变径管液压成形工艺设计与模具优化

【作者】 潘海彦；

【导师】 黄庆学；

【作者基本信息】 太原科技大学 ， 材料加工工程， 2012， 硕士

【摘要】 随着我国汽车工业的迅猛发展，车身及结构件的精细设计遍布于各种车型。因为尾气排放和能源节约等方面的要求愈加严格，高效率与轻量化成为在汽车工业中能否保持竞争力的重要因素。为了满足客户日趋提高的需求，不仅在材料性能方面必须提升而且在结构设计上要结合现代加工工艺，体现新一代制造水平。液压成形技术正是改变汽车工业结构设计理念的一种现代制造工艺，其优点在诸多文献中已经有详细阐述。随着液压成形技术在汽车工业、航天工业及其他领域被迅速推广，诸多不足逐渐体现出来，如由于发展历史较短并未制定出工艺标准等。在这种背景下本课题开展了对液压成形产品中最典型产品变径管变形规律的研究，以揭示液压成形各工艺参数对产品质量的影响规律。通过对自由胀形过程的模拟分析，了解变径管最基本的胀形过程、厚度分布和摩擦对产品厚度的影响规律。采用位移控制进行补料的方式，对不同补料压力进行分析，得出理想的补料压力区间。对比有、无摩擦两种结果得出：随补料压力增大，两种情况最小壁厚与壁厚分布的变化趋势相同。液压成形工艺中普遍存在摩擦接触难以控制的问题，本文提出尽量减少管坯与模具之间相对运动的思想。参照T型管模具的进化历史：由封闭整体模具发展到组合可运动模具，并提出平衡冲头的概念。对现行模具进行优化，把过渡区和导向区从模具中分离出来成为在补料过程中可运动的模具。除了变形区发生相对滑动摩擦之外，其它部分管坯和模具之间靠内压产生的摩擦力相互固定，从而使得接触摩擦变得简单。结果表明在同一补料行程条件下采用改进的模具所得结果与传统模具结果比较，成形区管坯壁厚较大而且分布均匀。更多还原

【Abstract】 With the rapid development of China’s automobile industry, the body andthe fine details design of the structure gradually spread over a variety of models.More stringent requirements from environmental protection and energyemissions and conservation, the pursuit of high efficiency and lightweight hasbecome an important factor in its ability to remain competitive in the automotiveengineering industry. In order to meet rising customer demands, not only inmaterial terms of performance is necessary to improve, and structural designmust combine with modern processing technology showing a new generation ofmanufacturing level. Hydroforming technology is a modern manufacturingtechnology to changing the auto industry structural design concepts, itsadvantages have been referred by a lot of thesis in detail. With hydroformingtechnology in the automotive industry, aerospace industry and other areas rapidspread, process standards did not work out due to the development of arelatively short history due to many deficiencies gradually reflected.In this context, this project to carry out the products as the simplest andmost typical adjustable tube hydroforming deformation law study for revealingthe impact of the hydroforming process parameters on product quality. Freebulging process simulation analysis to inspect the basic forming process and itsthickness distribution law affected from friction conditions on final productquality. Axial displacement control is working for the feeding. Different feedingpressure was analyzed to search the expected pressure range. Results of bothcases of friction and no-friction were compared, and both have the same trendthat as the feeding pressure increasing the minimum thickness.Contact and friction were most difficult problem in hydroforming, thatwould be solved with a optimized model. Inspecting into the history ofdevelopment of T-shape’s model, the concept of separated model was regardedas a landmark that made the balance punch born. For vanishing effect of thefriction, the contact area decreased in this model that guide zone and transition zone were separated further as movable partitions. Beside the forming zonethere was no area where sliding friction happened, that simplified the situationof contact. It showed that optimization of the model improved the distribution ofSTH.更多还原