High speed perforating apparatus

摘要

Disclosed is a high speed-perforating apparatus 1 comprising a rotor 17 into and through which a cylindrical rotary shaft 11 is integrally inserted, a stator 18 disposed around the outer periphery of the rotor 17 and a core bit 13 which is directly connected to the head end portion of the rotary shaft. A bit 15 having an outer diameter of up to 40mm and a cutting edge thickness of less than 2mm is used for the core bit 13. Perforation is carried out by the core bit 13 which is rotated at a high speed of 4000rpm or more by a direct motor 2 comprising the rotor 17 and the stator 18. A perforating time can be greatly shortened by rotating the core bit at high speed.