Silicon carbide capacitive pressure sensor

Abstract

The invention relates to the technical field of pressure sensors, in particular to a silicon carbide capacitive pressure sensor which comprises a flexible shell, an insulating support is fixedly mounted on the flexible shell, a central column is fixedly mounted on the insulating support and connected with an external circuit, and a fixed electrode is fixedly mounted on the central column. A movable electrode is fixedly mounted on the flexible shell and is connected with an external circuit; a first vertical part is arranged on the fixed electrode, a second vertical part is arranged on the movable electrode, the first vertical part and the second vertical part are matched with each other to form a capacitor, the flexible shell comprises a fixed plate, a bamboo joint part is fixedly installed on the fixed plate, and a pressure bearing plate is fixedly installed on the bamboo joint part. According to the invention, the measurement range of the capacitive pressure sensor is enlarged while the manufacturing difficulty of the capacitive sensor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensors, and in particular to a silicon carbide capacitive pressure sensor. Background Art

[0002] Silicon carbide capacitive pressure sensor is a sensor that uses capacitance changes to detect pressure. Generally speaking, there are two types of capacitive pressure sensors: single capacitance pressure sensor and differential capacitance pressure sensor. Both use the micro-deformation of a conductive film to change capacitance and thus detect pressure.

[0003] Among them, the existing single capacitive pressure sensor has the form shown in the patent number: CN105136351B, the patent name is: A capacitive pressure sensor and its preparation method, which is simple to make, but is limited by the physical characteristics and mechanical properties of the material, the deformation of the conductive film is limited, so the pressure measurement range is limited. The existing differential capacitive pressure sensor has the form shown in the patent number: CN105021325B, the patent name is: Capacitive pressure sensor, although it has high measurement sensitivity and good linearity, so it can be used in a wider range of pressure measurement conditions, but because its symmetry is difficult to ensure, it is difficult to process.

[0004] To this end, a silicon carbide capacitive pressure sensor is proposed. Summary of the invention

[0005] The object of the present invention is to provide a silicon carbide capacitive pressure sensor, which reduces the difficulty of manufacturing the capacitive pressure sensor and increases the measurement range of the capacitive pressure sensor.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A silicon carbide capacitive pressure sensor comprises a flexible shell, an insulating bracket is fixedly mounted on the flexible shell, a central column is fixedly mounted on the insulating bracket, the central column is connected to an external circuit, and a fixed electrode is fixedly mounted on the central column; a movable electrode is fixedly mounted on the flexible shell, the movable electrode is connected to the external circuit; a vertical portion 1 is provided on the fixed electrode, a vertical portion 2 is provided on the movable electrode, and the vertical portion 1 and the vertical portion 2 cooperate with each other to form a capacitor.

[0008] The flexible shell includes a fixed plate, a bamboo node portion is fixedly installed on the fixed plate, and a pressure plate is fixedly installed on the bamboo node portion; a mounting hole is opened on the fixed plate, and the central column is passed through and fixedly installed in the mounting hole; the fixed electrode is fixedly installed on a side of the fixed plate close to the bamboo node portion, and the movable electrode is fixedly installed on a side of the pressure plate close to the bamboo node portion; a reset spring is fixedly installed on the pressure plate, and the other end of the reset spring is fixedly installed on the fixed plate.

[0009] Based on this setting, when the present invention is used to measure pressure, first, the movable electrode and the center column are connected to the external measurement circuit, then, the flexible housing is fixed to the frame so that the fixed electrode remains fixed, and then the movable electrode is aligned to the measurement object. At this time, the pressure of the measurement object causes the flexible housing to be compressed, so that the movable electrode is displaced relative to the fixed electrode, thereby changing the size of the relative area between the vertical part 1 and the vertical part 2, and then changing the size of the capacitance formed by them, so that the pressure of the measurement object can be obtained through the adjustment and feedback of the measurement circuit. The measurement of the present invention does not change the pole distance between the electrodes of the capacitor, but changes the size of their relative area. It can be seen from the capacitance calculation formula that the present invention can have good linearity during the measurement process.

