A draw-wire displacement sensor based on fiber optic MEMS technology

Abstract

The present invention relates to a drawstring displacement sensor based on fiber optic MEMS technology, comprising: a mounting box, a reset assembly, a reel assembly, a displacement reduction assembly, and a MEMS displacement meter. The reset assembly utilizes a vortex spring structure. The reel assembly drives a wire roller for pulling a drawstring, and sequentially transmits rotational motion to a lead screw and a vortex spring shaft in the displacement reduction assembly. A connecting seat on the lead screw, which moves with rotation, drives a MEMS chip and a collimator in the displacement meter to undergo displacement changes, thereby transmitting an optical signal to an external demodulation device, thereby achieving readability of the drawstring. The present invention utilizes fiber optic MEMS technology, which is unaffected by electromagnetic radiation and temperature fluctuations. It utilizes a vortex spring reset method, resulting in high reset accuracy, multiple uses, easy installation and removal, and improved measurement speed. It utilizes a combination of theoretical algorithms and high-precision calibration to provide accurate and stable data support in engineering inspection fields such as coal mines, tunnels, and bridges. During engineering monitoring, it can detect subtle changes in the observed object to achieve early warning effects.

Description

Technical Field

[0001] The present invention relates to the field of optical sensing technology, and in particular to a draw-rope displacement sensor based on optical fiber MEMS technology. Background Art

[0002] Traditional electronic rope-type displacement sensors first wrap a stretchable rope around a threaded hub, which is then connected to a precision rotary sensor. The sensor can be an incremental encoder, an absolute (independent) encoder, a hybrid or conductive plastic rotary potentiometer, a synchronizer, or a resolver. The rope's end is then secured to a moving object, aligning the rope's linear motion with the object's axis of motion. Because these electronic rope-type displacement sensors use electrical strain gauges as their core sensing elements, they are inevitably susceptible to interference from ambient electromagnetic radiation and have poor long-term stability, making them unable to maintain stable operation in environments with electromagnetic radiation.

[0003] Although some displacement sensors use fiber grating sensors and can be used in electromagnetic radiation environments, there are also problems such as large signal fluctuations with temperature and time, and they cannot be used stably for a long time in environments with large temperature differences. In addition, when the rope of the electronic pull-rope displacement sensor is wound around the hub, the diameter of the rope drum will increase with the number of winding turns, resulting in inconsistent rope extension lengths for one rotation of the hub in the early and late stages of measurement, which will further affect the measurement accuracy. If a rotary sensor is used to measure the rope displacement, the sensor resolution and accuracy will also limit the overall accuracy of the rope displacement sensor. Currently, most existing sensors in the industry use manual or electric winding, which cannot be accurately reset to the initial position of the rope. The error of multiple measurements is large and regular calibration is required. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the existing displacement sensors in the prior art cannot have the advantages of strong anti-electromagnetic interference capability, strong environmental adaptability and high precision.

[0005] To solve the above technical problems, the present invention provides a drawstring displacement sensor based on optical fiber MEMS technology, comprising:

[0006] Install the box body, which includes a fixed bottom plate and a removable top cover;

[0007] A reset assembly is arranged in the installation box body, and the reset assembly includes a vortex spring, a vortex spring mounting seat and a vortex spring shaft. The vortex spring mounting seat is arranged at one end of the fixed base plate, and the main body of the vortex spring mounting seat is a circular groove, which faces the inner wall of the installation box body. One end of the vortex spring shaft passes through the center of the circular groove toward the inner wall of the installation box body. The vortex spring is clamped in the circular groove, and the outer end of the vortex spring is connected to the groove wall of the circular groove, and the inner end of the vortex spring is connected to the vortex spring shaft;

[0008] A wire wheel assembly is provided on one end of the fixed base plate away from the reset assembly, the wire wheel assembly includes a wire roller and a pull rope, the pull rope is tightly wound around the wire roller, the wire roller includes a roller shaft and a winding groove, one end of the pull rope is connected to the bottom of the winding groove, and the other end of the pull rope extends horizontally out of the mounting box body;

