基于B样条曲线建模预测复杂型面动态车削力

Dynamic force prediction model in complex surface turing based on B-spline curves

针对复杂型面切削中斜角切削剪切滑移变形的切削力模型的局限性,建立了基于刀具-工件接触区域动态特性的切削力预测模型.通过分析复杂型面车削中动态接触区的多种情形,采用B样条曲线插值参数化的方法构建刀具-工件接触区域动态边界的统一数学模型,基于该模型计算切削层面积、接触刃长度和摩擦力方向角等模型参数.利用直线车削试验确定预测模型的切削力系数和刃口摩擦系数,对包含有凹形型面、凸形型面和圆柱面的复杂型面车削进行了切削力预测,预测结果与实际测量相比误差在1015％以内,验证了所建模型的可行性和准确性.

Aiming at the limitations of cutting force model constructed by oblique cutting shear slip deformation, anew cutting forces prediction model base on dynamic chip loads was presented. Various kinds of chip loads in complex surfaces turning process were classified, and several Pspline curves were used to construct a unified mathematical model of the dynamic chip loads. The model＇s parameters such as chip loads＇ area, cutting edge contact lengthand effective lead angle were evaluated base on this model. The edge friction coefficients and cutting coefficients inthis model were determined by straight turning experiments. The experiments on cutting force measurement in turning of a complex surfaces workpiece with convex, concave and cylindrical surfaces were performed. Those resultsshowed that the results from the prediction model had good agreement with the experimental results within 10- 15percent error.