九轴联动叶片双刀铣削刀路平滑算法

Aiming at nine-axis twin-tool milling of blade profiles, a new path smoothing algorithm is proposed based on the geometric constraints in order to guarantee the smoothness of twin-tool paths and the synchronization of two cutters. Firstly, the structural constraint of two cutters in the nine-axis machine tool is analyzed, and the normal vector at cutting contact point is transformed into the cutter axis vector through rotation matrix for characterizing twin-tool pose. Meanwhile, the inclination angle and tilt angle of the cutter are calculated and the range of these two angles is determined to meet the twin-tool milling requirement. Secondly, the parameter increments in and between the cutting paths are calculated by iso-parametric solution on Δu_di, Δu_bi, Δv_di and Δv_bi, here Δu_di and Δu_bi are the parameter increments between two adjacent cutting contact points, one is on the dorsal surface and another on the basin surface of the blade, along the cutting direction; Δv_di and Δv_bi are the parameter increments between two adjacent cutting contact points (on the same aforementioned two surfaces) along feed direction, respectively. Finally, the self-defined coefficient is defined according to the range of milling area on the dorsal and basin surfaces of the blade, and the matching algorithm and twin-tool path smoothing algorithm are proposed. The twin-tool paths of rough machining are planned for typical turbine blade. The results of simulation and experiments show that the two surfaces of the blade can be simultaneously and entirely machined, and the contour errors do not exceed the tolerance range. Compared with the path planning algorithm considering the cutting force offset, the computational efficiency of our method is enhanced by 56%. In addition, the machining efficiency can be increased by about 41. 5% compared with the single-tool milling at equivalent cutting parameters.