Cross-member for bumper system of motor vehicle, bumper system having such cross-member, and motor vehicle having such bumper system
By designing a two-piece crossbeam structure and utilizing forming elements to lock the shape under specific working conditions, the problem of uneven stiffness and deformation of the crossbeam under different collision conditions is solved, achieving higher safety and rating requirements.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BAYERISCHE MOTOREN WERKE AG
- Filing Date
- 2024-12-18
- Publication Date
- 2026-05-15
AI Technical Summary
The crossbeams of existing motor vehicle bumper systems have difficulty achieving a uniform force-displacement curve under different collision conditions. In particular, they bend too softly under MPDB load conditions, failing to meet the requirement of uniform obstacle indentation. At the same time, they lack bending rigidity under "central pillar" load conditions, affecting the safety rating.
It adopts a two-piece beam structure, consisting of open profiles and closed plates. The central longitudinal section is equipped with forming elements. Under the load condition of the "central column", the forming elements are shape-locked and interlocked to increase the surface moment of inertia and bending stiffness, and do not form contact under other conditions to maintain consistent deformation behavior.
The beam's bending stiffness is enhanced under the "central column" load condition, improving the safety rating. At the same time, it maintains uniform obstacle indentation under the MPDB load condition, meeting the deformation requirements of different collision conditions.
Smart Images
Figure CN122055285A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a crossbeam for a bumper system of a motor vehicle. Furthermore, the invention also relates to a bumper system for a motor vehicle. Additionally, the invention relates to a motor vehicle having at least one such bumper system. This bumper system is advantageously usable on the front side or front of the motor vehicle. Background Technology
[0002] Vehicles are generally known to incorporate various structures designed to improve their behavior under different types of collisions or impacts. The behavior of vehicles and their various structures, arrangements, and components under collision conditions can be evaluated using various simulations and tests. In particular, bumper systems are known as impact buffers, intercepting and dissipating impact energy in the event of a collision, thus minimizing damage to the vehicle's load-bearing structure behind them. A bumper system (also known as a collision management system (CMS or Aufprall management system in German)) comprises a crossbeam, typically two deformable boxes, and optional longitudinal beams for connection to the vehicle structure. Energy generated by the impact is received and transferred by the crossbeam and absorbed by the deformable boxes. In other words, the crossbeam primarily serves to direct forces into the deformable boxes so that energy can be absorbed there. It is conceivable that motor vehicles also include other load-distribution frames for dissipating forces.
[0003] Within the scope of whole-vehicle testing, particularly the MPDB (Mobile Offset Progressive Deformable Barrier) analysis, test vehicles collide with a moving progressive deformable barrier (also known as an obstacle) mounted on an oncoming 1400 kg vehicle. This test simulates a frontal collision between the test vehicle and a typical mid-size family car to assess the risk of head, neck, chest, and abdominal injuries to vehicle occupants, especially by analyzing the barrier indentation after the collision. Under the MPDB frontal crash load condition, achieving the most uniform barrier indentation possible is crucial for vehicle ratings, especially in the NCAP rating sense. Due to the vehicle's tilt angle and the resulting mounting space, a uniform force-displacement curve across the entire vehicle width is desirable.
[0004] In addition, the so-called "center pillar" load case is analyzed within the scope of whole vehicle testing. This test is performed to check the vehicle's safety upon impact with a pillar. The "center pillar" load case involves impacting a pillar at the center of the vehicle. The pillar impact test is used to assess the vehicle's structural integrity and safety. The analysis of the "center pillar" load case includes evaluating various factors such as vehicle deformation, impact on occupants, and the effectiveness of safety devices.
[0005] In the aforementioned tests used for whole vehicle testing, there is a conflicting objective regarding the bending stiffness of the crossbeam. For the MPDB load condition, the desired obstacle indentation is as uniform as possible, which therefore requires sections with softer and stiffer bending across the vehicle width; while for the "center pillar" load condition, the crossbeam (especially in the middle of the vehicle) must be as bending stiff as possible. Summary of the Invention
[0006] Based on existing technology, the objective of this invention is to provide a crossbeam for a bumper system of a motor vehicle that resolves a conflict of interest. This objective is achieved by the crossbeam for a bumper system according to claim 1, the bumper system for a motor vehicle according to claim 9, and the motor vehicle according to claim 11. Preferred embodiments are given in the dependent claims.
