A variable area capacitance sensor

Abstract

The present invention provides a variable area capacitance sensor, which belongs to the field of sensor technology, and comprises a first annular plate; a plurality of fixed pole plates, which are equidistantly embedded on the outer surface of the first annular plate; a second annular plate, which is sleeved on the periphery of the first annular plate; and a plurality of rotating pole plates, which are equidistantly embedded on the inner surface of the second annular plate. The outer surface of the first annular plate is provided with a plurality of limit grooves, and the inner surface of the second annular plate is provided with a plurality of circular grooves equidistantly, and elastic limit buttons are provided in the circular grooves. When the fixed pole plate and the rotating pole plate are not in contact, the elastic limit buttons are located in the limit grooves. The device can detect material information inside a tubular object.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a variable area capacitance sensor. Background Art

[0002] Capacitive sensing technology is a technology based on capacitive coupling, which can be used to detect any conductive dielectric that is different from air. Capacitive sensing is widely used to measure physical quantities such as pressure, position, displacement, force, humidity, liquid level and acceleration. Capacitive sensing has high sensitivity, good stability, fast response and wide application. It is currently widely used in the field of non-destructive testing.

[0003] In the prior art, the capacitive sensor used to detect substances inside a pipeline is mainly an ECT sensor. The ECT sensor is based on capacitive tomography technology and consists of multiple capacitor plates arranged around the outside of the pipeline. By measuring the capacitance data between the capacitor plate pairs and then transmitting the capacitance data to a computer, a medium distribution image can be reconstructed based on the measurement data.

[0004] However, in actual operation, the plate parameters (plate width, plate length, and spacing between plates) of the ECT sensor need to be adjusted in different application scenarios to adapt to the measurement in different scenarios. The plate parameters of the ECT sensor in the prior art are fixed and cannot be flexibly changed, resulting in a small application range and inconvenience in use.

[0005] In summary, the prior art has the problem that the plate parameters of the ECT capacitive sensor cannot be flexibly changed and cannot adapt to the measurement of the material inside the pipeline in different application scenarios. Summary of the invention

[0006] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a variable area capacitance sensor.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A variable area capacitance sensor, comprising:

[0009] a first annular plate;

[0010] A plurality of fixed pole plates are embedded on the outer surface of the first annular plate at equal intervals;

[0011] A second annular plate, sleeved on the outer periphery of the first annular plate;

[0012] A plurality of rotating pole plates are embedded in the inner surface of the second annular plate at equal intervals, and the number of the rotating pole plates is the same as the number of the fixed pole plates;

[0013] The sensing principle used by the sensor is the ECT sensor principle; when the fixed pole plate and the rotating pole plate are in contact, the fixed pole plate and the rotating pole plate can be regarded as a combined pole plate.

[0014] Furthermore, a plurality of limit grooves are provided on the outer surface of the first annular plate, and the limit grooves are located on one side of the fixed pole plate. A plurality of circular grooves are equidistantly provided on the inner surface of the second annular plate, and elastic limit buttons are provided in the circular grooves. When the fixed pole plate is not in contact with the rotating pole plate, the elastic limit button is located in the limit groove.

[0015] Further, the elastic limit button comprises: a spring, one end of which is fixedly connected to the bottom surface of the circular groove;

[0016] A limit button is fixedly connected to the other end of the spring.

[0017] Furthermore, the limiting button has inclined surfaces on both sides around the first annular plate, and the included angles of the inclined surfaces on both sides point to the first annular plate.

[0018] Furthermore, it also includes: a plurality of shifting blocks fixedly connected to the outer surface of the second annular plate.

[0019] Furthermore, it also includes: a cylinder, wherein a plurality of rectangular first slide grooves are opened horizontally and equidistantly in the middle of the cylinder around the axis; an annular second slide groove is opened circumferentially in the middle of the cylinder, the second slide groove is located in the middle of the plurality of rectangular first slide grooves, and the shift block is located in the first slide groove or the second slide groove.

[0020] Furthermore, a plurality of slots are provided on both sides of the first slide slot, the shift block is a cube, and the four sides of the top thereof are hingedly connected to limit plates, the length of the limit plates is equal to the side length of the shift block, and the width of the slots is equal to the length of the limit plates.

[0021] The variable area capacitance sensor provided by the present invention has the following beneficial effects:

[0022] When the fixed pole plate and the rotating pole plate have no overlapping parts in the circumferential direction, the rotating pole plate can be rotated to change the distance between the rotating pole plate and the fixed pole plate; when the fixed pole plate and the rotating pole plate partially overlap in the circumferential direction, the fixed pole plate and the rotating pole plate are combined into a combined pole plate. The width of the combined pole plate can be changed by controlling the circumferential movement of the rotating pole plate; when the fixed pole plate and the rotating pole plate completely overlap in the circumferential direction, the length of the combined pole plate can be changed by controlling the axial movement of the rotating pole plate.

