Vector modeling of robotic helical milling hole movement and theoretical analysis on roughness of hole surface

SHAN Yi-cai(单以才)^{1, 2}, HE Ning(何宁)¹, LI Liang(李亮)¹, ZHAO Wei(赵威)¹, YANG Yin-fei(杨吟飞)¹

(1. College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China;
2. Nanjing College of Information Technology, Nanjing 210046, China)

Abstract:To avoid the machine problems of excessive axial force, complex process flow and frequent tool changing during robotic drilling holes, a new hole-making technology (i.e., helical milling hole) was introduced for designing a new robotic helical milling hole system, which could further improve robotic hole-making ability in airplane digital assembly. After analysis on the characteristics of helical milling hole, advantages and limitations of two typical robotic helical milling hole systems were summarized. Then, vector model of helical milling hole movement was built on vector analysis method. Finally, surface roughness calculation formula was deduced according to the movement principle of helical milling hole, then the influence of main technological parameters on surface roughness was analyzed. Analysis shows that theoretical surface roughness of hole becomes poor with the increase of tool speed ratio and revolution radius. Meanwhile, the roughness decreases according to the increase of tool teeth number. The research contributes greatly to the construction of roughness prediction model in helical milling hole.

Key words:helical milling hole; robotic hole-making system; vector modeling; theoretical surface roughness