| 摘要 |
PURPOSE: A button bit of a hammer for an auger drill machine is provided to bore in a larger diameter than the diameter of a button bit to interpose a guide pipe preventing the breaking of a boring wall together with a hammer. CONSTITUTION: In a hammer for an auger drill machine comprising a button bit(2) for boring the ground, a piston(3) blowing the button bit with air pressure, a pneumatic valve for supplying air pressure to the piston and a top sub connecting with a drill rod in a cylindrical casing(1), the button bit of the hammer for the auger drill machine comprises: an end-projection(21) formed on the outer circumference of the button bit; a casing shoe(6a) welded to the lower end of a guide pipe(6) having an internal looped projection(61) cogged to the end-projection; a fitting part comprising a vertical shaft hole(22) radially bored on the lower outer part of the button bit, a slope and an orthogonal plane formed around the shaft hole; and a bit head(7) comprising an eccentric shaft(72) fixing a pin(24) fixed after inserting into the shaft hole and a head part(71) projecting many ball tips(73).
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