Flow detection device and flow detection method

Abstract

The application provides a flow detection device and a flow detection method. The flow detection device comprises a flow pipe, a whistle pipe, a focusing strain gauge, a vibration detection assembly and a processing module. The whistle pipe is arranged at an inflow end of the flow pipe and is used for making the fluid flowing into the flow pipe generate an inflow sound field propagating in the inflow direction. The focusing strain gauge has a focusing concave surface, and the focusing concave surface can reflect the inflow sound field to form a focused sound field. The vibration detection assembly is arranged on the flow pipe and is located at a position corresponding to a focal point of the focused sound field. The vibration detection assembly is used for generating a corresponding first voltage signal based on the sound field intensity of the fluid in the flow pipe. The focusing strain gauge can generate a corresponding second voltage signal based on its own strain. The processing module is used for decoupling processing of the first voltage signal and the second voltage signal to determine the fluid flow rate of the flow pipe. The application determines the fluid flow rate by detecting the sound field and the strain of the focusing strain gauge, thereby improving the flow detection accuracy and expanding the flow detection range.

Description

Technical Field

[0001] This invention relates to the field of semiconductor process equipment, and more specifically, to a flow detection device and a flow detection method. Background Technology

[0002] The gas flow sensor is the core sensing component of gas flow meters and gas flow controllers. Its main function is to measure physical quantities such as instantaneous flow velocity, pressure, temperature, gas composition, positional movement, and force in a pipeline or container, and finally obtain the gas flow value through scientific conversion methods.

[0003] Nowadays, there are many types of gas flow sensors, such as throttling gas flow sensors, volumetric gas flow sensors, vortex gas flow sensors, electromagnetic gas flow sensors, thermal gas flow sensors, and ultrasonic gas flow sensors. Although there are many ways to implement gas flow sensors, the measurement accuracy of gas flow sensors is affected by the instability of gas flow. How to quickly and effectively measure flowing gas accurately has become a major issue in the industry.

[0004] Therefore, how to provide a flow detection device that can stably and accurately measure gas flow rate has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The present invention aims to provide a flow detection device and a flow detection method, wherein the flow detection device can stably and accurately measure gas flow.

[0006] To achieve the above objectives, as one aspect of the present invention, a flow detection device is provided, comprising a flow tube, a whistle, a focused strain gauge, a vibration detection component, and a processing module. The whistle is disposed at the inlet end of the flow tube and is used to generate an inflow sound field propagating along the inflow direction from the fluid flowing into the flow tube. The focused strain gauge has a focusing concave surface, which can reflect the inflow sound field to form a focused sound field. The vibration detection component is disposed on the flow tube and its position corresponds to the focal point of the focused sound field. The vibration detection component is used to generate a corresponding first voltage signal based on the sound field intensity of the fluid in the flow tube. The focused strain gauge can generate a corresponding second voltage signal based on its own strain. The processing module is used to decouple the first voltage signal and the second voltage signal to determine the flow rate of the fluid flowing through the flow tube.

[0007] Optionally, a mounting hole is formed on the side wall of the flow tube. The vibration detection assembly includes a resonant conduction cavity, a plurality of diaphragms fixedly disposed in the resonant conduction cavity, and at least one electromagnetic module. The resonant conduction cavity is fixedly disposed in the mounting hole. The electromagnetic module includes a magnetic strip and a pickup coil wound on the magnetic strip. The electromagnetic module is located on the side of the diaphragm away from the axis of the whistle tube. The diaphragm can vibrate under the action of the fluid in the flow tube to generate an induced electric field, thereby generating an induced electromotive force in the pickup coil, thus obtaining the first voltage signal.

[0008] Optionally, the vibrator is vertically arranged, and multiple thickness reduction grooves are formed on both sides of the vibrator, with the positions of the thickness reduction grooves on both sides corresponding. The thickness reduction grooves are located at the bottom end of the vibrator and are connected to the bottom edge of the vibrator. Multiple anti-snoring holes are also formed on the vibrator, with the positions of the multiple anti-snoring holes corresponding one-to-one with the multiple thickness reduction grooves, and each anti-snoring hole connects the two corresponding thickness reduction grooves on both sides.

[0009] Optionally, the resonant conduction cavity includes a mounting cylinder and a mounting block. The outer wall of the mounting cylinder is fixed in the mounting hole. The mounting block seals one end of the mounting cylinder away from the axis of the whistle tube, and the electromagnetic module is fixedly mounted on the mounting block.

[0010] Optionally, the vibration detection assembly further includes a magnetic shield, which surrounds the outer side of the plurality of electromagnetic modules around the axis of the mounting cylinder, and the magnetic shield is used to shield the magnetic field outside the magnetic shield.

[0011] Optionally, the vibration detection assembly further includes multiple energy-absorbing barrels, which are fixedly disposed on the inner wall of the mounting cylinder, and the extending direction of the energy-absorbing barrels is parallel to the axis of the mounting cylinder. The energy-absorbing barrels are used to absorb sound waves reflected from the inner wall of the mounting cylinder.

[0012] Optionally, a plurality of positioning blocks are fixedly provided on the side of the mounting block facing the axis of the whistle, the cross-sectional shape of the energy-absorbing barrel corresponds to the shape of the positioning blocks, and the plurality of positioning blocks are housed in the plurality of energy-absorbing barrels one by one.

[0013] Optionally, the vibration detection assembly further includes a vibrating plate frame, which is fixedly disposed on the inner wall of the mounting cylinder, and a plurality of vibrating plates are fixedly disposed in the vibrating plate frame. The energy-absorbing barrel is located between the vibrating plate frame and the inner wall of the mounting cylinder.

[0014] Optionally, the flow detection device further includes a clamping ring and a magnetically conductive skin. The clamping ring is sealed to one end of the mounting hole away from the axis of the whistle tube. The magnetically conductive skin seals the inner hole of the clamping ring and is used to shield the magnetic field outside the mounting hole.

[0015] Optionally, the flow tube includes an inlet section, a constriction section, and a flared section. The constriction section is connected between the inlet section and the flared section. The cross-sectional area of ​​the constriction section gradually decreases along the fluid flow direction, and the cross-sectional area of ​​the flared section gradually increases along the fluid flow direction. The focused strain gauge is disposed on the inner wall of the constriction section, and the axis of the whistle passes through the focused concave surface.

