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DE-102014115887-B4 - Crash box for a motor vehicle's bumper system

DE102014115887B4DE 102014115887 B4DE102014115887 B4DE 102014115887B4DE-102014115887-B4

Abstract

Crash box for a motor vehicle's bumper system with an upper wall (1), a bottom wall (2) and two side walls (9, 10) and a bumper crossmember (18) arranged on the crash box wherein the crashbox is divided in its longitudinal extent into a first longitudinal section (3) and a subsequent second longitudinal section (4), wherein in the first longitudinal section (3) a longitudinal plane (5) of the upper wall (1) intersects a central longitudinal plane (20) of the crashbox at an angle Δ1 and a longitudinal plane (6) of the lower wall (2) intersects the central longitudinal plane (20) of the crashbox at an angle Δ2, where: -5° ≤ Δ1 ≤ 5° and -5° ≤ Δ2 ≤ 5° and wherein in the second longitudinal section (4) a longitudinal plane (7) of the upper wall (1) intersects a longitudinal plane (8) of the lower wall (2) at an angle α, characterized by the fact that the upper wall (1) and/or the lower wall (2) and/or at least one of the side walls (9, 10) is provided with at least one predetermined deformation point in the form of a transverse rib (12).

Inventors

  • Frank Rabe
  • Andreas Schiller
  • Christian Handing
  • Dariusz Straznikiewicz

Assignees

  • BENTELER AUTOMOBILTECHNIK GMBH

Dates

Publication Date
20260513
Application Date
20141031

Claims (15)

  1. Crashbox for a bumper system of a motor vehicle comprising an upper wall (1), a lower wall (2), and two side walls (9, 10) and a bumper crossmember (18) arranged on the crashbox, wherein the crashbox is divided in its longitudinal extent into a first longitudinal section (3) and a subsequent second longitudinal section (4), wherein in the first longitudinal section (3) a longitudinal plane (5) of the upper wall (1) intersects a central longitudinal plane (20) of the crashbox at an angle Δ1 and a longitudinal plane (6) of the lower wall (2) intersects the central longitudinal plane (20) of the crashbox at an angle Δ2, wherein: -5° ≤ Δ1 ≤ 5° and -5° ≤ Δ2 ≤ 5° and wherein in the second longitudinal section (4) a longitudinal plane (7) of the upper wall (1) intersects a longitudinal plane (8) the lower wall (2) cuts at an angle α, characterized in that the upper wall (1) and/or the lower wall (2) and/or at least one of the side walls (9, 10) is provided with at least one predetermined deformation point in the form of a transverse groove (12).
  2. Crashbox after Claim 1 , characterized in that for a length ratio (LV) of the length (L1) of the first length segment (3) to the length (L2) of the second length segment (4) the following holds: LV=L1/L2 and 1/3 ≤ LV ≤ 2.
  3. Crashbox after Claim 1 or 2 , characterized in that the following applies to the angle α: 15 ° ≤ α ≤ 60 ° .
  4. Crashbox according to one of the preceding claims, characterized in that: Δ1 = Δ2 and either the longitudinal plane (6) of the lower wall (2) in the first length section (3) corresponds to the longitudinal plane (8) of the lower wall (2) in the second length section (4) or the longitudinal plane (5) of the upper wall (1) in the first length section (3) corresponds to the longitudinal plane (7) of the upper wall (1) in the second length section (4), such that either an angle β is formed between the longitudinal plane (5) of the upper wall (1) in the first length section (3) and the longitudinal plane (7) of the upper wall (1) in the second length section (4) or between the longitudinal plane (6) of the lower wall (2) in the first length section (3) and the longitudinal plane (8) of the lower wall (2) in the second length section (4), wherein: α+β+Δ2=180° or α+β-Δ2=180°.
  5. Crashbox according to one of the preceding claims, characterized in that two side walls (9, 10) connecting the upper wall (1) with the lower wall (2) are provided.
  6. Crashbox after Claim 5 , characterized in that the upper wall (1) and/or the lower wall (2) and/or at least one of the side walls (9, 10) is provided with at least one longitudinal bead and/or a weld or another heat-affected zone.
  7. Crashbox after Claim 5 or 6 , characterized in that a transverse groove (12) is provided in the upper wall (1) of the first longitudinal section (3) in the area adjacent to the second longitudinal section (4) and/or in a side wall (9, 10) of the second longitudinal section (4) in the area adjacent to the first longitudinal section (3).
  8. Crashbox after one of the Claims 5 until 7 , characterized in that it is formed from two half-shells (13, 14) which are joined together, preferably in the area of the side walls (9, 10).
  9. Crashbox after one of the Claims 5 until 7 , characterized in that it is formed from a u-shaped or o-shaped bent sheet metal, the ends of which are joined together.
  10. Crashbox after one of the Claims 5 until 7 characterized by the fact that it is designed as an extrusion profile.
  11. Crashbox according to one of the preceding claims, characterized in that it is made of steel, magnesium, aluminium or an aluminium alloy.
  12. Crashbox according to one of the preceding claims, characterized in that a flange (15) is arranged at the end of the first longitudinal section (3) opposite the second longitudinal section (4).
  13. Crashbox according to one of the preceding claims, characterized in that a connection section (16) is arranged on the upper wall (1) at the end of the second longitudinal section (4) opposite the first longitudinal section (3).
  14. Bumper system for a motor vehicle with at least one crash box according to one of the preceding claims.
  15. motor vehicle with a bumper system according to Claim 14 .

