Side member for motor vehicle

Abstract

The invention relates to a side member (1) for a motor vehicle, the side member (1) comprising a first wall (11) and a second wall (12) located opposite the first wall (11), the first wall (11) and the second wall (12) extending along an axis of proper elongation (O1) and providing between them a cavity within which are arranged: - a central web (13) bearing against the first wall (11) and extending in projection from the first wall (11) and in the direction of the second wall (12), the central web (13) extending in the cavity along the axis of proper elongation (O1); - a plurality of first cells (14) extending in the cavity between the first wall (11) and the second wall (12) and on a first side of the central web (13);- a plurality of second cells (15) extending in the cavity between the first wall (11) and the second wall (12) and on a second side of the central core (13) opposite to the first side with respect to the central core (13). Figure to be published with the abbreviation: Fig. 1;

Description

Title of the invention: Side member for motor vehicle

[0001] The technical context of the present invention is that of the structural elements of motor vehicles, and in particular of electrified motor vehicles, and more generally the problem of absorbing a lateral impact for such motor vehicles. More specifically, the invention relates to a side member fitted to a motor vehicle.

[0002] In the prior art, the use of side members extending along one lateral edge of a motor vehicle is known. The side members are part of the vehicle's underbody structure, which includes the front floor. The side members are then connected to each other by means of cross members extending transversely between the two side members. This underbody structure thus supports, in particular, the front floor of the motor vehicle.

[0003] Such structures are known in particular through documents FR3117987 Al and EP3209537 B1 which each describe particular architectures for such lateral stringers.

[0004] In the case of an electrified motor vehicle, the presence of a traction battery located under the floor—and therefore between the side members—leads to increased safety and behavior requirements, particularly in the event of a side impact. Indeed, the presence of the traction battery between the side members requires that these members exhibit greater resistance in the event of a side impact, in order to prevent any intrusion, perforation, or damage to the traction battery, which would lead to an increased risk of fire and considerable damage.

[0005] The present invention aims to propose a new spar in order to address at least largely the previous problems and to lead to other advantages.

[0006] Another object of the invention is to reinforce the rigidity of such a longeron in the event of a lateral impact.

[0007] Another objective of the invention is to reduce the manufacturing costs of such a longeron.

[0008] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a side member for a motor vehicle, the side member comprising a first wall and a second wall located opposite the first wall, the first wall and the second wall extending along their own axis of elongation and providing between them a cavity within which are arranged:

[0009] - a central core supported against the first wall and extending in projection from the first wall and towards the second wall, the central core extending into the cavity along the axis of proper elongation;

[0010] - a plurality of first cells extending into the cavity between the first wall and the second wall and on one side of the central core;

[0011] - a plurality of second cells extending into the cavity between the first wall and the second wall and a second side of the central core opposite to the first side with respect to the central core.

[0012] In the context of the present invention, a longitudinal axis, a lateral axis, and a vertical axis are defined with respect to the motor vehicle on which the side member conforming to the first aspect of the invention is intended to be mounted. More particularly, the transverse axis is understood as a direction taken between one lateral side of the motor vehicle and an opposite lateral side of said motor vehicle. In other words, the transverse axis is understood as a direction extending from a passenger side of the motor vehicle to a driver's side of said motor vehicle, or vice versa. The adjectives lateral, inside, and outside refer to such a transverse axis. Furthermore, the longitudinal axis is understood as being taken along a direction extending from front to rear or from rear to front of the motor vehicle. The longitudinal axis is perpendicular to the transverse axis. The adjectives front, front, and rear refer to this longitudinal axis.Finally, the vertical axis is understood as being taken along an axis extending from the wheels of the motor vehicle towards the roof of said motor vehicle, or vice versa, the vertical axis being simultaneously perpendicular to the transverse axis and the longitudinal axis. The adjectives above and below, or lower and upper, refer to this vertical axis.

[0013] In addition, a proper elongation axis is also defined in the frame of reference of the side member, the proper elongation axis being defined by the principal elongation direction of the side member, defined in particular by the principal elongation direction of the cavity, the central web, and the first and second walls, that is to say, the direction along which the first and second cells are arranged in the cavity. In the context of integrating the side member into the motor vehicle, the proper elongation axis of said side member coincides or is substantially coincident with the longitudinal axis.

[0014] In the context of the present invention, a side member is, for example, a lateral side member or a crossmember that forms a prismatic span extending respectively along the longitudinal axis of the motor vehicle. The side members extend at each lateral edge of said motor vehicle. The side members form structural elements of the vehicle. Side members are components of the vehicle to which other parts of the motor vehicle are attached. These side members provide the rigidity necessary for the vehicle's operation, both during driving and in the event of an accident, by transmitting the resulting forces to shock absorbers or the vehicle's suspension components, for example. Side members are generally made of steel profiles, which contribute to the body structure's robustness.