[0016] As a second aspect of the present invention, a flow detection method is provided, the flow detection method being applied to the aforementioned flow detection device, the flow detection method comprising:

[0017] Acquire the first voltage signal generated by the vibration detection component and the second voltage signal generated by the focused strain gauge;

[0018] The first voltage signal and the second voltage signal are decoupled to determine the flow rate of the fluid flowing through the flow tube.

[0019] The flow detection device and method provided by this invention determine the fluid flow rate by detecting the sound field intensity and the strain of the focused strain gauge. Both the focused strain gauge and the vibration detection component are in direct contact with the fluid in the flow tube, eliminating the need for branches to be drawn from the flow tube. This reduces the kinetic energy loss of the fluid flowing through the flow tube and lowers the sensitivity of the flow detection device to external interference factors (such as vibration and temperature). This improves the accuracy and stability of the flow detection device in detecting fluid flow rate, and also reduces the overall size of the flow detection device, improving the compactness of semiconductor process equipment and thus enhancing the convenience of machine installation, maintenance, and transmission.

[0020] Furthermore, this invention linearly outputs the gas flow rate value through acoustic conversion of gas flow rate. As long as the airflow can trigger the vector sound field energy conversion of the whistle, it can be detected. The whistle also has high sensitivity to small flow and low density fluids, thus enabling the flow detection device to detect small flow and low density fluid flow rates, thereby expanding the flow detection range of the flow detection device.

[0021] Furthermore, the flow detection device provided by the present invention determines the flow rate of the fluid flowing through the flow tube by performing linear signal decoupling between the first voltage signal and the second voltage signal, which can significantly improve the flow detection accuracy of the flow detection device. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0023] Figure 1This is a cross-sectional view of the flow detection device provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the flow detection device provided in an embodiment of the present invention;

[0025] Figure 3 This is an exploded view of the flow detection device provided in an embodiment of the present invention;

[0026] Figure 4 This is a cross-sectional view of the sentinel tube in the flow detection device provided in an embodiment of the present invention;

[0027] Figure 5 This is a perspective view of the sensor tube in the flow detection device provided in this embodiment of the invention;

[0028] Figure 6 This is a schematic diagram of the structure of the sentinel tube in the flow detection device provided in an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram illustrating the principle of a focused sound field formed by the reflection of sound waves by a focused strain gauge in the flow detection device provided in this embodiment of the invention.

[0030] Figure 8 This is a cross-sectional schematic diagram of the vibration detection component in the flow detection device provided in an embodiment of the present invention;

[0031] Figure 9 This is a cross-sectional schematic diagram of the vibration detection component in the flow detection device provided in an embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of a portion of the structure of the vibration detection component in the flow detection device provided in this embodiment of the invention;

[0033] Figure 11 yes Figure 10 A schematic diagram of the structure from another perspective;

[0034] Figure 12 This is a schematic diagram of another part of the structure of the vibration detection component in the flow detection device provided in this embodiment of the invention;

[0035] Figure 13 yes Figure 12 A schematic diagram of the structure from another perspective;

[0036] Figure 14 yes Figure 12 A schematic diagram of the structure from another perspective;

[0037] Figure 15 This is a schematic diagram showing the state of the vibrating plate in the vibration detection component of the flow detection device provided in this embodiment of the invention being in the magnetic field generated by the magnetic strip;

[0038] Figure 16 This is a schematic diagram showing the state of the vibrator in the magnetic field generated by the magnetic strip from the perspective of the axis of the conducting cavity;

[0039] Figure 17 This is a schematic diagram of the structure of the diaphragm in the flow detection device provided in an embodiment of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] 100: Flow pipe; 110: Inlet section

[0042] 111: Mounting hole; 112: Wiring hole

[0043] 120: Tightening section; 130: Flaring section

[0044] 200: Sentinel tube; 300: Focused strain gauge

[0045] 310: Focusing concave surface; 400: Vibration detection component

[0046] 410: Resonance conduction cavity; 411: Mounting cylinder

[0047] 412: Mounting block; 413: Positioning block

[0048] 420: Vibrating plate; 421: Anti-sound hole

[0049] 430: Electromagnetic module; 431: Magnetic strip

[0050] 432: Pickup coil; 440: Magnetic shield

[0051] 450: Energy Absorbing Bucket; 460: Vibrating Plate Frame

[0052] 470: Vibrator support; 480: Rivet

[0053] 500: Fastener; 510: Compression ring

[0054] 520: Magnetic conductive skin Detailed Implementation

[0055] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0056] The principle of fluid flow detection in the existing technology is to use a sensor tube to extend from the main pipeline to a branch, and to detect the fluid velocity in the branch to determine the fluid flow rate in the main pipeline.

[0057] Specifically, the fluid flowing into the branch will generate the Coriolis effect and drive the sensing tube to produce a torsional displacement. The fluid velocity flowing through the sensing tube can then be determined by the phase difference between the displacement of the sensor at the inlet and outlet ends of the sensing tube, thus determining the fluid flow rate. However, when a small flow rate of fluid (e.g., less than 12 SLM) enters the sensing tube, its velocity is too low to generate a sufficient mass flow rate change, and therefore insufficient to induce a sufficient torsional displacement in the sensing tube. Consequently, the two sensors cannot detect the phase difference, resulting in no signal output and the inability to detect small flow rates. This phenomenon is known as the sensor's "dead zone."

[0058] To address the aforementioned technical problems, as one aspect of the present invention, a flow detection device is provided, such as... Figures 1 to 3 As shown, the flow detection device includes a flow pipe 100, a whistle 200, a focused strain gauge 300, a vibration detection assembly 400, and a processing module. The whistle 200 is disposed at the inlet end of the flow pipe 100 and is used to generate an inflow sound field that propagates along the inflow direction for the fluid (e.g., gas) flowing into the flow pipe 100. Figure 7 As shown, the focused strain gauge 300 has a focusing concave surface 310, which can reflect the incoming sound field to form a focused sound field. The vibration detection component 400 is disposed on the flow pipe 100 and its position corresponds to the focal point of the focused sound field. The vibration detection component 400 is used to generate a corresponding first voltage signal U1 based on the sound field intensity of the fluid in the flow pipe 100 (which is positively correlated with the frequency and amplitude of the sound wave). The focused strain gauge 300 can generate a corresponding second voltage signal U2 based on its own strain. The processing module is used to decouple the first voltage signal U1 and the second voltage signal U2 to determine the flow rate of the fluid flowing through the flow pipe 100.

