Automotive Vehicle Structure

Abstract

The present invention relates to a structure (1) for an electric or hybrid vehicle comprising a floor (3), a battery container (4) fixed below the floor (3), and a compressed foam plate (2) placed between the battery container (4) and the floor (3). The present invention also relates to a vehicle comprising said structure (1), and to an assembly method.

Description

Technical Field

[0001] The present invention relates to the structure of motor vehicles. The present invention further relates to a vehicle having such a structure and a method of assembling such a structure.

Background Art

[0002] Vehicles, particularly motor vehicles, generate vibrations. In order to improve the ride comfort of these vehicles, it is necessary to reduce such vibrations, which particularly cause noise.

[0003] U.S. Patent Application Publication No. 2008 / 136110 (A1) describes a sound insulation system between the floor of a vehicle and an energy reservoir, which can be either a fuel tank or a battery tray. The space between the fuel tank and the floor is shielded using an acoustic seal so that noise does not enter the enclosed space.

[0004] However, this solution achieves shielding for the sound part but does not shield against vibrations.

Summary of the Invention

[0005] An object of the present invention is to provide a vehicle structure that eliminates the above disadvantages. Specifically, the present invention provides a vehicle structure that can be introduced simply and easily and can shield the floor of the vehicle against noise and vibrations.

[0006] The present invention relates to a structure for an electric or hybrid vehicle, comprising a floor, a battery tray fixed under the floor, and a compressed foam board disposed between the battery tray and the floor.

[0007] In one embodiment, the surface layer of the foam board is provided with micropores configured to discharge the air contained in the foam when the board is compressed and / or to prevent the intrusion of moisture into the foam.

[0008] In one embodiment, the foam board further comprises a hole that opens on one side of the foam board or penetrates the foam board from one side to the other, and this hole is configured to release air contained in the foam when the board is compressed.

[0009] In one embodiment, the foam plate further comprises a portion located near the rear of the vehicle, having holes on its surface configured to release air contained in the foam when the plate is compressed.

[0010] In one embodiment, the foam board is compressed between the floor and the battery tray with a compression ratio of 20% to 40%, particularly 30% to 40%.

[0011] In one embodiment, the thickness of the compressed foam board is 10 mm or more and 20 mm or less, preferably 13 mm or more and 14 mm or less, particularly equal to or substantially equal to 13 mm, and the compression ratio of the board is 30%.

[0012] In one embodiment, the foam board is made of polyurethane foam.

[0013] In one embodiment, the foam is a foam with a cell size smaller than 2 mm.

[0014] The present invention also relates to a vehicle having a structure according to the present invention, in particular to a hybrid vehicle or an electric motor vehicle.

[0015] Finally, the present invention relates to a method for assembling a vehicle structure, comprising the steps of: perforating a foam board; placing the foam board between the vehicle floor and the vehicle's battery tray; compressing the foam board to a compression ratio of 20% to 40%; and fixing the battery tray to the floor so that the foam board remains compressed to a compression ratio of 20% to 40%.

[0016] The attached drawings illustrate an example of an embodiment of the vehicle structure according to the present invention. [Brief explanation of the drawing]

[0017] [Figure 1] It is a diagram showing a vehicle structure. [Figure 2] It is a diagram showing a vehicle structure. [Figure 3A] It is a top view of a foam board according to a first embodiment for optimizing air discharge. [Figure 3B] It is a top view of a foam board according to a second embodiment for optimizing air discharge. [Figure 3C] It is a top view of a foam board according to a third embodiment for optimizing air discharge. [Figure 4] It is an exploded view of a vehicle structure according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0018] An example of a vehicle structure according to an embodiment of the present invention will be described hereinafter with reference to FIG. 1.

[0019] Structure 1 includes a vehicle floor 3 and a battery tray 4. The battery tray 4 is fixed to the floor 3. Specifically, the battery tray is fixed under the floor 3. The expression "under" should be understood to mean that the battery tray 4 is under the floor 3 when the vehicle having this structure is in an operating state in this case. Therefore, the battery tray 4 is preferably arranged outside the passenger compartment of the vehicle.

