Bumper framework optimized for improved pedestrian impact

Abstract

The invention relates to a framework (1) for supporting a front end bumper and which is designed to support, when fixed to the front end, a bumper reinforcement, the framework (1) comprising a transverse part (4) designed to extend in a transverse direction, the framework (1) comprising at least one strut (6) extending from the transverse part (4) towards an end (7) suitable for fixing the reinforcement to the framework (1) in a controlled-failure manner. The framework (1) comprises at least one absorbing element (10) projecting from said transverse part (4), each absorbing element (10) being designed to absorb, when the framework (1) is mounted on the front end, some of the energy of a front-end impact experienced by the front end by deforming so as to limit the extent to which at least part of the reinforcement fixed to the framework (1) is pushed back into the front end under the effect of the front-end impact.

Description

[0001] Description

[0002] Title of the invention: Bumper frame optimized for improved pedestrian impact.

[0003] The present invention claims priority from French application 2201336 filed on February 15, 2022, the content of which (text, drawings and claims) is incorporated herein by reference.

[0004] The technical field relates to bumper frames designed to fix a bumper to a front face of a motor vehicle, front faces having such a frame to support the bumper as well as vehicles having such a front face.

[0005] When it comes to road safety, car manufacturers must consider multiple concerns and regulations when developing new vehicles. For example, car manufacturers must ensure the safety of vehicle passengers in the event of a collision, but also protect other vulnerable road users such as pedestrians. Finally, it is important to control vehicle repair costs when they experience urban impacts, known as reparability impacts, at low speeds of around 15 to 20 kilometers per hour. The behavior of motor vehicles in these three situations is regulated and tested using standardized test procedures. The requirements for these test results are increasingly numerous and increasingly difficult to meet, forcing car manufacturers to constantly innovate. In addition, standardized tests are regularly evolving.Thus, a new test protocol, called improved pedestrian impact, consists of projecting a vehicle onto a particular pole divided into three superimposed zones, simulating a pedestrian's leg. The ideal behavior expected of the vehicle thus projected against such a pole must be different depending on the zone considered and offer different rigidity depending on the height considered. It is indeed necessary to meet the requirements of a repairability test, in particular by preserving the motor-fan unit in the upper part of the front face, but also to limit the injuries likely to be caused to a pedestrian's leg in the event of an impact.

[0006] Vehicles equipped with a bumper frame are already known from the prior art and make it possible to guarantee adequate behavior in the event of a repairable impact as well as in the event of a pedestrian impact. However, such front ends remain perfectible, in particular with regard to their behavior in the event of an improved pedestrian impact.

[0007] In this technical context, an aim of the present invention is to provide a bumper support frame making it possible to improve the behavior in the event of an improved pedestrian impact by allowing a differentiation of the rigidity according to the impact height on the front face.

[0008] To this end, the present invention relates to a bumper support frame for the front face of a motor vehicle, designed to support, when fixed to the front face, a bumper reinforcement, the frame comprising a transverse portion designed to extend in a transverse direction of the front face, the frame comprising at least one foot extending from the transverse portion towards one end, suitable for ensuring a fusible fixing of the bumper reinforcement on the frame, the frame being characterized in that it comprises at least one absorbing element projecting from said transverse portion, each absorbing element being designed to absorb, when the frame is mounted on the front face, a portion of the energy of a front impact suffered by the front face by deforming in order to limit the recoil in the front face, under the effect of the front impact, of at least a portion of the bumper reinforcement fixed on the frame.

[0009] The invention also relates to a vehicle front end comprising a frame according to the invention.

[0010] The invention also relates to a vehicle comprising at least one front face according to the invention.

[0011] Thus, a frame according to the invention makes it possible to assemble a front end of a vehicle according to the invention which has the advantages known for vehicles having a conventional frame. Thus, in the event of a pedestrian impact, the breaking of the foot allows the bumper reinforcement to recoil in the front end and therefore to guarantee adequate behavior in the event of a pedestrian impact. The presence of at least one absorbing element makes it possible to absorb, in the upper part of the front end, an increased quantity of energy released during a front impact compared to a conventional frame and to limit the recoil in the front end, in the direction of the motor-fan unit, of the bumper reinforcement. Indeed, the recoil of the reinforcement towards the motor-fan unit requires the prior deformation of each absorbing element. The behavior of the front end during an improved pedestrian impact is therefore improved since the rigidity of the front end varies according to the height of the impact.Furthermore, the increased rigidity in the upper part of the front face, at the level of the transverse part, makes it possible to improve the rigidity perceived by a vehicle user.

