Lightweight automobile bumper energy absorption beam
By using an aluminum alloy matrix and a gradient-distributed star-shaped honeycomb unit structure in the car bumper crossbeam, combined with shape memory alloy compensation pads, the problems of heavy weight and low energy absorption efficiency of traditional crossbeams are solved, achieving lightweight and high-efficiency energy absorption effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGZHOU ZHONGZHENG AUTO PARTS CO LTD
- Filing Date
- 2025-06-17
- Publication Date
- 2026-06-26
Smart Images
Figure CN224409159U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of automotive bumper technology, and in particular to a lightweight automotive bumper energy-absorbing crossbeam. Background Technology
[0002] Car bumpers are safety devices that absorb and mitigate external impacts, protecting the front and rear of the vehicle. Many years ago, car bumpers were made by stamping steel plates into channel steel, riveting or welding them to the chassis longitudinal beams, resulting in a significant gap between the bumper and the body, which looked unsightly. With the development of the automotive industry and the widespread use of engineering plastics, car bumpers, as an important safety device, have undergone significant innovation. Today's car bumpers, in addition to maintaining their original protective function, also strive for harmony and unity with the vehicle's styling, and are designed to be lightweight.
[0003] Traditional bumper beams are mostly made of steel with a closed cross section or aluminum alloy extrusion molding, which have problems such as heavy weight and low energy absorption efficiency. Existing lightweight solutions use honeycomb aluminum filling, but they have defects such as complex process, high cost and insufficient lateral stiffness. Utility Model Content
[0004] To address the aforementioned technical problems, a lightweight energy-absorbing crossbeam for automotive bumpers is provided.
[0005] To achieve the above objectives, this utility model discloses a lightweight automotive bumper energy-absorbing crossbeam, comprising a crossbeam body, wherein the crossbeam body is an extruded aluminum alloy substrate, and the cross-section of the crossbeam body has a double-walled hollow structure, including an outer load-bearing wall, and the hollow structure is filled with star-shaped honeycomb units, the density of which is gradient-distributed along the length of the crossbeam body. Both ends of the crossbeam body are provided with integrated connecting grooves to connect to external energy-absorbing boxes, and shape memory alloy compensation pads are pre-embedded in the connecting grooves.
[0006] Furthermore, the star-shaped honeycomb unit is composed of multiple intersecting ribs. The apex angle θ of the star-shaped honeycomb unit is 67° to 77°, the rib length L is 4.6mm to 5mm, the rib wall thickness T is 0.6mm to 1.2mm, the circumscribed circle diameter D of the star-shaped honeycomb unit is 9.5mm to 10.5mm, and the rib ends are provided with a chamfer radius R of 0.3mm to 0.5mm.
[0007] Furthermore, the star-shaped honeycomb unit is made of 6061-T6 aluminum alloy, the outer supporting wall material is 7003-T6 aluminum alloy, and the thickness ratio between the rib wall thickness and the supporting wall thickness is 1:2.5.
[0008] Furthermore, the centerline of the main body of the beam is the baseline. The density of the first unit in the 0-30% length region along the baseline is 8 cells / cm², the density of the third unit in the 60%-100% length region is 12 cells / cm², and the density of the second unit in the 30%-60% length region increases linearly.
[0009] Furthermore, the cross-sectional shape of the connecting groove is a T-shaped structure, the groove depth is 1.8 to 2.2 times the thickness of the bearing wall, and an annular groove is provided at a position 2mm to 4mm away from the groove opening, which surrounds the inner wall of the connecting groove. A shape memory alloy compensation gasket is embedded in the annular groove, and a bonding layer formed by laser welding is provided at the edge of the annular groove, with a welding depth ≥0.7mm.
[0010] Furthermore, the shape memory alloy compensation pad is a NiTiNOL alloy with a phase transformation temperature of 75℃~85℃ and a high-temperature phase volume expansion rate ≥4%.
[0011] Furthermore, the static three-point bending stiffness of the main body of the beam is ≥3000N / mm.
