| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a discharge hole opening bit for a blast furnace or the like, which has a relatively large discharge amount of drilling dust (sludge) discharged from a sludge discharging groove disposed on the outside surface of the drilling bit when drilling a discharge port for a blast furnace or the like, so that the relatively large drilling rate and the relatively large tip outer diameter enables a rapid hole opening.SOLUTION: A hole opening device for a blast furnace or the like includes: base metals 6a orthogonal to a central axisαon three or four sides at the tip; a sludge discharging groove 13 between the base metals 6a; a bit 6 equipped with a plurality of super hard tips 12 or hardened overlaying materials on the tip surface; and a hollow rod 5 which supports the bit 6. In the discharge hole opening bit of the hole opening device for a blast furnace or the like, the tip of the hollow rod 5 which shares the central axisαis connected to the rear end of the bit 6. The outer periphery of the hollow rod 5 spreads on the side of the central axisαfrom the inner face of each the slurry discharging grooves 13.</p> |
