Vibration-proof boring bar and vibration-proof bar

摘要

PURPOSE:To produce high steady vibration isolating effect by slidably fitting tublar magnets in a central blind hole, and enclosing a bar-shaped magnet at the center of the tubular magnets with a gap in which variation in magnet force is little to variation in distance to facilitate coinciding of natural frequency between an internal construction body and a boring bar body. CONSTITUTION:A boring bar is machinedly formed with a central blind hole 6 which is closed on the side of a cutting tool 5, and tubular magnets 10, 12 are slidably fitted in the hole 6. A bar-shaped magnet 15 is enclosed at the center of the tubular magnets 10, 12 in such condition as they can keep a fixed gap and mutually repulsive action between them, and the magnets 10, 12, 15 function as a built-in dynamic vibration reducer. High damping effect of the dynamic vibration reducer prevents the resonance of the boring bar, and cutting work can therefore be performed without the occurrence of chattering.