多腔串联压电泵结构设计及关键技术研究

发布时间：2019-06-26 15:27

【摘要】：压电泵是近年来发展起来的一种新型流体泵，在流体系统中有着广阔的应用前景。压电泵的输出性能不仅取决于进口和出口截止阀特性，而且与腔体的结构形式息息相关。本文结合国家自然科学基金项目-“主动阀压电泵作用机理与关键技术研究”（项目编号：50575093）和教育部高等学校科技创新工程重大项目培育基金项目-“驱动测试控制功能一体化新型压电机构研究”（项目编号：708028），利用压电双晶片驱动压电泵工作，采用一种轮式平板阀，构造多腔串联结构的小型系列压电泵。在研发多腔串联压电泵的基础上，开展了多腔串联压电泵的结构设计以及试验等方面的研究。 1、压电泵的国内外研究现状与发展压电泵具有结构简单、无电磁干扰、转换效率高、性能可靠等优点，是许多国家学者研究的热点课题，已经有30多年的研发历史。本文在查阅大量国内外相关文献的基础上，总结了压电泵的各种分类方法，并对有阀压电泵、无阀压电泵的国内外研究现状和应用情况进行了综述，了解到目前压电泵产品已经广泛应用于航空航天、化学分析、生物工程等各个领域。由于单腔压电泵的输出压力和输出流量均有限，采用多腔串联结构研发成为了一种良好的方案。国内外对于该方面的研究还处于起步阶段，研究成果较少，深入地了解多腔串联压电泵的工作特性，提高多腔压电泵的输出性能，为压电泵在更广泛领域的应用打下基础。 2、压电振子振动特性研究压电振子是压电泵的动力元件，它的性能直接影响到压电泵的输出能力。利用薄板变形理论，建立了圆形压电振子弯曲变形的曲线方程，推导了压电振子变形量和容积变化量的解析式。对本文选用基板直径为35mm、陶瓷直径为29mm压电双晶片振子变形量进行了理论计算。应用ANSYS仿真软件建立了压电振子的有限元模型，对振子振动时的各阶振型频率和变形量进行了仿真分析。通过试验方法对压电振子的静态特性进行了测试，从而验证了理论分析和有限元仿真结果的正确性。 3、压电泵被动截止阀的设计单向截止阀是决定有阀压电泵输出性能的关键部件，有阀压电泵研究与发展是伴随单向阀的发展而不断进步。针对多腔串联压电泵输出压力高的特点，为提高阀的承载能力和反向截止能力，本文采用一种由厚度5-7μm左右铍青铜加工的轮式平板阀。理论分析了轮式平板阀在静载荷作用下变形量及通流能力，确定了轮式平板阀的几何尺寸，研究了作用在阀两侧的压力差对阀通流能力的影响，并分析了其动态响应特性，为进一步提高输出流量提供了理论依据。 4、多腔串联压电泵工作性能分析与测试多腔串联压电泵可以看作是多个单腔压电泵的串联工作模式，具有较大的输出流量和较好的输出压力。多腔串联压电泵是脉动输出，很难建立精确的数学模型计算分析其输出性能。为此，采用多个压电晶片设计制作了双腔串联、三腔串联和四腔体串联等结构的压电泵系列样机，，对各个结构工作时的表现特性进行理论分析，并对输出压力、输出流量、阀的安装位置以及不同驱动方式等情况进行了试验测试。试验结果表明：①从输出压力来看，三腔串联压电泵在整个工作频率段的输出压力约为两腔串联的1.5倍，输出压力比较平稳，而四腔泵输出压力波动较大。但是，随着串联级数的增加，多腔串联压电泵的输出压力持续增大。②从输出流量来看，多腔压电泵在高频段（大于200Hz）工作时，随着腔体数量的增加，输出流量增加较多，在输出电压的工作频率为300Hz时，四腔串联压电泵的输出流量达到了将近1000ml/min。可见，多腔体串联压电泵可以有效地提高压电泵的输出流量性能。 5、多腔串联压电泵驱动电源设计为满足压电振子快速响应的要求，运用FPGA和DDS技术为多腔串联压电泵设计了快速响应的驱动电源。DDS是一种新型的频率合成技术，从“相位”的概念出发进行频率合成，具有较高的频率分辨率。以FPGA芯片作为硬件电路的核心，通过VHDL语言设计的DDS驱动电源的IP核嵌入在FPGA内部。采用模块化的思想，设计了DDS系统外围电路，进行了软件设计，并且对该驱动电源进行了试验测试，结果表明该驱动电源的输出波形（正弦波、三角波和方波）精度较高，当频率和波形等参数改变时响应速度快，达到电源输出稳定性要求。 6、多腔串联压电泵闭环控制系统设计压电泵在工作过程中，易受气泡、杂质等干扰，输出流量有时会不稳定。为此，设计了多腔串联压电泵闭环控制系统，它由缓冲电路、调幅电路、功率放大电路、升压变压器等部分组成，核心部件是在缓冲级之后由FPGA控制数字电位器组成的可变增益的调幅电路。实际的输出流量通过换算转换成电压值后，与参考电压值做比较，存在偏差则调节调幅电路的数字电位器抽头位置，运用FPGA芯片通过增益调整来实现多腔串联压电泵流量的稳定控制，为今后的研究提供新的思路和试验平台。
[Abstract]:Piezoelectric pump is a new kind of fluid pump developed in recent years, and has wide application prospect in fluid system. The output performance of the piezoelectric pump depends not only on the characteristics of the inlet and outlet shut-off valves but also in the form of the structure of the cavity. This paper combines the national natural science fund project-"Study on the action mechanism and key technology of active valve piezoelectric pump" (project number:50575093) and the project-"Research on a New Type of Piezoelectric Mechanism with Integrated Drive Test and Control Function" (project number:708028) of the major project of science and technology innovation engineering of the Ministry of Education, and uses the piezoelectric bimorph to drive the piezoelectric pump to work, and adopts a wheel type flat valve. A small series of piezoelectric pumps that construct a multi-lumen series structure. On the basis of R & D multi-cavity series piezoelectric pump, the structure design and test of multi-cavity series piezoelectric pump are carried out. 1. Current research situation of piezoelectric pump at home and abroad The development of the piezoelectric pump has the advantages of simple structure, no electromagnetic interference, high conversion efficiency and reliable performance. The paper summarizes the various classification methods of the piezoelectric pump on the basis of consulting a lot of relevant literature and abroad, and reviews the present situation and application of the valve piezoelectric pump and the non-valve piezoelectric pump. Space, chemical analysis, bioengineering, etc. Because the output pressure and output flow of the single-cavity piezoelectric pump are limited, the multi-cavity series-structure R & D has become a good At home and abroad, the research on this aspect is still in the initial stage, the research results are less, the working characteristics of the multi-cavity series piezoelectric pump are better understood, the output performance of the multi-cavity piezoelectric pump is improved, and the application of the piezoelectric pump in a wider field is achieved. lower foundation The characteristic of vibration is that the piezoelectric vibrator is the power element of the piezoelectric pump, and its performance directly influences the pressure. The output power of the electric pump is established. The curve equation of the bending deformation of the circular piezoelectric vibrator is established by the deformation theory of the thin plate. The deformation and the volume of the piezoelectric vibrator are derived. In this paper, the deformation of the piezoelectric bimorph vibrator with the substrate diameter of 35 mm and the ceramic diameter of 29 mm is selected. The