Bumper arrangement

Abstract

Bumper assembly (1) for a motor vehicle, comprising a cross member (2) and two crash boxes (3, 4) coupled to the cross member (2), wherein at least one of the crash boxes (3, 4) is designed as a sleeve crash box (3) and has a sleeve (5) arranged inside the sleeve crash box (3) for receiving a towing eye, characterized in that the sleeve crash box (3) has at least one opening (19, 21) on at least one side wall (15) which is arranged at the height (H52) of the sleeve (5), such that in the event of impact-induced wrinkling of the sleeve crash box (3), the at least one side wall (15) does not come into contact with the sleeve (5), or only to a non-blocking extent.

Description

[0001] The present invention relates to a bumper arrangement according to the features in the preamble of claim 1.

[0002] Bumpers are standard equipment on motor vehicles, fitted at both the front and rear, to absorb the impact energy of minor collisions, thus minimizing damage to the vehicle's structural frame. A bumper typically consists of a crossmember, which incorporates crash boxes positioned transversely to the longitudinal members of the vehicle frame. The crossmember serves to transfer the energy resulting from an impact into the crash boxes, where the impact energy is converted into deformation work.

[0003] To enable towing a vehicle, for example in the event of an accident, vehicles are equipped with permanently installed towing eyes or receptacles at the front and / or rear into which separate towing eyes can be screwed. These receptacles are usually concealed within the bumpers and accessible via an opening in the bumper. This ensures that the vehicle's exterior appearance is not affected. The tensile forces generated during towing are thus transferred directly to the bumper assembly.

[0004] The receptacle for the towing eye is usually located inside one of the crash boxes. Such an arrangement is known, for example, from DE 10 2013 015 518 A1 and DE 10 2015 113 773 B3.

[0005] WO 2015 / 189 500 A1 further discloses a metal insert for a towing device.

[0006] WO 2019 / 115 552 A1 describes a crash box for a motor vehicle. Further state of the art is described in DE 10 2018 106 224 A1.

[0007] To define the required force level for the deformation of the crash boxes in the event of an impact and to specify the direction of deformation, ribs are often incorporated into the side walls of the crash boxes. These ribs weaken the side walls in a controlled manner, causing the crash boxes to fold inwards in the area of ​​the ribs upon impact. A distinction is made between outwardly in ...

[0008] It has been shown that in the event of an impact, the side walls of the crash box with its internal mounting, particularly in the area of ​​the inner ribs, come into contact with the mounting. This can lead to uneven deformation of the crash box or to critical block formation, thus reducing the impact energy converted into deformation work. Block formation is defined as the deformation of the crash box and / or the mounting into a rigid structure, such that no further crash energy can be absorbed, even if the crash box is not yet completely crushed. Furthermore, a permissible force level can be exceeded, resulting in damage to the vehicle body.

[0009] The invention is therefore based on the objective of functionally improving a bumper arrangement, starting from the prior art, so that critical block formation or asymmetrical wrinkling does not occur in the event of a load.

[0010] According to the invention, the solution to this problem consists of a bumper arrangement according to claim 1.

[0011] Advantageous embodiments and further developments of the bumper according to the invention are the subject of the dependent claims.

[0012] The invention relates to a bumper assembly for a motor vehicle comprising a crossmember and two crash boxes coupled to the crossmember. A sleeve for receiving a towing eye is arranged within at least one crash box. This crash box is hereinafter referred to as the sleeve crash box.

[0013] According to the invention, the bumper arrangement is now characterized in that the sleeve crash box has at least one opening on at least one of its four side walls, which is arranged at the level of the sleeve. This has two decisive advantages. Firstly, the opening prevents the side wall of the sleeve crash box from coming into contact with the sleeve during impact-induced wrinkling, or only to a non-blocking extent, particularly under the conditions of an RCAR bumper test. Secondly, the sleeve crash box is selectively weakened via the openings, so that a defined force level for the deformation of the sleeve crash box is established.

[0014] Preferably, the length of the sleeve corresponds to at least one-third of the sleeve crash box length. Experience has shown that this is an optimal ratio in the event of an impact followed by deformation of the sleeve crash box, thus preventing contact between the stone walls of the sleeve crash box and the sleeve.

