Longitudinal member with programmed deformation kinematics, for a vehicle

Abstract

A longitudinal member (LV) is installed parallel to a longitudinal side (CL) of a floor (PV) of a structure (SV) of a motor vehicle (VA), and comprises a profile (PL) having longitudinal internal walls and delimiting longitudinal internal boxes (C11-C32) and an inner edge (BI) participating in the delimitation of two first upper (C11) and lower (C12) internal boxes separated by a first intermediate internal box (C13) having a cross section in the general shape of a convex pentagon pointing initially towards an outer edge (BE) and capable, in the event of forces absorbed during an impact by the latter, to deform into a concave pentagon pointing towards the inner edge (BI) in order to allow a rotation of the profile (PL) about a longitudinal axis that causes a majority transfer of the forces towards the floor (PV).

Description

DESCRIPTION TITLE: SPAR WITH DEFORMATION KINEMATICS PROGRAMMED, FOR A VEHICLE Technical field of the invention

[0001] The present invention claims priority from French application 2209962 filed on September 30, 2022, the content of which (text, drawings and claims) is incorporated herein by reference. The invention relates to motor vehicles comprising a structure comprising a floor having two opposite longitudinal sides, and more precisely the side members which frame these two opposite longitudinal sides. State of the art

[0002] Some motor vehicles comprise a structure comprising a floor having right and left longitudinal sides and two side members, right and left, installed respectively parallel to these right and left longitudinal sides. It should be noted that the floor may optionally be associated with at least one cross member (for example in the area located under the rear seat in the case of a car).

[0003] The vehicles (automobiles) presented above must be capable of protecting their passengers when they suffer a side impact on one of their right and left longitudinal sides. Here, "side impact" means an impact in a direction with a non-zero transverse component. This requires that their structure has a very high stiffness, and all the greater the heavier the vehicle is and the more this side impact results from a collision with an object of small longitudinal extension, such as a pole. It should be noted that when the vehicle has a powertrain (or GMP) of the all-electric or hybrid (thermal and electric) type, it includes a set (or "pack") of rechargeable batteries which can be installed between its side rails, under its floor and generally under at least one cross member, and must also be protected in the event of a side impact.

[0004] Since the side rails and cross member(s) must contribute to the aforementioned stiffness, they must absorb as much as possible of the energy of a side impact. However, in most vehicles, we seek to limit their drag and therefore their height as much as possible, which requires limiting the height of their side rails. It should be noted that in the presence of a rechargeable battery pack, the aforementioned constraint also imposes a limitation on the height of the latter. Consequently, if we want the mileage range not to be reduced, we are forced to increase the width of the rechargeable battery pack and therefore reduce the width of the side rails, even though the latter must also protect the rechargeable battery pack.

[0005] Ideally, the protection provided by a side member requires that it absorbs a certain level of energy (or force), controls the distribution and level of forces transferred to neighboring elements and allows for limitation of deformations in a predefined zone. To this end, current side members comprise an envelope made up of two metal half-shells fixedly secured to each other and housing a profile comprising longitudinal internal walls and delimiting longitudinal internal boxes which are supposed to absorb the energy of a lateral impact by deforming. However, this deformation is not currently well controlled, and therefore the transfers of forces during and after deformation are not well controlled and often too high, which can cause damage to the floor and / or the possible rechargeable battery assembly.

[0006] The invention therefore aims in particular to improve the situation to increase the passive protection of passengers, as well as a possible rechargeable battery assembly, in the event of a side impact. Presentation of the invention

[0007] For this purpose, it proposes in particular a side member, on the one hand, suitable for being installed parallel to a longitudinal side of a floor of a structure of a motor vehicle, and, on the other hand, comprising a profile comprising longitudinal internal walls and delimiting longitudinal internal boxes.

[0008] This spar is characterized by the fact that its profile comprises an inner edge participating in the delimitation of two first upper and lower internal boxes separated by a first intermediate internal box having a cross-section in the general shape of a convex pentagon initially pointing towards an outer edge, opposite the inner edge, and capable, in the event of forces absorbed during an impact by the outer edge, of deforming into a concave pentagon pointing towards the inner edge in order to allow rotation of the profile around a longitudinal axis inducing a majority transfer of these forces towards the floor.

