High-precision parallel plate capacitive sensor structure

Abstract

The utility model discloses a high-precision parallel-plate capacitive sensor structure, which belongs to the field of parallel-plate capacitive sensors and comprises a bottom plate, a sensor assembly is arranged on the bottom plate and consists of an upper polar plate and a lower polar plate, the upper polar plate and the lower polar plate are fixedly mounted on two insulating support columns respectively, and a distance adjusting mechanism is mounted on the bottom plate. The bottom plate is further provided with a shielding mechanism, the shielding mechanism comprises a permalloy shielding cover, a copper net is fixed in the permalloy shielding cover, a rectangular groove is formed in the top of the bottom plate, and the permalloy shielding cover and the copper net are installed in the rectangular groove in an embedded mode. According to the utility model, through the arrangement of the shielding mechanism, the effect of efficiently shielding various electromagnetic interferences is achieved, a double-layer structure formed by the permalloy shielding cover and the internal copper net can shield a low-frequency magnetic field and high-frequency electromagnetic radiation respectively, and permalloy has a good magnetic conduction shielding effect on the low-frequency magnetic field.

Description

Technical Field

[0001] This utility model relates to the field of parallel plate capacitive sensor technology, and in particular to a high-precision parallel plate capacitive sensor structure. Background Technology

[0002] Parallel plate capacitive sensors are widely used in industrial automation, precision measurement, and environmental monitoring due to their simple structure and high sensitivity. Based on the relationship between the capacitance value between parallel plates and the distance between the plates and the dielectric constant, the sensor converts changes in physical quantities such as displacement, liquid level, and thickness into capacitance signals for measurement. However, in actual working environments, the sensor is easily affected by external electromagnetic interference, which can lead to decreased measurement accuracy, large data fluctuations, or even failure to work properly.

[0003] With the popularization of modern electronic devices and the increasing complexity of power systems, electromagnetic interference sources in the environment are increasing. For example, high-frequency harmonics generated by frequency converters and motors in industrial sites, radio frequency signals emitted by communication equipment, and strong electromagnetic fields around high-voltage transmission lines. As a device based on the detection of weak capacitance signals, the parallel plate capacitive sensor typically has a signal strength in the picofarad or even femtofarad range. The induced current and voltage generated by external electromagnetic interference are easily superimposed on the sensor's measurement signal, causing signal distortion. Utility Model Content

[0004] The purpose of this invention is to solve the problem that in the prior art, sensors are easily affected by external electromagnetic interference, which leads to decreased measurement accuracy, large data fluctuations, or even failure to work properly. Therefore, this invention proposes a high-precision parallel plate capacitive sensor structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-precision parallel plate capacitive sensor structure includes a base plate on which a sensor assembly is mounted. The sensor assembly consists of an upper electrode plate and a lower electrode plate, which are respectively fixedly mounted on two insulating support columns. A spacing adjustment mechanism is installed on the base plate. A shielding mechanism is also provided on the base plate, which includes a permalloy shielding cover. A copper mesh is fixed inside the permalloy shielding cover. A rectangular groove is formed on the top of the base plate, and the permalloy shielding cover and the copper mesh are embedded in the rectangular groove.

[0007] Preferably, the shielding mechanism further includes fixing strips fixed to both sides of the permalloy shielding cover, and the fixing strips are provided with locking holes.

[0008] Preferably, the base plate is further provided with a limiting mechanism for installing a permalloy shielding cover. The limiting mechanism includes a mounting shell fixed to the top of the base plate. The top of the mounting shell has a slot, and the fixing strip is engaged in the slot.

[0009] Preferably, a pull rod slides inside the mounting housing, a connecting plate is fixed to one end of the pull rod near the slot, a locking rod is fixed to the side of the connecting plate away from the pull rod, the locking rod is slidably connected to the mounting housing, and the locking rod slides in the locking hole.

[0010] Preferably, a return spring is sleeved on the outer surface of the pull rod, and the two ends of the return spring are fixedly connected to the mounting shell and the connecting plate, respectively. A U-shaped rod is fixed to the end of the pull rod away from the connecting plate.

