新型蠕动式微细电火花加工机构

阐述了小型微细电火花加工机构的研究现状。针对现在遇到的主要问题,设计开发了一种新型的管状结构蠕动式微细电火花加工机构。介绍了该新型机构的原理和实现方式,并对其主要部件进行了理论建模和有限元分析。该新型机构能够对微细电极进行较为有效精确的夹持和定位,响应速度较高,其结构对称,紧凑可靠,可以实现从任意方位任意角度进行加工,有较高的实用价值。     

新型蠕动式微细电火花加工机构

阐述了小型微细电火花加工机构的研究现状.针对现在遇到的主要问题,设计开发了一种新型的管状结构蠕动式微细电火花加工机构.介绍了该新型机构的原理和实现方式,并对其主要部件进行了理论建模和有限元分析.该新型机构能够对微细电极进行较为有效精确的夹持和定位,响应速度较高,其结构对称、紧凑可靠,可以实现从任意方位任意角度进行加工,有较高的实用价值.     

压电自适应微细电火花加工技术

针对微细电火花加工技术的特点,开发、研制了新型的压电自适应微细电火花加工装置,介绍了该装置的结构和工作原理,分析了压电致动器的性能以及放电间隙与开路电压的关系,并利用该装置进行了试验研究。试验结果表明该加工技术可以实现放电间隙与放电状态的自适应调节,加工效率较高。     

三维微细电火花加工伺服控制系统设计及实验研究

针对微细电火花加工伺服控制系统的要求,进行了微细电火花加工伺服控制系统总体设计.伺服控制系统特点是执行机构采用步进电机+压电陶瓷的宏微细合式驱动机构,实现了大行程和小步距的有机结合,能够提高电火花加工机床的加工性能.同时Z轴增加一个振动源,实现自动排屑和微调加工间隙.通过实验验证,证明系统运行良好,运动平台能够达到较高的精度,并实现了简单的极微细电火花加工.     

压电自适应微细电火花加工系统特性分析

针对微细电火花加工过程中排屑困难,极易产生短路、拉弧等非正常加工现象,进而造成微细电火花加工效率低、电极损耗大等特点,基于压电陶瓷的逆压电效应提出了一种新的加工方法--压电自适应微细电火花加工技术,对其加工原理进行了详细阐述,并结合试验对该加工系统的加工特性进行了详细分析.试验证明该技术在加工过程中能够实现放电间隙与放电状态的自适应调节,促进捧屑,可有效控制短路及拉弧现象的出现,进而提高微细电火花的加工稳定性及加工效率,并能实现超低电压下的微细电火花加工.结合实例说明采用压电自适应微细电火花加工技术进行小孔加工的过程中能实现稳定加工,获得较高的加工效率,并且加工的小孔圆度较好,说明该技术在微小孔加工方面具有广阔的应用前景.     

微细电火花加工系统及其工艺技术

开发了一套微细电火花加工系统,该系统不仅能加工微细轴、微细孔,还能实现微三维结构的微细电火花加工。研究了针对该系统的微细电火花加工工艺技术,研究了放电电压、放电电容等工艺参数,主轴转速,以及工作液介质对微细电火花加工效率、相对电极损耗率的影响规律。采用旋转削边电极技术大大提高了进行大深径比微细孔加工时的加工效率。进行了大量的加工实验,加工出了最小直径为6μm的微细轴以及最小直径为10μm的微细孔;通过对电极损耗的在线补偿策略研究,实现了微三维结构的加工,加工出了外径为4mm、具有24个叶片的微型涡轮盘及具有微三维结构的微细梁,充分证实了该系统的广泛适用性。     

采用蠕动式微进给机构的微细电火花加工装置

介绍了一种采用蠕动式微进给机构的微细电火花加工装置，尝试微细火花加工的实用化和装置本身的微小型化。内容包括该装置机构的设计制作及初步的加工实验结果，特别是蠕动式微进给机构提高输出推力、适用于微细电火花加工的设计实现。     

