快走丝线切割机新型恒张力机构

针对传统恒张力机构的弊端，提出了一种新型恒张力机构。该机构提高了电极丝在加工区的动态位置精度，为快走丝多次切割技术创造了条件。     

高速走丝线切割机电极丝恒张力的实验及分析

通过在一种新型恒张力机构上进行的电极丝张力实验所得出的实验现象,分析和计算出电极丝与贮丝筒截交角影响电极丝张力的规律。     

基于多轴运动控制器的电极丝恒张力控制系统

为解决往复走丝电火花线切割加工空间复杂曲面中电极丝张力变化影响加工精度的问题,分析了张力变化的原因及其对加工精度的影响,介绍了现有电极丝恒张力机构的不足,提出了基于功能强大的可编程多轴运动控制器的电极丝恒张力控制系统,给出了完整的系统软硬件结构.该系统可对线切割加工过程进行随动响应,保持电极丝张力恒定,改善电极丝动态定位精度.进行了恒张力线切割加工对比试验.实际测量结果表明该控制系统的加工误差明显减小,验证了恒张力控制系统的有效性.     

线电极磨削系统电极丝恒张力模糊控制研究

针对自主设计的一种新型WEDG系统走丝机构,提出了采用模糊控制的方法实现电极丝的恒张力控制.首先分析了该新型WEDG系统走丝机构的工作原理,建立了系统的走丝机构控制模型.在此基础上,基于模糊控制理论,根据张力反馈对送丝轮的转速进行闭环控制,最终实现了电极丝的恒张力控制.基于该WEDG系统进行了微小工具电极的加工实验.结果表明,该WEDG系统走丝稳定、张力恒定,能够以很高的效率制作出直径小(直径小于10 μm)、几乎没有锥度的工具电极,很好地满足了的微细电火花加工机床微小工具电极的制作需要.     

数控线切割机床快速走丝系统的恒张力控制

目前,我国生产的数控线切割机床大多数是采用高速走丝系统,电极丝是反复使用的。其内在张力无法进行调节与控制。工作一段时间后,电极丝会产生,伸长现象,从而使其张力减小,引起电极丝抖动,直接影响工件的加工精度和表面粗糙度。本文提出一种能使电极丝张力维持恒定的装置。其结构简单、成本低、便于推广使用。它是在阻转情况下工作的,只要电极丝一有松动,电机立刻转动,产生恒拉力。经过钢丝绳13使紧丝滑块8向下移动,拉紧电极丝,使丝内的张力维持恒值。具体的张力数值应通过切割工艺试验,调节电压来达到。对于不同直径的电极丝,所需维持的张…     

新型电极丝恒张力控制系统的研究

在高速走丝线切割机上，储丝筒正反向循环时放电区电极丝张力是否一致，直接影响线切割机的加工质量。为此，研究了一种新型电极丝恒张力控制系统，能够很好地解决电极丝张力的测量和储丝筒正反向循环时放电区电极丝张力一致的控制问题。     

WEDM电极丝恒张力微机控制系统研究

电火花线切割机电极丝张力的大小,对加工精度和加工表面质量有着重要影响.设计了一种恒张力控制系统,采用ER阻尼嚣为执行元件,以微机作为控制处理核心,系统响应速度快,较好地解决了张力测量和控制精度问题,实现了电极丝的恒张力控制.     

慢走丝线切割机恒速恒张力的智能控制系统设计与研究

针对慢走丝线切割机床在加工过程中无法较好地保持恒速恒张力而严重影响机械零件的加工表面质量,提出了模糊PID与BP网络PID智能算法分别控制电极丝的恒速与恒张力控制的设计思路.通过实验分析,与传统PID控制相比,智能PID控制电极丝的恒速恒张力达到的效果更好.     

线切割电极丝退离电解抛光法二次切割工艺的研究

在快速走丝线切割机床上,要显著改善加工表面粗糙度,主要的方法是采用多次切割。但是由于丝速产生的钼丝剧烈振动,仿照慢速走丝所用的多次切割工艺无法实现。因此,必须根据快速走丝的特点,在第二次切割时设法减少振动的影响。当钼丝张力调整合适时,采用电极丝退离电解抛光法,不用限位器和恒张力机构,也能取得令人满意的结果。一、工作液和脉冲电源根据二次切割时电极丝需要退离的具体     

线电极张力检测机构设计

分析了快走丝线切割机床线电极张力机构存在的张力值不能量化，在实际工程中依靠经验估计等一些问题，改进设计了张力检测机构。定量分析了张力对加工质量和表面粗糙度的影响。指出了快走丝电火花线切割机床线电极的张力如果能够量化选择，在工作过程中能够适时补偿，将有利于提高该类机床的技术含量和快走丝线切割机床的加工质量。     

电火花线切割加工中线电极的动态特性仿真与实验研究

研究慢走丝电火花线切割加工中电极振动对加工状态的过程的影响。应用计算机仿真技术,分析连续放电力作用下线的振动模态以及对放电点转移和分布的作用。结果表明,加工工艺参数明显影响放电点的转移与分布,适当地选择工艺参数可获得最佳的放电分布率。该研究对提高慢走丝加工稳定性,防止断丝的发生提供了相应理论依据。     