[0020] The vehicle structure 1 further includes a foam board 2. The foam board 2 is arranged between the battery tray 4 and the floor 3 of the vehicle structure 1.

[0021] The floor 3 advantageously constitutes the horizontal floor surface of the passenger compartment of the vehicle.

[0022] The floor 3 is not limited to the first layer inside the passenger compartment of the vehicle, and may include a multilayer or assembly in which at least one layer of it is arranged on the inner surface of the vehicle.

[0023] The battery tray 4 may comprise at least a portion having a shape of a regular hexahedron or a substantially parallelepiped.

[0024] As shown in FIG. 2, the battery tray 4 houses a battery 43. The battery 43 is preferably electrically connected to an electric motor of a vehicle. In one embodiment, the battery tray 4 includes a cooling system 42. The cooling system 42 is preferably disposed under the battery 43.

[0025] The battery tray 4 further includes a compartment or enclosure configured to receive the battery and the cooling system. The upper surface 41 of the compartment contacts or is oriented towards the foam board 2.

[0026] The width and length of the foam board 2 are significantly larger than the thickness of the foam board 2. That is, the foam board 2 preferably has two main surfaces separated by a smaller dimension, namely the thickness.

[0027] It should be understood that the expression "significantly larger" means that the width and length are at least 10 times larger than the thickness, preferably at least 50 times.

[0028] The foam board 2 is a solid-phase foam board 2. The foam board 2 is made of an open-cell or closed-cell material. The open-cell material includes a fine-shaped solid-phase matrix impregnated with a fluid. The open-cell material preferably includes a continuous solid-phase network in which air bubbles are trapped.

[0029] Preferably, the foam board 2 is made of a polymer foam.

[0030] The polymer foam advantageously enables the realization of the foam board 2.

[0031] Preferably, the foam board 2 is made of a polymer matrix, most preferably a polyurethane matrix.

[0032] The foam board 2 can contain flame-retardant compounds. This allows the foam board 2 to also serve as a firewall between the battery tray 4 and the floor 3 of the vehicle structure 1.

[0033] Open-cell or closed-cell materials can be characterized by their density and matrix structure, particularly by their porosity and cell shape.

[0034] The loss coefficient (or internal damping coefficient) of an open-cell material can be between 0.1 and 0.3 at a frequency of 10 Hz and a temperature of 23°C. The loss coefficient is a measure of the ratio of energy dissipated by damping to the elastic energy that is conserved and then re-conserved during the deformation cycle.

[0035] The loss factor is equal to the tangent of the ratio of the loss modulus to the storage modulus (E').

[0036] The storage modulus (E') of open-cell material in compression can range from 1,000 to 50,000 Pa at a frequency of 10 Hz and a temperature of 23°C.

[0037] The density of open-cell material can range from 20 to 100 g / L.

[0038] Preferably, the foam board 2 is made of a microcell material, that is, the size of the network cells is 1 μm to 1 mm.

[0039] In one embodiment, the foam is a closed-cell foam, and the cell dimensions are less than 2 mm.

[0040] The foam board 2, positioned between the floor 3 and the battery tray 4, is compressed or pre-pressurized. In fact, compressing the foam board 2 advantageously allows it to better absorb vibrations and sounds from the floor 3. Compression increases the rigidity of the board.

[0041] In one embodiment, the foam board 2 is compressed by forces perpendicular to both main surfaces, that is, compressed in such a way that the thickness of the foam board 2 is reduced.

[0042] The battery tray 4 can be mechanically fixed to the floor 3 such that it leaves a space (between the battery tray and the floor 3) narrower than the thickness of the foam board 2 in its free state, i.e., when no load is applied to the board. In this way, the foam board 2 is deformed by the compression performed by the floor 3 and the upper surface 41 of the battery tray 4 during installation.

