Abstract
Development of a CNC lathe having a milling spindle has resulted in an improvement in the productivity of shafts that have a straight groove and a flat surface. However, for milling of shafts having a large length and a small diameter, workpiece deflection caused by the cutting force causes an increase in surface roughness of machined portion and chatter vibration. This study deals with an analysis of workpiece behavior and optimization of machining conditions with regards to milling of a shaft having a small flexural rigidity using ball end mills. In this paper, the workpiece deflection is analyzed based on calculated results of cutting forces obtained by using a cutting model proposed in previous papers. The predicted results are good agreement with the experimental results. Analysis of the resonance frequency of the workpiece is performed, and the relationship between the rotational speed of the spindle and displacement of the workpiece is clarified.
