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Multi-Point Forming Technology for Sheet Metal

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厦门大学学报（自然科学版） 2002年第S1期41卷 17-页

作者： li Ming-zhe, cai Zhong-yi, SUI Zhen, YAN Qing-guang (roll forging institute, jilin university of Technology, changchun 130025, china)

Multi-point forming (MPF) is an advanced manufacturing technology for three-dimensional sheet metal parts. In this paper, the MPF integrated system is described that can form a variety of part shapes without the need for solid dies, and given only geometry and material information about the desired part. The central component of this system is a pair of matrices of punches, and the desired discrete die surface is constructed by changing the positions of punches though the CAD and control system. The basic MPF process is introduced and the typical application examples show the applicability of the MPF technology. Wrinkle and dimple are the major forming defects in MPF process, numerical simulation is a feasible way to predict forming defects in MPF. In conventional stamping, the mode to form sheet metal with blankholder is an effective way to suppress wrinkling; the same is true in MPF. A MPF press with flexible blankholder was developed, and the forming results indicated the forming stability of this technique. Based on the flexibility of MPF, varying deformation path MPF and sectional MPF were explored that cannot be realized in conventional stamping. By controlling each punch in real-time, a sheet part can be manufactured along a specific forming path. When the path of deformation in MPF is designed properly, forming defects will be avoided completely and lager deformation is achieved. A work piece can be formed section by section though the sectional MPF, and this technique makes it possible to manufacture large size parts in a small MPF press. Some critical experiments were performed that confirmed the validity of two special MPF techniques.

关键词： sheet metal multi-point forming flexible forming forming path wrinkling forming defects

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图像拼接在板类件三维测量中的应用

塑性工程学报 2003年第5期10卷 30-34页

作者：孙刚付文智李明哲蔡中义吉林大学辊锻工艺研究所长春130025

建立了基于计算机视觉的图像拼接测量系统,采用基于摄像机径向畸变的非线性优化模型,同时确定图像中心点,运用空间点重建的方法,建立起板类件特征的二维平面坐标与空间坐标的联系。采用旋转矩阵和平移矩阵的方法使分块测量数据统一到同... 详细信息

建立了基于计算机视觉的图像拼接测量系统,采用基于摄像机径向畸变的非线性优化模型,同时确定图像中心点,运用空间点重建的方法,建立起板类件特征的二维平面坐标与空间坐标的联系。采用旋转矩阵和平移矩阵的方法使分块测量数据统一到同一个视场下,最后匀化、拼接成为一个整体。最后通过几种不同形状的典型件验证了此种方法的合理性。

关键词：立体视觉图像拼接匹配空间重建仿射变换

轿车内饰件包覆成型过程温度场变化对制件成型质量的影响

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吉林大学学报（工学版） 2024年第7期54卷 1887-1893页

作者：李义白亚赛梁继才姚卫国梁策吉林大学材料科学与工程学院长春130022 吉林大学辊锻工艺研究所长春130022

利用仿真模拟软件,在分析制件表皮施加位移对包覆成型制品质量影响的基础上,考察表皮温度对接触面强度的影响。研究过程中,对模型进行温度-位移耦合,加载方式不变,改变温度和加载位移。研究结果表明,在相同的温度变化差下,不同位移的模... 详细信息

利用仿真模拟软件,在分析制件表皮施加位移对包覆成型制品质量影响的基础上,考察表皮温度对接触面强度的影响。研究过程中,对模型进行温度-位移耦合,加载方式不变,改变温度和加载位移。研究结果表明,在相同的温度变化差下,不同位移的模拟结果特征相似。温度降低会加快胶层的损伤和失效,使失效载荷的值增大;温度升高会促进胶层起始损伤,但延缓胶层失效,使失效载荷的值降低。温度升高和降低均会引起应力变化,且变化的趋势为由内向外逐渐增大,加载过程中剥离力由位移载荷和应力共同提供。

关键词：汽车内饰件内聚区模型(CZM) 温度场

Rheological Study on the Cure Kinetics of Two-component Addition Cured Silicone Rubber

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Chinese Journal of Polymer Science 2016年第10期34卷 1290-1300页