[0009] The side member thus offers a programmed, very progressive deformation kinematics, which allows a substantially predefined distribution of the forces transferred to the floor, which makes it possible to avoid, and in any case at least minimize, the damage caused by a side impact.

[0010] The spar according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0011] - the outer edge may participate in the delimitation of two second upper and lower internal boxes superimposed on one another and separated respectively from the first upper and lower internal boxes by third upper and lower internal boxes. In this case, this third lower internal box may share with the second lower internal box a vertical internal wall, and this third upper internal box may share with the second upper internal box an internal wall inclined towards the inner edge so as to promote rotation of the profile around the longitudinal axis;

[0012] - in the presence of the first option, the third upper internal box can share with the first intermediate internal box a first internal wall inclined towards the inner edge, and the third lower internal box can share with the first intermediate internal box a second internal wall inclined towards the inner edge, these first and second inclined internal walls defining the part of the convex pentagon initially pointing towards the outer edge;

[0013] - also in the presence of the first option, the second upper and lower internal boxes may share a horizontal internal wall. In this case, the third upper and lower internal boxes may share another horizontal internal wall that extends the horizontal internal wall (mentioned in the previous paragraph) to an interface between the first and second inclined internal walls, in order to participate in the deformation of the pentagon from convex to concave;

[0014] - also in the presence of the first option, the third upper internal box can share with the first upper internal box a vertical internal wall, and the third lower internal box can share with the first lower internal box a vertical internal wall;

[0015] - its profile may comprise, on the one hand, an upper edge connecting the outer and inner edges and comprising a first part extending upwards the outer edge while being inclined towards the inner edge, and, on the other hand, a lower edge connecting the outer and inner edges and comprising a first part extending downwards the outer edge while being inclined towards the inner edge opposite to the inclination of the first part of the upper edge;

[0016] - the internal walls and / or the inner, outer, upper and lower edges may have a chosen thickness distribution;

[0017] - the internal walls and / or the inner, outer, upper and lower edges may have a thickness between 1.5 mm and 8 mm.

[0018] The invention also provides a motor vehicle comprising a structure comprising a floor having right and left longitudinal sides and two side members, right and left, of the type presented above and installed respectively parallel to the right and left longitudinal sides.

[0019] For example, this motor vehicle may also include a rechargeable battery pack installed under the floor between the right and left side rails. Brief description of the figures

[0020] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawings (obtained in CAD / CAM (“Computer Aided Design / Computer Aided Drawing”)), in which:

[0021] [Fig. 1] schematically and functionally illustrates, in a sectional view in a transverse and vertical plane, a part of an example of a motor vehicle structure comprising an example of an embodiment of a side member according to the invention,

[0022] [Fig. 2] schematically and functionally illustrates, in a sectional view in a transverse and vertical plane, the profile of the spar of figure 1, with a materialization of a chosen thickness distribution of its partitions and its edges, and

[0023] [Fig. 3] illustrates schematically and functionally, in a transverse and vertical plane, the temporal evolution (at four successive instants) of the profile of the spar of figures 1 and 2 during a lateral impact suffered by this spar. Detailed description of the invention

[0024] The invention aims in particular to propose a LV side member intended to form part of an SV structure of a VA motor vehicle and offering programmed deformation kinematics.

[0025] In the following, it is considered, by way of non-limiting example, that the motor vehicle VA is a car. But the invention is not limited to this type of motor vehicle. It in fact concerns any motor vehicle comprising a structure comprising a floor (incorporating possible crossmember(s)) framed by two side members.

[0026] In Figures 1 to 3, the X direction is the longitudinal direction of the vehicle (automobile) VA, which is substantially parallel to the lateral (or longitudinal) sides comprising the side doors, the Y direction is the transverse direction of the vehicle VA, which is perpendicular to the longitudinal direction X, and the Z direction is the vertical direction of the vehicle VA, which is perpendicular to the longitudinal X and transverse Y directions.

