Dynamic characteristics of conjunction of lengthened shrink-fit holder and cutting tool in high-speed milling

摘要

In high-speed milling of dies and moulds characterized by large-scale and deep cavities, how to design and select an appropriate cutter is a key to improve efficiency, quality and optimize machining parameters. This goal can be achieved by the lengthened shrink-fit holder with its high clamping force, excellent concentricity and easiness of touching workpiece, etc. At the same time the tool deflection and vibration is not allowed to ignore, thus to know more about the conjunction between the lengthened shrink-fit holder and cutting tool is necessary. In this study, attention is focus on the conjunction model between the lengthened shrink-fit holder and cutting tool in the way of a finite element analysis (FEA). The dynamic characteristics including natural frequency and mode shape of the conjunction model are analyzed and their influence on the machining quality in high-speed milling is discussed. The analysis results are verified by means of the experiment modal analysis (EMA). The results show that an accurate finite element model of conjunction of lengthened shrink-fit holder and cutting tool can be established combining the FEA and EMA technology. In addition, a reasonable rotation speed can be recommended for high-speed milling with less vibration based on the dynamic characteristics analysis.