Method and system for optimizing drive voltage waveform of piezoelectric injection valve

Abstract

The application provides a driving voltage waveform optimization method and system of a piezoelectric injection valve, and the application separately optimizes a lifting stage and a collision stage. In the lifting stage, trapezoidal acceleration and deceleration control and exponential acceleration and deceleration control voltage speed are applied. In the collision stage, the voltage speed of the front part is controlled to be large first and small later, and the voltage speed of the rear part is controlled to be decreased by more than a set threshold. The application solves the problems that bubbles are easily generated at a nozzle of the piezoelectric injection valve in the lifting stage, and the overshoot of the displacement of a needle is easily increased in the pursuit of a larger collision speed in the collision stage, and improves the dispensing performance.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric injection valve control technology, and relates to a method and system for optimizing the drive voltage waveform of a piezoelectric injection valve. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the rapid development of the electronics industry, the demand for precision electronic packaging technology is increasing, and the requirements for droplet size in electronic packaging and other fields are becoming more stringent. Piezoelectrically driven jet valves have many advantages, such as high dispensing accuracy, small volume error, and high repeatability, and are widely used in rapid manufacturing, chip manufacturing, and genetic engineering microelectronic packaging.

[0004] Based on the movement state of the ejector pin in the piezoelectric jet valve, the piezoelectric jet valve can complete one dispensing cycle as follows: lift-up – filling – impact – holding. To date, the nozzle of the widely used piezoelectric jet valve is prone to generating air bubbles during the lift-up phase, and the overshoot of the ejector pin displacement is easily increased in the impact phase in order to pursue a larger impact speed. Both of these problems will affect the dispensing effect to a certain extent and are not conducive to improving dispensing performance. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a method and system for optimizing the driving voltage waveform of a piezoelectric jet valve. This invention optimizes the lifting and impact phases separately, solving the problems of air bubbles easily generated at the nozzle during the lifting phase and the overshoot of the ejector pin displacement easily increased in the impact phase in pursuit of a larger impact speed, thereby improving dispensing performance.

[0006] According to some embodiments, the present invention adopts the following technical solution:

[0007] A method for optimizing the drive voltage waveform of a piezoelectric injection valve includes the following steps:

[0008] During the lifting phase, trapezoidal acceleration / deceleration control and exponential acceleration / deceleration control are applied to control the voltage speed.

[0009] During the impact phase, the voltage velocity of the first part is controlled to be high and then low, while the voltage velocity of the second part decreases beyond a set threshold.

[0010] As an alternative implementation, the voltage signal used in the method is a periodic trapezoidal signal, including a lifting phase, a filling phase, an impact phase, and a holding phase.

[0011] As an alternative implementation method, the specific process of applying trapezoidal acceleration / deceleration control and exponential acceleration / deceleration control to voltage speed includes:

[0012] In the first time period, trapezoidal acceleration and deceleration control is used to make the voltage speed accelerate uniformly to the maximum value;

[0013] In the second time period, exponential acceleration and deceleration control is performed to exponentially reduce the voltage speed from its maximum value to 0.

[0014] In the third time period, voltage amplitude control is performed. The voltage amplitude is obtained by integrating the voltage speed function over one cycle.

[0015] As a further defined implementation method, corresponding control equations are established for different time periods. By solving the equations simultaneously, the final expression for voltage speed is constructed, and the voltage value at any time during the lifting phase is obtained.

[0016] As an alternative implementation method, the specific process of controlling the voltage rate of the first part to be large and then small, and the voltage rate drop of the second part to exceed a set threshold, includes:

[0017] In the first period, voltage deceleration control is performed to reduce the voltage speed to the set value;

[0018] In the second time period, voltage deceleration control is implemented, and the voltage speed is reduced to 0 with an acceleration less than that in the first time period;

[0019] In the third time period, voltage amplitude control is performed. The voltage amplitude is obtained by integrating the voltage speed function over one cycle.

[0020] As a further defined implementation method, corresponding control equations are established for different time periods. By solving the equations simultaneously, the final expression for voltage speed is constructed, and the voltage value at any time during the lifting phase is obtained.

[0021] As an alternative implementation, the optimized voltage waveforms of the lifting and impact phases are used to replace the waveforms of the lifting and impact phases in the original periodic trapezoidal signal to form the final drive voltage waveform of the piezoelectric injection valve.

