Bolt loosening detection device

Abstract

The present invention provides a bolt loosening detection device, wherein an installation cavity is provided inside a shell, and a temperature regulating machine component is provided in the installation cavity; an ultrasonic measuring mechanism can detect the propagation speed of ultrasonic waves in the bolt to be detected; a calibration mechanism is provided in the shell, and the calibration mechanism can apply a tensile force to the bolt to be calibrated, and measure the propagation speed of ultrasonic waves in the bolt to be calibrated under the condition of the tensile force, and the bolt to be calibrated and the bolt to be detected are of the same model and material; a data analysis mechanism is connected to the ultrasonic measuring mechanism and the calibration mechanism, and a circumferential stress value of the bolt to be detected in a tightened state is preset inside, and the data analysis mechanism can obtain the detection stress value of the bolt to be detected based on the detection information of the ultrasonic measuring mechanism and the calibration mechanism, and compare it with the preset value. If the axial stress of the bolt to be measured is less than the preset value, the bolt is loose. The present invention has a simple structure, is easy to use, and has high measurement accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of detection devices, and more specifically, relates to a bolt loosening detection device. Background Art

[0002] Bolts are a type of connecting part commonly used in engineering. They are cylindrical threaded fasteners equipped with nuts. They are a type of fastener consisting of a head and a screw. They are widely used in the connection of parts of key devices or equipment in aerospace, locomotives, ships, bridges, petrochemicals, new energy and other fields to ensure the integrity, reliability and safety of mechanical structures.

[0003] Whether the preload force used in bolts in a device or structure is appropriate is directly related to the reliability and safety of the entire device or structure. Excessive preload force can easily lead to cracks and fatigue failure, weakening the bearing capacity of the connection node and, in severe cases, inducing structural instability. Insufficient preload force can cause vibration relaxation and slippage, affecting the integrity of the structure or causing seal leakage.

[0004] Currently, the commonly used method for detecting loose bolts is to use a detection device, which requires installing a sensor on each bolt. This is not only time-consuming and labor-intensive to install, but also has high maintenance costs. Summary of the Invention

[0005] The object of the present invention is to provide a bolt loosening detection device to solve the problem of high cost of bolt loosening detection.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a bolt loosening detection device, including a shell, an ultrasonic measuring mechanism, a calibration mechanism and a data analysis mechanism, wherein an installation cavity is provided inside the shell, and a temperature regulator assembly is provided inside the installation cavity; the ultrasonic measuring mechanism can detect the propagation speed of the ultrasonic wave in the bolt to be detected; the calibration mechanism is provided in the shell, and the calibration mechanism can apply a tensile force to the bolt to be calibrated, and measure the propagation speed of the ultrasonic wave in the bolt to be calibrated under the condition of the tensile force, and the bolt to be calibrated and the bolt to be detected are of the same model and material; the data analysis mechanism is connected to the ultrasonic measuring mechanism and the calibration mechanism, and the circumferential stress value of the bolt to be detected when it is in a tightened state is preset inside, and the data analysis mechanism can obtain the detection stress value of the bolt to be detected based on the detection information of the ultrasonic measuring mechanism and the calibration mechanism, and compare it with the preset value.

[0007] In one possible implementation, the calibration mechanism includes a stretching assembly and an ultrasonic calibration assembly, the stretching assembly includes a lower fixing frame, an upper fixing frame and a driving member arranged between the lower fixing frame and the upper fixing frame, one end of the bolt to be calibrated is fixed on the lower fixing frame, and the other end of the bolt to be calibrated is fixed on the upper fixing frame, the driving member is arranged on the lower fixing frame, the power output end of the driving member is connected to a telescopic rod, the top of the telescopic rod is provided with a pressure sensor, and the top of the pressure sensor abuts against the upper fixing frame.

[0008] In one possible implementation, the lower fixing frame includes a first horizontal plate, a second horizontal plate and two vertical plates, the two vertical plates are respectively arranged at the two ends of the first horizontal plate, the vertical plate extends below the first horizontal plate, the vertical plates are detachably connected to the top of the second horizontal plate, the two ends of the second horizontal plate extend to the two ends of the first horizontal plate, the driving members include two, the driving members are arranged on the parts of the second horizontal plate extending to the two sides of the first horizontal plate, the first horizontal plate is provided with a first through hole, the bolt to be calibrated is passed through the first through hole, the first horizontal plate is provided with a lower locking part, and the lower locking part can fix the bolt to be calibrated.

