Pull rope type displacement sensor based on optical fiber MEMS technology

Abstract

The invention relates to a pull rope type displacement sensor based on an optical fiber MEMS technology, and the sensor comprises an installation box body, a reset assembly, a wire wheel assembly, a displacement reduction assembly, and an MEMS displacement meter, the reset assembly employs a vortex spring structure, the wire wheel assembly drives a wire roller through the traction of a pull rope, and sequentially transmits the rotation motion to a lead screw and a vortex spring shaft in the displacement reduction assembly, and the connecting seat which moves along with rotation on the screw rod drives the MEMS chip and the collimator in the displacement meter to generate displacement change so as to transmit an optical signal to external demodulation equipment, so that the readability of the pull rope is realized. The optical fiber MEMS technology is adopted, and interference of electromagnetic radiation and temperature change is avoided; a vortex spring reset mode is used, the reset precision is high, repeated use can be achieved, mounting and dismounting are convenient, and the measuring speed is increased; a theoretical algorithm and high-precision calibration combined mode is used, accurate and stable data support is provided in the engineering detection field of coal mines, tunnels, bridges and the like, and tiny changes of an observed object can be found in engineering monitoring so as to achieve an early warning effect.

Description

Technical Field

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

[0002] The traditional electronic pull-rope displacement sensor is to first wrap a stretchable traction rope around a threaded hub, which is 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, etc. Then the end of the traction rope is fixed to the moving object, and the linear motion of the rope is aligned with the axis of motion of the moving object. This kind of electronic pull-rope displacement meter, because its core sensor element uses an electrical strain gauge, is inevitably susceptible to interference from environmental electromagnetic radiation and has poor long-term stability, and cannot meet the problem of long-term stable operation in an electromagnetic radiation environment.

[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 after one circle of the hub in the early and later stages of measurement, which will further affect the measurement accuracy. If a rotating 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] To this end, 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 ability, strong environmental adaptability and high precision.

[0005] In order to solve the above technical problems, the present invention provides a draw-wire displacement sensor based on optical fiber MEMS technology, comprising: An installation box body, which includes a fixed bottom plate and a removable top cover; A reset assembly is arranged in the installation box body, the reset assembly comprises 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 bottom plate, the main body of the vortex spring mounting seat is a circular groove, the circular groove 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, 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 arranged on one end of the fixed bottom plate away from the reset assembly, the wire wheel assembly comprises a wire roller and a pull rope, the pull rope is tightly wound around the wire roller, the wire roller comprises a roller shaft and a winding groove, one end of the pull rope is connected to the groove bottom of the winding groove, and the other end of the pull rope extends out of the mounting box body in a horizontal direction; A displacement reduction assembly, comprising a fixed bearing and a screw rod, wherein the fixed bearing is arranged on a side of the fixed base plate close to the reset assembly, one end of the screw rod 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 rod is connected to the roller shaft, a connecting seat is sleeved on the screw rod, the connecting seat is threadedly connected to the screw rod, the connecting seat is arranged between the wire wheel assembly and the fixed bearing, and the connecting seat can freely move in the horizontal direction as the screw rod 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 penetrated in the cylinder body. The MEMS chip is vertically attached to the head of the piston. The collimator is clamped at one 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 aligned with the MEMS chip in a horizontal direction. An optical fiber is arranged on the light-incoming side. The optical fiber extends out of the mounting box in a horizontal direction. The end of the piston away from the collimator is connected to the connecting seat. The axis of the piston and the axis of the lead screw are in the same plane.

[0006] In one embodiment of the present invention, the wire wheel assembly also 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 installation box.

[0007] 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 sliding block, wherein the sliding shaft is connected to the fixed base plate, the sliding block is clamped on the sliding shaft, and the sliding block is connected to the bottom surface of the connecting seat.

[0008] 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 sliding block, 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.

[0009] In one embodiment of the present invention, 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.

