盒形件液压成形有限元分析及实验装置设计
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摘要
充液拉深是特种拉深成形中的一种,相对于传统机械拉深工艺来说,可以获得更大的拉深比。在充液拉深过程中,板料在液压介质的压力作用下,紧紧地贴合于凸模,依据库仑摩擦定律可知,板料与凸模贴合面之间的摩擦力将增大,其结果是获得更高的拉深深度;同时,凹模的简化也是该方法经济性的一个重要表现。
充液拉深的基本过程如下(坯料为预先下好的板料): 1、将液压油泵入凹模型腔;2、将板料放置在凹模上;3、压边圈下行,将坯料压紧;4、凸模下行,对坯料施加载荷的同时对凹模型腔内的液体形成挤压作用,在密封型腔内压力达到溢流压力时,排出液压油,直到成形结束。
本论文介绍了采用Dynaform5.1 对矩形盒形件充液拉深成形进行模拟的过程。重点对型腔内的充液压力的变化路径和压边力的加载方式这两个因素进行了研究。
通过研究发现:型腔内液体压力的合理加载是该工艺的一个重要因素;充液压力的加载路径与凸模行程密切相关,合理地控制充液压力的加载是充液拉深成形获得最佳效果的关键。
压边力是另一重要因素,在充液拉深工艺中,压边圈不仅被用来防止起皱和拉裂,而且用来密封凹模型腔内的液压油,另外,由于盒形件各部分的成形机理不同,分块控制各部分的压边力是本论文研究的另一个方面。
另外,在吸收前人在液压成形方面的知识和借鉴国外先进结构的基础上,分析了充液拉深过程中,盒形件各部分所处的应力-应变状态;设计和制造了充液拉深的成形装置;引入监测系统,实现了对成形过程的实时监控。
由于影响盒形件成形的因素较多,定量地研究这些因素对成形结果的影响是全面分析该工艺的关键。模具各个部分结构参数的变化对成形有显著的影响,所以在设计成形装置时,重点考虑了结构的稳定性和部分结构的快换性。
本论文的研究对于后续的多参数试验设计和全面分析充液拉深过程奠定了基础。
Hydromechanical deep drawing is one of the special deep drawing processes which have been introduced to achieve higher tearing factors compared with those of the conventional deep drawing which used rigid tools. In the hydromechanical deep drawing, the sheet metal is pressed against the punch by the hydrostatic medium. According to the Coulomb’s law of friction, the friction between the sheet metal and punch is increased by this. This makes greater depth possible. The elimination of the female die make the draw die set cost less than a conventional drawing die set does.
The paper covers the finite element simulation (FEM) of the complete hydromechanical process for rectangular pieces with symmetrical geometry, performing process using the Dynaform-pc 5.1 of the explicit code LS-DYNA. The study focuses on two factors which are the path of hydraulic load and the path of binder force load.
The rectangular pieces hydromechanical process starts with the precut sheet. First, the oil is pumped into the die; Then, the sheet is placed on the die; After that, the blank holder press down on the sheet; Finally, the punch is loaded on the sheet and the counter pressure is generated by penetration of the punch till the forming process finished.
The study shows that a rational path of pressure load is a pivotal factor which can improve the forming condition in the process. The pressure load path and the motion path of punch are closely related. In order to get the best forming quality, the pressure load path must be controlled rationally.
The blank holder is another vital factor. Not only the blank holder is used to prevent the wrinkling and cracking of the pieces, but also to seal the oil in the die so that higher pressure can be present. In the process of the rectangular box forming, the forming in different parts of the box is in different states of stress and strain. So the control of binder force according to different states is another key point in this study.
On the basis of adoption of the knowledge of the hydroforming process and new devices invented recently abroad, the forming states of stress and strain in different parts of the box are analyzed in this study, and the forming device for the experiment is designed and manufactured, and the detector device is used to monitor the forming process.
Also, there are many parameters that affect the process. In order to study the whole
fact in this process, it is necessary to analyze every factor quantificationally. The tool parameters influence the forming process. So the economically changeable tool is considered in the design process. The study lays an important foundation for the succeeding multi-parameter experiment design and the study of the hydroforming process.
充液拉深的基本过程如下(坯料为预先下好的板料): 1、将液压油泵入凹模型腔;2、将板料放置在凹模上;3、压边圈下行,将坯料压紧;4、凸模下行,对坯料施加载荷的同时对凹模型腔内的液体形成挤压作用,在密封型腔内压力达到溢流压力时,排出液压油,直到成形结束。
本论文介绍了采用Dynaform5.1 对矩形盒形件充液拉深成形进行模拟的过程。重点对型腔内的充液压力的变化路径和压边力的加载方式这两个因素进行了研究。
通过研究发现:型腔内液体压力的合理加载是该工艺的一个重要因素;充液压力的加载路径与凸模行程密切相关,合理地控制充液压力的加载是充液拉深成形获得最佳效果的关键。
压边力是另一重要因素,在充液拉深工艺中,压边圈不仅被用来防止起皱和拉裂,而且用来密封凹模型腔内的液压油,另外,由于盒形件各部分的成形机理不同,分块控制各部分的压边力是本论文研究的另一个方面。
另外,在吸收前人在液压成形方面的知识和借鉴国外先进结构的基础上,分析了充液拉深过程中,盒形件各部分所处的应力-应变状态;设计和制造了充液拉深的成形装置;引入监测系统,实现了对成形过程的实时监控。
由于影响盒形件成形的因素较多,定量地研究这些因素对成形结果的影响是全面分析该工艺的关键。模具各个部分结构参数的变化对成形有显著的影响,所以在设计成形装置时,重点考虑了结构的稳定性和部分结构的快换性。
本论文的研究对于后续的多参数试验设计和全面分析充液拉深过程奠定了基础。
Hydromechanical deep drawing is one of the special deep drawing processes which have been introduced to achieve higher tearing factors compared with those of the conventional deep drawing which used rigid tools. In the hydromechanical deep drawing, the sheet metal is pressed against the punch by the hydrostatic medium. According to the Coulomb’s law of friction, the friction between the sheet metal and punch is increased by this. This makes greater depth possible. The elimination of the female die make the draw die set cost less than a conventional drawing die set does.
The paper covers the finite element simulation (FEM) of the complete hydromechanical process for rectangular pieces with symmetrical geometry, performing process using the Dynaform-pc 5.1 of the explicit code LS-DYNA. The study focuses on two factors which are the path of hydraulic load and the path of binder force load.
The rectangular pieces hydromechanical process starts with the precut sheet. First, the oil is pumped into the die; Then, the sheet is placed on the die; After that, the blank holder press down on the sheet; Finally, the punch is loaded on the sheet and the counter pressure is generated by penetration of the punch till the forming process finished.
The study shows that a rational path of pressure load is a pivotal factor which can improve the forming condition in the process. The pressure load path and the motion path of punch are closely related. In order to get the best forming quality, the pressure load path must be controlled rationally.
The blank holder is another vital factor. Not only the blank holder is used to prevent the wrinkling and cracking of the pieces, but also to seal the oil in the die so that higher pressure can be present. In the process of the rectangular box forming, the forming in different parts of the box is in different states of stress and strain. So the control of binder force according to different states is another key point in this study.
On the basis of adoption of the knowledge of the hydroforming process and new devices invented recently abroad, the forming states of stress and strain in different parts of the box are analyzed in this study, and the forming device for the experiment is designed and manufactured, and the detector device is used to monitor the forming process.
Also, there are many parameters that affect the process. In order to study the whole
fact in this process, it is necessary to analyze every factor quantificationally. The tool parameters influence the forming process. So the economically changeable tool is considered in the design process. The study lays an important foundation for the succeeding multi-parameter experiment design and the study of the hydroforming process.
引文
[1] Holzgarten. “Recent developments in hydroforming technology”. Journal of Materials Processing Technology 98 (2000) 251-258.
[2] Dr.-Ing.B.Engel. (Schuler Hydroforming GmbH & Co. KG, Wilnsdorf) Process Orientated Control of Hydroforming Production Lines. Papers of the “International Conference on Hydroforming”. Volume.1.1999.10. P191-200.
[3] S.H.Zhang. “Recent developments in sheet hydroforming technology”. Journal of Materials Processing Technology 151 (2004) 237-241.
[4] Shi-Hong Zhang. “Technology of sheet hydroforming with a movable femal die”. International Journal of Machine Tools& Manufacture 43 (2002) 781-785.
[5] P.Hein. “Hydroforming of sheet metal pairs”. Journal of Materials Processing Technology 87 (1999) 154-164
[6] Lihui Lang. “Investigation into the effect of pre-bulging during hydromechanical deep drawing with uniform pressure onto the blank”. International Journal of Machine Tools & Manufacture 44 (2001) 649-657.
[7] 苑世剑,郞利辉,王仲仁.高内压成形技术研究与应用进展.哈尔滨工业大学学报. 2000.10. vol.32(5):60-63
[8] T.J.Kim. “Numerical modeling of the multi-stage sheet pair hydroforming process”. Journal of Materials Processing Technology 151 (2004) 48-53.
[9] Amit Jaisingh. “Sensitivity analysis of a deep drawing process for miniaturized products”. Journal of Material Processing Technology 147 (2004) 321-327.
[10] J.C.Gelin, C.Labergere. Application of optimal design and control strategies to the forming of thin walled metallic components. Journal of Materials Processing Technology. 2002. Volume.125-126. P565-572
[11] Anwar Kandil. “An experimental study of hydroforming deep drawing”. Journal of Materials Processing Technology 134 (2003) 70-80.
[12] L.H.Lang. “Hydroforming highlights: sheet hydroforming and tube hydroforming”. Journal of Materials Processing Technology 151 (2004) 165-177.
[13] 朗利辉. “板液压成形及无模充液拉深技术”. 塑性工程学报第9 卷第4 期.
[14] 彭颖红. 金属塑性成形仿真技术. 上海交通大学出版社. 1999
[15] 孙成智. “变压边力对矩形件成形性能的影响”. 塑性工程学报第10 卷第4 期.
[16] 谭晶,赵振铎,孙胜. 液压成形技术的最新进展. 锻压机械.2001.2.P11-15
[17] 王孝培. 冲压手册(第二版). 机械工业出版社. 1988
[18] 王永志. “方盒形件拉深法兰区不均匀流动的模拟分析”. 材料科学与工艺第12 卷第1期.
[19] 郑晓丹. “方盒形件拉深摩擦状况的分析与控制”. 锻压技术2001 年第2 期.
[20] 鄂大辛. “矩形盒形件拉深成形中的几何形状效应”. 锻压技术2004 年第3 期.
[21] 李天佑. “筒形件液压拉深的数值模拟分析”. 锻压技术1995 年第1 期.
[22] 李天佑. “液压拉深中液体压力控制的研究”. 塑性工程学报第4 卷第4 期.
[23] S. Y. Chung H. W. Swift Cup Forming from a Flat Blank-Experimental Investigations 1951
[24] M.Schroeder, DaimlerChrysler AG, Hamburg. Hydroforming of BIW Structural Parts and Exhaust Components. Volume.1.1999.10.P335-352
[25] 张润楚. 试验设计与分析及参数优化. 中国统计出版社.
[26] Li-Ping lei, Dae-Hwan Kim, Sung-Jong Kang, Sang-Moon Hwang, Beom-Soo Kang. Bursting failure prediction in tube hydroforming processes by using rigid-plastic FEM combined with ductile fracture criterion. International Journal of Mechanical Sciences. 2002. Volume.44. P1411-1428.
[27] A.Birkert, J.Neubert,Krupp Drauz GmbH, Heibronn. Tool and Part Design for Tube Hydroforming. Volume.1.1999.10.P47-60
[28] W.Rimkus, H.Bauer, M.J.A.Mihsein. Design of load curves for hydroforming applications. Journal of Materials Processing Technology. 2000. Volume.108. P97-105.
[29] Jeong Kim, Li-Ping lei, Sang-Moon Hwang, Sung-Jong Kang, Beom-Soo Kang. Manufacture of an automobile lower arm by hydroforming. International Journal of Machine Tools & Manufacture. 2002. Volume.42. P69-78.
[30] Li-Ping lei, Dae-Hwan Kim, Sung-Jong Kang, Sang-Moon Hwang, Beom-Soo Kang. Analysis and design of hydroforming processes by the rigid-plastic finite element method. Journal of Materials Processing Technology. 2001. Volume.114. P201-206.
[31] S.Padmanabhan, CATIA Beratung und Schulung, Herrenberg. Design of Die Parting surfaces. Volume.1.1999.10.P61-76
[32] B.S.Levy, ISPAT Inland Inc., Chicago, USA. Recommendations on the use of Forming Limit Curves for Hydroforming Steel. Volume.1.1999.10.P77-96
[33] Ch.Hartl, Siempelkamp Pressen Systeme GnbH & Co., Krefeld. Theoretical fundaments of Hydroforming. Volume.1.1999.10.P23-36
[34] 雷天觉. 液压工程手册(第一版). 机械工业出版社. 1999
[35] 黄迷梅. 液压气动密封与泄漏防治(第一版). 机械工业出版社. 2003
[36] 王宝和. 流体传动与控制(第一版). 国防科技大学出版社. 2001
[2] Dr.-Ing.B.Engel. (Schuler Hydroforming GmbH & Co. KG, Wilnsdorf) Process Orientated Control of Hydroforming Production Lines. Papers of the “International Conference on Hydroforming”. Volume.1.1999.10. P191-200.
[3] S.H.Zhang. “Recent developments in sheet hydroforming technology”. Journal of Materials Processing Technology 151 (2004) 237-241.
[4] Shi-Hong Zhang. “Technology of sheet hydroforming with a movable femal die”. International Journal of Machine Tools& Manufacture 43 (2002) 781-785.
[5] P.Hein. “Hydroforming of sheet metal pairs”. Journal of Materials Processing Technology 87 (1999) 154-164
[6] Lihui Lang. “Investigation into the effect of pre-bulging during hydromechanical deep drawing with uniform pressure onto the blank”. International Journal of Machine Tools & Manufacture 44 (2001) 649-657.
[7] 苑世剑,郞利辉,王仲仁.高内压成形技术研究与应用进展.哈尔滨工业大学学报. 2000.10. vol.32(5):60-63
[8] T.J.Kim. “Numerical modeling of the multi-stage sheet pair hydroforming process”. Journal of Materials Processing Technology 151 (2004) 48-53.
[9] Amit Jaisingh. “Sensitivity analysis of a deep drawing process for miniaturized products”. Journal of Material Processing Technology 147 (2004) 321-327.
[10] J.C.Gelin, C.Labergere. Application of optimal design and control strategies to the forming of thin walled metallic components. Journal of Materials Processing Technology. 2002. Volume.125-126. P565-572
[11] Anwar Kandil. “An experimental study of hydroforming deep drawing”. Journal of Materials Processing Technology 134 (2003) 70-80.
[12] L.H.Lang. “Hydroforming highlights: sheet hydroforming and tube hydroforming”. Journal of Materials Processing Technology 151 (2004) 165-177.
[13] 朗利辉. “板液压成形及无模充液拉深技术”. 塑性工程学报第9 卷第4 期.
[14] 彭颖红. 金属塑性成形仿真技术. 上海交通大学出版社. 1999
[15] 孙成智. “变压边力对矩形件成形性能的影响”. 塑性工程学报第10 卷第4 期.
[16] 谭晶,赵振铎,孙胜. 液压成形技术的最新进展. 锻压机械.2001.2.P11-15
[17] 王孝培. 冲压手册(第二版). 机械工业出版社. 1988
[18] 王永志. “方盒形件拉深法兰区不均匀流动的模拟分析”. 材料科学与工艺第12 卷第1期.
[19] 郑晓丹. “方盒形件拉深摩擦状况的分析与控制”. 锻压技术2001 年第2 期.
[20] 鄂大辛. “矩形盒形件拉深成形中的几何形状效应”. 锻压技术2004 年第3 期.
[21] 李天佑. “筒形件液压拉深的数值模拟分析”. 锻压技术1995 年第1 期.
[22] 李天佑. “液压拉深中液体压力控制的研究”. 塑性工程学报第4 卷第4 期.
[23] S. Y. Chung H. W. Swift Cup Forming from a Flat Blank-Experimental Investigations 1951
[24] M.Schroeder, DaimlerChrysler AG, Hamburg. Hydroforming of BIW Structural Parts and Exhaust Components. Volume.1.1999.10.P335-352
[25] 张润楚. 试验设计与分析及参数优化. 中国统计出版社.
[26] Li-Ping lei, Dae-Hwan Kim, Sung-Jong Kang, Sang-Moon Hwang, Beom-Soo Kang. Bursting failure prediction in tube hydroforming processes by using rigid-plastic FEM combined with ductile fracture criterion. International Journal of Mechanical Sciences. 2002. Volume.44. P1411-1428.
[27] A.Birkert, J.Neubert,Krupp Drauz GmbH, Heibronn. Tool and Part Design for Tube Hydroforming. Volume.1.1999.10.P47-60
[28] W.Rimkus, H.Bauer, M.J.A.Mihsein. Design of load curves for hydroforming applications. Journal of Materials Processing Technology. 2000. Volume.108. P97-105.
[29] Jeong Kim, Li-Ping lei, Sang-Moon Hwang, Sung-Jong Kang, Beom-Soo Kang. Manufacture of an automobile lower arm by hydroforming. International Journal of Machine Tools & Manufacture. 2002. Volume.42. P69-78.
[30] Li-Ping lei, Dae-Hwan Kim, Sung-Jong Kang, Sang-Moon Hwang, Beom-Soo Kang. Analysis and design of hydroforming processes by the rigid-plastic finite element method. Journal of Materials Processing Technology. 2001. Volume.114. P201-206.
[31] S.Padmanabhan, CATIA Beratung und Schulung, Herrenberg. Design of Die Parting surfaces. Volume.1.1999.10.P61-76
[32] B.S.Levy, ISPAT Inland Inc., Chicago, USA. Recommendations on the use of Forming Limit Curves for Hydroforming Steel. Volume.1.1999.10.P77-96
[33] Ch.Hartl, Siempelkamp Pressen Systeme GnbH & Co., Krefeld. Theoretical fundaments of Hydroforming. Volume.1.1999.10.P23-36
[34] 雷天觉. 液压工程手册(第一版). 机械工业出版社. 1999
[35] 黄迷梅. 液压气动密封与泄漏防治(第一版). 机械工业出版社. 2003
[36] 王宝和. 流体传动与控制(第一版). 国防科技大学出版社. 2001