[0027] Figure 1 schematically illustrates part of an example of an SV structure of a (motor) vehicle VA, comprising an example of an embodiment of an LV side member according to the invention. Although this only appears partially in Figure 1 (only for the right side), the SV structure comprises in particular a PV floor having right and left longitudinal sides CL, and two right and left LV side members, installed respectively parallel to the right and left longitudinal sides CL.

[0028] It will be noted that in the example illustrated non-limitingly in Figure 1, the VA vehicle also comprises a rechargeable battery assembly EB installed under the PV floor between the right and left side members LV. But this is not obligatory, because the invention also applies when the VA vehicle is without a rechargeable battery assembly EB.

[0029] As illustrated at least partially in Figures 1 and 2, a spar LV, according to the invention, comprises a profile PL comprising internal walls PI1 to RH O longitudinal (and therefore extending in the longitudinal direction X) and delimiting internal boxes C11 to C32 longitudinal. It will be noted that in the example illustrated non-limitingly in figure 1 the spar LV also includes an envelope EL consisting of two metal half-shells fixedly secured to each other and housing the profile PL.

[0030] For example, the two metal half-shells of the EL enclosure can be made of steel or aluminum. Also, for example, the PL profile can be made of aluminum. But it could also be made of steel.

[0031] As illustrated, the profile PL comprises an inner edge Bl, intended to be oriented towards the floor PV and the possible rechargeable battery assembly EB, an outer edge BE, opposite the inner edge Bl and therefore intended to be oriented towards the exterior of the vehicle VA, an upper edge BS, connecting the outer edges BE and inner Bl, and a lower edge BF, connecting the outer edges BE and inner Bl but opposite the upper edge BS.

[0032] The inner edge Bl participates in the delimitation of two first internal upper C11 and lower C12 boxes and of a first intermediate internal C13 box separating these first internal upper C11 and lower C12 boxes.

[0033] The first intermediate internal box C13 has a cross-section (in the YZ plane) in the general shape of a convex pentagon which initially points towards the outer edge BE. This particular pointed shape is suitable, in the event of forces absorbed during an impact by the outer edge BE, to deform into a concave pentagon pointing towards the inner edge Bl (arrow F1 in Figure 3). This very advantageously allows a rotation R of the profile PL around a longitudinal axis AL which induces a majority transfer of the forces towards the floor PV. It will be understood in fact, as illustrated in Figure 3, that the particular deformation of the pentagon (of the first intermediate internal box C13), by sinking its point, allows a very progressive deformation of the PL profile with maximum crushing which promotes the rotation of at least part of the deformed PL profile, and at least of its “upper part” in the direction of the PV floor.

[0034] In other words, the LV spar, and more precisely its PL profile, offers a programmed, very progressive deformation kinematics, which allows a substantially predefined distribution of the forces which are transferred to the PV floor and to the possible rechargeable battery assembly EB (the majority of the forces going to the PV floor to protect, here, the rechargeable battery assembly EB). This makes it possible to avoid, and in any case to at least minimize, the damage caused by a lateral impact on an LV spar.

[0035] For example, and as illustrated non-limitingly in Figures 1 and 2, the outer edge BE can participate in the delimitation of two second upper internal boxes C21 and lower C22 which are superimposed one above the other. The second upper internal box C21 is separated from the first upper internal box C11 by a third upper internal box C31, and the second lower internal box C22 is separated from the first lower internal box C12 by a third lower internal box C32. In this case, the third lower internal box C32 can share with the second lower internal box C22 a vertical internal wall PI6 and the third upper internal box C31 can share with the second upper internal box C21 an internal wall PI5 which is inclined towards the inner edge Bl so as to promote the rotation R of the profile PL around the longitudinal axis AL (see Figure 3).It will be understood in fact, as illustrated in figure 3, that this inclination of the internal wall PI5 favors its verticalization during the progressive deformation of the profile PL, while at the same time the verticality of the internal wall PI6 favors an upward depression of the lower edge BF (arrow F2). This depression causes a substantially vertical thrust which, combined with the substantially horizontal force resulting from. the deformation substantially along the transverse direction Y towards the inner edge Bl in the upper part of the profile PL, induces a moment of force which causes the rotation R around the longitudinal axis AL (see figure 3).

