A fiber Bragg grating wind pressure sensor

Abstract

The present invention relates to the field of wind pressure detection technology and discloses a fiber Bragg grating (FBG) wind pressure sensor. This sensor addresses the difficulty of balancing both measurement range and accuracy when measuring wind pressure with the sensitive elements of conventional wind pressure sensors. By controlling the tuning system components, multiple spring bars can be flexibly connected. By varying the number of connected spring bars, the stiffness of the sensor when used in conjunction with the fiber Bragg grating (FBG) can be cleverly adjusted, converting the stiffness parameter into a variable factor. This adjustable stiffness parameter design effectively expands the measurement range while ensuring detection accuracy, enabling the sensor to easily cope with a variety of wind pressure environments and demonstrating excellent adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of wind pressure detection, in particular to a fiber grating wind pressure sensor. Background Art

[0002] A wind pressure sensor converts wind pressure signals into electrical signals, based on the sensing of wind pressure changes by a sensitive element. When wind pressure acts on a sensitive element (such as a piezoresistive or piezoelectric material), the element undergoes mechanical deformation, resulting in changes in physical quantities such as resistance or capacitance. These changes are converted into electrical signals, outputting a standard signal proportional to the wind pressure. A Chinese patent (patent number: CN 115307806 A) proposes a wind pressure sensor whose technical solution includes: a magnetic ring cylinder, driven by the negative pressure of a negative pressure chamber, pulls an elastic diaphragm toward an inductor column (the magnetic ring cylinder and the inductor column act as the sensitive element). Different negative pressure levels in the negative pressure chamber cause the inductor column to penetrate the cylinder cavity to different depths, resulting in different inductance values. The wind pressure is then inferred based on the inductance. This approach not only accurately measures wind pressure but also extends the service life of the sensitive element.

[0003] However, existing wind pressure sensors have certain limitations in the performance of their sensitive elements when measuring wind pressure. The measurement range of these sensors mainly depends on the deformation range of the elastic diaphragm (generally an integrated structure of a diaphragm and a spring) under the action of wind pressure. Specifically, if the elastic coefficient of the elastic diaphragm is large, although it can adapt to a wider wind pressure range, the measurement accuracy will be correspondingly reduced; conversely, if the elastic coefficient of the elastic diaphragm is small, although the measurement accuracy will be improved, the wind pressure measurement range will be correspondingly reduced. Therefore, traditional wind pressure sensors still have certain shortcomings in taking into account both measurement range and measurement accuracy. Summary of the Invention

[0004] The object of the present invention is to provide a fiber Bragg grating wind pressure sensor, which solves the problem that the sensitive element of the traditional wind pressure sensor is difficult to take into account both the measurement range and the measurement accuracy when measuring wind pressure.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a fiber Bragg grating wind pressure sensor, comprising an upper housing, a lower housing, and a diaphragm sandwiched between the upper and lower housings, the diaphragm separating a cavity formed by the upper and lower housings into a positive pressure cavity and a negative pressure cavity, a negative pressure interface being provided on the lower side of the lower housing and communicating with the negative pressure cavity, and further comprising:

[0006] The sensitive mechanism includes a plurality of spring bars arranged in parallel and vertically, an adjustment assembly being provided in the middle of the plurality of spring bars, mounting assemblies being provided at both ends of the spring bars for movably mounting the spring bars above the diaphragm, a fiber Bragg grating being provided on the lower surface of the lowermost spring bar, and the adjustment assembly being connected to the diaphragm;

[0007] The pressure relief mechanism includes a slide plate that slides on the upper side of the negative pressure interface and a second through hole opened on the lower side of the lower shell. The lower shell controls the negative pressure chamber to communicate with the negative pressure interface or the second through hole.

[0008] When the diaphragm is subjected to negative pressure, the adjustment system component pulls the lowermost elastic bar downward to bend. The fiber grating calculates the negative pressure tension based on the stiffness and bending radius of the elastic bar. After the working deformation of a single diaphragm reaches the maximum, the air pressure in the negative pressure chamber is restored by through hole three, so that the adjustment system component is reset by the elastic force of the connected diaphragm. Subsequently, the adjustment system component is connected upward to the adjacent diaphragms. According to the number of connected diaphragms, the rigidity coefficient is changed to increase the range of negative pressure tension detection of the sensitive mechanism.