[0007] According to a first aspect of the invention, a crossbeam for a motor vehicle bumper system is composed of a two-piece profile that is open on one side in cross-section and a closed plate that at least partially closes the profile, wherein a first forming element is arranged on a central longitudinal section of the closed plate, and a second and a third forming element are arranged on both sides of the central axis of the crossbeam at a distance from the central axis, wherein the second and third forming elements are arranged relative to the first forming element such that they are form-locked to each other in the event of a frontal collision at the central longitudinal section of the closed plate located on the central axis, and in a frontal collision with lateral overlap, the second and third forming elements remain without contact with the first forming element.
[0008] In other words, a reinforcement mechanism is achieved using forming elements for the "central pillar" load condition. Under this mechanism, the forming elements only form a shape-locking interaction when an object (especially a pillar under the "central pillar" load condition) collides with the crossbeam in the central longitudinal section. In this case, the first forming element forms a shape-locking interaction with both the second forming element (located on the left side of the vehicle or in the first deformation box) and the third forming element (located on the right side of the vehicle or in the second deformation box), resulting in a wedging or engagement that makes bending of the crossbeam under the "central pillar" load condition more difficult compared to its initial or undamaged state. Correspondingly, when the pillar intrudes into the crossbeam in the central longitudinal section (located in the Y0 region of the crossbeam) under the "central pillar" load condition, the forming elements engage or interlock to form a shape-locking interaction. Therefore, this reinforcement mechanism is triggered only under the "central pillar" load condition. Through this mechanism, the crossbeam's surface moment of inertia or drag moment increases, and bending of the crossbeam becomes more difficult. In other words, under the "central column" load condition, the bending stiffness increases when the central longitudinal section is subjected to force.
[0009] Each forming element should be understood as a reinforcing element, which, when they interlock (especially when they insert or push into each other), creates a form-locking effect to improve the stiffness of the beam, especially its bending stiffness.
[0010] Meanwhile, the forming elements are constructed and arranged relative to each other such that the first forming element (especially under MPDB load conditions or in a frontal collision with lateral overlap) does not engage or form a shape lock with either the second or third forming element. "No contact point" in this context means that the forming elements do not come into contact with each other under or during MPDB load conditions, and therefore cannot form a shape lock for locally reinforcing the crossbeam.
[0011] The crossbeam can be a hybrid crossbeam. It can consist of multiple components, which can be made of different materials. The closed panel is preferably made of metal, while the profile is made of fiber-reinforced plastic or metal.
[0012] The profile may have sections with different cross-sectional configurations and / or different mechanical properties in the longitudinal direction of the beam. The profile is coupled to a closing plate. The closing plate may have a substantially constant thickness in its longitudinal direction.
[0013] The profile is preferably constructed as a cap-type profile. The cap-type profile is formed in cross-section by two edges, which are connected to each other by a connecting tab on the back of the profile. The connecting tab is therefore adjacent to the edge. The connecting tab is configured to connect to or couple to the deformation box on its side opposite to the edge.
[0014] The profile has a concave profile in its central longitudinal section, located on the front side of the profile relative to the direction of travel of the vehicle. The concave profile in the central longitudinal section of the beam or profile is a partially circular recess in the bumper system or the X direction of the vehicle, wherein the concave profile is configured to receive an obstacle constructed as a pillar in a frontal collision under a "central pillar" load condition.
[0015] A concave shape, positioned at the front and in the central longitudinal section along the vehicle's forward direction, creates a designated bending section on the profile. This bending section enables targeted deformation behavior of the crossbeam under the "center pillar" load condition. Therefore, NCAP results for the "center pillar" load condition are improved because the crossbeam is locally reinforced, and the vehicle can be rated as safer. Simultaneously, for the MPDB load condition, uniform obstacle indentation is achieved because the crossbeam design does not negatively impact deformation behavior under the MPDB load condition.
[0016] Optionally, the closed plate also has a set bending section in the middle longitudinal section of the beam. This can further improve or better control the deformation behavior of the beam under the "central column" load condition.