微细电火花成形加工设备关键技术研究

基于微细电火花加工的要求,对微细电火花成形加工设备中的关键技术进行研究,成功研制了一套高精度的微细放电加工设备产品,包括一台微细电火花加工机床和一台精密脉冲电源。优化机床关键零/部件的结构后,机床的变形小,运动精度高;电源放电稳定,控制精确。经加工试验表明,该设备加工效果较好,加工精度和稳定性较高,加工出的窄槽工件的尺寸精度可达到5μm,加工直径为300μm的小孔,其圆度误差达到3μm,可满足微细电火花加工的要求。     

电火花机床微小孔加工调试

正电火花喷孔钻床的研制成功,解决了我国0.2 mm以下高精度微细孔不能加工的难题,打破了国外对这一技术的长期垄断。在电火花微小孔的加工中解决的难题有:电极宏微伺服控制系统、微细电火花间隙放电状态监测技术、微细电极自动进丝及高精度旋转机构、去离子水自动循环制取装置和微小孔加工工艺数据库的建立。以鲁南机床厂的电火花喷孔钻床为例,抽查其加工的任意50件工件,分别用塞规、三坐标测量仪、     

电火花机床加工高精密微细锥孔的研究

正随着工业的快速发展,电火花高精密加工技术在特殊加工中日趋广泛,其中微细孔的应用尤为突出。针对加工汽车喷油嘴的高精密微细锥孔,研制出了一种高精密旋转锥孔机构,以满足高标准的排放要求,从而实现喷油嘴的批量化电火花加工。1.结构方案的设计高精密旋转加工锥孔的机构是数控电火花喷孔钻加工机床的重要部件,为了满足电火花数控喷孔钻加工喷     

压电驱动技术在电火花加工中的应用

压电驱动技术可实现电极直接驱动进行电火花加工,该技术可以广泛地用于航天航空,精密模具,医疗器械等领域中微型器件或异形微小孔的加工,介绍几种典型的压电驱动技术,如椭圆式电火化加工技术,基于超声马达的电火化加工技术,蠕动式电火花加工技术,为提高电火花加工的效率,缩短加工时间,提出在压电驱动技术的基础上进一步在加工电极上附加超声振动,为该项新技术的发展提供了启示。     

RESEARCH OF MICRO ELECTRO DISCHARGE MACHINING EQUIPMENT AND PROCESS TECHNIQUES

Micro electro discharge machining (micro EDM) is a feasible way to manufacture micro structures and has potential application in advanced industrial fields. For the realization of micro EDM, it is necessary to pay careful attention to its equipment design and the development of process techniques. The present status of research and development of micro EDM equipment and process techniques is overviewed. A micro electro discharge machine incorporated with an inchworm type of micro feed mechanism is introduced, and a micro electro discharge machine for drilling micro holes suitable to industrial use is also introduced. Some of the machining experiments carried out on the micro EDM prototypes are shown and the feasibility of the micro EDM technology to practical use is discussed.     

磨粒辅助EDM与ECM复合加工技术

微机电系统(Micro electromechanical systems,MEMS)的快速发展与产品微型化的发展趋势对微细结构表面(包括微孔、微槽和微棱柱/锥等)的加工质量提出了更高的要求,为了提高微细结构表面的加工质量,提出一种磨粒辅助放电加工(Electrodischarge machining,EDM)与电化学加工(Electro chemical machining,ECM)复合加工新方法,通过建立微加工模型分析了该方法的加工机理,搭建了微加工试验平台,并进行了工艺参数优化研究,采用直径500μm和75μm的钨电极在SUS 304不锈钢上分别进行了微盲孔和微通孔加工试验研究,结果表明,在所用的EDM、EDM与ECM复合加工和磨粒辅助EDM与ECM复合加工三种方法中,磨粒辅助EDM与ECM复合加工方法获得的表面粗糙度(Ra15 nm)最高,因此该方法是微细结构表面高效和高质量加工的最佳方法之一。     

