Anti-fracture device and method for self-adaptive adjustment of bolt in vibration environment

Abstract

The invention relates to the technical field of mechanical connection, in particular to an anti-fracture device and method for self-adaptive adjustment of a bolt in a vibration environment. An anti-fracture device for bolt self-adaptive adjustment in a vibration environment comprises a shell provided with an internal thread, and an intelligent monitoring mechanism, a self-adaptive adjustment mechanism and a safety locking mechanism which are located in the shell. The intelligent monitoring mechanism is used for monitoring one or more parameters of the vibration frequency, the amplitude, the stress and the torque angle of the bolt at the joint; the self-adaptive adjusting mechanism is used for automatically adjusting the pre-tightening force of the bolt according to the parameters fed back by the intelligent monitoring mechanism; the safety locking mechanism is used for automatically locking the bolt and giving an alarm when parameters fed back by the intelligent monitoring mechanism exceed preset values.

Description

Technical Field

[0001] The present application relates to the field of mechanical connection technology, and in particular to an anti-fracture device and method for adaptively adjusting bolts in a vibration environment. Background Art

[0002] In a vibrating environment, large bolted connection structures often suffer from fatigue fracture due to long-term alternating stress, which not only affects the stable operation of the equipment, but may also cause serious safety accidents. In the prior art, although the fatigue resistance of bolts has been improved to a certain extent by optimizing bolt design, selecting high-strength materials, and accurately controlling preload force, there is still a risk of bolt breakage under extreme vibration conditions. Especially for large bolts in remote areas, such as those on wind turbines, due to the long maintenance cycle, when large bolts are loose, they cannot be retightened in time, so they are more likely to break when their design life is less than 50%. Therefore, it is particularly important to develop a device and method that can effectively prevent large bolts from breaking in a vibrating environment. Summary of the invention

[0003] In order to effectively prevent bolts from breaking in a vibration environment, the present application provides an anti-fracture device and method for adaptively adjusting bolts in a vibration environment.

[0004] In the first aspect, the present application provides an anti-fracture device for adaptive adjustment of bolts in a vibration environment, which adopts the following technical solution:

[0005] An anti-fracture device for self-adaptive adjustment of bolts in a vibration environment, comprising a housing provided with internal threads, and an intelligent monitoring mechanism, a self-adaptive adjustment mechanism and a safety locking mechanism located in the housing;

[0006] The intelligent monitoring mechanism is used to monitor one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolts at the connection;

[0007] The adaptive adjustment mechanism is used to automatically adjust the bolt preload according to the parameters fed back by the intelligent monitoring mechanism;

[0008] The safety locking mechanism is used to automatically lock the bolt and sound an alarm when the parameter fed back by the intelligent monitoring mechanism exceeds a preset value.

[0009] By adopting the above technical solution, when the intelligent monitoring mechanism detects that the linear change of one or more parameters among vibration frequency, amplitude, stress and torque exceeds the preset value, it means that the large bolts are loose. At this time, the bolt preload can be adjusted through the adaptive adjustment mechanism to prevent the large bolts from being in a loose state for a long time and causing the large bolts to break in a vibration environment. When the parameter is greater than the preset value, it means that an unexpected situation has occurred. At this time, the bolts are locked and an alarm is issued so that the large bolts can be replaced in time.

[0010] Preferably, the shell comprises an upper shell, a middle shell and a lower shell, a middle installation cavity is formed inside the middle shell, and the intelligent monitoring mechanism is located in the middle installation cavity.

[0011] Preferably, the intelligent monitoring mechanism comprises a vibration sensor and a stress-strain sensor, the stress-strain sensor is a vibrating-wire strain gauge, and the length direction of the vibrating-wire strain gauge is the same as the extension direction of the internal thread.

[0012] Preferably, the outer side surface of the lower shell is formed with at least two force-bearing surfaces, and the two force-bearing surfaces are not adjacent and form an angle of 60 degrees.

[0013] By adopting the above technical solution, the force-bearing surface can be used as the force base point to bear the force of the tool to preliminarily tighten the bolt.

