WO2021120989A1

WO2021120989A1 - Looseness monitoring device and system for bolts or nuts

Info

Publication number: WO2021120989A1
Application number: PCT/CN2020/130869
Authority: WO
Inventors: 张建平; 黄春华
Original assignee: 奥动新能源汽车科技有限公司
Priority date: 2019-12-20
Filing date: 2020-11-23
Publication date: 2021-06-24
Also published as: WO2021121410A1; CN113008150A

Abstract

Disclosed is a looseness monitoring device for bolts or nuts, the number of bolts or nuts is at least two, all the bolts or nuts are used for being fastened to a base (25), and the looseness monitoring device comprises an optical fiber deformation sensor (1, 21, 22), wherein the optical fiber deformation sensor (1, 21, 22) is provided with a deformation sensing section (12), and the deformation sensing section (12) of the optical fiber deformation sensor (1, 21, 22) is arranged to be located between the two bolts or nuts such that the deformation sensing section (12) can deform when any one of the two bolts or nuts rotates. Further disclosed is a looseness monitoring system for the bolts or nuts. According to the looseness monitoring device and system for the bolts or nuts provided, looseness and breakage conditions of adjacent fixing bolts or nuts can be found in time, such that timely maintenance is facilitated; meanwhile, the number of sensors is reduced, and the measurement accuracy is improved.

Description

Looseness monitoring device and system of bolts or nuts

This application claims the priority of the Chinese patent application CN201911321671.7 whose filing date is December 20, 2019. This application quotes the full text of the aforementioned Chinese patent application.

Technical field

This application relates to a technology for monitoring the state of adjacent fixed bolts or nuts, and in particular to a device and system for monitoring the looseness of bolts or nuts.

Background technique

At present, the wind power industry has achieved vigorous promotion all over the world. Because the installation locations are mostly offshore or in remote coastal mountainous areas, routine maintenance is extremely inconvenient. Moreover, there are a lot of bolts or nuts for fixing large wind turbines (a large wind turbine has more than 500 fixing bolts). Due to the extremely harsh environment, the fixing bolts or nuts on the wind turbine are very easy to loosen, and the bolts or nuts are loose. It will cause damage to the wind turbine or even collapse. During the normal operation of wind turbines, the inspection cycle of high-strength bolts is generally half a year to one year. The inspection cycle interval is long. Loose or broken bolts cannot be detected in time, and each inspection consumes a lot of time and manpower. , Material resources, especially for offshore wind turbines, several kilometers deep into the coastline, inconvenient unit inspections, high inspection costs and other issues are more prominent.

Summary of the invention

The technical problem to be solved by this application is to overcome the defect of bolt or nut looseness monitoring in the prior art and provide a bolt or nut looseness monitoring device and system.

This application solves the above technical problems through the following technical solutions:

A device for monitoring looseness of bolts or nuts, wherein the number of bolts or nuts is at least two and both are used for fastening on a base, and the device for monitoring looseness includes:

Optical fiber deformation sensor;

The optical fiber deformation sensor has a deformation sensing section, and the deformation sensing section of the optical fiber deformation sensor is arranged between two bolts or nuts, so that the deformation sensing section rotates on any one of the two bolts or nuts. Deformation occurs when.

Preferably, the two ends of the deformation sensing section of the optical fiber deformation sensor are respectively arranged between two adjacent or non-adjacent two bolts or nuts.

Preferably, the looseness monitoring device further includes a supporting device, the supporting device is arranged on the base and used to support the optical fiber deformation sensor;

The supporting device is arranged on two adjacent or non-adjacent bolts or nuts, and the optical fiber deformation sensor is arranged between the supporting devices of the two adjacent or non-adjacent bolts or nuts to make the deformation When any one of the two adjacent or non-adjacent bolts or nuts rotates, the sensing section is deformed by the relative force of the two supporting devices.

Preferably, the looseness monitoring device further includes a profiled nut;

The profiling nut is fixedly sleeved on the head of the bolt or nut; the supporting device is fixed on the profiling nut.

