Vibration electrode structure for electrostatic detection and verification method thereof

Abstract

The invention discloses a vibration electrode structure for electrostatic detection and a verification method thereof, and belongs to the field of electrostatic measurement. A static detection electrode with a symmetrical structure is arranged towards the static power supply; the electrostatic detection electrode comprises a fixed electrode, a vibration electrode and a piezoelectric ceramic electrode, the fixed electrode, the vibration electrode and the piezoelectric ceramic electrode are fixedly connected into a whole; the piezoelectric ceramic electrode completely covers and is connected with the connecting end surfaces of the fixed electrode and the vibration electrode; the longitudinal axis of the static detection electrode faces the static power supply; and an electrostatic charge induction electrode is arranged on one side, facing the static power supply, of the vibration electrode. The fixed electrode is fixedly connected to the circuit board; a sinusoidal voltage is applied to the fixed electrode, and the vibration electrode is connected with a zero-volt voltage to drive the piezoelectric ceramic electrode in the middle, so that the piezoelectric ceramic electrode forms longitudinal wave type back-and-forth movement / vibration in the detection direction, and finally, a standard sinusoidal oscillation capacitor is formed between the vibration electrode and the electrostatic charge induction electrode. And a standard sinusoidal voltage signal is formed on the electrostatic charge induction electrode.

Description

Technical Field

[0001] The present invention belongs to the field of measurement of electric charge quantity, and particularly relates to a vibration detection electrode for detecting the static voltage on the surface of an object and a verification method thereof. Background Art

[0002] A static voltage sensor is a professional and key instrument for detecting static charges on the surface of an object. The accuracy and stability of its detected data play a very important role in the electrostatic protection work of electrostatic sensitive devices.

[0003] Currently, most of the mainstream static voltage sensors on the market adopt a non-contact detection method. Using the principle of electrostatic induction, a vibrating capacitive test probe is brought close to a charged object, and the surface potential of the charged object is measured by using the distorted electric field generated between the probe and the measured charged object. In essence, it is a measurement of the electric field on the surface of the charged object.

[0004] Since this measurement is not in direct contact with the charged object, it is also called non-contact measurement. The static voltage sensor used is also called a non-contact static voltage sensor.

[0005] Compared with contact measurement, the non-contact measurement result is less affected by the input capacitance and input resistance of the instrument, and its measurement accuracy is significantly related to the mechanical / electrical structure of the vibrating electrode in the electrostatic induction sensor.

[0006] Therefore, continuously optimizing the electrical structure design of the vibrating electrode is of great significance to the detection performance of the non-contact static voltage sensor.

[0007] For the typical structure of the existing vibrating electrode, reference can be made to two patents previously applied by the applicant: the invention patent "A Portable Electrostatic Detection Device and Its Electrostatic Detection Method" with the authorization announcement date of November 13, 2013 and the authorization announcement number of CN 102353855 B, and the utility model patent "An Electrostatic Sensing Detection Head" with the authorization announcement date of October 11, 2019 and the authorization announcement number of CN 209486193U; the specific structure of its vibrating electrode is as Figures 1 to 2e shown: A sensing bracket and a charge induction sheet are arranged on a circuit board f. The cross-section of the sensing bracket is a U-shaped structure, which is composed of two longitudinal vertical edges of the sensing bracket and the top horizontal edge of the sensing bracket; the charge induction sheet is arranged perpendicular to the circuit board.

[0008] In this technical solution, two vibrating plates d are symmetrically arranged and connected together by a special-shaped connecting plate a located at the rear thereof; the two vibrating plates are fixed above the circuit board by 4 supporting plates b at the rear, and a "dot" - shaped fixing structure (also known as "dot" fixing method or "dot" type fixing) is formed through the welding feet b' at the bottom of the supporting plates, and is fixedly welded on the circuit board. Two piezoelectric ceramic plates c are located in front of the special-shaped connecting plate and are symmetrically arranged on the inner surfaces of the two vibrating plates; the two piezoelectric ceramic plates are electrically connected to the circuit board f through leads c'; the static charge induction electrode e is independently arranged at the front end of the vibrating plate. It makes the two longitudinal vertical edges of the sensing bracket generate transverse vibrations through the piezoelectric ceramic, forming an action mode similar to the vibration of a tuning fork, and the charge induction sheet is used to receive the action signal generated by the external static charge. It can effectively prevent the interference of the outside world to the static sensing signal; fundamentally solve the problem of quantitative detection of static electricity, and the subsequent amplification / processing of the monitoring data is easy, the repeatability of the detection data is good, improving the accuracy and stability of static electricity detection; helping to ensure the product qualification rate of the static electricity sensor.

[0009] In summary, the detection method adopted by the existing static voltage sensor is the vibration / alternating capacitance detection method, and the detection principle is the electrostatic induction principle.

[0010] However, it is found in the actual use process that the existing technical solution has the following technical defects:

[0011] 1) The fixing method of the vibrating electrode is "dot" type fixing, which is not conducive to regular vibration in the functional vibration direction (also known as the main vibration direction, and can also be expressed as "functional (main) vibration direction"), will form interfering vibrations in other directions, form a stray capacitance signal with the static charge induction electrode, distort the functional detection signal, and cannot form a standard sine wave signal on the static charge induction electrode, which is not conducive to the detection result;

[0012] 2) The functional (main) vibration direction of the vibrating plate is perpendicular to the length direction of the vibrating plate, that is, a "transverse wave" - type vibration is formed (see the illustration in Figure 2-1 、 Figure 2-2 ), the vibrating electrode cannot quickly reach a stable vibration state, and since the piezoelectric ceramic plate only covers a small part of the area of the vibrating plate, such a structural pattern setting is not conducive to the vibrating electrode quickly forming a stable vibration state, resulting in poor stability of the detection signal.

[0013] How to reduce the interfering vibration of the vibrating electrode and the stray capacitance signal caused by it, and make the detection result of the non - contact static voltage sensor more accurate and more stable is an actual technical problem urgently to be solved in the actual R & D work. Summary of the Invention

[0014] The technical problem to be solved by the present invention is to provide a vibrating electrode structure for electrostatic detection and its verification method.

[0015] The technical solution of the present invention is: to provide a vibrating electrode structure for electrostatic detection, characterized in that:

[0016] In the detection direction towards the static power source to be detected, an electrostatic detection electrode with a symmetrical structure is provided;

[0017] The electrostatic detection electrode with a symmetrical structure includes three main parts: a fixed electrode, a vibrating electrode, and a piezoelectric ceramic electrode;

[0018] The longitudinal axis of the electrostatic detection electrode faces the static power source;

[0019] On the side of the vibrating electrode facing the static power source, a static charge induction electrode is provided;

[0020] The fixed electrode, the vibrating electrode, and the piezoelectric ceramic electrode are fixedly connected as a whole;

[0021] The piezoelectric ceramic electrode is located between the fixed electrode and the vibrating electrode, and completely covers and connects the connection end faces of the fixed electrode and the vibrating electrode;

[0022] The fixed electrode is fixedly welded to the circuit board to restrict its movement;

[0023] A sine voltage is applied to the fixed electrode, and the vibrating electrode is connected to zero volts to drive the middle piezoelectric ceramic electrode to form a longitudinal wave type reciprocating motion / vibration in the detection direction, and finally a standard sine oscillation capacitor is formed between the vibrating electrode and the static charge induction electrode, and a standard sine voltage signal is formed on the static charge induction electrode.

[0024] Specifically, the detection direction is the same as the central axis direction of the induction surface / detection surface of the static charge induction electrode; the vibration direction of the vibrating electrode in the detection direction is parallel to the length direction of the vibrating electrode.

[0025] Specifically, the fixed electrode is fixedly welded to the circuit board in a "surface" contact structure form.

[0026] Furthermore, making a cross-section / section along the longitudinal length direction of the electrostatic detection electrode, the electrostatic detection electrode has a "mirror symmetry" structure form along its longitudinal axis.

[0027] Specifically, the position of the static charge induction electrode is fixed. When the surface of an object of a static power source carries static charges, the static charge induction electrode will sense an electrostatic signal; the vibrating electrode will perform periodic vibrations along its functional vibration direction; the capacitance C1 between the vibrating electrode and the static charge induction electrode also changes periodically, and there is the following relational expression:

[0028] C1 = C ∞ (1 + Ksinwt)

[0029] In the formula: C ∞ is the static capacitance between the vibrating electrode and the static charge induction electrode at the equilibrium position, F; w is the angular frequency of the mechanical vibration of the vibrating electrode, radian / S; K is the modulation coefficient of C1, K ＜＜ 1.

[0030] Specifically, the static charge induction electrode facing the front of the surface of the charged object will generate static charges corresponding to the surface of the charged object;

[0031] After applying a driving voltage to the piezoelectric ceramic electrode / sheet attached to the vibrating electrode, the piezoelectric ceramic electrode / sheet will longitudinally expand and contract along the detection direction, thereby driving the vibrating electrode to generate periodic reciprocating motion;

[0032] Through the periodic motion / vibration of the vibrating electrode, the electrostatic induction signal on the static charge induction electrode is periodically modulated, and the amount of static charges generated on the static charge induction electrode also increases and decreases periodically. Furthermore, it can be equivalently regarded as a variable capacitor with a periodically increasing and decreasing capacitance.