[0017] The corresponding bend is preferably located on the central axis. This ensures that in a frontal collision with side overlap, the deformation behavior of the crossbeam is substantially the same regardless of which side of the vehicle it is on.
[0018] The deepest point of the concave profile is preferably located on the central axis of the bumper system. In other words, the rearmost point of the recessed portion of the profile along the forward driving direction is located on the central axis or axis of symmetry of the crossbeam or bumper system. Therefore, the central longitudinal section is located on the longitudinal axis of the vehicle or the central axis of the crossbeam, and is mirror-symmetrically shaped.
[0019] The concave profile is preferably constructed to complement the external geometry of the column for the "central column" load condition, which typically has a diameter of 360 mm. Accordingly, the concave profile of the profile has at least a partial radius of 360 mm to create the largest possible contact area in a frontal collision. Therefore, the concave profile of the profile is constructed as a negative profile for the column in the "central column" load condition.
[0020] The forming elements are preferably arranged within the internal space of the crossbeam. In other words, the forming elements are integrated into the crossbeam. This allows the reinforcement mechanism to be achieved in a spatially neutral manner.
[0021] Preferably, the first forming element has open sections for receiving sections of the second and third forming elements that are complementary to the first forming element. This allows for an easily manufactured interlocking geometry by means of forming elements that engage with each other under a "central post" load condition. Depending on the specific design, the interlocking geometry can also be a ribbed structure.
[0022] The forming element can be an integral component of the beam (i.e., profile or closure). Alternatively, the forming element can be a separate component fixed to the profile or closure. In this sense, one embodiment of the invention specifies that a first forming element is connected to the closure in a material-locking manner, and / or a second and third forming element is connected to the profile in a material-locking manner. A material-locking connection describes an inseparable connection between two or more materials, wherein the molecules of the materials are interconnected. Here, stability is generated by chemical or physical forces (e.g., bonding or adhesion). An advantageous material-locking connection between two components is a welded connection. Adhesive connections are also conceivable. Welded connections are advantageous if both the profile and the closure are made of metal. Of course, it is conceivable that the forming element and the closure or profile are constructed such that they can be screwed together.
[0023] In one embodiment, the closing plate rests against the second and third forming elements. In other words, the second and third forming elements are arranged within the interior space of the crossbeam and positioned longitudinally between the profile (especially the connecting piece) and the closing plate, wherein the second and third forming elements are respectively fixed to the profile and are already resting against the closing plate in the initial state of the crossbeam. This further improves the bending stiffness of the crossbeam under "central pillar" load conditions and prevents load path interruption.
[0024] According to a second aspect of the invention, a bumper system for a motor vehicle includes a crossbeam according to a first aspect of the invention, wherein the crossbeam is arranged transversely to the longitudinal axis of the motor vehicle.
[0025] Therefore, the bumper system includes a crossbeam arranged transversely to the longitudinal axis of the vehicle and coupled to two deformable boxes oriented parallel to the longitudinal axis of the vehicle. The crossbeam is composed of a two-piece profile that is open on one side in cross-section and a closed plate that at least partially closes the profile. A first forming element is arranged in the middle longitudinal section of the closed plate. A second and a third forming element are arranged on both sides of the central axis of the crossbeam located on the longitudinal axis, between the central axis and the deformable box. The second and third forming elements are arranged relative to the first forming element and spaced apart relative to the central axis such that they are form-locked to each other in the event of a frontal collision at the middle longitudinal section of the closed plate located on the central axis, and in a frontal collision with lateral overlap, the second and third forming elements remain without contact with the first forming element.
[0026] The bumper system is designed to absorb the forces generated by a frontal collision. The bumper system can also be understood as a vehicle's collision management system, and it is directly or indirectly (especially through a deformable box) connected to the vehicle's load-bearing structure. The bumper system is designed to absorb the forces generated by a collision. The crossbeams are arranged substantially perpendicular to the vehicle's direction of travel or longitudinal axis, or extend across most of the vehicle's width in the lateral direction.
[0027] The crossbeam is preferably arranged on two deformable boxes oriented parallel to the longitudinal axis of the vehicle. In other words, the crossbeam is coupled to the deformable boxes. The deformable boxes are arranged at equal intervals relative to the central axis of the bumper system, which is preferably located on the longitudinal axis of the vehicle. The bumper system has a mirror-symmetric construction.