[0009] A displacement reduction assembly, comprising a fixed bearing and a screw, wherein the fixed bearing is arranged on a side of the fixed base plate close to the reset assembly, one end of the screw is passed through the inner ring of the fixed bearing and is connected to the vortex spring shaft, and the other end of the screw is connected to the roller shaft, a connecting seat is sleeved on the screw, the connecting seat is threadedly connected to the screw, the connecting seat is arranged between the pulley assembly and the fixed bearing, and the connecting seat can move freely in the horizontal direction as the screw rotates;

[0010] A MEMS displacement meter is arranged on one side of the displacement reduction component. The MEMS displacement meter includes: a cylinder body, a piston, a MEMS chip and a collimator. The cylinder body is connected to the fixed base plate, the head of the piston is passed through the cylinder body, the MEMS chip is vertically attached to the head of the piston, and the collimator is clamped at the end of the cylinder body away from the piston. The collimator includes a light-emitting side and a light-incoming side. The light-emitting side is horizontally aligned with the MEMS chip, and the light-incoming side is provided with an optical fiber, which extends horizontally out of the mounting box body. The end of the piston away from the collimator is connected to the connecting seat, and the axis of the piston and the axis of the lead screw are in the same plane.

[0011] In one embodiment of the present invention, the spool assembly further includes a guide wheel mounting seat and a plurality of auxiliary guide wheels, the plurality of auxiliary guide wheels are all connected to the guide wheel mounting seat, the guide wheel mounting seat is connected to the fixed base plate, and the pull rope is sequentially wrapped around the plurality of auxiliary guide wheels and finally led out from the mounting box body.

[0012] In one embodiment of the present invention, an auxiliary sliding assembly is further included, wherein the auxiliary sliding assembly includes a sliding shaft and a slider, the sliding shaft is connected to the fixed base plate, the slider is clamped on the sliding shaft, and the slider is connected to the bottom surface of the connecting seat.

[0013] In one embodiment of the present invention, limiting grooves are provided on both sides of the sliding shaft, a sliding groove is provided on the lower surface of the slider, a limiting strip is provided on the groove wall of the sliding groove, the limiting strip is clamped in the limiting groove, and the groove bottom of the sliding groove is in close contact with the upper surface of the sliding shaft.

[0014] In one embodiment of the present invention, two limit blocks are provided on the fixed base plate, and the two limit blocks are respectively provided at the front and rear ends of the connecting seat in the moving direction.

[0015] In one embodiment of the present invention, a connecting plate is provided at one end of the screw rod away from the reset assembly, one side of the connecting plate is fastened to the connecting seat, and the other side of the connecting plate is connected to the roller shaft, and a connecting column is provided at one end of the screw rod away from the pulley assembly, and the vortex spring shaft is T-shaped, and the vortex spring shaft includes a large end and a small end, and the small end is provided with a straight groove, and the inner end of the vortex spring is clamped in the straight groove, and the large end is provided with a first plug-in slot and a limiting hole, and the limiting hole is connected to the first plug-in slot, and the first plug-in slot is sleeved on the connecting column, and a set screw is provided in the limiting hole, and the set screw abuts against the connecting column.

[0016] In one embodiment of the present invention, a limiting waist-shaped hole is provided on the cylinder body, and a limiting pin is provided on the piston. The limiting pin always moves horizontally in the limiting waist-shaped hole, and the movable distance of the limiting pin is the same as the movable distance of the connecting seat between the two limiting blocks.

[0017] In one embodiment of the present invention, the head of the piston is provided with a second plug-in slot, a chip mounting column is clamped in the second plug-in slot, the MEMS chip is attached to the end of the chip mounting column, the cylinder body includes a first connecting tube, a second connecting tube and a third connecting tube, the first connecting tube and the second connecting tube are plugged in through the third connecting tube, the MEMS displacement meter also includes a collimator mounting seat and an optical fiber lead-out connector, the collimator is clamped in the collimator mounting seat, one end of the collimator mounting seat is passed through one end of the third connecting tube, the chip mounting seat is passed through the other end of the third connecting tube, and the optical fiber lead-out connector is connected to the end of the second connecting tube.

[0018] In one embodiment of the present invention, the fixed bottom plate has the same structure as the removable top cover, and the installation box body also includes a surrounding side panel, the bottom and top of the surrounding side panel are provided with a rectangular groove, a sealing ring is provided in the rectangular groove, and the surrounding side panel is provided with a fiber optic connector fixing hole and a pull rope lead-out hole.

