杆系柔性成形模具及板料冲压成形关键技术

【作者】 陈婷；

【导师】 宋爱平；

【作者基本信息】 扬州大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 板料冲压成形技术是一种重要的制造技术,在汽车、船舶、航空、日用品和国防等工业中都有广泛的应用。但在板料冲压成形加工中也存在一些问题,其中有:1、模具制造成本高,模具通用性差;2、板料在冲压过程中的起皱现象。随着机电产品向多样化、个性化方向发展,板件加工批量越来越小,板件加工必然向柔性化加工方向发展,这就需要研究板料冲压成形模具的可重构技术,以控制板件的加工成本与时间。本文首先分析和总结了国内外各种可重构模具的优缺点,从理论分析、试验、有限元模拟三个方面介绍了板料起皱的研究现状。探讨在板料冲压成形技术中存在的问题。阐述了曲面板件冲压成形机理,分析了球面板件在冲压成形过程中的受力状况;随后结合板条的受压失稳原理,研究板料起皱机理,得出板料起皱的临界条件。本文的重点是探讨减少板料起皱的基本方法与思路,提出从板料成形工艺与模具结构入手,抑制板料起皱的方法。通过对板料起皱机理的分析,提出了一种可重构的板件成形加工模具——杆系柔性成形模具。该模具以柔性杆为单元,若干个柔性杆组合成一个阵列,通过调节各杆的长度以及更换不同形式的冲压头,使各冲压头表面根据加工件的表面形状近似地组合成相应的曲面,从而组成一定尺寸的模具冲压面,最终构成冲压成形模具。同时提出了一种冲压加工工艺——多点压板成形冲压工艺,并且通过理论分析与演算证实该工艺与杆系柔性成形模具相结合可以显著地减少板件在成形过程中的起皱现象。课题在研究过程中使用可重构的杆系柔性成形模具对典型曲面板件(球面板件)、不对称曲面板件(半球面板件)以及空间复杂曲面板件(马鞍形板件)进行了冲压试验研究。目的是为了验证该模具的可重构性;该模具的板料冲压加工特性以及对成形过程中出现的起皱等缺陷的抑制效果。本课题研究的杆系柔性成形模具将板料成形、压边、顶料融合一体,具有可重构、低成本、高效率、成形精度高等特点。将多点压板成形冲压工艺与该模具相结合,可以减少板料的起皱现象。相信随着研究工作的不断深入,模具结构将不断完善。该模具对中小批量的曲面板件冲压加工具有明显的优势,其应用前景十分广阔。更多还原

【Abstract】 The sheet metal forming technology is an important manufacturing technology which is widely applied in the industry of aviation, aerospace, vehicle, shipping and engineering machinery. But there are some defects existed in the sheet metal forming technology. Manufacturing cost of die is high and the die cannot be widely used. And wrinkles existed in the sheet metal forming. As the diversity and individuality of mechanical and electrical products, the batch of the sheet forming is decreasingly demanded. So it is inevitably for the forming technology to develop to the flexibility and agility. For all, it needs to research the reconfigurable principle of the die and the new technique to control the cost and time in the processing.Firstly the paper analyzed and summarized the advantages and disadvantages of domestic and foreign reconfigurable dies. Present research on wrinkling is introduced through the theoretical analysis, the experiment, the finite element simulation, thus it obtained problems existed in the sheet metal forming technology. The forming mechanism of the curved sheet was elaborated. The stress condition of spherical sheet metal part in the forming process was analyzed. Combined with the compressive buckling mechanism of plank, it studied the mechanism of sheet metal wrinkling. Then critical buckling condition on sheet metal wrinkling was obtained. The key of the paper is discussing the basic methods and ideas of suppressing wrinkling. It proposed that wrinkles can be suppressed by improving the stamping process and the structure of the die.Under the guidance of the principle of wrinkling, the paper puts forward a new kind of reconfigurable sheet metal forming die-- Poles Flexible Die. The central component of the die is a pair of matrices of flexible poles. A desired discrete die surface is constructed by changing the positions of flexible poles and changing variant heads according to the surface of sheet metal parts. Then the die is made up. At the same time, the“Multi-point Forming and Pressing”stamping process was explored. Through theoretical analysis and calculation, the stamping process combined with Poles Flexible Die can suppress wrinkling in the process of forming sheet metal effectively. Next some experiments are made to form typical curved-face sheet (spherical face sheet), space twisted sheet (leaf blade of water pump) and bidirectional formed complex curved sheet (saddle-shaped board). Experiments verify that Poles Flexible Die has good capability of reconfiguration. It shows the forming properties of the die and the effect of suppressing wrinkling in the process of forming sheet metal parts.Poles Flexible Die integrates forming sheet metal, holding blank and discharging. It has many advantages such as reconfiguration, low cost, high efficiency and high forming precision etc. Combining the“Multi-point Forming and Pressing”stamping process and the die can suppress wrinkling occurred in the common die. It is firmly believed that the structure of the die will improve continually. The die has obvious advantages in middle-small batch of curved-surface sheet forming. It can be widely used.更多还原