Bolt, and system and method for real-time monitoring of loosening angle of bolt

Abstract

Embodiments of the present application provide a bolt, and a system and method for real-time monitoring of a loosening angle of the bolt. The bolt comprises a bolt main body, a resistance wire, and a contact assembly. The resistance wire is annularly sleeved on the bolt main body. The bolt main body is rotatable relative to the resistance wire. The contact assembly is arranged on the bolt main body and is electrically connected to an external circuit. The contact assembly is slidably connected to the resistance wire, so as to change the resistance value of the resistance wire connected to the external circuit. The method for monitoring of a loosening angle of the bolt comprises: fastening the bolt main body to connect the contact assembly to a measurement circuit; a data acquisition system acquiring the resistance value of the resistance wire connected to the measurement circuit; a data processing apparatus processing the resistance value of the measurement circuit; and the data processing apparatus outputting a resistance change value of the measurement circuit and, according to a preset formula, outputting the loosening angle of the bolt main body. The bolt has a simple structure and is convenient to use. The loosening condition of the bolt can be monitored in real time or regularly, and the rotation angle of a loose bolt can be obtained by means of analyzing the change in the resistance value.

Description

Real-time monitoring system and method for bolts and bolt loosening angles Technical Field

[0001] The present application relates to the technical field of bolt loosening angle monitoring, and in particular, to a bolt and a system and method for real-time monitoring of bolt loosening angles. Background Art

[0002] Threaded connections are a primary method of mechanical assembly. The appropriateness of installation methods and processes significantly impacts the reliability of mechanical operation. If bolts loosen during mechanical operation, fatal failures can occur. For example, numerous failures and accidents are caused by threaded connection failures. Therefore, monitoring and managing threaded connection status is a crucial task in addressing threaded connection installation methods and processes.

[0003] Commonly used methods for monitoring the tightening status of bolts include strain gauge method and manual visual inspection method.

[0004] The strain gauge method uses a force-measuring bolt to measure the axial force, thereby monitoring the tightening status of the bolt. The strain gauge method includes two methods.

[0005] One is the conventional strain gauge method. The conventional strain gauge method is to directly stick a resistance strain gauge on the polished rod part of the bolt to be tested. The axial force of the bolt is calculated based on the strain test results and the cross-sectional area of ​​the bolt. It is widely used in laboratory tests and actual measurements on production sites.

[0006] The second method is the special bolt strain gauge method. The special bolt strain gauge method is to drill a blind hole in the center of the head of the bolt to be tested, install an embedded special bolt strain gauge in the hole, and after the sealing and curing process, calibrate it on a tensile testing machine. The relationship between the axial force and strain on the bolt is given. The bolt equipped with the strain gauge is installed on the part, and after the load is applied, the strain data of the bolt is collected through the strain gauge. The strain is converted into the axial force of the bolt according to the calibration file.

[0007] However, the conventional strain gauge method and the special bolt strain gauge method often have the following disadvantages:

[0008] (1) The bolt surface patch needs to lead out the wires, which will be difficult for many structures. It is necessary to groove or punch holes in the local structure, which will reduce the structural stiffness and affect the test results.

[0009] (2) Bolts are prone to bending during installation, which has a significant impact on the axial force test results. To eliminate the impact of bending, strain gauges need to be arranged symmetrically on the bolt shank. However, space and lead issues in some structures limit the number of gauges.

[0010] (3) The bolt axial force test has high accuracy, but the preparation process is complicated and the cost is high.

[0011] (4) Considering the influence of the center hole of the bolt, it is not suitable to test the bolts that are too small.

[0012] (5) Due to limited space, in some cases the strain gauge cannot be protected and is easily damaged during installation. In addition, the strain gauge is relatively fragile and easily affected by the harsh conditions in the test environment and is prone to damage.

[0013] In engineering practice, the current troubleshooting method for bolts is mainly visual inspection by inspectors. The main implementation method is: after the bolts are assembled, anti-loosening marks are marked. If the bolts become loose, the marks will be damaged or misplaced.

[0014] However, manual visual inspection methods often have the following disadvantages:

[0015] (1) It relies on manual inspection. The technical level, proficiency and inspection status of experts are key factors affecting its reliability. Manual inspection involves human factors, which can easily lead to human errors such as missed inspections. The operating environment is harsh, and there is a lot of dust at the anti-loosening mark, which is difficult to observe and affects the inspection quality.

