Fiber grating packaging device and packaging method

Abstract

A fiber grating packaging device and packaging method, including a packaging instrument and a controller, the packaging instrument is connected to the controller through a wire; an adjustable packaging workbench is provided with a U-shaped groove, the bottom of the U-shaped groove is provided with at least 8 small holes, the small holes are connected to the vacuum valve through a sealing block and an air hose, the packaging tube in the U-shaped groove is fixed by air adsorption, a three-dimensional adjustment frame is provided below the adjustable packaging workbench, the three-dimensional adjustment frame is placed in a chamber composed of a pair of standing plates, a top plate and a bottom plate, two optical fiber fixing clamps are arranged on both sides of the adjustable packaging workbench, fixed to the surface of the top plate by screws, a stress applying instrument is fixed on the side of the top plate where the second optical fiber fixing clamp is located, and a heating top cover is connected to the adjustable packaging workbench through a metal rotating shaft. The present invention can apply constant prestress to the optical fiber grating before packaging, and perform standard and standardized tubular packaging on the optical fiber grating, so as to achieve precise control of the structural performance of the tubular packaged optical fiber grating.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber grating sensing, and in particular relates to an optical fiber grating packaging device and a packaging method. Background Art

[0002] Fiber optic sensor is a new type of sensor. Compared with traditional sensors, it has the advantages of high temperature resistance, corrosion resistance, electromagnetic interference resistance, small size, and flexibility. In addition to the advantages of general fiber optic sensors, fiber optic Bragg grating sensors also have the characteristics of wavelength encoding, which enhances the anti-interference ability of fiber optic Bragg gratings and is easy to network and multiplex. It is an ideal substitute for traditional sensors. However, fiber optic Bragg gratings are very fragile and easy to break. Directly using them as sensors in actual engineering applications encounters a big problem in the layout process. Therefore, it is of great significance to study practical fiber optic Bragg grating packaging processes for the problems that need to be solved.

[0003] Since fiber Bragg grating sensors have the problem of cross-sensitivity, that is, both temperature and strain will affect the wavelength of the fiber Bragg grating, it is currently difficult to effectively distinguish between strain and temperature when dealing with the coupling wavelength shift of the fiber Bragg grating. Therefore, dealing with the adverse effects of cross-sensitivity is a very important prerequisite for improving the accuracy of fiber Bragg grating sensors.

[0004] The double-layer metal tube packaging structure is a feasible solution to reduce the cross-sensitivity effect. The outer packaging tube does not directly contact the inner packaging tube, so that the sensor can accurately measure the temperature without being affected by external forces.

[0005] In addition, in the field of high temperature resistant fiber Bragg grating sensor packaging, double-layer tube packaging structure is also needed. When designing the packaging structure of high temperature resistant fiber Bragg grating sensor, three aspects need to be considered: first, the packaging material itself needs to be stable under high temperature conditions, and its own high temperature resistance should match that of the optical fiber as much as possible; second, whether this packaging structure can reliably protect the fiber Bragg grating; and finally, how is the sensing performance of the packaged fiber Bragg grating sensor.

[0006] To this end, in the process of researching high-temperature resistant fiber Bragg grating packaging technology, some teams have produced high-temperature fiber Bragg grating sensors with quartz-metal double-layer packaging.

[0007] The double-layer tube packaging structure has great potential in promoting the practical engineering application of fiber Bragg gratings, but this packaging process is difficult, and it is necessary to ensure that the fiber Bragg grating and the two layers of casing are spatially coaxial. At present, when the double-layer tube structure is used to package the fiber Bragg grating, it is often necessary for several people to operate manually at the same time, which also makes the size specifications of the packaged fiber Bragg grating sensor not uniform and the sensitivity varies greatly. It is difficult to achieve the purpose of reuse and it is difficult to formulate a unified standard for sensitivity. A practical packaging device and operation method for double-layer tube packaging of fiber Bragg gratings has not yet been proposed. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a fiber grating packaging device and packaging method, which can apply constant prestress to the fiber grating before packaging, and perform standard and normative tubular packaging on the fiber grating, thereby achieving precise control of the performance of the fiber grating tubular packaging structure.