[0036] Also for example, and as illustrated non-limitingly in Figures 1 and 2, the third upper internal box C31 can share with the first intermediate internal box C13 a first internal wall PI1 which is inclined towards the inner edge Bl, and the third lower internal box C32 can share with the first intermediate internal box C13 a second internal wall PI2 which is inclined towards the inner edge Bl, but with an angle of sign opposite to that of the first internal wall PI1 but necessarily of the same absolute value. In this case, the first PI1 and second PI2 inclined internal walls define the pointed part of the convex pentagon which initially points towards the outer edge BE.

[0037] It should be noted that the lengths of the first PI1 and second PI2 inclined internal walls are not necessarily identical (this is particularly the case in the example illustrated non-limitingly in figure 2).

[0038] Also for example, and as illustrated non-limitingly in Figures 1 and 2, the second upper C21 and lower C22 internal boxes may share an internal wall PI7 which is horizontal. In this case, the third upper C31 and lower C32 internal boxes may share another internal wall PI8 which is also horizontal and extends the horizontal internal wall PI7 to an interface between the first PI1 and second PI2 inclined internal walls. Thus, there is a long horizontal internal wall (defined by PI7 and PI8) which participates in the deformation of the pentagon from convex to concave.

[0039] It will be understood that the horizontality of this long internal wall (PI7 + PI8) makes it possible to transfer the forces of the shock to the tip (defined by the first PI1 and second PI2 internal walls), and thus pushing this point very gradually towards the inner edge Bl, as a kind of “harpoon” would do.

[0040] Also for example, and as illustrated non-limitingly in Figures 1 and 2, the third upper internal box C31 can share with the first upper internal box C11 a vertical internal wall PI9, and the third lower internal box C32 can share with the first lower internal box C12 a vertical internal wall RH0. This verticality of the internal walls PI9 and PI10 promotes the upward thrust (arrow F2), because this thrust is carried out substantially at the level of the internal wall RH0, and therefore this promotes the rotational drive R around the longitudinal axis AL (see Figure 3).

[0041] Also for example, and as illustrated non-limitingly in Figures 1 and 2, the upper edge BS may comprise a first part which extends upwards the outer edge BE while being inclined towards the inner edge Bl, and the lower edge BF may comprise a first part which extends downwards the outer edge BE while being inclined towards the inner edge Bl in a manner opposite (but not necessarily equal in absolute value) to the inclination of the first part of the upper edge BS. This makes it possible to promote the start of the programmed deformation kinematics.

[0042] Also for example, and as illustrated non-limitingly in Figures 1 and 2, the first upper internal boxes C11 and intermediate C13 can share a horizontal internal wall PI3, and the first lower internal boxes C12 and intermediate C13 can share a horizontal internal wall PI4.

[0043] Also for example, and as can be seen in Figure 2, the inner walls PI1 to PI10 and / or the inner edges Bl, outer BE, upper BS and lower BF may have a chosen thickness distribution. In other words, the inner walls PI1 to PI10 may have thicknesses that vary from one to the other, and / or the inner edges Bl, outer BE, upper BS and lower BF may have thicknesses that vary from one to the other. It is even possible to have portions of the same edge (Bl or BE or BS or BF) whose thicknesses are different from each other. This distribution of thicknesses is intended to promote the maximum and very progressive deformation of the PL profile with a rotation around the longitudinal axis AL.

[0044] Also for example, the internal walls PI1 to P110 and / or the inner edges Bl, outer BE, upper BS and lower BF may have a thickness between 1.5 mm and 8 mm. Preferably, their thicknesses may be between 2 mm and 7 mm. This option is notably compatible with the thickness distribution described in the previous paragraph.