[0016] (2) The parts structure is very complex and the background is messy, which increases the difficulty of detecting loose bolts in practice; the commonly used engineering practice inspection method requires inspectors to spend a lot of time and effort.

[0017] (3) Bolt nodes in areas that are difficult for personnel to reach increase the difficulty and danger of manual inspection, posing safety hazards.

[0018] (5) The anti-loosening marking method cannot achieve real-time monitoring.

[0019] Summary of the Invention

[0020] In order to solve one of the above technical defects, an embodiment of the present application provides a real-time monitoring system and method for bolts and bolt loosening angles.

[0021] A first aspect of an embodiment of the present application provides a bolt, comprising:

[0022] A resistance wire is annularly sleeved on the bolt body; the bolt body is rotatable relative to the resistance wire;

[0023] The contact assembly is arranged on the bolt body and is electrically connected to the external circuit. The contact assembly is slidably connected to the resistance wire to change the resistance value of the resistance wire connected to the external circuit.

[0024] A second aspect of an embodiment of the present application provides a system for real-time monitoring of bolt loosening angles, comprising:

[0025] The above bolts;

[0026] A data acquisition device, electrically connected to the contact assembly, for acquiring changes in the resistance value of the resistance wire connected to the measurement circuit;

[0027] The data processing device is connected to the data acquisition device and is used to process the change of the resistance value connected to the measurement circuit and output the corresponding rotation angle of the bolt body.

[0028] A third aspect of the embodiments of the present application provides a method for real-time monitoring of bolt loosening angles, using a system for real-time monitoring of bolt loosening angles, comprising the following steps:

[0029] tightening the bolt body to connect the contact assembly to the measurement circuit;

[0030] The data acquisition system collects the resistance value of the resistance wire connected to the measurement circuit;

[0031] The data processing device processes the resistance value of the measuring circuit;

[0032] The data processing device outputs the resistance change value of the measuring circuit and outputs the loosening angle of the bolt body according to a preset formula.

[0033] The bolt loosening angle monitoring device, real-time monitoring system, and method provided in the embodiments of the present application have the following technical effects compared to the prior art:

[0034] The present application provides a bolt loosening angle monitoring device, real-time monitoring system, and method, wherein the bolt loosening angle monitoring device includes a resistance wire and a contact assembly; the resistance wire is annularly sleeved on the bolt body; the bolt body can rotate relative to the resistance wire; the contact assembly is disposed on the bolt body and electrically connected to an external circuit; the contact assembly is slidably connected to the resistance wire to change the resistance value of the resistance wire connected to the external circuit; wherein the bolt loosening angle monitoring method includes tightening the bolt body to connect the contact assembly to the measurement circuit; a data acquisition system acquires the resistance value of the resistance wire connected to the measurement circuit; a data processing device processes the resistance value of the measurement circuit; the data processing device outputs the resistance change value of the measurement circuit and outputs the loosening angle of the bolt body according to a preset formula. The device has a simple structure and is easy to use; it can monitor the loosening of the bolt in real time or periodically, and obtain the rotation angle of the loosened bolt by analyzing the change in resistance value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0036] FIG1 is a schematic diagram of the use of a bolt provided in an embodiment of the present application;

[0037] FIG2 is a schematic diagram of the explosion structure of FIG1 ;

[0038] FIG3 is a schematic diagram of the resistance wire structure provided in an embodiment of the present application;

[0039] FIG4 is an enlarged structural diagram of A in FIG3 ;

[0040] FIG5 is a schematic diagram of the structure of a contact assembly provided in an embodiment of the present application;

[0041] FIG6 is a cross-sectional view of a local structure in the figure;

[0042] FIG7 is a schematic diagram of the bottom surface of an insulating gasket provided in an embodiment of the present application;

[0043] FIG8 is a schematic diagram of the three-dimensional structure of an insulating gasket provided in an embodiment of the present application;

[0044] Figure 9 is a schematic diagram of the length of the resistance wire connected to the measurement circuit in a bolt-tightened state;

[0045] Figure 10 is a schematic diagram of the resistance wire length connected to the measurement circuit after the bolt is loosened;

[0046] FIG11 is a schematic diagram of a fitting resistance-angle curve;

[0047] FIG12 is a schematic diagram showing the connection between the contact assembly and the resistance wire at different positions when the bolts are tightened;

[0048] FIG13 is a schematic diagram showing the connection between the contact assembly and the resistance wire at different positions after the bolts are loosened;

[0049] FIG14 is a schematic diagram of a real-time monitoring system for bolt loosening angle provided in an embodiment of the present application.

