Underbody assembly for vehicle provided with means for protecting an underfloor battery pack

Abstract

The invention relates to a motor vehicle underbody assembly (1) comprising a body underbody (100) provided with a floor, a battery pack (200) fixedly installed under said floor, a rear axle with a deformable cross member extending to the rear of said battery pack and comprising two lateral suspension arms (330) provided at their front end with an articulation block (332) crossed by a yoke (333) fixed to said body underbody, as well as two multifunction supports (400) arranged at said articulation blocks (332) and fixed with said yokes (333) to said body underbody (100);each said multifunctional support (400) comprising a U-shaped plate (410) arranged astride a said respective articulation block, as well as a protection member (420), taking root on said plate to which it is fixed, and extending substantially vertically towards the ground so as to project below said battery pack by a predetermined distance. Figure to be published with the abstract: Fig. 2;

Description

Title of the invention: Underbody assembly for vehicle provided with means for protecting an underfloor battery pack Technical field

[0001] The present invention lies in the field of passive vehicle safety, in particular in the field of protection of a propulsion battery pack for a hybrid or electric vehicle and of the sensitive elements connected to this battery pack, such as electrical power supply harnesses. Prior art

[0002] Traditionally, the battery packs of electric or hybrid powered motor vehicles are mounted under the floor of the vehicle, facing the ground, and must be protected from impacts to avoid any risk of damage to the electrical components they contain. Indeed, such damage can have serious consequences for the safety of the vehicle's occupants, particularly when it causes an explosion, a fire or an acid leak.

[0003] There are many situations that can cause such damage. In addition to the classic shock situations that the vehicle may experience, we can cite, but not be limited to, lifting the vehicle with a rolling jack resting on the battery pack housing, driving the vehicle up a guardrail or onto a curb, driving up or down a curb while moving forward or backward, or even deploying a retractable bollard under the vehicle body.

[0004] In order to protect such a battery pack when crossing or descending sidewalks, it is known to provide sheet metal or plastic screens under the vehicle covering this battery pack.

[0005] When they are made of plastic, protective screens must be designed to withstand very high forces, up to 1.5 tonnes. Even when they are reinforced with reinforcements and have a very dense network of ribs, the risk of breaking such plastic screens remains high. This is particularly the case when temperatures are very low, as plastic materials then tend to become brittle. However, the loss of all or part of such a screen on the road, when the vehicle is moving following an impact suffered by said screen, must be avoided because it is potentially dangerous for other road users. In particular, such a loss can cause a motorcyclist to fall if he runs over the screen. This is why vehicles are required not to lose parts weighing more than 10 grams after an impact.

[0006] Sheet metal screens do not present a better alternative. Indeed, to be able to perform their protective function, they must be able to deform during an impact. A To this end, they are arranged away from the lower wall of the casing of such a battery pack, so that they can sink in when absorbing an impact without damaging it. This solution therefore implies restrictions on the size of the battery packs that can be installed under the floor of the vehicle. However, in order to promote the autonomy of vehicles, the current trend is towards an increase in the size of these battery packs.

[0007] It is also known to fix longitudinal rails extending laterally on either side of the battery pack, along the latter and over a height greater than this battery pack, so as to protect it when crossing or descending pavements oriented substantially parallel to the vehicle.

[0008] Document FR 3 082 788 A1 discloses a vehicle comprising a battery pack fixed under the floor of the vehicle by at least one support device configured to have a height greater than that of this battery pack, so as to extend vertically from the floor of the vehicle towards the ground over a height greater than that of the battery pack in order to protect it when crossing or descending pavements oriented substantially parallel to the vehicle.

[0009] These solutions are interesting, but do not allow the rear part of such a battery pack to be effectively protected when the rear axle crosses or descends pavements oriented substantially perpendicular to the vehicle.

