MOTOR-VEHICLE BUMPER ASSEMBLY

Abstract

A bumper arrangement (1) for a motor vehicle, in particular for a lower load plane, wherein the bumper arrangement (1) has a bumper crossmember (2) and two spaced-apart supporting profiles (3, 3′), the first ends (4, 4′) of which are each fastened indirectly or directly to one of the two regions of the bumper crossmember (2) that are in the vicinity of the end and which are each fastened at a second end (5, 5′) to chassis parts or longitudinal member parts (6) formed on the motor vehicle, wherein the bumper crossmember (2) is held by the supporting profiles (3, 3′) on the vehicle structure and has a preferably symmetrically curved portion (7) in the form of a portion of a tube or a portion of a groove or a portion of a profile, wherein the portion (7) is fastened by its ends (8, 8′) in the vicinity of the second ends (5, 5′) of the supporting profiles (3, 3′) to the chassis parts or longitudinal member parts (6), wherein the curved portion (7) is shaped in a manner projecting with a central region (9) to the bumper crossmember (2) and therefore at least lies against the bumper crossmember (2).

Claims

1. A bumper assembly for a motor vehicle, the bumper assembly comprising a bumper cross member, two spaced mounting struts each having an outer end attached directly or indirectly at a respective region of the bumper cross beam and an inner end attached on the motor vehicle chassis or frame, the mounting struts fixing the cross member on the vehicle structure, and a curved brace in the form of a tube, channel, or profile, the brace having ends attached near the inner ends of the mounting struts to the chassis or frame, the brace having a center part projecting toward and at least bearing on the the bumper cross member such that in the event of a frontal impact the cross member, the brace, and in some cases the struts are deformed and absorb energy of the impact.

2. (canceled)

3. The bumper assembly according to claim 1, wherein the curved brace is of round, polygonal, oval, U-shaped or generally semicircular cross section.

4. The bumper assembly according to claim 1, wherein the brace is of semicircular shape.

5. The bumper assembly according to claim 1, wherein the brace is of C-shape.

6. The bumper assembly according to claim 1, wherein the curved brace has a straight region, with which the brace at least bears on the bumper cross member.

7. The bumper assembly according to claim 1, wherein the brace has regions of different cross sections.

8. The bumper assembly according to claim 1, wherein the brace tapers in cross-sectional size toward the center part.

9. The bumper assembly according to claim 1, wherein that the brace is made of steel, aluminum or magnesium or consist of fiber-composite material.

10. The bumper assembly according to claim 1, wherein that the brace has regions of lower strength.

11. The bumper assembly according to claim 1, wherein the center part rests on the bumper cross member and is frictionally, positively or unitarily connected therewith.

12. The bumper assembly according to claim 1, further comprising: respective hollow, shaped, sheet-metal bodies securing the outer ends of the mounting struts are secured by respective hollow shaped bodies (11, 11′) made of sheet metal to the bumper cross member, the hollow bodies each having first and second side walls parallel to each other and to the bumper cross member and at least one base wall connecting the side walls, each shaped body being fixed between the bumper cross member or respective parts of the bumper cross member and the outer end of a respective one of the mounting struts.

13. The bumper assembly according to claim 12, wherein a respective gap is formed between the bumper cross member and each of the first side walls.

14. The bumper assembly according to claim 12, wherein the outer end of each mounting strut is fixed with its end face on the side wall of the respective shaped body.

15. The bumper assembly according to claim 12, wherein the outer end of each mounting strut projects through at least the second side wall of the respective shaped part and at least part of the strut is in the cavity of the shaped body, each of the outer ends being preferable fixed to the second side wall at least where the strut passes through to the second side wall.

16. The bumper assembly according to claim 15, wherein the first end of each strut is unitarily fixed with its end face on the respective first side wall.

17. The bumper assembly according to claim 1, wherein the brace is of symmetrical shape.

18. The bumper assembly according to claim 1, wherein the mounting struts are each of round, polygonal, oval, U-shaped or generally semicircular cross section.

19. The bumper assembly according to claim 1, wherein the mounting struts have regions of different cross sections.

20. The bumper assembly according to claim 1, wherein the mounting struts are made of steel, aluminum or magnesium or consist of fiber-composite material.

21. The bumper assembly according to claim 1, wherein that the mounting struts have regions of lower strength.

Description

[0051] Embodiments of the bumper assembly according to the invention are shown in the figures and explained in more detail below. Therein:

[0052] FIG. 1 shows a bumper assembly of semicircular shape;

[0053] FIG. 2 shows a C-shaped bumper assembly;

[0054] FIG. 3 shows a bumper assembly with a center part of oval cross section;

[0055] FIG. 4 illustrates different cross sections of a bumper assembly;

[0056] FIG. 5 shows details of a bumper assembly for different connection variants between a mounting strut and the cross member.

