Bumper beam for a vehicle

Abstract

The invention relates to a bumper beam 2 for a vehicle, which extends in the transverse direction of the vehicle and has a hollow profile in cross section, in particular a rectangular cross section. A reinforcement plate 5 is inserted in the central longitudinal portion, the depth T of the reinforcement plate 5 decreasing in the longitudinal direction X of the vehicle towards the end of the reinforcement plate 5.

Description

Technical Field

[0001] This invention relates to bumper beams for vehicles. Background Technology

[0002] Existing bumper beams are known to couple to the front or end face of a vehicle body. This is typically achieved by incorporating a crash box. These bumper beams are usually made of metallic materials, particularly steel or lightweight metals, and are also referred to as bumpers or crossbeams.

[0003] The bumper beam should possess sufficient rigidity, especially having achieved adequate support in tests such as the Bohr test or pile foundation test. Therefore, the bumper beam itself is designed to be as rigid as possible. When a vehicle collides with an object, the impact chamber deforms, thus converting the collision energy into deformation work.

[0004] However, there are also bumper beams that should deform to a certain extent without losing any residual stiffness. In particular, for example, in the Bohr test or pile foundation test, the bumper beam should not bend or collapse when a force level is exceeded.

[0005] For this purpose, for example, WO 20 2005 3626 A1 discloses a bumper beam with a reinforcing plate in the central longitudinal section. The reinforcing plate helps to harden the bumper beam in the central section. Summary of the Invention

[0006] The purpose of this invention is to provide a bumper beam that has high bending stiffness, but at the same time dissipates collision energy through its own deformation in the Bohr test or pile foundation test without bending itself.

[0007] The aforementioned objective is achieved by a vehicle bumper beam that extends laterally in the vehicle and has a hollow profile in its cross-section, particularly a rectangular cross-section, with a reinforcing plate inserted in the central longitudinal portion, the depth of which decreases toward the ends of the reinforcing plate in the longitudinal direction of the vehicle.

[0008] In one embodiment, the hollow profile is formed as a hat-shaped profile, preferably with an impact plate.

[0009] In one embodiment, the impact plate is arranged facing forward in the longitudinal direction of the vehicle.

[0010] In one embodiment, the cross-section of the reinforcing plate is irregular, particularly W-shaped.

[0011] In one embodiment, the length of the reinforcing plate extending laterally in the vehicle is between 20-50% of the length of the bumper beam, preferably between 20-40%.

[0012] In one embodiment, the reinforcing plate has at least two legs in cross-section, which are parallel to or arranged at an angle of no more than + / -20° to the upper and lower edges of the bumper beam.

[0013] In one embodiment, the tapered cross-section of the reinforcing plate forms a greater distance from the rear wall of the hollow profile of the bumper beam relative to the central portion.

[0014] In one embodiment, the tapered end of the reinforcing plate is produced by a cutting process, or the tapered end of the reinforcing plate is produced by flattening or embossing, or the reinforcing plate is produced by pressing.

[0015] In one embodiment, the reinforcing plate is coupled to the front wall in the longitudinal portion, particularly by welding.

[0016] In one embodiment, the bumper beam has a soft zone in the central longitudinal portion, at the upper edge, and / or the lower edge.

[0017] In one embodiment, the bumper beam is formed by a hat-shaped profile and has a front impact plate, wherein the reinforcing plate is coupled to the impact plate.

[0018] The present invention also provides a bumper beam assembly having at least the above-described bumper beam, the bumper beam being coupled to the collision box.

[0019] In one embodiment, the collision box has a pressure-reducing element on the opposing side of the front region.

[0020] According to the invention, a bumper beam for a vehicle extends in the lateral direction of the vehicle. This typically covers a large portion of the vehicle's width. The bumper beam itself is made of a metallic material or also of a lightweight metallic material. The bumper beam has a hollow profile cross-section, particularly a hollow chamber. In particular, this cross-section is created by a hollow profile with an opening on one side, particularly a hat-shaped profile, which is closed by a strike plate. In particular, the cross-section is angled, particularly rectangular. The internal space of the cross-section is particularly angular, and very preferably rectangular. The bumper is fixed to the vehicle via a crash box. Therefore, a bumper assembly can also be specified.

