Motor vehicle front end with impact absorber for an overhanging reinforcement

Abstract

The present invention relates to a motor vehicle (2) comprising, at the front (1): - a bumper beam (12); - a bumper wall (10); - a bumper reinforcement (6); - an impact absorber (4) disposed between the bumper wall and the bumper beam; characterized in that the absorber comprises two vertical extensions (5) each comprising an upper face (5.1) forming a ramp extending upward and toward the front of the motor vehicle, said ramp facing a corresponding lower face (6.1) of the reinforcement, so as to allow the impact absorber to deform in compression against each of said lower faces of the reinforcement in the event of a front impact.

Description

[0001] DESCRIPTION

[0002] TITLE: FRONT PANEL OF MOTOR VEHICLE WITH SHOCK ABSORBER FOR CANTILEVER FRAME

[0003] Technical field

[0004] The present invention claims priority from French application 2309988 filed on September 21, 2023, the content of which (text, drawings and claims) is incorporated herein by reference.

[0005] The present invention relates to the field of motor vehicles, more particularly the field of motor vehicle bumpers.

[0006] Prior art

[0007] Current motor vehicles conventionally incorporate a shock absorber behind the front bumper skin and resting against the transverse beam, also referred to as: "absorption system", the absorber is capable of deforming elastically in the event of low-intensity frontal impacts against a buffer, in order to preserve the transverse beam and improve the performance of the motor vehicle in the event of small impacts, commonly referred to as: parking shocks.

[0008] The bumper is the most frequently damaged part in the event of an impact, and the cost of repairing it is not negligible. This is why a vehicle's responses to test protocols, such as the ECE42 impact or parking impacts at low speed, generally 4 km / h, are criteria increasingly taken into consideration by car manufacturers.

[0009] Conventionally, the absorber placed in abutment against the transverse beam is separated from the bumper skin in order to allow the establishment of different materials between said absorber and the bumper, for example, and respectively, in expanded polypropylene and in polyethylene, thus making it possible to absorb the kinetic energy of a light impact and to improve the response of the vehicles to the different impact protocols at low speed.

[0010] New motor vehicle models increasingly feature illuminated front grilles to provide a distinctive stylistic lighting signature that leaves a modern impression that is much appreciated by consumers, but also ensures better visibility of motor vehicles on the road.

[0011] However, illuminated grilles require a larger frame to be placed further longitudinally away from the cross beam. This leads to a weakness in terms of impact energy absorption at the bumper wall directly opposite the absorber.

[0012] Published patent document FR 3 096 321 A1 discloses a bumper module comprising a cross member from which extends vertically an upper bumper unit comprising two upper shock absorbers extending longitudinally to be directly attached to an upper front bumper beam.

[0013] However, the solution proposed by the document has room for improvement, as adding two upper shock absorbers in parallel with two lower absorbers is costly.

[0014] Statement of the invention

[0015] The present invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a simple, efficient and economical solution making it possible to effectively protect the bumper skin opposite a frame which is longitudinally forward relative to a transverse beam of the motor vehicle, in particular during parking impacts at low speed.

[0016] To this end, the invention relates to a motor vehicle comprising, at the front:

[0017] - a bumper beam;

[0018] - a bumper wall;

[0019] - a bumper frame;

[0020] - a shock absorber arranged between the bumper wall and the bumper beam; remarkable in that the absorber comprises two vertical extensions each comprising an upper face forming a ramp extending upwards and towards the front of the motor vehicle, said ramp being opposite a corresponding lower face of the frame, so as to allow the shock absorber to deform in compression against each of said lower faces of the frame in the event of a front impact.

[0021] According to one embodiment, the lower face of the frame is parallel to, and at a distance of at most 10 mm from, the ramp of the corresponding vertical extension.

[0022] According to one embodiment, the ramp is inclined relative to a longitudinal direction of said motor vehicle at an angle of between 30° and 60°.

[0023] According to one embodiment, each vertical extension further comprises a rear face facing a vertical wall of a lower part of the frame, said vertical wall forming a downward extension of the lower faces.

[0024] According to one embodiment, each vertical extension further comprises a lug extending vertically from a top of the ramp, said lug being configured to constitute a final compression contact point of the shock absorber against the frame.

[0025] According to one embodiment, the lug extends longitudinally and vertically over at least 5 mm and at most 15 mm.