[0015] In the context of the present invention, the first wall and the second wall form lateral walls for the longeron. The first wall and the second wall delimit the longeron and the cavity between them. The first wall and the second wall extend predominantly along the natural elongation axis of the longeron and along the vertical axis. The first wall and the second wall have an upper rebate and a lower rebate that form the edges of attachment of the first wall to the second wall. From this lower and upper rebate, the first and second walls each have concave shapes so as to be located at a distance from each other and thus delimit the cavity. The first and second walls are formed of stamped sheets and fixed rigidly to each other at their upper and lower rebates, preferably by welding.

[0016] In the context of the present invention, the central web forms a wall that extends across the cavity and along the natural elongation axis of the spar. The central web delimits the space inside the cavity and facilitates the integration of the first and second cells into the cavity. Advantageously, the central web defines a median plane between the first and second walls of the spar. In particular, the central web is located midway or substantially midway between the lower and upper rebates of the first and second walls of the spar according to the invention. Finally, the central web reinforces the mechanical strength of the spar, in conjunction with the first and second cells.

[0017] In the context of the present invention, the first and second cells form stiffening profiles that extend into the cavity. According to the invention, a plurality of such stiffeners are arranged within the cavity to enhance the mechanical behavior and rigidity of the spar, as described in the first aspect of the invention. The first and second cells form small sub-volumes within the cavity, juxtaposed with one another. The first and second cells thus enhance the rigidity of the spar while limiting the mass added by their insertion between the first and second walls of the spar. According to the invention, the central web divides the cavity into Two volumes are constructed within which the first and second cells are respectively placed. The first cells are located exclusively on one side of the central core, while the second cells are located exclusively on the other side. This advantageous configuration allows for two cell tiers within the cavity, thus enhancing its mechanical performance.

[0018] Thus, the invention proposes a structural element – ​​the side member – offering enhanced protection in the event of a side impact, and in particular in the event of a "pole impact" type side impact, thanks to the specific geometry of said side member and the presence of the first and second cells in the cavity. Indeed, the first and second cells, by virtue of their box-shaped geometry distributed within the cavity, allow for more effective absorption of impacts at the level of the side member according to the invention.

[0019] The invention thus solves the technical problem by enabling the manufacture of such a spar more economically and using a simplified and easy-to-implement manufacturing process. Furthermore, the specific geometry of the cells limits the added weight resulting from the insertion of the cells into the cavity between the first and second walls of the spar.

[0020] The invention is of very relevant interest when integrated into an electrified motor vehicle, although the invention is not limiting to this type of use.

[0021] The longeron conforming to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0022] - the central web is connected to the first wall of the spar. In particular, the web central is brought against the first wall and fixed to the first wall by a plurality of weld points or by a weld bead;

[0023] - the central core comprises a flap bearing against the first wall and a rebate an interlayer that extends between the first and second cells. The flap forms a rebate for support and fixing against the first wall of the spar. Thus, the central web is fixed securely to the first wall by means of its flap. The interlayer rebate extends across the cavity so as to divide the cavity into two distinct and equal or substantially equal volumes;

[0024] - the flap and / or the intermediate rebate of the central core are formed from a wall solid. In other words, the flap and / or the interleaf are free of holes and / or perforations. This advantageous configuration allows for a more rigid central core;

[0025] - the intermediate rebate of the central core extends perpendicularly or substantially perpendicular to the first wall. Relative to the vertical axis, the intermediate rebate of the central core extends between the first wall and the second wall so as to divide the cavity into two equal or substantially equal volumes;

[0026] - the central core is formed from a stamped sheet metal. This advantageous configuration This simplifies production and reduces associated manufacturing costs. The sheet metal forming the central web is a type of metal sheet. Preferably, the sheet metal forming the central web is made of a material containing steel or a steel alloy. This advantageous configuration thus provides high rigidity while reducing production costs, particularly material procurement costs.

[0027] - the first cells and the second cells are oriented between the first wall and the second wall. In other words, the first and second cells have lateral openings that face the first and second walls. This advantageous configuration provides rigidity to the spar in a direction perpendicular to the spar's natural elongation axis;

[0028] - the first cells are all adjacent to each other along the axis of proper elongation. Similarly, the second cells are all adjacent to each other along the axis of proper elongation. The first and second cells extend between two axial ends of the spar, relative to the axis of proper elongation;

[0029] - the first cells and the second cells are all identical in shape and in dimensions;

[0030] - the first cells and the second cells are arranged in a staggered pattern. This This advantageous configuration thus makes it possible to increase the density of cells along the natural elongation axis of the spar, and thus to reinforce the rigidity of said spar;

