FR2840573A1 - Motor vehicle fender assembly has outer skin, beam, energy absorber and protectors made from plastic with cells formed by ribs - Google Patents

Abstract

The fender assembly (2) consists of an outer trim skin (6) with a beam (3) behind it, and an energy absorber (18) beytween the two. The energy absorber is combined with lower (17) and upper (19) vehicle impact protectors in a plastic supporting frame (4) and ribs (21) forming a series of cells (22). The skin (6) is in two separate lateral sections (32) that are adjusted and fastened together by strips (7, 8).

Description

interface, cage (15, 21) to this antenna.

  The present invention relates to a set of bumpers for motor vehicles comprising an outer skin covering, a first beam intended to be disposed behind the skin relative to the direction of travel of the motor vehicle and an absorber impact energy intended to be placed between the bumper skin and the bumper beam. EP-232 993 describes such an assembly which further comprises a protection element for equipment of the motor vehicle in the form of a grille. The grille came in one piece with the energy absorber

  shock and it is formed from polypropylene foam molded into the skin.

  Such an assembly turns out to be expensive to produce, in particular because of the use of a foam and the fact that it is not possible to reduce the thickness of the skin without deteriorating the external appearance of the assembly which would present a

very stiff apparent rigidity.

  WO-00/58 114 also describes an assembly as mentioned above. It also includes a lower foam bar to protect an under engine fairing. The shock absorber has in front of the beam is

independently made of foam.

  The assembly described in this document entails significant assembly and realization costs. In addition, it is also not possible to reduce the thickness of the bumper skin without deteriorating the external appearance of the assembly.

  An object of the invention is to solve these problems.

  To this end, the invention relates to a set of bumpers for a motor vehicle comprising an external stripping skin, a first beam intended to be disposed behind the skin relative to the direction of travel of the motor vehicle, an absorber of impact energy intended to be disposed between the skin and the first bumper beam, and a first element for protecting a motor vehicle equipment against shocks, the first protective element being intended to be disposed above or below the first beam, in which the first protective element and the absorber wind two parts made of material of the same plastic support frame produced independently of the skin, the support frame comprising ribs delimiting cells, the skin comprising at least part

  independent to report on the frame.

  According to particular embodiments, the assembly may include one or more of the following characteristics, price (s) isolation or according to all technically possible combinations: - the assembly further comprises a second protective element of an automobile vehicle equipment against shocks, the second protective element being intended to be placed on the other side of the first beam relative to the first protective element, - the skin comprises at least two independent parts to be attached to the frame, - the assembly comprises at least one band for adjusting the relative position of the two parts of the skin, the band being intended to overlap the two parts of the skin and to be fixed thereto, - the parts of the wind skin of the lateral halves of the skin, - the first beam and the wind shock energy absorber intended to form a first upper percussion zone of a leg of a pedestrian, and in that ['together includes a second beam intended to be placed under the first beam to define a second lower percussion zone of the pedestrian's leg, - the second beam is intended to be fixed to the support frame, the frame comprises a central region and two lateral wings extending the central region towards the rear, and the second beam is a section, con

  of an arch intended to be fixed to the lateral wings of the support frame.

  The subject of the invention is furthermore a motor vehicle, characterized

  in that it comprises a set as defined above.

  The invention also relates to a method of producing an assembly as defined above, the method being characterized in that it comprises steps of: - producing the support frame independently of the skin shock then

  - fixing of the bumper skin on the support frame.

  The invention will be better understood on reading the description which will

  follow, given only by way of example, and made with reference to the accompanying drawings, in which: - Figure 1 is a schematic exploded perspective view of the front end of a motor vehicle according to the invention, and - Figure 2 is a schematic, partial and enlarged view of the part

circle 11 of figure 1.

  In all that follows, the orientations used are the usual orientations of a motor vehicle. Thus, the terms "front", "rear", right "and" left "are understood in relation to the position of a driver of the

vehicle and its direction of travel.

  Figure 1 illustrates the front end 1 of a motor vehicle. This

  front end 1 includes a set of bumpers 2 which itself

  same, successively from back to front: - a first upper beam 3, - a framework 4 for absorbing impact energy, - a reinforcement arch for [set 2, - an outer skin 6 of covering, a large lower band 7 or band, and

- a small upper strip 8.