[0028] Preferably, the closing plate is arranged facing forward in the longitudinal direction of the vehicle. In other words, the closing plate is oriented forward in the direction of travel of the vehicle. Therefore, the crossbeam can be installed forward or outward in the direction of travel by means of the closing plate.
[0029] According to a third aspect of the invention, a motor vehicle includes a bumper system according to a second aspect of the invention. The motor vehicle includes a load-bearing structure and a chassis, wherein a bumper system or impact buffer is provided before and after the load-bearing structure along the direction of travel, at least one of which is configured as a bumper system according to the second aspect of the invention. In one embodiment, both bumper systems are configured as bumper systems according to the second aspect of the invention.
[0030] The definitions and descriptions above regarding the technical effects, advantages, and advantageous embodiments of the crossbeam according to the first aspect of the invention are equally applicable to the bumper system according to the second aspect of the invention and the motor vehicle according to the third aspect of the invention, and vice versa. It is self-evident that the features mentioned above and further described below can be used not only in their respective specified combinations, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description
[0031] The invention will now be described in more detail with reference to the accompanying drawings, in which:
[0032] Figure 1 A highly schematic top view of a motor vehicle according to the invention, with a bumper system according to the invention according to a first embodiment, is shown;
[0033] Figure 2 The diagram shows a crossbeam according to the invention in its initial state. Figure 1 A first schematic top view of the bumper system according to the present invention;
[0034] Figure 3 It shows according to Figure 1 and Figure 2 A highly schematic cross-sectional view of the bumper system according to the present invention;
[0035] Figure 4 It shows according to Figures 1 to 3 A second schematic top view of the bumper system according to the invention in its initial state—shown only partially here;
[0036] Figure 5 The following is shown based on the frontal collision under the "central pillar" load condition. Figures 1 to 4 The third schematic top view of the bumper system according to the invention—shown only partially here;
[0037] Figure 6 The following is shown in the context of a frontal collision with side overlap. Figures 1 to 5 The fourth schematic top view of the bumper system according to the invention—shown only partially here; and
[0038] Figure 7 A schematic top view of the bumper system according to the second embodiment—shown only partially here—in its initial state is shown.
[0039] The same or similar components are given the same reference numerals. Detailed Implementation
[0040] according to Figure 1The diagram illustrates a motor vehicle 100, which has a load-bearing structure 105 and four wheels 110, two on the front axle and two on the rear axle, or two on the left and two on the right side of the vehicle. A bumper system 115 according to the invention is attached to the load-bearing structure 105 at the front of the motor vehicle 100. A bumper system may also be arranged at the rear of the motor vehicle 100, but this bumper system is not described in detail here. However, it is conceivable that the bumper system at the rear of the motor vehicle 100 is constructed similarly to the bumper system 115 described below and attached to the load-bearing structure 105. When moving forward, the motor vehicle 100 moves along a travel direction 120. Therefore, the travel direction 120 should be understood as the forward travel direction of the motor vehicle 100.
[0041] according to Figures 1 to 3 The bumper system 115 according to the invention includes a crossbeam 125 arranged transversely to the driving direction 120 of the vehicle 100, which is connected to the load-bearing structure 105 of the vehicle 100 via two deformable boxes 130, 135 coupled thereto. The deformable boxes 130, 135 are mirror-constructed about the longitudinal axis 140 of the vehicle 100. The bumper system 115 is mirror-symmetrically constructed with respect to a central axis 200, which is currently located on the longitudinal axis 140 of the vehicle 100. The bumper system 115 is part of a collision management system of the vehicle 100 (not shown in detail here).
[0042] according to Figure 2 Combination Figure 3 The crossbeam 125 is a two-piece structure consisting of a profile 205 that is open on one side in cross-section and a closed plate 210 that partially closes the profile 205. According to... Figure 3 Profile 205 has two edges 300 and 305, which are connected to each other in one piece by connecting piece 310. Through connecting piece 310, crossbeam 125 is coupled to deformation boxes 130 and 135. In this sense, profile 205 is constructed as a cap-type profile.
