Self-loosening monitoring device and method for tower crane standard knot fastener

Abstract

The invention belongs to the technical field of fastener looseness monitoring, and discloses a tower crane standard knot fastener self-looseness monitoring device and method. The tower crane standard knot fastener self-looseness monitoring device comprises a self-looseness monitoring device body, an anti-looseness fixing device and a magnetic attraction fixing device. The self-loosening monitoring device is located at the head position of a standard knot bolt and can be used for monitoring the self-loosening degree of a standard knot fastener. The anti-loosening fixing device is located at the position of the standard knot nut, further fixes the standard knot nut and can be used for improving the self-loosening resistance of the standard knot fastener. A magnetic plate is attached to the magnetic fixing device and used for fixing the device and a standard knot connecting groove and providing a connecting part of the self-loosening monitoring device and the anti-loosening fixing device. On the basis that the structural integrity of the tower crane standard knot fastener is not damaged, self-loosening real-time monitoring of the tower crane standard knot fastener is achieved, anti-loosening measures to a certain degree are provided, meanwhile, the shell further plays a good role in protecting the tower crane fastener, the service life of the tower crane standard fastener is greatly prolonged, and the safety of the tower crane standard knot fastener is improved. And the service safety of the tower crane is improved.

Description

Technical Field

[0001] This invention relates to the field of fastener loosening monitoring technology, specifically a device and method for monitoring the self-loosening of fasteners in standard sections of tower cranes, aiming to improve the structural integrity and reliability of tower crane fasteners. Background Technology

[0002] Tower cranes, as core equipment in high-rise building construction, are assembled from standard sections connected by fasteners. However, tower cranes have numerous characteristic dimensions, requiring varying numbers of standard sections. The stress state of fasteners at different locations also differs, and the key fasteners in these standard sections directly affect the structural integrity and reliability of the overall structure. Tower cranes endure alternating loads during lifting and unloading, and are also subject to vibrations under external loads such as typhoons, making them prone to gradual self-loosening. This leads to a decrease in friction at the contact surfaces of the standard sections, a reduction or even loss of pre-tightening force, ultimately resulting in fastener connection failure. In extreme cases, this can cause tower crane swaying and collapse, causing significant economic losses and casualties. However, traditional manual inspections rely on visual inspection or tapping and listening, which is not only inefficient (a complete inspection of a single crane requires 6-8 hours of downtime) but also limited by the dangers of working at heights and the experience of the inspectors, resulting in low accuracy and reliability. Fixed monitoring solutions, which involve installing sensors or cameras on the tower, can achieve continuous monitoring, but suffer from high installation costs, each camera can only monitor 3-5 bolt nodes, and cannot adapt to structural changes after the tower crane is raised. While contact-based detection methods based on vibration analysis can reflect changes in bolt preload, they are susceptible to environmental vibration interference and require sensors at every monitoring point, making them uneconomical. Although UAV monitoring technology has been applied in some fields, tower crane fastener monitoring suffers from insufficient image recognition accuracy, dynamic shooting interference, and environmental interference, making it difficult to accurately determine the loosening status of fasteners in standard tower crane sections.

[0003] In recent years, most existing fastener loosening monitoring technologies rely on monitoring the rotation angle of the fastener bolts. However, multiple factors and their combined effects can lead to significant non-rotational loosening of fasteners. For example: ① Preload loss: Fasteners generate a certain preload when tightened to ensure the tightness of the connection. However, long-term vibration gradually reduces the friction between the fastener and the connector, leading to a gradual loss of preload and ultimately causing non-rotational loosening. ② Embedding effect: Due to surface roughness or material properties, embedding may occur between the contact surfaces of the fastener and the connector. Under long-term vibration, especially in high-stress areas, this embedding effect may cause localized plastic deformation of the contact surface, leading to non-rotational loosening. ③ Material fatigue: Long-term vibration may cause material fatigue in both the fastener and the connector. This fatigue may manifest as microcracks or plastic deformation, affecting the fastening effect and causing non-rotational loosening. ④ Environmental factors: Under long-term service conditions, tower crane fasteners are subject to changes in environmental factors such as temperature and humidity. High temperatures can cause uneven thermal expansion of fastener materials, while humidity can lead to corrosion and exacerbate the non-rotational loosening of fasteners. Therefore, there is an urgent need for a tower crane critical fastener loosening detection technology and equipment with quantitative assessment capabilities and low cost, capable of identifying the degree of non-rotational loosening of fasteners, monitoring the degree of self-loosening of critical fasteners online, and preventing dangerous accidents. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a self-relaxation monitoring device and method applicable to key fasteners of standard sections of tower cranes.

