Developing continuous machining strategy for cost-effective five-axis CNC milling systems with a four-axis controller

摘要

This paper investigates the five-axis continuous machining strategy on cost-effective five-axis CNC milling systems, which is limited by simultaneous control of any four axes at a given time. The proposed strategy consists of (1) generation of five-axis continuous milling tool path for conventional five-axis machines using a CAD/CAM software, and (2) conversion of the generated tool path to four-axis tool trajectory based on a novel interpolation algorithm. The interpolation algorithm is built on the relationship between the position data of the tool and the displacement of the machine tool axis. The position of the interpolation point is determined by the offset distance of the interpolation point, and the error of the interpolation is controlled by the dichotomy method. Furthermore, two simulation case studies are conducted to verify the effectiveness of the proposed algorithm. One case study is on a standard 'S' test piece, and the other study is on a more complicated geometry - an impeller part. The generated five-axis continuous paths are converted to the four-axis trajectory by the proposed algorithm. Machining simulations are performed using both the five-axis continuous path and the converted four-axis continuous path. The conversion quality is found to be satisfactory for both cases.