Preferably, the opposite ends of the profiling nut are respectively provided with a protruding piece;

The protruding sheet is provided with grooves, the two ends of the optical fiber deformation sensor are provided with limiting components, and the two ends of the optical fiber deformation sensor are respectively fixedly arranged on the concaves on different ends of the adjacent profiling nut. In the groove, the limiting portion is attached to the outer side wall of the groove of the protruding sheet; or, the protruding sheet is provided with an engaging portion, and both ends of the optical fiber deformation sensor are fixedly provided with connecting portions, so The connecting parts at both ends of the optical fiber deformation sensor are respectively engaged in the engaging parts on different ends of the adjacent profiling nut.

A bolt or nut looseness monitoring system, the looseness monitoring system includes at least one of the aforementioned bolt or nut looseness monitoring devices, and the looseness monitoring system further includes a signal analysis device and a laser emitting device;

The signal analysis device and the laser emitting device are respectively communicatively connected with the optical fiber deformation sensor in the looseness monitoring device;

The laser emitting device is used to emit laser light to the optical fiber deformation sensor; the signal analysis device is used to receive and analyze the optical signal returned by the optical fiber deformation sensor, and determine the loose bolt or nut according to the analysis result.

Preferably, a first corresponding relationship between the number of the optical fiber deformation sensor and the number of the bolt or nut, and a second corresponding relationship between the number of the optical fiber deformation sensor and the sensitive wavelength band are pre-stored in the signal analysis device;

The signal analysis device is used to analyze the center wavelength of the optical signal returned by the optical fiber deformation sensor, determine the number of the optical fiber deformation sensor according to the center wavelength of the optical signal and the second correspondence, and then determine the number of the optical fiber deformation sensor according to the optical fiber The number of the deformation sensor and the first correspondence relationship determine the number of the bolt or nut corresponding to the optical signal.

Preferably, the signal analysis device is also used to calculate the loosening angle of the loose bolt or nut according to the result of the analysis;

The signal analysis device also prestores a third correspondence between the number of the optical fiber deformation sensor and the standard center wavelength of the sensitive wavelength band;

The signal analysis device determines the standard center wavelength of the optical fiber deformation sensor according to the number of the optical fiber deformation sensor and the third correspondence, and then compares the center wavelength of the optical signal returned by the optical fiber deformation sensor to the standard center. The wavelength is compared, and the looseness angle of the bolt or nut corresponding to the optical signal is calculated.

Preferably, the looseness monitoring system further includes an alarm device; the alarm device and the signal analysis device are in communication connection;

The alarm device is used to receive data uploaded by the signal analysis device. The data includes the number of the bolt or nut and the loosening angle generated by the bolt or nut. When the loosening angle exceeds a threshold, it generates and Describe the alarm signal corresponding to the number of the bolt or nut.

The alarm device is used for when the data uploaded by the signal analysis device is not received within a preset time period, the data includes the number of the bolt or nut, and the number of the bolt or nut that has not been received is generated. The corresponding alarm signal.

The positive progress effect of this application lies in the fact that the bolt or nut looseness monitoring device and system provided by this application realize the bolt or nut looseness monitoring, and can detect the looseness and fracture of the bolt or nut in time, so as to facilitate timely maintenance and improve wind power generation. The scientificity and reliability of machine inspection and maintenance realize the automatic monitoring function of the state of the adjacent fixed bolts or nuts of the wind turbine; the number of sensors in the bolt or nut looseness monitoring device is only one more than the number of bolts or nuts to be tested, but A bolt or nut can be monitored by two sensors at the same time to ensure that the normal operation of the monitoring can still be guaranteed in the special case of a sensor failure, and the purpose of improving the accuracy and reliability of the test by using a smaller number of sensors .

Description of the drawings

FIG. 1 is a schematic structural diagram of a bolt looseness monitoring device of Embodiment 1 of the application.

2a and 2b are schematic diagrams of the structure of the profiling nut of Example 1 of the present application.

FIG. 3 is a schematic diagram of the bolt rotation angle and the stretched length of the sensor sensing section of Embodiment 1 of the application.

4 is a schematic structural diagram of a monitoring device for loosening multiple bolts according to Embodiment 1 of the application.