Claims

CLAIMS

1. Side member (LV) suitable for being installed parallel to a longitudinal side (CL) of a floor (PV) of a structure (SV) of a motor vehicle (VA), said side member (LV) comprising a profile (PL) having longitudinal internal walls (PI1-PI10) and delimiting longitudinal internal boxes (C11-C32), characterized in that said profile (PL) comprises an inner edge (Bl) participating in the delimitation of two first upper (C11) and lower (C12) internal boxes separated by a first intermediate internal box (C13) having a cross section in the general shape of a convex pentagon initially pointing towards an outer edge (BE), opposite said inner edge (Bl), and clean, in the event of forces absorbed during an impact by said outer edge (BE),to deform into a concave pentagon pointing towards said inner edge (Bl) in order to allow rotation of said profile (PL) around a longitudinal axis inducing a majority transfer of said forces towards said floor (PV).,

2. A side member according to claim 1, characterized in that said outer edge (BE) participates in the delimitation of two second upper (C21) and lower (C22) internal boxes superimposed one above the other and separated respectively from said first upper (C11) and lower (C12) internal boxes by third upper (C31) and lower (C32) internal boxes, said third lower internal box (C32) sharing with said second lower internal box (C22) a vertical internal wall (PI6) and said third upper internal box (C31) sharing with said second upper internal box (C21) an internal wall (PI5) inclined towards said inner edge (Bl) so as to promote said rotation of the profile (PL) around said longitudinal axis.

3. A spar according to claim 2, characterized in that said third upper internal box (C31) shares with said first intermediate internal box (C13) a first internal wall (PI1) inclined towards said inner edge (Bl), and said third lower internal box (C32) shares with said first intermediate internal box (C13) a second internal wall (PI2) inclined towards said inner edge (Bl), these first (PI1) and second (PI2) inclined internal walls defining the part of said convex pentagon initially pointing towards said outer edge (BE).

4. A spar according to claim 2 or 3, characterized in that said second upper (C21) and lower (C22) internal boxes share a horizontal internal wall (PI7), and said third upper (C31) and lower (C32) internal boxes share another horizontal internal wall (PI8) which extends said horizontal internal wall (PI7) to an interface between said first (PI1) and second (PI2) inclined internal walls, in order to participate in said deformation of the pentagon from convex to concave.

5. Longeron according to one of claims 2 to 4, characterized in that said third upper internal box (C31) shares with said first upper internal box (C11) a vertical internal wall (PI9), and said third lower internal box (C32) shares with said first lower internal box (C12) a vertical internal wall (PH 0).

6. A spar according to one of claims 1 to 5, characterized in that said profile (PL) comprises i) an upper edge (BS) connecting said outer (BE) and inner (Bl) edges and comprising a first part extending said outer edge (BE) upwards while being inclined towards said inner edge (Bl), and ii) a lower edge (BF) connecting said outer (BE) and inner (Bl) edges and comprising a first part extending said outer edge (BE) downwards while being inclined towards said inner edge (Bl) opposite to the inclination of the first part of said upper edge (BS).

7. Longeron according to one of claims 1 to 5 taken in combination with claim 6, characterized in that said internal walls (PH -PH 0) and / or said inner (Bl), outer (BE), upper (BS) and lower (BF) edges have a chosen thickness distribution.

8. Longeron according to one of claims 1 to 5 taken in combination with claim 6 or 7, characterized in that said internal walls (Pim) and / or said inner (Bl), outer (BE), upper (BS) and lower (BF) edges have a thickness of between 1.5 mm and 8 mm.

9. Motor vehicle (VA) comprising a structure (SV) comprising a floor (PV) having right and left longitudinal sides, characterized in that said structure (SV) further comprises two side members (LV), right and left, according to one of the preceding claims, installed respectively parallel to said right and left longitudinal sides (CL).

10. Vehicle according to claim 9, characterized in that it comprises a rechargeable battery assembly (EB) installed under said floor (PV) between said right and left side members (LV).

Images