Apparatus for the internal high-pressure forming of a tubular blank

摘要

On an apparatus for the internal high-pressure forming of a tubular blank (3) made from ductile metal in a tool (1) having a die cavity, a pressure-medium feed (6) can be displaced axially behind the blank (3), the said feed being connectable to the end of the tubular blank (3) with sealing being provided by a flexible sealing ring (15; 25). In the tool (1), the die cavity adjoins a cylindrical cavity section (2), this section being open from the side of the tool and surrounding the tubular blank (3) at this point. A stub (10) of the pressure-medium feed (6) reaches into the said cylindrical cavity section (2) and into the end of the tubular blank (3) and here supports the sealing ring (15) on a circumferential surface (14) in front of an annular end face (13) in such a way that the pressure medium presses the sealing ring (15) against the end face (13) and, at the same time, by compression, against the inner surface of the tubular blank (3) and against the said circumferential surface (14). Arranged in front of the relatively hard sealing ring (15), which has an angular cross-section to match its contact surface (14; 13; 3) there is preferably another sealing ring (16) of softer material and of round cross-section on the same circumferential surface, which is then conical, this sealing ring coming to rest leaktightly against the inner surface of the tubular blank (3) before the first sealing ring (15) and pushing the first sealing ring (15). <IMAGE>