[0026] According to one embodiment, each of the vertical extensions extends vertically by at least 50 mm.

[0027] According to one embodiment, the vertical extensions are spaced transversely by at least 400 mm.

[0028] According to one embodiment, the vertical extensions are made of polypropylene foam.

[0029] According to one embodiment, the frame comprises a front face facing the bumper wall, said front face being arranged approximately 80 mm from the bumper beam, in a longitudinal direction.

[0030] The measures of the invention are advantageous in that the absorber having two vertical extensions gradually coming into contact against the lower face of the absorber, allow the absorber to deform in longitudinal compression in order to absorb the energy of the frontal impact at low speed, so as to allow only an elastic deformation of the bumper wall opposite the frame advanced relative to the bumper beam, and this without deformation and / or breakage of the bumper wall. Brief description of the drawings

[0031] [Fig 1] represents a perspective view of a front face of a motor vehicle comprising a shock absorber comprising two vertical extensions facing a lower face of the frame, said motor vehicle being according to the invention;

[0032] [Fig 2] shows a longitudinal sectional view of the front face of Figure 1, including the longitudinally spaced reinforcement of a bumper cross beam;

[0033] [Fig 3] represents a perspective view of one of the two vertical extensions of the absorber comprising an upper face forming a ramp arranged at a distance from the lower face of the frame;

[0034] [Fig 4] represents the perspective view of figure 3, during the start of compression of the absorber, caused by a front impact against the bumper wall;

[0035] [Fig 5] represents the perspective view of figure 3, during an end of compression of the absorber, caused by the front impact;

[0036] [Fig 6] represents the longitudinal sectional view of Figure 2, illustrating a deformation of the bumper wall after compression of the absorber following the front impact.

[0037] Detailed description

[0038] Figure 1 represents a perspective view of a front face 1 of a motor vehicle 2 comprising a shock absorber 4 facing a lower face 6.1 of the frame 6.

[0039] The motor vehicle 2 comprises an illuminated grille 8 supported vertically by the frame 6, the latter comprising a front face 6.2 arranged opposite a bumper wall, and longitudinally at a distance from a transverse bumper beam 12. The front face 6.2 being arranged approximately 80 mm from said beam 12, in the longitudinal direction.

[0040] This distance from the front face 6.2 of the beam 12 is clearly visible in Figure 2, in which said distance is represented by the distance x. In this configuration, and without the solution proposed by the present invention, a low-speed front impact may risk directly and abruptly striking the frame 6 and thus damaging (by breakage and / or plastic deformation) the bumper wall 10 located opposite the front face 6.2.

[0041] Advantageously, the present invention proposes the absorber 4 comprising two vertical extensions 5 each comprising an upper face 5.1 forming a ramp 5.1 extending upwards and towards the front of the motor vehicle 2, each of the two ramps 5.1 being opposite the lower face 6.1.

[0042] The vertical extensions 5 are formed with the absorber 4, preferably made of expanded polypropylene (EPP) foam. Preferably, the vertical extensions 5 are spaced transversely from each other by at least 400 mm, and more preferably by approximately 500 mm.

[0043] The two vertical extensions 5 allow the absorber 4 to deform in compression against each of said lower faces 6.1 of the frame 6 during a low-speed front impact. This has the advantage of extending both vertically and longitudinally the absorption capacity of the absorber 4 in the compartment between the bumper wall 10 and the beam 12, thus compensating for the distance x of the frame 6 from said beam 12.

[0044] Figures 3 to 5 illustrate a perspective view of one of the two vertical extensions 5, according to different periods during a low-speed front impact.

[0045] Figure 3 shows the extension 5 of the absorber 4 prior to the front impact. Here the absorber 14 is therefore in a normal mounting position in the motor vehicle 2, in which the lower face 6.1 of the frame 6 is preferably parallel to, and distanced by a distance a corresponding to at most 10 mm from the ramp 5.1.

[0046] Preferably, the ramp 5.1 is inclined relative to a longitudinal direction of the motor vehicle at an angle a of between 30° and 60°. This angle makes it possible to progressively distribute the energy of the front impact towards the frame 6.

[0047] It can be seen that the vertical extension 5 further comprises a lug 5.2 extending vertically from a top of the ramp 5.1, this extending longitudinally and vertically, respectively along the dimensions b and c, over at least 5 mm and at most 15 mm. More preferably, the dimension b is equal to 10 mm, and the distance c is equal to approximately 5 mm.