[0050] The markings in the accompanying drawings are as follows: 1. Resistance wire; 101. Slide groove; 102. First resistance wire; 103. Second resistance wire; 2. Contact assembly; 201. Mounting pad; 202. Terminal; 203. Metal ball contact; 3. Bolt body; 301. Bolt head; 302. Screw; 4. Insulating washer; 401. Mounting groove; 402. Anti-slip pattern; 5. Data acquisition device; 6. Data processing device. DETAILED DESCRIPTION

[0051] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless they conflict.

[0052] Figure 1 is a schematic diagram of the use of the bolt provided in an embodiment of the present application; Figure 2 is a schematic diagram of the exploded structure of Figure 1; Figure 3 is a schematic diagram of the resistance wire structure provided in an embodiment of the present application; Figure 4 is an enlarged structural schematic diagram of A in Figure 3; Figure 5 is a schematic diagram of the contact assembly structure provided in an embodiment of the present application; Figure 6 is a cross-sectional view of the local structure in the figure; Figure 7 is a schematic diagram of the bottom surface of the insulating gasket provided in an embodiment of the present application; Figure 8 is a schematic diagram of the three-dimensional structure of the insulating gasket provided in an embodiment of the present application; Figure 9 is a schematic diagram of the length of the resistance wire connected to the measurement circuit when the bolt is tightened; Figure 10 is a schematic diagram of the length of the resistance wire connected to the measurement circuit after the bolt is loosened; Figure 11 is a schematic diagram of the fitted resistance-angle curve; Figure 12 is a schematic diagram of the connection between the contact assembly and the resistance wire at different positions when the bolt is tightened; Figure 13 is a schematic diagram of the connection between the contact assembly and the resistance wire at different positions after the bolt is loosened; Figure 14 is a schematic diagram of the real-time monitoring system for bolt loosening angle provided in an embodiment of the present application.

[0053] The bolt loosening angle real-time monitoring system provided in this embodiment is based on an electrical measurement method and uses a sliding resistor to measure bolt loosening and loosening angle. It is suitable for both remote and local measurements.

[0054] As shown in Figures 1 and 2, the bolt provided in the embodiment of the present application includes a bolt body, a resistance wire 1 and a contact assembly 2.

[0055] Among them, the resistance wire 1 is annularly sleeved on the bolt body 3; the bolt body 3 can rotate relative to the resistance wire 1; the contact assembly 2 is set on the bolt body 3; it is electrically connected to the external circuit; the contact assembly 2 is slidably connected to the resistance wire 1 to change the resistance value of the resistance wire 1 connected to the external circuit.

[0056] That is to say, the contact assembly 2 is arranged on the bolt body 3; when the bolt body 3 is loose, the contact assembly 2 can rotate relative to the resistance wire 1 along with the bolt body 3, and the contact assembly 2 is slidably connected to the resistance wire 1 to form a structure similar to a sliding rheostat to change the resistance value of the resistance wire 1 connected to the external circuit; by monitoring the change in the resistance value of the resistance wire 1 connected to the external circuit, the loosening of the bolt is monitored; after converting the change in the resistance value of the resistance wire 1 connected to the external circuit, the angle of the bolt loosening can be obtained.

[0057] As shown in Figures 1 and 2 , the bolt provided in the embodiments of the present application has a bolt body 3 comprising a bolt head 301 and a screw 302. The bolt head 301 is provided with a mounting space for accommodating the contact assembly 2; the screw 302 is disposed on the bolt head 301; and the resistance wire 1 is wound around the screw 302. It is worth noting that the contact post 202 is provided with an insulating coating at the point where it contacts the contact assembly mounting space of the bolt body 3.

[0058] In practice, the bolt provided in the embodiments of the present application includes a resistance wire and a contact assembly; the resistance wire is annularly sleeved around the bolt body; the bolt body is rotatable relative to the resistance wire; the contact assembly is disposed within the bolt body and electrically connected to an external circuit; the contact assembly slidably connects to the resistance wire to change the resistance value of the resistance wire connected to the external circuit. The bolt has a simple structure and is easy to use. The bolt loosening can be monitored in real time or periodically, and the rotation angle of the loosened bolt can be determined by analyzing the change in resistance value.

