大型复杂轴类零件车铣复合加工动力学与运动规划

In the process of orthogonal turn-milling and general turn-milling, dynamics of machining system changes when machining process changes or when relative pose between cutter and workpiece changes. Also, cutting force changes along with machining parameters such as eccentricity, row width and so on. Both of above factors make machining stability discrimination really complicated. According to the geometric characteristics of complex outer cylinder and eccentric cavity of the support of the shafts, further study is required to research the relationship between dynamics of turn-milling and tool-path planning. In order to meet the urgent requirement of high-quality and high-efficiency NC turn-milling for the production of large-scale and complex shafts, it is essential to establish a new tool-path planning method. .Dynamics method of turn-milling for the large-scale and complex shafts is proposed. Tool-path planning based on it is also proposed. Firstly, dynamics model of turn-milling is established. Under cutting force excitation, nonlinear relationship between machining stability and dynamic characteristics of machining system is analyzed secondly for different relative-pose between cutter and workpiece in different machining processes. Lastly, tool-path for turn-milling is optimized on the premise of machining stability assurance. During tool-path optimization, resonable selection of machining parameters including eccentricity, row width, feed rate, etc. is considered. Tool-path optimization based on machining dynamics can ensure machining quality and efficiency for orthogonal turn-milling and general turn-milling of the large-scale and complex shafts.

在正交车铣和一般车铣复合加工大型复杂轴类零件的过程中，不同加工阶段、不同"刀具-工件"相对位置和姿态的工艺系统动态特性存在明显差异，切削力随偏心距和行距等加工参数改变，这些因素都使加工平稳性判别变得复杂。针对具体轴类零件外筒复杂轮廓和支柱偏心型腔的几何特点，深入研究正交车铣和一般车铣复合加工动态特性与运动规划之间的内在关系，建立新的运动规划理论和方法，可满足大型复杂轴类零件对高质高速车铣复合加工的迫切需求。.本项目提出大型复杂轴类零件车铣复合加工动力学与运动规划方法。建立车铣复合加工动力学模型，分析不同加工阶段、不同"刀具-工件"相对位置和姿态时，切削力激励作用下加工稳定性与工艺系统动态特性之间的非线性映射关系，建立加工稳定性多维叶瓣图；在保证加工稳定性的前提下，优化车铣复合加工刀具路径，合理选择偏心距、行距和进给速度等加工参数，保证大型复杂轴类零件正交车铣和一般车铣的加工效率和加工质量。

大型复杂轴类零件加工工序多，加工工艺系统动态特性复杂，加工过程中颤振的发生使得加工参数保守，从而导致加工效率低，给其高品质加工和高效加工带来了巨大的挑战。针对大型轴类零件起落架的车铣加工，迫切需要研究外筒复杂轮廓正交车铣和支柱偏心型腔一般车铣下的动态特性、切削力与失稳机制、运动规划之间的内在联系，建立新的运动规划理论和方法。针对该问题，辨识和分析了起落架外筒车铣复合加工工艺系统的动态特性，提出了基于RCSA法的工作模态下刀具端频响函数辨识方法，研究了考虑变切深、变切厚的正交车铣动态切削力预测模型，建立了考虑多阶模态交叉频响的铣削加工稳定性模型和考虑刀具-工件动态特性的三自由度铣削加工稳定性模型，分析了不同加工位置和不同加工阶段的加工稳定性。基于这些理论，探索了稳定性预测在起落架车铣复合加工刀具运动规划和加工参数优化上的综合应用。研究了基于混合约束条件的外筒复杂轮廓正交车铣加工参数优化、支柱偏心型腔一般车铣加工参数优化算法，提出以加工效率为先的车铣复合加工刀具运动规划策略，建立正交车铣和一般车铣复合加工工艺系统动态特性数字仿真与实验平台，开发了车铣复合加工运动规划系统软件平台。.本项目的研究成果已经通过多轴加工综合频响测试与评估软件模块、车铣复合加工运动规划软件模块等软件工具的形式形成高效车铣加工平台，并结合实施策略形成了比较完整的大型轴类零件高效车铣加工应用解决方案，在中航起落架公司、武汉重型机床厂等相关企业得到了应用和推广。到项目结题为止，发表论文12篇，SCI 刊源 11篇，EI刊源 11篇，其中International Journal of Machine Tools and Manufacture收录1篇，ASME the Journal of Manufacturing Science and Engineering收录1篇。受理发明专利2项，授权软件著作权1项，获得2013年度湖北省科学技术进步一等奖1项（排名4）。培养博士研究生2名，培养硕士研究生6名，参加国内外学术交流3人次。