对液力变矩器导轮内外环剖面轮廓线的逼近问题进行研究,提出了一种基于误差控制、自动分段的多段圆弧逼近方法.根据导轮内外环剖面轮廓线方程,用数值方法计算出离散点坐标;用三点构造圆弧的方法近似求得内外环剖面轮廓线的曲率半径;以极角为自变量确定曲率半径的变化规律;用给定允许误差控制逼近圆弧的段数;用等差数列确定各个逼近圆弧的半径;利用线性插值公式和非开平方计算方法对圆弧参数进行推演计算;最后进行实际逼近误差的计算.采用面向对象的设计方法开发了参数化程序.用该程序可以完成全部计算,生成自动绘制导轮模型旋转体的AutoLisp程序,输出旋转体剖切曲面的点云数据,还可以输出数值模拟后处理编程的数据.研究结果表明,该方法是可行的,可以大大减少建模时间,具有工程使用价值.%The approximation of core and shell section contour line of torque converter stator was investigated.A new method, automatically segmenting arc approximation method based on error control, was proposed.According to the section contour line equation of core and shell, the coordinates of discrete points were computed by using numeric method.Adjacent three points were used to construct an arc so as to obtain a curvature radius.Polar angle served as independent variable and the variation of curvature radius was determined.The given allowable error was used to control arc segment number.Arithmetic sequence was used to determine approximation arc radii.Linear interpolation and none-square-root method were used to compute arc parameters.Finally, actual approximation error was computed.A parametric program code was developed by using object-oriented design.The program code can perform whole calculation, output an AutoLisp program used to generate a revolution solid of the stator model, output point-cloud data used to generate slice curve surfaces, and output data used for post-process programming of flow field simulation.Investigation results show that the method proposed in this paper is feasible, the time consumption of stator modeling can be reduced greatly, and the method is of engineering application value.
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