HOLE FORMING DEVICE WITH UNDERCUTTING PART

摘要

PURPOSE: To obtain long life of a drilling tool used for boring work and undercut working by improving the device for making a hole with an undercut by machine controlled automatic turning operation. CONSTITUTION: An adapter 13 which stores a drilling tool 17 and is torque- transmissionably connected to a drilling machine 10 is formed by a driving part 12 torque-transmissionably connected to the drilling machine 10 and a tool holder 14 storing the drilling tool 17, the relative position of the driving part 12 to the tool holder 14 can be mutually turned and torque-transmissionably can be fixed its position, the center axis 15 of the tool holder 14 has a designated angle deviation to the center axis 16 of the driving part 12 matched with the driving axis of the drilling machine.