[0010] 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 wire wheel 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 groove and a limiting hole, and the limiting hole is connected with the first plug-in groove, and the first plug-in groove is sleeved on the connecting column, and a locking screw is provided in the limiting hole, and the locking screw abuts against the connecting column.

[0011] 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 in the horizontal direction 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.

[0012] 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 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 penetrated through one end of the third connecting tube, the chip mounting seat is penetrated 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.

[0013] 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 rectangular grooves, 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.

[0014] 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.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: When using this drawstring displacement sensor based on optical fiber 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 to move 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 in 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 optical fiber, and further demodulates the optical signal into readable information.

[0016] The advantages of the present invention include the following points: 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.

[0017] 2. The present invention can adopt a combination of theoretical algorithms and precise calibration. The theoretical relationship between the movement of the rope and the change in the displacement meter signal 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 movement of the rope and the change in the displacement meter. The change in the rope is cleverly converted into a relative position change between 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.

[0018] 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 lead screw and the connecting seat, thereby realizing a large-range and high-precision measurement.

[0019] 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 restore the initial position, thereby achieving repeatability of multiple measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein Figure 1 It is a schematic diagram of the overall structure of the draw-wire displacement sensor based on optical fiber MEMS technology of the present invention; Figure 2 for Figure 1 A top view of the internal structure of the mounting box in the draw-wire displacement sensor based on optical fiber MEMS technology is shown; Figure 3 for Figure 1 A front view of the internal structure of the mounting box in the draw-wire displacement sensor based on optical fiber MEMS technology is shown; Figure 4 for Figure 1 The left side view of the internal structure of the installation box in the draw-wire displacement sensor based on optical fiber MEMS technology is shown; Figure 5 for Figure 1 The right side view of the internal structure of the installation box in the draw-wire displacement sensor based on optical fiber MEMS technology is shown; Figure 6 for Figure 1 The overall structural diagram of the MEMS displacement meter in the draw-wire displacement sensor based on optical fiber MEMS technology is shown; Figure 7 for Figure 1 A cross-sectional view of a MEMS displacement meter in a draw-wire displacement sensor based on optical fiber MEMS technology is shown.

[0021] Description of the accompanying drawings in the specification: 1. Installation box; 110. Fixed bottom plate; 120. Removable top cover; 130. Surrounding side plate; 131. Draw rope lead-out hole; 132. Optical fiber connector fixing hole; 2. Reset assembly; 210. Vortex spring mounting seat; 220. Vortex spring shaft; 3. Wire wheel assembly; 310. Wire roller; 320. Draw 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 strip; 7, limiting block; 8, connecting plate; 9, limiting hole; 10, limiting waist hole; 11, limiting pin. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0023] Reference Figures 1 to 7 As shown, the present invention provides a wire-drawn displacement sensor based on MEMS technology, comprising: Install the box body 1, which includes a fixed bottom plate 110 and a removable top cover 120; A 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 bottom 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. The wire wheel assembly 3 is arranged on one end of the fixed bottom plate 110 away from the reset assembly 2. The wire wheel assembly 3 includes a wire roller 310 and a pull rope 320. The pull rope 320 is tightly wound around the wire roller 310. The wire roller 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 out of the mounting box body 1 in a horizontal direction. The displacement reduction component 4 includes a fixed bearing 410 and a screw rod 420. The fixed bearing 410 is arranged on the fixed base plate 110 on a side 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 freely move in the horizontal direction as the screw rod 420 rotates. 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 inserted into the cylinder body 510. The MEMS chip 530 is vertically attached to the head of the piston 520. The collimator 540 is clamped at one end of the cylinder body 510 away from the piston 520. The collimator 540 includes a light emitting side and a light input side. The light emitting side is aligned with the MEMS chip 530 in the horizontal direction. The light input side is provided with an optical fiber 550, which extends out of the mounting box body 1 in the horizontal direction. The end of the piston 520 away from the collimator 540 is connected to the connecting seat 430. The axis of the piston 520 and the axis of the lead screw 420 are in the same plane.

