A non-gel fiber Bragg grating strain sensor

Abstract

The present application relates to the technical field related to optical deformation measurement equipment, and discloses a non-glueized fiber grating strain sensor. In order to solve the problem that the device is prone to loosening due to the large number of fastening points required for packaging and fixing, a data optical fiber line passes through a tightening groove and is inserted and locked on a connecting frame, and the data optical fiber line is tightened by using the friction between the data optical fiber line and the tightening groove. At the same time, when the fastener fixes the mounting frame on the workpiece to be tested, the connecting frame and the workpiece to be tested are used to squeeze the data optical fiber line, further enhancing the friction between the data optical fiber line and the connecting frame, preventing the data optical fiber line from escaping from the tightening groove, thereby achieving the effect of packaging and overall fastening in one.

Description

Technical Field

[0001] The present application relates to the technical field related to optical deformation measurement equipment, and in particular to a non-gelatinized fiber Bragg grating strain sensor. Background Art

[0002] Fiber Bragg Grating strain sensor, or FBG strain gauge, is the leader in the fiber Bragg grating sensor series and is known for its wide range of applications and excellent performance characteristics. The core of this sensor uses Bragg fiber grating (FBG) as a sensitive element, which can accurately capture and measure the tiny changes in the Bragg wavelength of the fiber grating, thereby accurately reflecting the strain state of the object being measured. Its significant advantages include high precision, high sensitivity, excellent anti-electromagnetic interference ability and excellent corrosion resistance. These characteristics make FBG strain gauges an indispensable detection tool in many industrial and scientific research fields.

[0003] However, in the current application of fiber Bragg grating strain sensors, packaging and fixing technology is still one of the key factors affecting measurement accuracy and stability. Traditionally, the sensor is encapsulated on the strain carrier through adhesive, and then the carrier is firmly mounted on the surface of the test piece through fasteners such as bolts. Although this method can ensure the stable operation of the sensor in the early stage, after long-term use, the encapsulation colloid is easily affected by environmental factors and ages and falls off, which directly affects the close fit between the sensor and the test piece, thereby causing inaccurate test data.

[0004] In addition, the loosening of the fastening bolts is also a problem that cannot be ignored. Once the bolts are loose, the slight displacement between the sensor and the object to be measured will introduce errors, causing the impulse data to deviate from the true value. More seriously, since the traditional packaging and fixing methods involve multiple fastening points, the local looseness of any point may cause a chain reaction on the accuracy of the entire measurement system, affecting the reliability of the overall measurement data. Summary of the invention

[0005] The present application proposes a non-gelatinized fiber Bragg grating strain sensor, which has the advantages of packaging and overall fastening in one, and is used to solve the problem in the above background technology that the device is prone to loosening due to the large number of fastening points required for packaging and fixation.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution: a non-gelatinized fiber grating strain sensor, comprising: a mounting frame, the surface of which is arranged with fasteners, the side of which is fixedly connected to a connecting frame, and a strain carrier is fixed on the connecting frame; a grating fiber optic sensor, which is arranged on the inner side of the strain carrier, and the two ends of the grating fiber optic sensor are respectively connected to data optical fiber lines; a tensioning groove, which is opened on the surface of the connecting frame, for the data optical fiber line to pass through and fix it.

[0007] Furthermore, it also includes: a distance adjusting bolt, which is threadedly connected to the surface of the mounting frame, and a fastener passes through the middle of the distance adjusting bolt; a limit seat, which is fixedly connected to the bottom end of the distance adjusting bolt, and an intermediate sleeve is sleeved on the outer side of the limit seat; a distance adjusting pressure block, which is sleeved on the inner side of the intermediate sleeve, and a distance adjusting spring is connected between the distance adjusting pressure block and the limit seat.

