Energy-absorbing anti-collision anchor cable assembly and control method thereof

Abstract

The application discloses an energy-absorbing anti-collision anchor cable assembly and a control method thereof, and the energy-absorbing anti-collision anchor cable assembly comprises an anchor cable, an energy-absorbing sleeve, a tray, a variable-taper-angle and diameter-expanding table, a temperature control assembly and a pressure detection assembly. The variable-taper-angle and diameter-expanding table is arranged in the energy-absorbing sleeve and connected with the anchor cable, so that the anchor cable drives the variable-taper-angle and diameter-expanding table to axially slide relative to the energy-absorbing sleeve when the anchor cable is subjected to impact stretching. Meanwhile, the pressure detection assembly detects the radial contact pressure between the shape memory alloy and the inner wall of the energy-absorbing sleeve, and the temperature control assembly controls the outer expansion taper angles of different shape memory alloy groups, so that the variable-taper-angle and diameter-expanding table and the energy-absorbing sleeve form a graded and adjustable frictional energy-absorbing resistance.

Description

Technical Field

[0001] This invention relates to the field of anchor bolt and cable support technology for mine roadways, specifically to an energy-absorbing and anti-impact anchor cable assembly and its control method. Background Technology

[0002] Roadways are the main sites of rockburst accidents. Severe impact dynamic loads often cause a large number of anchor cable failures, hydraulic support breakages, and severe deformations such as U-shaped supports, leading to roadway instability, damage, or even closure. The effectiveness of rockburst prevention and support technology for roadways is severely tested and has gradually become a research focus at home and abroad.

[0003] Currently, scholars both domestically and internationally have conducted extensive research on rockburst-resistant support systems for roadways prone to rockbursts. A series of rockburst-resistant energy-absorbing hydraulic supports and high-resistance, high-elongation, high-deformation constant-resistance anchor cables have been developed and invented, along with technologies such as cone anchors, D-bolts, and Garford D-cables. The widespread application of these support materials and equipment in rockburst-prone roadways has effectively improved the rockburst-resistant support effect. However, it still cannot fully meet the support requirements for large deformations and high impact energy generated by rockbursts, especially for active support anchor cables, which still suffer from insufficient impact adaptability and self-protection capabilities.

[0004] Furthermore, some existing anchor bolts with shape memory function mainly use shape memory alloy sheets to directly expand and compress the borehole wall or soil to improve anchoring friction, making them suitable for rapid or temporary slope support. However, the friction of this type of structure is mainly generated between the outside of the anchor bolt and the borehole wall. The size and material of the borehole wall cannot be controlled, making it difficult to form stable and controllable frictional energy dissipation resistance during the tension slippage of the anchor cable. In addition, it is also difficult to classify and control the internal pressure absorption process of the anchor cable under instantaneous impact tension in roadways prone to rock bursts. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an energy-absorbing and anti-impact anchor cable assembly and its control method.

[0006] To address the aforementioned technical problems, this invention first discloses an energy-absorbing and anti-erosion anchor cable assembly, comprising an anchor cable, an energy-absorbing sleeve, a tray, a variable-cone-angle expansion platform, a temperature control component, and a pressure detection component. The variable-cone-angle expansion platform is inserted into the energy-absorbing sleeve and sleeved on the anchor cable. One end of the anchor cable is provided with a surrounding rock anchoring end, and the other end is connected to the tray. A shape memory alloy is disposed on the variable-cone-angle expansion platform. The pressure detection component is used to detect the radial contact pressure between the shape memory alloy and the inner wall of the energy-absorbing sleeve. The temperature control component controls the temperature of the shape memory alloy according to the radial contact pressure. In a hot state, the shape memory alloy forms a corresponding outward expansion cone angle. When the anchor cable is subjected to impact tension, it drives the variable cone angle expansion platform to slide axially relative to the energy-absorbing sleeve. After the shape memory alloy expands outward, it forms radial compression with the inner wall of the energy-absorbing sleeve to generate adjustable frictional energy absorption resistance. The variable cone angle expansion platform includes a guide rod and a shape memory alloy assembly installed along the axial direction of the guide rod. The shape memory alloy assembly includes at least two levels of shape memory alloy groups arranged sequentially along the anchor cable tension direction. Each level of the shape memory alloy group has a different preset outward expansion cone angle, which is used to form graded frictional energy absorption resistance under different radial contact pressures.

