Power losses in machine tools, e.g. during production process, are converted into thermal energy. This leads to a warming of the machine frame and further machine parts and accordingly to the displacement of the tool center point (TCP) of the machine. Consequently, the accuracy of the machine during the production process is reduced. The warmed-up parts or components need to be cooled; therefore, fluidic systems are installed to prevent this effect. Previous research projects mainly focused on the energy demand of the machine tool and its main drives, reducing the energy consumption by developing more efficient components and control strategies. However, the thermal behavior of the fluidic systems, especially of the cooling system, has not yet been described in detail. Therefore, a detailed analysis of the existing cooling system and its effectivity is necessary.
The main target of this paper is to analyze the thermal behavior and improve the system structure of the cooling system in a demonstration machine tool. This investigation will help to examine the efficiency of the cooling system for an idle and a manufacturing process. This makes it possible to study new concepts for the system structure of the cooling system in order to ensure a uniform temperature distribution of the machine tool at minimal energy consumption.
Firstly, the paper will describe the main fluidic systems of the demonstration machine DBF630 with a special focus on the cooling system. Secondly, with the aid of experimental investigation the thermal behavior of the cooling system will be investigated. Furthermore, a network-based model of the cooling system for two processes is developed and validated against the measured data. Lastly, the new concept of a decentralized supply unit will be studied with the network-based simulation model.
It can be shown that the decentralization of the cooling system has a high potential towards a better thermal behavior and a lower energy consumption of the machine tool. The simulation results show a more stable temperature profile of the components as well as a lower energy consumption of the cooling system.
Keywords: Fluidic system, Machine tools, Simulation, Cooling system, Thermo-elastic deformation, Energy consumption