[0014] Preferably, the adaptive adjustment device includes a stepper motor installed in the lower shell, a transmission shaft driven to rotate by the stepper motor, and a threaded sleeve installed in the upper shell for connecting bolts. The threaded sleeve is rotatably connected to the upper shell and a circle of gear teeth is formed on the outer side of the threaded sleeve. The other end of the transmission shaft extends to the upper shell and a transmission gear meshing with the threaded sleeve is provided at the end.

[0015] Preferably, an air cavity is formed in the upper shell, and the safety locking mechanism includes a locking rod penetrating the upper shell, and a locking tooth piece connected to one end of the locking rod and located in the air cavity; the locking tooth piece, except for the side facing the center of the anti-fracture device, is coated with a rubber layer on all sides thereof and is sealed to the inner wall of the air cavity; a sealing ring is provided in the outer shell and is sealed to the locking rod; a closed space is formed in the air cavity at a position between the locking tooth piece and the sealing ring; a compressed gas tank is provided in the upper shell, and the air outlet of the compressed gas tank is connected to the air outlet pipe through a valve, and the other end of the air outlet pipe is communicated with the closed space.

[0016] Preferably, a one-way bearing is installed on the upper end of the transmission shaft, the inner ring of the one-way bearing is connected to the transmission shaft, the outer ring of the one-way bearing is provided with a rotating wheel, the upper end surface of the rotating wheel is provided with an eccentric block located in an eccentric position, the eccentric block is rotatably connected to a hinged rod, and the other end of the hinged rod is hinged to the handle of the valve.

[0017] In a second aspect, the present application provides a method for using the above-mentioned anti-fracture device for a threaded hole direct-connected bolt, using the following technical solution:

[0018] A method for using the above-mentioned anti-fracture device for a threaded hole direct-connected bolt, characterized by comprising:

[0019] S1. Install the anti-fracture device to the threaded hole direct-connection bolt so that the end surface of the upper shell or the lower shell of the anti-fracture device abuts against the bolt head of the threaded hole direct-connection bolt;

[0020] S2. Tighten the threaded hole direct connection bolts on the threaded holes;

[0021] S3. The intelligent monitoring device obtains real-time status parameters of the bolt at every interval t. The real-time status parameters of the bolt include one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolt;

[0022] S4, judging whether the real-time state parameter of the bolt is greater than the first preset value, if so, proceeding to step S5, otherwise returning to step S3;

[0023] S5. Adjust the bolt preload force through the adaptive adjustment mechanism until the real-time state parameter of the bolt is less than the second preset value, the second preset value is less than or equal to the first preset value, and return to step S3.

[0024] In the third aspect, the present application provides a technical solution that adopts the following method:

[0025] A method for using the above-mentioned anti-fracture device for a through-hole bolt, characterized by comprising:

[0026] S1. After the through-hole bolt passes through the through-hole on the component, the anti-fracture device is screwed on the end of the through-hole bolt that passes through the component, so that the end surface of the upper shell abuts against the component and is tightened;

[0027] S2. The intelligent monitoring device obtains real-time status parameters of the bolt at every interval t. The real-time status parameters of the bolt include one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolt;

[0028] S3, judging whether the real-time state parameter of the bolt is greater than the first preset value, if so, proceeding to step S4, otherwise returning to step S2;

[0029] S4, judging whether the real-time state parameter of the bolt is less than a third preset value, if so, proceeding to step S7, otherwise proceeding to step S5;

[0030] S5, judging whether the real-time state parameter of the bolt changes linearly, if so, proceeding to step S6, otherwise, proceeding to step S7;

[0031] S6, adjusting the bolt preload force by the adaptive adjustment mechanism until the real-time state parameter of the bolt is less than the second preset value, the second preset value is less than or equal to the first preset value, and returning to step S3;

[0032] S7. The anti-fracture device and the bolt are relatively locked by the safety locking mechanism, and an alarm is sounded.

