Intelligent pre-tightening pressure-absorbing energy-absorbing support net and application method

Abstract

The present invention belongs to the technical field of underground engineering support, and specifically discloses an intelligent pre-tightening pressure-absorbing energy-absorbing support net and an application method, including: a mesh wire and a node hub device; the node hub device is arranged at the cross-connection node of four mesh wires; the node hub device includes: a shell, and a mesh wire installation module, a hot-melt fixing module and a rotation tensioning module arranged in the shell; the mesh wire installation module includes a circular ring, and a spring coil concentric with the circular ring is arranged inside the circular ring; through holes corresponding to the four mesh wires are arranged on the circular ring and the spring coil; the four mesh wires are respectively penetrated into the circular ring and the spring coil from their respective corresponding through holes in turn; the hot-melt fixing module can contact the mesh wire penetrated into the spring coil to achieve hot-melt fixing of the mesh wire; the rotation tensioning module can drive the spring coil to rotate. The present invention combines steel bars into a net or connects steel mesh sheets together through the node hub device, which can effectively reduce the probability of damage to the steel mesh.

Description

Technical Field

[0001] The present invention relates to the technical field of underground engineering support, and in particular to an intelligent pre-tightening pressure-absorbing energy-absorbing support net and an application method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous development of the coal industry, shallow coal resources are decreasing, and underground projects such as mine tunnels are developing deeper, and the mining depth is increasing. Deep underground projects face complex conditions such as high stress and extremely soft rock, which leads to stress concentration and energy accumulation in the surrounding rock, and the surface of the surrounding rock is broken, which in turn leads to a sharp increase in the difficulty of tunnel support.

[0004] Steel mesh is an important surface protection component for underground projects. However, in the process of supporting, the steel mesh of the existing technology will be subjected to large tension due to the crushing and squeezing of unstable rock layers, forming a mesh bag. Secondly, at the connection of the steel mesh, the binding wire is easy to break due to the large load, resulting in failure of the steel mesh. Moreover, stress concentration may occur at the welding nodes of the steel mesh and at unreasonable strength and structure, resulting in shear damage of the steel mesh and failure to play a supporting role. In addition, the steel mesh needs to be prefabricated and transported to the working surface in advance, which also increases costs and has low transportation efficiency. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes an intelligent pre-tightening pressure-absorbing energy-absorbing support mesh and an application method. By combining steel bars into a mesh or connecting steel mesh sheets together through a node central device, the probability of damage to the steel mesh can be effectively reduced.

[0006] In some embodiments, the following technical solutions are adopted:

[0007] An intelligent pre-tightening pressure-absorbing energy-absorbing support net comprises: a mesh wire and a node central device; the node central device is arranged at the cross-connection node of four mesh wires; the node central device comprises: a shell, and a mesh wire installation module, a hot-melt fixing module and a rotation tensioning module arranged in the shell;

[0008] The mesh installation module includes a circular ring, and a spring coil concentric with the circular ring is arranged inside the circular ring; through holes corresponding to the four mesh wires are arranged on the circular ring and the spring coil; the four mesh wires are respectively inserted into the circular ring and the spring coil in sequence from their respective corresponding through holes; the hot melt fixing module is arranged in the spring coil and fixed on the shell, and the hot melt fixing module can contact the mesh wire inserted into the spring coil to achieve hot melt fixing of the mesh wire; the rotating tensioning module is arranged in the spring coil and can drive the spring coil to rotate.

[0009] As a further solution, the inner wall of the circular ring is provided with a first arc-shaped serration, and the spring ring can fit with the first arc-shaped serration on the circular ring through expansion, thereby achieving a close fit between the spring ring and the circular ring.

[0010] As a further solution, the mesh installation module also includes a plurality of expansion devices, and the plurality of expansion devices are arranged in the spring coil; each of the expansion devices includes a cylinder and a propeller, and an arc-shaped docking port is provided at the front end of the propeller, and the arc-shaped docking port is connected to the spring coil. The cylinder can push the propeller to move outward, so that the spring coil expands outward until the spring coil is tightly fitted with the circular ring.