[0057] The figures show a bumper assembly 1 for a motor vehicle, for a low load plane.

[0058] The bumper assembly 1 has a bumper cross member 2 and two spaced mounting struts 3, 3′ whose outer ends 4, 4′ are each connected via a respective hollow shaped body 11, 11′ to or near a respective one of the ends of the bumper cross member 2. Inner ends 5, 5′ of the mounting struts 3, 3′ are each secured by a respective screw-on plate to the vehicle chassis or frame 6. The mounting struts 3, 3′ hold the bumper cross member 2 on the vehicle. Furthermore, the bumper assembly 1 includes a preferably symmetrically curved brace 7 mounted behind the transverse beam 2. This is tubular in the embodiments. The curved brace 7 is between the vehicle structure and the cross member 2, the brace 7 being attached at its ends 8, 8′ near the inner ends 5, 5′ of the mounting struts 3, 3′ on the chassis or frame 6 and having a center part 9 that extends outward toward the bumper cross member 2. The brace 7 bears outward with the center part 9 at least partially on the bumper cross member 2. It is also possible to fixed the center part 9 of the crossbeam 2 to the cross member 2 and thereby prevent a lateral sliding of the brace 7 in the event of an eccentric impact on the front of the vehicle.

[0059] The center part 9 supports and reinforces the cross member 2 in the event of a frontal impact. Upon impact, both the cross member 2 and the arcuate brace 7 are deformed so that an even higher impact energy can be absorbed than with bumper assemblies whose cross members 2 are braced directly against the vehicle structure.

[0060] Since the brace 7 bears with its center part 9 on the cross member 2, the cross member 2 is on and immediately after impact supported and reinforced from behind. By its preferably symmetrical curvature toward the cross member 2, the brace 7 has an optimal shape for dissipating the applied energy evenly over a defined path.

[0061] In the event of an impact acting centrally on the vehicle, such as in a pile test, the cross member 2 and the curved brace 7 behind it deform around the obstacle (for example the pile) and absorb the energy introduced, with the connection to the cross beam improved at the same time.

[0062] The mounting struts 3, 3′ serve to hold the cross member 2 on the vehicle structure and to support the cross member 2 near its ends. During impact, the mounting struts 3, 3′ partially deformed and absorb part of the impact energy, with the mounting struts 3, 3′ at the same time supporting and bracing the regions of the cross member 2 near the end for buckling of the cross member 2 and the curved brace 7 at the preferred locations.

[0063] This arrangement enables an even and increased energy dissipation, whereby at the same time ensuring good cross-connection with the vehicle frame. The bumper assembly 1 is particularly inexpensive to manufacture and is of very low weight. The curved brace 7 and the mounting struts 3, 3′ are tubular. Due to the tubular construction, the bumper assembly 1 has only a low weight. A section of pipe can also be inexpensively processed into the curved brace 7.

[0064] FIG. 1 shows a bumper assembly 1 in which the brace 7 is semicircular. Such a brace 7 is particularly inexpensive to manufacture because it is simply formed from a straight pipe, for example, without creating different cross sections or shapes.

[0065] FIG. 2 shows an alternative embodiment in which the curved brace 7 is C-shaped and the brace 7 has a straight part 10 bearing on the cross member 2.

[0066] The C-shaped brace 7 has straight end parts 8, 8′ connected to the chassis or frame 6. In the center part 9, the brace 7 has a straight region 10. These straight parts ensure a particularly advantageous deformation of the brace 7, so that improved energy absorption is achieved, while at the same time the cross-connection to the chassis or frame is improved. The center part 9 lies with the straight region 10 on the cross member 2 so that the center part 9 abuts not at a point, but over a larger a flat portion of the cross member 2, the term abut is also to be understood to include a small gap between the cross member 2 and the center part 9, in order to prevent rattling occurring during travel. This results in the advantage that the cross member 2 is supported from behind over a larger region and the brace 7 does move laterally when an obstacle hits the front of the vehicle off-center, but instead there is simultaneous deformation of the cross member 2 and the brace 7.

[0067] The brace 7 can also have regions that have different cross sections, as for example shown in FIG. 4 (right figure). The brace 7 is of round cross section, and the center part 9 is of approximately oval cross section. The elongated surfaces of the oval section have a larger contact region with the cross member 2 than, for example, with a round cross section. As a result, the possibility of lateral sliding of the brace 7 when an obstacle hits off-center on the front of the vehicle is avoided.

[0068] In the event of a front impact, the cross member 2 is approximately in the middle and the center of the cross member 2 bearing on the center part 9 of the brace 7 is first deformed. Due to the tapering cross section of the brace 7 in this region, it can be more easily deformed, so that over the deformation path a particularly uniform and thereby advantageous energy absorption can take place.

[0069] The brace 7 and/or the mounting struts 3, 3′ can preferably be made of steel, aluminum or magnesium or made of fiber composites. These materials enable inexpensive production of these parts.