[0031] - the first cells and / or the second cells are formed from a sheet Stamped. This advantageous configuration simplifies production and reduces associated manufacturing costs. The sheet metal forming the first and / or second cells is of the metal sheet type. Preferably, the sheet metal forming the first and / or second cells is made of a material containing steel or a steel alloy. This advantageous configuration thus provides high rigidity while reducing production costs, particularly material procurement costs;

[0032] - according to a first embodiment, the first cells are formed by a first accordion-like partition located on one side of the central core, the first partition extending into the cavity along the axis of proper elongation; and the second cells are formed by a second accordion-like partition located On a second side of the central core, opposite the first side, the second partition extends into the cavity along its natural elongation axis. This advantageous configuration simplifies the integration of the cells into the cavity: the first cells are—all or in part—linked together by a single stamped sheet forming said first cells; and the second cells are—all or in part—linked together by a single stamped sheet forming said second cells. Furthermore, the fixing of the first and second cells within the cavity is simplified.

[0033] - in the first embodiment, the first accordion partition and the The second accordion-like partition consists of a sheet metal shaped to delimit a plurality of compartments extending between the first and second walls, the compartments all being adjacent to each other along their own axis of elongation. Thus, the first and second cells here form compartments. The compartments forming the first cells are linked together by the stamped sheet metal that forms them, according to a general crenellated pattern, for example; similarly, the compartments forming the second cells are linked together by the stamped sheet metal that forms them, according to a general crenellated pattern, for example;

[0034] - in the first embodiment, the boxes of the first partition in The accordion-style compartments and the boxes of the second accordion-style partition are all identical in shape and dimensions. This advantageous configuration simplifies the integration of the cells into the cavity and allows for particularly interesting arrangements within the cavity;

[0035] - in particular, in the first embodiment, the boxes of the first The accordion partition and the boxes of the second accordion partition are arranged in a staggered pattern. This advantageous configuration thus makes it possible to increase the density of the boxes forming the first and second cells along the axis of natural elongation of the longeron, and thus to reinforce the rigidity of said longeron;

[0036] - in the first embodiment, the sheet metal forming the boxes of the first The accordion-style partition and the boxes of the second accordion-style partition have a plurality of perforations. Each perforation forms a through opening—for example, a circular one—in the sheet metal. This advantageous configuration makes it possible to lighten the spar conforming to the first aspect of the invention. The perforations are preferably located on the parts of the sheet metal and the boxes facing the upper or lower rebate of the first and second walls of the spar. Optionally, alternatively, or additionally, the perforations are located on the parts of the sheet metal delimiting two adjacent boxes;

[0037] - in the first embodiment, the first accordion partition is fixed securely attached to the central web, and in particular to the intermediate rebate of the central web. Preferably, the first accordion partition is securely attached to the central web by means of a plurality of weld points distributed along the axis of its own elongation or by means of a weld bead;

[0038] - in the first embodiment, the first accordion partition and / or the The second accordion partition is formed from a stamped sheet metal panel. This advantageous configuration simplifies production and reduces associated manufacturing costs. The sheet metal forming the first and / or second accordion partition is a metal sheet. Preferably, the sheet metal forming the first and / or second accordion partition is made of a material containing steel or a steel alloy. This advantageous configuration thus provides high rigidity while reducing production costs, particularly material procurement costs.

[0039] - according to a second embodiment, the first cells comprise several segments, each comprising a plurality of adjacent first cells, the segments being butted together in the cavity of the longeron, relative to the longitudinal axis. Similarly, in this second embodiment, the second cells comprise several segments, each comprising a plurality of adjacent second cells, the segments being butted together in the cavity of the longeron, relative to the longitudinal axis. This advantageous configuration facilitates the integration of the different segments into the cavity. Each segment thus forms an independent module which must then be interconnected and linked to the other modules and to the walls of the longeron according to the invention;

[0040] - according to a third embodiment, the first cells comprise a pluralities of first cells, all independent of each other and placed in the cavity, adjacent to each other with respect to the longitudinal axis. Similarly, in this third embodiment, the second cells comprise a plurality of second cells, all independent of each other and placed in the cavity, adjacent to each other with respect to the longitudinal axis. This advantageous configuration facilitates the integration of the different cells into the cavity. Each introduced cell is then interconnected and bonded to the other cells and to the walls of the spar according to the invention;

[0041] - in either of the aforementioned embodiments, the The longeron includes an upper reinforcement that extends transversely between the first wall and the second wall, the upper reinforcement extending into the following cavity the axis of natural elongation. In the first embodiment, the first accordion-like partition rests against the upper reinforcement. The upper reinforcement forms a mechanical reinforcement element housed in the cavity of the longeron. This advantageous configuration makes it possible to reinforce the longeron according to the first aspect of the invention;