[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model discloses a lightweight car bumper energy-absorbing beam. The star-shaped unit improves the lateral bending strength compared with the traditional hexagonal honeycomb structure. It induces orderly folding deformation during collision. The gradient density unit distribution matches the stress concentration characteristics of the offset condition in the collision test. The integrated connecting groove replaces the bolt connection, reducing the overall weight. The pre-embedded compensation gasket compensates for the assembly gap during high temperature expansion. Attached Figure Description
[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0014] Figure 1 This is the front view of the present invention.
[0015] Figure 2 This is a schematic diagram showing the partial arrangement of the star-shaped honeycomb units of this utility model.
[0016] Figure 3 This is a schematic diagram of the geometric unit of the star-shaped honeycomb unit of this utility model.
[0017] Figure 4 This is a schematic diagram of the connecting groove of this utility model.
[0018] In the diagram: 1 is the main body of the crossbeam; 2 is the star-shaped honeycomb unit; 21 is the first unit; 22 is the second unit; 23 is the third unit; 3 is the connecting groove; and 4 is the shape memory alloy compensation pad. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0020] One embodiment of this utility model is as follows: Figure 1 and Figure 4 As shown, the main body 1 of the crossbeam is an extruded aluminum alloy substrate. The cross-section of the main body 1 has a double-walled hollow structure, including an outer load-bearing wall. The hollow structure is filled with star-shaped honeycomb units 2. The density of the star-shaped honeycomb units 2 is gradient-distributed along the length of the main body 1. The two ends of the main body 1 are provided with integrated connecting grooves 3 to connect to the external energy-absorbing box. Shape memory alloy compensation gaskets 4 are pre-embedded in the connecting grooves 3. Compared with the traditional hexagonal honeycomb structure, the star-shaped units improve the lateral bending strength and induce orderly folding deformation during collision. The gradient density unit distribution matches the stress concentration characteristics of the offset condition in the collision test. The integrated connecting groove replaces the bolt connection, reducing the overall weight. The pre-embedded compensation gaskets compensate for the assembly gap during high-temperature expansion.
[0021] In this embodiment, as Figure 2 and Figure 3 As shown, the star-shaped honeycomb unit 2 is composed of six ribs of equal length. The apex angle θ of the star-shaped honeycomb unit 2 is 72°, the rib length L is 4.8mm, the rib wall thickness T is 0.8mm, the circumscribed circle diameter D of the star-shaped honeycomb unit 2 is 10mm, and the rib ends are chamfered with a radius R of 0.3mm to prevent stress concentration. The star-shaped honeycomb unit 2 is made of 6061-T6 aluminum alloy, and the outer load-bearing wall material is 7003-T6 aluminum alloy. The aluminum alloy billet is heated to 480℃ and extruded into a tubular substrate with honeycomb cavity. The star-shaped honeycomb cavity is laser-cut, plasma activated, and vacuum diffusion welded. Local heat treatment is carried out by T6 (quenching at 60℃ and aging treatment at 185℃ for 8 hours). The unit weight of the main beam in this embodiment can reach 2.8kg, which is 38% lighter than the same level of steel beam. According to GB / T 9341 standard, the static three-point bending stiffness of the main beam 1 reaches 3250N / mm.
[0022] like Figure 1As shown, the center line of the main body 1 of the crossbeam is the baseline. The density of the first unit 21 in the 0-30% length region along the baseline is 8 cells / cm², the density of the third unit 23 in the 60%-100% length region is 12 cells / cm², and the density of the second unit 22 in the 30%-60% length region increases linearly. The density change of the star-shaped honeycomb unit along the length of the main body of the crossbeam is ≥40%.
[0023] like Figure 4 As shown, the cross-sectional shape of the connecting groove 3 is a T-shaped structure, formed by milling. The groove depth of the connecting groove 3 is 1.8 to 2.2 times the thickness of the bearing wall. An annular groove is provided at the stress concentration position 3mm away from the groove opening of the connecting groove 3, which is circumferentially surrounding the inner wall of the connecting groove 3 to avoid insertion interference and ensure the initial assembly gap. A shape memory alloy compensation gasket 4 is embedded in the annular groove to compensate for anisotropic thermal deformation. A bonding layer formed by laser welding is provided at the edge of the annular groove. The annular groove and the compensation gasket are interference-fitted with an interference amount of 0.05mm. The pre-compressed compensation gasket is fixed by laser spot welding. The whole is heated to 120℃ and held for 1 hour. After cooling to room temperature, the compensation gasket obtains the memory expansion characteristics. The energy absorption box is inserted into the connecting groove axially.
