导　　师： 罗云华

学科专业： 080503

授予学位： 硕士

作　　者： ;

机构地区： 华中科技大学

摘　　要： 传统的精冲工艺需要专门的三动压力机,但由于精冲机价格昂贵,一般企业无力投资。只通过增加精冲机的数量来推广精冲技术,限制了其发展速度。因此,发展普通压力机精冲技术是推广精冲的一个重要途径。 通过分析精冲原理、比较精冲与普通冲裁的异同,得出实现精冲的两个主要条件是三向压应力和小间隙,并指出了普通压力机实现精冲的必要工艺措施,论证了普通压力机精冲技术的可行性。在此基础上,提出了设计氮气弹簧式精冲模的解决方案,利用氮气弹簧提供的压力使被冲工件处于三向压应力状态,使普通压力机精冲技术成为可能。 利用DEFORM-3D有限元软件对曲柄系列零件的弯曲过程进行数值模拟,根据模拟结果制定工艺方案、设计和优化模具结构,实现了不同规格的零件在同一副模具上弯曲成形,提高了生产效率,降低了生产成本。 利用DEFORM-2D有限元软件对圆孔的精冲过程进行数值模拟,针对有反压力和没有反压力两种情况,重点分析了精冲过程中的材料流动、静水应力分布、等效应力与等效应变分布及凸模载荷,并利用Oyane断裂准则对精冲件的断面质量进行了预测。 采用有限元模拟与工艺试验相结合的研究方法,对该系列零件的精冲过程进行工艺试验,并对精冲后孔的尺寸精度及冲裁面质量进行分析,验证了有限元分析与实际过程的一致性。 研究表明,通过设计氮气弹簧式精冲模,使被冲工件处于三向压应力状态,可在普通压力机上实现精冲工艺,获得尺寸精度高、断面质量好的精冲件。 The traditional fine blanking process is carried out on special triple-action press. However, general enterprises are unable to buy fine blanking presses because of the high price. As a result, the application of fine blanking technology will be restricted only by the increase of fine blanking presses. Therefore, it is an important way to make this technology more and more popular by the development of fine blanking process on common press. Two main conditions for the implementation of fine blanking, three-dimensional compressive stress and small clearance, were obtained by the analysis of fine blanking principle and comparison of fine blanking and conventional blanking. The necessary technological measures for fine blanking on common press were presented, and the feasibility of fine blanking on common press was demonstrated. Furthermore, the solution to fine blanking on common press was presented by die deigned with nitrogen gas springs. The blank is in the state of three-dimensional compressive stress with the help of nitrogen gas springs, and it makes the process of fine blanking on common press available. The numerical simulation for bending process of crank was carried out by the FE software DEFORM-3D. The process scheme and the die structure were designed with the help of simulation results. Parts of different sizes could be formed in one bending die with the optimization of die structure, as a result, the production efficiency is improved and the production cost is reduced. The numerical simulation for fine blanking process of circular hole is carried out by the FE software DEFORM-2D. The conditions with or without counter pressure were discussed respectively. The material flow, distribution of hydrostatic pressure, effective stress, effective strain and load of punch were analyzed. Furthermore, the quality of cut surface was predicted by using Oyane ductile fracture model. The research method of FE simulation combined with process test is used. The process tests of fine blanking were carri

关 键 词： 曲柄 精冲 普通压力机 氮气弹簧 有限元模拟 工艺试验

领　　域： [金属学及工艺]