A screw loosening detection method and device

Abstract

The application discloses a screw loosening detection method, comprising: acquiring pressure values Fn borne by n detection positions on the abutting surface of a bolt or a nut or a gasket in contact with a fastened device; outputting an abnormal signal according to the relationship between the pressure values Fn and a preset pressure value F0; and sending the abnormal signal, the pressure values and the position data of the bolt or the nut or the gasket to a receiving end. The application also discloses a screw loosening detection device, comprising a pressure acquisition module, a control module and a communication module, wherein the pressure acquisition module is used to acquire pressure values Fn borne by n detection positions on the abutting surface of a bolt or a nut or a gasket in contact with a fastened device; the control module is used to output an abnormal signal according to the relationship between the pressure values Fn and a preset pressure value F0; and the communication module is used to send the abnormal signal, the pressure values and the position data of the bolt or the nut or the gasket to a receiving end.

Description

Technical Field

[0001] This invention relates to the field of screw abnormality detection technology, and in particular to a method and apparatus for detecting loose screws. Background Technology

[0002] Bolts and other threaded fasteners are widely used for securing various structural components. They have extensive applications in railway track fixing, bridge support, machine part connection and fixing, and product assembly. Bolts and other threaded fasteners can provide connection pressure to several adjacent components, ensuring stable connection between them.

[0003] Bolts and other threaded fasteners are prone to loosening or breakage during use. To ensure that railway tracks and mechanical structures are in a stable and normal state, workers usually need to conduct regular inspections, which is time-consuming and labor-intensive. Moreover, for some products, the bolts are located inside the product and cannot be frequently inspected manually. Furthermore, there is no intuitive numerical indicator to show whether the screws are loose, and judgment is usually based on the worker's experience, which makes standardization impossible.

[0004] To address this issue, the present invention provides a screw loosening detection method and device, which can effectively solve the above problems. It has a simple structure, can accurately determine whether screws and other threaded fasteners have become loose or other abnormal, and can promptly feed back the information, making it convenient to understand the connection status of screws and other threaded fasteners. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a screw loosening detection method and device, which has a simple structure and can accurately determine whether screws and other threaded fasteners have become loose or other abnormal, and provide timely feedback of information to facilitate understanding of the connection status of screws and other threaded fasteners.

[0006] The technical solution adopted by this invention to solve its technical problem is: This invention discloses a method for detecting loose screws, comprising: Obtain the pressure values ​​Fn at n detection positions on the contact surface between the bolt, nut, or washer and the fastened device; An abnormal signal is output based on the relationship between the pressure value Fn and the preset pressure value F0; The abnormal signal, pressure value, and position data of the bolt, nut, or gasket are sent to the receiving end.

[0007] As an improvement of the present invention, the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: calculating the difference ∆Fn between the pressure value Fn and the preset pressure value F0.

[0008] As an improvement of the present invention, the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 further includes: determining whether there is a difference ∆Fn greater than the preset difference ∆F0, and if the result is negative, calculating the pressure change rate Vfn based on the difference ∆Fn and the time corresponding to the generation of the difference ∆Fn.

[0009] As an improvement of the present invention, the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 further includes: determining whether each difference ∆Fn is greater than the preset difference ∆F0, and outputting a first abnormal signal when the result is yes.

[0010] As an improvement of the present invention, the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: determining whether each difference ∆Fn is greater than the preset difference ∆F0, and if the result is negative, determining whether the detection position corresponding to the difference ∆Fn that is greater than the preset difference ∆F0 is located on the same side of the bolt, nut or washer; if the result is positive, outputting a second abnormal signal; if the result is negative, outputting a third abnormal signal.

[0011] As an improvement of the present invention, the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: determining whether each pressure change rate Vfn is greater than the preset pressure change rate VfF0, and outputting a fourth abnormal signal when the result is yes.

[0012] As an improvement of the present invention, the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: whether each pressure change rate Vfn is greater than the preset pressure change rate VfF0, and if the result is no, determining whether the detection position corresponding to the pressure change rate Vfn greater than the preset pressure change rate VfF0 is located on the same side of the bolt, nut or washer; if the result is yes, outputting a fifth abnormal signal; if the result is no, outputting a sixth abnormal signal.