[0009] As a further description of the above technical solution: the sensitive mechanism also includes an assembly cover arranged on the inner side of the upper shell, the assembly cover is provided with an embedded ring, a support plate is provided in the middle of the diaphragm, a displacement column is provided on the upper side of the support plate, the displacement column is movably inserted into the inner side of the assembly cover through the embedded ring, and the adjustment system component is fixedly assembled on the upper end of the displacement column.

[0010] As a further description of the above technical solution: the mounting assembly includes a fixing seat fixedly assembled on the inner wall of the assembly cover, a plurality of turntables 1 are rotatably assembled on one side of the fixing seat, a pair of rotating columns 2 are rotatably assembled on the surface of one side of the turntable, one end of the elastic bar is clamped between the pair of rotating columns 2, and the plurality of turntables 1 correspond one to one with the plurality of elastic bars.

[0011] As a further description of the above technical solution: gaps are provided between the multiple elastic bars, a push block is provided in the middle of the upper side of the elastic bar, the push block is fixed to the upper surface of the elastic bar through elastic bands on both sides, and embedded columns are fixedly connected at both ends of the push block.

[0012] As a further description of the above technical solution: bridge-shaped baffles are provided at both ends of the elastic bar to limit its lateral movement, and the bridge-shaped baffles are fixedly assembled on the inner wall of the assembly cover.

[0013] As a further description of the above technical solution: the adjustment system assembly includes a U-shaped frame fixedly assembled on the upper side of the displacement column, and the inner side walls of the U-shaped frame are respectively provided with a long groove and a card slot B, and the inner wall of the long groove is embedded with a plurality of clamping components, and the clamping components are movably clamped with the embedded columns. The outer surface of the U-shaped frame is provided with a circuit board for controlling the clamping of the clamping components and the embedded columns.

[0014] As a further description of the above technical solution: the slot B is engaged with the embedded column of the lowermost push block.

[0015] As a further description of the above technical solution: a through hole three is provided on the surface of the skateboard, the micro screw slide includes a frame, a micro motor is fixedly assembled on one side of the frame, the output end of the micro motor is connected to a screw, a movable block with threaded engagement is movably provided on the surface of the screw, a push rod is fixedly connected to one side of the movable block, one end of the push rod is fixedly connected to the protrusion on the upper surface of the skateboard, guide rails are provided on both sides of the skateboard to guide its sliding direction, and the through hole three is sealed and slidably fitted with the surface of the lower shell.

[0016] As a further description of the above technical solution: the two ends of the fiber Bragg grating are fixed to the lower surface of the elastic bar through fixing members, and the fiber Bragg grating is bonded to the surface of the elastic bar through a bonding member in the middle part between the two fixing members.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] 1. By controlling the tuning system components, multiple spring bars can be flexibly connected. By changing the number of connected spring bars, the stiffness when used in conjunction with the fiber Bragg grating (FBG) can be cleverly adjusted, converting the stiffness parameter into a variable factor. This adjustable stiffness parameter design effectively expands the measurement range while ensuring detection accuracy, enabling it to calmly cope with various wind pressure environments and demonstrate excellent adaptability.

[0019] 2. The mounting assembly cleverly adapts to the tilted end of the spring bar, precisely avoiding the significant friction caused by the mismatched angles between the two. This design significantly reduces the interference factors between the spring bar and the fiber Bragg grating when cooperating to detect negative pressure tension, thereby greatly improving the accuracy of the detection and providing a strong guarantee for precise measurement.

[0020] 3. The push block is used to indirectly push the spring bar to bend and perform work, making the bending arc of the spring bar natural and smooth, and the force-bearing point stable and reliable. This natural and smooth arc can be perfectly combined with the rigidity parameters of the spring bar after fiber grating detection, thereby more accurately calculating the negative pressure value, significantly improving the accuracy and consistency of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 It is a schematic diagram of a three-dimensional cross-sectional structure of the present invention;

[0023] Figure 3 It is a schematic diagram of a planar cross-sectional structure of the present invention;

[0024] Figure 4 For the present invention Figure 3 A is an enlarged schematic diagram;

[0025] Figure 5 For the present invention Figure 3 A magnified schematic diagram of middle B;