[0009] In one possible implementation, the lower locking portion includes two card plates slidably arranged on the first horizontal plate, a slide groove is provided on the bottom surface of the first horizontal plate, the first through hole is arranged through the slide groove, the card plates are arranged on both sides of the first through hole, and a reset spring is provided between each card plate and the side wall of the slide groove. When the reset spring is in a natural state, the two card plates abut against each other, and when the lower locking portion fixes the bolt to be calibrated, the card plates abut against both sides of the bolt to be calibrated, and the nut of the bolt abuts against the bottom of the card plate.

[0010] In one possible implementation, two baffles are provided at the bottom of the first horizontal plate, and the two baffles are respectively provided on both sides of the first through hole. The baffles cover the top of the slide groove, and the baffles are spaced apart from the first through hole. The length of the card plate is greater than the sum of the radius of the first through hole and the distance from the baffle to the first through hole, and the card plate can be completely provided below the baffle.

[0011] In one possible implementation, the upper fixing frame includes a third transverse plate, a second through-hole is provided on the second transverse plate, the first through-hole and the second through-hole are coaxially arranged, the bolt to be calibrated is passed through the second through-hole, the length of the third transverse plate is the same as the length of the second transverse plate, and the two ends of the third transverse plate extend to both sides of the first transverse plate, the top of the pressure sensor abuts on the part of the third transverse plate extending to the two ends of the first transverse plate, and an upper locking assembly is provided on the upper fixing frame, and the bolt to be calibrated is fixed to the upper fixing frame through the upper locking assembly.

[0012] In one possible implementation, the upper locking assembly includes a fixed sleeve and multiple connecting sleeves, the inner diameter of the fixed sleeve is the same as the inner diameter of the first through hole, a fixing thread is provided on the inner wall of the fixed sleeve, a jump ring is provided on the top of the fixed sleeve, the outer diameter of the jump ring is larger than the outer diameter of the fixed sleeve, the fixed sleeve is inserted into the second through hole, and the jump ring is overlapped on the third horizontal plate. The outer diameters of the multiple connecting sleeves gradually decrease, and the inner diameters of the multiple connecting sleeves gradually decrease. Each of the connecting sleeves can be screwed into a connecting sleeve, the largest connecting sleeve can be screwed into the fixed sleeve, and a bolt with the same inner diameter as the connecting sleeve can be screwed into the connecting sleeve.

[0013] In one possible implementation, the ultrasonic calibration component includes an ultrasonic transmitter and an ultrasonic receiver, the ultrasonic transmitter is arranged on the lower fixing frame, and the ultrasonic receiver is arranged on the upper fixing frame. The ultrasonic transmitter can transmit ultrasonic waves to the bolt to be calibrated, and the ultrasonic receiver receives the ultrasonic waves emitted by the ultrasonic transmitter. The ultrasonic transmitter and the ultrasonic receiver are both connected to the data analysis mechanism, and the data analysis mechanism can calculate the propagation speed of the ultrasonic wave in the bolt to be calibrated based on the length of the bolt to be calibrated and the ultrasonic transmission time.

[0014] In one possible implementation, the temperature regulator assembly includes an external temperature measuring component, an internal temperature measuring component, a heating component, a cooling component and a control component. The external temperature measuring component can measure the temperature of the bolt to be inspected, and the internal temperature measuring component can measure the temperature of the bolt to be calibrated. The external temperature measuring component, the internal temperature measuring component, the heating component and the cooling component are all connected to the data analysis mechanism. The control component can control the operation of the heating component or the cooling component to heat or cool the inside of the shell so that the bolt to be inspected and the bolt to be calibrated maintain the same temperature.

[0015] In one possible implementation, the rear side wall of the shell is provided with an opening, and the shell is provided with a door, which can open or close the open end of the shell; the ultrasonic measuring mechanism has an ultrasonic transmitting probe and an ultrasonic receiving probe, and the ultrasonic transmitting probe and the ultrasonic receiving probe pass through the side wall of the shell and extend to the outside of the shell; the heating element is provided on the inner bottom surface of the shell, and the refrigeration element is provided on the inner top wall of the shell.