[0015] The sleeve itself has a maximum and minimum outer width in the vertical direction of the integrated sleeve crash box. The maximum outer width of the sleeve preferably corresponds to at least one-third of the minimum inner dimension of the sleeve crash box. The minimum inner dimension of the sleeve crash box refers to the distance between the opposing side walls. Here, too, it has been shown that such a ratio is particularly advantageous in the event of an impact with subsequent deformation of the sleeve crash box.

[0016] Within the scope of the invention, the term "width" can also be replaced by the term "height" for both the crash box and the sleeve and opening. This would correspond to an installation position or arrangement of the crash box, sleeve, and opening within the motor vehicle rotated by 90° about the longitudinal axis. The same applies to the phrase "at height".

[0017] The opening in the side wall according to the invention has, in particular, a rectangular shape with rounded edges. This shape minimizes material removal from the side wall, thus avoiding an increased risk of cracking in the event of an impact. At the same time, this shape of the opening ensures, in particular, that the corresponding side wall does not come into contact with the sleeve in the event of an impact.

[0018] Furthermore, the opening preferably has an opening height in the vertical direction of the integrated sleeve crash box that corresponds to, or lies between, the minimum or maximum outer width of the sleeve. This design variant represents an optimum between minimal material removal from the side wall and preventing contact between the side wall and the sleeve when the sleeve crash box deforms.

[0019] In an advantageous embodiment, the bumper assembly has a vehicle-side flange plate, wherein the sleeve is coupled to the flange plate, in particular by welding. The sleeve and the sleeve crash box are coupled to a structural element or longitudinal member of the vehicle via the flange plate.

[0020] In a further embodiment of the invention, the sleeve is arranged on the rear side of the cross member, in particular joined to it. In this case, instead of a flange plate for body coupling, a screw insertion solution into the longitudinal member is also possible.

[0021] Preferably, the side walls with openings according to the invention have at least one inwardly inverted inner rib. The inner rib weakens the walls of the sleeve crash box and, in the event of an impact, defines a deformation path for the sleeve crash box. Furthermore, the force required to deform the sleeve crash box can be regulated via the inner rib, depending on its dimensions. In the event of deformation of the sleeve crash box, the side wall is pressed inwards in the area of ​​the inner rib.

[0022] Preferably, the opening according to the invention is arranged in a longitudinal section of the side wall which has an inner groove. Since the inner groove is pressed into the interior of the sleeve crash box and thus towards the sleeve in the event of an impact, the opening prevents direct contact between the side wall and the sleeve.

[0023] It is further preferred that the opening is arranged in a longitudinal section of the side wall that has a smaller internal dimension than adjacent longitudinal sections. In the event of an impact, the longitudinal section with the smaller internal dimension will again come into contact with the sleeve sooner than adjacent longitudinal sections with larger internal dimensions. Accordingly, this arrangement of the opening is particularly advantageous.

[0024] Furthermore, the side wall with an opening according to the invention has, in particular, an outer rib, which is preferably designed as a vertical rib. The vertical rib has a greater height in the vertical direction than its width in the horizontal direction. In the event of an impact with subsequent deformation of the sleeve crash box, the side wall of the sleeve crash box is folded outwards in the area of ​​the outer rib.

[0025] Preferably, the outer rib is arranged between two openings on the side wall. In the event of an impact, this causes the side wall to move outwards in the area of ​​the outer rib, while the side wall is pushed inwards in the area of ​​the openings. The openings prevent the side wall from coming into contact with the sleeve.

[0026] The opening is preferably positioned between two outer ribs in the side wall. In the event of an impact and subsequent deformation of the shell crash box, the side wall in the area of ​​the outer ribs folds outwards, while the side wall with the opening folds inwards towards the shell. This ensures that the side wall only folds towards the inner shell in the area of ​​the opening.

[0027] Preferably, at least one side wall has an opening designed as a vertical opening. This opening is particularly located between two outer ribs. It has been shown that the vertical shape of the opening is especially advantageous for defining the direction of deformation.

