Research on scientific evaluation method of thermal characteristics of CNC machine tools based on robustness

Abstract For the thermal test of CNC machine tools, the existing scientific researchers measured their main axis thermal deformation characteristics as a test index based on international standard ISO 230-3: 2020. However, according to the team's research, it is found that the thermal characteristics of machine tools reflected by the positions of different fixed points of different types of machine tools are quite different, and cannot fully and accurately reflect the thermal characteristics of machine tools. The thermal characteristics of modern machine tools are not only closely related to the structure, but also and the compensation model are inseparable. Therefore, on the basis of international standards, this paper selects three-axis and five-axis vertical machining centers as the research objects, And based on the current international advanced machining equipment robustness theory, combining the robustness model prediction effect and machine tool thermal characteristics, a scientific machine tool thermal characteristics detection method and evaluation standard are proposed, which can effectively demonstrate the actual performance of the machine tool. The research results show that the rigid and stable spindle of the three-axis CNC machining center can choose the fixed position of the worktable to evaluate the thermal characteristics of the machine tool, but it is necessary to optimize the position of the fixed point of the worktable according to the thermal characteristics prediction model. However, the rigidity of the spindle of the five-axis machining center is poor, which requires the modeling of the whole working area and the evaluation of thermal characteristics to be more scientific. Simply using the three-axis CNC machining center to select the fixed point of the worktable as the evaluation of the thermal characteristics of the machine tool has a large error.