[0033] As an embodiment, the electrostatic detection electrode with a symmetrical structure includes a pair of parallel clamping plate electrodes that are mirror images of each other;

[0034] Each parallel clamping plate electrode includes two rectangular electrode sheets made of metal that are parallel and coincident with each other, with a piezoelectric ceramic sheet in the middle layer. The three are bonded or fixed together by conductive adhesive;

[0035] Among them, in the two rectangular electrode sheets that make up each parallel clamping plate electrode, the outermost rectangular electrode sheet is the fixed electrode, the innermost rectangular electrode sheet is the vibrating electrode, and the piezoelectric ceramic electrode is located between the fixed electrode and the vibrating electrode;

[0036] In front of the vibration direction of the parallel clamping plate electrodes that are mirror images of each other, that is, on the side where the vibrating electrode faces the static power source, a static charge induction electrode is provided;

[0037] The outermost metal rectangular electrode sheet is fixedly welded to the circuit board to restrict its movement;

[0038] The central axis where the induction surface / detection surface of the static charge induction electrode is located coincides with the central axis in the vibration direction of the parallel clamping plate electrodes that are mirror images of each other, and is located inside the housing of the electrostatic sensor;

[0039] A sinusoidal voltage is applied to the two outermost fixed electrodes, and the two innermost vibrating electrodes are connected to zero volts to drive the middle piezoelectric ceramic sheet to generate a reciprocating motion in the length direction, forming a longitudinal wave vibration. Eventually, a standard sinusoidal oscillating capacitor is formed between the vibrating electrode and the static charge induction electrode, and a standard sinusoidal signal is formed on the static charge induction electrode.

[0040] As another embodiment, the electrostatic detection electrode with a symmetrical structure is an electrostatic detection electrode in a circular tube shape;

[0041] The electrostatic detection electrode in a circular tube shape includes a circular tube-shaped fixed electrode, an annular piezoelectric ceramic sheet, and a circular tube-shaped vibrating electrode;

[0042] The circular tube-shaped fixed electrode, the annular piezoelectric ceramic sheet, and the circular tube-shaped vibrating electrode are arranged coaxially, and the three are fixedly connected to each other in sequence and are located inside the housing of the static voltage sensor as a whole;

[0043] The circular tube-shaped fixed electrode is fixed on the circuit board, and the annular piezoelectric ceramic sheet is located between the circular tube-shaped fixed electrode and the circular tube-shaped vibrating electrode;

[0044] The annular piezoelectric ceramic sheet completely covers the end face of the vibrating electrode;

[0045] A cylindrical static charge induction electrode is arranged in front of the circular tube-shaped electrostatic detection electrode, and their central axes coincide; one end of the cylindrical static charge induction electrode faces the static power source;

[0046] A sinusoidal voltage is applied to the circular tube-shaped fixed electrode, and the circular tube-shaped vibrating electrode is connected to zero volts to drive the middle annular piezoelectric ceramic sheet to generate a reciprocating motion in the length direction, forming a longitudinal wave vibration. Eventually, a standard sinusoidal oscillating capacitor is formed between the circular tube-shaped vibrating electrode and the cylindrical static charge induction electrode, and a standard sinusoidal signal is formed on the cylindrical static charge induction electrode.

[0047] The technical solution of the present invention also provides a method for verifying the above vibrating electrode structure, which is characterized by including the following steps:

[0048] 1) Respectively construct the structural models of the existing vibrating electrode and the electrostatic detection vibrating electrode structure of the present invention;

[0049] 2) Respectively apply the linear elasticity and piezoelectric solid mechanics mathematical models to the two vibrating electrodes;

[0050] 3) Apply the mathematical model of electrostatic field to the piezoelectric ceramic structure;

[0051] 4) Use a sinusoidal voltage to drive the annular piezoelectric ceramic sheet in the middle of the electrostatic detection vibration electrode and the piezoelectric ceramic sheets of the existing vibration electrodes;

[0052] 5) Perform mesh division on the overall vibration electrode structure with mapping and sweeping operations;

[0053] 6) Execute simulation operations to obtain the corresponding simulation results;

[0054] 7) Analyze and compare the time-varying characteristics of the displacement fields of different vibration electrode structures based on the simulation results;

[0055] 8) Calculate the ratios of the interfering vibration displacements to the functional vibration displacements of the existing vibration electrodes and the electrostatic detection electrodes of the present invention respectively;

[0056] 9) Determine the superiority of this vibration electrode structure based on the time period of entering the steady state and the ratio of the interfering vibration displacement to the functional vibration displacement.

[0057] Specifically, during verification, fix and constrain the welding feet of the existing vibration electrodes and the tail end faces of the fixed electrodes of the electrostatic detection vibration electrodes of the present invention respectively, so that their displacements are zero;

[0058] Weld the static charge induction electrodes of the existing vibration electrodes and the static charge induction electrodes of the electrostatic detection vibration electrodes of the present invention to the circuit board, and set their displacement constraints to zero;

[0059] When using a sinusoidal voltage to drive the piezoelectric ceramic sheets in the middle of the electrostatic detection vibration electrodes and the piezoelectric ceramic sheets of the existing vibration electrodes, for the existing vibration electrodes, the sinusoidal voltage is electrically connected to the leads of its piezoelectric ceramic sheets, and its vibrating piece is connected to zero volts; for the electrostatic detection vibration electrodes of the present invention, the sinusoidal voltage is electrically connected to the fixed electrodes through the circuit board fixing it, while the vibration electrodes are connected to zero volts through leads;

[0060] During the stage of executing simulation operations, for the existing vibration electrodes, select the center point of one vibrating piece end face facing the static charge induction electrode as the displacement analysis point of the existing vibration electrodes; for the electrostatic detection vibration electrodes of the present invention, select a point on the end face of the vibration electrode facing the static charge induction electrode as the displacement analysis point of the electrostatic detection electrode of this technical solution; make the time-varying characteristic curve graphs of the displacement fields of both.

[0061] Compared with the prior art, the advantages of the present invention are:

[0062] 1. The vibration electrode structure of this technical solution changes the "point" fixing method of the existing vibration electrode to a "surface" fixing method, strengthening the constraint on the vibration electrode, significantly reducing the interfering vibration in the non-functional (main) vibration direction during vibration, effectively suppressing the generation of stray capacitance signals, and improving the accuracy of the detection result;

[0063] 2. In the vibration electrode structure of this technical solution, its functional (main) vibration direction is parallel to the length direction of the vibration electrode, forming a longitudinal wave type vibration, and the piezoelectric ceramic sheet completely covers and connects the connection end faces of the fixed electrode and the vibration electrode. In this way, the vibration electrode can quickly reach a stable vibration state, enhancing the stability of the detection signal;

[0064] 3. Compared with the structure of the existing vibration electrode, in the vibration electrode structure of this technical solution, since the piezoelectric ceramic sheet completely covers and connects the connection end faces of the fixed electrode and the vibration electrode, its vibration electrode hardly generates its own local deformation, but only generates the overall vibration / movement of the vibration electrode; its mechanical vibration frequency is consistent with the driving voltage frequency of its piezoelectric ceramic sheet, that is, the vibration frequency is completely controlled by the driving voltage frequency; in this way, the driving voltage frequency can be adjusted according to the change of the static power source, making the vibration frequency better adapt to the on-site process change and enhancing the applicability to the on-site environment;

[0065] 4. The vibration electrode structure of this technical solution has a faster startup response speed, thus saving the startup preheating and debugging time of the static voltage sensor;

[0066] 5. The vibration electrodes of this technical solution are all axisymmetric structures, with simple structures, reducing the processing and manufacturing difficulty and processing cost, and can more easily achieve high-precision requirements. Description of the Drawings

[0067] Figure 1 is a schematic structural diagram of the existing electrostatic detection electrode;

[0068] Figure 2a is a schematic expanded planar structural diagram of the existing electrostatic detection electrode;

[0069] Figure 2b Schematic side view structural diagram of the existing electrostatic detection electrode;

[0070] Figure 2c and Figure 2d are the left and right view structural diagrams of the existing electrostatic detection electrode;

[0071] Figure 2e is a schematic top view structural diagram of the existing electrostatic detection electrode;

[0072] Figure 2-1 is a schematic simulation diagram of the vibration / movement mode of the existing electrostatic detection electrode;

[0073] Figure 2-2 Another simulation diagram of the vibration / movement mode of the existing electrostatic detection electrode;

[0074] Figure 3 Schematic diagram of the working principle of the vibration capacitive static voltage sensor of the present invention;

[0075] Figure 4 Schematic three-dimensional structure diagram of the electrostatic detection electrode seen from one end of the parallel clamping plate electrode in the first embodiment of the present invention;

[0076] Figure 4-1 Top view structure diagram of the electrostatic detection electrode in the first embodiment of the present invention;

[0077] Figure 4-2 Schematic three-dimensional structure diagram of the electrostatic detection electrode seen from one end of the static charge induction electrode in the first embodiment of the present invention;

[0078] Figure 5 Flow chart of the simulation comparison test of the electrostatic detection electrode structure in the first embodiment of the present invention;

[0079] Figure 6 Simulation diagram of the vibration / movement mode of the electrostatic detection electrode in the first embodiment of the present invention;

[0080] Figure 7 Another simulation diagram of the vibration / movement mode of the electrostatic detection electrode in the first embodiment of the present invention;

[0081] Figure 8 Interference displacement X component diagram of the existing electrostatic detection electrode;

[0082] Figure 9 Functional (main) displacement Y component diagram of the existing electrostatic detection electrode;

[0083] Figure 10 Interference displacement Z component diagram of the existing electrostatic detection electrode;

[0084] Figure 11 Functional (main) displacement X component diagram of the electrostatic detection electrode in the first embodiment of the present invention;

[0085] Figure 12 Interference displacement Y component diagram of the electrostatic detection electrode in the first embodiment of the present invention;

[0086] Figure 13 Interference displacement Z component diagram of the electrostatic detection electrode in the first embodiment of the present invention;

[0087] Figure 14 Functional (main) displacement comparison diagram between the first embodiment of the present invention and the existing electrostatic detection electrode;

[0088] Figure 14-1 Function (main) displacement vibration waveform and drive voltage waveform comparison diagram of the electrostatic detection electrode in the first embodiment of the present invention and the existing electrostatic detection electrode;

[0089] Figure 15 Interference displacement comparison diagram between the electrostatic detection electrode in the first embodiment of the present invention and the existing electrostatic detection electrode;

[0090] Figure 16 Three-dimensional structure schematic diagram of the electrostatic detection electrode in the second embodiment of the present invention;

