said main extension part and said reinforcement element are made jointly by injection of a plastic material such as polypropylene, this plastic material being filled with fibers, in particular glass fibers.

However, there is still a real need for a motor vehicle body structure panel with a stiffened upper part and capable of directly receiving a spoiler skin panel.

Summary of the invention

The invention satisfies this need by providing a door for a motor vehicle trunk, said door comprising a one-piece trunk door structure panel made in a single piece by injection molding of a plastic material, said door structure panel comprising:

- a lower section intended to be covered by an outer door panel,

- an intermediate part forming a frame for a rear window, intended to be covered by a rear window of the door,

- an upper part, intended to be covered by a skin panel of an aerodynamic spoiler of the door, or by a part of the rear window of the door in which the upper part includes a concave part and a perimeter surrounding said concave part, stiffeners, in particular longitudinal and/or parallel, of stiffening extending from a bottom of said concave part.

The stiffening of the concave part of the upper section by means of stiffeners makes it possible to have an upper section that is sufficiently rigid and of sufficiently precise definition to directly receive the spoiler skin panel. According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention:

- the stiffeners traverse the entire concave section from a front edge to a rear edge of the perimeter,

- the stiffeners have longitudinal ends that are joined to the perimeter,

- the spoiler skin panel is fixed at least around the perimeter.

- the spoiler skin panel is further fixed to all or part of the longitudinal ends of the stiffeners,

- the stiffeners are at least locally of a determined height less than a depth of the cavity to determine in the cavity a passage of an electrical beam between said stiffeners and the spoiler skin, the upper part has at its transverse ends anchoring points for hinges of said door,

- the stiffeners are distributed transversely within the cavity with a higher density near said anchor points,

- the door includes a spoiler support extension, attached to the rear edge of the perimeter and extending vertically along the rear window frame of the door,

- the spoiler support extension extends transversely along a portion of the width of the rear edge of the perimeter,

- the spoiler skin panel extends at least to one free end of the spoiler support extension.

- The spoiler support extension includes:

• a first portion, notably straight, extending backwards from the rear edge of the perimeter, • at least one clamp extending from said first portion, pinching the rear edge of the perimeter,

• at least a second portion, in particular a straight one, extending below the rear edge of the perimeter,

• at least one fixing bracket extending under the upper part from said second portion and fixed to the upper part, in particular by screwing, stapling, or welding,

- the upper part and the spoiler skin panel have facing ribs suitable for being melted and then assembled to join said spoiler skin panel to the upper part,

- the veins include at least:

• a peripheral rib running around the entire perimeter,

• ribs formed at all or part of the longitudinal ends of the longitudinal stiffeners,

- the spoiler support extension and the spoiler skin panel have facing ribs suitable for being melted and then assembled to join said spoiler skin panel to said extension,

- the reinforcing element is hollow,

- the reinforcing element passes through the lower, middle and upper parts,

- the reinforcement element is made by injecting a fluid after the injection of the plastic material of the door structure panel.

Brief description of the figures

The invention will be better understood, and other purposes, details, features, and advantages thereof will become more apparent during the detailed explanatory description that will follow. to follow, by at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the attached schematic drawings, among which:

Figure 1 is an exploded perspective view of a rear door of a motor vehicle according to the invention;

Figure 2 is a perspective view showing the removal of the door from Figure 1 and elements of the metal inserts from that door;

Figure 3 is a perspective ghost view of the door structure panel fitted with its metal insert elements;

Figure 4 is a detailed top view of the door structure panel fitted with its metal insert elements;

Figure 5 is a schematic cross-sectional view of the intermediate part of the structural panel of the door in Figure 4;

Figure 6 is a detailed perspective view of a metallic insert according to the invention;

Figure 7 is a detailed perspective view of the door structure panel fitted with a metal insert element;

Figure 8 is a cross-sectional detail view of the door structure panel fitted with a metal insert element;

Figure 9 is a perspective view of the door structure panel fitted with its metal insert elements;

Figure 10 is a perspective view of the door structure panel fitted with a spoiler support extension;

Figure 11 is a perspective view of the spoiler support extension of Figure 10;

Figure 12 is a perspective ghost view of the door structure panel fitted with its spoiler support extension; Figure 13 is a side perspective view of the door structure panel fitted with its spoiler support extension;

Figure 14 is a longitudinal sectional side view of the door structure panel fitted with its spoiler support extension;

Figure 15 is a first detailed view of figure 14;

