预弯对铝合金管材内高压成形缺陷与尺寸精度的影响

发布时间：2018-06-08 00:01

本文选题：CNC弯曲 + 内高压成形　；参考：《材料工程》2017年09期

【摘要】：铝合金异形截面管件是实现汽车结构轻量化的有效途径之一,其成形工艺是先将铝合金管材经过数控弯曲获得轴线形状,然后进行内高压成形。弯曲产生的回弹、截面畸变及起皱等缺陷会影响后续内高压成形的质量。本工作通过建立管材塑性弯曲的理论模型和材料模型,计算任意弯曲角度的卸载回弹量,在弯曲过程考虑回弹量补偿,有效避免了内高压成形时的咬边缺陷。通过改善芯轴条件,使用带有一个芯球的芯轴,使截面不圆度由7.55%降低至1.43%,避免了弯曲件在内高压成形时发生破裂。同时对弯曲产生皱纹的管件进行内高压成形,证实了内高压成形过程不能够消除管件在弯曲过程形成的起皱。通过工艺实验研制出6063铝合金异形截面管件,获得了无缺陷的成形件。对47个内高压成形件进行尺寸精度测量,最大尺寸偏差为1.08mm(1.63%),尺寸和精度符合设计要求。
[Abstract]:Aluminum alloy special-section pipe fitting is one of the effective ways to realize the lightweight of automobile structure. The forming process is to obtain axis shape by numerical control bending of aluminum alloy tube and then to carry out internal high pressure forming. The springback, section distortion and wrinkle produced by bending will affect the quality of subsequent internal high pressure forming. In this work, the theoretical model and material model of plastic bending of pipe are established to calculate the unload springback at any bending angle, and the springback compensation is considered in the process of bending, which effectively avoids the edge cutting defect in the process of internal high pressure forming. By improving the condition of the core shaft, using the core shaft with one core ball, the non-roundness of the section is reduced from 7.55% to 1.43%, and the rupture of the bending part is avoided when the bending part is formed under internal high pressure. At the same time, the internal high pressure forming of the tube with wrinkling is carried out, which proves that the internal high pressure forming process can not eliminate the wrinkling of the tube in the bending process. 6063 aluminum alloy tube with special-shaped section was developed by technological experiment, and the non-defect forming part was obtained. The dimension accuracy of 47 inner high pressure forming parts is measured, the maximum dimension deviation is 1.08mm / 1.63mm, the dimension and precision are in line with the design requirements.
【作者单位】：哈尔滨工业大学材料科学与工程学院;
【基金】：长江学者和创新团队发展计划资助基金项目(IRT1229)
【分类号】：TG306

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