A pressure sensor

Abstract

The application relates to the technical field of sensors, in particular to a pressure sensor, an elastic body is arranged at the bottom of a pressure-sensitive diaphragm, a MEMS reflecting block is arranged at the bottom of the pressure-sensitive diaphragm and abuts against the elastic body, a collimator is arranged at the bottom of the MEMS reflecting block, the reflecting end surface of the MEMS reflecting block faces the collimator, the collimator is used for measuring the distance between the reflecting end surface of the MEMS reflecting block and the collimator, a base is arranged at the bottom of the collimator, wherein after the collimator measures the distance between the reflecting end surface of the MEMS reflecting block and the collimator, interference light signals carrying distance change information are generated and are transmitted to the outside of the base through an optical fiber, the distance change is analyzed through F-P demodulation technology, and the external fluid pressure is reversely deduced. The use of the pressure sensor is not limited to the temperature environment, the pressure sensor can be normally used under extreme temperature, meanwhile, the silicon oil used in the prior art is abandoned, the cavity does not need to guarantee sealing performance, and the structure is optimized.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a pressure sensor. Background Technology

[0002] Surface pressure sensors are sensors that measure the pressure of external fluids. Common surface pressure sensors on the market use a diaphragm to seal silicone oil within a sealed cavity. When external fluid pressure acts on the diaphragm, the diaphragm transmits the pressure to the inside of the cavity, compressing the silicone oil. The external fluid pressure can then be calculated by measuring the silicone oil pressure. Because this type of surface pressure sensor requires its sealed cavity to be filled with silicone oil, it is crucial to ensure both the cavity's sealing performance and the absolute fullness of the silicone oil. Failure to do so will lead to measurement errors. Furthermore, silicone oil solidifies and freezes at low temperatures (below -50 degrees Celsius), making these sensors unusable in cold environments. Therefore, there is a lack of pressure sensors in current technology that can operate in low-temperature environments. Summary of the Invention

[0003] This invention provides a pressure sensor to solve the technical problem of how to provide a pressure sensor that can be used in low-temperature environments.

[0004] This invention provides a pressure sensor, comprising: Pressure-sensitive diaphragm; An elastomer is disposed at the bottom of the pressure-sensitive diaphragm; MEMS reflector block, the MEMS reflector block is set at the bottom of the pressure-sensitive diaphragm and abuts against the elastomer; A collimator is located at the bottom of the MEMS reflector block, with the reflective end face of the MEMS reflector block aligned with the collimator. The collimator is used to measure the distance between the reflective end face of the MEMS reflector block and the collimator. The base is located at the bottom of the collimator; The collimator measures the distance between the reflective end face of the MEMS reflector and the reflector, generating an interference light signal that carries the distance change information. This signal is then transmitted to the outside of the base via optical fiber. The distance change is analyzed using FP demodulation technology, and the external fluid pressure is deduced from the result.

[0005] In one embodiment, the elastomer is disposed on the base, and the elastomer includes: An intermediate mass block, the top of which abuts against the bottom of the pressure-sensitive diaphragm, and a through hole is provided on the intermediate mass block, with the MEMS reflector block installed inside the through hole; Deformable beams, one end of which is connected to the central mass block, and multiple sets of deformable beams are set up circumferentially with the central mass block as the center. The other end of the deformable beam is connected to the ring structure.

[0006] In one embodiment, the deformable beam includes: The main stiffness beams are arranged in multiple sets and distributed radially along the annular structure. Auxiliary stiffness beams are provided in multiple sets and are distributed radially along the annular structure.

[0007] In one embodiment, the width of the main stiffness beam is equal to the width of the auxiliary stiffness beam, and the thickness of the main stiffness beam is greater than the thickness of the auxiliary stiffness beam.

[0008] In one embodiment, one end of the main stiffness beam is connected to the intermediate mass block via a set of flexible hinges, and the other end is connected to the ring structure via another set of flexible hinges. One end of the auxiliary stiffness beam is connected to the intermediate mass block via a set of flexible hinges, and the other end is connected to the ring structure via another set of flexible hinges.

[0009] In one embodiment, the connection ends of the main stiffness beam, auxiliary stiffness beam, and ring structure with the flexible hinge all adopt rounded transitions, and the end thickness of the flexible hinge is greater than the thickness of the middle part.

