Research On NC-machining Theory And Technology Of Shoe Last

In this thesis, the reverse engineering technology of shoe last is taken. The researching works include acquiring tool path through three-dimensional scatter data points of shoe last, making NC machining program through post-processing. Then these algorithms are proved in the 4-axis NC milling machine tool. The main works in this thesis are as follows:1. In this thesis, a NC tool path generation plan based on a cylindrical spiral is proposed. Build a cylindrical spiral which contains all of scatter data points of shoe last, and build a axis through the head and tail of the shoe last. Divide the scatter data points through the cylindrical spiral and axis.2. A method of constructing local curved based on the scatter data points is proposed, construct local curved surface of the shoe last by triangulation on three-dimensional data points, and optimize triangles which have divided. We may obtain the good effect triangles.3. Calculate cutting contact point through algorithm of computing intersection between line segment and plane. The intersection of line segment and plane is the cutting contact point. The account of normal vector can be computed by information of triangles.4. The method of computing cutter location data and tool shaft vector is proposed. Compute the cutter location data by tool selection, and match B-Spline curve which can compute the tangent vector of cutter location data.5. The post-processing of the 4-axis NC milling machine is also analyzed and the method of the post-processing is given by which compute the program.6. An experiment is implemented on 4-axis NC milling machine. The results indicate that the proposed algorithms are feasible.