超声喷雾电火花加工方法及其工艺研究

发布时间：2017-12-30 23:44

本文关键词：超声喷雾电火花加工方法及其工艺研究　出处：《哈尔滨工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：现代工业加工中,产品尺寸越来越小,要求精度越来越高,促使现代加工方式向精细,稳定,环保的方向不断发展。本文对传统电火花加工做出改进,提出了一种以超声喷雾辅助加工的新型加工方式。该方式改善了其它喷雾加工中雾化颗粒不均匀,雾化效果不完全的缺点,同时由超声雾化的雾滴直接作用于加工区域不仅可以冲刷加工区域帮助排出加工碎屑,而且在雾化过程中产生的超声空化效应还有助于提高加工质量与效率。本文在总结国内外电火花加工发展现状以及发展趋势的前提下,结合传统电火加工原理,对超声喷雾加工过程中放电各过程进行了分析。设计了一套由超声电源与换能器组成的超声喷雾装置,超声电源以DSP2812为控制核心,主要包含BUCK电路、全桥变换、电火花放电间隙电压检测、超声换能器电压电流检测等模块。超声换能器采用一维振动理论设计,结合有限元软件进行验证与改进。完成了从方案设计、硬件电路实验、到软件功能调试的过程。在加工装置实现的基础上,对超声喷雾电火花加工进行了相应的实验研究。设置了两类加工实验,第一类为超声喷雾加工与传统浸泡(冲液)加工和空气中加工的对比实验,对比分析了三者在材料去除率(MRR),相对电极损耗率(EWR),加工稳定性等方面的区别。第二类为超声喷雾加工参数对比实验,研究了包括喷雾流量、加工过程中换能器驱动电压大小、驱动电压频率等参数对于加工结果的影响。实验结果表明,超声喷雾加工相比于冲液加工,有着更低的电极损耗率和相似的材料去除率,且材料去除率远高于空气中加工。喷雾加工结果随流量变化改变明显。在一定范围内,材料去除率随着流量的增大而增大,当超出该范围后,材料去除率上升不明显,而电极损耗率显著增加。超声电压与频率对于喷雾加工结果的影响是多重的,一般规律是,低频率与高电压对于加工材料去除率有提升,而高频率与低电压则有助于降低电极损耗率。同时本文进一步进行了孔加工的探索性实验,并在实验的基础上总结了超声喷雾加工的规律与适用范围,对于实际生产加工具有理论指导作用。
[Abstract]:In modern industrial processing, the product size is becoming smaller and smaller, and the precision is getting higher and higher, which promotes the development of the modern machining mode in the direction of fine, stable and environmental protection. This paper improves the traditional EDM. A new type of machining method assisted by ultrasonic spray is proposed, which can improve the inhomogeneity of atomization particles and the incomplete atomization effect in other spray processes. At the same time, the ultrasonic atomized droplets acting directly on the processing area can not only wash the processing area to help remove the processing debris. And the ultrasonic cavitation effect in the atomization process also helps to improve the quality and efficiency of machining. This paper summarizes the current situation and development trend of EDM at home and abroad combined with the traditional principle of EDM. The discharge process in ultrasonic spray machining is analyzed. A set of ultrasonic spray device composed of ultrasonic power supply and transducer is designed. The control core of ultrasonic power supply is DSP2812. The main modules include BUCK circuit, full-bridge conversion, voltage detection of electric spark discharge gap, voltage and current detection of ultrasonic transducer, etc. The ultrasonic transducer is designed by one-dimensional vibration theory. Combined with finite element software to verify and improve. Completed from the program design, hardware circuit experiments, to the software function debugging process. On the basis of the implementation of the processing device. Two kinds of processing experiments were set up. The first one was the contrast experiment between ultrasonic spray machining and traditional immersion machining and air processing. The differences of the three methods in material removal rate (MRR), relative electrode loss rate (RPE) and machining stability are analyzed. The second category is the contrast experiment of ultrasonic spray machining parameters. The effects of the parameters such as spray flow rate, transducer driving voltage and driving voltage frequency on the machining results are studied. The experimental results show that ultrasonic spray machining is better than that of liquid injection machining. It has lower electrode loss rate and similar material removal rate, and the material removal rate is much higher than that in air processing. The spray processing results change obviously with the flow rate, and within a certain range. The material removal rate increases with the increase of flow rate. When the material removal rate exceeds this range, the material removal rate does not increase significantly, while the electrode loss rate increases significantly. The influence of ultrasonic voltage and frequency on the results of spray processing is multiple. The general rule is that low frequency and high voltage can improve the material removal rate, while high frequency and low voltage can help to reduce the electrode loss rate. At the same time, the exploratory experiment of hole machining is carried out in this paper. On the basis of experiments, the rule and applicable range of ultrasonic spray machining are summarized, which can be used as a theoretical guide for practical production and processing.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG661

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