A fiber grating demodulation device

Abstract

The application discloses a kind of demodulation devices of fiber grating, belong to fiber grating technical field.The device includes shell, detachable installation filter screen is installed at shell opening, two-way air blower is installed in shell interior, two-way air blower is connected with two opposite settings uniform heat disc by air outlet pipeline, uniform heat disc is opened with air outlet hole and is set with heating coil pipe, two uniform heat discs are located on the same axis, two supports for clamping fiber grating are provided on shell, temperature sensor is provided on uniform heat disc, drive assembly is provided between shell and support by positive and negative toothed screw rod, motor and guide rail.The present application is heated by bilateral symmetry and controlled by annular temperature sensor, to realize uniform, fast constant temperature heating, effectively inhibit the influence of temperature drift on demodulation accuracy;While drive assembly can accurately adjust the stretching and contraction of fiber grating, meet different demodulation working condition demand.

Description

Technical Field

[0001] This invention relates to the field of fiber Bragg grating technology, specifically to a fiber Bragg grating demodulation device. Background Technology

[0002] Fiber Bragg gratings (FBGs), as passive filtering devices, are widely used in fiber optic communication and sensing fields because their resonant wavelengths are sensitive to changes in external environmental factors such as temperature and strain. In FBG signal demodulation devices, changes in ambient temperature can alter the effective refractive index and grating pitch of the FBG, thus affecting demodulation accuracy. Therefore, temperature compensation for the FBG is necessary.

[0003] In existing technologies, for example, Chinese patent CN113009617B discloses a fiber Bragg grating signal demodulation device. Its temperature compensation mechanism includes a rectangular box, a heating chamber, and a hot air blower. The hot air blower generates airflow that enters the heating chamber, and the airflow from each heating hole is made uniform through the cooperation of a speed limiter and springs, thereby heating the grating. However, this solution has significant shortcomings in practical applications: First, the hot airflow generated by the hot air blower directly onto the fiber Bragg grating through the heating holes results in uneven airflow distribution, and the lack of closed-loop temperature detection in the heating area makes precise constant temperature control difficult. Second, this device can only heat one side of the fiber Bragg grating, easily leading to a temperature difference between the heated surface and the leeward side, affecting the temperature compensation effect. Third, its speed limiter structure is complex, and after long-term use, dust accumulation or spring fatigue can cause airflow imbalance, further reducing heating uniformity. These defects prevent the fiber Bragg grating from maintaining a stable operating temperature during demodulation, thus affecting the accuracy and repeatability of wavelength demodulation.

[0004] Therefore, it is necessary to provide a fiber grating demodulation device that can achieve uniform, rapid and precise constant temperature control to overcome the problem of poor heat preservation effect of air blowing in the prior art. Summary of the Invention

[0005] (a) Technical problems to be solved To address the problems existing in fiber Bragg grating demodulation devices during temperature compensation, such as uneven air blowing heating, temperature difference between the heated and leeward sides of the fiber Bragg grating due to unilateral heating, low demodulation accuracy due to lack of closed-loop constant temperature control, and complex airflow distribution structure prone to failure, this invention provides a fiber Bragg grating demodulation device that can achieve uniform air blowing heating from both sides, real-time temperature detection, and closed-loop control, thereby significantly improving the temperature stability and demodulation accuracy of the fiber Bragg grating during operation.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A demodulation device for a fiber Bragg grating includes a housing with a filter detachably installed at its opening. A bidirectional fan is installed inside the housing, connected via an air outlet duct to two opposing heat exchange plates. Each heat exchange plate has an air outlet and a sleeve, with a heating spiral tube fitted over the sleeve. The two heat exchange plates are located on the same axis. The housing also has two supports with clamping portions at their opposite ends, which together clamp the fiber Bragg grating located between the two heat exchange plates. A temperature sensor is installed on each heat exchange plate. A driving assembly is located between the housing and the supports, comprising a forward and reverse threaded screw, a motor, and a guide rail. The two supports slide on the guide rail, and their bottoms are threaded to different thread directions of the forward and reverse threaded screw.

