CUTTING EDGE POSITION CHANGEABLE CUTTING WORK DEVICE

摘要

PURPOSE:To easily change a cutting edge position and to improve the support rigidity of a cutting tool by providing an eccentric rotating member deflected from the shaft center of a rotary shaft and held by the rotary shaft and the cutting tool the cutting edge of which is mounted at a position deflected from the shaft center of the eccentric rotating member and rotating together with the eccentric rotating member. CONSTITUTION:A rotary shaft 45 is constituted by fixing an adapter 38 and a cylindrical casing 44 to a main shaft 10. An external thread part 48 deflected from the shaft center of the rotary shaft 45 and an eccentric rotating member 54 deflected by the same amount as that of the external thread part and rotatable about the shaft center of the external thread part 48 are held. Chips 64, 66 are fixed at end positions deflected from the shaft center of the eccentric rotating member 54. According to the start of a motor 116 connected to the main shaft 10, the main shaft 10 moves forward and the chip 64 moves outward to bore. When the main shaft moves backward, a boring work is performed by the chip 66. Thus, the amount of abrasion of a cutting part is decreased.