  The beam 3 comprises a cross member 10 which extends substantially over the entire width of the motor vehicle and two lateral branches 11 which extend the cross member 10 towards the rear and by means of which the beam 3 is connected

  to the side members 12 of the vehicle chassis.

  The frame 4 is made in one piece from rigid plastic,

for example polypropylene.

  The framework 4 has a top view of a curved form of concavity directed towards the rear and comprises a central region 14 extended towards the rear

  at its lateral ends by two lateral wings 16.

  The central region 14 successively comprises teas at the top: - a lower part 17 for protecting a heat exchanger of the motor vehicle arranged behind ['assembly 2, for example a radiator, - an intermediate part 18 which is arranged in front of the cross member of the beam 3 and which extends over the entire height and width thereof, and - an upper part 19 which is arranged above the beam 3

  to also protect the heat exchanger.

  Note that the upper part 19 has a markedly wide

  lower than that of the lower part 17 and of the intermediate part 18.

  The frame 4 comprises, as well in the parts 17, 18 and 19 of the central region 14 as in its lateral wings 16, ribs 21 which

  S delimit between them cells 22 passing through the thickness of the framework 4.

  The frame 4 is for example fixed by screwing to the beam 3, to the wings not shown in the vehicle body and to the cradle not shown in the engine. The intermediate part 14 of the frame 4 and the beam 3 form a

  first upper percussion area of a pedestrian's leg.

  The hoop 5 is made from a metal hanger tube, for example aluminum or steel. This tube has for example a circular circular section and comprises: - a section, central lower con 24 arch to present a concavity directed towards the rear and thus a curve correspond substantially to that of the lower part 17 of the central region 14 of the frame 4, - two sections, oblique intermediate cons 26 which extend the section, lower central con 24 and which wind inclines upwards and backwards, and - two ends 28 which extend the sections, intermediate cons 26

  towards the rear and which extend substantially horizontally.

  The arch 5 is fixed to the frame 4 by embedding the ends 28 in sleeves 30 formed in the upper parts of the lateral wings

  16, in the extension of the intermediate part 18 of the framework 4.

  This fixing can be completed, for example, by screwing. The section, lower con 24 can optionally be fixed on the part 17 of the framework 4,

for example by snap-fastening.

  The arch 5 reinforces the assembly 2. The lower cone 24 forms in

  besides a second lower percussion zone of the leg of a pedestrian.

  Note that this second zone is arranged below and in front of the first percussion zone. Thus, in the event of a frontal impact with a pedestrian, the second percussion zone comes into contact with the leg before the first percussion zone, which makes it possible to limit the risk of injury.

  serious knees of the pedestrian strikes.

  The skin 6 covers substantially the entire framework 4 and the arch 5.

  Wile includes two side half-skins 32 substantially

  symmetrical to each other and connected along a vertical line of joint 34.

  As illustrated in FIG. 2, the right half-skin 32 includes front hooks 36 and the left half-skin 32 includes complementary rear hooks 38 which allow the two half-skins

  32 to fit together along the vertical joint line 34.

  The half-skins 32 are made of plastic, for example polypropylene and preferably have a reduced thickness, for example

less than 2.8mm.

  A first upper central opening 40 is formed in the skin 6 to allow an air flow through the alveoli 22 of the

  upper part 19 towards the heat exchanger.

  A second lower opening 42 is formed in the skin 6 to allow air to pass through the alveoli 22 of the lower part 17

  from frame 4 to the heat exchanger.

  It will be noted that the lower opening 42 is of width greater than

that of the upper opening 40.

  The large lower strip 7 extends substantially over the entire width of the skin 6 in front thereof covering the two half-skins 32. The strip 7 extends between the two openings 40 and 42. Wile door for example a

license plate.

  The small strip 8 is of width much smaller than that of the large strip 7 and overlaps the two half-skins 32. Wile is disposed above the upper opening 42 in the web of a part 44 in C of the skin 6. In the example shown, the bands 7 and 8 are substantially flat. However, they can also have a U-shaped section open towards the rear. The two half-skins 32 wind fixed to the bands 7 and 8, for example

by snap-fastening.

  The skin 6 is moreover fixed to the framework 4, for example by

in cl iq uetting.

  To make the assembly 2, the beam 3, the frame 4, the hoop 5, the two half-skins 32 and the bands 7 and 8 are made independently.

  in particular, the framework 4 is preformed independently of the skin 6.