[0010] Among them, when the pressure of the measured object causes the flexible shell to be compressed, the measured object squeezes the pressure plate, thereby compressing the reset spring, and the movable electrode moves toward the fixed motor and the fixed plate. As a result, the vertical part one and the vertical part two slide relative to each other in a staggered arrangement, increasing the area facing each other between the vertical part one and the vertical part two, so the capacitance is also increased, thereby feeding back an electrical signal to the measurement circuit to reflect the pressure.

[0011] During this process, the bamboo joints cooperate with the fixed plate and the pressure plate to wrap the fixed electrode and the movable electrode to prevent them from being disturbed by the external environment. At the same time, when the pressure plate is pressed, the bamboo joints will also be able to deform in response to shorten their own length, thereby ensuring that the movement of the movable electrode will not be blocked by the existence of the bamboo joints.

[0012] At the same time, because the pole distances of the vertical part 1 and the vertical part 2 constituting the capacitor in the present invention are unchanged, the present invention has a definite and linear electrical feedback characteristic when it is manufactured. Therefore, the present invention has low requirements for the symmetry of the vertical part 1 and the vertical part 2 during manufacture, and the assembly difficulty is low, so the manufacturing difficulty of the present invention is low. In addition, by reserving enough travel for the flexible housing, the fixed electrode and the movable electrode, the present invention can have a large measurement range, and if it is desired to increase the measurement sensitivity of the present invention, the number of the vertical part 1 and the vertical part 2 can be increased. Therefore, the present invention can have excellent measurement sensitivity and measurement range through appropriate and simple adjustment.

[0013] Preferably, the bamboo joint portion includes a plurality of connecting plates; a silicone ring is fixedly mounted on the connecting plate, and the silicone ring is used to connect two adjacent connecting plates; the cross-section of the silicone ring is V-shaped, and the V-shaped opening faces the inside of the connecting plate.

[0014] Through this arrangement, when the bamboo joint is subjected to the pressure of the measured object, the silicone ring will bend and deform, and the two ends of the V-shape of the silicone ring will approach each other, thereby shortening the spacing between the connecting plates, and thus shortening the overall length of the bamboo joint. By selecting the silicone ring, the lower elastic modulus of the silicone itself can be used to reduce the elastic force generated by the bamboo joint to resist deformation when it is deformed, thereby reducing the interference of the elastic force of the bamboo joint when it is deformed on the measurement result, and improving the measurement accuracy of the present invention. At the same time, when the pressure of the measured object is withdrawn, the silicone ring can also use its own elastic force to completely restore its original state, which is conducive to ensuring that the present invention has the same state in each measurement process, and is more conducive to avoiding the influence of external interference on the measurement result.

[0015] On this basis, a deformation groove can be opened at the bottom of the V-shape of the silicone ring. Thus, the thickness of the silicone ring at the bottom of the V-shape can be reduced, thereby reducing the elastic force caused by the silicone ring when it is deformed at this position, thereby further reducing the elastic force generated by the silicone ring when it is deformed, further reducing the interference of the elastic force of the bamboo joint deformation on the measurement result, and improving the measurement accuracy of the present invention.

[0016] In addition, by providing a connecting plate, the structural strength of the connecting plate can be utilized to improve the bending resistance of the bamboo joint, which helps to reduce the lateral displacement or bending of the bamboo joint when under pressure, thereby preventing possible damage to the components in the bamboo joint.

[0017] Preferably, a plurality of arched portions are provided on the connecting plate, and the plurality of arched portions on the same connecting plate are evenly arranged in a circular array.

