数控加工中截面线法刀具轨迹的生成与仿真研究
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摘要
刀具轨迹的生成是指通过零件几何模型，根据所选用的加工机床、刀具、走刀方式以及加工余量等，按照一定的导动规则进行刀位计算并生成加工运动轨迹。刀具轨迹生成算法的优劣将决定刀具轨迹生成的质量和速度，从而影响生产效率。
在数控加工中，自由曲面的加工是一项比较常见且重要的内容。由于自由曲面形状复杂，在曲面的局部内凹区域及组合曲面的交线附近，曲面的法矢变化过大，加工时刀具易与零件产生干涉。因此，刀具轨迹生成中干涉处理不可避免。完善的干涉处理既要能对过切区域进行处理，又要能对欠切区域进行有效的后续加工处理。
截面线法是生成刀具轨迹的方法之一。它包括CC路径截面线法和CL路径截面法。它对走刀路线控制灵活，生成的刀具轨迹均匀，效率高，适合于自由曲面的加工。
本文以球形刀加工自由曲面为例，对截面线法进行了探讨，并且在截面线法的基础上，渗透快速干涉检验与处理的思想和方法，提出了截面线无干涉刀具轨迹的生成方法，同时采用MasterCAM软件进行了刀具轨迹生成过程的仿真研究。该方法计算量小，计算速度快，轨迹生成均匀，还可以确定加工中的欠切区域，进行后续加工处理。
The generation of the tool path means that by the geometrical models of parts, according to the adopted machines , the tools , the cutting patterns , the cutting allowance and etc., under some principles, the calculation of the cutter location was done and the tool path was generated. The superiority and inferiority of the algorithm of automatic generation of the tool path will affect the speed and quality of the generation of the tool path, even to affect the working efficiency of parts.
In NC, the machining of the freeform surfaces is one popular and important work. Because of the complex shapes, near the sunken region of the freeform surfaces and the united surfaces, the vertical vectors of the surfaces changed so much that the interference between the tools and the parts is easy forming while machining. So the resolution of the interference in the generation of the tool path is unable to avoid. The perfect resolution of the interference can solve not only the over-cutting region but also the under-cutting region effectively.
The method of curves of cross sections is one of the methods to generate the tool path. It includes: the method of curves of cross sections through CC route and the method of curves of cross sections through CL route. It can freely control the cutting-line, and can generate the average tool path. It is suit to the machining of freeform surfaces.
In this paper, with the example to machining the freeform surfaces by the ball tool, studied the method of curves of cross sections deeply, and added the idea and way of the quickly-interference-checking and solving to this method, finally extracted a new way-the interference-free tool path method of curves of cross sections. Moreover, simulated the cutting process with MasterCAM software. The calculation of this method is less relatively, the speed of this method
-2-
is quick and the quality of the tool path of this method is ideal, at the same time, mis method can find the under-cutting region in machining for the following process.
在数控加工中，自由曲面的加工是一项比较常见且重要的内容。由于自由曲面形状复杂，在曲面的局部内凹区域及组合曲面的交线附近，曲面的法矢变化过大，加工时刀具易与零件产生干涉。因此，刀具轨迹生成中干涉处理不可避免。完善的干涉处理既要能对过切区域进行处理，又要能对欠切区域进行有效的后续加工处理。
截面线法是生成刀具轨迹的方法之一。它包括CC路径截面线法和CL路径截面法。它对走刀路线控制灵活，生成的刀具轨迹均匀，效率高，适合于自由曲面的加工。
本文以球形刀加工自由曲面为例，对截面线法进行了探讨，并且在截面线法的基础上，渗透快速干涉检验与处理的思想和方法，提出了截面线无干涉刀具轨迹的生成方法，同时采用MasterCAM软件进行了刀具轨迹生成过程的仿真研究。该方法计算量小，计算速度快，轨迹生成均匀，还可以确定加工中的欠切区域，进行后续加工处理。
The generation of the tool path means that by the geometrical models of parts, according to the adopted machines , the tools , the cutting patterns , the cutting allowance and etc., under some principles, the calculation of the cutter location was done and the tool path was generated. The superiority and inferiority of the algorithm of automatic generation of the tool path will affect the speed and quality of the generation of the tool path, even to affect the working efficiency of parts.
In NC, the machining of the freeform surfaces is one popular and important work. Because of the complex shapes, near the sunken region of the freeform surfaces and the united surfaces, the vertical vectors of the surfaces changed so much that the interference between the tools and the parts is easy forming while machining. So the resolution of the interference in the generation of the tool path is unable to avoid. The perfect resolution of the interference can solve not only the over-cutting region but also the under-cutting region effectively.