[0013] As an improvement of the present invention, before the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0, the method further includes: determining whether the pressure value Fn is less than the preset pressure value F0, and if the result is yes, then performing the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0.

[0014] The present invention also discloses a screw loosening detection device, comprising: A pressure acquisition module is used to acquire the pressure values ​​Fn at n detection positions on the contact surface between the bolt, nut, or washer and the fastened device. The control module is used to output an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0. A communication module is used to send abnormal signals, pressure values, and position data of bolts, nuts, or washers to the receiving end.

[0015] As an improvement of the present invention, the control module further includes a pressure value comparison unit, a central control unit, a difference calculation unit, a difference comparison unit, a change rate calculation unit, and a change rate comparison unit. The pressure value comparison unit is used to determine the relationship between the pressure value Fn and the preset pressure value F0. The difference calculation unit is used to calculate the difference ∆Fn between the pressure value Fn and the preset pressure value F0. The difference comparison unit is used to determine the relationship between the difference ∆Fn and the preset difference ∆F0. The change rate calculation unit is used to calculate the pressure change rate Vfn based on the difference ∆Fn and the time corresponding to the generation of the difference ∆Fn. The change rate comparison unit is used to determine the relationship between the pressure change rate Vfn and the preset pressure change rate VfF0. The central control unit is used to execute different instructions based on the calculation results of the pressure value comparison unit, the difference calculation unit, the difference comparison unit, the change rate calculation unit, and the change rate comparison unit.

[0016] As an improvement to the present invention, it also includes a vibration energy harvesting module and a power management module. The vibration energy harvesting module is used to convert the mechanical energy of the bolt, nut or washer during vibration into electrical energy, and the power management module is used to control the charging or discharging of the battery.

[0017] The beneficial effects of this invention are as follows: Through the above-described structure, the pressure acquisition module acquires pressure values ​​Fn at multiple detection locations. Then, the control module determines whether bolts and other threaded fasteners are loose or whether uneven stress or other abnormalities have occurred based on the relationship between the pressure values ​​Fn at each detection location and the preset pressure value F0. When an abnormality occurs, an abnormal signal is output. The communication module receives the abnormal signal and sends the type of abnormal signal for the bolts and other threaded fasteners, the real-time pressure value Fn, and the bolt and other threaded fastener numbers and location data to a receiving end such as a computer. The receiving end can display the above data, allowing users to intuitively understand whether any abnormalities have occurred in the threaded fasteners and ensuring the stability of the structure. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. The accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a flowchart illustrating the first embodiment of the method of the present invention; Figure 2 This is a flowchart illustrating the second embodiment of the method of the present invention; Figure 3 This is a flowchart illustrating the third embodiment of the method of the present invention; Figure 4 This is a flowchart illustrating the fourth embodiment of the method of the present invention; Figure 5 This is a schematic diagram of the modular structure of the device of the present invention; Figure 6 This is a schematic diagram of the module structure of the control module of the present invention; Figure 7 This is a schematic diagram of the application state of the device of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Screw loosening detection device; 101. Contact surface; 10. Pressure acquisition module; 20. Control module; 21. Pressure value comparison unit; 22. Central control unit; 23. Difference calculation unit; 24. Difference comparison unit; 25. Change rate calculation unit; 26. Change rate comparison unit; 30. Communication module. Detailed Implementation

[0022] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0023] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms 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 this application 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 this application.

[0024] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0026] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0028] Reference Figure 1 A method for detecting loose screws, comprising: Step S101: Obtain the pressure values ​​Fn at n detection positions on the contact surface where the bolt, nut, or washer contacts the fastened device. Specifically, the pressure acquisition module 10 can acquire the pressure values ​​Fn at n detection positions on the contact surface. The pressure acquisition module 10 is a pressure sensor made of micro-thin film or MEMS technology. It has high sensitivity and small size. It can be uniformly arranged in a ring on the contact surface to acquire the pressure values ​​Fn at each detection position. The measurement is more accurate and the collected data is more comprehensive and sufficient. Step S102: Output an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0. Specifically, the control module 20 uses the relationship between the current pressure value Fn and the preset pressure value F0 at each detection position to determine whether the bolts or other threaded fasteners are loose or whether any abnormality has occurred. For example, when the ratio of the current pressure value Fn to the preset pressure value F0 at each detection position is less than 0.7, it can be determined that the bolts or other threaded fasteners are loose. Another example is when the ratio of the current pressure value Fn to the preset pressure value F0 at 50% of the detection positions is less than 0.7, and / or the ratio of the current pressure value Fn to the preset pressure value F0 at 40% of the detection positions is less than 0.6, it can be determined that the bolts or other threaded fasteners are loose. The preset pressure value F0 is generally the initial pressure value when tightening the threaded fastener, or it can be determined comprehensively based on the type, diameter, working environment, and the device being tightened of the threaded fastener. Abnormal signals also include whether the bolts or other threaded fasteners are already loose, about to loosen, have uneven force, or are under excessive force.