Figure 16 is a second detailed view of figure 14;

Figure 17 is a third detailed view of figure 14;

Figure 18 is a fourth detailed view of figure 14;

Figure 19 is a perspective view showing ribs connecting the structural panel and the spoiler support extension to the spoiler panel during peeling;

Figure 20 is a perspective view of a rib heating device, for joining the structural panel and the skin panel of the door;

Figure 21 is a perspective view of one face of the rib-locking heating device of Figure 20;

Figure 22 is a detailed top view of the structural panel and the location of its connecting ribs;

Figure 23 is a cross-sectional view of a connecting rib;

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;

Figure 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;

Figure 26 is a schematic cross-sectional view illustrating the realization of the second embodiment of the assembly of Figure 25; Figure 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;

Figure 28 is a schematic cross-sectional view illustrating the realization of the third embodiment of the assembly of Figure 27;

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

Figure 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

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

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

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

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

More specifically, the upper part 24 forms a box supporting the skin panel 26, which is fixed to it. The upper part 24 includes, in particular, a concave portion 34 and a perimeter 36 surrounding said concave portion, as can be better seen in figures 3, 4, 9, 10, 12 and 22.

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

According to one aspect of the invention, as illustrated in Figure 3, the structural panel 12 comprises a main extension part, here divided into three zones 15, 17, 23 corresponding respectively to said lower part 14, intermediate part 18 and upper part 24. The panel 12 further comprises a reinforcement element 28 defined by a rib 30 extending projecting over said main extension part.

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

The main extension section 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. As schematically illustrated in Figure 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, thus defining a vein 32 inside the rib 30. A vein is defined as a shape whose cross-section has a closed contour. The load-bearing fibers 25 can be seen in Figure 5.

A problem can arise during the molding of the structural panel 12. The hollow core, which extends throughout the entire reinforcement element 28, is created during the molding process. This process involves filling a mold that matches the shape of the structural panel and the solid reinforcement element, then injecting the plastic material. Before this plastic material has completely solidified, the reinforcement element 28 is hollowed out by injecting a pressurized fluid. Because the reinforcement element is solid, its periphery is already solidified while its core is still molten. It can therefore be hollowed out by injecting fluid into its molten core, which forces out the unsolidified plastic. The result of this operation is a reinforcement element 28 that is both hollow and rigid.

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.

This results, in the absence of specific provisions as described in 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. in which the geometry of the panel causes in itself an orientation of the fibers 25 in a direction parallel to that of said rib 30, that is to say along the axis A of the intermediate part 18. As it cools, the reinforcing element 28 deforms and no longer corresponds to the desired dimensions.

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.

The invention remedies these drawbacks by reinforcing these areas, in particular the middle part 18 and the upper part 24, to counteract this shrinkage phenomenon, as will be explained later.

Regarding the upper part 28, alternatively or cumulatively, parallel longitudinal stiffeners of rigidity 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.

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 in figure 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.

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. Details of the practical implementation of This attachment will be described later in the rest of this description.

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 figure 13, the stiffeners 38 define in the cavity 34 a passage P, represented by dashed lines in figure 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.

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.

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 with 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 closer together near the anchor points 42. This configuration allows for optimal support of the stresses induced in the material of the door 10 by the anchor points 42 of the hinges.

A particularly advantageous feature of the door 10 is that it can accommodate spoiler skin panels 26 of varying lengths, including very long spoiler skin panels 26. For this purpose, the door 12 can include a spoiler support extension 46. which is referred to the rear edge 36b of the perimeter 36, and which extends vertically to the frame 20 of the rear window of the door 12, as shown in figures 9 to 14, 19 and 22.

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 increase the rigidity of the spoiler support extension 46.

The spoiler support extension 46 does not necessarily occupy the entire width of the upper part 18. 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 Figure 14, the spoiler skin panel 26 extends at least to a free end 52 of the spoiler support extension 46.

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 18:

- a first portion 54, notably straight, which extends rearward from the rear edge 36b of the perimeter 36, in line with it

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

- at least a second portion 58, in particular straight, which extends under the rear edge 36b of the perimeter 36 from the first portion 54,

- at least one fixing tab 60 which extends under the upper part 24 from said second portion 58 and which is fixed to the upper part 24 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 along the X direction.

The spoiler support extension 46 can therefore be easily and reliably mounted at the end 36b of the perimeter 36, depending on the spoiler skin chosen. As shown in Figure 11, the spoiler will be closed under the spoiler skin extension by a trim piece 62, attached to the spoiler support extension 46.