[0021] According to the present invention, the bumper crossbeam is characterized by the insertion of a separate reinforcing plate in its central longitudinal portion. The depth of the reinforcing plate decreases towards both ends in the longitudinal direction of the vehicle. Therefore, the ends of the reinforcing plate are tapered. The reinforcing plate is designed as a separate, particularly independent, component. Thus, the reinforcing plate is a component independent of the impact plate. The reinforcing plate is also a component independent of the crossbeam, particularly the hollow profile of the crossbeam.

[0022] Surprisingly, according to the present invention, this achieves the following advantages. Upon impact during a Bohr test or pile foundation test, particularly impacting the center of the bumper beam, the bumper beam is dented or deformed into an arc shape. Due to the reinforcing plates on the cross-section, this arc shape is maintained for as long as possible during penetration. Bending of the cross-section is prevented by the reinforcing plates. Since the ends of the reinforcing plates are now tapered, the hollow profile cross-section of the bumper beam fits tightly against the ends of the reinforcing plates through deformation. Therefore, bending is avoided for as long as possible. Thus, in the longitudinal direction of the beam, specific bending or curvilinear deformation is promoted during penetration during a Bohr test or pile foundation test.

[0023] Therefore, the crossbeam can be deformed along a safe curve until a preset load level is reached without concern about bending or penetration of the drive unit, engine, and / or passenger compartment during Boll tests or pile foundation tests. This allows for the simultaneous control of deformation to achieve high stiffness or high residual drag, thereby also reducing the flexibility of the bumper crossbeam or lowering collision energy. The complex further steps of reworking the bumper crossbeam are avoided by simply inserting a reinforcing plate with tapered ends.

[0024] To allow for the installation of the reinforcing plate, the hollow profile is designed as a hat-shaped profile and closed with an impact plate. Particularly preferred is that the impact plate faces forward in the longitudinal direction of the vehicle, i.e., the opening of the hat-shaped profile faces forward, and then is closed with the impact plate. In this case, the impact plate forms the front wall of the bumper crossbeam. Due to the two-part structure of the bumper crossbeam, a reinforcing plate can be inserted, and the bumper crossbeam can be closed by welding the impact plate. For this purpose, the reinforcing plate is connected, particularly welded, to the impact plate. This coupling occurs at least in the longitudinal portion, especially in the end region of the reinforcing plate. The reinforcing plate is then coupled to the front wall of the bumper crossbeam, particularly here, abutting it according to the cross-sectional profile of the impact plate itself. The tapered ends then result in a greater distance from the rear wall of the bumper crossbeam in the installed state.

[0025] In the central middle section, the impact plate preferably has a depth equivalent to 70% to 100% of the hollow profile depth of the bumper beam, more preferably 80% to 90%. The tapered end decreases in the longitudinal direction of the vehicle, and its depth in the outer end region is about 40% or less of the cross-sectional depth of the hollow profile of the bumper beam.

[0026] In particular, the reinforcing plate is not directly coupled or attached to the rear wall of the bumper beam. In the event of a collision, this allows the bumper beam to bend, i.e., deform relative to the impact plate in a specific manner. Therefore, the rear wall of the bumper beam can move relative to the impact plate, especially in the lateral direction of the vehicle.

[0027] Furthermore, it is particularly preferred that the length of the reinforcing plate extending in the lateral direction of the vehicle accounts for 20% to 50% of the length of the bumper beam itself, preferably 20% to 40%. Furthermore, it is particularly preferred that the reinforcing plate has an irregular cross-section, especially a W-shaped profile. In particular, the three connection points of the W-shape are arranged facing forward.

[0028] Impact plates are preferably manufactured using molding processes. However, they can also be roll-formed or extruded. The tapered ends are particularly well-suited for production via cutting. Alternatively, the ends of the impact plates can be tapered to a certain depth by embossing or flattening.

