Front end of a motor vehicle and motor vehicle comprising such a front end

Abstract

Front end of a motor vehicle and motor vehicle comprising such a front end. The invention relates to a front end (1) of a motor vehicle, comprising a support frame (11) for a bumper mounted under a hood of said vehicle and bearing, at a front edge, on a top beam of said front end, and, at a rear edge (15), on an upper transverse cross member of said front end, said support frame comprising a rear transverse frangible line (23). According to the invention, the support frame (11) comprises a plurality of longitudinal structural reinforcement lines (25) extending from the front of said support frame (11) to said rear transverse frangible line (23). The invention also relates to a motor vehicle comprising a front end. Figure 3

Description

Title of the invention: Front end of a motor vehicle and motor vehicle comprising such a front end Technical field

[0001] The invention relates to the field of motor vehicles, in particular to the field of passive safety of the motor vehicle in the event of pedestrian impact.

[0002] The invention relates more particularly to a front end of a motor vehicle and a motor vehicle comprising such a front end. Prior art

[0003] A motor vehicle has a front end, including in particular a front bumper and a grille.

[0004] The front bumper is supported in its upper part by a support frame mounted under the front of a hood and resting on rigid structural elements of the front face of the motor vehicle.

[0005] In particular, the support frame rests on an upper transverse cross member and, by means of a set of feet, on a high beam, also called a “repairability beam”, mounted opposite longitudinal structural beams, also called “stretchers”.

[0006] In the case of a pedestrian impact, the upper mass of the pedestrian's leg presses on the hood, the bumper and the grille.

[0007] Coupling the support frame to the rigid structural elements of the front face of the motor vehicle increases the rigidity of the support frame, thereby increasing the risk of aggravated injury to the pedestrian.

[0008] Furthermore, when the motor vehicle is an electric vehicle, the grille constitutes a more rigid and / or heavier style element than when it equips a thermal vehicle, due to the elimination of the air routing grilles towards the engine provided in the grilles equipping thermal vehicles.

[0009] Thus, during a pedestrian impact, the grille of an electric vehicle impacts the bumper support frame even more.

[0010] In order to limit the rigidity of the support frame and allow its deformation in the event of a pedestrian impact to ensure sufficient penetration of the leg, it is known to weaken the support frame by making it fusible thanks to the presence of longitudinal and transverse frangible lines obtained by reducing the thickness of the support frame.

[0011] However, some support frames have a very large upper surface area so that, during a pedestrian impact, the support frame tends to deform by buckling.

[0012] Buckling of the support frame then prevents the transverse frangible lines from breaking.

[0013] Thus, in the event of a pedestrian impact, the deflection of the hood is very limited, and the risk of injury to the pedestrian remains very high.

[0014] A solution further aiming to reduce the thickness of the support frame at the frangible lines to increase the fusibility of the support frame would not be conceivable because the support frame must retain sufficient rigidity to support the bumper. Statement of the invention

[0015] The present invention aims to overcome the aforementioned drawbacks, and to do so relates to a front end of a motor vehicle, comprising a support frame for a bumper, said support frame being mounted under a hood of said motor vehicle and bearing, at a front edge, on a top beam of said front end, and, at a rear edge, on an upper transverse cross member of said front end, said support frame comprising a rear transverse frangible line, said front end being remarkable in that said support frame comprises a plurality of longitudinal structural reinforcement lines extending from the front of said support frame to said rear transverse frangible line.

[0016] Thus, by providing longitudinal structural reinforcement lines arranged in the support frame, the support frame is stiffened in its longitudinal direction, which makes it possible to avoid buckling of the support frame when the motor vehicle is subjected to a pedestrian impact.

[0017] By avoiding buckling, it is possible to concentrate the stresses on the rear transverse frangible line of the support frame given that the longitudinal structural reinforcement lines extend in the support frame from the front to the rear transverse frangible line.

[0018] By concentrating the stresses in this way on the rear transverse frangible line of the support frame, a rupture of the rear transverse frangible line is obtained fairly quickly after the pedestrian impact.

[0019] By breaking the rear transverse frangible line of the support frame, the support frame becomes detached from the upper transverse cross member, which allows the support frame to collapse upon pedestrian impact.

[0020] Thus, thanks to the present invention, a faster and more systematic deformation of the support frame is obtained, which makes it possible to absorb the shock suffered by the pedestrian and to avoid serious injuries.

