CN110986794B

CN110986794B - Fiber bragg grating displacement sensor with display function and capable of being recycled and measuring method

Info

Publication number: CN110986794B
Application number: CN201911329661.8A
Authority: CN
Inventors: 姜龙; 蒲志强; 曹鲁; 刘统玉; 石智栋
Original assignee: Shandong Micro Photographic Electronic Co ltd; Shaanxi Changwu Tingnan Coal Industry Co Ltd
Current assignee: Shandong Micro Photographic Electronic Co ltd; Shaanxi Changwu Tingnan Coal Industry Co Ltd
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2021-09-07
Anticipated expiration: 2039-12-20
Also published as: CN110986794A

Abstract

The invention discloses a fiber grating displacement sensor with self-display and reusability and a measuring method, wherein the fiber grating displacement sensor comprises: the device comprises a reel module, a sensor shell, and a strain beam fixing structure, a gear rack transmission structure, a worm gear transmission structure, a worm transmission structure, a secondary acceleration transmission structure and a mechanical digital display structure which are arranged in the sensor shell; the optical fiber displacement sensor and the reel are in modular design, a new reel module can be installed or replaced on the premise of not disassembling the sensor main body on site, the complex problem that the existing equipment cannot be replaced or needs to be returned to the factory for treatment is avoided, a large amount of cost is saved, and the optical fiber displacement sensor is green and environment-friendly.

Description

Fiber bragg grating displacement sensor with display function and capable of being recycled and measuring method

Technical Field

The invention belongs to the technical field of measurement, and particularly relates to a fiber bragg grating displacement sensor with a display function and capable of being recycled and a measurement method.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The traditional electronic displacement sensor for the coal mine is generally provided with an angle sensor in a gear meshing rack mechanical mode, when displacement occurs, a steel wire rope pulls a rack, the rack drives a gear, and the gear is connected with the angle sensor to output an electric signal. The whole structure of the mode is relatively simple, but the mode has the defects of small measuring range, difficult protection of rack leakage, easy damage and the like; the steel pulley structure can realize wide-range monitoring, but the angular displacement sensor still adopts an electronic sensor, the site still needs to be powered, the transmission distance is limited, and the electrical interference resistance is insufficient.

The fiber grating sensor generally adopts a spring tensile strain beam structure, and the sensor has a simple structure, but the structure is not easy to realize wide-range monitoring in practical application; other fiber grating structures also have the defects of complex integral structure, inconvenience in field installation, incapability of recycling and the like.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the fiber grating displacement sensor with self-display and reusability.

In order to achieve the above object, one or more embodiments of the present invention provide the following technical solutions:

the fiber grating displacement sensor with display and reutilization comprises:

the device comprises a reel module, a sensor shell, and a strain beam fixing structure, a gear rack transmission structure, a worm gear transmission structure, a worm transmission structure, a secondary acceleration transmission structure and a mechanical digital display structure which are arranged in the sensor shell;

the reel modules are fixed at corresponding positions outside the shell wall of the sensor and are coaxially connected with the worm transmission structure;

the worm gear teeth in the gear rack transmission structure and the worm gear transmission structure are meshed with the worm gear teeth in the worm transmission mechanism;

the stress surface of the strain beam in the strain beam fixing mechanism is contacted with the limit position of the left side of an ejector pin in the gear rack transmission mechanism, and the ejector pin is arranged on one side of the rack close to the strain beam;

the small teeth of the secondary accelerating gear shaft in the secondary accelerating transmission mechanism are meshed with the large teeth in the worm gear shaft of the worm transmission structure, so that a primary accelerating effect is achieved; the large teeth in the secondary accelerating gear shaft are meshed with the teeth in the digital gear shaft of the mechanical digital display structure, so that a secondary accelerating effect is achieved;

rotate the drive behind the reel module atress worm drive structure simultaneous occurrence rotates and stores energy, worm drive structure drives worm gear drive structure and rotates, and rack and pinion drive structure moves under worm gear drive structure drives, and the thimble acts on the roof beam stress surface that meets an emergency, makes the roof beam that meets an emergency take place flexural strain, and the roof beam that meets an emergency takes place flexural strain and can make the fiber grating who bonds on the roof beam that meets an emergency take place flexural strain, and the wavelength can change thereupon, through the demodulation to the FBG wavelength, thereby reachs the displacement volume through the formula calculation again.

In a further aspect, the sensor housing comprises: the sensor comprises a sensor barrel wall, a sensor base, a sensor upper cover, a sensor shell sealing ring, an optical cable fixed joint and an armored optical cable;

the sensor comprises a sensor upper cover, a sensor base, a sensor outer shell sealing ring and a sensor cylinder wall, wherein the sensor upper cover, the sensor base, the sensor outer shell sealing ring and the sensor cylinder wall jointly form a closed shell of the fiber grating displacement sensor, an optical cable fixed joint for fixing an optical cable is arranged on the outer side of the sensor base, and the optical cable fixed joint is connected with an armored optical cable.

Further technical solution, the strain beam fixing structure includes: the device comprises a strain beam, an optical fiber, a first fiber grating, a second fiber grating, a strain beam fixing frame and a strain beam limiting block;

the strain beam fixing frame is fixed on the sensor base; the strain beam is arranged on one side of the strain beam fixing frame, and the first fiber bragg grating and the second fiber bragg grating are respectively adhered to two sides of the strain beam; the strain beam limiting block is arranged on the other side of the strain beam fixing frame;

one end of the optical fiber is fixed on the strain beam, and the other end of the optical fiber enters the armored optical cable.

Further technical scheme, worm gear transmission structure and rack and pinion transmission structure include: the device comprises a worm gear shaft, a first support base, a second support base, a compression spring, a rack sliding rail, a thimble and an anti-skid column;

the first support base and the second support base are fixed at corresponding positions of the sensor base; the compression springs are respectively sleeved on the guide columns of the first support base and the second support base; the guide posts of the first support and the second support are respectively inserted into the guide holes of the first support base and the second support base; the anti-skid column is connected with the bottom threaded columns of the first support and the second support, and the guide columns of the second support extend out of the sensor base; the O-shaped ring is arranged in the grooves of the guide posts of the first bracket and the second bracket; the worm gear shaft is arranged between the first bracket and the second bracket; the rack sliding rail is fixed at the corresponding position of the second bracket; the rack is arranged in the groove of the rack sliding rail, and the rack is meshed with the small teeth on the worm gear shaft, so that the worm gear shaft drives the rack to move linearly on the rack sliding rail.

In a further technical solution, the worm drive structure includes: worm gear axle, spring box, spiral spring, third support, fourth support, O type circle.

The third support and the fourth support are fixed at corresponding positions of the sensor base; the worm gear shaft is arranged between the third support and the fourth support, and worm teeth on the worm gear shaft are meshed with worm gear teeth on the worm gear shaft, so that the worm gear shaft can freely rotate between the third support and the fourth support, and the worm gear shaft can drive the worm gear shaft to rotate by rotating; the spring box is fixed on the inner side of the fourth bracket, a volute spiral spring is arranged in the spring box, and the volute spiral spring is connected with the worm gear shaft; the O-shaped ring is arranged in a groove in the worm gear shaft and plays a role in sealing between the inside and the outside of the sensor shell.