[0029] The reinforcing plate, in particular, contacts the front wall. Then, the tapered impact plate follows an arc-shaped path around the vehicle's vertical axis, whereby, in each case, the inner side of the arc faces forward in the direction of travel via the front bumper crossbeam, or, in the case of the rear bumper, opposite in the direction of travel but always outward. This corresponds to the receiving profile of a concentrated impact in a Bohr test or pile foundation test. Therefore, in the event of a concentrated impact, the reinforcing plate will not exhibit any initial deformation.

[0030] Surprisingly, it was also found that the aforementioned reinforcement plates can be improved by incorporating soft zones along the upper and / or lower edges of the bumper beam. These soft zones are created specifically by specifying characteristics, particularly by using a material that is softer than the rest of the bumper beam material, thus reducing tensile strength. This also allows for specific deformation of the bumper beam in the middle region, particularly at the tapered ends of the reinforcement plates, while stiffness is maintained by the reinforcement plates and the front and rear walls of the bumper beam. Attached Figure Description

[0031] Further advantages, features, and performance characteristics of the present invention are the subject of the following description. Preferred design variations are illustrated in the schematic diagrams, which are provided to facilitate understanding of the invention.

[0032] It shows:

[0033] Figure 1 This is a top view of the bumper beam assembly according to the present invention;

[0034] Figure 2 (a)-(c) are different cross-sectional views;

[0035] Figure 3 (a)-(c) are alternative cross-sectional views;

[0036] Figure 4 (a)-(c) are also alternative cross-sectional views;

[0037] Figure 5 This is a top view of another design variant of the bumper beam assembly;

[0038] Figure 6 (a)-(d) is Figure 5 Different cross-sectional views;

[0039] Figure 7 (a)-(b) are a comparison of the prior art and the Bohr test of the bumper beam according to the present invention;

[0040] Figure 8 It is a soft zone design on the bumper crossbeam.

[0041] Figure 9 (a)-(b) show the rear view and perspective detailed sectional view of the impact plate 13.

[0042] In the figures, the same reference numerals are used for the same or similar parts, although repeated descriptions are omitted for simplicity. Detailed Implementation

[0043] Figure 1 A top view of the bumper beam assembly 1 is shown. The bumper beam 2 is connected to the crash box 3. The bumper beam assembly 1 is then coupled to the vehicle body, which is not described in more detail. The bumper beam 2 has a generally curved path along its length. The central longitudinal section 4 may also be generally straight.

[0044] In the central longitudinal section 4, as shown, a separate reinforcing plate 5 is arranged in the bumper beam 2 and coupled to the impact plate 13. The impact plate 13 with the reinforcing plate 5 is also coupled to the front wall or flange of the bumper beam 2. Therefore, the reinforcing plate 5, the impact plate 13, and the hollow profile of the bumper beam 2 are three independent components. The depth T of the reinforcing plate 5 is tapered at each end 7 of the reinforcing plate 5. The depth T is substantially oriented in the vehicle longitudinal direction X. The longitudinal extension of the central longitudinal section 4 is approximately 20% to 50% of the length L of the bumper beam 2, preferably 20% to 40%. The length L refers to the vehicle transverse direction Y.

[0045] The tapered ends 7 increase the distance A between the rear wall 8 of the bumper beam 2 and each tapered end 7. Particularly preferred is that the reinforcing plate 5 does not directly contact the rear wall 8 of the bumper beam 2 along the entire longitudinal path.

[0046] Furthermore, each of the longitudinal portions forms a welded longitudinal portion 9, wherein the reinforcing plate is welded to the impact plate 6. The welded longitudinal portion 9 is particularly preferably 5% to 20% of the central longitudinal portion 4, especially 5% to 10%. The intermediate non-welded longitudinal portion 10 may deform upon impact, or the front wall 6 and the reinforcing plate may move relative to each other.

[0047] Furthermore, it is particularly preferred that the pressure-reducing element 20 be arranged on the opposite sidewalls of the collision box 3. The pressure-reducing element 20 can be designed, for example, as a groove, slot, hole, or embossed. Here, the collision box 3 is specifically weakened. Figure 7 In the collision shown, the collision boxes 3 can therefore move towards each other, and this also promotes the deflection of the bumper beam 2, especially as... Figure 7 As shown in b.

