电火花加工脉冲电源研究现状与发展趋势

脉冲电源是电火花加工的关键技术。文中针对传统电火花加工脉冲电源使用的缺点和局限性,介绍了当前电火花加工脉冲电源的研究现状和新的发展趋势,并对几种新型脉冲电源的研究和应用进行了分析。     

电流型电火花加工脉冲电源的研究

分析了传统独立电火花加工脉冲电源和逆变式电火花加工脉冲电源的不足,论述了电源型电火花加工脉冲电源的工作原理,大量的样机和独立式脉冲电源的对比工艺试验表明,电流型脉冲电源不仅满足了电火花加工多项性能指标的要求,而且达到了高效节能的效果。     

CPLD器件在电火花加工脉冲电源中的应用

为了提高电火花加工的表面质量与精度,研究应用CPLD器件作为电火花加工脉冲电源的脉冲信号发生器,根据器件的特点,同时采用原理图输入和VHDL语言输入法,设计出适用于电火花加工的脉冲电源控制电路,并用示波器测试其脉冲电源的脉冲放电波形,获得满足电火花加工要求的脉冲电源。     

石墨电火花加工数控机床的脉冲电源设计

石墨作为电火花加工电极材料具有很多优点,石墨电火花加工数控机床在模具行业已得到越来越广泛的应用。脉冲电源是电火花加工的关键技术,研究石墨电火花加工数控机床的脉冲电源具有较高的应用价值。现从加工效率和加工质量方面入手,设计了适合石墨工具电极的电火花加工的复合脉冲波形,并设计了相应的脉冲电源。     

节能式电火花加工脉冲电源的系统设计

在对比传统电阻限流独立式电火花加工脉冲电源和节能式脉冲电源电路结构和控制策略的基础上，提出了节能式电火花加工脉冲电源的系统设计方案，并且通过工艺试验，在检验节能式电火花加工脉冲电源加工工艺性能的同时，也考察了其系统设计的方案可行性和加工稳定性。     

节能型电火花加工脉冲电源研究现状及发展趋势

分析了研制节能型电火花加工脉冲电源的实际意义．介绍了几种典型节能电火花加工脉冲电源的工作原理和提高际冲电源电能利用率的不同方法以及各自的特点．提出了节能型电火花加工脉冲电源未来的发展趋势。     

WDH—Ⅱ型脉冲电源的设计和使用效果

在电火花线切割加工机床中,脉冲电源性能的优劣,直接影响电火花线切割加工工件表面粗糙度和线切割加工速度。因此,电火花线切割脉冲电源的设计历来为人瞩目。WDH-Ⅱ型脉冲电源的设计,实质上是用TMOS(MOSFE7)场效应管控制输出的分     

新型微能可控的MWEDM脉冲电源

分析了以往的微细电火花线切割加工(MWEDM)脉冲电源的不足。在现代电力电子技术基础上，开发出新型微能可控的微细电火花线切割加工脉冲电源。试验表明，这种高质量的脉冲电源为改善微细电火花线切割加工整体性能、拓展加工领域提供了技术保证。     

一种基于MOSFET的晶体管式微细电火花加工脉冲电源的研究

通过对RC式脉冲电源和晶体管式脉冲电源的综合比较,提出一种基于FPGA的晶体管式微细电火花加工脉冲电源,该电源结合FPGA开发板和IR2101专用集成半桥驱动器,驱动半桥式结构的功率MOSFET,电源经实验验证后,在加工精度、效率及表面粗糙度等方面表现良好。经测试,该电源最高频率可达1 MHz,输出脉宽1～101 ms可调,开路电压1～200 V可调,同时结合微细电火花加工的实际需求,可以实现粗、半精、精三种加工形式。     

基于ISA总线的电火花线切割脉冲电源研究

为了提高电火花加工自动化和智能化程度,更方便地实现电火花加工脉冲电源的实时控制,在现有的脉冲电源基础上开发了一种基于ISA总线的电火花脉冲电源。在系统软件中,编制了电火花加工的电参数数据库,用户能根据数据库中提供的电参数或根据用户的需求方便地设置加工电参数。在硬件系统中采用了AT89C51单片机与8253作为核心产生脉冲信号,结构简单,脉冲周期范围大。     

Improvement of machining characteristics of micro-EDM using transistor type isopulse generator and servo feed control

This paper describes the improvement of machining characteristics of micro electrical discharge machining (micro-EDM) using a newly developed transistor type isopulse generator and servo feed control. The RC generator is mainly applied in conventional micro-EDM even though the transistor type isopulse generator is generally more effective for obtaining higher removal rate, because the transistor type generator is unable to generate iso-duration discharge current pulses with small pulse duration (several dozen nano-seconds), which is the normal level for micro-EDM. A new transistor type isopulse generator was therefore developed using a current sensor with high frequency response. With the new transistor type isopulse generator developed, the pulse duration can be reduced to about 30 ns, which is equivalent to the pulse duration used in finishing by the conventional RC pulse generator for micro-EDM. In order to achieve stable machining and improve machining characteristics, a new servo feed control system for micro-EDM using average ignition delay time to monitor the gap distance was also developed. By integrating the transistor type isopulse generator with this new servo feed control system, we were able to obtain a removal rate of about 24 times higher than that of the conventional RC pulse generator with a constant feed rate in both semifinishing and finishing. The effectiveness of the servo feed control proved higher in finishing than in semifinishing, whereas the transistor type isopulse generator was more effective in semifinishing than in finishing.     

