CN119164539A - An optical fiber gasket structure for fastener loosening alarm - Google Patents
An optical fiber gasket structure for fastener loosening alarm Download PDFInfo
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- CN119164539A CN119164539A CN202411404047.4A CN202411404047A CN119164539A CN 119164539 A CN119164539 A CN 119164539A CN 202411404047 A CN202411404047 A CN 202411404047A CN 119164539 A CN119164539 A CN 119164539A
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- Prior art keywords
- optical fiber
- bolt
- measuring head
- gasket
- grating measuring
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/24—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for determining value of torque or twisting moment for tightening a nut or other member which is similarly stressed
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/165—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge by means of a grating deformed by the object
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
本发明公开了一种用于紧固件松弛报警的光纤垫片结构，是一种基于光纤应变测量的紧固件松弛报警装置。该装置核心在于利用光纤光栅精确测量安装于螺栓与连接件之间的垫片变形，以此间接评估螺栓的预紧力情况。利用波长解调仪作为光信号处理单元，负责向光纤光栅发射光信号并接收反射回来的光束，通过分析光束波长的变化来解析垫片的应变情况，进而判断螺栓是否松弛。一旦检测到螺栓预紧力下降至预设阈值以下，装置将发出报警信号。光纤光栅的高灵敏度与光纤传输的远距离、抗电磁干扰特性相结合，确保了测量的准确性与数据传输的稳定性。因此，本发明提供了一种测量准确、抗干扰能力强的紧固件松弛报警装置，为机械设备的安全运行提供了重要保障。
The present invention discloses a fiber optic gasket structure for fastener loosening alarm, which is a fastener loosening alarm device based on fiber optic strain measurement. The core of the device is to use fiber optic Bragg grating to accurately measure the deformation of the gasket installed between the bolt and the connector, so as to indirectly evaluate the preload condition of the bolt. A wavelength demodulator is used as an optical signal processing unit, which is responsible for emitting optical signals to the fiber optic Bragg grating and receiving the reflected light beam. By analyzing the change in the wavelength of the light beam, the strain condition of the gasket is analyzed to determine whether the bolt is loose. Once it is detected that the bolt preload force drops below a preset threshold, the device will send an alarm signal. The high sensitivity of the fiber optic Bragg grating is combined with the long-distance and anti-electromagnetic interference characteristics of optical fiber transmission to ensure the accuracy of measurement and the stability of data transmission. Therefore, the present invention provides a fastener loosening alarm device with accurate measurement and strong anti-interference ability, which provides an important guarantee for the safe operation of mechanical equipment.
Description
Technical Field
The invention relates to the technical field of mechanical fastening monitoring, in particular to a fastener loosening alarm device utilizing an optical fiber strain measurement principle, which can monitor the fastening state of a fastener in real time, discover and alarm the fastener loosening caused by vibration, fatigue and other reasons in time, and ensure the safe operation of equipment.
Background
The constant vibration and dynamic loading present a significant challenge to the stability of the bolted connection during operation of the mechanical device. The locking of the bolt, that is, the reservation of proper looseness or the taking of specific locking measures when fastening the bolt, is important to ensure the stable connection of the key parts of the vehicle. Under the vibration environment of mechanical equipment, the bolts can be loosened gradually due to repeated vibration impact, so that the performance and the safety of the mechanical equipment can be affected, and parts can be damaged or fall off, so that serious accidents are caused.
Aiming at the mechanical vibration environment, the adoption of an effective bolt loosening and anti-loosening strategy is particularly important. These strategies include the use of lock washers, double nuts, wire looseness-preventing devices, etc., to increase the friction and stability of the bolted connection. However, the prior anti-loosening measures are mainly to periodically check and maintain the bolt fastening pieces, and are necessary measures for ensuring the safe operation of mechanical equipment. By periodically checking the fastening state and the anti-loosening effect of the bolts, the loosened or damaged bolts are timely found and processed, and further safety accidents caused by the loosening of the bolts are prevented. However, inspection and maintenance require the machine to be shut down, reducing the efficiency of the machine. Meanwhile, if the fastener suddenly loosens in the running process, mechanical equipment cannot give an alarm in time, and a great potential safety hazard still exists.
