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     

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。     

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。     

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。     

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。     

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。     

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。     

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。     

新型节能电火花加工脉冲电源的研制

在电火花加工机理的基础上,设计基于复合结构电流型新型节能电火花加工脉冲电源.实验结果证明其节能效果明显.     

基于模糊控制的微细电火花加工脉冲电源研究

设计了一套微细电火花加工脉冲电源,该电源采用有效放电火花数检测方法对放电状态进行统计,并利用模糊控制算法对脉冲宽度和脉冲间隔进行调整以改善加工性能。试验结果表明,该脉冲电源在保证加工稳定性的基础上,能够有效地提高加工精度及加工效率。     

节能式电火花加工脉冲电源的动态特性研究

运用状态空间平均法，建立了一种节能式电火花加工脉冲电源的等效电路模型和等效传递函数模型，进而对其放电电流的动态特性进行了分析和校正。电路仿真结果和实验样机加工实验证明，该种节能式脉冲电源的动态特性满足放电电流上升速度的暂态性能和放电电流纹波大小的稳态性能两方面的指标要求，可以实现低损耗、高速、稳定的放电加工。     

电火花加工脉冲电源功率器件的研究进展

功率器件是电火花加工脉；中电源中的一个核心元件，它对电火花加工的效率、加工精度和工具电极损耗等有很大的影响。本文综述了GTO、GTR、MOSFET、IGBT、MCT、IGOT和IPM等功率器件的研究现状和最新成果，并对它们在电火花加工脉冲电源中的应用与发展现状进行了分析评述。     

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。     

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.     

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。     

PULSE DISCRIMINATION FOR ELECTRICAL DISCHARGE MACHINING WITH ROTATING ELECTRODE

This article presents a new method for discrimination of various types of pulses generated during an electrical discharge machining process in presence of a rotating electrode. Existing pulse discrimination methods do not perform efficiently in an electrical discharge machine with rotating electrode, as arcs rarely occur during the machining process. Our method involves simultaneous comparison of the gap voltage and current signals with various thresholds. The main advantage of our proposed method is its efficient computation and significantly better accuracy in discriminating between various pulse classes for electrical discharge machining devices with rotating electrode. Experimental studies demonstrate a superior performance of our method in distinguishing normal pulses from harmful arcs, open circuit and short circuit pulses, compared with the state-of-art methods.     

Increasing discharge energy of micro-EDM with electrostatic induction feeding method through resonance in circuit

This paper describes the method to increase discharge energy in micro-EDM using electrostatic induction feeding as the pulse generator. In a previous study, controlled pulse train method was introduced to increase discharge energy and enlarge unit removal per discharge by allowing multiple discharges to occur at the same spot. During observation, it was found that the oscillation of discharge current is excited at higher amplitude even if the same capacitance is used. In this paper, the influence of frequency on discharge energy was investigated. It was found that higher discharge energy can be obtained when machining was done at the resonant frequency of the circuit. Influence of capacitance and inductance on resonant frequency was studied. Probability of discharge continuity at different frequencies was examined. The results confirmed that higher discharge continuity within the pre-determined pulse train duration can be achieved when machining is conducted at resonant frequency, leading to higher material removal rate (MRR).     

Modelling of surface finish,electrode wear and material removal rate in electrical discharge machining of hard-to-machine alloys

Hard-to-machine alloys are commonly used for industrial applications in the aeronautical, nuclear and automotive sectors, where the materials must have excellent resistance to corrosion and oxidation, high temperature resistance and high mechanical strength. In this present study the influence of different parameters of the electrical discharge machining process on surface roughness, electrode wear and material removal rate have been studied. Regression techniques are employed to model arithmetic mean deviation Ra (μm), peak count Pc (1/cm), material removal rate MRR (mm³/min) and electrode wear EW (%). All these parameters have been studied in terms of current intensity supplied by the generator of the electrical discharge machine I (A), pulse time t_i (μs), duty cycle η and open-circuit voltage U (V). This modelling allows us to obtain mathematical data and models to predict that the most influential factor in MRR and Ra is the current intensity and in the case of EW and Pc is the pulse time.