Abstract: A self-piercing rivet setting apparatus (9) comprises a punch (14) and a die (18) for driving a self-piercing rivet into a plurality of workpieces including a receiving-side workpiece adjacent to the die. The self-piercing rivet has a large-diameter head and a hollowed leg. The leg is driven to pierce the workpieces while allowing the front end of the leg to be expanded and deformed in its radial outward direction and to be stayed in the receiving-side workpiece without passing therethrough, to connect the plurality of workpieces with each other by the expanded leg and the head. The die includes a first die member (26) having a first cavity (25), and a second die member (30) having a second cavity (27) and a protruding pin (29) provided at the center of the second cavity. The first cavity is adapted to allow the leg of the self-piercing to be driven into the workpieces in a straight direction when the self-piercing rivet is pressed by the punch (14).

Abstract: 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.

Abstract: A self-piercing rivet setting apparatus (9) comprises a punch (14) and a die (18) for driving a self-piercing rivet into a plurality of workpieces including a receiving-side workpiece adjacent to the die. The self-piercing rivet has a large-diameter head and a hollowed leg. The leg is driven to pierce the workpieces while allowing the front end of the leg to be expanded and deformed in its radial outward direction and to be stayed in the receiving-side workpiece without passing therethrough, to connect the plurality of workpieces with each other by the expanded leg and the head. The die includes a first die member (26) having a first cavity (25), and a second die member (30) having a second cavity (27) and a protruding pin (29) provided at the center of the second cavity. The first cavity is adapted to allow the leg of the self-piercing to be driven into the workpieces in a straight direction when the self-piercing rivet is pressed by the punch (14).

Abstract: 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.

Abstract: The die 18 of the self-piercing rivet fastening device is equipped with a center pin 25 for receiving the hollow section of the legs 5 on the self-piercing rivet 1 and a die main body 27 having a cavity 26 for guiding the distortion of the tip of the legs on the self-piercing rivet outward radially on the outer periphery of the center pin 25. The center pin 25 and the die main body 27 are supported so as to move relatively freely in the axial direction of the center pin 25 towards the punch 14. It also has a plate spring 41 allowing the center pin 25 to move relative to the die main body 27 so the center pin 25 comes into contact with the die end surface of the fastened member 3 on the receiving end when the self-piercing rivet 1 under pressure from the punch 14 is driven into the fastened members 2, 3 and the tip of the legs begins to pierce the fastened member 3 on the receiving end. This reduces or eliminates the constraints on the fastened members in the rivet-driving direction.

Abstract: A self-piercing rivet comprises a flange with a large diameter and a shank with a hollow cavity extending from the flange inward. The rivet is made of aluminum or an aluminum alloy. The shank is a straight cylinder with outer diameter D1, and the hollow cavity in the shank has conical section tapered from the shank end and converging towards the flange at angle &agr; and a straight cylinder section with inner diameter D2 extending from the conical section to the end on the flange side. The shank has a substantially flat ring-shaped end with outer diameter D1 and radial length T1. The angle &agr; of the conical section ranges between 70° and 110°.