Motor vehicle underbody assembly, and motor vehicle comprising such an underbody assembly

Abstract

The invention relates to an underbody assembly (19) of a motor vehicle, which assembly comprises: - a floor (13), - lateral longitudinal side members (7g), laterally bordering the floor, - an area for assembling the floor on the lateral longitudinal side members. According to the invention, the floor is suitable for defining a vehicle traction battery cover and the underbody assembly comprises a set of drainage channels (23, 25) made in the assembly area, which channels are suitable for creating a clearance between the floor and the lateral longitudinal side members. The invention further relates to a motor vehicle comprising such an underbody assembly.

Description

DESCRIPTION TITLE: Underbody assembly of a motor vehicle and motor vehicle comprising such an underbody assembly [Technical field]

[0001] The present invention claims priority from French application 2310073 filed on September 22, 2023, the content of which (text, drawings and claims) is incorporated herein by reference.

[0002] The invention relates to the field of motor vehicles, and more particularly concerns a motor vehicle underbody assembly and a motor vehicle comprising such an underbody assembly. [Prior art]

[0003] A motor vehicle body structure comprises a set of sheet metal structural elements that provide rigidity to the motor vehicle, assembled together and forming the frame of the motor vehicle.

[0004] The body structure includes, among these sheet metal elements, a left side structure and a right side structure. Each side structure comprises a set of upper and lower horizontal elements, extending substantially longitudinally relative to the body, and a set of vertical elements, extending substantially vertically relative to the body.

[0005] The lower horizontal elements include lateral longitudinal stringers defining part of the perimeter of the body underbody.

[0006] The left and right side structures are connected to each other in the lower part of the vehicle by a floor, belonging to a vehicle underbody assembly and bordered laterally by the right and left longitudinal side rails.

[0007] The floor has a central, generally flat area, bordered laterally by a set of edges welded laterally to the longitudinal side members of the body structure.

[0008] After assembly of the floor and the body structure, the assembly thus formed is immersed in one or more successive baths in order to apply at least one coating by a cataphoresis process.

[0009] After applying the cataphoresis process to the assembly, it is necessary to drain the assembly to remove the excess coating. To do this, In a known realization of the prior art, the floor has a set of cataphoresis drainage holes arranged on the central area of ​​the floor.

[0010] When the vehicle is a battery electric motor vehicle (BEV, an Anglo-Saxon acronym for "Battery Electric Vehicle"), the vehicle includes a traction battery powering the electric motor of the motor vehicle.

[0011] 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.

[0012] The presence of drainage holes in the central area of ​​the floor is not feasible because this would break the airtightness of the battery tray.

[0013] Indeed, this would increase the humidity level inside the battery tray or cause water from the passenger compartment to seep into the battery tray, which would severely damage the battery modules. [Description of the invention]

[0014] The present invention aims to overcome the aforementioned drawbacks, and to this end relates to a motor vehicle underbody assembly, comprising: - a floor, - longitudinal lateral stringers, bordering laterally the said floor, - an assembly area for said floor on said lateral longitudinal stringers, said subframe assembly being notable in that said floor is adapted to define a traction battery cover for said motor vehicle and in that said subframe assembly includes a set of drainage channels made in said assembly area, adapted to create a gap between said floor and said lateral longitudinal stringers.

[0015] Thus, by providing a set of drainage channels made in the assembly area between the floor and the lateral longitudinal stringers and adapted to create a gap between the floor and the lateral longitudinal stringers, the excess coating applied during the cataphoresis stage is evacuated without the floor having drainage holes arranged on the central area of ​​the floor, as is the case in the prior art.

[0016] Thus, when the vehicle is an electric vehicle, the floor can define a traction battery cover for the motor vehicle while preserving the inside of the battery tray from the harmful effects of moisture or water infiltration from the passenger compartment which would severely damage the battery modules.