FIG. 5 is a schematic structural diagram of a bolt looseness monitoring device of Embodiment 2 of the application.

FIG. 6 is a schematic structural diagram of a bolt looseness monitoring system according to Embodiment 3 of the application.

Detailed ways

The following further describes the application by way of examples, but the application is not limited to the scope of the examples.

Example 1

As shown in Figure 1, a schematic structural diagram of a bolt looseness monitoring device of embodiment 1 of the present application. The bolt looseness monitoring device includes an optical fiber deformation sensor 1 and a supporting device 3. The optical fiber deformation sensor 1 has a deformation sensing section 12, and the monitored bolt The number is multiple and all are used for fastening on the base. In this embodiment, the monitored bolt is a hexagonal bolt with a hexagonal head. The deformation sensing section 12 of the optical fiber deformation sensor is arranged in two adjacent hexagonal bolts. In the middle of the bolt, the deformation sensing section 12 of the optical fiber deformation sensor is close to one side of the hexagonal head of the hexagonal bolt at the same time. When any one of the adjacent hexagonal bolts is loosened, the hexagonal head rotates to make the optical fiber deform. The deformation sensing section 12 of the sensor produces deformation, and the optical fiber deformation sensor 1 outputs a deformation signal to detect the loosening of the bolt.

The head of the bolt to be monitored in the bolt looseness monitoring device of this embodiment may also be quadrangular or any other non-circular shape. The number and arrangement of the optical fiber deformation sensors 1 in the bolt looseness monitoring device of this embodiment are not limited to this embodiment. Any method that monitors the bolt looseness by the deformation sensing section 12 of the optical fiber deformation sensor is essentially The scope of protection of this application.

The looseness monitoring device also includes a profiling nut 8. The profiling nut 8 is fixedly sleeved on the head of the bolt to be tested, and the profiling nut 8 is sleeved on the head of all the bolts to be tested. A profiled

nut

8 and 8L are sleeved on the head of the adjacent bolt to be tested;

The supporting device 3 is fixed on the profiling nut 8, and the structure of the profiling nut sleeved on the heads of all the bolts to be tested is the same as that of the profiling nut 8.

A protruding piece 9 is respectively provided at opposite ends of the profile nut 8;

The protruding piece 9 is provided with grooves 10, the two ends of the optical fiber deformation sensor are provided with limiting parts 11, and the two ends of the optical fiber deformation sensor are respectively fixedly arranged on the grooves on different ends of the adjacent profiled

nut

8 and 8L. In 10, the limiting portion 11 is attached to the outer side wall of the groove 10 on the protruding piece.

The protruding piece 9 of this embodiment may also be provided with a clamping part, and the two ends of the optical fiber deformation sensor may also be fixedly provided with connecting parts, and the connecting parts at both ends of the optical fiber deformation sensor are respectively clamped to the adjacent profiling screws. The cap 8 is in the engaging parts on the different ends.

In this embodiment, the profiling nut 8 is used as the sensor mounting bracket and the strain sensing point. The sensor mounting bracket is hung on both sides of the profiling nut 8. When the tested bolt is loose, it will rotate and drive the profiling on it. The nut 8 rotates together, and when the copy nut 8 rotates, the deformation sensing section of the optical fiber deformation sensor fixed on it is pulled to make a stretching action, so that the optical fiber deformation sensor sends a deformation signal. The profiling nut 8 and the supporting device 3 are integrally formed into a structure (injected part or thermoformed part), which is moulded by pouring or moulded by hot pressing.

In the bolt looseness monitoring device of this embodiment, the optical fiber deformation sensors are staggered and fixedly arranged on the adjacent profiled nut.

As shown in FIG. 2a, a schematic diagram of the structure of the profiling nut of Example 1 of the present application. A protruding piece 9 is provided on the opposite ends of the profiling nut. The protruding lobe 9 is provided with a groove 10, and the middle of the protruding nut is provided with a through hole 13 for sleeved fixing bolt heads.

As shown in FIG. 2b, a schematic diagram of the structure of the profiling nut of Example 1 of the present application. The profiling nut has a snap structure to prevent the profiling nut from slipping.

