Motor vehicle structure, and motor vehicle comprising such a structure

Abstract

The invention relates to a motor vehicle structure (11) comprising: - two lateral longitudinal members (13), extending longitudinally relative to the structure on either side of the structure; - a strut bar (15), extending transversely relative to the structure and connecting the lateral longitudinal members to one another; - a fastening device, arranged to fasten the strut bar to the lateral longitudinal members. According to the invention, the fastening device comprises a structural reinforcement assembly (19) interfacing between at least one of the lateral longitudinal members (13) and the strut bar (15), which assembly is arranged in the structure (11) in order to transmit transverse forces directly from the at least one of the lateral longitudinal members (13) to the strut bar (15) when the motor vehicle is subjected to a side impact. The invention also relates to a motor vehicle comprising such a structure (11).

Description

DESCRIPTION TITLE: Motor vehicle structure and motor vehicle comprising such a structure [Technical field]

[0001] The present invention claims priority from French application 2210099 filed on October 3, 2022, the content of which (text, drawings and claims) is incorporated herein by reference. The invention relates to the field of motor vehicles and more particularly concerns a motor vehicle structure and a motor vehicle comprising such a structure. [State of the prior art]

[0002] The body of a motor vehicle comprises a set of structural elements which give stiffness to the motor vehicle and which belong to a motor vehicle structure.

[0003] Reference is made to Figure 1 showing a structure 1 of a motor vehicle of the prior art.

[0004] The motor vehicle structure 1 comprises, among other things, at its lateral face, longitudinal members 3, lower horizontal elements mounted at the rear of the motor vehicle structure 1, symmetrically on either side of a longitudinal median plane of symmetry of the motor vehicle structure 1.

[0005] As is known, when the motor vehicle is electrically powered, a traction battery, supplying the electric motor of the motor vehicle, is fitted to the motor vehicle.

[0006] Among the many tests used for the approval of motor vehicles, a so-called "pole" impact is carried out.

[0007] This test consists of projecting the motor vehicle laterally at a speed of approximately 30 km / h onto a rigid pole.

[0008] The vehicle successfully passes the "pole" impact when, at the end of the impact, certain parts of the vehicle are not impacted, in particular the active elements of the motor vehicle's traction battery.

[0009] In order to protect the traction battery of the electric motor vehicle in the event of a "pole" impact, the side members 3 are connected to each other by means of a bar anti-approach 5, forming a transverse crosspiece and intended to prevent the side members 3 from approaching in the event of a “post” impact.

[0010] Each of the lateral ends of the anti-roll bar 5 is fixed to the corresponding side member 3 by means of a fixing screw.

[0011] In the event of a “post” impact, the post pushes the corresponding longitudinal member 3 towards the inside of the structure 1 of the motor vehicle, and the anti-roll bar 5 acts in such a way as to prevent the longitudinal member 3 from moving towards the inside of the vehicle.

[0012] During such a “post” impact, the fixing screw, ensuring the fixing of the anti-rapprochement bar 5 on the corresponding side member 3, is subjected to significant shear forces, which may cause it to break. [Statement of the invention]

[0013] The present invention aims to overcome the aforementioned drawbacks, and to this end relates to a motor vehicle structure, comprising: - two lateral longitudinal members, extending longitudinally relative to said structure, on either side of said structure, - an anti-approach bar, extending transversely relative to said structure and connecting said lateral side members together, - a fixing device, arranged to fix said anti-roll bar on said side rails, said structure being remarkable in that said fixing device comprises a structural reinforcement assembly interfacing between at least one of said side rails and said anti-roll bar, arranged in said structure to transmit transverse forces directly from said at least one of said side rails to said anti-roll bar when said motor vehicle is subjected to a side impact.

[0014] Thus, by providing a structural reinforcement assembly which interfaces between at least one of the side rails and the anti-roll bar, and which is arranged to transmit transverse forces directly from said at least one of the side rails to said anti-roll bar when said motor vehicle is subjected to a lateral impact, the shear forces absorbed by the fixing device which is arranged to fix said anti-roll bar to the corresponding side rail are limited.

