三元流闭式叶轮组合电加工技术研究Ⅲ——数控电火花精加工关键技术

Research of Combined Electrical Machining of 3D-flow Closed Impellers Ⅲ—Key Techniques of Numerically Controlled Electron Discharge Machining for Precision Work

数控电火花(NC-EDM)精加工,是三元流闭式叶轮组合电加工的最终加工工序,是决定三元流闭式叶轮整体制造精度的关键工序。本文专题介绍了其主要关键技术,包括工具电极、运动轨迹以及工装夹具设计。基于关键技术的解决,进行了某型三元流闭式叶轮组合电加工工艺试验,试制加工了合格零件。研究结果表明,数控电解(NC-ECM)预加工可充分发挥电解加工高效率的特点,而数控电火花精加工又可保证对复杂整体构件加工需要万无一失的高可靠性和高精度的要求。两者结合,可以实现高效、精密、可靠、整体制造三元流闭式叶轮的目标。

Numerically controlled electron discharge machining （NC-EDM） for precision work is the final process of the combined electrical machining technology for 3D closed impellers, and it has a crucial effect on the integral precision of the machining work. Such key techniques as the design of the electrodes and their tracks, the fixtures of the cathodes and the impeller are discussed. A series of technological experiments are made and a qualified 3D-flow closed impeller is machined successfully. The results show that high production efficiency can be obtained by numerically controlled electrochemical machining （NC-ECM） for pre-processing, while the precision and reliability of the machining of a complex integral component can be ensured by NCEDM for precision work. To sum up, a 3D-flow closed impeller can be machined efficiently, precisely, reliably and integrally with this method.