Device for fastening the rear end of the side rails of an engine mount housing a drive system of an electric vehicle to a vehicle chassis

Description

Technical field of the invention

[0001] The present invention claims priority from French application 1913962 filed on December 9, 2019.

[0002] The invention relates to the field of chassis comprising a motor vehicle, in the context of a motor vehicle whose propulsion energy is entirely or partly electric, being supplied from an electrical energy reserve equipping the vehicle. Within the framework of constraints linked to such a context, the invention relates more particularly to methods of protecting the chassis against its deformation in the event of a frontal impact sustained by the vehicle. Prior art

[0003] The relative concepts commonly used to define a motor vehicle, as well as its components and / or the relative positions of the vehicle components with respect to each other, are now specified. Subsequently, such relative concepts are used to set out the context of the invention and address the problems arising therefrom, as well as to describe the invention.

[0004] For this purpose and unless otherwise specified, reference is made to an orthonormal reference system conventionally identifying the directions of extension of the vehicle, including a longitudinal direction extending between the front and rear of the vehicle, a transverse direction extending between the right and left lateral sides of the vehicle identified in relation to the driver at the vehicle's driving position, and a vertical direction identifying the extension of the vehicle in elevation from bottom to top from its rolling plane on the ground. Consequently, a side member extends mainly longitudinally. The concepts such as bottom and top, or other related relative concepts such as upper and lower or below or under and above, or even overhang and below, are defined according to the vertical extension of the vehicle in elevation in relation to its rolling plane on the ground.

[0005] Motor vehicles have a chassis that provides a framework for stiffening the vehicle. The chassis includes, among other things, a vehicle underbody that is configured as a framework commonly composed of side members braced by cross members. A platform is commonly installed on the framework, positioned vertically between the underbody and the vehicle's passenger compartment.

[0006] Conventionally, the side members comprise at least right and left side members, and at least one middle side member which is interposed under the platform transversely between the side members. It is common for the chassis to comprise several so-called middle side members, at least one of which is potentially arranged in a tunnel. The cross members comprise at least one front fascia cross member arranged at the front of the vehicle and a front cross member interfaced between an engine compartment and the passenger compartment of the vehicle. It is usual for several middle cross members to be distributed longitudinally between the front cross member and a rear cross member of the chassis. The front fascia cross member and the front cross member delimit between them the engine compartment receiving the vehicle's engine, a vertical and transverse extension apron separating the engine compartment from the passenger compartment of the vehicle.

[0007] Furthermore, among motor vehicles, an evolution in their engine has pushed designers to develop vehicles whose propulsion energy is at least partly electric. The vehicle's engine is housed inside the engine compartment, commonly being installed on an engine cradle. The engine cradle is fixed on the one hand at its front end to the front fascia crossmember and on the other hand to the front crossmember via the rear end of longitudinal extension stretchers.

[0008] To provide the vehicle with electrical propulsion energy, the vehicle is equipped with an electrical energy reserve commonly composed of battery modules that can be advantageously installed under the platform extending under the vehicle's passenger compartment. The energy storage capacity of the electrical energy reserve can thus be optimized, which ultimately makes it possible to increase the vehicle's range in terms of electrical propulsion energy.

[0009] However, the search for an optimization of the energy storage capacity of the electrical energy reserve induces an increase in its overall volume. It is therefore appropriate that the electrical energy reserve extends as much as possible under the platform following its longitudinal and transverse extension plane.

[0010] This then poses the difficulty of installing an electrical energy reserve with a significant volume under the platform. This is why it is known to free the available space under the platform as much as possible from any clutter, to allow and / or facilitate the installation under the platform of an electrical energy reserve with a significant volume. For this purpose, the presence of side members and / or cross members extending under the platform is desirable, as is apparent for example from document EP2468609-B1 (TESLA MOTORS Inc).