[0010] In one embodiment, a pressure guide rod is installed at the bottom of the pressure-sensitive diaphragm, with one end of the pressure guide rod abutting against the intermediate mass block and the other end abutting against the annular structure.

[0011] In one embodiment, a cable outlet seat is installed on the base for carrying cables, and a fixing plate is also provided on the base. The pressure-sensitive diaphragm is fixed to the annular structure by a diaphragm pressure ring.

[0012] In one embodiment, both the main stiffness beam and the auxiliary stiffness beam have I-shaped or arc-shaped cross sections.

[0013] In one embodiment, a temperature compensation sheet is disposed inside the elastomer.

[0014] Compared with the prior art, the advantages of this invention are as follows: by opening a through hole in the middle of the intermediate mass block, setting a MEMS reflector block at the top of the through hole, and setting a collimator at the bottom to form a cavity, the distance between the reflective end face of the MEMS reflector block and the collimator is an initial value when not subjected to external pressure. When subjected to external pressure, the pressure-sensitive diaphragm transmits the pressure to the elastic body, causing the elastic body to bend and drive the MEMS reflector block to move downward. At this time, the distance between the reflective end face of the MEMS reflector block and the collimator changes. The collimator generates an interference light signal that indicates the distance change, which is transmitted to the outside of the base through an optical fiber. The distance change is analyzed by FP demodulation technology to calculate the fluid pressure. The pressure sensor of this invention is not limited by the temperature environment and can be used normally in extreme temperatures. At the same time, it eliminates the use of silicone oil used in the prior art, so that the cavity does not need to guarantee sealing performance, thus optimizing the structure. Attached Figure Description

[0015] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of a pressure sensor according to the present invention; Figure 2 This is a schematic diagram of the structure of the elastic body in a pressure sensor according to the present invention.

[0017] Figure 3 This is a schematic diagram of the pressure guide rod in a pressure sensor according to the present invention.

[0018] Reference numerals: 1. Pressure-sensitive diaphragm; 2. Elastomer; 21. Intermediate mass block; 22. Deformable beam; 221. Main stiffness beam; 222. Auxiliary stiffness beam; 23. Ring structure; 3. MEMS reflector; 4. Collimator; 5. Base; 6. Pressure guide rod; 7. Cable outlet seat; 8. Fixing plate; 9. Diaphragm pressure ring; 10. Flexible hinge. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0021] As described in the background section, existing pressure sensors utilize a diaphragm to seal silicone oil within a sealed cavity. When external fluid pressure acts on the diaphragm, the diaphragm transmits the pressure to the interior of the cavity, compressing the volume of the silicone oil. The external fluid pressure can then be calculated by measuring the silicone oil pressure. Because this type of surface pressure sensor requires its sealed cavity to be filled with silicone oil, it is crucial to ensure both the cavity's sealing performance and the complete filling of the cavity with silicone oil. Otherwise, measurement errors will occur. Furthermore, silicone oil solidifies and freezes at low temperatures (below -50 degrees Celsius), rendering this type of sensor unusable in low-temperature environments.

[0022] To solve the above problems, refer to Figures 1-3This invention provides a pressure sensor, comprising: a pressure-sensing diaphragm 1, an elastic body 2, a MEMS reflector 3, a collimator 4, and a base 5. The elastic body 2 is disposed at the bottom of the pressure-sensing diaphragm 1, the MEMS reflector 3 is disposed at the bottom of the pressure-sensing diaphragm 1 and abuts against the elastic body 2, the collimator 4 is disposed at the bottom of the MEMS reflector 3, and the reflective end face of the MEMS reflector 3 is aligned with the collimator 4. The collimator 4 is used to measure the distance between the reflective end face of the MEMS reflector 3 and the collimator 4. The base 5 is disposed at the bottom of the collimator 4. After measuring the distance between the reflective end face of the MEMS reflector 3 and the collimator 4, an interference light signal carrying distance change information is generated and transmitted to the outside of the base 5 through an optical fiber. The distance change is analyzed by FP demodulation technology to deduce the external fluid pressure.

