High-strength bolt loosening monitoring device

Abstract

The application provides a high-strength bolt loosening monitoring device, and relates to the technical field of bolt loosening monitoring devices.The device comprises a bolt, a nut, a gasket and a loosening monitoring sleeve.A sealed space for accommodating the nut is formed in the inner side of the loosening monitoring sleeve.A gas pressure sensor is further installed in the loosening monitoring sleeve on one side of the sealed space, and gas is pumped into the sealed space to generate positive gas pressure in the sealed space and the annular sealing groove.The loosening state of the bolt and the nut is determined by monitoring the pressure change in the sealed space.The application can truly reflect the pre-tightening force state of the fastening pair, and solves the problem of the failure of the existing technology in the overall axial loosening monitoring.The application also has the functions of physically isolating water vapor, salt mist and corrosive media, avoids rusting, seizure or fatigue degradation of the threaded pair due to long-term exposure, and thus realizes long-term protection of the fastening connection while monitoring, greatly improving the comprehensiveness and sensitivity of the loosening determination.

Description

Technical Field

[0001] This invention relates to the field of bolt loosening monitoring devices, specifically a high-strength bolt loosening monitoring device. Background Technology

[0002] As the core air supply and exhaust channel of underground transportation lifeline projects, the ventilation shaft of a tunnel is secured with high-strength bolts for key equipment such as fans, dampers, supports, and duct connections. The stability of these bolts directly determines the structural integrity and operational reliability of the entire ventilation system under long-term alternating wind loads, mechanical vibrations, and complex geological disturbances. Once the bolts loosen or break, it can lead to more severe consequences, such as increased equipment vibration, air leakage, and a sharp increase in energy consumption. In severe cases, it can cause catastrophic accidents such as fan falls, duct disconnection, or support collapse. This can not only paralyze the tunnel ventilation system and threaten traffic safety and human lives, but also bring incalculable economic losses and adverse social impacts. Especially in the extreme environment of high humidity, corrosive gases, drastic temperature and humidity changes, and confined space operations inside the tunnel, the preload of the bolts decays and the fatigue damage process is significantly accelerated. Therefore, continuous and reliable condition monitoring and early warning are not only key technical means to ensure the safe operation of the tunnel, but also an important cornerstone for realizing intelligent operation and maintenance of infrastructure.

[0003] To address this, the prior art discloses a bolt or nut loosening monitoring device and system, with publication number "CN112833805A". The bolt or nut is used to fasten to a base and has a non-circular head. The loosening monitoring device includes an optical fiber deformation sensor and a support device. The optical fiber deformation sensor has a deformation sensing section. The support device is located on the base and supports the optical fiber deformation sensor. The deformation sensing section of the optical fiber deformation sensor is positioned at a corresponding position on the non-circular head, so that the deformation sensing section deforms when the non-circular head rotates. This bolt or nut loosening monitoring device and system enables the monitoring of bolt or nut loosening, timely detection of loosening and breakage, and prompt repair. This improves the scientific rigor and reliability of wind turbine inspection and maintenance, and achieves automatic monitoring of bolt or nut status.

[0004] However, the aforementioned device still has significant drawbacks during use: 1. The core monitoring principle of the device relies on the relative rotation of the non-circular head of the bolt or nut. This means it can only identify angular displacement changes caused by rotational loosening, and cannot effectively address situations of overall bolt axial movement, preload reduction without significant head rotation, or "non-rotational" overall loosening caused by factors such as settlement of the connecting parts or vibration creep. Especially in complex alternating load scenarios within tunnel shafts, bolt groups often experience preload loss without significant rotation. The device has a substantial blind spot in monitoring such loosening conditions and cannot accurately reflect the true state of loosening. 1. The actual fastening safety condition; 2. The device only provides a loosening detection function and does not set any sealing or protective structure for the connection area of ​​the bolt and nut. In the actual service environment, the threaded pair is exposed to the atmosphere, water vapor, salt spray and corrosive media for a long time, which is very easy to rust, seize or thread damage. This not only accelerates the fatigue deterioration of the fastener, but also seriously affects the subsequent disassembly and maintenance, and may even cause the monitoring device itself to fail due to corrosion. Since the fiber optic sensor and support device are in an open state, they lack effective physical isolation and airtight protection, and their long-term stability and reliability are difficult to guarantee, making it difficult to meet the continuous monitoring needs under harsh working conditions such as high humidity and high corrosion. Summary of the Invention