[0011] As a further solution, the rotary tensioning module is connected to a central shell arranged at the center position of the node hub device, and the expansion device is fixedly connected to the central shell. The rotary tensioning module can drive the central shell to rotate, and the rotation of the central shell can drive the expansion device to rotate, thereby driving the spring coil to rotate.

[0012] As a further solution, the rotary tensioning module includes: a motor and a transmission shaft, the rotating shaft of the motor is connected to the transmission shaft, the transmission shaft penetrates into a central shell arranged in the center of the node hub device, and can drive the central shell to rotate; the spring coil is connected to the central shell through an expansion device; after the mesh wire is fixed to the hot melt fixing module, the rotary tensioning module can drive the spring coil to rotate through the central shell and the expansion device to achieve tensioning of the mesh wire and provide pre-tightening force for the mesh.

[0013] As a further solution, the rotation tensioning module further includes: a rotation limiter, a slew limiter and a damping unit;

[0014] The rotation limiter includes a signal transmitter and a signal receiver. When the signal transmitter rotates to a certain angle, the signal receiver receives the signal and the motor stops rotating.

[0015] The rotation limiter is used to limit the rotation angle of the motor;

[0016] The damping unit is arranged at the front end of the transmission shaft. When the transmission shaft is subjected to force and has a tendency to rotate, the damping unit can suppress its rotation.

[0017] As a further solution, a central control system is provided in the central shell for controlling the mesh installation module, the hot melt fixing module and the rotation tensioning module to work in a set sequence.

[0018] As a further solution, there are multiple hot-melt fixing modules, and each mesh wire that penetrates into the spring coil is connected to a hot-melt fixing module;

[0019] The hot melt fixing module includes: a melting column and an electromagnetic induction coil wound around the outside of the melting column; the melting column is fixed between two fixing plates, both fixing plates are fixed on the shell, and the electromagnetic induction coil is connected to the power supply unit through a wire; a hole is provided on the melting column, and the mesh wire can be inserted into the hole.

[0020] As a further solution, a node hub device is set at the connection node position of two adjacent meshes.

[0021] In other embodiments, the following technical solutions are adopted:

[0022] An application method of an intelligent pre-tightening pressure-absorbing energy-absorbing support net, comprising:

[0023] The four mesh wires are respectively passed through the through holes and sequentially penetrated into the circular ring and the spring coil, and contacted with the hot-melt fixing module, and the hot-melt fixing module is controlled to hot-melt fix the mesh wire; then the rotation tensioning module is controlled to drive the spring coil to rotate, so as to realize the rotation tensioning of the mesh wire; finally, the mesh wire installation module is controlled to drive the spring coil to expand outward, until the spring coil fits tightly with the circular ring, and the mesh wire is clamped to form a zigzag shape;

[0024] When the mesh is subjected to force and has a tendency to stretch, the mesh is stretched from a zigzag shape to a straight shape, achieving the pressure-absorbing energy effect; the spring coil tends to rotate and shrink in the circumferential direction under the action of the mesh, and the rotation and shrinkage of the spring coil is limited by rotating the tensioning module, further enhancing the pressure-absorbing energy effect.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The surrounding rock support mesh provided by the present invention combines steel bars into a mesh through a node central device or connects the steel mesh pieces into a whole through a connecting central device at their joints, thereby reducing the number of welding nodes, adjusting the steel mesh structure, and optimizing the force of the steel mesh, and can effectively control the bulging and bulging of the steel mesh. When the steel mesh is subjected to a large shearing force, the shearing force is relieved by releasing the arc-shaped toothed mesh wire in the central device, thereby avoiding the failure of the steel mesh due to shear damage and better controlling the deformation of the surrounding rock.

[0027] (2) The present invention is provided with a mesh installation module, a hot-melt fixing module and a rotational tensioning module, etc., and the mesh installation module is used to realize the installation of the mesh and the connecting central device, the hot-melt fixing module is used to realize the automatic hot-melt fixing of the mesh, and the rotational tensioning of the spring coil is automatically realized by the rotational tensioning module, thereby realizing the automatic connection and fixation of the node central device and the mesh; prefabricating the steel mesh on the well is avoided, the transportation efficiency is improved, and the cost is saved.

