窄细槽分段速进给电解加工方法研究

针对小间隙电解加工过程中极间间隙不稳定导致加工效率低下甚至发生短路等问题，以窄细槽电解加工过程为研究对象，提出自适应于工件蚀除速度的电极进给分段速加工方法。建立极间电流与加工深度之间的理论关系模型，采用单因素实验法对理论模型进行修正，使其反映实际加工过程。依据电解过程中深度与电流的变化规律，建立电极进给速度实时修正方程，实现电解过程不同进给速度段的划分。采用速度线性矢量混合算法，构建速度控制方程，实现各段速间的平稳过渡，保证电极进给速度变化时极间电流的稳定。实验结果表明，分段速进给控制方法能有效避免小间隙电解过程中由于进给速度与工件蚀除速度不匹配而导致的短路现象，有效保证窄细槽电解加工效率与轮廓精度。

Pulse Electrochemical Narrow Slot Machining Based on Segmented Feeding Control Method

To deal with low machining efficiency and short-circuits caused by the instability of the inter-electrode gap size in pulse electrochemical narrow slot machining, a segmented cathode feeding control method to be self-adaptive with the dissolution rate of work piece is proposed in this paper. A theoretical model between inter-electrode current and feeding depth is constructed and adjusted by experimental data to be accordant to real machining process. According to the relationship between current and feeding depth, a correction equation for feeding velocity is formulated, and cathode feeding process is divided into multiple stages with different feedrates. To make velocity smooth link between two neighbor stages and avoid inter-electrode current surge, a velocity blending algorithm is proposed and velocity control equation is constructed. Experimental results show that the segmented feeding control algorithm can avoid short-circuits, improve machining efficiency and achieve contour accuracy of industrial application in small gap pulse electrochemical machining.