共查询到20条相似文献,搜索用时 93 毫秒
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对大底圆角筒形件失稳起皱机理进行了分析。提出了由于大底圆角而形成的多元复合体及常规压边设计失稳的趋向性。提出了抗失稳起皱拉伸压边新工艺以及设计原则和参数取值。论述了设计技术及应用效果。 相似文献
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介绍了工件在拉深过程中 ,由于坯料在外力的压应力作用下所产生失稳而引发起皱的原因 ,并就防止起皱提出了增加压边力、拉应力等相应措施 相似文献
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汽车门框空腹铝型材弯曲工艺 总被引:1,自引:0,他引:1
空腹铝型材弯曲易产生断面畸变、起皱、表面压伤等缺陷.探讨了产生缺陷的原因,克服缺陷的措施,成功地设计了汽车门框铝型材弯曲模具.对该类型材弯曲工艺开发具有指导意义. 相似文献
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《Journal of Manufacturing Processes》2014,16(2):284-295
Cylindrical as well as conical cross-section structural parts are widely used in industrial applications worldwide. Such parts are produced from metal plates using many manufacturing methods. 3-roller conical bending process is one such process. In this process first the metal plates in specified blank shapes are given static bending in the rollers. Then the rollers are driven using motors for bending of the blanks under dynamic condition. During bending reaction forces will be there on the rollers. Forces acting on the rollers during the process are transmitted to the machine frame at the roller supports. In the paper an analytical model is developed for the prediction of force during the stage of dynamic bending. The model consists of various parameters like material parameters and geometrical parameters. Experimentation is carried out and the developed model is validated with the experimental results. Effects of various material and geometrical parameters are studied in the present paper. The present work can give insight in the process and can be helpful to the designers as well as to the researchers working in the area of metal forming. 相似文献
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端头多半圆弯曲件比较常见,但质量难以保证。此文通过对成形弯曲工艺的分析,提出了改进措施,并介绍了两种典型模具结构,及其零部件的设计。 相似文献
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目的 改善块体非晶合金的弯曲力学性能,同时考虑航空结构材料选材的经济性,研究激光表面处理工艺对工业级Zr49.7Ti2Cu37.8Al10Er0.5块体非晶合金弯曲变形和缺口韧性的影响规律。方法 采用低纯原料和低真空制备条件获得工业级Zr49.7Ti2Cu37.8Al10Er0.5块体非晶合金试样,考虑到弯曲条件下试样受到拉伸和压缩2种正应力状态,研究不同处理工艺和激光处理表面对试样弯曲变形和缺口韧性的影响。结果 当激光处理表面位于弯曲试样的2个侧表面时,其对试样的塑性变形能力和断裂强度没有明显的影响,但会显著降低试样的缺口韧性,从(56.4±3.4)MPa·m1/2降低到(26.2±4.8)MPa·m1/2;激光处理表面位于弯曲试样的受拉侧时,试样的弯曲断裂强度从2 150 MPa降低到1 800 MPa;当激光处理表面位于... 相似文献
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《Journal of Manufacturing Processes》2008,10(1):21-27
Press brake bending is a commonly used process for sheet metal part fabrication. It has been observed that the final bend angle, which is the angle achieved upon removal of the punch, is smaller than the initial bend angle. This springback is due to the elastic recovery of the sheet metal. Various theoretical models have been proposed to predict the springback using the tooling geometry and the known properties of the sheet metal. However, in a production environment, the actual properties of any given workpiece may vary from the nominal properties of the lot. This variation causes the actual springback to deviate from the theoretical predictions. This paper presents a practical incremental bending methodology to control punch displacement to achieve more accurate final bend angles. In the proposed approach, workpiece properties are estimated from measured loaded and unloaded bend angles. The estimated properties are used to determine the final punch position required to obtain the desired bend angle after springback. A series of bending experiments was performed. It was found that the proposed method can better predict springback and effectively control the bend angle variation in a production environment. 相似文献
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介绍了板材成形数值模拟技术的研究和应用在国内外发展的概况 ,并从基本算法、单元模型和网格划分、材料模型、接触摩擦、起皱问题、破裂问题和回弹计算等方面介绍了弹塑性有限元的基本原理、关键技术和主要难点 ,结合在工厂实际生产中的使用情况和存在的问题 ,展望了板材数值模拟技术今后的发展方向 相似文献
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弯曲线不重合且其精度要求较高的V形件的弯曲,是一较为棘手的问题。本文介绍了一种利用顶板侧壁的斜面,迫使下模框内摆块转动,从而克服工件回弹,并确保弯曲精度的V形弯曲模的设计。 相似文献
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实际工作中 ,常常会发现有的弯曲件经模具弯曲后的实际尺寸与预先计算的展开料尺寸有较大偏差。针对这一问题 ,从中性层弯曲半径的计算公式及中性层的位移、几种弯曲工艺方案的比较和不同弯曲模具结构的选择等方面 ,分析了造成这种偏差、影响弯曲件展开料尺寸计算准确性的几个因素 相似文献
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载重汽车车轮轮网滚弯变形分析 总被引:1,自引:0,他引:1
载重汽车车轮轮网的冷弯是异型截面板的弯曲和扭转过程 ,具有物理和几何非线性特性。采用一种半数值半解析的方法来分析其冷弯过程 ,说明了其主要缺陷产生的形式和原因 相似文献