Development of inclined planetary milling machine with automatic tool axis inclination instrument

Abstract

The study deals with a novel drilling technique of carbon fiber reinforced plastic (CFRP) with high precision and efficiency. The characteristic of high specific strength of CFRP. It enables to reduce the mass of the structure, improve the fuel economy, and reduce the environmental load. Alternating structural materials to CFRP for various products are ongoing. However, due to the structure of CFRP, burrs and delamination occurs when drilling a hole. Presently, it is reported that the helical machining and the planetary drilling processes are efficient to avoid burrs and delamination. Even though, by using those methods, there are limit to improve the circularity and the surface roughness of the hole. It is due to the vibration caused by the structure of the machine.In the research, we suggest the inclined planetary milling to solve the problems. The inclined planetary milling is a drilling method with a precession movement, which is performed by rotating an inclining spindle in the rotation of the tool. The inclined planetary milling enables to reduce the vibration of the machine, miniaturize the machine, improve the quality of the hole and reduce the machining cost. In our previous research, we have fabricated a prototype machine, carried out drilling experiments and confirmed its superiority to other machining methods. In the case of the prototype, the dimension of the hole sets manually. It does not seem practical and limits the conditions of experiments. In the study, we fabricated a new prototype that enable to set in practical conditions, conduct experiment and confirm superiority toward other processing methods.