[0011] Preferably, the spacing adjustment mechanism includes two support blocks symmetrically fixed to the top of the base plate, a bidirectional lead screw rotating between the two support blocks via a bearing, a movable bar threaded onto the outer surface of the bidirectional lead screw, a limit rod fixed between the two support blocks, the movable bar sliding on the outer surface of the limit rod, an insulating support column fixed to the top of the movable bar, and a motor for driving the bidirectional lead screw to rotate mounted on the support block.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] 1. The shielding mechanism effectively shields against various electromagnetic interferences. The double-layer structure, consisting of a permalloy shield and an internal copper mesh, can shield against low-frequency magnetic fields and high-frequency electromagnetic radiation respectively. Permalloy has excellent magnetic shielding properties against low-frequency magnetic fields, while the copper mesh effectively reflects high-frequency electromagnetic signals, providing a stable electromagnetic environment for the sensor components. This effectively avoids the influence of external electromagnetic interference on the measurement signal, improving measurement accuracy. The limiting mechanism securely fixes the shielding mechanism, preventing displacement or loosening due to vibration, external impact, or other factors during sensor use. This ensures the shielding mechanism continuously and stably performs its electromagnetic interference shielding function, guaranteeing the reliability of sensor measurements.

[0014] 2. The spacing adjustment mechanism allows for precise adjustment of the distance between the upper and lower plates. The motor on the support block drives the bidirectional lead screw to rotate. The moving bar, threaded to the bidirectional lead screw, can move precisely along a straight line under the limiting action of the limiting rod. This adjusts the distance between the upper and lower plates, which are fixed on the insulating support column at the top of the moving bar. This structure utilizes the high precision characteristics of lead screw transmission combined with the precise control of the motor to achieve minute and precise adjustment of the distance between the upper and lower plates, meeting the requirements of different measurement scenarios for plate spacing, thereby improving the accuracy and sensitivity of the parallel plate capacitance sensor measurement. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of a high-precision parallel plate capacitive sensor structure proposed in this utility model.

[0016] Figure 2 This is a schematic diagram of a sensor assembly structure for a high-precision parallel plate capacitive sensor proposed in this utility model.

[0017] Figure 3 This is a schematic diagram of a permalloy shielding structure for a high-precision parallel plate capacitive sensor proposed in this utility model.

[0018] Figure 4 This is a front view of the internal structure of the permalloy shielding cover of a high-precision parallel plate capacitive sensor structure proposed in this utility model.

[0019] Figure 5 This is an internal view of the mounting shell structure of a high-precision parallel plate capacitive sensor structure proposed in this utility model;

[0020] Figure 6 This utility model proposes a high-precision parallel plate capacitive sensor structure. Figure 5 Enlarged view of the structure at point A in the middle.

[0021] In the diagram: 1. Base plate; 21. Upper electrode plate; 22. Lower electrode plate; 23. Insulating support column; 41. Support block; 42. Bidirectional lead screw; 43. Moving bar; 44. Limiting rod; 45. Motor; 50. Rectangular groove; 51. Permalloy shielding cover; 52. Copper mesh; 53. Fixing bar; 54. Locking hole; 61. Mounting shell; 62. Slot; 63. Pull rod; 64. Connecting plate; 65. Locking rod; 66. Return spring; 67. U-shaped rod. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0023] Example 1

[0024] Reference Figures 1-6A high-precision parallel plate capacitive sensor structure includes a base plate 1, on which a sensor assembly is mounted. The sensor assembly consists of an upper electrode plate 21 and a lower electrode plate 22, which are respectively fixedly mounted on two insulating support columns 23. A spacing adjustment mechanism is mounted on the base plate 1, and a shielding mechanism is also mounted on the base plate 1. The shielding mechanism includes a permalloy shielding cover 51, in which a copper mesh 52 is fixed. A rectangular groove 50 is opened on the top of the base plate 1, and the permalloy shielding cover 51 and the copper mesh 52 are embedded in the rectangular groove 50.

[0025] Furthermore, the shielding mechanism also includes fixing strips 53 fixed to both sides of the permalloy shielding cover 51, and the fixing strips 53 are provided with locking holes 54.