[0011] Documents EP 2 497 699 A1, JP2009018724, JP2005231477, EP1306289 and EP1277648 describe vehicle chassis comprising a fixing device with a joining interface comprising at least a first joining member fixed on the one hand longitudinally to the rear end of a stretcher via a front end that comprises the first joining member, and on the other hand transversely to a lateral side member constituting the chassis via a rear end that comprises the first joining member. According to document EP2468609-B1, the chassis is free of median side members and median cross members under the platform. The space available under the platform is thus optimized for the installation of a modular electrical energy reserve that can have a substantial volume. The electrical energy reserve is mounted inside a frame via which the energy reserve is installed under the platform.The frame incorporates transverse stiffening elements that are longitudinally distributed within the frame and between which are installed modules making up the electrical energy reserve. The transversely stiffened frame then rests against the side members of the chassis to compensate for the removal of said middle members and said middle cross members that usually extend under the platform.

[0012] However, the chassis is then weakened along its longitudinal extension. It is therefore noted that such longitudinal weakening of the chassis affects its resistance in the event of a frontal impact sustained by the vehicle, to the detriment of satisfactory protection of the vehicle's passengers. It appears that it is then useful to seek a solution to reinforce the chassis against a frontal impact sustained by the vehicle, due to the absence of so-called median side members extending under the platform to optimize the volume of the electrical energy reserve. Presentation of the invention

[0013] In this context, the invention relates to a device for fixing to a motor vehicle chassis, the rear end of right and left side members that comprise an engine cradle mounted on the chassis. The invention also relates to a motor vehicle chassis equipped with a said engine cradle, the rear ends of said side members that it comprises being fixed to the chassis via a fixing device in accordance with the invention. The invention also relates to a motor vehicle comprising a chassis in accordance with the invention, the motorization of which is at least partly electrically powered. It is understood here that the vehicle of the invention is likely to be a vehicle commonly referred to as electric, the propulsion energy of which is exclusively electric, or to be a vehicle commonly referred to as hybrid, the propulsion energy of which is provided by an electric motorization and / or by a combustion motorization.

[0014] The aim of the invention is to propose a solution concerning the methods of fixing the rear end of the stretchers to the chassis, which is capable of containing a deformation of the chassis in the event of a frontal impact sustained by the vehicle, sufficiently effective to protect the passenger(s) of the vehicle.

[0015] An objective of the invention is to propose such a solution which compensates for a partial or total absence under a platform of a chassis base, of chassis stiffening elements, in particular longitudinally. As previously mentioned, such an absence of stiffening elements is desired to optimize the space available under the platform which can receive a reserve of electrical energy providing at least one propulsive electrical energy for the vehicle.

[0016] Another objective of the invention is to propose such a solution by limiting the increase in the mass of the vehicle induced by the methods of fixing the rear end of the stretchers to the chassis, in order to best preserve the resources and therefore the autonomy of the vehicle in propulsive energy.

[0017] Another objective of the invention is to propose such a solution that can be implemented under the constraint of an arrangement of a pre-existing chassis structure. It is particularly aimed at limiting as much as possible the impact of such an arrangement on the manufacturing process of said pre-existing chassis structure, so as to allow the use of the same assembly line to manufacture said pre-existing chassis structure selectively with or without its arrangement necessary for the implementation of the invention. Such an aim is in particular under the constraint of a search for reducing the costs linked to the desired solution, in the context of severe economic competition in the automotive field which can make a potential solution prohibitive due to the costs involved.

