Method for producing hollow bodies, profile for use in said method, hollow body, assembly unit and mold

Hollow body element for attachment to a component consisting in particular of sheet metal, said hollow body element being generally rectangular in plan view and having first and second generally oppositely disposed faces, first and second opposite sides and only first and second bars at said first face, said first and second bars extending parallel to one another at said first and second opposite sides, said hollow body element further having a centrally arranged aperture extending perpendicular to and between said first and second faces a cylindrical projection present at said first face and concentric to said aperture, said cylindrical projection being formed as a piercing projection and a recessed region present between said first and second bars and said cylindrical projection and having an at least substantially rectangular central region having a top side at said second face and a bottom said at said first face and, at said first and second opposite sides, first and second wings integral with said central region and extending at said first face beyond said central region and forming said first and second bars, said first and second wings extending parallel to said first and second opposite sides and merging via respective first and second inclined recesses into said bottom side of said central region, said first and second wings having top surfaces at said second face spaced below said top surface by first and second sidewalls of said central region extending parallel to said first and second opposite sides, said top surfaces of said first and second wings forming first and second shoulders which extend obliquely to said first and second side-walls and including an angle (α) with one another which is somewhat smaller than 180°.

A die in combination with a hollow body element, for the attachment of said hollow body element to a component, said hollow body element being of generally rectangular shape in plan view and having first, second third and fourth sides definina said generally rectangular shape, with said first and second sides being opposite to one another and said third and fourth sides being opposite to one another, said hollow body element further having first and second generally oppositely disposed faces and only first and second bars at said first face, said first and second bars extending parallel to one another at said first and second opposite sides of said hollow body element and, having a spacing and a length, said hollow body element further having a centrally arranged aperture extending perpendicular to and between said first and second faces, a cylindrical projection present at said first face and concentric to said aperture, said cylindrical projection being formed as a piercing projection and a recessed region present between said first and second bars and said cylindrical projection, said die having a free end face confronting said component, said free end face having a shaped projection which is at least substantially rectangular in plan view and in outline and has a width corresponding to said spacing less twice a thickness of said component and a length corresponding to said length of said first and second bars, said die further having a ring projection within said outline which brings about a deformation of said component into said recessed region formed around said cylindrical projection of said hollow body element and a central bore which cooperates with said piercing projection of said hollow body element in order to produce a piercing slug from said component during the attachment of said hollow body element thereto.

A die in combination with a hollow body element, for use with said hollow body element, said hollow body element being of generally rectangular shape in plan view and having first, second, third and fourth sides defining said generally rectangular shape, with said first and second sides being opposite to one another and said third and fourth sides being opposite to one another, said hollow body element further having first and second generally oppositely disposed faces and only first and second bars at said first face, said first and second bars extending parallel to one another at said first and second opposite sides of said hollow body element, said hollow body element further having a centrally arranged aperture extending perpendicular to and between said first and second faces, a cylindrical projection present at said first face and concentric to said aperture, said cylindrical projection being formed as a piercing projection and a recessed region present between said first and second bars and said piercing projection and said hollow body element further having first and second grooves at said first face which extend parallel to another and form the bars, wherein said die has an end face confronting said first face of said hollow body element in use and provided with first and second projections in the form of respective bars extending parallel to one another, said first and second projections in the form of a bar each having a maximum width which corresponds at least substantially to a width of a respective one of said first and second grooves less an amount corresponding to twice a thickness of a component to which said hollow body element is to be attached, said die further having a ring projection between said first and second bars which brings about a deformation of said component into an undercut formed around said piercing projection and a central bore which cooperates with said piercing projection to produce a piercing slug from said component during attachment of said hollow body element to said component.