[0015] According to optional characteristics of the structure according to the invention: - said structural reinforcement assembly comprises at least one hollow anti-shear body, fixed on said anti-approach bar, at least one fixing nut, fixed on at least one of said lateral side members, at least one tightening screw, arranged in said structure so as to tighten said at least one hollow anti-shear body on said at least one fixing nut. Thus, in the event of a side impact of the motor vehicle, in particular in the event of a "post" impact, the transverse force is transmitted from the side member to the fixing nut, which then transmits the transverse force to the hollow anti-shear body. The hollow anti-shear body then transmits the transverse force to the strut bar. Thus, the shear force at the clamping screw of the fixing device is largely limited. The clamping screw therefore only serves to tighten the hollow anti-shear body onto the fixing nut. Also, thanks to the present invention, the reinforcement of the vehicle structure does not require increasing the diameter of the tightening screw or the number of tightening screws, a solution which would be incompatible with integration into the architecture of the motor vehicle structure. Also, the removable aspect of the structure is advantageously preserved, unlike a solution which would aim to rivet the anti-rapprochement bar on the side member or to weld it via a weld bead; - in one embodiment of the structure according to the invention, said structural reinforcement assembly has, on the one hand, a radial clearance between said hollow anti-shear body and said fixing nut, and, on the other hand, a radial clearance between said hollow anti-shear body and said tightening screw, said radial clearance between said hollow anti-shear body and said fixing nut being less than said radial clearance between said hollow anti-shear body and said tightening screw; - in one embodiment of the structure according to the invention, said hollow anti-shear body comprises an upper internal opening and a lower cylindrical internal opening, and said fixing nut comprises a cylindrical external face opposite said lower cylindrical internal opening; - in another embodiment of the structure according to the invention, said hollow anti-shear body comprises an upper internal opening and a lower frustoconical internal opening, and said fixing nut comprises a frustoconical external face opposite said lower frustoconical internal opening; - according to one arrangement of the invention, said hollow anti-shear body has a stiffness greater than that of said clamping screw; - in another embodiment of the structure according to the invention, the hollow anti-shear body may consist of a spacer.

[0016] The invention also relates to a motor vehicle comprising a structure, remarkable in that said structure is obtained according to the invention. [Description of the drawings]

[0017] Other characteristics, aims and advantages of the invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the appended drawings in which:

[0018] [Fig. 1] is an isometric view of a prior art motor vehicle structure.

[0019] [Fig. 2] shows a partial top view of a structure of a motor vehicle according to the invention.

[0020] [Fig. 3] is a sectional view along line III-III of Figure 2.

[0021] [Fig. 4] schematically illustrates the kinematics of force transmission during a lateral impact applied to the motor vehicle according to the invention. [Description of embodiments]

[0022] In the remainder of the description, elements having an identical structure or similar functions are designated by the same reference.

[0023] By convention, we will adopt, without limitation, longitudinal, vertical and transverse orientations indicated by the direct trihedron (L, V, T) designating the longitudinal, vertical and transverse axes of the vehicle.

[0024] In the following, the terms "front", "rear", "left", "right", "lower" and "upper" refer to the vehicle.

[0025] Reference is made to Figure 2 showing a partial top view of a structure 11 of a motor vehicle according to the invention.

[0026] The motor vehicle structure 11 comprises, among other things, at its lateral faces 11a, 11b, two lateral longitudinal members 13, extending longitudinally relative to the structure 11, on either side of the structure 11.

[0027] The motor vehicle structure 11 admits a longitudinal median plane of symmetry of the motor vehicle structure 11. Thus, the description given for the right part of the motor vehicle structure 11 applies by analogy to the left part of the motor vehicle structure, and vice versa.

[0028] The lateral side members 13 form lower horizontal elements mounted at the rear of the motor vehicle structure 11 symmetrically on either side of the longitudinal median plane of symmetry of the motor vehicle structure 11.

[0029] The side rails 13 are connected to each other by means of an anti-approach bar 15, extending transversely relative to the structure 11 of the motor vehicle and connecting the side rails 13 to each other.

[0030] The anti-roll bar 15 thus forms a transverse cross member having the function, among other things, of preventing the side rails 13 from coming together in the event of a side impact of the vehicle, in particular a “post” impact.

[0031] The structure 11 further comprises a fixing device 17, arranged to fix the anti-approach bar 15 on the lateral side members 13.

[0032] More particularly, the anti-approach bar 15 is fixed on the corresponding lateral longitudinal members 13 at each of its lateral ends 15a, 15b.

[0033] The fixing device 17 comprises a structural reinforcement assembly 19 interfacing between the lateral beam 13 and the anti-approach bar 15.

