雾化涂覆阀优化设计及试验研究

发布时间：2018-10-23 17:21

【摘要】：随着我国电子市场的蓬勃发展，各种各样的电子产品充斥于我们的生活中。由于一些电子产品的使用环境较为恶劣，其内部电路板在潮湿、高温、灰尘、盐雾等条件下容易产生腐蚀、软化、变形、霉变等问题，会大大降低电子产品的性能和使用寿命。因此，一般会在此类电子产品的内部电路板上涂覆一层保护漆，用于电子元件的防潮、防盐雾及防霉，三防漆涂覆技术应运而生。随着电子产品的规模化生产，传统的电路板接触式涂覆技术越来越无法适应市场的需求，而非接触式涂覆技术由于高精度、高频率等优势，正在逐渐占领涂覆市场。本文对胶液的雾化机理进行了研究，找出影响胶液雾化质量的因素。利用FLUENT软件对不同喷嘴结构下气体的流动状态进行了分析，，并结合对胶液的雾化机理进行的研究，设计出一款非接触式雾化涂覆阀。本文的主要研究内容如下：首先，对胶液的雾化机理进行研究，分析胶液产生雾化的原因及液滴破碎的一般方式。阐述了衡量胶液雾化效果的一般指标，并从理论方面分析了气体流速、液体流速、气液体积比及胶液粘度对胶液雾化效果产生的影响。找到能够改善胶液雾化效果的途径，为雾化涂覆阀喷嘴结构的设计奠定了理论基础。其次，对气体在流道内的运动规律进行了分析，得到了流经管道的气体流速和流量的影响因素，并以此为基础，设计了不同的喷嘴结构。利用FLUENT软件分析了喷嘴处不同的撞针与喷嘴的配合方式、不同的流道内外锥角大小、不同的喷嘴气液出口大小对喷嘴内气体流动状态的影响。结合前文对于影响胶液雾化效果的因素所进行的研究，分析由于喷嘴结构参数的改变所引起的气体流动状态的改变对胶液雾化效果的影响，找到雾化效果比较好的喷嘴结构参数。再者，分析了雾化涂覆装置的结构组成和基本工作原理。对撞针抬起高度对胶液流量大小的影响进行了分析。并以此为基础，结合涂覆阀的工况条件，对涂覆阀气缸进行了设计计算。并根据气缸的运行条件，对气缸弹簧进行了分析，确定了弹簧的基本参数。设计并制作了涂覆阀实验样机及涂覆阀驱动控制器，搭建了雾化涂覆阀系统，并对搭建系统的各部分进行了阐述分析。最后，为研究涂覆过程中外部条件的改变对涂覆效果的影响，搭建了涂覆实验平台。对所设计的涂覆阀样机进行相关实验，找到影响涂覆阀涂覆效果的外部控制因素。并对涂覆阀样机进行一致性实验分析，检验涂覆效果的可靠性。
[Abstract]:With the rapid development of electronic market in our country, all kinds of electronic products are flooded in our life. Due to the bad environment of some electronic products, the internal circuit board is easy to corrode, soften, deform and mould under the conditions of humidity, high temperature, dust and salt mist, which will greatly reduce the performance and service life of electronic products. Therefore, the internal circuit board of this kind of electronic products is usually coated with a layer of protective paint, which is used for the moisture-proof, anti-salt fog and anti-mildew of electronic components, and the three anti-paint coating technology emerges as the times require. With the large-scale production of electronic products, the traditional contact coating technology of circuit board is more and more unable to meet the needs of the market, while the non-contact coating technology is gradually occupying the coating market because of the advantages of high precision and high frequency. In this paper, the atomization mechanism of colloid is studied, and the factors influencing the atomization quality are found out. The flow state of gas under different nozzle structures was analyzed by using FLUENT software, and a non-contact atomization coating valve was designed based on the study of the atomization mechanism of colloidal liquid. The main contents of this paper are as follows: firstly, the atomization mechanism of colloid is studied, and the cause of atomization and the general method of droplet breaking are analyzed. The general indexes for measuring the atomization effect of colloidal liquid are described, and the effects of gas flow rate, liquid flow rate, gas-liquid volume ratio and colloidal viscosity on the atomization effect of colloidal liquid are analyzed theoretically. To find a way to improve the atomization effect of colloidal liquid, and lay a theoretical foundation for the structure design of spray coating valve nozzle. Secondly, the law of gas movement in the channel is analyzed, and the influence factors of the gas velocity and flow rate through the pipeline are obtained, and on this basis, different nozzle structures are designed. By using FLUENT software, the effects of different ways of matching the pin and nozzle at the nozzle, the inner and outer cone angle of the flow channel and the gas-liquid outlet of the nozzle on the gas flow state in the nozzle are analyzed. Based on the previous research on the factors influencing the atomization effect of colloidal liquid, the influence of the change of gas flow state caused by the change of nozzle structure parameters on the atomization effect of colloidal liquid is analyzed. Find the nozzle structure parameters with good atomization effect. Furthermore, the structure and basic working principle of atomization coating device are analyzed. The influence of the height of the collider on the flow rate of the glue was analyzed. On this basis, combined with the working conditions of the coated valve, the design calculation of the coated valve cylinder is carried out. According to the operating conditions of the cylinder, the cylinder spring is analyzed, and the basic parameters of the spring are determined. The experimental prototype of the coating valve and the driving controller of the coating valve are designed and manufactured. The atomization coating valve system is built and the various parts of the system are described and analyzed. Finally, in order to study the influence of the external conditions on the coating effect, a coating experiment platform was built. The external control factors affecting the coating effect of the coating valve were found by the experiments on the prototype of the coating valve. The consistency analysis of the coating valve prototype was carried out to verify the reliability of the coating effect.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN02

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