第42卷第3期 Vol.42No.3
假压技术
FORGING &STAMPING TECHNOLOGY
5m直径大角度型材框拉弯成形工艺
李倩，张杰刚2，尹苹2，李继光'，金朝海3，刘祥龙2（1.天津航天长征火箭制造有限公司，天津300462；2.首都航天机械公司，北京100076；
3.北京航空航天大学机械工程及自动化学院，北京100191）
2017年3月 Mar.2017
摘要：针对某一运载火大角度型材框，对力控制模式下的拉弯成形进行了模拟及试验研究，模拟分析了拉弯力对成形件应力、应变分布及回弹量的影响规律。模拟结果显示，随着拉弯力增加，型材截面内外侧切向应力差减小，回弹和扭翘变形也减小，但不利的一面是变形量增大，零件壁厚减薄率增加，截面尺寸变化加大，综合考虑，选取合适的拉弯力为97.4kN。试验分析了拉弯力、第1次拉弯包角及补拉量对零件成形精度的影响规律。试验结果表明，拉弯力和补拉量越大，零件的角度、平度及弧度间隙越小，尺寸精度越高。通过试验，得出了优化的拉弯工艺参数，即拉弯力为105kN，第1次拉弯包角为65°，补拉量为60mm。在此参数下拉弯，零件率火后变形程度较小，扭翘现象较小，回弹量较小，成形出尺寸合格的零件。
关键词：拉弯成形；大角度型材框；拉弯力；补拉量；数值模拟 DOI; 10, 13330/j, issn. 1000-3940, 2017. 03, 020
中图分类号：TG386
文献标识码：A
文章编号：1000-3940（2017）03-0103-06
Stretch-wrapbendingof5m-diameterlargeangleprofileframe
Li Qian', Zhang Jiegang’, Yin Ping’, Li Jiguang", Jin Chaohai', Liu Xianglong”
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Beijing 100076, China; 3. School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China)
Abstract: For the large angle profile frame of a camier rocket, the stretch-wrap bending under the force control mode was simulated and experimented, and the influences of stretch-wrap bending force on stress, strain distribution and springbeack were simulated and analyzed. The simulation results show that the tangential stress difference between outside and inside of profile section decreases, springback and warping decrease with the increase of stretch-wrap bending force, However, the deformation, the thinning rate of wall thickness and the variation of cross-sectional dimension increase with the increase of stretch-wrap bending force, Considering all the above, the appropriate stretch-wrap bending force 97. 4 kN is selected. And the influences of the stretch-wrap bending force, the first comer wrap and the amount of compensation on the accuracy of forming were analyzed by experiment. The results show that the larger the stretch-wrap bending foree and the amount of compensation are, the smaller the angle, flatness and radian clearance of parts are, and the higher the accuracy of part size is. Thus, the optimized bending process parameters are attained by experiments with the stretch-wrap bending force 105 kN, the first corner wrap 65°and the amount of compensation 60 mm. Based on the above parameters, the qualified parts are fomed with less quench-ing deformation, wist phenomenon and springback.
Key words: stretch-wrap bending; large angle profile frame; stretch-wrap bending force; amount of compensation; numerical simulation
型材因其良好的力学性能在航空、航天、机车及汽车产业上得到广泛应用。型材拉弯是在毛料弯曲的同时施加切向拉力以克服内侧的起皱及改善截面内的应力分布，减少回弹，提高形状精度)。型材拉弯因具有回弹小、零件贴模度好的特点而成为
收稿日期：2016-0823；修订日期：2016-11-30 基金项目：航天一院院级工艺改进课题（Y41203-53C）作者简介：李倩（1985-），女，硕士，工程师
E-maill: liqianfly99163,com 万方数据
型材零件的主要成形方法。拉弯分为一次拉弯法和二次拉弯法，二次拉弯法具有成形尺寸精度高、回弹量小的特点，已被生产实践愈来愈广泛地采用，尤其对于弯角较大的大型型材零件应用上优势明[]香
型材拉弯成形是由成形件尺寸（包括弯曲角、弯曲半径等）、型材截面形状和尺寸、材料性能、成形工艺参数（如拉弯力、拉伸量）等多因素耦合交互作用的复杂成形过程，成形件的质量较难控制。型材拉弯成形中可能会出现起皱、截面畸变及回弹