Double-drive piezoelectric valve and piezoelectric valve displacement compensation control method

Abstract

The invention relates to the technical field of adhesive dispensing, and particularly discloses a double-drive piezoelectric valve and a piezoelectric valve displacement compensation control method.The double-drive piezoelectric valve comprises a valve body, a pressure sensor and a pressure sensor, the lever amplification structure is located in the valve cavity and comprises a lever rotating shaft and a lever rotating plate rotationally connected with the valve body through the lever rotating shaft; the top surface of the spring firing pin assembly elastically pushes the bottom surface of one end, far away from the lever rotating shaft, of the lever rotating plate; the bottom surface of the near-end piezoelectric ceramic and the bottom surface of the far-end piezoelectric ceramic abut against the top surface of the end, close to the lever rotating shaft, of the lever rotating plate. According to the double-drive piezoelectric valve and the displacement compensation control method of the piezoelectric valve, the problem that the stability of the glue outlet amount and the continuity of the glue dispensing track of an existing piezoelectric injection valve are poor can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of dispensing, and in particular to a dual-drive piezoelectric valve and a piezoelectric valve displacement compensation control method. Background Art

[0002] In the field of precision dispensing equipment, piezoelectric injection valves are widely used in precision manufacturing scenarios such as microelectronics packaging due to their high-frequency response characteristics. The current mainstream technology adopts a single piezoelectric ceramic drive structure, and the deformation movement of the piezoelectric ceramic is controlled by voltage to drive the plunger to complete the glue injection. However, this design has the following key technical defects:

[0003] (1) The intrinsic hysteresis characteristic of the piezoelectric ceramic material results in a non-linear correspondence between its displacement output and the driving voltage. During the voltage rise and fall process, the elongation of the ceramic corresponding to the same voltage value will produce unpredictable deviations. This non-linear hysteresis effect directly causes the instability of the plunger stroke. Especially in the high-frequency reciprocating motion condition, the displacement drift phenomenon of the piezoelectric ceramic is further aggravated, and finally the glue dot size fluctuates significantly;

[0004] The displacement when the piezoelectric ceramic is fully extended is only about 40 microns, and the displacement required by the plunger during the actual dispensing process is between 100 - 280 microns. Therefore, in the design of such injection dispensing valves, a lever amplification structure is usually required to amplify the displacement output of the piezoelectric ceramic; the introduction of the lever amplification structure will further amplify the displacement deviation of the piezoelectric ceramic output, affecting the stability of the glue output;

[0005] (2) The lever amplification structure of the existing piezoelectric injection valve continuously pushes against the bottom of the piezoelectric ceramic upward under the driving action of the spring, thereby realizing the connection between the lever amplification structure and the piezoelectric ceramic. During the actual working process, the deformation speed of the piezoelectric ceramic is very fast, and the telescopic deformation of the spring is significantly slower than the deformation speed of the piezoelectric ceramic. Therefore, the up and down movement of the lever amplification structure is difficult to follow the telescopic deformation of the piezoelectric ceramic;

[0006] That is, when the piezoelectric ceramic undergoes large-scale telescopic deformation, the lever amplification structure cannot quickly follow the piezoelectric ceramic for high-speed movement, and will be separated from the piezoelectric ceramic. At this time, the movement displacement of the lever amplification structure has a certain degree of uncertainty, which will cause the lever amplification structure to generate a jitter displacement deviation, resulting in a scattered point phenomenon during dispensing and affecting the continuity of the dispensing trajectory.

[0007] Therefore, it is necessary to improve the existing piezoelectric injection valve to solve the problems of poor stability of the glue output and poor continuity of the dispensing trajectory.

[0008] The above information disclosed in this background section is only included to enhance the understanding of the background of the present disclosure, and thus may include information that does not form the prior art already known to those of ordinary skill in the art at present. Summary of the Invention

[0009] An object of the present invention is to provide a dual-drive piezoelectric valve and a piezoelectric valve displacement compensation control method, which can effectively solve the problems that the stability of the glue output volume and the continuity of the dispensing trajectory of the existing piezoelectric injection valve are both poor.

[0010] To achieve the above object, on the one hand, the present invention provides a dual-drive piezoelectric valve, including:

[0011] A valve body, in which a valve cavity is provided;

[0012] A lever amplification structure, which is located in the valve cavity and includes a lever rotating shaft and a lever rotating plate rotatably connected to the valve body through the lever rotating shaft;

[0013] A spring plunger assembly, the top surface of which elastically pushes the bottom surface of one end of the lever rotating plate away from the lever rotating shaft;

[0014] A proximal piezoelectric ceramic and a distal piezoelectric ceramic, the bottom surfaces of both the proximal piezoelectric ceramic and the distal piezoelectric ceramic abut against the top surface of one end of the lever rotating plate close to the lever rotating shaft.