[0008] Furthermore, it also includes: a positioning gear row arm and a movable gear row arm, the ends of which are hinged, and a positioning rod is movably installed at the hinge point, and the positioning rod is movably installed on the side of the mounting frame; a tension spring is arranged between the movable gear row arm and the positioning gear row arm; a guide slide rail is fixed on the outside of the mounting frame; a lifting magnet is fixed on the end of the movable gear row arm; a fine-tuning rod is movably installed on the inner side of the guide slide rail, and a switching seat is coaxially fixed to the bottom of the fine-tuning rod, and a movable magnet that magnetically repels the lifting magnet is fixedly connected to the surface of the switching seat; a pre-tensioning top roller is movably installed on the side of the movable gear row arm, and the data optical fiber line bypasses the side of the pre-tensioning top roller.

[0009] Furthermore, a limiting tooth row located on one side of the positioning tooth row arm is fixedly connected to the side of the mounting frame.

[0010] Furthermore, a gear is fixedly connected to the top of the outer side of the middle sleeve, and a fastening sleeve is fixedly connected to the bottom of the outer side of the middle sleeve, and a cutter is installed on the outer side of the fastening sleeve.

[0011] Furthermore, a "C"-shaped ring is provided on the outer side of the switching seat, and a collar is fixedly connected to the bottom of the movable gear row arm.

[0012] Furthermore, a support ring is movably installed on the inner top of the intermediate sleeve, and an ejection spring is connected between the support ring and the mounting frame, and a synchronization pull rod is fixedly connected to the top of the support ring; the outer side of the distance adjusting pressure block and the inner side of the intermediate sleeve constitute a distance adjusting cavity, and a one-way liquid valve is fixedly connected to the top of the distance adjusting pressure block, and an oil filling part is provided on the top of the intermediate sleeve; the side of the cutter is located in the distance adjusting cavity, and a return spring is connected between the cutter and the fastening sleeve.

[0013] The present invention has the following beneficial effects:

[0014] The present application provides a non-gelatinized fiber Bragg grating strain sensor, which passes the data optical fiber through the tensioning groove and is cleverly inserted and locked on the connecting frame. In this process, the friction generated between the data optical fiber and the inner wall of the tensioning groove is used as the initial fastening mechanism. What is particularly unique is that when the fastener firmly fixes the mounting frame on the test piece, it not only enhances the overall stability of the structure, but also significantly improves the friction between the optical fiber and the connecting frame through the joint squeezing effect of the connecting frame and the test piece on the optical fiber, effectively preventing the optical fiber from accidentally slipping out of the tensioning groove under extreme conditions.

[0015] This design cleverly combines the fastening effect with the installation strength of the fastener. As long as the fastener remains firmly fixed, the data fiber line can be continuously and stably squeezed evenly from the DUT and the connection frame. This double fastening mechanism ensures that the fiber Bragg grating sensor can maintain extremely high fixing strength and stability even without any colloid assistance.

[0016] In addition, the design also reflects the optimization of the number of fastening points. By rationally arranging the fasteners, it is possible to reduce unnecessary fastening points while ensuring a stable connection, which not only simplifies the installation process but also improves the overall aesthetics and compactness of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute a part of the specification, illustrate embodiments disclosed in the present application and, together with the description, serve to explain the principles disclosed in the present application.

[0018] The present application can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0019] Figure 1 It is a schematic diagram of the overall external three-dimensional structure;

[0020] Figure 2 It is a schematic diagram of the overall top view structure;

[0021] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure at EE in the middle;

[0022] Figure 4 It is a schematic diagram of the main structure of the mounting frame;

[0023] Figure 5 It is a schematic diagram of the three-dimensional structure of the movable gear row arm;

[0024] Figure 6 It is a schematic diagram of the cooperation between two fastening sleeves;

[0025] Figure 7 It is a schematic diagram of the internal three-dimensional structure of the fastening sleeve.

