Development of production precision pipe-like parts by HDS

近年来，精密仪器、电器等领域对轻、小、高性能、高效率、高可靠性和低成本提出了强烈的要求，这表明这些仪器的部分领域正处于同样的境地。本研究的目的是开发精密管状零件的HDS（空心盘冲压）生产方法。HDS能够高效、精密、细、短地加工出传统方法难以加工出的管材，但其加工窗口必须相当窄。在本研究中，我们制作了一个HDS过程分析系统，并测量了冲压过程中冲床行程对载荷和应变的分布。在试验分析的基础上，采用有限元法进行了应力应变分析。在HDS中，管子是通过冲床将毛坯推入模具而制成的。在变形过程中，毛坯受拉内件与受压外件之间存在中性截面，中性截面的位置是确定工艺窗口范围的重要参数之一。坯料变形所需要的、摩擦带来的拉伸内力与压缩外力之间的平衡比张力的可变形性更重要。

Light, small, high performance, efficiency, high reliability and low cost have been strongly requested in precision instrument, electrical appliances and etc.recently, which indicates parts of these instruments being in the same situation.The aim of this study is to develop the production method for precision pipe-like parts by HDS (Hollow Disk Stamping). HDS is able to produce efficiently precision, thin and short pipe, which has been difficult by conventional method, however, the process window of HDS should be rather narrow.In this study, we made an analyzing system on the process of HDS and measured the stroke of punch vs.load and strain distribution during stamping. Adding to the experimental analysis, the analysis of stress and strain was done by finite element method. In the HDS,a pipe is made through a blank being pushed into die by punch. During the deformation, there is neutral section between tension inner part and compression outer part of blank and the position of the neutral section is one of the most important parameter to determine the range of process window. The balance among forces in tension inner part and compression outer part of blank needed for deformation and brought by friction is more important than deformability of tension.