[0023] Specifically, one end of the MEMS reflector 3 abuts against the pressure-sensitive diaphragm 1, and the other end (i.e., the reflective end face) is aligned with the collimator 4. Initially, the distance between the reflective end face and the collimator 4 is an initial value, i.e., the pressure is zero. When the pressure of the external fluid acts on the pressure-sensitive diaphragm 1, the pressure-sensitive diaphragm 1 transmits the pressure to the MEMS reflector 3. The MEMS reflector 3 moves downward, shortening the distance between itself and the collimator 4. At this time, the elastic body 2 bends under the pressure of the MEMS reflector 3. The collimator 4 converts the distance between itself and the reflective end face into an interference light signal, which is transmitted to the outside of the base 5 through the optical fiber. The distance change is analyzed by FP demodulation technology, and the external fluid pressure is deduced. When the external fluid pressure disappears, the MEMS reflector 3 resets under the action of the elastic body 2.

[0024] Furthermore, the core of FP demodulation is to analyze the output interference signal of the Fabry-Perot interferometer cavity, deduce the cavity length change, and ultimately calculate the external pressure. Its measurement logic chain is: external pressure → deformation of elastic body 2 → change in FP cavity length → change in interference signal → demodulation analysis → pressure deduction. The aforementioned Fabry-Perot interferometer cavity is composed of the reflective end face of the MEMS reflector 3, the fiber collimator 4, and the through-hole on the elastic body 2.

[0025] Furthermore, the FP demodulation technology used in this invention can specifically be... 1. Spectral Scanning Method: This method utilizes broadband light (such as white light or broadband LED) incident on the FP cavity. An interference spectrum is scanned using a spectrometer to locate the wavelength shift of interference peaks / valleys, thus inferring the cavity length change. Specific operational steps: Light Source and Incident Light: A broadband light source is coupled to the collimator 4 of the sensor via an optical fiber, ensuring the light is perpendicularly incident on the reflective end face of the MEMS reflector block 3. Interference and Spectral Acquisition: Light undergoes multiple reflections / transmissions within the FP cavity, forming multi-beam interference. The interference spectrum emitted from the collimator 4 is acquired using a fiber optic spectrometer. The cavity length is then calculated. Data obtained from a pre-set calibration experiment (applying a known pressure to the sensor and recording the corresponding cavity length change) establishes the correlation between the cavity length change and the pressure. Finally, the external fluid pressure can be inferred from the cavity length change.

[0026] 2. White light interferometry utilizes the extremely short coherence length of white light. Clear interference fringes are only produced when the optical path difference of the piezoelectric cavity approaches zero. The cavity length is then deduced by finding this location. First, a reference arm and interferometry system are constructed. A reference interferometry arm is built outside the sensor, forming a double-FP interferometry system with the sensor's FP cavity. White light is incident on the double interferometry system, and the optical path difference of the reference arm is changed by slowly moving the reflector of the reference arm through a piezoelectric ceramic. The clearest interference fringes appear when the optical path difference of the sensor's FP cavity matches that of the reference arm. At this point, the optical path difference of the reference arm equals the optical path difference of the sensor's FP cavity. By observing the change in the optical path difference of the reference arm, the optical path difference of the sensor's FP cavity is directly obtained, and the cavity length is calculated. This, combined with calibration relationships, allows for the deduction of the pressure.

[0027] 3. Frequency-modulated laser method: A linearly frequency-modulated laser is incident on the FP cavity. The frequency / phase of the output interference signal is directly related to the cavity length, and the cavity length is inversely calculated through signal processing. A narrow-linewidth semiconductor laser is used, and the laser frequency is linearly modulated with a triangular wave or sawtooth wave. The modulated laser is incident on collimator 4 through an optical fiber, and after reflection from the FP cavity, the interference intensity signal is collected by a high-speed photodetector. Signal processing and cavity length calculation are performed. A Fourier transform is performed on the collected interference signal to calculate the cavity length L. Then, the pressure value is obtained from the change in cavity length through calibration relationships.

[0028] The three FP demodulation techniques mentioned above are suitable for different measurement environments. The spectral scanning method is suitable for static, low-speed pressure monitoring, the white light interferometry method is suitable for pressure monitoring under strong interference environments, and the frequency-modulated laser method is suitable for dynamic pressure monitoring. Users can flexibly choose the appropriate method based on the structure of the sensor in this invention according to the monitoring environment.

[0029] Preferably, the elastic body 2 is disposed on the base 5, and the elastic body 2 includes: an intermediate mass block 21, a deformable beam 22 and an annular structure 23. The top of the intermediate mass block 21 abuts against the bottom of the pressure-sensitive diaphragm 1, and a through hole is provided on the intermediate mass block 21. The MEMS reflector block 3 is installed inside the through hole. One end of the deformable beam 22 is connected to the intermediate mass block 21, and multiple sets are provided. The multiple sets of deformable beams 22 are evenly arranged circumferentially with the intermediate mass block 21 as the center. The other end of the deformable beam 22 is connected to the annular structure 23.