[0022] A system for optimizing the drive voltage waveform of a piezoelectric injection valve, comprising:

[0023] The first optimization module is configured to apply trapezoidal acceleration / deceleration control and exponential acceleration / deceleration control to control the voltage speed during the lifting phase.

[0024] The second optimization module is configured to control the voltage velocity of the first part to be large and then small during the impact phase, and the voltage velocity of the second part to decrease beyond a set threshold.

[0025] A computer-readable storage medium storing a plurality of instructions adapted for loading by a processor of a terminal device and executing steps in the method.

[0026] A terminal device includes a processor and a computer-readable storage medium, the processor being configured to implement instructions; the computer-readable storage medium being configured to store a plurality of instructions adapted to be loaded by the processor and executed in accordance with the steps of the method described therein.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] This invention replaces the original periodic trapezoidal signal waveforms for the lift-up and impact phases with optimized voltage waveforms for these phases, serving as a method for optimizing the drive voltage waveform of piezoelectric jet valves. This invention solves the problems of air bubbles easily forming at the nozzle during the lift-up phase and the increased overshoot of the ejector pin displacement during the impact phase in pursuit of higher impact speeds in existing piezoelectric jet valves, thus improving dispensing performance. Attached Figure Description

[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0030] Figure 1 This invention relates to a method for optimizing the drive voltage waveform of a piezoelectric injection valve, which selects the applied voltage signal, namely a periodic trapezoidal signal.

[0031] Figure 2 This is a voltage velocity diagram of the lift-up phase in the drive voltage waveform optimization method for piezoelectric injection valves according to the present invention;

[0032] Figure 3 This is a diagram of the voltage value during the lift-up phase in the drive voltage waveform optimization method for piezoelectric injection valves according to the present invention;

[0033] Figure 4 This is the voltage velocity diagram during the impact phase in the drive voltage waveform optimization method for piezoelectric injection valves of the present invention;

[0034] Figure 5 This is a voltage value diagram of the impact stage in the drive voltage waveform optimization method for piezoelectric injection valves according to the present invention;

[0035] Figure 6 This is a voltage waveform diagram after optimization of the drive voltage waveform for the piezoelectric injection valve according to the present invention;

[0036] Figure 7 It is a comparison diagram of the displacement of the firing pin before and after optimization;

[0037] Figure 8 It is a comparison chart of the impact speed of the firing pin before and after optimization. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular form is also intended to include the plural form. Furthermore, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] Disclosed is a driving voltage waveform optimization method for a piezoelectric jet valve, wherein the applied voltage signal is selected as a periodic trapezoidal signal as Figure 1 shown, let 0<t1<t2<t3<t4, the voltage changes within one cycle as follows: the voltage rises from low level to high level during 0-t1, in this stage, the striker of the piezoelectric jet valve rises from the lowest position, which corresponds to the lifting stage of the piezoelectric jet valve; the voltage is in the high level stage during t1-t2, in this stage, the striker of the piezoelectric jet valve is at the highest position, colloid enters the nozzle, which corresponds to the glue filling stage of the piezoelectric jet valve; the voltage drops from high level to low level during t2-t3, in this stage, the striker of the piezoelectric jet valve descends from the highest position, which corresponds to the striking stage of the striker of the piezoelectric jet valve, and the colloid is extruded and ejected out of the nozzle; the voltage is at low level during t3-t4, in this stage, the striker of the piezoelectric jet valve is at the lowest position, which corresponds to the holding stage of the piezoelectric jet valve.

[0042] The voltage at the lifting stage of the piezoelectric jet valve is optimally designed, and the waveform design method combining trapezoidal acceleration and deceleration control and exponential acceleration and deceleration control is applied to achieve smoother movement of the striker while ensuring a certain speed. Figure 2 is a designed voltage-velocity diagram for the lifting stage, and the specific steps are as follows:

[0043] Step 1: Establish the equation of trapezoidal acceleration and deceleration control, in this process the speed uniformly accelerates to the maximum value:

[0044] v 0tq =a tq t 1tq (1)

[0045] wherein, v 0tq is the maximum value of the voltage speed at the lifting stage, a tq is the acceleration of the uniform acceleration motion of the voltage at the lifting stage, t 1tq is the time of the uniform acceleration motion of the voltage at the lifting stage.

[0046] Step 2: Establish the equations for exponential acceleration / deceleration control, in which the voltage speed decreases exponentially from its maximum value to 0:

[0047]

[0048] Among them, v ctq Let t be a constant velocity value. 2tq ——t 3tq The voltage deceleration time during the lifting phase is τ, where τ is the coefficient of the exponential function.

