Punching tool for producing breakthroughs in workpieces made of thermoplastic material, the punching ram for this purpose, as well as a method for the production of such openings

摘要

A punching tool (1) for the production of openings in workpieces (7) made of thermoplastic material has a punch (3) at the end face with a circumferential cutting edge (13). A cutting plate (6) of the punching tool (1) is configured in such a way that the workpiece (7) during the stamping against the cutting plate (6) is supported. The cutting edge (13) has an outer circumference (u_S), the inside an outer circumference (u_M) a jacket wall (14) of a base body (15) of the punch (3) is. The cutting edge (13) runs at the circumference from a peripheral edge (16) of the outer wall (14) via a circumferential concave embossing portion (17) from. For the concave radius of curvature of the latter applies: r 2 mm. For the production of the opening (19), the workpiece is initially (7) between the cutting plate (6) and a holding-down device (5) is inserted. Then, the opening (19) by means of the workpiece (7) with the punch (3) is punched, wherein the workpiece (7) against the cutting plate (6) is supported. A circumferential region of the workpiece (7) around the opening, by means of the punching die (3) are embossed in such a way that an edge area of the opening out of the plane of the workpiece surface in the direction of the cutting plate (6) is set by plastic deformation to. The embossing is carried out in such a manner that the offset by plastic deformation is greater than 1 mm. The result is a punching tool and a punching process, which a visually attractive appearance of the ..