Underbody for an electric or hybrid motor vehicle

Abstract

The invention relates to an underbody for an electric or hybrid motor vehicle, which underbody comprises: side sills (2), a packaging case (3) for an electric battery comprising a first side edge (13) extending laterally as far as the first sill (2), while covering said first sill from below, and a second side edge (14) extending laterally as far as the second sill (2) while covering said second sill from below, a plurality of structural spacers (18) between at least one side face of the packaging case (3) and a substantially vertical face of the side sill (2), and a plurality of structural spacers (18) between at least one side face of the packaging case (3) and a substantially vertical face of the side sill, said side faces of the packaging case including at least a substantially vertical upper zone and a second lower zone inclined at an angle of between 30° and 60° to a longitudinal vertical plane XZ.

Description

[0001] DESCRIPTION

[0002] Underbody of an electric or hybrid motor vehicle

[0003] Technical field

[0004] The present invention relates, in general, to electric or hybrid vehicles and, in particular, to the resistance to lateral impacts of the packaging box of an electric battery housed in the underbody of an electric or hybrid motor vehicle.

[0005] More specifically, the invention relates to an underbody of an electric or hybrid motor vehicle comprising reinforcing pieces positioned between side skirts and an electric battery conditioning box, as well as to a motor vehicle incorporating such an underbody.

[0006] Previous techniques

[0007] In current electric vehicles, electrical energy is stored in battery cells stored in a packaging box itself housed under the floor of the vehicle.

[0008] This packaging box ensures the storage function of the electrochemical cells that form the electric battery, generally by including intermediate packaging called modules. It also contributes to the protection against frontal and lateral impacts of the cells.

[0009] In the event of a side impact, the electric battery must remain attached to the body and the modules that make up the battery must remain intact to avoid a fire risk. Such a side impact is the subject of tests and numerical models generally referred to as a "post impact".

[0010] As is known, the electric battery conditioning box includes transverse beams, called crosspieces, ensuring its stiffness and resisting the forces it undergoes.

[0011] The dimensions of the electric battery conditioning box depend on the size of the electrochemical cells and the position of the side skirts is determined by the desired width of the motor vehicle so that there is a significant clearance between the side skirts and the conditioning box.

[0012] Given the presence of this play, the transmission of forces between the side flaps and the crosspieces is not optimal.

[0013] It is possible to further strengthen the side flaps by adding a reinforcement in the hollow body which constitutes them in order to reduce their deflection.

[0014] However, these reinforcements are expensive and lead to an increase in the weight of the vehicle.

[0015] Statement of the invention

[0016] The present invention therefore aims to overcome the aforementioned drawbacks and to reinforce the protection of the electrochemical cells of an electric battery of an electric or hybrid motor vehicle stored in a conditioning box in the underbody of the vehicle when there is a gap between the conditioning box and the side flaps of the underbody.

[0017] The present invention relates to a base for an electric or hybrid motor vehicle comprising: first and second side skirts each comprising a hollow body delimited by first and second walls, a housing for conditioning an electric battery positioned between the first and second side skirts, the conditioning housing comprising a first lateral edge extending laterally to the first side skirt, covering the latter at least in part from below, and a second lateral edge extending laterally to the second side skirt, covering the latter at least in part from below, a first plurality of structural spacers distributed along the longitudinal direction of the vehicle and positioned transversely between at least one lateral face of the electric battery conditioning housing and a substantially vertical face of the first side skirt,and a second plurality of structural spacers distributed along the longitudinal direction of the vehicle and positioned transversely between at least one lateral face of the electric battery conditioning box and a substantially vertical face of the second lateral flap, said lateral faces of the conditioning box including at least a first substantially vertical upper zone and at least a second lower zone inclined at an angle of between 30° and 60° relative to a longitudinal vertical plane XZ.,

[0018] The assembly formed by the first and second side skirts, the structural spacers and the conditioning box forms a structural continuity which will concentrate the energy absorption and the deformation essentially in the first and second skirts during a side impact, while preserving the integrity of the conditioning box of the electric battery. The electrochemical cells contained in the conditioning box are thus protected during the impact.