[0007] The outer shell is a hollow structure with openings at the front and rear ends; the bidirectional fan is installed on the bottom surface inside the outer shell; the two air outlets of the bidirectional fan are connected to air outlet pipes, which extend vertically through the upper surface of the outer shell and then towards each other, with two oppositely arranged heat equalization plates connected to their opposite ends.

[0008] The uniform heating plate has an air outlet in the middle, and a sleeve is installed on the opposite side of the uniform heating plate. The air outlet pipe is connected to the air outlet of the uniform heating plate through the sleeve. The sleeve includes a heat-conducting part and a heat-insulating part fixed to the uniform heating plate at one end. The heat-insulating part is sleeved with the air outlet pipe located on the same side of the uniform heating plate. The heating spiral tube is sleeved on the heat-conducting part.

[0009] The opposite surfaces of the heat equalization plates are air guide surfaces, and the temperature sensor is arranged in a ring on the air guide surface to detect the temperature between the two heat equalization plates.

[0010] The extension direction of the guide rail is perpendicular to the axial direction of the heat equalization plate; the positive and negative threaded screws are rotatably connected to the guide rail and one end of the screw passes through the guide rail and is connected to a motor.

[0011] The outer shell is also provided with two sets of fixing components. Each set of fixing components includes a base, a first locking frame, and a second locking frame. The bottom of the first locking frame and the second locking frame are both hinged to the upper end of the base, and the bottom ends of the first locking frame and the second locking frame are hinged to each other and the upper ends are connected by a buckle. The first locking frame and the second locking frame are used to lock the heat equalizing plate together. The locking side of the first locking frame and the second locking frame with the heat equalizing plate is provided with a protrusion. The side of the heat equalizing plate is provided with an annular groove, and the protrusion and the groove are engaged with each other.

[0012] The system also includes two sets of safety components, each set comprising two connecting blocks. The two connecting blocks of one set are respectively fixed to two first locking frames of two different fixing components, while the two connecting blocks of the other set are respectively fixed to two second locking frames of two different fixing components. A positioning sleeve is provided on one connecting block of the same safety component, and a positioning rod is provided on the other connecting block; the positioning rod and positioning sleeve cooperate with each other. Synchronously driven electric push rods are provided on opposite sides of the two bases, and the electric push rods are fixed to the outer casing. A pressure sensor is installed on the bottom surface inside the positioning sleeve, and the pressure sensor is used to control the start and stop of the two electric push rods. A telescopic structure is also provided on the connecting block where the positioning rod is installed, used to control the extension and retraction of the positioning rod.

[0013] Each of the two bases is vertically connected to two guide rods, and each guide rod is fitted with two springs. The two springs on the same guide rod are located on opposite sides of the two bases, and a limit ring is installed on the end face of the guide rod.

[0014] The filter screen is detachably connected to the outer shell. The upper end of the outer shell has an opening through which the filter screen is vertically inserted and covers the opening. The outer shell is also equipped with two locking mechanisms, which are respectively installed on the two bottom corners of the filter screen. Each locking mechanism includes a first limiting block fixed to the outer shell on the outside of the filter screen, a second limiting block fixed to the outer shell on the inside of the filter screen, and a bolt threadedly connected to the first limiting block. The bolt passes through the first limiting block and abuts against the filter screen.

[0015] The heat distribution plate is made of heat-insulating material.

[0016] (III) Beneficial Effects Compared with the prior art, the present invention provides a demodulation device for fiber Bragg gratings, which has the following beneficial effects: The demodulation device for the fiber Bragg grating, by setting up a bidirectional blower, an air outlet duct, and two oppositely arranged heat equalization plates, allows hot air to be blown out evenly from both sides of the fiber Bragg grating through the air outlet holes at the same time, realizing symmetrical heating of both sides of the fiber Bragg grating. This effectively avoids the temperature difference between the heated surface and the leeward side caused by unilateral heating, and significantly improves the uniformity and speed of temperature compensation.

