A conical buffer energy absorption device with induced structure and stiffness gradient

Abstract

The present invention discloses a conical buffer energy absorption device with an induced structure and a stiffness gradient, belonging to the field of buffer energy absorption technology. The conical buffer energy absorption device comprises: an outer thin-walled tube and an inner thin-walled tube, wherein the outer thin-walled tube is coaxial with the inner thin-walled tube and is 15 mm higher in the axial direction than the inner thin-walled tube; the outer thin-walled tube is a conical tube, and the inner thin-walled tube is a hexagonal square conical tube; the outer thin-walled tube and the inner thin-walled tube are connected by six connecting baffles, and the front end of the connecting baffle is a triangular structure, which is used to set a stiffness gradient to increase the stability of the energy absorption structure in the initial stage of the collision. Compared with a straight tube, the conical tube designed by the present invention is less likely to buckle as a whole during compression and has a higher strength to resist oblique loads.

Description

Technical Field

[0001] The present invention relates to the technical field of buffering and energy absorption, and in particular to a conical buffering and energy absorption device carrying an induction structure and a stiffness gradient. Background Art

[0002] Thin-walled metal tubing, as energy absorbers, has found widespread application in the automotive, aviation, and aerospace industries due to its excellent plastic deformation capacity and crushing stroke. Its primary operating principle is to absorb significant impact energy through plastic deformation during a collision, effectively reducing the impact force on the vehicle and its passengers. Traditional conical energy-absorbing buffers primarily consist of circular and square tubes. Research results have shown that these two structures can produce stable and controllable folding patterns during energy dissipation.

[0003] Compared to straight tubes, tapered tubes are less susceptible to overall buckling during compression and possess a robust resistance to both oblique and axial loads. Introducing a taper angle into a straight tube significantly reduces peak compression forces without reducing overall energy absorption. Furthermore, research has found that tapered tubes exhibit significantly greater deformation stability than ordinary straight tubes.

[0004] The introduction of the inducing structure is mainly to assist the deformation of the conical buffer energy absorbing device. Its essence is to introduce some local defect designs on the thin-walled structure to guide the thin-walled structure to produce reasonable deformation during the crushing deformation process, which can help avoid the overall bending instability of the conical buffer energy absorbing device and significantly reduce the initial peak load of the conical buffer energy absorbing device. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the main purpose of the present invention is to provide a conical buffer energy absorption device with an induced structure and a stiffness gradient, so as to solve the shortcomings of the existing energy absorption device structure such as uneven force, unstable deformation, excessive peak load and low energy absorption efficiency.

[0006] The present invention is achieved in that:

[0007] A conical buffer energy absorbing device with an induced structure and a stiffness gradient includes a conical buffer energy absorbing device, wherein the conical buffer energy absorbing device includes: an outer thin-walled tube and an inner thin-walled tube, wherein the outer thin-walled tube is coaxial with the inner thin-walled tube, and the outer thin-walled tube is 15 mm higher than the inner thin-walled tube in the axial direction; the outer thin-walled tube is a conical tube, and the inner thin-walled tube is a hexagonal square conical tube; the outer thin-walled tube and the inner thin-walled tube are connected by six connecting partitions, and the front end of the connecting partition is a triangular structure, which is used to set the stiffness gradient to increase the stability of the conical buffer energy absorbing device in the initial stage of collision and reduce the peak load in the initial stage of collision.

[0008] Furthermore, the front ends of the outer thin-walled tube and the inner thin-walled tube are both provided with a 45° chamfer; the connecting baffle is a connecting baffle with a variable cross-section, and the inner thin-walled tube, the outer thin-walled tube and the connecting baffle are combined to realize the stiffness gradient change of the conical buffer energy absorption device during the deformation process.

[0009] Furthermore, the thickness of the inner thin-walled tube and the outer thin-walled tube are consistent, and the ratio of their thickness to the thickness of the connecting partition is 1:1.7.

[0010] Furthermore, by adjusting the thickness ratio of the inner thin-walled tube, the outer thin-walled tube, and the connecting partition, the platform load during the compression process of the conical buffer energy absorption device can fluctuate around the peak load, thereby achieving a better energy absorption effect.

[0011] Furthermore, the head of the conical energy-absorbing device is welded to the mounting plate, which is then bolted to the front longitudinal beam of the vehicle. This bolted connection facilitates the reuse of the front longitudinal beam in minor collisions, requiring only the conical energy-absorbing device to be replaced, thus facilitating maintenance.

[0012] Furthermore, a stiffness gradient structure is provided on the connecting partition, so that there is a relatively smooth transition between the two peak loads of the inner thin-walled tube and the outer thin-walled tube in contact.

[0013] Furthermore, the conical buffer energy absorption device is made of aluminum alloy material.