[0019] In one embodiment of the present invention, the displacement reduction assembly further includes a bearing mounting seat, the bearing mounting seat is connected to the fixed base plate, and the fixed bearing is connected to the bearing mounting seat.

[0020] The above technical solution of the present invention has the following advantages over the prior art:

[0021] When using this drawstring displacement sensor based on fiber-optic MEMS technology, the free end of the drawstring is first fixed to the object to be measured. When the object to be measured pulls the drawstring outward, the drawstring drives the lead screw to rotate, and the connecting seat on the lead screw produces a corresponding displacement along the length direction of the lead screw, thereby driving the piston to move within the cylinder body; the MEMS displacement meter converts the displacement change into a change in light wavelength, connects to an external optical signal demodulation device through an optical fiber, and further demodulates the optical signal into readable information.

[0022] The advantages of the present invention include the following:

[0023] 1. The present invention adopts optical fiber MEMS technology to solve the problem of signal reception and transmission of existing displacement sensors in harsh working environments with electromagnetic interference and large temperature differences.

[0024] 2. The present invention can adopt a combination of theoretical algorithms and precise calibration. The theoretical relationship between the rope movement and the displacement meter signal change is calculated through modeling simulation and precise algorithms. The relationship is verified and improved during the calibration process to obtain the actual relationship between the rope movement and the displacement meter change. The change of the rope is cleverly converted into the relative position change of the chip and the collimator in the MEMS displacement meter, thereby improving the measurement accuracy of the sensor, providing accurate and stable data support in engineering detection fields such as coal mines, tunnels, and bridges. In engineering monitoring, tiny changes in the observed object can be discovered, and disaster warning information can be provided to the engineering site earlier.

[0025] 3. Since the measuring range of the MEMS displacement meter is relatively small, the present invention adopts a displacement reduction component to convert the displacement, and converts the long measuring range of the pull rope into the small measuring range of the MEMS displacement meter through the rotational displacement of the screw and the connecting seat, thereby realizing a large-scale and high-precision measurement.

[0026] 4. The present invention adopts a reset assembly to connect the lead screw. When the end of the pull rope is separated from the object to be measured, the vortex spring mechanism can drive the lead screw and the pull rope to return to the initial position, thereby achieving repeatability of multiple measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0028] Figure 1 This is a schematic diagram of the overall structure of the draw-wire displacement sensor based on optical fiber MEMS technology of the present invention;

[0029] Figure 2 for Figure 1 A top view of the internal structure of the mounting box of the draw-wire displacement sensor based on fiber optic MEMS technology is shown;

[0030] Figure 3 for Figure 1 A front view of the internal structure of the mounting box of the draw-wire displacement sensor based on fiber optic MEMS technology is shown;

[0031] Figure 4 for Figure 1 The left side view of the internal structure of the mounting box of the draw-wire displacement sensor based on fiber optic MEMS technology is shown;

[0032] Figure 5 for Figure 1 The right side view of the internal structure of the mounting box of the draw-wire displacement sensor based on fiber optic MEMS technology is shown;

[0033] Figure 6 for Figure 1 The overall structure diagram of the MEMS displacement meter in the draw-wire displacement sensor based on fiber optic MEMS technology is shown;

[0034] Figure 7 for Figure 1 A cross-sectional view of a MEMS displacement meter in a draw-wire displacement sensor based on fiber optic MEMS technology is shown.

[0035] Description of the accompanying drawings: 1. Mounting box; 110. Fixed bottom plate; 120. Removable top cover; 130. Enclosing side panel; 131. Pull rope lead-out hole; 132. Fiber optic connector fixing hole; 2. Reset assembly; 210. Vortex spring mounting seat; 220. Vortex spring shaft; 3. Wire wheel assembly; 310. Wire roller; 320. Pull rope; 330. Guide wheel mounting seat; 340. Auxiliary guide wheel; 4. Displacement reduction assembly; 410. Fixed bearing; 420. Screw rod; 430. Connecting seat; 440. Bearing mounting seat; 5. MEMS displacement meter; 510. Cylinder body; 511. First connecting tube; 512. Second connecting tube; 513. Third connecting tube; 520. Piston; 521. Second plug-in slot; 522. Chip mounting column; 530. MEMS chip; 540. Collimator; 550. Optical fiber; 560. Collimator mounting seat; 570. Optical fiber lead-out connector; 6. Auxiliary sliding assembly; 610. Sliding shaft; 611. Limiting groove; 620. Slider; 622. Limiting bar; 7. Limiting block; 8. Connecting plate; 9. Limiting hole; 10. Limiting waist-shaped hole; 11. Limiting pin. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0037] Reference Figures 1 to 7 As shown, the present invention provides a draw-wire displacement sensor based on MEMS technology, comprising:

[0038] Install the box body 1, which includes a fixed bottom plate 110 and a removable top cover 120;

[0039] The reset assembly 2 is arranged in the installation box body 1. The reset assembly 2 includes a vortex spring, a vortex spring mounting seat 210 and a vortex spring shaft 220. The vortex spring mounting seat 210 is arranged at one end of the fixed base plate 110. The main part of the vortex spring mounting seat 210 is a circular groove, which faces the inner wall of the installation box body 1. One end of the vortex spring shaft 220 passes through the center of the circular groove toward the inner wall of the installation box body 1. The vortex spring is clamped in the circular groove, and the outer end of the vortex spring is connected to the groove wall of the circular groove, and the inner end of the vortex spring is connected to the vortex spring shaft 220.

[0040] The spool assembly 3 is arranged on the fixed base plate 110 at one end away from the reset assembly 2. The spool assembly 3 includes a spool 310 and a pull rope 320. The pull rope 320 is tightly wound around the spool 310. The spool 310 includes a roller shaft and a winding groove. One end of the pull rope 320 is connected to the bottom of the winding groove, and the other end of the pull rope 320 extends horizontally out of the mounting box body 1.

[0041] The displacement reduction component 4 includes a fixed bearing 410 and a screw rod 420. The fixed bearing 410 is arranged on the side of the fixed base plate 110 close to the reset component 2. One end of the screw rod 420 is passed through the inner ring of the fixed bearing 410 and is connected to the vortex spring shaft 220. The other end of the screw rod 420 is connected to the roller shaft. A connecting seat 430 is sleeved on the screw rod 420. The connecting seat 430 is threadedly connected to the screw rod 420. The connecting seat 430 is arranged between the reel assembly 3 and the fixed bearing 410 and can move freely in the horizontal direction as the screw rod 420 rotates.

[0042] The MEMS displacement meter 5 is arranged on one side of the displacement reduction component 4. The MEMS displacement meter 5 includes: a cylinder body 510, a piston 520, a MEMS chip 530 and a collimator 540. The cylinder body 510 is connected to the fixed base plate 110, the head of the piston 520 is passed through the cylinder body 510, the MEMS chip 530 is vertically attached to the head of the piston 520, and the collimator 540 is clamped at the end of the cylinder body 510 away from the piston 520. The collimator 540 includes a light-emitting side and a light-incoming side. The light-emitting side is horizontally aligned with the MEMS chip 530, and the light-incoming side is provided with an optical fiber 550. The optical fiber 550 extends horizontally out of the mounting box body 1. The end of the piston 520 away from the collimator 540 is connected to the connecting seat 430, and the axis of the piston 520 and the axis of the lead screw 420 are in the same plane.

[0043] When using this MEMS-based pull-string 320 displacement sensor, the free end of the pull-string 320 is first fixed to the object to be measured. When the object to be measured pulls the pull-string 320 outward, the pull-string 320 drives the lead screw to rotate, and the connecting seat 430 mounted on the lead screw produces a corresponding displacement along the length direction of the lead screw 420, thereby driving the piston 520 to move in the cylinder body 510; the MEMS displacement meter 5 converts the displacement change into a change in light wavelength, connects to an external optical signal demodulation device through an optical fiber 550, and further demodulates the optical signal into readable information.

[0044] The advantages of the present invention include the following:

[0045] 1. The present invention adopts optical fiber MEMS technology to solve the problem of signal reception and transmission of existing displacement sensors in harsh working environments with electromagnetic interference and large temperature differences.

