FR2810941A1 - Automobile front bumper comprises bumper extending in front of vehicle and two lateral energy absorbing structures fixed to bumper end region - Google Patents

Abstract

The bumper comprises a bumper beam (3) which extends in front of the vehicle and two lateral energy absorbing structures (4). Each lateral structure is fixed by a front end (14) to a beam lateral end region (3E). At least one of the shock absorbing structures is of the same material as the corresponding lateral region of the bumper beam. Each of the shock absorbing structures and the corresponding bumper end region have a network of cells (7,15). An Independent claim is included for an automobile front unit.

Description

The present invention relates to an impact protection assembly

  for a motor vehicle, of the type comprising at least one barrier beam

  shock intended to extend to the front of the motor vehicle and two lateral structures for absorbing impact energy by plastic deformation, each fixed by a front end to a lateral end region of the beam

  so that it relies on shock energy absorption structures.

  In such an impact protection assembly, the front ends of the impact energy absorption structures are fixed to the rear face of the bumper beam by means of plates, and for example of screws, in order

  to join the structures and the beam satisfactorily.

  Due to the presence of these plates, the mass of such an assembly

  impact protection is relatively high.

  An object of the invention is to solve this problem by providing an assembly of the aforementioned type which is of reduced mass and which ensures a satisfactory connection between the bumper beam and the absorption structures.

shock energy.

  To this end, the invention relates to an assembly of the aforementioned type, characterized in that at least one of the impact energy absorption structures came integrally with the corresponding lateral end region of the beam bumper, and in that said or each impact energy absorbing structure and the corresponding side end region have a

network of cells.

  According to particular embodiments, the assembly comprises one or more of the following characteristics taken in isolation or in all the technically possible combinations: - the two shock energy absorption structures each came integrally with the corresponding lateral end region; - the bumper beam comprises two lateral sections, each made from a single piece with an impact energy absorption structure, the sections

  being connected to each other in a central region of the barrier beam

  shock; - The bumper beam comprises two lateral sections, each made from a single piece with an impact energy absorption structure, and a separate central section which connects the lateral sections together; said or each impact energy absorption structure and the corresponding lateral end region are made of an extruded material; - Said or each shock energy absorption structure and the corresponding lateral end region comprise an added reinforcement lining; and - said or each reinforcement lining has cells oriented in a direction intended to be substantially parallel to the direction of travel

of the vehicle.

  The invention further relates to a front unit for a motor vehicle comprising a front face and an impact protection assembly mounted on the front face, characterized in that the protection assembly against

  shock is a set as defined above.

  The invention also relates to a motor vehicle comprising a front unit, characterized in that the front unit is a front unit

as defined above.

  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 partial, schematic, exploded and perspective view of a front unit according to the invention, - Figure 2 is a partial, schematic, exploded view from above illustrating a variant of the impact protection assembly of the front unit of FIG. 1, and - FIG. 3 is a schematic view, in perspective, of a variant

  of an impact energy absorption structure of the front unit of FIG. 1.

  In all that follows, the orientations used are the orientations

  of a motor vehicle.

  We recognize in Figure 1 a front unit 1 of a motor vehicle essentially comprising a front face 2, a bumper beam 3 and two lateral structures 4 for absorbing impact energy by deformation

programmed plastic.

  The front face 2 is made for example of plastic material overmolded on a metal frame. It is intended to support various equipment such as optical units, a radiator and a fan unit. The bumper beam 3 is made in three sections, namely two

  lateral end sections 3E and a central section 3C.

  The bumper beam 3 is made of an extruded material, by

example of aluminum.

  Each of the sections 3E and 3C comprises vertical exterior and interior walls delimiting a network of cells 7. The cells are oriented vertically and distributed in a front row and in a rear row which follow the guideline of the bumper beam 3 The front and rear rows of the central section 3C are separated by an intermediate vertical wall 8C, and the front and rear rows of the end sections

  lateral 3E are separated by intermediate vertical walls 8E.

  The central section 3C has rear recesses 9 at each of its lateral ends. These recesses 9, of horizontal and rectangular section, correspond to the absence of cells 7 of the rear row. The recesses 9 are delimited at the front by the intermediate wall 8C. At each lateral end, the central section 3C therefore has a projection

  front 11 directed laterally outwards.

  The lateral end sections 3E each have, at their lateral end facing inwards, a front recess 12 of shape

  complementary to that of the corresponding projection 11.

  Thus, each lateral end section 3E has a rear projection 13 oriented laterally inwardly and which is shaped

  complementary to the dropout 9.

  The recesses 9 and 12 and the projections 11 and 13 form reliefs

  nesting of the central section 3C and the lateral end sections 3E.

  Thus, the projections 11 are received in the recesses 12 and the

  projections 13 in the recesses 9.