[0091] Figure 16-1 Another three-dimensional structure schematic diagram of the electrostatic detection electrode in the second embodiment of the present invention;

[0092] Figure 16-2 Front view of the electrostatic detection electrode in the second embodiment of the present invention;

[0093] Figure 16-3 Top view of the electrostatic detection electrode in the second embodiment of the present invention;

[0094] Figure 16-4 Bottom view of the electrostatic detection electrode in the second embodiment of the present invention;

[0095] Figure 16-5 Cross-sectional view of the electrostatic detection electrode in the second embodiment of the present invention;

[0096] Figure 17 Simulation schematic diagram of the vibration / movement mode of the electrostatic detection electrode in the second embodiment of the present invention;

[0097] Figure 18 Another simulation schematic diagram of the vibration / movement mode of the electrostatic detection electrode in the second embodiment of the present invention;

[0098] Figure 19 Interference displacement X-component diagram of the electrostatic detection electrode in the second embodiment of the present invention

[0099] Figure 20 Interference displacement Y-component diagram of the electrostatic detection electrode in the second embodiment of the present invention

[0100] Figure 21 Functional (main) displacement Z-component diagram of the electrostatic detection electrode in the second embodiment of the present invention

[0101] Figure 22 Function (main) displacement comparison diagram between the electrostatic detection electrode in the second embodiment of the present invention and the existing electrostatic detection electrode;

[0102] Figure 22-1 Function (main) displacement vibration waveform and drive voltage waveform comparison diagram of the electrostatic detection electrode in the second embodiment of the present invention and the existing electrostatic detection electrode;

[0103] Figure 23 This is a comparison diagram of the interference displacement between the electrostatic detection electrode in the second embodiment of the present invention and the existing electrostatic detection electrode.

[0104] Figures 1 to 2-2 In the figure: a is a special-shaped connecting piece, b is a support piece, b' is a welding leg, c is a piezoelectric ceramic sheet, c' is a lead wire, d is a vibrating piece, e is a static charge induction electrode, f is a circuit board; o is the point selected for displacement analysis of the prior art solution;

[0105] Figure 3 In the figure, 0 is the surface of the charged object, 1 is the fixed electrode, 2 is the vibrating electrode, 3 is the piezoelectric ceramic electrode (sheet), and 4 is the static charge induction electrode;

[0106] Figures 4 to 15 In the figure, A and A' are parallel clamping plate electrodes, 1' is an external rectangular electrode sheet, 1-1' is the outer surface of the external rectangular electrode sheet, 2' is an internal rectangular electrode sheet, 3' is a piezoelectric ceramic sheet, 4' is a static charge induction electrode, 4-1' is the induction surface / detection surface of the static charge induction electrode, and o' is the point selected for displacement analysis of this technical solution;

[0107] h is the spacing distance between the two parallel clamping plate electrodes A and A', h1 is the thickness of the external rectangular electrode sheet, h2 is the thickness of the internal rectangular electrode sheet, h3 is the thickness of the piezoelectric ceramic sheet, and M is the central axis of the rectangular electrostatic induction electrode induction surface / detection surface in the vibration direction of the parallel clamping plate electrodes that are mirror images of each other;

[0108] Figures 16 to 16-5 In the figure, 1″ is the fixed electrode, 1-1″ is the end face of the tail of the fixed electrode, 2″ is the vibrating electrode, 3″ is an annular piezoelectric ceramic sheet, 4″ is the static charge induction electrode, 4-1″ is the induction surface / detection surface of the static charge induction electrode, 5″ is a ceramic sleeve, and o″ is the point selected for displacement analysis of this technical solution;

[0109] h1″ is the outer diameter of the electrostatic detection electrode, h2″ is the inner diameter of the electrostatic detection electrode, and h3″ is the thickness of the annular piezoelectric ceramic sheet. Detailed implementation manners

[0110] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0111] Currently, for the static voltage sensor products on the market, the vast majority of their detection methods are non-contact detection. The detection method adopted is the vibration / alternating capacitance detection method, and the detection principle relied on is the electrostatic induction principle.

[0112] The vibration capacitance type electrostatic detection electrode described in this technical solution modulates the electrostatic induction signal on the electrostatic induction electrode into an alternating current signal by using mechanical vibration.

[0113] As Figure 3 shown, in this technical solution, in the detection direction towards the static power source to be detected (abbreviated as the static power source), an electrostatic detection electrode with a symmetrical structure is provided

[0114] The electrostatic detection electrode with a symmetrical structure has three main parts, one is the fixed electrode 1, one is the vibrating electrode 2, and one is the piezoelectric ceramic electrode 3.

[0115] On the side of the vibrating electrode facing the static power source, a static charge induction electrode 4 is provided.

[0116] The fixed electrode, the vibrating electrode, and the piezoelectric ceramic electrode are bonded or fixedly connected into one body through conductive adhesive.

[0117] The piezoelectric ceramic electrode is located between the fixed electrode and the vibrating electrode, and completely covers and connects the connection end faces of the fixed electrode and the vibrating electrode.

[0118] The said electrostatic detection electrode has its longitudinal axis line facing (pointing to) the static power source.

[0119] The fixed electrode is fixedly welded to the circuit board to restrict its movement.

[0120] A sine voltage is applied to the fixed electrode, and the vibrating electrode is connected to zero volts to drive the middle piezoelectric ceramic electrode to form a longitudinal wave type reciprocating motion / vibration (also known as longitudinal wave type vibration, abbreviated as longitudinal vibration) in the detection direction (that is, the central axis direction where the induction surface / detection surface of the static charge induction electrode is located), and finally a standard sine oscillation capacitance is formed between the vibrating electrode and the static charge induction electrode, and a standard sine voltage signal is formed on the static charge induction electrode.

[0121] The mechanical vibration frequency of the vibrating electrode is consistent with the driving voltage frequency of the piezoelectric ceramic piece.

[0122] The vibration direction of the above-mentioned vibrating electrode in the detection direction is called the functional vibration direction or the main vibration direction, also known as the functional (main) vibration direction.

[0123] The vibration direction of the said vibrating electrode in the detection direction is parallel to the length direction of the vibrating electrode.

[0124] The "symmetry" structure of the said electrostatic detection electrode means that when a cross-section (cutting plane) is made along the longitudinal (length) direction of the electrostatic detection electrode, the said electrostatic detection electrode has a "mirror symmetry / axial symmetry" structural form along its longitudinal axis line.

[0125] Further, on one side facing the static power source in the vibration direction of the vibration electrode, a static charge induction electrode 4 is provided; this static charge induction electrode is used to sense / detect the central axis of the induction surface / detection surface of the static power source, and the electrostatic detection electrode with a symmetrical structure coincides with the central axis in the functional (main) vibration direction.

[0126] The fixed electrode is fixedly welded to the circuit board in the form of "surface" contact (referred to as "surface" fixing method).

[0127] Further, the electrostatic detection electrode with a symmetrical structure Its size, especially the facing area between the vibration electrode and the static charge induction electrode, and the size in the relevant direction where the piezoelectric ceramic electrode can change the displacement amplitude, can be set according to the electrostatic detection requirements.

[0128] At the same time, the static charge induction electrode can adjust its relative position with the vibration electrode on the central axis of its induction surface / detection surface according to the electrostatic detection requirements.

[0129] The static charge induction electrode can also set its size according to the electrostatic detection requirements.

[0130] Such as Figure 3 As shown, the position of the static charge induction electrode 4 (on the circuit board) is fixed. When the object surface of the static power source carries static charges (represented by the charged object surface 0 in the figure), the static charge induction electrode 4 will sense an electrostatic signal; the vibration electrode 2 vibrates periodically along the bidirectional arrow direction in the figure (i.e., the aforementioned functional (main) vibration direction), so the capacitance C1 between it and the static charge induction electrode 4 also changes periodically, and there is the following relational expression:

[0131] C1 = C ∞ (1 + Ksinwt) (1)

[0132] In the formula:

[0133] C ∞ —— The static capacitance between the vibration electrode 2 and the static charge induction electrode 4 at the equilibrium position, F;

[0134] w —— The angular frequency of the mechanical vibration of the vibration electrode 2, radian / S;

[0135] K —— The modulation coefficient of C1. Since the amplitude of the vibration electrode 2 is extremely small, so K ＜＜ 1;

[0136] According to theoretical derivation, the voltage signal on the input resistance R i of the static voltage sensor can be obtained as:

[0137]

[0138] In the formula:

[0139] U1——Induced potential on the static charge induction electrode 4, V;

[0140] C i ——Input capacitance of the static voltage sensor, F;

[0141] R i ——Input resistance of the static voltage sensor, Ω;

[0142] The meanings of other symbols are the same as those in formula (1).

[0143] Since the obtained measurement signal is very weak, an impedance converter with high impedance input is used for reception. After the impedance-transformed signal is input to the range converter, it is amplified by an AC amplifier and detected, and then displayed by a meter head or an external monitoring device.

[0144] As can be seen from formula (2), the voltage V i on the input resistance R i (t) changes periodically with time t. Therefore, this type of measuring instrument has good stability, can be used for long-term and continuous static voltage monitoring, and has high sensitivity.

[0145] The static charge induction electrode 4 facing the front of the surface of the charged object 0 will generate static charges corresponding to the surface of the charged object.

[0146] After applying a driving voltage to the piezoelectric ceramic electrode (sheet) 3 attached to the vibrating electrode 2, the piezoelectric ceramic electrode (sheet) 3 will longitudinally expand and contract along the detection direction, thereby driving the vibrating electrode 2 to perform a periodic reciprocating motion.

[0147] Through the periodic motion / vibration of the vibrating electrode 2, the electrostatic induction signal on the static charge induction electrode 4 is periodically modulated, and the amount of charge generated on the static charge induction electrode 4 also increases and decreases periodically. Therefore, from the perspective of circuit principle, it can be equivalently regarded as a variable capacitor with a periodically changing capacitance.