[0021] According to optional characteristics of the front face according to the invention: - said rear transverse frangible line is arranged at said rear edge of said support frame; - said support frame comprises at least one initiator orifice positioned in said rear transverse frangible line, opposite at least one of said longitudinal structural reinforcement lines; - said support frame comprises an additional transverse frangible line arranged in front of said rear transverse frangible line and said longitudinal structural reinforcement lines extend from the additional transverse frangible line to said rear transverse frangible line; - said support frame comprises at least one longitudinal frangible line; - said longitudinal lines of structural reinforcement each have a length greater than or equal to approximately 50% of the length of said support frame; - said longitudinal lines of structural reinforcement are distributed discretely over said support frame and they are arranged to cover the entire width of said support frame; - each of said longitudinal lines of structural reinforcement consists of a boss; - said support frame comprises an upper face facing the hood of said motor vehicle and a lower face facing said upper beam and said upper transverse cross member of said front face, and said longitudinal structural reinforcement lines extend over said upper face.

[0022] The invention also relates to a motor vehicle comprising a front face, remarkable in that said front face is according to the invention. Brief description of the drawings

[0023] 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:

[0024] [Fig-1] shows a front face of a motor vehicle according to the invention, seen in perspective from the front of the vehicle.

[0025] [Fig.2] shows the front face of the motor vehicle seen in longitudinal section.

[0026] [Fig.3] is a top view of the front face of the motor vehicle.

[0027] [Fig.4] shows the support frame seen in perspective from above.

[0028] [Fig.5] illustrates the behavior of the front face of the pedestrian after an impact suffered by the motor vehicle.

[0029] [Fig.6] shows the front face of the motor vehicle in top view according to a variant of realization.

[0030] [Fig.7] shows the front face of the motor vehicle in top view according to another variant embodiment. Description of the embodiments

[0031] In the remainder of the description, elements having an identical structure or similar functions are designated by the same reference.

[0032] By convention, longitudinal, vertical and transverse orientations will be adopted, without limitation, indicated by the direct trihedron (L, V, T) designating the longitudinal, vertical and transverse axes of the vehicle.

[0033] In the following, the terms “left”, “right”, “lower” and “upper” are understood in relation to the vehicle.

[0034] Similarly, the terms “front” and “rear” are understood in relation to the general orientation of the vehicle as taken in its normal direction of travel.

[0035] Reference is made to Figures 1 and 2 showing a front face 1 of a motor vehicle 3, seen respectively in perspective from the front of the vehicle and in longitudinal section.

[0036] The front face 1 of the motor vehicle 3 comprises, in particular, a front bumper 5 (shown in [Fig.2] only) and a grille (not shown).

[0037] The front face 1 of the motor vehicle comprises a set of structural elements comprising longitudinal lower beams (not shown), commonly called “extensions” and positioned parallel on either side of the powertrain (not shown in the figures).

[0038] The longitudinal lower beams or extensions are mounted below, in the vertical direction of the motor vehicle 3, longitudinal structural beams 7 commonly called “stretchers” (shown in [Fig.l] only).

[0039] At the front of the front ends of the longitudinal lower beams there is a lower front beam (not shown in the figures), which beam extends transversely relative to the motor vehicle 3.

[0040] The lower front beam is mounted below a high beam 9, also called a “repairability beam”, mounted opposite the longitudinal structural beams 7 and extending substantially transversely relative to the motor vehicle 3.

[0041] The front bumper 5 is supported in its upper part by a support frame 11, mounted under the front of a hood 13 (shown in [Fig.2] only).

[0042] In particular, the support frame 11 rests at a rear edge 15 on an upper transverse cross member 17 extending substantially transversely relative to the motor vehicle 3. At a front edge 19, the support frame support 11 rests via a set of feet 21 on the upper beam 9.

[0043] We refer to [Fig.3] showing the front face 1 seen from above.

[0044] The support frame 11 comprises a rear transverse frangible line 23 (shown in dotted lines in [Fig. 3]) arranged substantially transversely relative to the support frame 11, that is to say substantially transversely relative to the motor vehicle 3.

[0045] The rear transverse frangible line 23 is obtained by a reduction in thickness of the support frame 11, the reduction in thickness being adapted to make the support frame 11 fusible at the rear transverse frangible line 23 while retaining sufficient rigidity to support the bumper 5.

[0046] The term "rear" used to designate the transverse frangible line 23 designates a positioning of the transverse frangible line 23 relative to the support frame 11 behind the support frame 11, that is to say close to the rear edge 15 of the support frame 11. More particularly, the support frame can be divided into three zones Zb Z2, Z3, of identical length and distributed over the entire length Li of the support frame 11. Zone Zi constitutes a front zone, zone Z2 constitutes a middle zone and zone Z3 constitutes a rear zone. The rear transverse frangible line 23 is included in the rear zone Z3 of the support frame 11. More particularly, the rear transverse frangible line 23 extends in front of the upper transverse cross member 17 on which the rear edge 15 of the support frame 11 rests.