[0005] The purpose of this invention is to provide a high-strength bolt loosening monitoring device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-strength bolt loosening monitoring device, comprising: A bolt consists of a nut and a threaded part; A nut is used to connect to the threaded part of a bolt; The washer is movably fitted onto the screw section and is used to abut against the nut. A loosening monitoring sleeve is installed on the side of the nut away from the bolt, and the inner side of the loosening monitoring sleeve has a sealed space for accommodating the nut; wherein, The gasket and nut have an annular sealing groove at one end. The annular sealing groove is connected to the sealed space through an air passage in the nut and the loosening monitoring sleeve. A pressure sensor is also installed in the loosening monitoring sleeve on one side of the sealed space. Gas is pumped into the sealed space to generate positive air pressure in the sealed space and the annular sealing groove. The loosening state of the bolt and nut is determined by monitoring the pressure change in the sealed space.

[0007] Preferably, the gasket has rubber sealing grooves on both the inner and outer sides of the annular sealing groove, and a first sealing ring is provided in the rubber sealing groove.

[0008] Preferably, the gasket has a plurality of sealing holes arranged in a ring array at the end away from the annular sealing groove. The sealing holes are connected to the annular sealing groove. A loosening detection pin is installed in the sealing hole in a lifting manner. The nut has a corresponding pin hole. The sealing state of the annular sealing groove is maintained by the abutting engagement between the loosening detection pin and the gasket. When the loosening detection pin moves, it disengages from the abutting engagement with the gasket, and the gas in the annular sealing groove leaks out through the sealing holes.

[0009] Preferably, the end of the loosening monitoring pin that is movably inserted into the pin hole is provided with an electrical contact protrusion. The electrical contact protrusion is movably engaged with the electrical contact groove provided at the upper end of the pin hole. The electrical contact groove is electrically connected to the sensing protrusion provided on the outer edge of the nut. By monitoring the communication state between the electrical contact protrusion and the electrical contact groove, the loosening state of the loosening monitoring pin can be determined.

[0010] Preferably, the bottom mating end face of the loosening monitoring sleeve is provided with an inductive ring that movably engages with the sensing protrusion, and the inductive ring is electrically connected to the control module disposed inside the loosening monitoring sleeve.

[0011] Preferably, an assembly hole is provided at the center of the loosening monitoring sleeve, and a sealing assembly bolt is movably inserted into the assembly hole. The sealing assembly bolt is threadedly engaged with the assembly threaded hole provided at the center of the screw shaft.

[0012] Preferably, the loosening monitoring sleeve is also equipped with a one-way pump valve plug, through which monitoring gas is pumped into the sealed space.

[0013] Preferably, the loosening monitoring sleeve also has several cylindrical chambers, and a pressure stabilizing piston is installed in the cylindrical chamber in a lifting manner. A pressure stabilizing spring is provided between the upper end of the pressure stabilizing piston and the loosening monitoring sleeve. The air passage opened in the loosening monitoring sleeve is connected to the sealed space through a connecting hole opened at the bottom of the cylindrical chamber.

[0014] Preferably, a second sealing rubber ring is provided on both the upper and lower sides of the air passage connection position of the nut and the loosening monitoring sleeve, and an annular rubber ring groove is provided at the corresponding position of the nut and the loosening monitoring sleeve.

[0015] Preferably, the inner side of the loosening monitoring sleeve is also provided with a ring array of positioning pins, which are movably engaged with the positioning holes opened on the nut.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention abandons the traditional discrimination method that relies on the angular displacement of non-circular heads, and instead adopts the principle of air pressure sealing monitoring. When the bolt and nut loosen in any way, the air pressure in the annular sealing groove and the sealed space will change measurably. This design is not limited by the shape of the bolt head, nor does it rely on visible angular displacement. It can truly reflect the preload state of the fastening pair, make up for the problem of failure of existing technology in monitoring overall axial loosening, and greatly improve the comprehensiveness and sensitivity of loosening judgment. In realizing the monitoring function, this invention makes full use of the enclosed space to form an airtight protective cavity isolated from the external environment. This enclosed space not only serves as a reference cavity for air pressure monitoring, but also has the function of physically isolating water vapor, salt spray and corrosive media, avoiding long-term exposure of the threaded pair to rust, seize or fatigue deterioration, thereby achieving long-term protection of the fastening connection while monitoring. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the overall structure of the present invention after disassembly. Figure 2 This is a cross-sectional schematic diagram of the loosening monitoring pin connection structure of the present invention; Figure 3 Included with instruction manual Figure 2 Enlarged schematic diagram of the structure of region A in the middle; Figure 4 This is a cross-sectional schematic diagram of the airway connection structure of the present invention; Figure 5 Included with instruction manual Figure 4 Enlarged schematic diagram of the structure of region B in the middle; Figure 6 This is a schematic diagram illustrating the loosening status of the loosening monitoring pin of the present invention; Figure 7 This is a schematic diagram showing the connection between the annular sealing groove and the air passage of the present invention.

