| 摘要 |
PROBLEM TO BE SOLVED: To provide a punch which secures excellent cutting-in performance even in the case of punching a thick sheet material, and further to provide a method for machining the punch. SOLUTION: The blade surface 12 of the punch 10 is composed of a groove 12a (a first groove) and a groove 12b (second groove) which have a V-shape cross-section cut in the radial directions so as to be perpendicular to each other in a plan view of the blade surface. The blade surface 12 of the punch 10 is formed by a first groove forming step, a position changing step, and a second groove forming step. In the first groove forming step, the groove 12a is formed on the base material by advancing the base material with respect to a cutting tool. In the position changing step, the base material is turned by 90°about its axis after the first groove forming step. In the second groove forming step, the groove 12b is formed on the base material by returning the base material with respect to the cutting tool after the position changing step. COPYRIGHT: (C)2008,JPO&INPIT
|
