Reduction of energy consumption has played a significant role in industry. This paper describes a study on reducing energy consumption by machining process improvements. Methods of reducing energy consumption in a manufacturing line consisting of multiple machines are verified. First, to consolidate the processes, a series of horizontal machining centers are replaced with a 5-axis machining center. The energy consumption can be reduced by approximately 8 %. The cycle time also becomes shorter by approximately 20 %. Since transfer equipment is not needed in the process, reduction of energy consumption by eliminating the equipment can also be expected. Second, energy consumption in the machine tool is classified in detail. As a result, it is found that coolant related equipment consumed approximately 54 % of the overall energy. Thus, the efforts are focused on the equipment. Coolant consumption of each pump is investigated. Based on the result, the coolant pumps can be concentrated in a single unit. In addition, energy consumption of the through-spindle coolant system is reduced and coolant pressure is optimized. Herewith energy consumption can be reduced by approximately 26 %. Finally, the inverter frequency is optimized. As a result, the overall energy consumption in the manufacturing line is reduced by approximately 42 %. (C) 2012 The Authors. Published by Elsevier B. V. Selection and/or peer-review under responsibility of Prof. Eiji Shamoto