[0059] As shown in FIG1 , FIG2 , FIG5 and FIG6 , based on the above solution, the embodiment of the present application provides a specific implementation of the contact assembly 2 , which includes a mounting pad 201 and two terminals 202 arranged in parallel.

[0060] Among them, the mounting pad 201 is arranged on the bolt body 3; two parallel terminal blocks 202 are arranged on the mounting pad 201; extending along the length direction of the bolt body 3; one end of one of the terminal blocks 202 is connected to the input end of the external circuit, and the other end is slidably connected to the resistance wire 1; one end of one of the terminal blocks 202 is connected to the output end of the external circuit, and the other end is slidably connected to the resistance wire 1.

[0061] Specifically, there are two binding posts 202 , the top of one binding post 202 is connected to the input end of the external circuit, and the bottom is connected to the resistance wire 1 ; the top of the other binding post 202 is connected to the output end of the external circuit, and the bottom is connected to the resistance wire 1 .

[0062] It is worth noting that the terminal 202 is made of a conductive material, such as copper, aluminum, or other metal materials, alloys, or composite metals.

[0063] It is worth noting that the mounting pad 201 is insulated from the bolt body 3 .

[0064] Based on the above scheme, the embodiment of the present application provides a specific implementation of the contact assembly 2, which also includes a metal ball contact 203; the metal ball contact 203 is arranged at one end of the terminal 202 facing the resistance wire 1; the terminal 202 is connected to the resistance wire 1 through the metal ball contact 203.

[0065] Specifically, a metal ball contact 203 is provided to be slidably connected to the resistance wire 1 ; during the sliding process, smooth movement relative to the resistance wire 1 can be ensured.

[0066] As shown in Figures 1, 2, 3, 4 and 6, based on the above-mentioned scheme, in the bolt loosening angle monitoring device provided by the embodiment of the present application, a slide groove 101 is provided on the resistance wire 1; the slide groove 101 extends along the extension direction of the resistance wire 1; the metal ball contact 203 moves relative to the resistance wire 1 along the extension direction of the slide groove 101.

[0067] It is worth noting that the resistance wire 1 used in the embodiment of the present application is made of a high-resistance metal wire.

[0068] Furthermore, a slide groove 101 is provided along the extension direction of the resistance wire 1, which ensures that the resistance wire 1 and the metal ball contact 203 have sufficient contact area to ensure the conductive performance.

[0069] As a specific implementation of the bolt provided in an embodiment of the present application, the end of the terminal 202 is provided with a first groove for accommodating the metal ball contact 203; the metal ball contact 203 partially extends out of the first groove; the metal ball contact 203 can rotate in the first groove; the mounting pad 201 is an elastic pad; the mounting pad 201 is provided with a first through hole for accommodating the terminal 202, and a second groove for accommodating the remaining part of the metal ball contact 203.

[0070] In a specific implementation, the metal ball contact 203 is inserted into the first groove at the lower end of the terminal 202. It is a rotatable metal ball that rotates within the upper slide groove 101 of the resistance wire 1 to ensure smooth relative movement and contact with the resistance wire 1. The mounting pad 201 is made of an elastic material and is used to fix the metal ball contact 203 and the terminal 202, ensuring that the contact assembly 2 is assembled as a whole into the contact assembly installation space of the bolt body 3. It also provides elasticity to the axis part and provides contact force between the metal ball contact 203 and the resistance wire 1, ensuring constant contact and achieving full contact conductivity.

[0071] As shown in Figures 2, 7 and 8, the bolt provided in the embodiment of the present application, based on the above-mentioned scheme, further includes an insulating washer 4; the insulating washer 4 is sleeved on the bolt body 3, and the insulating washer 4 is provided with a mounting groove 401 for accommodating the resistance wire 1; the insulating washer 4 is fixed to the external device; when the bolt body 3 is in the rotating state, the bolt body 3 can rotate relative to the insulating washer 4.

[0072] It is worth noting that the contact surface between the resistance wire 1 and the insulating washer 4 is provided with an insulating coating.