[0017] The demodulation device for this fiber optic grating, by setting a ring-shaped temperature sensor on the air guide surface of the heat exchanger plate and forming a closed-loop temperature control system with the heating solenoid and bidirectional air outlet mechanism, can detect the temperature between the two heat exchanger plates in real time and accurately adjust the heating power, so that the fiber optic grating maintains a constant temperature during operation, thereby effectively suppressing the impact of temperature drift on the wavelength demodulation accuracy and repeatability.

[0018] The demodulation device of this fiber optic grating, through the cooperation of the forward and reverse threaded screws, motor and guide rail in the drive assembly, enables the two supports to move relative to each other or in opposite directions along the guide rail, thereby precisely stretching or shrinking the fiber optic grating held between the two supports, realizing flexible adjustment of grating pitch and wavelength, and meeting the needs of different demodulation conditions.

[0019] The demodulation device for this fiber Bragg grating incorporates a fixed component and a safety component. The safety component has a pressure sensor installed inside its positioning sleeve, and a telescopic structure is provided on the positioning rod. When the two heat-equalizing plates move towards each other under the drive of an electric push rod, the pressure sensor can detect the contact pressure in real time and control the start and stop of the electric push rod. At the same time, the telescopic structure can adjust the extension length of the positioning rod according to the different thicknesses of the fiber Bragg grating, thereby achieving precise positioning of the heat-equalizing plates and anti-collision protection, improving the safety of the device and its adaptability to fiber Bragg gratings of different specifications.

[0020] The demodulation device of this fiber Bragg grating features a detachable filter at the opening of the housing, and a locking mechanism consisting of a first limiting block, a second limiting block, and bolts. This allows the filter to be easily inserted vertically and locked, facilitating regular cleaning or replacement. It effectively prevents dust from entering the device and contaminating the fiber Bragg grating or clogging the air outlet, ensuring the cleanliness of the heated airflow and the stability of the device during long-term use. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the fitting structure between the sleeve and the heating screw tube of the present invention; Figure 4 This is a schematic diagram of the cooperation structure between the fixing component and the heat equalization plate in this invention; Figure 5 This is a schematic diagram of the structure of the fixing component and the safety component in this invention; Figure 6 This is a schematic diagram of the heat equalization plate in this invention; Figure 7 This is a schematic diagram of the locking mechanism in this invention; Figure 8 This is a schematic diagram of the cooperation structure between the drive component and the bracket in this invention.

[0022] In the diagram: 1. Outer shell; 2. Two-way fan; 3. Air outlet duct; 4. Heat distribution plate; 401. Groove; 402. Air guide surface; 403. Air outlet; 5. Tube sleeve; 501. Heat-conducting part; 502. Heat-insulating part; 6. Bracket; 601. Clamping part; 7. Fiber optic grating; 8. Heating solenoid; 9. Drive assembly; 10. Fixing assembly; 11. Electric push rod; 12. Safety component; 13. Guide rod; 14. Spring; 15. Filter screen; 16. Locking mechanism 17. Temperature sensor; 901. Threaded screw; 902. Motor; 903. Guide rail; 1001. Base; 1002. First locking frame; 1003. Second locking frame; 1004. Protrusion; 1201. Connecting block; 1202. Positioning sleeve; 1203. Positioning rod; 1204. Pressure sensor; 1205. Adjusting rod; 1206. Adjusting disc; 1601. First limiting block; 1602. Second limiting block; 1603. Bolt. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] Please see Figure 1 and Figure 8 This invention discloses a demodulation device for a fiber Bragg grating, comprising a housing 1, with a filter 15 detachably installed at the opening of the housing 1; a bidirectional fan 2 is installed inside the housing 1, and the bidirectional fan 2 is connected to two opposing heat-equalizing plates 4 via an air outlet duct 3; the heat-equalizing plates 4 have air outlet holes 403, and are fitted with sleeves 5, with heating spiral tubes 8 fitted over the sleeves 5; the two heat-equalizing plates 4 are located on the same axis; the housing 1 also has two supports 6, with clamping portions 60 at their opposite ends. 1. Two clamping parts 601 are used to jointly clamp the fiber Bragg grating 7. The clamping parts 601 and the fiber Bragg grating 7 are fixed by bolt connection or the like. The fiber Bragg grating 7 is located between two heat equalization plates 4. A temperature sensor 17 is provided on the heat equalization plate 4. A driving assembly 9 is provided between the outer shell 1 and the bracket 6. The driving assembly 9 includes a positive and negative thread screw 901, a motor 902 and a guide rail 903. The two brackets 6 slide on the guide rail 903. The bottom of the two brackets 6 are threaded to different thread directions of the positive and negative thread screw 901.