[0010] Unfortunately, the addition of similar protective devices extending transversely along the rear edge of such a battery pack often proves impossible due to lack of available space, particularly on vehicles with a deformable rear axle generally equipped with multi-function supports pre-mounted on the front ends of the longitudinal suspension arms of this rear axle and fixed with the latter on the underbody. Statement of the invention

[0011] The present invention therefore aims to improve the situation.

[0012] To this end, it proposes a motor vehicle underbody assembly comprising a body underbody provided with a floor, a battery pack fixedly installed under said floor, a rear axle with a deformable cross member extending to the rear of said battery pack and comprising two lateral suspension arms provided at their front end with an articulation block crossed by a yoke fixed to said body underbody, as well as two multifunction supports arranged at the level of said articulation blocks and fixed with said yokes to said body underbody, each said multifunction support comprising a U-shaped plate arranged astride a said respective articulation block and comprising two lateral legs connected by a cross member; characterized in that each said multifunctional support also comprises a protective member, taking root on said plate to which it is fixed, and extending substantially vertically towards the ground so as to protrude below said battery pack by a predetermined distance.

[0013] The invention thus makes it possible, without having to install specific protection devices in congested areas where the available space did not allow it, to effectively protect the rear part of the battery pack (and the sensitive elements connected to this rear part of such a battery pack) when the rear axle crosses or descends pavements oriented substantially perpendicular to the vehicle.

[0014] According to preferred characteristics of said set of underbody panels according to the invention: - the protective member of each said multi-function support is in the form of a hollow half-bowl delimited by a lower bottom wall and by a side wall having a U-shaped section matching the internal profile of said plate; - the lower bottom wall of the protective member of each said multifunctional support forms a substantially horizontal plate; - the upper end edge of the protective member of each said multi-function support is fixed along the internal edge of the crosspiece and a portion of the internal edges of the lateral legs of the plate of this support by a single weld bead; - the protective member of each said multi-function support is made by stamping from a sheet of metal; - said spacing is greater than or equal to 5 millimeters; - said spacing is between 10 and 15 millimeters; - the plate of each said multifunction support comprises means for pre-holding this support on the front end of a said corresponding suspension arm before their definitive fixing together on said body underbody, said pre-holding means comprising two curved hooks extending from the external edge of one of said legs and intended to cooperate with the distal edge of a first lateral end of the transverse yoke of a said corresponding suspension arm, and an orifice provided on an internal protrusion of the other of said legs and intended to come to be superimposed on a respective hole of similar shape and dimensions provided in the second lateral end of this transverse yoke, so as to allow the insertion through this orifice and this hole of a pre-holding pin; and / or - the plate of each said multifunction support has several legs with attachment holes for equipment of said vehicle.

[0015] The invention also relates, in a second aspect, to a motor vehicle comprising such a set of underbody panels. Brief description of the drawings

[0016] The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below for illustrative but non-limiting purposes, with reference to the appended drawings, in which: - [Fig.l] represents a bottom view of the motor vehicle underbody assembly according to the invention; - [Fig.2] is a perspective view from below of the mounting area of the front end of a trailing arm and a multi-function bracket on the underbody of the vehicle of [Fig.l], near the rear edge of the battery pack; - [Fig.3] represents a perspective view of one of the two multifunctional supports that comprise the underbody assembly of [Fig.l]; and - [Fig.4] is a partial elevation view of a motor vehicle fitted with the underbody assembly of [Fig.l] reversing down a sidewalk oriented substantially perpendicular to this vehicle. Description of the embodiments

[0017] [Fig.l] represents a perspective view from above of a set of underbody panels according to the invention 1 of a motor vehicle comprising an electric propulsion machine not shown.

[0018] We define with respect to this set of rocker panels 1 an orthogonal reference XYZ comprising three axes perpendicular two by two, namely: - an X axis, defining a longitudinal, horizontal direction, parallel to the ground and coincident with the general direction of movement of the vehicle - a Y axis, defining a transverse, horizontal direction, also parallel to the ground and which with the X axis defines a horizontal XY plane, and - a Z axis, defining a vertical direction, perpendicular to the ground as well as to the horizontal XY plane.