The method of curves of cross sections is one of the methods to generate the tool path. It includes: the method of curves of cross sections through CC route and the method of curves of cross sections through CL route. It can freely control the cutting-line, and can generate the average tool path. It is suit to the machining of freeform surfaces.
In this paper, with the example to machining the freeform surfaces by the ball tool, studied the method of curves of cross sections deeply, and added the idea and way of the quickly-interference-checking and solving to this method, finally extracted a new way-the interference-free tool path method of curves of cross sections. Moreover, simulated the cutting process with MasterCAM software. The calculation of this method is less relatively, the speed of this method
-2-
is quick and the quality of the tool path of this method is ideal, at the same time, mis method can find the under-cutting region in machining for the following process.
引文
[1]周济，周艳红．数控加工技术．国防工业出版社．2002，1．
[2]吴光琳，倪其民，李从心等．曲面实时插补无干涉刀轨的生成方法．机械工程学报．2001，5．93-96．
[3]刘雄伟，张宝华，王增强等．数控加工理论与编程技术．机械工业出版社，第二版．2001，7．
[4]金建新．机床CNC系统中任意空间曲线的可控步长插补方法．机械工程学报．2002，4．12-13．
[5]沈建新，平雪良．数控加工总参数刀具轨迹生成方法的研究．计算机辅助设计与制造．2001，8．30-31．
[6]刘得福，陈峰．计算机数控系统三维刀具半径补偿研究．组合机床与自动化加工技术．2001，8．9-11．
[7]高军，王小椿．数控加工预控优化算法的实现．组合机床与自动化加工技术．2002，4．20-21．
[8]林巨广，朱华炳，李旗号等．模具型腔加工的实时无干涉刀具轨迹生成方法研究．计算机辅助设计与制造．2002，6．50-53．
[9]钟建琳，朱思南，喻道远等．曲面平头刀加工无干涉刀位轨迹自动生成的算法研究．机械工程学报．1999，12．93-97．
[10]陈涛，钟毅芳，周济．自由曲面5轴数控加工刀位轨迹的生成算法．机械工程学报．2001，12．100-103．
[11]李琼砚，陆际联．平头铣刀加工曲面的无干涉路径规划．机械工程学报．1998，2．75-81．
[12]王知行，王哲．一种新的数控加工刀具轨迹生成算法的研究．机械设计．2000，11．21-24．
[13]杨庆东，陈秀梅．应用MasterCAM软件进行5轴联动数控编程和仿真．计算机辅助设计与制造．2001，7．31-33．
[14] 桂贵生，杜世昌，王乾廷等．渐开线数控加工插补算法探讨．组合机床与自动化加工技术．2002，4．22-24．
[15] 马宏余，范牧昌．曲面铣削特征的刀具轨迹生成．组合机床与自动化加工技术．1999，11．27-30．
[16] 李浙昆，樊瑜瑾，杨晓京等．NC加工刀具轨迹设计中的几个优化问题．机械设计与制造．1999，4．37-38．
[17] 竺长安，吕达昱．CAM系统中粗加工刀具轨迹的优化设计．计算机辅助设计与制造．2000，3．33-34．
[18] 李剑，王文，谢金等．数控加工中自由曲面干涉区域求取算法的研究．组合机床与自动化加工技术．2001，9．41-44．
[19] 余卫东，陈建，Moldflow先进的前后置处理技术，CAD／CAM与制造业信息化，第9期2002
[20] 项辉宇．孙胜．赵国群，计算机辅助塑料模具设计和工艺改进，模具技术，第1期，2000
[21] En-Gang Wang and Ji-Cheng He, Finite element numerical simulation on thermomechanical behavior of steel billet in continuous casting mold, Science and Technology of Advanced Materials, .2001,2(1).-257-263
[22] C. P. HONG, S. Y. LEE and K. SONG, Development of a New Simulation Method of Mold Filling Based on a Body-fitted Coordinate System, ISIJ International/The Iron and Steel Institute of Japan, .-2001,41(9).-999-1005 R.