In a further technical solution, the two-stage acceleration transmission structure includes: the second-stage accelerating gear shaft, the fifth bracket and the sixth bracket;

the fifth support and the sixth support are fixed at corresponding positions of the sensor base; the second-stage accelerating gear shaft is arranged between the fifth bracket and the sixth bracket, and small teeth on the second-stage accelerating gear shaft are meshed with large teeth on the worm gear shaft.

According to a further technical scheme, the mechanical digital display structure comprises: digit wheel gear shaft, first gear, third gear, second gear, fourth gear, unit digit wheel, ten digit wheel, hundred digit wheel, first shoulder stopper, second shoulder stopper, first self-aligning ball bearing, second self-aligning ball bearing, seventh support, eighth support, digit wheel countershaft, fifth gear, sixth gear, digital display window, observation glass.

The digital wheel gear shaft is arranged between the fifth bracket and the sixth bracket, and teeth on the digital wheel gear shaft are meshed with large teeth on a secondary accelerating gear shaft in the secondary accelerating structure; the first gear is fixed on one side of the one-digit number wheel; the unit digit wheel is arranged on the digit wheel shaft through a set screw; a third gear and a second gear are respectively fixed on two sides of the ten-digit number wheel, and a through hole 1-1 of the number wheel is in interference fit with an outer ring of the first self-aligning ball bearing; the first self-aligning ball bearing is arranged at a corresponding position of the digital wheel shaft; the first shaft shoulder limiting block is fixed on the left side of the first self-aligning ball bearing through a set screw; a fourth gear is fixed on one side of the hundred-digit wheel, and a hundred-digit wheel through hole is in interference fit with the outer ring of the second self-aligning ball bearing; the second self-aligning ball bearing is arranged on the digital wheel shaft, one side of the second self-aligning ball bearing is in contact with the first shoulder limiting block, and the other side of the second self-aligning ball bearing is fixedly provided with a second shoulder limiting block;

the seventh support and the eighth support are fixed at corresponding positions of the sensor base; the digit wheel auxiliary shaft is arranged between the seventh bracket and the eighth bracket; the fifth gear is arranged on one side of a shaft shoulder of the counter shaft of the digital wheel, the other side of the fifth gear is limited by an E-shaped retainer ring, and the fifth gear is meshed with the fourth gear; the sixth gear is arranged on the other side of the shaft shoulder of the counter shaft of the digital wheel, the other side of the sixth gear is limited by an E-shaped retainer ring, and the sixth gear is meshed with the second gear;

the digital display window is fixed on the sensor base right below the digit wheel; the observation glass is bonded in the corresponding sink groove on the back of the sensor base.

In a further aspect, the reel module structure includes: the reel shell, the reel cover, the reel shell sealing ring, the reel shaft sealing ring, the steel wire rope, the fixing ring, the third self-aligning ball bearing, the ninth bracket, the reel sealing ring and the reel steel wire rope lock catch;

the third self-aligning ball bearing is arranged in an inner hole of the reel in an interference fit manner; one end of the winding wheel shaft is arranged on the inner ring of the self-aligning ball bearing in an interference fit manner; the winding wheel shaft sealing ring is arranged in the winding wheel shaft groove; the reel is arranged on a D-shaped shaft section of the winding wheel shaft; the steel wire rope is tightly wound in the V-shaped groove of the reel, and the free end of the steel wire rope penetrates out of the upper hole of the reel shell; the reel shell sealing ring is arranged in a groove of an opening surface of the reel shell; the winding wheel cover is arranged on the opening surface of the reel shell, and the winding wheel shaft penetrates out of the winding wheel cover central hole; the ninth bracket is arranged on the lower surface of the reel shell and is fixed at a corresponding position of the wall of the sensor cylinder; the reel sealing ring is arranged in a threaded hole on the reel shell; the thread of the steel wire rope lock of the reel is matched with the threaded hole on the reel shell and compresses the sealing ring of the reel, and the free end of the steel wire rope penetrates out of the hole; the fixing ring is fixed at the free end of the steel wire rope and prevents the steel wire rope from rebounding into the reel module.

According to a further technical scheme, the exposed end of a winding wheel shaft in the reel module mechanism and one end of a worm gear shaft in the worm transmission mechanism rotate coaxially with the winding wheel shaft through a set screw.

The measurement method of the fiber bragg grating displacement sensor with the display function and the reusability function comprises the following steps:

the winding wheel module rotates after being stressed to drive the worm transmission structure to rotate and store energy at the same time, the worm transmission structure drives the worm gear transmission structure to rotate, the gear rack transmission structure moves under the driving of the worm gear transmission structure, the thimble acts on the stress surface of the strain beam to enable the strain beam to generate flexural strain, the flexural strain of the strain beam can enable the fiber bragg grating bonded on the strain beam to generate flexural strain, the wavelength can change along with the flexural strain, and the displacement is obtained through demodulation of the FBG on the wavelength and formula calculation;

wherein epsilon_MFor amount of flexural strain, λ_BIs the central wavelength of the fiber grating, k is a constant, Z_{Pinion gear}The number of teeth of small teeth in a worm gear shaft, i is the worm gear transmission ratio, L is the moving distance of the free end of the steel wire rope, d is the diameter of the reel, m is the gear modulus, and delta lambda_B1And Δ λ_B2The variation of the central wavelength of the first fiber grating and the variation of the central wavelength of the second fiber grating are respectively.

The above one or more technical solutions have the following beneficial effects:

1. the optical fiber displacement sensor can carry out continuous measurement, and has large and adjustable measuring range; the large digital disc on site is used for mechanical display, the visual display of monitoring data under a passive condition is realized, and the method is more reliable and visual. The sensor is not electrified, is intrinsically safe and is particularly suitable for inflammable and explosive places; the sensor is made of fireproof, anti-falling and corrosion-resistant materials, and is high in strength and rigidity and not easy to damage.

2. The optical fiber displacement sensor and the reel are in modular design, a new reel module can be installed or replaced on the premise of not disassembling the sensor main body on site, the complex problem that the existing equipment cannot be replaced or needs to be returned to the factory for treatment is avoided, a large amount of cost is saved, and the optical fiber displacement sensor is green and environment-friendly.

3. The optical fiber sensor takes light waves as an information carrier, and optical fiber information acquisition and transmission are integrated. The coal mine underground fire extinguishing agent is uncharged, intrinsically safe and suitable for an inflammable and explosive environment under a coal mine; the optical fiber has small transmission loss, long transmission distance, high transmission reliability and no influence of electromagnetic field interference and temperature and humidity; the optical fiber sensing monitoring system has large capacity, is easy to realize multi-point multi-parameter online monitoring, greatly reduces the types and the number of equipment, and has simple system configuration and convenient maintenance; the optical fiber sensor has the unique advantage of distributed monitoring, can realize the online monitoring of the temperature strain of each point along the optical fiber, and has unique application value in the continuous monitoring of a large space range.