[0015] Optionally,

[0016] The horizontal distance a from the spring plunger assembly to the proximal piezoelectric ceramic, the horizontal distance b from the spring plunger assembly to the lever rotating shaft, and the horizontal distance c from the spring plunger assembly to the distal piezoelectric ceramic satisfy: a < b < c.

[0017] Optionally, it further includes:

[0018] A runner base, which is provided with a glue storage cavity for storing glue, an inclined runner for guiding the glue to the glue storage cavity, and a nozzle communicating the bottom of the glue storage cavity with the external space;

[0019] A glue storage cylinder, which is threadedly connected to the inlet of the inclined runner.

[0020] Optionally, the runner base is detachably connected to the valve body through a quick-release assembly, and the quick-release assembly includes:

[0021] An L-shaped connecting piece, one end of which is fixedly arranged at the bottom of the valve body and cooperates with the valve body to form a U-shaped card slot with a horizontal opening;

[0022] A limiting rotating plate is rotatably installed at the other end of the L-shaped connecting piece and is used to rotatably cover the opening of the U-shaped card slot.

[0023] Optionally, a fastening hole is provided in the valve body at a position corresponding to the limiting rotating plate;

[0024] A fastener for firmly connecting with the fastening hole is provided on the limiting rotating plate.

[0025] Optionally, the lower part of the spring plunger assembly is installed at the upper end opening of the glue storage cavity to cover the upper end opening of the glue storage cavity;

[0026] An upper plunger cavity for the upper part of the spring plunger assembly to extend into and communicate with the valve cavity is provided in the lower part of the valve body.

[0027] Optionally, the flow channel base is provided with a limiting cross bar that rotates around the axis of the upper plunger cavity and enters and exits the U-shaped card slot through the opening of the U-shaped card slot.

[0028] On the other hand, a piezoelectric valve displacement compensation control method is provided, which is executed by any one of the double-drive piezoelectric valves, and includes:

[0029] S10: Both ends of the proximal piezoelectric ceramic and the distal piezoelectric ceramic are connected to the drive power supply;

[0030] S20: Use a displacement sensor to respectively record the displacement amounts of the proximal piezoelectric ceramic and the distal piezoelectric ceramic at different voltages, and store the mapping relationship between the respective voltage values and displacement amounts of the two to form a number of two-dimensional arrays;

[0031] S30: Fit the stored two-dimensional arrays by using an odd-order polynomial fitting method to obtain a fitted polynomial function;

[0032] S40: Store the fitted polynomial function in the internal PCB board of the double-drive piezoelectric valve, and perform voltage control on the proximal piezoelectric ceramic and the distal piezoelectric ceramic through the internal PCB board.

[0033] Optionally,

[0034] The fitted polynomial function is F(u)=axu + bxu 2 + cxu 3 + dxu 4 + exu 5 ;

[0035] In the formula, u is the ratio between the actual working voltage and the maximum working voltage value Umax, and F(u) is the true deformation size;

[0036] a, b, c, d, e are fixed constants after polynomial fitting.

[0037] Optionally, S40 includes:

[0038] S401: First, obtain the target displacement amounts of the two piezoelectric ceramics according to the set rubber material flow parameters;

[0039] S402: Then substitute the target displacement amounts into the polynomial function to inversely calculate the voltage values of the two piezoelectric ceramics;

[0040] S403: Finally, output the calculated voltage values to the two piezoelectric ceramics to cause the two piezoelectric ceramics to expand and contract in the reverse direction, and jointly drive the lever rotating plate to rotate.

[0041] The beneficial effects of the present invention are as follows: A dual-drive piezoelectric valve and a piezoelectric valve displacement compensation control method are provided. The dual-drive piezoelectric valve forms a differential drive and a dynamic compensation mechanism by setting a dual-drive structure of a proximal piezoelectric ceramic and a distal piezoelectric ceramic. Specifically:

[0042] ① Hysteresis effect compensation: The two piezoelectric ceramics deform independently, and the output displacement deviation between the two is at least partially cancelled out, avoiding the situation where a large displacement output deviation occurs due to accidental factors in a single piezoelectric ceramic solution;

[0043] ② Linear displacement output: The dual piezoelectric ceramics drive the spring plunger assembly to move up and down. Compared with the drive scheme of a single adjustable piezoelectric ceramic, the corresponding relationship between the rotation angle of the lever rotating plate and the voltage change of the piezoelectric ceramic is more linear. Thus, the amplification effect of the lever amplification structure on the output displacement deviation can be weakened, the lifting stroke stability of the spring plunger assembly can be improved, and further the stability of the glue output amount can be improved;

