【作者】 汪学；

【导师】 郭钟宁；

【作者基本信息】 广东工业大学 ， 机械制造及其自动化， 2003， 硕士

【摘要】 本文研究了高速走丝电火花线切割机床(WEDM-HS)的高效率低损耗加工技术。对WEDM-HS目前存在相关问题进行了深入的分析，提出了相应对策和解决方案。 首先讨论了脉冲波形对线切割加工性能的影响，研究了电流阶梯波脉冲对优化极间放电能量分配的作用，并在深入研究线切割加工机理的基础上，提出了脉冲上升沿对提高加工效率和降低丝损的影响。通过实验发现了放电击穿延时的特点，并对放电延时对电流波形的改变进行了分析。 随后研究了传统脉冲发生器的特点，针对其缺陷，完成了用单片机控制的脉冲电源关键技术的研究。完成了单片机工作电路、中断电路、功放电路以及加速电路等电路的设计，编写了控制程序，并最终完成电路板的制作与调试。该电源输出控制信号稳定、波形振动小，关断迅速，可以实现对脉冲波形特别是上升沿的灵活控制。 最后采用单片机脉冲电源，进行了大量的切割工艺实验。实验内容包括三个方面：研究是否存在一个合适的电流斜率，使加工效率和钼丝损耗综合效果最好，研究最佳效率与哪些因素有关，通过正交实验比较电流斜率、脉宽和电流这三个参数对加工效率影响作用的大小，并确定优化的高效率低损耗加工参数。 本课题首次从理论与实践上探讨了线切割加工中，电流上升沿斜率对加工能量分配的机理，发现了电流波形影响线切割加工性能的规律。在理论研究基础上设计的单片机控制高频脉冲电源，在实验过程中取得了良好的效果。更多还原

【Abstract】 In this paper the machining technology with high cutting rate and low wire wear in WEDM-HS has been developed. The main problems of WEDM-HS machine tools have been analysed in detail. How to solve this problem is discussed and some solutions are put forward.Firstly the effects of current waveform on the machining performances are investigated. The results show that the slop-waveformed pulses can share the discharge energy in the gap better. Based on the study of the machining mechanism of WEDM, how the current slop affects the cutting rate and wire wear is pointed out. By the experiments the characteristics of ignition delay time are studied, then how the ignition delay time changes the current waveform is discussed.Secondly defects of the traditional pulse generators are analysed by which a new pulse generator is designed with MCU, including the main circuits of MCU, breaking off circuit, amplifying circuit and accelerating circuit . The control software is programmed. A circuit board is finished and adjusted. The waveform produced by pulse generator is stably and vibrates little. It can cut off rapidly and the slop of the current can be adjusted freely.At last a lot of experiments are performed using the pulse generator. From these experiments the questions below are discussed: whether there is a best current slop to make machining in high cutting rate and low wire wear; what factors affect the best current slop; which factor is the most influential on cutting rate among current slop, pulse length and current, and by orthogonal design the selection of these parameters is given.In this paper the effect of current slop on the distribution of discharge energy in the gap of WEDM is researched for the first time in theory, and some rules are found. Based on the theoretical research a pulse generator is designed and works well in the experiment.更多还原