基于机床体误差模型的加工面形误差预测

零件面形精度满足要求是超精密装备实现其关键功能的重要保证.影响工件加工面形精度的因素很多,机床体误差是其中最关键的因素.通过构建机床误差元与加工面形误差之间的直接关系来进行面形误差预测研究.提出了一种基于机床体误差模型的频域多尺度面形误差预测方法,该方法可结合机床体误差模型、工艺参数、加工轨迹等进行频域多尺度面形误差预测,可为加工路径规划、机床设计等提供理论参考,从而提高加工精度.进行了低频PV面形误差预测的实例研究,采用的机床为一台五轴联动超精密机床,加工表面为凹形截圆锥台锥面.通过实验与理论分别获得PV面形误差,其相对误差为17.3%,证明基于机床体误差模型的低频PV面形误差预测是可行的.

Machined Form Error Prediction Based on Volumetric Error Model of Machine Tool

Meeting the requirement of part form accuracy can guarantee that uhra-precision equipment realizes its key functions. Many factors influence the part form accuracy, in which the volumetric error ofmachine tool is the most pivotal. The machined surface form error prediction is studied through establis-hing direct relationship between the machine error components and form error. A method of predictingfrequency domain multiseale form error based on the machine volumetric error model is proposed, whichcombines the volumetric error model, processing parameters and machining path, for predicting the multi-scale form error. This method can provide theoretical reference for machining path planning as well asmachine design, which can be applied for machining accuracy improvement. A case study for predictingthe PV form error was carried out on a five-axis ultra-precision machine tool, in which the conical surfaceof a concave circular truncated cone was machined. The relative error between theoretical value and ex-perimental value of the PV form error is 17.3% , which verifies the effectiveness of the method for predic-ting the low spatial frequency PV form error.