Computer-Aided Programming For Curved-Surface Machining On The TH5632C Vertical Maching Center

The thesis aims to design the computer-aided program for the curved face machining based on the small three coordinate axes vertical machine center. In the two axes linked numerical control machine center, the spherical cutter is firstly used to subdivide the curved face to a plane curve that is parallel to one axis. Then the line, the arc and the parabola are adopted to form a fitted curve. Finally, the curved face is aggregated by each curve.Based on the analysis of the present domestic and overseas situation, the thesis discusses the normal techniques and arithmetic of fitting and approaching non-circularity curves and tabulate curves by line and arc in the numerical control milling. For the pretreatment of the plane non-circularity curve, the thesis then points out the approximate arithmetic of non-circularity curve, namely the point-to-point approaching and the flexible steps method, by using equal error line approaching. While for the pretreatment of the tabulate curves, the first step is to approach tabulate curves with accumulating cube parameter style curves. Then the double-arc is adopted to fit the cube parameter style curve. Finally the coordinate of nodes on the tabulate curve is calculated. Meeting the requirement of cut accuracy and real-time control, the thesis aims at achieving the above algorithm with C Language. Meanwhile, the summary of the advantages and disadvantages of each the algorithm lays the foundation for its implementation in the numerical control system and plotting system.Therefore, the thesis has been organized in the following way.Firstly, it will summarize the contents and requirements of numerical computation in the numerical program, in which the calculation of nodes coordination may be the most complicated. The approaching error δ≤δ允 and the real-time control are important and necessary during the selection of optimum nodes algorithm for configuration.There are three algorithms in the approaching non-circularity curve with line, namely the equal interval algorithm, the equal arc algorithm and the equal error algorithm. In the thesis, the computer programs of these algorithms will be realized with C Language. Furthermore, these programs can realize the computer interpolate nodes algorithm of three normal curves, including parabola, ellipse andhyperbola.There are also three algorithms in the approaching non-circularity curve with arc, namely the circum flexion algorithm, the three-point circle method and the tangency circle algorithm. In the thesis, the double-arc algorithm and its flowchart will be mainly discussed in approaching non-circularity curve.For the tabulate curve, the cube parameter style curve will be firstly adopted to fit the curve. Then the double-arc style curve will be implemented. The computer program and the running results with C Language will be included in this section based on examples. Finally, the thesis will discuss the selection of step length, string space and radius of spherical cutter in the three coordinate axes and two axes linked machining center based on the practice of NC machining for revolution surface parts.