抄録
This work presents the investigation of the errors induced by cutting forces. In order to predict tool deflection, an evaluation of the stiffness of the system formed by the machine-tool, shank and toolholder, collet and tool is presented. Cutting forces induce the deflection of the system, and consequently an error appears on the machined surface. Cutting forces have been estimated using a semi-empirical approach valid for complex surfaces and a previous study of the deflection chain in the cutting process is presented too. Results show that stiffness of the slender and flexible tools is 15 times lower than that of the machine and toolholder system. But this correlation is only 57 times lower for shorter and thicker tools. The final application is the ball-end milling of complex surfaces (moulds and dies), an operation commonly performed in the finishing of moulds or forging dies, where errors of more than 70μm are not unusual.
