Energy Consumption Analysis of Automatic Tool Change Processes

The automatic tool change system was used frequently in numerical control machining processes. Preliminary studies indicate that the power demand of an automatic tool change system is an important part of auxiliary units power demand for numerical control machining processes. Research to date on energy consumption modeling largely focuses on cutting processes while the power demand of automatic tool change processes is treated as a given constant. However, energy consumption modeling of automatic tool change processes is a method that has been overlooked in previous investigations. In fact, the tool change power demand and time vary depending on the turret motor rotation angle for changing tools. Thus, this study aims at solving the above problem by analyzing the power demands of different tool stations for changing tools. The energy consumption modeling method of an umbrella tool changer system was proposed to address the limitations of existing models and validated on a vertical milling machine. In this study, one tool change cycle was divided into five different power demand stages. This is different from the common method where the power demand of one tool change cycle is fixed. The milling case was investigated, and experimental results showed that the proposed modeling method can provide a reliable energy consumption prediction for tool change processes with high accuracy, which can assist manufacturers to develop potential energy saving strategies.