[0016] The beneficial effect of the bolt loosening detection device provided by the present invention is that, compared with the prior art, the present invention applies tension to the bolt to be calibrated to simulate the axial stress on the bolt, and measures the propagation speed of ultrasound in the bolt to be calibrated to obtain the corresponding value data of the axial stress of the bolt to be calibrated and the propagation speed of ultrasound on its inner wall, and then measures the propagation speed of ultrasound in the bolt to be detected, compares the speed with the aforementioned value, and obtains the axial stress on the bolt at this time, and compares the obtained axial stress with a preset value. If the obtained axial stress is less than the preset value, the bolt is loose. The present invention has a simple structure, is easy to use, and has high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A schematic structural diagram of a bolt loosening detection device provided in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the internal structure of a bolt loosening detection device provided by an embodiment of the present invention;

[0020] Figure 3 A schematic structural diagram of a calibration mechanism provided in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of a top view of the calibration mechanism provided in an embodiment of the present invention;

[0022] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure of the calibration mechanism along the AA direction.

[0023] Among them, the reference numerals in the figures are as follows:

[0024] 1. Shell; 2. Ultrasonic measuring mechanism; 3. Calibration mechanism; 4. Data analysis mechanism; 5. Bolts to be calibrated;

[0025] 101. Installation cavity; 102. External temperature measuring element; 103. Internal temperature measuring element; 104. Refrigeration element; 105. Heating element; 106. Control element; 107. Chamber door;

[0026] 201. Ultrasonic receiving probe; 202. Ultrasonic transmitting probe;

[0027] 301. Lower fixing frame; 302. Upper fixing frame; 303. Driving member; 304. Telescopic rod; 305. First horizontal plate; 306. Vertical plate; 307. Second horizontal plate; 308. First through hole; 309. Clamping plate; 310. Slide groove; 311. Return spring; 312. Baffle; 313. Third horizontal plate; 314. Fixed sleeve; 315. Connecting sleeve; 316. Ultrasonic transmitter; 317. Ultrasonic receiver. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] It should be further explained that the drawings and implementation methods of the present invention mainly describe the concept of the present invention. On the basis of this concept, the specific forms and settings of some connection relationships, positional relationships, power mechanisms, power supply systems, hydraulic systems and control systems may not be fully described. However, on the premise that those skilled in the art understand the concept of the present invention, those skilled in the art can implement the above-mentioned specific forms and settings in a well-known manner.

[0030] When an element is referred to as being “fixed to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] The directions or positional relationships indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, and "several" means one or more, unless otherwise specifically defined.

[0033] The bolt loosening detection device provided by the present invention is now described.

[0034] Please also refer to Figure 1 and Figure 2 The bolt loosening detection device includes a shell 1, an ultrasonic measuring mechanism 2, a calibration mechanism 3 and a data analysis mechanism 4, wherein an installation cavity 101 is provided inside the shell 1, and a temperature regulator assembly is provided inside the installation cavity 101; the ultrasonic measuring mechanism 2 can detect the propagation speed of the ultrasonic wave in the bolt to be detected; the calibration mechanism 3 is provided in the shell 1, and the calibration mechanism 3 can apply a tensile force to the bolt to be calibrated 5, and measure the propagation speed of the ultrasonic wave in the bolt to be calibrated 5 under the condition of tensile force. The bolt to be calibrated 5 is of the same model and material as the bolt to be detected; the data analysis mechanism 4 is connected to the ultrasonic measuring mechanism 2 and the calibration mechanism 3, and the circumferential stress value of the bolt to be detected when it is in a tightened state is preset inside. The data analysis mechanism 4 can obtain the detection stress value of the bolt to be detected based on the detection information of the ultrasonic measuring mechanism 2 and the calibration mechanism 3, and compare it with the preset value.

