Abstract
Effects of internal cooling for a cutting tool have been analyzed using the finite element method. Contact pressure at the tool-chip interface is so high that cutting fluid, which is normally supplied, does not work sufficiently for reducing crater wear. Internal cooling is aimed at enforcing heat transfer into the coolant which is introduced within a cutting tool, resulting in the decrease of tool temperature. Supposing the use of a heat pipe as a cooling device, which potentially has a coefficient of heat transfer more than 104 Wm-2K-1, optimum shape and position of a coolant path as well as the cooling characteristics were analyzed. It shows that tool temperature is decreased by 30 to 200°C by means of the internal cooling and there is no influence upon the strength of the tool. Besides, thermal displacement of the internally cooled cutting edge is found to decrease by a factor of 2 compared to that of a normal tool. This suggests that an internally cooled cutting tool is effective for precision machining.