[23] PANTANI, V. SPERANZA, G. TITOMANLIO, Relevance of Mold-Induced Thermal Boundary Conditions and Cavity Deformation in the Simulation of Injection Molding, Polymer engineerng and science, .-2001,000(11).-E16-E16
[24] Liangrong JIA, Shoumei XIONG, Study on Numerical Simulation of Mold Filling and Heat Transfer in Die Casting Process, Journal of Materials Science and Technology, .-2000,16(3).-269-272
[25] SHIA-CHUNG CHEN, SHENG-YAN HU, SHER-MENG CHAO, REAN-DER CHIEN, Designed With a Top Rib on the Gas Channel, Polymer engineering andscience, .-2000,40(3).-595-606
[26] L. G. OLSON, R. CRAWFORD, M. KEARNS, N. GEIGER, Rotational Molding of Plastics: Comparison of Simulation and Experimental Results for an Simulation of a Mold-Cooling Process for Gas-Assisted Injection Molded Parts Axisymmetric Mold, Polymer engineering and science, .-2000,40(8).-1758-1764
[27] PAVEL NEDANOV AND SURESH G. ADVANT, Mold Filling Simulation of SandwichComposite Structures Manufactured byLiquid Molding: A Parametric Study, Journal Of Sandwich Structures And Materials, .-2000,2(2).-117-130
[28] Najimi, Liaquat; Lee, Daeyong, Application of mold filling simulation to powder injection molding, International Journal of Powder Metallurgy(Princeton, New Jersey), .-1994,30(2).-231-240
[29] Kang, Moon Koo; Lee, Woo Ⅱ; Yoo, Jung Yul; Cho, Sung Min, Simulation of mold filling process during resin transfer molding, Journal of Materials Processings and Manufacturing Science, .-1995,3(3).-297-313
[30] Saito, Takushi; Kurosaki, Yasuo; Satoh, Isao, Precision injection molding process assisted by infrared radiation (2nd Report, Prediction of temperature distribution within polymer and mold by numerical simulation), Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, .-1997,63(613).-3114-3122
[31] Hung, C.F.; Shen, Y.K., Numerical simulation of fiber orientation in injection mold filling, International Communications in Heat and Mass Transfer, .-1995,22(6).-791-802
[32] Hu S.Y.; Cheng, N.T.; Chen S.C., Effect of cooling system design and process parameters on cyclic variation of mold temperatures-simulation by DRBEM, Plastics, Rubber and Composites Processing and Applications, .-1995,23(4).-221-232
[33] V. V. Bilovol, L. Kowalski, J. Duszczyk, Numerical Simulation of the Powder Injection Moulding Process for Optimization of Mould Design and Process Parameters, Advanced Engineering Materials, .-2000,2(3).-127-131 Y.C. Lam, Numerical simulation of the mould-filling process inresin-transfer moulding, Composites science and technology, .-2000,60(6).-845-855
[34] 孙家广，杨长贵．计算机图形学．清华大学出版社，1995
[35] 朱名铨，张树生等．虚拟制造系统与实现．西北工业大学出版社，2001
[36] 宁汝新，赵汝嘉等．CAD／CAM技术．机械工业出版社，2002
[37] 肖刚，李学志．机械CAD原理与实践．北京：清华大学出版社，2001．3
[38] 蔡颖，薛庆，徐弘山．CAD／CAM原理与应用．北京：机械工业出版社，1998．8
[39] 刘宏增，黄靖远．虚拟设计．北京：机械工业出版社，1999
[40] 苏志强等．计算机辅助装配顺序研究综述．机械科学与技术，1999，18(6)：1006—1009
[2]吴光琳，倪其民，李从心等．曲面实时插补无干涉刀轨的生成方法．机械工程学报．2001，5．93-96．
[3]刘雄伟，张宝华，王增强等．数控加工理论与编程技术．机械工业出版社，第二版．2001，7．
[4]金建新．机床CNC系统中任意空间曲线的可控步长插补方法．机械工程学报．2002，4．12-13．
[5]沈建新，平雪良．数控加工总参数刀具轨迹生成方法的研究．计算机辅助设计与制造．2001，8．30-31．
[6]刘得福，陈峰．计算机数控系统三维刀具半径补偿研究．组合机床与自动化加工技术．2001，8．9-11．
[7]高军，王小椿．数控加工预控优化算法的实现．组合机床与自动化加工技术．2002，4．20-21．
[8]林巨广，朱华炳，李旗号等．模具型腔加工的实时无干涉刀具轨迹生成方法研究．计算机辅助设计与制造．2002，6．50-53．
[9]钟建琳，朱思南，喻道远等．曲面平头刀加工无干涉刀位轨迹自动生成的算法研究．机械工程学报．1999，12．93-97．
[10]陈涛，钟毅芳，周济．自由曲面5轴数控加工刀位轨迹的生成算法．机械工程学报．2001，12．100-103．
[11]李琼砚，陆际联．平头铣刀加工曲面的无干涉路径规划．机械工程学报．1998，2．75-81．
[12]王知行，王哲．一种新的数控加工刀具轨迹生成算法的研究．机械设计．2000，11．21-24．
[13]杨庆东，陈秀梅．应用MasterCAM软件进行5轴联动数控编程和仿真．计算机辅助设计与制造．2001，7．31-33．
[14] 桂贵生，杜世昌，王乾廷等．渐开线数控加工插补算法探讨．组合机床与自动化加工技术．2002，4．22-24．
[15] 马宏余，范牧昌．曲面铣削特征的刀具轨迹生成．组合机床与自动化加工技术．1999，11．27-30．
[16] 李浙昆，樊瑜瑾，杨晓京等．NC加工刀具轨迹设计中的几个优化问题．机械设计与制造．1999，4．37-38．
[17] 竺长安，吕达昱．CAM系统中粗加工刀具轨迹的优化设计．计算机辅助设计与制造．2000，3．33-34．
[18] 李剑，王文，谢金等．数控加工中自由曲面干涉区域求取算法的研究．组合机床与自动化加工技术．2001，9．41-44．
[19] 余卫东，陈建，Moldflow先进的前后置处理技术，CAD／CAM与制造业信息化，第9期2002
[20] 项辉宇．孙胜．赵国群，计算机辅助塑料模具设计和工艺改进，模具技术，第1期，2000
[21] En-Gang Wang and Ji-Cheng He, Finite element numerical simulation on thermomechanical behavior of steel billet in continuous casting mold, Science and Technology of Advanced Materials, .2001,2(1).-257-263
[22] C. P. HONG, S. Y. LEE and K. SONG, Development of a New Simulation Method of Mold Filling Based on a Body-fitted Coordinate System, ISIJ International/The Iron and Steel Institute of Japan, .-2001,41(9).-999-1005 R.