[0059] In the flow detection device provided by the present invention, the whistle 200 can generate an inflow sound field that propagates along the inflow direction from the fluid flowing into the flow detection device. The focusing concave surface 310 of the focusing strain gauge 300 can reflect the inflow sound field and focus the reflected sound wave onto the vibration detection component 400. The greater the flow rate of the fluid, the greater the intensity of the inflow sound field generated by the whistle 200. The intensity I of the sound field focused onto the vibration detection component 400 also increases accordingly, so that the first voltage signal U1 can reflect the magnitude of the fluid flow rate in real time. At the same time, the second voltage signal U2 generated by the strain of the focusing strain gauge 300 under the action of fluid impact can also reflect the magnitude of the fluid flow rate.

[0060] In the process of continuous change of fluid flow rate, the sound wave generated by the transmitted sound field of the first voltage signal U1 exhibits the characteristics of a general complex exponential signal. Both the real and imaginary parts of this signal are sinusoidal signals that increase with the increase of its exponent and decrease with the decrease of its exponent. At the same time, the first voltage signal U1 is also a time-continuous function signal.

[0061] As for the second voltage signal U2, influenced by the material of the focused strain gauge 300 and its fixed frequency, when fluid impacts the focusing concave surface 310 of the focused strain gauge 300 and applies pressure, the focusing concave surface 310 undergoes a very small deformation, causing a change in the original frequency and thus outputting a signal reflecting the corresponding strain (i.e., the second voltage signal U2). With changes in flow rate, the surface pressure acting on the focused strain gauge 300 also increases with the increase in flow rate, and the deformation of the strained material on the surface of the focused strain gauge 300 also increases. Therefore, its output second voltage signal U2 has the characteristics of a real exponential signal, and U2 is also a time-continuous function signal.

[0062] The first voltage signal U1 and the second voltage signal U2, two time-continuous function signals, are input into the processing module as dual closed-loop negative feedback signals. By performing mutual coupling fitting on the first voltage signal U1 and the second voltage signal U2 through the processing module, the flow rate of the fluid flowing through the flow tube 100 can be determined.

[0063] The flow detection device provided by this invention determines the fluid flow rate by detecting the sound field intensity and the strain of the focused strain gauge 300. Both the focused strain gauge 300 and the vibration detection component 400 are in direct contact with the fluid in the flow pipe 100, eliminating the need for branches to be drawn from the flow pipe 100. This reduces the kinetic energy loss of the fluid flowing through the flow pipe 100 and lowers the sensitivity of the flow detection device to external interference factors (such as vibration and temperature). This improves the accuracy and stability of the flow detection device in detecting fluid flow rate, and also reduces the overall size of the flow detection device, improving the compactness of semiconductor process equipment and thus enhancing the convenience of machine installation, maintenance, and transmission.

[0064] Furthermore, this invention linearly outputs the gas flow rate value through acoustic conversion of gas flow rate. As long as the airflow can trigger the vector sound field energy conversion of the whistle 200, it can be detected. The whistle 200 can measure gas flow rates as low as 0.7 sccm and has high sensitivity to low flow and low density fluids. Therefore, the flow detection device can also detect low flow and low density fluid flow rates, thus expanding the flow detection range of the flow detection device.

[0065] Furthermore, the flow detection device provided by the present invention determines the flow rate of the fluid flowing through the flow tube 100 by performing linear signal decoupling between the first voltage signal U1 and the second voltage signal U2. The fluid flow output accuracy can reach 0.15%FS, which can significantly improve the flow detection accuracy of the flow detection device.

[0066] It should be noted that the flow rate values ​​corresponding to different sound field intensities can be calibrated before the flow detection device leaves the factory and pre-stored in the flow detection device or the corresponding control device, so as to realize the flow rate value in real time based on the value detected by the vibration detection component 400 when using the flow detection device.

[0067] To reduce the resistance of the flow pipe 100 to the fluid and improve the performance of the flow detection device, as a preferred embodiment of the present invention, such as... Figure 1 As shown, the flow pipe 100 includes an inlet section 110, a constriction section 120, and a flared section 130. The constriction section 120 is connected between the inlet section 110 and the flared section 130. The cross-sectional area of ​​the constriction section 120 gradually decreases along the fluid flow direction (i.e., the direction of the arrow in the figure), while the cross-sectional area of ​​the flared section 130 gradually increases along the fluid flow direction. The focused strain gauge 300 is disposed on the inner wall of the constriction section 120, and the axis of the whistle tube 200 passes through the focusing concave surface 310.

[0068] Since the focused strain gauge 300 needs to reflect sound waves, this process inevitably creates resistance to the fluid. This fluid resistance is the cause of the upstream and downstream pressure drop. Generally, the smaller the upstream and downstream pressure drop, the better the performance of the sensor (flow detection device). Therefore, in this embodiment of the invention, the flow pipe 100 adopts a mid-diameter reduction structure, which accelerates the flow velocity of the fluid passing through the focused strain gauge 300 at the reduction position. Finally, when the fluid flows out to the outlet end of the flow pipe 100, it is equal to k times the inflow velocity (k is a constant less than 1; the closer k is to 1, the smaller the air resistance, the smaller the measurable flow rate, and the better the performance). In this embodiment of the invention, the flow pipe 100 adopts a mid-diameter reduction structure, thereby increasing the value of the constant k, reducing the resistance of the flow pipe 100 to the fluid, and ensuring the performance of the flow detection device.

[0069] like Figures 4 to 6 As shown, the whistle 200 has multiple inflow guiding structures 210 evenly distributed around its axis. Its special structure can convert part of the kinetic energy of the fluid flowing into the flow pipe 100 into sound power W (the vibration period t, wavelength λ, and frequency f of the sound wave are all related to the fluid flow rate), and can fit the direction of the sound field vector composed of characteristic sound waves to the greatest extent, so that the sound wave has a relatively concentrated directivity, that is, it propagates along the inflow direction.

[0070] like Figure 1 , Figure 7As shown, after the sound wave is reflected and focused by the focusing strain gauge 300, a sound field with intensity I is generated at the vibration detection component 400. Under the action of the sound field, a sound pressure P is instantly generated inside the vibration detection component 400. When the fluid flow rate Q increases, the intensity I of the focused sound field increases, and at the same time, the focal point of the focused sound field moves from O' to O, that is, closer to the vibration detection component 400, so that the vibration detection component 400 can detect a higher sound field intensity.

[0071] As an optional embodiment of the present invention, the focusing concave surface 310 is a spherical surface.