[0018] According to the invention and for each of the stretchers, the fixing device comprises a junction interface comprising at least one first junction member fixed on the one hand longitudinally to the rear end of the stretcher via a front end that the first junction member comprises, and on the other hand transversely to a lateral side member constituting the chassis via a rear end that the first junction member comprises. It is understood that the fixing device comprises two right and left junction interfaces which are respectively assigned to the rear ends of the stretchers commonly comprising a right stretcher and a left stretcher. The first junction member houses at least one first reinforcing member connecting together the front end and the rear end of the first junction member.The first reinforcing member is transversely extended by being arched along a transverse-longitudinal plane between the front end and the rear end of the first joining member. According to an embodiment of the first joining member promoting its effectiveness, the first reinforcing member comprises: . ) a first vertical extension profile fixed to the first connecting member, extending between the front end and the rear end of the first connecting member, ) a vertical extension reinforcing wing with a folded upper edge which is made from the material of the first connecting member. Said reinforcing wing extends at a transverse distance from said first profile and at the edge of the first connecting member, at its edge which is transversely oriented towards the inner side of the chassis. As commonly defined in the automotive field, the relative notions of internal orientation and external orientation relative to the chassis are notably applied to the relative position between two objects, such as notably in the case in point between said first profile and said reinforcing wing.) a second profile extending longitudinally at least partially inside the volume delimited between said first profile and said reinforcing wing, the second profile being fixed in transversely antagonistic supports against said first profile and said reinforcing wing.

[0019] Each of the first connecting members is more particularly formed from a single-piece body, potentially composed of several elements secured to each other. The transverse extension and the longitudinal extension of said single-piece body are more specifically limited between the rear end of the stretcher and a docking zone of said single-piece body against the side member. The first connecting member is for example formed from a sheet metal shaped by stamping and / or other shaping, which extends between the front end and the rear end of the connecting member. Preferably, as referred to below, said sheet metal is reinforced by one or more reinforcements assembled together, then composing a first reinforcement member secured to the sheet metal by participating in said single-piece body constituting the first connecting member.

[0020] The stretchers are transversely arranged between the right and left lateral sides of the chassis, being transversely offset relative to the lateral side members of the chassis. Each of the two junction interfaces conforms to the arrangements provided by the invention, without excluding the possibility of being different from each other depending on the specific case of application of the invention.

[0021] In the event of a frontal impact supported by the chassis, a longitudinal thrust force generated by the impact is transmitted via the first connecting member from the side members to the side members assigned to them respectively. This reinforces the resistance of the chassis against its deformation in the event of a frontal impact, by transmitting the longitudinal thrust force supported by the engine cradle to the side members, via the side members which are connected to the side members by the first connecting members assigned to them.

[0022] This makes it possible to avoid installing longitudinal reinforcement members under a platform of the chassis underbody, which extends in particular under the passenger compartment of the vehicle to the rear of the engine compartment which houses the engine cradle and which is arranged at the front of the chassis. This ultimately makes it possible to optimize the space available under the platform for receiving a reserve of electrical energy at least for propulsion of the vehicle.

[0023] The first connecting member extends in particular below the stretcher and has a middle portion interposed between the front end and the rear end of the first connecting member. Said middle portion provides a transverse offset between the front end and the rear end of the first connecting member.

[0024] The concept of a lower part is understood as an extension of the first connecting member at a lower level of the stretcher assigned to it, without meaning an extension under the stretcher. In fact, the first connecting member extends below the stretcher from its front end fixed to the rear end of the stretcher towards its rear end fixed to the side rail.

[0025] The first connecting member is potentially more or less vertically inclined from its front end to its rear end. The expression "more or less" means that said inclination is in particular dependent on the vertical distance between the rear end of the stretcher and the side member to which the first connecting member is fixed, depending on the specific case of application of the invention.

[0026] More particularly, the front end and the rear end of the first connecting member each have a longitudinal extension and are connected to each other by said middle part. Said middle part extends longitudinally and transversely, comprising a double inflection providing said transverse offset between the rear end and the front end of the first connecting member.

[0027] The arrangement of the middle part of the first connecting member connects the front end and the rear end of the first connecting member together, such that said transverse offset is provided between them. The transverse offset between the front end and the rear end of the first connecting member, provided via its middle part, makes it possible to compensate for said transverse gap between the stretcher and the lateral side member to which the first connecting member is fixed, while allowing said longitudinal thrust force to be transmitted from the stretcher to the lateral side member.

[0028] The first reinforcing member reinforces the intrinsic robustness of the first connecting member against its deformation in the event of a frontal impact supported by the chassis. The first reinforcing member also promotes the transfer from the front end to the rear end of the first connecting member of the longitudinal thrust force generated in the event of a frontal impact supported by the chassis.

