Dust Collection Validity and Effect of Hole Shape Accuracy of CFRP with Developed Hollow-Type Drill and Dust Collector

抄録

The drilling of carbon fiber-reinforced plastic (CFRP) has many important aspects, such as collecting the fine cutting chips. Serious problems relating to machining accuracy can arise when the fine cutting chips diffused into the air are deposited or mixed in the sliding surface and spindle unit of a machine tool. Moreover, the environmental aspects of fine cutting chips can seriously affect the health and safety of workers. Our group has developed a new hollow-type drilling device with a cyclone-type dust collection system, which aspirates and ejects fine cutting chips from a penetration hole in the central part of the drill shank to outside the cutting area. We produced the tools with drills both without a point angle for the counter-boring hole processing and with a point angle for general drilling. In this study the effect of the dust collection rate for cutting chip and the drilling hole shape accuracy are evaluated for the hollow-type drill with two different cutting edge shapes. The results demonstrate the possibility of suppressing the occurrence of fine cutting chips when the hollow-type drill edge is similar to the shape of general twist drill edges. The hole-finish surface properties were improved, and we obtained a higher dust collection rate.