Patent ID: 7284319
Filing Date: 2007-10-23
Classification: B21J,Y10T

Abstract:
1. A die for use in a self-piercing rivet setting apparatus having a punch and the die which are operable to drive a self-piercing rivet into a plurality of workpieces positioned between the punch and die, said self-piercing rivet having a large-diameter head and a hollow leg extending downward from said head, wherein when said self-piercing rivet is driven into said workpieces, said leg of said self-piercing rivet is driven to pierce said workpieces while allowing a front end of said leg to be expandingly deformed in its radially outward direction and to be retained in said workpieces without passing therethrough, so as to connect said plurality of workpieces with each other by said expanded leg and said head, said die comprising: a cavity for receiving therein a protruded workpiece zone consisting of respective portions of said workpieces to be protrudingly deformed toward said die through the pressure of said self-piercing rivet pressed by said punch, wherein said cavity has a bottom surface provided with a central raised portion protruding from the center of the bottom surface toward a punch, said central raised portion of the cavity having a vertical angle in the range of 90 to 160 degrees, said cavity having an approximately cylindrical outer wall in the periphery thereof, said outer wall of said cavity having an upper end with the inner diameter approximately equal to: said cavity having a curved inner surface extending from the top of said central raised portion to the lower end of said outer wall through the bottom of said cavity.