曲面凹模拉深工艺的理论与试验研究
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摘要
拉深是筒形件零件生产的核心工艺，工艺生产中必不可少。如何在保证质量的前提下降低极限拉深系数，减少工序，提高效率和降低成本，成为拉深成形工艺的主要研究问题之一。
本文利用塑性理论和数学方法提出了一种新的拉深凹模型腔曲面：在整个拉深过程中，拉深件侧壁上缘和凹模型腔曲面始终相切接触，这样降低凹模圆角半径造成的摩擦阻力和弯曲变形阻力，凹模曲面对毛坯变形区的作用力也有助于使它产生切向压缩变形，从而可以采用相对厚度较小的毛坯而不致起皱，达到减小极限拉深系数，减少工序，降低成本的目的。
通过分析拉深变形过程，在力学分析的基础上，提出了工件起皱失稳的条件，进而确定了曲面凹模拉深的起皱极限表达式。
通过数值模拟，预测起皱、拉裂、回弹，计算毛坯尺寸，计算成形力，估计模具磨损，优化润滑方案等。
通过拉深试验，证明采用这种新的曲面凹模拉深，可以极大的降低极限拉深系数，试验中得到的最小极限拉深系数为0.382。
通过拉深试验，分析了厚向异性系数R和硬化指数n对极限拉深系数的影响规律，分析了平面各向异性系数与凸耳率的关系。
本文对曲面凹模拉深工艺进行了深入的理论和试验研究，其结果丰富和发展了冲压成形基础理论。曲面凹模拉深与普通平端面凹模拉深相比，能够降低极限拉深系数，减少工序，提高效率和降低成本。文中得出的工艺参数对极限拉深系数的影响规律为实际生产中工艺选择及制订提供了可靠的理论依据。
The drawing is the key technology on cup-drawing process, it is essential during blank forming. How to reduce limit drawing coefficient, cut down procedures, raise efficiency and reduce costs become one of the main research problems for drawing process on the premise of ensuring the quality of products.
In this paper a kind of new curved die profile has been created by plastic theory and mathematical method: on the whole drawing process, the top of the side wall keeps in touch tangentially with the curved die throughout, which can reduce the friction resistance that caused by the round corner of the die and bending resistance, the force of the die profile on the blank deformation zone is also beneficial to make it bring on tangential compression deformation, thus it can use the blank which has a smaller relative thickness to draw without wrinkling, and beats target with reducing limit drawing coefficient, reducing procedures and lowering costs.
By analyzing the forming process of the drawing, based on the analysis of mechanics, this paper has put forward the wrinkling criterion of the blank, deduced the wrinkling limit formula of the curved die sequentially.
It can forecast wrinkling, fracture and spring back, compute the dimension of blank, compute the deforming force, estimate the abrasion of die, and optimize the lubrication scheme by numerical simulation.
It has been proved that this kind of new curved die can reach smaller limit drawing coefficient by drawing experiment, the smallest limit drawing coefficient gotten in drawing experiment is 0.382.
By drawing experiment, this paper has investigated the effect laws of anisotropic hardening parameter R and work hardening exponent n on limit drawing coefficient. And also has analyzed the relationship between the anisotropy in the blank plane and the earring ratio.
The deeply theoretical and experimental research on drawing technology of curved die in this paper enriches and develops the fundamental theories of
stamping technology. Compared with general die, to use curved die can reduce limit drawing coefficient, reduce procedures, raise efficiency and reduce costs. The effect laws of process parameters on limit drawing coefficient which has been deduced in this paper provide a reliable theoretical basis for choice and design of the process in practice.