[0026] In the figure: 1, mounting frame; 101, guide rail; 102, connecting frame; 103, tensioning groove; 2, strain carrier; 3, data optical fiber line; 300, grating optical fiber sensor; 4, distance adjustment bolt; 5, fastener; 6, gear; 7, fastening sleeve; 8, limit gear row; 9, positioning gear row arm; 10, tension spring; 11, movable gear row arm; 110, positioning rod; 12, preload top roller; 13, switching seat; 130, fine-tuning rod; 14, movable magnetic block; 15, lifting magnetic block; 16, support ring; 160, ejection spring; 17, cutter; 170, return spring; 18, synchronous pull rod; 19, distance adjustment pressure block; 190, distance adjustment chamber; 191, one-way liquid valve; 20, intermediate sleeve; 21, distance adjustment spring; 22, limit seat; 220, oil filling part. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] Embodiment 1

[0029] See also Figure 1 It can be seen that fasteners 5 are symmetrically arranged on the surface of the mounting frame 1, and the fasteners 5 can be used to restrict the mounting frame 1 to the part to be tested. There are two mounting frames 1, and each mounting frame 1 is provided with two fasteners 5. Therefore, four fasteners 5 can be used to firmly connect the mounting frame 1 to the part to be tested, thereby ensuring the stability of the connection.

[0030] The side of the mounting frame 1 is provided with a connecting frame 102 fixedly connected by bolts, and the connecting frames 102 on the two mounting frames 1 are connected by a strain carrier 2. In actual arrangement, the metal strength of the connecting frame 102 and the mounting frame 1 is much greater than the metal strength of the strain carrier 2, so that the mounting frame 1 and the connecting frame 102 are used to firmly support the whole; the strain carrier 2 can protect the grating optical fiber sensor 300 while also causing stress deformation, thereby ensuring accurate detection of the part to be measured.

[0031] A grating optical fiber sensor 300 is arranged inside the strain carrier 2. Figure 2 and Figure 3It can be clearly seen that the grating fiber sensor 300 is placed in the strain carrier 2 for strain detection of the part to be measured. The two ends of the grating fiber sensor 300 are connected to the outside by the data fiber line 3, so as to output the detected data to the outside. The surface of the connecting frame 102 is provided with a tensioning groove 103 for the data fiber line 3 to pass through. When the data fiber line 3 passes through the tensioning groove 103, it will be connected in an interlaced and locked manner, and the movement of the data fiber line 3 is limited by friction, and finally the grating fiber sensor 300 connected to the data fiber line 3 is limited, so as to ensure that the grating fiber sensor 300 is firmly placed in the strain carrier 2, so that the strain carrier 2 can effectively protect the grating fiber sensor 300.

[0032] When tightening, the fastener 5 fastens the mounting frame 1 to the part to be tested. Figure 3 It can be seen that when the fastener 5 is locked, the connecting frame 102 tends to be squeezed toward the part to be tested. The squeezing of the data optical fiber line 3 by the connecting frame 102 and the part to be tested is used to further enhance the contact friction between the data optical fiber line 3 and the connecting frame 102, thereby preventing the data optical fiber line 3 from moving in the tensioning groove 103.

[0033] It can be seen that the first embodiment provides a glue-free fixing method for the grating optical fiber sensor 300, and the data optical fiber line 3 is squeezed and tightened while the mounting frame 1 is installed and tightened, so that the tightening points are concentrated on the fastener 5. The tightening of the fastener 5 is the basis for ensuring the stable detection of the grating optical fiber sensor 300. On the one hand, when the fastener 5 tightens the mounting frame 1, the grating optical fiber sensor 300 is affected by the part to be measured and deformed by stress, and its detection data is more accurate; on the other hand, after the mounting frame 1 is tightened, it will ensure that there is always an extrusion strength between the part to be measured and the connecting frame 102 for the data optical fiber line 3, which also avoids the phenomenon that the data optical fiber line 3 is insufficient in tightening force when working for a long time and affects the detection accuracy.