4. The sensitivity and the measuring range of the sensor can be changed according to the actual use requirement: when the transmission ratio of the worm and the gear and rack modulus is not changed, the range of the sensor can be increased by increasing the diameter of the reel, and the precision and the sensitivity can be improved by reducing the diameter of the reel; when the gear and rack modulus and the diameter of the reel are not changed, the range can be enlarged by increasing the worm gear transmission ratio, and the precision and the sensitivity can be improved by reducing the worm gear transmission ratio; when the transmission ratio of the worm gear and the worm and the diameter of the reel are not changed, the precision and the sensitivity can be improved by adding the rack modulus of the large gear; when the size of the strain beam body is not changed, the measurement precision and sensitivity can be improved by increasing the thickness of the beam body (the depth of the grating bonding groove is not changed); when the thickness of the strain beam body is not changed, the length of the lengthened beam body can increase the measurement range. Compared with a common fiber grating displacement sensor, the fiber grating displacement sensor can measure a large distance (0-9999 mm), the practical situation is considered, continuous measurement of 0-999 mm is carried out according to an example, and the measuring range is adjustable.

5. The linear distance is converted into the linear distance by the steel wire rope, the reel rotates to drive the worm gear shaft to axially rotate, the worm gear shaft drives the worm gear shaft to axially rotate and decelerate, and the small teeth in the worm gear shaft drive the rack to linearly displace, so that the long distance is converted into the radial displacement of the rack, and the large-range characteristic of the sensor is realized by the mechanical structure.

6. The sensor is divided into a working state or an adjusting state, can be reset, and the meshing part of the worm and the gear can be disconnected by one key. The digital wheel automatic resetting and the strain beam automatic resetting are realized, and the problem that real-time calibration cannot be carried out such as the on-site display data cannot be zeroed after the display numerical value of the fiber grating equipment is adjusted to be the reference in the field use process of the existing sensor is solved.

7. The invention adopts the worm gear and worm transmission device, has large reduction ratio and small helix angle, has self-locking function, and ensures that the sensor is only influenced by the tension change of the steel wire rope in the detection state and is not influenced by the elasticity of the strain beam or the elasticity change.

The large digital disc on site is mechanically displayed, the visual display of monitoring data under a passive condition is realized, and the problem of reading errors caused by the display of a site measuring scale and a pointer gauge outfit is solved.

The measuring range, the precision and the sensitivity of the sensor can be adjusted, and the technology is easy to realize. When the transmission ratio of the worm and the gear and rack modulus is not changed, the range of the sensor can be increased by increasing the diameter of the reel, and the precision and the sensitivity can be improved by reducing the diameter of the reel; when the gear and rack modulus and the diameter of the reel are not changed, the range can be enlarged by increasing the worm gear transmission ratio, and the precision and the sensitivity can be improved by reducing the worm gear transmission ratio; when the transmission ratio of the worm gear and the worm and the diameter of the reel are not changed, the precision and the sensitivity can be improved by adding the rack module of the large gear.

8. The invention is in modular design. The installation easy dismounting, the side is fixed the screw, can accomplish wire rope position module and change, realizes the used repeatedly, avoids present equipment fixing in roof or dark aloft, and the loaded down with trivial details problem that equipment can't be changed or change needs to return the factory to handle makes it energy-concerving and environment-protective more. The sensitivity and the measuring range of the sensor can be adjusted by adjusting the transmission ratio of the worm gear, the diameter of the reel, the modulus of the gear and the rack and the size of the strain beam; the reel is modularized, so that the replacement is more convenient; carrying out real-time displacement field digital display; the whole is passive and is intrinsically safe.

9. The fiber grating self-compensation structure can realize the change of related parameters of the sensor by adjusting the size or the shape of the strain structure. When the size of the strain beam body is not changed, the measurement precision and sensitivity can be improved by increasing the thickness of the beam body (the depth of the grating bonding groove is not changed); when the thickness of the strain beam body is not changed, the length of the lengthened beam body can increase the measurement range.

10. The mechanical display has the advantages that: the mechanical display does not need power supply, is intrinsically safe, and has higher safety level in complex environments under the flammable and explosive conditions of mines. The mechanical display cannot stop working due to circuit problems, and the display is more stable. The mechanical display is not interfered by electromagnetism, and can still accurately display under extreme environment. The mechanical display has higher strength than that of an electronic display device and high reliability.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is a schematic view of the overall structure of an optical fiber displacement sensor according to the present invention 1;

FIG. 2 is a schematic view of the overall structure of the optical fiber displacement sensor of the present invention 2;

FIG. 3 is a schematic diagram of the housing and the wire rope locking structure of the optical fiber displacement sensor according to the present invention;

FIG. 4 is a schematic view of a fixing structure of a strain beam of the optical fiber displacement sensor according to the present invention;

FIG. 5 is a schematic view of a worm gear transmission structure and a rack-and-pinion transmission structure of the optical fiber displacement sensor of the present invention;

FIG. 6 is a cross-sectional view of the worm driving structure of the optical fiber displacement sensor of the present invention;

FIG. 7 is a schematic cross-sectional view of a two-stage acceleration transmission structure of the optical fiber displacement sensor according to the present invention;

FIG. 8 is a schematic view of a mechanical digital display structure of the optical fiber displacement sensor of the present invention 1;

FIG. 9 is a schematic diagram of a mechanical digital display structure of the optical fiber displacement sensor of the present invention 2;

FIG. 10 is a cross-sectional view of a module of a winding wheel of an optical fiber displacement sensor according to the present invention;

FIG. 11 is a schematic view of a worm gear shaft of the optical fiber displacement sensor according to the present invention;

FIG. 12 is a schematic view of a worm gear shaft of the optical fiber displacement sensor according to the present invention;

FIG. 13 is a schematic view of a secondary accelerating gear shaft of the optical fiber displacement sensor according to the present invention;

FIG. 14 is a schematic view of an adjustable bracket of a worm gear of the optical fiber displacement sensor according to the present invention;

FIG. 15 is a schematic view of a spool of the optical fiber displacement sensor of the present invention;

FIG. 16 is a schematic view of a fiber displacement sensor reel in accordance with the present invention;

FIG. 17 is a linear relationship diagram of wavelength difference and displacement value of the optical fiber displacement sensor according to the present invention.

Wherein, 1, the wall of the sensor cylinder; 2. a sensor base; 3. a sensor upper cover; 4. a sensor housing seal ring; 5. an optical cable fixed joint; 6. an armored optical cable; 7. a first fixing screw;

8. a strain beam; 9. an optical fiber; 10. a first fiber grating; 11. a second fiber grating; 12. a strain beam fixing frame; 13. a strain beam limiting block; 14. a second fixing screw; 15. fixing a screw III;

16. a worm gear shaft; 17. a first bracket; 18. a first support base; 19. a second bracket; 20. a second support base; 21. a compression spring; 22. a fifth fixing screw; 23. fixing screws IV; 24. a rack; 25. a rack slide rail; 26. a thimble; 27. an anti-slip column; 28. a first O-ring;

29. a third support; 30. a fourth bracket; 31. a worm gear shaft; 32. a volute spiral spring; 33. a spring case; 34. a sixth fixing screw; 35. a second O-ring;

36. a fifth support; 37. a sixth support; 38. a secondary accelerating gear shaft;

39. a digit wheel gear shaft; 40. a seventh support; 41. an eighth bracket; 42. a digit wheel countershaft; 43. a fifth gear; 44. a sixth gear; 45. e-shaped check rings; 46. a unit digit wheel; 47. a first set screw; 48. a first gear; 49. a third gear; 50. a second gear; 51. a fourth gear; 52. a ten digit wheel; 53. a hundred digit numeric wheel; 54. a first self-aligning ball bearing; 55. a first shoulder stop; 56. a second self-aligning ball bearing; 57. a second shoulder stop block; 58. a second set screw; 59. a fixing screw eighth; 60. a digital display window; 61. a seventh fixing screw; 62. observing glass;

63. a reel housing; 64. a winding wheel cover; 65. a reel housing seal ring; 66. a winding wheel shaft sealing ring; 67. a spool shaft; 68. a reel; 69. a wire rope; 70. a third self-aligning ball bearing; 71. a ninth support; 72. a reel sealing ring; 73. a steel wire rope lock catch of the reel; 74. a third set screw; 75. a wire rope hold-down bolt; 76. a ninth fixing screw; 77. ten fixing screws; 78. a fixing ring; 79. and eleven fixing screws.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

Example one

The embodiment discloses a fiber grating displacement sensor with display and reusability, which is shown in fig. 1 and fig. 2 and comprises a sensor shell, a worm transmission mechanism, a worm gear transmission mechanism, a gear rack transmission mechanism, a strain beam fixing mechanism, a reel module, a two-stage acceleration transmission mechanism and a mechanical digital display mechanism.

