卧式电解加工机床导电轴结构设计

Structure Design of Conductive Shaft of Horizontal ECM Machine Tool

针对卧式电解加工机床导电轴在加工中出现发热严重、易烧蚀等问题,提出导电滑环和碳刷两种引电结构,利用软件对两种结构进行多物理场温度仿真,得到约束工况下导电轴温度分布规律,确定了一种基于碳刷引电方式的导电轴结构。通过建立基于SVM和多项式算法的温度数学模型,求解出监测点温度在约束条件下的最优解,分析工作电流、环境温度和电解液温度的影响水平,结果表明:工作电流对导电轴温度的影响水平最大,电解液温度对导电轴温度的影响水平最小。在主轴箱内设置降温结构,促进流场循环,降低导电轴温升。将主轴箱结构应用于卧式电解加工机床,开展性能测试试验,整个加工过程机床运行平稳,试验工件的成型精度可达±0.14 mm,表面粗糙度可达0.8μm,满足实际需求,验证了导电轴结构的可靠性,为工程实践提供了理论研究方法。

In view of the problems of serious heating and easy ablation of the conductive shaft of the horizontal ECM machine tool in processing,two conductive modes were proposed:conductive slip ring and carbon brush.The temperature simulation of the two structures was carried out by using the simulation software.The temperature distribution law of the conductive shaft under constrained conditions was obtained.A conductive shaft structure based on the carbon brush was determined.By establishing a temperature mathematical model based on SVM and polynomial algorithm,the optimal solution of the temperature at the monitoring point under the constraint conditions was solved.And the influence levels of working current,ambient temperature and electrolyte temperature were analyzed.The results show that the influence level of current on the temperature of conductive shaft is the largest,and the influence level of electrolyte temperature on the temperature of conductive shaft is the smallest.A cooling structure is arranged in the spindle box to promote the circulation of the flow field and reduce the temperature rise of the conductive shaft.The spindle box structure is applied to the horizontal ECM machine tool,and the performance test is carried out.The whole machining process is smooth,the forming accuracy of the test workpiece can reach±0.14 mm,and the surface roughness can reach 0.8μm.It meets the actual needs,verifies the reliability of the conductive shaft structure,and provides a theoretical research method for engineering practice.