[0034] Embodiment 2

[0035] Further improvements are made based on Example 1. Figure 6 and Figure 7It can be clearly seen that the surface of the mounting frame 1 is threadedly connected with a distance adjusting bolt 4, and a rectangular protrusion is provided on the top of the distance adjusting bolt 4. Twisting the rectangular protrusion can make the distance adjusting bolt 4 rotate on the mounting frame 1, so that the distance adjusting bolt 4 can move up and down along the mounting frame 1. The bottom end of the distance adjusting bolt 4 is fixedly connected to the limit seat 22, the middle sleeve 20 is sleeved on the outside of the limit seat 22, and the inner side of the middle sleeve 20 is sleeved with a distance adjusting pressure block 19. A distance adjusting spring 21 is connected between the distance adjusting pressure block 19 and the limit seat 22. Under normal conditions, the distance adjusting pressure block 19 extends outward under the action of elasticity. The fastener 5 passes through the middle of the distance adjusting bolt 4 and is screwed onto the part to be measured. Due to the locking of the fastener 5, the mounting frame 1 will continue to approach the part to be measured, forcing the distance adjusting pressure block 19 to be pressed on the part to be measured. As the distance adjusting pressure block 19 squeezes the distance adjusting spring 21, the distance adjusting pressure block 19 will eventually be squeezed together with the limit seat 22. Since the limit seat 22 is restricted by the threaded fastening between the distance adjusting bolt 4 and the mounting frame 1 and cannot move, the distance adjusting pressure block 19 is also unable to move when it hits the limit seat 22.

[0036] The advantage of this method is that the extension length of the distance-adjusting block 19 is controlled by turning the distance-adjusting bolt 4. After the distance-adjusting block 19 is pressed on the part to be measured, the distance between the connecting frame 102 and the part to be measured is further controlled by extending the distance-adjusting block 19, thereby avoiding the phenomenon of being too tight or too loose between the connecting frame 102 and the part to be measured, and ensuring that the squeezing force on the data optical fiber line 3 between the connecting frame 102 and the part to be measured is within a controllable range.

[0037] Embodiment 3

[0038] Further improvements based on the first and second embodiments are shown in Figure 4 It can be seen that the ends of the positioning gear row arm 9 and the movable gear row arm 11 are both movably mounted on the positioning rod 110, and the positioning rod 110 is used as the hinge point of the movable gear row arm 11 and the positioning gear row arm 9, so that the movable gear row arm 11 and the positioning gear row arm 9 can deflect freely. The positioning rod 110 is movably mounted on the support arm extending from the side of the mounting frame 1, and the positioning rod 110 can move up and down along the support arm. A tension spring 10 is connected between the movable gear row arm 11 and the positioning gear row arm 9, and the tension of the tension spring 10 forces the positioning gear row arm 9 and the movable gear row arm 11 to always have a tendency to move closer. The outer sides of the two mounting frames 1 are respectively fixedly mounted with guide rails 101 for limiting the movable gear row arm 11 and the positioning gear row arm 9. The ends of the movable gear row arm 11 and the positioning gear row arm 9 are both restricted in the corresponding guide rails 101, so that when the movable gear row arm 11 and the positioning gear row arm 9 move up and down, they can only move up and down along the guide rails 101.

[0039] The end of the movable gear row arm 11 is fixedly connected to a lifting magnetic block 15. Figure 1It can be seen that the inner side of the guide rail 101 is movably mounted with a fine-tuning rod 130 located above the lifting magnet 15, and the bottom of the fine-tuning rod 130 is coaxially fixed with a switching seat 13 located below the lifting magnet 15, and the surface of the switching seat 13 is fixedly connected with a movable magnet 14 that magnetically repels the lifting magnet 15. When the switching seat 13 is rotated by the fine-tuning rod 130 to move the movable magnet 14 to the bottom of the lifting magnet 15, the magnetic repulsion between the movable magnet 14 and the lifting magnet 15 forces the movable gear arm 11 to drive the positioning gear arm 9 and the positioning rod 110 to move upward. In this process, Figure 1 and Figure 3 It can be seen that the side of the movable gear row arm 11 is movably installed with a pre-tightening top roller 12, and the data optical fiber line 3 is bypassed from the side of the pre-tightening top roller 12. When the movable gear row arm 11 moves upward, the pre-tightening top roller 12 is used to drag the data optical fiber line 3 upward. The tension of the data optical fiber line 3 adjusts the initial pre-tension of the grating optical fiber sensor 300, so that the grating optical fiber sensor 300 has a suitable initial pre-tension for detection. The relative area of ​​the magnetic surface between the movable magnetic block 14 and the lifting magnetic block 15 can be controlled by rotating the fine-tuning rod 130, so that the strength of the movable gear row arm 11 moving upward can be controlled, that is, the pre-tension of the grating optical fiber sensor 300 can be controlled.

