New Prediction Method of Instantaneous Cutting Force in Finish Machining with consideration of Cutting Edge Roundness

摘要

This study deals with prediction method of instantaneous cutting force in finish machining with ball end-mill. In finish machining process, accuracy of generated surface is one of the most important factors that influences success of machining process. In order to estimate cutting error caused by elastic deformation on cutting tool, spindle and machine tool, it is required to predict quantitatively accurate instantaneous cutting force at the moment when objective part of workpiece surface is generated. In this study, we propose a new prediction method, which can cope with cutting condition using minute feed rate. The proposed prediction method consists of following new simulation models. One is the workpiece removal model, which is designed to consider influences of cutting edge roundness about cutting force and spring back. Another is the geometric description model of machined workpiece shape, which is designed to be able to estimate a reproduction of cutting error by trochoidal movement of cutting edges. In order to evaluate the effectiveness of introduced models, we develop a prototype simulation system and conduct experimental cutting using ball end-mill with throwaway chip. The measured cutting force in the experiment shows a good qualitative agreement with the predicted force.