[0025] The demodulation device of this fiber optic grating, through the cooperation of the forward and reverse threaded screws 901, motor 902 and guide rail 903 in the drive assembly 9, enables the two supports 6 to move relative to or opposite to each other along the guide rail 903, thereby precisely stretching or shrinking the fiber optic grating 7 held between the two supports 6, realizing flexible adjustment of grating pitch and wavelength, and meeting the needs of different demodulation conditions.

[0026] Please see Figure 2In this embodiment, the outer shell 1 is a hollow structure with openings at the front and rear ends. The outer shell 1 is made of high-strength, corrosion-resistant aluminum alloy to ensure the stability and reliability of the device during long-term use, while reducing the overall weight of the device and facilitating installation and movement. The bidirectional fan 2 is installed on the bottom surface inside the outer shell 1. The two air outlets of the bidirectional fan 2 are connected to air outlet pipes 3. The air outlet pipes 3 extend vertically through the upper surface of the outer shell 1 and then extend towards each other. The opposite ends are connected to two oppositely arranged heat equalizing plates 4. The air outlet pipes 3 are made of stainless steel, which has good pressure resistance and corrosion resistance, and the inner wall of the pipe is smooth to reduce airflow resistance and ensure smooth airflow.

[0027] The demodulation device of the fiber Bragg grating, by setting up a bidirectional fan 2, an air outlet duct 3 and two oppositely arranged heat equalization plates 4, allows hot air to be blown out evenly from both sides of the fiber Bragg grating 7 through the air outlet 403 at the same time, realizing symmetrical heating of both sides of the fiber Bragg grating 7, effectively avoiding the temperature difference between the heated surface and the leeward surface caused by unilateral heating, and significantly improving the uniformity and speed of temperature compensation.

[0028] Please see Figure 3 In this embodiment, the heat equalization plate 4 has an air outlet 403 in the middle, and a sleeve 5 is installed on the opposite side of the heat equalization plate 4; the air outlet pipe 3 communicates with the air outlet 403 of the heat equalization plate 4 through the sleeve; the sleeve 5 includes a heat-conducting part 501 fixed to the heat equalization plate 4 at one end and a heat-insulating part 502. The heat-conducting part 501 is made of copper alloy material with high thermal conductivity, which can quickly transfer the heat generated by the heating spiral tube 8 to the heat equalization plate 4, making the temperature distribution more uniform; the heat-insulating part 502 is made of polystyrene material, which has an extremely low thermal conductivity, effectively preventing heat from being transferred to the air outlet pipe 3 and reducing heat loss; the heat-insulating part 502 is sleeved with the air outlet pipe 3 located on the same side of the heat equalization plate 4, and the heating spiral tube 8 is sleeved on the heat-conducting part 501. The heating spiral tube 8 is made of nickel-chromium alloy resistance wire, which has high resistivity and good oxidation resistance, and can stably generate heat when energized.