Description

The invention relates to a crash box for a bumper system of a motor vehicle according to the preamble of claim 1, as well as a bumper system of claim 14 and a motor vehicle of claim 15. Crash boxes for vehicle bumper systems are known in a variety of forms. The crash box is positioned between a bumper or bumper crossmember and a vehicle or vehicle longitudinal member. To protect the vehicle frame from thrust and/or shear forces that are transmitted into the crash box via the bumper or bumper crossmember in the event of a collision, the crash box limits the transmitted force components to a level that is harmless to the vehicle frame by converting the kinetic energy into heat and internal stresses through plastic deformation of the crash box. During this process, the joints between the crash box and the frame, the bumper or bumper crossmember, and the vehicle or vehicle longitudinal member remain intact. In addition to tubular crash boxes with a ring-shaped or polygonal cross-sectional area, which serve to absorb shear and/or tensile forces and are manufactured, for example, as extruded profiles or pultruded profiles made of fiber-filled plastics or an aluminum alloy, box-shaped or conical crash boxes in shell construction are used, which have a greater resistance to transverse forces or bending moments compared to the tubular crash boxes and thus have a greater buckling strength. In tubular crash boxes, a nearly constant force absorption can be achieved by machining or separating the outer shell, as well as by turning the outer surface of the crash box from the inside out along its length. In box-shaped or conical crash boxes, force absorption occurs through the compression and expansion of the outer shell. Due to bulges and dents formed in a regular pattern within the shell, it folds during this process. Beads and/or pressure relief openings in the outer surface of the crash boxes reduce the component mass and facilitate the intended or uniform forming of the crash box. In this process, both the speed-dependent forming properties of the material and the joints must be considered, and the unintentional formation of cracks or breakage of the crash box must be prevented. For example, in the DE 10 2004 013 713 A1 A crash box is described in which the upper and lower walls of the crash box run continuously towards each other from a flange with which the crash box can be attached to a vehicle cross member until they meet the bumper cross member to which the crash box is also attached. Furthermore, it is from the DE 100 14 469 A1 A box-shaped crash box is known in which the upper and lower walls on the one hand and the side walls on the other hand are arranged parallel to each other over the entire longitudinal extent of the crash box. The DE 10 2005 053 778 A1 also describes a crash box in which the upper wall and the lower wall converge along the entire longitudinal extent of the crash box. Furthermore, the following are from the species-specific DE 10 2008 045 515 A1 , DE 10 2008 022 564 A1 , DE 10 2007 051 815 A1 Crash box arrangements are known. While all known crash box designs achieve a satisfactory conversion of kinetic energy into heat or deformation energy following a collision involving a vehicle equipped with such a crash box, it has been shown that this can sometimes result in asymmetrical deformation of the crash box, particularly in the vertical direction, and in extreme cases, even tearing of the crash box walls. This is especially true when there is a height difference between the bumper and the vehicle's longitudinal frame rails. It is therefore an object of the invention to further develop a crash box according to the preamble of claim 1 in such a way that asymmetrical deformations of the crash box, in particular in the vertical direction, and tearing of the crash box walls as a result of a collision of the motor vehicle are avoided, wherein preferably a height offset between the bumper on the one hand and the vehicle longitudinal member on the other hand can be realized by the crash box. This problem is solved by a crash box for a bumper system of a motor vehicle with all the features of claim 1. Furthermore, this problem is solved by a bumper system of claim 14 and by a force vehicle according to claim 15. Advantageous embodiments of the invention are found in the dependent claims. The crash box according to the invention for a bumper system of a motor vehicle with an upper wall and a lower wall is characterized in that the crash box is divided in its longitudinal extent into a first longitudinal section and a second longitudinal section adjoining it, wherein in the first longitudinal section a longitudinal plane of the upper wall intersects a central longitudinal plane of the crash box at an angle Δ1 and a longitudinal plane of the lower wall intersects the central longitudinal plane of the crash box at an angle Δ2, wherein: -5° ≤ Δ1 ≤ 5° and -5° ≤ Δ1 ≤ 5° and wherein in the second longitudi