| 摘要 |
The invention relates to an expansion head (1) for expansion tools for hollow workpieces, especially for the ends of plastic pipes and metal-plastic composite pipes, comprising a union cap (2), which has a guide flange (3) directed radially inward, and a set of sector-shaped expandable jaws (4), which are each received individually by an inner flange sector (5), which overlaps the guide flange (3), so as to be radially movable in the union cap (2), the set of sector-shaped expandable jaws (4) being movable between a closed state and an expanded state, and, when the jaws are closed, an envelope of the outer walls (7) of the set of expandable jaws (4) approximately forming the surface area of a cylinder, every expandable jaw (4) having at least one recess extending in the direction of the longitudinal axis of the expandable jaws (4) such that the area of the outer walls (7) of the set of expandable jaws (4) corresponds, when the expansion head (1) is closed, to 25 % to 75 % of the area of the envelope of the outer walls (7) of the set of expandable jaws. The invention further relates to an expansion tool for hollow workpieces, especially for the ends of pipes made of plastics and made of metals covered with plastics, comprising an expansion head (1) according to the invention. |