As shown in Figure 3, a schematic diagram of the bolt rotation angle and the tensile length of the sensor sensing section in Example 1 of the present application. When the bolt under test is loosened, it rotates and drives the profiling nut to rotate. The bolt looseness is reversed. The hour hand turns. When the bolt rotates 30°, the profiling nut rotates 30°, so that the deformation sensing section of the optical fiber deformation sensor is stretched and deformed by 2.63mm; when the bolt continues to rotate, the deformation sensing section of the optical fiber deformation sensor is continuously elongated , And even been pulled off.

As shown in FIG. 4, a schematic structural diagram of a monitoring device for loosening of multiple bolts in Embodiment 1 of the present application.

The principle of the bolt looseness monitoring device of the embodiment 1 of the present application for realizing the bolt looseness monitoring is as follows:

The profiling nut 8 is sleeved on the head of the bolt to be tested. The profiling nut 8 is provided with an installation position for the optical fiber deformation sensor. After the bolts are fixed, two adjacent profiling nuts 8 and the optical fiber deformation sensor 1 on 8L are provided. Directly hang each other in pairs, check each other, and judge the position of the loose bolt through the strain point. When the bolts are not loosened, the deformation sensing section of the optical fiber deformation sensor 1 is not stressed, and only slightly expands and contracts due to temperature. At this time, the deformation signal output by the optical fiber deformation sensor is none or outputs a weak deformation signal.

When the bolt under test is loosened, the bolt makes a rotating movement, which drives the profile nut 8 to make a rotating movement, and when the bolt is loosened, it rotates counterclockwise. For example, when the bolt under test is loosened, the bolt is loosened and turned counterclockwise. If the rotation is calculated by 30°, the deformation sensing section of the optical fiber deformation sensor 1 is elongated by 2.6mm. If two adjacent bolts are loose at the same time, the deformation sensing of the sensor The segment is stretched larger and even broken. At this time, the optical fiber deformation sensor outputs a large deformation signal or the output signal of the optical fiber deformation sensor is missing, indicating that the bolt is loose.

Since any one of the

adjacent copy nut

8 and 8L rotates, the deformation sensing section of the optical fiber deformation sensor 1 can be deformed or broken. At this time, it is necessary to check the optical

fiber deformation sensors

1L and 1L adjacent to the left and right of the optical fiber deformation sensor 1 at the same time. In the case of 1R, if the optical fiber deformation sensor 1L on the adjacent left outputs a deformation signal or the signal is missing, and the optical fiber deformation sensor 1R on the adjacent right does not output a deformation signal or the signal is missing, it is determined that the optical fiber deformation sensor 1 and the adjacent left optical fiber deformation sensor The bolts of the profiled nut 8L between 1L are loose.

The bolt looseness monitoring device of Embodiment 1 of the present application uses two fiber optic deformation sensors to monitor the same bolt at the same time, and simultaneously monitors the sensing points on both sides of the bolt. If the deformation signal changes output by two adjacent fiber optic deformation sensors are the same or the signal is missing, it indicates If the tested bolt is loose, it can be analyzed in the background to make the test result more reliable. If the continuous three fiber optic deformation sensors all output large deformation signals or the signal is missing, it indicates that the two consecutive bolts are loose.

The number of sensors in the bolt looseness monitoring device of this embodiment is only one more than the number of bolts to be tested, but a bolt can be monitored by two sensors at the same time, so as to ensure that the monitoring can still be guaranteed in the special case of a sensor failure. The normal operation of the sensor achieves the purpose of improving the accuracy and reliability of the test by using a smaller number of sensors.

The bolt looseness monitoring device of this embodiment is also suitable for nut looseness monitoring.

Example 2

As shown in FIG. 5, it is a schematic structural diagram of a bolt looseness monitoring device of Embodiment 2 of the present application.