[0007] Furthermore, the pressure detection component includes a pressure sensor and a pressure controller connected together. The pressure sensor is disposed on the shape memory alloy and between the shape memory alloy and the inner wall of the energy-absorbing sleeve.

[0008] Furthermore, the temperature control assembly includes a heating element and a temperature controller connected together, the shape memory alloy assembly includes a shape memory alloy sheet mounted circumferentially along the guide rod, the shape memory alloy sheet is fixedly connected to the heating element, and the temperature controller is connected to the pressure controller.

[0009] Furthermore, the shape memory alloy assembly includes a first shape memory alloy group and a second shape memory alloy group arranged sequentially along the anchor cable tension direction. The plurality of first shape memory alloy sheets of the first shape memory alloy group and the plurality of second shape memory alloy sheets of the second shape memory alloy group are evenly distributed along the circumference of the guide rod. The outer cone angle of the first shape memory alloy sheet is smaller than the outer cone angle of the second shape memory alloy sheet.

[0010] Furthermore, both the first shape memory alloy sheet and the second shape memory alloy sheet include an arc transition section, a fixed section and a deformation section disposed at both ends of the arc transition section. The fixed section is an arc structure that fits against the outer side of the guide rod, and the deformation section is an arc structure that fits against the inner side of the energy-absorbing sleeve.

[0011] Furthermore, the first outward expansion cone angle of the deformation segment of the first shape memory alloy sheet is smaller than the second outward expansion cone angle of the deformation segment of the second shape memory alloy sheet.

[0012] Furthermore, the first outward expansion cone angle of the first shape memory alloy sheet is 11°±1°, and the second outward expansion cone angle of the second shape memory alloy sheet is 21°±1°.

[0013] Furthermore, the inner wall of the energy-absorbing sleeve is provided with a friction-enhancing structure, which is one or more of the following: a roughening layer, circumferential grooves, spiral grooves, or a wear-resistant friction layer.

[0014] Then, the present invention discloses a control method for an energy-absorbing and anti-impact anchor cable assembly, comprising the following steps:

[0015] S1: When the radial contact pressure detected by the pressure detection component reaches the first preset pressure threshold and is less than the second preset pressure threshold, the temperature control component controls the heating element in the first shape memory alloy group to be de-energized, so that the first shape memory alloy sheet returns to the first outward expansion cone angle, so as to generate the first level of radial extrusion on the energy-absorbing sleeve and form the first level of frictional energy-absorbing resistance. S2: When the radial contact pressure detected by the pressure detection component reaches the second preset pressure threshold, the temperature control component controls the heating element in the second shape memory alloy group to be de-energized, so that the second shape memory alloy sheet returns to the second outward expansion cone angle, so as to generate a second level of radial extrusion on the energy-absorbing sleeve and form a second level of frictional energy-absorbing resistance.

[0016] Compared with the prior art, the advantages of the present invention are as follows: This invention utilizes a variable-cone-angle expanding platform within an energy-absorbing sleeve to accommodate the anchor cable. When the anchor cable is subjected to impact and tension, this platform slides axially relative to the sleeve. Simultaneously, a pressure detection component monitors the radial contact pressure between the shape memory alloy and the inner wall of the sleeve, while a temperature control component regulates the outward expansion angle of different shape memory alloy groups. This creates a stable and adjustable frictional energy absorption resistance between the expanding platform and the sleeve. Compared to structures that directly rely on shape memory alloy sheets to expand the hole wall and increase anchoring force, this invention converts impact energy into frictional energy dissipation within the sleeve during the anchor cable's impact and tension process, thereby improving the anchor cable's impact resistance, energy absorption stability, and self-protection capabilities. Attached Figure Description

[0017] Figure 1 This is a front view schematic diagram of the energy-absorbing and anti-impact anchor cable assembly disclosed in a preferred embodiment of the present invention; Figure 2 This is a front view schematic diagram of the cooperation between the fixed cone angle expanding stage and the variable cone angle expanding stage disclosed in the preferred embodiment of the present invention; Figure 3 This is a three-dimensional schematic diagram of the cooperation between the fixed cone angle expanding platform and the variable cone angle expanding platform disclosed in the preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the cooperation structure between the shape memory alloy sheet and the pressure detection component and the temperature control component disclosed in a preferred embodiment of the present invention.