[0028] Other features and advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The overall structure of the intelligent pre-tightening pressure-absorbing energy-absorbing support net in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0030] Figure 2 The overall structure of the intelligent pre-tightening pressure-absorbing energy-absorbing support net in the embodiment of the present invention is shown in FIG. Figure 2 ;

[0031] Figure 3 Schematic diagram of the structure of a node hub device in an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of a hot melt fixing module in an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the structure of the expansion device in an embodiment of the present invention;

[0034] Figure 6 A schematic diagram of spring coil combination in an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the internal structure of the housing in an embodiment of the present invention;

[0036] Among them, 1. Support net, 2. Node hub device;

[0037] 2-1. mesh, 2-2. ring, 2-3. spring coil, 2-4. heating circuit, 2-5. motor, 2-6. central control system, 2-7. transmission shaft, 2-8. damping unit, 2-9. signal receiver, 2-10. signal transmitter, 2-11. sensor line;

[0038] 3. Hot melt fixing module, 4. Expansion device;

[0039] 3-1. Electromagnetic induction coil, 3-2. Melting column, 3-3. Fixed plate;

[0040] 4-1. Propulsion cylinder, 4-2. Oil pressure pad, 4-3. Outer cylinder, 4-4. Arc-shaped docking port;

[0041] 5-1. Spring coil before change, 5-2. Spring coil after change; 6. Rotation limiter. DETAILED DESCRIPTION

[0042] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] Embodiment 1

[0045] In one or more embodiments, an intelligent pre-tightening pressure-absorbing energy-absorbing support net is disclosed, combined with Figure 1 and Figure 2 The support net 1 specifically includes: a mesh wire 2-1 and a node central device 2; the node central device 2 is arranged at the cross-connection node of four mesh wires; each node central device is interlaced and connected with four mesh wires, and is fixed by hot melting and pre-tightened by rotation to form a whole, and a plurality of node central devices are combined with a plurality of mesh wires to form a steel mesh, or, as Figure 2 As shown, two or more finished steel mesh sheets are combined and connected through a node central device to form a large-area steel mesh.

[0046] Combination Figure 3 The node hub device in this embodiment specifically includes: a mesh installation module, a hot melt fixing module 3 and a rotation tensioning module.

[0047] Among them, the mesh installation module includes: a circular ring 2-2, inside which is a spring coil 2-3 concentric with the circular ring; the circular ring is at the outermost side, has a certain thickness, and is constant in size, the inner wall is covered with first arc-shaped serrations, and four through holes with the same aperture and cross distribution are opened around the ring, and the mesh wire can pass through the inside of the circular ring from the through holes. The spring coil is inside the circular ring and is set concentrically with the circular ring. The spring coil can be expanded and has an arc-shaped serration as a whole. The spring coil has through holes with the same number, aperture and distribution as those on the circular ring, and the four mesh wires pass through the circular ring and the spring coil from their corresponding through holes in turn. After the spring coil expands, the arc-shaped serrations of the spring coil will change, and the changed size matches the first arc-shaped serrations on the circular ring, so that the spring coil and the circular ring can fit tightly; Figure 6 A schematic diagram of the combination of the ring and the spring ring is given.

[0048] In this embodiment, the mesh installation module further includes a plurality of expansion devices 4, and the plurality of expansion devices 4 are all disposed inside the spring coil and connected to the spring coil; the expansion of the spring coil is achieved through the expansion devices.

[0049] Combination Figure 5The specific structure of each expansion device includes: an oil cylinder and a thruster, and an arc-shaped docking port is provided at the front end of the thruster; the thruster specifically includes a thrust tube 4-1, an oil pressure pad 4-2 and an outer tube 4-3, the thrust tube and the oil pressure pad are both arranged in the outer tube, the oil cylinder is connected to the oil pressure pad, and the oil pressure pad is connected to the thrust tube, and the oil pressure pad can drive the thrust tube to move back and forth in the outer tube under the action of the oil cylinder; an arc-shaped docking port 4-4 is provided at the front end of the thrust tube, and the arc-shaped docking port can be tightly connected with the arc-shaped serrations of the spring coil.