[0017] Depending on optional features of the base assembly: - which said floor comprises a central zone and lateral longitudinal edges bordering said central zone laterally, and at least one of said drainage channels is made at the level of at least one of said lateral longitudinal edges of said floor; - said longitudinal lateral edges of said floor include a vertical longitudinal face, extending from said central area towards a lower part of said motor vehicle, and at least one of said drainage channels is made at the level of said vertical longitudinal face of said longitudinal lateral edges of said floor; - at least one of said drainage channels extends substantially vertically relative to the motor vehicle; - at least one of said drainage channels made at the level of said vertical longitudinal face of said lateral longitudinal edges of said floor is adapted to create a gap between said floor and said lateral longitudinal stringers of approximately 5mm; - at least one of said drainage channels is made at the level of said lateral longitudinal stringers; - said lateral longitudinal stringers comprise a vertical face assembled to said vertical longitudinal face of said lateral longitudinal edges of said floor, a horizontal face extending from a lower edge of said vertical face, and at least one of said drainage channels is made at the level of said horizontal face of said lateral longitudinal stringers; - said longitudinal lateral edges of said floor have a horizontal longitudinal face extending from a lower edge of said vertical longitudinal face, and at least one of said drainage channels made at the level of said lateral longitudinal stringers is adapted to create a gap between said horizontal longitudinal face of said floor and said horizontal face of said lateral longitudinal stringers less than or equal to about 3mm; - said drainage channels made at the level of said lateral longitudinal stringers have a width of between approximately 10mm and approximately 20mm.

[0018] The invention also relates to a motor vehicle comprising a subframe assembly, notable in that said subframe assembly is according to the invention. [Description of the drawings]

[0019] 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:

[0020] [Fig. 1] shows a body structure of a motor vehicle according to the invention, seen in perspective from below.

[0021] [Fig. 2] is a top perspective view of a subframe assembly of the motor vehicle according to the invention.

[0022] [Fig. 3] shows the entire underbody of the motor vehicle in perspective from below.

[0023] [Fig. 4] shows the floor of the entire substructure in perspective from above.

[0024] [Fig. 5] is an enlargement of area V in figure 4.

[0025] [Fig. 6] is an enlargement of area VI of figure 2.

[0026] [Fig. 7] is a cross-sectional view along lines VII-VII of figure 6 passing out of the drainage channels.

[0027] [Fig. 8] is a cross-sectional view along lines VIII-VIII of figure 6, passing through the level of the drainage channels. [Description of the embodiments]

[0028] In the following description, elements with an identical structure or analogous functions are designated by the same reference.

[0029] By convention, and without limitation, we will adopt longitudinal, vertical and transverse orientations indicated by the direct trihedron (L, V, T) designating the longitudinal, vertical and transverse axes of the vehicle.

[0030] In what follows, the terms "left", "right", "lower" and "upper" are understood in relation to the vehicle.

[0031] Similarly, the terms "front" and "rear" are understood in relation to the general orientation of the vehicle as taken according to its normal direction of travel.

[0032] We refer to figure 1 showing a body structure 1 of a motor vehicle 3, seen in perspective from below.

[0033] The body structure 1 comprises a set of sheet metal structural elements that provide rigidity to the motor vehicle, assembled together and forming the framework of the motor vehicle.

[0034] In particular, the crate structure 1 includes a left lateral structure 5g and a right lateral structure 5d.

[0035] Each lateral structure comprises a set of upper and lower horizontal elements, extending substantially longitudinally relative to the body, and a set of vertical elements, extending substantially vertically relative to the body.

[0036] The lower horizontal elements include lateral longitudinal stringers 7g, 7d extending substantially longitudinally relative to the motor vehicle 3.

[0037] At the front, the longitudinal side members 7g, 7d are connected to the front block 9 of the motor vehicle 3. At the rear, the longitudinal side members 7g, 7d are connected to the rear axle 11 of the motor vehicle 3.

[0038] The left and right lateral structures 5g, 5d are connected to each other in the lower part of the motor vehicle 3 by a floor 13 (visible in figure 2).

[0039] Motor vehicle 3 is a battery electric vehicle (BEV, an acronym for "Battery Electric Vehicle"). To this end, motor vehicle 3 includes a traction battery (not shown) that powers the electric motor (not shown) of motor vehicle 3.