[0024] When using this pull rope 320 displacement sensor based on MEMS technology, the free end of the pull rope 320 is first fixed to the object to be measured. When the object to be measured pulls the pull rope 320 to move outward, the pull rope 320 drives the lead screw to rotate, and the connecting seat 430 sleeved 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 the wavelength of light, connects to an external optical signal demodulation device through an optical fiber 550, and further demodulates the optical signal into readable information.

[0025] The advantages of the present invention include the following points: 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.

[0026] 2. The present invention can adopt a combination of theoretical algorithms and precise calibration. The theoretical relationship between the movement of the pull rope 320 and the change in the displacement meter signal is calculated through modeling simulation and precise algorithms. The relationship is verified and improved during the calibration process to obtain the actual movement of the pull rope 320 and the change in the displacement meter. The change in the pull rope 320 is cleverly converted into a relative position change between the chip and the collimator 540 in the MEMS displacement meter 5, 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, small changes in the observed object can be discovered, and disaster warning information can be provided to the engineering site earlier.

[0027] 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 a small measuring range of the MEMS displacement meter 5 through the rotational displacement of the lead screw plus the connecting seat 430, thereby realizing a large-range and high-precision measurement.

[0028] 4. The present invention adopts 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 restore the initial position, thereby achieving repeatability of multiple measurements.

[0029] Specifically, the number of turns of the rope 320 wound on the wire 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 wire 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) and the number of turns (n), the wire diameter d of the rope 320, and the diameter (R) of the wire roller 310 are obtained by calculation. The relationship is: Ln=π*{(n*d+R}. This relationship is introduced into the system of the lead screw 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 displacement data of the rope 320. The fitted coefficients and the calibration tool are used for verification. The test shows that the accuracy of the MEMS displacement meter 5 can reach 0.05%.

[0030] Specifically, the mounting box body 1 is made of a high-strength metal material as a whole, which is resistant to 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 assembly 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 the present 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 displacement data of the pull rope 320 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 assembly 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 After the connecting seat 430, the connecting plate 8 is used to fix it to the connecting seat 430. One side of the connecting seat 430 is used to fix the piston 520 on the MEMS displacement meter 5. It can be seen that the connection between the connecting seat 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 further limit 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 seat 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, thereby solving the problem of signal reception and transmission of existing displacement sensors in harsh working environments with electromagnetic interference and large temperature differences.

[0031] Furthermore, the reel assembly 3 also includes a guide wheel mounting seat 330 and multiple auxiliary guide wheels 340, and 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, and the pull rope 320 is sequentially wrapped around the multiple auxiliary guide wheels 340 and finally led out from the installation box body 1.

[0032] Specifically, in the present embodiment, the auxiliary guide wheels 340 are designed to be two and are 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 to prevent the pull rope 320 from being entangled in the installation box body 1. Furthermore, more auxiliary guide wheels 340 can be provided.

[0033] Furthermore, it also includes an auxiliary sliding component 6, which includes a sliding shaft 610 and a sliding block 620, the sliding shaft 610 is connected to the fixed base plate 110, the sliding block 620 is clamped on the sliding shaft 610, and the sliding block 620 is connected to the bottom surface of the connecting seat 430.

[0034] Specifically, the auxiliary sliding assembly 6 provides support for the movement of the connecting seat 430 along the direction of the screw rod 420 .

[0035] 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, 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 groove bottom of the sliding groove is in close contact with the upper surface of the sliding shaft 610.

[0036] Specifically, the arrangement of the limiting groove 611 and the limiting strip 622 ensures the movement stability of the connecting seat 430 .

[0037] Furthermore, two limit blocks 7 are arranged on the fixed bottom plate 110 , and the two limit blocks 7 are respectively arranged at the front and rear ends of the connecting seat 430 in the moving direction.

[0038] 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 body 510 from exceeding the readable range of the MEMS displacement meter 5 .

