Thermal optimization of an ultra-precision machine tool by the thermal displacement decomposition and counteraction method

Abstract

The thermal error of an ultra-precision machine tool has a great influence on machining accuracy. In order to improve the machining accuracy, the thermal performance of the machine tool has to be improved. In this paper, the thermal behaviors of a machine tool are studied by the finite volume element method (FVEM) considering the influence of temperature rise, preload forces, contact surfaces, and gravity. Then, a new thermal optimization method is proposed to reduce the thermal error in the designing stage, which is the thermal displacement decomposition and counteraction method. By the thermal displacement decomposition method, the thermal behaviors of each part are studied, and the thermal displacement of the tool nose is decomposed. Meanwhile, the design variables are determined to carry out the thermal optimization of the machine tool. By the thermal displacement counteraction method, the thermal deformations of different parts are counteracted with each other by minimizing the proposed objective function. Finally, the machine tool optimized by the thermal performance is built, and the machining tests are carried out to validate the proposed thermal optimization method.