Die-pressing punch capable of adjusting initial load of coil spring in accordance with material of workpiece, die-pressing die set, and beveling method

A die-pressing punch used for die-pressing a workpiece, the die-pressing punch comprising:

• a hollow cylindrical punch guide;
• a punch body provided inside the punch guide vertically movably and non-rotatable about an axial center thereof with respect to the punch guide;
• a punch head provided at an upper end of the punch body by being screw-fitted therewith;
• a roller unit provided inside the punch guide beneath the punch body vertically movably and having a rotatable roller protruding downward from a bottom face of the punch guide;
• an urging member provided inside the punch guide between the punch body and the roller unit and urging the roller unit downward;
• a ring-shaped joint member provided on a side of an outer circumferential surface of the punch body and on an upper side of the punch guide and jointed with the punch head non-rotatably about the axial center;
• and
• an operable member for switching the joint member between a rotatable state and a non-rotatable state about the axial center with respect to the joint member, wherein
• an initial load of the urging member is adjusted by adjusting and then fixing a height position of the punch body with respect to the punch guide to change an initially-compressed amount of the urging member.

A die-pressing punch used for die-pressing a workpiece, the die-pressing punch comprising:

• a hollow cylindrical punch guide;
• a roller unit provided inside the punch guide vertically movably and having a rotatable roller protruding downward from a bottom face of the punch guide;
• an urging member provided inside the punch guide on an upper side of the roller unit and urging the roller unit downward;
• a pressing member provided inside the punch guide on an upper side of the urging member and pressing the urging member downward, a height position thereof with respect to the punch guide being configured to be adjustable;
• and
• a lock mechanism fixing the height position of the pressing member with respect to the punch guide, wherein
• an initial load of the urging member is adjusted by adjusting and then fixing the height position of the pressing member with respect to the punch guide to change an initially-compressed amount of the urging member.