[0030] Specifically, in a preferred embodiment, the present invention has four deformable beams 22, which are arranged in a cross-shaped structure, that is, the included angle between two adjacent deformable beams 22 is 90 degrees. When the intermediate mass block 21 is subjected to pressure and moves downward, the deformable beams 22 bend, thereby converting the pressure into the height difference between the intermediate mass block 21 and the annular structure 23. The height difference between the intermediate mass block 21 and the annular structure 23 is equal to the change in cavity length before the MEMS reflector block 3 and the collimator 4.

[0031] Preferably, the deformable beam 2 includes: a main stiffness beam 221 and an auxiliary stiffness beam 222. Multiple sets of main stiffness beams 221 are provided and are distributed radially along the annular structure 23. Multiple sets of auxiliary stiffness beams 222 are provided and are distributed radially along the annular structure 23.

[0032] Preferably, the width of the main stiffness beam 221 is equal to the width of the auxiliary stiffness beam 222, and the thickness of the main stiffness beam 221 is greater than the thickness of the auxiliary stiffness beam 222.

[0033] Specifically, in order to accommodate the measurement of pressure in a wider range, the present invention includes a main stiffness beam 221 and an auxiliary stiffness beam 222. Based on the aforementioned cross-shaped distribution structure, the main stiffness beam 221 and the auxiliary stiffness beam 222 each consist of two sets, and both sets of the main stiffness beam 221 and the auxiliary stiffness beam 222 are distributed along a straight line. The main stiffness beam 221 has a higher bending stiffness and is responsible for bearing high pressure, while the auxiliary stiffness beam 222 has a lower bending stiffness and is responsible for bearing low pressure. The arrangement of the main stiffness beam 221 and the auxiliary stiffness beam 222 achieves dual-range coverage of high pressure and low pressure, so that the pressure range of the present invention is not limited by the material of the elastomer 2.

[0034] Preferably, one end of the main stiffness beam 221 is connected to the intermediate mass block 21 through a set of flexible hinges 10, and the other end is connected to the ring structure 23 through another set of flexible hinges 10. One end of the auxiliary stiffness beam 222 is connected to the intermediate mass block 21 through a set of flexible hinges 10, and the other end is connected to the ring structure 23 through another set of flexible hinges 10.

[0035] Specifically, to avoid the high stiffness of the main stiffness beam 221 affecting the bending of the auxiliary stiffness beam 222 during micro-pressure monitoring, this invention incorporates a flexible hinge 10. The flexible hinge is a key structure for eliminating the obstruction from the main stiffness beam 221. Its design inherently involves extremely low stiffness in the deformation direction of the auxiliary stiffness beam 222, transmitting only pressure and not stiffness. Under micro-pressure, the downward movement of the intermediate mass block 21 is entirely dominated by the auxiliary stiffness beam 222, while the main stiffness beam 221 is isolated from the intermediate mass block 21 via the flexible hinge 10, thus preventing interference with the mass block's movement. In other words, under micro-pressure, the auxiliary stiffness beam 222 bends, causing the intermediate mass block 21 to move downwards, while the flexible hinge 10 connecting the main stiffness beam 221 and the intermediate mass block 21 rotates, preventing the rigidity of the main stiffness beam 221 from interfering with the movement of the intermediate mass block 21.

[0036] Furthermore, the flexible hinge 10 enables graded measurement and also prevents excessive stress concentration at the connection between the main stiffness beam 221 and the auxiliary stiffness beam 222 and the intermediate mass block 21, which could lead to fatigue cracking at the root of the main stiffness beam 221 and the auxiliary stiffness beam 222 after long-term use.

[0037] Preferably, the connection ends of the main stiffness beam 221, the auxiliary stiffness beam 222 and the ring structure 23 with the flexible hinge 10 are all rounded, and the thickness of the end of the flexible hinge 10 is greater than the thickness of the middle part.

