| 摘要 |
A machine for continuous production of a composite pipe (10) with a tube sleeve, consisting of a smooth inner pipe welded to an outer tube with transverse grooves, has circulating pairs of half chill molds together completing a mold with a molding zone (16) provided with an injection head (8) with two nozzles connected to respective extruders (1, 2). A controller (50) operates the extruder drive motors (3, 3') at specific rotational speeds during the molding phases. A machine for continuous production of a composite pipe (10) with a tube sleeve, consisting of a smooth inner pipe welded to an outer tube with transverse grooves, comprises pairs of half chill molds which (a) have annular mold indentations (at least one pair having a sleeve indentation), (b) together complete a mold with a central longitudinal axis in a molding zone (16) and (c) are guided in a circuit and in a transport direction (4). An excess pressure (relative to the exterior) can be generated in the machine. The molding zone is provided with an injection head (8) of a first extruder (1), the head having an outer nozzle (22) for extruding the outer tube, upstream of an inner nozzle (21) for extruding the inner tube, and a calibrating mandrel at the downstream end. The inner and outer nozzles are connected to first and second extruders (1, 2) respectively. A controller (50) operates the drive motors (3, 3') for the extruders so that the rotational speed of the first extruder is increased from a value (n1.1) during production of the inner tube and transverse grooves to a value (n1.2) while the widened transition section of the sleeve opening moves over the inner nozzle, then reduced to a value (n1.3), between (n1.2) and (n1.1), while the sleeve opening moves over the inner nozzle. |
