板料成形中回弹问题的研究.doc

摘 要 板料成形过程中普遍存在着回弹问题，特别在弯曲和拉深过程中回弹现象更严重。在板料成形领域，回弹已成为模具设计中要考虑的关键问题。由于回弹的存在，卸载后零件的形状尺寸与模具表面的形状尺寸不能完全符合，零件的尺寸精度达不到设计要求，对生产效率造成极大的影响，所以有必要对其进行深入的研究和有效的控制。 回弹是不可避免的。在实际生产中，准确掌握回弹规律和回弹值大小，剖析影响回弹的因素，实用的工艺技术方法，有助于改善和消除弯曲回弹倾向，提高生产效率和工艺质量。因此，对回弹机理以及影响回弹因素的研究至关重要。本文旨在浅析板料成形回弹现象，研究影响回弹的主要因素，主要对回弹控制的常用方法进行讨论研究，以及最后对板料回弹的模拟预测方法的研究。 关键词：板料成形，回弹，模具设计，模拟 Abstract Sheet forming process generally exists in the rebound problem, especially in bending and drawing process of rebound phenomenon which is more serious. In sheet metal forming, spring back has become the key issues for consideration in the mold design .Due to the presence of spring back, the shape and size of the die surface can not be completely consistent with mold surface after unloading the parts. Besides, the dimensional accuracy of parts is not up to the design requirements and the production efficiency was greatly influenced. So it is necessary to conduct in-depth research and effective control. Spring back is inevitable. In actual production, accurately grasp the resilience law and rebound value, analysis of the affecting factors of spring back, practical technique are all contribute to the improvement and the elimination of bending spring back tendency, improving the production efficiency and the process quality. Therefore, the mechanism and influencing factors of rebound resilience research is essential. This article aims at the analysis of phenomenon of spring back in sheet metal forming, the influence of spring back factors, mainly on the spring back control method used for the study, and finally to the forecast method research on sheet spring back simulation . Key words: Sheet metal forming, Spring back, Mold design, Simulation 目 录 前 言 1 1 绪论 2 1.1 课题的背景和研究意义 2 1.2 板料回弹的发展前景及其研究方法 2 1.3 本文研究的主要内容 4 2 板料成形中回弹的理论研究 6 2.1弯曲变形过程及变形特点 6 2.1.1弯曲变形过程 6 2.1.2 弯曲变形特点 6 2.2 最小弯曲半径 7 2.2.1 影响最小弯曲半径的因素 7 2.2.2 提高弯曲极限变形程度的方法 8 2.3 板料弯曲卸载后的回弹 8 2.3.1 回弹现象及机理 8 2.3.2 板料回弹量的计算 10 2.4 影响回弹的主要因素 12 3 板料成形中回弹控制方法的