[0026] Furthermore, the base plate 1 is also provided with a limiting mechanism for installing the permalloy shield 51. The limiting mechanism includes a mounting shell 61 fixed to the top of the base plate 1. The top of the mounting shell 61 is provided with a slot 62, and the fixing strip 53 is engaged in the slot 62.

[0027] Furthermore, a pull rod 63 slides inside the mounting housing 61. A connecting plate 64 is fixed to one end of the pull rod 63 near the slot 62. A locking rod 65 is fixed to the side of the connecting plate 64 away from the pull rod 63. The locking rod 65 is slidably connected to the mounting housing 61 and slides in the locking hole 54.

[0028] Furthermore, a return spring 66 is sleeved on the outer surface of the pull rod 63. The two ends of the return spring 66 are fixedly connected to the mounting shell 61 and the connecting plate 64, respectively. A U-shaped rod 67 is fixed to the end of the pull rod 63 away from the connecting plate 64.

[0029] The shielding mechanism consists of a permalloy shielding cover 51, a copper mesh 52, a rectangular groove 50, fixing strips 53, and locking holes 54. During operation, the permalloy shielding cover 51 and the copper mesh 52 are embedded in the rectangular groove 50 of the base plate 1, forming a closed space that encloses the sensor assembly. Permalloy has excellent magnetic permeability to low-frequency magnetic fields, guiding external low-frequency magnetic field interference to itself, thus protecting the internal sensor assembly from the influence of low-frequency magnetic fields. The copper mesh 52 utilizes the principle of electromagnetic induction to generate an induced current in high-frequency electromagnetic radiation. The reverse magnetic field generated by this induced current can cancel out external high-frequency electromagnetic signals, achieving reflective shielding of high-frequency electromagnetic radiation and providing a stable electromagnetic environment for the sensor assembly, avoiding the influence of external electromagnetic interference on capacitance signal measurement. When installing the shielding mechanism, the fixing strips 53 on both sides of the permalloy shielding cover 51 are snapped into the top of the mounting housing 61. When the shielding mechanism needs to be fixed in the slot 62, pull the U-shaped rod 67. The U-shaped rod 67 drives the pull rod 63 to slide in the mounting shell 61. The pull rod 63 drives the locking rod 65 to move through the connecting plate 64, so that the locking rod 65 is inserted into the locking hole 54 of the fixing strip 53. At this time, the return spring 66 is compressed. The cooperation between the locking rod 65 and the locking hole 54, as well as the elastic force of the return spring 66, firmly fixes the permalloy shielding cover 51 to the base plate 1, preventing it from shifting or loosening due to vibration, external force collision, or other factors during the use of the sensor. This ensures that the shielding mechanism can continuously and stably play its role in shielding electromagnetic interference. When the shielding mechanism needs to be disassembled, pull the U-shaped rod 67 again to disengage the locking rod 65 from the locking hole 54. Under the elastic force of the return spring 66, the pull rod 63, the connecting plate 64, and the locking rod 65 are reset, and the shielding mechanism can be removed.

[0030] The sensor assembly consists of an upper electrode plate 21, a lower electrode plate 22, and an insulating support column 23. When the physical quantity to be measured, such as displacement, liquid level, or thickness, changes, it will cause changes in parameters such as the distance between the upper electrode plate 21 and the lower electrode plate 22 and the dielectric constant. According to the parallel plate capacitance formula, these parameter changes will cause corresponding changes in capacitance. By detecting the change in capacitance, the change in physical quantity can be converted into an electrical signal output, thereby realizing the measurement of the physical quantity.

[0031] Based on Example 1, Example 2:

[0032] Reference Figures 1-6 ,

[0033] Furthermore, the spacing adjustment mechanism includes two support blocks 41 symmetrically fixed to the top of the base plate 1. A bidirectional lead screw 42 rotates between the two support blocks 41 via a bearing. A moving bar 43 is threadedly connected to the outer surface of the bidirectional lead screw 42. A limit rod 44 is fixed between the two support blocks 41. The moving bar 43 slides on the outer surface of the limit rod 44. An insulating support column 23 is fixed to the top of the moving bar 43. A motor 45 for driving the bidirectional lead screw 42 to rotate is installed on the support block 41.