[0005] The technical solution of the present invention is as follows: A self-relaxation monitoring device for critical fasteners in standard tower crane sections, comprising: Self-loosening monitoring device, anti-loosening fixing device, magnetic fixing device; The self-loosening monitoring device is located at the head of the standard section bolt and can be used to monitor the loosening degree of the standard section fasteners; The anti-loosening fixing device is located at the standard section nut position, further fixing the standard section nut, and can be used to improve the anti-loosening ability of the standard section fastener; The magnetic fixing device is equipped with a magnetic plate for fixing the device to the standard section connecting groove, and provides a connection point for the self-loosening monitoring device and the anti-loosening fixing device.

[0006] Furthermore, the self-loosening monitoring device includes a monitoring housing, a strain integrated plate, a telescopic push rod, a pressure sensor, and a top cover plate; The upper cover plate is located at the end of the monitoring housing, and a telescopic push rod is installed on the upper cover plate. The telescopic push rod is controlled by an external controller to extend and retract. The pressure sensor is located at the center of the strain integrated plate and is connected to the tail end of the telescopic push rod during detection. The strain integrated plate is equipped with multiple micro strain gauges and a signal transceiver. The micro strain gauges are installed on the bottom surface of the strain integrated plate and are in contact with the head of the standard section bolt during monitoring. The signal transceiver is located on the top surface of the strain integrated plate and is connected to the pressure sensor and each micro strain gauge. It collects and sends real-time electrical signals to the external control terminal, and simultaneously receives external control information.

[0007] Furthermore, the anti-loosening fixing device includes an anti-loosening housing, a hexagonal push block, a telescopic rod, a spring, a limiting platform, fixing screws, a lower cover plate, a limiting block, and a pull rod; Multiple springs are fixed to the lower cover plate, and each spring has a telescopic rod inside, with the other end of the telescopic rod connected to a hexagonal push block. A limiting block is located on the outer edge of the lower cover plate, and a limiting groove is provided on the anti-loosening shell. When the lower cover plate is pushed into the anti-loosening shell, the limiting block is in a retracted state. When it reaches the limiting groove, the limiting block pops out to fix the lower cover plate. The fixing screw is located on the anti-loosening shell and corresponds to the position of the hexagonal push block, used to lock the hexagonal push block. The pull rod is located on the bottom surface of the lower cover plate to facilitate the pushing of the lower cover plate. The limiting platform is fixed to the lower cover plate and leaves a gap (a certain distance) with the hexagonal push block to prevent the spring from being over-compressed when the lower cover plate is pushed in.

[0008] Furthermore, the magnetic fixing device includes a connecting housing, a magnetic plate, an elastic ring, and multiple semi-circular fixing sleeves; The connecting housing is arched and installed outside the standard section bolt connecting groove, with its shape fitting the connecting groove. The elastic ring is set at both ends of the connecting housing for sealing between the magnetic fixing device, the self-loosening monitoring device, and the anti-loosening fixing device. The magnetic plate is attached to both sides inside the connecting housing. A groove is opened in the semi-circular fixing sleeve to form a self-locking with the hemispherical ball. The buttons on the upper and lower sides of the semi-circular fixing sleeve are used to release the locking of the hemispherical ball when disassembling.

[0009] Another object of the present invention is to provide a self-relaxation monitoring method for fasteners of standard sections of tower cranes, comprising the following steps: S1. Based on the actual situation of the tower crane, a simulation analysis is established, including the inertial load, wind load and static load on the tower crane. Based on static analysis, modal analysis, harmonic response analysis and transient dynamic analysis, the preload attenuation of fasteners in various parts of the tower crane is evaluated and the thread stress is analyzed to determine the location of the key fasteners that are most prone to loosening. S2, fix the magnetic fixing device to the appropriate position of the connecting groove of the standard section of the tower crane, use the semi-circular fixing sleeve to fix the monitoring shell and the anti-loosening shell, push it into a certain position until the hemispherical ball pops out to form a self-locking; S3, push in the strain integrated plate and the upper cover plate, fix the upper cover plate, push in the hexagonal push block and the lower cover plate, rotate the pull rod to make the hexagonal groove in the hexagonal push block fit with the first nut of the standard section, push in again to make the limiting block of the lower cover plate fit with the limiting groove of the anti-loosening shell, and then tighten the fixing screw to achieve the anti-loosening of the standard section fasteners. S4, extend the telescopic push rod to make the pressure sensor value reach the preset value. At this time, the strain integrated plate is in contact with the head of the standard section bolt. The micro strain gauge will have an initial strain value. When the preload of the fastener decreases, the strain value changes differently at different positions of the bolt head. The signal is collected by the signal transceiver and transmitted to the external control terminal. The preload reduction is calculated. When the preload decreases to a certain threshold, the control terminal will issue a warning message.

