BUMPER ARRANGEMENT WITH DOUBLE CROSS BEAM AND TOWING EYE

Description

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

[0002] It is known from the prior art to use bumper assemblies at the front and rear of motor vehicles. This involves a cross member that extends essentially across a large part of the vehicle's width. The cross member can be curved around the vehicle's vertical axis. The cross member is coupled to the vehicle via crash boxes.

[0003] If the vehicle encounters an obstacle or collides with another vehicle, the vehicle impacts the cross member, causing the crash boxes to deform and convert crash energy into deformation energy. This reduces the initial crash energy. The cross member itself also prevents further intrusion into the vehicle or engine compartment.

[0004] It is necessary to provide a towing eye or towing hook on a motor vehicle so that the vehicle can be towed in the event of an accident or technical defect.

[0005] For example, DE 10 2022 001 443 A1 discloses a cross member arrangement with a towing device.

[0006] Furthermore, a towing eye must be provided so that the vehicle can be transported overseas, for example. The vehicle is then secured in a container or on a ship using the towing eye to prevent it from rolling away. The forces acting on the towing eye therefore act in the longitudinal direction of the vehicle. However, when lashed to the ground, they also act proportionally in the vertical and transverse directions of the vehicle.

[0007] Furthermore, from DE 20 2021 103 263 U1 a bumper arrangement is known comprising a main cross member and an auxiliary cross member which are integrally connected to one another via vertical struts with the integration of a towing eye.

[0008] For aesthetic and safety reasons, a tow hook or towing eye is removed during normal vehicle operation. A bushing, i.e., a threaded opening, is then provided on the vehicle into which the towing eye is inserted or screwed. Such a towing eye or towing eye bushing therefore conflicts with the rigidity of the cross member and the potential for the crash box to deform.

[0009] Furthermore, it is known from the state of the art to meet crash requirements, in particular for the MPDB crash test, i.e. a crash test with lateral overlap or a large impact area.

[0010] The object of the present invention is, based on the prior art, to provide a bumper arrangement which enables improved crash behavior compared to the prior art while simultaneously allowing the integration of a towing eye and being inexpensive to produce.

[0011] The above-mentioned object is achieved according to the invention in a bumper arrangement for a motor vehicle having the features in claim 1.

[0012] Advantageous embodiments are the subject of the dependent claims.

[0013] The aforementioned bumper assembly for a motor vehicle comprises a main cross member and an auxiliary cross member arranged underneath it, relative to the vertical direction of the vehicle. The main cross member and auxiliary cross member preferably extend across a large part of the vehicle width. The main cross member and auxiliary cross member are made in particular from steel material, preferably as a hollow profile with a locking plate. However, the main cross member and the auxiliary cross member are preferably each made from an extruded material. The main cross member and auxiliary cross member can have a curvature around the vertical direction of the vehicle. The main cross member and the auxiliary cross member are coupled to one another via vertical struts. The bumper assembly itself is coupled to the vehicle via crash boxes.

[0014] According to the invention, the bumper assembly is now characterized in that the vertical struts are formed as a separate hollow profile. A towing eye bushing extending through the wall surface is inserted into at least one vertically extending wall surface of the separate hollow profile and coupled to this wall surface. The coupling is achieved, in particular, by a thermal joining process.

[0015] The vertical strut is preferably made as an extruded hollow profile, in particular from a light metal material, most preferably from an aluminum alloy. In cross-section, the vertical strut is designed, in particular, as a multi-chamber hollow profile. The individual chambers can be arranged side by side in relation to the transverse direction of the vehicle. However, the chambers can also be arranged one behind the other in the longitudinal direction of the vehicle.

[0016] In addition to being particularly easy to install, the invention has proven to be particularly effective in that the vertical struts firmly connect the main cross member and the auxiliary cross member. By integrating the towing eye bushing into the vertical strut, the rigidity of neither the main cross member nor the auxiliary cross member is affected. Furthermore, the towing eye bushing is not connected to a crash box, so the deformation of the crash box in the event of a crash is also not influenced by the towing eye bushing.

[0017] In addition, the arrangement of the towing eye socket in the vertical strut allows a much greater degree of freedom in vertical positioning and thus more additional scope for design requirements of the vehicle front or vehicle construction.