[0042] - the upper reinforcement is connected to the first wall. In particular, the upper reinforcement It comprises an upper reverse side resting against the first wall, and an upper panel extending from the upper reverse side and across the cavity. The upper reverse side forms a flap relative to the upper panel. The upper panel extends from the upper reverse side and perpendicularly or substantially perpendicularly to the upper reverse side;

[0043] - the upper panel of the upper reinforcement has a plurality of perforations. Each perforation forms an opening – for example, a circular one – through the upper panel. This advantageous configuration makes it possible to lighten the spar conforming to the first aspect of the invention. The perforations are distributed along the spar's natural elongation axis. Preferably, the perforations are regularly spaced along the natural elongation axis. This advantageous configuration ensures isotropic operation and response of the spar along its natural elongation axis.

[0044] - at the level of a free end of the upper panel of the upper reinforcement, distal of the first wall, the said free end is distant from the second wall. In other words, there is a non-zero transverse clearance between the free end of the upper panel and the second wall of the stringer.

[0045] - the upper reinforcement is formed from a stamped sheet metal. This advantageous configuration This simplifies production and reduces associated manufacturing costs. The sheet metal forming the upper reinforcement is a type of metal sheet. The sheet metal forming the upper reinforcement is made of a material containing steel or a steel alloy. This advantageous configuration thus provides high rigidity while reducing production costs, particularly material procurement costs;

[0046] - in the first embodiment, the first accordion partition is fixed attached to the upper reinforcement, and in particular to the upper panel of the upper reinforcement and / or the upper reverse of said upper reinforcement. In particular, the first accordion partition is attached to the upper reinforcement and fixed to the upper reinforcement by a plurality of spot welds or by a weld bead.

[0047] - in either of the aforementioned embodiments, the The longeron includes a lower reinforcement that extends transversely between the first wall and the second wall, the lower reinforcement extending into the cavity along its own axis of elongation. In the first embodiment, the second The accordion-style partition rests against the lower reinforcement. The lower reinforcement forms a mechanically reinforcing element housed in the cavity of the longeron. This advantageous configuration makes it possible to reinforce the longeron according to the first aspect of the invention;

[0048] - according to a first embodiment, the lower reinforcement is connected to the same wall as the upper reinforcement, that is to say the first wall. Alternatively, according to a second embodiment, the lower reinforcement is linked to the opposite wall to that to which the upper reinforcement is linked, that is to say the second wall;

[0049] - the lower reinforcement has a lower fold bearing against the first wall, and a lower panel extending from the lower reverse and across the cavity. The lower reverse forms a flap relative to the lower panel. The lower panel extends from the lower reverse and perpendicularly or substantially perpendicularly to the lower reverse;

[0050] - the lower panel of the lower reinforcement has a plurality of perforations. Each perforation forms an opening – for example, a circular one – through the lower panel. This advantageous configuration makes it possible to lighten the spar conforming to the first aspect of the invention. The perforations are distributed along the spar's natural elongation axis. Preferably, the perforations are regularly spaced along the natural elongation axis. This advantageous configuration ensures isotropic operation and response of the spar along its natural elongation axis.

[0051] - at the level of a free end of the lower panel of the lower reinforcement, distal to the first wall, said free end is distant from the second wall. In other words, there is a non-zero transverse clearance between the free end of the lower panel and the second wall of the stringer;

[0052] - the lower reinforcement is formed from a stamped sheet metal. This advantageous configuration This simplifies production and reduces associated manufacturing costs. The sheet metal forming the lower reinforcement is a type of metal sheet. The sheet metal forming the lower reinforcement is made of a material containing steel or a steel alloy. This advantageous configuration thus provides high rigidity while reducing production costs, particularly material procurement costs;

[0053] - in the first embodiment, the second accordion partition is fixed securely to the lower reinforcement, and in particular to the lower panel of the lower reinforcement and / or the lower reverse side of said lower reinforcement. In particular, the second accordion-style partition is attached to the lower reinforcement and fixed to the lower reinforcement by a plurality of spot welds or by a weld bead.

[0054] According to a second aspect of the invention, a motor vehicle is proposed comprising a chassis equipped with at least one longitudinal member conforming to the first aspect of the invention or according to any of its improvements and forming a side member for the motor vehicle.

[0055] Advantageously, the motor vehicle is of the type of an electrified motor vehicle.

[0056] In the context of the present invention, an electrified motor vehicle may be of the type of an electric vehicle pulled exclusively by an electric motor powered by a traction battery, or of the type of a hybrid motor vehicle comprising both the electric motor powered by the traction battery and associated with another propulsion system, such as an internal combustion engine, to propel the motor vehicle. Among hybrid motor vehicles, a distinction is made between plug-in hybrid vehicles, for which the traction battery can be recharged by connecting to an external power source, and non-plug-in hybrid vehicles, i.e., those not equipped for such recharging of the traction battery from an external electrical grid.