[0033] In summary, the present application includes at least one of the following beneficial technical effects:

[0034] 1. When the intelligent monitoring mechanism detects that one or more parameters of vibration frequency, amplitude, stress, and torque have linear changes and increase beyond the preset value, it means that the large bolts are loose. At this time, the bolt preload can be adjusted through the adaptive adjustment mechanism. When the parameter is greater than the preset value, it means that an unexpected situation has occurred. At this time, the bolts are locked and an alarm is issued so that the large bolts can be replaced in time. Effectively prevent large bolts from breaking before reaching their design life in a vibration environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the structure when the anti-fracture device is combined with a large bolt;

[0036] Figure 2 is a schematic cross-sectional view of an anti-fracture device;

[0037] Figure 3 is a schematic diagram of the structure of the middle shell and the lower shell of the anti-fracture device;

[0038] Figure 4 yes Figure 2 Enlarged view of point A in the middle.

[0039] Explanation of the accompanying drawings: 1. Shell; 2. Upper shell; 3. Middle shell; 4. Lower shell; 5. Middle mounting cavity; 6. Vibration sensor; 7. Stress and strain sensor; 8. Force surface; 9. Stepper motor; 10. Active bevel gear; 11. Driven bevel gear; 12. Transmission shaft; 13. Upper mounting cavity; 14. Threaded sleeve; 15. Connecting protrusion; 16. Connecting groove; 17. Transmission gear; 18. Locking rod; 19. Locking tooth piece; 20. Indicator; 21. Air cavity; 22. Sealing ring; 23. Compressed gas tank; 24. Valve; 25. Exit pipe; 26. One-way bearing; 27. Rotating wheel; 28. Eccentric block; 29. ​​Articulated rod. DETAILED DESCRIPTION

[0040] The following is combined with Figure 1-4 This application is described in further detail.

[0041] The embodiments of the present application disclose an anti-fracture device and method for adaptive adjustment of bolts in a vibration environment. The "up", "down", "left" and "right" used in the embodiments are all used to describe the relative directions of positional relationships, and are not limitations of the positional relationships.

[0042] like Figure 1 As shown, the anti-fracture device for adaptive adjustment of bolts in a vibration environment includes a housing 1 for connecting large bolts, and an intelligent monitoring mechanism, an adaptive adjustment mechanism and a safety locking mechanism located in the housing 1. The intelligent monitoring mechanism is used to monitor one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolts at the connection; the adaptive adjustment mechanism is used to automatically adjust the bolt preload according to the parameters fed back by the intelligent monitoring mechanism; the safety locking mechanism is used to automatically lock the bolt when the parameters fed back by the intelligent monitoring mechanism exceed the preset value.

[0043] like Figure 1 and Figure 2 As shown, the housing 1 includes an upper shell 2, a middle shell 3 and a lower shell 4, wherein the lower shell 4 is fixedly connected to the middle shell 3. A middle installation cavity 5 is formed inside the middle shell 3, and the intelligent monitoring mechanism includes a vibration sensor 6 and a stress strain sensor 7 installed in the middle installation cavity 5. The vibration sensor 6 can be a piezoelectric vibration sensor 6, and the stress strain sensor 7 can be a vibrating wire strain gauge, which is fixedly installed on the inner side wall of the middle installation cavity 5 close to the large bolt in a state where the length direction is parallel to the length direction of the large bolt (a torque sensor can be used in other embodiments). The side of the lower shell 4 is formed with a threading hole connected to the middle installation cavity 5.

[0044] like Figure 2 and Figure 3 As shown, the center of the lower shell 4 is formed with an internal thread adapted to the large bolt, and the outer side of the lower shell 4 is formed with three force-bearing surfaces 8, each of which has an equal width, and the adjacent force-bearing surfaces 8 form an angle of 120 degrees. The three force-bearing surfaces 8 cooperate as force-bearing parts, so that the tool that applies force can apply force to the lower shell 4 through the force-bearing surfaces 8 so that the lower shell 4 is rotated and tightened relative to the large bolt. The adaptive adjustment mechanism includes a stepper motor 9 installed in the lower shell 4, and an active bevel gear 10 is installed on the output shaft of the stepper motor 9. The driven bevel gear 11 meshing with the active bevel gear 10 outputs torque to the outside through the connected transmission shaft 12. A shaft sleeve is sleeved at the position outside the transmission shaft 12 in the lower shell 4.

