Patent ID: 6536253
Filing Date: 2003-03-25
Classification: B21D,B21H,B23P,Y10T

Abstract:
A slotting method in which a disk-like metal blank is clampingly held between upper and lower rotary dies, a slotting roller die is pressed against an outer peripheral portion of said blank, and said outer peripheral portion of said blank is split into two parts in a thickness direction, whereina blank housing recess a depth of which is smaller than a thickness of said blank is formed in an upper face of said lower rotary die on which said blank is to be placed, a roller die guiding face is formed horizontally and continuously with an outer periphery of an upper end of an outer peripheral wall of said blank housing recess to be lower in level than an upper face of said blank in the said blank housing recess, said upper rotary die is formed to have an outer diameter which is smaller than an outer diameter of said lower rotary die, thereby allowing an upper face of said outer peripheral portion of said blank in said blank housing recess to be exposed, said slotting roller die has a blade edge on an outer periphery of said die, and, while said slotting roller die is rotated in synchronization with said blank about a roller axis which is inclined with respect to a rotation axis of said upper and lower rotary dies, said blade edge is slid on said roller die guiding face in an inward radial direction to be pressed against said outer peripheral portion of said blank which is protruded from said blank housing recess, whereby said outer peripheral portion is slit into two parts in the thickness direction.