[0073] Specifically, the resistance wire 1 is secured to the external device via an insulating washer 4. It is worth noting that the resistance wire 1 is fixedly disposed within the mounting slot 401. In practice, the resistance wire 1 can be secured within the mounting slot 401 using high-strength glue, or other methods. When the bolt is loosened and rotated, the insulating washer 4 remains completely fixed, allowing for relative angular movement with the bolt.

[0074] On the basis of the above solution, the insulating washer 4 is further stably mounted on the mounting structure of the external device, and an anti-slip pattern 402 is provided on the side of the insulating washer 4 away from the resistance wire 1 .

[0075] It is worth noting that other structures that can increase stability can also be provided on the side of the insulating washer 4 away from the resistance wire 1 , for example, an anti-slip pad can be provided on the side of the insulating washer 4 away from the resistance wire 1 .

[0076] As shown in Figures 1, 2, 3, 4 and 6, based on the above solution, the embodiment of the present application provides a specific implementation of the resistance wire 1, and the resistance wire 1 includes a first resistance wire 102 and a second resistance wire 103.

[0077] Specifically, the first resistance wire 102 is arranged in a ring shape on the bolt body 3; one end of the second resistance wire 103 is connected to one end of the first resistance wire 102, and the other end is wound around the outside of the first resistance wire 102, in a ring shape; the second resistance wire 103 and the first resistance wire 102 are arranged in concentric rings.

[0078] In a specific implementation, the resistance wire 1 can be formed by a resistance wire surrounded by a circle, and the two ends of the resistance wire 1 are not closed; the resistance wire 1 is divided into two circles, the first resistance wire 102 is the inner circle resistance wire, and the second resistance wire 103 is the outer circle resistance wire.

[0079] As shown in FIG14 , an embodiment of the present application further provides a system for real-time monitoring of bolt loosening angles, comprising the above-mentioned bolt loosening angle monitoring device, a data acquisition device 5 and a data processing device 6 .

[0080] The above-mentioned bolt; the data acquisition device 5 is electrically connected to the contact assembly 2, and is used to collect changes in the resistance value of the resistance wire 1 connected to the measurement circuit; the data processing device 6 is connected to the data acquisition device 5, and is used to process changes in the resistance value connected to the measurement circuit, and output the corresponding rotation angle of the bolt body 3.

[0081] The present application also provides a method for real-time monitoring of bolt loosening angles, which uses the system for real-time monitoring of bolt loosening angles, including the following steps:

[0082] (1) Tighten the bolt body 3 to connect the contact assembly 2 to the measurement circuit;

[0083] (2) The data acquisition system collects the resistance value of the resistance wire 1 connected to the measurement circuit;

[0084] (3) the data processing device 6 processes the resistance value of the measurement circuit;

[0085] (4) The data processing device 6 outputs the resistance change value of the measurement circuit and the loosening angle of the bolt body 3 according to a preset formula.

[0086] The default formula is:

[0087] Where ΔR is the resistance change value connected to the measurement circuit, r1 is the radius of the second resistance wire, r2 is the radius of the first resistance wire, S is the cross-sectional area of ​​the resistance wire, ρ is the resistivity of the resistor, and α is the loosening angle of the bolt body.

[0088] Based on the above solution, before the data acquisition system acquires the resistance value of the resistance wire connected to the measurement circuit, the method further includes: acquiring the resistance value of the resistance wire connected to the measurement circuit when the bolt is in a tightened state.

[0089] This application is further explained with reference to design principles, drawings and examples.

[0090] (1) For a resistance wire 1 with a constant cross-section and a constant and uniform material, the relationship between the length of the resistance wire and its resistance is:

[0091] ρ represents the resistivity of the resistor, which is determined by the properties of the material itself;

[0092] L represents the length of the resistance wire connected to the circuit;

[0093] S represents the cross-sectional area of ​​the resistance wire 1.

[0094] For this application, the cross-sectional area of ​​the resistance wire 1 of a single smart bolt system remains unchanged, and the resistivity of the resistance wire 1 remains unchanged. Therefore, by collecting the resistance of the connected measurement circuit, the length of the resistance wire 1 connected to the circuit can be obtained, and the resistance and the length of the resistance wire connected to the circuit are positively correlated, that is, R∝L Formula 2

[0095] (2) Relationship between rotation angle and resistance change

[0096] As shown in FIG9 , when the bolt body 3 is tightened, the contact assembly 2 connects the resistance wire 1 to the measuring circuit. When the bolt body 3 itself loosens by an angle α (in degrees), the length of the resistance wire connected to the circuit by the contact assembly 2 changes, as shown in FIG10 .

