A pressure sensor

Abstract

The present invention relates to the technical field of pressure sensors, in particular to a pressure sensor; comprising a housing, an induction coil, a vibrating string and two string end clamping assemblies, wherein the induction coil and the vibrating string are both arranged on the inner middle side of the housing, and the two string end clamping assemblies are oppositely installed on the inner sides of the housing; the vibrating string comprises a vibrating string body, both ends of the vibrating string body are integrally formed with spherical ends, and the spherical ends are movably connected in the string end clamping assemblies; the present application can control the stretching and contraction of the vibrating string on the basis of ensuring the overall sealing of the device and maintaining a constant distance between the vibrating string and the induction coil, and can deal with the deformation of the length of the vibrating string caused by the temperature increase or temperature decrease, and can make a large-scale correction and adjustment to the vibration frequency of the vibrating string, thereby increasing the detection accuracy of the pressure sensor.

Description

Technical Field

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

[0002] Vibrating string pressure sensors have the characteristics of high precision, high stability, wide measurement range and fast response, but they are sensitive to temperature changes. Fluctuations in ambient temperature may cause deviations in the sensor output frequency, affecting the measurement accuracy.

[0003] In order to correct the influence of temperature change on the vibration frequency of the vibrating string, the existing patent document with application number CN201710919061.1 discloses a temperature influence correction method for a vibrating string pressure sensor. In the patent document, a scheme of clamping the end of the vibrating string with an elastic member is disclosed. By applying pressure to the elastic member, the original vibration frequency of the vibrating string is changed. Specifically, the following steps are included: measuring the original length l and cross-sectional area s of the test vibrating string and the cross-sectional area A of the elastic body; tightening the test vibrating string and fixing its two ends on the elastic body; measuring the initial first vibration frequency f0 of the test vibrating string; applying a test external force to the elastic body, measuring the temperature change of the test vibrating string during the application of the test external force as t, measuring the second vibration frequency of the test vibrating string as f, analyzing the frequency difference, and correcting the error;

[0004] However, when using the technical solution in the above patent document, the elastic part will age over time, affecting the service life of the sensor, and the elastic part has a limited degree of deformability, so only compression force but not tension force can be applied to it, resulting in a limited adjustment range of the vibration frequency of the vibrating string. Therefore, the present application provides a pressure sensor. Summary of the invention

[0005] In order to solve the deficiencies in the above-mentioned prior art, the object of the present invention is to provide a pressure sensor, which can control the stretching and contraction of the vibrating string on the basis of ensuring the overall sealing of the device and maintaining a constant distance between the vibrating string and the induction coil, and can deal with the deformation of the vibrating string caused by the increase or decrease in temperature on the length of the vibrating string itself, and can make a large-scale correction and adjustment to the vibration frequency of the vibrating string, thereby increasing the detection accuracy of the pressure sensor.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] A pressure sensor is provided, comprising a housing, an induction coil, a vibrating string and two string end clamping assemblies, wherein the induction coil and the vibrating string are both arranged on the inner middle side of the housing, and the two string end clamping assemblies are oppositely installed on the inner sides of the housing; the vibrating string comprises a vibrating string body, both ends of the vibrating string body are integrally formed with spherical ends, and the spherical ends are movably connected in the string end clamping assemblies.

[0008] Furthermore, the string end clamping assembly includes a fixed seat, on which a sliding seat is slidably mounted, the sliding seat is connected to a string frame via a shock-absorbing gasket, a plurality of string clamps are mounted at equal angles on the side of the string frame, and the string clamps are provided with a concave surface matching the outer side surface of the spherical end.

[0009] Furthermore, a slide post is fixedly mounted on the string clamp, the slide post is slidably connected to the string frame, a stud is rotatably mounted on the string clamp, and the stud is connected to the string frame through threaded transmission.

[0010] Furthermore, a groove is provided in the fixed seat, the sliding seat is slidably installed in the groove, and a baffle is detachably fixedly installed at the end of the groove. The sealing cover includes a primary sealing cover and a secondary sealing cover. A stepped shaft rod is rotatably installed in the middle of the primary sealing cover and the secondary sealing cover. The stepped shaft rod penetrates the baffle and is rotatably connected to the baffle. The end of the stepped shaft rod is connected to a gear through a key, and the gear and the rack are connected through meshing transmission. The rack is fixedly installed on the sliding seat; the other end of the stepped shaft rod with the gear installed penetrates the primary sealing cover and extends to the outer side of the primary sealing cover to form a driving end.