[0018] In the diagram: 1 Bolt, 2 Nut, 3 Screw section, 4 Nut, 5 Washer, 6 Loosening monitoring sleeve, 7 Sealed space, 8 Annular sealing groove, 9 Air passage, 10 Pressure sensor, 11 Rubber sealing groove, 12 First sealing ring, 13 Sealing hole, 14 Loosening monitoring pin, 15 Pin hole, 16 Electrical contact protrusion, 17 Electrical contact groove, 18 Sensing protrusion, 19 Induction ring, 21 Assembly hole, 22 Sealing assembly bolt, 23 Assembly threaded hole, 24 One-way pump valve plug, 25 Cylindrical chamber, 26 Pressure stabilizing piston, 27 Pressure stabilizing spring, 28 Connecting hole, 29 Second sealing rubber ring, 30 Annular rubber ring groove, 31 Positioning pin, 32 Positioning hole. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figures 1 to 7 The present invention provides a technical solution: This invention provides a high-strength bolt loosening monitoring device, comprising a bolt 1, a nut 4, a washer 5, and a loosening monitoring sleeve 6.

[0021] Bolt 1 consists of nut 2 and threaded part 3. Nut 4 is threadedly connected to threaded part 3 of bolt 1. Washer 5 is movably sleeved on threaded part 3. Washer 5 is located between nut 4 and the connected part and is used to abut against nut 4. Loosening monitoring sleeve 6 is installed on the side of nut 4 away from nut 2. The inner side of loosening monitoring sleeve 6 has a sealed space 7 for accommodating nut 4. In this embodiment, bolt and nut are made of low carbon alloy steel with nominal tensile strength not less than 800MPa and yield strength not less than 640MPa. They are quenched and tempered to obtain good comprehensive mechanical properties so as to adapt to the harsh working conditions of high humidity, corrosive gas and long-term alternating load in tunnel.

[0022] An annular sealing groove 8 is provided at the end of the gasket 5 that abuts against the nut 4. The annular sealing groove 8 is connected to the sealed space 7 through an air passage 9 opened in the nut 4 and the loosening monitoring sleeve 6. Specifically, the air passage 9 includes a first section and a second section connected in sequence. The first section is opened in the nut 4, and the second section is opened in the loosening monitoring sleeve 6 and is connected to the first section. A pressure sensor 10 is also installed in the loosening monitoring sleeve 6 on one side of the sealed space 7. The pressure detection end of the pressure sensor 10 extends into the sealed space 7 and is powered by a battery installed in the loosening monitoring sleeve 6.

[0023] The loosening monitoring sleeve 6 is also equipped with a one-way pump valve 24. The one-way pump valve 24 pumps monitoring gas into the sealed space 7. The monitoring gas enters the annular sealing groove 8 through the air passage 9, thereby generating positive air pressure in the sealed space 7 and the annular sealing groove 8. The pressure sensor 10 monitors the pressure in the sealed space 7 in real time. When the bolt 1 and nut 4 become loose, the pressure between the gasket 5 and nut 4 decreases, the sealing state of the annular sealing groove 8 is destroyed, and the gas in the groove leaks outward through the loose mating surface, causing the pressure in the sealed space 7 to drop. After detecting the pressure change, the pressure sensor 10 transmits the signal to the external monitoring terminal or control module to determine the loosening state of the bolt 1 and nut 4.

