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根据对电火花加工原理以及进给系统的分析,可知放电间隙是影响微小孔加工质量的重要因素,可靠地控制放电间隙是提高微小孔加工质量和效率的关键。为了更好地控制放电间隙,分析放电间隙的控制规律,应用模糊理论,设计了电火花加工控制系统的模糊控制器。并运用李雅普诺夫稳定性理论,对控制系统的稳定性进行了分析,并进行了验证。结果表明:该系统是稳定性且可行的。 相似文献
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本文对超声频间隙脉冲放电加工的放电特性和加工特性进行了详细的理论研究。研究结果表明:超声频间隙脉冲放电加工的放电电流和电压特性与一般的电火花加工是不同的。并且加工效率高于普通电火花加的效率,而其加工表面粗糙和加工形状精度接近于普通电火花和加工的表面粗糙度和加工形状精度。 相似文献
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基于田口法考查了电火花加工在煤油、空气状态下的临界放电间隙及主要加工电参数(峰值电流、放电电压、脉冲宽度)的变化规律和影响顺序,为进一步理解电火花加工机理提供了实验基础。 相似文献
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从模具制造电火花成形加工实际出发,简述了电火花加工放电过程的机理,全面分析了电火花成形加工中影响工艺指标的因素,提出了稳定放电加工,提高加工质量的相应措施以及获得最佳加工效果的途径。 相似文献
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通过观测电火花放电现象对加工的影响,发现可控的双极性电火花加工能用更低的加工刀具磨损率获得比传统单极性电火花加工更高的材料去除率和效率,因此基于先进的电力电子技术,提出了一种双极性通用型电火花加工用脉冲电源,并给出相应的能量控制策略,还采用可提供连续正负脉冲输出的全桥电路作为该脉冲电源的主电路,并引入间隙电压和间隙电流的和作为唯一的控制量,在引弧阶段采用电压控制,在放电阶段采用电流控制。用一个电路完成放电间隙的击穿和放电能量的控制,减小脉冲电源系统的体积,同时在单个放电过程的各个阶段,对脉冲电压、放电电流、放电持续时间和消电离时间等参数进行合理灵活的调整,在维持放电频率一定的情况下,保证加工过程中单次放电能量的一致,从而实现高效均匀的电火花加工。 相似文献
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混粉电火花镜面加工技术及应用 总被引:2,自引:0,他引:2
利用自行研制的混粉电火花镜面加工装置,对混粉电火花镜面加工影响因素,加工表面性能等进行了深入研究,找出了粉末特性,工件材料,粉末浓度及放电参数等对混粉电火花镜面加工的影响规律,给出了合理的混粉电火花镜面加工工艺条件,以文中确定的加工工艺条件对铸造和压铸模具进行混粉电火花镜面加工,结果表明,该技术能提高模具制造质量,降低工人劳动强度,缩短模具制造周期。 相似文献
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对电火花数控仿铣加工成形规律进行了研究 ,分析了加工间隙的规律和对工具电极轨迹进行间隙补偿的必要性以及放电面积的计算方法 相似文献
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为了研究旋转电极电火花沉积/堆焊的放电机理,文中进行单点间隙放电、单点接触放电和旋转电极连续放电试验,对放电过程中两极之间的电压和电流波形进行了采集和分析. 结果表明,在一定的电压和间隙条件下,电极与基体之间的介质能够被击穿出现间隙放电现象. 接触放电现象主要包括短路放电和间隙放电两个阶段. 旋转电极沉积/堆焊过程中电极与基体的接触状态复杂多变,放电过程中既存在非接触放电现象,也存在接触放电和短路放电现象,其中大部分是接触放电现象. 相似文献
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目的 分析不同电极运动形式下,电极与基体之间接触状态的变化,研究其对电火花堆焊放电机理的影响.方法 通过旋转电极连续放电试验、超声振动电极连续放电试验、旋转电极与超声振动电极的沉积效率试验,对旋转电极和超声振动电极的连续放电电压和电流波形、电极与基体的接触状态和相对运动进行了分析.结果 旋转电极的放电类型有短路放电、间隙放电和1种混合放电,超声振动电极的放电类型有短路放电、间隙放电和6种混合放电.在放电参数相同的条件下,旋转电极的短路放电平均电流为11.29 kA,间隙放电平均电流为6.9 kA,转移系数为79%;超声振动电极的短路放电平均电流为6.0 kA,间隙放电平均电流为3.66 kA,转移系数为92%.结论 电极的运动形式直接影响电极与基体接触点之间接触状态(即接触间隙、接触面积和接触电阻等)的变化,从而影响其放电类型、放电电流和沉积效率等.旋转电极和基体之间为切向旋转运动,接触点处的电阻小且间隙变化小,放电电流较大而放电类型较少.超声振动电极与基体之间为上下超声振动,接触点处的电阻大,间隙变化范围大且变化速度快,放电电流较小而放电类型较多. 相似文献
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Debris concentration and bubble volume fraction in the bottom gap between the electrode and workpiece affect the state of consecutive-pulse discharge and the efficiency of electrical discharge machining (EDM). Thus, the mechanisms of debris and bubble movement during consecutive-pulse discharge should be elucidated. However, these mechanisms have not been fully understood because of debris and bubble movement in the machining gap are difficult to simulate and observe. This study proposes a three-dimensional model of flow field with liquid, gas, and solid phases for machining gap in EDM. The mechanisms of debris and bubble movement in the machining gap during consecutive-pulse discharge were analyzed through the model. Debris and bubble movement in consecutive-pulse discharge was observed through experiments. The results showed that the proposed simulation model is feasible. The bubble expansion is the main way that the bubbles exclude from machining gap. Much debris moves outside the machining gap following the excluded bubbles, which is the main way that the debris excludes from machining gap. The bubble expansion becomes strong with the increase of the discharge current and pulse-on time. 相似文献
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A new concept has been verified for a plasma spray electrode system that improves plasma plume uniformity over that of a single
arc torch. A six-electrode, circular, arc-cascade discharge was formed by mounting seven tungsten-rod electrodes radially
around a stream of argon gas. To maintain the plasma plume, the cascade-arc discharge was repetitively triggered using a cascaded
high-voltage spark initiated by a secondary spark gap. The typical cascade arc voltage and current were 130 V and 20 A. Results
show that the cascaded arc array system can create a ring-shaped plasma plume having near-uniform electrical energy in the
circular direction. This feature suggests that the configuration may have future use in plasma torch systems requiring uniform
circular symmetry. In such a system, spray particles can be injected into the center of the plasma ring. At the same time,
such an arrangement also could provide a lower-cost alternative to systems that use multiple two-electrode plasma torches
arranged in a circular configuration. In the latter system, each two-electrode plasma torch is fed by a separate power supply. 相似文献
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Achieving high accuracy and high removal rate in micro-EDM by electrostatic induction feeding method 总被引:1,自引:0,他引:1
T. Koyano 《CIRP Annals》2010,59(1):219-222
With conventional relaxation pulse generators used in micro-electrical discharge machining, due to the difficulty in keeping the minimum necessary discharge interval between pulse discharges, localized discharge and abnormal arc occur frequently. In contrast, with the newly developed electrostatic induction feeding method, only a single discharge occurs for each cycle of the periodic pulse voltage. As this realizes sufficient cooling of the discharge gap between pulses, thermal stress on the machined surface is less and duty factors can be increased, resulting in higher accuracy and machining speed compared to the relaxation pulse generator. 相似文献