[0028] Preferably, at least one side wall has an opening designed as a horizontal opening. In particular, the horizontal opening is arranged in a vertically oriented inner groove. Here, too, it has been shown that the arrangement of a horizontal opening in a vertically oriented inner groove is particularly advantageous for the deformation path of the sleeve crash box.

[0029] Both crash boxes are preferably made from one or two metal sheets joined along their contacting longitudinal edges.

[0030] Crash boxes are particularly favored for having inner and outer ribs in all four side walls.

[0031] The invention is described in more detail below with reference to the drawings. They show Fig. 1 a top view of a bumper arrangement according to the invention, Fig. 2 a top view of a bumper arrangement according to the invention in an alternative embodiment, Fig. 3 a top view of a sleeve crash box according to the invention, Fig. 4 a side view of a sleeve crash box according to the invention, and Fig. 5 a rear view of a sleeve crash box according to the invention.

[0032] In the figures, the same reference symbols are used for identical or similar parts or component parts, even if a repeated description is omitted for the sake of simplicity.

[0033] Fig. Figure 1 shows a bumper assembly 1 comprising a cross member 2 and two crash boxes 3, 4 coupled to the cross member 2. In addition to the cross member 2, the crash boxes 3, 4 absorb the energy resulting from an impact by converting it into deformation work.

[0034] The in Fig. 1. The crash box 3, located on the left side of the crossbeam 2, has an internal sleeve 5. This crash box 3 will henceforth be referred to as the sleeve crash box 3. The sleeve 5 and the sleeve crash box 3 are connected at their lower ends according to Fig. 1 coupled to a flange 6. The sleeve 5 has a thread (not shown) at its upper end, via which a towing eye can be connected to the sleeve 5.

[0035] Fig. Figure 2 shows an alternative embodiment of the invention. Here, the sleeve 5 is at its upper end according to Fig. 2 is coupled to the rear wall 7 of the crossbeam 2. The sleeve crash box 3 is directly coupled to a longitudinal beam 9 via a screw arrangement 8. Here, too, a towing eye can be connected to the sleeve 5 via a thread located at the upper end of the sleeve 5 (not shown here).

[0036] Fig. Figure 3 shows a top view of the sleeve crash box 3 without crossbeam 2 and flange 6. The length LH of the sleeve 5 corresponds to more than one third of the length LHC of the sleeve crash box 3.

[0037] In the upper side wall 10 of the sleeve crash box 3, four beads 11, 12, 13, 14 are arranged. All beads 11, 12, 13, 14 are arranged at height H51 of the sleeve 5. According to Fig. Starting from the left, an outer bead 11 is arranged on the upper side wall 10 and in the lower longitudinal half of the sleeve 5. The outer bead 11 has a rectangular shape with rounded edges.

[0038] An inner groove 12 is arranged in the upper side wall 10 of the sleeve crash box 3. This also has a rectangular shape with rounded edges and is located in the upper longitudinal half of the sleeve 5.

[0039] Further downstream, an outer groove 13 is arranged in the upper side wall 10. This also has a rectangular shape with rounded edges and is located in the inner end region of the sleeve 5.

[0040] The fourth bead 14 is also designed as an outer bead 14, but has an oval shape. The outer bead 14 does not overlap with the sleeve 5.

[0041] All grooves 11, 12, 13, 14 are designed as vertical grooves.

[0042] The opposite lower side wall of the sleeve crash box 3, not shown, is designed analogously to the upper side wall 10 in this embodiment. The arrangement of the beads 11, 12, 13, 14 can also be different between opposite side walls.

[0043] Fig. Figure 4 shows a side view of the sleeve crash box 3, which is coupled at its vehicle-side end to the flange 6 and at its other end to the cross member 2.

[0044] The sleeve 5 has a constant outer width BH in the vertical direction. The minimum inner dimension of the sleeve crash box 3 is equal to the inner dimension L5i in the illustrated embodiment, see Figure 1. Fig. 3. The maximum external width BH of the sleeve 5 corresponds to at least one third of the minimum internal dimension L5i of the sleeve crash box 3.