[0044] ③ Multi-point contact to avoid separation: The proximal piezoelectric ceramic and the distal piezoelectric ceramic respectively abut and drive the lever rotating plate. During the high-speed rotation of the lever amplification structure, at least one piezoelectric ceramic can abut the lever rotating plate, suppressing the separation and jitter phenomenon of the lever rotating plate caused by spring hysteresis, and further avoiding glue dispensing scatter points and improving the continuity of the glue dispensing trajectory.

[0045] Therefore, the dual-drive piezoelectric valve and the piezoelectric valve displacement compensation control method provided by the present invention can effectively solve the problems that the stability of the glue output amount and the continuity of the glue dispensing trajectory of the existing piezoelectric injection valve are both poor. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 Schematic structural diagram of the dual-drive piezoelectric valve provided for the embodiment;

[0048] Figure 2 For Figure 1 Partial enlarged schematic diagram at position A in

[0049] Figure 3 Schematic diagram of the alignment of the valve body and the flow channel base provided for the embodiment;

[0050] Figure 4 For Figure 3 Schematic diagram of the assembly process of the dual-drive piezoelectric valve provided for the embodiment;

[0051] Figure 5 Flow chart of the piezoelectric valve displacement compensation control method provided for the embodiment.

[0052] In the figure:

[0053] 1. Valve body; 101. Valve cavity; 102. Fastening hole; 103. Upper cavity of the striker;

[0054] 2. Lever amplification structure; 201. Lever rotating shaft; 202. Lever rotating plate;

[0055] 3. Spring striker assembly; 301. Striker body; 302. Striker spring;

[0056] 4. Proximal piezoelectric ceramic;

[0057] 5. Distal piezoelectric ceramic;

[0058] 6. Flow channel base; 601. Glue storage cavity; 602. Inclined flow channel; 603. Nozzle; 604. Limit cross bar;

[0059] 7. Glue storage cylinder;

[0060] 8. Quick-release assembly; 801. L-shaped connecting piece; 8011. U-shaped card slot; 802. Limit rotating plate; 803. Fastener. Specific embodiments

[0061] Referring to "embodiments" in the present invention means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present invention. The term "embodiment" appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it particularly limited to the independence or relevance with other embodiments. In principle, in the present invention, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0062] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which the present invention pertains; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit the present invention.

[0063] In the description of the present invention, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that there can be three relationships, for example, A and / or B, which means: the existence of A, the existence of B, and the simultaneous existence of both A and B. In addition, the character " / " herein generally represents an "or" logical relationship between the associated objects before and after.

[0064] In the present invention, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary, or sequential relationships between these entities or operations.

[0065] Without further limitations, in the present invention, the expressions such as "comprising", "including", "having", or other similar expressions used in the statements are intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product including the said elements. Thus, a process, method, or product including a series of elements may not only include those defined elements, but also include other elements not explicitly listed, or elements inherent to such a process, method, or product.

[0066] Similar to the understanding in the "Examination Guidelines", in the present invention, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the number itself; expressions such as "above", "below", "within", etc. are understood to include the number itself. In addition, in the description of the embodiments of the present invention, the meaning of "a plurality of" is two or more (including two), and similar expressions related to "multiple", such as "multiple groups", "multiple times", etc., are understood in the same way, unless otherwise specifically defined.

[0067] In the description of the embodiments of the present invention, the spatially related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiment or the accompanying drawings. It is only for the convenience of describing the specific embodiments of the present invention or facilitating the understanding of the readers, and does not indicate or imply that the indicated device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it cannot be understood as a limitation to the embodiments of the present invention.

[0068] Unless otherwise clearly specified or defined, in the description of the embodiments of the present invention, terms such as "installation", "connection", "linkage", "fixation", "setting", etc. shall be understood in a broad sense. For example, the "connection" may be a fixed connection, a detachable connection, or an integral setting; it may be a mechanical connection, an electrical connection, or a communication connection; it may be a direct connection or an indirect connection through an intermediate medium; it may be the communication inside two components or the interaction relationship between two components. For those skilled in the art to which the present invention pertains, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0069] The present invention provides a dual-drive piezoelectric valve and a piezoelectric valve displacement compensation control method, which are applicable to high-precision dispensing scenarios (such as semiconductor packaging, microelectronic component assembly). Through dual piezoelectric ceramic differential drive and odd-order polynomial hysteresis compensation algorithm, the problems of glue output fluctuation and dispensing trajectory discontinuity caused by the hysteresis effect and lever amplification deviation of the piezoelectric valve are solved.