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

For this purpose, at least one initial 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 initial bead of adhesive is located, for example, around the perimeter 36 of the structural panel.

As 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.

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 previous aspects, the invention aims to develop alternative approaches to eliminate, replace, limit, or improve adhesives containing such compounds.

For this purpose, 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 via 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 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.

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.

To do this, as illustrated in Figure 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.

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 the plastic injection. These ribs 66 and 68 are respectively formed from the material of the structural panel 12 and the spoiler skin panel 26.

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

Within the framework of the invention, as illustrated in Figures 26, 28 and 29, assembly step ii) comprises at least one phase P1 of securing said spoiler skin panel 26 to the structural panel 12, comprising a sub-phase ii.a) during which the ribs 66, 68 are arranged opposite each other, and a sub-phase ii.b) during which the ribs are arranged opposite each other. melt the plastic material of free edges 70, 72 of said ribs 66, 68, then a sub-phase ii.c) (not shown) during which said edges 70, 72 of said ribs 66, 68 are brought into contact and finally a sub-phase ii.d) (not shown) during which the structure panel 12 and the spoiler skin panel 26 are pressed together so as to form the bead 34 of molten plastic material.

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

Figure 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 Figure 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 Figure 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).

To ensure optimal weldability of the ribs 66, 68, as illustrated in Figure 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 I which is between one third and one quarter of a thickness E of said structural panel 12 or of said skin panel 26.

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

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 skin panel 12 preferably has a thickness less than the corresponding rib 66 of the structural panel 12. Advantageously, therefore, of the two ribs 66, 68 welded to the other, one penetrates the other.

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.

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.

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.

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.

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.

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 P1, mentioned above, of securing said spoiler skin panel 26 to the structure panel 12.

Subphases 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.

This configuration has been shown in Figures 19 and 22. In Figure 19, 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, with opposite them the locations of the structural assembly ribs 68a of the skin panel 26 and the sealing ribs 68b of the spoiler skin panel 26 which have been peeled off in order to visualize their locations. It should be noted that the structural assembly ribs 66a of the structural panel 12 are essentially formed from an upper part 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, on the other hand, run along the entire perimeter 36. Figure 22 shows only the locations of the structural assembly ribs 66a of the structural panel 12 and the sealing ribs 66b of the structural panel 12.

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

As can be seen in Figure 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 connection rib 66a. Figure 16 shows the sealing rib 66b of the rear edge 36b of the perimeter 36, above the spoiler support extension 46. Figure 17 shows the structural connection rib 66a of the rear end 38b of the stiffener 38. Finally, Figure 18 shows the structural connection rib 66a of the spoiler support extension 46.

According to the 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.

Thus, in the case of the assembly in Figure 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.

In this case, only phase P3 of creating a sealing joint corresponds to phase P1.

The sealing joint P3 phase is therefore carried out by the bonding phase P1 applied to a pair of opposing ribs 66b, 68b, and the structural assembly phase P1 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 figure 26.

Preferably, sub-phase ii.a), during which the ribs 66b, 68b are arranged opposite each other, takes place before sub-phase ii.b), during which the free-edge plastic material 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 12 and the structural panel 26, with a thermally insulating mask 94 interposed between the heating device 82 and the two-component polyurethane (PII2K) adhesive bead 92 applied to the structural panel 12. The purpose of this mask 94 is to prevent the heating device from causing the adhesive bead 92 to harden before the ribs 66b, 68b are melted and assembled.

Thus, in the case of the assembly in Figure 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.

In this case, the structural assembly phase P2 is carried out by the bonding phase P1 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, on one of the structural panels 12 or skin panel 26 prior to sub-phase ii. b), in this case the skin panel 12. In the same way as before, preferably sub-phase ii.a), during which ribs 66a, 68a are arranged opposite each other, occurs before sub-phase ii.b).

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.

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.

Since the reinforcing element 28 and the main extension portion are, as already mentioned, produced jointly by injecting 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 includes a metal insert element 98 which is overmolded by the plastic material at least along a portion of said rib 30.

By "overmolded," we mean that the plastic material is present around the insert element, following a molding process, without necessarily covering the entire surface of the metal insert element 98. Thus, by observing the said panel, it 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.

More specifically, 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 reinforcement element 28.

As illustrated in particular by 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.

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

Furthermore, as can be seen in Figure 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.

