炭素繊維強化プラスチックを対象としたプラネタリ機構による穴あけ加工に関する研究 (第2報)

—傾斜プラネタリ加工用スピンドルの開発—

抄録

The study deals with development of the inclined planetary milling spindle unit. Although CFRP and composite materials are known as difficult-to-cut-material due to their abrasive action for intensive wear of cutting tools, they are widely used as structural materials in recent aviation industries. The orbital drilling technique is one of possible solutions for making hole drilling faster and more effective in aviation assembling process. However the orbital drilling has some drawbacks such as vibration and cutting with 0 velocity point. In order to improve machinability of the orbital drilling, the authors propose an inclined planetary milling system which is inspired by the oblique and helical milling by 5-DOF machining center to avoid cutting with 0 velocity point. Eccentricity is realized by a few degrees inclination of tool rotation spindle and it can reduce mechanical vibration. In the study, analysis of geometric machining model of the inclined planetary milling has been considered. A prototype of the spindle unit was developed and actual drilling experiment were carried out. Comprehensive observation revealed that vibration, machining force, burrs and delaminations are greatly improved in comparison with the orbital one. This inclined planetary milling method has some advantages and its practicality and usability has been demonstrated.