Underbody assembly of a motor vehicle with aerodynamic deflector attached to the rear axle

Abstract

Underbody assembly of a motor vehicle with aerodynamic deflector attached to the rear axle. The invention relates to an underbody assembly (1) of a motor vehicle (3), comprising a front axle (9) and a rear axle (11) rotatable about an axis of travel extending transversely relative to said motor vehicle, said rear axle having a left rear wheel (11g) and a right rear wheel (11d) and a rear track that is narrower than a front track of said front axle (9). According to the invention, said underbody assembly (1) is notable in that it comprises a rear aerodynamic deflector (17) arranged between said right rear wheel (11d) and said left rear wheel (11g) and being attached directly to said rear axle (11) of said motor vehicle (3). Figure 2

Description

Title of the invention: Underbody assembly for a motor vehicle with aerodynamic deflector attached to the rear axle. Technical field

[0001] The invention relates to the field of motor vehicles, in particular to the field of aerodynamic deflectors mounted under motor vehicles.

[0002] The invention relates more particularly to a subframe assembly for a motor vehicle. Previous technique

[0003] In order to improve the aerodynamic efficiency of a motor vehicle, it is known to seek to make the underside of the vehicle as flat as possible.

[0004] This is all the more desirable when the vehicle is an electric motor vehicle, in order to reduce its energy consumption and thus improve battery range.

[0005] For this purpose, a motor vehicle may in particular include one or more aerodynamic deflectors, mounted under the vehicle at the level of the underbody and defining a fairing of a part of the underbody.

[0006] In particular, a motor vehicle may include a front aerodynamic deflector, a central aerodynamic deflector behind the front aerodynamic deflector, and a rear aerodynamic deflector behind the central aerodynamic deflector.

[0007] Such aerodynamic deflectors typically consist of plastic material plates mounted on the underbody of the vehicle in a fixed manner relative to the vehicle, i.e. the parts of the aerodynamic deflectors are fixed on fixed parts of the vehicle, typically on the body structure of the vehicle.

[0008] In particular, a rear aerodynamic deflector can be mounted at the rear axle of the vehicle and can extend to a rear edge of the rear bumper, so that the air flowing under the vehicle does not enter the rear bumper but flows behind it. In this way, resistance to forward motion that would be generated by the air in contact with the inner face of the rear bumper is avoided.

[0009] The rear aerodynamic deflector is fixed to the vehicle's body structure. It runs between the rear wheels and typically extends to a rear edge of the rear bumper, behind the rear bumper.

[0010] The rear aerodynamic deflector, as well as the front aerodynamic deflector, may include lateral cutouts arranged to allow movement of the vehicle's wheel suspensions, depending on the road relief when the vehicle is moving, particularly at a speed above 80 km / h.

[0011] Certain types of motor vehicles have a reduced rear track compared to the front track, that is to say that the rear wheels are closer together compared to each other, compared to the distance separating the front wheels.

[0012] This is typically the case of vehicle 101 illustrated in [Fig.1] which is a view from below of a vehicle which may be a vehicle of category "L5" according to European regulations, i.e. a vehicle whose rear track is less than or equal to 460mm.

[0013] The vehicle 101 comprises a subframe assembly 103, including a front aerodynamic deflector 105 and a central aerodynamic deflector 107 arranged behind the front deflector 103, both fixedly mounted on a vehicle body structure.

[0014] The left rear wheel 109g and the right rear wheel 109d, arranged at the rear axle 113 of the vehicle, are located in the airflow from the front to the rear of the vehicle, disrupting its flow. Furthermore, the airflow towards the rear of the vehicle is drawn into the rear bumper 115.

[0015] The mounting of a rear aerodynamic deflector fixed to the body structure of the vehicle and running between the left rear wheel 109g and the right rear wheel 109d, as is the case in a vehicle whose rear track is not reduced, is not transposable to vehicles with a reduced rear track.

[0016] Indeed, such a rear aerodynamic deflector assembly entails a high risk of interference with the rear axle of the vehicle in the event of rear axle movement according to the terrain encountered by the moving vehicle.

[0017] Also, the small distance between the rear wheels of the vehicle does not allow the arrangement of cutouts in the rear aerodynamic deflector to allow the rear axle travel. Description of the invention

[0018] The present invention aims to overcome the aforementioned drawbacks, and to this end relates to a motor vehicle underbody assembly, comprising a front axle and a rear axle, said rear axle being rotatable about an axis of travel extending transversely relative to said motor vehicle, said rear axle comprising a left rear wheel and a right rear wheel and having a rear track lower than a front track of said front axle, said assembly being notable in that it comprises an aerodynamic deflector rear arranged between said right rear wheel and said left rear wheel and being fixed directly to said rear axle of said motor vehicle.

