| 摘要 |
PURPOSE:To manufacture easily a cylinder having many recessed parts on the outside face, by pressing plural pins having a sharp tip, which are placed at a prescribed pitch on one straight line from the upper and lower parts, against a straight cylinder by strong pressure. CONSTITUTION:In a state that a through-hole 36 of a punch 33 is fitted to a guide pin 22 of a die 4, it is placed on a press device. In this state, between a base 2 and a pressing plate 3, a cushion material 40 on a cylinder is placed in a state that the left and right sides of a metallic die are pinched. In this state, a prepared straight cylinder 41 is fitted between grooves 5, 34. Subsequently, strong pressure is put on the pressing plate 3 by operating the press device. The cushion material 40 and a cushion sheet 30 are compressed, pins 14, 28 withdrawn from through-holes 6, 36 project from the through-holes, encroach on the upper and lower faces of the cylinder 41 and a recessed part 41a is formed. |