[0029] Step S103: The abnormal signal, pressure value, and position data of the bolt, nut, or washer are sent to the receiving end. Specifically, a wireless communication module is used to output and transmit the abnormal signal, pressure value, and position data of the bolt, nut, or washer to a receiving end such as a computer. The receiving end can display the above data, allowing users to intuitively understand whether any threaded fasteners are abnormal and ensuring structural stability. For example, through the receiving end such as a computer, users can intuitively understand whether a certain threaded fastener has become loose, is about to become loose, or is under abnormal stress. They can also learn the fastener's number, its location on the equipment, and the real-time stress value of the current threaded fastener.

[0030] Reference Figure 2 A method for detecting loose screws, comprising: Step S201: Obtain the pressure values ​​Fn at n detection positions on the contact surface where the bolt, nut, or washer contacts the fastened device. Specifically, the pressure acquisition module 10 can acquire the pressure values ​​Fn at n detection positions on the contact surface. The pressure acquisition module 10 is a pressure sensor made of micro-thin film or MEMS technology. It has high sensitivity and small size. It can be uniformly arranged in a ring on the contact surface to acquire the pressure values ​​Fn at each detection position. The measurement is more accurate and the collected data is more comprehensive and sufficient. Step S202: Determine whether the pressure value Fn is less than the preset pressure value F0. Specifically, if the pressure value Fn is greater than the preset pressure value F0, it means that the threaded fastener is under greater force and is firmly connected to the fastened device, and the bolts and other threaded fasteners are not loose. However, when at least some of the pressure values ​​Fn are less than the preset pressure value F0, step S203 needs to be executed to further determine whether the bolts and other threaded fasteners are loose or whether there are any abnormalities based on the relationship between the pressure value Fn and the preset pressure value F0.

[0031] Step S203: Output an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0. Specifically, the control module 20 uses the relationship between the current pressure value Fn and the preset pressure value F0 at each detection position to determine whether the screw is loose or whether an abnormality has occurred. For example, if the ratio of the current pressure value Fn to the preset pressure value F0 at each detection position is less than 0.7, the screw can be determined to be loose. Another example is when the ratio of the current pressure value Fn to the preset pressure value F0 at 50% of the detection positions is less than 0.7, and / or the ratio of the current pressure value Fn to the preset pressure value F0 at 40% of the detection positions is less than 0.6, the screw is determined to be loose. The preset pressure value F0 is generally the initial pressure value when tightening the threaded fastener, or it can be determined comprehensively based on the type, diameter, working environment, and the device being tightened of the threaded fastener. Abnormal signals also include that the screw is already loose, the screw is about to loosen, the screw is under uneven force, and the screw is under excessive force.

[0032] Step S204: The abnormal signal, pressure value, and position data of the bolt, nut, or washer are sent to the receiving end. Specifically, a wireless communication module is used to output and transmit the abnormal signal, pressure value, and position data of the bolt, nut, or washer to a receiving end such as a computer. The receiving end can display the above data, allowing users to intuitively understand whether any threaded fasteners are abnormal and ensuring structural stability. For example, through the receiving end such as a computer, users can intuitively understand whether a certain threaded fastener has become loose, is about to become loose, or is under abnormal stress. They can also learn the fastener's number, its location on the equipment, and the real-time stress value of the current threaded fastener.