[23] PANTANI, V. SPERANZA, G. TITOMANLIO, Relevance of Mold-Induced Thermal Boundary Conditions and Cavity Deformation in the Simulation of Injection Molding, Polymer engineerng and science, .-2001,000(11).-E16-E16
[24] Liangrong JIA, Shoumei XIONG, Study on Numerical Simulation of Mold Filling and Heat Transfer in Die Casting Process, Journal of Materials Science and Technology, .-2000,16(3).-269-272
[25] SHIA-CHUNG CHEN, SHENG-YAN HU, SHER-MENG CHAO, REAN-DER CHIEN, Designed With a Top Rib on the Gas Channel, Polymer engineering andscience, .-2000,40(3).-595-606
[26] L. G. OLSON, R. CRAWFORD, M. KEARNS, N. GEIGER, Rotational Molding of Plastics: Comparison of Simulation and Experimental Results for an Simulation of a Mold-Cooling Process for Gas-Assisted Injection Molded Parts Axisymmetric Mold, Polymer engineering and science, .-2000,40(8).-1758-1764
[27] PAVEL NEDANOV AND SURESH G. ADVANT, Mold Filling Simulation of SandwichComposite Structures Manufactured byLiquid Molding: A Parametric Study, Journal Of Sandwich Structures And Materials, .-2000,2(2).-117-130
[28] Najimi, Liaquat; Lee, Daeyong, Application of mold filling simulation to powder injection molding, International Journal of Powder Metallurgy(Princeton, New Jersey), .-1994,30(2).-231-240
[29] Kang, Moon Koo; Lee, Woo Ⅱ; Yoo, Jung Yul; Cho, Sung Min, Simulation of mold filling process during resin transfer molding, Journal of Materials Processings and Manufacturing Science, .-1995,3(3).-297-313
[30] Saito, Takushi; Kurosaki, Yasuo; Satoh, Isao, Precision injection molding process assisted by infrared radiation (2nd Report, Prediction of temperature distribution within polymer and mold by numerical simulation), Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, .-1997,63(613).-3114-3122
[31] Hung, C.F.; Shen, Y.K., Numerical simulation of fiber orientation in injection mold filling, International Communications in Heat and Mass Transfer, .-1995,22(6).-791-802
[32] Hu S.Y.; Cheng, N.T.; Chen S.C., Effect of cooling system design and process parameters on cyclic variation of mold temperatures-simulation by DRBEM, Plastics, Rubber and Composites Processing and Applications, .-1995,23(4).-221-232
[33] V. V. Bilovol, L. Kowalski, J. Duszczyk, Numerical Simulation of the Powder Injection Moulding Process for Optimization of Mould Design and Process Parameters, Advanced Engineering Materials, .-2000,2(3).-127-131 Y.C. Lam, Numerical simulation of the mould-filling process inresin-transfer moulding, Composites science and technology, .-2000,60(6).-845-855
[34] 孙家广，杨长贵．计算机图形学．清华大学出版社，1995
[35] 朱名铨，张树生等．虚拟制造系统与实现．西北工业大学出版社，2001
[36] 宁汝新，赵汝嘉等．CAD／CAM技术．机械工业出版社，2002
[37] 肖刚，李学志．机械CAD原理与实践．北京：清华大学出版社，2001．3
[38] 蔡颖，薛庆，徐弘山．CAD／CAM原理与应用．北京：机械工业出版社，1998．8
[39] 刘宏增，黄靖远．虚拟设计．北京：机械工业出版社，1999
[40] 苏志强等．计算机辅助装配顺序研究综述．机械科学与技术，1999，18(6)：1006—1009