Self-piercing rivet setting die and apparatus

摘要

A die ( 18 ) for use in a self-piercing rivet setting apparatus comprises a cavity ( 25 ) for receiving therein a protruded workpiece zone consisting of respective portions of the workpieces ( 2, 3 ) to be protrudingly deformed toward the die through the pressure of the self-piercing rivet ( 1 ). The cavity has a bottom surface provided with a central raised portion ( 29 ) protruding from the center of the bottom surface toward a punch. The central raised portion of the cavity has a vertical angle in the range of 90 to 160 degrees. Preferably, the central raised portion has a top formed in a spherical shape. The cavity has an approximately cylindrical outer wall ( 27 ) in the periphery thereof. The cavity has a curved inner surface extending from the top of the central raised portion to the lower end ( 33 ) of the outer wall through the bottom ( 35 ) of the cavity.