基于数值模拟的车用螺纹管件冷镦缺陷优化与试验验证

Optimization and experimental verification of cold heading defects for automotive threaded pipe fitting based on numerical simulation

为解决车用螺纹管件在7工位冷镦试模试验中出现的材料折叠问题,通过冷压缩试验获得了实际冷镦材料的塑性流动特性,并导入体积成形软件Deform-3D中完成了现行工艺流程的成形模拟。通过比较数值模拟和实际冷镦成形结果,验证了模拟试验的可靠性,同时详细介绍了局部工位的缺陷产生过程及原因,并进行了合理改进。对工位改进后的零件成形过程进行了模拟,检验了改进后的成形情况。结果表明,材料流动情况得到极大改善,不仅原折叠缺陷得以消除,零件外形的成形情况也满足预期。最后,按照改进后工艺进行了冷镦试模,冷镦结果与模拟情况完全相同,各工位零件及最终螺纹管件均未出现折叠等缺陷,成形质量较好,表明新工艺切实可行,可使螺纹管件的产量显著提升。

To solve the material folding problem of automotive threaded pipe fitings during the die trial experiment of seven-station cold heading,the plastic flow characteristics of the actual cold heading material were obtained by the cold compression experiment,and the forming simulation of the current process was completed by the volume forming software Deform-3D.Then,by comparing the numerical simulation and the actual cold heading results,the reliability of the simulation experiment was verified.At the same time,the process and reasons for local station defects were introduced in detail,and the reasonable improvements were made.Furthermore,the forming process of the parts in the improved station was simulated,and the forming situation after improvement was tested.The results show that the mate-rial flow situation is greatly improved,not only the original folding defects are eliminated,but also the forming of the part shape meets the expectation.Finally,the die trial experiment of cold heading is carried out according to the improved process,and the cold heading results are exactly the same as the simulation results.There are no folding defects in the part of each station and the final threaded pipe fitings,and the forming quality is good,indicating that the new process is feasible,and the production of threaded pipe fittings can be significantly increased.