[0011] In the present application, an optional technical solution for the rotational drive mode of the stepped shaft is: a handle is installed on the driving end.

[0012] In the present application, for the rotational drive mode of the stepped shaft, another optional technical solution is: a stepper motor and a temperature probe are installed on the outside of the primary sealing cover, and the output shaft of the stepper motor is connected to the driving end through a coupling.

[0013] Furthermore, a round rod is provided in the middle of the sliding seat, a sliding groove opening is provided in the fixed seat, the round rod is slidably connected to the sliding groove opening, and the side surface of the sliding seat always covers the edge of the sliding groove opening.

[0014] Furthermore, the secondary sealing cover and the baffle are rotatably mounted with an I-shaped structured sleeve I and sleeve II, respectively, and the stepped shaft rod penetrates the sleeve I and sleeve II and is tightly connected to the inner side surfaces of the sleeve I and sleeve II.

[0015] Furthermore, the end edges of the fixing seat and the secondary sealing cover are respectively abutted against the limiting edge I and the limiting edge II in the outer shell.

[0016] Furthermore, a plurality of step surfaces are provided on the side of the stepped shaft rod, and the plurality of step surfaces are respectively abutted and connected with the inner wall of the primary sealing cover, the end surface of the shaft sleeve I and the end surface of the shaft sleeve II.

[0017] In the present application, in order to ensure that the spherical end can rotate smoothly in multiple concave surfaces, an optional technical solution is: grease is applied to the concave surface on the string clamp.

[0018] In the present application, in order to ensure that the spherical end can rotate smoothly in multiple concave surfaces, another optional technical solution is: a gasket is installed in the concave surface on the string clamp, and the inner side of the gasket abuts against the outer side of the spherical end; wherein the gasket can use polytetrafluoroethylene material with self-lubricating properties that can be purchased on the market.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. In the pressure sensor of the example of the present invention, in the initial state, the extension direction of the vibrating string is at a certain angle to the axial direction of the shell; when the vibration frequency of the vibrating string needs to be adjusted, the two slides are controlled to move synchronously in opposite directions, driving the spherical ends at both ends of the vibrating string body to move towards each other, so that the vibrating string body contracts to a certain extent while maintaining a taut state. In order to cope with the deformation of the length of the vibrating string caused by the increase or decrease in temperature, the vibration frequency of the vibrating string is corrected and adjusted over a large range, thereby increasing the detection accuracy of the pressure sensor.

[0021] 2. In the pressure sensor of the example of the present invention, when the slides on the two string end clamping assemblies slide synchronously and oppositely in their respective corresponding fixed seats, the two spherical ends rotate in their respective corresponding multiple concave surfaces, and the rotation center of the vibrating string body corresponds to the middle position of the induction coil, so that there is no offset between the middle of the vibrating string and the induction coil; in addition, because the sliding direction of the slide is perpendicular to the installation direction of the induction coil, the distance between the vibrating string and the induction coil is kept constant, thereby ensuring the stable operation of the pressure sensor.

[0022] 3. In the pressure sensor of the example of the present invention, the side surface of the slide always covers the edge of the slide groove, and the slide is slidably installed in the groove. On the basis of stably limiting the slide, the air pressure between the two fixed seats will not change, thereby not causing interference to the working area of ​​the induction coil and the vibrating string.

[0023] 4. The pressure sensor of the example of the present invention has a handle installed on the driving end. When the temperature change is detected, the handle is held and rotated to control the rotation of the stepped shaft, and the sliding seat is driven to slide in the corresponding fixed seat by the meshing transmission between the gear and the rack. In addition, a stepper motor and a temperature probe can be installed on the outside of the first-level sealing cover. According to the temperature change, the stepper motor is started to control the rotation of the stepped shaft and adjust the vibration frequency of the vibrating string.

[0024] 5. The pressure sensor of the example of the present invention utilizes two primary sealing covers and two secondary sealing covers to achieve double-layer sealing of the equipment, which is suitable for use in harsh environments. On this basis, combined with the use of sleeve I and sleeve II, the smoothness of rotation of the stepped shaft is increased while maintaining the sealing performance of the equipment.