[0019] Thus, by attaching the rear aerodynamic deflector directly to the rear axle of the vehicle, the rear aerodynamic deflector follows the movement of the vehicle's rear axle caused by the road surface as the vehicle moves. In this way, any risk of interference between the rear aerodynamic deflector and the vehicle's rear axle that could occur during rear axle movement is avoided.

[0020] Furthermore, attaching the rear aerodynamic deflector directly to the rear axle of the vehicle limits its reach compared to a deflector attached to the rear of the vehicle, for example, to the rear bumper. This reduces the vibration of the rear aerodynamic deflector, thereby limiting the risk of the rear aerodynamic deflector contacting the ground and thus reducing the risk of breakage, particularly when the vehicle goes over a speed bump, for example.

[0021] Also, fixing the rear aerodynamic deflector directly onto the rear axle of the vehicle eliminates the need to make cutouts, which are useful in the prior art to allow the rear axle to move, thus making it possible to install it on a motor vehicle with a reduced rear track, in particular less than 460mm.

[0022] According to optional features of the base assembly according to the invention: - said rear aerodynamic deflector comprises a fixed front portion relative to said underbody assembly and a central portion, arranged behind said front portion, fixed to said rear axle and articulated relative to said front portion around an axis of rotation of said rear aerodynamic deflector, said axis of rotation extending transversely relative to said motor vehicle; - said axis of rotation of said rear aerodynamic deflector is contained in a transverse plane coinciding with a transverse plane containing said axis of travel of said rear axle; - said axis of rotation of said rear aerodynamic deflector is contained in a transverse plane located in front of or behind a transverse plane containing said axis of travel of said rear axle; - said rear aerodynamic deflector is made of a plastic material and said central portion of said rear aerodynamic deflector is articulated relative to said front portion, by means of a hinge film defined between said front portion of said rear aerodynamic deflector and said central portion of said deflector rear aerodynamics, and consisting of a reduction in thickness between said front portion and said central portion; - said central portion of said rear aerodynamic deflector is articulated in relation to said front portion of said rear aerodynamic deflector by means of a mechanical hinge arranged between said front portion and said central portion; - said rear aerodynamic deflector comprises a rear portion, fixed relative to said subframe assembly and arranged behind said central portion of said rear aerodynamic deflector; - said rear portion is attached to a rear bumper of said motor vehicle; - said central portion of said rear aerodynamic deflector is connected to said rear portion of said rear aerodynamic deflector by means of a flexible connecting membrane fixed on one side to said rear portion and on the other side to said central portion; - said rear track of said rear axle is less than 460mm. Brief description of the drawings

[0023] Other features, purposes and advantages of the invention will become apparent from the following detailed description, for the understanding of which reference should be made to the accompanying drawings in which:

[0024] [Fig-1] is a view from below of a prior art vehicle.

[0025] [Fig.2] is a bottom view of a vehicle underbody assembly automobile according to the invention.

[0026] [Fig.3] shows the entire base assembly according to the invention, seen in section longitudinal in an initial vehicle driving situation.

[0027] [Fig.4] shows the entire base assembly according to the invention, seen in section longitudinal in a second first situation of vehicle movement.

[0028] [Fig.5] is an enlargement of area V of [Fig.2]. Description of the implementation methods

[0029] In the following description, elements having an identical structure or analogous functions are designated by the same reference.

[0030] By convention, and without limitation, longitudinal, vertical and transverse orientations will be adopted as indicated by the direct trihedron (L, V, T) designating the longitudinal, vertical and transverse axes of the vehicle.

[0031] In what follows, the terms "left", "right", "lower" and "upper" are understood in relation to the vehicle.

[0032] 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.

[0033] Reference is made to [Fig.2] showing a subframe assembly 1 of a motor vehicle 3 according to the invention seen from below and to [Fig.3] showing the subframe assembly 1 seen in longitudinal section in a first driving situation of the vehicle 3.

[0034] The vehicle 3 rests on a ground 4 on which it moves.

[0035] The underbody assembly 1 of the vehicle 3 includes an aerodynamic deflector front 5 and a central aerodynamic deflector 7 arranged behind the front deflector 3, both being for example fixedly mounted on fixed areas of the vehicle, for example on a body structure of the vehicle 3.

[0036] The vehicle 3 comprises a front axle 9 and a rear axle 11. The front axle 9 comprises a left front wheel 9g and a right front wheel 9d. The rear axle 11 comprises a left rear wheel 11g and a right rear wheel 11d.

[0037] The rear axle 11 is mobile in rotation around a travel axis 13 extending substantially transversely relative to the vehicle 3, i.e. substantially transversely relative to the subframe assembly 1. The mobility of the rear axle 11 is ensured in particular by means of suspensions 15 arranged to allow travel of the rear axle 11 according to the reliefs of the road when the vehicle is moving.