[0026] Figure 6 It is a schematic diagram of the split structure of the present invention;

[0027] Figure 7 It is a schematic diagram of the bottom surface structure of the elastic bar of the present invention;

[0028] Figure 8 For the present invention Figure 7 A magnified schematic diagram of middle C;

[0029] Figure 9 It is a partial cross-sectional schematic diagram of the adjustment system assembly of the present invention;

[0030] Figure 10 This is a schematic diagram of the disassembled structure of the adjustment system components of the present invention;

[0031] Figure 11 This is a schematic cross-sectional view of the clamping component of the present invention;

[0032] Figure 12 This is a schematic diagram of the state in which the spring bars of the present invention are arranged in parallel and vertically;

[0033] Figure 13 It is a schematic structural diagram of the pressure relief mechanism of the present invention.

[0034] In the figure: 11, upper shell; 111, through hole 1; 12, lower shell; 121, through hole 2; 13, negative pressure interface; 14, diaphragm; 141, support plate; 142, displacement column; 20, sensitive mechanism; 21, adjustment system component; 211, U-shaped frame; 212, clamping component; 2121, clamping column; 2122, clamping slot A; 2123, cylinder; 2124, winding; 2125, magnet; 213, circuit board; 214, long slot; 215, clamping slot B; 22, spring bar; 221, fillet; 222, push Block; 223, embedded column; 224, elastic band; 23, mounting assembly; 231, fixed seat; 232, turntable one; 233, turntable two; 24, fiber Bragg grating; 241, fixing part; 242, fitting part; 25, assembly cover; 251, embedded ring; 26, bridge-type baffle; 30, pressure release mechanism; 31, slide plate; 311, bump; 32, micro screw slide; 321, frame; 322, screw; 323, movable block; 324, push rod; 325, micro motor; 33, through hole three; 40, control unit. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings.

[0037] Fiber Bragg Bragg grating (FBG) sensing technology operates based on the properties of fiber Bragg gratings (FBGs). When a light signal passes through a fiber Bragg grating (FBG), it reflects light of a specific wavelength while allowing light of other wavelengths to propagate. This specific wavelength is called the Bragg wavelength. When the physical structure of the fiber Bragg grating changes, such as when it is bent, its Bragg wavelength also changes accordingly. By measuring this change in Bragg wavelength, the curvature of the fiber Bragg grating due to the bending can be inferred.

[0038] During the fabrication process of a fiber Bragg grating (FBG), its surface is typically coated with a sensing material. The physical structure and properties of this sensing material are tailored to the physical quantity being measured. For example, in wind force detection, when wind acts on the sensing material, it causes it to bend, which in turn causes the fiber Bragg grating (FBG) to bend as well. By combining the curvature of the FBG with the mechanical properties of the sensing material, the measurement system can calculate the wind force.

[0039] It should be noted that, depending on the range of wind force, the force acting on the sensing material should be controlled within the deformation range of the sensing material to ensure that the effective measurement range can cover the wind force, thereby ensuring the accuracy and reliability of the measurement results.

[0040] Combine Figures 1-13 A fiber Bragg grating wind pressure sensor includes an upper shell 11 and a lower shell 12, and a diaphragm 14 sandwiched between the upper shell 11 and the lower shell 12. The diaphragm 14 separates the cavity formed by the upper shell 11 and the lower shell 12 into a positive pressure cavity and a negative pressure cavity. The positive pressure cavity is connected to the external environment through a through hole 111 opened on the upper side of the upper shell 11. A negative pressure interface 13 connected to the negative pressure cavity is provided on the lower side of the lower shell 12. The sensor also includes:

[0041] The sensitive mechanism 20 includes a plurality of spring bars 22 arranged in parallel and vertically. An adjustment assembly 21 is provided in the middle of the plurality of spring bars 22. Mounting assemblies 23 are provided at both ends of the spring bars 22 for movably mounting the spring bars above the diaphragm 14. A fiber Bragg grating 24 is provided on the lower surface of the lowermost spring bar 22. The adjustment assembly 21 is connected to the diaphragm 14.

[0042] The pressure relief mechanism 30 includes a slide plate 31 that slides on the upper side of the negative pressure interface 13 and a second through hole 121 formed on the lower side of the lower housing 12. The lower housing 12 controls the communication between the negative pressure chamber and the negative pressure interface 13 or the second through hole 121.