[0070] Embodiment 1

[0071] See Figures 1 - 2 , this embodiment provides a dual-drive piezoelectric valve, including:

[0072] Valve body 1, inside which there is a valve cavity 101;

[0073] Lever amplification structure 2, which is located in the valve cavity 101 and includes a lever rotating shaft 201 and a lever rotating plate 202 rotatably connected to the valve body 1 through the lever rotating shaft 201;

[0074] Spring plunger assembly 3, the top surface of which elastically pushes the bottom surface of one end of the lever rotating plate 202 away from the lever rotating shaft 201; Optionally, the spring plunger assembly 3 includes a plunger body 301 that slides up and down and a plunger spring 302 that drives the plunger body 301 to move upward relative to the valve seat until it abuts against the lever rotating plate 202;

[0075] Proximal piezoelectric ceramic 4 and distal piezoelectric ceramic 5, the bottom surfaces of both the proximal piezoelectric ceramic 4 and the distal piezoelectric ceramic 5 abut against the top surface of one end of the lever rotating plate 202 close to the lever rotating shaft 201;

[0076] Flow channel base 6, which is provided with a glue storage cavity 601 for storing glue, an inclined flow channel 602 for guiding the glue to the glue storage cavity 601, and a nozzle 603 for communicating the bottom of the glue storage cavity 601 to the external space;

[0077] Glue storage cylinder 7, which is threadedly connected to the inlet of the inclined flow channel 602;

[0078] Among them,

[0079] The horizontal distance a from the spring striker assembly 3 to the proximal piezoelectric ceramic 4, the horizontal distance b from the spring striker assembly 3 to the lever rotation shaft 201, and the horizontal distance c from the spring striker assembly 3 to the distal piezoelectric ceramic 5 satisfy: a < b < c.

[0080] Generally speaking, the glue material in the glue storage cylinder 7 enters the glue storage cavity 601 through the inclined flow channel 602. The proximal piezoelectric ceramic 4 and the distal piezoelectric ceramic 5 cooperate with each other to drive the spring striker assembly 3 to move downward, and then the glue material in the glue storage cavity 601 is ejected outward through the nozzle 603, thus completing the dispensing operation.

[0081] Specifically, for the dual-drive piezoelectric valve provided in this embodiment, the working process is as follows:

[0082] (1) Initial state

[0083] Initially, both the proximal piezoelectric ceramic 4 and the distal piezoelectric ceramic 5 are in a medium-sized voltage state (that is, both the proximal piezoelectric ceramic 4 and the distal piezoelectric ceramic 5 are slightly elongated but not elongated to the longest state), and the lever rotating plate 202 is basically in a horizontal state;

[0084] At this time, the dual-drive piezoelectric valve is in an open valve state, and the valve opening is of moderate size;

[0085] (2) Valve closing operation

[0086] When it is necessary to gradually reduce the valve opening of the dual-drive piezoelectric valve until the dual-drive piezoelectric valve is closed, it is necessary to gradually increase the voltage of the proximal piezoelectric ceramic 4 and gradually reduce the voltage of the distal piezoelectric ceramic 5, so that the proximal piezoelectric ceramic 4 elongates and the distal piezoelectric ceramic 5 shortens;

[0087] Under the cooperative action of the two piezoelectric ceramics, the lever rotating plate 202 rotates counterclockwise, and finally overcomes the elastic force to drive the spring striker assembly 3 to move downward;

[0088] Thus, the valve opening of the dual-drive piezoelectric valve can be gradually reduced until the valve opening is completely closed;

[0089] (3) Valve opening operation

[0090] When it is necessary to gradually increase the valve opening of the dual-drive piezoelectric valve until the dual-drive piezoelectric valve is fully opened, it is necessary to gradually reduce the voltage of the proximal piezoelectric ceramic 4 and gradually increase the voltage of the distal piezoelectric ceramic 5, so that the proximal piezoelectric ceramic 4 shortens and the distal piezoelectric ceramic 5 elongates;

[0091] Under the cooperative action of the two piezoelectric ceramics, the lever rotating plate 202 rotates clockwise, and the spring striker assembly 3 moves upward under its own elastic force;

[0092] Thus, the opening degree of the valve port of the dual-drive piezoelectric valve can be gradually increased until the valve port is completely opened.