[0039] Furthermore, a connecting plate 8 is provided at one 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 one end of the screw rod 420 away from the reel 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 locking screw is provided in the limiting hole 9, and the locking screw abuts against the connecting column.

[0040] 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 between 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.

[0041] 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 in the horizontal direction 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.

[0042] Specifically, the limiting waist-shaped hole 10 and the limiting pin 11 on the MEMS displacement meter 5 have a movement range of the adjustment piston 520 in the cylinder 510, and the relative position of the limiting block 7 and the connecting seat 430 can be determined through this movement range.

[0043] Furthermore, a second plug-in slot 521 is provided at the head of the piston 520, and a chip mounting column 522 is clamped in the second plug-in slot 521, and 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, and the first connecting tube 511 and the second connecting tube 512 are plugged through 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 clamped 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.

[0044] 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, so as to realize the readability of the displacement of the pull rope 320.

[0045] 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, the bottom and top of the surrounding side panel 130 are provided with rectangular grooves, a sealing ring is provided in the rectangular groove, and 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.

[0046] 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 polluted by water vapor, and further ensure the measurement accuracy of the sensor.

[0047] Furthermore, the displacement reduction component 4 also 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 .

[0048] Specifically, the bearing mounting seat 440 is connected to the fixed base plate 110 through a set screw and is used to install the fixed bearing 410. The fixed bearing 410 used in this embodiment is a ball bearing.

[0049] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A draw-wire displacement sensor based on optical fiber MEMS technology, characterized in that: include: An installation box body, which includes a fixed bottom plate and a removable top cover; A reset assembly is arranged in the installation box body, the reset assembly comprises 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 bottom plate, the main body of the vortex spring mounting seat is a circular groove, the circular groove 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, 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 arranged on one end of the fixed bottom plate away from the reset assembly, the wire wheel assembly comprises a wire roller and a pull rope, the pull rope is tightly wound around the wire roller, the wire roller comprises a roller shaft and a winding groove, one end of the pull rope is connected to the groove bottom of the winding groove, and the other end of the pull rope extends out of the mounting box body in a horizontal direction; A displacement reduction assembly, comprising a fixed bearing and a screw rod, wherein the fixed bearing is arranged on a side of the fixed base plate close to the reset assembly, one end of the screw rod 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 rod is connected to the roller shaft, a connecting seat is sleeved on the screw rod, the connecting seat is threadedly connected to the screw rod, the connecting seat is arranged between the wire wheel assembly and the fixed bearing, and the connecting seat can freely move in the horizontal direction as the screw rod 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 penetrated in the cylinder body. The MEMS chip is vertically attached to the head of the piston. The collimator is clamped at one 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 aligned with the MEMS chip in a horizontal direction. An optical fiber is arranged on the light-incoming side. The optical fiber extends out of the mounting box in a horizontal direction. The end of the piston away from the collimator is connected to the connecting seat. 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 is characterized in that: The wire wheel 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, the guide wheel mounting seat is connected to the fixed base plate, and 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 sliding block. The sliding shaft is connected to the fixed base plate, the sliding block is clamped on the sliding shaft, and the sliding block 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 is characterized in that: Limiting grooves are arranged on both sides of the sliding shaft, a sliding groove is arranged on the lower surface of the sliding block, a limiting strip is arranged 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: The fixed bottom plate is provided with two limit blocks, and the two limit blocks are respectively provided 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. A connecting column is provided at one end of the screw rod away from the wire wheel 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 groove and a limiting hole, and the limiting hole is connected with the first plug-in groove, and the first plug-in groove is sleeved on the connecting column, and a locking screw is provided in the limiting hole, and the locking 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 arranged on the cylinder body, and a limiting pin is arranged on the piston. The limiting pin always moves in the limiting waist-shaped hole along the horizontal direction, 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 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 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 penetrated through one end of the third connecting tube, the chip mounting seat is penetrated 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 plate, the bottom and top of the surrounding side plate are both provided with rectangular grooves, a sealing ring is provided in the rectangular groove, and the surrounding side plate 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 component also 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.

Images