[0049] Step 3: Establish an equation for the voltage amplitude. The voltage amplitude is obtained by integrating the function of voltage velocity over one period.

[0050]

[0051] Among them, t 1tq ——t 2tq V0 represents the time during which the voltage moves at a constant speed, and V0 is the set voltage amplitude.

[0052] Solve the three equations (1), (2), and (3) simultaneously, where t 1tq t 2tq t 3tq V0 and τ are set according to production needs, therefore, v can be solved from the three equations. 0tq v ctq a tq Three unknowns.

[0053] Based on the above calculations, the expression for the voltage velocity v can be written as follows:

[0054]

[0055] Based on the expression for v, the value of voltage V(t) at any time t during the lifting phase can be obtained as follows:

[0056]

[0057] Based on this, the voltage value during the lift-up phase in the drive voltage waveform optimization method for piezoelectric injection valves of this invention is obtained as follows: Figure 3 As shown.

[0058] The impact phase of the piezoelectric jet valve is optimized. Based on the principle of acceleration and deceleration control, the impact waveform can adopt the following voltage output: in the first half of the waveform, the voltage speed is high and then decreases, which can increase the speed of the ejector pin. In the second half, the voltage speed drops significantly, reducing the overshoot of the ejector pin displacement, making the ejector pin displacement more controllable, and helping to improve the dispensing effect. Figure 4 The specific steps for designing the voltage-velocity diagram during the impact phase are as follows:

[0059] Step 1: Establish the equations for the first stage of uniform deceleration of the voltage:

[0060] v czj -ka zj t 1zj =v 0zj (4)

[0061] Among them, v czj ka represents the maximum voltage velocity during the impact phase. zj Let t be the acceleration of the voltage during the first segment of uniform deceleration in the impact phase, where k is a coefficient and k > 1. 1zj v is the time of the first segment of uniform deceleration during the impact phase. 0zj To decelerate to t 1zj The speed afterwards.

[0062] Step 2: Establish the equation for the second stage of uniform deceleration of the voltage, in which the voltage velocity decreases to 0 with an acceleration less than that in the first stage:

[0063] v 0zj -a zj (t 2zj -t 1zj )=0 (5)

[0064] Among them, a zj Let t be the acceleration of the second segment of uniformly decelerated motion during the impact phase. 1zj ——t 2zj This refers to the time of the second stage of uniform deceleration motion of the voltage during the impact phase.

[0065] Step 3: Establish an equation for the voltage amplitude. The voltage amplitude is obtained by integrating the function of voltage velocity over one period.

[0066]

[0067] V0 is the set voltage amplitude.

[0068] Solve the three equations (4), (5), and (6) simultaneously, where t 1zj t 2zj V0 and k are set according to production needs, therefore, v can be solved from the three equations. czj v 0zj a zj Three unknowns.

[0069] Based on the above calculations, the expression for the voltage velocity v can be written as follows:

[0070]

[0071] Based on the expression for v, the value of voltage V(t) at any time t during the lifting phase can be obtained as follows:

[0072]

[0073] Based on this, the voltage value during the impact phase in the drive voltage waveform optimization method for piezoelectric injection valves of this invention is obtained as follows: Figure 5 As shown.

[0074] The present invention also provides the following product examples:

[0075] A system for optimizing the drive voltage waveform of a piezoelectric injection valve, comprising:

[0076] The first optimization module is configured to apply trapezoidal acceleration / deceleration control and exponential acceleration / deceleration control to control the voltage speed during the lifting phase.

[0077] The second optimization module is configured to control the voltage velocity of the first part to be large and then small during the impact phase, and the voltage velocity of the second part to decrease beyond a set threshold.

[0078] A computer-readable storage medium storing a plurality of instructions adapted for loading by a processor of a terminal device and executing steps in the method.

[0079] A terminal device includes a processor and a computer-readable storage medium, the processor being configured to implement instructions; the computer-readable storage medium being configured to store a plurality of instructions adapted to be loaded by the processor and executed in accordance with the steps of the method described therein.