[0029] Please see Figure 6 In this embodiment, the opposite surface of the heat distribution plate 4 is the air guide surface 402. The air guide surface 402 undergoes special smoothing treatment, with a surface roughness Ra≤0.8μm, to reduce the frictional resistance of the airflow on the air guide surface 402, so that the airflow can be blown more evenly onto the fiber optic grating 7. The temperature sensor 17 is arranged in a ring on the air guide surface 402 to detect the temperature between the two heat distribution plates 4. The temperature sensor 17 adopts a high-precision platinum resistance temperature sensor, and its measurement accuracy can reach ±0.1℃, which can accurately sense temperature changes and provide reliable data for the temperature control of the device.

[0030] It should be noted that the side structure of the air guide surface 402 has a structure that transitions smoothly from the central concave part to the surrounding area. The specific advantage is that when the air is blown directly onto the fiber grating 7, some airflow will bounce back onto the heat equalization plate 4 and be discharged along the air guide surface 402 of the heat equalization plate 4. If the air guide surface 402 is a traditional flat shape, it cannot exhaust air well. In addition, the design of the groove 401 in the middle makes the heat preservation effect of the fiber grating 7 located between the two heat equalization plates 4 better.

[0031] The demodulation device of the fiber grating, by setting an annular temperature sensor 17 on the air guide surface 402 of the heat distribution plate 4, and forming a closed-loop temperature control system with the heating solenoid 8 and the bidirectional fan 2, can detect the temperature between the two heat distribution plates 4 in real time and accurately adjust the heating power, so that the fiber grating 7 maintains a constant temperature during operation, thereby effectively suppressing the influence of temperature drift on the wavelength demodulation accuracy and repeatability.

[0032] In this embodiment, the extension direction of the guide rail 903 is perpendicular to the axial direction of the heat equalization plate 4; the positive and negative thread screw 901 is rotatably connected to the guide rail 903 and one end passes through the guide rail 903 and is connected to the motor 902. The motor 902 is a stepper motor, which has high control accuracy and good stability, and can accurately control the rotation angle and speed of the positive and negative thread screw 901, thereby realizing the precise adjustment of the relative position of the two supports 6; the guide rail 903 is a linear guide rail, which is equipped with balls or rollers inside, which can effectively reduce the friction when the support 6 slides, and improve the smoothness and accuracy of the movement.

[0033] Please see Figure 4 In this embodiment, the outer shell 1 is further provided with two sets of fixing components 10. Each set of fixing components 10 includes a base 1001, a first locking frame 1002, and a second locking frame 1003. The base 1001 is made of high-strength engineering plastic, which has a certain toughness and rigidity and can withstand large external forces without deformation. The bottoms of the first locking frame 1002 and the second locking frame 1003 are both hinged to the upper end of the base 1001, and the bottom ends of the first locking frame 1002 and the second locking frame 1003 are hinged to each other and the upper ends are... The locking mechanism is connected by a latch; the first locking frame 1002 and the second locking frame 1003 are used to lock the heat equalizing plate 4 together. The locking side of the first locking frame 1002 and the second locking frame 1003 and the heat equalizing plate 4 is provided with a protrusion 1004. The side of the heat equalizing plate 4 is provided with an annular groove 401. The protrusion 1004 and the groove 401 are engaged with each other. The protrusion 1004 is made of wear-resistant rubber material, which can increase the friction between it and the groove 401, improve the stability of locking, and at the same time avoid damage to the heat equalizing plate 4.

[0034] Please see Figure 5In this embodiment, two sets of safety components 12 are also provided. Each set of safety components 12 includes two connecting blocks 1201. The two connecting blocks 1201 of one set of safety components 12 are respectively fixed on two first locking frames 1002 of two different fixing components 10, and the two connecting blocks 1201 of the other set of safety components 12 are respectively fixed on two second locking frames 1003 of two different fixing components 10. A positioning sleeve 1202 is provided on one connecting block 1201 of the same safety component 12, and a positioning rod 1203 is provided on the other connecting block 1201. The positioning rod 1203 cooperates with the positioning sleeve 1202. The positioning sleeve 1202 is made of high-precision metal material with finely machined surface to ensure fitting accuracy and accurately limit the relative position between the two fixed components 10, preventing the heat equalizing plate 4 from shifting during operation. Two synchronously driven electric push rods 11 are provided on opposite sides of the two bases 1001, and the electric push rods 11 are fixed to the outer shell 1. A pressure sensor 1204 is installed on the bottom surface inside the positioning sleeve 1202, and the pressure sensor 1204 is used to control the start and stop of the two electric push rods 11. A telescopic structure is also provided on the connecting block 1201 on which the positioning rod 1203 is installed, for controlling the extension and retraction of the positioning rod 1203.