[0045] like Figure 2 and Figure 4As shown, an upper mounting cavity 13 is provided in the upper shell 2, and a threaded sleeve 14 is installed in the upper mounting cavity 13. The upper end surface of the threaded sleeve 14 is formed with a circle of annular connecting protrusions 15, and the connecting protrusions 15 are inserted into the connecting grooves 16 inside the upper shell 2, so that the threaded sleeve 14 is rotatably connected to the upper shell 2. The upper end surface of the threaded sleeve 14 abuts against the upper side wall of the upper mounting cavity 13, and the distance between the lower end surface of the lower threaded sleeve 14 and the lower side surface of the upper mounting cavity 13 is less than the height of the connecting protrusion 15. The inner side surface of the threaded sleeve 14 is formed with an internal thread that matches the large bolt, and the outer side surface of the threaded sleeve 14 is formed with a circle of gear teeth. The upper end of the transmission shaft 12 passes through the middle shell 3 and enters the upper mounting cavity 13 of the upper shell 2, and the part of the transmission shaft 12 in the upper mounting cavity 13 is fixed with a transmission gear 17 that meshes with the outer ring of the threaded sleeve 14. The gear ratio of the outer ring of the threaded sleeve 14 to the transmission gear 17 is greater than 10, and the thickness of the outer ring of the threaded sleeve 14 is greater than the thickness of the transmission gear 17.

[0046] like Figure 2 and Figure 4 As shown, the safety locking mechanism includes a plurality of locking rods 18 passing through the upper shell 2, a locking tooth piece 19 connected to one end of the locking rod 18 located inside the upper shell 2, and an indicator 20 connected to one end of the locking rod 18 located outside the upper shell 2. An air cavity 21 is formed in the upper shell 2 at a position corresponding to the locking rod 18, and the locking tooth piece 19 is located in the air cavity 21. The locking tooth piece 19 is made of stainless steel, and the other sides of the locking tooth piece 19 except the side facing the large bolt are covered with a rubber layer to fit and seal with the inner wall of the air cavity 21. A sealing ring 22 is provided in the outer shell to fit and seal with the locking rod 18, so that a closed space is formed in the position between the locking tooth piece 19 and the sealing ring 22 in the air cavity 21. A compressed gas tank 23 is also provided in the upper mounting cavity 13, and the gas outlet of the compressed gas tank 23 is connected to the gas outlet pipe 25 through a valve 24, and the other end of the gas outlet pipe 25 is connected to the closed space of the air cavity 21. A one-way bearing 26 is installed at the upper end of the transmission shaft 12, the inner ring of the one-way bearing 26 is fixedly connected to the transmission shaft 12, a rotating wheel 27 is fixed to the outer ring of the one-way bearing 26, an eccentric block 28 located at an eccentric position is formed on the upper end surface of the rotating wheel 27, a hinge 29 rod is rotatably connected to the eccentric block 28, and the other end of the hinge 29 rod is hinged 29 to the handle of the valve 24. Through the one-way bearing 26, only when the servo motor rotates in the reverse direction, the rotating wheel 27 will be driven to rotate and drive the hinge 29 rod to open the valve 24; when the servo motor rotates in the forward direction, the rotating wheel 27 will not rotate.

[0047] Specific use process:

[0048] When the intelligent monitoring mechanism detects that one or more parameters of vibration frequency, amplitude, stress, and torque increase linearly beyond the preset value, it means that the large bolt is loose. At this time, the servo motor is controlled to rotate forward to rotate the transmission shaft 12 and the transmission gear 17 on the transmission shaft 12, and the threaded sleeve 14 meshing with the transmission gear 17 rotates accordingly. After the threaded sleeve 14 rotates, it moves upward along the large bolt, so that the distance between the upper end face of the upper shell 2 and the lower end face of the lower shell 4 increases, and the preload force is reapplied to the bolt. When the intelligent monitoring mechanism detects that one or more parameters of vibration frequency, amplitude, stress, and torque increase instantaneously beyond the preset value, the servo motor is reversed to rotate the rotating wheel 27, and the eccentric block 28 on the rotating wheel 27 drives the handle through the hinge 29 rod to open the valve 24, and the compressed air in the compressed gas tank 23 enters the closed space of the air cavity 21 through the outlet pipe 25, and the locking tooth 19 is pressed on the large bolt under the gas pressure, so that the relative position of the upper shell 2 and the large bolt is locked.