[0072] To ensure the reliability of the flow detection device, as a preferred embodiment of the present invention, the focused strain gauge 300 is a spherical focused piezoelectric strain gauge.

[0073] As an optional embodiment of the present invention, such as Figures 8 to 11 As shown, a mounting hole 111 is formed on the side wall of the flow tube 100. The vibration detection assembly 400 includes a resonant conduction cavity 410 and a plurality of vibrating plates 420 fixedly disposed in the resonant conduction cavity 410 and at least one electromagnetic module 430. The resonant conduction cavity 410 is fixedly disposed in the mounting hole 111. The electromagnetic module 430 includes a magnetic strip 431 and a pickup coil 432 wound on the magnetic strip 431. The electromagnetic module 430 is located on the side of the vibrating plate 420 away from the axis of the whistle tube 200. The vibrating plate 420 can vibrate under the action of the fluid in the flow tube 100 to generate an induced electric field to generate an induced electromotive force in the pickup coil 432, thereby obtaining a first voltage signal U1.

[0074] In this embodiment of the invention, the vibration detection component 400 includes a resonant conduction cavity 410, a plurality of diaphragms 420 and at least one electromagnetic module 430. The diaphragms 420 in the resonant conduction cavity 410 will vibrate under the influence of the sound field. After their own natural frequency is fitted with the frequency of the sound wave in the sound field, the diaphragms 420 will vibrate at a real-time frequency fg until the sound field intensity in the resonant conduction cavity 410 changes again.

[0075] like Figure 15 , Figure 16 As shown, the diaphragm 420 is located in the magnetic field generated by the magnetic strip 431 of the electromagnetic module 430 and is parallel to the direction of the magnetic field. When the diaphragm 420 in the resonant conduction cavity 410 vibrates under the influence of the sound field, the particles on the diaphragm 420 will move by cutting the magnetic field lines in the fixed magnetic field of the magnetic strip 431, generating an electromagnetic induction phenomenon. Based on the Lorentz effect, an induced current will be generated in the pickup coil 432 wrapped around each magnetic strip 431, thereby forming a potential difference (i.e., induced electromotive force) between the two ends (lead A and lead B) of the pickup coil 432. The potential difference also changes accordingly with the change of the amplitude and frequency of the sound wave in the sound field.

[0076] There is a very good linear relationship between the induced electromotive force in the pickup coil 432 and the sound field strength in the resonant cavity 410. That is, the greater the flow rate of the fluid through the whistle tube 200, the greater the sound field strength in the resonant cavity 410. The greater the sound field strength, the higher the amplitude and frequency of the oscillator 420 in the resonant cavity 410, and the higher the induced electromotive force output by the pickup coil 432. After simplifying the complex physical transformation relationship, a near-linear relationship between flow rate and induced electromotive force can be obtained.

[0077] Optionally, such as Figure 14 As shown, both ends of each pickup coil 432 can be led outward to form leads A and leads B, so as to output the induced electromotive force generated therefrom.

[0078] To ensure the parallelism of the magnetic field lines of the magnetic field where the vibrator 420 is located, in a preferred embodiment of the present invention, the magnetic strip 431 is parallel to the axial direction of the resonant cavity 410 along the direction from the south pole to the north pole. For example, as shown in the figure... Figure 9 As shown, the north pole of the magnetic strip 431 faces the vibrator 420, and the south pole faces away from the vibrator 420.

[0079] To ensure the accuracy and stability of the first voltage signal U1, as a preferred embodiment of the present invention, such as... Figure 8 , Figure 10 , Figure 11 As shown, the vibrator 420 is vertically arranged, and multiple thickness reduction grooves 422 are formed on both sides of the vibrator 420. The positions of the thickness reduction grooves 422 on both sides correspond. The thickness reduction grooves are located at the bottom end of the vibrator 420 and are connected to the bottom edge of the vibrator 420. Multiple anti-snoring holes 421 are also formed on the vibrator 420. The positions of the multiple anti-snoring holes 421 correspond one-to-one with the multiple thickness reduction grooves 422, and each anti-snoring hole 421 connects the two corresponding thickness reduction grooves 422 on both sides.

[0080] In this embodiment of the invention, a thickness reduction groove 422 is formed on the vibrating plate 420. The thickness reduction groove 422 is distributed in pairs on both sides of the bottom end of the vibrating plate 420 and is connected to the bottom edge of the vibrating plate 420, thereby forming multiple "thin parts" at the bottom end of the vibrating plate 420 with a thickness smaller than other areas. This makes these "thin parts" have a higher elastic modulus and lower flexural strength material properties compared to other parts (hereinafter referred to as "thick parts").

[0081] After a sound source is generated within the resonant cavity 410, the sound waves drive the vibrator 420 to vibrate under the influence of the sound field. Because the "thin part" of the vibrator 420 has a significant modulus difference from the "thick part," the "thick part" vibrates at a higher frequency and with a smaller amplitude compared to the "thin part," resulting in a more stable electrical signal with a higher frequency and minimal energy loss. Furthermore, the amplitude of the "thin part" is relatively larger than that of the "thick part," allowing for sensitive transmission of the signal to the "thick part" of the vibrator even when measuring very small flow rates, even with relatively low sound field intensity.

[0082] Furthermore, the "thin part" also has anti-whistling holes 421. After the sound source focal point is generated, the sound waves generated by the sound source will propagate within the resonant conduction cavity 410 for a short time and then be reflected inside the resonant conduction cavity 410. After multiple in-phase superpositions at a certain position, there is a certain probability that a high-frequency and large-amplitude energy group will be formed at a certain moment. This phenomenon is called howling. The anti-whistling holes 421 on the diaphragm 420 can suppress such abrupt energy groups. When howling occurs, the "thin part" of the diaphragm will be the first to sense the occurrence of this phenomenon, while the "thick part" will not be affected for a short time. The "thin part" stores these sudden energy groups in the anti-whistling holes 421. Since the diaphragm itself is vibrating regularly in positive and negative phases, and these abrupt energy groups are rapidly attenuated within the anti-whistling holes 421 over a certain period of time, the thick part is not greatly affected, thereby achieving the function of filtering stray waves and ensuring the accuracy and stability of the first voltage signal U1.

[0083] As a preferred embodiment of the present invention, such as Figure 17 As shown, the projection of the sidewall of the reducing groove 422 on the surface of the vibrator 420 corresponding to the top side of the vibrator 420 is an arc shape protruding towards the top of the vibrator 420, so that the transition between the "thick part" and the "thin part" can be vibrated through the arc-shaped parting surface, thereby improving the uniformity of vibration energy propagation.