[0025] 6. In the pressure sensor of the example of the present invention, the secondary sealing cover, the primary sealing cover and the fixed seat are respectively provided with ventilation holes, and sealing plugs can be detachably fixedly installed at the ventilation holes, so as to facilitate the regulation of the gas pressures in various areas on the inner side of the shell isolated by the secondary sealing cover, the primary sealing cover and the fixed seat.

[0026] 7. In the pressure sensor of the example of the present invention, the gasket is used to increase the smoothness of rotation between the spherical end and the concave surface on the string clamp; in addition, it can be replaced by adding grease between the outer side surface of the spherical end and the concave surface. Compared with the prior art solution of clamping the vibrating string by controlling the deformation of the elastic part, the present application has better stability in use, good anti-interference factors, is not affected by the life of the elastic part and environmental factors, and has a wider adjustment range for the vibration frequency of the vibrating string.

[0027] 8. In the pressure sensor of the example of the present invention, the multiple step surfaces on the side of the stepped shaft rod are respectively abutted against the inner wall of the primary sealing cover, the end face of the sleeve I and the end face of the sleeve II, so that when the primary sealing cover is installed on the side of the outer shell, the stepped shaft rod can push the sleeve I and the sleeve II, drive the secondary sealing cover and the fixed seat to move quickly to the specified position, and quickly position and splice the various components of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0029] Figure 1 A schematic diagram of the overall structure of the pressure sensor provided by an embodiment of the present invention;

[0030] Figure 2 A partial schematic diagram of an induction coil and a vibrating string body provided in an embodiment of the present invention;

[0031] Figure 3A partial schematic diagram of a vibrating string body, a fixing seat, a sliding seat and a string holder provided in an embodiment of the present invention;

[0032] Figure 4 A partial schematic diagram of a vibrating string body, a spherical end and a string holder provided by an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of the structure of a string clamp, a gasket, a slide post and a stud provided in an embodiment of the present invention;

[0034] Figure 6 A schematic diagram of the structure of the induction coil, the vibrating wire body and the fixing seat provided in an embodiment of the present invention;

[0035] Figure 7 A schematic diagram of the exploded structure of a fixed seat, a sliding seat, a stepped shaft rod and a baffle provided in an embodiment of the present invention;

[0036] Figure 8 A cross-sectional view of a secondary sealing cover, a primary sealing cover and a stepped shaft provided in an embodiment of the present invention;

[0037] Fig. 9 A schematic structural diagram of a housing provided by an embodiment of the present invention.

[0038] In the figure: 1 shell, 11 induction coil, 12 outer wall of equal thickness, 13 limit edge I, 14 limit edge II, 15 secondary sealing cover, 16 sleeve I, 17 primary sealing cover, 2 vibrating string, 21 vibrating string body, 22 spherical end, 3 string end clamping assembly, 31 fixed seat, 311 groove, 312 slide groove, 32 slide seat, 33 string frame, 34 round rod, 35 string clamp, 351 slide column, 352 gasket, 353 stud, 41 stepped shaft rod, 42 gear, 43 rack, 44 handle, 45 baffle, 46 sleeve II. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0040] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0041] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings.

[0045] Embodiment 1:

[0046] like Figure 1-4 , Figure 6 and Fig. 9 As shown, this embodiment provides a pressure sensor, including a shell 1, an induction coil 11, a vibrating string 2 and two string end clamping assemblies 3, wherein the induction coil 11 and the vibrating string 2 are both arranged on the inner middle side of the shell 1, and the two string end clamping assemblies 3 are oppositely installed on the inner sides of the shell 1; the vibrating string 2 includes a vibrating string body 21, and both ends of the vibrating string body 21 are integrally formed with spherical ends 22, and the spherical ends 22 are movably connected in the string end clamping assemblies 3.

[0047] Among them, an outer wall 12 of equal thickness is arranged on the outer side of the middle part of the shell 1, so that the pressure sensor is easy to deform in the middle part, thereby increasing the sensitivity of product pressure detection.

[0048] Among them, sealing covers are respectively installed on both sides of the shell 1, and the sealing covers include a primary sealing cover 17 and a secondary sealing cover 15, so as to realize double-layer sealing of the equipment and adapt to the use in harsh environments; the primary sealing cover 17 and the secondary sealing cover 15 can be connected to the shell 1 by threaded engagement or using fasteners.