[0035] It should be noted that the telescopic structure includes a threaded adjusting rod 1205. One end of the adjusting rod 1205 is equipped with an adjusting disc 1206. The adjusting disc 1206 is marked with the feed distance of the positioning rod 1203. Through experience, the safe distance between the two heat exchange plates 4 can be controlled according to the different thicknesses of the fiber gratings 7. Specifically, the adjusting rod 1205 is connected to the positioning rod 1203 by a thread. A limit slider is also fixed on one side of the positioning rod 1203 to prevent the positioning rod 1203 from rotating. The positioning rod 1203 slides on the connecting block 1201 through the limit slider.

[0036] The demodulation device for the fiber Bragg grating is equipped with a fixing component 10 and a safety component 12. The positioning sleeve 1202 of the safety component 12 is equipped with a pressure sensor 1204, and the positioning rod 1203 is equipped with a telescopic structure. When the two heat equalizing plates 4 move towards each other under the drive of the electric push rod 11, the pressure sensor 1204 controls the start and stop of the electric push rod 11 by contacting the pressure. At the same time, the telescopic structure can adjust the extension length of the positioning rod 1203 according to the different thicknesses of the fiber Bragg grating 7, thereby achieving precise positioning and anti-collision protection of the heat equalizing plates 4, improving the safety of the device and its adaptability to fiber Bragg gratings 7 of different specifications.

[0037] In this embodiment, two guide rods 13 are vertically connected to each of the two bases 1001. The guide rods 13 are made of high-strength stainless steel, possessing high rigidity and straightness, ensuring the stability of the bases 1001 during movement. Each guide rod 13 is fitted with two springs 14, which provide buffering and resetting functions during the movement of the bases 1001, reducing impact. The two springs 14 on the same guide rod 13 are located on opposite sides of the two bases 1001, and a limit ring is installed on the end face of the guide rod 13. The limit ring restricts the range of movement of the bases 1001, preventing the bases 1001 and springs 14 from detaching from the guide rods 13.

[0038] It should be noted that one end of the spring 14 is fixedly connected to the limiting ring, and the other end is fixedly connected to the surface of the corresponding base 1001. The spring 14 has a pulling effect on the base 1001, so that the electric push rod 11 is in a retracted state when the power is off, which facilitates the installation of the fiber optic grating 7 and the bracket 6.

[0039] Please see Figure 7 In this embodiment, the filter screen 15 is detachably connected to the outer shell 1. The upper end of the outer shell 1 has an opening, through which the filter screen 15 is vertically inserted into the outer shell 1 and covers the opening. Two locking mechanisms 16 are also installed on the outer shell 1, respectively installed on the two bottom corners of the filter screen 15. Each locking mechanism 16 includes a first limiting block 1601 fixed to the outer shell 1 on the outside of the filter screen 15, a second limiting block 1602 fixed to the outer shell 1 on the inside of the filter screen 15, and a bolt 1603 threadedly connected to the first limiting block 1601. The bolt 1603 passes through the first limiting block 1601 and abuts against the filter screen 15.

[0040] It should be noted that the first limiting block 1601 and the second limiting block 1602 are located at opposite positions on different sides of the filter screen 15, and are used to clamp and fix the filter screen 15 close to each other.