[0035] The beneficial effects of the bolt loosening detection device provided by the present embodiment are as follows: compared with the prior art, the present embodiment applies tension to the bolt to be calibrated, simulating the axial stress on the bolt, and measures the propagation speed of ultrasound inside the bolt 5 to be calibrated to obtain corresponding value data of the axial stress of the bolt 5 to be calibrated and the propagation speed of ultrasound on its inner wall, and then measures the propagation speed of ultrasound in the bolt to be detected, compares the changed speed with the aforementioned value, and obtains the axial stress on the bolt at this time, and compares the obtained axial stress with the preset value to obtain the axial stress of the bolt to be measured at this time. If the axial stress of the bolt to be measured is less than the preset value, the bolt is loose. The present invention has a simple structure, is easy to use, and has high measurement accuracy.

[0036] Combine Figure 3 、 Figure 4 and Figure 5As shown, in a specific implementation manner of the bolt loosening detection device provided in an embodiment of the present invention, the calibration mechanism 3 includes a stretching component and an ultrasonic calibration component, the stretching component includes a lower fixing frame 301, an upper fixing frame 302 and a driving member 303 arranged between the lower fixing frame 301 and the upper fixing frame 302, one end of the bolt to be calibrated is fixed on the lower fixing frame 301, and the other end of the bolt to be calibrated is fixed on the upper fixing frame 302, the driving member 303 is arranged on the lower fixing frame 301, and the power output end of the driving member 303 is connected to a telescopic rod 304, and a pressure sensor is provided at the top of the telescopic rod 304, and the top of the pressure sensor abuts on the upper fixing frame 302.

[0037] One end of the bolt to be calibrated is fixed on the lower fixing frame 301, and the other end is fixed on the upper fixing frame 302. The driving member 303 is set on the lower fixing frame 301 and pushes the upper fixing frame 302 through the telescopic rod 304, so as to apply circumferential stress to the calibrated bolt.

[0038] Specifically, in a specific implementation of the bolt loosening detection device provided in an embodiment of the present invention, the lower fixing frame 301 includes a first horizontal plate 305, a second horizontal plate 307 and two vertical plates 306, the two vertical plates 306 are respectively arranged at both ends of the first horizontal plate 305, the vertical plates 306 extend downwardly from the first horizontal plate 305, the vertical plates 306 are detachably connected to the top of the second horizontal plate 307, and the two ends of the second horizontal plate 307 extend to the two ends of the first horizontal plate 305, the driving members 303 include two, the driving members 303 are arranged on the parts of the second horizontal plate 307 extending to the two sides of the first horizontal plate 305, the first horizontal plate 305 is provided with a first through hole 308, the bolt 5 to be calibrated is passed through the first through hole 308, and the first horizontal plate 305 is provided with a lower locking portion, which can fix the bolt 5 to be calibrated.

[0039] The arrangement of the first horizontal plate 305, the second horizontal plate 307 and the vertical plate 306 enables an installation space to be enclosed between the three, which is convenient for accommodating the nuts of the bolts to be calibrated on the one hand, and on the other hand, it is also convenient for installing the internal temperature measuring component 103, the ultrasonic emitting component 316, etc. mentioned below.

[0040] As a preferred solution, the lower locking portion includes two clamping plates 309 slidably arranged on the first horizontal plate 305, a sliding groove 310 is provided on the bottom surface of the first horizontal plate 305, the first through hole 308 is set through the sliding groove 310, and the clamping plates 309 are arranged on both sides of the first through hole 308, and a return spring 311 is provided between each clamping plate 309 and the side wall of the sliding groove 310. When the return spring is in a natural state, the two clamping plates 309 abut against each other. When the lower locking portion fixes the bolt 5 to be calibrated, the clamping plates 309 abut against both sides of the bolt 5 to be calibrated, and the nut of the bolt abuts against the bottom of the clamping plate 309, so that the lower fixing frame 301 can fix the bolts 5 to be calibrated of different diameters, thereby improving the applicability of the lower fixing frame 301.

[0041] In addition, two baffles 312 are provided at the bottom of the first horizontal plate 305, one on either side of the first through hole 308. The baffles 312 cover the top of the chute 310. The baffles 312 secure the card 309 within the chute 310, preventing one end of the card 309 from tilting when subjected to force.