[0046] 2. The present invention can adopt a method that combines theoretical algorithms with precise calibration. The theoretical relationship between the movement of the rope 320 and the change in the displacement meter signal is calculated through modeling simulation and precise algorithms. The theoretical relationship is verified and improved during the calibration process to obtain the actual relationship between the movement of the rope 320 and the change in the displacement meter. The change in the rope 320 is cleverly converted into a change in the relative position of the chip in the MEMS displacement meter 5 and the collimator 540, thereby improving the measurement accuracy of the sensor. It provides accurate and stable data support in engineering detection fields such as coal mines, tunnels, and bridges. In engineering monitoring, it can detect subtle changes in the observed object and provide disaster warning information to the engineering site earlier.

[0047] 3. Since the measuring range of the MEMS displacement meter 5 is relatively small, the present invention adopts a displacement reduction component 4 to convert the displacement, and converts the long measuring range of the pull rope 320 into the small measuring range of the MEMS displacement meter 5 through the rotational displacement of the screw plus the connecting seat 430, thereby achieving a large-scale and high-precision measurement.

[0048] 4. The present invention uses a reset assembly 2 to connect the lead screw. When the end of the pull rope 320 is separated from the object to be measured, the vortex spring mechanism can drive the lead screw and the pull rope 320 to return to the initial position, thereby achieving repeatability of multiple measurements.

[0049] Specifically, the number of turns of the rope 320 wound on the roller 310 is proportional to the length of each turn of the rope 320. During use, as the rope 320 is pulled, the number of turns of the rope 320 on the roller 310 decreases, the coil winding radius decreases, and the length of a single turn of the rope 320 also changes accordingly. In order to obtain a more accurate change in the length of the rope 320, the length of each turn of the rope 320 (Ln) is calculated to be proportional to the number of turns (n), the wire diameter d of the rope 320, and the diameter (R) of the roller 310. The relationship is: Ln=π*{(n*d+R}. This relationship is introduced into the system of the screw rod 420 and the connecting seat 430, that is, the relationship between the length of each turn of the rope 320 and the displacement of the MEMS displacement meter 5. The length of the rope 320 and the displacement of the MEMS displacement meter 5 are fitted multiple times using a software algorithm to obtain accurate rope 320 displacement data. The fitted coefficients and calibration fixture are used for verification. Tests show that the accuracy of the MEMS displacement meter 5 can reach 0.05%.

[0050] Specifically, the mounting box body 1 is made of high-strength metal material as a whole, which has the ability to resist corrosion and damage, and can effectively protect all parts inside the box body; the vortex spring, vortex spring mounting seat 210 and vortex spring shaft 220 in the reset component 2 should be of appropriate sizes and the vortex spring should have relatively high fatigue resistance to ensure multiple repetitive resets of the screw rod 420 and the pull rope 320; in this embodiment, the pull rope 320 is a high-strength steel wire rope, and the material of the wire roller 310 is also a high-strength wear-resistant material, which ensures that the calibrated pull rope 320 displacement data is still applicable during the long-term repeated use of the sensor, and the roller shaft of the wire roller 310 is suspended and fixed by the screw rod 420, and the rotation of the wire roller 310 is synchronized with the screw rod 420; the connecting seat 430 in the displacement reduction component 4 is L-shaped as a whole, and the part connected to the screw rod 420 is in the shape of a "mountain", as described below, one end of the screw rod 420 passes through The connecting base 430 is fixed to the connecting base 430 by the connecting plate 8. One side of the connecting base 430 is used to fix the piston 520 on the MEMS displacement meter 5. It can be seen that the connection between the connecting base 430 and the piston 520 is fixed by a set screw. A corresponding pin hole can be set on the piston 520 to facilitate the insertion of the set screw to form a further limit on the piston 520. The screw rod 420 and the roller shaft also rotate synchronously. What's more, the screw rod 420 is a high-precision screw rod 420, which cooperates with the connecting base 430 to form a common high-precision screw rod 420 nut system, thereby ensuring the accuracy of displacement transmission; the MEMS displacement meter 5 adopts optical fiber MEMS technology, which is not affected by electromagnetic radiation and temperature changes, and can work stably for a long time in an environment with strong electromagnetic radiation and large temperature differences, solving the problem of signal reception and transmission of existing displacement sensors in harsh working environments with electromagnetic interference and large temperature differences.

