STAMPING PUNCH DIE CAPABLE OF ADJUSTING INITIAL LOAD OF COIL SPRING IN ACCORDANCE WITH MATERIAL QUALITY OF WORKPIECE, STAMPING DIE SET, AND CHAMFERING METHOD

摘要

Provided are a die-pressing punch, a die-pressing die set and a beveling method each of which can improve operational efficiency of die-pressing such as beveling by adjusting an initial load of a coil spring according to a material of a workpiece. A punch body 25 is provided inside a punch guide 17 vertically movably, and a punch head 33 is provided at an upper end of the punch body 25 by being screw-fitted therewith. A coil spring 49 is disposed, inside the punch guide 17, between the punch body 25 and an upper free ball bearing 41. A ring-shaped joint member 51 is provided on a side of an outer circumferential surface of the punch body 25 and on an upper side of the punch guide 17, and the joint member 51 is jointed with the punch head 33 non-rotatably about an axial center C with respect to the punch guide and non-removably therefrom. An operable member 63 switches the joint member 51 between the rotatable state and the non-rotatable state, about the axial center C with respect to the punch guide 17.