| 摘要 |
PURPOSE:To reduce the burden of dies and to improve the service life of the dies by preliminarily striking a shaft body at least once or above with a pair of preliminary dies then finishing the same to the shape of a drill edge by a pair of finishing dies. CONSTITUTION:Dies 1, 1' attached to slide rams 2, 2' have two front head parts of the dies, one of which is front head parts 4, 4' of preliminary dies and the other one is front head parts 5, 5' of finishing dies. A shaft part 101 supplied from a chuting rail 7 fits into the recess 6 of a carrying dial 3. Head parts 102 are placed atop the dial 3 and are repeatedly rotated and stopped at an equal angle in the direction A to feed the body 101 to the position 101a between the parts 4 and 4' and to stop temporarily the same. The dies 1, 1' are then stroken to mate each other to form the shaft body 101 to the preliminary shape of the drill edge. The dial 3 feeds the body 101 to the position 101b between the parts 5 and 5' and the body 101 is formed to the perfect shape of the drill edge by the parts 5, 5'. |
