【作者】 陈敬；

【导师】 彭成允；

【作者基本信息】 重庆理工大学 ， 材料加工工程， 2009， 硕士

【摘要】 金属材料是现代文明的基础,塑性加工技术是人类历史上一种最为久远的制造方式。随着冲压技术的快速发展及其应用范围的不断扩大,拉深工艺和胀形工艺凭其各自独有的特点,在冲压生产中发挥着举足轻重的作用。但是,许多零件的成形不完全是拉深,也不完全是胀形,而是表现为拉胀结合的成形性质。同时在拉胀结合成形方面目前缺少这方面的较深入一点的研究与相关成形极限理论、数表和公式。围绕着这一问题,本文在综合借鉴了大量技术资料的基础上,主要以球底直筒形零件拉深作为研究对象,结合理论分析、物理试验和数值模拟分析,探讨了压边力、润滑条件、板料厚度、变形速度、凹模圆角等因素对拉胀成形极限的影响规律;并以某企业生产的离心器盖为例,对其局部凸包的拉胀成形问题作了进一步研究,取得了较好的工程应用效果;提出了计算成形过程中有拉胀成形性质的该类零件的方法。具体作了以下方面的研究工作:1.理论上分析了半球形件、球底筒形件和圆筒形件在拉深成形过程中的应力应变状态。2.运用LS-DYNAFORM软件模拟了带凸缘球底筒形件和圆筒形件的拉深成形,分析了压边力、润滑条件、速度条件、板料厚度、凹模圆角半径、不同材料对其成形极限的影响规律。3.选取普通钢板St14和不锈钢板0Cr18Ni9,利用物理试验的方法,分析了压边力、润滑条件、凹模圆角半径、不同材料对带凸缘球底筒形件球形底部应变的影响规律。4.运用理论分析、数值模拟和数值拟合的方法,推导了带凸缘球底筒形件在不同成形条件下成形极限高度的计算公式。5.将推导出的公式,用于分析计算离心器盖零件局部凸包的成形。本项研究工作,可望弥补拉胀成形方面理论研究的不足,对丰富冲压工艺理论,提高冲压件的质量等方面有一定的学术意义及工程意义,该项研究成果可以作为工程技术人员的设计参考资料。更多还原

【Abstract】 Metal material is the foundation of modern civilization.Plastic processing technology is a kind of manufacturing method with the longest history. With the fast development of the sheet metal stamping technology and the continuously expansion in the scope of application ,drawing process and bulging process, based on their respective particular characteristics, play a decisive role in the punching production.However, the forming of many accessories is incomplete drawing or bulging , but manifests as drawing and bulging forming property.In addition, for now, there is a shortage of comparatively further study in the aspect of drawing and bulging forming and related forming limit theory, processing parameter, and formula. According to this problem, on the basis of using a large amount of technical data for reference, taking the spherical-bottomed cylindrical cup as research object, combined with the analysis of the theoretical, physical experiment, numerical simulation, this article analyses the effect rule of blank holder force, lubrication, material thickness, deformation rate and caving die circular-arc upon drawing and bulging forming limit. Taking the cover board of centrifuges produced by some industry as an example, this article makes a further study for the problem of raising forming. Besides, this application of it has result in good effect. This paper also put forward some methods of these accessories with drawing and bulging in the process of calculating forming.A concrete analysis is made as follows:1. During the drawing processing, the stress-strain state for the semisphere-part and the cylinder shape with flanger has been analyzed in theory.2. The simulation for the drawing and forming of the cylinder shape and spherical-bottomed cylindrical cup with flanger is conducted by using LS-DYNAFORM. The influence law of blank holder force, lubrication, deformation rate, material thickness, cavity die circular-arc semester and different materials upon forming limit has been analyzed.3. Selecting the common plate Stl4 and stainless steel plate 0Cr18Ni9, by means of physical experiment, the influence of the blank holder force, lubrication, cavity die circular-arc semester and different materials upon the spherical-bottomed cylindrical cup has been analyzed.4. Based on the methods of theoretical analysis, numerical simulation and numerical fitting, the calculation equation of forming limit height for the spherical-bottomed cylindrical cup, under different forming conditions, has been deduced.5. The formula deduced is put into use in the field of calculating the forming of cover board of centrifuges.This research is able to make up for the deficiency of this theory in drawing. It also has some academic value and engineering practice significance in sheet metal stamping theory and the improvement of punching in quality. The results can be also used as a reference for engineering in quality control.更多还原