Improvement of Simultaneous 5-Axis Controlled Machining Accuracy by CL-Data Modification

Abstract

As the motion accuracy of 5-axis machining centers directly influences the geometrical shape accuracy of the machined workpieces, accuracy enhancement of the 5-axis machining centers is strongly needed. To improve the shape accuracy during the machining by a 5-axis machine tool, a method that modifies the CL-data based on the motion trajectory errors normal to the machined surface at each command point has been proposed. In this study, the proposed method is applied to simultaneous 5-axis controlled machining to improve motion accuracy. A normal vector calculation method for the simultaneous 5-axis controlled motion is newly proposed, and the compensation method is applied to turbine blade machining by 5-axis controlled motion. Measurement tests of the cutting motion for blade shape machining by a ball-end mill were carried out with a different control mode of NC. The CL-data for the machining tool path was also modified based on the calculated trajectory of the tool center point. Experimental results reveal that the feed speed and machining accuracy significantly depend on the control mode of NC, and that the shape accuracy can be improved by applying the proposed compensation method without any decrease in motion speed.