五轴联动数控加工中心结构动特性分析与优化
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摘要
结构动态特性是影响数控机床加工效率、精度等性能指标的重要因素,有关数控机床结构动态特性建模、优化和试验技术一直是机床动力学领域的研究热点问题,具有重要学术价值和工程意义。本文针对某型号五轴联动加工中心存在的结构动态特性问题,较深入地开展了机床关键部件滑动结合面动力学参数识别、整机和关键部件有限元建模与仿真、以及结构试验模态分析和结构薄弱环节修改等方面的研究工作。具体工作如下:
1)基于立式加工中心工作台,构建了滑动导轨结合面动力学参数实验平台,并通过大量实验,给出了滑动导轨结合面等效参数随润滑、正压力、镶条预紧力等参数变化的基本规律;
2)建立了五轴联动加工中心整机和关键部件结构的有限元仿真模型,给出了相应的结构模态振型与参数,以及机床AB双摆头和立柱的基本变形规律;
3)借助于LMS Test Lab模态分析系统,进行了机床结构试验模态分析和抗振性切削实验、以及机床立柱进给运动特性分析,提出了机床结构动态特性薄弱环节;
4)针对上述机床结构动态特性薄弱环节,提出了相应的结构改进方案,并借助于有限元仿真,验证了结构改进方案的有效性。
本文工作是国家科技重大专项“用于钛合金航空结构件加工的五轴联动加工中心”课题的一部分,所提出的机床改进措施已被企业所采用,为提高该机床的结构动态特性奠定了理论与实验基础。
As it is of great importance to the machining efficiency and precision of NC machine tools, the study concerning the modeling, optimization and test technique of the structural dynamic characteristic takes an academic value as well as engineering significance. Aiming at the problems about the dynamic characteristic of a certain 5-axis machining center, this paper focuses on the parameter identification of a slide ways contact surface, Ansys modeling and simulation of the machining center and its key component, modal analysis based on experiments together with the structural modification to the weakness. The details of this paper are as follows:
1) Based on the table of a vertical machining center, the experiment platform of parameter identification is set up. After plenty of experiments, the law of the equivalent parameters of the guide ways contact surface is obtained when the press, lubrication and the preload of inlaid strips change respectively.
2) The finite element model of the 5-axis linkage machining center is built and its modal vibration and parameter are obtained through simulation. Meantime, the law of the upright post and AB axis deformation is acquired.
3) By means of LMS Test.Lab, experimental modal analysis, anti-vibration cutting experiment together with motion characteristic analysis of the upright post are conducted to the machining center and the weakness of the structure is found.
4) Several structural modification solutions to the weakness of the machining center have been proposed and validated through finite element analysis.
The modification proposals have been used by the cooperative enterprise. The work of this paper is part of the subject“5-axis machining center to the machining of the titanium alloy aviation structural products”which belongs to the state project“Major Projects for Science and Technology Development”. It lays the foundation of the theoretical and experimental basis for the dynamic characteristic of the machining center.
1)基于立式加工中心工作台,构建了滑动导轨结合面动力学参数实验平台,并通过大量实验,给出了滑动导轨结合面等效参数随润滑、正压力、镶条预紧力等参数变化的基本规律;
2)建立了五轴联动加工中心整机和关键部件结构的有限元仿真模型,给出了相应的结构模态振型与参数,以及机床AB双摆头和立柱的基本变形规律;
3)借助于LMS Test Lab模态分析系统,进行了机床结构试验模态分析和抗振性切削实验、以及机床立柱进给运动特性分析,提出了机床结构动态特性薄弱环节;
4)针对上述机床结构动态特性薄弱环节,提出了相应的结构改进方案,并借助于有限元仿真,验证了结构改进方案的有效性。
本文工作是国家科技重大专项“用于钛合金航空结构件加工的五轴联动加工中心”课题的一部分,所提出的机床改进措施已被企业所采用,为提高该机床的结构动态特性奠定了理论与实验基础。
As it is of great importance to the machining efficiency and precision of NC machine tools, the study concerning the modeling, optimization and test technique of the structural dynamic characteristic takes an academic value as well as engineering significance. Aiming at the problems about the dynamic characteristic of a certain 5-axis machining center, this paper focuses on the parameter identification of a slide ways contact surface, Ansys modeling and simulation of the machining center and its key component, modal analysis based on experiments together with the structural modification to the weakness. The details of this paper are as follows:
1) Based on the table of a vertical machining center, the experiment platform of parameter identification is set up. After plenty of experiments, the law of the equivalent parameters of the guide ways contact surface is obtained when the press, lubrication and the preload of inlaid strips change respectively.