[0080] This invention replaces the waveforms of the original periodic trapezoidal signal for the lift-up and impact phases with optimized voltage waveforms for the lift-up and impact phases. The optimized waveforms are as follows: Figure 6 As shown

[0081] like Figure 7 As shown, during the striker lift-off phase, the trapezoidal-exponential acceleration / deceleration voltage does indeed have an optimization effect compared to the ordinary trapezoidal voltage. This is manifested in reducing the overshoot of the striker displacement, reducing the oscillation of the striker motion, reducing the rise time and settling time, and improving the system response speed, thus playing a good optimization role.

[0082] By adopting a trapezoidal-exponential acceleration / deceleration voltage, the overshoot and oscillation characteristics of the impact pin are reduced, the response speed is improved, and the impact velocity is increased, such as... Figure 8 As shown.

[0083] This invention solves the problems of air bubbles easily generated at the nozzle during the lifting phase and the overshoot of the ejector pin displacement easily increased during the impact phase in pursuit of a larger impact speed in the existing piezoelectric injection valve, thus improving the dispensing performance.

[0084] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0085] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0086] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0089] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for optimizing the drive voltage waveform of a piezoelectric injection valve, characterized in that, Includes the following steps: During the lifting phase, trapezoidal acceleration control and exponential deceleration control are applied to control the voltage speed, including: The expression for voltage velocity v: , Based on the expression for v, the value of voltage V(t) at any time t during the lifting phase can be obtained as follows: An equation for voltage amplitude is established, and the voltage amplitude is obtained by integrating the function of voltage velocity over one period: , in , , , Configure it yourself according to production needs. For the set voltage amplitude, To achieve the acceleration of uniformly accelerated motion during the voltage lifting phase, To achieve the maximum voltage speed during the lifting phase, It is a constant velocity value; 0—— In the first time period, trapezoidal acceleration control is used to uniformly accelerate the voltage speed to its maximum value; In the second time period, the voltage changes at a constant rate. In the third period, exponential deceleration control is implemented to exponentially reduce the voltage speed from its maximum value to 0. During the impact phase, the voltage velocity in the first part is controlled to be high initially and then decrease, while the voltage velocity in the latter part decreases beyond a set threshold, including: The expression for voltage velocity v: , Based on the expression for v, the value of voltage V(t) at any time t during the impact phase can be obtained as follows: ， An equation for voltage amplitude is established, and the voltage amplitude is obtained by integrating the function of voltage velocity over one period: in , Configure it yourself according to production needs. For the set voltage amplitude, This represents the maximum voltage velocity during the impact phase. Let k be the acceleration of the voltage uniformly decelerated motion during the impact phase, and k be a coefficient, requiring k >

1. To slow down The speed after; 0—— In the first period, voltage deceleration control is implemented to reduce the voltage speed to the set value; —— In the second period, voltage deceleration control is implemented, and the voltage speed is reduced to 0 with an acceleration less than that in the first period.

2. The method for optimizing the drive voltage waveform of a piezoelectric injection valve as described in claim 1, characterized in that, The applied voltage signal is a periodic trapezoidal signal, including a lifting phase, a filling phase, an impact phase, and a holding phase.

3. The method for optimizing the drive voltage waveform of a piezoelectric injection valve as described in claim 1, characterized in that, At different time periods, corresponding control equations are established. By solving the equations simultaneously, the final expression for voltage velocity is constructed, and the voltage value at any time during the lifting phase is obtained.

4. The method for optimizing the drive voltage waveform of a piezoelectric injection valve as described in claim 1, characterized in that, The optimized voltage waveforms of the lifting and impact phases replace the original periodic trapezoidal signal waveforms of the lifting and impact phases, forming the final drive voltage waveform of the piezoelectric injection valve.

5. A system for optimizing the drive voltage waveform of a piezoelectric injection valve, characterized in that, The method for optimizing the drive voltage waveform of a piezoelectric injection valve as described in any one of claims 1-4 includes: The first optimization module is configured to apply trapezoidal acceleration / deceleration control and exponential acceleration / deceleration control to control the voltage speed during the lifting phase. The second optimization module is configured to control the voltage velocity of the first part to be large and then small during the impact phase, and the voltage velocity of the second part to decrease beyond a set threshold.

6. A computer-readable storage medium, characterized in that, It stores multiple instructions adapted for loading by the processor of a terminal device and executing the steps of the method according to any one of claims 1-4.

7. A terminal device, characterized in that, It includes a processor and a computer-readable storage medium, the processor being used to implement various instructions; the computer-readable storage medium being used to store a plurality of instructions adapted to be loaded by the processor and executed in the steps of the method of any one of claims 1-4.

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