[0019] Preferably, the electric battery conditioning box comprises a plurality of transverse beams, each of the structural spacers being positioned opposite one of the transverse beams and arranged on the proper longitudinal axis of said transverse beam.

[0020] In one embodiment, the first and second lateral edges of the packaging box may have a cross-section considered in a transverse vertical plane YZ having the general shape of an L, the first lateral edge comprising a first portion forming a first lateral side of the packaging box and a second portion extending from the first portion to the first lateral flap, at an angle of approximately 90° relative to the first portion, and the second lateral edge comprising a first portion forming a second lateral side of the packaging box and a second portion extending from a first end of the first portion to the second lateral flap, at an angle of approximately 90° relative to the first portion.

[0021] Advantageously, the structural spacers can be made up of hollow bodies, each made from a sheet metal element shaped by stamping and / or folding.

[0022] Preferably, the structural spacers comprise an opening opening onto a cavity of the hollow body, preferably the opening being positioned opposite one of the first and second side flaps. Preferably, the structural spacers comprise a first lateral side positioned opposite one of the first and second side flaps and a second lateral side opposite the first lateral side and positioned opposite the packaging housing, the first lateral side of the structural spacers being wider than the second lateral side.

[0023] Advantageously, the structural spacers may comprise one or more fixing lugs for fixing the structural spacers, the fixing lugs extending a free end on one side of the structural spacers.

[0024] Preferably, the structural struts comprise at least one stamping conformation extending substantially in the transverse direction of the vehicle, in order to stiffen the structural strut in this direction.

[0025] Preferably, the first and second side flaps each comprise a flap reinforcement extending in the longitudinal direction within each flap, the first side edge being attached to the flap reinforcement of the first side flap and the second side edge being attached to the flap reinforcement of the second side flap.

[0026] The invention also relates to an electric or hybrid motor vehicle comprising a base as described above.

[0027] Brief description of the drawings

[0028] The present invention will be better understood and other aims, advantages and characteristics will emerge from the detailed description which follows, comprising embodiments given purely for illustrative purposes and made with reference to the appended drawings, presented as non-limiting examples, which may serve to complete the understanding of the invention and the description of its implementation and, where appropriate, contribute to its definition, in which:

[0029] [Fig 1] represents a base of a hybrid or electric motor vehicle according to one embodiment of the invention.

[0030] [Fig 2] is a top view of the base shown in Figure 1.

[0031] [Fig 3A] is a view of a first side of a reinforcement piece for an underbody of an electric or hybrid motor vehicle according to an embodiment of the invention. [Fig 3B] is a view of a second side of a reinforcement piece for an underbody of an electric or hybrid motor vehicle according to an embodiment of the invention.

[0032] In the remainder of the description, the terms “longitudinal”, “transverse”, “vertical”, “horizontal”, “front”, “rear”,

[0033] "left", "right", "lower", "upper", "under", "on", "above" and "below" are understood in relation to the usual orthogonal reference system for motor vehicles, shown in Figures 1, 2, 3A and 3B, and including:

[0034] - a longitudinal axis X, horizontal and directed from the front to the rear of the vehicle;

[0035] - a transverse axis Y, horizontal, perpendicular to the X axis and directed from the left to the right of the vehicle moving forward;

[0036] - a Z axis, orthogonal to the X and Y axes and vertically directed from bottom to top.

[0037] In the description of the invention which is to be made, the expression "at least one" used must be considered as equivalent to the expression "one or more".

[0038] The term "substantially" means that the indicated direction or value admits a slight deviation from a given nominal direction or value. For example, "substantially vertical" means that a deviation of the order of approximately 10° from a strictly vertical direction is included in the embodiments of the invention.

[0039] Detailed description of at least one embodiment

[0040] Figure 1 illustrates a base 1 for an electric or hybrid motor vehicle.