[0049] like Figure 3-4As shown, the string end clamping assembly 3 includes a fixed seat 31, a sliding seat 32 is slidably mounted on the fixed seat 31, the sliding seat 32 is connected to a string frame 33 through a shock-absorbing gasket, and a plurality of string clamps 35 are mounted on the side of the string frame 33 at equal angles through fasteners. The string clamp 35 is provided with a concave surface matching the outer side surface of the spherical end 22, the concave surface can abut against the outer side surface of the spherical end 22, and the spherical end 22 can rotate freely in the plurality of concave surfaces, and the connection flexibility is good.

[0050] The end edges of the fixing seat 31 and the secondary sealing cover 15 are respectively in contact with the limiting edge Ⅰ13 and the limiting edge Ⅱ14 in the housing 1 to define the installation positions of the fixing seat 31 and the secondary sealing cover 15 .

[0051] like Figure 3 and Figure 7-8 As shown, a groove 311 is provided in the fixing seat 31, and the sliding seat 32 is slidably installed in the groove 311. A baffle 45 is detachably fixedly installed at the end of the groove 311. The sealing cover includes a primary sealing cover 17 and a secondary sealing cover 15, thereby realizing double-layer sealing of the equipment and adapting to use in harsh environments.

[0052] A stepped shaft rod 41 is rotatably installed in the middle of the primary sealing cover 17 and the secondary sealing cover 15. The stepped shaft rod 41 passes through the baffle 45 and is rotatably connected to the baffle 45. The end of the stepped shaft rod 41 is connected to a gear 42 through a key. The gear 42 is connected to a rack 43 through meshing transmission. The rack 43 is fixedly installed on the slide seat 32. The other end of the stepped shaft rod 41 with the gear 42 passes through the primary sealing cover 17 and extends toward the outside of the primary sealing cover 17 to form a driving end.

[0053] In this embodiment, in order to ensure that the spherical end 22 can rotate smoothly in the multiple concave surfaces, grease is applied to the concave surfaces on the string clamp 35 .

[0054] In this embodiment, the rotation driving method for the stepped shaft 41 is as follows: Figure 7-8 As shown, a handle 44 is installed on the driving end. When the temperature change is detected, the handle 44 is held and rotated to control the rotation of the stepped shaft 41. The gear 42 and the rack 43 are meshed to drive the slide 32 to slide in the corresponding fixed seat 31.

[0055] In the process of using the pressure sensor of the present application, when the vibration frequency of the vibrating string 2 needs to be adjusted: the two slides 32 are controlled to move synchronously in opposite directions, driving the spherical ends 22 at both ends of the vibrating string body 21 to move towards or away from each other, so that the vibrating string body 21 contracts or stretches to a certain extent while maintaining a taut state. In order to cope with the deformation of the length of the vibrating string 2 caused by the increase or decrease in temperature of the vibrating string 2, the vibration frequency of the vibrating string is corrected and adjusted over a large range, thereby increasing the detection accuracy of the pressure sensor.

[0056] When the slides 32 on the two string end clamping assemblies 3 slide synchronously and oppositely in their respective corresponding fixed seats 31, the two spherical ends 22 rotate in their respective corresponding multiple concave surfaces, and the rotation center of the vibrating string body 21 corresponds to the middle position of the induction coil 11, so that there is no offset between the middle of the vibrating string and the induction coil 11; in addition, since the sliding direction of the slide 32 is perpendicular to the installation direction of the induction coil 11, the distance between the vibrating string and the induction coil 11 remains constant, thereby ensuring the stable operation of the pressure sensor.

[0057] It should be noted that, in the initial state of the pressure sensor of the present application, the extension direction of the vibrating string 2 is at a certain angle to the axial direction of the housing 1 , so that the vibrating string 2 can contract to a certain extent.

[0058] In order to reduce the interference to the working area of ​​the induction coil 11 and the vibrating wire 2, as Figure 3 and Figure 7 As shown, a round rod 34 is provided in the middle of the slide seat 32, and a slide slot 312 is provided in the fixed seat 31, so that the round rod 34 is slidably connected with the slide slot 312, so that the side surface of the slide seat 32 always covers the edge of the slide slot 312, and on the basis of stably limiting the slide seat 32, the air pressure between the two fixed seats 31 will not change, thereby not causing interference to the working area of ​​the induction coil 11 and the vibrating string 2.

