Abstract: The invention relates to a method and an apparatus for producing a workpiece with internal toothing, especially an internal geared wheel, by using a cup shaped preform (N) with a substantially cylindrical side wall (N1) and a mandrel (5) with an external profile (6) according to the internal toothing to be produced, as well as with a forming tool which reduces the outside diameter of the cylindrical side wall during an advancing movement, as a result of which the material of the cylinder wall region flows into the external profile (6) of the mandrel (5). In accordance with the invention, the forming tool is configured as a drawing ring (14) ensuring the ironing of the cylinder wall region (N1) during an advancing movement and that two tool elements act upon the preform (N) during the ironing, which tool elements produce axial compressive stresses in the cylinder wall region (N1) of the preform.

Abstract: The invention relates to a hydromechanical clamping device having two movable die halves and two punches, a first hydraulic piston, and a second hydraulic piston. The second die half is fixed to the frame and the second punch is arranged on the second hydraulic piston. The first hydraulic cylinder is connected to a third hydraulic cylinder. The latter acts on a fourth hydraulic piston. The first hydraulic cylinder is connected to the third hydraulic cylinder, so that the pressure medium displaced from the first hydraulic cylinder during a feed movement flows into the third hydraulic cylinder and the third hydraulic piston moves the fourth hydraulic piston in the feed direction, so that pressure medium is displaced into the second hydraulic cylinder, and the requisite forming pressure can be applied to the second hydraulic piston and the punches move toward one another.

Abstract: The invention relates to a hydromechanical clamping device having two movable die halves (M1, M2) and two punches (S1, S2), a first hydraulic piston (K1) being mounted in a displaceable manner in an axially movable first hydraulic cylinder (Z1), and a second hydraulic piston (K2) being mounted in a displaceable manner in a second hydraulic cylinder (Z2). The second die half (M2) is fixed to the frame and the second punch (S2) is arranged on the second hydraulic piston (K2). According to the invention, the first hydraulic cylinder (Z1) is connected to a third hydraulic cylinder (Z3), in which a third hydraulic piston (K3) is mounted. The latter acts on a fourth hydraulic piston (K4), which is guided in a fourth hydraulic cylinder (Z4).

Abstract: The invention relates to a method and an apparatus for producing a workpiece with internal toothing, especially an internal geared wheel, by using a cup-like preform (N) with a substantially cylindrical side wall (N1) and a mandrel (5) with an external profile (6) according to the internal toothing to be produced, as well as with a forming tool which reduces the outside diameter of the cylindrical side wall during an advancing movement, as a result of which the material of the cylinder wall region flows into the external profile (6) of the mandrel (5). In accordance with the invention, the forming tool is configured as a drawing ring (14) ensuring the ironing of the cylinder wall region (N1) during an advancing movement and that two tool elements act upon the preform (N) during the ironing, which tool elements produce axial compressive stresses in the cylinder wall region (N1) of the preform.