An Analytic Method of Computing the Envelope Surface of General Cutter with Runout in 5-axis Machining for Manufacturing Systems

Qiang Guo ； Ge Qing ； Yan Jiang

《中國機械工程學刊》 38卷4期 (2017/08) Pp. 403-412

摘要

1Derived from the setting and manufacturing errors, cutter runout, which has influence on the cutter envelope surface and the quality of the machined surface, is almost inevitable in 5-axis machining process of manufacturing systems. Therefore it is necessary to integrate the runout into the modeling process of the cutter envelope surface to simulating the machining process realistically. In the paper, a new analytic method, which considers the cutter runout effect in 5-axis machining, is proposed for computing the envelope surface of a general cutter. In the proposed method, the cutter runout is first defined using five parameters: offset distance, inclination angle, location angle, length of cutter edge and initial angle, and then is integrated into the calculation of the rotational surfaces of all cutter edges about the spindle axis. According to the basic properties of the rotational surface, two strategies calculating the normal of the rotational surface are given, which do not involve the partial differential of the rotational surface, thus avoiding the disadvantage of the numerical method. At the same time, the formula of velocity vector of a point on the rotational surface is also derived. Based on the obtained normal and velocity vectors, the analytic model of calculating the general cutter envelope surface along the tool path is given. Finally, an example of 5-axis machining is used to verify the validity of this method, and the influence of the runout on the cutter envelope surface and the geometry error are also discussed in detail.

關鍵字

analytic method ； 5-axis machining ； envelope surface ； cutter runout ； geometry error