[0024] To further improve the sealing reliability of the annular sealing groove 8, the gasket 5 is provided with rubber sealing grooves 11 on both the inner and outer sides of the annular sealing groove 8. A first sealing ring 12 is provided in the rubber sealing groove 11. The first sealing ring 12 is pressed when the nut 4 and the gasket 5 come into contact, forming a double sealing barrier on the inner and outer sides of the annular sealing groove 8. This effectively prevents the monitoring gas in the annular sealing groove 8 from leaking directly from the mating end face of the gasket 5 and the nut 4, ensuring that the air pressure signal only changes significantly when the bolt is actually loosened.

[0025] The gasket 5 has several sealing holes 13 arranged in a ring array at the end away from the annular sealing groove 8. The sealing holes 13 communicate with the annular sealing groove 8. A loosening detection pin 14 is installed in a lifting manner in the sealing holes 13. A corresponding pin hole 15 is provided on the nut 4. The upper end of the loosening detection pin 14 passes through the annular sealing groove 8 and enters the pin hole 15. In the normal loose bolt state, the loosening detection pin 14 protrudes from the lower end face of the gasket 5 under the action of the compression spring. When the bolt is tightened, the upper end of the loosening detection pin 14 abuts against the gasket 5, thereby maintaining the sealing state of the annular sealing groove 8. When the bolt loosens, the loosening detection pin 14 protrudes outward from the gasket 5. At this time, the sealing state at the abutment connection between the loosening detection pin 14 and the gasket 5 disappears, and the gas in the annular sealing groove 8 leaks outward through the sealing holes 13, accelerating the decrease in air pressure in the sealed space 7. The loosening detection pin 14 is designed to monitor the loosening state of bolt 1. To improve the air leakage effect, an air groove is also provided on the loosening detection pin 14. When the end face of the loosening detection pin 14 and the gasket 5 abuts together disengages, the gas leaks outward through the sealing hole 13. The loosening detection pin 14 is designed to determine the gap between the fastening bolt and the fastening workpiece. When bolt 1 and nut 4 loosen in any way, including but not limited to rotational loosening, axial movement, preload decay or non-rotational overall displacement caused by vibration creep, the tightness between nut 4 and gasket 5 will inevitably change, causing the loosening detection pin 14 to protrude outward, which in turn causes a measurable change in air pressure in the annular sealing groove 8 and the sealed space 7. This design is not limited by the shape of the bolt head and does not need to rely on visible angular displacement, and can truly reflect the preload state of the fastening pair.

[0026] The loosening detection pin 14 has an electrical contact protrusion 16 at one end of its movable insertion into the pin hole 15. The electrical contact protrusion 16 is movably engaged with the electrical contact groove 17 at the upper end of the pin hole 15. The electrical contact groove 17 is electrically connected to the sensing protrusion 18 on the outer edge of the nut 4. When the bolt is normally tightened, the loosening detection pin 14 is pushed upward, and the electrical contact protrusion 16 is inserted into the electrical contact groove 17, forming an electrical connection. When the bolt loosens, the loosening detection pin 14 slides downward, the electrical contact protrusion 16 disengages from the electrical contact groove 17, and the circuit is broken. By monitoring the connection between the electrical contact protrusion 16 and the electrical contact groove 17, the loosening state of the loosening detection pin 14 can be determined. This structure is designed to determine whether the loosening detection pin 14 has disengaged from the contact state of the washer 5, thereby assisting in the determination of the bolt's looseness and eliminating factors such as minor air leakage that affect the determination of the loosening state.

[0027] The bottom mating end face of the loosening monitoring sleeve 6 is provided with an induction ring 19 that movably engages with the sensing protrusion 18. The induction ring 19 is electrically connected to the control module installed inside the loosening monitoring sleeve 6. When the loosening monitoring sleeve 6 is correctly installed on the nut 4, the sensing protrusion 18 and the induction ring 19 make contact and conduct, thereby informing the control module that the device has been correctly installed. At the same time, the connection signal between the electrical contact protrusion 16 and the electrical contact groove 17 is transmitted to the control module in sequence through the sensing protrusion 18 and the induction ring 19, realizing the electrical transmission of the loosening signal. Meanwhile, the air pressure sensor is also electrically connected to the control module through a wire. The control module also integrates a wireless communication module, such as a Bluetooth module, Wi-Fi module, LoRa wireless communication module, ZigBee module, or NB-IoT module, which is used to wirelessly send the loosening status signal, pressure change trend, and early warning information determined by the control module to a remote monitoring terminal, such as a handheld inspection device, a field base station, or a cloud server, thereby realizing unmanned, long-distance real-time online monitoring and alarm.