[0018] The single connecting plate in the present invention is annular, and the circle where the outer diameter of the ring is located is not on the same plane as the circle where the inner diameter is located, so that the single connecting plate presents an annular shape similar to a cone. When the connecting plate of this shape is squeezed along the direction of its rotation axis, due to the squeezing between materials, the outer edge of the ring has a tendency to expand outwards, thereby increasing the outer diameter of the ring, and this tendency may cause the outer edge of the connecting plate to be torn and produce cracks.

[0019] During the measurement process of the present invention, the bamboo joint portion needs to change in length frequently. Therefore, the annular outer edge of the connecting plate will often be subjected to the above-mentioned direct extrusion force inside its material, which may cause cracks and damage to the outer edge of the connecting plate, thereby affecting the sealing degree of the closed space surrounded by the bamboo joint portion, the fixed plate and the pressure plate, and further causing the purity of the conductive medium in the closed space to be affected, and finally leading to inaccurate measurement results of the present invention.

[0020] For this purpose, an arched portion is provided on the connecting plate. When the connecting plate is squeezed along the direction of its rotation axis, the outer edge of the connecting plate attempts to expand outward, at which time the arched portion will be able to deform, the height of the arch is reduced, and the span is increased, so that the annular outer edge of the connecting plate can expand to a certain extent, relieving the mutual squeezing inside the connecting plate material, thereby reducing the risk of cracking of the outer edge of the connecting plate, helping to ensure the sealing degree of the closed space surrounded by the bamboo section, the fixing plate and the pressure plate, and improving the accuracy of the measurement results of the present invention.

[0021] Preferably, a plurality of comb-teeth portions are evenly arranged on the connecting plate in a circular array, and different comb-teeth portions on adjacent connecting plates are arranged alternately with each other; the comb-teeth portions are used to limit the deformation of the silicone ring.

[0022] When the bamboo section is squeezed and its length is shortened, the volume of the closed space surrounded by the bamboo section, the fixing plate and the pressure plate will also decrease, so the medium pressure inside will also increase, and this pressure will act on the silicone ring, forcing the silicone ring to produce additional deformation. In order to avoid damage caused by this additional deformation, the silicone ring must have a certain thickness, which will cause the elastic force generated by the silicone ring when it is deformed to be greater, and the interference with the measurement result is also greater, which is not conducive to ensuring the measurement accuracy of the present invention.

[0023] Therefore, this arrangement is made. As a result, the different comb teeth on the adjacent connecting plates are staggered to block the deformation of the silicone ring toward the outside of the bamboo joint, thereby preventing the silicone ring from deforming too much in this direction, which helps to ensure that the silicone ring will not be damaged when it is subjected to the medium pressure inside the bamboo joint. At the same time, this also means that the silicone ring can be made with a smaller thickness, thereby reducing the interference of the elastic force of the silicone ring on the measurement result, and improving the measurement accuracy of the present invention.

[0024] Preferably, a slide buckle is fixedly installed on the connecting plate, a telescopic rod is fixedly installed on the fixing plate, the other end of the telescopic rod is fixedly installed on the pressure plate, and the slide buckle is sleeved on the telescopic rod; the telescopic rod is composed of a plurality of sleeves with decreasing diameters nested in sequence.

[0025] By providing a telescopic rod, the structural strength of the telescopic rod can be used to prevent the bamboo joint from bending and lateral deformation, thereby preventing the components in the bamboo joint from being damaged. At the same time, by providing a slide buckle and sleeve the slide buckle on the telescopic rod, the telescopic rod can also be used to position the connecting plate, thereby preventing the connecting plate from rotating around its rotation axis under the action of external force, thereby avoiding unnecessary shearing force on the silicone ring due to rotational dislocation of adjacent connecting plates, which is beneficial to prolonging the service life of the silicone ring and improving the reliability of the present invention.