[0029] Preferably, the first joining member comprises a first shell which has a bottom raised by vertically extending edge walls, the bottom of the first shell being delimited between a first edge wall and a second edge wall. More precisely, the bottom of the first shell is delimited between the edge walls, so that an interior volume of the shell provides a space for receiving at least the first reinforcing member. The first shell preferably forms a single-piece body by assembling the components of the first reinforcing member together and to the first shell. According to one embodiment, an edge of the bottom of the first shell is delimited between the first edge wall and a second said edge wall.Said edge of the bottom of the first hull, in particular of longitudinal extension, is transversely pressed against the lateral spar, being longitudinally bordered by a wing for fixing the first joining member vertically under the lateral spar.

[0030] According to one embodiment, a first fixing lug of the first connecting member to the rear end of the stretcher is provided at the front end of the first connecting member between the first edge wall and the second edge wall. The second edge wall is provided with a second fixing lug of the first connecting member at its rear end, transversely against a lateral face of the lateral side member.

[0031] More specifically, the reinforcing wing is made up of said second edge wall which comprises the first shell. Said first profile constituting the first reinforcing member is docked at its rear end against said reinforcing wing, in front of the second fixing lug.

[0032] According to one embodiment, the junction interfaces respectively assigned to the stretchers each further comprise a second junction member which is transversely interfaced between the first junction member and a transversely median shoe equipping the chassis. The respective second junction members of the junction interfaces are transversely docked respectively on either side of the shoe.

[0033] The second connecting members in this case form, among other potential functionalities, members for damping a transverse thrust force. Such a transverse thrust force may result from a possible transverse thrust component of the thrust force which is applied to the front of the chassis in the event of a frontal impact which it undergoes, in particular in the event of a frontal-lateral impact applied to the front of the vehicle. Preferably and for each of the connecting interfaces, the first connecting member and the second connecting member are transversely abutted against each other, jointly forming a single-piece body. The single-piece body formed by the first connecting member and the second connecting member is preferably produced by assembling them together. For example, the first connecting member and the second connecting member are transversely joined and fixed to each other via interlocking combs which they respectively comprise.

[0034] More particularly according to one embodiment, the second joining member is arranged in a second longitudinal and transverse extension shell, which preferably houses at least one second reinforcing member. Said reinforcing wing advantageously provides a partition between the interior volume of the first shell and the interior volume of the second shell, the reinforcing wing participating in the stiffening of the second shell.

[0035] The invention also relates to a motor vehicle comprising a chassis on which are fixed the respective rear ends of right and left side members which comprise an engine cradle mounted on the chassis. The vehicle of the invention is recognizable in that the rear ends of the side members are fixed to the chassis via a fixing device according to the invention. Presentation of figures

[0036] The invention will be better understood upon reading the following detailed description of an exemplary embodiment of the present invention, in relation to the following figures in the attached drawings: [ Fig. 1 ] There figure 1 is a partial illustration in perspective seen from below, of a chassis underbody of a motor vehicle. The figure 1 more particularly represents a device for fixing to the chassis the rear ends of stretchers, respectively right and left, which comprise an engine cradle mounted on the chassis, via right and left junction interfaces. Fig. 2 ] There figure 2 is a perspective illustration seen from above, of the stretchers shown on the figure 1 . On the figure 2 , the right and left junction interfaces that comprise the fixing device illustrated in the figure 1 , are respectively fixed to the rear ends of the right and left stretchers. Fig. 3 ] There figure 3 is a partial top view perspective illustration of a left junction interface shown in the figures 1 And 2 . On the figure 3 , the left junction interface is interfaced between the rear end of a left stretcher shown in the figures 1 And 2 and a left side member that includes the chassis. Fig. 4 ] There figure 4 is a top view perspective illustration of the left junction interface shown in the figures 1 à 3 , composed of a first joining member and a second joining member which are transversely abutted and fixed to each other. Fig. 5 ] There figure 5 is a top view illustration of the left junction interface shown in the figures 1 à 4 . [ Fig. 6 ] There figure 6 is a top view perspective illustration of the left junction interface shown in the figures 1 à 5 . On the figure 6 , the junction interface is shown truncated transversely at its rear end, to illustrate more precisely the reinforcing members with which it is provided. Fig. 7 ] There figure 7 is a perspective illustration seen from below of the straight junction interface shown in the figures 1 à 3 . Since the junction interfaces are identical in being installed symmetrically on the chassis, the bottom illustration of the right junction interface is consistent with the top illustration of the left junction interface. Detailed description of the invention

