Method for the production of hollow elements, hollow element, assembly piece, and follow-on composite tool for carrying out said method

Abstract

Disclosed is a method for producing hollow elements ( 200 ), such as nut elements, which are to be mounted on parts generally made of sheet metal, particularly for producing hollow elements having an at least substantially square or rectangular outer contour ( 202 ). According to said method, individual elements are cut to size from a profiled member that is provided in the form of a profiled bar or a reel after punching holes into said profiled member, optionally followed by embodying a threaded cylinder ( 206 ) using a follow-on composite tool ( 10 ) with several workstations (A, B, C, D). The inventive method is characterized in that a penetrating process, a punching process, and a flattening process are carried out in the workstations (A, B, C, D). Also disclosed are hollow elements ( 200 ), assembly pieces, and a follow-on composite tool ( 10 ).

1 . Hollow body element for attachment to a component normally comprising sheet metal, the hollow body element comprising:
 one of an at least substantially square and rectangular outline with a first broad side and a second broad side forming a sheet metal contact surface,   a piercing section, which projects beyond the second broad side and has an undercut and is surrounded by a ring recess having a conical outer surface in the second broad side, wherein the conical outer surface merges into the second broad side,   an aperture, which extends from the first broad side through the piercing section, with the aperture optionally having a thread cylinder, and   features providing security against rotation are formed one of outwardly at the hollow cylindrical projection and inwardly in a region of the ring recess around the hollow cylindrical projection.   
   
   
       2 . Hollow body element in accordance with  claim 1 , wherein the features providing security against rotation are formed by one of ribs and grooves at a radially outer side of the hollow cylindrical projection. 
   
   
       3 . Hollow body element in accordance with  claim 1 , wherein the features providing security against rotation are formed by ribs, which extend in an axial direction and bridge the undercut of the hollow cylindrical projection. 
   
   
       4 . Hollow body element in accordance with  claim 3 , wherein the ribs providing security against rotation have a radial width, which lies at least substantially in a region between 40% and 90% of a maximal radial depth of the undercut. 
   
   
       5 . Hollow body element in accordance with  claim 1 , wherein the features providing security against rotation are provided in the form of radially extending ribs, which bridge the ring recess. 
   
   
       6 . Hollow body element in accordance with  claim 1 , wherein the features providing security against rotation are provided in the form of obliquely set ribs providing security against rotation, which extend in a radial direction across the ring recess and in an axial direction along the undercut of the piercing section. 
   
   
       7 . Hollow body element in accordance with  claim 1 , wherein the features providing security against rotation are provided in the form of ribs, which extend in a radial direction across the ring recess and in an axial direction along the undercut of the piercing section. 
   
   
       8 . Hollow body element in accordance with  claim 1 , wherein the features providing security against rotation are provided in the form of recesses, which are arranged in an obliquely set surface of the ring recess. 
   
   
       9 . Hollow body element in accordance with  claim 1 , wherein the second broad side lies in a plane radially outside of the ring recess, and apart from any features at the transitions into the side flanks of the hollow body element. 
   
   
       10 . Hollow body element in accordance with  claim 1 , wherein an opening of the cylindrical recess at the first broad side of the section is executed with one of a rounded and chamfered run-in edge. 
   
   
       11 . Hollow body element in accordance with  claim 1 , wherein an opening of the hollow cylindrical projection is provided at its free end with one of a rounded and chamfered run-out edge. 
   
   
       12 . Hollow body element in accordance with  claim 1 , wherein the ring recess is provided with a ring-like base region, which stands at least approximately in a plane parallel to the first and second broad side, and merges at a radially inner side with an at least substantially rounded transition into an outer side of the hollow cylindrical projection and at a radially outer side into a conical surface. 
   
   
       13 . Hollow body element in accordance with  claim 1 , wherein the ring recess is executed with an external diameter, which is only somewhat smaller than a smallest transverse dimension of the hollow body element, which is rectangular in plan view, whereby the ring recess forms webs with the second broad side of the section that remain at narrowest points in a plane of the second broad side in a range from 0.25 to 1 mm, preferably of approximately 0.5 mm. 
   
   
       14 . Component assembly comprising a hollow body element in accordance with  claim 1 , which is attached to a component, for example to a sheet metal part, with the material of one of the component and the sheet metal part contacting a surface of the ring recess of the hollow body element at a surface of features providing security against rotation and also at a surface of the undercut of the piercing section of the hollow body element, and with a ring recess being present in the material of one of the component and the sheet metal part around the piercing section. 
   
   
       15 . Component assembly in accordance with  claim 14 , wherein an axial depth of the ring groove in the sheet metal part is selected in dependence on a length of the piercing section and a thickness of the sheet metal part so that the end face of the piercing section does not project beyond a side of the sheet metal part, which is remote from a body of the hollow body element and is present in a region beneath the second broad side of the hollow body element around the ring recess of the hollow body element. 
   
   
       16 . Component assembly in accordance with  claim 14 , wherein the second broad side of the hollow body element is at least substantially not pressed into the sheet metal material in a region around the ring recess of the hollow body element.