Therefore, the invention provides the fastener loosening alarm device using the optical fiber strain measurement, which can detect the connection state of the bolt fastener in real time in the operation process of mechanical equipment. When the bolt fastener is loosened, the optical fiber strain measurement system can measure the loosening of the bolt and timely send out an alarm signal. By utilizing the technology of the invention, whether each bolt fastener is loosened or not can be detected on line in real time under the condition that the mechanical equipment is not stopped, thereby improving the safety of the movement of the equipment.
Disclosure of Invention
The invention aims to provide an optical fiber gasket structure for fastener loosening alarm.
The technical scheme for realizing the aim of the invention is that the structure of the fastener relaxation alarm device utilizing the optical fiber strain measurement mainly comprises a gasket, a protective shell, an optical fiber protective sleeve, a grating measuring head, an optical fiber connector, a wavelength demodulator, alarm equipment and the like.
Further, the gasket is used for being clamped in the bolt fastener, protecting the surface of a workpiece, increasing the stressed contact area, or providing anti-loosening supporting elastic force.
Further, the spacer is mounted between the fastener and the fastened component as a load bearing basis for the fiber optic sensor while having some elasticity in response to changes in tightness of the fastener.
Furthermore, the gasket is made of metal or nonmetal, and the function of measuring the strain of the gasket is not affected as long as the gasket is pressed by the stress in the bolt fastener.
Furthermore, the protective housing covers and protects the core component of the whole device, prevents the damage of the external environment to sensitive elements such as optical fibers and the like, and has certain sealing performance so as to cope with severe working environments.
Further, the optical fiber protection sleeve is placed in the protection shell and used for protecting the optical fiber from mechanical damage and external environment interference, ensuring stable transmission of optical fiber signals, and the grating measuring head and part of optical fiber are placed in the optical fiber protection sleeve.
Further, the grating measuring head is used as a core component of the optical fiber sensor and is placed in the optical fiber protection sleeve or fixed at a specific position of the gasket, and the sensitivity of the optical fiber grating to strain is utilized to measure the micro deformation of the fastener caused by loosening in real time.
Further, the optical fiber is connected with the grating measuring head and the optical fiber connector and is responsible for transmitting the strain information captured by the grating measuring head to the wavelength demodulator in the form of an optical signal.
Further, the optical fiber connector provides a stable connection interface between the optical fiber and the wavelength demodulator, so that reliable transmission of optical signals is ensured.
Further, the wavelength demodulator is used for transmitting and receiving optical signals transmitted by the optical fibers, converting the optical signals into corresponding strain values or wavelength offsets, and judging whether the fastener is loosened or not through a built-in algorithm. A data processing unit is integrated or separately placed within the wavelength demodulator for data processing and analysis.
Further, when the wavelength demodulator detects that the fastener is loosened and exceeds a preset threshold value, the alarm device is triggered to send out an audible and visual alarm or send an alarm signal to the remote monitoring system.
Compared with the prior art, the invention has the remarkable advantages that:
(1) The invention designs a fiber grating strain measurement device, which mainly aims to measure the strain of a gasket under the compression state of a bolt fastener, and when the gasket is strained, the bolt fastener still generates larger pretightening force, and the bolt is not loosened. Compared with the prior art, the pre-tightening force state of the bolt fastener can be detected on line in real time, when loosening occurs, the pre-tightening force changes, and the loosening device can send an alarm signal, so that the monitoring accuracy and timeliness are improved.
(2) Compared with the prior art of transmitting electric signals by using wires, the optical fiber transmission device has the advantages that the pad structure connected with the fiber bragg grating is designed, and the signals transmitted by the fiber bragg grating are free of electromagnetic radiation and interference of surrounding electromagnetic radiation, so that false alarm signals are avoided, and stability and reliability of monitoring data are ensured.
(3) The grating measuring head has high sensitivity and high resolution, and can accurately capture micro deformation of the fastener caused by loosening, so that the grating measuring head has higher detection precision. And the method is suitable for various severe working environments such as high temperature, high humidity, strong vibration and other scenes, and provides powerful guarantee for the safe operation of engineering equipment.