[0057] Generally, the drivetrain of such an electrified motor vehicle is rotated by an electric machine, powered by a traction battery, in order to generate motor torque for propelling the motor vehicle. Complementarily or alternatively, the electric machine is configured to recover mechanical energy from the drivetrain and convert it into electrical energy, thereby producing braking torque on the drivetrain and recharging the traction battery.

[0058] Various embodiments of the invention are provided, incorporating, according to all their possible combinations, the different optional features set out here.

[0059] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given by reference to the accompanying schematic drawings on the other hand, in which:

[0060] [Fig. 1] illustrates a general and three-dimensional view of an example of an embodiment of a spar conforming to the first aspect of the invention in a nominal operating state;

[0061] [Fig.2] illustrates a general and three-dimensional view of the spar shown on the [Fig.1] but in a state resulting from a lateral impact;

[0062] [Fig.3] illustrates a cross-sectional view of the spar shown in [Fig.1];

[0063] [Fig.4] illustrates a three-dimensional view of the longeron shown in [Fig.1] but in in which the first and second cells have been masked;

[0064] [Fig. 5] illustrates a detailed, three-dimensional view of the first cells and the second cells of the longitudinal beam illustrated in [Fig.1];

[0065] [Fig.6] illustrates a detailed view of the longeron shown in [Fig. 1].

[0066] Of course, the features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0067] In particular, all the variants and all the embodiments described are combinable with each other if nothing prevents this combination from a technical point of view.

[0068] In the figures, the elements common to several figures retain the same reference.

[0069] In the FIGURES described below, a longitudinal axis X, a lateral axis and a vertical axis Z are defined relative to the motor vehicle on which the side member 1 according to the invention is intended to be mounted.

[0070] More specifically, the transverse axis Y is understood as a direction between one side of the motor vehicle and the opposite side of the same motor vehicle. In other words, the transverse axis Y is understood as a direction extending from a passenger side of the motor vehicle to a driver's side of the same motor vehicle, or vice versa. The adjectives lateral, inside, and outside refer to such a transverse axis Y.

[0071] Furthermore, the longitudinal axis X extends as if taken along a direction extending from front to rear or rear to front of the motor vehicle. The longitudinal axis X is perpendicular to the transverse axis Y. The adjectives front, front, and rear refer to this longitudinal axis X.

[0072] Finally, the vertical axis Z is understood as being taken along an axis which extends from the wheels of the motor vehicle and towards the roof of said motor vehicle, or vice versa, the vertical axis Z being simultaneously perpendicular to the transverse axis Y and to the longitudinal axis X. The adjectives above and below, or lower and upper, refer to this vertical axis Z.

[0073] Complementarily, a proper elongation axis 01 is also defined in the frame of reference of the spar 1, the proper elongation axis 01 being defined by the principal elongation direction of the spar 1, defined in particular by the principal elongation direction of the cavity 10, the central web 13 and the first and second walls 12s, that is to say the direction along which the first cells 14 and the second cells 15 are arranged in the cavity 10. In the context of the integration of the longitudinal member 1 in the motor vehicle, the axis of proper elongation 01 of said longitudinal member 1 is coincident or substantially coincident with the longitudinal axis X.

[0074] With reference to FIGURES 1 to 6, the invention relates to a side member 1 for a motor vehicle, the side member 1 comprising a first wall 11 and a second wall 12 located opposite the first wall 11, the first wall 11 and the second wall 12 extending along a natural elongation axis 01 and providing between them a cavity 10 inside which are arranged:

[0075] - a central core 13 supported against the first wall 11 and extending outwards from the first wall 11 and towards the second wall 12, the central core 13 extending into the cavity 10 along the axis of proper elongation 01;

[0076] - a plurality of first cells 14 extending into the cavity 10 between the first wall 11 and the second wall 12 and on one side of the central core 13;

[0077] - a plurality of second cells 15 extending into the cavity 10 between the first wall 11 and the second wall 12 and a second side of the central core 13 opposite to the first side with respect to the central core 13.

[0078] As can be seen more particularly in FIGURES 3 and 4, the first wall 11 and the second wall 12 define a cavity 10 in which the first cells 14 and the second cells 15 are housed. To this end, the first wall 11 and the second wall 12 each have a concave shape so as to move away from each other from an upper rebate 18 and to meet at a lower rebate 19. Between the upper rebate 18 and the lower rebate 19, the first wall 11 has a first lateral flank 111 and the second wall 12 has a second lateral flank 121, the first lateral flank 111 and the second lateral flank 121 extending parallel or substantially parallel to each other.