[0050] When the mesh wire is hot-melt fixed and rotationally pre-tightened, the oil cylinder pushes the propulsion tube outward through the oil pressure pad, causing the spring coil to expand outward until the spring coil fits tightly against the ring. At this time, the mesh wire can be clamped into a zigzag shape, thereby automatically clamping and fixing the mesh wire; and the expansion device can always provide thrust to prevent the spring from retracting. Figure 6 A schematic diagram of the spring coil 5-1 before and after the spring coil 5-2 is changed under the action of the expansion device is given.

[0051] In this embodiment, the hot melt fixing module 3 is arranged in the spring coil and connected to the housing. The hot melt fixing module can contact the mesh wire inserted into the spring coil to achieve hot melt fixing of the mesh wire. Specifically, there are multiple hot melt fixing modules 3, and each mesh wire inserted into the spring coil is connected to a hot melt fixing module; Figure 4 The hot melt fixing module includes: a melting column 3-2 and an electromagnetic induction coil 3-1 wound around the outside of the melting column; the melting column is fixed between two fixing plates 3-3, and the two fixing plates are fixed at the bottom of the shell, and the electromagnetic induction coil is connected to the power supply unit through a heating line 2-4; the power supply unit can be a battery for powering the electromagnetic induction coil; a hole is provided on the melting column, and the mesh can be inserted into the hole; the eddy current heating principle can be used to achieve rapid and efficient heating of the melting column.

[0052] When the mesh wire is inserted into the hole of the molten column, the electromagnetic induction coil automatically heats the molten column to melt and form a whole with the mesh wire. After the hot melting is completed, the heating is automatically disconnected to ensure that other components are not damaged. At this time, the mesh wire and the molten column are combined into a whole, and the mesh wire will not be pulled out of the molten column under the action of external force.

[0053] In this embodiment, the rotation and tensioning module is connected to the central shell arranged at the center of the node hub device, and the multiple expansion devices are also connected to the central shell. The rotation and tensioning module is used to drive the spring ring and the mesh to rotate after the mesh and the spring ring are firmly combined, so as to realize the rotation and tensioning of the mesh.

[0054] Combination Figure 7The rotary tensioning module includes: a motor 2-5 and a transmission shaft 2-7. The motor is arranged under the central shell of the node hub device. The rotating shaft of the motor is connected to the transmission shaft. The transmission shaft penetrates into the central shell and can drive the central shell to rotate; the spring ring is connected to the central shell through an expansion device; after the mesh is fixed by hot melt, the rotary tensioning module can drive the central shell to rotate, and the rotation of the central shell can drive the expansion device to rotate, and then drive the spring ring to rotate; the rotary tensioning module can drive the spring ring to rotate a certain angle (such as a quarter of a circle) through the central shell and the expansion device to achieve the tension of the mesh, which can provide pre-tightening force for the steel mesh, ensure that the mesh is in a taut state, and avoid the mesh from sagging.

[0055] As a further solution, the rotation tensioning module also includes: a rotation limiter, a slew limiter 6 and a damping unit 2-8. The rotation limiter includes a signal transmitter 2-10 and a signal receiver 2-9. The signal transmitter rotates with the motor, and the signal receiver is fixed on the bottom of the shell. The signal receiver is connected to the central control system through a sensor line 2-11. When the signal transmitter rotates to a certain angle and aligns with the signal receiver up and down (for example, the maximum rotation angle is 90°), the signal receiver receives the laser signal emitted by the signal transmitter, indicating that the rotation is in place, and the signal transmitter transmits a signal to the central control system, and the central control system controls the motor to stop rotating.

[0056] The rotation limiter 6 is used to limit the rotation angle of the motor, and the maximum rotation angle is 30°.