[0040] In order to prevent the data optical fiber line 3 from being forced downward during operation, refer to Figure 1 It can be seen that the side of the mounting frame 1 is fixedly connected with a limit gear row 8 located on one side of the positioning gear row arm 9, and the guide rail 101 connected to the positioning gear row arm 9 can make the positioning gear row arm 9 deflect within a certain angle. Figure 1 It can be seen that when the positioning gear row arm 9 moves upward, the inner spacing of the guide rail 101 at this end will increase, so that the positioning gear row arm 9 can deflect at a certain angle, which ensures that the teeth on the positioning gear row arm 9 can be pushed onto the limit gear row 8. In detail, since the cross-sectional shape of the limit gear row 8 is a right triangle, it has a unidirectional limiting effect, so that the positioning gear row arm 9 can only move unidirectionally upward along the limit gear row 8.

[0041] In specific implementation, the fixing strength of the connecting frame 102 to the data optical fiber line 3 is controlled by adjusting the screwing amount of the distance adjusting bolt 4, and then the fastener 5 is fixed on the part to be tested. The specific process refers to the content described in Example 2 and will not be repeated here.

[0042] After the mounting frame 1 is fastened, the switch seat 13 is rotated by twisting the fine-tuning rod 130, forcing the movable magnetic block 14 to move to the bottom of the lifting magnetic block 15. As the relative magnetic surface between the movable magnetic block 14 and the lifting magnetic block 15 increases, the strength of the lifting magnetic block 15 pushing the movable gear row arm 11 upward increases. When the movable gear row arm 11 drives the positioning gear row arm 9 upward, the pre-tightening top roller 12 pushes the data optical fiber line 3 upward. Figure 3It can be seen that the data optical fiber lines 3 are all squeezed and fixed by the connecting frame 102 and the part to be measured. When the preload top roller 12 pushes the data optical fiber line 3 to move upward, the strength of the data optical fiber line 3 pulling the grating optical fiber sensor 300 will increase, so that the grating optical fiber sensor 300 can work under the prestress required by the environment. As the movable gear row arm 11 drives the positioning gear row arm 9 upward, the positioning gear row arm 9 will also move upward along the limit gear row 8. When the positioning gear row arm 9 passes through the inclined surface of the limit gear row 8, the positioning gear row arm 9 will be pushed by the limit gear row 8 to stretch the tension spring 10. When the positioning gear row arm 9 moves to the right angle surface of the limit gear row 8, the tension of the tension spring 10 is used to move the positioning gear row arm 9 above the right angle surface of the limit gear row 8, thereby limiting the downward movement of the positioning gear row arm 9.

[0043] Embodiment 4

[0044] Further improvements based on Example 3 are provided. Figure 6 and Figure 7 It can be seen that the outer top of the intermediate sleeve 20 is fixedly connected with a gear 6, and the outer teeth of the gear 6 between the two intermediate sleeves 20 are meshed, so that the two intermediate sleeves 20 can rotate synchronously.

[0045] The outer bottom of the middle sleeve 20 is fixedly connected with a fastening sleeve 7, and the data optical fiber line 3 can be clamped by two fastening sleeves 7. Figure 1 and Figure 2 It can be seen that when the clamped data optical fiber line 3 is pulled, the two fastening sleeves 7 can be rotated synchronously. Figure 6 and Figure 7 It can be known that a cutter 17 is installed on the outer side of the fastening sleeve 7 . When the cutters 17 on the two fastening sleeves 7 are brought close to each other, the data optical fiber 3 clamped between the fastening sleeves 7 can be cut.