[0023] The present invention changes the plate spacing parameter, plate area parameter, and plate axial length parameter of the capacitive sensor by circumferentially or axially moving the rotating plate. The capacitive sensor can flexibly change the sensor parameters, breaking the limitation of the traditional ETC capacitive sensor with unchanged plate area. The sensor structure parameters can be adjusted to obtain a better sensor structure to adapt to the measurement of the material inside the pipeline in different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiment of the present invention and its design scheme, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic structural diagram of a variable area capacitive sensor according to Embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the second annular plate of Embodiment 2 of the present invention;

[0027] Figure 3 This is a schematic diagram of the first annular plate structure of Example 2 of the present invention;

[0028] Figure 4 This is a schematic structural diagram of a cylinder according to Embodiment 3 of the present invention;

[0029] Figure 5 This is a schematic diagram of the shift block structure of Example 3 of the present invention. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0031] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply 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 a limitation on the present invention.

[0032] In addition, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified or limited, the terms "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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In the description of the present invention, unless otherwise specified, "plurality" means two or more, which will not be described in detail here.

[0033] Embodiment 1:

[0034] The present invention provides a variable area capacitance sensor, specifically Figure 1 As shown, including:

[0035] A first annular plate 4; a plurality of fixed pole plates 1, equidistantly embedded on the outer surface of the first annular plate 4; a second annular plate 2, sleeved on the outer periphery of the first annular plate 4; a plurality of rotating pole plates 3, equidistantly embedded on the inner surface of the second annular plate 2.

[0036] In this embodiment, the fixed electrode plate 1 and the rotating electrode plate 3 are co-arc surface capacitors, and the fixed electrode plate 1 and the rotating electrode plate 3 have the same area and shape. The fixed electrode plate 1 and the rotating electrode plate 3 are used to generate capacitance signals, and the first annular plate 4 is used to be sleeved on the pipeline to be detected.

[0037] In this embodiment, when the fixed pole plate 1 and the rotating pole plate 3 have no overlapping parts in the circumferential direction, the fixed pole plate 1 and the rotating pole plate 3 are regarded as two pole plates. At this time, the rotating pole plate 3 is rotated to change the pole plate spacing between the rotating pole plate 3 and the fixed pole plate 1; when the fixed pole plate 1 and the rotating pole plate 3 partially overlap in the circumferential direction, the fixed pole plate 1 and the rotating pole plate 3 are combined into a combined pole plate. By controlling the circumferential movement of the rotating pole plate 3, the width of the combined pole plate can be changed; when the fixed pole plate 1 and the rotating pole plate 3 completely overlap in the circumferential direction, the axial movement of the rotating pole plate 3 can be controlled to change the length of the combined pole plate.

[0038] This device is used as a capacitance detection device of capacitance tomography technology. When in use, the fixed plate 1 and the rotating plate 3 are connected to the detection circuit, and the parameters of the sensor are adjusted according to the usage scenario and measurement requirements. A single plate is used as an excitation plate in turn, and the remaining plates are used as receiving plates in turn to generate capacitance signals and collect them in the computer. For example: there are N plates, numbered D1-DN. The first time, D1 is used as the excitation plate, and D2-DN are used as receiving plates in turn, generating N-1 capacitance signals. The second time, D2 is used as the excitation plate, and D3-DN are used as receiving plates in turn, generating N-2 capacitance signals. And so on. A total of N*(N-1) / 2 capacitance signals are collected.

[0039] The variable area structure of the present application allows the sensor to have plates of different areas, and the sensor structure can be flexibly changed, breaking the limitation of the traditional ETC capacitive sensor with a constant plate area. By adjusting the sensor structure to obtain a better sensor structure, a solution can be provided for the detection of substances in the tube.

[0040] Embodiment 2:

[0041] like Figure 2 , 3 As shown, based on Example 1:

[0042] The outer surface of the first annular plate 4 is provided with a plurality of limiting grooves 6, and the inner surface of the second annular plate 2 is provided with a plurality of circular grooves 12 at equal intervals. The circular grooves 12 are provided with elastic limiting buttons of the same number as the limiting grooves 6. When the fixed pole plate 1 is not in contact with the rotating pole plate 3, the elastic limiting buttons are located in the limiting grooves 6. The elastic limiting buttons include: a spring 10, one end of which is fixedly connected to the bottom surface of the circular groove 12; and a limiting button 11, which is fixedly connected to the other end of the spring 10. The limiting button 11 has inclined surfaces on both sides of the direction around the first annular plate 4, and the angles of the inclined surfaces on both sides point to the first annular plate 4.

[0043] In this embodiment, the limit groove 6 is used to clamp the elastic limit button, so that the rotating pole plate 3 cannot produce axial movement when there is no overlap with the fixed pole plate 1. The circular groove 12 is used to accommodate the limit button 11 in a compressed state. The inclined surfaces on both sides of the limit button 11 enable it to be smoothly squeezed out of the limit groove 6 when the second annular plate 2 rotates.

