Underbody assembly of a motor vehicle and motor vehicle comprising such an underbody assembly

Abstract

Motor vehicle underbody assembly and motor vehicle comprising such an underbody assembly. The invention relates to an underbody assembly (1) of a motor vehicle, comprising:- an underbody structural platform (3),- a floor (5), adapted to define a traction battery cover of said motor vehicle.According to the invention, the underbody assembly (1) comprises at least one inflatable insert (13) comprising an expandable foam arranged in an assembly zone of said floor (5) on said underbody structural platform (3).The invention also relates to a motor vehicle comprising such an underbody assembly. Figure 2

Description

Title of the invention: Underbody assembly of a motor vehicle and motor vehicle comprising such an underbody assembly Technical field

[0001] The invention relates to the field of motor vehicles, and more particularly concerns an underbody assembly for a motor vehicle and a motor vehicle comprising such an underbody assembly. Prior art

[0002] A motor vehicle body structure comprises a set of sheet metal structural elements providing stiffness to the motor vehicle, assembled together and forming the frame of the motor vehicle.

[0003] The body structure comprises, in particular, among these sheet metal elements, a structural platform for the underbody of the body belonging to a underbody assembly.

[0004] The underbody assembly further comprises a floor defining a part of the platform of the passenger compartment of the motor vehicle.

[0005] The floor comprises a central, generally flat area, bordered laterally by a set of edges welded to the structural base platform at an assembly area of the floor on the structural base platform.

[0006] When the floor is in contact with the sheets of the structural base platform, the seal between the floor and the structural base platform is obtained by means of sealing cords.

[0007] When the vehicle is an electric motor vehicle with battery (motor vehicle known as “BEV”, an English acronym for “Battery Electric Vehicle”), the vehicle includes a traction battery powering the electric motor of the motor vehicle.

[0008] The traction battery comprises a set of battery modules, mounted in a battery tray. The battery tray is mounted under the floor of the underbody assembly and the floor defines a cover of the traction battery.

[0009] The geometric shape of the floor is such that the floor does not exactly match the shapes of the structural platform of the vehicle's underbody at the level of the lateral rear parts.

[0010] Thus, significant clearances exist between the floor and the structural base platform at the rear lateral ends of the floor.

[0011] The presence of these games creates spaces through which water from the exterior can infiltrate the passenger compartment of the motor vehicle.

[0012] Adding sealing cords in these areas would not be feasible, as the space to be filled between the floor and the structural base platform is too large.

[0013] Also, the addition of intermediate parts to fill the gaps would not be possible either due to the presence of the rear axle at the rear end of the floor. Statement of the invention

[0014] The present invention aims to overcome the aforementioned drawbacks, and to this end relates to an underbody assembly for a motor vehicle, comprising: - a structural base platform, - a floor, adapted to define a traction battery cover of said motor vehicle, said underbody assembly being characterized in that it comprises at least one inflatable insert comprising an expandable foam arranged in an assembly zone of said floor on said structural underbody platform.

[0015] Thus, by providing a base assembly comprising at least one inflatable insert comprising an expandable foam arranged in an assembly zone of the floor on the structural base platform, it is possible to make the base assembly watertight in an extremely simple manner, without adding sealing cords and without adding intermediate parts. This limits the risk of untimely introduction of water from the outside into the passenger compartment of the motor vehicle.

[0016] According to optional features of the underbody assembly: - said at least one inflatable insert is fixed on said structural base platform; - said at least one inflatable insert is fixed on said floor; - said at least one inflatable insert is arranged at a rear edge of said structural base platform; - said structural underbody platform comprises lateral longitudinal side members and said at least one inflatable insert extends from at least one of said lateral longitudinal side members to said rear edge of said structural underbody platform; - said underbody assembly comprises two inflatable inserts comprising an expandable foam arranged in an assembly zone of said floor on said structural underbody platform; - said inflatable inserts are arranged symmetrically relative to a plane longitudinal median of said motor vehicle.

[0017] The invention also relates to a motor vehicle comprising an underbody assembly, remarkable in that said underbody assembly is according to the invention. Brief description of the drawings

[0018] Other characteristics, aims and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0019] [Fig-1] shows an underbody assembly of a motor vehicle, in view in perspective from below and partially exploded.

[0020] [Fig.2] shows the underbody assembly viewed from the rear, the assembly being shown in the inverted position relative to its final position in the motor vehicle.

[0021] [Fig.3] shows the underbody structural platform viewed in perspective, the platform being shown in an inverted position relative to its final position in the motor vehicle. Description of the embodiments

[0022] In the remainder of the description, elements having an identical structure or similar functions are designated by the same reference.

[0023] By convention, we will adopt, without limitation, longitudinal, vertical and transverse orientations indicated by the direct trihedron (L, V, T) designating the longitudinal, vertical and transverse axes of the vehicle.

[0024] In the following, the terms “left”, “right”, “lower” and “upper” are understood in relation to the vehicle.

[0025] Similarly, the terms “front” and “rear” are understood in relation to the general orientation of the vehicle as taken in its normal direction of travel.

[0026] Reference is made to [Fig.l] showing an underbody assembly 1 of a motor vehicle, in perspective view from below and partially exploded.

[0027] The underbody assembly 1 comprises a structural underbody platform 3, belonging to a body structure of the motor vehicle and comprising a set of structural sheet metal elements conferring stiffness to the motor vehicle.