[0010] Furthermore, step S4 detects the self-loosening status of the standard section fasteners based on the change in strain. The principle is that when the fastener is tightened, the bolt head undergoes uneven deformation, with the center concave and the outer ring convex and concave. When the fastener loosens and the preload decreases, the entire bolt head becomes horizontal, and the axial strain changes before and after loosening. In other words, by first testing the bolts used in the tower crane to obtain the relationship between the bolt head deformation before and after loosening and the bolt preload, micro-strain gauges can be used to monitor the bolts, analyzing the strain changes at various positions on the bolt top surface. This allows for monitoring of the fastener preload changes. A signal transceiver collects strain data and sends it to an external control terminal. When the preload falls below a certain threshold, the control terminal issues an alarm signal, thus monitoring the standard section fasteners.

[0011] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows: 1) This invention provides an integrated modification for monitoring the self-loosening of key fasteners in tower crane standard sections. It enables real-time monitoring of fastener self-loosening and provides a degree of anti-loosening measures. In use, simply fix the device at each location. Through high-precision detection using numerous micro-strain gauges, the changes in fastener preload can be quickly calculated, and the degree of self-loosening can be determined. Simultaneously, this invention does not damage the integrity of the tower crane standard section or its fasteners. On the contrary, the outer casing of the device provides excellent protection for the fasteners, effectively reducing corrosion caused by temperature and humidity during service, significantly extending the service life of the tower crane standard section's bolts. Furthermore, this invention is lightweight, simple to install, and easy for on-site personnel to carry, install, and disassemble, improving the convenience and safety of fastener self-loosening monitoring.

[0012] 2) This invention discloses a device for monitoring the self-loosening status of fasteners in standard sections of tower cranes and provides certain anti-loosening and protection capabilities. First, a simulation analysis is established to screen out some key locations that are prone to self-loosening, reducing the installation scale and cost. By monitoring the axial strain at the edge and center of the fastener bolt head, the self-loosening status can be determined before the fastener rotates and loosens, thus issuing an early warning. At the same time, by clamping and controlling the rotation of the nut, the fastener is prevented from continuing to loosen before maintenance, reducing the safety hazards of the tower crane.

[0013] 3) The expected benefits and commercial value of the technical solution after transformation are as follows: The tightness of the fasteners connecting the standard sections of the tower crane directly affects the overall structural safety. Under long-term alternating loads, wind vibration, and temperature changes, they are prone to gradual self-loosening. The friction force on the contact surface of the standard section of the tower crane may decrease or even be lost under load, and the safety hazards increase with the service time. In the construction industry, fastener self-loosening is one of the common causes of accidents, and the direct losses from a single fatal accident may reach millions of yuan. Currently, manual inspection is inefficient and limited by the dangers of high-altitude operations and the experience of inspectors. Fixed monitoring methods have problems such as high installation costs and limited coverage. Although UAV inspection technology has been applied in the field of building inspection, it still faces the challenge of detection accuracy for targets such as tower crane fasteners. The tower crane standard section fastener self-loosening monitoring device proposed in this patent integrates self-loosening monitoring and anti-loosening. It is lightweight, low-cost, has the technical potential for commercial mass production, and has a wide market demand for self-loosening monitoring equipment, thus possessing extremely high commercial value. After the technical solution of this patent is transformed, the self-loosening status of fasteners on the standard section of the tower crane can be monitored in real time. This can not only reduce tower crane overturning accidents caused by self-loosening of fasteners, avoiding casualties and property losses, but also reduce operation and maintenance costs, reduce downtime caused by safety inspections, improve the utilization rate of tower cranes, and speed up project progress.