[0047] In the embodiment illustrated in the figures, the rear transverse frangible line 23 is arranged at the rear edge 15 of the support frame 11.

[0048] According to the invention, the support frame 11 comprises a plurality of longitudinal structural reinforcement lines 25, arranged substantially longitudinally relative to the support frame 11, that is to say substantially longitudinally relative to the motor vehicle 3.

[0049] The longitudinal structural reinforcement lines 25 extend from the front of the support frame 11 to the rear transverse frangible line 23. Thus, the longitudinal structural reinforcement lines 25 are adapted to transmit the forces to the rear transverse frangible line 23.

[0050] Thus, by providing longitudinal structural reinforcement lines 25 arranged in the support frame 11, the support frame 11 is stiffened in its longitudinal direction, which makes it possible to avoid buckling of the support frame 11 when the motor vehicle is subjected to a pedestrian impact.

[0051] By avoiding buckling, it is possible to concentrate the stresses on the rear transverse frangible line of the support frame given that the longitudinal structural reinforcement lines 25 extend into the support frame 11 from the front to the rear transverse frangible line 23.

[0052] By concentrating the stresses in this way on the rear transverse frangible line 23 of the support frame 11, a rupture of the rear transverse frangible line 23 is obtained fairly quickly after the pedestrian impact.

[0053] By breaking the rear transverse frangible line 23 of the support frame 11, the support frame 11 becomes detached from the upper transverse cross member 17, which allows the support frame 11 to collapse during pedestrian impact.

[0054] The longitudinal structural reinforcement lines 25 are adapted to transmit the forces to the rear transverse frangible line 23. In an exemplary embodiment of the invention, the longitudinal structural reinforcement lines 25 may consist of a boss of the support frame 11.

[0055] The longitudinal structural reinforcement lines 25 may be made of the same material as that used for the manufacture of the support frame 11. For example, the longitudinal structural reinforcement lines 25 and the support frame 11 are made of a plastic material. For example, the longitudinal structural reinforcement lines 25 and the support frame 11 may be obtained by plastic injection during a common molding step of the support frame 11 and the longitudinal structural reinforcement lines 25.

[0056] In the embodiment illustrated in the figures, the support frame 11 comprises an upper face 27, facing the hood 13 (visible in [Fig.2]) of the motor vehicle 3 and a lower face 29 (visible in [Fig.2]) facing the upper beam 9 and the upper transverse cross member 17. The longitudinal structural reinforcement lines 25 extend over the upper face 27 of the support frame 11.

[0057] In the embodiment illustrated in the figures, the longitudinal reinforcement lines each have a length L2 greater than or equal to approximately 50% of the length Li of the support frame 11, which allows good stiffening of the support frame 11 in its longitudinal direction. The buckling resistance of the support frame 11 is further reinforced when the motor vehicle 3 is subjected to a pedestrian impact.

[0058] Also, in the embodiment illustrated in the figures, the longitudinal reinforcement lines 25 are distributed discretely over the support frame 11. Their distribution over the width 1 of the support frame 11 is such that the longitudinal reinforcement lines 25 cover the entire width 1 of the support frame 11. Thus, all possible impact points of the pedestrian's leg are covered during a pedestrian impact.

[0059] Depending on the width 1 of the support frame 11, the number of longitudinal reinforcement lines 25 varies between five and nine. In the exemplary embodiment illustrated in the figures, seven longitudinal reinforcement lines 25 equip the support frame 11.

[0060] We now refer to [Fig.4] showing the support frame 11 in top perspective, centered on two consecutive longitudinal reinforcement lines 25.

[0061] In the embodiment illustrated in the figures, the support frame 11 comprises a plurality of initiator orifices 31, positioned in the rear transverse frangible line 23 opposite the longitudinal structural reinforcement lines 25.

[0062] The presence of such initiator orifices 31 makes it possible to further improve the rupture of the rear transverse frangible line 23.

[0063] The support frame 11 may comprise as many starter holes 31 as there are longitudinal lines of structural reinforcement 25.

[0064] Alternatively, the support frame 11 may comprise a different number of starter holes 31 and longitudinal structural reinforcement lines 25.

[0065] Also, in an embodiment not shown in the figures, no primer orifice 31 is provided in the support frame 11.

[0066] We refer to [Fig.5] illustrating the behavior of the front face 1 after a pedestrian impact suffered by the motor vehicle.