[0018] Legend: 1. Anchor cable; 11. Rock anchoring end; 2. Energy-absorbing sleeve; 3. Tray; 4. Variable cone angle expansion platform; 41. Guide rod; 42. First shape memory alloy assembly; 421. First shape memory alloy sheet; 422. Arc transition section; 423. Fixed connection section; 424. Deformation section; 425. First outward expansion cone angle; 43. Second shape memory alloy assembly; 431. Second shape memory alloy sheet; 432. Second outward expansion cone angle; 5. Lock; 6. Temperature control assembly; 61. Heating element; 62. Temperature controller; 7. Pressure detection assembly; 71. Pressure sensor; 72. Pressure controller; 73. Pressure transmission cable groove; 8. Screw. Detailed Implementation

[0019] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0020] like Figure 1-4As shown, this embodiment first discloses an energy-absorbing anti-impact anchor cable assembly, including an anchor cable 1, an energy-absorbing sleeve 2, a tray 3, a variable cone angle expansion platform 4, a temperature control component 6, and a pressure detection component 7. The variable cone angle expansion platform 4 is inserted into the energy-absorbing sleeve 2 and fixedly sleeved on the anchor cable 1. One end of the anchor cable 1 passes through the energy-absorbing sleeve 2, and a surrounding rock anchoring end 11 is provided outside the energy-absorbing sleeve 2. The other end of the anchor cable 1 is connected to the tray 3. One end of the energy-absorbing sleeve 2 is fixedly connected to the tray 3, and the other end of the anchor cable 1 is locked to the tray 3 by a lock 5. A shape memory alloy is provided on the variable cone angle expansion platform 4. The shape memory alloy is an alloy sheet trained by two-way shape memory, and its high-temperature phase morphology is a conformal guide. The retracted form of rod 41, the low-temperature phase form is an outward expansion form with a preset outward expansion cone angle, which can achieve a preset shape structure during deformation. The pressure detection component 7 is used to detect the radial contact pressure between the shape memory alloy and the inner wall of the energy-absorbing sleeve 2 (the radial contact pressure can characterize the stress state of the anchor cable assembly under the action of surrounding rock deformation or impact load). The temperature control component 6 controls the heating state of the shape memory alloy according to the radial contact pressure, so that the shape memory alloy forms the corresponding outward expansion cone angle. When the anchor cable 1 is subjected to impact and tension, it drives the variable cone angle expansion platform 4 to slide axially relative to the energy-absorbing sleeve 2. After the shape memory alloy expands outward, it forms radial compression with the inner wall of the energy-absorbing sleeve 2 to generate adjustable frictional energy absorption resistance. This invention incorporates a variable-cone-angle expansion platform 4 within the energy-absorbing sleeve 2, which is fitted with the anchor cable 1. When the pressure detection component 7 detects different radial contact pressures, the temperature control component 6, linked to the pressure detection component 7, controls the temperature of the shape memory alloy. This controls the shape memory alloy to form different sizes of outward-expanding cone angles, causing the anchor cable 1 to pull the variable-cone-angle expansion platform 4 and the energy-absorbing sleeve 2 to generate corresponding frictional resistance. This allows the energy absorption resistance to exceed traditional ranges, adapting to various scenarios such as shallow low-impact and deep high-impact environments. Specifically, the greater the impact, the greater the pressure detected by the pressure detection component 7, the larger the outward-expanding cone angle of the shape memory alloy, and the greater the frictional resistance generated between the variable-cone-angle expansion platform 4 and the energy-absorbing sleeve 2, and vice versa. Simultaneously, this invention improves energy absorption stability, prevents instantaneous impact hardening fracture of the anchor cable 1, and significantly enhances the anti-impact effect of roadway support and the self-protection capability of the anchor cable 1.