[0038] Specifically, the connection ends of the flexible hinge 10 all adopt rounded corner transitions, which can avoid stress concentration caused by the use of right-angle transitions in the prior art. At the same time, the structure of the flexible hinge 10, which is thin in the middle and thick on both sides, can further optimize the stress distribution. The structure of being thin in the middle and thick on both sides ensures that the main stiffness beam 221 and the auxiliary stiffness beam 222 are almost not interfered with by the flexible hinge 10 in the vertical bending direction, while the horizontal movement will be subject to greater resistance. This structure also further realizes that when the auxiliary stiffness beam 222 bends, the flexible hinge 10 on the main stiffness beam 221 rotates without interfering with the bending of the auxiliary stiffness beam 222.

[0039] Furthermore, the intermediate mass block 21 is connected to two main stiffness beams 221 and two auxiliary stiffness beams 222 respectively through four flexible hinges. Under slight pressure, only the auxiliary stiffness beams 222 bend, while the two flexible hinges 10 corresponding to the main stiffness beams 221 rotate, and the main stiffness beams 221 remain stationary and rigid. Under high pressure, the two flexible hinges 10 corresponding to the main beams bend and rotate with the main stiffness beams 221, while the hinges corresponding to the auxiliary stiffness beams 222 stop rotating due to the elastic saturation of the auxiliary stiffness beams 222, thus achieving smooth range switching.

[0040] Preferably, a pressure guide rod 6 is installed at the bottom of the pressure-sensitive diaphragm 1, with one end of the pressure guide rod 6 abutting against the intermediate mass block 21 and the other end abutting against the annular structure 23.

[0041] Specifically, the pressure guide rod 6 is supported below the entire pressure-sensitive diaphragm 1, and does not only abut against the center of the pressure-sensitive diaphragm 1. When external fluid pressure acts on any position on the pressure-sensitive diaphragm 1, the deformation of the pressure-sensitive diaphragm 1 will disperse and evenly transmit the pressure to the pressure guide rod 6 through its own mechanical properties. As an intermediate force transmission component, the pressure guide rod 6 can integrate the pressure transmitted from different positions of the pressure-sensitive diaphragm 1 and stably transmit it to the intermediate mass block 21 of the elastic body 2, avoiding uneven force transmission due to force position deviation.

[0042] Furthermore, the elastic body 2 adopts a cross-shaped deformable beam structure. This symmetrical design ensures that regardless of whether the pressure on the intermediate mass block 21 originates from the center or edge of the pressure-sensitive diaphragm 1, the bending deformation of the main stiffness beam 221 or the auxiliary stiffness beam 222 will occur in a centrally symmetrical manner. In other words, the deformation pattern of the main stiffness beam 221 or the auxiliary stiffness beam 222 is determined by the overall magnitude of the force, not by the specific location of the force. Therefore, the height difference between the intermediate mass block 21 and the annular structure 23 is only related to the magnitude of the pressure, and is independent of the location of the pressure on the pressure-sensitive diaphragm 1.

[0043] Preferably, a cable outlet seat 7 is installed on the base 5, which is used to carry the cable. A fixing plate 8 is also provided on the base 5, and the pressure-sensitive diaphragm 1 is fixed on the annular structure 23 by the diaphragm pressure ring 9.

[0044] Specifically, the cable of collimator 4 is connected to an external device through cable outlet 7 to transmit interference light signals, and the fixing plate 8 is used to fix the base 5.

[0045] Preferably, the cross sections of the main stiffness beam 221 and the auxiliary stiffness beam 222 are both I-shaped or arc-shaped.

[0046] Specifically, in existing technologies, a rectangular cross-section deformable beam 22 is often used. The connection between the rectangular cross-section deformable beam 22 and the mass block 21 or the ring structure 23 is a right-angle transition, which easily generates local stress peaks under stress. Long-term use can easily lead to fatigue cracking. At the same time, the bending stiffness of the rectangular cross-section has a slight nonlinearity with the increase of deformation, which leads to deviation in the pressure-displacement conversion relationship and affects the accuracy of FP cavity length measurement. Therefore, this invention uses an I-shaped or arc-shaped deformable beam 22. The I-shaped cross-section expands the stress area through the flange and ensures the bending stiffness through the web, making the stress distribution of the deformable beam 22 more uniform and improving the bending linearity by 15%-20%. The arc-shaped profile of the arc-shaped cross-section can disperse the local stress peaks to the entire arc surface, significantly reducing the stress concentration factor. At the same time, the arc deformation-displacement curve is closer to the ideal linearity, resulting in higher accuracy of FP cavity length measurement.

[0047] Preferably, the elastomer 2 has a temperature compensation sheet inside.