[0048] The vertical extension 5 extends vertically, from the absorber 4 to the lug 5.2, over at least 50 mm and at most 150 mm.

[0049] Advantageously, the vertical extension 5 also comprises a rear face 5.3 facing a vertical wall 6.3 arranged at a lower part of the frame 6, directly below the corresponding lower face 6.1, thus forming a downward extension of the latter.

[0050] Preferably, the rear face 5.3 is arranged at a distance from the vertical wall 6.3, by a distance substantially equal to the dimension a.

[0051] At the beginning of the compression of the absorber 4, the rear face 5.3 comes into contact with the vertical wall 6.3. This constitutes the first compression peak between the absorber 4 and the frame 6, as illustrated in Figure 4.

[0052] Preferably, the rear face 5.3 extends vertically from the absorber 4 by approximately 20 mm.

[0053] From this first contact between the vertical extension 5 and the frame 6, the ramp 5.1 then gradually comes into contact with the lower face 6.1, until the compression is stopped by the lug 5.2. Indeed, the latter advantageously constitutes a final point of contact for compression of the absorber 4 against the frame 6, as illustrated in Figure 5.

[0054] Preferably, the upper face 5.1 constituting the ramp 5.1 of the vertical extension 5, extends upwards and forwards from the rear face 5.3 to the lug 5.2 over approximately 80 mm.

[0055] Figure 6 illustrates a deformation of the bumper wall 10 after compression of the absorber 4 following the front impact.

[0056] It can be seen that the bumper wall 10' in the deformed state comes exclusively into contact with the PPE foam absorber 4, and does not come into contact with the front face 6.2 of the frame 6. For this purpose, the deformation of the bumper wall 10 remains elastic during the low-speed front impact, thus preserving both the bumper wall 10 and the frame 6.

Claims

CLAIMS [Claim 1.] Motor vehicle (2) comprising, at the front (1): - a bumper beam (12); - a bumper wall (10); - a bumper frame (6); - a shock absorber (4) arranged between the bumper wall (10) and the bumper beam (12); characterized in that the absorber (4) comprises two vertical extensions (5) each comprising an upper face (5.1) forming a ramp (5.1) extending upwards and towards the front of the motor vehicle (2), said ramp (5.1) being opposite a corresponding lower face (6.1) of the frame (6), so as to allow the shock absorber (4) to deform in compression against each of said lower faces (6.1) of the frame (6) in the event of a front impact. [Claim 2.] Motor vehicle (2) according to claim 1, wherein the lower face (6.1) of the frame (6) is parallel to, and at a distance of at most 10 mm from, the ramp (5.1) of the corresponding vertical extension (5). [Claim 3.] Motor vehicle (2) according to one of claims 1 and 2, wherein the ramp (5.1) is inclined relative to a longitudinal direction of said motor vehicle (2) by an angle (a) of between 30° and 60°. [Claim 4.] Motor vehicle (2) according to one of claims 1 to 3, in which each vertical extension (5) further comprises a rear face (5.3) facing a vertical wall (6.3) of a lower part of the frame (6), said vertical wall (6.3) forming a downward extension of the lower faces (6.1). [Claim 5.] Motor vehicle (2) according to one of claims 1 to 4, in which each vertical extension (5) further comprises a lug (5.2) extending vertically from a top of the ramp (5.1), said lug (5.2) being configured to constitute a final compression contact point of the shock absorber (4) against the frame (6). [Claim 6.] Motor vehicle (2) according to claim 5, wherein the lug (5.2) extends longitudinally and vertically over at least 5 mm and at most 15 mm. [Claim 7.] Motor vehicle (2) according to one of claims 1 to 6, wherein each of the vertical extensions (5) extends vertically over at least 50 mm. [Claim 8.] Motor vehicle (2) according to one of claims 1 to 7, wherein the vertical extensions (5) are spaced transversely by at least 400 mm. [Claim 9.] Motor vehicle (2) according to one of claims 1 to 8, wherein the vertical extensions (5) are made of polypropylene foam. [Claim 10.] Motor vehicle (2) according to one of claims 1 to 9, wherein the frame (6) comprises a front face (6.2) facing the bumper wall, said front face (6.2) being arranged at approximately 80 mm from the bumper beam (12), in a longitudinal direction.

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