  Next, the two half-skins 32 and the strips are assembled on the one hand

  S 7 and 8, and on the other hand the arch 5 and the framework 4.

  Strips 7 and 8 offer several mounting positions for the half

  skins 32. Thus, the two bands 7 and 8 make it possible to adjust the relative position

of the two half-skins.

  We then assemble the skin 6 provided with bands 7 and 8 on the frame 4 provided with the arch 5. The assembly 2 then forms a module

  preassemble that can be manipulated and fixed to the rest of the motor vehicle.

  The frame 4 incorporating the intermediate part 18 forming a shock energy absorber and the parts 17 and 19 for protecting equipment of the motor vehicle, these different elements are installed in the vehicle by simple mounting of the frame 4. Thus, the number of operations required to

  The installation of these elements is limited.

  The structure of the framework 4, made with ribs 21 made of rigid plastic material allows it to confer a role of support for the other elements of the module 2, in particular the skin 6. Thus, this skin 6 can have a very limited thickness without as far as the apparent stiffness of this skin, and therefore its

external appearance, is not affected.

  In addition, it will be noted that the same frame 4 and the same hoop 5 can be used with different skins 6 and bands 7 and 8 and therefore for different models of vehicles. Thus, the set 2 described achieves a

  standard isation i mporta nte and therefore redu its costs.

  In addition, the set 2 described does not require the use of a foam

costly implementation.

  In addition, this assembly 2 proves to be light, in particular thanks to the alveolar structure of the framework 4. In variants not shown, the assembly 2 may not include an arch 5, and may not include in the central region 14 only a lower part 17 in addition to the intermediate part 18. Conversely, the central region 14 may include only the upper part

  19 in addition to the intermediate part 18.

  It should also be noted that the skin 32 can be made in more than two parts or in a single part, although this is less practical for

['assembly of [' set 2.

  Similarly, more than three bands or a single band 7 can be used to assemble different parts of the bumper skin 6. The set 2 can be marketed with its different elements

iIbre from each other.

Claims (10)

  1. Set (2) of bumpers for motor vehicles comprising an outer skin (6) covering, a first beam (3) intended to be disposed behind the skin (6) relative to the direction of travel of the vehicle automobile, a shock energy absorber (18) intended to be placed between the skin (6) and the first bumper beam (3), and a first element (17, 19) for protecting an equipment of the motor vehicle against impact, the first protective element (17, 19) being intended to be arranged above or below the first beam (3), in which the first protective element (17, 19) and the absorber (18) is made of two parts made of the same support frame (4) made of plastic produced independently of the skin (6), the support frame (4) comprising ribs (21) delimiting cells (22), the skin (6) comprising at least one independent part (32) to be attached to I'ossature.   2. Assembly according to claim 1, characterized in that it further comprises a second element (19) for protecting a piece of equipment of the motor vehicle against shocks, the second protective element being intended to be disposed of the other dimension of the first beam (3) relative to the first protective element.   3. An assembly according to claim 1 or 2, characterized in that the skin   (6) comprises at least two independent parts (32) to be attached to the framework.   4. An assembly according to claim 3, characterized in that the assembly comprises at least one band (7, 8) for adjusting the relative position of the two parts (32) of the skin, the band (7, 8) being intended to overlap the two parts   (32) of the skin and to be fixed thereto.   5. The assembly of claim 3 or 4, characterized in that the parts   (32) of the skin (6) wind from the lateral halves of the skin (6).   6. Assembly according to one of the preceding claims, characterized in that   that the first beam (3) and the shock energy absorber (18) wind intended to form a first upper percussion zone of a leg of a pedestrian, and in that the assembly comprises a second beam ( 24) intended to be placed under the first beam (3) to define a second lower zone of percussion of the pedestrian's leg.   7. The assembly of claim 6, characterized in that ia second   beam (24) is intended to be fixed to the support frame (4).   8. The assembly of claim 7, characterized in that the frame (4) comprises a central region (14) and two lateral wings (16) extending the central region (14) towards the rear, and in that the second beam (24) is a section, cone of   hoop (5) intended to be fixed to the lateral wings (16) of the support frame (4).   9. Vehicu le automobile, characterized in that it comprises a set   according to one of the preceding claims.   10. Method for producing an assembly according to one of claims 1   a 8, characterized in that it comprises steps of: - making the support frame (4) independently of the bumper skin (6), then