Modelling of energy and resource-efficient machining
The key goal of high performance cutting is to increase the material removal rate and product quality combined with a decrease of the cost of resources and energy. Energy and raw material prices are expected to rise as demand increases in the near future. Thus, the share of energy costs will have a much more significant impact in the overall production costs. The minimisation of energy consumption per unit material removed becomes, therefore, a very important goal in investigations of machining processes. The present study focuses on the development of an energy balance of the drilling process. It considers the process energy, the efficiency of the machine during the cutting process, and the tool wear with the aim of finding conditions requiring minimum energy and ressource consumption. The influence of removal rate, tool type, and lubrication on the energy and ressource consumption are analyzed using experimental drilling tests on cast iron. During the investigation it was found that the energy efficiency increases with an increase of the removal rate. Machining with high feeds and cutting speeds resulted in lower energy consumption per drilled hole. In the case of dry maching, the machine efficiency could be increased but on the other hand the tool wear and the resulting tool cost rise significantly. The experimentally determined resource and energy balances laid ground for a modelling approach based on 3D Finite Element simulations of the drilling process. The process energy and energy efficiency of drilling on high-strength steel were numerically determined to show the validity of the approach as a process planning tool in the development of resource-efficient metalworking chains.