【摘要】 由椭圆-偏心圆组成的活塞组合型外廓线,在高速插补时通常是对外廓线的型值点用三次样条曲线进行拟合,由于三次样条曲线拟合不能实现2阶参数(即C~2)连续而引起冲击,影响被加工活塞的轮廓及尺寸精度.为了减小冲击,将椭圆-偏心圆交点按奇异点处理,删除奇异点及其相邻角度范围的型值点,并采用五次样条曲线进行拟合.以重构后组合型线的加速度最小为目标,在满足精度要求的条件下,对可删除插值角度进行了优化.加工实验结果表明,优化后的活塞外圆能实现加速度无突变且轮廓满足精度要求.更多还原

【Abstract】 In the case of high-speed interpolation,the combined external piston profile composed of ellipse-eccentric circle is usually fitted with cubic spline curves at the data point of the external profile.Since the fitting of cubic spline curve cannot achieve the continuity of second-order parameters(C~2),the impact will originate,affecting the contour and dimensional accuracy of the processed piston.For the purpose of reduceing the impact,the method treats the intersection point of the elliptic-eccentricity circle as a singular point,deletes the singular point and its adjacent angle range,and then uses the quintic spline curve for fitting.To minimize the acceleration of the reconstructed composite line,we optimize the expendable interpolation angle under the condition of satisfying the precision requirement.Machining-experiment results show that the optimized piston outer circle can achieve no abrupt acceleration and the contour meets the precision requirements.更多还原