Thermal deformation control of a pipe structure frame CNC lathe - Evaluation of control effects of thermal deformation by considering thermal distribution

The miniaturization of many machine parts for machine tools is desired for the purpose of effectively utilizing space, energy saving, and realizing desktop factories. However, it is predicted that the reduction of the calorific capacity of machine leads increase in thermal deformation caused by downsizing of the machine. Thus, there are few effective report to reduce this thermal deformation. Therefore, in spite of the many requirements of the market related to the miniaturization of machine tools, a miniaturized NC machine tool has not been widely regarded. The conventional structure of machine tools such as a cast body or welded steel plate body is recognized as being the best. This preconception is one of the obstacles to solving this problem. We have developed a new CNC lathe with a pipe frame structure. This structure is expected to enable the miniaturization of machine tools while ensuring sufficient space for the discharge of cutting chips. In this structure, the heat transfer between the pipe elements and connecting blocks strongly affects the axial displacement of the pipes. Therefore, the heat transfer between the pipes can be reduced by controlling the temperature at the appropriate connecting blocks. The thermal deformation is controlled by using Peltier devices set on the connecting blocks. Results for the thermal deformation control of this lathe and the effects on workpiece dimensions by cutting are reported in this paper.