Expansion forming device for forming, e.g. tubular side beams, has two pressure transmitters for exerting and equalizing pressure differences between portions of outer faces of a tool during expansion forming

摘要

An expansion forming device includes a first and a second pressure transmitter applicable to respective outer faces of expansion forming tool. The two pressure transmitters exert pressure and equalize pressure differences between different portions of a first and a second outer face during the expansion forming, respectively. An expansion forming device comprises an expansion forming tool (90) having at least one cavity for receiving a blank having an inner hollow space, and pressure intensifier(s) for pressurizing a pressure medium in the hollow space of the blank so that the blank is forced against the wall of the forming space and the blank will expands into an article shaped according to the shape of the cavity. A first and a second pressure transmitter (84) are applicable to first and second outer faces of the tool to exert pressure and to equalize pressure differences between different portions of the first and second outer faces during the expansion forming, respectively. The two faces are located opposite to one another and oriented away from one another. Independent claims are also included for the following: (a) a method for expansion forming of an article; and (b) use of plate for defining a pressure cell (86, 92) in a press and for transmitting the liquid pressure in the cell to an expansion forming tool to counteract internal forming forces in the tool.