[0037] The figures and their detailed non-limiting descriptions set out the invention according to particular methods which are not restrictive as to the scope of the invention. The figures and their detailed descriptions of an exemplary embodiment of the invention can be used to better define it, if necessary in relation to the general description which has just been given. Furthermore, to avoid overloading the figures and to facilitate their reading, the reference numbers assigned to the terms and / or concepts used to describe the invention and indicated in any one of the figures are potentially repeated in the description of any other figure without implying their presence in all of the figures.

[0038] In the figures, reference is made to an orthonormal reference system commonly used in the automotive field to define a vehicle, its components and / or the relative positions of the vehicle components with respect to each other.

[0039] According to this orthonormal reference frame, the vehicle extends longitudinally L1 between the front AV1 and the rear AR1, transversely T1 between its right lateral sides DR1 and left G1, and vertically V1 in elevation relative to the rolling plane of the vehicle, from the bottom B1 to the top H1 of the vehicle.

[0040] On the figure 1 , a chassis base 1 of a motor vehicle is shown seen from below. The base comprises lateral side members 1a, 1b respectively right and left between which a platform 2 extends. A clear space is provided under the platform 2 for the installation of an electrical energy reserve providing in particular the electrical energy for propulsion of the vehicle. The propulsion engine of the vehicle is installed inside a front engine compartment of the vehicle, being supported by an engine cradle fixed to the chassis 1 at its front end and at its rear end.

[0041] Also referring to the figure 2 , the engine cradle comprises a right stretcher 3a and a left stretcher 3b which are fixed to the chassis 1 via their rear end 4. The invention provides a device for fixing the rear end 4 of the stretchers 3a, 3b to the chassis 1, via junction interfaces 5a, 5b. More specifically, a left junction interface 5b provides a fixing of the rear end 4 of the left stretcher 3b to a left lateral side member 1b of the chassis 1, as shown in the figure 3 , and a right junction interface 5a similarly provides an attachment of the rear end 4 of the right stretcher 3a to a right side member 1a of the chassis 1.

[0042] According to the illustrated example, the left junction interface 5b and the right junction interface 5a are identical in being installed symmetrically on the chassis 1 with respect to a transversely median longitudinal axis A1 of extension of the chassis 1. The arrangement of the fixing interfaces 5a, 5b does not prevent them from being shaped to receive fitting members, such as for example marks 6 for their control, which are used during the assembly of the components of the chassis 1 on a pre-existing vehicle production line. A chassis 1 conforming to the provisions of the invention can thus be handled on an assembly line of differentiated vehicles which nevertheless have identical rolling bases.

[0043] As more visible on the figures 1 à 7 , each of the junction interfaces 5a, 5b comprises a first junction member 7a and a second junction member 7b which are transversely abutted and fixed to each other.

[0044] More particularly visible on the figure 2 , the right 5a and left 5b junction interfaces, and therefore the first junction members 7a and the second junction members 7b that they comprise respectively, extend below the stretchers 3a, 3b. The junction interfaces 5a, 5b extend in particular at the rear of a separation apron between the engine compartment and the passenger compartment of the vehicle, from the rear end 4 of the stretchers 3a, 3b towards the side members 1a, 1b which are respectively assigned to the junction interfaces 5a, 5b.