[0048] Figure 2 A, B, and C show their respective cross-sectional views. It can be seen that the cross-section of the bumper beam 2 is a closed, hollow profile. It is formed by a cap-shaped profile 14, which forms the rear wall 8, as well as the upper edge 11 and lower edge 12. The front wall 6 is formed by an impact plate 13. The impact plate 13 is coupled to the cap-shaped profile 14, particularly the flange of the cap-shaped profile. According to... Figure 2 The cross-sectional lines of b and 2c show that the reinforcing plate 5 is shown as a hollow outline. Figure 2 b shows an end region 7 of the reinforcing plate 5. The end region 7 has a depth T7, which is less than the depth T of the intermediate region. The depth T of the intermediate region is preferably 70% to 100%, more particularly preferably 80% to 95%, and especially about 85% to 95% of the depth T2 of the bumper beam 2 in this region. Therefore, it does not have direct contact with the rear wall 8. Then, the depth T7 decreases towards the end region. The distance A to the rear wall 8 increases. Here, the W-shaped cross-section of the reinforcing plate 5 is shown from... Figure 2 The middle region of c towards Figure 2 The depth T of the end region 7 of b decreases. Weld 19 is particularly formed on all contact surfaces of the W-shaped profile on the front wall 6. For example... Figure 2 As shown in Figure c, no weld seam is formed, therefore, relative displacement between the reinforcing plate 5 and the front wall is possible during a collision, especially in the lateral direction of the vehicle. However, the cross-section remains unchanged.

[0049] Figure 3 a, b, and c show alternative design variations. Here, the cross-section of the reinforcing plate 5 is flattened or embossed, as shown... Figure 3 As shown in b.

[0050] Figure 4 a, b, and c show alternative design variations. Here, the end region 7 of the reinforcing plate 5 has been mechanically cut, so the W-shaped cross-section has been removed.

[0051] Figure 5 Showing Figure 1 Alternative design variations are available. Behind the end 7 of the reinforcing profile 5 is another longitudinal section, with a significantly larger depth T in the cross-section of the reinforcing profile compared to the tapered end 7. This is based on... Figure 6 The profile DD is shown. The depth T15 here again corresponds to... Figure 6 The depth T of the reinforcement plate 5 in the middle section shown in c. This can provide additional hardening or reinforcement for other collision scenarios, such as RCAR bumper testing.

[0052] Now, according to the invention, the effects are... Figure 7 Shown for comparison in sections a and b. The bumper assembly 2 is shown to have been dented, bent, or deformed due to a Pohl test or pile foundation test 16. According to... Figure 7 a, forming a bend 17. Here, either no reinforcing plate is used, or a reinforcing plate 5 without tapered ends is used.

[0053] according to Figure 7 b. The rear wall of the bumper beam 8 is deformed relative to the tapered end 7 of the reinforcing plate 5. This prevents bending. The front wall 6 and the rear wall 8 can each move laterally within the vehicle relative to the reinforcing plate 5. On the rear wall 8, this is done according to the principle of a tension band. Slight protrusions 18 appear on the front wall 6, but there is no kinking or bending. According to the invention, this ensures that specific deformation is provided for energy dissipation in the absence of damage to the bumper beam 2.

[0054] Figure 8 A bumper assembly 2 is shown. Here, a soft zone of length L8 is formed in the upper edge 11, which is particularly preferably equivalent to 20% to 40% of the length of the distance A2 between the impact chambers. In this soft zone, the material properties change, particularly the tensile strength decreases. This soft zone may also exist in the lower edge 12, but is not shown in more detail. Due to the presence of the soft zone, according to... Figure 7 The collision scenario for b is therefore more favorable for bending around the pile foundation.

[0055] Figure 9 A and B show a rear view and a detailed sectional view in perspective of the impact plate 13. The impact plate 13 has an arcuate path. A reinforcing plate 5 with its tapered end 7 is arranged on the rear wall 21 of the impact plate 13 itself. In particular, as Figure 9 The reinforcing plate 5 shown in Figure b is connected to the rear wall 21 of the impact plate 5 at the tapered end 7, specifically by welding. The impact plate 13 can be prepared in this manner and then inserted into the cap-shaped profile 14, and the impact plate 13 can also be thermally connected to the flange of the cap-shaped profile 14 at least in the longitudinal portion. This ensures optimal positioning and assembly of the reinforcing plate 5. In this case, as... Figure 9 As shown in b, the reinforcing plate 5 itself is cap-shaped, at least in its longitudinal portion. Therefore, the reinforcing plate 5 can be easily produced as a sheet metal component, especially a steel plate component, by pressing.