Furthermore, the first part 100 of the metal insert element 98 is covered, in whole or in part, with plastic material from the main extension part 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 form, and are for example intertwined.

In other words, the rib network 106 is located on one face of the metal insert element 98, and on the opposite face, continuous with the material through the holes 104, the remainder of the 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 rib network 106, while on the opposite side, it is embedded in the plastic material of the panel 12.

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.

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 section 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 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 Figure 8.

As illustrated in Figures 2 to 4, the metal insert element 98 further comprises a third part 1 16, 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 1 18 suitable for being passed through by a screw (not shown) for fixing a hinge of the door, visible in Figure 2. 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 into the intermediate part 18 of the structural element 12 towards the rear window frame 20 and which has a vertical wing shape.

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

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.

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.

As illustrated in Figure 30, the structural panel 12 can be manufactured using a process with a plastic injection mold consisting of two shells (not shown) defining the overall shape of the structural panel 12. The shells also define a cavity between them, which is a counter-form of the reinforcing element 24 of said structural panel, and two ends of said cavity open outside said mold.

This process first involves a step I) during which the shells of the plastic injection mold are disassembled in order to make the cavity accessible.

Then, during step II, the insert element is placed

98 in the mold, between the two shells. It should be noted that of Preferably, the mold advantageously includes means for positioning the insert element 98 relative to the cavity, so as to define a unique position of the insert element 98.

Then, during a step I II), a plastic material is injected into the mold, which allows the element 28 to be overmolded.

Finally, during 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.

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

Claims

DEMANDS 1. Door (10) for a motor vehicle trunk, said door (10) comprising a one-piece trunk door structural panel (12) made in one piece by injection molding of a plastic material, said door structural panel (12) comprising: - a lower part (16) intended to be covered by an outer panel (16) of the door, - an intermediate part (18) forming a frame (20) for a rear window, intended to be covered by a rear window of the door, - an upper part (24), intended to be covered by a skin panel (26) of an aerodynamic spoiler or by the rear window of the door, in which the upper part (24) comprises a concave part (34) and a perimeter (36) surrounding said concave part (34), stiffening stiffeners (38) extending from a bottom (35) of said concave part (34). 2. Door (10) according to the preceding claim, in which the stiffeners (38) pass through the entire concave portion (34) from a front edge (36a) to a rear edge (36b) of the perimeter (36). 3. Door (10) according to the preceding claim, in which the stiffeners (38) have longitudinal ends (38a, 38b) joined with the perimeter (36). 4. Door (10) according to any one of the preceding claims, in which the spoiler skin panel (26) is fixed at least around the perimeter (36). 5. Door (10) according to any one of claims 3 or 4, in which the spoiler skin panel (26) is fixed to all or part of the longitudinal ends (38a, 38b) of the stiffeners (38). 6. Door (10) according to any one of claims 2 to 5, wherein the stiffeners are at least locally of a determined height (h) less than a depth (H) of the cavity (34) to determine in the cavity a passage (P) of an electrical beam between said stiffeners (38) and the spoiler skin panel (26). 7. Door (10) according to the preceding claim, wherein the upper part has at its transverse ends anchoring points (42) for hinges of said door (10). 8. Door (10) according to the preceding claim in which the stiffeners (38) are distributed transversely in the cavity (34) with a higher density in the vicinity of said anchor points (42). 9. Door (10) according to any one of claims 2 to 8, comprising a spoiler support extension (46), attached to the rear edge (36b) of the perimeter (36) and extending vertically below said rear window frame (20) of the door (10). 10. Door according to claim 9, wherein the spoiler support extension (46) comprises: - a first portion (54), notably straight, which extends towards the rear from the rear edge (36b) of the perimeter (36), - at least one clamp (56) extending from said first portion (54), pinching the rear edge (36b) of the perimeter (36), - at least a second portion (58), in particular straight, which extends below the rear edge (36b) of the perimeter (36), - at least one fixing tab (60) which extends under the upper part from said second portion (58) and which is fixed to the upper part (24) in particular by screwing, stapling or welding. 1. Door (10) according to any one of the preceding claims, wherein the upper part (24) and the skin panel of spoiler (26) have facing ribs (66a, 66b, 68a, 68b) suitable for being melted and then assembled to join said spoiler skin panel (26) to the upper part (24). 12. A door (10) according to any one of the preceding claims, comprising a reinforcing element (28), said reinforcing element being hollow and formed by injecting a fluid after the injection of the plastic material of the door structure panel (12).