[0043] The vehicle structure may include fixing means that can secure the battery tray 4 to the floor 3. Preferably, these fixing means can be used without penetrating the foam board 2.

[0044] In one embodiment, the compressibility of the foam board 2 is 20% to 60%. Preferably, the compressibility of the foam board 2 is approximately 30%. The term "compressibility" should be understood as the ratio obtained by dividing the difference between the thickness of the foam board 2 in its free state and the thickness of the foam board 2 when compressed by the thickness of the foam board 2 in its free state.

[0045] The foam board 2 can be 10mm to 20mm thick when compressed between the floor 3 and the battery tray 4. Preferably, the foam board 2 is about 20mm thick in its free state. When the structure is installed, the foam board 2 is compressed by about 30%. That is, the thickness of the foam board 2 after being compressed and installed between the floor 3 and the battery tray 4 is about 13mm.

[0046] The foam board 2 also includes means for discharging air contained within the solid-phase matrix. This air discharge means allows air to be discharged from the foam board 2 when it is compressed. This air discharge reduces the risk of the board 2 bursting due to increased air pressure during compression.

[0047] In the first embodiment shown in Figure 3A, at least one surface layer of the foam board 2 is provided with micropores. The surface layer with micropores is preferably the upper surface of the foam board 2. In this case, air discharge is not obstructed by the surfaces of the floor 3 or the battery tray 4.

[0048] The micropores extend through a portion of the volume of the foam plate 2. This allows air trapped in the solid-phase matrix network to escape more easily through these pores.

[0049] The micropores may have a thickness or diameter of 0.05 mm to 3 mm. The micropores may extend within the volume of the foam board 2 over a length of 20% to 99% of the length or width of the foam board 2.

[0050] In one embodiment, at least one micropore extends from one end of the foam board 2 to the other along its length or width.

[0051] The foam board 2 may have a micropore density of 2 to 10 micropores per square millimeter, preferably 2 to 6 micropores per square millimeter.

[0052] These properties of micropores are advantageous because they allow for better release of air contained in the foam during compression of the sheet and help prevent moisture from entering the foam.

[0053] Micropores can be arranged on both sides of the plate 2, but preferably, micropores should be provided on only one of the two sides, and that side should be positioned on the upper surface of the plate 2, that is, facing the passenger compartment of the vehicle (in contact with the floor of the automatic vehicle structure).

[0054] In the second embodiment shown in Figure 3B, the foam board 2 has at least one hole 7 opening on at least one main surface, specifically the hole 7 penetrating the thickness of the board. The opening 7 works to minimize the distance that air must travel to exit the foam board 2.

[0055] If the foam board 2 has a single opening 7, the opening 7 is preferably located in the central region of the foam board 2.

[0056] In one embodiment, the area of ​​the orifice of the opening 7 is less than 5% or less than 1% of the area of ​​the foam plate 2 that is in contact with the battery tray 4, or the area of ​​the foam plate 2 that is in contact with the floor 3.

[0057] In one embodiment in which the foam board 2 has a number of openings 7, the total area of ​​the orifices of the openings 7 is less than 20% or less than 10% of the area of ​​the foam board 2 that is in contact with the battery tray 4, or the area of ​​the foam board 2 that is in contact with the floor 3.

[0058] The second embodiment described above can also be combined with the first embodiment.

[0059] In a third embodiment shown in Figure 3C, which is compatible with the first and / or second embodiments, the foam plate 2 comprises a portion located near the rear of the vehicle and having air-releasing holes 8 on its surface.

[0060] In fact, by placing larger diameter holes 8 in the rear region, it becomes possible to expel a larger volume of air. This solution is particularly effective when micropores cannot adequately expel a large volume of air in a relatively short time. The rear region, facing away from the vehicle's direction of travel, has less stringent durability requirements.

[0061] In this way, the risk of excessive air pressure in the center of the matrix is ​​reduced.

[0062] The assembly, with the battery tray 4 and foam plate 2 beneath the floor 3, produces a mass-spring-mass effect. Vibrations and sound waves from the walls of the battery tray 4 are attenuated within the spring (foam plate 2). Ultimately, the sound and vibration are attenuated.