[0093] In the above process, the dual-drive piezoelectric valve forms a differential drive and dynamic compensation mechanism by setting a dual-drive structure of the proximal piezoelectric ceramic 4 and the distal piezoelectric ceramic 5. Specifically:

[0094] ① Hysteresis effect compensation: The two piezoelectric ceramics deform independently, and the output displacement deviation between them is at least partially offset from each other, avoiding the situation where a large displacement output deviation is caused by accidental factors in the single piezoelectric ceramic solution;

[0095] ② Displacement linearized output: The dual piezoelectric ceramics drive the spring plunger assembly 3 to move up and down. Compared with the drive scheme of the single adjustable piezoelectric ceramic, the corresponding relationship between the rotation angle of the lever turntable 202 and the voltage change of the piezoelectric ceramic is more linear. Thus, the amplification effect of the lever amplification structure 2 on the output displacement deviation can be weakened, the lifting stroke stability of the spring plunger assembly 3 can be improved, and the stability of the glue output can be further improved;

[0096] ③ Avoiding separation by multi-point contact: The proximal piezoelectric ceramic 4 and the distal piezoelectric ceramic 5 respectively abut and drive the lever turntable 202. During the high-speed rotation of the lever amplification structure 2, at least one piezoelectric ceramic can abut the lever turntable 202, suppressing the separation jitter phenomenon of the lever turntable 202 caused by spring hysteresis, and further avoiding glue dispensing scatter points and improving the continuity of the glue dispensing trajectory.

[0097] Therefore, the dual-drive piezoelectric valve and the piezoelectric valve displacement compensation control method provided by the present invention can effectively solve the problems that the stability of the glue output and the continuity of the glue dispensing trajectory of the existing piezoelectric injection valve are both poor.

[0098] See Figure 3 , in this embodiment, the flow channel base 6 is detachably connected to the valve body 1 through a quick-release assembly 8, and the quick-release assembly 8 includes:

[0099] An L-shaped connecting piece 801, one end of the L-shaped connecting piece 801 is fixedly arranged at the bottom of the valve body 1, and cooperates with the valve body 1 to enclose a U-shaped card slot 8011 with a horizontal opening;

[0100] A limit turntable 802, the limit turntable 802 is rotatably installed at the other end of the L-shaped connecting piece 801 for rotatably covering the opening of the U-shaped card slot 8011.

[0101] Wherein, the valve body 1 is provided with a fastening hole 102 corresponding to the position of the limit turntable 802; the limit turntable 802 is provided with a fastener 803 for tightly connecting with the fastening hole 102.

[0102] Further, the lower part of the spring plunger assembly 3 is installed at the upper opening of the glue storage cavity 601 to cover the upper opening of the glue storage cavity 601; a plunger upper cavity 103 is provided at the lower part of the valve body 1 for the upper part of the spring plunger assembly 3 to extend into and communicate with the valve cavity 101.

[0103] The runner base 6 is provided with a limit cross bar 604 that rotates around the axis of the plunger upper cavity 103 and enters and exits the U-shaped card slot 8011 through the opening of the U-shaped card slot 8011.

[0104] See Figure 4 , when assembling:

[0105] ① First, install and fix the lower part of the spring plunger assembly 3 on the runner base 6;

[0106] ② Slightly insert the upper part of the spring plunger assembly 3 into the plunger upper cavity 103 of the valve body 1, and then, appropriately rotate the valve body 1 to move the quick-release assembly 8 away from the area directly above the limit cross bar 604 to avoid affecting the subsequent complete insertion of the spring plunger assembly 3 into the plunger upper cavity 103;

[0107] ③ Completely insert the spring plunger assembly 3 into the plunger upper cavity 103. At this time, the U-shaped card slot 8011 and the limit cross bar 604 are at the same height. Rotate the valve body 1, and the limit cross bar 604 can enter the U-shaped card slot 8011 through the opening of the U-shaped card slot 8011;

[0108] ④ Finally, after rotating the limit turning plate 802 upward to cover the opening of the U-shaped card slot 8011, insert the fastener 803 into the fastening hole 102 to lock the limit turning plate 802 and prevent the limit turning plate 802 from being accidentally touched and opened.

[0109] Optionally, the fastener 803 is a movable bolt or a bolt, etc.

[0110] The design of the quick-release assembly 8 is beneficial to the quick installation and disassembly of the runner base 6 for cleaning or maintenance of the inclined runner 602, the spring plunger assembly 3, etc.

[0111] In summary, the dual-drive piezoelectric valve provided in this embodiment has the following advantages:

[0112] ① Dual piezoelectric ceramic differential compensation mechanism: Through the coordinated deformation of the proximal and distal piezoelectric ceramics 5, the output displacement deviation is mutually offset, the influence of the hysteresis effect is reduced, and the control accuracy is improved.