作者： Dong-bo Guan Zhong-yi cai Xin-chun liu Bo Lou Yan-li Dou 许东华姚卫国 Key Laboratory of Automobile Materials Ministry of Education College of Materials Science and Engineering Jilin University Changchun 130025 China jilin university roll forging Technology Research institute Changchun 130025 China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Zhejiang Zhulishen Medical Co. LTD Zhzffi 311814 China

The cure kinetics for two-component silicone rubber formed by addition reaction was studied by the rheological method. The influence of reaction temperature （7） on the cure kinetics was explored in detail. It was observed that the data of gel time （tgel, i.e. the time when the reaction reaches the gel point） or a specific reaction time （tnc）（defined as the reaction time before which time the influence of confinement of network on the diffusion of reaction components can be neglected） versus T obey certain functional relationship, which was well explained by the cure kinetics model of thermoset network. The cure kinetics for the two-component silicone rubber can be well fitted by the Kamal-Sourour（autocatalyst） reaction model rather than Kissinger model. When the reaction time was before or equal to tnc, the reaction order obtained by the Kamal-Sourour reaction model was 2, which was consistent with the reaction order inferred from the two components chemical reaction when the diffusion of reaction components was not influenced by the formed cross-linked polymer network. When the reaction time was larger than tnc, such as to the end of reaction （re）, the influence of confinement of network on the diffusion of reaction components cannot be neglected, and the reaction order obtained by the Kamal-Sourour reaction model was larger than 2. It was concluded that the confinement effect of network had a greater influence on the cure kinetics of the silicone rubber. The reaction rate constants （kτ） under different temperatures were also determined by Kamal-Sourour reaction model. The activation energy （E） for the two-component silicone rubber was also calculated from the results of lntgcl, lnlnc, and lnkτ versus 1/T, respectively. The three values of E were close, which indicated that above analyses were self-consistent.

关键词： Silicone Rubber Cure kinetics Rheology Gel point Reaction model.

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曲面辊弯成形的实验研究

锻压技术 2021年第6期46卷 99-105页

作者：兰英武胡松景李鹏蔡中义河南德力新能源汽车有限公司河南安阳455000 吉林大学辊锻工艺研究所吉林长春130022

为了满足高效地制造单件或小批量的个性化、多样化、大型化的三维曲面钣金零件的市场需求,开发了一种新的柔性成形技术——曲面辊弯成形技术。该工艺采用一个上柔性辊和两个下柔性辊作为成形工具,并可以在垂直方向上调整柔性辊的轴线形... 详细信息

为了满足高效地制造单件或小批量的个性化、多样化、大型化的三维曲面钣金零件的市场需求,开发了一种新的柔性成形技术——曲面辊弯成形技术。该工艺采用一个上柔性辊和两个下柔性辊作为成形工具,并可以在垂直方向上调整柔性辊的轴线形状,通过柔性辊的旋转,钣金同时在纵向和横向上发生弯曲,可以实现连续成形。阐述了曲面辊弯成形的原理及其实验装置,进行了典型的双曲面零件——鞍面件和凸面件的成形实验,并利用双目立体视觉测量系统对实验结果进行了测量,分析了成形曲面件的成形精度、光滑度及厚度的变化规律。结果表明:成形曲面件具有良好的精度,成形曲面与所要求的曲面形状吻合良好,为曲面辊弯成形工艺的开发设计提供了一定的参考。

关键词：辊弯成形曲面测量成形精度表面光滑度厚度

Theory and Method of Optimum Path Forming for Sheet Metal

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Chinese Journal of Aeronautics 2001年第2期14卷 118-122页

作者：蔡中义李明哲冯肇华 roll forging Research institute Jilin University Changchun 130025 China

Ideal forming results will be achieved if the sheet metal is formed along an optimum forming path. Such a path can be realized by multi-point forming technique. On the basis of the theory of the ideal forming path (or minimum plastic work path), the concept of an optimum forming path is proposed in this paper. The forming path can be described by the initial configuration, objective configuration and a series of intermediate configurations. According to the deformation theory and constitutive equation in ideal path forming, a finite element method to calculate the initial configuration is set up. The functional to determinate intermediate configurations is introduced and the numerical method to solve the configuration is presented. Based on the method presented in the paper, multi-step multi-point forming tests for sheet metal are designed. The test results demonstrate that when the sheet is deformed along an approximate optimum forming path, the maximum deformation curvature for the sphere objective shape and saddle objective shape are 11%∼40% and 15%∼50% greater than those of a sheet deformed along a common path respectively.