[0046] The advantage of this design is that, referring to the contents of the third embodiment, it can be known that when the fine-tuning rod 130 adjusts the magnetic surfaces of the movable magnetic block 14 and the lifting magnetic block 15 to face each other, the pre-tensioning top roller 12 will push the data optical fiber line 3 upward to tighten it, so that the grating optical fiber sensor 300 initially has a pre-tension. This pre-tension also acts on the data optical fiber line 3. If the data optical fiber line 3 slides from the tensioning groove 103, it means that the grating optical fiber sensor 300 cannot be fixed normally. As the pre-tensioning top roller 12 goes up and pulls the data optical fiber line 3, the data optical fiber line 3 will force the fastening sleeve 7 to rotate when passing through the fastening sleeve 7, so that the cutter 17 on the outside of the fastening sleeve 7 touches together, thereby cutting off the data optical fiber line 3. When the operator checks that the signal of the grating optical fiber sensor 300 is cut off after the fixation is completed, it means that the mounting frame 1 is not tightened tightly or the connecting frame 102 is not tightened to the data optical fiber line 3 in place. The signal is cut off to warn the operator that it is necessary to reinstall here to ensure the normal operation of the equipment.

[0047] As a safety limitation, Figure 5 It can be seen that a "C"-shaped ring is provided on the outer side of the switching seat 13, and a corresponding collar is fixedly connected to the bottom of the movable gear row arm 11. Under normal conditions, the end of the "C"-shaped ring is stuck in the collar. At this time, the magnetic surfaces of the movable magnetic block 14 and the lifting magnetic block 15 are not opposite to each other. Figure 1 It can be seen that the positioning gear row arm 9 and the movable gear row arm 11 respectively lock the gear 6 at this time. The advantage of this design is that when the mounting frame 1 is being installed or the equipment needs to be disassembled and replaced during normal use, the positioning gear row arm 9 and the movable gear row arm 11 limit the rotation of the gear 6, so that the fastening sleeve 7 will not rotate accidentally during the disassembly and assembly of the mounting frame 1, and the cutter 17 will not accidentally cut the data optical fiber line 3 due to rotation. When the mounting frame 1 is installed in place and the pre-tension of the grating optical fiber sensor 300 is adjusted, the rotating fine-tuning rod 130 will drive the "C"-shaped ring to disengage from the ring, thereby releasing the movement lock of the movable gear row arm 11 by the switching seat 13.

[0048] Embodiment 5

[0049] Further improvements are made on the basis of Example 4. Figure 6 and Figure 7 As can be seen in the figure, a support ring 16 is movably installed on the inner top of the intermediate sleeve 20, and a plurality of ejection springs 160 arranged at equal angles are connected between the support ring 16 and the mounting frame 1. The support ring 16 is always pushed by the elastic force of the ejection springs 160 to push the intermediate sleeve 20 away from the mounting frame 1. Figure 1 It can be seen that the support rings 16 are connected by a synchronous pull rod 18, and the shape of the synchronous pull rod 18 is "U". When the support ring 16 is pushed downward by the ejection spring 160, the synchronous pull rod 18 will push against the surface of the mounting frame 1, thereby limiting the movement of the support ring 16. The outer side of the distance adjustment block 19 and the inner side of the intermediate sleeve 20 form a distance adjustment cavity 190, and the top of the distance adjustment block 19 is fixedly connected with a one-way liquid valve 191 for the medium of the inner cavity of the intermediate sleeve 20 to flow unidirectionally into the distance adjustment cavity 190. Under normal conditions, the inner cavity of the intermediate sleeve 20 is injected with hydraulic oil through the oil injection part 220 fixed at the top, and the oil injection part 220 can be connected to the outside through a pipeline, so as to facilitate the input of hydraulic oil.

[0050] The side of the cutter 17 is located in the distance adjustment cavity 190, and a return spring 170 is connected between the cutter 17 and the fastening sleeve 7. The elastic force of the return spring 170 makes the side of the cutter 17 always tend to extend into the distance adjustment cavity 190, thereby ensuring that the cutter 17 is always attached to the outside of the fastening sleeve 7.

[0051] In specific implementation, the distance adjusting bolt 4 is first rotated to limit the retracted length of the distance adjusting block 19, so as to adjust the squeezing strength of the connecting frame 102 on the data optical fiber line 3 after the mounting frame 1 is tightened. Subsequently, the hydraulic oil is transported from the oil injection part 220 to the inside of the intermediate sleeve 20 by pumping or syringe injection. When the hydraulic oil is added, the installation process of the mounting frame 1 can begin.