[0148] The periodic potential change generated on the static charge induction electrode 4 will pass through the combined impedance of the input capacitance C i and the input resistance R i inside the impedance conversion preamplifier to generate a voltage output centered on the reference static potential (see formula 2). The electrostatic induction between the static charge induction electrode 4 and the surface of the charged object 0 is related to the distributed capacitance C0 and the static voltage U0 on the object surface between them; when the facing area, distance, and dielectric constant of the intermediate medium between the two are certain, the distributed capacitance C0 is determined, and the induced potential on the static charge induction electrode 4 is proportional to the static voltage U0 on the object surface.

[0149] Finally, the AC output V of the preamplifier i will be processed and calibrated by the subsequent circuit so that the detected value displayed by the static voltage sensor is consistent with the static voltage value of the object surface.

[0150] Thus, it can be known that the AC output V of the preamplifier i is proportional to the ground potential U0 of the measured surface of the object (the static voltage of the object surface). At the same time, referring to formula (2), the following relationship will be formed between the amplitude of the vibrating electrode 2 and the AC output of the preamplifier, that is:

[0151] 1) When the ground potential U0 of the object is constant, the AC output of the preamplifier is proportional to the amplitude of the vibrating electrode;

[0152] 2) When the amplitude of the vibrating electrode is constant, the AC output of the preamplifier is proportional to the ground potential U0 of the object.

[0153] Therefore, the stability of the amplitude of the vibrating electrode 2 will have an important impact on static electricity detection.

[0154] Embodiment 1:

[0155] In this embodiment, the static electricity detection electrode with a symmetrical structure is a pair of parallel clamping plate electrodes that are mirror images of each other. Each parallel clamping plate electrode includes two rectangular electrode sheets made of metal that are parallel and coincident with each other, and the middle interlayer is a piezoelectric ceramic sheet. The three are bonded or fixed together by conductive adhesive.

[0156] Among them, in the two rectangular electrode sheets that make up each parallel clamping plate electrode, the outermost rectangular electrode sheet is the fixed electrode 1′, and the innermost rectangular electrode sheet is the vibrating electrode 2′. The piezoelectric ceramic electrode 3′ is located between the fixed electrode 1′ and the vibrating electrode 2′.

[0157] In front of the vibration direction of the parallel clamping plate electrodes that are mirror images of each other, that is, on the side where the vibrating electrode faces the static power source, a static charge induction electrode 4′ is provided.

[0158] The outermost metal rectangular electrode sheet is fixedly welded to the circuit board to restrict its movement.

[0159] The central axis of the sensing surface 4-1′ (i.e., the detection surface) of the static charge induction electrode coincides with the central axis in the vibration direction of the parallel clamping plate electrodes that are mirror images of each other, and is located inside the housing of the static electricity sensor.

[0160] A sinusoidal voltage is applied to the two outermost rectangular electrode plates (i.e., the fixed electrode 1′), and the two innermost rectangular electrode plates (i.e., the vibrating electrode 2′) are connected to zero volts to drive the middle piezoelectric ceramic sheet to generate a reciprocating motion in the length direction (the detection direction, which is also the central axis direction where the rectangular electrostatic induction electrode induction surface (detection surface) is located), that is, to form a longitudinal wave vibration. Finally, a standard sinusoidal oscillating capacitor is formed between the vibrating electrode and the static charge induction electrode, and a standard sinusoidal signal is formed on the static charge induction electrode.

[0161] The following specifically describes the technical solution with reference to the drawings:

[0162] 1. As shown in Figure 4 、 Figure 4-1 In this technical solution, a pair of parallel clamping plate electrodes A and A′ that are mirror images of each other (along the length direction) are provided. Each of the parallel clamping plate electrodes A and A′ includes two mutually parallel and coincident metal rectangular electrode plates, that is, the external rectangular electrode plate 1′ of the electrostatic detection electrode (referred to as the external electrode plate) and the internal rectangular electrode plate 2′ of the electrostatic detection electrode (referred to as the internal electrode plate). A piezoelectric ceramic sheet 3′ is provided between each external electrode plate and the internal electrode plate.

[0163] Specifically, the parallel clamping plate-shaped vibrating electrode of this technical solution includes a pair of parallel clamping plate electrodes A and A′ that are mirror-image arranged;

[0164] Each parallel clamping plate electrode A or A′ is composed of an external electrode plate and an internal electrode plate;

[0165] A piezoelectric ceramic sheet is provided between the external electrode plate and the internal electrode plate;

[0166] The external electrode plate and the internal electrode plate have the same shape and are arranged in parallel;

[0167] The piezoelectric ceramic sheet has the same shape as the external electrode plate and the internal electrode plate;

[0168] The external rectangular electrode plate 1′, the internal rectangular electrode plate 2′, and the piezoelectric ceramic sheet 3′ are bonded / fixed together as a whole through conductive adhesive to form the parallel clamping plate electrodes A and A′ with a layered composite structure.

[0169] 2. Each of the parallel clamping plate electrodes A or A′ is fixed on the circuit board through the external rectangular electrode plate 1′.

[0170] Furthermore, each parallel clamping plate electrode A or A′ is fixed on the circuit board through the outer surface 1-1′ of the external rectangular electrode plate.

[0171] 3. Refer to Figure 4-1As shown, the distance h between two parallel clamping plate electrodes A and A' that are mirror images of each other can be set or adjusted according to the needs of electrostatic detection.

[0172] 4. For two parallel clamping plate electrodes A and A' that are mirror images of each other, the sizes of their metallic outer rectangular electrode sheets 1', inner rectangular electrode sheets 2', and piezoelectric ceramic sheets 3' located in the middle sandwich layer, especially the sizes related to thickness (see Figure 4-1 As shown, for example, the thickness h1 of the outer rectangular electrode sheet of the electrostatic detection electrode, the thickness h2 of the inner rectangular electrode sheet of the electrostatic detection electrode, and the thickness h3 of the piezoelectric ceramic sheet of the electrostatic detection electrode), can be set or adjusted according to the needs of electrostatic detection.

[0173] For example, increasing the thickness h3 of the piezoelectric ceramic sheet 3' can make the vibration amplitude of the inner rectangular electrode sheet 2' larger, and then make the vibration capacitance between the parallel clamping plate electrodes that are mirror images of each other and the rectangular electrostatic induction electrode 4' larger, so as to enhance the ability to receive electrostatic signals.

[0174] Also, for example, increasing the thickness h2 of the inner rectangular electrode sheet 2' can also make the vibration capacitance between the inner rectangular electrode sheets that are mirror images of each other and the electrostatic induction electrode 4' larger, so as to enhance the ability to receive electrostatic signals.

[0175] 5. The outer surface 1-1' of the outermost outer rectangular electrode sheet is fixedly welded to the circuit board to keep it always in a static state.

[0176] Since the outer surface 1-1' of the outer rectangular electrode sheet is fixedly welded to the circuit board, the connection relationship formed between the rectangular electrode sheet and the circuit board in this technical solution is a "surface contact" type of fixing method (abbreviated as "surface" fixing method); due to strengthening the constraint on the mechanical structure of the vibrating electrode, the interference vibration in the non-functional (main) vibration direction during vibration is greatly reduced, the generation of stray capacitance signals can be effectively suppressed, and thus the accuracy of the electrostatic detection result is improved.

[0177] 6. At one end of the parallel clamping plate electrodes A and A', a rectangular electrostatic induction electrode 4' is provided.

[0178] The rectangular electrostatic induction electrode 4' is independently fixed to the circuit board.

[0179] The side of the rectangular electrostatic induction electrode 4' facing away from the parallel clamping plate electrodes A and A' is the induction surface / detection surface 4-1' of the static charge induction electrode.

[0180] Further, in front of the vibration directions of the parallel clamping plate electrodes A and A' that are mirror images of each other, a rectangular electrostatic induction electrode 4' is provided. The central axis M of the induction surface / detection surface 4-1' of this static charge induction electrode coincides with the central axis in the vibration direction of the parallel clamping plate electrodes that are mirror images of each other, and is located inside the electrostatic sensor housing.

[0181] 7. The rectangular electrostatic induction electrode 4' can adjust its relative position with respect to the parallel clamping plate electrodes that are mirror images of each other on the central axis of its induction surface / detection surface 4-1' according to the needs of electrostatic detection.

[0182] The rectangular static charge induction electrode can also set its size according to the needs of electrostatic detection.

[0183] 8. A sinusoidal voltage is applied to the two outer external rectangular electrode plates 1', while the two inner internal rectangular electrode plates 2' are connected to zero volts (i.e., "grounded"). In this way, the piezoelectric ceramic plate 3' in the middle can be driven to generate a reciprocating motion in the length direction (which refers to the detection direction of the external electrostatic voltage or field strength, that is, the direction of the central axis of the induction surface / detection surface 4-1' of the static charge induction electrode, see Figure 6 、 Figure 7 shown in the x direction in), that is, a longitudinal wave vibration mode is formed, and finally a standard sinusoidal oscillating capacitor is formed with the static charge induction electrode 4', and a standard sinusoidal signal is detected on the static charge induction electrode 4'.