[0019] In the remainder of the description and with reference to the reference defined above, the terms “longitudinal” or “longitudinally” will refer to a direction parallel to the X axis, the terms “transverse” or “transversely” will refer to a direction parallel to the Y axis, and the terms “vertical” or “vertically” will refer to a direction parallel to the Z axis.

[0020] On the other hand and by convention, the terms "lower", "upper", "front" and "rear" will be understood in relation to the general orientation of the vehicle. The terms "lower" and "low" will indicate a greater proximity to the ground depending on the vertical direction than the terms "upper" or "top". The term "front" will indicate a positioning oriented towards the front of a vehicle in the horizontal direction and the term "rear" will indicate a positioning oriented towards the rear of a vehicle in the same horizontal direction.

[0021] Finally, the use of the term "substantially" will indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining within the scope of the invention. For example, "substantially vertical" will indicate that a deviation of the order of 10° to 25° from a strictly vertical orientation is permitted within the scope of the invention.

[0022] With reference to this [Fig.l], the underbody assembly 1 comprises a sheet metal underbody 100 comprising a floor 110 extending transversely between two lateral side members 120.

[0023] This underbody assembly 1 also comprises a battery pack 200 extending along a substantially horizontal mean plane and fixedly installed under the floor 110 of the underbody 100 between the lateral side members 120.

[0024] This battery pack 200 is provided with a hollow metal casing 210 defining an internal volume containing several non-visible battery modules each comprising several electrochemical cells capable of generating current by chemical reaction.

[0025] This casing 210 can also house other sensitive elements such as a mounting interface, electrical and fluid connection connectors, and / or electrical or electronic means for managing the electrical energy of these modules.

[0026] Still with reference to [Fig.l], the underbody assembly 1 also comprises a rear axle with deformable cross member 300 mounted on the underbody 100 at the rear of the battery pack 200.

[0027] With reference to this [Fig.l], this rear axle 300 comprises two wheels 310 connected to each other by a cross member 320 located under the body underbody 100 and from which two lateral suspension arms 330 extend substantially longitudinally near the two lateral edges of the body underbody 100.

[0028] As illustrated by [Fig.2], the front end of each longitudinal suspension arm 330 comprises a ring 331 oriented substantially transversely and receiving an elastically deformable articulation block 332 crossed by a metal yoke 333, the two lateral ends of which are each fixed by a respective screw not shown to the body underbody 100, to produce an elastic articulation filtering the vibrations.

[0029] Still with reference to [Fig. 2], these screws also ensure, in a known manner, the fixing against the underbody 100 of two multifunction supports 400 each arranged near a front end of a longitudinal suspension arm. 330 corresponding and on which are fixed a certain number of pieces of vehicle equipment such as in particular the electrical supply harness 3 of a wheel speed sensor 4, said wheel speed sensor 4, the support 5 of a body height sensor 6, the end of the rear brake hose 7 and an aerodynamic deflector not shown.

[0030] The use of such multifunctional supports 400 and the fact that their fixing is ensured by the same screws and corresponding fixing holes provided in the body underbody 100 as those used for fixing the suspension arms 330 thus makes it possible to reduce as much as possible the number of fixing holes to be made in this body underbody 100 so as to limit sealing problems.

[0031] In a known manner and with reference to [Fig. 3], each multifunction support 400 comprises a U-shaped main plate 410 allowing it to be arranged along a horizontal mean plane parallel to the body underbody 100, straddling a corresponding suspension arm 330 as illustrated by [Fig. 2].

[0032] Advantageously produced by cutting and folding from a sheet of metal, the plate 410 of each support 400 comprises a first and a second lateral leg 411, 412 connected at their front ends by a crosspiece 413 and each comprising a respective flat fixing portion 411 A, 412A intended to come to rest, as illustrated by [Fig. 2], against the flat lower face of a corresponding lateral end of the yoke 333 of a corresponding suspension arm 330.