[0034] The structural reinforcement assembly 19 of the fixing device 17 is mounted at each of the lateral ends 15a, 15b of the anti-approach bar 15.

[0035] Reference is made to Figure 3, seen in section along line III-III of Figure 2, to illustrate an exemplary embodiment of the structural reinforcement assembly 19 of the fixing device 17 of the structure 11 of the invention.

[0036] The structural reinforcement assembly 19 comprises a hollow anti-shear body 21.

[0037] The hollow anti-shear body 21 comprises a longitudinal axis 22 extending substantially vertically when it is mounted in the motor vehicle structure 11.

[0038] The hollow anti-shear body 21 consists, for example, of a spacer or a tube.

[0039] The hollow anti-shear body 21 comprises an upper internal opening 23, which may for example be cylindrical, and a lower internal opening 25, for example cylindrical, of diameter greater than that of the upper internal opening 23.

[0040] The upper internal opening 23 and the lower internal opening 25 are for example made over the entire length of the hollow anti-shear body 21.

[0041] The hollow anti-shear body 21 has an external face 27, for example cylindrical.

[0042] The hollow anti-shear body 21 is mounted in a bore 29 made in the anti-approximation bar 15. The hollow anti-shear body 21 is fixed to the anti-approximation bar 15, for example by welding or by crimping. Other methods of fixing can however be envisaged.

[0043] The structural reinforcement assembly 19 also includes a fixing nut 31.

[0044] The fixing nut 31 has an external face 33, for example cylindrical, facing the lower internal opening 25 of the hollow anti-shear body 21.

[0045] The fixing nut 31 is fixed at its base 35 on the lateral beam 13, for example by welding or by crimping. Other fixing methods can however be envisaged.

[0046] The hollow anti-shear body 21 is held on the fixing nut 31 by means of a clamping screw 37, screwed onto the fixing nut 31.

[0047] According to one arrangement of the invention, the hollow anti-shear body 21 has a stiffness greater than that of the clamping screw 37.

[0048] The clamping screw 37 is arranged in the structure 11 so as to clamp the hollow anti-shear body 21 onto the fixing nut 31.

[0049] The structural reinforcement assembly 19 has a radial clearance J1, between the hollow anti-shear body 21 and the fixing nut 31, as well as a radial clearance J2, between the hollow anti-shear body 21 and the clamping screw 37.

[0050] The radial clearance J1 between the hollow anti-shear body 21 and the fixing nut 31 extends more particularly between the lower internal opening 25 of the hollow anti-shear body 21 and the external face 33 of the fixing nut 31.

[0051] According to the invention, the radial clearance J1 between the hollow anti-shear body 21 and the fixing nut 31 is less than the radial clearance J2 between the hollow anti-shear body 21 and the clamping screw 37.

[0052] According to an alternative embodiment not shown, the lower internal opening 25 of the hollow anti-shear body 21 may be frustoconical.

[0053] In this case, the external face 33 of the fixing nut 31 is also frustoconical, so as to extend in a complementary manner to the lower internal opening 25 of the hollow anti-shear body 21.

[0054] According to this embodiment variant, the radial clearance J1 between the hollow anti-shear body 21 and the fixing nut 31, more particularly between the external face 33 of the fixing nut 31 and the lower internal opening 25 of the hollow anti-shear body 21, is less than the radial clearance J2 between the hollow anti-shear body 21 and the clamping screw 37.

[0055] According to this embodiment variant, the radial clearance J1 between the hollow anti-shear body 21 and the fixing nut 31, more particularly between the external face 33 of the fixing nut 31 and the lower internal opening 25 of the hollow anti-shear body 21, can be zero.

[0056] The operation of the invention is now described with reference to Figure 4 showing schematically the kinematics of transmission of forces during a lateral impact applied to the motor vehicle according to the invention.

[0057] During a side impact, in particular during a “pole” impact consisting of projecting the motor vehicle laterally at a speed of approximately 30 km / h onto a rigid pole, the side member 13 is subjected to a transverse force directed towards the inside of the structure 11 of the motor vehicle, as represented by the arrow 39.

[0058] The assembly formed by the longitudinal member 13, by the fixing nut 31, fixed on the longitudinal member 13, and by the clamping screw 37 screwed onto the fixing nut 31, forms a solid assembly which moves relative to the assembly formed by the hollow anti-shear body 21 and by the anti-approximation bar 15 on which the hollow anti-shear body 21 is fixed.