[0041] The underbody 1 comprises a first side skirt 2 and a second side skirt, not visible in FIG. 1, extending in the longitudinal direction of the vehicle. These skirts are also commonly referred to as "side members". The underbody also comprises an electric battery conditioning box 3. The technical definition of the underbody is symmetrical between the two sides of the vehicle, relative to a longitudinal vertical median plane XZ of the vehicle.

[0042] The first and second side flaps 2 are positioned on either side of the conditioning box 3. Advantageously, the conditioning box 3 is arranged under an upper floor (not shown) of the base 1.

[0043] The electric battery stored in the packaging box 3 can be packaged in the form of modules each incorporating a plurality of electrochemical cells. The packaging box in this case designates the enclosure or protective casing of the battery.

[0044] By sill, we mean in the present invention a structural element, also called a side member, which extends in the longitudinal direction X of the vehicle on each side of the floor and the packaging box 3, in particular below the doors of the vehicle.

[0045] In the illustrated example, each of the first and second right and left side sills 2 defines a hollow body extending along the longitudinal direction X of the vehicle, delimited by first 4 and second walls 5 opposite each other along a transverse axis X of the vehicle. Each wall has a cross-section considered in the section plane YZ which has the general shape of a U or an omega having free ends of the U which extend towards the outside of the U. These free ends of the walls form faces assembled to each other by welding. The free ends of the first wall 4 and the second wall 5 are, preferably, and as illustrated, connected in a substantially vertical plane of the vehicle. The first wall 4 is also called a “body side reinforcement”. The second wall 5 is also called a “sill closing element” by those skilled in the art.

[0046] The second wall 5 of each of the first and second side flaps 2 comprises a substantially vertical portion arranged opposite the packaging box 3, defining the central branch of the U, and two horizontal portions, lower and upper, forming the lateral branches of the U shape.

[0047] In addition, the first and second side skirts 2 preferably each comprise a skirt reinforcement 6, even more preferably arranged in the hollow body. The skirt reinforcement 6 also extends in the longitudinal direction X of the vehicle, inside the hollow body of the skirt 2.

[0048] In the example illustrated, the sill reinforcement 6 has a particularly rigid right-angle shape, comprising first and second portions, respectively 7 and 8. This right-angle shape is considered in cross section along a cutting plane YZ of the vehicle.

[0049] In the illustrated example, the second portion 8 extends from the first portion 7 along an axis substantially equal to 90° relative to the first portion 7.

[0050] Preferably, the first portion 7 of each flap reinforcement 6 extends substantially vertically along the vertical portion of the second wall 5 of one of the first and second lateral flaps 2, and the second portion 8 extends substantially horizontally along the lower horizontal portion of the second wall 5 of one of the first and second lateral flaps 2.

[0051] Referring to Figure 2, the illustrated packaging case 3 comprises first and second opposite lateral sides, respectively 9 and 10, and front and rear opposite sides, respectively 11 and 12.

[0052] The packaging box 3 comprises a first side rim 13 and a second side rim 14.

[0053] In the illustrated example, the first and second side edges 13 and 14 have an L shape.

[0054] The first lateral edge 13 arranged opposite the first flap 2 comprises a first substantially vertical portion formed by the first lateral side 9 of the packaging box 3, and a second substantially horizontal portion 15 extending from the first portion

[0055] 9, preferably at an angle substantially equal to 90°.

[0056] In the illustrated example, the second portion 15 extends from a lower end of the first portion 9 of the first lateral rim 13 of the packaging box 3.

[0057] The second lateral edge 14 arranged opposite the second flap 2 comprises a first substantially vertical portion formed by the first lateral side 10 of the packaging box 3, and a second substantially horizontal portion 16 extending from the first portion

[0058] 10, preferably at an angle substantially equal to 90°.

[0059] The second portion 16 extends from a lower end of the first portion 10 of the second lateral rim 14 of the packaging box 3.