[0009] The present invention provides a fiber grating packaging device, comprising a packaging instrument and a controller, wherein the packaging instrument is connected to the controller via a wire;

[0010] The packaging instrument comprises an adjustable packaging workbench 11, a three-dimensional adjustment frame 13, a No. 1 optical fiber fixing fixture 8, a No. 2 optical fiber fixing fixture 9, a stress applying instrument 10, a heating top cover 12, a sealing block 14, a vacuum valve 15, an air hose 16, a bottom plate 1, a No. 1 vertical plate 2, a No. 2 vertical plate 3 and a top plate 4; a U-shaped groove is arranged on the adjustable packaging workbench 11, and 8 small holes are arranged at the bottom of the U-shaped groove, and the small holes are connected to the vacuum valve 15 through the sealing block 14 and the air hose 16, and the U-shaped groove is fixed by air adsorption. A packaging tube in the groove, a three-dimensional adjustment frame 13 is arranged below the adjustable packaging workbench 11, the three-dimensional adjustment frame 13 is placed in a chamber formed by the bottom plate 1, the No. 1 vertical plate 2, the No. 2 vertical plate 3 and the top plate 4, the No. 1 optical fiber fixing clamp 8 and the No. 2 optical fiber fixing clamp 9 are arranged on both sides of the adjustable packaging workbench 11, and are fixed to the surface of the top plate by screws, a stress applicator 10 is fixed on the edge of the side where the No. 2 optical fiber fixing clamp 9 is located, and the heating top cover 12 is connected to the adjustable packaging workbench 11 through a metal rotating shaft.

[0011] As a further technical solution of the present invention, the controller includes a temperature control unit, a stress control unit, a suction control unit and a central processing unit; the receiving ends of the temperature control unit, the stress control unit and the suction control unit are all connected to the control end of the central processing unit;

[0012] A temperature control unit, used to control the temperature and duration of the heating top cover;

[0013] A stress control unit, used to control the magnitude of the axial stress applied by the stress applying instrument;

[0014] The suction control unit is used to control the suction force of the vacuum valve.

[0015] Furthermore, the three-dimensional adjustment frame 13 includes an X-direction distance adjustment micrometer head 5, a Y-direction distance adjustment micrometer head 6 and a Z-direction distance adjustment micrometer head 7. The connecting rod of the Z-direction distance adjustment micrometer head 7 is connected to the adjustable packaging workbench 11. The distance adjustment accuracy of the X-direction distance adjustment micrometer head 5, the Y-direction distance adjustment micrometer head 6 and the Z-direction distance adjustment micrometer head 7 is 0.005mm.

[0016] Furthermore, the first optical fiber fixing fixture 8 and the second optical fiber fixing fixture 9 are both provided with a plurality of V-shaped grooves.

[0017] Furthermore, the heating top cover includes a heating top cover body 12-1, a heating resistor wire 12-3 and a temperature sensor 12-2. The temperature sensor 12-2 is installed on the inner surface of the heating top cover body 12-1. The temperature sensor 12-2 is provided with a heating resistor wire 12-3 along the boundary. The heating top cover 12 is connected to the adjustable packaging workbench 11 through a metal rotating shaft.

[0018] The present invention also provides a packaging method for a fiber grating packaging device, comprising the following steps:

[0019] S1, open the covers of the No. 1 optical fiber fixing fixture 8, the No. 2 optical fiber fixing fixture 9 and the heating top cover 12, and adjust the X-direction distance adjustment micrometer head 5, the Y-direction distance adjustment micrometer head 6 and the Z-direction distance adjustment micrometer head 7 on the three-dimensional adjustment frame 13 respectively, so that the U-shaped groove opened on the adjustable packaging workbench 11 is consistent with the axis of the V-shaped groove on the optical fiber fixing fixture selected according to the optical fiber diameter;

[0020] S2, pass the fiber Bragg grating through the packaging tube, so that the fiber Bragg grating area is located in the middle of the packaging tube, and place the packaging tube in the U-shaped groove opened on the adjustable packaging workbench 11, and the optical fibers on both sides of the packaging tube are freely and horizontally placed in the V-shaped grooves corresponding to the two optical fiber fixing fixtures;