Referring to fig. 3, in an embodiment, the sensor housing includes: the sensor comprises a sensor barrel wall, a sensor base, a sensor upper cover, a sensor shell sealing ring, an optical cable fixed joint and an armored optical cable;

the sensor upper cover, the sensor base, the sensor outer shell sealing ring and the sensor cylinder wall jointly form a closed shell of the fiber grating displacement sensor, an optical cable fixing joint for fixing an optical cable is arranged on the outer side of the lower cover, and the optical cable fixing joint is connected with an armored optical cable; one end of the optical fiber is fixed on the strain beam, and the other end of the optical fiber penetrates through the lower cover to enter the armored optical cable.

The number of the sensor bases 2 is 1, and the sensor bases are used for fixing all transmission mechanisms inside.

The sensor cylinder wall 1 is 1 for protecting all transmission mechanisms in the sensor and providing a fixed platform for the reel module.

The number of the sealing rings 4 of the sensor shell is 2, and the sealing rings are used for sealing the sensor base 2 and the sensor cylinder wall 1, and the sealing rings 4 of the sensor shell are used for sealing the upper cover of the sensor and the sensor cylinder wall 1 of the sensor base 3.

The number of the first fixing screws 7 is 8, and the first fixing screws are used for fixing the sensor base 2 and the sensor upper cover 3.

The number of the optical cable fixed joints 5 is 1, and the optical cable fixed joints are used for connecting the sensor base 2 with the armored optical cable 6 and standard parts.

The armored optical cable 6 is 1 and is used for connecting the sensor and the demodulator.

In an embodiment, referring to fig. 4, the strain beam fixing structure includes: the device comprises a strain beam, an optical fiber, a first fiber grating, a second fiber grating, a strain beam fixing frame and a strain beam limiting block;

the strain beam fixing frame is fixed on the sensor base; the strain beam is arranged on the left side of the strain beam fixing frame, and the first fiber bragg grating and the second fiber bragg grating are respectively adhered to two sides of the strain beam; the strain beam limiting block is arranged on the right side of the strain beam fixing frame.

The number of the optical fibers 9 is 1, and a first fiber grating 10 and a second fiber grating 11 are connected on the optical fibers 9 in series.

The number of the strain beams 8 is 1, and a fixed platform is provided for the bonding of the fiber bragg grating.

The number of the strain beam fixing frames 12 is 1, and the strain beam fixing frames are used for fixing the strain beams 8.

The number of the strain beam limiting blocks 13 is 1, and the strain beam limiting blocks are used for limiting excessive bending of the strain beam 8.

In an embodiment, as shown in fig. 5, the worm gear transmission structure and the rack and pinion transmission structure include: the device comprises a worm gear shaft, a first support base, a second support base, a compression spring, a rack sliding rail, an ejector pin, an anti-slip column and a first O-shaped ring.

The worm gear shaft is shown in fig. 12. The worm gear adjustable bracket is shown in figure 14.

The first support base and the second support base are fixed at corresponding positions of the sensor base; the compression springs are respectively sleeved on the guide columns of the first support base and the second support base; the guide posts of the first support and the second support are respectively inserted into the guide holes of the first support base and the second support base; the anti-skid column is connected with the bottom threaded columns of the first support and the second support, and the guide columns of the second support extend out of the sensor base; the first O-shaped ring is arranged in the grooves of the guide posts of the first bracket and the second bracket; the worm gear shaft is arranged between the first bracket and the second bracket; the rack sliding rail is fixed at the corresponding position of the second bracket; the rack is arranged in the rack sliding rail groove, and the rack is meshed with the small teeth on the worm gear shaft, so that the worm gear shaft drives the rack to move linearly on the rack sliding rail; the thimble is installed in rack and is close to strain roof beam one side.

The number of the first bracket base 18 and the second bracket base 20 is 1 respectively, and a mounting base is provided for the worm gear transmission mechanism.

The number of the compression springs 21 is 4, and the compression springs have a tight meshing effect when the worm gear is meshed with the worm; when the meshing of the worm gear and the worm needs to be disconnected, the compression spring 21 is compressed, and the effects of reducing the axis of the worm gear shaft 16 and disconnecting the meshing can be achieved.

The number of the first bracket 17 and the second bracket 19 is 1, and the first bracket 17 provides a mounting bracket for the worm gear shaft 16, wherein the first bracket 17 also provides a fixed platform for the rack slide rail 25.

The number of the first O-rings 28 is 2, and the first support 17 and the second support 19 are used for sealing the guide post and the outside.

The number of the anti-slip columns 27 is 2, and the anti-slip columns are used for pulling down the first support 17 and the second support 19 to play a role in gripping and anti-slip when the worm gear is disconnected from the worm gear.

The number of the worm gear shafts 16 is 1, and the worm gear shafts are arranged between the brackets.

The number of the rack slide rails 25 is 1, and the rack slide rails play a role in guiding the rack 24.

The number of the racks 24 is 1, and the racks are meshed with the small teeth on the worm gear shaft 16 to convert the rotary motion into the linear motion.

The number of the thimbles 26 is 1, and the thimbles act on the stress surface of the strain beam 8.

In a specific embodiment, as shown in fig. 6, the worm driving structure includes: worm gear axle, spring box, spiral spring, third support, fourth support, second O type circle.

The third support and the fourth support are fixed at corresponding positions of the sensor base; the worm gear shaft is arranged between the third support and the fourth support, and worm teeth on the worm gear shaft are meshed with worm gear teeth on the worm gear shaft. The worm gear shaft can freely rotate between the third support and the fourth support, and the worm gear shaft can drive the worm gear shaft to rotate by rotating; the spring box is fixed on the inner side of the fourth bracket, a volute spiral spring is arranged in the spring box, and the volute spiral spring is connected with the worm gear shaft; the second O-shaped ring is arranged in a groove in the worm gear shaft and plays a role in sealing between the inside and the outside of the sensor shell.

The number of the

third brackets

29 and 30 is 1, which provides a mounting bracket for the worm gear shaft 31 and also provides a fixed platform for the spring case 33 and the spiral spring 32.

1 worm gear shaft 31 is meshed with the worm gear shaft 16, and has the effects of speed reduction and self locking; also providing a fixed platform for the wrap spring 32.

