基于静刚度的变轴数控机床加工误差仿真研究

Simulation of the Machining Error of Variable-Axis NC Machine Tool Based on Static Stiffness

以变轴数控机床的运动部件——Stewart平台为研究对象,从变形的角度对机床的加工误差进行了分析和研究,得出了静态载荷条件下加工误差的矢量表达式,并对误差进行了预调,建立了相应的预调模型.该方法为从静刚度方面提高机床的加工精度提供了必要的理论依据,且具有通用性.最后给出了仿真实例,仿真结果表明了由于静刚度而导致加工误差的存在性和误差预调的必要性.

The machining error of a variableaxis NC machine tool is analyzed by studying the deformation of Stewart platform, the kinetic part of the machine tool. Vector expression of machining error is derived on the condition of static loads. Moreover, the machining error is preadjusted by establishing a relevant preadjusted model. The method is universal and provides a theoretical foundation to improve the machining accuracy of the machine tool in static stiffness. A simulation example is finally given, demonstrating that the machining error arisen from the static stiffness does exist and the error has to be corrected.