[0051] Furthermore, the reel assembly 3 also includes a guide wheel mounting seat 330 and multiple auxiliary guide wheels 340. The multiple auxiliary guide wheels 340 are all connected to the guide wheel mounting seat 330. The guide wheel mounting seat 330 is connected to the fixed base plate 110. The pull rope 320 is sequentially wrapped around the multiple auxiliary guide wheels 340 and finally led out from the installation box body 1.

[0052] Specifically, in this embodiment, the auxiliary guide wheels 340 are designed to be two and connected to the guide wheel mounting seat 330 in the vertical direction. The bottom of the guide wheel mounting seat 330 is fastened to the fixed base plate 110 by bolts. After the pull rope 320 is led out from the wire roller 310, it is wrapped around the auxiliary guide wheel 340 in an S shape and then led out from the outside of the installation box body 1. The auxiliary guide wheel 340 can play a role in organizing the pull rope 320 and prevent the pull rope 320 from being entangled in the installation box body 1. In addition, more auxiliary guide wheels 340 can be set.

[0053] Furthermore, it also includes an auxiliary sliding component 6, which includes a sliding shaft 610 and a slider 620. The sliding shaft 610 is connected to the fixed base plate 110, and the slider 620 is clamped on the sliding shaft 610, and the slider 620 is connected to the bottom surface of the connecting seat 430.

[0054] Specifically, the auxiliary sliding assembly 6 provides support for the movement of the connecting seat 430 along the direction of the screw rod 420.

[0055] Furthermore, limiting grooves 611 are provided on both sides of the sliding shaft 610, a sliding groove is provided on the lower surface of the slider 620, and a limiting strip 622 is provided on the groove wall of the sliding groove. The limiting strip 622 is clamped in the limiting groove 611, and the bottom of the sliding groove is in close contact with the upper surface of the sliding shaft 610.

[0056] Specifically, the arrangement of the limiting groove 611 and the limiting bar 622 ensures the movement stability of the connecting seat 430 .

[0057] Furthermore, two limiting blocks 7 are provided on the fixed base plate 110 , and the two limiting blocks 7 are respectively provided at the front and rear ends of the connecting seat 430 in the moving direction.

[0058] Specifically, since the measuring range of the MEMS displacement meter 5 is relatively small, adding limit blocks 7 at the front and rear ends of the connecting seat 430 can prevent the movement range of the piston 520 in the cylinder 510 from exceeding the readable range of the MEMS displacement meter 5 .

[0059] Furthermore, a connecting plate 8 is provided at the end of the screw rod 420 away from the reset assembly 2, one side of the connecting plate 8 is fastened to the connecting seat 430, and the other side of the connecting plate 8 is connected to the roller shaft. A connecting column is provided at the end of the screw rod 420 away from the pulley assembly 3, and the vortex spring shaft 220 is T-shaped. The vortex spring shaft 220 includes a large end and a small end. The small end is provided with a straight groove, and the inner end of the vortex spring is clamped in the straight groove. The large end is provided with a first plug-in groove and a limiting hole 9. The limiting hole 9 is connected to the first plug-in groove, and the first plug-in groove is sleeved on the connecting column. A setting screw is provided in the limiting hole 9, and the setting screw is in contact with the connecting column.

[0060] Specifically, as mentioned above, the connecting plate 8 is used to fix the screw rod 420, the roller shaft and the connecting seat 430, and at the same time can ensure that the screw rod 420, the roller shaft and the vortex spring shaft 220 are concentrically arranged. The connection method of the vortex spring shaft 220 and the screw rod 420 is plug-in limit fixation, which is convenient for assembly. Furthermore, a pin hole can be set on the connecting column, and the set screw passes through the limit hole 9 and falls into the pin hole of the connecting column, which can strengthen the connection between the screw rod 420 and the vortex spring shaft 220.

[0061] Furthermore, a limiting waist-shaped hole 10 is provided on the cylinder body 510, and a limiting pin 11 is provided on the piston 520. The limiting pin 11 always moves horizontally in the limiting waist-shaped hole 10, and the movable distance of the limiting pin 11 is the same as the movable distance of the connecting seat 430 between the two limiting blocks 7.