[0060] The second portion 15 of the first lateral edge 13 advantageously extends to the first lateral flap 2, supporting the latter from below. The second portion 16 of the second lateral edge 14 advantageously extends to the second lateral flap, supporting the latter from below.

[0061] Preferably, the first lateral flange 13 is fixed to the first lateral flap 2 and, even more preferably, fixed to the flap reinforcement 6 of the first lateral flap 2 by fixing means 17. This arrangement and this fixing sandwich the second wall 5 of the flap concerned between the flap reinforcement 6 and the first lateral flange 13. The fixing is typically carried out by a series of screws distributed along the flap, each screw cooperating with a corresponding nut crimped or welded onto the structure of the flap.

[0062] Symmetrically, the first lateral edge 14 is preferably fixed to the second lateral flap 2 and, even more preferably, fixed to the flap reinforcement 6 of the second lateral flap 2 by fixing means 17. This arrangement and this fixing sandwich the second wall 5 of the flap concerned between the flap reinforcement 6 and the second lateral edge 14. The fixing is typically carried out by a series of screws distributed along the flap, each screw cooperating with a corresponding nut crimped or welded onto the structure of the flap.

[0063] In the example illustrated, the second portion 15 of the first lateral edge 13 is fixed to the lower horizontal portion of the second wall 5 of the first lateral flap 2, and the second portion 16 of the second lateral edge 14 is fixed to the lower horizontal portion of the second wall 5 of the first lateral flap.

[0064] Furthermore, the base 1 comprises a plurality of structural spacers 18 positioned on each side of the vehicle, on the one hand between the conditioning box 3 and the first side skirt 2, and on the other hand between the conditioning box 3 and the second side skirt. More precisely, a series of structural spacers 18 is distributed along the longitudinal direction X of the vehicle, between the conditioning box 3 and each side skirt 2.

[0065] The assembly formed by the first lateral edge 13 of the conditioning box 3 and the structural spacers 18 positioned between the conditioning box 3 and the first lateral flap 2 is devoid of play between the latter two to achieve structural continuity which will concentrate the absorption of energy and the deformation essentially in the flap during a lateral impact, while preserving the integrity of the conditioning box 3 of the electric battery. The objective is to protect the electrochemical cells during the impact.

[0066] Symmetrically, the assembly formed by the second lateral edge 14 of the packaging box 3 and the structural spacers 18 positioned between the packaging box 3 and the second lateral flap is free of play between the latter two.

[0067] In the example illustrated, the structural spacers 18 are fixed to the second wall 5 of one of the first and second flaps 2. This fixing is typically carried out by welding. In the example illustrated in Figures 1 and 2, a clearance has been provided between the structural spacers and the packaging box 3 to take into account the geometric dispersions of manufacture and to facilitate assembly. This clearance is of the order of 5 to 15 mm, and in particular approximately 10 mm.

[0068] According to an alternative not shown, the structural spacers 18 can be fixed on the conditioning box 3 or both on the conditioning box 3 and on one of the first and second side flaps 2 if other means of compensating for geometric dispersions are provided in the assembly between the conditioning box 3 and each side flap 2.

[0069] Referring to Figures 3A and 3B, the illustrated structural spacers 18 comprise a hollow body formed by a plurality of walls defining a cavity 19 and forming a housing.

[0070] In the illustrated example, the hollow body of the structural spacers 18 comprises a front wall 18a, a rear wall 18b opposite the front wall 18a, a bottom wall 18c and a top wall 18d opposite the bottom wall 18c and a side wall 18e.

[0071] The hollow body represented by the structural spacers 18 further comprises an opening 20 opening onto the cavity 19. The opening 20 is delimited by the free end of the front 18a, rear 18b, lower 18c and upper 18d walls.

[0072] Each structural spacer 18 comprises a first lateral side, corresponding to the opening 20, oriented towards the outside of the vehicle and positioned opposite one of the first and second lateral flaps 2. Each structural spacer 18 comprises a second opposite lateral side, oriented towards the inside of the vehicle and positioned opposite the packaging box 3 formed in the example illustrated by the lateral wall 18e.