2) The finite element model of the 5-axis linkage machining center is built and its modal vibration and parameter are obtained through simulation. Meantime, the law of the upright post and AB axis deformation is acquired.
3) By means of LMS Test.Lab, experimental modal analysis, anti-vibration cutting experiment together with motion characteristic analysis of the upright post are conducted to the machining center and the weakness of the structure is found.
4) Several structural modification solutions to the weakness of the machining center have been proposed and validated through finite element analysis.
The modification proposals have been used by the cooperative enterprise. The work of this paper is part of the subject“5-axis machining center to the machining of the titanium alloy aviation structural products”which belongs to the state project“Major Projects for Science and Technology Development”. It lays the foundation of the theoretical and experimental basis for the dynamic characteristic of the machining center.
引文
[1]杜玉湘,陆启建等,五轴联动数控机床的结构与应用,机械制造与研究,2008,37(3):14~16
[2]刘士玉,徐树洛,五轴联动龙门加工中心现状与发展对策,产品与技术,2008,(6):84~87
[3]曹文平,杨庆东,五轴联动机床的实验模态分析,机械制造与研究,2008,37(1):71~73
[4]李明,杨庆东,五轴联动数控铣床的高速动态特性分析,北京机械工业学院学报,2007,22(4):59~61
[5]彭文,倪向阳,五坐标龙门加工中心动特性分析与振动控制,制造技术与机床,2006,(2):61~63
[6]张学良,徐格宁等,机械结合面静动态特性研究回顾及展望,太原重型机械学院学报,2002,23(3):276~281
[7] M. P. Dolbey.The Normal Dynamic Characteristics of Machine Tool Plain Slide Ways:[PhD Thesis].University of Manchester Institute of Science and Technology, 1968
[8] Z. M. Levina.Calculation of Contact Deformations in Slideways.Machine and Tooling,1965,36(1):1~8
[9] Z. M. Levina.Research on the Static Stiffness of Joints in Machine Tools.8th Intern.Confer.M.T.D.R.,1967,(36):15~23
[10] V. I. Ostrovskii.The Influence of Machining Methods on Slideway Contact Stiffness,Machine and Tooling,1965, 36(1):9~17
[11] M. P. Dolbey,R. Bell.The Contact Stiffness of Joints at Low Apparent Interface Pressure.Annals of CIRP,1971,(19):67~69
[12] N.Back,M.Burdekin, A. Cowley.Review of the Research on Fixed and Sliding Joints.Proc.13rd Intern.Confer.M.T.D.R.,1973: 87~97
[14] R. Connoly, R. H. Thornley.Determining the Normal Stiffness of Joint Faces. ASME,Paper, 1967,(67):6~13
[15] R. Connoly, R. E. Schofield, R. H. Thornley.The Approach of machined Surfaces with Particular Reference to Their Hardness.Proc.8th Intern.Confer.M.T.D.R., 1967,759~775
[16] V. N. Kirsanova.The Shear Compliance of Flat Joints.Machines and Tooling, 1967,38(7):30~34
[17]堤正臣,伊东谊,益子正已,机床螺栓结合部的动态特性—固体接触状态,精密机械,1977,(1):105~111
[18] P. F. Rogers, G. Boothroyd. Damping at Metallic Interfaces Subjected to Oscillating Tangential Loads[J]. J. Eng. for Industry, Trans. ASME, 1975:1087~1093