[0097] Assuming the radius of the outer resistance wire is r1 and the radius of the inner resistance wire is r2, when the bolt loosening angle is α, the change in the length of the resistance wire connected to the circuit is

[0098] Combining Formula 2 and Formula 3, we can get that when the bolt loosening angle is α, the resistance change measured by the measurement circuit is

[0099] (3) Measurement circuit

[0100] As shown in Figure 14, two contacts are connected to the resistance acquisition system to form a sliding rheostat for resistance measurement. In the measurement circuit of this application, A1 and A2 represent the two contacts of the contact assembly 2; These represent two signal output wires, each connected to a data acquisition system circuit. The data acquisition device connects to a computer, collects the resistance changes generated by this application, and calculates the resistance measurement value. Suitable for remote measurement.

[0101] It is worth noting that the measurement method suitable for local use is to use a high-precision multimeter to measure Column resistance can be measured.

[0102] (4) Fitting strain-displacement curve

[0103] Because the principle reasoning is based on fundamental physical principles, errors are inevitably introduced. For example, various parameters are set to theoretical values, without considering factors such as machining errors, material inhomogeneity, and unstable performance between batches. Therefore, it is necessary to perform multi-step resistance-angle acquisition for each range before use. Since resistance and angle change continuously, there are no singularities when measuring within a single turn of looseness. By fitting the multi-step resistance-angle data to a curve, the unique characteristics of each smart bolt system are derived.

[0104] Furthermore, considering that bolt loosening angle monitoring is controlled within a small angle range, 360° rotation is sufficient for practical monitoring. Specifically, considering that loosening may occur over a period of several weeks, the fitting curve will appear as shown in Figure 11. Each time the contact assembly 2 passes through the connection between the inner and outer rings of the resistance wire, the resistance will be disconnected, and further rotation will cause a reset. This is not a problem for real-time continuous monitoring, but for interval monitoring, attention should be paid to the device characteristics of this application to distinguish whether one rotation has occurred, as shown in Figures 12 and 13.

[0105] Finally, it's worth noting that the principles and circuits of this application are clear. Multiple structures of this application can be connected in series or parallel to form a system circuit, requiring only a single channel for resistance measurement to simultaneously monitor the resistance changes of the entire system for complete bolt loosening monitoring. Alternatively, standard resistors and various electronic components can be connected in parallel or series to form the required measurement circuit to achieve monitoring requirements of varying accuracy and requirements.

[0106] Based on the above, this application has the following advantages:

[0107] (1) This application can be used to monitor the status of tightened bolts in real time, and even slight looseness can be detected through precise electrical measurements. This application can be used in conjunction with any acquisition system that can collect resistance data, and has strong applicability to acquisition systems. It can also monitor the looseness of bolts using this application remotely in real time. The system resistance can also be measured after tightening. When it is necessary to understand the tightening status of the bolt, a high-precision multimeter can be used to measure its resistance. By comparing the resistance value when tightening, the current looseness status can be obtained.

[0108] (2) This application is combined with its test method: calibration is performed within each range to obtain a fitting resistance-angle curve, and the fitting curve is used to obtain the loosening angle of different fastening bolts after loosening.

[0109] (3) The principle of this application is simple and clear, and the functions of each component and the effects of various correlation coefficients on the system are described in detail. It can be selected and replaced by the user independently, and has strong operability.

[0110] In summary, it is worth noting that this application involves a number of alternative methods for achieving bolt loosening and angle acquisition, but all of them require expert experience and professional measurement and analysis equipment. For example, the bolt loosening detection method based on digital image processing requires the use of professional photography equipment and professional image processing software, with sophisticated algorithms as technical support. Piezoelectric sensors combined with ultrasonic detection methods require the coordination of multiple professional systems, a large amount of professional equipment and manpower investment, and excessively high costs, which are all detrimental to basic bolt loosening detection work.

[0111] In the description of this application, it should be understood that the terms "front", "rear", "head", "tail", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They 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, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0112] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0113] In this application, unless otherwise specified or limited, terms such as "mounted" and "connected" should be understood broadly. For example, "connected" can refer to direct connection or indirect connection through an intermediate medium, and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0114] Although some optional embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including some optional embodiments and all changes and modifications that fall within the scope of the present application.

