An integrated process–machine approach for designing productive and lightweight milling machines

Abstract

This paper provides an integrated approach for designing large milling machines, taking both mass reduction of mobile structural components and the maximum material removal rate into account. This approach considers a representative milling operation and a productivity target as a starting point, and then deals with the design of the machine to achieve the targeted productivity with structural components of minimum mass. The procedure is based on modeling the interactions between process and machine by means of a stability model of the milling process in modal coordinates. The model allows the identification of the mechanical design parameters that limit the productivity as well as the threshold values that must be met to ensure the targeted productivity. Those values are reached in an iterative procedure that minimizes the mass of the critical structural components of the machine. This approach has been applied to the re-design of an actual milling machine, on which, once built and adjusted, the machining tests conducted have shown increases above 100% in productivity, consuming at the same time 13% less energy due to mass reduction above 20% in mobile structural components. In this way, an eco-efficient milling machine that performs highly productive machining processes has been designed and built.