Bending tools for pre-bending and hemming

A bending tool combination (1) for the v-shaped prebending and subsequent hemming of a flat workpiece section (6), comprising a bending die (2) and a bending punch (3), wherein the bending die (1) is designed with a die section (7) arranged centrally relative to the working plane (4) of the bending die (2) with a slot (8) leading from a bearing surface (5) into the interior of the bending die (2) for partly receiving the bending punch (3) during the hemming, and a hemming section (9) with a hemming surface (10) arranged laterally relative to the working plane (4), wherein the hemming surface (10) is set back step-like relative to a bearing surface (5) of the die section (7), whereby a stop surface (25) is formed extending from the bearing surface (5) to the hemming surface (10) and the bending punch (3) is designed with a punch section (12) arranged centrally relative to the working plane (4) of the bending punch (3) and coming from a punch base surface (32), and a hemming section (14) with a hemming surface (15) arranged laterally to the latter, wherein the hemming section (14) projects relative to the punch base surface (32) in the direction of the punch tip (13), whereby the hemming surface (15) projects step-like relative to the punch base surface (32) and between the punch section (12) and the hemming surface (15) a groove-like recess (33) is formed and wherein as measured in operating direction, a slot depth (36) measured from the hemming surface (10) of the bending die (2) is greater than a punch length (35) measured from the hemming surface (15) of the bending punch (3) up to the punch tip (13).

A bending tool set (18) for the v-shaped prebending and subsequent hemming of a flat workpiece section (6), comprising one or more bending punches (3) with a constant punch thickness (17) perpendicular to the working plane (4) and at least two bending dies (2, 19, 20 . . . ), wherein the bending dies (2, 19, 20, . . . ) are designed with a die section (7) arranged centrally relative to the working plane (4) of the bending die (2, 19, 20, . . . ) with a slot (8) leading into the interior of the bending die (2, 19, 20, . . . ) for partly receiving the bending punch (3) during the hemming, and a hemming section (9) arranged laterally with respect to the working plane (4) with a hemming surface (10), wherein the hemming surface (10) is set back step-like relative to a bearing surface (5) of the die section (7), whereby a stop surface (25) extending from the bearing surface (5) to the hemming surface (10) is formed, wherein the bending dies (2, 19, 20, . . . ) on the inside of the slot (8) each have an identical internal support width (24) corresponding to the punch thickness (17) in addition to play and the die sections (7) in the region of the bearing surface (5) have different die widths (16, 21, 22) and the bending punch is designed with a punch section (12) arranged centrally relative to the working plane (4) of the bending punch (3) extending from a punch base surface (32) and a hemming section (14) arranged laterally thereto with a hemming surface (15), wherein the hemming section (14) protrudes with respect to the punch base surface (32) in the direction of the punch tip (13), with the result that the hemming surface (15) protrudes in a step-like manner with respect to the punch base surface (32) and between the punch section (12) and the hemming surface (15) a groove-like recess (33) is formed.