Drawings
FIG. 1 is a schematic diagram of a fiber measurement relaxation alarm pad according to the present invention.
FIG. 2 is an exploded schematic view of the fiber optic measurement relaxation alarm pad of the present invention.
The device comprises a gasket 1, a protective shell 2, an optical fiber protective sleeve 3, a grating measuring head 4, an optical fiber 5, an optical fiber connector 6, a wavelength demodulator 7 and an alarm device 8.
Detailed Description
The invention provides a fastener loosening alarm device structure using optical fiber strain measurement, which adopts the principle that a grating measuring head is used for accurately measuring the tiny deformation of a gasket so as to indirectly judge the pretightening force state of a bolt, thereby realizing real-time monitoring and early warning of the loosening condition of the bolt. The core components of the system comprise a gasket integrated with a grating measuring head, an optical fiber transmission line, a wavelength demodulator, alarm equipment and the like.
The grating measuring head is embedded or clung to the surface of the gasket, and when the bolt is correctly screwed, the gasket can be stressed by pressure from the bolt and the connecting piece, so that certain deformation is generated. This deformation can cause minor changes in the physical structure inside the fiber grating, thereby affecting the specific wavelength of the reflected light. The wavelength demodulator emits an optical signal to the grating measuring head and receives the optical signal reflected by the grating measuring head. The change of the wavelength of the reflected light is analyzed through an algorithm, the demodulator can calculate the deformation of the gasket, and the deformation directly reflects the current pretightening force state of the bolt.
Under the normal working state of the bolt, the bolt keeps enough pretightening force, the pressure born by the gasket is stable, and the deformation detected by the grating measuring head is also maintained in a certain range. However, once the pretightening force of the bolt is gradually reduced due to vibration, temperature change or material fatigue, the pressure applied to the gasket is reduced, and the deformation of the gasket is reduced. This process is captured quickly by the grating measuring head and converted into a wavelength change of the optical signal which is transmitted to the wavelength demodulator. The wavelength demodulator analyzes that the deformation of the gasket is obviously reduced, and when the deformation is lower than a preset safety threshold, an alarm mechanism is triggered immediately.
The gasket is arranged between the bolt and the connecting piece, compatibility with the fiber bragg grating measuring head is considered in design, and deformation of the gasket can be accurately measured by the grating measuring head. The gasket material may be selected according to the particular application, such as a metal, alloy, plastic, or high performance composite, to ensure adequate strength and durability.
The optical fiber protection sleeve is made of high-strength and corrosion-resistant materials, and the optical fiber is effectively protected from being damaged by the external environment. The grating measuring head is placed in the optical fiber protection sleeve and can be tightly adhered with the optical fiber protection sleeve by adopting a special adhesive. The optical fiber protective sleeve is tightly attached to the surface of the gasket, and can accurately reflect the micro deformation of the gasket through bonding or welding. And transmitting the minute deformation to the grating measuring head, thereby causing the minute deformation of the grating measuring head.
After the micro deformation of the grating measuring head occurs, the wavelength of the optical signal transmitted from the optical fiber changes during reflection, so that the optical signal can be detected by a wavelength demodulator. The optical fiber is led out from the grating measuring head, passes through the optical fiber protection sleeve and is finally connected to the optical fiber connector for long-distance transmission of optical signals.
The protective shell is designed to wrap the whole fiber bragg grating measuring head, the fiber bragg grating protective sleeve and part of the optical fibers, is made of waterproof and impact-resistant materials, and ensures that the device can stably work for a long time in a severe environment. The protective shell is mounted in place on the pad by bonding, welding or other fastening means.
The wavelength demodulator is connected with the optical fiber through an optical fiber connector and is responsible for sending optical signals to the grating measuring head and receiving the reflected optical signals. The demodulator is internally provided with a high-precision signal processing algorithm, and a data processing unit is internally integrated or independently arranged for data processing and analysis. The wavelength change of the grating measuring head caused by the deformation of the gasket can be analyzed in real time, so that the pretightening force state of the bolt can be calculated. Once the pretension is detected to be lower than the set threshold, the bolt is considered to be loosened, and the demodulator immediately sends a signal to the alarm device.