[0073] Preferably, the structural struts 18 have a flared portion, the first lateral side of the structural struts 18 being wider than the second lateral side.

[0074] Preferably, the first flared lateral side comprising the opening 20 of each structural spacer 18 is positioned opposite one of the first and second lateral flaps 2.

[0075] In the embodiment of the invention, each structural spacer 18 is made from a piece of sheet metal, shaped by stamping and / or folding. Before its shaping, the starting piece of sheet metal consists of a central strip defining the walls 18c, 18e and 18d juxtaposed one after the other, and two extensions located on either side of the central strip and defining the front 18a and rear 18b walls after shaping of the spacer. The extensions laterally extend the side wall 18e. The names of these walls are assigned according to the final arrangement of the structural spacer 18, as illustrated in Figures 1 and 2.

[0076] The lower wall 18c and the side wall 18e form between them an angle of between 120° and 150°, and typically an angle of approximately 135° (90°+45°) in the illustrated example. The side wall 18e and the upper wall 18d form between them an angle of between 30° and 60°, and more particularly approximately 45°. The side wall 18e is connected to the upper wall by an intermediate flat portion which is substantially vertical in FIG. 1, this flat portion being located opposite the first lateral side 9, 10 respectively of the first or second lateral edge of the packaging box 3. When shaping the structural spacer 18, the extensions are first folded relative to the side wall 18e so as to be substantially opposite one another.Each extension has a central free edge folded towards the outside of the spacer, substantially at a right angle, and thereby forming a fixing lug 23 for fixing the spacer to one or other of the side flaps 2 (Figures 3A, 3B). Each extension also has an upper free edge and a lower free edge folded substantially at a right angle towards the inside of the spacer 18. The upper free edges of the extensions define bearing faces against which the upper wall 18d is folded and fixed, typically by welding. The lower free edges of the extensions define bearing faces against which the lower wall 18c is folded and fixed, typically by welding. The fold line between the side wall 18e and the extensions has notches at its ends allowing folding between the walls of the central strip and the extensions.

[0077] In the example illustrated, the structural spacers 18 comprise stamping conformations 21 making it possible to stiffen the part.

[0078] According to the example illustrated, each structural spacer 18 comprises two stamping conformations 21 on the extensions, that is to say on the front wall 18a and on the rear wall 18b. The stamping conformations 21 are concavities formed on the outer side of the front wall 18a and the rear wall 18b. These concavities have elongated, substantially straight shapes, extending substantially in the transverse direction Y of the vehicle, which corresponds to the direction of a force transmitted by the side skirt during a side impact. The function of these stamping conformations 21 is to stiffen the structural spacers 18 to avoid or limit as much as possible their crushing during a side impact.

[0079] As shown in Figure 3A, the fixing lugs 23 also include stamping conformations in their middle, intended to stiffen the area concerned.

[0080] In alternative embodiments of the invention not shown, the structural spacers 18 may be stamped, molded, forged, extruded parts along extrusion directions parallel to the longitudinal direction X or to the transverse direction Y or to the vertical direction Z of the vehicle, or even be 3D printed parts.

[0081] The structural spacers 18 are interposed on each side of the vehicle, between on the one hand the first or second side flap 2 and on the other hand the packaging box 3. The shape of the structural spacers 18 is complementary to the shape of the first and second side edges 13, 14.

[0082] The first and second lateral edges 13, 14 each comprise a lateral face defining one or more support zones for the structural struts 18 in the event of a lateral impact. A first upper zone is substantially vertical and extends into a second lower zone inclined at an angle of between 30° and 60° relative to a longitudinal vertical plane XZ. In the embodiment illustrated in FIG. 1, the second lower zone of the lateral face is inclined at an angle substantially equal to 45° relative to the plane XZ. The second lower zone delimits a support portion, respectively 24 and 25, positioned in the angle of the L (FIGS. 1 and 2) and intended to reinforce the mechanical strength between the first portion and the second portion of each lateral edge 13, 14. This support portion has, in a cross section YZ, the general shape of a triangle.On each side of the battery, this bracket is arranged in the angle formed between the first portion corresponding to the first lateral side 9, 10 and the second portion 15, 16 of the same lateral edge.

