弹、塑性传力介质下三通管轴压胀形工艺分析

填充在初始管件内部的传力介质是三通管轴压胀形工艺中的重要因素。内高压充液胀形具有工装结构复杂、成本高、密封条件苛刻的缺点;为寻求结构简单、成本低廉的工装结构需要选用其他成形传力介质。文章采用聚氨酯橡胶弹性材料和石蜡、石墨混合塑性材料为传力介质,分别以紫铜三通管和硬铝三通管轴压胀形为例,在自行研制的30t轴压胀形试验平台上进行了工艺试验,分析了不同传力介质对胀形工艺的影响,获得了合格成形件和较理想的传力介质。结果表明,聚氨酯橡胶弹性材料不适合成形高径比大于1的支管,塑性传力介质中石蜡石墨以4∶1混合时,三通管成形质量比较理想。

Analysis of axial force and internal pressure bulging process for tri-branch tube with the elastic and plastic medium

The medium filled in the tube before forming is an important factor in tri-branch tube bulging process.Hydraulic forming process has the disadvantages which need high price and rigorous hermetic condition.In order to design simple structure and reduce cost,other medium should be selected.Elastic material rubber and admixture material with olefin and graphite were selected and used in the tri-branch tube bulging process of copper and aluminum alloy.Forming tests were carried out in the 30 tone independently-established machine.The influences of different mediums were analyzed and the perfect medium was fond out.The results show that elastic material rubber is not fit for tri-branch tube which branch ratio is more than 1.The medium of olefin and graphite in 4∶1 admixture is suitable.