Method and device for mounting a fastening element on a part, particularly a sheet metal part

1. System comprising an apparatus for the attachment of a fastener element ( 12 ; 12 ′) to a sheet metal part ( 13 ) having a pre-formed hole and a ring collar ( 35 ) surrounding said pre-formed hole, wherein the fastener element has an axis of symmetry ( 18 ), a head part ( 14 ) having a contact surface ( 22 ) which enters into contact with the sheet metal part ( 13 ), a fastening section having a thread ( 15 ; 15 ′) and also at least one undercut ( 24 ; 82 ) which receives the material of the sheet metal part, with the thread ( 15 ) being formed at a shaft part ( 16 ) of the fastener element and wherein the shaft part ( 16 ) can be guided through the pre-formed hole of the sheet metal part, wherein the material of the sheet metal part can he pressed against the contact surface and into the undercut by means of a first tool ( 26 ′) and a second tool ( 62 ), said first tool having a die button shape, a first aperture accommodating said shaft part with clearance and a central ring projection ( 36 ) with an at least substantially conical inner surface ( 38 ) adapted to press the material of said ring collar ( 35 ) radially inwardly into the undercut ( 24 ), said second tool ( 62 ) having a cut-out ( 60 ) receiving said head part ( 14 ) of said fastener element ( 12 ), an end face ( 64 ) which supports the sheet metal part ( 13 ) at least substantially at least at the level of said contact surface ( 22 ) wherein the apparatus has a device generating a force adapted to exert a local force (K) onto said first tool ( 26 ′) to the side of the axis of symmetry ( 18 ) and to move this local force circularly around the axis of symmetry (arrow 43 ) while simultaneously carrying out a relative feed movement (arrow 28 ) between said first tool ( 26 ′) and the fastener element ( 12 ; 12 ′) between which the sheet metal part ( 13 ) is arranged and wherein the local force (K) can be exerted onto the sheet metal part ( 13 ), with the first tool ( 26 ′) which is disposed at an inclined position ( 42 , 42 ′) relative to the axis of symmetry ( 18 ) and being rotatable about the axis of symmetry in order to press the material of the sheet metal part onto the contact surface and into the undercut ( 24 ; 82 ) while said fastener element ( 12 , 12 ′) is supported in said second tool ( 62 ).

2. System in accordance with claim 1 , wherein the fastener element is a bolt element (l 2 ).

3. System in accordance with claim 1 , wherein the first tool works directly on the sheet metal part ( 13 ) in the region of the fastener element ( 12 ).

4. System in accordance with claim 1 , wherein the fastener element ( 12 ) has an axial ring groove ( 34 ) or concave fields in the contact surface and also a radial undercut ( 24 ) which can be formed by the thread ( 15 ) in the region of the head part ( 14 ); wherein the metal sheet part has a hole with a collar surrounding the hole; and in that the fastener element ( 12 ) can be passed through the ring collar ( 35 ) surrounding the hole from the side of the metal sheet part ( 13 ) remote from the ring collar ( 35 ).

5. System in accordance with claim 1 , wherein the fastener element ( 12 ; 12 ′) has features ( 84 ) providing security against rotation in the region of the contact surface and/or of the transition from the contact surface into any shaft part that is present and/or in the region of a hollow recess ( 80 ) of the fastener element, wherein the material of the sheet metal part can also be brought by the action of the local force (K) and the feed movement into engagement with the features providing security against rotation.

6. System in accordance with claim 1 , wherein it is incorporated into a type of drill press in order to achieve the relative movements.

7. System in accordance with claim 5 , wherein said security against rotation can be realized by the at least one undercut ( 24 ; 82 ) or by recesses ( 84 ) in the contact surface ( 22 ).