| 摘要 |
For the purpose of further developing pipe expansion methods the invention proposes a stepwise effective pipe expander with an expander head acting stepwise locally from radially inside upon a pipe, which pipe expander is held on a support rod, as well as with shifting means for axially shifting the expander head relative to the pipe, wherein an external outer matrix element forming an outer calibre is provided on the expander head at the axial height of the expander head. Preferably expansion is carried out by means of a radially outward hydroforming effective surface / by means of directional bending forces being simultaneously applied. |
