基于特征的直纹面5轴侧铣精加工刀位计算方法

提出了基于加工特征的直纹面5轴侧铣精加工刀位轨迹的计算方法,给出了误差估算方法。通过对直纹面微分几何特性的研究,用扭曲度来刻画直纹面特征,将直纹面划分为可展化曲面和非可展化曲面。对于可展化曲面,通过调整直纹面上母线方向的变化规律,使之成为可展曲面,以便在加工中获得无脊棱的光滑曲面;对于非可展化曲面,提出用最小偏置角原理来求取刀轴矢量,以使加工误差在刀具与被加工曲面切触状态下趋于最小,最终获得无干涉刀位轨迹。

AlGORITHM OF CUTTER POSITION IN 5-AXIS SIDE MILLING OF RULED SURFACE BASED ON SURFACE FEATURE

The algorithm of cutter position in 5-axis side milling of ruled surface based on surface feature is proposed and the scallop height estimating is introduced as well. The torsion degree is used to express the ruled surface feature according to differential geometrical structure. The ruled surfaces to be machined are divided into extensible surface and non-extensible surface. For the former, by means of adjusting the changing rate of straight generatrix, the surface can be reformed into an extensible ruled surface; for the later, tool axis bias angle is used to avoid interference, and the principle of the least bias being adopted to reduce the scallop height across the surface. And the interference-free cutter position can be obtained.