[0040] The traction battery comprises a set of battery modules, mounted in a battery box 15 mounted under the floor 13. The battery box 15 is assembled to the body structure 1 for example by screwing at the fixing holes 17 (visible in figure 2) provided on the longitudinal side rails 7g, 7d.

[0041] We refer to figure 2 which is a top perspective view of a subframe assembly 19 of the motor vehicle 3.

[0042] The underbody assembly 19 of the motor vehicle 3 includes, in particular, the floor 13 and the longitudinal side members 7g, 7d which laterally border the floor 13.

[0043] The floor 13 and the longitudinal side stringers 7g, 7d are assembled together at an assembly area 21.

[0044] According to the invention, the base assembly 19 includes a set of drainage channels 23, 25 (visible in figures 5 to 8) made in the assembly area 21 and adapted to create a gap between the floor 13 and the lateral longitudinal stringers 7g, 7d.

[0045] Thus, by providing a set of drainage channels 23, 25 made in the assembly area 21 between the floor 13 and the longitudinal lateral stringers 7g, 7d and adapted to create a gap between the floor 13 and the longitudinal lateral stringers 7g, 7d, the excess coating applied during the cataphoresis step is evacuated without the floor 13 having evacuation holes arranged on the central area 27 of the floor 13.

[0046] The floor 13 thus defines the cover of the traction battery of the motor vehicle while preserving the interior of the battery tray 15 from the harmful effects of humidity or water infiltration from the passenger compartment which would severely damage the battery modules.

[0047] We refer to figures 3 and 4 showing respectively the underbody assembly 19 of the motor vehicle 3 in perspective from below and the floor 13 in perspective from above.

[0048] According to the invention, the floor 13 is adapted to define a cover for the traction battery of the motor vehicle 3.

[0049] For this purpose, the floor 13 comprises a central zone 27, generally flat, front lateral transverse edges 29 and rear 31 and lateral longitudinal edges 33g, 33d bordering laterally the central zone 27.

[0050] In the embodiment illustrated in the figures, the drainage channels 23 of the floor 13 are made at the level of at least one of the lateral longitudinal edges 33g, 33d of the floor 13.

[0051] The drainage channels 23 of the floor 13 consist for example of a surface offset which can for example be obtained by shoring.

[0052] We refer to figure 5 showing an enlargement of area V of figure 4.

[0053] In the embodiment illustrated in the figures, the lateral longitudinal edges 33g, 33d of the floor 13 have a vertical longitudinal face 35, extending from the central area 27 of the floor 13 towards a lower part of the motor vehicle 3.

[0054] The vertical longitudinal face 35 extends substantially vertically and substantially longitudinally relative to the motor vehicle 3. In other words, the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13 extends in a plane (L, V) of the motor vehicle 3.

[0055] In the embodiment illustrated in the figures, the drainage channels 23 of the floor 13 are made at the level of the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13.

[0056] Each drainage channel 23 of the floor 13 consists, for example, of a surface offset at the level of the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d. The surface offset can, for example, be obtained by a wedging step carried out on the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13.

[0057] For example, one or more of the drainage channels 23 of the floor 13 may extend substantially vertically relative to the motor vehicle 3.

[0058] In the embodiment illustrated in the figures, the lateral longitudinal edges 33g, 33d of the floor 13 further comprise a horizontal longitudinal face 37 which extends from a lower edge 39 of the vertical longitudinal face 35. In other words, the horizontal longitudinal face 37 of the lateral longitudinal edges 33g, 33d of the floor 13 extends in a plane (L, T) of the motor vehicle 3.

[0059] In the embodiment illustrated in the figures, three drainage channels 23 are fitted to the floor 13. However, in another embodiment not illustrated, more drainage channels 23 may be provided on the floor 13, for example depending on the dimensions of the floor 13.

[0060] In one embodiment, the floor 13 is welded to the longitudinal side members 7g, 7d. For this purpose, the floor 13 has weld areas 41 onto which the longitudinal side members 7g, 7d are intended to be welded. The weld areas 41 are interspersed with drainage channels 23.

[0061] We refer to figure 6 showing an enlargement of area VI of figure 2.