Machining characteristics of micro EDM in water using high frequency bipolar pulse

Micro EDM using conventional pulse generators such as the RC type or transistor type with water as the dielectric fluid suffers from poor accuracy of machined structures due to electrolytic corrosion. In this study, a new high frequency bipolar pulse generator for micro EDM in water was developed in order to prevent electrolytic corrosion. The new pulse generator produced a high frequency bipolar pulse possessing a positive pulse duration of several hundred nanoseconds with a high repetition rate provided to the machining gap. Discharge characteristics of micro EDM using the new pulse generator were investigated. Machining characteristics were also investigated according to machining conditions such as the repetition rate, positive voltage, capacitance and resistivity. Using the new pulse generator, micro holes without electrolytic corrosion were successfully fabricated in deionized water and tap water. Machining time, tool wear and clearance using the new pulse generator in deionized water decreased compared with those using the RC circuit in kerosene.     

微细电火花加工中电极材料的蚀除机理研究

在微细电火花加工过程中 ,由于放电时间极短 ,使得其阴阳两极的电极材料蚀除过程产生较大的差异。本文应用传热学和电场的基本理论 ,分别对微细电火花加工阴阳两极的材料蚀除机理进行了理论研究 ,得出了在窄脉宽微细电火花加工中 ,尽量缩短脉宽可提高阳极材料的去除效率 ,同时又不会明显增加阴极材料损耗的结论。为微细电火花加工脉冲电源设计及加工工艺的改进提供了理论依据     

Review of size effects in micro electrical discharge machining

Electrical discharge machining (EDM) is one of the most promising non-traditional micro-scale machining methods. Because several operating parameters that are insignificant in macro EDM cannot be neglected during micro EDM process, models derived from the macro EDM process may be inappropriate at the micro scale. This paper contains a comprehensive review of size effects in traditional micro-machining and characteristics specific to micro EDM compared to macro EDM techniques. The very concept of size effects in micro EDM is thoroughly defined and three categories of effects are presented: material microstructure, processing parameter and thermal conduction size effects. Future potential research directions on the subject are also summarized. We assert that careful research and precise attention must be given to size effects in micro EDM. Size effect information especially benefits the machining speed and machining precision of micro EDM.     

Assembling ball-ended styli for CMM's tactile probing heads on micro EDM

This paper describes a hybrid gluing and assembling process on micro electrical discharge machine (EDM) to produce micro ball-ended spherical stylus tips for micro coordinate measurement machine's (CMM's) tactile probing heads. Combining wire electro-discharge grinding technology and position controlling function of EDM, a micro glass ball could be glued onto the cantilever successfully. The experimental results show that the roundness of the largest profile micro glass-ball-ended styli with a 0.07-mm diameter could be as small as 0.613 μm. The deviation and roundness of the stylus tips can be controlled more effectively by this gluing and assembling process. The adhesion strength of the gluing stylus tip is approximately 12 mN. These ball-ended stylus tips could be used on micro CMM's tactile probing head for micro component metrology in the near future.     

Scale effects and a method for similarity evaluation in micro electrical discharge machining

Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of “scale effects” in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM.     

Study of the Batch Production of Micro Parts Using the EDM Process

The micro machining of copper plates by the electrical discharge machining (EDM) process is described. Tungsten carbide was selected as the material for the electrode. Experiments were carried out on a conventional CNC-EDM machine to investigate machining of micro holes, and micro slots. The results show that micro holes, and micro slots can be successfully processed on a conventional CNC-EDM machine. To improve the productivity of micro parts using the EDM process, a batch production method of micro EDM using multi-electrodes has been studied. A new technique for preparing multi-electrodes has been developed. Results also show that the batch production of micro parts using EDM is feasible and that the batch production of micro parts using EDM process with multi-electrodes is very effective.