[0062] Specifically, the limiting waist-shaped hole 10 and the limiting pin 11 on the MEMS displacement meter 5 have the function of adjusting the movement range of the piston 520 in the cylinder 510 , and the relative position of the limiting block 7 and the connecting seat 430 can be determined by this movement range.

[0063] Furthermore, the head of the piston 520 is provided with a second plug-in slot 521, and a chip mounting column 522 is fixed in the second plug-in slot 521. The MEMS chip 530 is attached to the end of the chip mounting column 522. The cylinder body 510 includes a first connecting tube 511, a second connecting tube 512 and a third connecting tube 513. The first connecting tube 511 and the second connecting tube 512 are plugged into the third connecting tube 513. The MEMS displacement meter 5 also includes a collimator mounting seat 560 and an optical fiber lead-out connector 570. The collimator 540 is fixed in the collimator mounting seat 560, one end of the collimator mounting seat 560 is passed through one end of the third connecting tube 513, the chip mounting seat is passed through the other end of the third connecting tube 513, and the optical fiber lead-out connector 570 is connected to the end of the second connecting tube 512.

[0064] Specifically, the cylinder body 510 is a plug-in structure as a whole, which is convenient for the assembly of the entire MEMS displacement meter 5. The collimator 540 is fixed on the collimator mounting seat 560 by welding, and the chip mounting column 522 and the piston 520 are interference fit. As shown in the figure, the cylinder body 510 is connected to the fixed base plate 110 through the cylinder body 510 mounting seat, and the cylinder body 510 mounting seat is fastened to the fixed base plate 110 by bolts, ensuring that the cylinder body 510 and the internal collimator 540 always remain fixed relative to the fixed base plate 110. The piston 520 drives the change in the distance between the MEMS chip 530 and the collimator 540, thereby changing the wavelength of the reflected wave, and is connected to the external demodulation equipment through the optical fiber 550 and the optical fiber lead-out connector 570, thereby realizing the readability of the displacement of the pull rope 320.

[0065] Furthermore, the fixed bottom plate 110 has the same structure as the removable top cover 120, and the installation box body 1 also includes a surrounding side panel 130, and the bottom and top of the surrounding side panel 130 are provided with rectangular grooves, and a sealing ring is provided in the rectangular groove. The surrounding side panel 130 is provided with an optical fiber 550 connector fixing hole 132 and a pull rope 320 lead-out hole 131.

[0066] Specifically, the design of the sealing ring can ensure the sealing of the installation box body 1, ensure that the internal components will not be contaminated by water vapor, and further ensure the measurement accuracy of the sensor.

[0067] Furthermore, the displacement reduction assembly 4 further includes a bearing mounting seat 440 , the bearing mounting seat 440 is connected to the fixed base plate 110 , and the fixed bearing 410 is connected to the bearing mounting seat 440 .

[0068] Specifically, the bearing mounting seat 440 is connected to the fixed base plate 110 via set screws and is used to mount the fixed bearing 410 . The fixed bearing 410 used in this embodiment is a ball bearing.

[0069] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A draw-wire displacement sensor based on optical fiber MEMS technology, characterized in that: include: Install the box body, which includes a fixed bottom plate and a removable top cover; A reset assembly is arranged in the installation box body, and the reset assembly includes a vortex spring, a vortex spring mounting seat and a vortex spring shaft. The vortex spring mounting seat is arranged at one end of the fixed base plate, and the main body of the vortex spring mounting seat is a circular groove, which faces the inner wall of the installation box body. One end of the vortex spring shaft passes through the center of the circular groove toward the inner wall of the installation box body. The vortex spring is clamped in the circular groove, and the outer end of the vortex spring is connected to the groove wall of the circular groove, and the inner end of the vortex spring is connected to the vortex spring shaft; A wire wheel assembly is provided on one end of the fixed base plate away from the reset assembly, the wire wheel assembly includes a wire roller and a pull rope, the pull rope is tightly wound around the wire roller, the wire roller includes a roller shaft and a winding groove, one end of the pull rope is connected to the bottom of the winding groove, and the other end of the pull rope extends horizontally out of the mounting box body; A displacement reduction assembly, comprising a fixed bearing and a screw, wherein the fixed bearing is arranged on a side of the fixed base plate close to the reset assembly, one end of the screw is passed through the inner ring of the fixed bearing and is connected to the vortex spring shaft, and the other end of the screw is connected to the roller shaft, a connecting seat is sleeved on the screw, the connecting seat is threadedly connected to the screw, the connecting seat is arranged between the pulley assembly and the fixed bearing, and the connecting seat can move freely in the horizontal direction as the screw rotates; A MEMS displacement meter is arranged on one side of the displacement reduction component. The MEMS displacement meter includes: a cylinder body, a piston, a MEMS chip and a collimator. The cylinder body is connected to the fixed base plate, the head of the piston is passed through the cylinder body, the MEMS chip is vertically attached to the head of the piston, and the collimator is clamped at the end of the cylinder body away from the piston. The collimator includes a light-emitting side and a light-incoming side. The light-emitting side is horizontally aligned with the MEMS chip, and the light-incoming side is provided with an optical fiber, which extends horizontally out of the mounting box body. The end of the piston away from the collimator is connected to the connecting seat, and the axis of the piston and the axis of the lead screw are in the same plane.

2. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: The spool assembly also includes a guide wheel mounting seat and multiple auxiliary guide wheels. The multiple auxiliary guide wheels are all connected to the guide wheel mounting seat, and the guide wheel mounting seat is connected to the fixed base plate. The pull rope is sequentially wrapped around the multiple auxiliary guide wheels and finally led out from the installation box.

3. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: It also includes an auxiliary sliding component, which includes a sliding shaft and a slider. The sliding shaft is connected to the fixed base plate, the slider is clamped on the sliding shaft, and the slider is connected to the bottom surface of the connecting seat.

4. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 3, characterized in that: Limiting grooves are provided on both sides of the sliding shaft, a sliding groove is provided on the lower surface of the slider, a limiting strip is provided on the groove wall of the sliding groove, the limiting strip is clamped in the limiting groove, and the groove bottom of the sliding groove is in close contact with the upper surface of the sliding shaft.

5. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: Two limit blocks are arranged on the fixed bottom plate, and the two limit blocks are respectively arranged at the front and rear ends of the connecting seat in the moving direction.

6. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: A connecting plate is provided at one end of the screw rod away from the reset assembly, one side of the connecting plate is fastened to the connecting seat, and the other side of the connecting plate is connected to the roller shaft, and a connecting column is provided at one end of the screw rod away from the pulley assembly, and the vortex spring shaft is T-shaped, and the vortex spring shaft includes a large end and a small end, and the small end is provided with a straight groove, and the inner end of the vortex spring is clamped in the straight groove, and the large end is provided with a first plug-in slot and a limiting hole, and the limiting hole is connected to the first plug-in slot, and the first plug-in slot is sleeved on the connecting column, and a set screw is provided in the limiting hole, and the set screw abuts against the connecting column.

7. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 5, characterized in that: A limiting waist-shaped hole is provided on the cylinder body, and a limiting pin is provided on the piston. The limiting pin always moves horizontally in the limiting waist-shaped hole, and the movable distance of the limiting pin is the same as the movable distance of the connecting seat between the two limiting blocks.

8. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: The head of the piston is provided with a second plug-in slot, and a chip mounting column is fixed in the second plug-in slot. The MEMS chip is attached to the end of the chip mounting column. The cylinder body includes a first connecting tube, a second connecting tube and a third connecting tube. The first connecting tube and the second connecting tube are plugged into the third connecting tube. The MEMS displacement meter also includes a collimator mounting seat and an optical fiber lead-out connector. The collimator is fixed in the collimator mounting seat, one end of the collimator mounting seat is passed through one end of the third connecting tube, the chip mounting seat is passed through the other end of the third connecting tube, and the optical fiber lead-out connector is connected to the end of the second connecting tube.

9. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: The fixed bottom plate has the same structure as the removable top cover, and the installation box body also includes a surrounding side panel, the bottom and top of the surrounding side panel are both provided with a rectangular groove, a sealing ring is provided in the rectangular groove, and the surrounding side panel is provided with a fiber optic connector fixing hole and a pull rope lead-out hole.

10. The draw-wire displacement sensor based on optical fiber MEMS technology according to claim 1, characterized in that: The displacement reduction assembly further includes a bearing mounting seat, the bearing mounting seat is connected to the fixed base plate, and the fixed bearing is connected to the bearing mounting seat.

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