[0057] The damping unit is set at the front end of the transmission shaft. It will not work when the transmission shaft rotates clockwise, but will limit the rotation of the transmission shaft when the transmission shaft rotates counterclockwise. When the transmission shaft is subjected to force and has a tendency to rotate, the damping unit will inhibit its rotation, absorbing energy while avoiding damage to the motor.

[0058] The central control system 2-6 is arranged in the central shell, and is used to control the mesh installation module, the hot melt fixing module and the rotary tensioning module to work in a set order; specifically including: controlling the electromagnetic induction coil in the hot melt fixing module to be energized to realize the hot melting of the molten column; after the hot melt fixing is completed, the mesh is fixed on the molten column, and the rotation of the motor in the rotary tensioning module is controlled to realize the rotational tensioning of the mesh; finally, the oil cylinders of multiple expansion devices in the mesh installation module are controlled to drive the propulsion cylinder to move forward, so that the spring coil and the ring fit tightly, clamping the mesh to form a zigzag shape, and realizing the clamping and fixing of the mesh.

[0059] The power supply unit is located under the motor and is used to supply power to electrical components such as the electromagnetic induction coil, motor, central control system, signal receiver and signal transmitter. The power supply unit can be recycled and replaced and can continue to be used for the support of the next working surface.

[0060] The specific working principle of the node hub device in this embodiment is as follows:

[0061] The four mesh wires at the cross-connection of the mesh wires are respectively inserted into the spring coil from the through holes on the circular ring and the spring coil and contact the molten column of the hot-melt fixing module, and the electromagnetic induction coil of the hot-melt fixing module is powered to realize automatic heating of the electromagnetic induction coil, so that the molten column melts and connects the mesh wire and the molten column together; after the mesh wire and the molten column are firmly combined, the rotating tensioning module drives the spring coil and the mesh wire to rotate, so as to realize the rotational tensioning of the mesh wire; after rotating into place, the expansion device of the mesh installation module pushes the spring coil to expand outward until the spring coil and the circular ring are tightly fitted, and the mesh wire is clamped into a zigzag shape through the cooperation of the spring coil and the circular ring, thereby automatically realizing the clamping and fixation of the mesh wire.

[0062] When the mesh is stressed and stretches, it stretches from a zigzag shape to a straight line, absorbing energy and releasing pressure. At this time, the spring coil will reverse under the action of the mesh, and the spring coil will shrink. At this time, the damping unit will work to limit the rotation of the transmission shaft. The rotation angle of the motor is limited by the rotation limiter, further enhancing its energy absorption effect.

[0063] This embodiment combines the steel bars into a mesh through the node hub device or connects the steel mesh pieces into a whole through the connection hub device at the connection point, which can effectively control the steel mesh from bulging and bulging. When the steel mesh is subjected to a large shearing effect, the shearing effect is alleviated by releasing the zigzag mesh wire in the hub device, thereby avoiding the failure of the steel mesh due to shear damage and better controlling the deformation of the surrounding rock.

[0064] The operation of the node central device in this embodiment is controlled by a central control system, which can automatically complete hot melting, rotation and spring coil expansion, thereby automatically and tightly combining the node central device with the mesh wire, and can realize automatic installation and underground installation, avoiding prefabricated steel mesh above the well, improving transportation efficiency and saving costs.

