共查询到20条相似文献,搜索用时 109 毫秒
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旋压成形模在变薄拉深中的应用 总被引:2,自引:0,他引:2
旋压成形是将毛坯夹紧在模芯上,由旋压机带动模芯和毛坯一起以高速旋转,同时利用滚轮的压力和进给运动,使毛坯产生局部变形,最后获得轴对称零件,旋压模具简单,脸为局部变形,可用功率和吨位较小扔设备加工大型零件,多用于批量小而形状复杂的零件。并介绍旋压成形技术在薄壁筒形件制造中的应用。 相似文献
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基于有限元反向法的板料成形毛坯设计 总被引:9,自引:0,他引:9
由反向法计算出的毛坯存在一定的形状误差。为获得优化的毛坯 ,根据冲压件成形后的形状误差和变形趋势 ,提出了毛坯形状修正算法。结合Hyperform和Dynaform软件应用所提出的毛坯形状修正算法实现了毛坯设计方法。数值模拟结果表明 ,这种设计方法具有较高的精度和计算效率的同时 ,还可以评价冲压件的成形性。 相似文献
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一步成形有限元法,是从产品的形状出发,将其作为成形后工件的中面并对其离散,通过有限元方法确定在满足一定边界条件下,工件中的节点在初始毛坯中的位置。由一步成形有限元法可以得到对应的毛坯形状,通过计算毛坯结点到工件上的位移可得到工件上的应力和应变。此法计算速度快,不需要模具和工艺信息,建立分析模型简单,可用于板料成形设计早期,用来估计零件的成形性能。 相似文献
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板料形状与润滑状况对板料成形的影响 总被引:1,自引:0,他引:1
通过对一个大型复杂冲压件成形过程进行数值模拟,研究了坯料初始形状与润滑状况对板料成形性的影响,并从中得出了合理的毛坯初始形状和润滑条件。 相似文献
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介绍了为实现可持续发展的目标,在成形加工技术方面的一些新的进展,如轻质合金、高强度钢等新材料的开发应用,以及拼接毛坯、液压成形、半固态成形、金属注射成形等新工艺. 相似文献
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针对钢球毛坯热锻成形的变形特点,分析了钢球毛坯热锻成形后的常见缺陷及其产生原因.以在JB31-160压力机上加工公称直径27.5mm钢球毛坯为例,分析了钢球毛坯压力机热锻成形的模具结构特点.从合理设计钢球毛坯锻件图开始,对钢球毛坯进行了有关工艺参数计算,确定了热锻钢球毛坯模具工作的部分尺寸,提出了钢球毛坯压力机热锻成形工艺设计的新方法.生产实践表明,该新工艺能显著提高热锻成形钢球毛坯的质量,降低锻件废品率,提高模具使用寿命. 相似文献
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板料拉伸成形中确定合理毛坯形状的理论方法综述 总被引:1,自引:0,他引:1
合理的毛坯形状不仅可以提高原材料的利用率,减少成形后的修边余量,而且能改善可成形性,大大提高成形质量。对此,人们提出了许多预测方法和估算方法。本着重对各种确定毛坯外形的理论方法做原理上的介绍及比较,并讨论了有关方法中存在的问题和今后研究的方向。 相似文献
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板料多次弯曲成形回弹的数值模拟研究 总被引:2,自引:1,他引:1
对金属板料多次弯曲成形回弹的数值模拟方法进行研究,分析并解决了模拟过程中出现的板料与模具的干涉和各次弯曲间模拟结果的数据传递等问题。通过金属板料的二次卷圆试验并与数值模拟结果比较,模拟结果与试验结果基本相符。采用的有限元数值模拟方法可提高预测板料多次弯曲成形后回弹量的准确度。 相似文献
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变形路径对于板材的成形质量有着重要的影响。多点压机成形和多道次多点模具成形充分利用多点成形的柔性特点,实现了对板材变形路径的控制。文章通过有限元数值模拟研究了这两种成形方式各自的特点和规律,并进行了比较。结果表明,多点压机成形和多道次多点模具成形,都能够优化板材变形路径,使变形均匀,有效地抑制起皱,提高板材变形能力。在同样条件下,多点压机方式好于多道次成形,但当多道次成形道次逐渐增多时,成形质量接近于多点压机成形。多点压机成形是理想化的成形方式,但设备造价昂贵,多道次多点模具成形可以近似实现多点压机成形效果。 相似文献
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Zhengchun Du Shujie Zhang Maisheng Hong 《International Journal of Machine Tools and Manufacture》2010,50(3):270-280
Machining accuracy is directly influenced by the quasi-static errors of a machine tool. Since machine errors have a direct effect on both the surface finish and geometric shape of the finished work piece, it is imperative to measure the machine errors and to compensate for them. A revised geometric synthetic error modeling, measurement and identification method of 3-axis machine tool by using a cross grid encoder is proposed in this paper. Firstly a revised synthetic error model of 21 geometric error components of the 3-axis NC machine tools is developed. Also the mapping relationship between the error component and radial motion error of round work piece manufactured on the NC machine tools are deduced. Aiming to overcome the solution singularity shortcoming of traditional error component identification method, a new multi-step identification method of error component by using the cross grid encoder measurement technology is proposed based on the kinematic error model of NC machine tool. Finally the experimental validation of the above modeling and identification method is carried out in the 3-axis CNC vertical machining center Cincinnati 750 Arrow. The entire 21 error components have been successfully measured by the above method. The whole measuring time of 21 error components is cut down to 1–2 h because of easy installation, adjustment, operation and the characteristics of non-contact measurement. It usually takes days of machine down time and needs an experienced operator when using other measuring methods. Result shows that the modeling and the multi-step identification methods are very suitable for ‘on machine’ measurement. 相似文献
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Baohong Zhu Baiqing Xiong Yong’an Zhang Jianbo Zhang Feng Wang Zhihui Li 《稀有金属(英文版)》2011,30(4):419-423
The effects of interrupted multi-step aging on the microstructure and properties of Al-Cu-Mg-Ag-Zr alloy were studied by tensile,hardness,electrical conductivity tests and transmission electron microscopy(TEM).Interrupted multi-step aging delayed the peak aging time compared to one-step aging and kept the same levels of hardness,electrical conductivity,ultimate tensile strength(UTS),yield strength(YS) and elongation as those of the T6 temper alloy while increased the fracture toughness notably.Ω phase and a little θ’ phase precipitated and grew simultaneously in the process of one-step aging at 160℃.During the second-step aging at 65℃ of interrupted multi-step aging,no TEM characteristic of Ω precipitates could be found.During the third step of interrupted multi-step aging,Ω began to dominate the microstructure like what happened in the process of one-step aging.The difference of properties between the T6 temper and the interrupted multi-step aged alloys might be related to the different precipitation sequences in the process of the two heat treatment technologies. 相似文献
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运用一种基于全量理论的多步有限元方法计算分析了金属体积成形过程.该方法针对刚塑性不可压缩材料,在静力平衡条件下以约束变分原理通过最小化近似塑性势能进行有限元求解.多步模拟在各中间构形的虚拟滑动约束下沿变形路径进行分步迭代计算,考虑了接触和变形历史,能够快速模拟较复杂的体积成形问题.运用该方法对几个典型金属体积成形过程进行了正向一步和多步数值模拟,将计算结果与增量有限元法计算结果进行了比较.结果表明:在计算金属体积成形过程中,基于全量理论的多步有限元模拟能够在大大缩短计算时间的同时获得与增量法计算结果相比偏差小于10%的计算结果. 相似文献
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