The number of the scroll springs 32 is 1, and the scroll springs provide power supply elements and provide rebound power for the steel wire rope 69.

The number of the spring boxes 33 is 1, and the spring boxes are fixed structures of the spiral springs 32.

The worm gear shaft is shown in fig. 11.

In a specific embodiment, as shown in fig. 7, the two-stage acceleration transmission structure includes: the second-stage accelerating gear shaft, the fifth bracket and the sixth bracket.

The secondary accelerator shaft is shown in fig. 13.

The number of the fifth bracket 36 and the sixth bracket 37 is 1 respectively, which provides a support platform for the secondary accelerating gear shaft 38 and also provides a support platform for the mechanical digital display structure.

The number of the two-stage accelerating gear shaft 38 is 1, and the small teeth of the two-stage accelerating gear shaft are meshed with the large teeth on the worm gear shaft 31, so that the accelerating effect is achieved.

In a specific embodiment, as shown in fig. 8 and 9, the mechanical digital display mechanism includes: digit wheel gear shaft, first gear, third gear, second gear, fourth gear, unit digit wheel, ten digit wheel, hundred digit wheel, first shoulder stopper, second shoulder stopper, first self-aligning ball bearing, second self-aligning ball bearing, seventh support, eighth support, digit wheel countershaft, fifth gear, sixth gear, digital display window, observation glass.

A digital wheel gear shaft is arranged between the fifth bracket and the sixth bracket, and teeth on the digital wheel gear shaft are meshed with large teeth on a secondary accelerating gear shaft in the secondary accelerating structure; the first gear is fixed on one side of the one-digit number wheel; the unit digit wheel is arranged on the digit wheel shaft through a set screw; a third gear and a second gear are respectively fixed on two sides of the ten-digit number wheel, and a through hole 1-1 of the number wheel is in interference fit with an outer ring of the first self-aligning ball bearing; the first self-aligning ball bearing is arranged at a corresponding position of the digital wheel shaft; the first shaft shoulder limiting block is fixed on the left side of the first self-aligning ball bearing through a set screw; a fourth gear is fixed on one side of the hundred-digit wheel, and a hundred-digit wheel through hole is in interference fit with the outer ring of the second self-aligning ball bearing; the second self-aligning ball bearing is arranged on the digital wheel shaft, one side of the second self-aligning ball bearing is in contact with the first shoulder limiting block, and the other side of the second self-aligning ball bearing is fixedly provided with a second shoulder limiting block;

The number of the digit wheel gear shafts 39 is 1, and a rotating shaft is provided for other components.

The unit digit wheel 46 is 1 providing a display of the digits on the unit and also providing a fixed platform for the first gear 48.

The number of tens digit wheel 52 is 1, which provides the digit display on the tens digit, and also provides a fixed platform for the 50 second gear and the 49 third gear.

The number of the hundred digit wheels 53 is 1, which provides the digit display on the hundred digit and also provides a fixed platform for the fourth gear 51.

The number of the first self-aligning ball bearings 54 is 1, and an intermediate medium is provided for the connection of the ten-digit wheel 52 and the digit wheel gear shaft 39, so that the friction force between the ten-digit wheel 52 and the digit wheel gear shaft is reduced.

The number of the second self-aligning ball bearings 56 is 1, and an intermediate medium is provided for connecting the hundred-digit number wheel 53 and the number wheel gear shaft 39, so that the friction force between the hundred-digit number wheel and the number wheel gear shaft is reduced.

The number of the first shoulder stoppers 55 is 1, and the first shoulder stoppers are used for restricting the right position of the hundreds digit wheel 53.

The number of the second shoulder stoppers 57 is 1, and the second shoulder stoppers are used for limiting the left position of the hundreds digit wheel 53.

The number of the fifth gears 43 is 1, and the transfer is provided for indirect meshing of 48 the first gear and 50 the second gear.

The number of the sixth gear 44 is 1, and the sixth gear provides the intermediate for the indirect meshing of the third gear 49 and the fourth gear 51.

The number of the E-shaped retaining rings 45 is 2, and the E-shaped retaining rings are used for limiting the axial movement of the gear.

The number wheel sub-shaft 42 is 1, and provides a rotation shaft for the fifth gear 43 and the sixth gear 44.

The seventh bracket 40 and the eighth bracket 41 are 1 each, and provide a mounting platform for the number wheel countershaft 42.

The number of the digital display windows 60 is 1, and a channel for observing the digital display wheel from the outside is provided.

The sight glass 62 is 1 piece, prevents external connections to the sensor interior, and provides a sight glass.

In a specific embodiment, as shown in fig. 10, the reel module structure includes: the reel shell, the reel cover, the reel shell sealing ring, the reel shaft sealing ring, the steel wire rope, the fixing ring, the third self-aligning ball bearing, the ninth support, the reel sealing ring and the reel steel wire rope lock catch.

The spool shaft is shown in figure 15. The reel is shown in figure 16.

The exposed end of a winding wheel shaft in the reel module mechanism and one end of a worm gear shaft in the worm transmission mechanism rotate coaxially with the winding wheel shaft through a set screw.

The reel 68 is 1, and provides a platform for fixing the joint of the steel cable 69, and plays a role in guiding and limiting the position for winding the steel cable 84.

The steel wire rope 69 is 1 and is a conductive member.

The number of retainer rings 78 is 1, fixed to the free end of the cable 69, to prevent the cable from rebounding into the reel housing.

The number of the winding wheel shafts 67 is 1, a rotating shaft is provided for the winding wheel 68, a platform for radial movement of the winding wheel 68 is provided, and a mounting groove is provided for a sealing ring of the winding wheel 66. And meanwhile, the connecting shaft is used as a connecting shaft of the winding wheel module structure and other mechanisms of the sensor main body.

The number of reel seals 66 is 1, and is used for sealing between the spool shaft 67 and the spool cover 64.

The number of reel covers 64 is 1, providing an extended hole position for the reel shaft 67.

The number of reel rope catches 73 is 1, and the reel rope catches are used for pressing the reel sealing rings 72, so that the rope holes in the reel housing 63 play a role in sealing and increasing damping.

Reel shell 63 is 1, plays the effect of protection inner structure, provides the mounting platform simultaneously for spool shaft 67, still provides fixed platform simultaneously for ninth support 71.

The reel housing seal rings 65 are 1 in number, and are used for sealing between the reel housing 63 and the reel cover 64.

The ninth bracket 71 is 1 bracket for attachment of the reel module to the sensor body.

The reel module mechanism independently exists, and the coaxial connection between the winding wheel shaft and the worm gear shaft can be disconnected according to actual needs on site, so that reel modules with other ranges can be replaced or a new reel module mechanism can be replaced.

As shown in fig. 1 and 2, the worm transmission mechanism is fixed at a corresponding position of the sensor base 2; the reel modules are fixed at corresponding positions on the outer side of the sensor cylinder wall 1, and the reel shaft 67 is coaxially connected with the worm gear shaft 31 and is fastened by a third fastening screw 74; the worm gear teeth in the worm gear transmission and gear rack transmission mechanism are meshed with the worm teeth in the worm gear transmission mechanism, and the mechanism is integrally fixed on the sensor base 2; the stress surface of a strain beam 8 in the strain beam fixing mechanism is in contact with the left limit position of a thimble 26 in the gear rack transmission mechanism and is fixed on the sensor base 2, and the optical fiber 9 penetrates into the armored optical cable 6.