[0021] S3, close the cover of the No. 1 optical fiber fixing fixture 8; freely place the right end of the optical fiber in the stress applying instrument, set the magnitude of the stress to be applied, and apply a constant prestress to the optical fiber Bragg grating; close the cover of the No. 2 optical fiber fixing fixture 9;

[0022] S4, re-adjust the X-direction distance adjustment differential head 5, the Y-direction distance adjustment differential head 6 and the Z-direction distance adjustment differential head 7 on the three-dimensional adjustment frame 13 so that the packaging tube and the fiber grating are spatially coaxial; open the vacuum valve switch to ensure that the packaging tube is fixed in position through air adsorption;

[0023] S5, using a needle to add glue or other packaging materials to both ends of the packaging tube; closing the heating top cover 12, setting the temperature to heat and cure the packaging material;

[0024] S6. After the curing is completed, repeat the above operation at least once to complete the curing of at least one layer of packaging tube according to the design requirements;

[0025] S7. After the final packaging is completed, use a tool to take out the packaged fiber Bragg grating.

[0026] The present invention can control two layers of packaging tubes to be coaxial and non-contacting in space by adjusting the three-dimensional adjustment frame, but not limited to the two layers; a prestressing device is provided to further improve the reliability of the packaging effect; an air adsorption device is provided in the U-shaped groove of the adjustable packaging workbench to effectively fix the packaging tube, especially the packaging tube of a small size. The tubular fiber grating sensor packaged by the device has a relatively uniform size and shape, which also makes the tubular packaging of the fiber grating more standardized and normative; the manufactured sensor is independent of the object to be measured, so that the sensor can be reused; the sensor can also be calibrated before use, which improves the accuracy of use and can effectively control the performance of the packaged sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2 It is a structural front view of the present invention;

[0029] Figure 3 It is a structural schematic diagram of the air adsorption module of the present invention;

[0030] Figure 4 A top view of the present invention;

[0031] Figure 5 The structural block diagram of the controller of the present invention is

[0032] In the figure, 1 is a bottom plate, 2 is a vertical plate No. 1, 3 is a vertical plate No. 2, 4 is a top plate, 5 is a distance-adjustable micrometer head in the X direction, 6 is a distance-adjustable micrometer head in the Y direction, 7 is a distance-adjustable micrometer head in the Z direction, 8 is a fiber optic fixing fixture No. 1, 9 is a fiber optic fixing fixture No. 2, 10 is a stress applicator, 11 is an adjustable packaging workbench, 12 is a heating top cover, 12.1 is a heating top cover body, 12.2 is a temperature sensor, 12.3 is a heating resistance wire, 13 is a three-dimensional adjustment frame, a sealing block 14, a vacuum valve 15, and an air hose 16. DETAILED DESCRIPTION

[0033] See also Figure 1-Figure 5 This embodiment provides a fiber grating packaging device and a packaging method. Specifically, the packaging device includes a packaging device and a controller. The packaging device and the controller are connected by a wire.

[0034] The packaging instrument comprises an adjustable packaging workbench 11, a three-dimensional adjustment frame 13, a No. 1 optical fiber fixing fixture 8, a No. 2 optical fiber fixing fixture 9, a stress applying instrument 10, a heating top cover 12, a sealing block 14, a vacuum valve 15, an air hose 16, a bottom plate 1, a No. 1 vertical plate 2, a No. 2 vertical plate 3 and a top plate 4; a U-shaped groove is arranged on the adjustable packaging workbench 11, and 8 small holes are arranged at the bottom of the U-shaped groove, and the small holes are connected to the vacuum valve 15 through the sealing block 14 and the air hose 16, and the U-shaped groove is fixed by air adsorption. A packaging tube in the groove, a three-dimensional adjustment frame 13 is arranged below the adjustable packaging workbench 11, the three-dimensional adjustment frame 13 is placed in a chamber formed by the bottom plate 1, the No. 1 vertical plate 2, the No. 2 vertical plate 3 and the top plate 4, the No. 1 optical fiber fixing clamp 8 and the No. 2 optical fiber fixing clamp 9 are arranged on both sides of the adjustable packaging workbench 11, and are fixed to the surface of the top plate by screws, a stress applicator 10 is fixed on the edge of the side where the No. 2 optical fiber fixing clamp 9 is located, and the heating top cover 12 is connected to the adjustable packaging workbench 11 through a metal rotating shaft.

