BURRLESS DRILLING BY VIBRATION CUTTING APPLYING ULTRASONIC TORSIONAL MODE VIBRATION

摘要

Drilling system applying ultrasonic torsional mode vibration, in which a torsional vibration of 27 kHz is superimposed on a twist drill rotating at a constant speed, is newly designed and assembled by using BLT ( torsional bolt clamped langevin type ultrasonic transducer ) having high power of 200 W. A rotational speed of twist drill being selected at under one third of maximum vibrational speed, cutting resistance reduces to one fifth smaller than that without vibration because of instantaneous cutting mechanism within one period of torsional vibration. The drilling system enables the following advantages; reduction of burr at the outlet of hole, improvement of breakage and taking away of chip, elongation of tool life and so on, in practical drilling operations.