In the bolt looseness monitoring device of this embodiment, the bolt to be tested wraps around the edge of the circular base 25, and the supporting device 20 is arranged on the same side of the profiling nut 23. The structure of the supporting device 20 is the same as that of the supporting device 3 in the first embodiment. The structure is the same. The two ends of the optical fiber deformation sensor 21 are respectively fixedly arranged on the supporting devices on the adjacent profiled nut 23 and the profiled nut 24, and the optical fiber deformation sensor 21 is arranged around the edge of the base 25. After the bolts are fixed, the optical fiber deformation sensor 21 on the two adjacent profiled nuts 23 and 24 is simultaneously restrained by the profiled nuts 23 and 24, and the rotation of any one of the profiled nuts 23 and 24 can make the optical fiber deformation sensor 21 The deformation sensing section of the sensor is deformed or broken. At this time, it is necessary to check the condition of the optical fiber deformation sensor adjacent to the left and right of the optical fiber deformation sensor 21 at the same time. If the adjacent left optical fiber deformation sensor outputs a deformation signal or the signal is missing, the adjacent right fiber is deformed at the same time If the sensor does not output a deformation signal or the signal is missing, it is determined that the bolt on which the profile nut is located between the optical fiber deformation sensor 21 and the adjacent left optical fiber deformation sensor is loose. The optical fiber deformation sensor is arranged around the edge of the base 25 according to the arrangement of the optical fiber deformation sensor 21 and the optical fiber deformation sensor 22 in the figure.

The bolt looseness monitoring device of Embodiment 2 of the present application uses two fiber optic deformation sensors to monitor the same bolt at the same time, and simultaneously monitors the sensing points on both sides of the bolt. If the deformation signals output by the two adjacent fiber optic deformation sensors have the same amount of change or the signal is missing, it indicates If the tested bolt is loose, it can be analyzed in the background to make the test result more reliable. If the continuous three fiber optic deformation sensors all output large deformation signals or the signal is missing, it indicates that the two consecutive bolts are loose.

Embodiment 3 is shown in FIG. 6, which is a schematic structural diagram of a bolt looseness monitoring system of Embodiment 3 of the present application.

The bolt looseness monitoring system of this embodiment includes several bolt looseness monitoring devices 100 of the above-mentioned embodiment 1.

The looseness monitoring system also includes a signal analysis device 200 and a laser emitting device 300;

The signal analysis device 200 is in communication connection with the optical fiber deformation sensor in the looseness monitoring device 100;

The laser emitting device 300 is communicatively connected with the optical fiber deformation sensor in the looseness monitoring device 100;

The laser emitting device 300 is used to emit laser light to the optical fiber deformation sensor; the signal analysis device 200 is used to receive and analyze the optical signal returned by the optical fiber deformation sensor, and determine the loose bolt or nut according to the analysis result.

The communication connection between the signal analysis device 200 and the optical fiber strain sensor is a wired communication connection.

The signal analysis device 200 prestores the first corresponding relationship between the number of the optical fiber deformation sensor and the number of the bolt, the second corresponding relationship between the number of the optical fiber deformation sensor and the sensitive wavelength band, and the number of the optical fiber deformation sensor and the first corresponding relationship of the standard center wavelength of the sensitive wavelength band. Three correspondences.

Each optical fiber deformation sensor has sensitivity corresponding to a specific wavelength of light, and the sensitivity means that the optical fiber deformation sensor reflects or diffracts light energy of a specific wavelength.

In this embodiment, the signal analysis device 200 uses a frequency sweep laser, which has the function of rapid wavelength scanning, and can work at any optional wavelength, from a specified start wavelength to a specified end wavelength for linear wavelength scanning at a specified speed, and a frequency sweep laser is used Analyzing the optical signal returned by the optical fiber deformation sensor can obtain the central wavelength of the optical signal. When the optical fiber deformation sensor receives the laser light emitted by the laser emitting device 300, it reflects or diffracts light of a certain wavelength. The signal analysis device 200 analyzes the received optical signal returned by the optical fiber deformation sensor, and when the center wavelength of the optical signal returned by the optical fiber deformation sensor is scanned, it will search for the second correspondence between the number of the optical fiber deformation sensor and the sensitive wavelength band, and find the center Which sensitive waveband the wavelength is in to determine the number of the optical fiber deformation sensor. Then, the number of the bolt is determined by searching for the first corresponding relationship between the number of the optical fiber deformation sensor and the number of the bolt.