[0084] To facilitate the installation of the vibrating plate 420 in the resonant conduction cavity 410, as a preferred embodiment of the present invention, such as... Figure 3 , Figure 8 As shown, the resonant conduction cavity 410 includes a mounting cylinder 411 and a mounting block 412. The outer wall of the mounting cylinder 411 is fixed in the mounting hole 111. The mounting block 412 seals one end of the mounting cylinder 411 away from the axis of the whistle tube 200, and the electromagnetic module 430 is fixedly mounted on the mounting block 412.

[0085] In this embodiment of the invention, the resonant conduction cavity 410 includes a mounting cylinder 411 and a mounting block 412. The mounting block 412 seals the end of the mounting cylinder 411 that is away from the axis of the whistle tube 200, so that the resonant conduction cavity 410 is only open to the side facing the focused sound field, so as to ensure the purity of the sound waves in the resonant conduction cavity 410. Furthermore, the resonant conduction cavity 410 adopts a split design, which can effectively reduce the difficulty of installing the vibrator 420 in the mounting cylinder 411 and improve the convenience of disassembly and maintenance of the device.

[0086] As an optional embodiment of the present invention, the mounting cylinder 411 is interference-fitted with the mounting hole 111.

[0087] To ensure the stability of the position of the resonant conduction cavity 410 in the mounting hole 111, as a preferred embodiment of the present invention, such as... Figures 1 to 3 , Figure 8 As shown, the flow detection device also includes a fixing member 500, which is fixedly connected to one end of the mounting hole 111 away from the axis of the whistle tube 200 to prevent the mounting cylinder 411 from shifting in the mounting hole 111, thereby ensuring the stability of the position of the resonant conduction cavity 410 in the mounting hole 111, and thus ensuring the flow detection accuracy of the flow detection device.

[0088] To further ensure the flow detection accuracy of the flow detection device, as a preferred embodiment of the present invention, such as... Figure 3 , Figure 8 As shown, the fastener 500 includes a clamping ring 510 and a magnetically conductive skin 520. The clamping ring 510 is sealed to one end of the mounting hole 111 away from the axis of the whistle tube 200. The magnetically conductive skin 520 seals the inner hole of the clamping ring 510 and is used to shield the magnetic field outside the mounting hole 111.

[0089] In this embodiment of the invention, the fixing member 500 includes a clamping ring 510 and a magnetic conductive skin 520. The magnetic conductive skin 520 can shield the magnetic field outside the mounting hole 111, thereby avoiding interference from the external magnetic field to the pickup coil 432 in the resonant conduction cavity 410, and further ensuring the flow detection accuracy of the flow detection device.

[0090] As an optional embodiment of the present invention, the clamping ring 510 and the mounting hole 111 are connected by laser welding.

[0091] To further ensure the flow detection accuracy of the flow detection device, as a preferred embodiment of the present invention, such as... Figure 8 , Figures 12 to 14As shown, the vibration detection assembly 400 also includes a magnetic shield 440. The magnetic shield 440 covers the outside of the multiple electromagnetic modules 430 around the axis of the mounting cylinder 411. The magnetic shield 440 is used to shield the magnetic field outside the magnetic shield 440, thereby avoiding interference from the external magnetic field to the pickup coil 432 in the resonant conduction cavity 410, and further ensuring the flow detection accuracy of the flow detection device.

[0092] To further ensure the flow detection accuracy of the flow detection device, as a preferred embodiment of the present invention, such as... Figures 9 to 11 As shown, the vibration detection assembly 400 also includes a plurality of energy-absorbing barrels 450. The energy-absorbing barrels 450 are fixedly disposed on the inner wall of the mounting cylinder 411, and the extending direction of the energy-absorbing barrels 450 is parallel to the axis of the mounting cylinder 411. The energy-absorbing barrels 450 are used to absorb the sound waves reflected from the inner wall of the mounting cylinder 411.

[0093] In this embodiment of the invention, an energy-absorbing barrel 450 is fixedly provided on the inner wall of the mounting cylinder 411. The energy-absorbing barrel 450 can absorb the sound waves reflected back by the inner wall of the mounting cylinder 411, so as to avoid the reflected sound waves from interfering with the vibrating plate 420 in the resonant conduction cavity 410, thereby further ensuring the flow detection accuracy of the flow detection device.

[0094] To ensure the circumferential positioning accuracy between the vibrator 420 and the electromagnetic module 430, as a preferred embodiment of the present invention, such as... Figure 9 , Figures 12 to 14 As shown, multiple positioning blocks 413 are fixedly installed on the side of the mounting block 412 facing the axis of the whistle tube 200. The cross-sectional shape of the energy-absorbing barrel 450 corresponds to the shape of the positioning blocks 413, as shown in the figure. Figure 9 As shown, multiple positioning blocks 413 are housed in multiple energy-absorbing barrels 450 in a one-to-one correspondence.

[0095] In this embodiment of the invention, a plurality of positioning blocks 413 are fixed on the side of the mounting block 412 facing the interior of the resonant conduction cavity 410, and the plurality of positioning blocks 413 are embedded one-to-one into the plurality of energy-absorbing barrels 450. This allows the mounting block 412 to cooperate with the energy-absorbing barrels 450 to achieve circumferential positioning between the mounting block 412 and the mounting cylinder 411, thereby preventing relative rotation between them from affecting the circumferential positioning accuracy between the vibrator 420 and the electromagnetic module 430, ensuring the stability of the magnetic field where the vibrator 420 is located, and thus ensuring the flow detection accuracy and stability of the flow detection device. Furthermore, it also seals the end of the energy-absorbing barrel 450 away from the focusing sound field, preventing the energy entering the energy-absorbing barrel 450 from diffusing outwards, and instead reflecting and dissipating it on the inner wall of the energy-absorbing barrel 450, ensuring the purity of the sound waves in the resonant conduction cavity 410, and further ensuring the flow detection accuracy of the flow detection device.

[0096] As a preferred embodiment of the present invention, such as Figure 12As shown, multiple positioning structures are fixedly installed on the side of the mounting block 412 away from the axis of the whistle tube 200. The circumferential positions of the multiple positioning structures correspond one-to-one with the multiple positioning blocks 413, so as to play a marking and auxiliary assembly role when fixing the mounting block 412 onto the mounting cylinder 411, so as to quickly and accurately determine the circumferential alignment angle between the mounting block 412 and the mounting cylinder 411.

