Installation of a vehicle floor covering panel

Abstract

The invention relates to an assembly (1) for a panel (2) covering the floor of a motor vehicle, said assembly comprising said panel and at least two receiving areas (3) for said panel, said panel having at least two peripheral portions (4) respectively mounted in support on each of said receiving areas and a central portion (5), said panel comprising a cellular stiffening core (6) defining a front face (7) and a back face (8), two front (10) and back (11) layers of flexural reinforcement for said core, said layers being based on entangled reinforcing fibers embedded in polyurethane foam, the surface density in the central portion (5) of said reinforcing fibers in each of said reinforcing layers being greater than said density in the peripheral portions (4). Figure 2a

Description

Title of the invention: Assembly of a floor covering panel for a motor vehicle

[0001] The invention relates to an assembly of a floor covering panel of a motor vehicle, a panel of such an assembly and a method of making such a panel.

[0002] It is known to produce an assembly for a floor covering panel of a motor vehicle, said assembly comprising said panel and at least two receiving areas for said panel originating from the body of said vehicle, said panel having at least two peripheral parts arranged along two of its opposite edges, said peripheral parts being respectively mounted in support on each of said receiving areas, and a central part extending between said peripheral parts without bearing support, said panel comprising: • a stiffening honeycomb core generally inscribed within a rectangular parallelepiped defining a front face and a back face, • two front and back layers of flexural reinforcement of said core, said layers being based on entangled reinforcing fibers embedded in polyurethane foam, said reinforcing layers extending respectively over said front and back faces, said foam overmolding said core so as to associate said reinforcing layers with said front and back faces.

[0003] We thus have a panel provided with reinforcing layers spaced apart from each other by the core playing the role of a spacer to produce a "beam effect".

[0004] According to known embodiments, the surface density of the reinforcing fibers is substantially homogeneous over the entire surface of the reinforcing layers.

[0005] And it is necessary to provide a sufficient surface density of reinforcing fibers to allow the panel to exhibit over its entire surface, and in particular in the middle part which has the lowest resistance to bending, a stiffness which allows it to receive a load without excessive bending.

[0006] However, such a surface density of fibers proves unnecessary in the vicinity of peripheral parts which exhibit a resistance to bending that is much greater than that of the middle part.

[0007] It follows that the surface density of fibers is dictated by the desired flexural strength in the middle part, leading to an excessive use of fibers, with the resulting disadvantages in terms of additional cost and weight of the panel.

[0008] The invention aims to overcome these drawbacks.

[0009] To this end, and according to a first aspect, the invention proposes an assembly for a floor covering panel of a motor vehicle, said assembly comprising said panel and at least two receiving zones for said panel originating from the body of said vehicle, said panel having at least two peripheral parts arranged along two of its opposite edges, said peripheral parts being respectively mounted in support on each of said receiving zones, and a central part extending between said peripheral parts without bearing support, said panel comprising: • a honeycomb stiffening core generally inscribed within a rectangular parallelepiped defining a front face and a back face, • two front and back layers of flexural reinforcement for said core, said layers being based on entangled reinforcing fibers embedded in polyurethane foam,said reinforcing layers extending respectively over said front and back faces, said foam overmolding said core so as to associate said reinforcing layers with said front and back faces, ,

[0010] the surface density in the middle part of said reinforcing fibers of each of said reinforcing layers being greater than said density in peripheral parts.

[0011] With the proposed arrangement, the surface density of the reinforcing fibers to be used is adapted according to the different parts of the panel, the middle part being provided with a larger quantity of fibers than the peripheral parts which are lightened in fibers.

[0012] This results in a reduction in the cost and weight of the panel.

[0013] In particular, with the proposed arrangement, panels can be produced whose mass can be reduced by about 20 to 30%, while preserving their flexural strength properties.

[0014] According to other aspects, the invention provides a panel of such an assembly and a method for making such a panel.

[0015] Other features and advantages of the invention will become apparent from the following description, made with reference to the accompanying figures, in which:

[0016] [Fig. 1] is a schematic front view of a panel of an assembly according to one embodiment, said panel having various types of peripheral parts,

[0017] [Fig.2a] and

[0018] [Fig.2b] are schematic cross-sectional views of an assembly in which the density surface area of ​​the reinforcing fibers varies in steps ([Fig.2a]) and continuously ([Fig.2b]).

[0019] With reference to the figures, an assembly 1 of a panel 2 for covering the floor of a motor vehicle - in particular a luggage compartment - is described, said assembly comprising said panel and at least two receiving areas 3 of said panel originating from the body of said vehicle, said panel having at least two peripheral parts 4 arranged along two of its opposite edges, said peripheral parts being respectively mounted in support on each of said receiving areas, and a central part 5 extending between said peripheral parts without bearing, said panel comprising: • a cellular stiffening core 6, generally inscribed within a rectangular parallelepiped defining a front face 7 and a back face 8, • two layers of front 10 and back 11 of flexural reinforcement of said core, said layers being based on reinforcing fibers - for example mineral (glass,...) or vegetable (flax, hemp,...) - intertwined and embedded in polyurethane foam, said reinforcing layers extending respectively over said front and back faces, said foam overmolding said core so as to associate said reinforcing layers with said front and back faces,

[0020] the surface density in the middle part 5 of said reinforcing fibers of each of said reinforcing layers being greater than said density in peripheral parts 4.