[0041] The demodulation device of this fiber Bragg grating has a filter 15 that can be detachably installed at the opening of the housing 1, and a locking mechanism 16 consisting of a first limiting block 1601, a second limiting block 1602 and a bolt 1603. This allows the filter 15 to be easily inserted vertically and locked, facilitating regular cleaning or replacement. It effectively prevents dust from entering the device and contaminating the fiber Bragg grating 7 or clogging the air outlet 403, ensuring the cleanliness of the heated airflow and the stability of the device during long-term use.

[0042] In this embodiment, the heat equalization plate 4 is made of heat insulation material. The heat insulation material is a nanoporous silica heat insulation material with an extremely low thermal conductivity, which can effectively reduce heat loss to the outside and improve energy utilization efficiency, while ensuring the uniformity and stability of the internal temperature of the heat equalization plate 4.

[0043] Working principle: In use, firstly, based on the thickness of the fiber grating 7 to be measured, the extension length of the positioning rod 1203 is precisely controlled by adjusting the rotating adjustment rod 1205 of the disc 1206 to preset the safe distance between the two heat equalization discs 4. Then, the two ends of the fiber grating 7 are fixed to the clamping parts 601 of the two supports 6 with bolts. The motor 902 is started, and the motor 902 drives the positive and negative thread screws 901 to rotate. Since the bottom threads of the two supports 6 are connected in different thread directions of the positive and negative thread screws 901, when the positive and negative thread screws 901 rotate, they drive the two supports 6 to move closer or further apart along the guide rail 903, thereby applying a tensile or contractile force to the fiber grating 7, realizing the initial adjustment of the grating pitch and center wavelength of the fiber grating 7.

[0044] When constant temperature is required, the electric push rod 11 drives the fixing component 10 to move the heat equalizing disks 4 towards each other. The positioning rod 1203 of the safety component 12 cooperates with the positioning sleeve 1202. After the pressure sensor 1204 detects the contact pressure, it controls the electric push rod 11 to stop to prevent excessive compression. The distance between the two heat equalizing disks 4 and the fiber optic grating 7 is preset through the telescopic structure.

[0045] The heating solenoid 8 and the bidirectional fan 2 are activated. The heating solenoid 8 generates heat upon power supply, which is rapidly transferred to the heat-conducting part 501 of the sleeve 5 to the heat-equalizing plate 4, causing the internal temperature of the heat-equalizing plate 4 to rise uniformly. The bidirectional fan 2 generates airflow, which is transported to the two heat-equalizing plates 4 via the air outlet 3. The airflow is evenly blown out from the air outlet 403 in the middle of the heat-equalizing plate 4, simultaneously blowing towards the fiber optic grating 7 from both sides. Because the air guide surface 402 of the heat-equalizing plate 4 has a structure with a concave center and a smooth transition to the surrounding area, part of the airflow bounces back after hitting the fiber optic grating 7 and is smoothly discharged along the arc-shaped surface of the air guide surface 402, effectively avoiding airflow turbulence. Simultaneously, the concave structure forms a heat-insulating air curtain around the fiber optic grating 7, further enhancing the heat preservation effect.

[0046] The annular temperature sensor 17 detects the temperature between the two uniform heating plates 4 in real time and feeds the temperature signal back to the control system. The control system adjusts the heating power of the heating solenoid 8 or the wind speed of the bidirectional fan 2 in a closed loop according to the set temperature value, so that the fiber optic grating 7 is always in a constant temperature environment.

[0047] The filter 15 can be detached and installed via the locking mechanism 16, and regular cleaning can ensure the cleanliness of the airflow.

[0048] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A demodulation device for a fiber Bragg grating, comprising a housing, characterized in that: A filter screen is detachably installed at the opening of the outer casing; a bidirectional fan is installed inside the outer casing, and the bidirectional fan is connected to two oppositely arranged heat equalization plates through an air outlet duct; the heat equalization plates have air outlet holes, and a sleeve is installed on the heat equalization plate, with a heating spiral tube installed on the sleeve; the two heat equalization plates are located on the same axis; two supports are also provided on the outer casing, and clamping parts are provided at opposite ends of the two supports, which are used to jointly clamp the fiber optic grating, which is located between the two heat equalization plates; a temperature sensor is provided on the heat equalization plate; a driving assembly is provided between the outer casing and the supports, and the driving assembly includes a positive and negative thread screw, a motor, and a guide rail, with the two supports sliding on the guide rail, and the bottom of the two supports being threadedly connected to different thread directions of the positive and negative thread screw.

2. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: The outer shell is a hollow structure with openings at the front and rear ends; the bidirectional fan is installed on the bottom surface inside the outer shell; the two air outlets of the bidirectional fan are connected to air outlet pipes, the air outlet pipes extend vertically through the upper surface of the outer shell and then extend towards each other, with two oppositely arranged heat equalization plates connected to their opposite ends.

3. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: An air outlet is provided in the middle of the heat equalization plate, and a sleeve is installed on the opposite side of the heat equalization plate; the air outlet pipe is connected to the air outlet of the heat equalization plate through the sleeve; the sleeve includes a heat-conducting part and a heat-insulating part fixed at one end to the heat equalization plate, the heat-insulating part is sleeved with the air outlet pipe located on the same side of the heat equalization plate, and the heating spiral tube is sleeved on the heat-conducting part.

4. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: The opposite surfaces of the heat equalization plates are air guide surfaces, and the temperature sensor is arranged in a ring on the air guide surface to detect the temperature between the two heat equalization plates.

5. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: The extension direction of the guide rail is perpendicular to the axis of the heat equalization plate; the positive and negative threaded screws are rotatably connected to the guide rail and one end of the screw passes through the guide rail and is connected to a motor.

6. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: The outer shell is also provided with two sets of fixing components. Each set of fixing components includes a base, a first locking frame, and a second locking frame. The bottom of the first locking frame and the second locking frame are both hinged to the upper end of the base, and the bottom ends of the first locking frame and the second locking frame are hinged to each other and the upper ends are connected by a buckle. The first locking frame and the second locking frame are used to lock the heat equalizing plate together. The locking side of the first locking frame and the second locking frame with the heat equalizing plate is provided with a protrusion. The side of the heat equalizing plate is provided with an annular groove, and the protrusion and the groove are engaged with each other.

7. The demodulation device for fiber Bragg gratings according to claim 6, characterized in that: Two sets of safety components are also provided, each set including two connecting blocks; the two connecting blocks of one set of safety components are respectively fixed to the two first locking frames of two different fixing components, and the two connecting blocks of the other set of safety components are respectively fixed to the two second locking frames of two different fixing components; a positioning sleeve is provided on one connecting block of the same safety component, and a positioning rod is provided on the other connecting block, the positioning rod and the positioning sleeve cooperating with each other; synchronously driven electric push rods are provided on opposite sides of the two bases, the electric push rods being fixed to the outer shell; a pressure sensor is installed on the bottom surface inside the positioning sleeve, the pressure sensor being used to control the start and stop of the two electric push rods; a telescopic structure is also provided on the connecting block on which the positioning rod is installed, for controlling the extension and retraction of the positioning rod.

8. The demodulation device for fiber Bragg gratings according to claim 6, characterized in that: Two guide rods are vertically connected to each of the two bases. Each guide rod is fitted with two springs. The two springs on the same guide rod are located on opposite sides of the two bases. Limit rings are installed on the end faces of the guide rods.

9. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: The filter screen is detachably connected to the outer casing. The upper end of the outer casing has an opening through which the filter screen is vertically inserted and covers the opening. The outer casing is also equipped with two locking mechanisms, which are respectively installed on the two bottom corners of the filter screen. Each locking mechanism includes a first limiting block fixed to the outer casing on the outside of the filter screen, a second limiting block fixed to the outer casing on the inside of the filter screen, and a bolt threadedly connected to the first limiting block. The bolt passes through the first limiting block and abuts against the filter screen.

10. The demodulation device for fiber Bragg gratings according to claim 1, characterized in that: The heat-equalizing plate is made of heat-insulating material.

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