[0113] ② Linear displacement output optimization: The dual piezoelectric ceramics cooperate to drive the lever turning plate 202, making the rotation angle and voltage change approach a linear relationship, weakening the lever amplification deviation, and improving the stability of the glue output volume.

[0114] ③Multi-point contact anti-separation design: Two piezoelectric ceramics alternately abut against the lever rotating plate 202 to suppress the spring hysteresis jitter during high-speed movement and ensure the continuity of the dispensing trajectory.

[0115] ④Quick-release runner base 6 structure: A quick-release assembly 8 that uses a U-shaped card slot 8011 in cooperation with a limit rotating plate 802 is adopted to realize the quick installation and disassembly of the runner base 6, which is convenient for cleaning and maintenance.

[0116] Embodiment 2

[0117] This embodiment provides a piezoelectric valve displacement compensation control method, which is executed by the dual-drive piezoelectric valve described in Embodiment 1 and has the same functions and beneficial effects.

[0118] See Figure 5 , the piezoelectric valve displacement compensation control method provided by this embodiment includes:

[0119] S10: Both ends of the proximal piezoelectric ceramic and the distal piezoelectric ceramic are connected to the drive power supply;

[0120] Optionally, the output voltage range of the drive power supply is from -30V to 120V, with a gradient of 0.5V. When performing voltage control, first boost the voltage from -30V to 120V, and then lower the voltage from 120V to -30V;

[0121] S20: Use a displacement sensor to record the displacement amounts of the proximal piezoelectric ceramic and the distal piezoelectric ceramic under different voltages respectively, and store the mapping relationship between their respective voltage values and displacement amounts to form several groups of two-dimensional arrays;

[0122] For example, the storage format is (X voltage value, Y displacement amount);

[0123] S30: Fit the stored two-dimensional arrays by using an odd-order polynomial fitting method to obtain the fitted polynomial function;

[0124] It can be understood that the fitted polynomial function contains the functional relationship between the X voltage value and the Y displacement amount. Subsequently, as long as one of them is known, the other can be calculated through the polynomial function; further, more discrete two-dimensional arrays can be calculated and supplemented independently through this polynomial function;

[0125] Specifically, the fitted polynomial function is F(u)=axu + bxu 2 + cxu 3 + dxu 4 + exu 5 ;

[0126] In the formula, u is used to represent the voltage magnitude of the piezoelectric ceramic, and F(u) is used to represent the deformation magnitude of the piezoelectric ceramic;

[0127] a, b, c, d, and e are fixed constants obtained through polynomial fitting, which are used for linear compensation of the hysteresis effect of piezoelectric ceramics and are unique for each piezoelectric ceramic.

[0128] In this embodiment, u is the ratio between the actual working voltage and the maximum working voltage value Umax, and F(u) is the true deformation size. For example, when u takes the minimum value of 0%, the actual deformation size F(u) of the piezoelectric ceramic is 0 μm; when u takes the maximum value of 100%, the actual deformation size F(u) of the piezoelectric ceramic is 40 μm.

[0129] The odd-order polynomial fitting method is adopted in the piezoelectric valve displacement compensation control method, mainly based on the following technical considerations:

[0130] 1. Asymmetric adaptation of the hysteresis effect

[0131] The hysteresis effect of piezoelectric ceramics is manifested as an asymmetric response of displacement during the voltage rising and falling processes (i.e., the displacements corresponding to the same voltage are different when the voltage rises and falls).

[0132] Odd-order polynomials (such as cubic and quintic terms) have an asymmetric function form and can more accurately describe this bidirectional asymmetric hysteresis curve.

[0133] For example, the fifth-order polynomial F(u) = axu + bxu 2 + cxu 3 + dxu 4 + exu 5 , through the combination of odd-order terms, can flexibly fit the "S-shaped" displacement growth when the voltage rises and the "hysteresis loop" when the voltage falls.

[0134] 2. Higher-order compensation for nonlinear characteristics

[0135] The displacement-voltage relationship of piezoelectric ceramics is essentially highly nonlinear. Using only low-order or even-order polynomials will result in insufficient fitting:

[0136] Even-order terms (such as u 2 , u 4 ) show symmetry in the positive and negative voltage ranges and cannot characterize the unidirectional offset characteristics of the actual hysteresis curve.

[0137] Odd-order terms, by introducing asymmetric high-order terms (such as u 3 , u 5 ), can cover more complex curvature changes and significantly reduce the fitting residuals.