[0014] 4) The technical solution of this invention fills a technological gap in the domestic and international industry: Common methods for checking fastener self-loosening include the traditional tapping inspection method and the ultrasonic measurement method. The tapping inspection method uses a hammer to tap the fastener. Since the sound difference between when the fastener is tightened and when it is self-loosening is large, the tightness of the bolt can be judged by the tapping sound. However, this method is highly dependent on the skill of the operator, the test results are not quantitative, and it is prone to misjudgment. The ultrasonic axial force measurement method obtains the axial force and preload of the fastener by analyzing the intensity and time delay of the echo signal generated when the ultrasonic wave passes through the fastener. However, there are many fasteners on tower cranes, which is time-consuming and the cost of ultrasonic testing instruments is high. In recent years, most of the fastener self-loosening detection technologies based on image detection determine the degree of self-loosening and whether re-tightening is needed by detecting the size of the bolt rotation angle. This method can only determine whether the fastener is self-loosening and can only detect it qualitatively, not quantitatively. Meanwhile, fasteners that have been in service for a long time usually exhibit significant non-rotational self-loosening before rotational self-loosening occurs. This is especially true for fasteners like tower cranes, which are subjected to long-term vibration. In high-stress areas of the fasteners, local plastic deformation of the contact surface may occur, leading to non-rotational self-loosening. These self-loosening conditions are difficult to detect using existing fastener self-loosening monitoring technologies, i.e., monitoring the magnitude of the bolt rotation angle.

[0015] 5) This invention is based on the principle that the head of a fastener will undergo a certain degree of uneven deformation when tightened. By detecting the axial strain value of the head at different positions when the preload decreases, the degree of fastener self-loosening can be determined by the relationship between the strain value change and the preload decrease, thus solving the problem of difficulty in monitoring the non-rotational self-loosening of fasteners in tower crane standard sections. The technical solution of this invention, through statics, modal analysis, harmonic response, and transient dynamics simulation, combined with parameters such as stress distribution, displacement field, vibration characteristics, and preload attenuation, identifies key fastener locations with stress concentration, large slippage, or severe vibration. Large-scale installation and monitoring are not required. Furthermore, in addition to achieving self-loosening monitoring and improving anti-loosening capabilities, this device can effectively protect the standard section fastener body, significantly extending its service life. This is of great significance for fastener self-loosening monitoring and tower crane safety assurance. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the device of the present invention; Figure 2 This is a cross-sectional view of the self-loosening monitoring device of the present invention; Figure 3 This is a component diagram of the magnetic attraction fixing device of the present invention; Figure 4 This is a cross-sectional view of the anti-loosening fixing device of the present invention; Figure 5 This is a cloud diagram analyzing the stress load on a standard section of a tower crane. Figure 6This is a diagram showing the force applied to the head of a fastener bolt before and after tightening. Figure 7 This is a schematic diagram of the self-loosening monitoring operation provided in this invention example; In the diagram: A. Self-loosening monitoring device; B. Magnetic fixing device; C. Anti-loosening fixing device; A1. Top cover; A2. Monitoring housing; A3. Telescopic push rod; A4. Pressure sensor; A5. Strain gauge plate; A6. Signal transceiver; A7. Standard section bolt head; A8. Standard section bolt washer; A9. Miniature strain gauge; B1, semi-circular fixing sleeve; B2, elastic ring; B3, connecting housing; B4, magnetic plate; B5, standard section bolt connection groove; B6, hemispherical ball; C1, Pull rod; C2, Lower cover plate; C3, Limiting block; C4, Limiting groove; C5, Anti-loosening shell; C6, Telescopic rod; C7, Spring; C8, Limiting platform; C9, Hexagonal push block; C10, Set screw; C11, Standard section nut. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Specific application examples of the present invention are as follows: Example 1: Key Fasteners for Standard Sections of Tower Cranes in the Construction Industry Key location identification: Establish a simulation analysis based on the actual situation of the specified tower crane equipment, conduct a risk assessment of the results, and determine the location of key fasteners.

[0019] Installation and monitoring: The installation device monitors the self-loosening of fasteners in key locations, operates the telescopic push rod to bring the pressure to the preset value, and collects strain data through the signal transceiver device and transmits it to the external control terminal.