The signal analysis device 200 is also used to calculate the loosening angle of the loose bolt according to the optical signal returned by the optical fiber deformation sensor. The signal analysis device 200 compares the center wavelength of the optical signal returned by the optical fiber deformation sensor with the standard center wavelength of the sensitive band according to the center wavelength of the optical signal returned by the optical fiber deformation sensor, calculates the looseness angle of the corresponding bolt, and then searches The third correspondence between the number of the optical fiber deformation sensor and the standard center wavelength of the sensitive waveband determines the number of the optical fiber deformation sensor, and then determines the looseness angle of the corresponding bolt.

The bolts are set with numbers during installation, such as L1, L2 to Ln; each optical fiber deformation sensor is also set with numbers, such as T1a, T2a to T(n+1)a; bolt L1 is set between the optical fiber deformation sensors T1a and T2a In the meantime, the bolt L2 is arranged between the optical fiber deformation sensors T2a and T3a, and the bolt Ln is arranged between the optical fiber deformation sensors Tna and T(n+1)a. The optical fiber deformation sensor numbered T1a can reflect or diffract 332nm light, and the optical fiber deformation sensor numbered T2a can reflect or diffract light with a center wavelength of 352nm. Therefore, when the signal analysis device 200 analyzes that the center wavelength of the optical signal returned by the received optical fiber deformation sensor is 332nm, find the sensitive wavelength band of the 332nm, and then through the first correspondence relationship, it can be determined that it is the optical fiber deformation sensor numbered T1a. This determines the number of the optical fiber deformation sensor, and then uses the same method to determine the optical fiber deformation sensor numbered T2a. The fiber optic deformation sensors numbered T1a and T2a simultaneously monitor the loosening of the bolt numbered L1, the fiber optic deformation sensors numbered T2a and T3a simultaneously monitor the loosening of the bolt numbered L2, and so on, the numbered Tna and T(n+ 1) A fiber optic deformation sensor simultaneously monitors the loosening of the bolt numbered Ln.

When an optical fiber deformation sensor is deformed by tension due to the loosening of the corresponding bolt, the center wavelength of the optical signal reflected by it will shift, but the center wavelength of the optical signal reflected by each optical fiber deformation sensor will shift by Limitedly, in this embodiment, it is ensured that the center wavelength of the optical signal reflected by each optical fiber deformation sensor does not coincide when the maximum deviation occurs. Therefore, when the center wavelength of the optical signal returned by the optical fiber deformation sensor received by the signal analysis device 200 is shifted, the number of the optical fiber deformation sensor that reflects the light can also be determined; for example, the number of the optical fiber deformation sensor received by the signal analysis device 200 can be determined. The central wavelength of the optical signal is 334nm. The wavelength of 334nm is the maximum deviation range of the central wavelength of the optical signal reflected by the optical fiber deformation sensor numbered T1a. Through the first correspondence, it can be confirmed that the optical fiber deformation sensor numbered T1a is deformed. . By searching for the third corresponding relationship, it is determined that the standard central wavelength of the sensitive wavelength band of the optical fiber deformation sensor numbered T1a is 332nm, and the central wavelength of the optical signal returned by the optical fiber deformation sensor numbered T1a is subtracted from the standard of the sensitive wavelength band of 334nm. The center wavelength of 332nm results in a 2nm deformation of the optical fiber deformation sensor and a 5° looseness of the bolt. When the optical fiber deformation sensor numbered T3a is deformed or the signal is missing, the bolts numbered L2 or L3 are predicted to loosen. At this time, it is necessary to determine which bolt is loosened according to the situation of the adjacent optical fiber deformation sensor number. If the number is T2a If the optical fiber deformation sensor numbered T4a has no deformation or signal loss, the bolt numbered L2 is determined to be loose; if the optical fiber deformation sensor numbered T2a has no deformation or signal loss, At the same time, if the optical fiber deformation sensor numbered T4a is deformed and the signal is missing, it is determined that the bolt numbered L3 is loosened, so as to determine which bolt is loosened.

