Reinforcement grille and acoustic insulation element for motor vehicle opening.

Abstract

The invention relates to a reinforcing grid (1a) for a sound insulation element of a motor vehicle opening, the reinforcing grid (1a) being designed to be bonded to an area to be covered with a sealing sheet, to form the sound insulation element, the grid (1a) being designed to increase the rigidity of the area to be covered when the grid (1a) is fixed to the area to be covered in order to increase the acoustic impedance of the sound insulation element, the grid (1a) being delimited by a perimeter (5a) corresponding to the contour of the area to be covered, the grid (1a) comprising a skeleton (6a), formed of at least one stiffening element (7a), supporting a honeycomb structure (8a) covering the surface delimited by the perimeter (5a). (Figure 1)

Description

Title of the invention: Reinforcement grid and acoustic insulation element for motor vehicle opening.

[0001] The technical field relates to reinforcement grids designed to stiffen a sealing sheet, as well as acoustic insulation elements designed to equip a motor vehicle opening, vehicle openings having such an element and finally motor vehicles equipped with such an opening.

[0002] Automobile manufacturers are particularly attentive to offering their customers comfortable vehicles for their passengers. Among the essential comfort criteria is, of course, the management of noise generated by the vehicle's movement. A significant source of unwanted noise comes from the vibrations induced in the vehicle's doors and windows while in motion. Acoustic characteristics are among those that most influence a customer's judgment of the perceived quality of the vehicle they are driving. It is therefore important for automobile manufacturers to improve the acoustic characteristics of their vehicles as much as possible.

[0003] In this context, car manufacturers typically line the interior spaces of their vehicle doors with acoustic insulation sheets. Since these often prove insufficient, particularly for filtering vibrations with frequencies below 70 Hz, the acoustic insulation sheets are sometimes reinforced with textile and / or foam stiffeners. However, these known stiffeners considerably increase the mass of the door panel without providing sufficient acoustic comfort. Sometimes, the stiffeners even reduce access for mounting the window regulator mechanism inside the door panel.

[0004] The mass of existing solutions is relatively significant, on the order of 50 to 400g per opening, which represents between 200g and 1600g per vehicle. In the case of an electric vehicle, such mass is obviously detrimental to the vehicle's range.

[0005] Thus, there is a need for a solution that reduces noise pollution while also reducing the mass of the vehicle.

[0006] The present invention aims to overcome the problems described above. In this technical context, one objective of the present invention is to provide a reinforcing grid that reduces vibrations of the acoustic insulation sheet while limiting the added mass in each opening.

[0007] To this end, the present invention relates to a reinforcement grid for a sound insulation element of a motor vehicle opening, the reinforcement grid being designed to be glued onto an area to be covered with a sealing sheet, to form the acoustic insulation element, the grid being designed to increase the rigidity of the area to be covered, when the grid is fixed on the area to be covered, and to increase the acoustic impedance of the acoustic insulation element, the grid being delimited by a perimeter corresponding to the contour of the area to be covered, the grid comprising a skeleton, formed of at least one stiffening element, supporting a honeycomb structure covering the surface delimited by the perimeter.

[0008] The invention further relates to an acoustic insulation element designed to equip an opening of a motor vehicle and comprising a sealing sheet having at least one area to be covered, a grid according to the invention being fixed on each area to be covered to stiffen the area to be covered.

[0009] The invention further relates to a motor vehicle opening comprising an acoustic insulation element according to the invention.

[0010] The invention finally relates to a motor vehicle having at least one opening according to the invention.

[0011] Thus, the reinforcement grid according to the invention makes it possible to obtain a sound insulation element according to the invention whose acoustic characteristics are improved compared to existing solutions, while allowing control of the added mass in each opening. Indeed, the reinforcement grid according to the invention has a reduced mass, thanks to its honeycomb structure. In addition, the skeleton stiffens the area to be covered. The area to be covered is cleverly chosen by experimental modal analysis to identify and locate the areas to be covered exhibiting a drop in dynamic stiffness. The grid according to the invention has the advantage of allowing easy adaptation of its structure by modifying its perimeter and / or its honeycomb structure. Experience shows that, thanks to the reinforcement grid according to the invention, the acoustic characteristics of the opening according to the invention are increased compared to a conventional door.Furthermore, experience shows that the sound insulation element helps to reduce the added mass in the opening.