[0079] As can be seen particularly in FIGURES 1, 5 and 6, the first cells 14 are arranged adjacent to each other along the natural elongation axis 01 of the spar 1. The second cells 15 are arranged adjacent to each other along the natural elongation axis 01 of the spar 1. Relative to the vertical axis Z, the first cells 14 are located above the second cells 15. Furthermore, the first cells 14 and the second cells 15 are staggered relative to each other. Finally, the first cells 14 and the second cells 15 are all oriented between the first lateral flank 111 of the first wall 11 and the second lateral flank 121 of the second wall 12 of the spar 1.In other words, the first cells 14 and the second cells 15 are all open on the first lateral flank 111 of the first wall 11 and on the second lateral flank 121 of the second wall 12 of the longeron 1. In other words again, the first cells 14 and the second. cells 15 delimit boxes 20 across the cavity 10 and which open respectively onto the first lateral side 111 of the first wall 11 and onto the second lateral side 121 of the second wall 12 of the longeron 1.

[0080] The first cells 14 and the second cells 15 are located on either side of the central web 13 of the spar 1, and in particular of the intermediate rebate of said central web 13. The intermediate rebate of the central web 13 divides the cavity 10 into two almost identical sub-volumes. In other words, the rebate of the central web 13 extends at the level of a median plane of the cavity 10. The two sub-volumes of the cavity 10 thus delimited are superimposed on each other with respect to the vertical axis Z. Thus, each first cell 14 and second cell 15 extends within one of these sub-volumes and between the first wall 11 and the second wall 12 of the spar 1.

[0081] As seen in FIGURES 3 and 4, the central web 13 is attached to the first wall 11 of the spar 1. In particular, the central web 13 is attached to the first lateral side 111 of the first wall 11 of the spar 1. For this purpose, the central web 13 has a flap 131 which allows the attachment against the first lateral side 111 of the first wall 11, directly or indirectly by means of a lower flange 171 of a lower reinforcement 17 which will be described later.

[0082] The central core 13 is advantageously welded against the first lateral side 111 of the first wall 11 and / or against the lower reverse 171 of the lower reinforcement 17 of the longeron 1.

[0083] The central web 13 is preferably formed from a sheet of metal shaped to form both the flap 131 and the intermediate rebate, for example by stamping. Preferably, in order to guarantee the best mechanical performance for the spar 1, the central web 13 is formed from a steel sheet, the thickness of which is, for example, less than 2 mm, preferably between 1 mm and 2 mm. The central web 13 extends inside the cavity 10 and between two axial ends of the spar 1, relative to the axis of natural elongation 01.

[0084] In order to increase the rigidity of the spar 1, the spar 1 advantageously comprises an upper reinforcement 16 and a lower reinforcement 17. The upper reinforcement 16 and the lower reinforcement 17 extend into the cavity 10 and between two axial ends of the spar 1, relative to the axis of natural elongation 01. The upper reinforcement 16 is located opposite the lower reinforcement 17. The upper reinforcement 16 is located on the side of the upper rebate 18 of the first wall 11 and the second wall 12 of the spar 1; and the lower reinforcement 17 is located on the side of the lower rebate 19 of the first wall 11 and the second wall 12 of the spar 1.

[0085] The upper reinforcement 16 and the lower reinforcement 17 extend parallel to each other. In particular:

[0086] - the upper reinforcement 16 comprises an upper reverse 161 and an upper panel 162. The upper reverse 161 forms a folded edge resting against the first lateral side 111 of the first wall 11 of the spar 1. The upper reinforcement 16 is fixed securely to the first wall 11 by means of its upper reverse 161 and the first lateral side 111 of the first wall 11, preferably by welding. Furthermore, the upper panel 162 extends from the upper reverse 161 and across the cavity 10, that is, towards the second lateral flank 121 of the second wall 12 of the stringer 1. However, a free end of the upper panel 162 remains at a distance from the second lateral flank 121 of the second wall 12, so that there is a non-zero distance between the free end of the upper panel 162 and the second lateral flank 121. The upper panel 162 advantageously extends parallel to the intermediate rebate of the central web 13;

[0087] - the lower reinforcement 17 comprises a lower reverse 171 and a lower panel 172. The lower reverse 171 forms a folded edge resting against the first lateral side 111 of the first wall 11 of the spar 1. The lower reinforcement 17 is fixed securely to the first wall 11 via its lower reverse 171 and the first lateral side 111 of the first wall 11, preferably by welding. Furthermore, the lower panel 172 extends from the lower reverse 171 and across the cavity 10, i.e., towards the second lateral flank 121 of the second wall 12 of the stringer 1. However, a free end of the lower panel 172 remains at a distance from the second lateral flank 121 of the second wall 12, so that there is a non-zero distance between the free end of the lower panel 172 and the second lateral flank 121. The lower panel 172 advantageously extends parallel to the intermediate rebate of the central web 13.Additionally, the lower reverse 171 is larger than the upper reverse 161, relative to the vertical axis Z, so that the flap 131 of the central core 13 is placed against the lower reverse 171 of the lower reinforcement 17 and fixed securely to it by welding; .