[0043] exist Figures 4 to 7As shown, a first forming element 405 is arranged at the profile 205 or on the inward-facing side of the central longitudinal section 400 of the closed plate 210. The first forming element 405 is located on the central axis 200 of the crossbeam 125. Forming elements 410 and 415 are arranged on both sides of the central axis 200. A second forming element 410 is arranged on the left side between the central axis 200 and the first deformable box 130, while a third forming element 415 is arranged on the right side between the central axis 200 and the second deformable box 135. The forming elements 405, 410, and 415 form the aforementioned reinforcement mechanism for the "central column" load condition. The forming elements 405, 410, and 415 are arranged in the internal space 420 of the crossbeam 125. The profile 205 and the closed plate 210 spatially define the internal space 420 of the crossbeam 125, in which the reinforcement mechanism for the "central column" load condition is arranged. The first forming element 405 is welded to the closed plate 210. The second and third forming elements 410 and 415 are welded to the profile 205.
[0044] The closed panel 210 is arranged forward-facing in the direction of travel 120 or forward travel direction of the motor vehicle 100. The profile 205 has a concave profile 425 at the front side of the central longitudinal section 400 relative to the direction of travel 120. According to... Figures 2 to 4 In the initial state shown, the closed plate 210 extends spaced apart from the profile 205 in the region of the concave profile 425. The concave profile 425 forms a defined bending portion for the closed plate 210, which ensures that the beam 125 is under the "central column" load condition (i.e., in relation to...). Figure 5 When the column 500 shown in the diagram undergoes a frontal collision at the center, it achieves the desired deformation behavior for that load condition.
[0045] Figure 5 This illustrates the state at the start of the "central column" load condition. When column 500 impacts the central longitudinal section 400 of the enclosed plate 210 located on the central axis 200, the force acts on beam 125 in the direction of arrow 505. Figure 5 As can be clearly seen, the concave profile 425 is constructed as a negative shape relative to the column 500. Under the "central column" load condition, it first overcomes a short stroke with relatively small resistance, then the closing plate 210 adheres to the concave profile 425 of the profile 205, and guides the force into the profile 205. This ensures that the load path remains uninterrupted or continuous.
[0046] according to Figure 4The first forming element 405 has a recess 430 for receiving sections 435 and 440 of the second and third forming elements 410 and 415, which have complementary structures to the first forming element. Due to the force, the crossbeam 125 deforms, causing the sections 435 of the second forming element 410 and 440 of the third forming element 415 to respectively engage with the corresponding recesses 430 of the first forming element 405, such as... Figure 5 This is visible in the diagram. Therefore, the forming elements 405, 410, and 415 are shape-locked together, thereby increasing the planar moment of inertia of the beam 125 with respect to the "central column" load condition. Consequently, the bending stiffness of the beam 125 is locally increased compared to other load conditions (especially the MPDB load condition).
[0047] MPDB load condition in Figure 6 As shown, in a frontal collision with lateral overlap (here on the left side of the vehicle), the crossbeam 125 deforms due to the force in the direction of arrow 600. The forming elements 405, 410, and 415 are shaped and arranged relative to each other such that they do not engage or form a shape lock under MPDB load conditions. In this sense, the planar moment of inertia of the crossbeam 125 does not increase. Therefore, the bending stiffness of the crossbeam 125 under MPDB load conditions is lower than that under "center pillar" load conditions.
[0048] exist Figure 7 An alternative embodiment of the bumper system 115 in its initial state is shown. Therefore, the closure plate 210 rests against the second and third forming elements 410, 415 with its inwardly oriented side, rather than being connected in a material-locking manner. The shape of the second and third forming elements 410, 415, as presented herein, allows for better maintenance of the load path during the "center post" load condition, since energy is already transferred from the second and third forming elements 410, 415 to the profile 205 when the force begins to act on the crossbeam 125. In this case, the bending stiffness is already greater than under other load conditions, even before the second and third forming elements 410, 415 engage with the first forming element 405 under the "center post" load condition. Shape locking, or the activation of the reinforcement mechanism, only occurs when the closure plate 210 deforms along the X direction or against the driving direction 120, as defined by the design of the concave shape 425, or more precisely, until the first forming element 405 engages with the second and third forming elements 410, 415.