关键词： Finite element method Metal forming Numerical methods Plastic deformation

基于韧性断裂准则的铝合金壁板多点成形断裂预测

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吉林大学学报（工学版） 2019年第2期49卷 513-520页

作者：刘纯国崔琪岳韬李东来吉林大学辊锻工艺研究所长春130022

基于韧性断裂准则,预测了单筋条试件和多筋条试件多点压弯成形中的断裂位置和启裂时刻,并进行了多点压弯实验。对比分析结果显示:预测的试件断裂位置与实验基本一致,启裂时刻对应的上模临界下压量与实验相比,误差在10%以内。分析了不同... 详细信息

基于韧性断裂准则,预测了单筋条试件和多筋条试件多点压弯成形中的断裂位置和启裂时刻,并进行了多点压弯实验。对比分析结果显示:预测的试件断裂位置与实验基本一致,启裂时刻对应的上模临界下压量与实验相比,误差在10%以内。分析了不同筋条试件多点成形中断裂产生的原因,针对腹板在变形量过大时易出现断裂、难成形的问题,提出了整体壁板试件多道次成形方法。仿真结果显示,多道次多点成形能抑制壁板断裂。

关键词：材料合成与加工工艺铝合金整体壁板多点成形韧性断裂

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矩形截面型材三维多点拉弯成形减薄率

吉林大学学报（工学版） 2021年第1期51卷 163-171页

作者：梁继才廖雁飞滕菲梁策李义吉林大学材料科学与工程学院长春130022 吉林大学辊锻工艺研究所长春130022 长春大学机械与车辆工程学院长春130012 吉林大学汽车材料教育部重点实验室长春130022

针对铝型材在加工过程中易出现的减薄缺陷,在自主研制的铝型材柔性三维拉弯装置上,进行多点柔性成形制件的减薄率研究。矩形截面型材三维多点拉弯变形后,外腹板与内腹板沿着型材长度方向减薄率的变化结果表明:成形过程中型材的外腹板与... 详细信息

针对铝型材在加工过程中易出现的减薄缺陷,在自主研制的铝型材柔性三维拉弯装置上,进行多点柔性成形制件的减薄率研究。矩形截面型材三维多点拉弯变形后,外腹板与内腹板沿着型材长度方向减薄率的变化结果表明:成形过程中型材的外腹板与内腹板减薄率会从型材的对称中心沿着型材方向逐渐变大,外腹板的减薄率比内腹板的减薄率大;模具头体个数的变化使得外腹板的减薄率最大为1.682%,最小为1.317%,减薄率变化幅度为0.365%;内腹板减薄率最大为1.657%,最小为1.198%,变化幅度为0.459%,单元体个数是引起制件减薄率变化的主要加工参数。

关键词：材料成形与加工多点成形三维拉弯铝合金型材减薄率

工艺参数对汽车防护梁绕弯成形的截面变形影响

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吉林大学学报（工学版） 2021年第4期51卷 1182-1189页

作者：金文明梁田梁策李义李俊涛梁继才吉林大学材料科学与工程学院长春130022 吉林大学辊锻工艺研究所长春130022 长春富维安道拓汽车饰件系统有限公司长春130033

针对“日”字截面型材在绕弯成汽车防护梁过程中产生的截面变形缺陷,基于自主研发的绕弯装置,利用有限元分析软件ABAQUS和正交试验模拟方法,探究了工艺参数中绕弯半径,芯棒的芯头数及芯模间隙对截面变形的综合影响规律。结果表明:最大... 详细信息

针对“日”字截面型材在绕弯成汽车防护梁过程中产生的截面变形缺陷,基于自主研发的绕弯装置,利用有限元分析软件ABAQUS和正交试验模拟方法,探究了工艺参数中绕弯半径,芯棒的芯头数及芯模间隙对截面变形的综合影响规律。结果表明:最大变形截面位置受芯头个数的影响;截面的各变形量都随绕弯半径和芯头个数的增加而减小,随芯模间隙先减小后增大;工艺参数组合为绕弯半径600 mm,芯头数为2,间隙为0.75 mm的防护梁成形方案减轻截面变形效果较好,并且通过试验验证了模拟结果的有效性。

关键词：材料成形与加工绕弯成形 “日”字截面型材截面变形缺陷正交试验