三阶切触法加工自由曲面无干涉刀位规划

Interference-Free Tool Positioning for Five-Axis Sculptured Surface Machining Using Third-Order Point Contact Approach

基于三阶切触法刀具包络曲面的局部重建原理,提出了刀具可行空间约束下平底刀加工自由曲面的无干涉刀位规划方法.通过工件表面到刀具轴线的距离来分析刀具与工件的局部和整体干涉,并解析求解二阶切触刀具姿态,进而建立二阶切触无干涉刀具可行空间.在此基础上,通过计算设计曲面与包络曲面沿进给垂直方向的诱导法曲率导数,在可行空间内优化搜索最接近三阶切触的刀位.拉伸曲面和螺旋曲面的刀位规划和切削带宽的计算结果表明,该方法可以有效地避免刀具干涉,并显著提高加工效率.

Based on the third-order local approximation of tool envelope surface,an interference-free tool positioning strategy was proposed for five-axis sculptured surface machining with a constraint on the tool feasibility space.The tool feasibility space is constructed by analyzing the local and global interferences,which is indicated by the distance between the design surface and the tool axis.On this basis,the tool orientations are adjusted and optimized to achieve the optimal contact between the tool envelope surface and the design surface within the computed tool feasibility space.The numerical examples indicate that the proposed method can avoid interferences effectively and improve the machining strip width greatly.