[0049] according to Figure 7 The bumper system 115 exhibits deformation behavior in the remaining parts in response to MPDB and "center pillar" load conditions. Figure 5 and Figure 6The same applies as shown, therefore no further explanation will be given. Accordingly, refer to the references based on... Figures 1 to 6 Description of the first embodiment shown.
[0050] Of course, it is conceivable that the design of the forming elements could be reversed. Therefore, the first forming element 405 could have forming sections similar to sections 435 and 440, while the second and third forming elements 410 and 415 could have corresponding empty portions similar to the empty portion 430. Regardless of the form and design of the forming elements, reinforcement of the beam 125 or wedging of the profile 205 relative to the closed plate 210 is achieved under any circumstances during the "central column" load condition, making bending of the beam 125 more difficult. Other design variations of the forming elements 405, 410, and 415 are also conceivable, thereby achieving shape locking or increased bending stiffness of the beam 125 under the "central column" load condition.
[0051] List of reference numerals
[0052] 100 motor vehicles
[0053] 105 load-bearing structure
[0054] 110 wheels
[0055] 115 bumper system
[0056] 120 vehicle's direction of travel
[0057] 125 crossbeam
[0058] 130 First Transformation Box
[0059] 135 Second Transformation Box
[0060] 140 Longitudinal axis of motor vehicle
[0061] 200 bumper system center axis
[0062] 205 profile
[0063] 210 Closed Panel
[0064] 300 First side
[0065] 305 Second side
[0066] 310 connector
[0067] The middle longitudinal section of the 400 crossbeam
[0068] 405 First forming element
[0069] 410 Second forming element
[0070] 415 Third Forming Component
[0071] The interior space of the 420 beam
[0072] 425 profile
[0073] 430 The blanking portion on the first forming element
[0074] 435 Section of the second forming element
[0075] 440 Section of the third forming element
[0076] 500 pillars
[0077] 505 arrow
[0078] 600 arrows
Claims
1. A crossbeam (125) for a bumper system (115) of a motor vehicle (100), the crossbeam being constructed in two parts by a profile (205) open on one side in cross-section and a closed plate (210) at least partially closing the profile (205), wherein, A first forming element (405) is arranged on the central longitudinal section (400) of the closed plate (210), wherein a second and a third forming element (410, 415) are arranged on both sides of the central axis (200) of the crossbeam (125) spaced apart from the central axis (200), wherein the second forming element (410) and the third forming element (415) are arranged relative to the first forming element (405) such that they are fitted together in a shape-locking manner when a frontal collision occurs in the central longitudinal section (400) of the closed plate (210) located on the central axis (200), and the second forming element and the third forming element remain without contact with the first forming element (405) in a frontal collision with side overlap.
2. The crossbeam (125) according to claim 1, wherein, The profile (205) has a concave profile (425) in the central longitudinal section (400) located on the front side of the profile (205) in the forward direction (120) relative to the motor vehicle (100).
3. The crossbeam (125) according to claim 1 or 2, wherein, Each forming element (405, 410, 415) is arranged in the internal space (420) of the crossbeam (125).
4. The crossbeam (125) according to claim 3, wherein, The first forming element (405) has a gap (430) for receiving the second and third forming elements (410, 415) in sections (435, 440) that are complementary to the first forming element.
5. The crossbeam (125) according to any one of the preceding claims, wherein, The first forming element (405) is connected to the closed plate (210) by means of material locking.
6. The crossbeam (125) according to any one of the preceding claims, wherein, The second and third forming elements (410, 415) are connected to the profile (205) by means of material locking.
7. The crossbeam (125) according to claim 6, wherein, The closed plate (210) is attached to the second and third forming elements (410, 415).
8. The crossbeam (125) according to any one of the preceding claims, wherein, The profile (205) is a cap-shaped profile.
9. A bumper system (115) for a motor vehicle (100), comprising a crossbeam (125) according to any one of the preceding claims, wherein, The crossbeam (125) is arranged transversely to the longitudinal axis (140) of the motor vehicle (100).
10. The bumper system (115) according to claim 9, wherein, The closed plate (210) is arranged in a forward-pointing manner in the longitudinal direction of the motor vehicle.
11. A motor vehicle (100) comprising a bumper system (115) according to any one of claims 9 or 10.