大拉深比薄壁筒形件充液成形过程数值模拟  

Numerical Simulation Analysis of Hydroforming Process for Thin-wall Tube Workpiece with Big Deep Drawing Ratio

作　　者：张泉达 郎利辉[1] 孔德帅[1] 王耀[1] 李奎[1] 

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191

出　　处：《精密成形工程》2015年第5期93-98 114,114,共7页Journal of Netshape Forming Engineering

基　　金：国家科技重大专项(2014ZX04002-071)

摘　　要：目的利用充液成形工艺成形普通拉深工艺难成形的大拉深比筒形件。方法通过理论公式计算了冷冲压工艺成形该制件的道次,利用有限元软件Dynaform对充液成形过程进行了3个步骤模拟,并研究了第1步拉深时初始反胀高度对成形制件减薄率的影响规律。结果利用理论公式计算,传统冲压方法成形拉深比为3.2的筒形件至少需要5个道次,而采用被动式充液成形方法只需要3个道次。每个道次的最大减薄率都在8%以内,最后得到拉深制件的最大减薄率为8.53%,在安全范围以内;第1步充液拉深时,反胀高度分别为1.75,2.75,3.75,4.75,5.75 mm时,得到制件的最大减薄率分别为5.28%,5.08%,4.8%,5.03%,5.03%。结论充液成形工艺较传统冲压工艺可以大大提高板料的成形极限,减少成形道次,成形制件质量好;合适的初始反胀高度,可以减小成形制件壁厚的最大减薄率。ABSTRACT:The sheet hydroforming process was used to form the Tube workpiece with big deep drawing ratio, which is difficult to form by the ordinary deep drawing process. The forming steps of the part using traditional deep drawing process were calculated by theoretical equation. The three steps of the hydroforming process were simulated by means of the finite element software Dynaform, and the impact of initial inverse bulging height on the part thinning rate in the first step was studied. Results At least five steps were needed to form the tube workpiece with a drawing ratio of 3. 2 using traditional stamping as calculated by the theoretical equation, while only three steps were needed with the passive hydroforming process. The maximum sheet reduction of every step was less than 8% and the maximum sheet reduction of the final part was 8. 53%, so it was within the safe range. In the first step of the hydroforming process, when the inverse bulging heights were 1. 75,2. 75,3. 75,4. 75 and 5. 75 mm, the part’s maximum thinning rates were 5. 28%,5. 08%,4. 8%,5. 03% and 5. 03%, respectively. The forming limit of the sheet was improved by the hydroforming process compared with the tradition-al deep drawing process, the number of the forming steps was reduced and the part quality was good. The maximum thinning rate of the part wall thickness could be effectively decreased by using an appropriate initial inverse bulging height.

关 键 词：充液成形 拉深比 反胀高度 数值模拟 

分 类 号：TG394[金属学及工艺—金属压力加工]