[0014] The present invention provides a conical energy-absorbing and buffering device with an inductive structure and a stiffness gradient. When a collision occurs, the conical energy-absorbing and buffering device undergoes local buckling, causing a sharp increase in the initial peak load. The front end of the outer thin-walled tube is designed with a 45° chamfer, which is a 45° inward chamfer (the inductive structure). The initial deformation of the inductive structure can significantly reduce the initial peak load during a collision. After the initial peak load, the top of the connecting partition deforms first. Due to the stiffness gradient structure, the contact load continues to increase until the rigid wall contacts the inner thin-walled tube, generating a second load peak. An induction structure in the same direction is provided at the front end of the inner thin-walled tube to reduce the second peak load generated by this collision; afterwards, under the action of the inner thin-walled tube, the outer thin-walled tube and the connecting partition, the collision contact force fluctuates around the contact peak, increasing the average collision force during the collision; the design of the inner thin-walled tube and the outer thin-walled tube enables the conical buffer energy absorption device to gradually absorb energy when impacted by external force and deform in a relatively stable manner, thereby effectively dispersing the impact of external force, avoiding excessive local stress and causing failure of the overall structure, and significantly improving the safety and reliability of the structure.

[0015] The beneficial effects of the present invention compared with the prior art are:

[0016] The present invention proposes a conical buffer energy-absorbing device with an inductive structure and a stiffness gradient. Based on the traditional double-layer conical tube, the energy-absorbing device introduces a height difference between the outer thin-walled tube and the inner thin-walled tube, and a connecting baffle with a variable cross-section is arranged inside. The combination of the two realizes the stiffness gradient change of the conical buffer energy-absorbing device during the deformation process. By adjusting the wall thickness of the outer thin-walled tube, the inner thin-walled tube and the connecting baffle, when a collision occurs, energy can be transferred through gradual deformation, reducing local stress concentration, thereby achieving more efficient energy absorption. In addition, the introduction of the inductive structure at the end enables the device to have a lower peak load when a collision occurs, thereby ensuring the safety of the structure. Therefore, it can be widely used in aerospace, vehicles, rail transportation and other fields.

[0017] Compared with a straight tube, the conical buffer energy-absorbing device designed in the present invention is less likely to buckle as a whole during compression and has a higher strength ability to resist oblique loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the conical buffer energy absorption device;

[0019] Figure 2 This is a schematic diagram of the internal structure of the conical buffer energy absorption device

[0020] Figure 3 It is a cross-sectional view of the internal structure of the conical buffer energy absorption device;

[0021] Figure 4 This is a schematic diagram of the installation of a conical buffer energy absorption device;

[0022] Figure 5 Schematic diagram of conical buffer energy absorption devices with different cross-sectional shapes;

[0023] Figure 6 Comparison of the force-displacement curves of the structure of the present invention and the traditional double-layer conical tube;

[0024] Among them, 1-inner thin-walled tube, 2-outer thin-walled tube, 3-connecting partition, 4-45° chamfer, 5-car front longitudinal beam, 6-mounting plate, 7-conical buffer energy absorption device, 8-bolt. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the following examples are given to further illustrate the present invention in detail. It should be noted that the specific implementation described here is only used to explain the present invention and is not intended to limit the present invention.

[0026] The present invention provides a conical buffer energy absorbing device with an inductive structure and a stiffness gradient, which is made of aluminum alloy and has a structure as follows: Figures 1-3The device comprises an outer thin-walled tube 2, an inner thin-walled tube 1, connecting baffles 3, and a 45° chamfer 4. The 45° chamfer 4 is an inductive structure. The outer thin-walled tube 2 is a conical tube (conical shape), while the inner thin-walled tube 1 is a hexagonal square-taper tube (hexagonal structure). The outer thin-walled tube 2 and the inner thin-walled tube 1 are coaxial and 15 mm higher in the axial direction. The outer thin-walled tube 2 and the inner thin-walled tube 1 are connected by six connecting baffles 3. The front ends of the connecting baffles 3 are triangular in structure, which are used to set a stiffness gradient to increase the stability of the conical buffer energy absorption device during the initial collision.

[0027] The installation method is as follows Figure 4 As shown, one end of the conical energy-absorbing device 7 is welded to the mounting plate 6, and the other end is welded to the bottom baffle. The mounting plate 6 is fastened to the front longitudinal beam 5 of the vehicle via connecting bolts. The mounting plate 6 has grooves. This bolted connection facilitates the reuse of the front longitudinal beam 5 in the event of a minor collision, requiring only the replacement of the conical energy-absorbing device 7, thus facilitating maintenance.

[0028] In order to verify that the inner hexagonal conical buffer energy absorbing device 7 has structural advantages, a comparative analysis is first conducted on conical buffer energy absorbing devices with different cross-sectional shapes, such as Figure 5 The conical energy-absorbing devices with different cross-sectional shapes include: a double-layer conical tube, a double-layer conical tube with an inner quadrilateral, a double-layer conical tube with an inner pentagon, and a double-layer conical tube with an inner hexagon. The energy absorption performance data for these conical energy-absorbing devices with different cross-sections are shown in Table 1. As can be seen from Table 1, the conical energy-absorbing device 7 with an inner hexagonal shape outperforms other structures in terms of energy absorption and specific energy absorption, while also exhibiting less variation in peak load compared to other structures. Furthermore, when subjected to eccentric or lateral loads, the hexagonal structure's corners create natural partitions that limit deformation diffusion, while other structures are susceptible to overall deformation induced by lateral forces. Therefore, the conical energy-absorbing device 7 with an inner hexagonal shape offers certain advantages over other structures. By introducing the height difference between the inner thin-walled tube 1 and the outer thin-walled tube 2, and the inducing structure (45° chamfer 4) at the front ends of the inner and outer thin-walled tubes 1 and 2, the peak contact load can be significantly reduced.