The bolt looseness monitoring system in this embodiment also includes an alarm device 400, which is wirelessly connected to the signal analysis device 200; the data analyzed by the signal analysis device 200 includes the number of the bolt and the looseness angle generated by the bolt; the signal analysis device The data parsed by 200 is uploaded to the alarm device 400. The alarm device 400 determines whether the loosening angle of the bolt exceeds a preset threshold. If it exceeds the preset threshold, the alarm device 400 generates an alarm signal corresponding to the bolt number; If the alarm device 400 does not receive the data uploaded by the signal analysis device 200 within the preset time period, assuming that the preset time is 10 seconds, it will generate an alarm signal corresponding to the number of the bolt that has not been received. If the bolt has a small looseness, the deformation sensing section of the optical fiber deformation sensor does not break and deforms. At this time, the signal analysis device 200 receives the deformation signal output by the optical fiber deformation sensor, and when the bolt rotates 30°, the optical fiber deformation sensor is deformed. The sensing section is stretched and deformed by 2.6mm; when the bolt continues to rotate, the deformation sensing section of the optical fiber deformation sensor is continuously elongated or even broken. The preset bolt looseness angle threshold is 5°. When the looseness angle received by the alarm device 400 is greater than 5°, the bolt is considered to be loose, the alarm device 400 will generate an alarm signal and send it to the operator, and the operator will issue maintenance Instruction, while monitoring the subsequent loosening situation. If a bolt is loose, the deformation sensing sections of the optical fiber deformation sensor on both sides of the bolt will be stretched and deformed. The limit of the deformation sensing section of the stretched optical fiber deformation sensor is that the deformation sensing section of the sensor is broken. At this time, the signal source signal is lost. The signal analysis device 200 detects that the signal is lost. If the signal analysis device 200 detects that the signal output by the optical fiber deformation sensor is missing, that is, the deformation sensing section of the optical fiber deformation sensor is broken, it means that the corresponding bolt is loose, and the sensor should be repaired and replaced. At this time, the signal analysis device 200 Determine the number of the normal optical fiber deformation sensor according to the optical signal returned by the received optical fiber deformation sensor to determine the number of the broken optical fiber deformation sensor, and then determine that a certain or certain number of bolts are loose, and the alarm device 400 An early warning is issued to the operator, and the operator issues maintenance instructions. Under normal circumstances, the loosening of a bolt will continue, and the optical fiber deformation sensor will continue to detect the deformation data, so when the bolt looseness angle is detected to be small, you can also do the maintenance record first and continue the monitoring. Moreover, the loosening of one bolt will cause the other bolts to be loosened at the same time. At this time, the signal analysis device 200 can fully record the loosening information of all the bolts.

In the bolt looseness monitoring system of this embodiment, the key bolts such as the blades and the fixed base are added with an optical fiber deformation sensor that is one more than the number of bolts to be tested, and the optical fiber deformation sensor is arranged between two adjacent bolts. A copying cap or a copying nut is installed on the two bolts to monitor the loosening of the bolts. The nut profiling cap or profiling nut rotates with the loosening of the bolt, so that the deformation sensing section of the optical fiber deformation sensor on both sides of the tested bolt is deformed or even broken. The optical fiber deformation sensor transmits the deformation signal to the signal analysis device 200, and the signal is analyzed. The device 200 transmits the signal of each point through Wi-Fi (Wireless Fidelity, mobile hotspot) signals to the wind turbine operator for data analysis, discovers problems in time, and repairs after warning, without blind or purposeful maintenance.

Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these implementations without departing from the principle and essence of the application, but these changes and modifications all fall within the protection scope of the application.

Claims

A device for monitoring the looseness of bolts or nuts, wherein the number of bolts or nuts is at least two and both are used to be fastened to a base. The device is characterized in that the device for monitoring looseness includes:

Optical fiber deformation sensor;

The optical fiber deformation sensor has a deformation sensing section, and the deformation sensing section of the optical fiber deformation sensor is arranged between two bolts or nuts, so that the deformation sensing section rotates on any one of the two bolts or nuts. Deformation occurs when.
The bolt or nut looseness monitoring device according to claim 1, wherein the two ends of the deformation sensing section of the optical fiber deformation sensor are respectively set between two adjacent or non-adjacent two bolts or nuts .
The bolt or nut looseness monitoring device according to at least one of claims 1-2, wherein the looseness monitoring device further comprises a supporting device, and the supporting device is provided on the base and used to support the The optical fiber deformation sensor;