[19] C. Dekoninck. Deformation Properties of Metallic Contact Surfaces of Joints under the Influence of Dynamic Tangential Loads. Int. J. Mach. Des. Res., 1972,(12): 193~199
[20] K. K. Padmanbhan, A. S. R. Murry. Damping in Structural Joints Subjected to Tangential Loads[J]. Proc. Instn. Mech. Engrs.,1991,(205):121~129
[21] K. K. Padmanbhan. Prediction of Damping in Machine Joints[J]. Int.J. Mach. Tools Manufact.,1992, (3): 305~314
[22]伊东谊,机床结合部问题研究的最新展望,日本机械学会论文集,1988,(4):807~815
[23]刘晓平,徐燕申等,基于正交性条件识别机械结构结合面参数方法改进.应用力学学报,1996,13(93):103~109
[24]刘晓平,徐燕申等,机械结构结合面阻尼参数识别的研究,振动与冲击,1995,14(3):61~65
[25]黄玉美,获取结合面实用切向阻尼参数的方法[J].西安理工大学学报,1996,32(1):32~36
[26]张广鹏,基于结合面基础特性参数的机床导轨结合部的动态特性解析方法,江苏机械制造与自动化,2001,56(4):12~14
[27]于德介,宋健伟等,子结构物理参数的一种识别方法,应用力学学报, 1992,9(3):115~118
[28]童忠纺,张杰,加工中心立柱床身结合面动态特性研究及参数识别,振动与冲击,1993,43(3):13~19
[29]张杰,童忠纺,机床固定结合面动力学建模问题,振动与冲击,1994,51(3):15~21
[30] J. X. Yuan.Identification of the Joint Structural Parameters of Machine Tool by DDS and FEM[J]. Eng. for Industry,Tran(ASME),1985,107(11):64~69
[31]廖伯瑜,周新民,尹志宏,现代机床动力学及其应用,北京:机械工业出版社,2004.232~278
[32]伍良生,董金城,周大帅,粉末冶金多空材料结合面力学性质的实验研究,现代制造工程,2008,(7):1~4
[33]刘习军,贾启芬,工程振动理论与测试技术,北京:高等教育出版社,2006.406~409
[34] T. Inamura, T. Sata. Stiffness and damping identification of element of a machine tool structure. CIRP Annals-Manufacturing Technology, 1979,25(1):41~48
[35] R. H. Thornley, R. Connlly, M. M. Barash. The Effect of Surface Topography upon the Static Stiffness of Machine Tool Joints.Intern.J.M.T.D.R.,1965,(5):57~74
[36]梁志强,加工中心整机试验模型分析及主要结合面参数识别方法研究:[硕士学位论文],昆明;昆明理工大学,2004
[37]王富强,精密机床床身的动态特性分析与优化:[硕士学位论文],兰州;兰州理工大学,2007
[38]张耀满,王旭东,蔡光起等,高速机床有限元分析及其动态性能实验,组合机床与自动化加工技术,2004,12:15~17
[39] M. Masuko, Y. Ito,C. Fujinoto.Behavior of Horizontal Stiffness and Micro-sliding on the Bolted Joint under the Normal Preload[C].Proc.12nd Intern. Confer. M.T.D.R.,1971,38(7):81~88
[2]刘士玉,徐树洛,五轴联动龙门加工中心现状与发展对策,产品与技术,2008,(6):84~87
[3]曹文平,杨庆东,五轴联动机床的实验模态分析,机械制造与研究,2008,37(1):71~73
[4]李明,杨庆东,五轴联动数控铣床的高速动态特性分析,北京机械工业学院学报,2007,22(4):59~61
[5]彭文,倪向阳,五坐标龙门加工中心动特性分析与振动控制,制造技术与机床,2006,(2):61~63
[6]张学良,徐格宁等,机械结合面静动态特性研究回顾及展望,太原重型机械学院学报,2002,23(3):276~281
[7] M. P. Dolbey.The Normal Dynamic Characteristics of Machine Tool Plain Slide Ways:[PhD Thesis].University of Manchester Institute of Science and Technology, 1968
[8] Z. M. Levina.Calculation of Contact Deformations in Slideways.Machine and Tooling,1965,36(1):1~8
[9] Z. M. Levina.Research on the Static Stiffness of Joints in Machine Tools.8th Intern.Confer.M.T.D.R.,1967,(36):15~23
[10] V. I. Ostrovskii.The Influence of Machining Methods on Slideway Contact Stiffness,Machine and Tooling,1965, 36(1):9~17
