| 摘要 |
PROBLEM TO BE SOLVED: To provide a punching device and a punching method which can form a circular hole having high circularity and have longevity in a punch and a die.SOLUTION: A punching device 10 forms a true circular hole 37 in a work piece 18 pressed and held by a stripper member 17, by means of a punch 14 and a die 15 constituting a pair. In the punching device 10, a rotary drive mechanism 39 rotates the punch 14 by a predetermined angle in every predetermined stroke to prevent uneven wear of the punch 14. |