[0138] 3. Mathematical mapping of the physical model

[0139] Physically speaking, the deformation of piezoelectric ceramics is driven by lattice distortion induced by an electric field, and its constitutive equation contains odd-order nonlinear terms:

[0140] ΔL = k1U + k3U3 + k5U5 + … (kn is a material constant, and U is the voltage)

[0141] Odd-order polynomials naturally fit this physical model and can more directly invert material parameters through experimental data.

[0142] 4. Stability Guarantee of Dynamic Compensation

[0143] In a dynamic control scenario (such as high-frequency on-off valve operation), the system needs to quickly respond to voltage changes and suppress oscillations:

[0144] The derivative (velocity characteristic) of the odd-order polynomial fitting is smoother, avoiding the acceleration mutation that may be caused by even-order terms, which is beneficial to improving control stability.

[0145] For example, the first derivative of a fifth-order polynomial is a fourth-order polynomial, which still maintains continuity and smoothness and is suitable for real-time control algorithms.

[0146] After the piezoelectric ceramics are subjected to displacement compensation by discrete data recording + odd-order polynomial fitting, the original nonlinear symmetric hysteresis between the true voltage value and the actual displacement is transformed into a linear correlation between the equivalent drive voltage value (the ratio between the actual working voltage and the maximum working voltage value Umax) and the actual displacement; ensuring the consistency and synchronism of the displacement output between the two piezoelectric ceramics in the present invention, avoiding the output displacement deviation and jitter caused by the asynchronous movement of the two piezoelectric ceramics at different distances of the lever, and having higher dispensing consistency and fewer dispensing scatter points during the high-speed movement of the lever turntable.

[0147] In some other embodiments,

[0148] Optionally, u is the true voltage value (for example, 10V, 20V, 30V, etc.), and F(u) is the true deformation size (for example, 10 microns, 20 microns, 30 microns, etc.);

[0149] Or, u is the ratio between the actual working voltage and the maximum working voltage value Umax (for example, 10%Umax, 20%Umax, 30%Umax, etc.), and F(u) is the ratio between the actual deformation size and the maximum deformation size ∆Lmax (for example, 10%∆Lmax, 20%∆Lmax, 30%∆Lmax, etc.).

[0150] S40: Store the fitted polynomial function in the internal PCB board of the dual-drive piezoelectric valve, and control the voltages of the proximal piezoelectric ceramic and the distal piezoelectric ceramic through the internal PCB board.

[0151] Specifically, when controlling the valve opening in step S40, it includes:

[0152] S401: First, obtain the target displacement amounts of the two piezoelectric ceramics through the set rubber material flow parameters (the relationship between the rubber material flow parameters and the target displacement amounts needs to be experimentally calibrated);

[0153] S402: Then substitute the target displacement amounts into the polynomial function to inversely calculate the voltage values of the two piezoelectric ceramics;

[0154] S403: Finally, output the calculated voltage values to the two piezoelectric ceramics to make the two piezoelectric ceramics contract and expand in the opposite direction (such as the voltage of the proximal end increases and the voltage of the distal end decreases), and jointly drive the lever rotating plate to rotate.

[0155] Through the above control, precise adjustment of the valve opening and stable control of the glue output amount can be achieved.

[0156] The piezoelectric valve displacement compensation control method based on the dual-drive piezoelectric valve provided in this embodiment uses methods such as voltage gradient control, calibrating the voltage-displacement relationship of the piezoelectric ceramics, using an odd-order polynomial to fit the hysteresis curve, and establishing a dynamic compensation model. It accurately describes the asymmetric hysteresis effect of the piezoelectric ceramics using a fifth-order polynomial function, and combines the differential control strategy of the proximal and distal piezoelectric ceramics to achieve linear adjustment of the valve opening by inversely calculating the target voltage value. The technical core lies in adapting to the physical mechanism of lattice distortion through odd terms, synchronously compensating for nonlinear displacement deviation and dynamic response hysteresis, and finally embedding the fitting function into the valve body PCB board to achieve closed-loop control, significantly improving the consistency of the glue output amount and the continuity of the trajectory under high-frequency working conditions.

[0157] Based on Embodiment 1, for the features not explained in this embodiment, the explanations in Embodiment 1 are adopted and will not be elaborated here.

[0158] Finally, it should be noted that although the above embodiments have been described in the text of the specification and drawings of this application, it does not limit the patent protection scope of this application. Any technical solutions obtained by equivalent structure or equivalent process substitution or modification using the content recorded in the text of the specification and drawings of this application based on the essential concept of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, are all included in the patent protection scope of this application.