[0059] In order to improve the rotation smoothness of the stepped shaft 41, as Figure 3 and Figure 7-8 As shown, the I-shaped structure sleeve Ⅰ16 and sleeve Ⅱ46 are rotatably installed on the secondary sealing cover 15 and the baffle 45 respectively, and the stepped shaft rod 41 passes through the sleeve Ⅰ16 and sleeve Ⅱ46 and is tightly connected with the inner side surfaces of the sleeve Ⅰ16 and sleeve Ⅱ46. Combined with the use of the sleeve Ⅰ16 and sleeve Ⅱ46, the rotation smoothness of the stepped shaft rod 41 is increased while maintaining the sealing performance of the equipment.

[0060] Embodiment 2:

[0061] The features of this embodiment that are the same as those of the first embodiment are not described in detail. The difference between this embodiment and the first embodiment is that: Figure 4-5As shown, in this embodiment, a slide post 351 is fixedly installed on the string clamp 35, and the slide post 351 is slidably connected to the string frame 33. A stud 353 is rotatably installed on the string clamp 35, and the stud 353 is connected to the string frame 33 through a threaded transmission. An electric torque screwdriver is used to control the stud 353 to rotate a specified number of times, so that the string clamp 35 and the slide post 351 slide together in the string frame 33 to clamp or relax the spherical end 22, so that when the vibrating string body 21 is disassembled and assembled, the string clamp 35 can be stably connected to the string frame 33, and the operation is convenient.

[0062] Embodiment three:

[0063] The features of this embodiment that are the same as those of the first embodiment are not described in detail. The difference between this embodiment and the first embodiment is that: Figure 8 As shown, in this embodiment, the side of the stepped shaft rod 41 is provided with a plurality of stepped surfaces, which are respectively abutted and connected with the inner wall of the primary sealing cover 17, the end face of the sleeve I16 and the end face of the sleeve II46; so that during the installation of the primary sealing cover 17 on the side of the outer casing 1, the stepped shaft rod 41 can push the sleeve I16 and the sleeve II46, drive the secondary sealing cover 15 and the fixing seat 31 to move quickly to the specified position, and quickly position and splice the various components of the equipment.

[0064] Embodiment 4:

[0065] The features of this embodiment that are the same as those of the first embodiment are not repeated here. The difference between this embodiment and the first embodiment is that in this embodiment, a stepper motor and a temperature probe are installed on the outer side of the first-level sealing cover 17. The output shaft of the stepper motor is connected to the driving end through a coupling. According to the temperature change detected by the temperature probe, the stepper motor is started to control the rotation of the stepped shaft 41 to adjust the vibration frequency of the vibrating string 2. Compared with the manual rotation of the handle 44, the automation effect is good and the operation is convenient.

[0066] Embodiment five:

[0067] The features of this embodiment that are the same as those of the first embodiment are not described in detail. The difference between this embodiment and the first embodiment is that: Figure 5 As shown, in this embodiment, a gasket 352 is installed in the concave surface of the string clamp 35, and the inner side of the gasket 352 abuts against the outer side of the spherical end 22; the gasket 352 is used to increase the smoothness of rotation between the spherical end 22 and the concave surface on the string clamp 35, and can be made of polytetrafluoroethylene with self-lubricating properties that can be purchased on the market.

[0068] Compared with the prior art solution of clamping the vibrating string by controlling the deformation of the elastic part, the present application has better stability in use, better anti-interference factors, is not affected by the life of the elastic part and environmental factors, and has a wider adjustment range for the vibration frequency of the vibrating string.

[0069] In the present application, ventilation holes are respectively provided on the secondary sealing cover 15, the primary sealing cover 17 and the fixed seat 31, and sealing plugs can be removably fixedly installed at the ventilation holes, so as to facilitate regulating the gas pressure of each area isolated by the secondary sealing cover 15, the primary sealing cover 17 and the fixed seat 31 on the inner side of the shell 1.

