【作者】 张臣；

【导师】 周儒荣；

【作者基本信息】 南京航空航天大学 ， 航空宇航制造工程， 2006， 博士

【摘要】 数控铣削加工物理仿真是一个复杂的研究课题,涉及多方面的基础和理论、实验的研究,是数控加工技术进一步发展和应用必须突破的难点,在数控加工几何仿真基础上进行物理仿真关键技术的研究,对提高数控加工效率和质量具有重要意义。本文采用理论分析与实验研究相结合的思路,进一步研究了几何仿真与精度验证技术,研究了铣削力模型的建立、刀具磨损模型的建立、加工误差模型与误差补偿技术、基于加工仿真的加工参数优化等物理仿真关键技术,主要研究内容和成果如下:1.设计了集几何仿真和物理仿真为一体的数控加工仿真系统的体系结构。提出以仿真数据库为中心的系统结构模型,实现几何仿真与物理仿真的高效紧密集成。2.在几何仿真方面,改进了几何仿真局部刷新算法,提出动态方向区域法,使在加工仿真过程中可以进行旋转、放大和缩小等动态操作,便于了解工件在仿真加工过程中的具体情况。在精度验证方面,提出了扩展Z&N精度验证算法和法向N&N精度验证算法,分别提高了验证效率和改善了验证效果。3.在球头铣刀铣削力建模和仿真方面,基于Z-map模型,提出了识别球头铣刀数控加工中参与切削的切削刃单元的PEEM方法,建立了球头铣刀铣削力模型,同时根据单刃切削条件,提出了确定刀具偏心参数的方法,开发了考虑刀具偏心和刀具变形的球头铣刀三轴加工过程的仿真系统。实验证明,该仿真方法是正确、可靠的。4.提出了球头铣刀刀具磨损的衡量方法,建立了磨损模型,用以衡量由刀具磨损而可能产生的加工误差;建立了球头铣刀在端铣加工中因刀具变形而可能产生的加工误差模型;提出了相应的由于刀具磨损和刀具变形引起的加工误差补偿方法。5.提出了数控铣削加工多目标变参数优化方法和控制铣削力优化进给率的参数优化方法,修改NC程序反映优化结果,并通过加工实验验证了优化效果。本文坚持理论研究与实验研究的紧密结合,不仅建立了理论模型,而且进行了大量的数控加工实验,包括铣削力建模和验证试验、刀具磨损建模和验证实验、加工误差补偿验证实验、加工参数优化验证实验等。这是本文的一个重要特点。更多还原

【Abstract】 Physical simulation is a complicated research subject, including plenty of foundations, theory and experiments to study. It must solve in order to develop further in NC machining technology. Physical simulation research based on NC geometric simulation has an important meaning for improving machining efficiency and machining quality of workpiece.This dissertation integrates theory analysis with experiment research and makes further research on NC geometric simulation. The establish of the cutting forces model, cutter wear model, machining error predition and compensation, machining parameter optimization in the physical simulation fields are made more research on the basis of the above research contents. The main achievements are as follows:1. System structure of NC machining simulation by integrating NC geometric simulation with physical simulation is designed. System structure model based on simulation database is presented, by which realize effectively to integrate NC geometric simulation with physical simulation.2.In the NC geometric simulation and NC verification, a partial rendering algorithm is improved by using dynamic OOB(oriented bounding box). The NC verification algorithm named Z&N method and named N&N method is presented, Z&N method is involved in verification efficiency and N&N method lays a particular stress on verification effect.3. In the milling forces simulation model, the algorithm to identify the engaging cutting edges is proposed using Z-map simulation model in ball-end milling process. The expression of instantaneous chip thickness is discussed by analyzing the effect of cutter eccentricity and deflection. Then ball-end cutter milling forces simulation model is established on the basis of the relationship between milling forces and chip load. In the process of establishing model of ball-end cutter milling forces, the algorithm of determining cutter eccentricity parameters are presented to integrate the condition of single edge cutting. The cutter eccentricity parameters are decided by using the above algorithm in the process of calculating milling force coefficients according to the experiment data of milling force. Results of experiment show that the simulation algorithm is satisfying.4.The machining errors arised from the cutter deflection and tool wear are更多还原