Abstract:  The shapes of the initial blanks and the final products are quite different in the complex curved surface machining for some brittle materials, such as natural stone and artificial crystal. The large removal of rough machining material leaded to the low processing efficiency and serious tool wear. A new solution was proposed based on the cooperative removal of wire saw cutting and point-cutting for the high-efficiency rough machining. According to the characteristics of wire saw processing, a new modeling method was proposed herein. The digital model of final product was layered, the polygons were used to envelope the two-dimensional outer contour curves of each layer, a ruled surface model was established with fitting the polygons between the layers. The influences of different ruled surface models constructed by different envelope polygon sides and connection methods on roughing processing time were analyzed. The simulation results show that although increasing the numbers of polygon sides or rotating between layers may reduce the volumes of remaining unprocessed materials, the overall rough machining time increases, which is not conducive to improving efficiency. The rough machining time may be used as a comprehensive evaluation index to optimize the construction of the ruled surface model.

Key words: wire saw cutting, ruled surface model, brittle material, simulation

摘要： 针对天然石材、人工晶体等材料复杂曲面加工中，初始毛坯与最终产品形状差别较大，粗加工材料去除量大，导致加工效率低、刀具磨耗严重的问题，提出了一种基于线锯加工和点加工协同去除的高效粗坯加工的解决思路。根据线锯加工特点，提出了对最终产品的数字化模型进行分层处理，利用多边形对各层二维外轮廓曲线进行包络，将层与层之间的多边形进行顺序拟合得到相应直纹面模型的建模思路。分析了不同包络多边形边数、连接方式所构建的不同直纹面模型对粗坯加工时间的影响。仿真结果表明，虽然增加多边形的边数或者通过层间旋转可以减小剩余未加工材料体积，但整体粗坯加工时间反而有所增加，从而不利于提高效率。粗坯加工时间可作为综合评价指标来优化构建直纹面模型。

关键词: 线锯切割, 直纹面模型, 脆性材料, 仿真