The wavelength demodulator is internally provided with a temperature compensation system, and parameters can be correspondingly adjusted along with the change of temperature. Or the wavelength demodulator is externally connected with a temperature compensation optical fiber, detects the temperature change of the measured piece, and adjusts parameters.
The fastener loosening alarm device can also comprise a data processing unit which is used for receiving the output signal of the wavelength demodulator and further processing and analyzing the data so as to improve the accuracy and the reliability of the alarm.
The alarm equipment starts an alarm program immediately after receiving the signal of the demodulator, and can give an alarm to operators through sound, light flash, display screen display or remote communication and other modes. Meanwhile, the alarm equipment can record information such as alarm time, position and the like, and remind the alarm equipment to take measures in time to fasten or replace the bolt so as to prevent structural failure or safety accidents caused by loosening of the bolt.
The present invention will be described in detail below with reference to the drawings and examples.
Examples
The invention provides an optical fiber gasket structure for fastener looseness alarm, which is shown in fig. 1, wherein a gasket 1 is arranged between a bolt and a connecting piece and is used as a measuring object. When the device is not installed, the gasket 1 is not deformed, and the grating measuring head 4 does not measure the deformation of the gasket 1, so that the gasket 1 is not stressed. When the bolts are tightened, the gasket 1 is subjected to a large pretension pressure and a slight deformation is generated. The grating measuring head 4 can accurately measure the tiny deformation of the gasket 1, and if the gasket 1 is deformed, the gasket 1 is indicated to be already subjected to larger pressure, and then a larger pretightening force exists on the bolt fastener. If the deformation of the spacer 1 is reduced, it means that the pre-tightening force of the bolt fastener is reduced, and the bolt is likely to be loosened. Thereby, the pretightening force state of the bolt fastener is judged through the deformation condition of the gasket 1.
A grating measuring head 4 as shown in fig. 2 is placed inside the fiber-optic protective sleeve 3. The optical fiber protection sleeve 3 is of a hollow structure, and the grating measuring head 4 and part of the optical fiber 5 penetrate into the optical fiber protection sleeve 3. The inside of the optical fiber protection sleeve 3 is filled and sealed by high-strength glue, the grating measuring head 4 and part of the optical fiber 5 are fixed, the overall rigidity is enhanced, and the deformation state of the gasket 1 is accurately transferred while the grating measuring head 4 and the optical fiber 5 are protected from external physical damage and chemical corrosion. The optical fiber protection sleeve 3 is tightly attached to the surface of the gasket 1, and can accurately reflect the micro deformation of the gasket 1 by means of bonding or welding.
The protective shell 2 shown in fig. 2 is located on the outermost layer of the spacer 1 and is made of a sturdy and durable material, so that the optical fiber protective sleeve 3, the grating measuring head 4 and part of the optical fiber 5 are protected, and the device can work stably for a long time in a severe environment. The optical fiber 5 is connected with the grating measuring head 4 and the wavelength demodulator 7, so that stable transmission of optical signals is realized. The outer skin of the optical fiber 5 is made of a firm and durable material, has the characteristics of electromagnetic interference resistance, corrosion resistance and the like, and is suitable for severe environments and complex electromagnetic environments.
One end of the optical fiber 5 is connected to the grating measuring head 4 and the other end is connected to the optical fiber connector 6 as shown in fig. 2. The optical fiber connector 6 is a quick plug-in mechanism, and can conveniently and quickly connect the optical fiber 5 to the wavelength demodulator 7 and other instruments. The wavelength demodulator 7 is used for transmitting and receiving optical signals, analyzing the wavelength change of the fiber grating caused by the deformation of the gasket 1, and when the deformation of the gasket 1 is reduced, the pretightening force of the bolt is considered to be reduced, and the loosening condition may occur. A data processing unit is integrated or separately placed in the wavelength demodulator 7 for data processing and analysis. Inside or outside the wavelength demodulator 7, there is a temperature compensation unit, which changes the detection parameters with temperature changes. When the bolt pretightening force is detected to be lower than a preset threshold value (namely, the bolt is judged to be loose), the wavelength demodulator 7 sends alarm information to the alarm equipment 8. The alarm device 8 immediately emits an alarm signal in various forms such as sound, light, display screen display, remote communication and the like.