[0026] On this basis, a flat chamfer can be provided at the edge of each sleeve of the telescopic rod, and the cross section of the slider can be made circular, so that the slider can cooperate with the flat chamfer by utilizing the curved surface shape of its surface to ensure that the slider can slide smoothly on the telescopic rod.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. By setting the vertical part 1, the vertical part 2, the flexible housing and the bamboo joint part, when the present invention is used to measure pressure, the movable electrode is aligned with the measurement object, and the pressure of the measurement object is used to change the size of the relative area between the vertical part 1 and the vertical part 2, thereby changing the size of the capacitance formed by them, so that the pressure of the measurement object can be obtained through the adjustment and feedback of the measurement circuit. The measurement of the present invention does not change the distance between the electrodes of the capacitor, but changes the size of their relative area, so that good linearity can be achieved during the measurement process.

[0029] 2. At the same time, by adopting a fixed pole distance between the vertical part 1 and the vertical part 2, the present invention has a definite and linear electrical feedback characteristic when it is manufactured. Therefore, the present invention has low requirements for the symmetry of the vertical part 1 and the vertical part 2 during manufacturing, and the difficulty of assembly is low. In addition, by reserving enough travel for the flexible housing, the fixed electrode and the movable electrode, the present invention can have a large measurement range, and if it is desired to increase the measurement sensitivity of the present invention, the number of the vertical part 1 and the vertical part 2 can be increased. Therefore, the present invention can have excellent measurement sensitivity and measurement range through appropriate and simple adjustments.

[0030] 3. By providing the connecting plate and the silicone ring, when the bamboo joint is subjected to the pressure of the measured object, the lower elastic modulus of the silicone itself can be used to reduce the elastic force generated by the bamboo joint to resist deformation when it is deformed, thereby reducing the interference of the elastic force of the bamboo joint deformation on the measurement result, and improving the measurement accuracy of the present invention. At the same time, when the pressure of the measured object is withdrawn, the silicone ring can also use its own elastic force to completely restore to its original state, which is conducive to ensuring that the present invention has the same state in each measurement process, and further conducive to avoiding the influence of external interference on the measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 for Figure 1 A partial enlarged schematic diagram of part A;

[0033] Figure 3 It is a plan front view schematic diagram of the internal structure of the present invention;

[0034] Figure 4 for Figure 3 A partial enlarged schematic diagram of part B;

[0035] Figure 5 for Figure 3 A partial enlarged schematic diagram of part C in the middle;

[0036] Figure 6 for Figure 4 Schematic diagram of the cross section of the middle DD section;

[0037] Figure 7 for Figure 4 Schematic diagram of the state after the bamboo joint is compressed;

[0038] Figure 8 for Figure 6 Schematic diagram of the state in which the arched portion is deformed when the bamboo joint portion is compressed.

[0039] In the figure: 1. center column; 2. insulating bracket; 3. fixed plate; 4. pressure plate; 5. bamboo section; 31. fixed electrode; 32. vertical section one; 41. movable electrode; 42. vertical section two; 51. connecting plate; 52. silicone ring; 53. reset spring; 54. telescopic rod; 511. arched section; 512. comb tooth section; 521. deformation groove; 541. sleeve; 542. slide buckle; 543. chamfer. DETAILED DESCRIPTION

[0040] The following content will use the drawings listed in the aforementioned "Description of the Drawings" section to clearly explain the specific implementation of the present invention, in the hope that readers can more completely and objectively understand the working principle and corresponding technical effects of the present invention. Specifically, Figures 1 to 8 As shown, a specific implementation of the present invention is shown below.

[0041] When the present invention is installed, first, the fixing plate 3, which is one of the parts of the flexible shell, is taken out, and a bamboo section 5 is fixedly installed on the fixing plate 3, and a pressure plate 4 is fixedly installed on the bamboo section 5; a mounting hole is opened on the fixing plate 3, and an insulating bracket 2 is fixedly installed on the fixing plate 3, and a central column 1 is fixedly installed on the insulating bracket 2, and the central column 1 is connected to an external circuit, and a fixed electrode 31 is fixedly installed on the central column 1; a movable electrode 41 is fixedly installed on the flexible shell, and the movable electrode 41 is connected to an external circuit; a vertical section 1 32 is provided on the fixed electrode 31, and a vertical section 2 42 is provided on the movable electrode 41, and the vertical section 1 32 and the vertical section 2 42 cooperate with each other to form a capacitor.