[0035] The controller includes a temperature control unit, a stress control unit, a suction control unit and a central processing unit. The temperature control unit is used to control the size and duration of the heating temperature of the heating top cover, the stress control unit is used to control the size of the axial stress applied by the stress applicator, and the suction control unit is used to control the size of the vacuum valve suction. The temperature control unit, the stress control unit and the suction control unit are all connected to the central processing unit and are uniformly controlled by it;

[0036] As an embodiment, the packaging of a double-layer stainless steel tube is realized by using a packaging device of a fiber grating, which includes the following steps:

[0037] S1. As an embodiment, the diameter of the fiber Bragg grating is 250μm, and the length of the grating area is 20mm. Open the covers of the No. 1 fiber fixing fixture 8 and the No. 2 fiber fixing fixture 9 and the heating top cover 12, and adjust the X-direction distance adjustment differential head 5, the Y-direction distance adjustment differential head 6 and the Z-direction distance adjustment differential head 7 on the three-dimensional adjustment frame respectively, so that the U-shaped groove opened on the adjustable packaging workbench 11 is consistent with the axis of the V-shaped groove of the No. 1 fiber fixing fixture and the No. 2 fiber fixing fixture that fixes the 250μm diameter optical fiber;

[0038] S2. As an embodiment, the inner packaging tube is a 304 stainless steel tube with a diameter of 0.6 mm, a wall thickness of 0.1 mm, and a length of 30 mm. The fiber grating is passed through the inner packaging tube so that the fiber grating area is located in the middle of the packaging tube. The packaging tube is placed in the U-shaped groove opened on the adjustable packaging workbench 11. The optical fibers on both sides of the packaging tube are freely and horizontally placed in the 250μm V-shaped grooves of the two optical fiber fixing fixtures;

[0039] S3, tightly cover the cover of the No. 1 optical fiber fixing fixture 8, freely place the right end of the optical fiber in the stress applying device 10, apply a constant prestress to the optical fiber Bragg grating, as an embodiment, set the prestress to 1N, and tightly cover the cover of the No. 2 optical fiber fixing fixture 9;

[0040] S4, adjust the X-direction distance adjustment differential head 5, the Y-direction distance adjustment differential head 6 and the Z-direction distance adjustment differential head 7 on the three-dimensional adjustment frame again, so that the packaging tube and the fiber grating are kept coaxial in space, and open the vacuum valve 15 switch to ensure that the packaging tube is fixed in position through the effect of air adsorption;

[0041] S5. Use a needle to inject high temperature resistant silicone into both ends of the packaging tube, close the heating cover 12, and as an embodiment, set the temperature to 60° C. and maintain it for four hours to heat and cure the high temperature silicone;

[0042] S6. After curing is completed, the packaging structure is inserted into the outer metal sleeve. As an embodiment, the outer sleeve is a 304 stainless steel tube with a diameter of 1.4 mm, a wall thickness of 0.1 mm, and a length of 40 mm. No axial prestress is applied to the fiber Bragg grating, and the above operation is repeated;

[0043] S7. After the final packaging is completed, use a tool to take out the packaged fiber grating sensor.

[0044] This patent has multiple implementation methods. All technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of this patent.

[0045] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above specific embodiments. The above specific embodiments and the description in the specification are only for further illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of the present invention to be protected is defined by the claims and their equivalents.