The secondary accelerating transmission mechanism is fixed on the sensor base 2. The small teeth of the secondary accelerating gear shaft 38 in the secondary accelerating transmission mechanism are meshed with the large teeth in the worm gear shaft 31, so that the primary accelerating effect is achieved; the large teeth of the secondary acceleration gear shaft 38 are engaged with the teeth of the digital gear shaft 39, thereby achieving the effect of secondary acceleration.

In another embodiment, a measurement method of a fiber grating displacement sensor with a display and reusability comprises the following steps: comprises that

A digital display section:

when the distance between the steel wire rope fixing ring and the reel module main body is increased, the steel wire rope drags the reel to rotate, the reel drives the reel shaft to rotate, the reel shaft drives the worm gear shaft to rotate, the large teeth on the worm gear shaft are meshed with the secondary accelerating mechanism, and the secondary accelerating mechanism is meshed with the digital gear shaft. The effect of digital wheel gear shaft acceleration is realized through the cooperation of two-stage gear.

N_{Digital wheel gear shaft}＝10N_{Wound around}

Wherein N is_{Digital wheel gear shaft}Number of revolutions of the digital wheel gear shaft, N_{Wound around}The number of turns of the reel.

The digital wheel gear shaft drives the unit digital wheel to coaxially rotate, the unit digital wheel drives the first gear to rotate, the first gear is matched with the second gear through the fifth gear, and each time the first gear rotates for one circle, the third gear rotates for one digital position. And so on the relationship between the third gear and the fourth gear. The effect of different rotating speeds of the hundred digit wheel, the ten digit wheel and the single digit wheel is realized through two times of speed reduction.

100N_Bai＝10N_{Ten pieces of cloth}＝N_An。

Wherein N is_BaiNumber of revolutions of the hundreds digit wheel, N_{Ten pieces of cloth}Number of revolutions of ten digit wheel, N_AnThe number of rotations of the unit number wheel.

The guide post extending out of the first support on the sensor base is pulled, so that a worm gear transmission mechanism and a gear rack transmission mechanism inside the sensor are integrally reduced, worm teeth and worm gear teeth are not meshed any more, and the characteristic of worm and gear self-locking is cancelled. The worm gear shaft rotates reversely under the elastic force of the volute spiral spring. On one hand, the worm gear shaft sequentially drives the secondary accelerating gear shaft and the digital wheel gear shaft to rotate reversely, so that the digital display returns to zero; on the other hand, the worm gear shaft drives the reel to rotate reversely, so that the distance between the fixing ring and the reel module body is reduced, and the steel wire rope is wound on the reel.

Strain beam strain section:

when the distance between the fixed ring and the reel module main body is increased, the steel wire rope drags the reel to rotate, the reel drives the reel shaft to rotate, the reel shaft drives the worm gear shaft to rotate, the volute spiral spring stores energy, the worm teeth are meshed with the worm gear teeth to drive the worm gear shaft to rotate, the small teeth on the worm gear shaft drive the rack to move towards one side close to the strain beam, the flexural strain of the strain beam is increased, and the measured displacement is obtained through a displacement and flexural strain calibration formula;

the fixed ring and the sensor main body part are respectively fixed at two ends of a part to be displaced of the measurement target.

The guide post extending out of the first support on the sensor base is pulled, so that a worm gear transmission mechanism and a gear rack transmission mechanism in the sensor are lowered, worm teeth and worm gear teeth are not meshed any more, and the self-locking characteristic of the worm gear is cancelled. The rack moves to one side far away from the strain beam under the action of the resilience force of the strain beam, and the strain beam restores to the original position.

When the transmission ratio of the worm and the gear and rack modulus is not changed, the range of the sensor can be increased by increasing the diameter of the reel, and the precision and the sensitivity can be improved by reducing the diameter of the reel; when the gear and rack modulus and the diameter of the reel are not changed, the range can be enlarged by increasing the worm gear transmission ratio, and the precision and the sensitivity can be improved by reducing the worm gear transmission ratio; when the transmission ratio of the worm gear and the worm and the diameter of the reel are not changed, the precision and the sensitivity can be improved by adding the rack module of the large gear.

The measuring range, the measuring precision and the measuring sensitivity can be improved by changing relevant parameters of the strain beam. When the size of the strain beam body is not changed, the measurement precision and sensitivity can be improved by increasing the thickness of the beam body (the depth of the grating bonding groove is not changed); when the thickness of the strain beam body is not changed, the length of the lengthened beam body can increase the measurement range.

The linear relationship between the wavelength difference and the displacement value of the optical fiber displacement sensor is shown in the attached figure 17.

The specific calculation formula is as follows: the prior art and the data show that the wavelength change Δ λ is generated by temperature and strain_Β＝0.74λ_Βε_ΒWherein λ is_ΒIs the center of FBGWavelength epsilon_ΒIs strain. Namely:

after the deformation is generated, the strain of the two gratings is as follows:

ε_Β1＝ε_T+ε_M (2)

ε_Β2＝ε_T-ε_M (3)

wherein epsilon_TFor strain due to temperature influence, epsilon_MStrain due to deflection.

Obtained from formula (2) and formula (3):

is shown by the formula (1)

Fiber Bragg Grating (FBG) wavelength variation

And flexural strain ε_MLinear and one-to-one correspondence.

Meanwhile, the temperature has the same strain on the grating under the same environment, and the strain is epsilon_TBy combining formula (1), formula (2) and formula (3), epsilon is eliminated_TThereby eliminating the temperature from the desired measurement epsilon_MThe influence of (c).

Assuming that the horizontal displacement of the thimble acting on the strain beam (directly acting on the stress surface of the strain beam) is Δ l, the flexural strain is simplified:

ε_M＝k·Δl (6)

in the formula, k is a coefficient (only related to the size of the strain beam), and delta l is the horizontal displacement of the thimble (directly acting on the stress surface of the strain beam).

Suppose that the displacement between the sensor body and the wire rope fixing ring is L

Relationship between displacement amount L and number of turns of the reel:

L＝S·n_{reel with a rotatable handle} (7)

S＝π·d (8)

The following equations (7) and (8) show that:

wherein L is the displacement between the sensor body and the wire rope fixing ring, S is the reel circumference, n_{Reel with a rotatable handle}The number of turns of the winding wheel shaft is d, and the diameter of the winding wheel is d.

The relation between the number of turns of the winding wheel shaft and the number of turns of the worm gear shaft:

because the worm gear shaft rotates coaxially with the spool shaft.

So that it is known that:

n_{reel with a rotatable handle}＝n_{Worm screw} (10)

From the formulae (9), (10), (11):

wherein n is_{Worm screw}The number of turns of the worm gear shaft, n_{Worm wheel}The number of turns of the worm gear shaft is, and i is the transmission ratio of the worm gear and the worm.

The relationship between the number of turns of the worm gear shaft and the number of teeth of the small teeth in the worm gear shaft:

α＝n_{worm wheel}·2π (13)

From the formulae (12), (13), and (14):

wherein Δ Z_{Pinion gear}∈[0，+∞) (15)

Wherein alpha is the rotation angle of the pinion in the worm gear shaft, and delta Z_{Pinion gear}Number of teeth rotated by pinion gear, Z_{Pinion gear}The number of teeth of the pinion.