[0042] The central column 1 is passed through and fixedly installed in the installation hole; the fixed electrode 31 is fixedly installed on the side of the fixed plate 3 close to the bamboo section 5, and the movable electrode 41 is fixedly installed on the side of the pressure plate 4 close to the bamboo section 5; a reset spring 53 is fixedly installed on the pressure plate 4, and the other end of the reset spring 53 is fixedly installed on the fixed plate 3. The bamboo section 5 includes a plurality of connecting plates 51; a silicone ring 52 is fixedly installed on the connecting plate 51, and the silicone ring 52 is used to connect two adjacent connecting plates 51; the cross section of the silicone ring 52 is V-shaped, and the V-shaped opening faces the inside of the connecting plate 51.

[0043] In addition, a plurality of arched portions 511 are provided on the connecting plate 51, and the plurality of arched portions 511 on the same connecting plate 51 are uniformly arranged in a circular array. A deformation groove 521 is provided at the bottom of the V-shape of the silicone ring 52. A plurality of comb teeth 512 are uniformly arranged in a circular array on the connecting plate 51, and different comb teeth 512 on adjacent connecting plates 51 are arranged alternately; the comb teeth 512 are used to limit the deformation of the silicone ring 52. A slide buckle 542 is fixedly installed on the connecting plate 51, a telescopic rod 54 is fixedly installed on the fixed plate 3, the other end of the telescopic rod 54 is fixedly installed on the pressure plate 4, and the slide buckle 542 is sleeved on the telescopic rod 54; the telescopic rod 54 is composed of a plurality of sleeves 541 with decreasing diameters nested in sequence. A flat chamfer 543 is provided at the edge of each sleeve 541 of the telescopic rod 54; the cross section of the slide buckle 542 is circular.

[0044] When the present invention is working, firstly, the movable electrode 41 and the center column 1 are connected to the external measurement circuit, then, the flexible shell is fixed to the frame so that the fixed electrode 31 remains fixed, and then the movable electrode 41 is aligned to the measurement object. At this time, the pressure of the measurement object causes the flexible shell to be compressed, so that the movable electrode 41 is displaced relative to the fixed electrode 31, thereby changing the size of the relative area between the vertical part 1 32 and the vertical part 2 42, and then changing the size of the capacitance formed by them, so that the pressure of the measurement object can be obtained through the adjustment and feedback of the measurement circuit. The measurement of the present invention does not change the pole distance between the electrodes of the capacitor, but changes the size of their relative area. It can be seen from the capacitance calculation formula that the present invention can have good linearity during the measurement process.

[0045] Among them, when the pressure of the measured object causes the flexible shell to be compressed, the measured object squeezes the pressure plate 4, thereby compressing the reset spring 53, and the movable electrode 41 moves toward the fixed motor and the fixed plate 3, so that the vertical part 1 32 and the vertical part 2 42 slide relative to each other in a staggered arrangement, thereby increasing the facing area between the vertical part 1 32 and the vertical part 2 42, so the capacitance is also increased, thereby feeding back an electrical signal to the measurement circuit to reflect the pressure.

[0046] During this process, the bamboo joint 5 cooperates with the fixed plate 3 and the pressure plate 4 from beginning to end to wrap the fixed electrode 31 and the movable electrode 41 inside to prevent them from being disturbed by the external environment. At the same time, when the pressure plate 4 is pressed, the bamboo joint 5 will also be able to deform in response to shorten its own length, thereby ensuring that the movement of the movable electrode 41 will not be blocked by the existence of the bamboo joint 5.