[0028] A mounting hole 21 is provided at the center of the loosening monitoring sleeve 6. A sealing mounting bolt 22 is movably inserted into the mounting hole 21. The sealing mounting bolt 22 is threadedly engaged with the mounting threaded hole 23 provided at the center of the screw part 3. The sealing mounting bolt 22 is used to fix the loosening monitoring sleeve 6 to the upper end of the bolt 1. At the same time, the head of the sealing mounting bolt 22 closes the upper opening of the mounting hole 21 to ensure the airtightness of the sealed space 7. In order to improve the sealing effect, a rubber sealing ring can also be used here to improve the sealing effect.

[0029] The loosening monitoring sleeve 6 also has several cylindrical chambers 25. A pressure-stabilizing piston 26 is installed vertically within each cylindrical chamber 25. A pressure-stabilizing spring 27 is positioned between the upper end of the pressure-stabilizing piston 26 and the loosening monitoring sleeve 6. The air passage 9 of the loosening monitoring sleeve 6 connects to the sealed space 7 through a connecting hole 28 at the bottom of the cylindrical chamber 25. When the air pressure in the sealed space 7 increases, the air pressure pushes the pressure-stabilizing piston 26 upwards and compresses the pressure-stabilizing spring 27, thus stabilizing the pressure. When the air pressure decreases, the pressure-stabilizing spring 27 pushes the pressure-stabilizing piston 26 downwards to reset, maintaining a relatively stable system pressure and preventing pressure fluctuations due to temperature changes, etc. Minor pressure fluctuations not caused by loosening factors can lead to false alarms. If gas leakage continues in the sealed space 7, the pressure stabilizing spring 27 will be insufficient to stabilize the internal space. Therefore, the control module will perform real-time online monitoring and alarm. Since there may still be minor leaks after the device is installed, it is necessary to observe it promptly after the alarm. If it is only a minor leak alarm, it is necessary to continue to fill the sealed space 7 with gas to maintain pressure. If the gas leakage is too fast, it is necessary to check whether the bolt 1 is loose and whether the airtight structure of the device is installed properly.

[0030] A second sealing rubber ring 29 is provided on both the upper and lower sides of the air passage 9 connecting the nut 4 and the loosening monitoring sleeve 6. An annular rubber ring groove 30 is opened at the corresponding position of the nut 4 and the loosening monitoring sleeve 6. The second sealing rubber ring 29 is embedded in the annular rubber ring groove 30, forming a seal between the mating surfaces of the nut 4 and the loosening monitoring sleeve 6, ensuring the airtightness of the air passage 9 at each connection section, and preventing the monitoring gas from leaking during transmission.

[0031] The loosening monitoring sleeve 6 is also provided with a ring array of positioning pins 31 on its inner side. The positioning pins 31 are in active cooperation with the positioning holes 32 opened on the nut 4. The positioning pins 31 are inserted into the positioning holes 32 to ensure that the loosening monitoring sleeve 6 and the nut 4 are accurately positioned in the circumferential direction, so that the various sections of the airway 9, the sensing protrusion 18 and the induction ring 19 and other mating structures can be accurately connected.

[0032] During installation, the gasket 5 is first placed on the screw section 3, and the nut 4 is tightened so that the upper end face of the gasket 5 abuts against the nut 4. Then, the loosening monitoring sleeve 6 is placed on the outside of the nut 4, so that the positioning pin 31 is inserted into the positioning hole 32. At the same time, the sensing protrusion 18 contacts and engages with the induction ring 19. Then, the sealing assembly bolt 22 is screwed into the assembly threaded hole 23 through the assembly hole 21 to fix the loosening monitoring sleeve 6. Finally, the monitoring gas is pumped into the sealed space 7 through the one-way pump valve 24. The monitoring gas is nitrogen or argon. Using nitrogen or argon as the monitoring gas takes advantage of its stable chemical properties and its resistance to reaction with the components of the device. This ensures the stability of the gas medium during long-term monitoring and avoids the accuracy of gas pressure monitoring due to gas deterioration or reaction with metal components. At the same time, nitrogen and argon are both inert gases and will not accelerate the corrosion of bolted connection structures. They are suitable for long-term monitoring in high humidity and corrosive gas environments such as tunnel ventilation shafts.