[0033] The flat fixing portions 41 1A, 412A each have a respective circular orifice 41 1B, 412B intended to overlap with a respective hole of similar shape and dimensions provided in a corresponding lateral end of the transverse yoke 333 of a suspension arm 330, so as to allow the insertion of a screw for fixing this yoke 333 and the support 400 corresponding to the body underbody 100.

[0034] In the remainder of this description, the terms “external” and “internal” will be used to define the relative position of an element with reference to the median vertical longitudinal plane of a support 400. The element closest to this plane will thus be described as internal as opposed to the other element further away from this same plane which will itself be described as external.

[0035] Of greater length than the second leg 412, the first leg 411 extends at the rear of its flat fixing portion 41 1A by a first substantially horizontal tab 414 having: - a fastening hole 414A intended to allow the snap-fitting of a first clamping clip Al (partially visible in [Fig.2]) of the electrical supply harness 3 of a wheel speed sensor 4; and - two attachment holes 414B intended to allow the fixing by screwing against this tab 114 of a support 5 for a body height sensor 6.

[0036] The first leg 411 also extends at the front of its flat fixing portion 411A by a second substantially vertical tab 415 having an attachment orifice 415A intended to allow the fixing of one end of the rear brake hose 7.

[0037] This first leg 411 is further extended at the level of the external edge of its flat fixing portion 411A by a third substantially vertical leg 416 having: - a fastening hole 416A intended to allow the snap-fitting of a second clamping clip (not visible in [Fig.2]) of the electrical supply harness 3 of the wheel speed sensor 4; and - a fastening hole 416B intended to allow mounting by screwing against this tab 416 of the wheel speed sensor 4.

[0038] The tab 416 is extended laterally at its lower edge by a substantially horizontal right-angle return 417 also having an attachment orifice 417A intended to participate in the fixing by screwing using a screw V of an aerodynamic deflector not shown partially covering the battery pack 200.

[0039] Again with reference to [Fig. 3], the plate 410 of each support 400 comprises means for pre-holding this support 400 on the front end of a corresponding suspension arm 330 before their definitive fixing together by screwing onto the body underbody 100.

[0040] These pre-maintenance means include in this case: - two curved hooks 418 extending from the outer edge of the leg 412 at its orifice 412B and intended to cooperate with the distal edge of a first lateral end of the transverse yoke 333 of a corresponding suspension arm 330; and - an orifice 419 provided on an internal protrusion of the leg 411 at the level of its orifice 41 IB and intended to be superimposed on a respective hole of similar shape and dimensions provided in the second lateral end of this transverse yoke 333, so as to allow the insertion through this orifice 419 and this hole of a pre-retaining pin not shown.

[0041] According to the invention, each multifunction support 400 also comprises a protection member 420, taking root on the plate 410 to which it is fixed, and extending substantially vertically towards the ground so as to project below the battery pack 200 by a predetermined distance e as illustrated by [Fig.4].

[0042] This spacing e will preferably be greater than or equal to 5 millimeters and advantageously between 10 and 15 millimeters in order to ensure that the battery pack 200 is not impacted when reversing down a sidewalk T oriented substantially perpendicular to vehicle 1.

[0043] Preferably and as illustrated by figures 2 and 3, this protection member 420 is in the form of a hollow half-bowl delimited by a lower bottom wall 421 and by a side wall 422 having a U-shaped section matching the internal profile of the plate 410.

[0044] Such a conformation in fact offers excellent mechanical strength allowing this protection member 420 to withstand very significant forces without deforming, which can reach 500 kg when reversing down a sidewalk T oriented substantially perpendicular to the vehicle (see [Fig.4]).

[0045] The protective member 420 of each multifunction support 400 is advantageously produced by stamping from a sheet of metal.