[0062] In the embodiment illustrated in the figures, the drainage channels 25 are made at the level of the lateral longitudinal stringers 7g, 7d (only stringer 7g being visible in figure 5) to allow to create a gap between the floor 13 and the lateral longitudinal stringers 7g, 7d.

[0063] The evacuation channels 25 of the lateral longitudinal stringers 7g, 7d consist for example of a surface offset which can for example be obtained by swaging.

[0064] The longitudinal side members 7g, 7d have a vertical face 43 extending substantially vertically and substantially longitudinally relative to the motor vehicle 3. In other words, the vertical face 43 of the longitudinal side members 7g, 7d extends in a plane (L, V) of the motor vehicle 3.

[0065] The vertical face 43 of the lateral longitudinal stringers 7g, 7d is assembled to the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13, at the level of the assembly area 21, at the level of the weld areas 41 of the floor 13.

[0066] The longitudinal side members 7g, 7d further comprise a horizontal face 45 which extends substantially horizontally and substantially longitudinally relative to the motor vehicle 3 from a lower edge 47 of the vertical face 43. In other words, the horizontal face 45 of the longitudinal side members 7g, 7d extends in a plane (L, T) of the motor vehicle 3.

[0067] The drainage channels 25 of the lateral longitudinal stringers 7g, 7d are made at the horizontal face 45 of the lateral longitudinal stringers 7g, 7d.

[0068] Each drainage channel 25 of the lateral longitudinal stringers 7g, 7d consists, for example, of a surface offset at the horizontal face 45 of the lateral longitudinal stringers 7g, 7d. The surface offset can, for example, be achieved by a wedging step carried out on the horizontal face 45 of the lateral longitudinal stringers 7g, 7d.

[0069] In the embodiment illustrated in the figures, six drainage channels 25 are fitted to each lateral longitudinal stringer 7g, 7d. However, in another embodiment not illustrated, more drainage channels 25 may be provided on the lateral longitudinal stringers 7g, 7d, for example depending on the dimensions of the lateral longitudinal stringers 7g, 7d.

[0070] According to one arrangement of the invention, the drainage channels 25 of the lateral longitudinal stringers 7g, 7d have a width I between approximately 10mm and approximately 20mm.

[0071] We refer to figures 7 and 8 which illustrate the entire base 19 in section respectively along lines VII-VII of figure 6, passing outside the drainage channels 23, 25, and along lines VIII-VIII of figure 6, passing through the drainage channels 23, 25.

[0072] The floor 13 and the longitudinal side stringers 7g, 7d (only the longitudinal stringer 7g being visible in figures 7 and 8) are assembled together at the assembly area 21.

[0073] The floor 13 and the longitudinal side stringers 7g, 7d are welded together at the weld areas 41 made on the longitudinal edges lateral 33g, 33d of floor 13 (only the lateral longitudinal edge 33g being visible in figures 7 and 8) and intercalated with the drainage channels 23.

[0074] Thus, the vertical face 43 of the lateral longitudinal stringers 7g, 7d is assembled to the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13.

[0075] In the lower part of the assembly, the horizontal longitudinal face 37 of the lateral longitudinal edges 33g, 33d of the floor 13 is assembled to the horizontal face 45 of the lateral longitudinal stringers 7g, 7d.

[0076] As seen in figure 8, according to an example of an embodiment of the invention, one or more of the drainage channels 23 made at the level of the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13 is adapted to create a gap Ji between the floor 13 and the lateral longitudinal stringers 7g, 7d of approximately 5mm.

[0077] According to another embodiment of the invention, one or more of the drainage channels 25 of the longitudinal side members 7g, 7d, formed on the horizontal face 45 of the longitudinal side members 7g, 7d, are adapted to create a gap J2 between the horizontal longitudinal face 37 of the longitudinal side edges 33g, 33d of the floor 13 and the horizontal face 45 of the longitudinal side members 7g, 7d, less than or equal to approximately 3 mm. This makes the use of the drainage channels 25 compatible with sealing gaskets (not shown) adapted to prevent water from entering the battery tray from outside the vehicle.