本文利用塑性理论和数学方法提出了一种新的拉深凹模型腔曲面：在整个拉深过程中，拉深件侧壁上缘和凹模型腔曲面始终相切接触，这样降低凹模圆角半径造成的摩擦阻力和弯曲变形阻力，凹模曲面对毛坯变形区的作用力也有助于使它产生切向压缩变形，从而可以采用相对厚度较小的毛坯而不致起皱，达到减小极限拉深系数，减少工序，降低成本的目的。
通过分析拉深变形过程，在力学分析的基础上，提出了工件起皱失稳的条件，进而确定了曲面凹模拉深的起皱极限表达式。
通过数值模拟，预测起皱、拉裂、回弹，计算毛坯尺寸，计算成形力，估计模具磨损，优化润滑方案等。
通过拉深试验，证明采用这种新的曲面凹模拉深，可以极大的降低极限拉深系数，试验中得到的最小极限拉深系数为0.382。
通过拉深试验，分析了厚向异性系数R和硬化指数n对极限拉深系数的影响规律，分析了平面各向异性系数与凸耳率的关系。
本文对曲面凹模拉深工艺进行了深入的理论和试验研究，其结果丰富和发展了冲压成形基础理论。曲面凹模拉深与普通平端面凹模拉深相比，能够降低极限拉深系数，减少工序，提高效率和降低成本。文中得出的工艺参数对极限拉深系数的影响规律为实际生产中工艺选择及制订提供了可靠的理论依据。
The drawing is the key technology on cup-drawing process, it is essential during blank forming. How to reduce limit drawing coefficient, cut down procedures, raise efficiency and reduce costs become one of the main research problems for drawing process on the premise of ensuring the quality of products.
In this paper a kind of new curved die profile has been created by plastic theory and mathematical method: on the whole drawing process, the top of the side wall keeps in touch tangentially with the curved die throughout, which can reduce the friction resistance that caused by the round corner of the die and bending resistance, the force of the die profile on the blank deformation zone is also beneficial to make it bring on tangential compression deformation, thus it can use the blank which has a smaller relative thickness to draw without wrinkling, and beats target with reducing limit drawing coefficient, reducing procedures and lowering costs.
By analyzing the forming process of the drawing, based on the analysis of mechanics, this paper has put forward the wrinkling criterion of the blank, deduced the wrinkling limit formula of the curved die sequentially.
It can forecast wrinkling, fracture and spring back, compute the dimension of blank, compute the deforming force, estimate the abrasion of die, and optimize the lubrication scheme by numerical simulation.
It has been proved that this kind of new curved die can reach smaller limit drawing coefficient by drawing experiment, the smallest limit drawing coefficient gotten in drawing experiment is 0.382.
By drawing experiment, this paper has investigated the effect laws of anisotropic hardening parameter R and work hardening exponent n on limit drawing coefficient. And also has analyzed the relationship between the anisotropy in the blank plane and the earring ratio.
The deeply theoretical and experimental research on drawing technology of curved die in this paper enriches and develops the fundamental theories of
stamping technology. Compared with general die, to use curved die can reduce limit drawing coefficient, reduce procedures, raise efficiency and reduce costs. The effect laws of process parameters on limit drawing coefficient which has been deduced in this paper provide a reliable theoretical basis for choice and design of the process in practice.
引文
[1] 李硕本．冲压工业学．北京：机械工业出版社，1982
[2] 卢险峰．冲压工艺模具学．北京：机械工业出版社，1998：39
[3] 刘湘云，邵全统．冷冲压工艺与模具设计．北京：航空工业出版社，1994：160～161