[0021] In this embodiment, in order to monitor the radial contact pressure change of the anchor cable assembly under impact tension, the pressure detection component 7 includes a pressure sensor 71 and a pressure controller 72 connected to each other (other components, including the power supply, are all located inside the energy-absorbing sleeve 2 and are not shown). The pressure sensor 71 is located on the outer surface of the shape memory alloy, and a pressure transmission groove 73 is provided inside the shape memory alloy for transmitting pressure signals through the wire. The pressure sensor 71 is located between the shape memory alloy and the inner wall of the energy-absorbing sleeve 2. The radial contact pressure is applied to the pressure sensor 71 through the tube wall of the energy-absorbing sleeve 2. By measuring indirectly, the radial contact pressure can be detected, and the pressure sensor 71 can also be isolated, thus protecting the pressure sensor 71 and improving its service life.

[0022] In this embodiment, the temperature control assembly 6 includes a heating element 61 and a temperature controller 62 connected together (similarly, other components, including the power supply, are all located inside the energy-absorbing sleeve 2 and are not shown). The variable taper angle expansion stage 4 includes a guide rod 41 and a shape memory alloy assembly mounted axially along the guide rod 41. The shape memory alloy assembly includes a shape memory alloy sheet mounted circumferentially along the guide rod 41. The shape memory alloy sheet is fixedly connected to the heating element 61. The temperature controller 62 is connected to the pressure controller 72. The heating element 61 is a resistance heating component embedded in the shape memory alloy assembly. Inside the mounting groove of the shape memory alloy sheet, when the temperature controller 62 controls the heating element 61 to continuously heat, the shape memory alloy sheet adheres to the guide rod 41. At this time, the frictional energy absorption performance is relatively weak, and the variable cone angle expansion platform 4 can slide axially with the anchor cable 1 relative to the energy-absorbing sleeve 2. When the pressure sensor 71 detects an increase in the roadway rock pressure, the temperature controller 62 controls the heating element 61 to be de-energized, causing the shape memory alloy sheet to cool down and deform outward. The shape memory alloy sheet follows the displacement of the anchor cable 1 relative to the inner wall of the energy-absorbing sleeve 2, thereby expanding and absorbing energy through friction on the energy-absorbing sleeve 2. The shape memory alloy sheet undergoes two-way shape memory training, causing it to tend to contract and adhere to the guide rod 41 or the anchor cable 1 when heated, and return to the preset outward expansion cone angle when de-energized and cooled. When its outward expansion is constrained by the inner wall of the energy-absorbing sleeve 2, the shape memory alloy sheet generates a radial restoring force on the inner wall of the energy-absorbing sleeve 2, thereby increasing the frictional resistance between the variable cone angle expansion platform 4 and the energy-absorbing sleeve 2.

[0023] In this embodiment, in order to achieve multi-level, gradient expansion and frictional energy absorption of the energy-absorbing sleeve 2, the shape memory alloy assembly includes at least two levels of shape memory alloy groups arranged sequentially along the tension direction of the anchor cable 1. Each level of shape memory alloy group has a different preset outward expansion cone angle, which is used to form graded frictional energy absorption resistance under different radial contact pressures. Specifically, the shape memory alloy assembly includes a first shape memory alloy group 42 and a second shape memory alloy group 43 arranged sequentially along the tension direction of the anchor cable 1. The first shape memory alloy group 42 is close to the rock anchoring end 11 of the anchor cable 1. Multiple first shape memory alloy pieces 421 of the first shape memory alloy group 42 and multiple second shape memory alloy pieces 431 of the second shape memory alloy group 43 are evenly distributed circumferentially along the guide rod 41. The outer expansion cone angle of the first shape memory alloy piece 421 is smaller than that of the second shape memory alloy piece 431. When the pressure detection component 7 detects the radial contact pressure of the shape memory alloy piece and thus indirectly monitors that the first preset pressure threshold has been reached, but has not increased to the limit energy absorption resistance of the first shape memory alloy group 42, the first shape memory alloy piece 421 cools down and returns to the preset first outer expansion cone angle 425, expanding and absorbing energy through friction in the energy absorption sleeve 2. When the pressure detection component 7 indirectly detects that the radial contact pressure of the shape memory alloy sheet increases to a level greater than the second preset pressure threshold of the first shape memory alloy group 42, the second shape memory alloy sheet 431 cools down and returns to the preset second outward expansion cone angle 432, expanding and absorbing energy through friction in the energy-absorbing sleeve 2. This breaks through the traditional range of energy absorption resistance, making it suitable for various scenarios, including shallow low-impact and deep high-impact applications.

