用切触线法加工曲线轮廓

用切触线近似表示满足正则条件的曲线,将切触线沿法向偏移刀具半径大小位置,以计算得到曲线轮廓数控铣削的刀位轨迹,简化了常用的隐式方程或参数方程形式计算刀位数据的过程。分析了误差影响的因素并提出了控制方法;以摆线的轮廓加工为例,阐述了该算法的正确性与高效性。该方法可移植到运算能力较强的数控系统中,并可作为乘积型曲面刀位点数据计算的基础。

Machining curved contour by contact curve

The curve which is in accord with regular terms is expressed by its contact curve approximately, and the cutting location track of each interpolation point is generated based on the normal vector offset of the tangent curve with respect to the milling cutter radius. The calculation of the cutting location data, which is expressed by latent or parameter form, is simplified. The factors which cause the tolerance are analyzed,and the controlling means of tolerance is presented. An example of cycloid machining is given to show the validity and efficiency of the method. The method of contact curve can be transplanted to the computerized numerical control(CNC) system which has enough capability of calculation, and it also provides a basis for the calculation of the cutting location data of product curved surface.