[0043] When the diaphragm 14 is subjected to negative pressure, the adjustment system component 21 pulls the lowermost elastic strip 22 to bend downward. The fiber grating 24 calculates the negative pressure tension based on the stiffness of the elastic strip 22 (the stiffness of a single fiber grating 24 is determined by the elastic coefficient of the corresponding material) and the bending curvature. The stiffness of the fiber grating 24 determines the detection range of the negative pressure tension. After the working deformation of a single diaphragm 14 reaches the maximum, the air pressure in the negative pressure chamber is restored by the through hole 33, so that the adjustment system component 21 is reset by the elastic force of the connected diaphragm 14. Subsequently, the adjustment system component 21 is connected upward to the adjacent diaphragms 14. According to the number of connected diaphragms 14, the stiffness coefficient is changed to increase the range of negative pressure tension detection by the sensitive mechanism 20.

[0044] The control terminal for transmitting and receiving optical signals in cooperation with the fiber Bragg grating 24 is not shown in the figure and can be assembled at any position in the upper housing 11. The principle of measuring curvature between the control terminal and the fiber Bragg grating 24 is detailed in the working principle of the fiber Bragg grating 24 described above.

[0045] The curvature of the spring bar 22 is measured using the fiber Bragg grating (FBG) 24. The downward pulling force on the adjustment system 21 is calculated based on the stiffness parameter of the spring bar 22. This is accomplished by the measurement system. The operating principle is equivalent to that of an existing fiber Bragg grating (FBG) sensor. The spring bar 22 is equivalent to the sensing material that cooperates with the fiber Bragg grating (FBG) 24. Unlike existing sensing materials, which have fixed stiffness parameters after being set, the present invention employs multiple spring bars 22. The stiffness is determined based on the spring bar 22 used in the application, making the stiffness parameter variable. This ensures that the measurement range is maintained while maintaining detection accuracy.

[0046] The above-mentioned control end and measurement system are collectively referred to as the control unit 40 below. The control unit 40 also includes a control chip. The control chip controls the adjustment system component 21 to cooperate with the pressure release mechanism 30 based on the curvature of the elastic bar 22 and the electrical signal.

[0047] Specifically, the wind pressure detection range of existing wind pressure sensors is primarily determined by the stiffness of the spring. Specifically, while a higher spring stiffness can accommodate a wider wind pressure range, the spring's compression is also smaller when the wind pressure changes slightly. This can lead to a lack of sensitivity in the connected sensing mechanism 20 and a decrease in measurement accuracy. Conversely, a lower spring stiffness improves measurement accuracy but reduces the wind pressure measurement range.

[0048] In this embodiment, the control system assembly 21 is controlled to connect multiple spring bars 22. By varying the number of spring bars 22, the stiffness of the fiber Bragg grating (FBG) 24 used for detection is adjusted, making this stiffness parameter a variable. This adjustable stiffness parameter allows for adapting to varying wind pressure environments.

[0049] When responding to lower wind pressures, a single spring bar 22 works in conjunction with the fiber Bragg grating (FBG) 24 to detect wind pressure with reduced stiffness. Compared to existing wind pressure sensors with a wide measurement range, the spring bar 22 exhibits greater deformation under low pressure and with small wind pressure variations, significantly improving detection accuracy. Furthermore, compared to existing wind pressure sensors with high detection accuracy but a narrow measurement range, this embodiment improves overall stiffness by increasing and adjusting the number of spring bars 22 connected to the assembly 21. This increased stiffness accommodates increased wind pressure, thereby extending the wind pressure detection range of the present invention.

[0050] It's worth noting that the stiffness parameter used in conjunction with the fiber Bragg grating (FBG) 24 increases linearly with the number of spring bars 22. Therefore, as wind pressure increases, the stiffness parameter can be controlled to match it, keeping the wind pressure within the detection range. Furthermore, proper control of the stiffness parameter also makes the deformation of the spring bars 22 more sensitive to changes in wind pressure during operation. This means that the present invention simultaneously addresses the requirements for both measurement range and accuracy.