[0028] The underbody assembly 1 further comprises a floor 5 defining a part of the platform of the passenger compartment of the motor vehicle.

[0029] The motor vehicle is an electric motor vehicle with battery (motor vehicle called “BEV”, an English acronym for “Battery Electric Vehicle”). For this purpose, the motor vehicle includes a traction battery powering the motor electric (not shown) of the motor vehicle. The traction battery comprises a set of battery modules 7, mounted in a battery tray 9 mounted under the floor 5 (the battery tray 9 being in [Fig.l] detached from the underbody assembly 1 for better visibility). The battery tray 9 is assembled to the underbody assembly 1 for example by screwing. The floor 5 defines a cover of the traction battery.

[0030] The floor 5 comprises a central zone, generally flat, bordered laterally by a set of edges 11 welded to the structural base platform 3 at an assembly zone. The sealing between the floor 5 and the structural base platform 3 is partly obtained by means of sealing cords (not shown).

[0031] Reference is made to [Fig.2] showing the underbody assembly 1 seen from the rear, the assembly being shown in the inverted position relative to its final position in the motor vehicle.

[0032] According to the invention, in the assembly zone of the floor 5 on the structural base platform 3, the base assembly 1 comprises inflatable inserts 13 comprising an expandable foam (not shown).

[0033] After assembling the floor 5 and the structural base platform 3, the assembly thus formed is immersed in a bath or in several successive baths in order to apply at least one coating thereto by a cataphoresis process.

[0034] After applying the cataphoresis process, the assembly is placed in an oven to dry the cataphoresis, which makes it possible to expand the foam of the inflatable inserts 13 between the floor 5 and the structural base platform 3.

[0035] Thus, when the base assembly 1 is placed in an oven, the expanding foam of the inflatable inserts 13 expands in the clearances present between the floor 5 and the structural base platform 3.

[0036] Thus, thanks to the present invention, the underbody assembly 1 is made watertight in an extremely simple manner, without adding sealing cords and without adding intermediate parts. This limits the risk of untimely introduction of water from outside into the passenger compartment of the motor vehicle.

[0037] In the embodiment illustrated in the figures, the base assembly 1 comprises two inflatable inserts 13.

[0038] However, more inflatable inserts 13 can be used in order to fill all of the clearances present between the floor 5 and the structural base platform 3.

[0039] Also, depending on the geometry of the floor 5 and the structural base platform 3, it may be possible to consider using a single inflatable insert 13.

[0040] According to one arrangement, the inflatable inserts 13 are arranged symmetrically rela- tively to a longitudinal median plane Pi of the motor vehicle.

[0041] Reference is made to [Fig. 3] showing the structural underbody platform 3 seen in perspective, the platform being shown in the inverted position relative to its final position in the motor vehicle.

[0042] In the embodiment illustrated in the figures, the inflatable inserts 13 are fixed to the structural base platform 3.

[0043] According to an alternative embodiment not shown in the figures, the inflatable inserts 13 can be fixed to the floor 5.

[0044] Also, in the embodiment illustrated in the figures, the inflatable inserts 13 are arranged at a rear edge 15 of the structural base platform 3.

[0045] When the inflatable inserts 13 are arranged at the rear edge 15 of the underbody structural platform 3, each inflatable insert 13 extends from lateral longitudinal beams 17g, 17d of the underbody structural platform 3 to the rear edge 15 of the underbody structural platform 3.

[0046] As goes without saying, the present invention is not limited to the sole embodiments of this underbody assembly and of this motor vehicle comprising such an underbody assembly, described above solely as illustrative examples, but on the contrary it embraces all the variants involving the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

Claims

Claims

1. Underbody assembly (1) of a motor vehicle, comprising: - an underbody structural platform (3), - a floor (5), adapted to define a traction battery cover of said motor vehicle, said underbody assembly (1) being characterized in that it comprises at least one inflatable insert (13) comprising an expandable foam arranged in an assembly zone of said floor (5) on said underbody structural platform (3).

2. Underbody assembly (1) according to claim 1, characterized in that said at least one inflatable insert (13) is fixed on said structural underbody platform (3).

3. Underbody assembly (1) according to claim 1, characterized in that said at least one inflatable insert (13) is fixed on said floor (5).

4. Underbody assembly (1) according to any one of claims 1 to 3, characterized in that said at least one inflatable insert (13) is arranged at a rear edge (15) of said underbody structural platform (3).

5. Underbody assembly (1) according to claim 4, wherein said underbody structural platform (3) comprises lateral longitudinal side members (17g, 17d), characterized in that said at least one inflatable insert (13) extends from at least one of said lateral longitudinal side members (17g, 17d) to said rear edge (15) of said underbody structural platform.

6. Base assembly (1) according to any one of claims 1 to 5, characterized in that it comprises two inflatable inserts (13) comprising an expandable foam arranged in an assembly zone of said floor (5) on said structural base platform (3).

7. Underbody assembly (1) according to claim 6, characterized in that said inflatable inserts (13) are arranged symmetrically relative to a longitudinal median plane (Pi) of said motor vehicle.

8. Motor vehicle comprising an underbody assembly (1), characterized in that said underbody assembly (1) is according to any one of claims 1 to 7.

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