[0088] The upper reinforcement 16 and the lower reinforcement 17 are advantageously formed from folded sheet metal, preferably stamped. Preferably, in order to guarantee the best mechanical performance for the longeron 1, the upper reinforcement 16 and the lower reinforcement 17 are formed from steel sheet, the thickness of which is, for example, less than 2 mm, preferably between 1 mm and 2 mm. The upper reinforcement 16 and the lower reinforcement 17 extend inside the cavity 10 and between two axial ends of the longeron 1, relative to the axis of natural elongation 01.

[0089] In order to reduce the weight of the longeron 1 without weakening its mechanical properties, the upper panel 162 of the upper reinforcement 16 and the lower panel 172 of the lower reinforcement 17 have a plurality of perforations 25. The perforations 25 of the upper panel 162 and the lower panel 172 are through, relative to the vertical axis Z. The perforations 25 of the upper panel 162 and the lower panel 172 take the form of circular or oblong perforations 25.

[0090] The perforations 25 of the upper panel 162 and the lower panel 172 are distributed along the natural elongation axis 01 of the spar 1. The perforations 25 of the upper panel 162 of the upper reinforcement 16 are all aligned along a single line located near a median axis of the upper panel 162, relative to the transverse axis Y. In contrast, the lower panel 172 of the lower reinforcement 17 has more perforations 25 distributed both between the two axial ends of the lower reinforcement 17, relative to the natural elongation axis 01, but also relative to the transverse axis Y, between the lower reverse 171 and the free edge of the lower panel 172.

[0091] With reference to [Fig.5], the first cells 14 and the second cells 15 brought into the cavity 10 of the spar 1 form boxes 20. In the illustrated embodiment, the first cells 14 are formed by a first accordion partition 140 located on a first side of the central web 13, the first accordion partition 140 extending into the cavity 10 along the axis of proper elongation 01; and the second cells 15 are formed by a second accordion partition 150 located on a second side of the central web 13, opposite the first side, the second accordion partition 150 extending into the cavity 10 along the axis of proper elongation 01.

[0092] The first accordion partition 140 is stamped so as to form a plurality of slots juxtaposed to one another along the proper elongation axis 01 of the longeron 1. Each slot thus delimits a box 20. More particularly, each box 20 of the first accordion partition 140 is delimited by lateral walls 23 and a vertical wall 24, alternately located at the top and then at the bottom, relative to the vertical axis Z.

[0093] The boxes 20 of the first accordion partition 140 thus delimited are open, at a first lateral end, on the first lateral side 111 of the first wall 11 of the spar 1 and, at a second lateral end, on the second lateral side 121 of the second wall 12 of the spar 1. At the level of an edge of the first accordion partition 140 located opposite the first lateral side 111 of the first wall 11 of the spar 1, the first accordion partition 140 has tabs 22 which extend projecting from said edge.

[0094] In order to lighten the weight of the first accordion partition 140, several perforations 25 are provided on the side walls 23 and the vertical walls 24 delimiting the boxes 20 of each first cell 14.

[0095] Finally, to fix the first accordion partition 140 to the stringer 1, the first accordion partition 140 has, at each longitudinal end, taken relative to the proper elongation axis 01, fixing tabs 21 which allow fixing by welding to the upper panel 162 of the upper reinforcement 16.

[0096] Similarly, the second accordion partition 150 is stamped so as to form a plurality of slots juxtaposed to one another along the proper elongation axis 01 of the longeron 1. Each slot thus delimits a box 20. More particularly, each box 20 of the second accordion partition 150 is delimited by lateral walls 23 and a vertical wall 24, alternately located at the top and then at the bottom, relative to the vertical axis Z.

[0097] The boxes 20 of the second accordion partition 150 thus delimited are open, at a first lateral end, on the first lateral side 111 of the first wall 11 of the spar 1 and, at a second lateral end, on the second lateral side 121 of the second wall 12 of the spar 1. At the level of an edge of the second accordion partition 150 located opposite the first lateral side 111 of the first wall 11 of the spar 1, the second accordion partition 150 has tabs 22 which extend projecting from said edge.

[0098] In order to lighten the weight of the second accordion partition 150, several perforations 25 are provided on the side walls 23 and the vertical walls 24 delimiting the boxes 20 of each second cell 15.