[0042] The baffle 312 is spaced apart from the first through hole 308, and the length of the card plate 309 is greater than the sum of the radius of the first through hole 308 and the distance from the baffle 312 to the first through hole 308. The card plate 309 can be completely set below the baffle 312, so that no matter what position the card plate 309 slides to, there will always be a part of the card plate 309 set below the baffle 312, effectively preventing the card plate 309 from falling off from the slide groove 310.

[0043] like Figure 5 As shown, in a specific implementation manner of the bolt loosening detection device provided in an embodiment of the present invention, the upper fixing frame 302 includes a third transverse plate, a second through-hole is provided on the second transverse plate 307, the first through-hole 308 is coaxially arranged with the second through-hole, the bolt 5 to be calibrated is passed through the second through-hole, the length of the third transverse plate is the same as the length of the second transverse plate 307, and the two ends of the third transverse plate extend to both sides of the first transverse plate 305, the top of the pressure sensor abuts on the part of the third transverse plate extending to the two ends of the first transverse plate 305, and an upper locking assembly is provided on the upper fixing frame 302, and the bolt 5 to be calibrated is fixed to the upper fixing frame 302 through the upper locking assembly.

[0044] The first through hole 308 and the second through hole are coaxially arranged to facilitate the insertion of the calibrated bolt 5. Furthermore, the second and third transverse plates 307 are of the same length, and the first transverse plate 305 is shorter than the second transverse plate 307. This allows the ends of the second and third transverse plates 307 to extend beyond the first transverse plate 305, providing space for the driver 303 and telescopic rod 304.

[0045] Specifically, in a specific implementation of the bolt loosening detection device provided in an embodiment of the present invention, the upper locking assembly includes a fixed sleeve 314 and a plurality of connecting sleeves 315, the inner diameter of the fixed sleeve 314 is the same as the inner diameter of the first through hole 308, a fixing thread is provided on the inner wall of the fixed sleeve 314, and a lap ring is provided on the top of the fixed sleeve 314, the outer diameter of the lap ring is larger than the outer diameter of the fixed sleeve 314, the fixed sleeve 314 is inserted into the second through hole, and the lap ring is overlapped on the third horizontal plate, the outer diameters of the plurality of connecting sleeves 315 gradually decrease, and the inner diameters of the plurality of connecting sleeves 315 gradually decrease, each connecting sleeve 315 can be screwed into a connecting sleeve 315, the largest connecting sleeve 315 can be screwed into the fixed sleeve 314, and a bolt with the same inner diameter as the connecting sleeve 315 can be screwed into the connecting sleeve 315.

[0046] The provision of the overlapping ring facilitates the overlapping connection of the fixed sleeve 314 to the third cross plate. The combination of the fixed sleeve 314 and the connecting sleeve 315 enables the fixing of bolts 5 to be calibrated of different diameters. The multiple connecting sleeves 315 are numbered 1, 2, ..., n, with connecting sleeve 315 No. 1 having the largest diameter and connecting sleeve 315 No. n having the smallest diameter. Connecting sleeve 315 No. 2 can be threaded into connecting sleeve 315 No. 1, connecting sleeve 315 No. 3 can be threaded into connecting sleeve 315 No. 2, and so on. Connecting sleeve 315 No. n can be threaded into connecting sleeve 315 No. n-1. For example, when it is necessary to fix the bolt 5 to be calibrated that is compatible with the connecting sleeve No. 3 315, it is necessary to screw the bolt 5 to be calibrated into the connecting sleeve No. 3 315, screw the connecting sleeve No. 2 315 into the connecting sleeve No. 1 315, screw the connecting sleeve No. 1 315 into the fixed sleeve 314, insert the fixed sleeve 314 into the second through hole and overlap it on the third horizontal plate.

[0047] like Figure 5 As shown, in a specific implementation of the bolt loosening detection device provided in an embodiment of the present invention, the ultrasonic calibration component includes an ultrasonic transmitter 316 and an ultrasonic receiver 317. The ultrasonic transmitter 316 is arranged on the lower fixing frame 301, and the ultrasonic receiver 317 is arranged on the upper fixing frame 302. The ultrasonic transmitter 316 can transmit ultrasonic waves to the bolt to be calibrated, and the ultrasonic receiver 317 receives the ultrasonic waves emitted by the ultrasonic transmitter. The ultrasonic transmitter 316 and the ultrasonic receiver 317 are both connected to the data analysis mechanism 4. The data analysis mechanism 4 can calculate the propagation speed of the ultrasonic wave in the bolt 5 to be calibrated according to the length of the bolt 5 to be calibrated and the transmission time of the ultrasonic wave.