[0047] At the same time, because the pole pitch of the vertical part 1 32 and the vertical part 2 42 constituting the capacitor in the present invention is unchanged, the present invention has a definite and linear electrical feedback characteristic when it is manufactured. Therefore, the present invention has low requirements for the symmetry of the vertical part 1 32 and the vertical part 2 42 during manufacturing, and the assembly difficulty is low, so the manufacturing difficulty of the present invention is low. In addition, by reserving enough travel for the flexible housing, the fixed electrode 31 and the movable electrode 41, the present invention can have a large measurement range, and if it is desired to increase the measurement sensitivity of the present invention, the number of the vertical part 1 32 and the vertical part 2 42 can be increased. Therefore, the present invention can have excellent measurement sensitivity and measurement range through appropriate and simple adjustments.

[0048] In addition, when the bamboo section 5 is subjected to the pressure of the measured object, the silicone ring 52 will bend and deform, and the two ends of the V-shape of the silicone ring 52 will be close to each other, so that the spacing between the connecting plates 51 is shortened, and the overall length of the bamboo section 5 is shortened. By selecting the silicone ring 52, the lower elastic modulus of the silicone itself can be used to reduce the elastic force generated by the bamboo section 5 when it is deformed to resist deformation, thereby reducing the interference of the elastic force of the bamboo section 5 when it is deformed on the measurement result, and improving the measurement accuracy of the present invention. At the same time, when the pressure of the measured object is withdrawn, the silicone ring 52 can also use its own elastic force to completely restore to its original state, which is conducive to ensuring that the present invention has the same state in each measurement process, and is more conducive to avoiding the influence of external interference on the measurement result.

[0049] On this basis, a deformation groove 521 can be opened at the bottom of the V-shape of the silicone ring 52. Thus, the thickness of the silicone ring 52 at the bottom of the V-shape can be reduced, thereby reducing the elastic force caused by the silicone ring 52 when it is deformed at this position, thereby further reducing the elastic force generated by the silicone ring 52 when it is deformed, further reducing the interference of the elastic force of the bamboo section 5 when it is deformed on the measurement result, and improving the measurement accuracy of the present invention.

[0050] In addition, by providing the connecting plate 51, the structural strength of the connecting plate 51 can be utilized to improve the bending resistance of the bamboo joint 5, which helps to reduce the lateral displacement or bending of the bamboo joint 5 when under pressure, thereby preventing the components in the bamboo joint 5 from being damaged.

[0051] It is worth adding that the single connecting plate 51 in the present invention is annular, and the circle where the outer diameter of the ring is located is not on the same plane as the circle where the inner diameter is located, so that the single connecting plate 51 presents an annular shape similar to a cone. When the connecting plate 51 of this shape is squeezed along the direction of its rotation axis, due to the squeezing between the materials, the outer edge of the ring has a tendency to expand outward, thereby increasing the outer diameter of the ring, and this tendency may cause the outer edge of the connecting plate 51 to be torn and cracks to be generated. During the measurement process of the present invention, the bamboo section 5 needs to change in length frequently, so the annular outer edge of the connecting plate 51 will also often bear the above-mentioned direct squeezing force inside its material, which may cause the outer edge of the connecting plate 51 to crack and be damaged, thereby affecting the sealing degree of the closed space surrounded by the bamboo section 5, the fixing plate 3 and the pressure plate 4, and then causing the purity of the conductive medium in the closed space to be affected, and finally causing the inaccurate measurement results of the present invention.

[0052] For this purpose, an arched portion 511 is provided on the connecting plate 51, as shown in FIG. Figure 4 , Figure 6 and Figure 8When the connecting plate 51 is squeezed along the direction of its rotation axis, the outer edge of the connecting plate 51 attempts to expand outward. At this time, the arched portion 511 will be able to deform, the height of the arch is reduced, and the span is increased, so that the annular outer edge of the connecting plate 51 can expand to a certain extent, relieving the mutual squeezing of the materials inside the connecting plate 51, thereby reducing the risk of cracking of the outer edge of the connecting plate 51, helping to ensure the sealing degree of the closed space surrounded by the bamboo section 5, the fixing plate 3 and the pressure plate 4, and improving the accuracy of the measurement results of the present invention.

