THREAD GROOVING METHOD AND DEVICE BY OVERLAPPING ULTRASONIC AND LOW FREQUENCY VIBRATION OF INTERRUPTED PULSE CUTTING FORCE WAVEFORM

摘要

PURPOSE:To cut an accurate internal thread by rotating a tool, while it is vibrated at a low frequency in a lead angle direction simultaneously with the ultrasonic vibration in an axial or circumferential direction, and applying an interrupted pulse-cutting force waveform acting on a workpiece in ultrasonic vibration, in the case of cutting a thread groove for a hard fragile material. CONSTITUTION:An electrodeposited tap 1 of diamond standard shape is rotated while it is vibrated at a low frequency in a lead angle direction by an electric stepping motor 22 with the ultrasonic vibration in a circumferential direction by using an ultrasonic torsional vibrator 3. While ceramics 44, serving as a workpiece, is also given ultrasonic vibration in an axial direction by a vertical ultrasonic vibrator 31, applying an interrupted pulse-cutting force waveform by the diamond tap 1, and an accurate internal thread is cut by injecting cutting fluid of water or the like from a fluid supply device 33. Thus in a hard fragile material of ceramics or the like, the accurate internal thread sharp with no chip in a thread ridge can be cut by the sense similar to a metal material.