[0045] The junction interfaces 5a, 5b are more or less inclined relative to the rolling plane of the vehicle depending on the configuration of the chassis 1, in particular depending on the longitudinal and / or transverse separation distance between the rear ends 4 of the stretchers 3a, 3b and the zone of attachment of the junction interfaces 5a, 5b to the lateral side members 1a, 1b which are respectively assigned to them.

[0046] On the figures 2 And 3, and for each of the junction interfaces 5a, 5b, the junction interface 5a, 5b connects the rear end 4 of the stretcher 3a, 3b to the lateral side member 1a, 1b via the first junction member 7a. A front end 8a of longitudinal extension of the first junction member 7a is fixed longitudinally to the rear end 4 of the stretcher 3a, 3b, via a first fixing lug 9a that the first junction member 7a comprises. A rear end 8b of longitudinal extension of the first junction member 7a is fixed transversely to the lateral side member 1a, 1b via a second fixing lug 9b that the first junction member 7a comprises.

[0047] More particularly visible on the figures 4 , 5 And 7, the first connecting member 7a is also fixed vertically under the lateral spar 1a, 1b via a fixing wing 10 which the first connecting member 7a comprises. Said fixing wing 10 has a transverse extension and extends longitudinally along a docking edge 11 of the first connecting member 7a which is transversely pressed against the lateral spar 1a, 1b as shown in the figures 1 And 3 .

[0048] More particularly visible on the figures 4 à 7 , the first connecting member 7a has a middle portion 8c which is interposed between the front end 8a and the rear end 8b of the first connecting member 7a. Said middle portion 8c has a double inflection formed between the front end 8a and the rear end 8b of the first connecting member 7a, which provides a transverse offset between the front end 8a and the rear end 8b of the first connecting member 7a. Such a transverse offset provides the transverse connection, via the first connecting member 7a, between the rear end 4 of the stretcher 3a, 3b and the lateral side member 1a, 1b.

[0049] The first connecting member 7a comprises a first shell 12a which extends longitudinally and transversely. The first shell 12a provides a bottom 13a raised by edge walls 14a, 14b which extend vertically from the bottom 13a of the first shell 12a towards the top of the chassis 1, including a first edge wall 14a and a second edge wall 14b.

[0050] Said docking edge 11 is formed by the bottom 13a of the first hull 12a, extending between the outer transverse ends E1 of the first edge wall 14a and the second edge wall 14b, which are oriented towards the lateral spar 1a, 1b. The first fixing lug 9a extends transversely and in elevation between the front ends of the first edge wall 14a and the second edge wall 14b. The second fixing lug 9b is formed by a longitudinal extension of the second edge wall 14b at its rear end.

[0051] The first connecting member 7a incorporates a first reinforcing member 15a which is housed inside the first shell 12a for its reinforcement against its deformation in the event of a frontal impact supported by the chassis 1. The first reinforcing member 15a connects the front end 8a and the rear end 8b of the first connecting member 7a to each other, extending longitudinally and transversely. The first reinforcing member 15a partially occupies the interior volume of the first shell 12a by having an arcuate spindle conformation following a transverse-longitudinal plane between the front end 8a and the rear end 8b of the first connecting member 7a.

[0052] More particularly visible on the figure 6 , the first reinforcing member 15a comprises various components derived from the material of the first shell 12a and / or fixed to the first shell 12a constituting the first joining member 7a. A first component is formed of a first profile 16a, a second component is formed of a reinforcing wing 14b which the first shell 12a comprises and which is made up of said second edge wall 14b, and a third component is formed of a second profile 16b extending transversely and longitudinally between the first profile 16a and said reinforcing wing 14b.

[0053] The first profile 16a has an S-shaped profile and extends vertically from the bottom 13a of the first shell 12a to which it is fixed. The first profile 16a is oriented transversely on the outer side E1 of the chassis 1, or in other words in the direction of the lateral side member 1a, 1b to which it is fixed. The first profile 16a extends longitudinally and transversely from the front end 8a of the first connecting member 7a and is docked at its rear end against the reinforcing wing 14b, in front of the second fixing lug 9b.