Claims

1. A dual-drive piezoelectric valve, characterized in that, Comprising: A valve body (1), within which a valve cavity (101) is provided; A lever amplification structure (2), which is located within the valve cavity (101), and includes a lever rotating shaft (201) and a lever rotating plate (202) rotatably connected to the valve body (1) through the lever rotating shaft (201); A spring plunger assembly (3), the top surface of which elastically pushes against the bottom surface of one end of the lever rotating plate (202) away from the lever rotating shaft (201); A proximal piezoelectric ceramic (4) and a distal piezoelectric ceramic (5), the bottom surfaces of both the proximal piezoelectric ceramic (4) and the distal piezoelectric ceramic (5) abut against the top surface of one end of the lever rotating plate (202) close to the lever rotating shaft (201).

2. The dual-drive piezoelectric valve according to claim 1, wherein: The horizontal distance a from the spring plunger assembly (3) to the proximal piezoelectric ceramic (4), the horizontal distance b from the spring plunger assembly (3) to the lever rotating shaft (201), and the horizontal distance c from the spring plunger assembly (3) to the distal piezoelectric ceramic (5) satisfy: a < b < c.

3. The dual-drive piezoelectric valve according to claim 1, characterized in that Further comprising: A runner base (6), which is provided with a glue storage cavity (601) for storing glue, an inclined runner (602) for guiding the glue to the glue storage cavity (601), and a nozzle (603) communicating the bottom of the glue storage cavity (601) to the external space; A glue storage cylinder (7), which is threadedly connected to the inlet of the inclined runner (602).

4. The dual-drive piezoelectric valve according to claim 3, wherein The runner base (6) is detachably connected to the valve body (1) through a quick-release assembly (8), and the quick-release assembly (8) includes: An L-shaped connecting piece (801), one end of which is fixedly provided at the bottom of the valve body (1) and cooperates with the valve body (1) to form a U-shaped card slot (8011) with a horizontal opening; A limiting rotating plate (802), which is rotatably installed at the other end of the L-shaped connecting piece (801) for rotatably covering the opening of the U-shaped card slot (8011).

5. The dual-drive piezoelectric valve according to claim 4, characterized in that, The valve body (1) is provided with a fastening hole (102) corresponding to the position of the limiting rotating plate (802); The limiting rotating plate (802) is provided with a fastener (803) for tightly connecting with the fastening hole (102).

6. The dual-drive piezoelectric valve according to claim 4, wherein, The lower part of the spring plunger assembly (3) is installed at the upper opening of the glue storage cavity (601) to cover the upper opening of the glue storage cavity (601); The lower part of the valve body (1) is provided with a plunger upper cavity (103) for the upper part of the spring plunger assembly (3) to extend into and communicate with the valve cavity (101).

7. The dual-drive piezoelectric valve according to claim 6, wherein, The runner base (6) is provided with a limiting cross bar (604) that rotates around the axis of the plunger upper cavity (103) and enters and exits the U-shaped card slot (8011) through the opening of the U-shaped card slot (8011).

8. A piezoelectric valve displacement compensation control method, which is executed by the dual-drive piezoelectric valve according to any one of claims 1-7, characterized in that, Comprising: S10: Both ends of the proximal piezoelectric ceramic and the distal piezoelectric ceramic are connected to a driving power source; S20: Use a displacement sensor to record the displacement of the proximal piezoelectric ceramic and the distal piezoelectric ceramic under different voltages respectively, and store the mapping relationship between their respective voltage values and displacements to form several groups of two-dimensional arrays; S30: Fit each group of the stored two-dimensional arrays by using an odd-order polynomial fitting method to obtain the fitted polynomial function; S40: Store the fitted polynomial function in the internal PCB board of the dual-drive piezoelectric valve, and control the voltages of the proximal piezoelectric ceramic and the distal piezoelectric ceramic through the internal PCB board.

9. The piezoelectric valve displacement compensation control method according to claim 8, wherein The fitted polynomial function is F(u) = ax^u + bx^u 2 + cx^u 3 + dx^u 4 + ex^u 5 ; In the formula, u is the ratio between the actual working voltage and the maximum working voltage value Umax, and F(u) is the true deformation size; a, b, c, d, and e are fixed constants after polynomial fitting.

10. The piezoelectric valve displacement compensation control method according to claim 8, characterized in that S40 includes: S401: First, obtain the target displacements of the two piezoelectric ceramics through the set rubber material flow parameters; S402: Then substitute the target displacements into the polynomial function and calculate the voltage values of the two piezoelectric ceramics in reverse; S403: Finally, output the calculated voltage values to the two piezoelectric ceramics to make the two piezoelectric ceramics expand and contract in reverse and drive the lever turntable to rotate cooperatively.

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