[0184] 9. Compared with the structure and working mode of the existing vibrating electrode vibrating piece, for the parallel clamping plate type vibrating electrode of this technical solution, since the piezoelectric ceramic plate completely covers the vibrating electrode plate, the vibrating electrode plate hardly generates its own local deformation, but only generates the overall vibration / movement of the vibrating plate (compared with Figure 2-1 、 2-2 and Figure 6 、 Figure 7 shown in; in Figure 2-1 、 Figure 2-2 for the existing vibrating electrode vibrating piece, a piezoelectric ceramic plate is locally provided on the inner surface of the vibrating piece, and the vibration / movement of the vibrating piece occurs at the end of the vibrating piece near the static charge induction electrode, and its vibration process is similar to the "vibration" mode of the front end of a tuning fork (also known as the transverse wave vibration mode), that is, the aforementioned vibrating electrode plate generates its own local deformation; and, due to the influence of factors such as its material and structural shape, the mechanical vibration frequency at the front end of the vibrating electrode plate cannot be completely consistent with the driving voltage frequency of the piezoelectric ceramic plate; and from Figure 6 、 Figure 7It can be seen that in the parallel clamping plate type vibration electrode of the present technical solution, since the piezoelectric ceramic sheet completely covers the vibration electrode sheet, the vibration electrode sheet hardly generates local deformation of its own, but only generates the overall vibration / movement (also known as longitudinal wave type vibration) of the vibration sheet along the direction of its length axis, that is Figure 6 , Figure 7 the vibration in the x-axis direction in ); its mechanical vibration frequency is consistent with the driving voltage frequency, that is, the vibration frequency is completely controlled by the driving voltage frequency; thus, the driving voltage frequency can be adjusted according to the change of the static power source, so that the vibration frequency better adapts to the on-site process change and enhances the applicability to the on-site environment.

[0185] Verification of Example 1:

[0186] To verify the rationality, effectiveness and superiority of the above-mentioned parallel clamping plate electrodes A, A' (referred to as the vibration electrode of the present technical solution or this vibration electrode) scheme, a simulation comparison test is carried out for the structure of the existing electrostatic detection vibration electrode (referred to as the existing vibration electrode) and the structure of the vibration electrode of the present technical solution. The method flow and result analysis of the comparison test are as follows:

[0187] 1) Refer to Figure 1 , Figure 4 , Figure 4-1 As shown, respectively construct the structure models of the existing electrostatic detection vibration electrode and the vibration electrode of the present technical solution.

[0188] 2) Apply the linear elastic and piezoelectric solid mechanics mathematical models to the above two types of vibration electrodes respectively:

[0189] Since the metal vibration sheet belongs to micro-vibration / movement (nanometer to micrometer level) during actual operation, it conforms to the strain equation of the linear elastic material in solid mechanics:

[0190]

[0191] S = S inel + S el , ε el = ε - ε inel

[0192] ε inel = ε0 + ε th

[0193] S el = C:ε el

[0194] S inel = S0 + S ext + S q

[0195]

[0196] C = C(E, ν)

[0197] In the above formula, C is the elastic tensor, a dimensionless number; E is Young's modulus, with the unit of Pa. In this technical solution, the Young's modulus of copper, 120e9 Pa, is adopted; ν is Poisson's ratio, a dimensionless number. In this technical solution, the Poisson's ratio of copper, 0.34, is adopted; u is the displacement of material deformation, with the unit of m; S is the stress tensor, with the unit of N / m 2 ; ρ is the material density, with the unit of kg / m 3 , and in this technical solution, the density of copper, 8960 kg / m, is taken 3 ; F V is the external body force. In this technical solution, there is no action of additional force, and it is set that F V = 0; ε is the total strain tensor, a dimensionless number; ε th is the thermal strain tensor. In this technical solution, the thermal effect is ignored, and it is set that ε th = 0; ε inel is the inelastic strain tensor; ε el is the elastic strain tensor; ε0 is the initial strain tensor. Since there is no displacement at the initial moment, it is set that ε0 = 0

[0198] The welding leg b' in Figure 2 and Figure 4 the outer side 1 - 1' of the metallic rectangular electrode sheet 1' in

[0199] are respectively fixed and constrained so that their displacements are zero, that is: u = 0 Figure 4 Since the static charge induction electrode e in Figure 2 and

[0200] the static charge induction electrode 4 in

[0201]

[0202]

[0203] S = S0 + S el - E·e

[0204] ε el = ε - ε inel , ε inel = ε0 + ε th

[0205]

[0206] S el = c:ε el , c = c(c E ), e = e(eES )

[0207] D = D r + ε 0,vac ε rs E + e:ε el

[0208]

[0209] In the above formula: c E is the stress-charge type elastic matrix, with the unit of Pa; s E is the strain-charge type compliance matrix, with the unit of 1 / Pa; e ES is the stress-charge type coupling matrix, with the unit of C / m 2 ; d ET is the strain-charge type coupling matrix, with the unit of C / N; ε rS is the stress-charge type relative permittivity of the piezoelectric material, dimensionless; ε rT is the strain-charge type relative permittivity of the piezoelectric material, dimensionless; ε 0,vac is the permittivity of free space, ε 0,vac = 8.854187817×10 -12 F / m; D is the total electric displacement of the piezoelectric material, with the unit of C / m 2 ; D r is the remanent electric displacement, with the unit of C / m 2 ; E is the electric field strength, with the unit of V / m; e is the piezoelectric strain tensor, a dimensionless number; ρ V is the charge density, with the unit of C / m 3 .

[0210] The elastic matrix, coupling matrix and relative permittivity of the above materials can be found through relevant literature.

[0211] 3) Apply the electrostatic field mathematical model to the piezoelectric ceramic structure:

[0212]

[0213] D = ε0E + P(E) + P e (S elast )

[0214]

[0215] P = ε0(ε rS - 1)E

[0216] In the above formula: P is the polarization intensity, with the unit of C / m 2 ; ε0 is the permittivity of free space, ε0 = 8.854187817×10 -12 F / m, with the unit of F / m; εrS is the relative permittivity of the piezoelectric material, dimensionless; V is the spatial electric potential, in V; P e (S elast ) is the polarization caused by elastic strain, in C / m 2 .

[0217] 4) A sine voltage, such as V = 5×sin(2×π×f×t), is used to drive the piezoelectric ceramic sheet 3' in the middle of the vibration electrode of this technical solution and the piezoelectric ceramic sheet c of the existing vibration electrode; where f is the voltage frequency, and f = 450 (Hz) is taken.

[0218] For the existing vibration electrode, the sine voltage is electrically connected to the lead c' in Figure 2, and the vibrating plate d is connected to zero volts.

[0219] For the vibration electrode of this technical solution, the sine voltage is electrically connected to the Figure 4 external rectangular electrode sheet 1' through the circuit board fixing it, and the internal rectangular electrode sheet 2' can be connected to zero volts through the lead.

[0220] 5) Mesh generation with mapping and sweeping operations is performed on the overall vibration electrode structure.

[0221] 6) Perform simulation operations to obtain the corresponding simulation results;

[0222] Select Figure 1 the center point o of one end face of the vibrating plate facing the static charge induction electrode e shown in Figure 2 as the displacement analysis point of the existing electrostatic detection electrode.

[0223] Select Figure 4-1 the center point o' of the end face of one internal rectangular electrode sheet 2' facing the static charge induction electrode 4' shown as the displacement analysis point of the vibration electrode of this technical solution.

[0224] Make the time-varying characteristic curves of the displacement fields of both, as shown in Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 .

[0225] 7) According to the simulation results, analyze and compare the time-varying characteristics of the displacement fields of different vibration electrode structures, as shown in Figure 14 , Figure 14-1 and Figure 15 .

[0226] From Figure 14 and Figure 14-1As can be seen, after 5 cycles (about 0.01111 s) of the vibrating electrode in this technical solution, stable functional vibration is achieved; thus, the detection / detection signal of the static power source will also enter a stable state; this will help the static voltage sensor to enter a stable working state more quickly and achieve stable detection of the static power source.

[0227] 8) As can be seen from Figure 15 that the interfering displacement of the vibrating electrode in this technical solution is much smaller than that of the existing vibrating electrode, so the detected interfering signal is also much smaller than that of the existing vibrating electrode.

[0228] 9) As shown in Figure 14 and Figure 14-1 the existing vibrating electrode fails to effectively form stable vibration within a long period (at least 22 cycles, about 0.04889 s), which will lead to unstable functional detection signals and unable to accurately detect the static power source.

[0229] 10) By comparing Figure 2-1 , 2-2 with Figure 6 , Figure 7 and combining with Figure 14 , Figure 14-1 as shown in, it can be seen that compared with the vibrating piece of the existing vibrating electrode, in the parallel clamping plate type vibrating electrode of this technical solution, since the piezoelectric ceramic sheet 3' completely covers the internal rectangular electrode sheet 2', almost no local deformation of the internal rectangular electrode sheet 2' occurs, but only the overall vibration / movement of the internal rectangular electrode sheet 2' occurs, and its main deformation part is concentrated on the piezoelectric ceramic sheet 3'; the mechanical vibration frequency of the internal rectangular electrode sheet 2' is consistent with the driving voltage frequency of the piezoelectric ceramic sheet (while it is not consistent in the existing technology vibrating electrode), that is, the vibration frequency is completely controlled by the driving voltage frequency; thus, the driving voltage frequency can be adjusted according to the change of the static power source to make the vibration frequency better adapt to the on-site process change and enhance the applicability to the on-site environment.

[0230] 11) According to Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 the simulation data statistically obtained, calculate the ratio of the interfering vibration displacement to the functional (main) vibration displacement of the existing electrostatic detection vibrating electrode and the vibrating electrode of this technical solution respectively:

[0231] For the existing vibrating electrode, take the maximum amplitude in each vibration direction:

[0232]

[0233]

[0234] For the vibrating electrode of this technical solution, the maximum amplitude is taken in the non-major vibration direction, and the amplitude during stable vibration is taken in the major vibration direction:

[0235]

[0236]

[0237] Thus, it can be seen that the relative interference caused by the vibration of the vibrating electrode in this technical solution in the non-major vibration direction to the vibration in the major vibration direction is significantly less than that of the existing vibrating electrode.

[0238] In addition, for the existing vibrating electrode, the displacement in its functional (major) vibration direction mainly occurs in Figure 2-1 , Figure 2-2 shown in the y-axis direction. Relative to the body of the vibrating piece of the existing vibrating electrode, the front end of its vibrating piece makes a "lateral swing" type of vibration (abbreviated as transverse wave type vibration).

[0239] For the vibrating electrode of this technical solution, the displacement in its functional (major) vibration direction only generates the overall vibration / movement of the internal rectangular electrode piece, belonging to the longitudinal wave type vibration mode.

