Reduction of precise machining centre column thermal deformations caused by changes in ambient temperature by means of liquid cooling

Abstract

This paper describes various internal cooling methods and conditions aimed at reducing the displacements of the vertical jig centre column as an isolated unit caused by fluctuations in machining room temperature. The column's internal walls with horizontal and vertical ribs were cooled by the flow of liquid coolant from top to bottom. The cooling process was studied changing the rate of coolant flow and the method of flow generation. The interactions between the thermal phenomena occurring in the column and the conditions prevailing in the machine tool operating room and those occurring in the column areas cooled by the forced flow of liquid coolant are discussed. The FEA Abaqus System and numerical simulations were used to study the heat transfers and to accurately model the displacements. The results of the computations were experimentally validated in industrial operating conditions. On the basis of this study a precise model of the behaviour of the column in cooling conditions was created and the effectiveness of the considered ways of cooling the ribbed internal walls of the jig centre column was evaluated.It has been shown that the division of the column channel into several sections and the spraying of cooling liquid in combination with gravity flow significantly increases the cooling efficiency.