[0056] Figure Labels

[0057] 1-Bumper crossbeam assembly

[0058] 2-Bumper crossbeam

[0059] 3-Collision Box

[0060] 4-Central longitudinal section

[0061] 5-Reinforced Plate

[0062] 6-2 Anterior wall

[0063] 7-5 end

[0064] 8-2 posterior wall

[0065] 9-Welding longitudinal section

[0066] 10-Non-welded longitudinal section

[0067] 11-upper edge

[0068] 12-lower edge

[0069] 13-Impact plate

[0070] 14- Hat Shape Outline

[0071] 15 - Another vertical section

[0072] 16-Bohr / Pile Foundation

[0073] 17-Bend

[0074] 18-protrusion

[0075] 19-Welding

[0076] 20-Reducing pressure element

[0077] 21-5 posterior wall

[0078] A-Distance

[0079] T-Depth

[0080] T7-7 Depth

[0081] T15-15 depth

[0082] Length of L-2

[0083] X-vehicle longitudinal direction

[0084] Y-vehicle perpendicular

Claims

1. A bumper beam (2) for a vehicle, extending in the transverse (Y) direction of the vehicle and having a hollow profile in a rectangular cross-section, characterized in that, A reinforcing plate (5) is inserted into the central longitudinal section (4), the depth (T) of which decreases toward the tapered end (7) of the reinforcing plate (5) in the longitudinal direction (X) of the vehicle; relative to the central section, the tapered end (7) of the reinforcing plate (5) forms a greater distance (A) with the rear wall (8) of the hollow profile of the bumper beam (2), and the reinforcing plate (5) does not directly contact the rear wall (8) along the entire longitudinal route.

2. The bumper beam (2) according to claim 1, characterized in that, The hollow profile is formed into a hat-shaped profile (14) and has an impact plate (13).

3. The bumper beam (2) according to claim 1 or 2, characterized in that, Along the longitudinal direction (X) of the vehicle, the impact plate (13) is arranged to face forward.

4. The bumper beam (2) according to claim 1 or 2, characterized in that, The cross-section of the reinforcing plate (5) is W-shaped.

5. The bumper beam (2) according to claim 1 or 2, characterized in that, The length (L) of the reinforcing plate (5) extending in the transverse (Y) direction of the vehicle is between 20-40% of the length of the bumper beam (2).

6. The bumper beam (2) according to claim 1 or 2, characterized in that, The reinforcing plate (5) has at least two legs in its cross-section, which are parallel to or at an angle of no more than + / -20° to the upper and lower edges of the bumper beam (2).

7. The bumper beam (2) according to claim 1 or 2, characterized in that, The tapered end (7) of the reinforcing plate (5) is produced by a cutting process, or the tapered end (7) of the reinforcing plate (5) is produced by flattening or embossing, or the reinforcing plate is produced by pressing.

8. The bumper beam (2) according to claim 1 or 2, characterized in that, The reinforcing plate (5) is welded to the front wall (6) in the longitudinal section.

9. The bumper beam (2) according to claim 1 or 2, characterized in that, The bumper beam (2) has a soft zone in the central longitudinal portion (4), at the upper edge (11) and / or the lower edge (12).

10. The bumper beam (2) according to claim 1 or 2, characterized in that, The bumper beam (2) is formed by a cap-shaped profile (14) and has a front impact plate (13), wherein the reinforcing plate (5) is coupled to the impact plate (13).

11. A bumper crossbeam assembly (1), characterized in that, The bumper beam assembly (1) has at least the bumper beam (2) as described in claim 1, the bumper beam (2) being coupled to the collision box (3).

12. The bumper beam assembly (1) according to claim 11, characterized in that, The collision box (3) has a pressure-reducing element (20) on the opposing side of the front region.

Images