| 摘要 |
A method for forming a sleeve joint which has an inner groove, at an end segment of a thermoplastic pipe, involves heating the end segment to a shaping temperature, after which it is axially upset to enlarge its wall thickness until it fills an annular gap in a heated upsetting layout, and then shaped into the sleeve joint under axial displacement in a shaping layout, and finally it is cooled down. The heating and the upsetting of the end segment is done starting at the region for the free end of the end segment at a relatively narrow shaping temperature range just below the crystallite melting temperature of the crystalline or semicrystalline plastic. The heated and upset end segment is removed from the upsetting layout. When shaping the sleeve joint in the shaping layout maintained at the shaping temperature, the end segment is upset in the mould to equalize the losses in wall thickness during the widening. <IMAGE> |