Basic study on pulse generator for micro-EDM

An RC pulse generator can easily generate a pulse on-time as short as a several dozen nanoseconds in micro-electro-discharge machining (micro-EDM), but its discharge frequency is low due to the time needed to charge the capacitor in micro-EDM, which has a strong negative effect on the pulse generator’s working efficiency. Therefore, a new transistor-type isopulse generator has been developed for micro-EDM in this research. Evaluation of the machining characteristics proved that the transistor-type isopulse generator is suitable for micro-EDM. The experimental results reveal that the transistor-type pulse train generator is unsuitable for micro-EDM due to its low removal rate: 80-ns and 30-ns pulse on-times of discharge current can be obtained by using the transistor-type isopulse generator developed in this research, and the removal rate of this generator is two or three times higher than that of the traditional RC pulse generator.     

微细电火花加工用晶体管脉冲电源的研究

在传统晶体管脉冲电源的基础上，研制开发了一种适用于微细加工的晶体管脉冲电源，这种脉；中电源可以满足微细加工中粗加工、精加工的不同需要，可实现最小脉宽为50ns的放电电流。通过微细孔加工实验，对所开发的晶体管脉冲电源的加工特性与传统的RC脉冲电源进行了分析比较，实验结果表明前者的加工效率约为后者的2～6倍。     

基于线电极的电火花铣削加工及其脉冲能量控制

介绍了基于线电极电火花铣削加工的产生背景及其基本原理,分析了在该加工中对单个脉冲放电能量进行控制的必要性,研制出了通过控制放电持续时间来控制脉冲能量的能量控制型脉冲电源,并给出了其放电脉冲波形。     

小孔加工电火花脉冲电源实验研究

针对传统脉冲电源普遍存在的电能利用率低、电阻发热严重、散热设备庞大等问题,提出了一种取消限流电阻的电火花脉冲电源结构。电源由PWM控制器、DC/DC变换器、加工脉冲时序发生器等组成。电源本身具有自动调节输出电压的功能,可实现空载击穿电压、脉冲宽度、脉冲间隔独立可调,取消了体积庞大的工频变压器。通过多次小孔加工实验获得了脉冲电源加工过程中电极损耗率、小孔椭圆度以及单边放电间隙等和电源稳定性相关参数的数据曲线,所得数据表明电源具有较好的加工稳定性和可靠性。     

An experimental study on micro wire-EDM of polycrystalline diamond using a novel pulse generator

This paper presents a new pulse generator for cutting of polycrystalline diamond (PCD) by micro wire electrical discharge machining (micro wire-EDM). The pulse generator using anti-electrolysis circuitry and digital signal processor-based pulse control circuit was developed to suppress damages on the machined surface of PCD while achieving stable machining. A novel pulse control method was proposed to provide high-frequency pulse control signals with a period of off duty cycle for reionization of the dielectric in the spark gap so as to reduce the consecutive occurrence of short circuits. A series of experiments were carried out to investigate the effect of open voltage on machining performance in terms of material removal rate, slit width, thickness of the damaged layer on machined surface, and surface finish. An increase of open voltage increases peak current, thus producing greater discharge energy and, thereby, contributing to improvements in material removal rate, but leading to larger slit width and thickness of the damaged layer and worse surface finish. Experimental results not only demonstrate that the developed pulse generator could achieve satisfactory machining results but also have verified the applicability of this new technique in micro wire-EDM.     

基于PWM技术节能型线切割脉冲电源的研制

分析了线切割脉冲电源电能的利用现状，简要介绍了目前节能型电火花脉冲电源的研究情况。研制了一种新型的节能型线切割加工脉冲电源。并对其原理进行了探讨。     

Development of parallel spark electrical discharge machining

This paper describes the development of parallel spark EDM method. In the discharge circuit, the electrode is divided into multiple electrodes, each of which is electrically insulated and connected to the pulse generator through a diode. A capacitor is inserted parallel to each discharge gap between each electrode and workpiece (here workpiece is common for each electrode). Compared with conventional EDM in which only a singular discharge can be generated for each pulse, multiple discharges can dispersively be generated for each pulse in parallel spark EDM. Results of experiments on parallel spark EDM and conventional EDM show that not only is the machining process more stable, but the machining speed and surface roughness can also be improved with parallel spark EDM.