| 摘要 |
<p>A method and a device for drilling a through hole in the peripheral wall of a work capable of preventing burrs from occurring on the inner peripheral surface of the cylindrical part of the work, providing high productivity, and reducing manufacturing cost. The work (10) is positioned at a die (20), and a punch (30) projectedly formed on a cantilevered bar-like core (32) is inserted into the cylindrical part (12) of the work so as to face the portion of the inner wall surface of the work at which a through hole (70) is to be formed. Next, the punch (30) is pressurized and moved relative to the die (20) through the core (32) in a direction for punching the work by the punch (30) and the die (20), and a pressing pin (35) inserted into the work (10) from working through holes (72) formed at the peripheral wall portion in which the through hole (70) is to be formed and at its opposite portion is pressurized and moved together with the core (32) and the punch (30), and the punch (30) is driven into the peripheral wall (15) from the inside of the cylindrical part (12) to form the through hole (70). Then, a push back pin (55) is moved in the opposite direction together with the core (32) and the punch (32) until the punch (30) is extracted from the work (10).</p> |