[0065] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. An intelligent pre-tightening pressure-absorbing energy-absorbing support net, characterized in that: include: Web and node hubs; The node hub device is arranged at the cross-connection node of the four mesh wires; The node hub device comprises: a shell, and a mesh installation module, a hot melt fixing module and a rotation tensioning module arranged in the shell; The mesh installation module includes a circular ring, and a spring coil concentric with the circular ring is arranged inside the circular ring; through holes corresponding to the four meshes are arranged on the circular ring and the spring coil; the four meshes are respectively inserted into the circular ring and the spring coil from the corresponding through holes in sequence; the hot-melt fixing module is arranged in the spring coil and fixed on the housing, and the hot-melt fixing module can contact the mesh inserted into the spring coil to achieve hot-melt fixing of the mesh; the rotating tensioning module is arranged in the spring coil and can drive the spring coil to rotate; The inner wall of the circular ring is provided with a first arc-shaped sawtooth, and the spring ring can fit with the first arc-shaped sawtooth on the circular ring through expansion, so as to achieve a close fit between the spring ring and the circular ring; The mesh installation module also includes a plurality of expansion devices, which are arranged in the spring coil; each expansion device includes an oil cylinder and a pusher, and an arc-shaped docking port is provided at the front end of the pusher, and the arc-shaped docking port is connected to the spring coil. The oil cylinder can push the pusher to move outward, so that the spring coil expands outward until the spring coil fits tightly with the ring; The rotating tensioning module is connected to the central shell arranged at the center of the node hub device, and the expansion device is fixedly connected to the central shell. The rotating tensioning module can drive the central shell to rotate, and the rotation of the central shell can drive the expansion device to rotate, thereby driving the spring coil to rotate; The rotary tensioning module includes: a motor and a transmission shaft, the rotating shaft of the motor is connected to the transmission shaft, the transmission shaft penetrates into a central shell arranged at the center of the node hub device, and can drive the central shell to rotate; the spring ring is connected to the central shell through an expansion device; after the mesh wire is fixed to the hot-melt fixing module, the rotary tensioning module can drive the spring ring to rotate through the central shell and the expansion device to achieve tensioning of the mesh wire and provide pre-tightening force for the mesh.

2. The intelligent pre-tightening pressure-absorbing energy-absorbing support net according to claim 1, characterized in that: The rotary tensioning module further comprises: a rotary limiter, a slewing limiter and a damping unit; The rotation limiter includes a signal transmitter and a signal receiver. When the signal transmitter rotates to a certain angle, the signal receiver receives the signal and the motor stops rotating. The rotation limiter is used to limit the rotation angle of the motor; The damping unit is arranged at the front end of the transmission shaft. When the transmission shaft is subjected to force and has a tendency to rotate, the damping unit can suppress its rotation.

3. The intelligent pre-tightening pressure-absorbing energy-absorbing support net according to claim 1, characterized in that: A central control system is arranged in the central shell, which is used to control the mesh installation module, the hot melt fixing module and the rotation tensioning module to work in a set sequence.

4. The intelligent pre-tightening pressure-absorbing energy-absorbing support net according to claim 1, characterized in that: There are multiple hot-melt fixing modules, and each mesh wire that penetrates into the spring coil is connected to a hot-melt fixing module; The hot melt fixing module includes: a melting column and an electromagnetic induction coil wound around the outside of the melting column; the melting column is fixed between two fixing plates, both fixing plates are fixed on the shell, and the electromagnetic induction coil is connected to the power supply unit through a wire; a hole is provided on the melting column, and the mesh wire can be inserted into the hole.

5. An intelligent pre-tightening pressure-absorbing energy-absorbing support net according to any one of claims 1 to 4, characterized in that: A node hub device is set at the connection node position of two adjacent mesh sheets.

6. An application method of the intelligent pre-tightening pressure-absorbing energy-absorbing support net according to claim 1, characterized in that: include: The four mesh wires are respectively passed through the through holes and sequentially penetrated into the circular ring and the spring coil, and contacted with the hot-melt fixing module, and the hot-melt fixing module is controlled to hot-melt fix the mesh wire; then the rotation tensioning module is controlled to drive the spring coil to rotate, so as to realize the rotation tensioning of the mesh wire; finally, the mesh wire installation module is controlled to drive the spring coil to expand outward, until the spring coil fits tightly with the circular ring, and the mesh wire is clamped to form a zigzag shape; When the mesh is subjected to force and has a tendency to stretch, the mesh is stretched from a zigzag shape to a straight shape, achieving the pressure-absorbing energy effect; the spring coil tends to rotate and shrink in the circumferential direction under the action of the mesh, and the rotation and shrinkage of the spring coil is limited by rotating the tensioning module, further enhancing the pressure-absorbing energy effect.

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