[0240] Its main deformation part is concentrated on the piezoelectric ceramic sheet 3'; the mechanical vibration frequency of the internal rectangular electrode sheet 2' is consistent with the driving voltage frequency of the piezoelectric ceramic sheet, that is, the vibration frequency is completely controlled by the driving voltage frequency.

[0241] In summary, as Figure 5 shown, in the verification stage of this technical solution, the structural models of the existing electrostatic detection vibrating electrode and the vibrating electrode of this technical solution are respectively constructed; the mathematical models of linear elasticity and piezoelectric solid mechanics are applied to the overall vibrating electrode; the electrostatic field mathematical model is applied to the piezoelectric ceramic structure (sheet); mesh division with mapping and sweeping operations is performed on the overall vibrating electrode structure; simulation operations are executed to obtain the corresponding simulation results; the time-varying characteristics of the displacement fields of different vibrating electrode structures are analyzed and compared; finally, the superiority of the vibrating structure described in this technical solution is determined by the size of the time period to enter the stable state and the ratio of the interfering vibration displacement to the functional (major) vibration displacement.

[0242] Embodiment 2:

[0243] In this embodiment, the electrostatic detection electrode with a symmetrical structure is a vibrating electrode with a circular tube structure.

[0244] The vibrating electrode of the tubular structure includes a tubular fixed electrode 1″, an annular piezoelectric ceramic sheet 3″, and a tubular vibrating electrode 2″; the tubular fixed electrode, the annular piezoelectric ceramic sheet, and the tubular vibrating electrode are arranged coaxially, and the three are fixedly connected to each other in sequence and are located inside the housing of the static voltage sensor; the tubular fixed electrode is fixed on the circuit board, and the annular piezoelectric ceramic sheet is located between the tubular fixed electrode and the tubular vibrating electrode; the annular piezoelectric ceramic sheet completely covers the end face of the vibrating electrode.

[0245] The size of the tubular vibrating electrode, especially the inner and outer diameters, and the thickness of the annular piezoelectric ceramic sheet can be set according to the needs of electrostatic detection.

[0246] A cylindrical static charge induction electrode 4″ is arranged in front of the tubular vibrating electrode, and their central axes coincide; one end of the cylindrical static charge induction electrode (referred to as the induction surface / detection surface 4-1″ of the static charge induction electrode) faces the static power source.

[0247] The cylindrical static charge induction electrode can adjust its relative position (also known as the relative distance) with respect to the tubular vibrating electrode on the central axis according to the detection needs.

[0248] The cylindrical static charge induction electrode can set its diameter and length according to the detection needs.

[0249] Furthermore, the cylindrical static charge induction electrode is sleeved in a ceramic sleeve 5″, and the exposed part of the cylindrical static charge induction electrode faces the static power source; their central axes coincide with the central axis of the tubular vibrating electrode, and they are located in front of the tubular vibrating electrode. Similarly, according to the detection needs, the relative position or relative distance with respect to the tubular vibrating electrode can be adjusted on the central axis.

[0250] The cylindrical static charge induction electrode can approach or contact the static power source, and the function of the ceramic sleeve is to prevent the cylindrical static charge induction electrode from discharging to the vibrating electrode after inducing a large amount of static charge, damaging the vibrating electrode.

[0251] Apply a sinusoidal voltage to the tubular fixed electrode, and connect the tubular vibrating electrode to zero volts to drive the intermediate annular piezoelectric ceramic sheet to generate a reciprocating motion in the length direction (axial / detection direction, that is, the central axis direction where the induction surface (detection surface) of the cylindrical static charge induction electrode is located) (i.e., form a longitudinal wave vibration), and finally form a standard sinusoidal oscillating capacitor between the tubular vibrating electrode and the cylindrical static charge induction electrode, and form a standard sinusoidal signal on the cylindrical static charge induction electrode.

[0252] In this technical solution, since the circular piezoelectric ceramic sheet 3″ completely covers the end face of the vibrating electrode 2″, and due to its own structural reasons, compared with the existing vibrating electrode vibrating sheet, the vibrating electrode in this technical solution hardly produces local deformation of itself, but only produces overall vibration / movement of the vibrating electrode (for comparison Figure 2-1 、 2-2 and Figure 17 、 Figure 18 shown in; in Figure 2-1 、 Figure 2-2 , in the existing vibrating electrode vibrating sheet, a piezoelectric ceramic sheet is locally arranged on the inner surface of the vibrating sheet, and the vibration / movement of the vibrating sheet occurs at the end of the vibrating sheet near the static charge induction electrode, and its vibration process is similar to the front-end “vibration” mode of a tuning fork (also known as the transverse wave vibration mode), that is, the aforementioned vibrating electrode sheet produces local deformation of itself; and, due to the influence of factors such as its material and structural shape, the mechanical vibration frequency at the front end of the vibrating electrode sheet cannot be completely consistent with the driving voltage frequency of the piezoelectric ceramic sheet; and from Figure 17 、 Figure 18 it can be seen that for the tubular vibrating electrode of this technical solution, since the circular piezoelectric ceramic sheet completely covers the end face of the vibrating electrode, the tubular vibrating electrode only produces overall vibration / movement along the length axis direction of the tubular vibrating electrode (also known as the longitudinal wave type vibration), that is Figure 17 、 Figure 18 the vibration in the z-axis direction shown in); its mechanical vibration frequency is consistent with its driving voltage frequency, that is, the vibration frequency is completely controlled by the driving voltage frequency. In this way, the driving voltage frequency can be adjusted according to the change of the static power source, so that the vibration frequency can better adapt to the on-site process change and enhance the applicability to the on-site environment.

[0253] In addition, as Figures 16 to 16-5 shown, a ceramic sleeve 5″ is sleeved on the cylindrical static charge induction electrode; the length of the cylindrical static charge induction electrode is greater than the length of the ceramic sleeve; the cylindrical static charge induction electrode is partially sleeved in the ceramic sleeve along its length direction.

[0254] Specifically, the part of the cylindrical static charge induction electrode that exceeds the length of the ceramic sleeve is arranged towards the static power source; the part of the cylindrical static charge induction electrode that exceeds the length of the ceramic sleeve is arranged outside the housing of the static voltage sensor.

[0255] Furthermore, the central axes of the cylindrical static charge induction electrode and the ceramic sleeve coincide with the central axis of the tubular vibrating electrode; the cylindrical static charge induction electrode and the ceramic sleeve are arranged in front of the tubular vibrating electrode.

[0256] The technical solution of this embodiment will be specifically described below:

[0257] 1. SeeFigures 16 to 16-5 As shown in Figures 16 to 16-5 , this technical solution provides a circular tube-shaped vibration detection electrode A, which consists of three parts: a metallic fixed electrode 1″, a circular piezoelectric ceramic sheet 3″, and a metallic vibration electrode 2″.

[0258] The fixed electrode 1″ is fixedly welded to the circuit board. The circular piezoelectric ceramic sheet 3″ is located between the fixed electrode 1″ and the vibration electrode 2″, and the three are bonded or fixedly connected together by conductive adhesive; and the whole is located inside the housing of the static voltage sensor.

[0259] 2. Refer to the figure Figure 16-5 As shown in Figure 16-5 , the size of the circular tube-shaped vibration electrode, especially the inner and outer diameters (h2″, h1″) and the thickness h3″ of the circular piezoelectric ceramic sheet, can be set according to the needs of static electricity detection.

[0260] For example, by increasing the thickness h3″ of the circular piezoelectric ceramic sheet 3″, the vibration amplitude of the metallic vibration electrode 2″ can be increased, and then the vibration capacitance between the metallic vibration electrode 2″ and the cylindrical static charge induction electrode 4″ can be increased to enhance the ability to receive static electricity signals.

[0261] 3. A cylindrical static charge induction electrode 4″ is arranged in front of the circular tube-shaped vibration electrode, and their central axes coincide.

[0262] 4. One end of the cylindrical static charge induction electrode 4″ (such as the end face 4-1″) faces the static power source.

[0263] The cylindrical static charge induction electrode 4″ can adjust its relative position with respect to the circular tube-shaped vibration electrode on the central axis according to the needs of static electricity detection. The cylindrical static charge induction electrode 4″ can set its diameter and length according to the detection needs.

[0264] 5. Further, a cylindrical static charge induction electrode 4″ can be sleeved in a ceramic sleeve 5″.

[0265] The exposed part of the cylindrical static charge induction electrode faces the static power source, and the exposed part can be located outside the housing of the static voltage sensor. Their central axes coincide with the central axis of the circular tube-shaped vibration electrode, and they are located in front of the circular tube-shaped vibration electrode. Similarly, their relative position with respect to the circular tube-shaped vibration electrode can be adjusted on the central axis according to the detection needs.

[0266] 6. The cylindrical static charge induction electrode 4″ can approach or contact the static power source, and the function of the ceramic sleeve 5″ is to prevent the cylindrical static charge induction electrode from discharging to the vibration electrode 2″ after inducing a large amount of static charge, damaging the vibration electrode.

[0267] 7. Apply a sinusoidal voltage to the fixed electrode 1″ through the circuit board. The vibrating electrode 2″ can be electrically connected to the zero-volt voltage through a lead to drive the middle annular piezoelectric ceramic sheet 3″ to generate a reciprocating motion in the length direction (axial / detection direction, that is, the central axis direction where the cylindrical static charge induction electrode induction surface (detection surface) 4-1 is located), that is, to form a longitudinal wave vibration. Finally, a standard sinusoidal oscillating capacitance is generated between the vibrating electrode 2″ and the static charge induction electrode 4″, and a standard sinusoidal signal is formed on the static charge induction electrode.