[0045] The side wall 15 of the sleeve crash box 3 has two outer ribs 16, 17. Both outer ribs 16, 17 have a rectangular shape with rounded edges. The outer ribs 16, 17 are located at height H52 of the sleeve 5. One outer rib 16 is arranged in the upper longitudinal region of the sleeve 5. The other outer rib 17 is located above and according to Fig. 4 further to the right of the sleeve 5.

[0046] A longitudinal section L1 is arranged between the outer ribs 16, 17. This section has a smaller internal dimension L1i than the internal dimensions L3i and L4i of the adjacent longitudinal sections L3 and L4. This is in Fig. Figure 3 shows a vertical internal groove 18 arranged within the longitudinal section L1. An opening 19 is arranged within the longitudinal section L1 and the internal groove 18. This opening has a rectangular shape with rounded edges, is designed as a vertical opening, and is located at the height H52 of the sleeve 5.

[0047] The opening 19 is thus located between the outer ribs 16, 17 and within the longitudinal section L1, which has a smaller internal dimension L1i compared to the internal dimensions L3i and L4i of the adjacent longitudinal sections L3 and L4, so that in the event of an impact, the longitudinal section L1 with the opening 19 is pressed into the interior of the sleeve crash box 3 towards the sleeve 5. The opening 19 prevents the side wall 15 from contacting the sleeve 5.

[0048] Above and according to Fig. 4. To the right of the outer bead 17, a longitudinal section L2 is arranged. Within this section, a vertical inner bead 20 is arranged. An opening 21 is located in the longitudinal section L2 and the inner bead 20, overlapping on the right side wall 15. The opening 21 has a rectangular shape with rounded edges, is designed as a horizontal opening, and is also located at height H52 of the sleeve 5.

[0049] The vertical opening height HO of the opening 21 corresponds to the vertical width BH of the sleeve 5.

[0050] The opening 21 is located in a longitudinal section L2, which has a smaller internal dimension L2i compared to the internal dimensions L4i and L5i of the adjacent longitudinal sections L4 and L5. Therefore, in the event of an impact, the longitudinal section L2 with the opening 21 is pressed into the interior of the shell crash box 3 towards the shell 5. The opening 21 prevents the side wall 15 from contacting the shell 5.

[0051] The opposite left side wall of the sleeve crash box 3, not shown, is designed analogously to the right side wall 15 in this embodiment. The arrangement of the beads 16, 17, 18, 20 can also be different between opposite side walls.

[0052] Furthermore, it should be noted that in the event of an impact, the sleeve crash box 3 is compressed in the direction of the flange 6, so that both the opening 19 and the opening 21 are located in the area of ​​the sleeve 5.

[0053] Fig.Figure 5 shows a rear view of the sleeve crash box 3. It can be seen that the sleeve crash box 3 is formed from two metal sheets 22, 23. These are joined along their contacting longitudinal edges 24, 25. Reference symbol: 1 Bumper arrangement 2 crossbeams 3 shell crash box 4 Crashbox 5 Sleeve 6 flange 7 Back panel of 2 8 Insert screw solution 9 longitudinal beams 10 upper side wall 11 Outer groove 12 inner groove 13 Outer groove 14 Outer groove 15 right side wall 16 Outer groove 17 Outer groove 18 inner groove 19 Opening 20 inner groove 21 Opening 22 sheet metal 23 Sheet metal 24 Long edge of 22 25 Long edge of 23 H51 Height of 5 H52 Height of 5 L1 length section L1i Internal dimension of L1 L2 length segment L2i Internal dimension of L2 L3 length section L3i Internal dimension of L3 L4 length section L4i Internal dimension of L4 L5 length section L5i Internal dimension of L5