[0053] It should be emphasized that, based on the contents recorded in the above text, although the beneficial effects of the present invention have been elaborated in detail and corresponding specific implementation methods have been provided for this purpose, ordinary technicians in this field can still make conventional substitutions, deformations, etc. based on the given technical solutions without creative labor to achieve the same technical effects, based on the full understanding of the working principle of the present invention, but this should not be considered to exceed the scope of the present invention. Specifically, the scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A silicon carbide capacitive pressure sensor, characterized in that: The invention comprises a flexible shell, an insulating bracket (2) is fixedly mounted on the flexible shell, a central column (1) is fixedly mounted on the insulating bracket (2), the central column (1) is connected to an external circuit, and a fixed electrode (31) is fixedly mounted on the central column (1); a movable electrode (41) is fixedly mounted on the flexible shell, the movable electrode (41) is connected to an external circuit; a vertical portion 1 (32) is arranged on the fixed electrode (31), a vertical portion 2 (42) is arranged on the movable electrode (41), and the vertical portion 1 (32) and the vertical portion 2 (42) cooperate with each other to form a capacitor.

2. A silicon carbide capacitive pressure sensor according to claim 1, characterized in that: The flexible shell comprises a fixing plate (3), a bamboo joint (5) is fixedly mounted on the fixing plate (3), and a pressure-bearing plate (4) is fixedly mounted on the bamboo joint (5); a mounting hole is opened on the fixing plate (3), and the central column (1) is passed through and fixedly mounted in the mounting hole; the fixed electrode (31) is fixedly mounted on a side of the fixing plate (3) close to the bamboo joint (5), and the movable electrode (41) is fixedly mounted on a side of the pressure-bearing plate (4) close to the bamboo joint (5); a return spring (53) is fixedly mounted on the pressure-bearing plate (4), and the other end of the return spring (53) is fixedly mounted on the fixing plate (3).

3. A silicon carbide capacitive pressure sensor according to claim 2, characterized in that: The bamboo joint portion (5) comprises a plurality of connecting plates (51); a silicone ring (52) is fixedly mounted on the connecting plate (51), and the silicone ring (52) is used to connect two adjacent connecting plates (51); the cross section of the silicone ring (52) is V-shaped, and the V-shaped opening faces the inside of the connecting plate (51).

4. The silicon carbide capacitive pressure sensor according to claim 3, characterized in that: A plurality of arched portions (511) are provided on the connecting plate (51), and the plurality of arched portions (511) on the same connecting plate (51) are evenly arranged in a ring array.

5. The silicon carbide capacitive pressure sensor according to claim 3, characterized in that: A deformation groove (521) is provided at the bottom of the V-shape of the silicone ring (52).

6. The silicon carbide capacitive pressure sensor according to claim 3, characterized in that: A plurality of comb teeth (512) are evenly arranged on the connection plate (51) in a ring array, and different comb teeth (512) on adjacent connection plates (51) are arranged in an interlaced manner; the comb teeth (512) are used to limit the deformation of the silicone ring (52).

7. The silicon carbide capacitive pressure sensor according to claim 5, characterized in that: A sliding buckle (542) is fixedly mounted on the connecting plate (51), a telescopic rod (54) is fixedly mounted on the fixing plate (3), the other end of the telescopic rod (54) is fixedly mounted on the pressure bearing plate (4), and the sliding buckle (542) is sleeved on the telescopic rod (54); the telescopic rod (54) is composed of a plurality of sleeves (541) of decreasing diameters which are nested in sequence.

8. The silicon carbide capacitive pressure sensor according to claim 5, characterized in that: A flat chamfer (543) is provided at the edge of each sleeve (541) of the telescopic rod (54); and the cross section of the sliding buckle (542) is circular.

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