[11] M. P. Dolbey,R. Bell.The Contact Stiffness of Joints at Low Apparent Interface Pressure.Annals of CIRP,1971,(19):67~69
[12] N.Back,M.Burdekin, A. Cowley.Review of the Research on Fixed and Sliding Joints.Proc.13rd Intern.Confer.M.T.D.R.,1973: 87~97
[14] R. Connoly, R. H. Thornley.Determining the Normal Stiffness of Joint Faces. ASME,Paper, 1967,(67):6~13
[15] R. Connoly, R. E. Schofield, R. H. Thornley.The Approach of machined Surfaces with Particular Reference to Their Hardness.Proc.8th Intern.Confer.M.T.D.R., 1967,759~775
[16] V. N. Kirsanova.The Shear Compliance of Flat Joints.Machines and Tooling, 1967,38(7):30~34
[17]堤正臣,伊东谊,益子正已,机床螺栓结合部的动态特性—固体接触状态,精密机械,1977,(1):105~111
[18] P. F. Rogers, G. Boothroyd. Damping at Metallic Interfaces Subjected to Oscillating Tangential Loads[J]. J. Eng. for Industry, Trans. ASME, 1975:1087~1093
[19] C. Dekoninck. Deformation Properties of Metallic Contact Surfaces of Joints under the Influence of Dynamic Tangential Loads. Int. J. Mach. Des. Res., 1972,(12): 193~199
[20] K. K. Padmanbhan, A. S. R. Murry. Damping in Structural Joints Subjected to Tangential Loads[J]. Proc. Instn. Mech. Engrs.,1991,(205):121~129
[21] K. K. Padmanbhan. Prediction of Damping in Machine Joints[J]. Int.J. Mach. Tools Manufact.,1992, (3): 305~314
[22]伊东谊,机床结合部问题研究的最新展望,日本机械学会论文集,1988,(4):807~815
[23]刘晓平,徐燕申等,基于正交性条件识别机械结构结合面参数方法改进.应用力学学报,1996,13(93):103~109
[24]刘晓平,徐燕申等,机械结构结合面阻尼参数识别的研究,振动与冲击,1995,14(3):61~65
[25]黄玉美,获取结合面实用切向阻尼参数的方法[J].西安理工大学学报,1996,32(1):32~36
[26]张广鹏,基于结合面基础特性参数的机床导轨结合部的动态特性解析方法,江苏机械制造与自动化,2001,56(4):12~14
[27]于德介,宋健伟等,子结构物理参数的一种识别方法,应用力学学报, 1992,9(3):115~118
[28]童忠纺,张杰,加工中心立柱床身结合面动态特性研究及参数识别,振动与冲击,1993,43(3):13~19
[29]张杰,童忠纺,机床固定结合面动力学建模问题,振动与冲击,1994,51(3):15~21
[30] J. X. Yuan.Identification of the Joint Structural Parameters of Machine Tool by DDS and FEM[J]. Eng. for Industry,Tran(ASME),1985,107(11):64~69
[31]廖伯瑜,周新民,尹志宏,现代机床动力学及其应用,北京:机械工业出版社,2004.232~278
[32]伍良生,董金城,周大帅,粉末冶金多空材料结合面力学性质的实验研究,现代制造工程,2008,(7):1~4
[33]刘习军,贾启芬,工程振动理论与测试技术,北京:高等教育出版社,2006.406~409
[34] T. Inamura, T. Sata. Stiffness and damping identification of element of a machine tool structure. CIRP Annals-Manufacturing Technology, 1979,25(1):41~48
[35] R. H. Thornley, R. Connlly, M. M. Barash. The Effect of Surface Topography upon the Static Stiffness of Machine Tool Joints.Intern.J.M.T.D.R.,1965,(5):57~74
[36]梁志强,加工中心整机试验模型分析及主要结合面参数识别方法研究:[硕士学位论文],昆明;昆明理工大学,2004
[37]王富强,精密机床床身的动态特性分析与优化:[硕士学位论文],兰州;兰州理工大学,2007
[38]张耀满,王旭东,蔡光起等,高速机床有限元分析及其动态性能实验,组合机床与自动化加工技术,2004,12:15~17
[39] M. Masuko, Y. Ito,C. Fujinoto.Behavior of Horizontal Stiffness and Micro-sliding on the Bolted Joint under the Normal Preload[C].Proc.12nd Intern. Confer. M.T.D.R.,1971,38(7):81~88