[0033] Reference Figure 3 A method for detecting loose screws, comprising: Step S301: Obtain the pressure values ​​Fn at n detection positions on the contact surface where the bolt, nut, or washer contacts the fastened device. Specifically, the pressure acquisition module 10 can acquire the pressure values ​​Fn at n detection positions on the contact surface. The pressure acquisition module 10 is a pressure sensor made of micro-thin film or MEMS technology. It has high sensitivity and small size. It can be uniformly arranged in a ring on the contact surface to acquire the pressure values ​​Fn at each detection position. The measurement is more accurate and the collected data is more comprehensive and sufficient. Step S302: Determine whether the pressure value Fn is less than the preset pressure value F0, and execute step S303 if the result is yes; specifically, if the pressure value Fn is greater than the preset pressure value F0, it means that the threaded fastener is under greater force and is firmly connected to the fastened device, and the bolts and other threaded fasteners are not loose; when at least some of the pressure values ​​Fn are less than the preset pressure value F0, step S303 needs to be executed to further calculate the difference ∆Fn between the pressure value Fn and the preset pressure value F0, and determine whether the bolts and other threaded fasteners are loose or whether there is any abnormality based on the difference value.

[0034] Step S303: Calculate the difference ∆Fn between the pressure value Fn and the preset pressure value F0. Specifically, the difference calculation unit 23 on the control module 20 can calculate the difference ∆Fn between each pressure value Fn and the preset pressure value F0, which is convenient for subsequent judgment of the force at each detection position and analysis of whether bolts and other threaded fasteners are loose or abnormal. Step S304: Determine whether each difference ∆Fn is greater than the preset difference ∆F0. If the result is yes, proceed to step S306; otherwise, proceed to step S305. Specifically, when each difference ∆Fn is greater than the preset difference ∆F0, it indicates that the bolts and other threaded fasteners are subjected to relatively small forces at each detection location, and the force variation is large. At this time, the bolts and other threaded fasteners have loosened. Proceed to step S306 and output the first abnormal signal. When each difference ∆Fn is not greater than the preset difference ∆F0, only some differences ∆Fn are greater than the preset difference ∆F0. At this time, the bolts and other threaded fasteners are not completely loose. Further determination is needed to determine whether there are other abnormalities. Proceed to step S305.

[0035] Step S305: Determine whether the detection position corresponding to the difference ∆Fn greater than the preset difference ∆F0 is located on the same side of the bolt, nut, or washer. If the result is yes, proceed to step S307; if the result is no, proceed to step S308. Specifically, when the difference ∆Fn at some detection positions is greater than the preset difference ∆F0, analyze whether the detection position corresponding to this difference ∆Fn is located on the same side of the bolt or other threaded fastener. If the result is yes, it means that the bolt or other threaded fastener is subjected to excessive force on one side, and the bolt or other threaded fastener is subjected to uneven force. Proceed to step S307 and output the second abnormal signal. If the result is no, it means that only some detection positions are subjected to insufficient force, and the above positions are relatively evenly distributed. The bolt or other threaded fastener is generally in normal working condition, but because some points are subjected to insufficient force, there is a greater risk of loosening. Proceed to step S308 and output the third abnormal signal.

[0036] Step S306: Output the first abnormal signal and proceed to step S309; Step S307: Output the second abnormal signal and execute step S309; Step S308: Output the third abnormal signal and execute step S309; Step S309: The abnormal signal, pressure value, and position data of the bolt, nut, or washer are sent to the receiving end. Specifically, a wireless communication module is used to output and transmit the abnormal signal, pressure value, and position data of the bolt, nut, or washer to a receiving end such as a computer. The receiving end can display the above data, allowing users to intuitively understand whether any threaded fasteners are abnormal and ensuring structural stability. For example, through the receiving end such as a computer, users can intuitively understand whether a certain threaded fastener has become loose, is about to become loose, or is under abnormal stress. They can also learn the fastener's number, its location on the equipment, and the real-time stress value of the current threaded fastener.

[0037] Reference Figure 4 A method for detecting loose screws, comprising: Step S401: Obtain the pressure values ​​Fn at n detection positions on the contact surface where the bolt, nut, or washer contacts the fastened device. Specifically, the pressure acquisition module 10 can acquire the pressure values ​​Fn at n detection positions on the contact surface. The pressure acquisition module 10 is a pressure sensor made of micro-thin film or MEMS technology. It has high sensitivity and small size. It can be uniformly arranged in a ring on the contact surface to acquire the pressure values ​​Fn at each detection position. The measurement is more accurate and the collected data is more comprehensive and sufficient. Step S402: Determine whether the pressure value Fn is less than the preset pressure value F0, and execute step S403 if the result is yes; specifically, if the pressure value Fn is greater than the preset pressure value F0, it means that the threaded fastener is under greater force and is firmly connected to the fastened device, and the bolts and other threaded fasteners are not loose; when at least some of the pressure values ​​Fn are less than the preset pressure value F0, step S403 needs to be executed to further determine whether the bolts and other threaded fasteners are loose or whether there is any abnormality based on the relationship between the pressure value Fn and the preset pressure value F0.

