A novel approach to model the energy consumption of machine tools for machining cylindrical parts

Abstract

Machine tools plays a significant role in manufacturing industries and are unfortunately responsible for huge energy consumption and associated greenhouse gas emissions. In industry, the length and diameter are reduced to obtain the final dimensions of a cylindrical part. Typically, external turning operation is used to reduce the diameter of the part i.e. Constant-Material Removal Rate (CMRR) machining process and facing is conducted to reduce the length of the part i.e. Variable-Material Removal Rate (VMRR) machining process. In the past, energy evaluation models for machine tools are developed based on CMRR machining processes only, while the machining of a cylindrical part requires both CMRR and VMRR machining processes to manufacture the final product. In the present study, the energy consumption of a machine tool is divided into different energy modules: start-up, standby, spindle acceleration, idle, rapid positioning, air-cutting, CMRR machining process and VMRR machining process. Energy consumption models for each module are developed and integrated to establish the total energy consumption model for a machine tool. Experiments are conducted on a LMW-Smarturn CNC lathe machine tool in the dry and wet environment to obtain the fitting coefficients of the developed models for different energy modules. The validation test results show that the developed model's accuracy is more than 97 %. The developed model can be applied in the industry by the process planners to identify the most energy-efficient process plan before the actual machining of a cylindrical part.