辊筒模具微透镜阵列的慢刀伺服成形加工

In order to realize the high-efficiency and high-precision fabrication of micro-lens array in a large-sized drum lathe, a study on tool path fitting and servo parameter optimization for micro-lens machining with slow tool servo was presented theoretically and experimentally in this paper. The original trajectory characteristics of the micro-lens array were analyzed first, and the chatter marks on the micro-lens surface were caused by sharp points at the original machining trajectory. Secondly, a method was proposed to fit the machining trajectory of the transition section using cubic spline interpolation and Fourier series fitting in order to ensure the trajectory's continuity of the second derivative. Finally, the capability of dynamic response was improved by adjusting the servo parameters, so that the follow error (FE) of the feed axis caused by the inertia and damping effect was reduced with the optimization of machining trajectory. Machining experiments on micro-lens with diameter of 800 μm and depth of 26.7 μm were carried out. The results show that the homemade ultra-precision machine can fabricate eight micro-lenses per second with 300 nm FE, and the chatter marks of the micro-lens surface caused by sharp points are eliminated. The diameter error of micro-lens is 1.075% of the designed value. The fitting method has a good effect on the surface quality of micro-lens array.