[0051] Combine Figure 2-Figure 3 The sensitive mechanism 20 further includes an assembly cover 25 disposed inside the upper housing 11. The assembly cover 25 is provided with an insert ring 251. A support plate 141 is provided in the middle of the diaphragm 14. A displacement column 142 is provided on the upper side of the support plate 141. The displacement column 142 is movably inserted into the inner side of the assembly cover 25 through the insert ring 251. The adjustment assembly 21 is fixedly assembled to the upper end of the displacement column 142. When negative pressure is generated in the negative pressure chamber, the support plate 141 is pulled downward through the diaphragm 14, causing the displacement column 142 to linearly displace inside the insert ring 251. The adjustment assembly 21 and the spring bar 22 cooperate to pull the support plate 141 in the opposite direction. Therefore, the displacement of the displacement column 142 within the insert ring 251 is positively correlated with the magnitude of the negative pressure in the negative pressure chamber.

[0052] Combine Figure 2 、 Figure 3 、 Figure 5 The mounting assembly 23 includes a fixing base 231 fixedly assembled on the inner wall of the assembly cover 25. A plurality of turntables 232 are rotatably assembled on one side of the fixing base 231. A pair of rotating columns 233 are rotatably assembled on the side surface of the turntable 1 232. One end of the elastic bar 22 is clamped between the pair of rotating columns 233. The plurality of turntables 232 correspond one to one with the plurality of elastic bars 22.

[0053] like Figure 2 、 Figure 3 、 Figure 5 As shown, when the adjustment assembly 21 pulls down the elastic bar 22, the elastic bar 22 will bend into an arc shape. At this time, one end of the elastic bar 22 will tilt and slide between a pair of rotating columns 233. If one end of the elastic bar 22 adopts a traditional connection structure, such as overlapping, a huge friction force will be generated in this process. This friction force will significantly affect the deformation amount of the elastic bar 22 when it is bent, resulting in the elastic bar 22 cooperating with the fiber grating 24 to detect the negative pressure tension. The detection result is not accurate enough.

[0054] The present embodiment effectively solves this problem through a clever design. Specifically, the rotating turntable 1 232 can adapt to the inclined end of the elastic bar 22, so that the angle at which the rotating column 233 clamps the elastic bar 22 can adapt to the inclination of one end of the elastic bar 22. In this way, the large friction force generated by the mismatch between the two angles can be avoided. At the same time, with the help of the rotating rotating column 233, rolling friction is achieved between the rotating column 233 and the elastic bar 22, further reducing the friction force. Through the above working principle, the interference factors when the elastic bar 22 and the fiber grating 24 cooperate to detect the negative pressure tension are significantly reduced, thereby improving the accuracy of the detection.

[0055] Combine Figure 12 There are gaps between the multiple elastic bars 22, and a push block 222 is provided in the middle of the upper side of the elastic bar 22. The push block 222 is fixed to the upper surface of the elastic bar 22 through the elastic bands 224 on both sides, and the two ends of the push block 222 are fixedly connected with embedded columns 223.

[0056] like Figure 12 As shown, adjacent elastic bars 22 are separated by push blocks 222. The upper and lower surfaces of the embedded column 223 are designed with arcuate structures, which are tightly fitted with the upper and lower surfaces of the corresponding elastic bars 22 respectively. When the adjustment assembly 21 applies downward pressure to the corresponding elastic bar 22 through the push block 222, the elastic bar 22 will bend. Furthermore, in the process of causing multiple elastic bars 22 to bend synchronously, the push block 222 will squeeze the corresponding elastic bar 22 downward, and the lower surface of the elastic bar 22 will squeeze another elastic bar 22 on the lower side through the push block 222 in contact with it, and so on. When several elastic bars 22 are needed to participate in the work, it is only necessary to count from the bottom up and control the corresponding push block 222 to move downward, so that all the elastic bars 22 below the push block 222 can bend and perform work.

[0057] It is worth mentioning that the push block 222 has many advantages in contacting the elastic bar 22 through the arc surface. Since the push block 222 is not integrally formed on the elastic bar 22, the stress distribution in the overall structure of the elastic bar 22 is uniform. When the elastic bar 22 is bent under pressure, the curvature of the elastic bar 22 is natural and smooth. When this natural curvature is detected by the fiber optic Bragg grating 24, it can be better combined with the rigidity parameters of the elastic bar 22, so as to more accurately calculate the negative pressure value. In addition, when the push block 222 applies downward pressure to the elastic bar 22, its force point remains fixed, which further improves the stability and consistency of the elastic bar 22 during the bending process. In addition, due to the gap between the elastic bars 22, when the elastic bar 22 bends, its raised end also has sufficient space for upward movement.