[4] 吴诗淳，何声健．冲压工艺学．西安：两北工业大学出版社，1987
[5] 陈金杰．锥形拉深凹模没计．锻压技术，1995．20(2)：56～60
[6] 李森泉，南琦．改进锥形凹模，提高拉深件质量．锻压技术，1990．15(5)：63
[7] 胡成武．筒形件拉伸锥形凹模倾角的计算．模具工业，1999(5)：14～16
[8] 王彪．无压边圈的深拉延工艺．锻压机械，1988(1)：54～69
[9] 王孝培．无压边拉深凹模成形曲面优化．锻压技术，1990．15(4)：24～27
[10] Conry T E, Odell E L, Dauis W J, optimization of die profiles for deep-drawing. Journal of mechanical design, 1980(102):452-459
[11] Dejmal I, Tirosh J, Shirizly A et al. On the optimal die curvature in deep drawing processes. International Journal of Mechanical Sciences, 2002.44(6): 1245～1258
[12] Shirizly A, Yossifon S, Tirosh J. The role of die curvature on the performance of deep drawing processes. International Journal of Mechanical Sciences, 1994(36):121～135
[13] YouMin Huang, JiaWine Chen. Influence of the die arc on formability in cylindrical cup-drawing. Journal of Material Processing Technology, 1995(55):360～369
[14] Woo D W. Analysis of deep-drawing over a tractrix die. Journal of Engineering Materials and Technology, 1976(10):337～341
[15] AL-Makky M M, Woo D M. Deep-drawing through tractrix type dies. Int. J. Mech. Sci, 1980(22):467～480
[16] Narayanasamy R, Sowerby R. Wrinkling behaviour of cold-rolled sheet metals when drawing through a tractrix die. Journal of Materials Processing Technology. 1995.49(1-2):199～211
[17] 刘浩．曲面凹模拉深工艺的理论研究及其软件设计：[武汉理工大学硕士学位论文]．武汉：武汉理工大学材料学院，2003
[18] 徐士良．数值分析与算法．北京：机械工业出版社，2003
[19] 徐士良．C常用算法程序集(第二版)．北京：清华大学出版社，1996
[20] 马秋成，聂松辉，张高峰等．UG-CAM篇．北京：机械工业出版社，2002
[21] 胡世光．板料冷压成形原理．北京：国防工业出版社，1979
[22] 梁炳文，胡世光．板料成形塑性理论．北京：机械工业出版社，1987
[23] 梁炳文，胡世光．弹塑性稳定理论．北京：国防工业出版社，1983
[24] 雷君相，李笠．圆筒形件不用压边多次拉深时的皱曲预报．锻压技术，1994(5)：21～23
[25] 雷君相，赵焱，李笠．圆筒形件不用压边拉深时的皱曲预报．中国机械工程，1995．6(3)：62～63
[26] 雷君相，李笠．拉深过程中的皱曲控制．热加工工艺，1996(1)：15～17
[27] 熊志卿，杨征宁．杯拉深法凸缘皱曲预测与控制．机械工程学报，2001．37(7)：82～87
[28] 王沫然．MATLAB 6.0与科学计算．北京：电子工业出版社，2001
[29] Makinouchi A, Kawka M. Process simulation in sheet metal forming. J. Mater. Process. Technol., 1994(46):291～307
[30] Makinouchi A. Sheet metal forming simulation in industry. J. Mater. Process. Technol., 1996(60):19～26
[31] Hongzhi Dong, Prior A M. Applications of implicit and explicit finite element techniques to metal forming. J. Mater. Process. Technol., 1994(45):649～656
[32] Taylor L, Cao J, Karafillis A P et al. Numerical simulations of sheet-metal forming. J. Mater. Process. Technol., 1995(50):168～179
[33] Zhongqin Lin, Investigation of sheet metal forming by numerical simulation and experiment. J. Mater. Process. Technol., 2000(103):404～410
[34] 张晓静，周贤宾，孔永明．板料成形数值模拟研究．锻压技术，2001．26(1)：13～17
[35] 解后循．材料结构参数对薄板冲压成形仿真结果的影响．金属成形工艺，2003．21(2)：16～18
[36] 倪向贵，王宇等．用于板料成形数值模拟的各向异性本构模型研究．中国科学技术大学学报，2000．30(6)700～706
[37] Hosford W E Comments on anisotropic yield criteria. Int. J. Mech. Sci., 1985(27):
423-427
[38] Hosford W E Limitation of non-quadratic anisotropic yield criteria and their use in analysis of sheet forming. ASM international, 1998(8):163-170
[39] Bassani J L. Yield characterization of metals with transversely isotropic plastic properties. Int. J. Mech. Sci., 1997(19):651～656