[0038] Step S403: Calculate the difference ∆Fn between the pressure value Fn and the preset pressure value F0. Specifically, the difference calculation unit 23 on the control module 20 can calculate the difference ∆Fn between each pressure value Fn and the preset pressure value F0, which is convenient for subsequent judgment of the force at each detection position and analysis of whether bolts and other threaded fasteners are loose or abnormal. Step S404: Determine if there is a difference ∆Fn greater than a preset difference ∆F0. If the result is yes, proceed to step S405; if the result is no, proceed to step S406. Specifically, if there is no difference ∆Fn greater than the preset difference ∆F0, it indicates that the bolts and other threaded fasteners are under significant force and can still firmly fix the fastened device. In this case, proceed to step S406 to determine the pressure change rate to further detect whether there are other abnormalities in the bolts and other threaded fasteners. However, if there is a difference ∆Fn greater than the preset difference ∆F0, it indicates that the bolts and other threaded fasteners have loosened or are at risk of loosening. Proceed to step S405 to further determine the working status of the bolts and other threaded fasteners.

[0039] Step S405: Determine whether each difference ∆Fn is greater than the preset difference ∆F0. If the result is yes, proceed to step S410; if the result is no, proceed to step S407. Specifically, when each difference ∆Fn is greater than the preset difference ∆F0, it means that the bolts and other threaded fasteners are subjected to relatively small forces at each detection position, and the force variation value is relatively large. At this time, the bolts and other threaded fasteners have loosened. Proceed to step S410 and output the first abnormal signal. When each difference ∆Fn is not greater than the preset difference ∆F0, only some differences ∆Fn are greater than the preset difference ∆F0. At this time, the bolts and other threaded fasteners are not completely loose. Further determination is needed to determine whether there are other abnormal situations. Proceed to step S407.

[0040] Step S406: Calculate the pressure change rate Vfn based on the difference ∆Fn and the time corresponding to the generation of the difference ∆Fn, and then proceed to step S408. If no difference ∆Fn is greater than the preset difference ∆F0, it indicates that the bolts and other threaded fasteners are under greater force and can still firmly fix the fastened device. At this time, calculate the pressure change rate Vfn based on the generated difference ∆Fn and the time corresponding to the generation of the difference ∆Fn, and then proceed to step S408 to further detect whether there are other abnormalities in the bolts and other threaded fasteners based on the pressure change rate.

[0041] Step S407: Determine whether the detection position corresponding to the difference ∆Fn greater than the preset difference ∆F0 is located on the same side of the bolt, nut, or washer. If the result is yes, execute step S411; if the result is no, execute step S412. Specifically, when the difference ∆Fn at some detection positions is greater than the preset difference ∆F0, analyze whether the detection position corresponding to this difference ∆Fn is located on the same side of the bolt or other threaded fastener. If the result is yes, it means that the bolt or other threaded fastener is subjected to excessive force on one side, and the bolt or other threaded fastener is subjected to uneven force. Execute step S411 and output the second abnormal signal. If the result is no, it means that only some detection positions are subjected to insufficient force, and the above positions are relatively evenly distributed. The bolt or other threaded fastener is generally in normal working condition, but because some points are subjected to insufficient force, there is a greater risk of loosening. Execute step S412 and output the third abnormal signal.

[0042] Step S408: Determine whether the pressure change rate Vfn of each detection position is greater than the preset pressure change rate VfF0. If the result is yes, proceed to step S413; if the result is no, proceed to step S409. Specifically, when the pressure change rate Vfn of each detection position is greater than the preset pressure change rate VfF0, it means that the pressure at each detection position on the entire bolt or other threaded fastener is rapidly decreasing, and the bolt or other threaded fastener may loosen quickly. Proceed to step S413 and output the fourth abnormal signal. When only the pressure change rate Vfn of some detection positions is greater than the preset pressure change rate VfF0, it is necessary to further determine whether there are other abnormalities. Proceed to step S409.