[0268] Verification of Embodiment 2:

[0269] To verify the rationality of the above vibrating electrode structure scheme, a simulation test was specifically carried out on the structure of the existing electrostatic detection vibrating electrode (referred to as the existing vibrating electrode) and the circular tube type electrostatic detection electrode structure of the present technical solution (referred to as the present circular tube type detection electrode). The method flow and result analysis of the comparative test are as follows:

[0270] 1) As shown in Figure 1 , Figure 16-4 , Figure 16-5 , respectively construct the structure models of the existing vibrating electrode and the present circular tube type detection electrode.

[0271] 2) Apply the linear elastic and piezoelectric solid mechanics mathematical models to the above two vibrating electrodes respectively:

[0272] Since the metal vibrating electrode belongs to micro-vibration / movement (nanometer and micrometer order) during actual operation, it conforms to the strain equation of the linear elastic material in solid mechanics:

[0273]

[0274] S = S inel + S el , ε el = ε - ε inel

[0275] ε inel = ε0 + ε th

[0276] S el = C:ε el

[0277] S inel = S0 + S ext + S q

[0278]

[0279] C = C(E,ν)

[0280] In the above formula, C is the elastic tensor, a dimensionless number; E is the Young's modulus, with the unit of Pa. In this technical solution, the Young's modulus of copper is 120e9 Pa; ν is the Poisson's ratio, a dimensionless number. In this technical solution, the Poisson's ratio of copper is 0.34; u is the material deformation displacement, with the unit of m; S is the stress tensor, with the unit of N / m 2 ; ρ is the material density, with the unit of kg / m 3 , and in this technical solution, the density of copper is taken as 8960 kg / m 3 ; F V is the external body force. In this technical solution, there is no action of additional force, and it is set that F V = 0; ε is the total strain tensor, a dimensionless number; ε th is the thermal strain tensor. In this technical solution, the thermal effect is ignored, and it is set that ε th = 0; ε inel is the inelastic strain tensor; ε el is the elastic strain tensor; ε0 is the initial strain tensor. Since there is no displacement at the initial moment, it is set that ε0 = 0.

[0281] Fixing constraints are respectively imposed on the welding leg b' in Figure 2 and Figure 16-4 , Figure 16-5 the tail end face 1-1″ of the metallic fixed electrode 1″ in, so that its displacement is zero, that is: u = 0.

[0282] Since the static charge induction electrode e in Figure 2 and Figure 16-5 the static charge induction electrode 4″ (including the ceramic sleeve 5″) in are both fixedly welded on the circuit board, their displacement constraints are also set to zero, that is: u = 0.

[0283] The PZT-5H type piezoelectric ceramic is adopted in this technical solution, and it conforms to the following solid mechanics and electrical equations of piezoelectric materials:

[0284]

[0285]

[0286] S = S0 + S el - E·e

[0287] ε el = ε - ε inel ε inel = ε0 + ε th

[0288]

[0289] S el = c:ε el , c = c(c E ), e = e(e ES )

[0290] D = D r + ε 0,vac ε rs E + e:ε el

[0291]

[0292] In the above formula: c E is the stress-charge type elastic matrix, with the unit of Pa; s E is the strain-charge type compliance matrix, with the unit of 1 / Pa; e ES is the stress-charge type coupling matrix, with the unit of C / m 2 ; d ET is the strain-charge type coupling matrix, with the unit of C / N; ε rS is the stress-charge type relative permittivity of the piezoelectric material, dimensionless; ε rT is the strain-charge type relative permittivity of the piezoelectric material, dimensionless; ε 0,vac is the permittivity of vacuum, ε 0,vac = 8.854187817×10 -12 F / m; D is the total electric displacement of the piezoelectric material, with the unit of C / m 2 ; D r is the remanent electric displacement, with the unit of C / m 2 ; E is the electric field strength, with the unit of V / m; e is the piezoelectric strain tensor, a dimensionless number; ρ V is the charge density, with the unit of C / m 3 . The elastic matrix, coupling matrix and relative permittivity of the above materials can be found through literature.

[0293] 3) Apply the electrostatic field mathematical model to the piezoelectric ceramic structure:

[0294]

[0295] D = ε0E + P(E) + P e (S elast )

[0296]

[0297] P = ε0(ε rS - 1)E

[0298] In the above formula: P is the polarization intensity, with the unit of C / m 2 ; ε0 is the permittivity of vacuum, ε0 = 8.854187817×10 -12 F / m, with the unit of F / m; ε rS is the relative permittivity of the piezoelectric material, dimensionless; V is the space electric potential, with the unit of V; Pe (S elast ) is the polarization caused by elastic strain, with the unit C / m 2 .

[0299] 4) Apply a sinusoidal voltage, such as V = 5×sin(2×π×f×t), to drive the middle circular piezoelectric ceramic sheet 3″ and piezoelectric ceramic sheet c; where f is the voltage frequency, and f = 450 (Hz) is taken.

[0300] For the existing vibrating electrode, the sinusoidal voltage is electrically connected to the lead c' in Figure 2, and the vibrating piece d is connected to zero volts;

[0301] For this circular tube type detection electrode, the sinusoidal voltage is electrically connected to Figure 16-5 the fixed electrode 1″ through the circuit board fixing it, and the vibrating electrode 2″ can be connected to zero volts through the lead.

[0302] 5) Perform mesh division on the overall vibrating electrode structure with mapping and sweeping operations.

[0303] 6) Execute the simulation operation to obtain the corresponding simulation results; and respectively select Figure 1 , Figure 2a the center point o of one end face of the vibrating piece facing the static charge induction electrode e shown as the displacement analysis point of the existing vibrating electrode, and Figure 16-4 , Figure 16-5 a point o″ on the center circumference of the end face of the circular ring of the vibrating electrode 2″ facing the static charge induction electrode 4″ shown as the displacement analysis point of the electrostatic detection electrode of this technical solution, and make the time-varying characteristic curves of the displacement fields of both, as shown in Figures 8 to 10 and Figures 19 to 21 .

[0304] 7) According to the simulation results, analyze and compare the time-varying characteristics of the displacement fields of different vibrating electrode structures, see Figures 22 to 23 .

[0305] It can be seen from Figures 22 to 23 that this circular tube type detection electrode realizes stable functional vibration after 5 cycles (about 0.01111 s later); thus, the detection signal for the static power source will also enter a stable state; this will help the static voltage sensor enter a stable working state faster and realize stable detection of the static power source.

[0306] 8) It can be seen from Figures 22 to 23 that the interfering displacement of the vibration detection electrode of this technical solution is much smaller than that of the existing vibration detection electrode; therefore, the detected interfering signal is also much smaller than that of the existing vibration detection electrode.

[0307] 9) See Figures 22 to 23As shown, the existing vibration detection electrodes have not effectively formed stable vibrations within a long period (at least 22 periods, approximately 0.04889 s), which will result in unstable functional detection signals and inability to accurately detect static power sources.

[0308] 10) Comparison Figure 2a With Figures 16 to 16-5 and in combination with Figure 17 、 Figure 18 , in the tubular vibration electrode of the present technical solution, since the annular piezoelectric ceramic sheet 3″ completely covers the end face of the vibration electrode 2″, and due to its own structural reasons, the vibration electrode hardly generates local deformation of its own compared with the vibration piece of the existing vibration electrode, but only generates the overall vibration / movement of the vibration electrode 2″, and its main deformation part is concentrated on the annular piezoelectric ceramic sheet 3″; the mechanical vibration frequency of the vibration electrode 2″ is consistent with the driving voltage frequency, that is, the vibration frequency is completely controlled by the driving voltage frequency; thus, the driving voltage frequency can be adjusted according to the change of the static power source, so that the vibration frequency better adapts to the on-site process change and enhances the applicability to the on-site environment.

[0309] 11) According to Figures 19 to 21 the simulation data statistically obtained, calculate the ratio of the interfering vibration displacement to the functional (main) vibration displacement of the existing vibration electrode and the tubular detection electrode of the present invention respectively:

[0310] For the existing vibration electrode: Take the maximum amplitude in each vibration direction:

[0311]

[0312]

[0313] For the tubular detection electrode of the present invention: Take the maximum amplitude in the non-main vibration direction and the amplitude at stable vibration in the main vibration direction:

[0314]

[0315]

[0316] Thus, it can be seen that the relative interference of the vibration of the tubular detection electrode of the present invention in the non-main vibration direction to the vibration in the main vibration direction is significantly less than that of the existing vibration electrode.

[0317] In addition, for the existing vibration electrode, the displacement in the functional (main) vibration direction mainly occurs in Figure 2-1 、 Figure 2-2 the y-axis direction shown in, and relative to the body of the vibration piece of the existing vibration electrode, the front end of its vibration piece makes a "lateral swing" type of vibration (abbreviated as transverse wave type vibration).

[0318] For this circular tube type detection electrode, for the displacement in the functional (main) vibration direction, a sinusoidal voltage is applied to the fixed electrode, and the vibrating electrode is connected to zero volts to drive the middle circular piezoelectric ceramic sheet to generate reciprocating motion in the length direction (axial direction / detection direction, that is, the central axis direction where the induction surface (detection surface) of the cylindrical static charge induction electrode is located, which is the z-axis direction in Figure 17 , Figure 18 ), forming longitudinal vibration, also known as longitudinal wave type vibration. The main deformation part is concentrated on the piezoelectric ceramic sheet; the mechanical vibration frequency of the vibrating electrode is the same as the driving voltage frequency of the piezoelectric ceramic sheet, that is, the vibration frequency is completely controlled by the driving voltage frequency.

[0319] Similar to that in the first embodiment, to verify the rationality of the above vibrating electrode structure scheme, a simulation test was specifically carried out on the existing vibrating electrode structure and the structure of this circular tube type detection electrode. The specific process and steps of the simulation test can be seen in Figure 5 shown, and will not be repeated here.

