| 摘要 |
<p>PURPOSE:To make it possible to carry out the drilling of a flexible material, with the use of a drilling device, with a satisfactory cutting quality and without deforming a hole to be drilled, by carrying out the drilling under such a condition that the tip of the drill is inserted through a suction holder having a hollow section which is connected to a suction source for making the pressure of the hollow chamber negative. CONSTITUTION:A drill 2 formed, at its front end, with a drilling tooth having an invert U-shape, is attached to a vertically movable luter 1 which is then rotated. A suction holder 12 having a hollow section 14 through which the drill 2 slidably and rotatably passes, is provided to cover the front end of the drill 2, and the hollow section 14 is connected to the suction side of a suction means through a ventilation hole 16. Upon drilling, after the abutting section 18 of the suction holder 12 is abutted against a part to be drilled in a flexible material 3, the luter 1 is lowered to pass the drill 2 through the holder 12. Then, under the condition that the inside of the hollow section 12 is evacuated to be negative in pressure, the drill 2 on rotating is lowered together with the luter 1 to drill the material 3 while the latter is in the sucked condition.</p> |
