Study on the Thermal Deformation Compensation of Machine Tool in the Condition which the Heat Source Temperature Changes
This paper describes an experimental study for the thermal deformation compensation under control of machine tool，in the condition which the heat source temperature changes with time. We made the machine model in which the piezo-electric element is joined in the machine construction parts，in order to compensate the influence on cutting accuracy，which is caused by the thermal deformation of machine tool，and constructed a compensation system of the thermal deformation. The experiment was performed by using this system，with the following procedure. First，if the relative displacement of cutting area is represented asδ=Ki(θA-θB) -Kcθc [Ki and Kc are compensation coefficient] by measuring the surface temperature at two specific places of machine model: θA and θB，and the mean surface temperature at constraint part of machine model: θc，the equations how the compensation coefficients: Ki and Kc are calculated can be deduced. Next，by means of comparing the relative displacement in cutting area calculated by these compensation coefficients and the experimental relative displacement，we set up a coefficient to correct the compensation coefficients and thereby constructed the procedure for compensation experiment of thermal deformation. By means of this compensation method the experiment was put in operation. As a result，this confirmed that the compensation of thermal deformation with high accuracy was possible enough，in the condition which the heat source temperature of machine tool changes with time.
Departmental Bulletin Paper