METHOD OF MANUFACTURE OF CONNECTED SECTION BY PRESSING OF CONNECTING UNIT INTO FLAT MATERIAL AND CONNECTING UNIT FOR THIS METHOD

摘要

A process for inserting an insert element into a flat sheet metal piece to form a connected element includes the steps of providing the insert element with a head and a shank. A concentric annular groove forms a constriction between the head and the shank. A plurality of separate projections are circumferentially arranged on a seating surface of the head and provide a twisting resistance between the insert element and the sheet metal piece. Each separate projection has a length that extends approximately radially relative to a longitudinal axis of the insert element. The sheet metal piece is provided with a perforation for receiving the shank. The perforation has an edge that forms a collar that projects out from a plane defined by a surface of the sheet metal piece. The shank is inserted through the perforation, and is pressed toward the sheet metal piece to cause the collar to be bent in a direction toward the plane so that the collar is essentially level with the surface of the sheet metal piece in a region between adjacent projections. The pressing causes the seating surface to firmly rest against the surface of the sheet metal piece, and causes a reduction in the perforation diameter so that the collar fills the annular groove, and so that only the projections enter the sheet metal piece in an axial direction.