[0049] Embodiment 2:

[0050] The method of using the anti-fracture device in the first embodiment for a threaded hole direct-connected bolt comprises:

[0051] S1. Install the anti-fracture device to the threaded hole direct-connection bolt so that the end surface of the upper shell 2 or the lower shell 4 of the anti-fracture device abuts against the bolt head of the threaded hole direct-connection bolt.

[0052] S2. Tighten the threaded hole direct connection bolts into the threaded holes.

[0053] S3. The intelligent monitoring device obtains real-time status parameters of the bolt at every time interval t. The real-time status parameters of the bolt include one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolt.

[0054] S4, judging whether the real-time state parameter of the bolt is greater than the first preset value, if so, proceeding to step S5, otherwise returning to step S3.

[0055] S5. Adjust the bolt preload force through the adaptive adjustment mechanism until the real-time state parameter of the bolt is less than the second preset value, the second preset value is less than or equal to the first preset value, and return to step S3.

[0056] This embodiment can be applicable to both the cases where the threaded hole passes through and does not pass through the component, and can also be applicable to both the cases where the threaded hole direct-connected bolt passes through or does not pass through the component with the threaded hole.

[0057] Embodiment three:

[0058] The method of using the anti-fracture device in the first embodiment for a through-hole bolt comprises:

[0059] S1. After the through-hole bolt passes through the through-hole on the component, an anti-fracture device is screwed on the end of the through-hole bolt that passes through the component, so that the end surface of the upper shell 2 abuts against the component and is tightened.

[0060] S2. The intelligent monitoring device obtains real-time status parameters of the bolt at every time interval t. The real-time status parameters of the bolt include one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolt.

[0061] S3, judging whether the real-time state parameter of the bolt is greater than the first preset value, if so, proceeding to step S4, otherwise returning to step S2.

[0062] S4, judging whether the real-time state parameter of the bolt is less than the third preset value, if so, proceeding to step S7, otherwise, proceeding to step S5.

[0063] S5. Determine whether the real-time state parameters of the bolts change linearly. If so, proceed to step S6, otherwise proceed to step S7. The specific method for determining whether the real-time state parameters of the bolts change linearly is that the parameter obtained at the current time Tn is An, the parameter obtained at time Tn-1 is An-1, and the parameter obtained at time Tn-2 is An-2. Divide the value of An / An-1 by the value of An-1 / An-2. When the divided value is less than 1.2, the real-time state parameters of the bolts are determined to change linearly, otherwise the real-time state parameters of the bolts are considered to change nonlinearly. This solution is not limited to the above-mentioned specific method for determining whether the real-time state parameters of the bolts change linearly, and other methods may also be used to determine whether the real-time state parameters of the bolts change linearly.

[0064] S6. Adjust the bolt preload force through the adaptive adjustment mechanism until the real-time state parameter of the bolt is less than the second preset value, the second preset value is less than or equal to the first preset value, and return to step S3.

[0065] S7. The anti-fracture device and the bolt are relatively locked by the safety locking mechanism, and an alarm is sounded.

[0066] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An anti-fracture device for adaptive adjustment of bolts in a vibration environment, characterized in that: It includes a shell with internal threads, and an intelligent monitoring mechanism, an adaptive adjustment mechanism and a safety locking mechanism located in the shell; The intelligent monitoring mechanism is used to monitor one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolts at the connection; The adaptive adjustment mechanism is used to automatically adjust the bolt preload according to the parameters fed back by the intelligent monitoring mechanism; The safety locking mechanism is used to automatically lock the bolt and sound an alarm when the parameter fed back by the intelligent monitoring mechanism exceeds a preset value.

2. The anti-fracture device for adaptive adjustment of bolts in a vibration environment according to claim 1 is characterized in that: The shell comprises an upper shell, a middle shell and a lower shell. A middle installation cavity is formed inside the middle shell, and the intelligent monitoring mechanism is located in the middle installation cavity.

3. The anti-fracture device for self-adaptive adjustment of bolts in a vibration environment according to claim 2 is characterized in that: The intelligent monitoring mechanism comprises a vibration sensor and a stress-strain sensor. The stress-strain sensor is a vibrating-wire strain gauge. The length direction of the vibrating-wire strain gauge is the same as the extension direction of the internal thread.