[40] Hill R. Theoretical plasticity of textured aggregates. Math. Proc. Camb. Phil. Soc., 1979(85):179～191
[41] Logan R W, Hosford W E. Upper-bound anisotropic yield locus calculations assuming <111>-pencil glide. Int. J. Mech. Sci., 1980(22):419～430
[42] Chou C H. Analysis of sheet metal forming operations by a stress resultant constitutive law. Int. J. Numer. Methods. Eng., 1994.37(5):717～735
[43] Barlat F, Lian J. Plastic behavior and stretchability of sheet metals-part l:a yield function for orthotropic sheets under plane stress conditions. Int. J. Plas., 1989.5(1):51～66
[44] 邱晓刚，卢国清，陈文龙等．板材成形有限元仿真技术的应用．钢铁钒钛，2003．24(1)：54～60
[45] 余雷，袁国定．有限元数值模拟在汽车覆盖件设计和制造中的应用．锻压技术，2002．6(2)：23～26
[46] 胡轶敏，秦长灯．车身覆盖件冲压成形动态仿真的研究进展．力学进展，2000．30(2)：252～271
[47] 钟志华，李光耀．薄板冲压成型过程的计算机仿真与应用．北京：北京理工大学出版社，1998
[48] Dynaform-PC Applications Manual. Engineering Technology Associates,Inc., 1999
[49] Dynaform-PCUser's Manual. Engineering Technology Associates,Inc., 1999
[50] eta/PostGL Post Tutorial. Engineering Technology Associates,Inc., 1999
[51] eta/PostGL User's Manual. Engineering Technology Associates,Inc., 1999
[52] LS-DYNATheoretical Manual. Livermore Software Technology Corporation, 1998
[53] LS-DYNA Keyword User's Manual/Nonlinear Dynamic Analysis of Structures. Livermore Software Technology Corporation, 1999
[54] 黎雪芬．基于PFEA法的板料成形工艺参数优化．金属成形工艺，2003．21(5)：67～
68
[55]姜奎华．冲压工艺与模具设计．北京：机械工业出版社，1997：32～34
[2] 卢险峰．冲压工艺模具学．北京：机械工业出版社，1998：39
[3] 刘湘云，邵全统．冷冲压工艺与模具设计．北京：航空工业出版社，1994：160～161
[4] 吴诗淳，何声健．冲压工艺学．西安：两北工业大学出版社，1987
[5] 陈金杰．锥形拉深凹模没计．锻压技术，1995．20(2)：56～60
[6] 李森泉，南琦．改进锥形凹模，提高拉深件质量．锻压技术，1990．15(5)：63
[7] 胡成武．筒形件拉伸锥形凹模倾角的计算．模具工业，1999(5)：14～16
[8] 王彪．无压边圈的深拉延工艺．锻压机械，1988(1)：54～69
[9] 王孝培．无压边拉深凹模成形曲面优化．锻压技术，1990．15(4)：24～27
[10] Conry T E, Odell E L, Dauis W J, optimization of die profiles for deep-drawing. Journal of mechanical design, 1980(102):452-459
[11] Dejmal I, Tirosh J, Shirizly A et al. On the optimal die curvature in deep drawing processes. International Journal of Mechanical Sciences, 2002.44(6): 1245～1258
[12] Shirizly A, Yossifon S, Tirosh J. The role of die curvature on the performance of deep drawing processes. International Journal of Mechanical Sciences, 1994(36):121～135
[13] YouMin Huang, JiaWine Chen. Influence of the die arc on formability in cylindrical cup-drawing. Journal of Material Processing Technology, 1995(55):360～369
[14] Woo D W. Analysis of deep-drawing over a tractrix die. Journal of Engineering Materials and Technology, 1976(10):337～341
[15] AL-Makky M M, Woo D M. Deep-drawing through tractrix type dies. Int. J. Mech. Sci, 1980(22):467～480
[16] Narayanasamy R, Sowerby R. Wrinkling behaviour of cold-rolled sheet metals when drawing through a tractrix die. Journal of Materials Processing Technology. 1995.49(1-2):199～211
[17] 刘浩．曲面凹模拉深工艺的理论研究及其软件设计：[武汉理工大学硕士学位论文]．武汉：武汉理工大学材料学院，2003
[18] 徐士良．数值分析与算法．北京：机械工业出版社，2003
[19] 徐士良．C常用算法程序集(第二版)．北京：清华大学出版社，1996
[20] 马秋成，聂松辉，张高峰等．UG-CAM篇．北京：机械工业出版社，2002
[21] 胡世光．板料冷压成形原理．北京：国防工业出版社，1979
[22] 梁炳文，胡世光．板料成形塑性理论．北京：机械工业出版社，1987
[23] 梁炳文，胡世光．弹塑性稳定理论．北京：国防工业出版社，1983
[24] 雷君相，李笠．圆筒形件不用压边多次拉深时的皱曲预报．锻压技术，1994(5)：21～23
[25] 雷君相，赵焱，李笠．圆筒形件不用压边拉深时的皱曲预报．中国机械工程，1995．6(3)：62～63
[26] 雷君相，李笠．拉深过程中的皱曲控制．热加工工艺，1996(1)：15～17
[27] 熊志卿，杨征宁．杯拉深法凸缘皱曲预测与控制．机械工程学报，2001．37(7)：82～87
[28] 王沫然．MATLAB 6.0与科学计算．北京：电子工业出版社，2001
[29] Makinouchi A, Kawka M. Process simulation in sheet metal forming. J. Mater. Process. Technol., 1994(46):291～307
[30] Makinouchi A. Sheet metal forming simulation in industry. J. Mater. Process. Technol., 1996(60):19～26
[31] Hongzhi Dong, Prior A M. Applications of implicit and explicit finite element techniques to metal forming. J. Mater. Process. Technol., 1994(45):649～656
[32] Taylor L, Cao J, Karafillis A P et al. Numerical simulations of sheet-metal forming. J. Mater. Process. Technol., 1995(50):168～179
[33] Zhongqin Lin, Investigation of sheet metal forming by numerical simulation and experiment. J. Mater. Process. Technol., 2000(103):404～410
[34] 张晓静，周贤宾，孔永明．板料成形数值模拟研究．锻压技术，2001．26(1)：13～17
[35] 解后循．材料结构参数对薄板冲压成形仿真结果的影响．金属成形工艺，2003．21(2)：16～18
[36] 倪向贵，王宇等．用于板料成形数值模拟的各向异性本构模型研究．中国科学技术大学学报，2000．30(6)700～706
[37] Hosford W E Comments on anisotropic yield criteria. Int. J. Mech. Sci., 1985(27):
423-427
[38] Hosford W E Limitation of non-quadratic anisotropic yield criteria and their use in analysis of sheet forming. ASM international, 1998(8):163-170
[39] Bassani J L. Yield characterization of metals with transversely isotropic plastic properties. Int. J. Mech. Sci., 1997(19):651～656
[40] Hill R. Theoretical plasticity of textured aggregates. Math. Proc. Camb. Phil. Soc., 1979(85):179～191
[41] Logan R W, Hosford W E. Upper-bound anisotropic yield locus calculations assuming <111>-pencil glide. Int. J. Mech. Sci., 1980(22):419～430
[42] Chou C H. Analysis of sheet metal forming operations by a stress resultant constitutive law. Int. J. Numer. Methods. Eng., 1994.37(5):717～735
[43] Barlat F, Lian J. Plastic behavior and stretchability of sheet metals-part l:a yield function for orthotropic sheets under plane stress conditions. Int. J. Plas., 1989.5(1):51～66
[44] 邱晓刚，卢国清，陈文龙等．板材成形有限元仿真技术的应用．钢铁钒钛，2003．24(1)：54～60
[45] 余雷，袁国定．有限元数值模拟在汽车覆盖件设计和制造中的应用．锻压技术，2002．6(2)：23～26
[46] 胡轶敏，秦长灯．车身覆盖件冲压成形动态仿真的研究进展．力学进展，2000．30(2)：252～271
[47] 钟志华，李光耀．薄板冲压成型过程的计算机仿真与应用．北京：北京理工大学出版社，1998
[48] Dynaform-PC Applications Manual. Engineering Technology Associates,Inc., 1999
[49] Dynaform-PCUser's Manual. Engineering Technology Associates,Inc., 1999
[50] eta/PostGL Post Tutorial. Engineering Technology Associates,Inc., 1999
[51] eta/PostGL User's Manual. Engineering Technology Associates,Inc., 1999
[52] LS-DYNATheoretical Manual. Livermore Software Technology Corporation, 1998
[53] LS-DYNA Keyword User's Manual/Nonlinear Dynamic Analysis of Structures. Livermore Software Technology Corporation, 1999
[54] 黎雪芬．基于PFEA法的板料成形工艺参数优化．金属成形工艺，2003．21(5)：67～
68
[55]姜奎华．冲压工艺与模具设计．北京：机械工业出版社，1997：32～34