共查询到19条相似文献,搜索用时 218 毫秒
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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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往复走丝线切割加工过程中电极丝的横向振动是影响加工质量的重要因素,制约了其进一步应用发展。基于此,对电极丝振动的产生原因和影响因素进行深入分析,设计了一种智能张力控制系统,通过检测间隙放电过程中的间隙电压和间隙电流,应用模糊算法识别采样周期内的间隙放电状态,然后对间隙放电状态中火花率的占比情况二次应用模糊算法得出紧丝机构所需要的进给量。经实验验证,这种方法可以通过张力控制来减少电极丝的振动,使工件的表面粗糙度和尺寸误差分别减低13.4%和9.5%,有效地提高了往复走丝线切割的加工质量。 相似文献
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电火花加工是一种非常复杂的过程。即通过击穿浸于工作液中的工件和电极之间的间隙,迅速形成电弧,并借其蚀除工件。在这个周期内,包括选择电弧时问以控制表面光洁度,并切断电源的电流和电压。加工速度 相似文献
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Monitoring and control of the micro wire-EDM process 总被引:1,自引:1,他引:1
Mu-Tian Yan Hsing-Tsung Chien 《International Journal of Machine Tools and Manufacture》2007,47(1):148-157
A new pulse discriminating and control system has been developed for process monitoring and control in micro wire-EDM. The pulse discriminating and control system identifies four major gap states classified as open circuit, normal spark, arc discharge and short circuit based on the characteristics of gap voltage waveform. The effect of pulse interval, machining feedrate and workpiece thickness on the variations of the proportion of normal spark, arc discharge and short circuit in the total sparks (defined as normal ratio, arc ratio and short ratio, respectively) were investigated. It is found that a long pulse interval results in an increase of the short ratio under a constant feedrate machining condition. A high machining feedrate or an increase of workpiece height results in an increase of the short ratio. To achieve the stability of the machining operation, a control strategy is proposed by regulating the pulse interval of each spark in real-time according to the identified gap states. Experimental results indicate that the developed pulse discriminating and control system can significantly reduce the arc discharge and short sparking frequency as well as achieve stable machining under the condition where the instability of machining operation is prone to occur. 相似文献
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Masahiro FujikiGap-Yong Kim Jun NiAlbert J. Shih 《International Journal of Machine Tools and Manufacture》2011,51(1):77-83
A new gap control strategy for five-axis milling using near-dry electrical discharge machining (EDM) has been experimentally investigated. The conventional EDM control strategy only allows the retraction of the electrode in the direction of machining trajectory, which results in inefficient gap control when the electrode is not perpendicular to the workpiece. The new gap controller is capable of retracting the electrode in the direction of its orientation. This enables more efficient enlargement of the discharge gap leading to faster recovery of average gap voltage. Experimental results show a 30% increase in material removal rate while the tool electrode wear ratio and surface roughness are not affected. Furthermore, EDM efficiency is improved due to the change in the electrode retraction in its axial direction. The gain tuning of the proposed controller is also discussed. This study shows the direction of electrode retraction is important for five-axis near-dry EDM milling. 相似文献
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提出了叶盘型面电解加工的全过程电流控制方法,基于电流控制思想,通过全程控制电流这一重要参数,使其在多次加工中基本保持一致,从而提高型面加工的重复精度。开展了电流控制方法的理论分析,掌握了工具进给速度和电流变化的对应关系,形成了加工过程中的电流调控策略,并设计了以电解加工电流为调控目标的实时运动调节系统。针对Ti60整体叶盘开展了一系列对比试验研究,结果表明:采用该电流控制方法可保证多次加工电流的一致性,进而保证加工间隙及型面重复精度。叶盆、叶背受控线重复精度可控制在0.06 mm,有效地保证了每次加工精度的一致性。 相似文献
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In order to improve the performance of machines, there is a growing need to develop a highly stable servo control system for electrical discharge machining (EDM). With the perpetual push towards the untended EDM operation, an adaptive control system is and will continue to be a primary option. In this paper, a new EDM adaptive control system which directly and automatically regulates tool-down-time has been developed. Based on the real-time-estimated parameters of the EDM process model, by using minimum-variance control strategy, the process controller, a self-tuning regulator, was designed to control the machining process so that the gap states follow the specified gap state. With a properly selected specified gap states, this adaptive system improves the machining rate by, approximately, 100% and in the meantime achieves a more robust and stable machining than the normal machining without adaptive control. This adaptive control system helps to gain the expected goal of an optimal machining performance. 相似文献
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为实现电解加工机床自动控制,提高加工精度,针对复杂零件电解加工控制要求,设计了控制系统。采用PC机、数据采集卡和运动控制卡等硬件实现集成控制,并采用VB6.0软件平台对主控制系统软件进行设计,主要包括软件控制界面的设计、伺服驱动器参数的设置和单轴独动、多轴联动的控制程序设计,并根据实际应用添加手动加工、自动加工和故障诊断等功能。最后,通过基于该控制系统软件的加工实验,评估工具阴极的进给定位精度和试件的加工质量情况,以确保软件运行的可靠性和稳定性。实验结果表明:工具阴极的进给定位精度能够达到±0.005 mm,试件加工后的缝宽尺寸为0.278 mm,满足尺寸精要求,反映出控制系统可靠性高、稳定性好。 相似文献