中文摘要：

针对管材的精密下料问题,给出一种基于疲劳断裂机理的新型精密下料方法。完成了精密下料机和控制系统的实验平台搭建,利用径向循环加载和管料表面缺口的应力集中效应,通过变频器改变下料模具的旋转速度,控制在不同下料阶段对管料的加载频率,实现管材的精密下料。通过不同的实验控制曲线,进行45钢管、304不锈钢管和T2Y铜管的下料实验,得出了下料时相应的最佳变频规律和理想控制曲线,并获得了良好质量的管料断面。在理想控制曲线下,304不锈钢管断面最大凸起高度仅为0.08 mm,凹陷深度仅为0.05 mm。实验结果表明,所研究的下料方法切实可行,能满足工业中多种材料中小直径厚壁管的下料要求。

英文摘要：

A new type of precision blanking method based on the fatigue fracture mechanism was proposed pointing to the problem of pre- cision blanking of tubes. Experimental platform including precision blanking machine and control system was established. Using the radial cyclic loading and stress concentration effect of tube surface gap, precision blanking of tubes was achieved by changing the rotation speed of mould which was controlled by frequency converter to adjust the loading frequency of tubes at different blanking stages. Three materials of tubes which were 45 steel, 304 stainless steel and T2Y copper were tested by using different experimental control curves. The relative optimal frequency variety law and ideal control curve during blanking were got, as well as the cross section of tubes with good quality was obtained. Under the condition of ideal control curves the peak bump height and sunken height of 304 stainless steel tube cross section were just 0. 08 and 0. 05 ram, respectively. The experimental results show that the new type of precision blanking technology is feasible, and it can satisfy requirements for blanking of thick-wailed tubes with various materials in the industrial production.