[0097] As an optional embodiment of the present invention, such as Figures 9 to 11 As shown, the vibration detection assembly 400 also includes a vibrator frame 460, which is fixedly mounted on the inner wall of the mounting cylinder 411. Multiple vibrators 420 are fixedly mounted in the vibrator frame 460, and the energy-absorbing barrel 450 is located between the vibrator frame 460 and the inner wall of the mounting cylinder 411.

[0098] As an optional embodiment of the present invention, such as Figures 9 to 11 As shown, the vibration detection assembly 400 also includes multiple sets of vibrator supports 470, and multiple vibrators 420 are arranged in parallel at intervals. Both sides of each vibrator 420 are fixedly mounted on the inner wall of the vibrator frame 460 by a set of vibrator supports 470.

[0099] To further ensure the flow detection accuracy of the flow detection device, in a preferred embodiment of the present invention, the diaphragm bracket 470 and the diaphragm frame 460 are connected by laser welding.

[0100] In this embodiment of the invention, the diaphragm support 470 and the diaphragm frame 460 are fixedly connected by laser welding. Laser welding has a fast welding speed and a small cross-sectional area, which can effectively reduce the impact on the crystal phase structure of the materials of the diaphragm support 470 and the diaphragm frame 460 and the internal stress of the structure, thereby ensuring the stability of the structural performance and thus ensuring the flow detection accuracy of the flow detection device.

[0101] In a preferred embodiment of the present invention, the vibrator 420 and the vibrator support 470 are connected by galvanometer welding. Galvanometer welding is a special laser welding technology that can effectively reduce the impact on the crystal phase structure and internal stress of the materials of the vibrator 420 and the vibrator support 470, and can also improve the efficiency of welding complex welds between the vibrator 420 and the vibrator support 470, thereby ensuring the manufacturing efficiency of the flow detection device.

[0102] As an optional embodiment of the present invention, the diaphragm frame 460 is an approximately rectangular frame, specifically, as shown in the figure below. Figures 10 to 11 As shown, the diaphragm frame 460 includes four frame plates and a transition strip connecting each pair of adjacent frame plates. The four frame plates are aligned and spaced apart. Multiple sets of diaphragm supports 470 are fixedly mounted on one pair of frame plates.

[0103] To further ensure the flow detection accuracy of the flow detection device, in a preferred embodiment of the present invention, the vibrating plate frame 460 is riveted and welded to the mounting cylinder 411. Specifically, as shown in the figure... Figures 9 to 11 As shown, a plurality of first riveting holes are formed on the transition strip and penetrate the transition strip along the thickness direction. A plurality of second riveting holes are formed on the side wall of the mounting cylinder 411 and penetrate the mounting cylinder 411 along the thickness direction. The positions of the plurality of second riveting holes correspond one-to-one with the positions of the plurality of first riveting holes. The vibration detection assembly 400 also includes a plurality of rivets 480. The rivets 480 are formed by riveting and welding and pass through the plurality of first riveting holes and the corresponding second riveting holes one-to-one to fix the vibrator frame 460 to the mounting cylinder 411.

[0104] Considering that the welding connection between the mounting block 412 and the mounting cylinder 411 may cause magnetic interference inside the resonant conduction cavity 410, and that due to the precision of its structure, the structure is not suitable for demagnetization, in this embodiment of the invention, the mounting block 412 and the mounting cylinder 411 are fixedly connected by cold-press riveting, thereby avoiding the magnetic interference that may be generated by welding and further ensuring the flow detection accuracy of the flow detection device.

[0105] As an optional embodiment of the present invention, the outer contour shape of the diaphragm 420 is rectangular.

[0106] As an optional embodiment of the present invention, the surface shapes of the energy-absorbing barrel 450 facing the inner wall of the mounting cylinder 411 and the surface shapes facing the vibrator frame 460 correspond to the surface shapes of the inner wall of the mounting cylinder 411 and the vibrator frame 460, respectively. Specifically, as shown in the figure... Figures 10 to 11 As shown, the outer wall of the energy-absorbing barrel 450 includes a connecting arc surface, a spacer plane, and a transition connecting surface connecting the two sides of the connecting arc surface and the spacer plane. The connecting arc surface contacts and is fixedly connected to the inner wall of the mounting cylinder 411, and the spacer plane is spaced apart from the outer side of the vibrator frame 460 of the vibration detection assembly 400.

[0107] As an optional embodiment of the present invention, the connecting arc surface of the energy-absorbing barrel 450 is brazed to the inner wall of the mounting cylinder 411.

[0108] As an optional embodiment of the present invention, such as Figure 1 As shown, a wiring hole 112 is also formed on the overcurrent tube 100, through which the cable of the vibration detection component 400 (e.g., the lead wires at both ends of the pickup coil 432) is led out from the inside of the overcurrent tube 100 through the wiring hole 112 to the outside of the overcurrent tube 100.

[0109] The flow detection device provided by this invention determines the fluid flow rate by detecting the sound field intensity. Compared with the prior art, which uses a conduit to lead a branch from the main pipeline and detects the fluid velocity in the branch to determine the fluid flow rate, the focused strain gauge 300 and the vibration detection component 400 in this invention are in direct contact with the fluid in the flow pipe 100, eliminating the need for a branch from the flow pipe 100. This reduces the kinetic energy loss of the fluid flowing through the flow pipe 100, lowers the sensitivity of the flow detection device to external interference factors, thereby improving the accuracy and stability of the flow detection device in detecting fluid flow rate. Furthermore, it reduces the overall size of the flow detection device, improves the compactness of semiconductor process equipment, and enhances the convenience of machine installation, maintenance, and transmission.

[0110] To facilitate understanding by technical personnel, the following provides the specific principle of decoupling the first voltage signal U1 and the second voltage signal U2:

[0111] The transient first voltage signal U1 and the second voltage signal U2 are simultaneously input into the processing module for mutual coupling fitting. This signal processing system is an LTI (linear time-invariant system). The impulse response signal U2 exists in this LTI system, and during the normal growth of the exponential vector input through the complex exponential signal U1, it will be differentiated at a certain transient time point t0, presenting a discrete state. In fact, it is a Laplace transform of U2 on U1. For general continuous time signals, the transient signal fitting point is actually a two-sided integral of the complex exponential operator parameters in U1 and U2 over the domain from time 0 to time t0, and finally outputs the processed signal.