[0012] According to one embodiment of the reinforcement grid, one of the stiffening elements forms a bar extending over at least part of the perimeter.

[0013] According to one possibility of the reinforcement grid, the honeycomb structure has a plurality of cells of identical shapes, preferably hexagonal or triangular in shape.

[0014] According to one embodiment of the reinforcement grid, the skeleton has at least one reinforcement bar, each designed to extend across the area to be covered when the grid is fixed to the area to be covered.

[0015] According to one possibility, the alveolar structure comes from material with the skeleton.

[0016] Advantageously, the grid is made of plastic material, preferably polyethylene terephthalate.

[0017] According to one possibility of the invention, the acoustic insulation element comprises at least two distinct areas to be covered.

[0018] The invention will be better understood upon reading the following detailed description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0019] [Fig-1] [Fig.1] represents a top view of a first reinforcement grid according to a first embodiment presenting an alveolar structure with hexagonal alveoli;

[0020] [Fig.2] [Fig.2] represents a top view of a second reinforcement grid according to a second embodiment having a honeycomb structure with triangular cells;

[0021] [Fig.3] [Fig.3] represents a top view of a third reinforcing grid according to a third embodiment presenting a skeleton with a plurality of reinforcing bars;

[0022] [Fig.4] [Fig.4] shows a top view of a sound insulation element according to the invention implementing the first and third reinforcement grids;

[0023] In these figures, the same references are used to designate the same elements.

[0024] A grid 1b, the reinforcement according to the invention, illustrated in the figures, is designed to equip an acoustic insulation element 2 according to the invention, illustrated in [Fig.4], designed to equip an opening of a motor vehicle, not illustrated.

[0025] The reinforcing grid 1a, 1b, is designed to be bonded to a coverage area 3a, 3b of a sealing sheet 4, illustrated in [Fig. 4], to form the acoustic insulation element 2. The grid 1a, 1b, increases the rigidity of the coverage area 3a, 3b when the grid 1a, 1b, is fixed to the coverage area 3a, 3b. The grid 1a, 1b, then increases the acoustic impedance of the acoustic insulation element 2, particularly within a range of vibrations of a predetermined frequency. The targeted vibration range advantageously corresponds to vibrations with a frequency below 70 Hz. In the example illustrated in [Fig. 4], the insulation element 2 comprises two distinct coverage areas 3a, 3b. In order to achieve element 2 of acoustic insulation, on each area to be covered 3a, 3b, a grid la respectively le is fixed on the sealing sheet 4.

[0026] As illustrated in figures 1 to 3, the grid la, 1b, le is delimited by a perimeter 5a, 5b corresponding to the contour of the area to be covered 3a, 3b.

[0027] The grid la, 1b, le comprises a skeleton 6a, 6b formed of at least one stiffening element 7a, 7b supporting a honeycomb structure 8a, 8b, 8c covering the surface delimited by the perimeter 5a, 5b.

[0028] In the examples illustrated in figures 1 and 2, the grids la, 1b differ in their alveolar structure 8a, 8b.

[0029] Advantageously, the alveolar structure 8a, 8b, 8c comes from material with the skeleton 6a, 6b.

[0030] As illustrated in Figures 1 to 3, the grid la, 1b, le advantageously comprises a stiffening element 7a forming a bar 9a, 9b extending over at least part of the perimeter 5a, 5b of the grid la, 1b, le. In this case, the bar 9a, 9b extends over the entire perimeter 5a, 5b of the grid la, 1b, le. In the grids la and 1b illustrated in Figures 1 and 2, the skeleton 6a is composed of the bar 9a extending over the perimeter 5a of the grid la, 1b.

[0031] In the embodiment of the grid illustrated in [Fig. 3], the skeleton 6b has at least one stiffening element 7b forming a reinforcing bar 10, each designed to extend across the area to be covered 3b, when the grid is fixed to the area to be covered 3b. This stiffening element 7b advantageously allows the natural modes of vibration of the grid to be modified by increasing the natural vibration frequencies.

[0032] As illustrated in Figures 1 to 3, the honeycomb structure 8a, 8b, 8c has a plurality of cells 1la, 11b of similar shapes. In a first embodiment, illustrated in Figures 1 and 3, each cell 1la has a hexagonal shape. In [Fig. 2], another embodiment is shown, depicting cells 11b with a triangular shape. Along the perimeter 5a, 5b, the shapes of the cells 1la, 11b may be affected by that of the perimeter 5a, 5b, such that some cells 1la, 11b are incomplete. Similarly, as illustrated in [Fig. 3], along a stiffening element 7b forming a reinforcing bar 10, some cells 1la are incomplete.