[0052] During the installation process, the switching seat 13 is connected with the collar on the movable gear row arm 11 by a "C"-shaped ring, and the positioning gear row arm 9 and the movable gear row arm 11 are restricted to mesh with the gear 6 during installation, so as to prevent the gear 6 from uncontrollable deflection during the installation process. At this time, the cutter 17 is relatively far away from the data optical fiber line 3. As the fastener 5 is connected to the part to be measured, the distance adjustment pressure block 19 is squeezed by the part to be measured and compresses the distance adjustment spring 21 upward. At the same time, the hydraulic oil in the intermediate sleeve 20 enters the distance adjustment chamber 190 through the one-way liquid valve 191. As the fastener 5 is continuously screwed in, until the distance adjustment pressure block 19 is attached to the limit seat 22, the distance adjustment pressure block 19 will no longer move due to the compression of the fastener 5. The connecting frame 102 squeezes the data optical fiber line 3, further enhancing the contact friction between the two, and preventing the data optical fiber line 3 from moving in the tensioning groove 103.

[0053] The fine-tuning rod 130 rotates, so that the movable magnetic block 14 pushes the lifting magnetic block 15 upward. During this process, the movable gear row arm 11 and the positioning gear row arm 9 will both be separated from the gear 6. The movable gear row arm 11 pulls the data optical fiber line 3 upward through the pre-tightening top roller 12, so that the grating optical fiber sensor 300 has a certain pre-tension at the beginning. At the same time, if the data optical fiber line 3 moves in the tensioning groove 103, it means that the fastening is not tight. The data optical fiber line 3 will pull the fastening sleeve 7 to rotate, and the fastening sleeve 7 rotates synchronously through the transmission between the gears 6. The data optical fiber line 3 is cut off by the cutter 17, and the missing signal of the grating optical fiber sensor 300 is used to warn the operator that the fixation here is not tight, the detected data is inaccurate, and adjustment is required.

[0054] During long-term operation, if the rotational resistance of the fastening sleeve 7 increases due to erosion by dust or the like, the data optical fiber line 3 will slide relative to the fastening sleeve 7 when passing through the fastening sleeve 7 (the reason is that when the rotational resistance of the fastening sleeve 7 is small, it will rotate with the data optical fiber line 3; similarly, when its rotational resistance is large, it will slide relative to the data optical fiber line 3). When the data optical fiber line 3 continues to pass through the tensioning groove 103, the magnetic repulsion of the movable magnetic block 14 and the lifting magnetic block 15 forces the movable gear row arm 11 and the pre-tightening top roller 12 to continue to move upward. When the movable gear row arm 11 passes over the guide rail 101, the positioning gear row arm 9 is still in the guide rail 101 at this time, and the tension of the tension spring 10 forces the movable gear row arm 11 to deflect in the direction of the positioning gear row arm 9 until the spacing adjustment bolt 4 is pressed against the movable gear row arm 11. The movable gear row arm 11 blocks, at this time, the lifting magnet 15 moves to the top of the mounting frame 1, and the support ring 16 is attracted by the lifting magnet 15 to drag the middle sleeve 20 upward. After the support ring 16 moves upward, the synchronous pull rod 18 is used to make the two support rings 16 drag the middle sleeve 20 upward at the same time. The upward moving middle sleeve 20 squeezes the hydraulic oil in the distance adjustment chamber 190, and the hydraulic oil pressure in the distance adjustment chamber 190 increases and pushes the cutter 17 to extend outward, and the return spring 170 is compressed. The two return springs 170 extending outward will eventually cut off the data optical fiber line 3, ensuring that the data optical fiber line 3 and the fastening sleeve 7 can still cut off the data optical fiber line 3 when the rotation resistance of the fastening sleeve 7 increases and the data optical fiber line 3 and the fastening sleeve 7 slide relative to each other after working for a long time.