[0018] In particular, the hollow profile of the separate strut is designed as a hollow profile with a closed cross-section. This hollow profile has two wall surfaces spaced apart from one another in the longitudinal direction of the vehicle, with the towing eye bushing extending through both wall surfaces. For this purpose, the towing eye bushing is radially widened, particularly at a rear end, or has a radially protruding flange. The radially protruding flange engages behind the rear wall surface in the longitudinal direction of the vehicle. This measure ensures that a tensile force applied in the longitudinal direction of the vehicle is additionally supported by the radially protruding flange, in addition to an otherwise possible coupling of the towing eye bushing to the hollow profile. In the event of a vehicle crash, the vertical strut can also deform and dissipate crash energy.The towing eye bushing is preferably additionally coupled only to the rear wall of the vertical strut, so that in the event of a frontal crash the towing eye bushing pushes out rearward through the vertical strut without influencing the deformation behavior of the vertical strut itself.

[0019] Furthermore, the penetration of two wall surfaces, preferably in combination with the radially projecting flange, has proven to be advantageous for lashing the motor vehicle. Due to the fact that the towing eye bushing penetrates two wall surfaces and the wall surfaces are spaced apart from one another in the longitudinal direction of the motor vehicle, the application of tensioning forces of up to several tons acting in the vertical direction of the motor vehicle and / or in the transverse direction of the motor vehicle can be easily absorbed without the cross member arrangement becoming deformed.

[0020] Furthermore, the crash boxes are particularly preferably arranged in the vertical direction of the motor vehicle at the height of the main cross member.

[0021] The vertical strut is preferably positioned directly below the crash box in the transverse direction of the vehicle and is preferably narrower than the crash box itself. It is also possible for the vertical strut to be offset transversely from the position of the crash box, in particular by a maximum of the width of the crash box, measured from the center of the crash box to the center of the vertical strut. This further ensures optimal stability, force transmission, and stiffening between the cross members.

[0022] The crash boxes are therefore located behind the main cross member.

[0023] Preferably, additional crash boxes can also be arranged. The additional crash boxes are then preferably arranged at the height of the auxiliary cross member relative to the vertical direction of the vehicle and / or at the height of the vertical struts.

[0024] The vertical struts themselves are particularly designed as hollow profiles. The vertical struts can be made of steel or aluminum. The vertical struts are then preferably coupled to a lower wall of the main cross member or to an upper wall of the auxiliary cross member, in particular by means of a material-to-material joining.

[0025] Alternatively or additionally, it is also possible for the vertical strut to have a flange projecting in the vertical direction, preferably two flanges, each projecting upwards and downwards with respect to the vertical direction. The flanges then preferably engage behind a rear wall of the main cross member or a rear wall of the auxiliary cross member and are preferably coupled to the rear wall. This ensures that when a tensile force is applied in the longitudinal direction of the vehicle via the towing eye socket, the vertically extending struts on the main cross member and auxiliary cross member are supported and thus apply a tensile force to the vehicle to be towed or lashed down. Two vertical struts are preferably arranged. These are preferably arranged in a length range between 5 and 30%, in particular 5 to 15%, each coming from one end of the main cross member and auxiliary cross member.

[0026] In addition, additional struts can also be arranged vertically in the vehicle. These additional struts are then located in the area of ​​or at the end of the main cross member and the auxiliary cross member.

[0027] Further advantages, features, properties, and aspects of the present invention are the subject of the following description. Preferred embodiments are illustrated in the schematic figures. These serve to facilitate understanding of the invention.

[0028] They show: Figures 1a to d show various embodiments of a bumper arrangement according to the invention, in different views. Figures 2a to f show various embodiments of a bumper arrangement according to the invention, in different views. Figures 3a to e show various embodiments of a bumper arrangement according to the invention, in different views. Figures 4a to f show various embodiments of a bumper arrangement according to the invention, in different views. Figures 5a to e show various embodiments of a bumper arrangement according to the invention, in different views. Figures 6a to d show various embodiments of a bumper arrangement which serves to illustrate the inventive concept, in different views.

[0029] In the figures, the same reference symbols are used for identical or similar components, even if a repeated description is omitted for reasons of simplification.