[0038] The rear track, i.e. the distance di between the rear wheels 1 Id, 11g of the rear axle 11, is reduced in relation to the front track corresponding to the distance d2 between the front wheels 9d, 9g of the front axle 9.

[0039] Vehicle 3 may, for example, be a vehicle of category "L5" according to European regulations, i.e. a vehicle considered as a tricycle. For this purpose, the rear track is less than or equal to 460 mm.

[0040] According to the invention, the underbody assembly 1 comprises a rear aerodynamic deflector 17 arranged between the right rear wheel 1 Id and the left rear wheel 11g and being directly fixed to the rear axle 11 of the vehicle 3.

[0041] The attachment of the rear aerodynamic deflector 17 to the rear axle 11 of the vehicle 3 is carried out by any means known to a person skilled in the art.

[0042] The attachment of the rear aerodynamic deflector 17 to the rear axle 11 of the vehicle 3 is operated by a fastening assembly 18 designed to allow relative movement between the rear aerodynamic deflector 17 and the rear axle 11 along the longitudinal axis of the vehicle 3.

[0043] The rear aerodynamic deflector 17 is conventionally made of a plastic material, for example polypropylene. The flexibility of the plastic allows the rear aerodynamic deflector 17 to follow the movement of the vehicle's rear axle 11 as it travels due to road irregularities while the vehicle is moving.

[0044] The rear aerodynamic deflector 17 may include a front portion 19, fixed relative to the underbody assembly 1, and a central portion 21 arranged behind the front portion 19, fixed to the rear axle 11 of the vehicle 3 and articulated relative to the front portion 19.

[0045] In such an embodiment, the central portion 21 is articulated relative to the front portion 19 around an axis of rotation 22 extending substantially transversely relative to the vehicle 3, that is to say substantially transversely relative to the subframe assembly 1.

[0046] In the embodiment illustrated in the figures, the axis of rotation 22 of the rear aerodynamic deflector 17 is contained in a transverse (V, T) plane Pi coinciding with a transverse (V, T) plane P2 containing the axis of travel 13 of the rear axle 11.

[0047] However, in an unillustrated embodiment, the axis of rotation 22 of the rear aerodynamic deflector 17 can be contained in a transverse plane located in front of or behind the transverse plane P2 containing the axis of travel 13 of the rear axle 11.

[0048] In one embodiment of the invention, the articulation of the central portion 21 of the rear aerodynamic deflector 17 relative to the front portion 19 can be operated by means of a hinge film defined between the front portion 19 and the central portion 21 of the rear aerodynamic deflector 17. The hinge film consists of a reduction in thickness between the front portion 19 and the central portion 21 making the central portion 21 mobile relative to the fixed front portion 19.

[0049] In another embodiment of the invention, the central portion 21 is articulated with respect to the front portion 19 by means of a mechanical hinge arranged between the front portion 19 and the central portion 21. The mechanical hinge used in the context of the invention comprises, for example, an axis, for example metallic, carried by the central portion 21, pivotally mounted on a plate carried by the front portion 19.

[0050] In the embodiment illustrated in the figures, the rear aerodynamic deflector 17 further comprises a rear portion 23, arranged behind the central portion 21 of the rear aerodynamic deflector 17.

[0051] The rear portion 23 is fixedly mounted in the subframe assembly 1, unlike the central portion 21 which is mobile relative to the subframe assembly 1.

[0052] For example, the rear portion 23 is fixed to a rear bumper 25 of the vehicle 3.

[0053] In particular, the rear portion 23 can be fixed at a rear edge of the rear bumper 25 so that the air flowing under the vehicle 3 does not rush into the rear bumper 25 but flows behind the rear bumper 25 in order to avoid creating resistance to forward motion which would be generated by the air in contact with the inner face of the rear bumper 25.

[0054] Also, in the embodiment illustrated in the figures, the rear aerodynamic deflector 17 may also include two lateral deflectors 26g, 26d bordering laterally the front portion 19 of the rear aerodynamic deflector 17 and extending between the central aerodynamic deflector 7 and the rear portion 23 of the rear aerodynamic deflector 17.

[0055] In the embodiment illustrated in the figures, the central portion 21 can be connected to the rear portion 23 of the rear aerodynamic deflector 17 by means of a flexible connecting membrane 27, fixed on one side to the rear portion 23 and on the other side to the central portion 21.

[0056] The flexible connecting membrane 27 can, for example, be made of an elastomeric material, for example rubber, which allows a clearance between the central portion 21 and the rear portion 23 of the rear aerodynamic deflector 17.

[0057] The flexible connecting membrane can be fixed to the front end of the rear portion 23 of the rear aerodynamic deflector 17 and to the rear end of the central portion 21 of the rear aerodynamic deflector 17 by any means and method known to a person skilled in the art.