[0033] In use, the air pressure sensor 10 continuously monitors the air pressure within the sealed space 7 and transmits the monitoring data to the control module in real time. The control module processes and analyzes the air pressure data, and when the air pressure drops beyond a preset threshold, it issues a loosening alarm signal. Simultaneously, the control module continuously monitors the connection status between the electrical contact protrusion 16 and the electrical contact groove 17, issuing an auxiliary alarm signal when the circuit is broken. The air pressure monitoring and electrical monitoring methods are independent and mutually verify each other, effectively avoiding false alarms or missed alarms that might occur with a single monitoring method, thus improving the reliability of the monitoring.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-strength bolt loosening monitoring device, characterized in that, include: A bolt consists of a nut and a threaded shank. A nut is used to connect to the threaded part of a bolt; The washer is movably fitted onto the screw section and is used to abut against the nut. A loosening monitoring sleeve is installed on the side of the nut away from the bolt, and the inner side of the loosening monitoring sleeve has a sealed space for accommodating the nut; wherein, The gasket and nut have an annular sealing groove at one end. The annular sealing groove is connected to the sealed space through an air passage in the nut and the loosening monitoring sleeve. A pressure sensor is also installed in the loosening monitoring sleeve on one side of the sealed space. Gas is pumped into the sealed space to generate positive air pressure in the sealed space and the annular sealing groove. The loosening state of the bolt and nut is determined by monitoring the pressure change in the sealed space.

2. The high-strength bolt loosening monitoring device according to claim 1, characterized in that: The gasket has rubber sealing grooves on both the inner and outer sides of the annular sealing groove, and a first sealing ring is provided in the rubber sealing groove.

3. The high-strength bolt loosening monitoring device according to claim 2, characterized in that: The gasket has several sealing holes arranged in a ring array at the end away from the annular sealing groove. The sealing holes are connected to the annular sealing groove. A loosening detection pin is installed in the sealing hole in a lifting manner. The nut has a corresponding pin hole. The loosening detection pin and the gasket are in abutting fit to maintain the sealing state of the annular sealing groove. When the loosening detection pin moves, it disengages from the abutting fit with the gasket. At this time, the gas in the annular sealing groove leaks out through the sealing hole.

4. The high-strength bolt loosening monitoring device according to claim 3, characterized in that: The loosening monitoring pin has an electrical contact protrusion at one end of the side that is inserted into the pin hole. The electrical contact protrusion is in movable engagement with the electrical contact groove at the upper end of the pin hole. The electrical contact groove is electrically connected to the sensing protrusion on the outer edge of the nut. The loosening state of the loosening monitoring pin is determined by monitoring the connection between the electrical contact protrusion and the electrical contact groove.

5. The high-strength bolt loosening monitoring device according to claim 4, characterized in that: The bottom mating end face of the loosening monitoring sleeve is provided with an inductive ring that moves in conjunction with the sensing protrusion. The inductive ring is electrically connected to the control module installed inside the loosening monitoring sleeve.

6. The high-strength bolt loosening monitoring device according to claim 5, characterized in that: An assembly hole is provided at the center of the loosening monitoring sleeve, and a sealing assembly bolt is movably inserted into the assembly hole. The sealing assembly bolt is threadedly engaged with the assembly threaded hole provided at the center of the screw shaft.

7. The high-strength bolt loosening monitoring device according to claim 6, characterized in that: The loosening monitoring sleeve is also equipped with a one-way pump valve plug, through which monitoring gas is pumped into the sealed space.

8. The high-strength bolt loosening monitoring device according to claim 7, characterized in that: The loosening monitoring sleeve also has several cylindrical chambers. A pressure stabilizing piston is installed in the cylindrical chamber in a lifting manner. A pressure stabilizing spring is provided between the upper end of the pressure stabilizing piston and the loosening monitoring sleeve. The air passage opened in the loosening monitoring sleeve is connected to the sealed space through the connecting hole opened at the bottom of the cylindrical chamber.

9. The high-strength bolt loosening monitoring device according to claim 8, characterized in that: A second sealing rubber ring is provided on both the upper and lower sides of the air passage connection position of the nut and the loosening monitoring sleeve, and an annular rubber ring groove is opened at the corresponding position of the nut and the loosening monitoring sleeve.

10. A high-strength bolt loosening monitoring device according to claim 9, characterized in that: The inner side of the loosening monitoring sleeve is also provided with a ring array of positioning pins, which are movably engaged with the positioning holes opened on the nut.

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