[0029] The present invention sets a stiffness gradient structure on the connecting baffle 3, so that there is a relatively smooth transition between the two peak loads of the inner thin-walled tube 1 and the outer thin-walled tube 2. In addition, by adjusting the thickness ratio of the inner thin-walled tube 1, the outer thin-walled tube 2, and the connecting baffle 3, the platform load during the compression process of the conical buffer energy absorption device can fluctuate around the peak load, achieving a better energy absorption effect. Figure 6As shown in the force-displacement curve, the structure of the present invention has a smoother load change during a collision, a smaller peak load, and a higher energy absorption efficiency compared to the traditional double-layer conical tube.

[0030] Table 1 Comparison of the effects of conical buffer energy absorption devices with different cross-sectional shapes

[0031]

[0032] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A conical buffer energy absorption device with an inductive structure and a stiffness gradient, characterized in that: The conical buffer energy absorbing device (7) comprises an outer thin-walled tube (2) and an inner thin-walled tube (1), wherein the outer thin-walled tube (2) is coaxial with the inner thin-walled tube (1), and the outer thin-walled tube (2) is 15 mm higher than the inner thin-walled tube (1) in the axial direction; The outer thin-walled tube (2) is a conical tube, and the inner thin-walled tube (1) is a hexagonal square conical tube; the outer thin-walled tube (2) and the inner thin-walled tube (1) are connected by six connecting partitions (3), and the front ends of the connecting partitions (3) are triangular structures, which are used to set a stiffness gradient to increase the stability of the conical buffer energy absorption device (7) in the initial stage of the collision and reduce the peak load in the initial stage of the collision; The front ends of the outer thin-walled tube (2) and the inner thin-walled tube (1) are both provided with a 45° chamfer (4); the connecting baffle (3) is a baffle structure with a variable cross-section, and the inner thin-walled tube (1), the outer thin-walled tube (2), and the connecting baffle (3) are combined to realize the gradient change of the stiffness of the conical buffer energy absorption device (7) during the deformation process; When a collision occurs, the energy absorbing device will undergo local buckling, causing a sharp increase in the initial peak load; the front end of the outer thin-walled tube (2) is designed with a 45° chamfer (4) to induce the structure to undergo initial deformation, which can greatly reduce the initial peak load during the collision; After the initial peak load, the top of the connecting partition (3) deforms first. Due to the existence of the stiffness gradient structure, the contact load continues to increase until the rigid wall contacts the inner thin-walled tube (1), generating a second load peak. The front end of the inner thin-walled tube (1) is provided with an induction structure in the same direction to reduce the second peak load generated by the collision; thereafter, under the action of the inner thin-walled tube (1), the outer thin-walled tube (2), and the connecting partition (3), the collision contact force fluctuates around the contact peak, thereby increasing the average collision force during the collision process; the design of the layered conical buffer energy absorbing device (7) enables the conical buffer energy absorbing device (7) to gradually absorb energy when impacted by an external force and deform in a relatively stable manner, thereby effectively dispersing the impact of the external force, avoiding excessive local stress, and causing failure of the entire conical buffer energy absorbing device (7), thereby significantly improving the safety and reliability of the conical buffer energy absorbing device (7).

2. A conical buffer energy absorption device with an inductive structure and a stiffness gradient according to claim 1, characterized in that: The inner thin-walled tube (1) and the outer thin-walled tube (2) have the same thickness, and the ratio of their thickness to the thickness of the connecting partition (3) is 1:1.

7.

3. The conical energy-absorbing buffer device with an inductive structure and a stiffness gradient according to claim 2, characterized in that: By adjusting the thickness ratio of the inner thin-walled tube (1), the outer thin-walled tube (2), and the connecting partition (3), the platform load of the conical buffer energy absorption device (7) during compression can fluctuate around the peak load, thereby achieving a better energy absorption effect.

4. The conical buffer energy absorption device with an inductive structure and a stiffness gradient according to claim 1, characterized in that: The head of the conical buffer energy absorbing device (7) is connected to the mounting plate (6) by welding, and the mounting plate (6) is connected to the front longitudinal beam (5) of the automobile by bolts (8).

5. The conical buffer energy absorption device with an inductive structure and a stiffness gradient according to claim 1, characterized in that: A stiffness gradient structure is provided on the connecting partition (3), so that there is a relatively smooth transition between two peak loads when the inner thin-walled tube (1) and the outer thin-walled tube (2) come into contact.

6. The conical buffer energy absorption device with an inductive structure and a stiffness gradient according to claim 1, characterized in that: The conical buffer energy absorbing device (7) is made of aluminum alloy material.

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