[0020] Data analysis and maintenance decision-making: The collected data is analyzed and calculated to obtain the real-time loosening status of fasteners, and corresponding maintenance plans are formulated to ensure the stable and safe operation of the tower crane.

[0021] This invention addresses the following problems and deficiencies in the prior art, achieving significant technological advancements: Low efficiency: Traditional manual inspection methods are not only inefficient, but also require equipment to be shut down during the inspection period.

[0022] Insufficient accuracy and precision: Traditional inspections are limited by the dangers of working at heights and the experience of the inspectors, and with existing monitoring technology, it is still difficult to achieve real-time monitoring of the loosening status of fasteners.

[0023] High cost: Current fixed monitoring solutions and high-precision UAV monitoring suffer from high installation costs.

[0024] To address the problems existing in the prior art, the technical solution adopted in this invention is as follows: Continuous monitoring: This device can continuously collect data on fasteners and calculate and monitor preload without stopping the equipment or disassembling it, which greatly improves efficiency.

[0025] Precise measurement: By arranging multiple micro strain gauges and using telescopic push rods to make them fully contact the bolt head, the real-time strain value changes can be accurately measured.

[0026] Simulation positioning: By using simulation, the load conditions of each fastener are analyzed, and key locations are evaluated and determined, which greatly reduces monitoring costs.

[0027] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanation of the embodiments.

[0028] like Figure 1 As shown in the example, the present invention provides a self-loosening monitoring device for key fasteners of a tower crane standard section, comprising: a self-loosening monitoring device A for monitoring the degree of self-loosening of bolts in the standard section; a fixing device C for fixing the bolts of the standard section and improving their resistance to self-loosening; and a magnetic fixing device B with a magnetic suction plate for fixing the connection groove between the device and the standard section, and providing the connection between the self-loosening monitoring device and the anti-loosening fixing device. The position of the key fastener is determined by establishing a simulation analysis to evaluate the preload decay and the thread stress.

[0029] like Figure 2 As shown, the self-loosening monitoring device A in this embodiment of the invention includes an upper cover A1, a monitoring housing A2, a telescopic push rod A3, a pressure sensor A4, a strain gauge integrated plate A5, a signal transceiver A6, a standard section bolt head A7, a standard section bolt washer A8, and micro strain gauges A9. The strain gauge integrated plate A5 is equipped with multiple micro strain gauges A9 and a signal transceiver A6. The micro strain gauges A6 are located at the bottom of the strain gauge integrated plate and are in contact with the head of the standard section bolt to be tested. The signal transceiver and the pressure sensor A4 are located at the top of the strain gauge integrated plate. After the self-loosening monitoring device is fixed in place, the telescopic push rod A3 is extended, applying force to the pressure sensor to a preset value, causing the multiple micro strain gauges to contact the bolt head, thus initiating self-loosening monitoring. The signal transceiver collects real-time strain data and sends it to an external control terminal.

[0030] like Figure 3As shown, the magnetic fixing device B in this embodiment of the invention includes a semi-circular fixing sleeve B1, an elastic ring B2, a connecting housing B3, a magnetic plate B4, a standard section bolt connecting groove B5, and a hemispherical ball B6. The connecting housing B3 is equipped with a magnetic plate B4, and the magnetic fixing device is fixed to the standard section connecting groove B4 by the magnetic plate. Both ends are connected to the self-loosening monitoring device A and the anti-loosening fixing device C, respectively. The elastic ring B2 is used to improve the fixing ability between them, and the semi-circular fixing sleeve B1 is used for fixing. The fixing sleeve has a groove that can form a self-locking with the hemispherical ball B6. The buttons on the upper and lower sides are used to release the locking of the hemispherical ball when disassembling.

[0031] like Figure 4 As shown, the anti-loosening fixing device in this embodiment of the invention includes a pull rod C1, a lower cover plate C2, a limiting block C3, a limiting groove C4, an anti-loosening shell C5, a telescopic rod C6, a spring C7, a limiting platform C8, a hexagonal push block C9, a set screw C10, and a standard section nut C11. The size of the hexagonal push block C9 matches the nut. It is connected to the lower cover plate C2 via the telescopic rod C6 and the spring C7. During installation, the pull rod C1 is used to push the hexagonal push block into the lower cover plate. The angle is rotated to make the hexagonal push block engage with the nut. The lower cover plate has a limiting block C3 at its edge. Pushing it in again makes the limiting block lock into the limiting groove C4 in the anti-loosening shell. Finally, the set screw C10 is tightened.