[0030] Figures 1a to dshow a bumper arrangement 1 according to the invention in different views. According to Figure 1a is the bumper arrangement 1 in plan view and Figure 1bshown in front view. A main cross member 2, relative to the vertical direction Z of the motor vehicle, is connected to the auxiliary cross member 3 arranged underneath it via vertical struts 4. Furthermore, crash boxes 5 are arranged behind the main cross member 2, via which the bumper arrangement 1 is coupled to a motor vehicle (not shown in detail). The main cross member 2 is arranged offset to the front relative to the auxiliary cross member 3 in relation to the longitudinal direction X of the motor vehicle. Furthermore, a towing eye socket 6 with an internal thread (not shown in detail) is arranged in the vertical strut 4, relative to the right-hand plane of the image. The vertical struts 4 are arranged over a length L, relative to an end 7 of the main cross member 2, between 5 and 20% in a longitudinal section in the transverse direction Y of the motor vehicle.

[0031] According to Figure 1c , which is a sectional view along line AA from Figure 1b, the vertical strut 4 itself is designed in cross-section as a closed hollow profile 10. This has a front wall 8 and a rear wall 9.

[0032] According to Figure 1d , which is a longitudinal section along the section line BB of Figure 1b , the towing eye bushing 6 is arranged so as to pass through the front wall 8 and the rear wall 9 of the hollow profile 10 of the vertical strut 4 of the hollow profile 10. At the rear end there is a flange 11 which engages behind the rear wall 9 of the hollow profile 10 and is coupled to it in particular by a material fit. When a tensile force F is applied in the longitudinal direction X of the vehicle, the towing eye bushing 6 is thus additionally supported on the rear wall 9 of the vertical strut 4. The vertical strut 4 is further coupled to an upper wall 12 of the lower auxiliary cross member 3 and to a lower wall 13 of the upper main cross member 2, here by a material fit.

[0033] Figures 2a to fshow a second design variant, similar to the first. However, it is clear, on the one hand, that Figure 2e that the vertical strut 4 is formed with a flange 14 projecting in the vertical direction Z of the motor vehicle. Here, an additional coupling takes place, for example by screwing or riveting to the main cross member 2 or auxiliary cross member 3. The flange projecting in the vertical direction Z of the motor vehicle is formed starting from a front wall 18 of the vertical strut 4.

[0034] It is further shown that additional struts 16 are arranged at the ends 7 of the main cross member 2 and the auxiliary cross member 3, which additionally couple the ends together in addition to the vertical struts 4. Furthermore, the additional struts 16 can support an impact on a wheel (not shown in detail behind it in the vehicle's longitudinal direction X) at this wheel, thus resulting in improved crash performance by providing additional load paths.

[0035] Figures 3a to e show a third alternative design variant. This is, with regard to the bumper arrangement 1, initially with regard to the vertical struts 4, analogous to the design variant in Figure 1 The additional strut 16 is attached to the ends 7 of the main cross member 2 and the auxiliary cross member 3. This is shown in Figure 3c According to Figure 3eIf the main cross member 2 and the auxiliary cross member 3 are of one piece and made of the same material, a connecting part 17 in the form of a vertical strut 4 can be formed in the ends of the front wall extension. The additional strut 16 is then also attached, which in Figure 3d is evident.

[0036] Figures 4a to f show a further embodiment of the present invention. It is shown here that the main cross member 2 and the auxiliary cross member 3 are manufactured in one piece and from the same material. A respective front wall is thus formed continuously in longitudinal sections, so that a vertical front wall extension 18 exists there. According to the section line AA, the hollow profile 10 is arranged behind the front wall, and according to Figure 4fWelded to the lower wall 13 of the main cross member 2 and the upper wall 12 of the auxiliary cross member 3. Alternatively, it is welded to the front wall extension 18. A recess 19 allows the towing eye bushing 6 to penetrate the front wall. The towing eye bushing 6 is then arranged in the hollow profile 10 and its front wall 8 and rear wall 9.

[0037] Figures 5a to e show a further design variant. Here, the crash box 5 is connected laterally to the main cross member 2 via an additional support strut 20. A lateral flange 21 protrudes from the vertical strut 4. This lateral flange 21 engages laterally behind the hollow profile 10. All other designs apply to Figure 4 analogue.

