Process for the production of a toothed rack via cold forming, the rack

Abstract

Process for the production of a toothed rack via cold forming, the rack produced thereby, and an apparatus for practicing the process. The cold formed rack workpiece shows multiple traces of cold forming in the toothing direction. During the production process, the workpiece, in the apparatus, is moved transversely to the axis of the rolling head, relative to the rotatably driven rolling head. Rolls, having forming ribs, are rotatably journalled within the rolling head, along at least one helical line, with the rolls rotating with the rolling head in a planetary manner. Thereby, each roll performs, in quick sequence, single rolling steps that overlap each other in the feed direction of the apparatus slide. Therein, the tooth space form-type forming ring ribs engage the workpiece. During the cold forming step of the workpiece, working material is displaced by the forming ring ribs from the bottom land area of the toothings to the top land area of the toothings, during which the top land area of the toothing can also be form rolled. An apparatus for carrying out the method includes a holding device for retaining the workpiece and a driven rolling head, rotatable about its own axis, together with feeding means and a stroke adjustor. Several rollers, each having at least one tooth spaced type forming ring rib, are journalled in the rolling head in a planetary manner.