Heat Flux Estimation at Heat Sources of Machine Tools by Solving Inverse Problems

Abstract

An increase in frictional heat due to the increase in rotational speed and feed rate causes thermal deformation of machine tools, resulting in a decrease in machining accuracy. To establish a method for reducing thermally induced machining errors of machine tools, a method has been proposed to estimate the heat flux acting upon a machine tool body by solving inverse problems. Experiments were carried out with the cross slide of a machine tool. Using the heat flux estimated at the heat source, the temperature rise of the body in a steady state could be obtained with sufficient accuracy. Effects of both the number of evaluating and measuring points of the temperature on the estimation accuracy were also examined experimentally. More accurate estimation of the heat flux requires that the number and position of both temperature measurement points and candidates for heat sources are selected considering how the machine tool is actually operated.