[0054] The reinforcing wing 14b has a vertical extension and has a folded upper edge, being made from the material constituting the first shell 12a. The reinforcing wing 14b extends at a variable transverse distance from the first profile 16a, bordering the first shell 12a on its side transversely oriented towards the second joining member 7b, or in other words on its side transversely oriented towards the inner side I1 of the chassis 1 or in other words still on its side oriented transversely opposite the lateral side member 1a, 1b to which the joining interface 5a, 5b is fixed. The reinforcing wing 14b and the first profile 16a delimit between them the conformation of the first reinforcing member 15a in an arcuate spindle.

[0055] The second profile 16b is transversely interfaced between the first profile 16a and the reinforcing wing 14b. The second profile 16b has a U-shaped profile by being fixed to the first profile 16a and to the reinforcing wing 14b via the branches of the U-shaped profile of the second profile 16b. The second profile 16b extends longitudinally at least partially inside the volume delimited between the first profile 16a and the reinforcing wing 14b, taking transverse antagonistic supports against the first profile 16a and the reinforcing wing 14b.

[0056] The second joining member 7b is formed of a second shell 12b which is reinforced by a second reinforcing member 15b which it houses. The second shell 12b extends longitudinally and transversely in extension, on the inner side I1 of the chassis, of the first shell 12a 1. The second shell 12b comprises a bottom 13b raised by edge walls which extend vertically from the bottom 13b of the second shell 12b towards the top of the chassis 1.

[0057] The edge wall of the second shell 12b on its face oriented towards the first joining member 7a is formed by the reinforcing wing 14b which the first joining member 7a comprises, or in other words is formed by the second edge wall 14b which the first shell 12a comprises.

[0058] The reinforcing wing 14b thus forms a partition between the interior volume of the first shell 12a and the interior volume of the second shell 12b. The reinforcing wing 14b also participates in reinforcing the second shell 12b in the event of a frontal impact sustained by the vehicle, in particular in the event of a frontal-lateral impact applied to the front of the vehicle. The second reinforcing member 15b housed inside the second shell 12b has a step-like configuration following the vertical extension of the second shell 12b, each of the steps being individually fixed to the bottom 13b that the second shell 12b comprises.

[0059] The first connecting member 7a and the second connecting member 7b are each provided with a sole 17a, 17b for plating and / or fixing the connecting members under the platform 2, as illustrated in the figure 1 . Said soles 17a, 17b are at least partly formed by returns which comprise at least one of the edge walls 14a, 14b of the first shell 12a and of the second shell 12b. The sole 17a of the first joining member 7a is formed at least by the flap of the upper edge of the reinforcing wing 14b and by a wing of the first profile 16a formed by the S-shaped conformation of its profile. The sole 17b of the second joining member 7b is formed at the upper periphery and at least partially around the edge walls of the second shell constituting the second joining member 7b.

[0060] On the figure 1, the underbody of the vehicle is provided with a longitudinal reinforcement tunnel 18 which extends along said transversely median longitudinal axis A1 and which extends vertically projecting towards the top of the chassis 1. The tunnel 18 provides a shoe 19 to which the junction interfaces 5a, 5b are transversely connected via the second junction members 7b which they comprise, respectively on either side of the shoe 19 along its transverse extension.