The supporting device is arranged on two adjacent or non-adjacent bolts or nuts, and the optical fiber deformation sensor is arranged between the supporting devices of the two adjacent or non-adjacent bolts or nuts to make the deformation When any one of the two adjacent or non-adjacent bolts or nuts rotates, the sensing section is deformed by the relative force of the two supporting devices.
The bolt or nut looseness monitoring device according to claim 3, wherein the looseness monitoring device further comprises a profiled nut;

The profiling nut is fixedly sleeved on the head of the bolt or nut; the supporting device is fixed on the profiling nut.
The bolt or nut looseness monitoring device according to claim 4, wherein the protruding piece is respectively provided at the opposite ends of the profiled nut;

The protruding sheet is provided with grooves, the two ends of the optical fiber deformation sensor are provided with limiting parts, and the two ends of the optical fiber deformation sensor are respectively fixedly arranged on the concaves on different ends of the adjacent profiling nut. In the groove, the limiting portion is attached to the outer side wall of the groove of the protruding piece; or, the protruding piece is provided with a clamping portion, and both ends of the optical fiber deformation sensor are fixedly provided with connecting portions, so The connecting parts at both ends of the optical fiber deformation sensor are respectively engaged in the engaging parts on different ends of the adjacent profiling nut.
A bolt or nut looseness monitoring system, wherein the looseness monitoring system comprises at least one bolt or nut looseness monitoring device according to any one of claims 1-5, and the looseness monitoring system further comprises Signal analysis device and laser emitting device;

The signal analysis device and the laser emitting device are respectively communicatively connected with the optical fiber deformation sensor in the looseness monitoring device;

The laser emitting device is used to emit laser light to the optical fiber deformation sensor; the signal analysis device is used to receive and analyze the optical signal returned by the optical fiber deformation sensor, and determine the loose bolt or nut according to the analysis result.
The bolt or nut looseness monitoring system according to claim 6, characterized in that:

The signal analysis device prestores a first correspondence between the number of the optical fiber deformation sensor and the number of the bolt or nut, and a second correspondence between the number of the optical fiber deformation sensor and the sensitive waveband;

The signal analysis device is used to analyze the central wavelength of the optical signal returned by the optical fiber deformation sensor, determine the number of the optical fiber deformation sensor according to the central wavelength of the optical signal and the second correspondence, and then determine the number of the optical fiber deformation sensor according to the optical fiber The number of the deformation sensor and the first corresponding relationship determine the number of the bolt or nut corresponding to the optical signal.
The bolt or nut looseness monitoring system according to claim 7, wherein:

The signal analysis device is also used to calculate the loosening angle of the loose bolt or nut according to the analysis result;

The signal analysis device also prestores a third correspondence between the number of the optical fiber deformation sensor and the standard center wavelength of the sensitive wavelength band;

The signal analysis device determines the standard center wavelength of the optical fiber deformation sensor according to the number of the optical fiber deformation sensor and the third correspondence, and then compares the center wavelength of the optical signal returned by the optical fiber deformation sensor to the standard center. The wavelength is compared, and the looseness angle of the bolt or nut corresponding to the optical signal is calculated.
The bolt or nut looseness monitoring system according to claim 8, wherein:

The looseness monitoring system also includes an alarm device; the alarm device is in communication connection with the signal analysis device;

The alarm device is used to receive data uploaded by the signal analysis device. The data includes the number of the bolt or nut and the loosening angle generated by the bolt or nut. When the loosening angle exceeds a threshold, it generates and Describe the alarm signal corresponding to the number of the bolt or nut.
8. The bolt or nut looseness monitoring system according to claim 7, wherein the looseness monitoring system further comprises an alarm device; the alarm device and the signal analysis device are in communication connection;

The alarm device is used for when the data uploaded by the signal analysis device is not received within a preset time period, the data includes the number of the bolt or nut, and the number of the bolt or nut that has not been received is generated. The corresponding alarm signal.