Abstract: The disclosure relates to a method for pre-shaping sheet metal (1) in strip- or panel-form having a flat cross-sectional profile into a circular arc-shaped cross-sectional profile, in a pre-shaping section (3) of a plant for producing open-seam pipes. The circular arc-shaped cross-sectional profile is provided to the sheet metal (1) in the pre-shaping section (3) by means of roll profiling in a plurality of successive bending steps in a transport direction. The cross-sectional profile is created by step-by-step bending of individual circular arc portions (8) from an outer edge of the sheet metal (1) toward a center line (7) such that the individual circular arc portions (8) directly adjoin one another or at least partially overlap. The disclosure further relates to a device for carrying out the method.

Abstract: A method for producing open-seam pipes from flat metal products, in particular sheet metal, includes a plurality of individual bending steps using at least one bending tool and at least one externally located lower tool. A plurality of positions of individual bending steps and the insertion depth of the bending tool are calculated in advance. Based thereon the flat metal product is then shaped step-by-step to form the open-seam pipe. After each of the bending steps, a target/actual comparison of the distance between two edges and/or between one of the two edges and the axial center line of the flat metal product is carried out. In case of a deviation, a correction value for the subsequent bending step is determined using a correction algorithm so as then to adapt the insertion depth for the bending tool.

Abstract: A method for producing open-seam pipes from sheet metal panels, in particular thick sheet metal panels. A sheet metal panel, having bending edges on the long sides thereof, is fed to a pipe forming press where the sheet metal panel is formed, lying on a lower tool having of two supporting elements which are horizontally spaced apart from each other, by an upper tool, which can be raised and lowered, by application of a bending force, progressively into an open-seam pipe having bending edges on opposite long sides with a gap for later longitudinal seam welding. In order that the sheet metal panel can be easily, progressively formed or shaped from the start, at least the bending sections immediately adjacent on the bending edges of the sheet metal panel are each formed from the outside to the inside, deviating from a numerically ascending bending step sequence in a pilgering process sequence.

Abstract: A method for producing open-seam pipes from sheet metal panels, in particular thick sheet metal panels. A sheet metal panel, having bending edges on the long sides thereof, is fed to a pipe forming press, in which the sheet metal panel is formed, lying on a lower tool having of two supporting elements which are horizontally spaced apart from each other, by an upper tool, which can be raised and lowered, by application of a bending force, progressively into an open-seam pipe having bending edges on opposite long sides with a gap for later longitudinal seam welding. In order that the sheet metal panel can be easily, progressively formed or shaped from the start, at least the bending sections immediately adjacent on the bending edges of the sheet metal panel are each formed from the outside to the inside, deviating from a numerically ascending bending step sequence in the pilgering process.