[0038] Figure 6shows a further design variant. Here, a towing eye bushing 6 is inserted into the vertical strut 4. The towing eye bushing 6 is inserted from the inside and then coupled to the front wall as well as to the rear wall of the vertical strut 4, here by pressing or clinching. The towing eye bushing 6 can thus be positioned at any desired height within the vertical strut 4 with respect to the vehicle's vertical direction Z. The towing eye bushing 6 is preferably a profile block with a threaded bore. In particular, it is made of a light metal alloy. It can itself be H-shaped or have a hollow inner region. Thus, the towing eye bushing 6 is not solid. In the event of a crash, this can then also compress or shrink in the vehicle's longitudinal direction X and dissipate crash energy. Reference symbol:

[0039] 1 - bumper assembly 2 - main cross member 3 - auxiliary cross member 4 - vertical strut 5 - crash box 6 - towing eye socket 7 - end to 2 8 - front wall to 10 9 - rear wall to 10 10 - hollow profile 11 - flange to 6 12 - upper wall to 3 13 - lower wall to 2 14 - flange to 4 15 - coupling 16 - additional strut 17 - connecting part 18 - front wall extension 19 - recess 20 - support strut 21 - additional flange X - longitudinal direction of the vehicle Y - transverse direction of the vehicle Z - vertical direction of the vehicle L - length F - tensile force

Claims

1. Bumper assembly (1) for a motor vehicle, having a main cross beam (2) and an auxiliary cross beam (3) arranged underneath, which are coupled to one another via vertical struts (4), wherein the bumper assembly (1) is coupled to the motor vehicle via crash boxes (5), characterised in that the vertical strut (4) is configured as a separate hollow profile (10), wherein the hollow profile (10) has two wall surfaces (8, 9) spaced apart from one another in the longitudinal direction (X) of the motor vehicle, wherein a tow lug bush (6) extends through both wall surfaces (8, 9).

2. Bumper assembly (1) according to claim 1, characterised in that the tow lug is only coupled to the wall surface at the rear in the longitudinal direction of the motor vehicle.

3. Bumper assembly (1) according to any one of the preceding claims, characterised in that the crash boxes (5) are arranged at the level of the main cross beam (2) in relation to the vertical direction (Z) of the motor vehicle.

4. Bumper assembly (1) according to any one of the preceding claims, characterised in that a pair of additional crash boxes are provided, wherein the additional crash boxes are arranged at the level of the lower auxiliary cross beam (3) or in that the additional crash boxes are arranged at the level of the vertical struts (4).

5. Bumper assembly (1) according to any one of the preceding claims, characterised in that the hollow profile (10) is joined in a material-bonded manner to the main cross beam (2) on its lower wall (13) and / or to the auxiliary cross beam on its upper wall (12).

6. Bumper assembly (1) according to any one of the preceding claims, characterised in that the vertical struts (4) are arranged at the level of the crash boxes (5) in the transverse direction (Y) of the motor vehicle.

7. Bumper assembly (1) according to any one of the preceding claims, characterised in that additional struts (16) extend in the vertical direction (Z) of the motor vehicle at the outer ends (7) of the main cross beam (2) and auxiliary cross beam (3).

8. Bumper assembly (1) according to any one of the preceding claims, characterised in that the hollow profile (10) has a flange (14) projecting in the vertical direction (Z), wherein the flange (14) is coupled to the main cross beam (2) and / or auxiliary cross beam (3), in particular on a side facing away from the vehicle.

9. Bumper assembly (1) according to any one of the preceding claims, characterised in that the main cross beam (2) and the auxiliary cross beam (3) are in one piece and made from a single material and are additionally connected to one another via a vertical front wall extension (18), wherein the separate vertical strut (4) is arranged behind the front wall extension (18) in the longitudinal direction (X) of the motor vehicle.

10. Bumper assembly (1) according to any one of the preceding claims, characterised in that the tow lug bush (6) has a radially projecting flange (11) at one end, wherein the flange (11) engages behind a vertically extending wall of the vertical strut (4) and is coupled thereto, wherein the flange (14) is preferably arranged at the rear in the longitudinal direction (X) of the motor vehicle.