Research On Tool-Path Planning With The Rotary Surface Cutters Flank Milling For The Impeller Surface

Machining of complex parts impeller class is important and difficult in the field of numerical control technology. Its processing difficulty is mainly reflected in the cross-section of thin blades, curved shape of complex, tool paths serious interference and so on. Compared with the traditional processing methods, side milling have high working efficiency, good surface finish, low cost processing. And now five-axis CNC milling side of the impeller blades have become a trend. The tool for side milling cutter is usually cylindrical, conical cutters as the representative of rotary cutters. Most of the impeller blade surface is non developable ruled surface. And the principle error occur in side milling process. In view of this, this paper in a conical cutter as the main object of study, to explore suitable for rotary cutter tool path planning method in common.Based on the discrete data points the structure features of impeller blade surface and the functions and features of CATIA, the mathematical model and the physical model of the impeller blade surface is established by using quasi-uniform cubic B-spline interpolation technique, lay the foundation for further work.The tool path planning problem of side milling is studied based on particle swarm optimization algorithm. The cutter point on the axis to the conical surface distance is defined as the equivalent radius of the point corresponding to the optimal tool position, given the conditions that a single cutter shaft of each point on the distance to the ruled surface and the equivalent radius of the square of the difference is the minimum, thus the tool envelope for the ruled surface approximation problem transformed into the problem of optimal conditions of each cutter location. This paper gives the implementation process of solving the optimal tool axis trajectory surface based on particle swarm optimization algorithm.Combined with the rigid body kinematics and experimental design method, the paper put forward another tool axis trajectory generation strategy. This paper defines the set point to the projection of all points in the design of the tool axis surface method for normal mapping curve, and gives a theoretical calculation method of feature points, and then puts forward another single cutter position optimality criteria, namely each instantaneous normal mapping curves and characteristic line least squares approximation. Using rigid body kinematics method, the cutter shaft position with 3 rotational and 3 translational motion parameters is described. A single optimization conditions and 6 motion parameters of the non-dominant function is established. The optimal tool axis trajectory surface solution obtained by Latin hypercube experimental design method.