[0115] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A bolt, characterized in that: include: Bolt body; The resistance wire is annularly sleeved on the bolt body; the bolt body can rotate relative to the resistance wire; A contact assembly is arranged on the bolt body; The contact assembly is electrically connected to an external circuit; the contact assembly is in electrical contact with the resistance wire and can slide along the resistance wire to change the resistance value of the resistance wire connected to the external circuit.

2. The bolt according to claim 1, characterized in that The bolt body comprises: A bolt head, wherein a mounting space for accommodating a contact assembly is provided on the bolt head; A screw rod is arranged on the bolt head; and the resistance wire is wound around the screw rod.

3. The bolt according to claim 1, characterized in that The contact assembly comprises: A mounting pad, arranged on the bolt body; Two parallel binding posts are arranged on the mounting pad; the binding posts extend along the length direction of the bolt body; one end of one of the binding posts is connected to the input end of the external circuit, and the other end is slidably connected to the resistance wire; One end of one of the binding posts is connected to the output end of the external circuit, and the other end is slidably connected to the resistance wire.

4. The bolt according to claim 3, characterized in that The contact assembly also includes: The metal ball contact is arranged at one end of the terminal toward the resistance wire; the terminal is connected to the resistance wire through the metal ball contact.

5. The bolt according to claim 4, characterized in that The resistance wire is provided with a slide groove; the slide groove extends along the extension direction of the resistance wire; the metal ball contact moves relative to the resistance wire along the extension direction of the slide groove.

6. The bolt according to claim 4, characterized in that The end of the terminal is provided with a first groove for accommodating the metal ball contact; the metal ball contact partially extends out of the first groove; the metal ball contact can partially rotate in the first groove; The mounting pad is an elastic pad; the mounting pad is provided with a first through hole for accommodating a terminal post, and a second recess for accommodating the remaining portion of the metal ball contact.

7. The bolt according to claim 1, characterized in that Also includes: An insulating washer is sleeved on the bolt body, and a mounting groove for accommodating a resistance wire is provided on the insulating washer; the insulating washer is fixed to the external device; when the bolt body is in a rotating state, the bolt body can rotate relative to the insulating washer.

8. The bolt according to claim 7, characterized in that The side of the insulating gasket away from the resistance wire is provided with anti-slip texture.

9. The bolt according to claim 1, characterized in that The resistance wire comprises: A first resistance wire, annularly arranged on the bolt body; The second resistance wire has one end connected to one end of the first resistance wire and the other end wound around the outside of the first resistance wire in a ring-shaped arrangement; the second resistance wire and the first resistance wire are arranged in concentric rings.

10. A real-time monitoring system for bolt loosening angle, characterized in that: include: The bolt according to any one of claims 1 to 9; A data acquisition device, electrically connected to the contact assembly, for acquiring changes in the resistance value of the resistance wire connected to the measurement circuit; The data processing device is connected to the data acquisition device and is used to process the change of the resistance value connected to the measurement circuit and output the corresponding rotation angle of the bolt body.

11. A method for real-time monitoring of bolt loosening angle, characterized in that: The system for real-time monitoring of bolt loosening angle as claimed in claim 10 comprises the following steps: tightening the bolt body to connect the contact assembly to the measuring circuit; The data acquisition system collects the resistance value of the resistance wire connected to the measurement circuit; The data processing device processes the resistance value of the measuring circuit; The data processing device outputs the resistance value change of the measuring circuit and outputs the loosening angle of the bolt body according to a preset formula.

12. The method for real-time monitoring of bolt loosening angle according to claim 11, characterized in that: The preset formula is: Among them, ΔR is the resistance change value connected to the measurement circuit, r1 is the radius of the second resistance wire, r2 is the radius of the first resistance wire, S is the cross-sectional area of ​​the resistance wire, ρ is the resistivity of the resistor, and α is the loosening angle of the bolt body.

13. The method for real-time monitoring of bolt loosening angle according to claim 11, characterized in that: Before the data acquisition system acquires the resistance value of the resistance wire connected to the measurement circuit, it also includes: When the bolt is tightened, the resistance value of the resistance wire connected to the measurement circuit is collected.

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