[0058] Both ends of the spring bar 22 are provided with bridge-shaped baffles 26 to limit its lateral movement. The bridge-shaped baffles 26 are fixedly mounted on the inner wall of the mounting cover 25. Since the present invention is used in an actual environment, its installation angle is uncertain. For example, if the negative pressure interface 13 is horizontal, the spring bar 22 is likely to slide to one side under the action of gravity, causing the spring bar 22 to lose its function and even affect the normal operation of other spring bars 22. However, by limiting the position of the bridge-shaped baffles 26, it is possible to effectively prevent its displacement and avoid malfunctions. Figure 5 As shown, the R corner on the lower side of one end of the push block 222 is designed as a rounded corner 221 to prevent the original R corner position from being squeezed against the surface of the bridge-shaped blocking piece 26 during the initial bending of the elastic bar 22.

[0059] Combine Figure 9 、 Figure 10 The adjustment system assembly 21 includes a U-shaped frame 211 fixedly mounted on the upper side of the displacement column 142. The inner wall of the U-shaped frame 211 is defined by a long slot 214 and a latching slot B 215. Multiple latching components 212 are embedded within the inner wall of the long slot 214. These latching components 212 are movably engaged with corresponding latching posts 223. A circuit board 213 is mounted on the outer surface of the U-shaped frame 211 to control the engagement of the latching components 212 with the latching posts 223. The circuit board 213 is electrically connected to the control unit 40, enabling the control unit 40 to control the corresponding latching components 212 based on data fed back by the fiber Bragg grating 24.

[0060] like Figure 9 、 Figure 10 As shown, the clamping members 212 are arranged on both sides of the U-shaped frame 211. By controlling the clamping ends of the clamping members 212 to extend out of the inner side of the elongated slot 214 and engage with the corresponding embedded posts 223, a force-bearing connection is achieved between the corresponding push blocks 222 and the U-shaped frame 211. When the U-shaped frame 211 moves downward, the corresponding push blocks 222 press down on the spring bars 22, causing them to bend.

[0061] Preferably, the engaging component 212 is similar to an existing electric telescopic lock, and when the lock column portion thereof is extended, it can be engaged with the embedded column 223 .

[0062] like Figure 11 As shown, this embodiment also provides an improved clamping component 212, which includes a cylinder 2123. A clamping post 2121 is slidably mounted on the inner side of the cylinder 2123. A winding 2124 is provided on the outer surface of the cylinder 2123, the power supply of which is controlled by the circuit board 213. The clamping post 2121 is made of iron. When the cylinder 2123 is energized, the clamping post 2121 generates magnetism, similar to the principle of an electromagnet. A clamping slot A2122 is defined at the end of the clamping post 2121 that is closest to the embedded post 223, while a magnet 2125 is fixedly connected to the end of the cylinder 2123 that is away from the embedded post 223. The magnet 2125 is preferably a neodymium iron boron magnet.

[0063] Its operating principle is as follows: when no current flows through winding 2124, magnet 2125 attracts latch 2121. However, when DC current flows through winding 2124, latch 2121 acts as an electromagnet, causing repulsion between the adjacent ends of latch 2121 and magnet 2125. This forces latch 2121 to extend toward latch 223, causing latch slot A 2122 to engage latch 223. In this manner, the desired function of latch component 212 is achieved.

[0064] The card slot B215 is engaged with the embedded column 223 of the lowest push block 222. Since the U-shaped frame 211 needs to remain connected to at least one push block 222 in order for the device to have a detection effect, the embedded column 223 of the lowest push block 222 can be normally connected to the U-shaped frame 211 through the card slot B215, thereby saving the number of card-connecting components 212 used.