theoretical calculation is carried out. The finite element model of the piezoelectric vibrator is established by using the ANSYS simulation software, and the frequency and deformation of each step in the vibration of the vibrator are obtained. The static characteristic of the piezoelectric vibrator is tested by the test method, and the theoretical analysis and the finite element simulation are verified. true of true results.3, pressure The design one-way stop valve of the passive stop valve of the electric pump is the key component which determines the output performance of the valved piezoelectric pump, and the research and development of the valve piezoelectric pump are accompanied by the development of the valve According to the characteristics of high output pressure of multi-cavity series piezoelectric pump, this paper adopts a kind of one-way valve with the thickness of 5-7. m In this paper, the deformation and the flow capacity of the wheel-type plate valve under the static load are analyzed, and the geometric dimension of the wheel-type plate valve is determined. The influence of the pressure difference on the flow capacity of the valve on the two sides of the valve is studied. The dynamic response characteristics of the system are analyzed and the dynamic response characteristics are further improved. The output flow provides a theoretical basis. The series piezoelectric pump working performance analysis and testing multi-cavity series piezoelectric pump can be regarded as a series working mode of a plurality of single-cavity piezoelectric pumps, The large output flow and the better output pressure. The multi-cavity series piezoelectric pump is a pulsating output and it is difficult to establish the essence. In this paper, a series of piezoelectric pump series of two-cavity series, three-cavity series and four-cavity series and other structures are fabricated by using a plurality of piezoelectric crystal plates, and the performance characteristics of the two-cavity series, three-cavity series and four-cavity series are made. the analysis, and the output pressure, the output flow rate, the installation position of the valve, The test results show that the output pressure of the three-cavity series piezoelectric pump in the whole working frequency range is about 1.5 times that of the two-cavity series and the output pressure is compared with the output pressure. The output pressure of the four-cavity pump is large, however, with the increase of the series series, the output pressure of the four-cavity pump is large. The output pressure of the cavity series piezoelectric pump is continuously increased. According to the output flow, the multi-cavity piezoelectric pump is operated at a high frequency band (more than 200 Hz), the output flow is increased as the number of cavities is increased, the output flow of the four-cavity series piezoelectric pump is increased when the working frequency of the output voltage is 300 Hz, It can be seen that the multi-cavity series piezoelectric pump can effectively improving the output flow performance of the piezoelectric pump and 5, the multi-cavity series piezoelectric pump driving power supply is designed to meet the requirement of the fast response of the piezoelectric vibrator, The multi-cavity series piezoelectric pump has designed a fast response driving power supply. DDS is a new kind of frequency synthesis technology, from the concept of the "phase" The FPGA chip is used as the core of the hardware circuit and is designed by the VHDL language. The IP core of the DS drive power supply is embedded in the FPGA. The design of the peripheral circuit of the DDS system is designed. The software design is carried out, and the driving power supply is tested and tested. The result shows that the drive power is lost. The output waveform (sine wave, triangular wave and square wave) is high in precision, and when the parameters such as frequency and waveform change The response speed of the power supply is high, and the output stability of the power supply is achieved Requirement.6. The closed-loop control system of multi-cavity series piezoelectric pump is designed to design the piezoelectric pump in the working process in that invention, the closed-loop control system of the multi-cavity series piezoelectric pump is designed, the actual output flow is converted into a voltage value, compared with the reference voltage value, the position of the digital potentiometer tap of the amplitude-modulation circuit is adjusted by the deviation, and the FPGA chip is used Multi-cavity series piezoelectric pump flow by gain adjustment
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH38

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