[0043] Step S409: Determine whether the detection position corresponding to the pressure change rate Vfn greater than the preset pressure change rate VfF0 is located on the same side of the bolt, nut, or washer. If the result is yes, proceed to step S414; if the result is no, proceed to step S415. Specifically, when the pressure change rate Vfn of some detection positions is greater than the preset pressure change rate VfF0, and these detection positions are located on the same side of the bolt, nut, or washer, it indicates that the pressure on one side of the bolt or other threaded fastener is rapidly decreasing, and uneven stress may occur subsequently, which may easily lead to abnormalities in the bolt or other threaded fastener. Therefore, the fifth abnormal signal is output, and step S414 is executed. When the pressure change rate Vfn of some detection positions is greater than the preset pressure change rate VfF0, and these detection positions are evenly distributed on the bolt, nut, or washer, the bolt or other threaded fastener is generally in normal working condition. However, because the pressure change rate Vfn of some detection positions is too large, there may be a certain risk of loosening in the future. Therefore, step S415 is executed, and the sixth abnormal signal is output.

[0044] Step S410: Output the first abnormal signal and execute step S416; Step S411: Output the second abnormal signal and execute step S416; Step S412: Output the third abnormal signal and execute step S416; Step S413: Output the fourth abnormal signal and execute step S416; Step S414: Output the fifth abnormal signal and execute step S416; Step S415: Output the sixth abnormal signal and execute step S416; Step S416: The abnormal signal, pressure value, and position data of the bolt, nut, or washer are sent to the receiving end. Specifically, a wireless communication module is used to output and transmit the abnormal signal, pressure value, and position data of the bolt, nut, or washer to a receiving end such as a computer. The receiving end can display the above data, allowing users to intuitively understand whether any threaded fasteners are abnormal and ensuring structural stability. For example, through the receiving end such as a computer, users can intuitively understand whether a certain threaded fastener has become loose, is about to become loose, or is under abnormal stress. They can also learn the fastener's number, its location on the equipment, and the real-time stress value of the current threaded fastener.

[0045] Reference Figures 5 to 7 A screw loosening detection device 1, comprising: Pressure acquisition module 10, the pressure acquisition module 10 is used to acquire the pressure values ​​Fn at n detection positions on the contact surface 101 of the bolt or nut or washer in contact with the fastened device; Control module 20, the control module 20 is used to output an abnormal signal according to the relationship between the pressure value Fn and the preset pressure value F0; The communication module 30 is used to send abnormal signals, pressure values, and position data of bolts, nuts, or washers to the receiving end.

[0046] With the above-described structure, the pressure acquisition module 10 acquires pressure values ​​Fn at multiple detection locations. Then, the control module 20, based on the relationship between the pressure values ​​Fn at each detection location and the preset pressure value F0, determines whether bolts or other threaded fasteners are loose or experiencing uneven stress. When an abnormality occurs, it outputs an abnormal signal. The communication module 30 receives the abnormal signal and sends the type of abnormal signal, the real-time pressure value Fn, and the bolt's or other threaded fastener's number and location data to a receiving end such as a computer. The receiving end can display this data, allowing users to intuitively understand whether any threaded fasteners are experiencing abnormalities, ensuring structural stability. For example, a computer or other receiving end can intuitively show whether a particular threaded fastener is loose, about to loosen, or experiencing abnormal stress, and can also display the fastener's number, its location on the device, and the current real-time stress value. Preferably, the communication module 30 is a Bluetooth Low Energy (BLE) module, which is small in size, has low power consumption, and provides stable data transmission.

[0047] In this embodiment, the control module 20 further includes a pressure value comparison unit 21, a central control unit 22, a difference calculation unit 23, a difference comparison unit 24, a change rate calculation unit 25, and a change rate comparison unit 26. The pressure value comparison unit 21 is used to determine the relationship between the pressure value Fn and the preset pressure value F0. The difference calculation unit 23 is used to calculate the difference ∆Fn between the pressure value Fn and the preset pressure value F0. The difference comparison unit 24 is used to determine the relationship between the difference ∆Fn and the preset difference ∆F0. The change rate calculation unit 25 is used to calculate the pressure change rate Vfn based on the difference ∆Fn and the time corresponding to the generation of the difference ∆Fn. The change rate comparison unit 26 is used to determine the relationship between the pressure change rate Vfn and the preset pressure change rate VfF0. The central control unit 22 is used to execute different instructions based on the calculation results of the pressure value comparison unit 21, the difference calculation unit 23, the difference comparison unit 24, the change rate calculation unit 25, and the change rate comparison unit 26.