[0070] The brace 7 and/or the mounting struts 3, 3′ can have regions of lower strength so that they are deformed uniformly and particularly advantageously and there is even energy dissipation. The brace 7 can for example be made of high strength manganese boron steel, and in the center part 9 an additional temperature control process the component 7 can impart to it a lower strength in connection with higher elongation value.

[0071] In addition, the center part 9 that bears on the bumper cross member 2 can be non-positively, positively or cohesively connected to the cross member 2, and for example, to prevent, in the event of an eccentric impact, that the brace 7 slips and therewith possibly the deformation and energy absorption does not take place in this case, the center part 9 lies directly and flat on the cross member 2.

[0072] The outer ends 4, 4′ of the mounting struts 3, 3′ are made with the hollow shaped body 11, 11′ of sheet metal that is attached to the bumper cross beam 2. The hollow shaped body 11, 11′ has a rectangular cross section with first and second side walls parallel to each other and to the bumper cross member 2 and two side walls connecting first and second side walls, so that the shaped body 11, 11′ is fixed to parts of the cross member 2 and the outer ends 4, 4′ of the mounting struts 3, 3′ are fixed to the shaped body 11, 11′. The hollow shaped body 11, 11′ serves as an additional deformation element between the outer ends 4, 4′ of the mounting struts 3, 3′ and the cross member 2. The shaped body 11, 11′ is on parts of the fixed cross member 2, the cross member 2 being of U-section with a base 14 and two side walls 15, 16 projecting therefrom and a base wall of the shaped part 11, 11′ fixed to a leg 15 or 16 of the cross member 2, for example screwed or welded on. The side walls of the shaped part 11, 11′ are parallel to the cross member 2, in particular to the base wall 14 of the cross member 2, and the base wall 14 forms the surface facing an obstacle and the side walls 15, 16 project from the base wall 14 toward the vehicle structure.

[0073] Between the cross member 2 and the first side wall of the shaped body 11, 11′ is a gap 12, 12′ shown in FIGS. 1, 2, 3 and 5. The size of this gap 12, 12′ can be selected as desired, so that a larger or smaller spacing is provided between the first side wall and the cross member 2, the gap 12, 12′ ensures no damage in the event of a light impact to the hollow shaped body 11, 11′, but only an elastic deformation of the cross member 2 takes place. FIG. 5 shows examples of gaps 12, 12′ of different sizes, with the gap 12, 12′ largest in example a) and smallest in example c).

[0074] FIG. 5 also shows possibilities of using a mounting strut 3, 3′ with a tubular shaped body 11, 11′.

[0075] The outer end 4, 4′ of the mounting strut 3, 3′ can be fixed with its end face on the second side wall of the shaped part 11, 11′, as shown in variant c). On impact the shaped body 11, 11′ deforms before deformation of the mounting strut 3, 3′. If it is a light impact, shaped part 11, 11′ will only be deformed. The mounting struts 3, 3′ remain undamaged. The mounting strut 3, 3′ is welded on its outer side to the shaped body 11, 11′.

[0076] Alternatively, the outer end 4, 4′ of the mounting strut 3, 3′ can extend through the second side wall of the shaped part 11, 11′ so part of the end 4, 4′ is in a cavity 13, 13′ of the shaped body 11, 11′. In the penetration region, the mounting strut 3, 3′ is fixed to the second fixed side wall. This variant is shown in FIG. 5b. The second leg region is formed with through holes through which the mounting strut 3, 3′ is inserted and where it projects into the cavity 13, 13′ between the side walls. The mounting strut 3, 3′ is welded in place at the through holes, with the mounting strut 3, 3′ extending as far as desired through the through-hole into the cavity 13, 13′ and then fixed to the second leg. The force-displacement curve for impact can be determined and optimally adjusted by the insertion depth.

[0077] The more the mounting strut 3, 3′ is inserted into the perforation, the smaller is the spacing of the end face of the mounting strut 3, 3′ to the first side wall and thus to the cross member 2 and the sooner the energy acting on the vehicle in the event of a collision the mounting struts 3, 3′ is applied.

[0078] A third variant is shown in FIG. 5a, in which the mounting strut 3, 3′ so far through the through hole is pushed that it pierces the first side wall and a part of the outer end 4, 4′ of the mounting strut 3, 3′ in the gap 12, 12′ between the cross member 2 and the first side wall is arranged. For this purpose, the first side wall also has a through holes through which the end 4, 4′ of the strut 3, 3′ is inserted and in which the mounting strut 3, 3′ is additionally fixed.

[0079] The different variants allow a particularly advantageous setting of the force-displacement curve, so that an optimal energy absorption of the bumper assembly 1 can be set.

[0080] The invention is not limited to the embodiment, but within the scope of revelation variable in many ways.

[0081] All in the description and/or drawing disclosed individual and combination features are regarded as essential to the invention.