Analysis of Dynamic Behavior of Boring Tool Holders

Cantilever cutting tools are commonly used in drilling and boring. Since in the most of cases the boring is the last operation step in finishing holes, the requirements on tolerances and surface finish are consequently high on this process. This paper considers the boring process performed on a machining centre, i.e., with stationary workpiece and rotating boring bar. A novel concept for a boring tool with stable cutting geometry and good vibration dissipation is presented. This concept demonstrated high stability and high precision cutting. A dynamic model for machining process is presented. The model is further used to calculate the dynamic stability of the boring process. The main objective of the research presented in this paper is to characterize the machinability of hard alloy steel material during boring with focus on dynamics of various types of tool holding systems and their influence on the cutting process stability in terms of tool wear, cutting forces, vibrations, acoustic sound, surface finish, and modal parameters