[0065] Combine Figure 6 、 Figure 13 A through hole three 33 is provided on the surface of the skateboard 31, and the micro screw slide 32 includes a frame 321, and a micro motor 325 is fixedly assembled on one side of the frame 321. The output end of the micro motor 325 is connected to a screw rod 322, and a movable block 323 with threaded engagement is movably provided on the surface of the screw rod 322. A push rod 324 is fixedly connected to one side of the movable block 323, and one end of the push rod 324 is fixedly connected to the protrusion 311 on the upper surface of the skateboard 31. Guide rails are provided on both sides of the skateboard 31 to guide its sliding direction, and the through hole three 33 is sealed and slidably fitted with the surface of the lower shell 12.

[0066] like Figure 6 、 Figure 13As shown, the micro motor 325 drives the screw rod 322 to rotate, thereby driving the movable block 323 to move linearly. Subsequently, the movable block 323 moves linearly, and the push rod 324 pushes the slide plate 31, causing the slide plate 31 to achieve sealed sliding on the inner bottom surface of the lower shell 12.

[0067] Under normal conditions, the slide plate 31 shields the second through-hole 121, while the third through-hole 33 remains connected to the negative pressure interface 13. The negative pressure interface 13 is connected in parallel to one side of the ventilation duct. For example, in the case of a blower used on a wall-mounted gas stove, the negative pressure interface 13 is connected in parallel to the side of the ventilation duct via a hose. During operation, when air flows through the ventilation duct, the negative pressure interface 13 generates negative pressure within the lower housing 12. At this time, the support plate 141 moves toward the lower housing 12 and bends the spring bar 22 through the adjustment assembly 21. Simultaneously, the fiber grating 24 detects the degree of bending of the spring bar 22 and outputs a signal to the control unit 40. The control unit 40 calculates the negative pressure tension of the support plate 141 based on the degree of bending of the spring bar 22 and the current rigidity parameters of the spring bar 22, and further converts it into wind pressure within the ventilation duct.

[0068] In particular, a range is set for the maximum bending degree of the spring bar 22. When the bending degree of the spring bar 22 exceeds the preset range, it indicates that the wind pressure in the ventilation duct is high. At this time, the control unit 40 controls the micro-screw slide 32 to move the slide plate 31, causing the through hole 33 to connect with the through hole 2 121. At the same time, the negative pressure interface 13 is blocked, isolating the suction force of the negative pressure interface 13. At this time, the negative pressure chamber is connected to the external environment through the through hole 2 121, and the pressure is released. Subsequently, the adjustment system assembly 21 is reset under the elastic force of the spring bar 22. Under the control of the control unit 40, the adjustment system assembly 21 increases the number of connections with the mounting assembly 23 to increase the stiffness coefficient. Finally, under the control of the micro-screw slide 32, the slide plate 31 is reset, and negative pressure is re-established in the lower housing 12. The control unit 40 then calculates the current wind pressure based on the new stiffness coefficient and the bending degree of the spring bar 22.

[0069] Combine Figure 7 、 Figure 8 The two ends of the fiber Bragg grating 24 are fixed to the lower surface of the elastic bar 22 by fixing parts 241, preferably fixed by silicone. The fiber Bragg grating 24 is bonded to the surface of the elastic bar 22 by a bonding part 242 in the middle part of the two fixing parts 241, preferably by adhesive tape, so that the fiber Bragg grating 24 is caused to bend synchronously with the elastic bar 22.