[0059] The radial clearance J1, present between the hollow anti-shear body 21 and the fixing nut 31, is then taken up before the radial clearance J2 present between the clamping screw 37 and the hollow anti-shear body 21 taking into account the fact that the radial clearance J1 is less than the radial clearance J2.

[0060] Thus, the transverse force 39 is taken up by the fixing nut 31, which then transmits it to the hollow anti-shear body 21 without transmitting the transverse force 39 to the clamping screw 37, as represented by the arrows 41, 43.

[0061] Thus, the role of the clamping screw 37 is thus limited to the sole clamping of the hollow anti-shear body 21 on the fixing nut 31.

[0062] The hollow anti-shear body 21, dimensioned so as to transmit to the longitudinal member 13 the transverse forces without yielding, in particular the forces undergone during the “post” impact, then transmits the radial force to the anti-approach bar 15, as represented by the arrows 45.

[0063] Thanks to the present invention, when the motor vehicle is subjected to a lateral impact, in particular a "post" impact, the structural reinforcement assembly 19 transmits the transverse forces from the lateral side member 13 opposite which the lateral impact occurs to the anti-roll bar 15, without the clamping screw 37 taking up the transverse forces.

[0064] This avoids subjecting the clamping screw 37 to significant shear forces during a “post” impact, unlike the structures of the prior art.

[0065] The risk of breakage of the clamping screw 37 of the structure 11 of the invention during a “post” impact is thus advantageously greatly reduced.

[0066] As goes without saying, the present invention is not limited to the sole embodiments of this motor vehicle structure and of this motor vehicle comprising such a structure, described above solely as illustrative examples, but on the contrary it embraces all variants involving the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

Claims

Claims

1. Structure (11) of a motor vehicle, comprising: - two lateral longitudinal members (13), extending longitudinally relative to said structure (11), on either side of said structure (11), - an anti-approach bar (15), extending transversely relative to said structure (11) and connecting said lateral longitudinal members (13) together, - a fixing device (17), arranged to fix said anti-roll bar (15) on said lateral side members (13), said structure (11) being characterized in that said fixing device (17) comprises a structural reinforcement assembly (19) interfacing between at least one of said lateral side members (13) and said anti-roll bar (15), arranged in said structure (11) to transmit transverse forces directly from said at least one of said lateral side members (13) to said anti-roll bar (15) when said motor vehicle is subjected to a lateral impact.

2. Structure (11) of a motor vehicle according to claim 1, characterized in that said structural reinforcement assembly (19) comprises: - at least one hollow anti-shear body (21), fixed on said anti-approach bar (15), - at least one fixing nut (31), fixed on at least one of said lateral longitudinal members (13), - at least one clamping screw (37), arranged in said structure (11) so as to tighten said at least one hollow anti-shear body (21) on said at least one fixing nut (31).

3. Structure (11) of a motor vehicle according to claim 2, characterized in that said structural reinforcement assembly (19) has: - on the one hand, a radial clearance (J1) between said hollow anti-shear body (21) and said fixing nut (31), and - on the other hand, a radial clearance (J2) between said hollow anti-shear body (21) and said clamping screw (37), said radial clearance (J1) between said hollow anti-shear body (21) and said fixing nut (31) being less than said radial clearance (J2) between said hollow anti-shear body (21) and said clamping screw (37).

4. Structure (11) of a motor vehicle according to one of claims 2 or 3, characterized in that said hollow anti-shear body (21) comprises an opening upper internal opening (23) and a lower internal cylindrical opening (25), and in that said fixing nut (31) comprises a cylindrical external face (33) opposite said lower internal cylindrical opening (25).

5. Motor vehicle structure (11) according to one of claims 2 or 3, characterized in that said hollow anti-shear body (21) has an upper internal opening (23) and a lower internal frustoconical opening (25), and in that said fixing nut (31) has a frustoconical external face (33) opposite said lower internal frustoconical opening (25).

6. Structure (11) of a motor vehicle according to any one of claims 2 to 5, characterized in that said hollow anti-shear body (21) has a stiffness greater than that of said clamping screw (37).

7. Motor vehicle structure (11) according to any one of claims 2 to 6, characterized in that the hollow anti-shear body (21) consists of a spacer.

8. Motor vehicle comprising a structure (11), characterized in that said structure (11) is obtained according to any one of claims 1 to 7.

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