Claims

[1] Bumper assembly (1) for a motor vehicle, comprising a cross member (2) and two crash boxes (3, 4) coupled to the cross member (2), wherein at least one of the crash boxes (3, 4) is designed as a sleeve crash box (3) and has a sleeve (5) arranged inside the sleeve crash box (3) for receiving a towing eye, characterized by , that the sleeve crash box (3) has at least one opening (19, 21) on at least one side wall (15) which is arranged at the height (H52) of the sleeve (5) such that in the event of impact-induced wrinkling of the sleeve crash box (3) the at least one side wall (15) does not come into contact with the sleeve (5), or only to a non-blocking extent. [2] Bumper arrangement (1) according to claim 1, characterized by that the length (LH) of the sleeve (5) is at least one third of the sleeve crash box length (LHC). [3] Bumper arrangement (1) according to claim 1 or 2, characterized by, that the sleeve (5) has a maximum external width (BH) and the sleeve crash box (3) has a minimum internal dimension (L5i), wherein the maximum external width (BH) of the sleeve (5) is at least one third of the minimum internal dimension (L5i) of the sleeve crash box (3). [4] Bumper arrangement (1) according to any one of claims 1 to 3, characterized by , that the opening (19, 21) has a rectangular shape with rounded edges. [5] Bumper arrangement (1) according to any one of claims 1 to 4, characterized by , that the opening (21) has an opening height (HO) where the opening height (HO) corresponds to 50% to 150% of a mean outside width (BH) of the sleeve (5). [6] Bumper arrangement (1) according to any one of claims 1 to 5, characterized by , that the crashbox (3, 4) has a vehicle-side flange plate (6), wherein the sleeve (5) is coupled to the flange plate (6). [7] Bumper arrangement (1) according to any one of claims 1 to 5, characterized bythat the sleeve (5) is arranged on the rear wall side of the cross member (2). [8] Bumper arrangement (1) according to any one of claims 1 to 7, characterized by , that the side wall (15) with opening (19, 21) has at least one internal groove (18, 20) [9] Bumper arrangement (1) according to any one of claims 1 to 8, characterized by , that the opening (19, 21) is arranged in a longitudinal section (L1, L2) of the side wall (15) which has an internal groove (18, 20). [10] Bumper assembly (1) according to any one of claims 1 to 9, characterized by , that the opening (19, 21) is arranged in a longitudinal section (L1, L2) of the side wall (15) which has a smaller internal dimension (L1i, L2i) than the internal dimensions (L3i, L4i, L5i) of the adjacent longitudinal sections (L3, L4, L5). [11] Bumper arrangement (1) according to any one of claims 1 to 10, characterized by , that the side wall (15) with opening (19, 21) has an outer groove (16, 17). [12] Bumper arrangement (1) according to claim 11, characterized by , that the outer groove (17) is arranged between two openings (19, 21) on the side wall (15). [13] Bumper arrangement (1) according to any one of claims 1 to 12, characterized by , that an opening (19) is arranged between two outer beads (16, 17) in the side wall (15). [14] Bumper arrangement (1) according to any one of claims 1 to 13, characterized by , that at least one side wall (15) has an opening (19) designed as a vertical opening. [15] Bumper arrangement (1) according to claim 14, characterized by , that the opening (19) designed as a vertical opening is arranged between two outer beads (16, 17). [16] Bumper arrangement (1) according to any one of claims 1 to 15, characterized by , that at least one side wall (15) has an opening (21) designed as a horizontal opening. [17] Bumper arrangement (1) according to claim 16, characterized by, that the opening (21) designed as a horizontal opening is arranged in a vertically oriented inner groove (20). [18] Bumper arrangement (1) according to any one of claims 1 to 17, characterized by , that the crash boxes (3, 4) are formed from one or two metal sheets (22, 23) and are joined along their contacting longitudinal edges (24, 25). [19] Bumper arrangement (1) according to any one of claims 1 to 18, characterized by , that the crash boxes (3, 4) have grooves (11, 12, 13, 14, 16, 17, 18, 20) in all side walls (10, 15). [20] Bumper arrangement (1) according to any one of claims 1 to 19, characterized by , that the sleeve (5) is arranged centrally in the crashbox (3, 4) and openings (19, 21) are formed in exactly two opposite side walls (10, 15) at the height (H52) of the sleeve (5). [21] Bumper arrangement (1) according to any one of claims 1 to 19, characterized by, that the sleeve (5) is arranged off-center in the crashbox (3, 4) and closer to a side wall (10, 15) and only the closer side wall (10, 15) has the at least one opening (19, 21).

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