4. The anti-fracture device for adaptive adjustment of bolts in a vibration environment according to claim 2 is characterized in that: The outer side surface of the lower shell is formed with at least two force-bearing surfaces, and the two force-bearing surfaces are not adjacent and form an angle of 60 degrees.

5. The anti-fracture device for self-adaptive adjustment of bolts in a vibration environment according to claim 2 is characterized in that: The adaptive adjustment device includes a stepper motor installed in the lower shell, a transmission shaft driven to rotate by the stepper motor, and a threaded sleeve installed in the upper shell for connecting bolts. The threaded sleeve is rotatably connected to the upper shell and a circle of gear teeth is formed on the outer side of the threaded sleeve. The other end of the transmission shaft extends to the upper shell and is provided with a transmission gear meshing with the threaded sleeve at the end.

6. The anti-fracture device for self-adaptive adjustment of bolts in a vibration environment according to claim 5 is characterized in that: An air cavity is formed in the upper shell, and the safety locking mechanism includes a locking rod penetrating the upper shell, and a locking tooth piece connected to one end of the locking rod and located in the air cavity. The locking tooth piece is coated with a rubber layer on all sides except the side facing the center of the anti-fracture device, and is sealed to the inner wall of the air cavity. A sealing ring is provided in the outer shell and is sealed to the locking rod. A closed space is formed in the air cavity between the locking tooth piece and the sealing ring. A compressed gas tank is provided in the upper shell, and the air outlet of the compressed gas tank is connected to the air outlet pipe through a valve, and the other end of the air outlet pipe is connected to the closed space.

7. The anti-fracture device for self-adaptive adjustment of bolts in a vibration environment according to claim 1 is characterized in that: A one-way bearing is installed at the upper end of the transmission shaft, the inner ring of the one-way bearing is connected to the transmission shaft, a rotating wheel is provided on the outer ring of the one-way bearing, an eccentric block located at an eccentric position is provided on the upper end face of the rotating wheel, a hinged rod is rotatably connected to the eccentric block, and the other end of the hinged rod is hinged to the handle of the valve.

8. A method for using the anti-fracture device according to any one of claims 1 to 7 for a threaded hole direct-connected bolt, characterized in that: include: S1. Install the anti-fracture device to the threaded hole direct-connection bolt so that the end surface of the upper shell or the lower shell of the anti-fracture device abuts against the bolt head of the threaded hole direct-connection bolt; S2. Tighten the threaded hole direct connection bolts on the threaded holes; S3. The intelligent monitoring device obtains real-time status parameters of the bolt at every interval t. The real-time status parameters of the bolt include one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolt; S4, judging whether the real-time state parameter of the bolt is greater than the first preset value, if so, proceeding to step S5, otherwise returning to step S3; S5. Adjust the bolt preload force through the adaptive adjustment mechanism until the real-time state parameter of the bolt is less than the second preset value, the second preset value is less than or equal to the first preset value, and return to step S3.

9. A method for using the anti-fracture device according to any one of claims 1 to 7 for a through-hole bolt, characterized in that: include: S1. After the through-hole bolt passes through the through-hole on the component, the anti-fracture device is screwed on the end of the through-hole bolt that passes through the component, so that the end surface of the upper shell abuts against the component and is tightened; S2. The intelligent monitoring device obtains real-time status parameters of the bolt at every interval t. The real-time status parameters of the bolt include one or more parameters of the vibration frequency, amplitude, stress, and torque angle of the bolt; S3, judging whether the real-time state parameter of the bolt is greater than the first preset value, if so, proceeding to step S4, otherwise returning to step S2; S4, judging whether the real-time state parameter of the bolt is less than a third preset value, if so, proceeding to step S7, otherwise proceeding to step S5; S5, judging whether the real-time state parameter of the bolt changes linearly, if so, proceeding to step S6, otherwise, proceeding to step S7; S6, adjusting the bolt preload force by the adaptive adjustment mechanism until the real-time state parameter of the bolt is less than the second preset value, the second preset value is less than or equal to the first preset value, and returning to step S3; S7. The anti-fracture device and the bolt are relatively locked by the safety locking mechanism, and an alarm is sounded.

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