用二阶密切曲率法加工自由曲面

采用二阶密切曲率法，即采用中凹的盘形铣刀取代传统的球头或鼓形铣刀，在每一行程中让刀具轴线相对于工件按特定的规律摆动，使得在垂直于进给方向的法截面中，由刀尖轨迹形成的包络面与理论曲面的法截线具有相同的1阶～2阶导数，从而在保证加工精度不变的前提下，使切削带宽度大幅度增加，提高加工效率。主要讨论了刀位及刀具轨迹的算法。

MACHINING SCULPTURED SURFACES BY SECOND ORDER CURVATURE CATERING

By means of using a disc cutter with a concave end instead of traditional ball ended or flat ended ones,and adjusting the cutter axis to move relatively to the component being machined according to some special rules,the envelop formed by the trace of the tool nose in each pass and the required surface have the same derivatives up to the second order in the plane normal to the feeding direction Thus the machining width in each tool pass increcasses greatly and efficiency is raised highly while the same accuracy is guaranteed The algorithm of tool position and traces is discussed mainly