[0012] According to one embodiment of the invention, at least one absorber element has a fixing interface designed to allow the bumper reinforcement to be fixed to the absorber element.

[0013] According to one possibility, each absorber element forms an absorption box. Advantageously, each box has a truncated cone shape, in particular a truncated cone shape with a rectangular base.

[0014] According to one embodiment, each end of each leg has indexing means designed to index and fix the reinforcement relative to the frame.

[0015] Advantageously, the indexing means comprise a fixing strap. Advantageously again, each fixing strap is fusible in order to break under the effect of a front impact suffered by the front face to release the bumper reinforcement.

[0016] The invention will be better understood upon reading the detailed description which follows, given solely as a non-limiting example and made with reference to the appended drawings in which:

[0017] [Fig. 1] Figure 1 represents a perspective view of a bumper support frame according to the invention;

[0018] [Fig. 2] Figure 2, represents a perspective view of a front end showing a bumper reinforcement mounted on the frame of Figure 1;

[0019] [Fig. 3] Figure 3 represents a detailed view of indexing means of the frame of Figure 1.

[0020] In these figures, the same references are used to designate the same elements.

[0021] A bumper support frame 1 according to the invention, illustrated in Figure 1, is intended to be mounted on a front face 2 of a motor vehicle, illustrated in Figure 2. In particular, the frame 1 is designed to be fixed to the metal structure of the front face 2. The frame 1 is designed to support, when it is fixed to the front face 2, a bumper reinforcement 3 and / or a bumper skin, not shown in the figures. The bumper reinforcement 3 makes it possible to reinforce the bumper skin, in particular by stiffening certain areas of the latter. The frame 1 is, for example, made of molded plastic material. The bumper reinforcement 3 is, for example, made of molded plastic material.

[0022] The frame 1 comprises a transverse portion 4 designed to extend in a transverse direction T, illustrated in Figure 2, of the front face 2. The transverse portion 4 is curved in the transverse direction T, as illustrated in Figures 1 and 2. On the one hand, extending from the transverse portion 4, the frame

[0023] 1 has an upper part 5, substantially flat, designed to participate in the fixing of the frame 1 on the front face 2 and to cover at least in part a motor-fan unit (not shown) of the front face 2. On the other hand, the frame 1 comprises at least one foot 6, in this case three feet 6, extending from the transverse part 4 towards an end 7, suitable for ensuring a fusible fixing of the bumper reinforcement 3 on the frame 1. By fusible fixing, it is meant a fixing designed to break in the event of a front impact, suffered by the front face 2, the intensity of which is greater than a predetermined threshold intensity. All of the ends 7 of feet 6 are connected together by a lower crosspiece 8. Each end 7 of each foot 6 has, for example, indexing means 9 making it possible to index and fix the reinforcement 3 relative to the frame 1.In order to obtain the fusible attachment of the reinforcement 3, each foot 6 is shaped to break in the event of a front impact suffered by the front face.

[0024] 2 with an intensity greater than a predetermined threshold, in order to separate the reinforcement 3 from the reinforcement 1 and allow the movement of the reinforcement 3.

[0025] As illustrated in Figure 1, the frame 1 comprises at least one absorber element 10 projecting from said transverse part 4. In this case, the frame 1, illustrated in the figures, has six absorber elements 10 distributed in two groups arranged symmetrically along the transverse part 4.

[0026] In the embodiment described, each absorber element 10 forms an absorption box 11. Advantageously, each box 11 has a truncated cone shape, in particular a truncated cone shape with a rectangular base. Each absorber element 10 is designed to absorb, when the frame 1 is mounted on the front face 2, a portion of the energy of a front impact suffered by the front face 2 by deforming in order to limit the recoil, in the front face 2 under the effect of the front impact, of at least a portion of the bumper reinforcement 3 fixed to the frame 1.