[0034] When it is necessary to adjust the distance between the upper electrode plate 21 and the lower electrode plate 22, the motor 45 on the support block 41 is started. The motor 45 drives the bidirectional lead screw 42 to rotate between the two support blocks 41 through the bearing. Since the moving bar 43 is threadedly connected to the bidirectional lead screw 42 and can only move in a straight line under the limiting action of the limiting rod 44, the rotation of the bidirectional lead screw 42 will drive the moving bar 43 to move in a straight line on the outer surface of the limiting rod 44. The insulating support column 23 is fixed to the top of the moving bar 43, and the upper electrode plate 21 and the lower electrode plate 22 are respectively installed on On the insulating support column 23, the movement of the moving bar 43 will drive the upper electrode plate 21 and the lower electrode plate 22 to move synchronously, thereby adjusting the distance between the upper electrode plate 21 and the lower electrode plate 22. By controlling the rotation direction and number of turns of the motor 45, combined with the pitch of the bidirectional lead screw 42, the movement distance of the moving bar 43 can be precisely controlled, thereby achieving a small and precise adjustment of the distance between the upper electrode plate 21 and the lower electrode plate 22 to meet the requirements of different measurement scenarios for the distance between the upper electrode plate 21 and the lower electrode plate 22, and thus improve the accuracy and sensitivity of the parallel plate capacitance sensor measurement.

[0035] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A high-precision parallel plate capacitive sensor structure, comprising a base plate (1), characterized in that, A sensor assembly is provided on the base plate (1). The sensor assembly consists of an upper electrode plate (21) and a lower electrode plate (22). The upper electrode plate (21) and the lower electrode plate (22) are respectively fixedly installed on two insulating support columns (23). A spacing adjustment mechanism is installed on the base plate (1). A shielding mechanism is also provided on the base plate (1). The shielding mechanism includes a permalloy shielding cover (51). A copper mesh (52) is fixed inside the permalloy shielding cover (51). A rectangular groove (50) is opened on the top of the base plate (1). The permalloy shielding cover (51) and the copper mesh (52) are embedded in the rectangular groove (50).

2. The high-precision parallel plate capacitive sensor structure according to claim 1, characterized in that, The shielding mechanism also includes fixing strips (53) fixed on both sides of the permalloy shielding cover (51), and the fixing strips (53) are provided with locking holes (54).

3. The high-precision parallel plate capacitive sensor structure according to claim 2, characterized in that, The base plate (1) is also provided with a limiting mechanism for installing the permalloy shield (51). The limiting mechanism includes a mounting shell (61) fixed to the top of the base plate (1). The top of the mounting shell (61) is provided with a slot (62), and the fixing strip (53) is engaged in the slot (62).

4. The high-precision parallel plate capacitive sensor structure according to claim 3, characterized in that, A pull rod (63) slides inside the mounting housing (61). A connecting plate (64) is fixed to one end of the pull rod (63) near the slot (62). A locking rod (65) is fixed to one side of the connecting plate (64) away from the pull rod (63). The locking rod (65) is slidably connected to the mounting housing (61) and slides in the locking hole (54).

5. The high-precision parallel plate capacitive sensor structure according to claim 4, characterized in that, A return spring (66) is sleeved on the outer surface of the pull rod (63). The two ends of the return spring (66) are fixedly connected to the mounting shell (61) and the connecting plate (64) respectively. A U-shaped rod (67) is fixed to the end of the pull rod (63) away from the connecting plate (64).

6. The high-precision parallel plate capacitive sensor structure according to claim 1, characterized in that, The spacing adjustment mechanism includes two support blocks (41) symmetrically fixed on the top of the base plate (1). A bidirectional lead screw (42) rotates between the two support blocks (41) via a bearing. A moving bar (43) is threaded onto the outer surface of the bidirectional lead screw (42). A limit rod (44) is fixed between the two support blocks (41). The moving bar (43) slides on the outer surface of the limit rod (44). An insulating support column (23) is fixed on the top of the moving bar (43). A motor (45) for driving the bidirectional lead screw (42) to rotate is installed on the support block (41).

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