Finite Element Static Stiffness Analysis of the A/C Axes Bi-Rotary Milling Head

Abstract

A/C axes bi-rotary milling head is an important functional component in gantry type five-axis CNC machine tool. The static characteristics affect directly the machining accuracy of machine tool. The paper investigates the static stiffness of A/C axes bi-rotary milling head in gantry type five-axis CNC machine tool XK2320-5X developed by a domestic company. Because this product developed depend on the experience of designers, the machining accuracy of A/C axes bi-rotary milling head of primitive XK2320-5X type cannot meet the accuracy requirement under actual working conditions. On the basis of structure design, the static stiffness analysis of the milling head under two working conditions is carried out using finite element method. The deformations of the main mechanical parts in the milling head are obtained. The analysis results indicate that the static stiffness in direction X is the weakest of the milling head and the milling head shell is the most important factor of deformation. The work done provides foundation for further structure design and machining accuracy improvement of A/C axes bi-rotary milling head.