[0112] The mathematical model for the generation of the voltage signal and the decoupling and feedback judgment of the signal is described below:

[0113] According to Faraday's law of electromagnetic induction, the motion of a conductor cutting magnetic field lines in a static magnetic field generates a motional electromotive force (EMF). This EMF is the output voltage signal U1, and its expression is as follows:

[0114]

[0115] Substituting the parameters, we can obtain:

[0116]

[0117] Where Qm is the instantaneous flow rate, L is the length of the vibrator 420, λ is the wavelength of the sound wave emitted by the whistle 200, Δf is the frequency change of the sound wave emitted by the whistle 200, μ0 is the elastic modulus of the vibrator 420, v is the velocity of the gas flow, and ρ m This represents the gas density.

[0118] The above formula represents the motional electromotive force generated by the vibrator 420 cutting magnetic field lines in a static magnetic field, which is the signal U1 output by the vibration detection component 400.

[0119] The output change of U1 is directly related to the intensity of the sound waves collected in the sound field of the resonant cavity 410. Under the influence of the sound field, the balance between the strain force and the internal polarization force of the diaphragm 420 is broken, and it begins to cut magnetic field lines within the fixed magnetic field. At the same time, due to the continuous generation and sustained action of the sound waves, the diaphragm 420 can overcome the Lorentz force and quickly reach a stable amplitude and frequency.

[0120] As previously mentioned, the focused strain gauge 300 itself generates solid-frequency vibrations. In this physical model, it is used as a resonator, and its resonant frequency can be mathematically expressed as:

[0121] Where n is the phase coefficient, For phase drift, V R Where L is the velocity of the sound wave and L is the length of the 420mm diaphragm.

[0122] Under normal circumstances L are both constants, and there are two different thicknesses in the special structure of the 420 diaphragm; they perturb each other under the action of the sound field, and the resulting wave velocity difference can be expressed as:

[0123]

[0124] Where h is the thickness of the 420mm diaphragm, P R ρ′ is the input pressure, λ′ is the material density of the 420 diaphragm, μ′ is the Rehm constant, and μ′ is the shear modulus.

[0125] Ignoring external disturbances, the relationship between frequency change and flow rate can be derived. Combining this with Hagen-Poiseuille's law, the correspondence between voltage signal and gas flow rate can be obtained:

[0126]

[0127]

[0128] Where R is the outer diameter of the flow channel, R is the inner diameter of the flow channel, η is the gas viscosity coefficient, and l is the pipe length, we can obtain:

[0129]

[0130]

[0131] Since the analog quantities of the signals to be sought are all strains generated based on the physical properties of the materials, the law of continuous-time translation characteristics has been obtained and summarized as the variation law in the LTI system with continuous time quantity t.

[0132] After sorting, we can conclude that:

[0133]

[0134] The U2 signal is an analog signal generated by the deformation of the strain gauge inside the spherical focusing transmitter due to the surface pressure of the gas-fluid. The strain sensor used here is a resistive strain gauge. The pressure-bearing surface of the focusing strain gauge 300 acts as an elastic sensing element and is in close contact with the resistive strain gauge. It operates through a single-arm bridge model and outputs the U2 signal through the strain effect of the resistor. Its analog output can be expressed as:

[0135]

[0136] Where DR / R is the resistance change ratio, and the static characteristics of its strain system are: S is the sensitivity coefficient of the strain gauge, e x The longitudinal strain of the strain gauge.

[0137] DR / R is the dynamic change ratio of resistance, which can be expressed as:

[0138]

[0139] Among them, S x S is the longitudinal sensitivity coefficient. y e is the lateral sensitivity coefficient. y For the longitudinal strain of the strain gauge, a = e x / e y For a bidirectional strain ratio, H = S y / S x It represents the ratio of the two-way strain sensitivity coefficient.

[0140] Therefore, the output of the U2 signal can be expressed as:

[0141]

[0142] The mathematical expression for fluid flow rate is:

[0143]

[0144] Where A is the cross-sectional area of ​​the fluid flow path.

[0145] The flow parameters and the transverse and longitudinal strains generated by the surface forces on the focused strain gauge 300 are as follows:

[0146]

[0147]

[0148] Therefore, the transverse and longitudinal deformations of the strain gauge can be mathematically expressed using the flow rate as follows:

[0149]

[0150] Where ΔM is the thickness of the strain gauge, μ is Poisson's ratio, and Em is the elastic modulus of the strain gauge, after simplification we can obtain:

[0151]

[0152] In the complete signal processing system, U1 is a voltage signal generated by the vibration of the diaphragm 420 after the change in sound field generated by the change in gas flow in the resonant conduction cavity 410. Based on the material and the generation mechanism, the initial signal is a complex exponential signal. At the same time, the real and imaginary parts of the signal also represent the phase properties of the signal generation.

[0153] U2 is generated by the focused strain gauge 300. Here, the generated U2 is only related to the strain voltage generated by the change in pressure on the surface of the focused strain gauge 300 due to the change in flow rate. Since the change in flow rate cannot produce a step change but is a linear change, the output U2 also linearly reflects the magnitude of the flow rate according to the nature of strain.

[0154] U1 and U2 together form an approximately linear signal system with a region of convergence. When the effective range of values ​​is taken by discretizing the signal of U1 with U2 as the center phase maximum value, the entire signal processing system is comprehensive enough. The main signal transformation is that U1 and U2 are compared with the main function through double negative feedback and then output.

[0155] Since in the whole system, the physical model of U2 is the convergence boundary condition of U1.

[0156] The propagation relationship between U1 and U2 is determined by fitting the mutual decoupling of the signals:

[0157]

[0158] Among them G uu (U o ) is the coupling condition, which simultaneously satisfies the convergence region of values ​​[+U1, -U1].

[0159] System output signal U o It must be a non-singular quantity;

[0160] Then fit the decoupling function

[0161] For a two-variable signal processing system with boundary conditions, the boundary convergence condition is transformed into a non-singular condition matrix that restricts the coupled boundary after matrix transformation.

[0162]

[0163] The transformation conditions are:

[0164] Therefore, the voltage output signal U of the entire sensing system o It is generated by the mutual coupling of U1 and U2 under boundary conditions. The coupling conditions are:

[0165]

[0166] so:

[0167]

[0168] As a second aspect of the present invention, a flow detection method is provided, which is applied to the flow detection device provided in the embodiments of the present invention, and the flow detection method includes:

[0169] Acquire the first voltage signal U1 generated by the vibration detection component 400 and the second voltage signal U2 generated by the focused strain gauge 300;

[0170] The first voltage signal U1 and the second voltage signal U2 are decoupled to determine the flow rate of the fluid flowing through the flow tube.