[0046] As can be seen in [Fig. 3], the upper end edge of this protective member 420 is in this case fixed along the internal edge of the crosspiece 413 and a portion of the internal edges of the lateral legs 411, 412 by a single weld bead C.

[0047] The lower bottom wall 421 of this protective member 420 forms a substantially horizontal flat so as to constitute a sliding surface for the sidewalk T when the vehicle 1 descends.

[0048] According to alternative embodiments not shown, the protection member 420 of each multifunction support 400 could be shaped differently, for example by being constituted by a simple plate of substantially vertical orientation.

[0049] Many other variants are conceivable and it is recalled in this regard that the present invention is not limited to the embodiments described and shown, but also encompasses all the variants of execution within the reach of those skilled in the art.

Claims

Claims

1. A motor vehicle underbody assembly (1) comprising a body underbody (100) provided with a floor (110), a battery pack (200) fixedly installed under said floor (110), a rear axle with a deformable cross member (300) extending to the rear of said battery pack (200) and comprising two lateral suspension arms (330) provided at their front end with an articulation block (332) crossed by a yoke (333) fixed to said body underbody (100), as well as two multifunction supports (400) arranged at said articulation blocks (332) and fixed with said yokes (333) to said body underbody (100), each said multifunction support (400) comprising a U-shaped plate (410) arranged astride a respective said articulation block (332) and comprising two lateral legs (411, 412) connected by a crosspiece (413);characterized in that each said multifunctional support (400) also comprises a protective member (420), taking root on said plate (410) to which it is fixed, and extending substantially vertically towards the ground so as to project below said battery pack (200) by a predetermined spacing (e).;

2. Underbody assembly (1) according to claim 1, characterized in that the protective member (420) of each said multifunction support (400) is in the form of a hollow half-bowl delimited by a lower bottom wall (421) and by a side wall (422) having a U-shaped section matching the internal profile of said plate (410).

3. Underbody assembly (1) according to claim 2, characterized in that the lower bottom wall (421) of the protective member (420) of each said multifunctional support (420) forms a substantially horizontal flat.

4. Underbody assembly (1) according to one of claims 2 or 3, characterized in that the upper end edge of the protective member (420) of each said multifunctional support (400) is fixed along the internal edge of the crossmember (413) and a portion of the internal edges of the lateral legs (412, 412) of the plate (410) of this support (400) by a single weld bead (C).

5. Underbody assembly (1) according to one of claims 1 to 4, characterized in that the protective member (420) of each said support multifunction (400) is made by stamping from a sheet of metal.

6. Underbody assembly (1) according to one of claims 1 to 5, characterized in that said spacing (e) is greater than or equal to 5 millimeters.

7. Underbody assembly (1) according to claim 6, characterized in that said spacing (e) is between 10 and 15 millimeters.

8. Underbody assembly (1) according to one of claims 1 to 7, characterized in that the plate of each said multifunction support (400) comprises means for pre-holding this support (400) on the front end of a said corresponding suspension arm (330) before their definitive fixing together on said body underbody (100), said pre-holding means comprising two curved hooks (418) extending from the external edge of one (412) of said legs (4111, 412) and intended to cooperate with the distal edge of a first lateral end of the transverse yoke (333) of a said corresponding suspension arm (330), and an orifice (419) provided on an internal protrusion of the other (411) of said legs (411, 412) and intended to come to overlap on a respective hole of similar shape and dimensions provided in the second lateral end of this transverse yoke (333),so as to allow the insertion through this orifice and this hole of a pre-retaining pin.,

9. Underbody assembly (1) according to one of claims 1 to 8, characterized in that the plate (410) of each said multifunction support (410) comprises several tabs (414, 415, 416, 417) provided with attachment holes (414A, 414B, 415A, 416A, 416B, 417A) for equipment (3, 4, 5, 6, 7) of said vehicle.

10. Motor vehicle comprising a set of underbody panels (1) according to one of claims 1 to 9.

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