[0099] Finally, to fix the second accordion partition 150 to the stringer 1, the second accordion partition 150 has, at each longitudinal end, taken relative to the proper elongation axis 01, fixing tabs 21 which allow fixing by welding to the lower panel 172 of the lower reinforcement 17.

[0100] The vertical walls 24 of the boxes 20 of the first accordion partition 140 are fixed rigidly - preferably by welding - against a vertical wall 24 of the boxes 20 of the second accordion partition 150 when said vertical wall 24 of the boxes 20 of the second accordion partition 150 is in contact with said vertical wall 24 of the boxes 20 of the first accordion partition 140. For this purpose, the intermediate rebate of the central web 13 can be sandwiched between the two vertical walls 24 considered here, or else the intermediate rebate of the central web 13 remains set back from the vertical walls 24, as can be seen in particular in [Fig.3].

[0101] Thus, the longeron 1 according to the invention provides enhanced mechanical performance against a lateral impact, as shown in [Fig. 2]. The presence of the first cells 14 and the second cells 15 form energy absorption devices for the impact. Consequently, the resistance capabilities of the longeron 1 thus equipped are increased. The choice of a material other than aluminum, such as In particular, the use of steel to form the various parts of the spar 1 also reduces manufacturing costs. Finally, the modular composition of the spar 1 according to the invention, resulting from the assembly of several elements, facilitates its assembly. The first cells 14 and the second cells 15 are inserted into the cavity 10 and fixed to the upper reinforcement 16, the lower reinforcement 17, and the central web by several welds.

[0102] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the various features, forms, variants, and embodiments of the invention can be combined with one another in various ways, provided they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above are combinable with each other.

Claims

Demands

1. Side member (1) for motor vehicle, the side member (1) comprising a first wall (11) and a second wall (12) located opposite the first wall (11), the first wall (11) and the second wall (12) extending along an axis of proper elongation (01) and providing between them a cavity (10) inside which are arranged: - a central web (13) bearing against the first wall (11) and extending in projection from the first wall (11) and in the direction of the second wall (12), the central web (13) extending in the cavity (10) along the axis of proper elongation (01); - a plurality of first cells (14) extending in the cavity (10) between the first wall (11) and the second wall (12) and on a first side of the central web (13);- a plurality of second cells (15) extending in the cavity (10) between the first wall (11) and the second wall (12) and on a second side of the central core (13) opposite to the first side with respect to the central core (13).;

2. Longeron (1) according to the preceding claim, in which the central web (13) is brought against the first wall (11) and fixed to the first wall (11) by a plurality of weld points or by a weld bead.

3. Longeron (1) according to any one of the preceding claims, wherein the central web (13) has a flap (131) bearing against the first wall (11) and an intermediate rebate extending between the first cells (14) and the second cells (15).

4. Longeron (1) according to the preceding claim, in which, relative to the vertical axis (Z), the intermediate rebate of the central web (13) extends between the first wall (11) and the second wall (12) so as to divide the cavity (10) into two equal or substantially equal volumes.

5. Longeron (1) according to any one of the preceding claims, wherein the first cells (14) are formed by a first accordion partition (140) extending in the cavity (10) along the proper elongation axis (01); and the second cells (15) are formed by a second accordion partition (150) extending in the cavity (10) along the proper elongation axis (01).

6. Longeron (1) according to the preceding claim, in which the first accordion partition (140) and the second accordion partition (150) comprise a sheet metal shaped so as to delimit a plurality of boxes (20) which extend between the first wall (11) and the second wall (12), the boxes (20) all being adjacent to each other along the axis of proper elongation (01).

7. Longeron (1) according to any one of claims 5 or 6, wherein the longeron (1) comprises an upper reinforcement (16) which extends transversely between the first wall (11) and the second wall (12), the first accordion partition (140) being supported against the upper reinforcement (16), the upper reinforcement (16) extending into the cavity (10) along the axis of proper elongation (01).

8. Longeron (1) according to the preceding claim, wherein the upper reinforcement (16) has an upper lap (161) bearing against the first wall (11), and an upper panel (162) which extends from the upper lap (161) and across the cavity (10).

9. Longeron (1) according to any one of claims 5 to 8, wherein the longeron (1) comprises a lower reinforcement (17) which extends transversely between the first wall (11) and the second wall (12), the second accordion partition (150) being supported against the lower reinforcement (17), the lower reinforcement (17) extending into the cavity (10) along the axis of proper elongation (01).

10. Longeron (1) according to the preceding claim, wherein the lower reinforcement (17) has a lower reverse (171) bearing against the first wall (11), and a lower panel (172) which extends from the lower reverse (171) and across the cavity (10).

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