On application mannered null Tip side of our punched lock volt/bolt and

摘要

PROBLEM TO BE SOLVED: To provide a drilling bit which is suitable for a drilling method concurrently using an outer pipe, which dispenses with the enlargement of drilling diameter by virtue of good straight advance properties even in usage like that and which can also be applied to a small-size drilling machine with low running torque, a self-drilling rock bolt using the drilling bit, and a construction method for the self-drilling rock bolt.;SOLUTION: A groove 15, which continues from a leading end side to a back end side, is formed in the outer peripheral surface of the drilling bit 1, and a through-hole 19, which communicates with an internal space part of a bit body 2, is opened in the groove 15. A hollow rod 2, whose tip is fitted with the drilling bit 1, drills a hole in the state of being enclosed with the outer pipes 5 and 51. A pressurized fluid, which is supplied from the drilling machine 42, passes through the inside of the hollow rod 2 so as to be ejected to the tip side of the drilling bit 1, passes through the groove 15 along with cuttings cut away there, so as to move backward through the inside of the outer pipes 5 and 51, and is discharged from an opening 72 of an adaptor 7.;COPYRIGHT: (C)2005,JPO&NCIPI