大型多轴机床轴间耦合表征及其对刀尖点联动精度的影响机理研究

The multi-axis NC machine tool aiming at machining large parts with complex curved surface plays a decisive role in national strategical new industries such as aviation, aerospace, navigation and so on. However, during the machining process of the large multi-axis machine tool, the elastic deformation and vibration of machine tool are caused by the coupling forces in acceleration and braking, which detrimentally affect dynamic accuracy of tool center point(TCP) and limit the velocity and efficiency of the machine tool. Therefore, this project focus on the axial coupling characterization of the large multi axis machine tool and its effect mechanism on the dynamic accuracy of TCP. Firstly, the exact characterization of axial coupling during the movement process of the large multi-axis machine tool is solved. Secondly, based on an combined model including the mechanical system, the servo system and the control system, the relation between the axial coupling and the dynamic accuracy of TCP is presented, and the evaluation and the effect law are studied. Thirdly, a matching method considering the mechanical parameter, the servo parameter, the control parameter and the feed parameter is developed. By using the new method, the active design of mechanical parameter can be realized, and the debugging of the servo parameter and feed parameter can also be implemented. Finally, the findings are verified and applied on a large machine tool.Therefore, this project has important scientific significance and application value.

大型多轴联动机床在航空航天和航海等国家战略新型产业具有举足轻重的地位。但是在大型多轴机床加工复杂曲面零件过程中，以惯性力为代表的轴间耦合力造成的机械弹性变形与振动对刀尖点联动精度的影响不可忽略，是目前仍然限制机床高速高效加工的突出问题，迫切需要解决。.本项目以提高大型多轴机床刀尖点联动精度和整机性能为目标，研究机床联动过程中轴间力学行为及其对关键耦合界面接触特性的影响，建立能够准确描述轴间耦合作用的理论模型，解决大型多轴机床轴间耦合作用准确表征与计算的问题；构建包含机械系统、伺服系统、控制系统的机床联合模型，解决轴间耦合作用与刀尖点联动精度之间的定量关系、评价及影响规律的问题；探索机械、伺服、控制和进给参数的匹配关系，从而实现考虑轴间耦合作用的大型多轴机床机械参数的主动设计与伺服、进给参数的主动调试。最终在某大型机床进行理论验证和示范推广。因此，本项目具有重要的科学意义和应用价值。

大型多轴联动机床在航空航天和航海等国家战略新型产业具有举足轻重的地位。但是在大型多轴机床加工复杂曲面零件过程中，以惯性力为代表的轴间耦合力造成的机械弹性变形与振动对刀尖点联动精度的影响不可忽略，是目前仍然限制机床高速高效加工的突出问题，迫切需要解决。 .本项目以提高大型多轴机床刀尖点联动精度和整机性能为目标，首先，提出了多向复合载荷作用下的直线导轨滑块副多向刚度混合模型，研究了机床联动过程中轴间力学行为及其对关键耦合界面接触特性的影响；其次，建立了能够准确描述轴间耦合作用的多轴联动机床的多体动力学模型，通过对大型多轴机床轴间耦合作用进行准确表征与计算，解决了轴间耦合作用与刀尖点联动精度之间的定量关系、评价及影响规律的问题；其次，提出了一种机床参数及其变化范围的主动设计方法，从而实现考虑轴间耦合作用的大型多轴机床机械参数的主动设计。最后，项目研究成果在某镗铣床机床进行了理论验证和示范应用。