[0055] When the data optical fiber line 3 is firmly restrained in the tensioning groove 103, if the fastener 5 and the part to be measured become loose, the distance between the mounting frame 1 and the part to be measured will increase, so that the distance adjustment pressure block 19 squeezes the hydraulic oil in the distance adjustment chamber 190 under the elastic force of the distance adjustment spring 21, and finally the cutter 17 is pushed outward and cuts off the data optical fiber line 3. This method can ensure that the fastener 5 can also be pushed and cut off the data optical fiber line 3 autonomously when the fixation is unstable. It should be noted that in the actual application process, since the two cutters 17 can cut off the data optical fiber line 3 when they are relatively close, therefore, when both fasteners 5 on a mounting frame 1 are loose, the prerequisite for the cutter 17 to cut off the data optical fiber line 3 is met. When only one fastener 5 is loose, the mounting frame 1 is still fixed by the other fastener 5, and there is no need to cut off the data optical fiber line 3 at this time, thereby extending the service life of the equipment.

Claims

1. A non-gelled fiber Bragg grating strain sensor, characterized in that: include: A mounting frame (1) having fasteners (5) arranged on its surface, a connecting frame (102) fixedly connected to its side, and a strain carrier (2) fixed to the connecting frame (102); A grating optical fiber sensor (300) is arranged on the inner side of the strain carrier (2), and two ends of the grating optical fiber sensor (300) are respectively connected to data optical fiber lines (3); A tensioning groove (103) is provided on the surface of the connecting frame (102) and is used for the data optical fiber line (3) to pass through and fix it; The distance adjusting bolt (4) is threadedly connected to the surface of the mounting frame (1), and the fastener (5) passes through the middle of the distance adjusting bolt (4); A limit seat (22) is fixedly connected to the bottom end of the distance adjusting bolt (4), and an intermediate sleeve (20) is sleeved on the outer side of the limit seat (22); A distance-adjusting pressing block (19) is sleeved on the inner side of the intermediate sleeve (20), and a distance-adjusting spring (21) is connected between the distance-adjusting pressing block (19) and the limit seat (22); The ends of the positioning tooth row arm (9) and the movable tooth row arm (11) are hinged, and a positioning rod (110) is movably mounted at the hinge point, and the positioning rod (110) is movably mounted on the side of the mounting frame (1); A tension spring (10) is arranged between the movable tooth row arm (11) and the positioning tooth row arm (9); A guide rail (101) is fixed on the outer side of the mounting frame (1); A lifting magnetic block (15) is fixed to the end of the movable gear row arm (11); A fine-tuning rod (130) is movably mounted on the inner side of the guide rail (101), and a switching seat (13) is coaxially fixed to the bottom of the fine-tuning rod (130), and a movable magnetic block (14) that magnetically repels the lifting magnetic block (15) is fixedly connected to the surface of the switching seat (13); A pre-tensioning top roller (12) is movably mounted on the side of the movable toothed arm (11), and the data optical fiber line (3) is passed around the side of the pre-tensioning top roller (12); A limiting tooth row (8) located on one side of the positioning tooth row arm (9) is fixedly connected to the side of the mounting frame (1).

2. The non-gelled fiber Bragg grating strain sensor according to claim 1, characterized in that: The outer top of the middle sleeve (20) is fixedly connected to a gear (6), and the outer bottom of the middle sleeve (20) is fixedly connected to a fastening sleeve (7), and a cutter (17) is installed on the outer side of the fastening sleeve (7).

3. The non-gelled fiber Bragg grating strain sensor according to claim 2, characterized in that: A "C"-shaped ring is arranged on the outer side of the switching seat (13), and a collar is fixedly connected to the bottom of the movable gear row arm (11).

4. The non-gelled fiber Bragg grating strain sensor according to claim 2, characterized in that: A support ring (16) is movably mounted on the inner top of the intermediate sleeve (20), an ejection spring (160) is connected between the support ring (16) and the mounting frame (1), and a synchronous pull rod (18) is fixedly connected to the top of the support ring (16); The outer side of the distance-adjusting pressure block (19) and the inner side of the intermediate sleeve (20) form a distance-adjusting cavity (190), and a one-way liquid valve (191) is fixedly connected to the top of the distance-adjusting pressure block (19), and an oil injection portion (220) is provided at the top of the intermediate sleeve (20); The side of the cutter (17) is located in the distance adjustment cavity (190), and a return spring (170) is connected between the cutter (17) and the fastening sleeve (7).

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