特殊ぎりによるアルミニウム (2S) 板の穴あけについて

抄録

Aluminum (2S) plate is inferior to aluminum alloy plates in drilling machinability, because aluminum is a very soft material. Drilling tests were performed on aluminum plate to obtain proper drilling conditions of fishtail point drill, having a specially ground shape of tip, for good accuracy in the dimensions of drilled hole and small drilling resistance. That is, the accuracy of drilled hole was investigated with respect to diameter of hole inlet, diameter of hole outlet, heap at the hole inlet, burr at the hole outlet, etc. as well as drilling resistance by various shapes of the drill tip.
As the results, the proper drilling conditions for aluminum plate obtained in the experiments were as follows:
Chisel edge angle……about 140°
Fishtail angle……about 170°
Lip clearance angle……about 6°
Height of chisel edge……about 1mm