环形丝单向运丝电解线切割加工技术试验研究

为了解决加工间隙内电解加工产物的排除问题,在分析电解线切割加工特点的基础上,采用环形镀锌黄铜丝作为阴极,在电机的驱动下,使环形丝的运动方向与重力方向保持一致, 从而便于带出加工区的电解产物;在搭建的加工系统上进行了正交试验,研究加工电压、进给速度、电解液浓度及环形丝单向运丝速度对加工间隙的影响。最后采用优化的加工参数加工出缝宽为250μm、深宽比达20的五角星结构。     

精密高速走丝电火花线切割机研究与开发

对影响高速走丝线切割机(HS-WEDM)加工精度的主要因素进行了理论分析和实验研究,提出了开发精密HS-WEDM的技术方案,研究开发了提高HS-WEDM加工质量的四项关键技术:新型恒张力机构、电极丝浮动限位器、模糊控制间隙伺服进给系统、带工艺参数库的CAD/CAM一体化自动编程系统,并将其应用于生产实际,取得了较好的效果。     

模具线切割精密加工电极丝的应用分析

模具数控线切割加工电极丝的定位是加工程序的起始位置,整个切割图形相对于模具件的位置正确性完全取决于电极丝的严格定位。CTW机床的走丝机构采用十字滑板,U、V轴移动并具有独特的四连杆技术实现锥度加工。通过电极丝位置调整方法、电极丝的选择、线切割加工前的工艺准备及常见断丝、抖丝故障的介绍,目的是为了更好地使用快走丝电火花线切割机床来加工复杂模具精密零件。     

The influence of spatially nonuniform temperature fields on the vibration and stability characteristics of EDM wires

This is an investigation into the effect of spatially nonuniform temperature fields on the free vibration and stability characteristics of the wire electrode in the wire electro-discharge machining (EDM) process. In particular, a nonlinear multi-mode structural model is developed for the translating wire along with a thermal model which accounts for heat input (from sparking), axial conduction, radial convection, and energy storage. The two models are then coupled through the internal thermal stress terms of the structural model. Using these combined models, an equilibrium and eigenvalue analysis is performed to examine the behavior of the small amplitude natural frequencies as a function of the transport speed under normal cutting conditions. It is shown that both divergence and Hopf bifurcations may occur in this system. Specifically, at low transport speeds the straight wire configuration is unstable due to a thermal buckling instability. At intermediate speeds, the straight configuration is restabilized by the reduced residency time of the wire in the kerf. At high speeds the straight configuration is again unstable; this is due to a series of transport instabilities. The influence of the input discharge energy and the applied axial wire tension on the size of the restabilized zone is determined and the implications for cutting accuracy are discussed.     

Feed rate of wire electrochemical machining using pulsed current

The effect of various parameters on the feed rate in electrochemical machining has been investigated. Parameters considered were velocity of the electrolyte flow, nozzle diameter, material, diameter and tension of the wire, pulse period and peak value of the applied voltage. On the assumption that the feed rate is limited by accumulation of generated sludge or gas, the feed rate equation and favourable pulse conditions were derived and verified experimentally. The rate was improved by applying a shorter pulse period than the ‘residential’ time of the electrolyte between electrodes. Above the critical pressure, at which the feed rate is a maximum, the adverse effects of wire vibration cannot be neglected. Measures proposed to prevent it were reduction of nozzle diameter and length of wire span, and increase in applied voltage and wire tension.     

Research of micro EDM/ECM method in same electrolyte with running wire tool electrode

A micro rod machining method which can switch between electrical discharge machining (EDM) and electrochemical machining (ECM) by attaching/detaching a diode to/from a bipolar pulse generator in parallel to the working gap was newly developed using a wire electrode made of tungsten. The problem of the wire electrode wear was eliminated by the use of the wire electrochemical turning (WECT) method in which the tungsten wire electrode is continuously running. The ultra-short bipolar pulse current was generated by the electrostatic induction feeding method where a pulse voltage is coupled to the working gap through a feeding capacitance. The machining characteristics of three types of wire guide; disk-shaped WC guide, laminated wire guide and cylindrical acrylic guide, were studied. The experimental results showed that the cylindrical acrylic guide has the best machining characteristics without the influence of guide wear and with less stray current flowing through the working gap. Using the cylindrical acrylic guide, the influences of the feeding capacitance C₁, and the total amplitude of the pulse voltage on the machining characteristics were studied. Finally, a stainless steel SUS 304 micro-rod with a high aspect ratio of 14 was fabricated efficiently by using the EDM and ECM modes for rough and finish machining in sequence with the same setup, pulse generator, and neutral electrolyte.     

高速走丝线切割加工质量的改善与提高

深入分析了影响电火花线切割加工工件表面质量的各种因素，提出了改善并提高电火花线切割加工精度和表面质量的措施和方法。