[0024] The shape memory alloy compensation pad 4 is made of NiTiNOL alloy with a phase transformation temperature of 75℃~85℃ and a high-temperature phase volume expansion rate of ≥4%. Under normal assembly conditions at 25℃, after inserting the energy-absorbing box, the gap between the compensation pad and the energy-absorbing box is 0.3mm. Under high-temperature conditions, the aluminum alloy substrate of the crossbeam body and the energy-absorbing box expand, and the shape memory pad expands at the same time to fill the gap, eliminating the risk of loosening and improving the efficiency of collision force transmission.
[0025] Several points need to be clarified: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and the relative positional relationships may change when the absolute position of the described objects changes. Second, in this document, relational terms such as "first" and "second" are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities.
[0026] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this utility model.
Claims
1. A lightweight automotive bumper energy-absorbing crossbeam, comprising a crossbeam body (1), characterized in that, The main body of the beam (1) is an extruded aluminum alloy substrate. The cross section of the main body of the beam (1) has a double-walled hollow structure, including an outer bearing wall. The hollow structure is filled with star-shaped honeycomb units (2). The density of the star-shaped honeycomb units (2) is distributed in a gradient along the length of the main body of the beam (1). The two ends of the main body of the beam (1) are provided with an integrated connecting groove (3) to connect to the external energy-absorbing box. A shape memory alloy compensation pad (4) is pre-embedded in the connecting groove (3).
2. A lightweight automotive bumper energy-absorbing beam according to claim 1, characterized in that, The star-shaped honeycomb unit (2) is composed of multiple intersecting ribs. The apex angle θ of the star-shaped honeycomb unit (2) is 67° to 77°, the rib length L is 4.6 mm to 5 mm, the rib wall thickness T is 0.6 mm to 1.2 mm, the circumscribed circle diameter D of the star-shaped honeycomb unit (2) is 9.5 mm to 10.5 mm, and the rib ends are provided with a chamfer radius R of 0.3 mm to 0.5 mm.
3. A lightweight automotive bumper energy-absorbing beam according to claim 2, characterized in that, The star-shaped honeycomb unit (2) is made of 6061-T6 aluminum alloy, the outer bearing wall material is 7003-T6 aluminum alloy, and the thickness ratio between the rib wall thickness and the bearing wall thickness is 1:2.
5.
4. A lightweight automotive bumper energy-absorbing beam according to claim 1, characterized in that, The center line of the main body of the beam (1) is the baseline. The density of the first unit (21) in the 0-30% length region along the baseline is 8 cells / cm², the density of the third unit (23) in the 60%-100% length region is 12 cells / cm², and the density of the second unit (22) in the 30%-60% length region increases linearly.
5. A lightweight automotive bumper energy-absorbing beam according to claim 1, characterized in that, The cross-sectional shape of the connecting groove (3) is a T-shaped structure. The groove depth of the connecting groove (3) is 1.8 to 2.2 times the thickness of the bearing wall. An annular groove is provided at a position 2 mm to 4 mm away from the groove opening of the connecting groove (3) and surrounds the inner wall of the connecting groove (3). A shape memory alloy compensation pad (4) is embedded in the annular groove. A bonding layer formed by laser welding is provided at the edge of the annular groove, with a welding depth ≥ 0.7 mm.
6. A lightweight automotive bumper energy-absorbing beam according to claim 5, characterized in that, The shape memory alloy compensation pad (4) is a NiTiNOL alloy with a phase transformation temperature of 75℃~85℃ and a high-temperature phase volume expansion rate ≥4%.
7. A lightweight automotive bumper energy-absorbing beam according to claim 1, characterized in that, The static three-point bending stiffness of the main body of the crossbeam (1) is ≥3000N / mm.