[0063] In one embodiment, the battery tray 4 includes at least one fixed area 6. The at least one fixed area 6 may extend laterally with respect to the upper surface 41.

[0064] The top surface 41 can be positioned to leave space for inserting the foam plate 2 (between the battery tray 4 and the floor 3) as described above.

[0065] At least one fixed area 6 may be equipped with fixing means such as drilling or screw holes for fixing the battery tray 4 to the floor 3.

[0066] The present invention also relates to a vehicle having the above-described structure 1. The vehicle preferably relates to an automatic vehicle, most preferably an automobile having an electric motor to move the vehicle.

[0067] The present invention also relates to a method for assembling a vehicle structure 1. One embodiment of the assembly method is described below. The vehicle structure 1 is preferably the vehicle structure 1 described above.

[0068] The method includes the following steps: - The step of placing the foam board 2 between the vehicle floor 3 and the battery tray 4, - A step of compressing the foam board 2 to a compression ratio of 20% to 40%, - A step of fixing the battery tray 4 to the floor 3 such that the distance between the battery tray 4 and the floor 3 is less than the thickness of the foam board 2 in its free state. That is the case.

[0069] Preferably, the above distance is 60% to 80% of the thickness of the free-state foam board 2.

[0070] In one embodiment, the compression step and the fixing step are performed simultaneously.

[0071] In this application, the expression "approximately" should be understood to mean a range of 10% on both sides of a number that follows it.

Claims

1. A vehicle structure (1) for an electric or hybrid vehicle, comprising a floor (3), a battery tray (4) fixed under the floor (3), and a compressed foam plate (2) arranged between the battery tray (4) and the floor (3), A structure (1), wherein the surface layer of the foam board (2) comprises micropores configured to allow air contained within the foam to escape when the foam board is compressed and / or configured to prevent the ingress of moisture into the foam.

2. 2. The vehicle structure (1) of claim 1, wherein the foam plate (2) further comprises holes (7) opening on one side of the foam plate or penetrating the foam plate from one side to the other, the holes being configured to allow air contained in the foam to escape when the foam plate is compressed.

3. 3. A vehicle structure (1) as claimed in claim 1 or 2, further comprising a portion in which the foam plate (2) is located near the rear of the vehicle and has a surface with holes (8) configured to expel air contained in the foam when the foam plate is compressed.

4. 4. A vehicle structure (1) as claimed in any one of claims 1 to 3, wherein the foam plate (2) is compressed between the floor (3) and the battery tray (4) by a compression ratio of 20% to 40%, for example 30% to 40%.

5. A vehicle structure (1) as described in any one of claims 1 to 4, wherein the thickness of the foam plate (2) when compressed at a compression rate of 30% of the foam plate is equal to or substantially equal to 10 mm or more and 20 mm or less, for example 13 mm or more and 14 mm or less, for example 13 mm.

6. 6. The vehicle structure (1) according to any one of the preceding claims, wherein the foam plate (2) comprises a polyurethane foam.

7. 7. A vehicle structure (1) according to any one of the preceding claims, wherein the foam is a foam with a cell size smaller than 2 mm.

8. A vehicle (5), for example a hybrid vehicle or an electric motor vehicle, comprising a structure (1) according to any one of claims 1 to 7.

9. A method for assembling a vehicle structure (1), comprising the steps of: - drilling holes in the foam plate (2), - placing said foam plate (2) between the floor (3) of the vehicle and a battery tray (4) of the vehicle; - compressing said foam board (2) to a compression ratio of between 20% and 40%; - fixing said battery tray (4) to said floor (3) so that said foam plate (2) remains compressed to a compression ratio of 20% to 40%; Including, The method of claim 1, wherein the surface layer of the foam plate (2) comprises micropores configured to allow air contained within the foam to escape when the foam plate is compressed and / or configured to prevent the ingress of moisture into the foam.

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