[0320] In summary, the technical solution of the present invention adopts a vibrating electrode with a symmetrical structure, and the fixed electrode of the electrostatic detection electrode adopts a "surface" type fixing method. Its functional (main) vibration direction is parallel to the length direction of the vibrating electrode, forming a longitudinal wave type vibration mode; the piezoelectric ceramic sheet completely covers and connects the connection end surfaces of the fixed electrode and the vibrating electrode; thus, it makes the startup response speed faster, saves the startup preheating and debugging time of the static voltage sensor, has a shorter time period to enter the stable state, can adjust the driving voltage frequency according to the change of the static power source, makes the vibration frequency better adapt to the on-site process change, enhances the applicability to the on-site environment, can effectively reduce the interfering vibration and the stray capacitance signal caused by it, makes the detection result more accurate and has better stability. It adopts a symmetrical structure, is simple in structure, reduces the processing and manufacturing difficulty and processing cost, and can more easily meet the high-precision requirements.

[0321] The present invention can be widely used in the design and manufacturing field of vibration detection electrodes in static voltage sensors.

Claims

1. A vibrating electrode structure for electrostatic detection, characterized in that: In the detection direction towards the static power source to be detected, an electrostatic detection electrode with a symmetrical structure is provided; The longitudinal axis of the electrostatic detection electrode faces the static power source; The electrostatic detection electrode with a symmetrical structure includes three main parts: a fixed electrode, a vibrating electrode, and a piezoelectric ceramic electrode; The fixed electrode, the vibrating electrode, and the piezoelectric ceramic electrode are fixedly connected as a whole; The piezoelectric ceramic electrode is located between the fixed electrode and the vibrating electrode, and completely covers and connects the connection end faces of the fixed electrode and the vibrating electrode; On the side of the vibrating electrode facing the static power source, a static charge induction electrode is provided; The fixed electrode is fixedly welded to the circuit board to restrict its movement; A sinusoidal voltage is applied to the fixed electrode, and the vibrating electrode is connected to zero volts to drive the middle piezoelectric ceramic electrode to form a longitudinal wave type reciprocating motion / vibration in the detection direction, and finally a standard sinusoidal oscillating capacitor is formed between the vibrating electrode and the static charge induction electrode, and a standard sinusoidal voltage signal is formed on the static charge induction electrode.

2. The vibrating electrode structure for electrostatic detection according to claim 1, wherein The detection direction is the same as the central axis direction of the induction surface / detection surface of the static charge induction electrode; The vibration direction of the vibrating electrode in the detection direction is parallel to the length direction of the vibrating electrode.

3. The vibrating electrode structure for electrostatic detection according to claim 1, characterized in that The fixed electrode is fixedly welded to the circuit board in a "surface" contact structure form.

4. The vibrating electrode structure for electrostatic detection according to claim 1, characterized in that Making a cross-section / section along the longitudinal length direction of the electrostatic detection electrode, the electrostatic detection electrode has a "mirror symmetry" structure form along its longitudinal axis.

5. The vibrating electrode structure for electrostatic detection according to claim 1, characterized in that The position of the static charge induction electrode is fixed. When the object surface of the static power source carries static charge, the static charge induction electrode will sense an electrostatic signal; the vibrating electrode will vibrate periodically along its functional vibration direction; the capacitance C1 between the vibrating electrode and the static charge induction electrode also changes periodically, and there is the following relational expression: C1 = C ∞ (1 + Ksinwt) Where: C ∞ is the static capacitance between the vibrating electrode and the static charge induction electrode at the equilibrium position, in F; w is the angular frequency of the mechanical vibration of the vibrating electrode, in radians / s; K is the modulation coefficient of C1, K ＜＜ 1.

6. The vibrating electrode structure for electrostatic detection according to claim 1, characterized in that The static charge induction electrode facing the positive surface of the charged object will generate static charge corresponding to the charged object surface; After applying a driving voltage to the piezoelectric ceramic electrode / sheet attached to the vibrating electrode, the piezoelectric ceramic electrode / sheet will longitudinally expand and contract along the detection direction, thereby driving the vibrating electrode to generate a periodic reciprocating motion; Through the periodic motion / vibration of the vibrating electrode, the electrostatic induction signal on the static charge induction electrode is periodically modulated, and the amount of static charge generated on the static charge induction electrode also increases and decreases periodically, and thus it can be equivalently regarded as a variable capacitor with periodically increasing and decreasing capacitance.

7. The vibrating electrode structure for electrostatic detection according to claim 1, characterized in that The electrostatic detection electrode with a symmetrical structure includes a pair of parallel clamping plate electrodes that are mirror images of each other; Each parallel clamping plate electrode includes two mutually parallel and overlapping rectangular electrode sheets made of metal, with a piezoelectric ceramic sheet in the middle layer, and the three are bonded or fixedly connected as a whole through conductive adhesive; Among them, in the two rectangular electrode sheets that make up each parallel clamping plate electrode, the outermost rectangular electrode sheet is the fixed electrode, the innermost rectangular electrode sheet is the vibrating electrode, and the piezoelectric ceramic electrode is located between the fixed electrode and the vibrating electrode; A static charge induction electrode is arranged in front of the parallel clamping plate electrodes in the vibration direction that are mirror images of each other, that is, on the side where the vibrating electrode faces the static power source. The outermost metallic rectangular electrode piece is fixedly welded to the circuit board to restrict its movement. The central axis where the sensing surface / detection surface of the static charge induction electrode is located coincides with the central axis in the vibration direction of the parallel clamping plate electrodes that are mirror images of each other, and is located inside the housing of the electrostatic sensor. A sinusoidal voltage is applied to the two outermost fixed electrodes, and the two innermost vibrating electrodes are connected to zero volts to drive the piezoelectric ceramic sheet in the middle, causing it to perform a reciprocating movement in the length direction, forming a longitudinal wave vibration. Eventually, a standard sinusoidal oscillating capacitor is formed between the vibrating electrode and the static charge induction electrode, and a standard sinusoidal signal is formed on the static charge induction electrode.

8. The vibrating electrode structure for electrostatic detection according to claim 1, characterized in that The electrostatic detection electrode with a symmetrical structure is a circular tube-shaped electrostatic detection electrode. The circular tube-shaped electrostatic detection electrode includes a circular tube-shaped fixed electrode, an annular piezoelectric ceramic sheet, and a circular tube-shaped vibrating electrode. The circular tube-shaped fixed electrode, the annular piezoelectric ceramic sheet, and the circular tube-shaped vibrating electrode are arranged coaxially, and the three are fixedly connected to each other in sequence, and the whole is located inside the housing of the static voltage sensor. The circular tube-shaped fixed electrode is fixed on the circuit board, and the annular piezoelectric ceramic sheet is located between the circular tube-shaped fixed electrode and the circular tube-shaped vibrating electrode. The annular piezoelectric ceramic sheet completely covers the end face of the vibrating electrode. A cylindrical static charge induction electrode is arranged in front of the circular tube-shaped electrostatic detection electrode, and their central axes coincide. One end of the cylindrical static charge induction electrode faces the static power source. A sinusoidal voltage is applied to the circular tube-shaped fixed electrode, and the circular tube-shaped vibrating electrode is connected to zero volts to drive the annular piezoelectric ceramic sheet in the middle, causing it to perform a reciprocating movement in the length direction, forming a longitudinal wave vibration. Eventually, a standard sinusoidal oscillating capacitor is formed between the circular tube-shaped vibrating electrode and the cylindrical static charge induction electrode, and a standard sinusoidal signal is formed on the cylindrical static charge induction electrode.

9. A method for verifying the vibration electrode structure described in claim 1, characterized in that It includes the following steps: 1) Respectively construct the structural models of the existing vibrating electrode and the structural model of the electrostatic detection vibrating electrode of the present invention. 2) Respectively apply the mathematical models of linear elasticity and piezoelectric solid mechanics to the two vibrating electrodes. 3) Apply the electrostatic field mathematical model to the piezoelectric ceramic structure. 4) Use a sinusoidal voltage to drive the annular piezoelectric ceramic sheet in the middle of the electrostatic detection vibrating electrode of the present invention and the piezoelectric ceramic sheet of the existing vibrating electrode. 5) Perform mesh division on the overall vibrating electrode structure with mapping and sweeping operations. 6) Execute simulation operations to obtain the corresponding simulation results. 7) According to the simulation results, analyze and compare the time-varying characteristics of the displacement fields of different vibrating electrode structures. 8) Respectively calculate the ratios of the interfering vibration displacements to the functional vibration displacements of the existing vibrating electrode and the electrostatic detection electrode of the present invention. 9) Determine the superiority of the electrostatic detection vibrating electrode structure of the present invention through the size of the time period to enter the stable state and the ratio of the interfering vibration displacement to the functional vibration displacement.

10. The method for verifying the vibration electrode structure according to claim 9, characterized in that During verification, the welding feet of the existing vibrating electrode and the tail end faces of the fixed electrodes of the present electrostatic detection vibrating electrode are respectively fixed and constrained so that their displacements are zero; The static charge induction electrodes of the existing vibrating electrode and the static charge induction electrodes of the present electrostatic detection vibrating electrode are fixedly welded on the circuit board, and their displacement constraints are set to zero; When using a sinusoidal voltage to drive the circular piezoelectric ceramic sheet in the middle of the present electrostatic detection vibrating electrode and the piezoelectric ceramic sheet of the existing vibrating electrode, for the existing vibrating electrode, the sinusoidal voltage is electrically connected to the lead wire of its piezoelectric ceramic sheet, and its vibrating piece is connected to zero volts; for the present electrostatic detection vibrating electrode, the sinusoidal voltage is electrically connected to the fixed electrode through the circuit board fixing it, and the vibrating electrode is connected to zero volts through the lead wire; During the simulation operation stage, for the existing vibrating electrode, the center point of one vibrating piece end face facing the static charge induction electrode is selected as the displacement analysis point of the existing vibrating electrode; for the present electrostatic detection vibrating electrode, a point on the end face of the vibrating electrode facing the static charge induction electrode is selected as the displacement analysis point of the electrostatic detection electrode of the present technical solution; the time-varying characteristic curves of the displacement fields of both are made.

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