[0078] After immersing the box structure in one or more successive baths in order to apply at least one coating by cataphoresis, the box structure 1 is extracted from the bath from the top.

[0079] The excess coating applied is removed by gravity through the drainage channels 23 made at the level of the vertical longitudinal face 35 of the lateral longitudinal edges 33g, 33d of the floor 13, as illustrated by arrow 49. The removal then continues through the drainage channels 25 of the lateral longitudinal stringers 7g, 7d, as illustrated by arrow 51.

[0080] As can be understood, the present invention is not limited to the embodiments of this subframe assembly and of this motor vehicle comprising such a subframe assembly, described above only as illustrative examples, but on the contrary it encompasses all 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 (19) of a motor vehicle (3), comprising: - a floor (13), - lateral longitudinal side members (7g, 7d), laterally bordering said floor (13), - an assembly zone (21) of said floor (13) on said lateral longitudinal side members (7g, 7d), said underbody assembly (19) being characterized in that said floor (13) is adapted to define a traction battery cover of said motor vehicle (3) and in that said underbody assembly (19) comprises a set of evacuation channels (23, 25) made in said assembly zone (21), adapted to create a clearance between said floor (13) and said lateral longitudinal side members (7g, 7d).

2. Base assembly (19) according to claim 1, wherein said floor (13) comprises a central zone (27) and lateral longitudinal edges (33g, 33d) laterally bordering said central zone (27), characterized in that at least one of said evacuation channels (23, 25) is formed at the level of at least one of said lateral longitudinal edges (33g, 33d) of said floor (13).

3. Underbody assembly (19) according to claim 2, wherein said lateral longitudinal edges (33g, 33d) of said floor (13) comprise a vertical longitudinal face (35), extending from said central zone (27) towards a lower part of said motor vehicle (3), characterized in that at least one of said evacuation channels (23) is made at the level of said vertical longitudinal face (35) of said lateral longitudinal edges (33g, 33d) of said floor (13).

4. Underbody assembly (19) according to claim 3, characterized in that at least one of said evacuation channels (23) extends substantially vertically relative to the motor vehicle (3).

5. Underbody assembly (19) according to one of claims 3 or 4, characterized in that at least one of said evacuation channels (23) made at the level of said vertical longitudinal face (35) of said lateral longitudinal edges (33g, 33d) of said floor (13) is adapted to create a clearance (Ji) between said floor (13) and said lateral longitudinal side members (7g, 7d) approximately equal to 5mm.

6. Underbody assembly (19) according to any one of claims 1 to 5, characterized in that at least one of said evacuation channels (25) is made at the level of said lateral longitudinal side members (7g, 7d).

7. Underbody assembly (19) according to claim 6 combined with any one of claims 3 to 5, characterized in that said lateral longitudinal side members (7g, 7d) comprise: - a vertical face (43) assembled to said vertical longitudinal face (35) of said lateral longitudinal edges (33g, 33d) of said floor (13), - a horizontal face (45) extending from a lower edge (47) of said vertical face (43), and in that at least one of said evacuation channels (23, 25) is formed at the level of said horizontal face (45) of said lateral longitudinal side members (7g, 7d).

8. Underbody assembly (19) according to claim 7, characterized in that said lateral longitudinal edges (33g, 33d) of said floor (13) comprise a horizontal longitudinal face (37) extending from a lower edge (39) of said vertical longitudinal face (35), and in that at least one of said evacuation channels (25) made at the level of said lateral longitudinal side members (7g, 7d) is adapted to create a clearance (J2) between said horizontal longitudinal face (37) of said floor (13) and said horizontal face (45) of said lateral longitudinal side members (7g, 7d) less than or equal to approximately 3mm.

9. Underbody assembly (19) according to any one of claims 6 to 8, characterized in that said evacuation channels (25) made at the level of said lateral longitudinal side members (7g, 7d) have a width of between approximately 10mm and approximately 20mm.

10. Motor vehicle (3) comprising an underbody assembly (19), characterized in that said underbody assembly (19) is according to any one of claims 1 to 9.

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