[0070] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0071] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. A pressure sensor, comprising a housing (1), and an induction coil (11) and a vibrating wire (2) arranged in the middle of the inner side of the housing (1), characterized in that: A sealing cover and a string end clamping assembly (3) are respectively installed on both sides of the housing (1), and the end of the vibrating string (2) is connected to the string end clamping assembly (3); The vibrating string (2) comprises a vibrating string body (21), and both ends of the vibrating string body (21) are integrally formed with spherical ends (22); The string end clamping assembly (3) comprises a fixed seat (31), a sliding seat (32) is slidably mounted on the fixed seat (31), the sliding seat (32) is connected to a string frame (33) via a shock-absorbing gasket, a plurality of string clamps (35) are mounted at equal angles on the side of the string frame (33), and a concave surface matching the outer side surface of the spherical end (22) is provided on the string clamp (35), and the concave surface can abut against the outer side surface of the spherical end (22); The two string end clamping assemblies (3) are oppositely mounted on two sides of the housing (1), and during the process in which the slide seats (32) in the two string end clamping assemblies (3) slide synchronously in the corresponding fixed seats (31), the spherical ends (22) at both ends of the vibrating string body (21) move in a direction approaching each other or moving away from each other, and the vibrating string body (21) rotates relative to the induction coil (11); The sliding direction of the sliding seat (32) is perpendicular to the axial direction of the housing (1).

2. The pressure sensor according to claim 1, characterized in that: A slide post (351) is fixedly mounted on the string clamp (35), the slide post (351) is slidably connected to the string frame (33), a stud (353) is rotatably mounted on the string clamp (35), and the stud (353) is connected to the string frame (33) through a threaded transmission.

3. The pressure sensor according to claim 1, characterized in that: The fixed seat (31) is provided with a groove (311), the slide seat (32) is slidably mounted in the groove (311), a baffle (45) is detachably fixedly mounted at the end of the groove (311), the sealing cover comprises a primary sealing cover (17) and a secondary sealing cover (15), a stepped shaft (41) is rotatably mounted in the middle of the primary sealing cover (17) and the secondary sealing cover (15), the stepped shaft (41) penetrates the baffle (45) and is rotatably connected to the baffle (45), the end of the stepped shaft (41) is connected to a gear (42) via a key, the gear (42) is connected to a rack (43) via meshing transmission, and the rack (43) is fixedly mounted on the slide seat (32); The other end of the stepped shaft (41) on which the gear (42) is mounted penetrates the primary sealing cover (17) and extends toward the outside of the primary sealing cover (17) to form a driving end.

4. The pressure sensor according to claim 3, characterized in that: A round rod (34) is provided in the middle of the sliding seat (32), a sliding groove opening (312) is provided in the fixed seat (31), the round rod (34) is slidably connected to the sliding groove opening (312), and the side surface of the sliding seat (32) always covers the edge of the sliding groove opening (312).

5. The pressure sensor according to claim 3, characterized in that: The secondary sealing cover (15) and the baffle (45) are rotatably mounted with an I-shaped shaft sleeve I (16) and a shaft sleeve II (46), respectively. The stepped shaft rod (41) passes through the shaft sleeve I (16) and the shaft sleeve II (46) and is tightly connected to the inner side surfaces of the shaft sleeve I (16) and the shaft sleeve II (46).

6. The pressure sensor according to claim 3, characterized in that: The end edges of the fixing seat (31) and the secondary sealing cover (15) are respectively in contact with the limiting edge I (13) and the limiting edge II (14) in the outer shell (1).

7. The pressure sensor according to claim 5, characterized in that: The side of the stepped shaft rod (41) is provided with a plurality of stepped surfaces, and the plurality of stepped surfaces are respectively abutted and connected with the inner wall of the primary sealing cover (17), the end surface of the shaft sleeve I (16), and the end surface of the shaft sleeve II (46).

8. The pressure sensor according to claim 1, characterized in that: The concave surface on the string clamp (35) is smeared with lubricating grease.

9. The pressure sensor according to claim 1, characterized in that: A gasket (352) is installed in the concave surface of the string clamp (35), and the inner side surface of the gasket (352) abuts against the outer side surface of the spherical end (22).

10. The pressure sensor according to claim 1, characterized in that: An outer wall (12) of uniform thickness is provided on the outer side of the middle portion of the outer shell (1).

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