Thermal Deformation of Machinetool-workpiece System Caused by Accumulating Chips : 1st Reaort; Thermal Conductivity of Accumulating Chips

Abstract

One of the causes of the thermal deformation of a machinetool-workpiece system is the heat of chips piled on it. The amount of the thermal deformation due to this cause, however, is hardly yet known. Because, the values of thermal conductivity of accumulating chips and thermal contact resistance between accumulating chips and the surface of the system are hardly clarified. In this paper, the thermal properties mentioned above have been experimentally investigated by using accumulating chips made of different kinds of material and under different cutting conditions and moreover a theoretical investigation has also been carried out considering a model of accumulating ideal chips. From above results, it has been made clear that the value of the thermal conductivity of accumulating chips can be estimated by using the values of the thermal conductivity of the material, the void ratio and the number of chips per unit volume and that the value of thermal contact resistance can be approximately estimated by using the same factors mentioned above.