[0033] The shape and dimensions of each cell 1a, 11b are chosen to give the acoustic insulation element 2 the desired acoustic properties. In particular, the dimensions of the segments 12a, 12b delimiting the honeycomb structure 8a, 8b, 8c are chosen in order to optimize the mass of the grid 1a, 1b, 1e and the acoustic properties of the latter.

[0034] Advantageously, the reinforcing grid la, 1b, le is made of plastic material, preferably polyethylene terephthalate. The grid la, 1b, le is, for example, obtained by molding and / or 3D printing.

[0035] Thus, the grid la, 1b, the reinforcement according to the invention makes it possible to obtain the acoustic insulation element 2. Experience shows that the latter presents The invention provides improved acoustic characteristics compared to existing solutions while allowing control of the added mass in each opening. Indeed, the reinforcing grid (la, 1b, le) has a reduced mass thanks to its honeycomb structure (8a, 8b, 8c), and the skeleton (6a, 6b) stiffens the area to be covered (3a, 3b). The area to be covered (3a, 3b) is cleverly chosen through experimental modal analysis to identify and locate the areas (3a, 3b) that exhibit a drop in dynamic stiffness in the absence of the grid (la, 1b, le). The grid (la, 1b, le) has the advantage of allowing easy adaptation of its structure by modifying its perimeter (5a, 5b) and / or its honeycomb structure (8a, 8b, 8c).

[0036] The invention is not limited to the embodiment of the reinforcement grid described above, only by way of example, but other embodiments can be designed by a person skilled in the art without departing from the scope and extent of the present invention.

Claims

Demands

1. A reinforcing grid (la, 1b, le) for a sound insulation element (2) of a motor vehicle opening, the reinforcing grid (la, 1b, le) being designed to be bonded to a cover area (3a, 3b) of a sealing sheet (4) to form the sound insulation element (2), the grid (la, 1b, le) being designed to increase the rigidity of the cover area (3a, 3b) when the grid (la, 1b, le) is fixed to the cover area (3a, 3b), and to increase the acoustic impedance of the sound insulation element (2), the grid (la, 1b, le) being delimited by a perimeter (5a, 5b) corresponding to the contour of the cover area (3a, 3b), the grid (la, 1b, le) comprising a skeleton (6a, 6b) formed of at least one stiffening element (7a, 7b), supporting an alveolar structure (8a, 8b, 8c) covering the surface delimited by the perimeter (5a, 5b).

2. Reinforcement grid (la, 1b, le) according to claim 1, characterized in that one (7a) of the stiffening elements (7a, 7b) forms a bar (9a, 9b) extending over at least a part of the perimeter (5a, 5b).

3. Reinforcement grid (la, 1b, le) according to claim 1 or 2, characterized in that the honeycomb structure (8a, 8b, 8c) has a plurality of cells (lia, 11b) of identical shapes, preferably hexagonal or triangular in shape.

4. Reinforcement grid (la, 1b, le) according to any one of claims 1 to 3, characterized in that the alveolar structure (8a, 8b, 8c) is made of material with the skeleton (6a, 6b).

5. Reinforcing grid (the) according to any one of claims 1 to 4, characterized in that the skeleton (6b) has at least one reinforcing bar (10), each designed to extend across the area to be covered (3b) when the grid (the, 1b, the) is fixed to the area to be covered (3b).

6. Reinforcement grid (la, 1b, le) according to any one of claims 1 to 5, characterized in that it is formed of plastic material, preferably polyethylene terephthalate.

7. Acoustic insulation element (2) designed to equip a motor vehicle opening and comprising a sealing sheet (4) having at least one area to be covered (3a, 3b), a grid (la, 1b, le) according to any one of claims 1 to 6 being fixed on each area to be covered (3a, 3b) to stiffen the area to be covered (3a, 3b).

8. Acoustic insulation element (2) according to claim 7, characterized in that it comprises at least two distinct areas to be covered (3a, 3b).

9. Motor vehicle opening comprising a sound insulation element (2) according to claim 7 or 8.

10. Motor vehicle having at least one opening according to claim 9.

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