[0058] The presence of the flexible connecting membrane 27 is optional. In one embodiment, no connection is made between the central portion 21 and the rear portion 23.

[0059] Reference is made to [Fig.4] showing the entire underbody 1 seen in longitudinal section in a second driving situation of the vehicle 3.

[0060] Compared with the position it occupies in [Fig.3], the base assembly 1 has descended towards the ground 4, as represented by arrow 29, due to the relief of the road 4 during the movement of the vehicle 3.

[0061] When the subframe assembly 1 descends towards the ground 4, the rear axle 11 performs a rotation around its axis of travel 13, in the counter-clockwise direction, as represented by the arrow 31.

[0062] The rear aerodynamic deflector 17, directly fixed to the rear axle 11 of the vehicle 3 and arranged between the right rear wheel 1 Id and the left rear wheel 11g, moves in concert with the rear axle 11, thus avoiding any risk of interference between the rear aerodynamic deflector 17 and the rear axle 11.

[0063] Reference is made to [Fig.5] showing an enlargement of area V of [Fig.2].

[0064] In the embodiment illustrated in the figures, the fastening assembly 18 designed to allow relative movement between the rear aerodynamic deflector 17 and the rear axle 11 along the longitudinal axis of the vehicle 3 comprises two fastening elements 33, 35.

[0065] Each fastening element 33, 35 has an oblong opening 37 receiving a fastening member 39, for example a fastening screw, fixed on the rear axle 11.

[0066] As will be understood, the present invention is not limited to the forms of embodiment of this base assembly described above solely by way of illustrative examples, but on the contrary 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

Demands

1. Underbody assembly (1) of a motor vehicle (3), comprising a front axle (9) and a rear axle (11), said rear axle (11) being rotatable about a travel axis (13) extending transversely relative to said motor vehicle (3), said rear axle (11) comprising a left rear wheel (11g) and a right rear wheel (1Id) and having a rear track lower than a front track of said front axle (9), said underbody assembly (1) being characterized in that it comprises a rear aerodynamic deflector (17) arranged between said right rear wheel (1Id) and said left rear wheel (11g) and being fixed directly on said rear axle (11) of said motor vehicle (3).

2. Underbody assembly (1) according to claim 1, characterized in that said rear aerodynamic deflector (17) comprises a front portion (19) fixed relative to said underbody assembly (1) and a central portion (21), arranged behind said front portion (19), fixed to said rear axle (11) and being articulated relative to said front portion (19) around an axis of rotation (22) of said rear aerodynamic deflector (17), said axis of rotation (22) extending transversely relative to said motor vehicle (3).

3. Underbody assembly (1) according to claim 2, characterized in that said axis of rotation (22) of said rear aerodynamic deflector (17) is contained in a transverse plane (Pi) coinciding with a transverse plane (P2) containing said axis of travel (13) of said rear axle (11).

4. Underbody assembly (1) according to claim 2, characterized in that said axis of rotation (22) of said rear aerodynamic deflector (17) is contained in a transverse plane (Pi) located in front of or behind a transverse plane (P2) containing said axis of travel (13) of said rear axle (11).

5. A subframe assembly (1) according to any one of claims 2 to 4, wherein said rear aerodynamic deflector (17) is made of a plastic material, characterized in that said central portion (21) of said rear aerodynamic deflector (17) is articulated relative to said front portion (19) by means of a hinge film defined between said portion front (19) of said rear aerodynamic deflector (17) and said central portion (21) of said rear aerodynamic deflector (17) and consisting of a reduction in thickness between said front portion (19) and said central portion (21).

6. Base assembly (1) according to any one of claims 2 to 4, characterized in that said central portion (21) of said rear aerodynamic deflector (17) is articulated with respect to said front portion (19) of said rear aerodynamic deflector (17) by means of a mechanical hinge arranged between said front portion (19) and said central portion (21).

7. Underbody assembly (1) according to any one of claims 1 to 6, characterized in that said rear aerodynamic deflector (17) comprises a rear portion (23), fixed relative to said underbody assembly (1) and arranged behind said central portion (21) of said rear aerodynamic deflector (17).

8. Underbody assembly (1) according to claim 7, characterized in that said rear portion (23) is fixed to a rear bumper (25) of said motor vehicle (3).

9. Underbody assembly (1) according to any one of claims 7 or 8, characterized in that said central portion (21) of said rear aerodynamic deflector (17) is connected to said rear portion (23) of said rear aerodynamic deflector (17) by means of a flexible connecting membrane (27) fixed on one side to said rear portion (23) and on the other side to said central portion (21).

10. Underbody assembly (1) according to any one of claims 1 to 9, characterized in that said rear track of said rear axle (11) is less than 460mm.

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