[0048] like Figure 1 and Figure 2As shown, in a specific embodiment of the bolt loosening detection device provided by an embodiment of the present invention, the temperature regulator assembly includes an external temperature measuring element 102, an internal temperature measuring element 103, a heating element 105, a cooling element 104 and a control element 106. The external temperature measuring element 102 can measure the temperature of the bolt to be inspected, and the internal temperature measuring element 103 can measure the temperature of the bolt to be calibrated. The external temperature measuring element 102, the internal temperature measuring element 103, the heating element 105 and the cooling element 104 are all connected to the data analysis mechanism 4. The control element 106 can control the heating element 105 or the cooling element 104 to heat or cool the inside of the housing 1 so that the bolt to be inspected and the bolt to be calibrated 5 maintain the same temperature. The internal temperature measuring element 103 is set on the second horizontal plate 307 to facilitate temperature measurement of the nut.

[0049] Finally, the rear sidewall of the housing 1 is opened, and a door 107 is provided on the housing 1. The door 107 can open or close the open end of the housing 1. The ultrasonic measuring mechanism 2 includes an ultrasonic transmitting probe 202 and an ultrasonic receiving probe 201. The ultrasonic transmitting probe 202 and the ultrasonic receiving probe 201 extend through the sidewall of the housing 1 to the outside of the housing 1. The heating element 105 is provided on the inner bottom surface of the housing 1, and the cooling element 104 is provided on the inner top wall of the housing 1. The heating element 105 is provided at the bottom, and the cooling element 104 is provided at the top, so that the air in the housing 1 forms convection, thereby facilitating the maintenance of the same temperature between the bolt 5 to be calibrated and the bolt to be measured.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bolt loosening detection device, characterized in that: include: The housing has an installation cavity provided therein, and a temperature regulating machine component is provided in the installation cavity; Ultrasonic measuring mechanism, capable of detecting the propagation speed of ultrasonic waves in the bolt to be tested; a calibration mechanism disposed in the housing, the calibration mechanism being capable of applying a tensile force to a bolt to be calibrated and measuring a propagation velocity of an ultrasonic wave in the bolt to be calibrated under the tensile force, wherein the bolt to be calibrated and the bolt to be tested are of the same model and material; a data analysis mechanism connected to the ultrasonic measuring mechanism and the calibration mechanism, and having a preset circumferential stress value of the bolt to be tested in a tightened state. The data analysis mechanism is capable of deriving a detected stress value of the bolt to be tested based on the detection information of the ultrasonic measuring mechanism and the calibration mechanism, and comparing the stress value with the preset stress value; The calibration mechanism includes a stretching assembly and an ultrasonic calibration assembly, the stretching assembly includes a lower fixing frame, an upper fixing frame and a driving member arranged between the lower fixing frame and the upper fixing frame, one end of the bolt to be calibrated is fixed to the lower fixing frame, and the other end of the bolt to be calibrated is fixed to the upper fixing frame, the driving member is arranged on the lower fixing frame, the power output end of the driving member is connected to a telescopic rod, the top end of the telescopic rod is provided with a pressure sensor, and the top end of the pressure sensor abuts against the upper fixing frame; The ultrasonic calibration assembly includes an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic transmitter is provided on the lower fixing frame, and the ultrasonic receiver is provided on the upper fixing frame. The ultrasonic transmitter can transmit ultrasonic waves to the bolt to be calibrated, and the ultrasonic receiver receives the ultrasonic waves emitted by the ultrasonic transmitter. The ultrasonic transmitter and the ultrasonic receiver are both connected to the data analysis mechanism. The data analysis mechanism can calculate the propagation speed of the ultrasonic wave in the bolt to be calibrated based on the length of the bolt to be calibrated and the ultrasonic wave transmission time. The temperature regulator assembly includes an external temperature measuring component, an internal temperature measuring component, a heating component, a cooling component and a control component. The external temperature measuring component can measure the temperature of the bolt to be inspected, and the internal temperature measuring component can measure the temperature of the bolt to be calibrated. The external temperature measuring component, the internal temperature measuring component, the heating component and the cooling component are all connected to the data analysis mechanism. The control component can control the operation of the heating component or the cooling component to heat or cool the inside of the shell so that the bolt to be inspected and the bolt to be calibrated maintain the same temperature.