Claims

1. Device for fixing the rear end (4) of right and left bearing structures (3a, 3b) to a motor vehicle frame (1), the device for fixing each of the bearing structures (3a, 3b) having a connecting interface (5a, 5b) comprising at least one first connecting item (7a) fixed on the one hand in the longitudinal management (L1) by a front end (8 a) comprising the first connecting item (7 a) to the rear end (4) of the bearing structure (3a, 3b) and on the other hand in the transverse management (T1) by a rear end (8b) comprising the first connecting item (7a) on a lateral spar (1a, 1b) forming the frame (1), the first connecting item (7a) receiving at least one first reinforcing item (15a) connecting the front end (8a) and the rear end (8b) of the first connecting item (7a), the first reinforcing item (15a) being transverse (T1) in a longitudinal transverse drawing (T1-L1) between the front end (8 a) and the rear end (8b) of the first connecting item (7a), characterised in that the first reinforcing item (15a) comprises: first vertical section (16a) (V1) fixed to the first connecting item (7a) and extending between the front end (8a) and the rear end (8b) of the first connecting item (7a), a reinforcing wing (14b) (V1) extending vertically, with a top folded edge, which is realised from the material of the first connecting item (7a), the reinforcing wing (14b) extending at a transverse distance (T1) from the first section (16a) and at the edge of the first connecting item (7a) to the level of its edge directed transversely (T1) towards the inside (11) of the frame (1). second section (16b) extending longitudinally (L1) at least partially inside the quantity delimited between the first section (16a) and the reinforcing branch (14b), the second section (16b) being fixed transversely in opposing supports (T1) to the first section (16a) and to the reinforcing branch (14b).

2. Fastening device according to claim 1, wherein the first connecting item (7a) extends below the support rod (3a, 3b) and has a central part (8c) arranged between the front end (8a) and the rear end (8b) of the first connecting item (7a), the central part (8c) forming a transverse offset (T1) between the front end (8a) and the rear end (8b) of the first connecting item (7a).

3. Fastening device according to one of Claims 1 to 2, characterised in that characterised in that the first connecting member (7a) comprises a first shell (12a) having a raised bottom (13a) of marginal walls (V1) extending vertically, the bottom (13a) of the first shell (12a) being delimited between a first marginal wall (14a) and a second marginal wall (14b), wherein an edge (11) of the bottom (13a) of the first shell (12a) is delimited between the first marginal wall (14a) and the second marginal wall (14b), is pressed transversely (T1) against the spar (1a, 1b) and is delimited in the longitudinal management (L1) by a fixing branch (10) of the first connecting member (7a) vertically (V1) under the spar (1a, 1b), first fixing lug (9 a) of the first connecting item (7 a) is formed at the front end (8 a) of the first connecting item (7 a) between the first marginal wall (14 a) and the second marginal wall (14 b) at the rear end (4) of the support rod (3 a, 3 b), and wherein the second marginal wall (14b) is provided, at its rear end (8b), transversely (T1), against a lateral face of the lateral spar (1a, 1b), with a second fixing lug (9b) of the first connecting item (7a).

4. Fastening device according to claim 3, characterised in that characterised in that the reinforcing wing (14b) is constituted by the second peripheral wall which surrounds the first shell (12a), and The first section member (16a), which forms the first reinforcing member (15a), is pressed at its rear end against the reinforcing flange (14b), in front of the second fixing lug (9b).

5. Fastening device according to any one of Claims 1 to 4, characterised in that the connecting interfaces (5a, 5b) associated respectively with the branches (3a, 3b) also comprise respectively a second connecting item (7b) mounted transversely (T1) between the first connecting item (7a) and a transverse central shoe (T1) (19) fitted to the frame (1), the respective second connecting items (7b) of the connecting interfaces (5a, 5b) being in transverse abutment (T1) on either side of the shoe (19).

6. Fixing device according to claim 5, wherein, for each of the connecting interfaces (5a, 5b), the first connecting item (7a) and the second connecting item (7b) are in transverse abutment (T1) against each other, together forming a body of a single component.

7. Fastening device according to one of claims 1 to 4 and according to claim 6, wherein the second connecting item (7b) is arranged in a second shell (12b) extending longitudinally (L1) and transversely (T1) and receiving a second reinforcing item (15b), the reinforcing branch (14b) forming a partition between the internal volume of the first shell (12a) and the internal volume of the second shell (12b).

8. Motor vehicle comprising a frame (1) on which are fixed the respective rear ends (4) of the right and left bearing structures (3a, 3b) which has an engine frame mounted on the frame (1), wherein the rear ends (4) of the bearing structures (3a, 3b) are fixed to the frame (1) by means of a fixing device according to any one of claims 1 to 7.