[0021] According to one embodiment, the web 6 has a thickness 9 generally between 6 and 30 mm, the term "generally" meaning that this thickness can be locally reduced, in particular by compression, for example at the periphery of said web or in areas receiving attachment elements.

[0022] According to the embodiment shown, the core 6 has a honeycomb structure, in particular based on cardboard or thermoplastic material.

[0023] In an alternative not shown, the core 6 is in the form of a block based on rigid foam, i.e. non-elastically compressible.

[0024] According to various embodiments, the surface density of the reinforcing fibers of each of the reinforcing layers 10,11 increases from the peripheral parts 4 to the middle part 5: • either in stages, as shown in Figure 2A, • either continuously, as shown in Figure 2B.

[0025] According to the embodiment shown in [Fig. 1], at least one peripheral part 4 (that at the bottom of the figure) extends along an edge of the panel 2, so that said panel rests along said edge on the corresponding receiving area 3.

[0026] According to the same embodiment, two peripheral parts (those at the top in [Fig. 1]) are located respectively at the ends of an edge of the panel 2, so that said panel rests by two of its corners on the corresponding receiving areas 3.

[0027] According to the embodiments shown in Figures 2, the reinforcing layers of place 10 and The reverse sides 11 have the same distribution of reinforcing fibers in surface mass, so as to ensure symmetrical flexural reinforcement on the reverse and front sides of panel 2.

[0028] According to one embodiment, the surface density of the reinforcing fibers in each of the reinforcing layers 10,11 is between 100 and 600 g / m2.

[0029] According to one embodiment, the surface density of the polyurethane in each of the reinforcement layers 10,11 is between 100 and 600 g / m2.

[0030] According to one embodiment, the surface density of the polyurethane is proportional - in particular in a ratio of 1 / 1 - to that of the reinforcing fibers in each part 4,5 of the panel 2, such an arrangement making it possible to ensure homogeneous impregnation of the reinforcing fibers by the polyurethane over the entire surface of the reinforcing layers 10,11.

[0031] A panel 2 of an assembly 1 as described above is now described, said panel having at least two peripheral parts 4 arranged along two of its opposite edges and a central part 5 extending between said peripheral parts, said panel comprising: • a cellular stiffening core 6, generally inscribed within a rectangular parallelepiped defining a front face 7 and a back face 8, • two layers of front 10 and back 11 flexural reinforcement of said core, said layers being based on entangled reinforcing fibers embedded in polyurethane foam, said reinforcing layers extending respectively over said front and back faces, said foam overmolding said core so as to associate said reinforcing layers with said front and back faces,

[0032] the surface density in the middle part 5 of said reinforcing fibers of each of said reinforcing layers being greater than said density in peripheral parts 4.

[0033] According to an embodiment not shown, the panel 2 further comprises a facing layer of covering, for example carpet, of the reinforcing facing layer 10.

[0034] According to various embodiments, the coating surface layer is bonded or overmolded by the foam of the reinforcement surface layer 10.

[0035] According to an embodiment not shown, the reinforcing back layer 11 is coated with a backing layer of coating, for example of non-woven material.

[0036] According to various embodiments, the backing layer of the coating is glued or overmolded by the foam of the backing layer of reinforcement 11.

[0037] Finally, a method for manufacturing such a panel 2 is described, said method comprising the following successive steps: • provide a cellular stiffening core 6, generally inscribed within a rectangular parallelepiped defining a front face 7 and a front face d'envers 8, • deposit on each of said faces reinforcing fibers and a precursor mixture of polyurethane foam, the surface density of said reinforcing fibers in the central part 5 being greater than said density in the peripheral parts 4, • Place everything in a mold, • wait for the foam to expand so as to form layers of front 10 and back 11 of reinforcement, said foam overmolding said core so as to associate said layers with said faces, • remove the entire mold.

[0038] According to a first embodiment of this process, not shown, the step of depositing reinforcing fibers and a precursor mixture of polyurethane foam on the front 7 and back 8 faces is carried out according to the following successive substeps: • placing on each of said faces a main layer of reinforcing fibers, and at least one format - for example in the form of a medallion placed in the central part of said faces, or a strip extending between two opposite edges of said faces - of an additional layer of reinforcing fibers in the middle part 5 of said main layer, so as to increase in stages the surface mass of said fibers in said middle part, • pour a precursor mixture of polyurethane foam onto each main layer equipped with its additional layer.

