A novel impact load model for tool-changer mechanism of spindle system in machine tool

作者:Shen, Huipeng; Dong, Huimin; Wang, Delun*; Wu, Yu; Wu, Guanglei
来源:International Journal of Advanced Manufacturing Technology, 2018, 94(1-4): 1477-1490.
DOI:10.1007/s00170-017-0960-3

摘要

In this paper, a novel impact load model for a tool-changer mechanism of spindle system in machine tool is proposed to determine the impact load of tool-changer during unclamping tool. The tool-changer mechanism is composed of cam (frame), shift fork, headstock, and spindle system with cutter bar. In order to build the model, the working principles of the tool-changer and the spindle system structure are briefly introduced, and the load transmitting path of spindle system is analyzed. By combining the kinetostatic behavior and energy conservation law, the computational model to calculate the impact load of tool-changer mechanism is established to obtain the theoretical result. Moreover, a transmitting model of the impact load is set up to collect the experiment result in the light of bolted connection equivalent model, which is in agreement with the impact load transmitting path. With the computational model, the theoretical result of impact load can be determined based on the motion of shift fork and cutter bar system constrained by both headstock movement and cam contour curve. Using the transmitting model, the experimental result of impact load can be calculated by measuring check ring strain. From the comparison of the theoretical and experimental results, it is found that the experimental measurement agrees well with theoretical analysis. This means that the built model is valid, which can be used to predict the impact load during the unclamping tool process. This work aims to provide some fundamental analysis for both the design of the spindle system and the selection of the spindle bearings of high-performance machine tools.