[0048] Specifically, in the prior art, the elastomer 2 is a solid structure. Although the FP cavity itself is less affected by temperature, the elastomer material has the characteristic of thermal expansion and contraction. The technical solution of the present invention is designed for low-temperature environments. In low-temperature environments, the elastomer 2 will shrink, causing measurement errors in the FP cavity length. Therefore, the present invention provides a temperature compensation plate inside the elastomer 2 to avoid deformation of the elastomer 2 that would cause measurement errors in the FP cavity length. At the same time, due to the setting of the temperature compensation plate, the pressure sensor of the present invention can be used for fluid pressure monitoring in more medium-temperature environments.

[0049] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pressure sensor, characterized in that, include: Pressure-sensitive diaphragm (1); An elastomer (2) is disposed at the bottom of the pressure-sensitive diaphragm (1); MEMS reflective block (3), the MEMS reflective block (3) is disposed at the bottom of the pressure-sensitive diaphragm (1) and abuts against the elastomer (2); Collimator (4), the collimator (4) is disposed at the bottom of the MEMS reflector (3), the reflective end face of the MEMS reflector (3) is directly facing the collimator (4), the collimator (4) is used to measure the distance between the reflective end face of the MEMS reflector (3) and the collimator (4); A base (5) is disposed at the bottom of the collimator (4); The collimator (4) measures the distance between the reflective end face of the MEMS reflector (3) and the reflector, and generates an interference light signal carrying distance change information. The signal is transmitted to the outside of the base (5) through an optical fiber. The distance change is analyzed by FP demodulation technology, and the external fluid pressure is deduced.

2. A pressure sensor according to claim 1, characterized in that, The elastomer (2) is disposed on the base (5), and the elastomer (2) comprises: An intermediate mass block (21) is provided, the top of which abuts against the bottom of the pressure-sensitive diaphragm (1), and a through hole is provided on the intermediate mass block (21), and the MEMS reflector (3) is installed inside the through hole; Deformable beam (22), one end of which is connected to the intermediate mass block (21), and multiple sets of the deformable beam (22) are provided, with the multiple sets of the deformable beam (22) being evenly arranged circumferentially with the intermediate mass block (21) as the center; The other end of the deformable beam (22) is connected to the annular structure (23).

3. A pressure sensor according to claim 2, characterized in that, The deformable beam (22) includes: Main stiffness beam (221), wherein multiple sets of main stiffness beam (221) are provided and distributed radially along the annular structure (23); Auxiliary stiffness beams (222) are provided in multiple sets and are distributed radially along the annular structure (23).

4. A pressure sensor according to claim 3, characterized in that, The width of the main stiffness beam (221) is equal to the width of the auxiliary stiffness beam (222), and the thickness of the main stiffness beam (221) is greater than the thickness of the auxiliary stiffness beam (222).

5. A pressure sensor according to claim 4, characterized in that, One end of the main stiffness beam (221) is connected to the intermediate mass block (21) through a set of flexible hinges (10), and the other end is connected to the ring structure (23) through another set of flexible hinges (10). One end of the auxiliary stiffness beam (222) is connected to the intermediate mass block (21) through a set of flexible hinges (10), and the other end is connected to the ring structure (23) through another set of flexible hinges (10).

6. A pressure sensor according to claim 5, characterized in that, The connection ends of the main stiffness beam (221), auxiliary stiffness beam (222) and ring structure (23) with the flexible hinge (10) are all rounded, and the end thickness of the flexible hinge (10) is greater than the middle thickness.

7. A pressure sensor according to claim 2, characterized in that, A pressure guide rod (6) is installed at the bottom of the pressure-sensitive diaphragm (1). One end of the pressure guide rod (6) abuts against the intermediate mass block (21), and the other end abuts against the annular structure (23).

8. A pressure sensor according to claim 2, characterized in that, The base (5) is equipped with a cable outlet seat (7), which is used to carry cables. The base (5) is also provided with a fixing plate (8). The pressure-sensitive diaphragm (1) is fixed on the annular structure (23) by a diaphragm pressure ring (9).

9. A pressure sensor according to claim 3, characterized in that, The cross sections of the main stiffness beam (221) and the auxiliary stiffness beam (222) are both I-shaped or arc-shaped.

10. A pressure sensor according to claim 1, characterized in that, The elastomer (2) has a temperature compensation plate inside.

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