Influence of Spindle Vibrationon Surface Waviness and Prediction Model
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摘要: 机床加工精度的影响因素中,静压主轴系统的动态特性引起的振动是加工表面波纹度产生的重要因素。基于主轴振动信息建立波纹度的生成模型,求解得到6个影响因素的灵敏度中径向轴承的位置是影响表面波纹度的主要因素。建立评价体系,通过相关法来评估生成模型与实际加工表面波纹结果之间的关系,得到了高于0.45的相关系数。最后利用功率谱密度提取主轴系统的频谱特性,发现主轴振动是影响加工精度的主要因素。Abstract: In the analysis of the factors affecting the machining accuracy of the machine tool, the vibration caused by the dynamic characteristics of the hydrostatic spindle system is an important factor in the surface waviness of the machined surface. The generation model for waviness is established according to the vibration information of the main shaft, and the sensitivity of the six influencing factors is obtained. The position of the radial bearing is the main factor affecting the surface waviness. Then the evaluation system is established, and the relationship between the generated model and the actual processed surface ripple result is evaluated by using the correlation method, and a correlation coefficient above 0.45 is obtained. Finally, with the power spectral density to extract the spectral characteristics of the spindle system, it is found that the spindle vibration is the main factor affecting the machining accuracy.
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Key words:
- surface waviness /
- spindle vibration /
- correlation /
- evaluation system
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表 1 主轴系统的参数
主轴系统的质量 300 kg 径向刚度Kra, Krb 100 N/μm 推力轴承刚度Kt 300 N/μm 距离理想中心的偏心距 1 μm 主轴半径R 120 mm 工作台半径 500 mm 表 2 影响因素的灵敏度比
因素 L4-Lc Kx Kz Cx和Cz M ω 初始值 0.258 0.258 0.258 0.258 0.258 0.258 10倍 0.326 0.261 0.262 0.259 0.265 0.26 误差/% 26 1.1 1.5 0.38 1.9 0.77 -
[1] Hung J P, Lai Y L, Luo T L, et al. Analysis of the machining stability of a milling machine considering the effect of machine frame structure and spindle bearings: experimental and finite element approaches[J]. The International Journal of Advanced Manufacturing Technology, 2013, 68(9-12): 2393-2405 doi: 10.1007/s00170-013-4848-6 [2] Huang P, Lee W B, Chen C Y. Investigation of the effects of spindle unbalance induced error motion on machining accuracy in ultra-precision diamond turning[J]. International Journal of Machine Tools and Manufacture, 2015, 94: 48-56 doi: 10.1016/j.ijmachtools.2015.04.007 [3] Marsh E, Arneson D A, Van Doren M J, et al. The effects of spindle dynamics on precision flycutting[C]//The Twentieth Annual Meeting of the American Society for Precision Engineering.The Pennsylvania State University, 21 Reber Building, University Park, PA 16802, USA, 2005 [4] Maeda O, Cao Y Z, Altintas Y. Expert spindle design system[J]. International Journal of Machine Tools and Manufacture, 2005, 45(4-5): 537-548 doi: 10.1016/j.ijmachtools.2004.08.021 [5] 万德安, 袁建畅, 杨公仆. 导轨磨床加工工件表面波度成因的探索[J]. 西安交通大学学报, 1986, 20(2): 99-108Wan D A, Yuan J C, Yang G P. Investigation on the cause of formation of work-piece surface waviness during machining on slideway grinding machines[J]. Journal of Xi'an Jiaotong University, 1986, 20(2): 99-108 (in Chinese) [6] 曹宏瑞, 何正嘉. 机床—主轴耦合系统动力学建模与模型修正[J]. 机械工程学报, 2012, 48(3): 88-94 doi: 10.3901/JME.2012.03.088Cao H R, He Z J. Dynamic modeling and model updating of coupled systems between machine tool and its spindle[J]. Journal of Mechanical Engineering, 2012, 48(3): 88-94 (in Chinese) doi: 10.3901/JME.2012.03.088 [7] Martin D L, Tabenkin A N, Parsons F G. Precision spindle and bearing error analysis[J]. International Journal of Machine Tools and Manufacture, 1995, 35(2): 187-193 doi: 10.1016/0890-6955(94)P2372-M [8] Kim D K, Chang I C, Kim S W. Microscopic topographical analysis of tool vibration effects on diamond turned optical Surfaces[J]. Precision Engineering, 2002, 26(2): 168-174 doi: 10.1016/S0141-6359(01)00115-5 [9] Lin S C, Chang M F. A study on the effects of vibrations on the surface finish using a surface topography simulation model for turning[J]. International Journal of Machine Tools and Manufacture, 1998, 38(7): 763-782 doi: 10.1016/S0890-6955(97)00073-4 [10] 王伟, 庄文浩, 陶文坚. 采用测量不确定度的复杂自由曲面表面质量测试与评价[J]. 西安交通大学学报, 2016, 51(8): 20-25Wang Wi, Zhuang W H, Tao W J. Measurement and evaluation method for quality of complex free-form surface based on uncertainty of measurement[J]. Journal of Xi'an Jiaotong University, 2016, 51(8): 20-25 (in Chinese) [11] Jiang L, Yahya E, Ding G F, et al. The research of surface waviness control method for 5-axis flank milling[J]. The International Journal of Advanced Manufacturing Technology, 2013, 69(1): 835-847 [12] Zhang S J, To S, Wang H T. A theoretical and experimental investigation into five-DOF dynamic characteristics of an aerostatic bearing spindle in ultra-precision diamond turning[J]. International Journal of Machine Tools and Manufacture, 2013, 71: 1-10 doi: 10.1016/j.ijmachtools.2013.03.001 [13] Movahhedy M R, Mosaddegh P. Prediction of chatter in high speed milling including gyroscopic effects[J]. International Journal of Machine Tools and Manufacture, 2006, 46(9): 996-1001 doi: 10.1016/j.ijmachtools.2005.07.043 [14] Khanfir H, Bonis M, Revel P. Improving waviness in ultra precision turning by optimizing the dynamic behavior of a spindle with magnetic bearings[J]. International Journal of Machine Tools and Manufacture, 2005, 45(7-8): 841-848 doi: 10.1016/j.ijmachtools.2004.11.007 [15] An C H, Zhang Y, Xu Q, et al. Modeling of dynamic characteristic of the aerostatic bearing spindle in an ultra-precision fly cutting machine[J]. International Journal of Machine Tools and Manufacture, 2010, 50(4): 374-385 doi: 10.1016/j.ijmachtools.2009.11.003 [16] Li J S, Huang M, Liu P K. Analysis and experimental verification of dynamic characteristics of air spindle considering varying stiffness and damping of radial bearings[J]. The International Journal of Advanced Manufacturing Technology, 2019, 104(5-8): 2939-2950 doi: 10.1007/s00170-019-04121-2 [17] Chen D J, Cui X X, Pan R, et al. A prediction model of the surface topography due to the unbalance of the spindle system in ultra-precision fly-cutting machining[J]. Advances in Mechanical Engineering, 2018, 10(1): 168781401774714 [18] 赵斌. 导轨表面粗糙度功能参数表征及其对摩擦特性的影响[D]. 济南: 山东大学, 2017.Zhao B. Characteristic of functional parameters of surface roughness on guide way and its' effects on tribological properties[D]. Ji'nan: Shandong University, 2017 (in Chinese).