Abstract: In a method for the production of a rim hole in hollow profiles, a tubular piece is pushed into the hollow profile and placed there in such a way that it coaxially surrounds the location of the rim hole to be produced. The hollow profile is then acted upon from outside to inside at this location by a tool, with the rim hole being formed. In order to make possible a rim hole in hollow profiles in a relatively simple manner, this rim hole also satisfying high strength requirements even in the case of a small wall thickness of the hollow profile, it is proposed to first punch two opposite holes out of the hollow profile. At least one of these holes has a diameter which is smaller than that of the rim hole to be produced. The tubular piece is then inserted into the hollow profile interior, so that it comes to lie there coaxially to the common axis of the holes.

Abstract: A punch designed for producing holes in the walls of hollow parts, the part being subjected to the action of high pressure in the interior by a medium during the punching. In particular when producing hollow parts by the internal high pressure forming process, it is normal practice, following the forming and with the part still located in the forming tool, to make holes in the wall. In order to avoid a drop in the internal high pressure when cutting through the wall of the part, the punch is designed so as to taper at an angle toward the cutting edge in its region plunging into the part to be punched. As a result, sealing of the hole occurs during the punching.

Abstract: The invention relates to a method for the production of a rim hole (20, 26, 30) in hollow profiles (1), a tubular piece (9) being pushed into the hollow profile (1) and being placed there in such a way that it coaxially surrounds the location of the rim hole (20, 26, 30) to be produced. The hollow profile (1) is then acted upon from outside to inside at this location by means of a tool, with the rim hole (20, 26, 30) being formed.