[0027] As illustrated in Figure 1, at least one absorber element 10, in this case the absorber elements 10 located on the edges of the transverse part 4 each have a fixing interface 12 designed to allow the bumper reinforcement 3 to be fixed to the absorber element 10. The fixing interface 12 has, for example, fixing orifices 13 allowing the bumper reinforcement 3 to be screwed or clipped onto the fixing interface 12.

[0028] Thus, during a front impact of an intensity greater than a predetermined threshold, in particular an impact against a post of the improved pedestrian impact type, each foot 6 of the frame 1 is shaped to break and release the lower part of the bumper reinforcement 3, while the recoil of the upper part of the reinforcement 3 is limited by the absorbing elements 10. This makes it possible, for example, to limit injuries to the shins of a pedestrian while limiting the recoil of the upper part of the reinforcement 3, which thus remains at a distance from the motor-fan unit. This improves the behavior in terms of repairability of the vehicle according to the invention.

[0029] In order to facilitate the positioning and assembly of the reinforcement 3 on the frame 1, as illustrated in FIG. 3, each foot 6 has a U-shaped profile, the indexing means 9 comprising a fixing strap 14 at the end 7 of each foot 6. The indexing of the bumper reinforcement 3 on the frame 1 is obtained by complementarity of shape, allowing the bumper reinforcement 3 to fit into the U-shaped profile of the foot 6, and the indexing means 9 comprise bearing surfaces 15 provided on each foot 6, designed to form stops during the assembly of the reinforcement 3 on the frame 1.

[0030] Advantageously finally, each fixing strap 14 is fusible in order to break under the effect of a front impact suffered by the front face 2 to release the bumper reinforcement 3. Such a result is obtained, for example, by at least one thinning of material 16, visible in FIG. 3, on each fixing strap 14.

[0031] Thus, the frame 1 according to the invention makes it possible to produce a front face 2 according to the invention whose rigidity varies according to the impacted height. In the lower part, the front face 2 allows a significant recoil of the bumper reinforcement 3 by the rupture of each foot 6 while in the upper part, each absorbing element 10 makes it possible to limit the recoil towards the motor-fan unit of the reinforcement 3. The behavior of a vehicle according to the invention is therefore optimized for an improved pedestrian impact.

[0032] The invention is not limited to the embodiment of the frame described above, only by way of example, but other embodiments can be designed by those skilled in the art without departing from the scope and scope of the present invention.

Claims

DEMANDS 1. A bumper support frame (1) for the front face (2) of a motor vehicle, designed to support, when fixed to the front face (2), a bumper reinforcement (3), the frame (1) comprising a transverse portion (4) designed to extend in a transverse direction (T) from the front face (2), the frame (1) comprising at least one foot (6) extending from the transverse portion (4) to an end (7), suitable for ensuring a fusible attachment of the bumper reinforcement (3) to the frame (1), the frame (1) being characterized in that it comprises at least one energy-absorbing element (10) projecting from said transverse portion (4), each energy-absorbing element (10) being designed to absorb, when the frame (1) is mounted on the front face (2), a portion of the energy of a frontal impact sustained by the front face (2) by deforming in order to limit recoil in the front face (2), under the effect from the front-end collision,of at least part of the bumper reinforcement (3) fixed to the frame (1).

2. Frame (1) according to claim 1, characterized in that at least one absorber element (10) has a fixing interface (12) designed to allow the fixing of the bumper reinforcement (3) onto the absorber element (10).

3. Frame (1) according to claim 1 or 2, characterized in that each absorber element (10) forms an absorption box (11).

4. Frame (1) according to claim 3, characterized in that each box (11) has a frustoconical shape, in particular a frustoconical shape with a rectangular base.

5. Reinforcement (1) according to any one of claims 1 to 4, characterized in that each end (7) of each foot (6) has indexing means (9) designed to index and fix the reinforcement (3) relative to the reinforcement (1).

6. Frame (1) according to claim 5, characterized in that the indexing means (9) comprise a fixing strap (14).

7. A frame (1) according to claim 6, characterized in that each fastening strap (14) is fusible so as to break under the effect of a frontal impact to the front face (2) in order to release the bumper reinforcement (3).

8. A vehicle front face (2) comprising a frame (1) according to any one of claims 1 to 7.

9. Vehicle comprising at least one front face (2) according to claim 8.

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