[0048] This embodiment also includes a vibration energy harvesting module 40 and a power management module 50. The vibration energy harvesting module 40 converts the mechanical energy of a bolt, nut, or washer vibrating into electrical energy, and the power management module 50 controls the charging or discharging of the battery. Through this structure, the vibration energy harvesting module 40 can convert the mechanical energy of threaded fasteners such as bolts vibrating into electrical energy, and the power management module 50 stores this electrical energy in an energy storage device such as a battery. When the pressure acquisition module 10, control module 20, and communication module 30 are working, the power management module 50 controls the battery to discharge, providing power to them. Using the vibration energy harvesting module 40 and the power management module 50 can improve the product's battery life and make efficient use of energy.

Claims

1. A method for detecting loose screws, characterized in that, include: Obtain the pressure values ​​Fn at n detection positions on the contact surface between the bolt, nut, or washer and the fastened device; An abnormal signal is output based on the relationship between the pressure value Fn and the preset pressure value F0; The abnormal signal, pressure value, and position data of the bolt, nut, or gasket are sent to the receiving end.

2. The screw loosening detection method according to claim 1, characterized in that, The step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: calculating the difference ∆Fn between the pressure value Fn and the preset pressure value F0.

3. The screw loosening detection method according to claim 2, characterized in that, The step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 further includes: determining whether there is a difference ∆Fn greater than the preset difference ∆F0, and if the result is negative, calculating the pressure change rate Vfn based on the difference ∆Fn and the time corresponding to the generation of the difference ∆Fn.

4. The screw loosening detection method according to claim 3, characterized in that, The step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 further includes: determining whether each difference ∆Fn is greater than the preset difference ∆F0, and outputting a first abnormal signal when the result is yes.

5. The screw loosening detection method according to claim 4, characterized in that, The step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: determining whether each difference ∆Fn is greater than the preset difference ∆F0, and if the result is negative, determining whether the detection position corresponding to the difference ∆Fn that is greater than the preset difference ∆F0 is located on the same side of the bolt, nut or washer. If the result is positive, a second abnormal signal is output; if the result is negative, a third abnormal signal is output.

6. The screw loosening detection method according to claim 3, characterized in that, The step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: determining whether each pressure change rate Vfn is greater than the preset pressure change rate VfF0, and outputting a fourth abnormal signal when the result is yes.

7. The screw loosening detection method according to claim 6, characterized in that, The step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 includes: whether each pressure change rate Vfn is greater than the preset pressure change rate VfF0, and if the result is no, determining whether the detection position corresponding to the pressure change rate Vfn greater than the preset pressure change rate VfF0 is located on the same side of the bolt, nut or washer. If the result is yes, output the fifth abnormal signal; if the result is no, output the sixth abnormal signal.

8. The screw loosening detection method according to claim 1, characterized in that, Before the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0, the method further includes: determining whether the pressure value Fn is less than the preset pressure value F0; if the result is yes, then the step of outputting an abnormal signal based on the relationship between the pressure value Fn and the preset pressure value F0 is executed.

9. A screw loosening detection device, characterized in that, include: Pressure acquisition module (10), the pressure acquisition module (10) is used to acquire the pressure values ​​Fn at n detection positions on the contact surface of the bolt or nut or washer in contact with the fastened device; Control module (20), the control module (20) is used to output an abnormal signal according to the relationship between the pressure value Fn and the preset pressure value F0; The communication module (30) is used to send abnormal signals, pressure values ​​and position data of bolts, nuts or washers to the receiving end.

10. The screw loosening detection device according to claim 9, characterized in that, It also includes a vibration energy harvesting module (40) and a power management module (50). The vibration energy harvesting module (40) is used to convert the mechanical energy of the bolt, nut or washer when it vibrates into electrical energy, and the power management module (50) is used to control the charging or discharging of the battery.

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