Relationship between the number of teeth rotated by the pinion and the amount of horizontal displacement of the rack:

P_n＝π·m (16)

Δl＝P_n·ΔZ_{pinion gear} (17)

From the formulae (15), (16), and (17):

wherein m is the module of the gear rack, P_nIs the rack pitch.

From the formulae (5), (6), (18):

it can be seen from the equation (19) that the displacement amount is linearly dependent on the flexural strain amount (k is a constant value after the strain beam is dimensioned), and the flexural strain ε_MAnd the wavelength change of the fiber grating

Linear relation between the displacement and the wavelength variation of the fiber grating

And has a linear relationship. The linear relation is obtained through calibration, and the change of the displacement can be obtained according to the wavelength change of the fiber bragg grating.

In this case, 2 fiber gratings with different center wavelengths are respectively arranged on the upper and lower sides of the strain beam.

When the sensor is installed, the fixing ring and the sensor are required to be respectively fixed between the positions needing to be detected and displaced.

The working principle of the sensor is as follows:

FBG flexural Strain section

Pulling the retainer ring 78 away from the reel module body; the wire rope 69 drags the reel 68 and the winding wheel shaft 67 to rotate; the worm gear shaft 31 is driven by the winding gear shaft 67 to rotate coaxially; the scroll spring 32 rotates along with the worm gear shaft 31 at the same time, and the scroll spring 32 stores energy along with the rotation of the worm gear shaft 31; the worm teeth in the worm gear shaft 31 drive the worm gear and the coaxial small teeth in the worm gear shaft 16 to rotate; the rack 24 is driven by the small teeth in the worm gear shaft 16 to do linear motion on the rack slide rail 25; the thimble 26 acts on the stress surface of the strain beam 8 to enable the strain beam 8 to generate flexural strain, the flexural strain of the strain beam 8 enables the first fiber grating 10 and the second fiber grating 11 which are bonded on the strain beam 8 to generate flexural strain, the wavelength can be changed accordingly, and the FBG wavelength is demodulated, and then the displacement is calculated through a formula.

The worm gear and worm transmission has a self-locking function, can only rotate along the same direction and cannot rotate reversely, and the thrust of the strain beam is ensured to be only related to the displacement of the steel wire rope to the maximum extent and is unrelated to other factors.

The worm gear and worm transmission has a larger reduction ratio, and the characteristic can realize the function of realizing a large range of the displacement sensor.

When the anti-skid columns 27 are pulled to enable the axis of the worm gear shaft 16 to be lowered, the engagement of the worm gear and the worm is disconnected, and self-locking disappears. The strain beam 8 can restore to the original state under the self elasticity, and the rack 24 can move towards the side far away from the strain beam 8; since the scroll spring 32 has stored energy before, the worm gear shaft 31 is rotated in the reverse direction by the elastic force of the scroll spring 32; the reel 68 and the spool shaft 67 are also rotated in the reverse direction by the worm gear shaft 31, and the wire rope 69 is retracted.

A digital display section:

pulling the retainer ring 78 away from the reel module body; the wire rope 69 drags the reel 68 and the winding wheel shaft 67 to rotate; the worm gear shaft 31 is driven by the winding gear shaft 67 to rotate coaxially; the scroll spring 32 rotates along with the worm gear shaft 31 at the same time, and the scroll spring 32 stores energy along with the rotation of the worm gear shaft 31; the secondary accelerating gear shaft 38 is driven to rotate under the meshing action of the large teeth of the worm gear shaft 31; the digital wheel gear shaft 39 is driven by the secondary accelerating gear shaft 38 to rotate; the one-digit number wheel 46 and the number wheel gear shaft 39 rotate coaxially; under the indirect meshing of the first gear 48 and the second gear 50, the effect that the ones digit wheel 46 rotates for one circle and the tens digit wheel 52 rotates for one digit is realized; under the indirect meshing of the third gear 49 and the fourth gear 51, the ten-digit wheel 52 rotates for one circle, and the hundred-digit wheel 53 rotates for one digit. Implementation of 100N_Bai＝10N_{Ten pieces of cloth}＝N_An。

When the anti-skid columns 27 are pulled to enable the axis of the worm gear shaft 16 to be lowered, the engagement of the worm gear and the worm is disconnected, and self-locking disappears. Since the spiral spring 32 has stored energy, the worm gear shaft 31 is rotated in the opposite direction by the elastic force of the spiral spring 32; and the second-stage accelerating gear shaft 38 drives the digital wheel gear shaft 39 to rotate reversely, so that the digital wheel is automatically zeroed. At the same time, the reel 68 and the spool shaft 67 are rotated in the reverse direction by the worm gear shaft 31, and the wire rope 69 is retracted.

When the sensor is normally used, the main part of the sensor and the free end of the steel wire rope 69 are respectively fixed at two ends of a part to be displaced of a measurement target, the free end of the steel wire rope is fixed by the fixing ring 78, and the main part of the sensor is fixed on an object to be measured by a bolt.

And (3) calibrating the sensor:

after the sensor is packaged, firstly, the sensor is calibrated, and the calibration equipment is an electronic displacement calibration platform.

The calibration interval is set to be 10mm (or other interval lengths) by fixing the sensor and the steel wire rope, the calibration is sequentially carried out to 999mm from the positive stroke of 0mm, and the calibration is repeated for 2 times. And recording the wavelengths of the first fiber grating and the second fiber grating and the actual displacement of the calibration platform in the calibration process, and then calculating each parameter value.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.

Claims

1. From showing reuse's fiber grating displacement sensor, characterized by includes:

the device comprises a reel module, a sensor shell, and a strain beam fixing structure, a gear rack transmission structure, a worm gear transmission structure, a worm transmission structure, a secondary acceleration transmission structure and a mechanical digital display structure which are arranged in the sensor shell; the sensor housing includes: the sensor comprises a sensor barrel wall, a sensor base, a sensor upper cover, a sensor shell sealing ring, an optical cable fixed joint and an armored optical cable; the sensor upper cover, the sensor base, the sensor shell sealing ring and the sensor cylinder wall jointly form a closed shell of the fiber bragg grating displacement sensor;

the reel module is fixed on the outer side of the sensor shell wall and is coaxially connected with the worm transmission structure;

the worm gear teeth in the gear rack transmission structure and the worm gear transmission structure are meshed with the worm gear teeth in the worm transmission structure;

the stress surface of the strain beam in the strain beam fixing structure is in contact with the limit position of the left side of an ejector pin in the gear rack transmission structure, and the ejector pin is arranged on one side, close to the strain beam, of the rack; the strain beam fixing structure comprises a strain beam limiting block, and the strain beam limiting block is arranged on one side of the strain beam fixing frame;

the small teeth of the secondary accelerating gear shaft in the secondary accelerating transmission structure are meshed with the large teeth in the worm gear shaft of the worm transmission structure, so that a primary accelerating effect is achieved; the large teeth in the secondary accelerating gear shaft are meshed with the teeth in the digital gear shaft of the mechanical digital display structure, so that a secondary accelerating effect is achieved;

the winding wheel module rotates after being stressed to drive the worm transmission structure to rotate and store energy at the same time, the worm transmission structure drives the worm gear transmission structure to rotate, the gear rack transmission structure moves under the driving of the worm gear transmission structure, the thimble acts on the stress surface of the strain beam to enable the strain beam to generate flexural strain, the flexural strain of the strain beam enables the fiber bragg grating bonded on the strain beam to generate flexural strain, the wavelength can change along with the flexural strain, and the displacement is obtained through demodulation of the FBG wavelength and formula calculation; the worm gear transmission structure and the gear rack transmission structure comprise a first bracket and a second bracket;

worm gear drive structure and rack and pinion drive structure still include: the device comprises a worm gear shaft, a first bracket base, a second bracket base, a compression spring, a rack sliding rail, a thimble and an anti-slip column;

the first support base and the second support base are fixed on the sensor base; the compression springs are respectively sleeved on the guide columns of the first support base and the second support base; the guide posts of the first support and the second support are respectively inserted into the guide holes of the first support base and the second support base; the O-shaped ring is arranged in the grooves of the guide posts of the first bracket and the second bracket;

and the anti-slip column is connected with the bottom threaded columns of the first support and the second support guide column extending out of the sensor base.