2. The bolt loosening detection device according to claim 1, characterized in that: The lower fixing frame includes a first transverse plate, a second transverse plate and two vertical plates, the two vertical plates are respectively arranged at the two ends of the first transverse plate, the vertical plate extends to the bottom of the first transverse plate, the vertical plate is detachably connected to the top of the second transverse plate, and the two ends of the second transverse plate extend to the two ends of the first transverse plate. The driving members include two, and the driving members are arranged on the parts of the second transverse plate extending to the two sides of the first transverse plate. The first transverse plate is provided with a first through hole, and the bolt to be calibrated is passed through the first through hole. The first transverse plate is provided with a lower locking part, and the lower locking part can fix the bolt to be calibrated.

3. The bolt loosening detection device according to claim 2, characterized in that: The lower locking portion includes two card plates slidably arranged on the first horizontal plate, a sliding groove is provided on the bottom surface of the first horizontal plate, the first through-hole is arranged through the sliding groove, the card plates are arranged on both sides of the first through-hole, and a return spring is provided between each of the card plates and the side wall of the sliding groove. When the return spring is in a natural state, the two card plates abut against each other. When the lower locking portion fixes the bolt to be calibrated, the card plates abut against both sides of the bolt to be calibrated, and the nut of the bolt abuts against the bottom of the card plate.

4. The bolt loosening detection device according to claim 3, characterized in that: Two baffles are provided at the bottom of the first horizontal plate, and the two baffles are respectively provided on both sides of the first through hole. The baffles cover the top of the slide groove, and the baffles are arranged at intervals from the first through hole. The length of the card plate is greater than the sum of the radius of the first through hole and the distance from the baffle to the first through hole, and the card plate can be completely provided below the baffle.

5. The bolt loosening detection device according to claim 4, characterized in that: The upper fixing frame includes a third transverse plate, a second through-hole is provided on the second transverse plate, the first through-hole and the second through-hole are coaxially arranged, the bolt to be calibrated is passed through the second through-hole, the length of the third transverse plate is the same as the length of the second transverse plate, and the two ends of the third transverse plate extend to the two sides of the first transverse plate, the top of the pressure sensor abuts on the part of the third transverse plate extending to the two ends of the first transverse plate, the upper fixing frame is provided with an upper locking assembly, and the bolt to be calibrated is fixed to the upper fixing frame through the upper locking assembly.

6. The bolt loosening detection device according to claim 5, characterized in that: The upper locking assembly includes a fixed sleeve and multiple connecting sleeves, the inner diameter of the fixed sleeve is the same as the inner diameter of the first through hole, a fixing thread is provided on the inner wall of the fixed sleeve, a lap ring is provided on the top of the fixed sleeve, the outer diameter of the lap ring is larger than the outer diameter of the fixed sleeve, the fixed sleeve is inserted into the second through hole, and the lap ring is overlapped on the third horizontal plate. The outer diameters of the multiple connecting sleeves gradually decrease, and the inner diameters of the multiple connecting sleeves gradually decrease. Each of the connecting sleeves can be screwed into a connecting sleeve, and the largest connecting sleeve can be screwed into the fixed sleeve. A bolt with the same inner diameter as the connecting sleeve can be screwed into the connecting sleeve.

7. The bolt loosening detection device according to claim 1, characterized in that: The rear side wall of the shell is opened, and the shell is provided with a door, which can open or close the open end of the shell. The ultrasonic measuring mechanism has an ultrasonic transmitting probe and an ultrasonic receiving probe, and the ultrasonic transmitting probe and the ultrasonic receiving probe pass through the side wall of the shell and extend to the outside of the shell; the heating element is provided on the inner bottom surface of the shell, and the refrigeration element is provided on the inner top wall of the shell.

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