| 摘要 |
PURPOSE:To select a circumferential setting angle of a tool and situate a chip discharging groove to an angle favorable in dischargeability, by installing plural pieces of a bearing surface on the circumference of a shank part of a drilling tool in the circumferential direction. CONSTITUTION:A drill is attached to a lathe in a way of fitting its chank part 14 in the drill inserting hole. At this time, the drill is inserted so as to cause two straight grooves 13b to be situated sideways to a drill axial center so as to make chips easily dischargeable, and it is clamped with a clamping bolt 25 pressed to a bearing surface 31. Since this bearing surface 31 is installed several pieces on the circumference of a shank part 14, the straight groove 13b can be situated sideways at the drill axial center irrespective of a setting angle of the clamping bolt 25. Therefore, for any kind of a device, drill attachment is made performable in a state favorable in chip dischargeability.
|