[0171] The flow detection method provided by this invention determines the fluid flow rate by detecting the sound field intensity and the strain of the focused strain gauge 300. Both the focused strain gauge 300 and the vibration detection component 400 are in direct contact with the fluid in the flow pipe 100, eliminating the need for branches to be drawn from the flow pipe 100. This reduces the kinetic energy loss of the fluid flowing through the flow pipe 100 and lowers the sensitivity of the flow detection device to external interference factors (such as vibration and temperature). This improves the accuracy and stability of the flow detection device in detecting fluid flow rate, and also reduces the overall size of the flow detection device, improving the compactness of semiconductor process equipment and thus enhancing the convenience of machine installation, maintenance, and transmission.

[0172] Furthermore, this invention linearly outputs the gas flow rate value through acoustic conversion of gas flow rate. As long as the airflow can trigger the vector sound field energy conversion of the whistle 200, it can be detected. The whistle 200 can measure gas flow rates as low as 0.7 sccm and has high sensitivity to low flow and low density fluids. Therefore, the flow detection device can also detect low flow and low density fluid flow rates, thus expanding the flow detection range of the flow detection device.

[0173] Furthermore, the flow detection method provided by the present invention determines the flow rate of the fluid flowing through the flow tube 100 by performing linear signal decoupling between the first voltage signal U1 and the second voltage signal U2. The fluid flow output accuracy can reach 0.15%FS, which can significantly improve the flow detection accuracy of the flow detection device.

[0174] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A flow detection device, characterized in that, The system includes a flow tube, a whistle, a focused strain gauge, a vibration detection component, and a processing module. The whistle is located at the inlet end of the flow tube and is used to generate an inflow sound field propagating along the inflow direction for the fluid flowing into the flow tube. The focused strain gauge has a focusing concave surface that can reflect the inflow sound field to form a focused sound field. The vibration detection component is located on the flow tube and its position corresponds to the focal point of the focused sound field. The vibration detection component is used to generate a corresponding first voltage signal based on the sound field intensity of the fluid in the flow tube. The focused strain gauge can generate a corresponding second voltage signal based on its own strain. The processing module is used to decouple the first voltage signal and the second voltage signal to determine the fluid flow rate through the flow tube.

2. The flow detection device according to claim 1, characterized in that, A mounting hole is formed on the side wall of the flow tube. The vibration detection assembly includes a resonant conduction cavity, a plurality of diaphragms fixedly disposed in the resonant conduction cavity, and at least one electromagnetic module. The resonant conduction cavity is fixedly disposed in the mounting hole. The electromagnetic module includes a magnetic strip and a pickup coil wound on the magnetic strip. The electromagnetic module is located on the side of the diaphragm away from the axis of the whistle tube. The diaphragm can vibrate under the action of the fluid in the flow tube to generate an induced electric field, thereby generating an induced electromotive force in the pickup coil, thus obtaining the first voltage signal.

3. The flow detection device according to claim 2, characterized in that, The vibrating plate is vertically arranged, and multiple thickness reduction grooves are formed on both sides of the vibrating plate. The positions of the thickness reduction grooves on both sides correspond. The thickness reduction grooves are located at the bottom end of the vibrating plate and are connected to the bottom edge of the vibrating plate. Multiple anti-snoring holes are also formed on the vibrating plate. The positions of the multiple anti-snoring holes correspond one-to-one with the multiple thickness reduction grooves, and each anti-snoring hole connects the two corresponding thickness reduction grooves on both sides.

4. The flow detection device according to claim 2, characterized in that, The resonant conduction cavity includes a mounting cylinder and a mounting block. The outer wall of the mounting cylinder is fixed in the mounting hole. The mounting block seals the end of the mounting cylinder away from the axis of the whistle tube, and the electromagnetic module is fixedly mounted on the mounting block.

5. The flow detection device according to claim 4, characterized in that, The vibration detection assembly also includes a magnetic shield, which surrounds the outer side of the plurality of electromagnetic modules around the axis of the mounting cylinder, and the magnetic shield is used to shield the magnetic field outside the magnetic shield.

6. The flow detection device according to claim 5, characterized in that, The vibration detection assembly also includes multiple energy-absorbing barrels, which are fixedly disposed on the inner wall of the mounting cylinder, and the extending direction of the energy-absorbing barrels is parallel to the axis of the mounting cylinder. The energy-absorbing barrels are used to absorb sound waves reflected from the inner wall of the mounting cylinder.

7. The flow detection device according to claim 6, characterized in that, Multiple positioning blocks are fixedly installed on the side of the mounting block facing the axis of the whistle tube. The cross-sectional shape of the energy-absorbing barrel corresponds to the shape of the positioning block, and the multiple positioning blocks are housed in the multiple energy-absorbing barrels one by one.

8. The flow detection device according to claim 6, characterized in that, The vibration detection assembly also includes a vibrating plate frame, which is fixedly disposed on the inner wall of the mounting cylinder. Multiple vibrating plates are fixedly disposed in the vibrating plate frame, and the energy-absorbing barrel is located between the vibrating plate frame and the inner wall of the mounting cylinder.

9. The flow detection device according to claim 2, characterized in that, The flow detection device further includes a clamping ring and a magnetically conductive skin. The clamping ring is sealed to the end of the mounting hole opposite to the axis of the whistle tube. The magnetically conductive skin seals the inner hole of the clamping ring and is used to shield the magnetic field outside the mounting hole.

10. The flow detection device according to any one of claims 1 to 9, characterized in that, The flow tube includes an inlet section, a constriction section, and a flared section. The constriction section is connected between the inlet section and the flared section. The cross-sectional area of ​​the constriction section gradually decreases along the fluid flow direction, and the cross-sectional area of ​​the flared section gradually increases along the fluid flow direction. The focused strain gauge is disposed on the inner wall of the constriction section, and the axis of the whistle passes through the focused concave surface.

11. A flow rate detection method, characterized in that, The flow detection method is applied to the flow detection device according to any one of claims 1 to 10, and the flow detection method includes: Acquire the first voltage signal generated by the vibration detection component and the second voltage signal generated by the focused strain gauge; The first voltage signal and the second voltage signal are decoupled to determine the flow rate of the fluid flowing through the flow tube.

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