[0024] In this embodiment, in order to smoothly transition between the working and non-working parts of the first shape memory alloy sheet 421 and the second shape memory alloy sheet 431, reduce stress concentration, and prevent the working and non-working parts from being pulled apart, both the first shape memory alloy sheet 421 and the second shape memory alloy sheet 431 include an arc transition section 422 and fixed sections 423 and deformable sections 424 disposed at both ends of the arc transition section 422. The fixed section 423 is an arc structure that fits against the outer side of the guide rod 41 and is connected as one piece by screws 8. The deformable section 424 is an arc structure that fits against the inner side of the energy-absorbing sleeve 2, increasing the contact area and thus increasing the mutual friction force.

[0025] In this embodiment, the first outward expansion cone angle 425 of the deformation segment 424 of the first shape memory alloy sheet 421 is smaller than the second outward expansion cone angle 432 of the deformation segment 424 of the second shape memory alloy sheet 431. Specifically, after verification, the first outward expansion cone angle 425 of the first shape memory alloy sheet 421 is 11°±1°, and the second outward expansion cone angle 432 of the second shape memory alloy sheet 431 is 21°±1°, which can meet most shallow low-impact and deep high-impact application scenarios. The outward expansion cone angles are all relative to the axial direction of the anchor cable 1.

[0026] In this embodiment, the inner wall of the energy-absorbing sleeve 2 is provided with a friction-enhancing structure, which is one or more of the following: a roughening layer, circumferential ridges, spiral ridges, or a wear-resistant friction layer, thereby increasing the friction coefficient and enhancing the effect of frictional energy absorption.

[0027] Then, the present invention discloses a control method for an energy-absorbing and anti-impact anchor cable assembly, comprising the following steps: S1: When the radial contact pressure detected by the pressure detection component 7 reaches the first preset pressure threshold and is less than the second preset pressure threshold, the temperature control component 6 controls the heating element 61 in the first shape memory alloy group 42 to be de-energized, so that the first shape memory alloy sheet 421 returns to the first outward expansion cone angle 425, so as to generate the first level of radial extrusion on the energy-absorbing sleeve 2 and form the first level of frictional energy-absorbing resistance; thereby adapting to the needs of shallow low-impact scenarios.

[0028] S2: When the radial contact pressure detected by the pressure detection component 7 reaches the second preset pressure threshold, the temperature control component 6 controls the heating element 61 in the second shape memory alloy group 43 to be de-energized, causing the second shape memory alloy sheet 431 to return to the second outward expansion cone angle 432, thereby generating a second-stage radial compression on the energy-absorbing sleeve 2 and forming a second-stage frictional energy-absorbing resistance. This adapts to the needs of deep high-impact scenarios, that is, through segmented coordinated energy absorption, the energy-absorbing resistance breaks through the traditional range.

[0029] The first and second preset pressure thresholds are preset based on the roadway surrounding rock grade, impact hazard level, or anchor cable design energy absorption resistance.

[0030] Optionally, this application may further set more gradient energy-absorbing shape memory alloy groups, such as a third shape memory alloy group and a fourth shape memory alloy group, to match more specific energy absorption scenarios.

[0031] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. An energy-absorbing and shock-resistant anchor cable assembly, characterized in that, The system includes an anchor cable (1), an energy-absorbing sleeve (2), a tray (3), a variable cone angle expansion platform (4), a temperature control component (6), and a pressure detection component (7). The variable cone angle expansion platform (4) is inserted into the energy-absorbing sleeve (2) and sleeved on the anchor cable (1). One end of the anchor cable (1) is provided with a surrounding rock anchoring end (11), and the other end is connected to the tray (3). A shape memory alloy is provided on the variable cone angle expansion platform (4). The pressure detection component (7) is used to detect the radial contact pressure between the shape memory alloy and the inner wall of the energy-absorbing sleeve (2). The temperature control component (6) controls the heating state of the shape memory alloy according to the radial contact pressure. The shape memory alloy forms a corresponding outward expansion cone angle. When the anchor cable (1) is subjected to impact tension, the variable cone angle expansion platform (4) slides axially relative to the energy-absorbing sleeve (2). After the shape memory alloy expands outward, it forms radial compression with the inner wall of the energy-absorbing sleeve (2) to generate adjustable frictional energy absorption resistance. The variable cone angle expansion platform (4) includes a guide rod (41) and a shape memory alloy assembly installed axially along the guide rod (41). The shape memory alloy assembly includes at least two levels of shape memory alloy groups arranged sequentially along the tension direction of the anchor cable (1). Each level of the shape memory alloy group has a different preset outward expansion cone angle, which is used to form graded frictional energy absorption resistance under different radial contact pressures.