  The sections 3E and 3C are fixed to each other, for example by screwing the intermediate walls 8C and 8E at the recesses 9 and 12, or for example by welding the sections 3C and 3E at the sockets thus produced. The shock energy absorption structures 4 have come integrally through their front ends 14 with the lateral end sections 3E. Thus, each structure 4 extends a section 3E towards the rear. This structure 4 has, like the corresponding section 3E, a network of cells 15 oriented vertically and ends with a rear plate 16 for attachment to

the front panel 2.

  Each structure 4 is for example fixed on the front face 2 using screws passing through the front face 2 and connecting the plate 16 to a front plate of a lateral spar 18 of the motor vehicle. Thus, the front face 2 is clamped

  between the structure 4 considered and the spar 18 located opposite.

  Conventionally, the beam 3 is covered with a layer not

  depicted of a relatively flexible material.

  The structures 4 having come in one piece with the sections 3E of the bumper beam 3, it was not necessary to provide plates 4 on the structures before fixing. The mass of the impact protection assembly

  including the beam 3 and the structures 4 is therefore reduced.

  Furthermore, the connection between the front ends 14 of the structures 4 and the beam 3 is satisfactory insofar as it allows, on the one hand, during a front impact at low speed to absorb the energy of the impact by deformation elastic of the beam 3 and of the structures 4, and on the other hand, for a high speed forward impact, transmission of the impact energy to the structures 4 so that they deform plastically along the longitudinal direction of the

  vehicle to absorb the impact energy.

  The presence of cells 7 and 15 makes it possible to give the impact protection assembly satisfactory mechanical strength while limiting its mass. According to the variant illustrated in FIG. 2, the bumper beam 3 no longer comprises a central section 3C. The two sections of lateral ends 3E extend laterally inwards more significantly than in

  the case of Figure I to each form a half of the bumper beam 3.

  The right section 3E has at its left lateral end a front recess 20 of rectangular section delimiting a rear projection 21 projecting laterally to the left. The left section 3E has at its right lateral end a rear recess 22 of shape complementary to that of the projection 21 and thus comprises a front projection 23 oriented to the right and of shape

  complementary to that of the offset 20 of the straight section 3E.

  The sections 3E fit into each other thanks to the recesses 20 and 22 and the projections 21 and 23 and are fixed at the level of

  the nesting thus produced, for example by screws or welds.

  In this variant, the number of parts making up the bumper beam is limited and the corresponding assembly costs are therefore

reduced.

  FIG. 3 illustrates a variant of FIG. 1, in which each impact energy absorption structure 4 and the corresponding lateral end section 3E comprise an attached reinforcement lining 22. This lining 22 is housed in a cell 23, of rectangular section and whose long side is oriented longitudinally relative to the vehicle. The lining 22 has a honeycomb structure whose cells, of hexagonal section, are oriented longitudinally relative to the vehicle. The lining 22 is for example made of extruded aluminum and is fixed for example by

  welds or screws to structure 4 and to the corresponding section 3E.

  The presence of the lining 22 in each structure 4 and in each lateral end section 3E makes it possible to increase the rigidity of the

structures 4 and beam 3.

Claims (9)

  1. Shock protection assembly for a motor vehicle, of the type comprising at least one bumper beam (3) intended to extend at the front of the motor vehicle and two lateral structures (4) for absorbing impact energy by plastic deformation, each fixed by a front end (14) to a lateral end region (3E) of the beam so that it rests on the shock energy absorption structures (4) , characterized in that at least one of the structures for absorbing impact energy has come integrally with the corresponding lateral end region (3E) of the bumper beam, and in that said or each structure of shock energy absorption and the corresponding lateral end region present a network cells (7, 15, 23).   2. Assembly according to claim 1, characterized in that the two structures (4) for absorbing impact energy each have come from one material   with the corresponding lateral end region (3E).   3. An assembly according to claim 2, characterized in that the bumper beam comprises two lateral sections (3E), each made in one piece with a structure (4) for absorbing impact energy, the lateral sections being   connected to each other in a central region of the bumper beam.   4. An assembly according to claim 2, characterized in that the bumper beam (3) comprises two lateral sections (3E), each integrally formed with a structure (4) for absorbing impact energy, and a section   central (3C) separate which connects the lateral sections together.   5. Assembly according to one of the preceding claims, characterized   in that said or each impact energy absorption structure (4) and the corresponding lateral end region are made of an extruded material.   6. Assembly according to one of the preceding claims, characterized   in that said or each impact energy absorption structure and the corresponding lateral end region comprise an added reinforcement lining (22). 7. An assembly according to claim 6, characterized in that said or each reinforcement lining (22) has cells oriented in a   direction intended to be substantially parallel to the direction of travel of the vehicle.   8. Front unit for a motor vehicle comprising a front face and an impact protection assembly mounted on the front face (2), characterized in that the impact protection assembly is an assembly according to one of previous claims.   9. Motor vehicle comprising a front unit, characterized in that   that the front unit is a front unit according to claim 8.