Method for producing hollow body elements, hollow body element, component, follow-on composite tool for producing hollow body elements

A method for the manufacture of hollow body elements (200) for attachment to a sheet metal component (280), the hollow body elements having an at least substantially square or rectangular external outline (202) obtained by cutting individual elements by length from a section present in the form of a bar section (1) or of a coil after prior piercing of holes (204) into the section by using a progressive tool (10) having a plurality of working stations (A, B and D;

• B and D) in which respective operations are carried out, wherein the following steps are carried out:
• a) in a first step, starting from a section (1) of rectangular cross-section, carrying out an upsetting process which leads to a cylindrical recess (208) having a first base (214) at a first broad side (2) of the section and to a hollow cylindrical projection (210) having a second base (216) and forming a rivet section (210′) at a second broad side (3) of the section lying opposite to the first broad side (2), with the projection being surrounded by a ring recess (212), the ring recess including a portion having a surface substantially parallel with the second broad side and wherein the hollow cylindrical projection has a substantially constant diameter from its distal end to the recess,
• b) in a second step piercing or punching out a web (218) remaining between the first base (214) and the second base (216) to form a through-going hole (204), with an internal diameter of side through-going hole (204) being less than an internal diameter of said hollow cylindrical projection (210),
• c) in a last step separating the hollow body elements (200) from the section, wherein points of weakening which extend from one longitudinal side (7) to the other longitudinal side (8) of the sectional strip (1) and are arranged in the second broad side (3) of the sectional strip (1), are formed at points between adjacent hollow body elements (200) of the sectional strip, the points of weakness being formed by notches.