[0032] This device is designed for monitoring critical fasteners on standard sections of tower cranes, aiming to improve the accuracy and safety of fastener monitoring. The following is a detailed explanation of how the device works: like Figure 5 As shown, a simulation analysis was established based on the actual situation of the tower crane, including the inertial load, wind load and static load on the tower crane. Based on static analysis, modal analysis, harmonic response analysis and transient dynamic analysis, the preload attenuation of bolts in standard sections of various parts of the tower crane was evaluated and the thread stress was analyzed to determine the key position most prone to loosening. like Figure 6 As shown, when a bolt is tightened, the bolt head undergoes uneven deformation, with the center of the bolt head concave and the outer ring convex and concave. When the bolt loosens and the preload decreases, the entire bolt head becomes horizontal. In other words, by first testing the bolts used in the tower crane to obtain the relationship between the bolt head deformation before and after loosening and the bolt preload, micro-strain gauges can be used to monitor the bolts, analyzing strain changes at various locations on the bolt's top surface. This allows for the detection of changes in bolt preload. A signal transceiver collects strain data and sends it to an external control terminal. When the preload falls below a certain threshold, the control terminal issues an alarm signal, thus monitoring the bolts in the standard section.

[0033] like Figure 7As shown in the embodiment of the present invention, the method for monitoring the self-relaxation of key fasteners in a tower crane standard section includes the following specific steps: The first step is to establish a simulation analysis based on the actual situation of the tower crane, including the inertial load, wind load and static load on the tower crane. Based on static analysis, modal analysis, harmonic response analysis and transient dynamic analysis, the preload attenuation of bolts in standard sections of the tower crane and the thread stress analysis are carried out to determine the key position most prone to loosening. The second step is to fix the magnetic fixing device at a suitable position in the connecting groove of the standard section of the tower crane, use the semi-circular fixing sleeve to fix the monitoring shell and the anti-loosening shell, and push it in to a certain position until the hemispherical ball pops out to form a self-locking mechanism. The third step is to push in the strain integrated plate and the upper cover plate, fix the upper cover plate, push in the hexagonal push block and the lower cover plate, and rotate the pull rod to make the hexagonal groove in the hexagonal push block fit with the first bolt of the standard section. Push it in again to make the limiting block of the lower cover plate fit with the limiting groove of the anti-loosening shell. At this time, tighten the fixing screw to achieve the anti-loosening of the standard section bolt. The fourth step involves extending the telescopic push rod to bring the pressure sensor reading to the preset value. At this point, the strain gauge plate is in contact with the head of the standard section bolt, and the micro strain gauge will have an initial strain value. When the bolt preload decreases, the strain value changes differently at different locations. The signal transceiver collects the data and transmits the signal to the external control terminal, and calculates the preload reduction. When the preload decreases to a certain threshold, the control terminal will issue a warning message.

[0034] This invention achieves real-time monitoring of the self-loosening of the fasteners in the standard section of the tower crane without damaging the structural integrity of the fasteners, and provides a certain degree of anti-loosening measures. At the same time, the outer shell also plays a good protective role for the fasteners, greatly improving the service life of the standard fasteners and enhancing the safety of the tower crane in operation.

[0035] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A self-loosening monitoring device for key fasteners in a tower crane standard section, characterized in that, It includes a self-loosening monitoring device, an anti-loosening fixing device, and a magnetic fixing device installed between the self-loosening monitoring device and the anti-loosening fixing device; The self-loosening monitoring device is located at the head of the standard section bolt and is used to monitor the degree of self-loosening of the standard section fasteners; The anti-loosening fixing device is located at the standard section nut position and is used to fix the standard section nut, which can be used to improve the anti-loosening ability of the standard section fastener; The magnetic fixing device is located outside the bolt connection groove of the standard section and is used to connect the self-loosening monitoring device and the anti-loosening fixing device.