[0083] The support portion 24, 25 is arranged opposite the side wall 18e of the structural struts 18. This support portion is substantially parallel to the side wall 18e of the structural strut 18.

[0084] With reference to Figure 1, each lateral edge 13, 14 consisting of the first portion (first lateral side 9, 10), the second portion 15, 16 and the supporting portion is a single-piece profiled assembly produced from an extrusion die. It comprises internal reinforcing ribs extending in the same longitudinal direction X of the lateral edge.

[0085] It is noted that each lateral edge 13, 14 has a lateral face oriented towards the adjacent lateral flap 2, this lateral face being composed of an upper zone of the first portion (first lateral side 9, 10) extended by an upper face inclined at 45° of the support portion 24.

[0086] The height considered along the vertical direction Z of the first lateral side 9, 10 corresponds substantially to the height of the packaging box 3, by means of lower and upper closing panels of the packaging box 3 of the battery. In the example illustrated in FIG. 1, the lower panel and the upper panel encroach on the first lateral side 9, 10, covering them substantially over their entire width.

[0087] As illustrated in Figures 1 and 2, the base 1 preferably comprises a plurality of structural spacers 18 between the first side skirt 2 and the conditioning box 3, distributed along the longitudinal direction X of the vehicle. Symmetrically, the base comprises a plurality of structural spacers between the second side skirt and the conditioning box 3, distributed along the longitudinal direction X of the vehicle. The structural spacers are generally distributed uniformly, that is to say substantially with the same distance between two consecutive structural spacers. In the example illustrated in Figure 2, the base 1 comprises a series of five structural spacers 18 regularly distributed on either side of the conditioning box 3.

[0088] Advantageously, the conditioning box 3 comprises a plurality of transverse beams 22 each extending inside the volume of the conditioning box 3, along a specific longitudinal axis which extends along the transverse axis Y of the vehicle (figure 2).

[0089] Each of the structural spacers 18 is positioned opposite one of the transverse beams 22 and more precisely arranged on the specific longitudinal axis of the transverse beam.

[0090] The structural struts 18 constrain the side skirts 2 to be deformed and bent during a side impact. These structural struts 18 are not specifically intended to distribute the load along the longitudinal direction of the conditioning box 3 of the electric battery (this function is provided by the skirt). The structural struts 18 are designed to be as rigid as possible and are intended not to be deformed. The stamping conformations 21 on the vertical sides of the structural struts 18 extend along essentially the transverse direction Y of the vehicle, corresponding to the direction of the side impact, which shows that these lateral structural struts 18 are intended to be rigid in this direction.This being the case, when a lateral impact has caused the deformation and / or folding of a side skirt 2, the resulting thrust of one or more structural spacers 18 towards the inside of the vehicle causes the latter to come into contact with the corresponding lateral edge 13, 14 of the conditioning box 3 of the electric battery. The structural spacers 18 arranged in alignment with the transverse beams 22 are then arranged in abutment against the conditioning box 3 to better resist the residual force transmitted by the side skirt 2.

[0091] In the example illustrated in Figure 1, the sill reinforcement 6 and the structural spacers 18 are positioned on either side of the second wall 5 of the first and second side sills 2 which is arranged opposite the packaging box 3.

[0092] The structural spacers 18 and the first and second lateral flanges 13 and 14 define a force path between the lateral flaps 2 and the packaging box 3. This force path makes it possible to concentrate the absorption of energy and the deformation induced in the structure of each lateral flap 2, while preserving the integrity of the packaging box 3.

