Installing a self-attaching fastener in a panel

摘要

A self-piercing fastener (150) such as a stud, bolt or nut, has a body portion (152, 154) and a self-piercing and riveting annular wall portion (156) having an open free end defining an angled piercing surface (166) which slopes outwardly from the inner surface (164) of the wall (156) and a curved surface (160) adjacent the outer surface (158) of the wall (156). The fastener is secured to a panel (206) by driving the fastener into the panel supported on a die member (180) having an annular concave die cavity (202) surrounding a central projecting die portion (184) having a peripheral piercing edge (196) which co-operates with the piercing surface (166) so that a slug (216) is pierced from the panel. The slug (216) is forced into the wall as the free end of the wall (156) is simultaneously deformed radially outwardly by the die cavity (202) to form a U-shaped annular channel (156c) and the portion of the panel (218) adjacent the pierced edge is drawn and subsequently driven by the body portion (152) into the channel (156c).