2. The energy-absorbing and anti-impact anchor cable assembly according to claim 1, characterized in that, The pressure detection assembly (7) includes a pressure sensor (71) and a pressure controller (72) connected to each other. The pressure sensor (71) is disposed on the shape memory alloy and between the shape memory alloy and the inner wall of the energy-absorbing sleeve (2).

3. The energy-absorbing and anti-impact anchor cable assembly according to claim 2, characterized in that, The temperature control assembly (6) includes a heating element (61) and a temperature controller (62) connected to each other. The shape memory alloy assembly includes a shape memory alloy sheet mounted circumferentially along the guide rod (41). The shape memory alloy sheet is fixed to the heating element (61). The temperature controller (62) is connected to the pressure controller (72).

4. The energy-absorbing and anti-impact anchor cable assembly according to claim 3, characterized in that, The shape memory alloy assembly includes a first shape memory alloy group (42) and a second shape memory alloy group (43) arranged sequentially along the tension direction of the anchor cable (1). The first shape memory alloy group (42) has multiple first shape memory alloy sheets (421), and the second shape memory alloy group (43) has multiple second shape memory alloy sheets (431) evenly distributed around the guide rod (41). The outer cone angle of the first shape memory alloy sheet (421) is smaller than the outer cone angle of the second shape memory alloy sheet (431).

5. The energy-absorbing and anti-impact anchor cable assembly according to claim 4, characterized in that, The first shape memory alloy sheet (421) and the second shape memory alloy sheet (431) both include an arc transition section (422) and a fixed section (423) and a deformable section (424) disposed at both ends of the arc transition section (422). The fixed section (423) is an arc structure that fits against the outside of the guide rod (41), and the deformable section (424) is an arc structure that fits against the inside of the energy-absorbing sleeve (2).

6. The energy-absorbing and anti-impact anchor cable assembly according to claim 5, characterized in that, The first outward expansion cone angle (425) of the deformation segment (424) of the first shape memory alloy sheet (421) is smaller than the second outward expansion cone angle (432) of the deformation segment (424) of the second shape memory alloy sheet (431).

7. The energy-absorbing and anti-impact anchor cable assembly according to claim 6, characterized in that, The first outward expansion cone angle (425) of the first shape memory alloy sheet (421) is 11°±1°, and the second outward expansion cone angle (432) of the second shape memory alloy sheet (431) is 21°±1°.

8. The energy-absorbing and shock-resistant anchor cable assembly according to any one of claims 1-7, characterized in that, The inner wall of the energy-absorbing sleeve (2) is provided with a friction-enhancing structure, which is one or more of the following: a roughening layer, circumferential ridges, spiral ridges, or a wear-resistant friction layer.

9. A control method for an energy-absorbing and anti-impact anchor cable assembly, characterized in that, The energy-absorbing and anti-erosion anchor cable assembly according to any one of claims 6-7 includes the following steps: S1: When the radial contact pressure detected by the pressure detection component (7) reaches the first preset pressure threshold and is less than the second preset pressure threshold, the temperature control component (6) controls the heating element (61) in the first shape memory alloy group (42) to be de-energized, so that the first shape memory alloy sheet (421) returns to the first outward expansion cone angle (425) to generate the first level of radial extrusion on the energy-absorbing sleeve (2) and form the first level of frictional energy-absorbing resistance; S2: When the radial contact pressure detected by the pressure detection component (7) reaches the second preset pressure threshold, the temperature control component (6) controls the heating element (61) in the second shape memory alloy group (43) to be de-energized, so that the second shape memory alloy sheet (431) returns to the second outward expansion cone angle (432) to generate a second level of radial extrusion on the energy-absorbing sleeve (2) and form a second level of frictional energy-absorbing resistance.

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