2. The reusable fiber grating displacement sensor with self-display as claimed in claim 1, wherein an optical cable fixing joint for fixing an optical cable is arranged outside the sensor base, and the optical cable fixing joint is connected with an armored optical cable.

3. The fiber grating displacement sensor with display and reuse of claim 1, wherein the strain beam fixing structure further comprises: the device comprises a strain beam, an optical fiber, a first fiber grating, a second fiber grating and a strain beam fixing frame;

the strain beam fixing frame is fixed on the sensor base; the strain beam is arranged on the other side of the strain beam fixing frame, and the first fiber bragg grating and the second fiber bragg grating are respectively bonded on the two sides of the strain beam;

4. The fiber grating displacement sensor with display and reuse of claim 1, wherein the worm gear shaft is installed between the first bracket and the second bracket; the rack sliding rail is fixed on the second bracket; the rack is arranged in the groove of the rack sliding rail, and the rack is meshed with the small teeth on the worm gear shaft, so that the worm gear shaft drives the rack to move linearly on the rack sliding rail.

5. The fiber grating displacement sensor with display and reuse of claim 1, wherein the worm drive structure comprises: the worm gear shaft, the spring box, the volute spiral spring, the third bracket, the fourth bracket and the O-shaped ring;

the third support and the fourth support are fixed on the sensor base; the worm gear shaft is arranged between the third support and the fourth support, and worm teeth on the worm gear shaft are meshed with worm gear teeth on the worm gear shaft, so that the worm gear shaft can freely rotate between the third support and the fourth support, and the worm gear shaft can drive the worm gear shaft to rotate by rotating; the spring box is fixed on the inner side of the fourth bracket, a volute spiral spring is arranged in the spring box, and the volute spiral spring is connected with the worm gear shaft; the O-shaped ring is arranged in a groove in the worm gear shaft and plays a role in sealing between the inside and the outside of the sensor shell.

6. The fiber grating displacement sensor with display and reuse of claim 1, wherein the secondary acceleration transmission structure comprises: the second-stage accelerating gear shaft, the fifth bracket and the sixth bracket;

the fifth support and the sixth support are fixed on the sensor base; the second-stage accelerating gear shaft is arranged between the fifth bracket and the sixth bracket, and small teeth on the second-stage accelerating gear shaft are meshed with large teeth on the worm gear shaft.

7. The reusable fiber grating displacement sensor with display of claim 1, wherein the mechanical digital display structure comprises: the device comprises a digit wheel gear shaft, a first gear, a third gear, a second gear, a fourth gear, a unit digit wheel, a ten-digit wheel, a hundred-digit wheel, a first shoulder limiting block, a second shoulder limiting block, a first self-aligning ball bearing, a second self-aligning ball bearing, a seventh support, an eighth support, a digit wheel countershaft, a fifth gear, a sixth gear, a digit display window and observation glass;

the digital wheel gear shaft is arranged between the fifth bracket and the sixth bracket, and teeth on the digital wheel gear shaft are meshed with large teeth on a secondary accelerating gear shaft in the secondary accelerating transmission structure; the first gear is fixed on one side of the one-digit number wheel; the unit digit wheel is arranged on the digit wheel shaft through a set screw; a third gear and a second gear are respectively fixed on two sides of the ten-digit number wheel, and a number wheel through hole is in interference fit with the outer ring of the first self-aligning ball bearing; the first self-aligning ball bearing is arranged on the digital wheel shaft; the first shaft shoulder limiting block is fixed on the left side of the first self-aligning ball bearing through a set screw; a fourth gear is fixed on one side of the hundred-digit wheel, and a hundred-digit wheel through hole is in interference fit with the outer ring of the second self-aligning ball bearing; the second self-aligning ball bearing is arranged on the digital wheel shaft, one side of the second self-aligning ball bearing is in contact with the first shoulder limiting block, and the other side of the second self-aligning ball bearing is fixedly provided with a second shoulder limiting block;

the seventh bracket and the eighth bracket are fixed on the sensor base; the digit wheel auxiliary shaft is arranged between the seventh bracket and the eighth bracket; the fifth gear is arranged on one side of a shaft shoulder of the counter shaft of the digital wheel, the other side of the fifth gear is limited by an E-shaped retainer ring, and the fifth gear is meshed with the fourth gear; the sixth gear is arranged on the other side of the shaft shoulder of the counter shaft of the digital wheel, the other side of the sixth gear is limited by an E-shaped retainer ring, and the sixth gear is meshed with the second gear;

8. The fiber grating displacement transducer with display and reusability of claim 1, wherein the reel module comprises: the reel shell, the reel cover, the reel shell sealing ring, the reel shaft sealing ring, the steel wire rope, the fixing ring, the third self-aligning ball bearing, the ninth bracket, the reel sealing ring and the reel steel wire rope lock catch;

the third self-aligning ball bearing is arranged in an inner hole of the reel in an interference fit manner; one end of the winding wheel shaft is arranged on the inner ring of the self-aligning ball bearing in an interference fit manner; the winding wheel shaft sealing ring is arranged in the winding wheel shaft groove; the reel is arranged on a D-shaped shaft section of the winding wheel shaft; the steel wire rope is tightly wound in the V-shaped groove of the reel, and the free end of the steel wire rope penetrates out of the upper hole of the reel shell; the reel shell sealing ring is arranged in a groove of an opening surface of the reel shell; the winding wheel cover is arranged on the opening surface of the reel shell, and the winding wheel shaft penetrates out of the winding wheel cover central hole; the ninth bracket is arranged on the lower surface of the reel shell and is fixed on the wall of the sensor cylinder; the reel sealing ring is arranged in a threaded hole on the reel shell; the thread of the steel wire rope lock of the reel is matched with the threaded hole on the reel shell and compresses the sealing ring of the reel, and the free end of the steel wire rope penetrates out of the hole; the fixing ring is fixed at the free end of the steel wire rope and prevents the steel wire rope from rebounding into the reel module.

9. The reusable fiber grating displacement sensor with self-display as claimed in claim 1, wherein the exposed end of the winding wheel shaft in the winding wheel module structure and the end of the worm gear shaft in the worm transmission structure rotate coaxially therewith through a set screw.

10. The measurement method of the fiber grating displacement sensor with the display and the reusability is characterized in that the fiber grating displacement sensor with the display and the reusability as claimed in any one of claims 1 to 9 is adopted; the method comprises the following steps: