The bar shearing process is the first step of multi-station cold forming machine,and section quality of the billet has a great influence on the next forming steps. The bar shearing process without radial clamping was studied, and the shearing process was divided into four stages including original stage, bar inclining, elastic-plastic deformation and crack initiation-propagation. Then, the characteristic of every stage was analyzed. Furthermore, for the material 20Cr, the shearing experiments were carried out under the different shearing speed 200, 400, 600 and 800 mm·s-1 respectively, and the characteristics of both billet section and bar section were qualitatively analyzed. It is found that the burnished surface ratio of billet end and section roughness of bar end decrease obviously with the increase of the shearing speed. After comparing the ovality and section angle of billet section and bar section, it is found that the ovality decreases with the increase of shearing speeding, while the section angle is constant.
|
[1]赵仁峰,赵升吨,钟斌,等. 低周疲劳精密下料新工艺及试验研究[J]. 机械工程学报, 2012, 48(24):38-43.Zhao R F, Zhao S D, Zhong B, et al. Experimental study on new low cycle fatigue precision cropping process[J].Journal of Mechanical Engineering, 2012, 48(24):38-43. [2]成宗胜. 棒料高速剪切机设计及其关键技术研究[D]. 锦州:辽宁工业大学,2012.Cheng Z S. The Design of High-speed Bar Shear Machine and Research on Key Technology of It [D]. Jinzhou: Liaoning University of Technology, 2012. [3]刘忠德,孔洋,石成伟,等. 2024铝棒复合加压精密剪切工艺的有限元模拟及试验研究[J].热加工工艺,2012,41(15): 118-120.Liu Z D, Kong Y, Shi C W, et al. Finite element simulation and experimental study on precision shearing of 2024 Al bar under composite pressing[J]. Hot Working Technology, 2012, 41(15): 118-120. [4]金茵,姚荣庆. 精密棒料剪切设备设计[J].机床与液压,2015,43(22): 44-46.Jin Y, Yao R Q. Design of precision hydraulic bar shearing machine [J]. Machine Tool & Hydraulic, 2015, 43(22): 44-46. [5]郑晓华, 徐志杰, 付宇, 等. 管件精密剪切研究[J]. 机械工程与自动化, 2014,(5): 104-105.Zheng X H, Xu Z J, Fu Y, et al. Tube precision shearing research [J]. Mechanical Engineering & Automation, 2014,(5): 104-105. [6]许春龙,李耀辉,刘旭. 基于夹紧状态的棒料高速精密剪切机理及试验研究[J]. 热加工工艺,2009,38(11): 30-33.Xu C L, Li Y H, Liu X. Mechanism and experimental research on high-speed precision shearing of metal bar under clamping state[J]. Hot Working Technology, 2009,38(11): 30-33. [7]高丽娟. 金属棒料高速精密剪切的实验研究[D]. 太原:太原科技大学,2008.Gao L J. Experimental Research on the High-speed Precision Bar Cutting [D]. Taiyuan: Taiyuan University of Science and Technology, 2008. [8]赵仁峰, 赵升吨, 景飞,等. 厚壁管精密下料新工艺的实验研究[J]. 锻压技术, 2014, 39(8):105-108.Zhao R F, Zhao S D, Jing F, et al. Experimental study of new precision blanking technology for thick-wall tubes[J]. Forging & Stamping Technology, 2014, 39(8):105-108. [9]Breitling J, Chernauskas V, Taupin E, et al. Precision shearing of billets-special equipment and process simulation[J]. Journal of Materials Processing Technology,1997,71(1): 119-125. [10]韦尧兵,靳伍银. 应力法剪切的实验分析[J]. 甘肃工业大学学报,1996,22(3): 21-27.Wei Y B, Jin W Y. Experimental study on stress shearing[J]. Journal of Gansu University of Technology, 1996, 22(3): 21-27. [11]Chen J D, Wang Y W, Yu D H, et al. Brittle precision cropping of metal materials[J]. International Journal of Machine Tools and Manufacture, 1992, 32(3): 415-424. [12]杨扬,程信林. 绝热剪切的研究现状及发展趋势[J]. 中国有色金属学报,2002,12(3): 401-408.Yang Y, Chen X L. Research status and development trend of adiabatic shear[J]. The Chinese Journal of Nonferrous Metals, 2002, 12(3): 401-408. [13]Chen J D, Wang Y W, Yu D H, et al. Plastic precision cropping of metal materials[J]. International Journal of achine Tools and Manufacture, 1992, 32(3): 425-433. [14]诸楠,赵震,庄新村. 一种考虑剪切作用机制的 Johnson-Cook 断裂准则[J]. 锻压技术,2015,40(8): 127-131.Zhu N, Zhao Z, Zhuang X C. A modified Johnson-Cook fracture criterion considering shear effect [J]. Forging & Stamping Technology, 2015, 40(8): 127-131. [15]李耀辉,李永堂. 金属圆棒料径向夹紧高速剪切合理间隙值的研究及应用[J]. 热加工工艺,2014,43(5): 92-95.Li Y H, Li Y T. Research and application of reasonable clearance of metal round bar radial clamping high speed shear[J]. Hot Working Technology, 2014,43(5): 92-95.
|