BORE BIT FOR DRILLING SMALL-DIAMETER BLAST HOLES

摘要

FIELD: process engineering.SUBSTANCE: invention relates to drilling of blast holes in solid and hard rock. This drill bit comprises body with coupled thread and is separated by radial channels to sectors provided, on end surface, with hard metal inserts. Elements of rock crushing indenters are composed of diamond-carbide inserts with point diverged steep-grade incident surface and its converged rear surface. Said inserts are located at drill bit end surface composing three identical sets each of three parallel inserts and arranged at angles equal to 20 degrees to radial axes of said set of inserts with complete coverage of the face in radial direction and parallel with face plane. In plan, axes of said sets of inserts are located at 120 degrees relative to each other. Recesses are made between said sets of inserts for removal of slack diverging from the center to periphery of drill bit body with grooves at the body side surface for slack release and channels for feed of flushing fluid. Each flushing sector makes the angle of 60 degrees over the drill bill outer cylindrical perimeter. Central flushing fluid feed channel is arranged at 20 degrees to drill bit vertical lengthwise axis and coupled with three flushing sectors at end surface.EFFECT: higher efficiency, longer life.4 dwg