切削工况下机床主轴回转精度动态预测方法

Rotational accuracy is an important indicator of spindle machining performance. The existing measurement methods of the rotational accuracy are usually carried out by means of a standard ball and under idling conditions, which cannot take into account the influence of the load such as the cutting load. Therefore the existing methods are difficult to reflect the true accuracy of the spindle in the cutting state. Aiming at this problem, a dynamic prediction method of spindle rotational accuracy based on dynamic model is proposed. Firstly, a high-fidelity high-speed spindle-bearing system dynamics model is established, and the excitation load such as cutting force is taken as the input boundary condition. Then, the cutting force is measured by a dynamometer and modified and input into the dynamic model to realize the dynamic prediction of vibration response and radial rotational error of the spindle. A set of on - line measuring device for spindle rotational error is designed and manufactured, and the prediction results of the rotational accuracy are experimentally verified. The simulation and experimental results under different cutting conditions are compared and analyzed. The results show that the proposed method can accurately predict the variation of spindle rotational accuracy and provide a basis for the evaluation of spindle machining performance.