[0044] In this embodiment, when the fixed pole plate 1 and the rotating pole plate 3 have no overlapping parts, the elastic limit button is located in the limit groove 6, so that the rotating pole plate 3 cannot move in the axial direction. When the fixed pole plate 1 and the rotating pole plate 3 overlap, the limit button 11 is squeezed out of the limit groove 6 by the outer wall of the first annular plate 4, and the rotating pole plate 3 can move in the axial direction. When the rotating pole plate 3 partially overlaps with the fixed pole plate 1, the rotating pole plate 3 moves in the axial direction, and the area and shape of the combined pole plate formed by the rotating pole plate 3 and the fixed pole plate 1 also change accordingly. To adapt to more complex usage scenarios.

[0045] Embodiment 3:

[0046] like Figure 4 As shown, based on Example 1:

[0047] It also includes: a cylinder 7, with multiple rectangular first slide grooves 8 equidistantly opened in the middle of the cylinder 7 around the axis; an annular second slide groove 9 circumferentially opened in the middle of the cylinder 7, and the second slide groove 9 is located in the middle of the multiple rectangular first slide grooves 8. Multiple shifting blocks 5 are fixedly connected to the outer surface of the second annular plate 2. Multiple slots 13 are opened on both sides of the first slide groove 8. The shifting block 5 is a cube, and the four sides of the top are hinged to the limit plate 14, and the length of the limit plate 14 is equal to the side length of the shifting block 5.

[0048] In this embodiment, the user can turn the dial block 5 to control it to rotate circumferentially in the second slide groove 9, thereby driving the rotating pole plate 3 to rotate circumferentially around the pipe. The length of the first slide groove 8 is equal to the length of the three rotating pole plates 3, which is used to control the axial movement range of the rotating pole plate 3. Ensure that the rotating pole plate 3 and the fixed pole plate 1 are between complete overlap and edge contact in the axial direction.

[0049] The limiting plates 14 hinged on the four sides of the top of the shift block 5 can be folded up and down to fix the position of the shift block 5, and then fix the position of the rotating pole plate 3. When the shift block 5 is in the first chute 8, the limiting plates 14 on both sides of the shift block 5 close to the side walls of the first chute 8 are lowered to be stuck in the slot 13. At this time, the circumferential rotation of the shift block 5 is limited by the side walls of the first chute 8, and the axial movement of the shift block 5 is limited by the limiting plates 14, so that the position of the shift block 5 in the first chute 8 is fixed.

[0050] When the shift block 5 is in the second chute 9, the limit plates 14 on the four sides of the top of the shift block 5 are lowered to make the limit plates 14 stuck in the first chute 8 and the second chute 9. At this time, the circumferential rotation of the shift block 5 is limited by the limit plates 14 stuck in the first chute 8, and the axial movement of the shift block 5 is limited by the limit plates 14 stuck in the second chute 9, so that the position of the shift block 5 in the second chute 9 is fixed.

[0051] The embodiments described above are only preferred specific implementation modes of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belong to the protection scope of the present invention.

Claims

1. A variable area capacitance sensor, characterized in that: include: A first annular plate (4); A plurality of fixed pole plates (1) are embedded at equal intervals on the outer surface of the first annular plate (4); A second annular plate (2) is sleeved on the outer periphery of the first annular plate (4); A plurality of rotating pole plates (3) are embedded at equal intervals on the inner surface of the second annular plate (2), and the number of the rotating pole plates (3) is the same as the number of the fixed pole plates (1); The sensing principle used by the sensor is the ECT sensor principle; when the fixed electrode plate (1) and the rotating electrode plate (3) are in contact, the fixed electrode plate (1) and the rotating electrode plate (3) can be regarded as a combined electrode plate; The outer surface of the first annular plate (4) is provided with a plurality of limiting grooves (6), the limiting grooves (6) are located on one side of the fixed pole plate (1), the inner surface of the second annular plate (2) is provided with a plurality of circular grooves (12) at equal intervals, the circular grooves (12) are provided with elastic limiting buttons, and when the fixed pole plate (1) is not in contact with the rotating pole plate (3), the elastic limiting buttons are located in the limiting grooves (6); The elastic limiting button comprises: A spring (10), one end of which is fixedly connected to the bottom surface of the circular groove (12); A limit button (11) fixedly connected to the other end of the spring (10); The two sides of the limit button (11) surrounding the first annular plate (4) are inclined surfaces, and the included angles of the inclined surfaces on the two sides point to the first annular plate (4); It also includes: a plurality of shifting blocks (5) fixedly connected to the outer side surface of the second annular plate (2); It also comprises: a cylinder (7), wherein a plurality of rectangular first sliding grooves (8) are opened in the middle of the cylinder (7) at equal intervals around the axis in the transverse direction; an annular second sliding groove (9) is opened in the middle of the cylinder (7) in the circumferential direction, wherein the second sliding groove (9) is located in the middle of the plurality of rectangular first sliding grooves (8), and the shifting block (5) is located in the first sliding groove (8) or the second sliding groove (9); A plurality of slots (13) are provided on both sides of the first slide groove (8); the shift block (5) is a cube, and the four sides of the top thereof are hingedly connected to a limiting plate (14); the length of the limiting plate (14) is equal to the side length of the shift block (5); and the width of the slot (13) is equal to the length of the limiting plate (14).

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