【作者】 贾男；

【导师】 王福吉；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2010， 硕士

【摘要】 随着科技的不断发展,具有微小孔的零件被广泛的应用在航空、航天、汽车、医疗器械等重要行业的核心装备中。微细电火花加工技术因其具有非接触式加工、无宏观切削力、对工具的强度和刚度要求低、材料适用范围广的特点,在微尺度加工领域有着无可比拟的优越性,是一种特别适合用于加工微小孔的方法。但是这种方法存在自身的弊端,即加工间隙极其细微,加工爆炸力小,电蚀产物排除困难,电蚀产物堆积在加工间隙内容易造成短路并且极易产生二次放电的现象,使加工稳定性大大降低。为了改善微小孔电火花加工中电蚀产物的排除状况,本文就工件振动、电极旋转等工艺手段对排屑效果的影响进行了一系列研究。以电蚀产物的有效排出为目标采用流体动力学方法进行了间隙内电蚀产物颗粒排除的仿真研究。建立了电蚀产物排出的流体动力学分析模型,并应用流体动力学分析软件Fluent对电极旋转、电极振动、电极旋转振动、工件振动、电极旋转工件振动五种加工方式下电蚀产物的排出情况进行了仿真,仿真结果表明：电极旋转工件振动的加工方式下间隙内电蚀产物的排出情况最好。研制了一台超磁致伸缩执行器,并将其作为微小孔电火花加工中的工件振动器使用。通过振动器带动工件振动,辅助电蚀产物迅速排除,创造良好的放电环境,提高放电机率,进而提高微小孔电火花的加工效率。对所设计的超磁致伸缩振动器的静动态特性进行了测试,从而为微小孔电火花加工实验提供准备。在自主研发的加工设备上进行微小孔电火花加工实验。实验对比了电极旋转、工件振动和电极旋转工件振动三种加工方式下的加工时间。由实验结果可知：工件振动电极旋转时所用的加工时间最短,从而验证了流体动力学的仿真结果。最后针对工件振动频率对加工效率的影响进行了实验研究。实验结果表明：工件的振动频率越高,微小孔电火花加工的加工时间越短。所以提高工件振动频率是减小加工时间、提高加工效率的有效手段。更多还原

【Abstract】 With the development of technology, parts with micro-hole have been widely in aviation, aerospace, automotive, medical equipment and other important industries. Micro-EDM has the advantages of non-contact processing, no macroscopic cutting force, and low requirement of strength and stiffness of the tools, wide material application range, is especially suitable for micro-hole processing method. However, this method also has its own drawbacks, that is its machining gap is extremely subtle and its processing explosive force is very small, electric erosion products is hard to exclude, electric erosion products deposited on the processing of the content could easily lead to short-circuit the gap. Greatly reduce the processing stability, easy to produce secondary discharge phenomenon. In order to improve the debris exclusion phenomenon, a series of researches are carried out in this paper.In chapter two we conducted a simulation focus on debris using fluid dynamics method and established a fluid dynamics model.Then the debris excluding phenomenon under the conditions that there is only electrode rotation, there is only electrode vibration, there are electrode rotation and vibration, there is only work piece vibration, there are electrode rotation and work piece vibration has been studied using software FLUENT. Simulation results show that, under the condition that there are electrode rotation and work piece vibration, the debris excluding phenomenon is the best.In this paper, a giant magnetostrictive actuator is designed and built using as the vibration table of the micro-hole EDM to aid the process of EDM debris exclusion, and create an ideal discharge environment, enhance discharge probability, thereby increase the machining efficiency.Experiments are carried out to test about the static and dynamic characteristics of the giant magnetostrictive vibration table in this paper, so that do prepare for the next research. In the micro-hole EDM processing experiments, the processing time under the working condition that there is no electrode rotation none work piece vibration, there is only electrode rotation, there is only work piece vibration, there are electrode rotation and work piece vibration are compared. Through the experimental results, we can find the best processing condition, and proof the simulation result. At last, the experiment about the relationship between vibration frequency and working efficiency is carried out. The experiment results show that the higher vibration frequency, the shorter the working time, that is the higher working efficiency. So to increase the work piece vibration frequency is an effective mean to improve the working efficiency.更多还原