[0067] When the motor vehicle 3 experiences a pedestrian impact, the force generated by the impact of a pedestrian's leg on the support frame 11 (step A) is transmitted behind the support frame 11 (step B).

[0068] The presence of the longitudinal reinforcement lines 25 (only one being visible in [Fig.5]) makes it possible to avoid buckling of the support frame 11.

[0069] Consequently, the forces are very quickly transmitted to the rear transverse frangible line 23, which breaks (step C).

[0070] The support frame 11 becomes detached from the upper transverse cross member 17 (not visible in [Fig.5]), causing the support frame 11 to collapse.

[0071] According to an alternative embodiment not shown in the figures, in order to further improve the behavior of the support frame 11, the support frame 11 may comprise one or more longitudinal frangible lines in addition to the rear transverse frangible line 23.

[0072] We refer to [Fig.6] showing the front face 1 in top view according to an alternative embodiment.

[0073] According to the embodiment variant shown in [Fig. 6], the support frame 11 of the front face 1 further comprises an additional transverse frangible line 33 arranged in front of the rear transverse frangible line 23. The longitudinal structural reinforcement lines 25 extend from the additional transverse frangible line 33 to the rear transverse frangible line 23.

[0074] We refer to [Fig.7] showing the front face 1 in top view according to another variant of realization.

[0075] In this variant embodiment, the support frame 11 comprises, in addition to the additional transverse frangible line 33, another additional transverse frangible line 35 arranged in front of the additional transverse frangible line 33.

[0076] Also, the support frame 11 here comprises a set of longitudinal frangible lines 37 arranged between the transverse frangible lines 33, 35.

[0077] Alternatively, the support frame 11 may comprise one or more longitudinal frangible lines 37 arranged differently in the support frame 11, i.e. not necessarily between the transverse frangible lines 33, 35.

[0078] According to an arrangement common to the variant embodiments, the distribution of the transverse and / or longitudinal frangible lines on the support frame 11 can be adapted according to the constraints to be supported and the geometry of the support frame 11.

[0079] As goes without saying, the present invention is not limited to the sole embodiments of this motor vehicle front end and of this motor vehicle comprising such a front end, described above solely as illustrative examples, but on the contrary it embraces all the 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. Front end (1) of a motor vehicle (3), comprising a support frame (11) for a bumper (5), said support frame (11) being mounted under a hood (13) of said motor vehicle (3) and bearing, at a front edge (19), on a top beam (9) of said front end (1), and, at a rear edge (15), on an upper transverse cross member (17) of said front end (1), said support frame (11) comprising a rear transverse frangible line (23), said front end (1) being characterized in that said support frame (11) comprises a plurality of longitudinal structural reinforcement lines (25) extending from the front of said support frame (11) to said rear transverse frangible line (23).

2. Front face (1) according to claim 1, characterized in that said rear transverse frangible line (23) is arranged at said rear edge (15) of said support frame (11).

3. Front face (1) according to one of claims 1 or 2, characterized in that said support frame (11) comprises at least one initiator orifice (31) positioned in said rear transverse frangible line (23), opposite at least one of said longitudinal structural reinforcement lines (25).

4. Front face (1) according to any one of claims 1 to 3, characterized in that said support frame (11) comprises an additional transverse frangible line (33) arranged in front of said rear transverse frangible line (23) and in that said longitudinal structural reinforcement lines (25) extend from the additional transverse frangible line (33) to said rear transverse frangible line (23).

5. Front face (1) according to any one of claims 1 to 4, characterized in that said support frame (11) comprises at least one longitudinal frangible line (37).

6. Front face (1) according to any one of claims 1 to 5, characterized in that said longitudinal structural reinforcement lines (25) each have a length (L2) greater than or equal to approximately 50% of the length (LJ) of said support frame (11).

7. Front face (1) according to any one of claims 1 to 6, characterized in that said longitudinal structural reinforcement lines (25) are distributed discreetly on said frame of support (11) and in that they are arranged to cover the entire width (1) of said support frame (11).

8. Front face (1) according to any one of claims 1 to 7, characterized in that each of said longitudinal structural reinforcement lines (25) consists of a boss.

9. Front face (1) according to any one of claims 1 to 8, characterized in that said support frame (11) comprises an upper face (27) facing the hood (13) of said motor vehicle (3) and a lower face (29) facing said upper beam (9) and said upper transverse cross member (17) of said front face (1), and in that said longitudinal structural reinforcement lines (25) extend over said upper face (27).

10. Motor vehicle (3) comprising a front face (1), characterized in that said front face (1) is according to any one of claims 1 to 9.

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