[0070] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A fiber Bragg grating wind pressure sensor, comprising an upper shell (11), a lower shell (12) and a diaphragm (14), wherein a support plate (141) is provided in the middle of the diaphragm (14), a displacement column (142) is provided on the upper side of the support plate (141), the diaphragm (14) separates the cavity formed by the upper shell (11) and the lower shell (12) into a positive pressure cavity and a negative pressure cavity, and a negative pressure interface (13) is provided on the lower side of the lower shell (12) and communicated with the negative pressure cavity, characterized in that: Also includes: The sensitive mechanism (20) comprises a plurality of spring bars (22) arranged in parallel and vertically, gaps being provided between the plurality of spring bars (22), a push block (222) being provided in close contact with the middle portion of the upper side of the spring bar (22), the push block (222) being fixedly attached to the upper surface of the spring bar (22) via elastic bands (224) on both sides, and embedded columns (223) being fixedly connected at both ends of the push block (222); An adjustment assembly (21) is provided in the middle of the plurality of elastic bars (22), and mounting assemblies (23) for movably mounting the elastic bars (22) above the diaphragm (14) are provided at both ends of the elastic bars (22), and a fiber grating (24) is provided on the lower surface of the lowermost elastic bar (22), and the adjustment assembly (21) is connected to the diaphragm (14); The adjustment system assembly (21) includes a U-shaped frame (211) fixedly mounted on the upper side of the displacement column (142), the inner side wall of the U-shaped frame (211) is respectively provided with a long groove (214) and a clamping groove B (215), and the inner wall of the long groove (214) is embedded with a plurality of clamping components (212), and the clamping components (212) are correspondingly and movably clamped with the embedded column (223); The pressure release mechanism (30) includes a slide plate (31) sliding on the upper side of the negative pressure interface (13), and a second through hole (121) provided on the lower side of the lower shell (12), wherein the lower shell (12) controls the negative pressure chamber to communicate with the negative pressure interface (13) or the second through hole (121); When the diaphragm (14) is subjected to negative pressure, the lowermost elastic strip (22) is pulled downward by the adjustment assembly (21) to bend. After the single diaphragm (14) is deformed to the maximum during operation, the air pressure in the negative pressure chamber is restored by the through hole three (33), so that the adjustment assembly (21) is reset by the elastic force of the connected diaphragm (14). Subsequently, the adjustment assembly (21) is connected upward to the adjacent diaphragm (14). According to the number of connected diaphragms (14), the rigidity coefficient is changed to improve the range of the sensitive mechanism (20) to detect the negative pressure tension.

2. The fiber Bragg grating wind pressure sensor according to claim 1, characterized in that: The sensitive mechanism (20) further comprises an assembly cover (25) provided on the inner side of the upper shell (11), wherein the assembly cover (25) is provided with an embedded ring (251), and the displacement column (142) is movably inserted into the inner side of the assembly cover (25) through the embedded ring (251), and the adjustment system assembly (21) is fixedly assembled on the upper end of the displacement column (142).

3. The fiber Bragg grating wind pressure sensor according to claim 2, characterized in that: The mounting assembly (23) includes a fixing seat (231) fixedly mounted on the inner wall of the mounting cover (25); a plurality of turntables (232) are rotatably mounted on one side of the fixing seat (231); a pair of rotating columns (233) are rotatably mounted on the side surface of the turntable (232); one end of the elastic bar (22) is clamped between the pair of rotating columns (233); and the plurality of turntables (232) correspond one to one with the plurality of elastic bars (22).

4. The fiber Bragg grating wind pressure sensor according to claim 3, characterized in that: Both ends of the elastic bar (22) are provided with bridge-shaped baffles (26) for limiting its lateral movement, and the bridge-shaped baffles (26) are fixedly assembled on the inner wall of the assembly cover (25).

5. The fiber Bragg grating wind pressure sensor according to claim 4, characterized in that: The outer surface of the U-shaped frame (211) is provided with a circuit board (213) for clamping the control clamping component (212) and the embedded column (223).

6. The fiber Bragg grating wind pressure sensor according to claim 5, characterized in that: The slot B (215) is engaged with the embedded column (223) of the lowermost push block (222).

7. The fiber Bragg grating wind pressure sensor according to claim 1, characterized in that: A through hole three (33) is provided on the surface of the slide plate (31); A micro screw slide (32), the micro screw slide (32) includes a frame (321), a micro motor (325) is fixedly mounted on one side of the frame (321), the output end of the micro motor (325) is connected to a screw (322), a movable block (323) with threaded engagement is movably provided on the surface of the screw (322), one side of the movable block (323) is fixedly connected to a push rod (324), one end of the push rod (324) is fixedly connected to a protrusion (311) on the upper surface of the slide (31), guide rails are provided on both sides of the slide (31) to guide its sliding direction, and the through hole three (33) is sealed and slidably fitted with the surface of the lower shell (12).

8. The fiber Bragg grating wind pressure sensor according to claim 1, characterized in that: The two ends of the fiber grating (24) are fixed to the lower surface of the elastic bar (22) through fixing members (241), and the fiber grating (24) is bonded to the surface of the elastic bar (22) through a bonding member (242) in the middle portion between the two fixing members (241).

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