Claims

1. A fiber Bragg grating packaging device, characterized in that: It comprises a packaging instrument and a controller, wherein the packaging instrument is connected to the controller via a wire; The packaging instrument comprises an adjustable packaging workbench (11), a three-dimensional adjustment frame (13), a first optical fiber fixing fixture (8), a second optical fiber fixing fixture (9), a stress applying instrument (10), a heating top cover (12), a sealing block (14), a vacuum valve (15), an air hose (16), a bottom plate (1), a first vertical plate (2), a second vertical plate (3) and a top plate (4); the adjustable packaging workbench (11) is provided with a U-shaped groove, and the bottom of the U-shaped groove is provided with 8 small holes, and the small holes are connected to the vacuum valve (15) through the sealing block (14) and the air hose (16), and the packaging tube in the U-shaped groove is fixed by air adsorption; the three-dimensional adjustment frame (13) is arranged below the adjustable packaging workbench (11), and the three-dimensional adjustment frame (14) is arranged below the adjustable packaging workbench (11). The adjustment frame (13) is placed in a chamber formed by the bottom plate (1), the first vertical plate (2), the second vertical plate (3) and the top plate (4); the first optical fiber fixing fixture (8) and the second optical fiber fixing fixture (9) are arranged on both sides of the adjustable packaging workbench (11) and fixed to the surface of the top plate by screws; the stress applying instrument (10) is fixed on the edge of the side where the second optical fiber fixing fixture (9) is located; the heating top cover (12) is connected to the adjustable packaging workbench (11) through a metal rotating shaft; the controller includes a temperature control unit, a stress control unit, a suction control unit and a central processing unit; the receiving ends of the temperature control unit, the stress control unit and the suction control unit are all connected to the control end of the central processing unit; The temperature control unit is used to control the temperature and duration of the heating top cover; The stress control unit is used to control the magnitude of the axial stress applied by the stress applying instrument; The suction control unit is used to control the suction force of the vacuum valve; The three-dimensional adjustment frame (13) comprises an X-direction distance adjustment micrometer head (5), a Y-direction distance adjustment micrometer head (6) and a Z-direction distance adjustment micrometer head (7); a connecting rod of the Z-direction distance adjustment micrometer head (7) is connected to an adjustable packaging workbench (11); and the distance adjustment accuracy of the X-direction distance adjustment micrometer head (5), the Y-direction distance adjustment micrometer head (6) and the Z-direction distance adjustment micrometer head (7) is 0.005 mm.

2. A fiber grating packaging device according to claim 1, characterized in that: The first optical fiber fixing fixture (8) and the second optical fiber fixing fixture (9) are both provided with a plurality of V-shaped grooves.

3. The fiber grating packaging device according to claim 1, characterized in that: The heating top cover comprises a heating top cover body (12-1), a heating resistance wire (12-3) and a temperature sensor (12-2); the temperature sensor (12-2) is mounted on the inner surface of the heating top cover body (12-1); the temperature sensor (12-2) is provided with a heating resistance wire (12-3) along a boundary; the heating top cover (12) is connected to the adjustable packaging workbench (11) via a metal rotating shaft.

4. A packaging method for a fiber Bragg grating packaging device according to claim 1, characterized in that: The steps include: S1, open the covers of the No. 1 optical fiber fixing fixture (8) and the No. 2 optical fiber fixing fixture (9) and the heating top cover (12), and adjust the X-direction distance adjustment micrometer head (5), the Y-direction distance adjustment micrometer head (6) and the Z-direction distance adjustment micrometer head (7) on the three-dimensional adjustment frame (13) respectively, so that the U-shaped groove on the adjustable packaging workbench (11) is consistent with the axis of the V-shaped groove on the optical fiber fixing fixture selected according to the optical fiber diameter; S2, passing the fiber Bragg grating through the packaging tube so that the fiber Bragg grating area is located in the middle of the packaging tube, placing the packaging tube in a U-shaped groove provided on the adjustable packaging workbench (11), and placing the optical fibers on both sides of the packaging tube freely and horizontally in the V-shaped grooves corresponding to the two optical fiber fixing fixtures; S3, tightly cover the cover of the No. 1 optical fiber fixing fixture (8); freely place the right end of the optical fiber in the stress applying instrument, set the magnitude of the stress to be applied, and apply a constant prestress to the optical fiber Bragg grating; tightly cover the cover of the No. 2 optical fiber fixing fixture (9); S4, re-adjusting the X-direction distance adjustment micrometer head (5), the Y-direction distance adjustment micrometer head (6) and the Z-direction distance adjustment micrometer head (7) on the three-dimensional adjustment frame (13) so that the packaging tube and the fiber grating are spatially coaxial; opening the vacuum valve switch to ensure that the packaging tube is fixed in position through air adsorption; S5. Use a needle to add glue or other packaging materials to both ends of the packaging tube; close the heating cover (12), and set the temperature to heat and cure the packaging material; S6. After the curing is completed, repeat the above operation at least once to complete the curing of at least one layer of packaging tube according to the design requirements; S7. After the final packaging is completed, use a tool to take out the packaged fiber Bragg grating.

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