| 摘要 |
The invention relates to an expanding tool for a shaping device, in particular a forging die, for the production of hollow workpieces, having a ram and an expanding sleeve which accommodates the free end portion of the latter positively in a location opening, consists of radially movable segments separated by parting seams and the outer contour of which corresponds to the inner contour of the workpiece, the parting seams being formed by mutually adjoining boundary surfaces of adjacent segments. In known expanding tools, the segments are separated from one another by radially extending parting seams which widen when the expanding sleeve is expanded, with the result that plastic or molten workpiece material can penetrate during the shaping operation. In order to prevent an increase in the width of the parting seams between the segments during the expansion of the expanding sleeve, an even number of at least four segments (11, 12) is provided according to the invention, the planes of the parting seams extending outside the longitudinal centre axis of the expanding sleeve (2) such that, with the expanding sleeve (2) expanded, the parting seams (18) are closed in the region of their outer contour. <IMAGE> |