2. The self-relaxation monitoring device for key fasteners of a tower crane standard section according to claim 1, characterized in that, The self-loosening monitoring device includes a monitoring shell, a strain gauge integrated plate, a telescopic push rod, a pressure sensor, and a top cover plate. The top cover plate is located at the end of the monitoring shell, and the telescopic push rod is installed on the top cover plate. The telescopic push rod is controlled by an external controller to extend and retract. The pressure sensor is located at the center of the strain gauge integrated plate and is connected to the tail end of the telescopic push rod during detection. The strain gauge integrated plate is equipped with multiple micro-strain gauges and a signal transceiver. The micro-strain gauges are installed on the bottom surface of the strain gauge integrated plate and are in contact with the head of the standard section bolt during monitoring. The signal transceiver is located on the top surface of the strain gauge integrated plate and is connected to the pressure sensor and each micro-strain gauge. It collects and sends real-time electrical signals to an external control terminal, and simultaneously receives external control information.

3. The self-relaxation monitoring device for key fasteners of a tower crane standard section according to claim 1, characterized in that, The anti-loosening fixing device includes an anti-loosening shell, a hexagonal push block, a telescopic rod, a spring, a fixing screw, a lower cover plate, a limiting block, and a pull rod. Multiple springs are fixed to the lower cover plate, and each spring contains a telescopic rod, the other end of which is connected to the hexagonal push block. The limiting block is located on the outer edge of the lower cover plate, and a limiting groove is formed on the anti-loosening shell. When the lower cover plate is pushed into the anti-loosening shell, the limiting block is in a retracted state; when it reaches the limiting groove, the limiting block pops out to fix the lower cover plate. The fixing screw is located on the anti-loosening shell and corresponds to the position of the hexagonal push block, used to lock the hexagonal push block. The pull rod is located on the bottom surface of the lower cover plate to facilitate the pushing of the lower cover plate. It also includes a limiting platform, which is fixed to the lower cover plate and has a gap with the hexagonal push block to prevent excessive compression of the springs when the lower cover plate is pushed in.

4. The self-loosening monitoring device for key fasteners of a tower crane standard section according to claim 1, characterized in that, The magnetic fixing device includes a connecting housing, a magnetic plate, an elastic ring, and a semi-circular fixing sleeve. The connecting housing is arched and installed outside the standard section bolt connection groove, with its shape fitting the connection groove. The elastic ring is located at both ends of the connecting housing and is used for sealing between the magnetic fixing device and the self-loosening monitoring device and the anti-loosening fixing device. The magnetic plate is attached to both sides inside the connecting housing. The semi-circular fixing sleeve has a groove that forms a self-locking mechanism with the hemispherical ball. Buttons on the upper and lower sides of the semi-circular fixing sleeve are used to release the hemispherical ball from locking during disassembly.

5. The self-relaxation monitoring device for key fasteners of a tower crane standard section according to claim 4, characterized in that, The magnetic fixing device, the self-loosening monitoring device, and the anti-loosening fixing device are each provided with connecting ears, and the connecting ears on the magnetic fixing device correspond to the connecting ears on the self-loosening monitoring device and the anti-loosening fixing device, and are fixedly installed by a semi-circular fixing sleeve.

6. A self-relaxation monitoring method for fasteners in standard tower crane sections, characterized in that, Includes the following steps: S1. Based on the actual situation of the tower crane, a simulation analysis is established, including the inertial load, wind load and static load on the tower crane. Based on static analysis, modal analysis, harmonic response analysis and transient dynamic analysis, the preload attenuation of fasteners in various parts of the tower crane and the thread stress analysis are carried out to determine the location of the key fasteners that are most prone to loosening. S2, fix the magnetic fixing device to the appropriate position of the connecting groove of the standard section of the tower crane, use the semi-circular fixing sleeve to fix the monitoring shell and the anti-loosening shell, push it in until the hemispherical ball pops out to form a self-locking; S3, push in the strain integrated plate and the upper cover plate, fix the upper cover plate, push in the hexagonal push block and the lower cover plate, rotate the pull rod to make the hexagonal groove in the hexagonal push block fit with the first nut of the standard section, push in again to make the limiting block of the lower cover plate fit with the limiting groove of the anti-loosening shell, and then tighten the fixing screw to achieve the anti-loosening of the standard section fasteners. S4, extend the telescopic push rod to make the pressure sensor value reach the preset value. At this time, the strain integrated plate is in contact with the head of the standard section bolt. The micro strain gauge will have an initial strain value. When the preload of the fastener decreases, the strain value changes differently at different positions of the bolt head. The signal is collected by the signal transceiver and transmitted to the external control terminal. The preload reduction is calculated. When the preload decreases to the set threshold, the control terminal will issue a warning message.

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