[0039] According to a second embodiment of this process, the step of depositing reinforcing fibers and precursor mixture of polyurethane foam on the front faces 7 and back faces 8 is carried out by mixing reinforcing fibers with the precursor mixture of polyurethane foam at the outlet of the casting head of said mixture, said casting head following a trajectory controlled by a robot, the quantity of fibers mixed with said mixture being introduced in a variable way depending on the position of said casting head on its trajectory so as to place said fibers in an increased quantity in the middle part 5 of said faces, the distribution of the surface mass of said fibers being carried out either in steps or discontinuously.

[0040] It may also be provided that at least one coating layer is associated with at least one reinforcement layer 10,11, in particular by bonding or by overmolding in the mold.

Claims

Demands

1. Assembly (1) of a panel (2) for covering a motor vehicle floor, said assembly comprising said panel and at least two receiving areas (3) of said panel originating from the body of said vehicle, said panel having at least two peripheral parts (4) arranged along two of its opposite edges, said peripheral parts being respectively mounted in support on each of said receiving areas, and a central part (5) extending between said peripheral parts without bearing, said panel comprising: • a cellular stiffening core (6) generally inscribed within a rectangular parallelepiped defining a front face (7) and a back face (8), • two front (10) and back (11) layers of flexural reinforcement of said core, said layers being based on entangled reinforcing fibers embedded in polyurethane foam,said reinforcing layers extending respectively over said front and back faces, said foam overmolding said core so as to associate said reinforcing layers with said front and back faces, said panel being characterized in that the surface density in the middle part (5) of said reinforcing fibers of each of said reinforcing layers is greater than said density in the peripheral parts (4).

2. Assembly according to claim 1, characterized in that the core (6) has a honeycomb structure.

3. Assembly according to any one of the preceding claims, characterized in that the surface density of the reinforcing fibers of each of the reinforcing layers (10,11) increases, from the peripheral parts (4) to the middle part (5): • either in steps, • or continuously.

4. Assembly according to any one of the preceding claims, characterized in that at least one peripheral part (4) extends along an edge of the panel (2), so that said panel rests along said edge on the corresponding receiving area (3).

5. Assembly according to any one of the preceding claims, characterized in that two peripheral parts (4) are located respectively at the ends of an edge of the panel (2), so that said panel rests by two of its corners on the corresponding receiving areas (3).

6. Assembly according to any one of the preceding claims, characterized in that the front (10) and back (11) reinforcing layers have the same distribution of reinforcing fibers in surface mass.

7. Panel (2) of an assembly according to any one of the preceding claims, said panel having at least two peripheral parts (4) arranged along two of its opposite edges and a central part (5) extending between said peripheral parts, said panel comprising: • a cellular stiffening core (6) generally inscribed within a rectangular parallelepiped defining a front face (7) and a back face (8), • two front (10) and back (11) layers of flexural reinforcement of said core, said layers being based on entangled reinforcing fibers embedded in polyurethane foam, said reinforcing layers extending respectively over said front and back faces, said foam overmolding said core so as to associate said reinforcing layers with said front and back faces,said panel being characterized in that the surface density in the middle part (5) of said reinforcing fibers of each of said reinforcing layers is greater than said density in the peripheral parts (4).

8. A method for producing a panel according to claim 7, said method comprising the following successive steps: • providing a cellular stiffening core (6) generally inscribed within a rectangular parallelepiped defining a front face (7) and a back face (8), • depositing on each of said faces reinforcing fibers and a precursor mixture of polyurethane foam, the surface density of said reinforcing fibers in the central part (5) being greater than said density in the peripheral parts (4), • Place everything in a mold, • wait for the foam to expand so as to form reinforcing front (10) and back (11) layers, said foam overmolding said core so as to bond said layers to said faces, • remove the entire mold.

9. A method according to claim 8, characterized in that the step of depositing reinforcing fibers and precursor mixture of polyurethane foam on the front (7) and back (8) faces is carried out according to the following successive substeps: • to arrange on each of said faces a main layer of reinforcing fibers, and at least one format of an additional layer of reinforcing fibers in the middle part (5) of said main layer, so as to increase in stages the surface mass of said fibers in said middle part, • pour a precursor mixture of polyurethane foam onto each main layer equipped with its additional layer.

10. A method according to claim 8, characterized in that the step of depositing reinforcing fibers and precursor mixture of polyurethane foam on the front (7) and back (8) faces is carried out by mixing reinforcing fibers with the precursor mixture of polyurethane foam at the outlet of the casting head of said mixture, said casting head following a trajectory controlled by a robot, the quantity of fibers mixed with said mixture being introduced variably depending on the position of said casting head on its trajectory so as to place said fibers in an increased quantity in the middle part (5) of said faces, the distribution of the surface mass of said fibers being carried out either in steps or discontinuously.

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