The foregoing is merely a preferred embodiment of the invention, and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (12)
1. The utility model provides an optical fiber gasket structural design for fastener looseness warning, is a fastener looseness warning device based on optical fiber strain measurement, and its characterized in that includes gasket (1), protective housing (2), optical fiber protection sleeve (3), grating measuring head (4), optic fibre (5), optical fiber connector (6), wavelength demodulator (7), alarm device (8).
2. A spacer according to claim 1, mounted between a bolt and a connector, or between a nut and a connector, or between other fasteners, as a measurement object to sense a change in the pretension of the bolt.
3. The grating measuring head according to claim 1, wherein the grating measuring head is directly attached to the surface of the spacer for measuring the strain of the spacer caused by the change of the pretightening force of the bolt, or is placed in the optical fiber protection sleeve by using glue or pressing and fixing, and the deformation of the spacer can be transmitted to the optical fiber protection sleeve and then to the grating measuring head.
4. The fiber optic protection sleeve of claim 1, wherein the fiber optic protection sleeve is securely fastened to the spacer by at least one fastening means (e.g., glue or welding) to ensure accurate measurement of the strain of the spacer. The inner glue filling and sealing material has the characteristics of high strength, corrosion resistance and ageing resistance so as to provide long-term protection effect.
5. The optical fiber protective sleeve according to claim 1 can be an integral structure with the grating measuring head, and the grating measuring head can be directly adhered to a proper position of the gasket without using a specially manufactured optical fiber protective sleeve.
6. The optical fiber according to claim 1, wherein the grating measuring head is connected with the wavelength demodulator for realizing remote transmission of optical signals, and has electromagnetic interference resistance.
7. The protective case of claim 1, located on the outermost layer, surrounding and protecting the grating measuring head, the fiber protecting collar and the fiber connection portion, ensuring stable operation of the device for a long period of time in a harsh environment.
8. The wavelength demodulator according to claim 1, wherein the wavelength demodulator is configured to transmit an optical signal to the grating measuring head, receive the reflected optical signal, and analyze a wavelength change of the fiber grating due to deformation of the spacer, so as to determine a pre-tightening state of the bolt. The demodulator is internally integrated or is independently provided with a data processing unit which is used for receiving the output signal of the wavelength demodulator and further processing and analyzing the data so as to improve the accuracy and the reliability of the alarm.
9. The wavelength demodulator according to claim 1, wherein a temperature compensation system is provided, and parameters can be adjusted accordingly with temperature changes. Or the wavelength demodulator is externally connected with a temperature compensation optical fiber, detects the temperature change of the measured piece, and adjusts parameters.
10. The alarm device according to claim 1, connected to the wavelength demodulator, and configured to send an alarm signal when detecting that the bolt pretightening force is lower than a preset threshold, that is, the bolt is loosened, according to an analysis result of the wavelength demodulator.
11. The fastener loosening warning device of claim 1, wherein the grating measuring head is attached to the spacer in a manner that sensitively captures the micro-strain of the spacer due to the change in bolt preload.
12. The fastener loosening warning device as claimed in claim 1, wherein the warning apparatus is capable of emitting various forms of warning signals such as sound, light, display screen display or remote communication to meet the use requirements in different situations.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411404047.4A CN119164539A (en) | 2024-10-09 | 2024-10-09 | An optical fiber gasket structure for fastener loosening alarm |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411404047.4A CN119164539A (en) | 2024-10-09 | 2024-10-09 | An optical fiber gasket structure for fastener loosening alarm |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN119164539A true CN119164539A (en) | 2024-12-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411404047.4A Pending CN119164539A (en) | 2024-10-09 | 2024-10-09 | An optical fiber gasket structure for fastener loosening alarm |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119164539A (en) |
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2024
- 2024-10-09 CN CN202411404047.4A patent/CN119164539A/en active Pending
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