[0093] The structural spacers 18 ensure structural continuity while being particularly compact, reducing the mass of the vehicle, and freeing up space under the vehicle body, to allow the passage of welding pliers or robots which will apply beads of mastic or even the passage of operators' hands to fix equipment.

[0094] According to an exemplary embodiment, the structural spacers 18 may be made of steel or aluminum.

[0095] In other non-illustrated embodiments of the invention, the structural struts may be attached to the packaging housing, or to the floor.

Claims

CLAIMS 1. Underbody for an electric or hybrid motor vehicle, extending in a longitudinal direction (X) and comprising: first and second side flaps (2) each comprising a hollow body delimited by first and second walls (4, 5); and a packaging box (3) for an electric battery positioned between the first and second side flaps (2), the packaging box (3) comprising: a first lateral edge (13), facing the first side flap (2) and covering the latter at least in part from below and a second lateral edge (14) facing the second side flap (2) and covering the latter at least in part from below; the underbody being characterized in that: - each of the first (13) and second (14) lateral edges of the packaging box (3) comprises: a first portion (9, 10) forming a lateral side of the packaging box (3); a second portion (15, 16) extending from the first portion (9, 10) to the first lateral flap (2), at an angle of approximately 90° relative to the first portion, said second portion at least partially covering the corresponding lateral flap (2) from below; - each of the first (13) and second (14) lateral edges further comprises a triangular supporting portion (24, 25), positioned in the angle between the first (9, 10) and second (15, 16) portions of the corresponding lateral edge; the first (13) and second (14) lateral edges thus respectively forming a first and a second lateral face of the packaging box (3), each of said first and second lateral faces including: a first upper zone, substantially vertical and formed by the first portion (9, 10); and a second lower zone, inclined at an angle of between 30° and 60° relative to a longitudinal vertical plane and formed by the supporting portion (24, 25); and - the base further comprises: a first plurality of structural spacers (18), distributed along the longitudinal direction (X) and positioned transversely between the first lateral face of the packaging box (3) and a substantially vertical face of the first lateral flap (2); and a second plurality of spacers structural (18), distributed along the longitudinal direction (X) and positioned transversely between the second lateral face of the conditioning box (3) of the electric battery and a substantially vertical face of the second lateral flap.

2. Base according to claim 1, in which the packaging box (3) of the electric battery comprises a plurality of transverse beams (22), each of the structural spacers (18) being positioned opposite one of the transverse beams (22) and arranged on the proper longitudinal axis of said transverse beam (22).

3. Base according to claim 1 or 2, in which the structural spacers (18) consist of hollow bodies each derived from a sheet metal element shaped by stamping and / or folding.

4. Base according to claim 3, in which the structural spacers (18) comprise an opening (20) opening onto a cavity (19) of the hollow body, preferably the opening (20) being positioned opposite one of the first and second side flaps (2).

5. Base according to any one of the preceding claims, in which the structural spacers (18) comprise a first lateral side positioned opposite one of the first and second lateral flaps (2) and a second lateral side opposite the first lateral side and positioned opposite the packaging box (3), the first lateral side of the structural spacers (18) being wider than the second lateral side.

6. A base according to any preceding claim, wherein the structural struts (18) comprise one or more fixing lugs (23) for fixing the structural struts (18), the fixing lugs (23) extending a free end on one side of the structural struts (18).

7. Underbody according to any one of the preceding claims, in which the structural spacers (18) comprise at least one stamping conformation (21) extending substantially in the transverse direction (Y) of the vehicle, in order to stiffen the structural spacer (18) in this direction.

8. Base according to any one of the preceding claims, in which the first and second side flaps (2) each comprise a flap reinforcement (6) extending along the longitudinal direction (X) inside each sill, the first lateral edge (13) being fixed to the sill reinforcement (6) of the first lateral sill (13) and the second lateral edge (14) being fixed to the sill reinforcement (6) of the second lateral sill.

9. Electric or hybrid motor vehicle comprising a base (1) according to any one of the preceding claims.