| 摘要 |
A process for injection moulding a connection pipe (10) made of a thermoplastic is presented. The connection pipe comprises a cylindrical tube (12) of circular cross-section provided at one end with an external annular bead (14) having a rotational symmetry. In a first process step a charge of liquid thermoplastic is injected into a mould cavity having the form of the connection pipe (10), and is allowed to solidify. Then the moulded connection pipe (10) is extracted in force from the mould cavity while it is still hot, whereby the connection pipe (10) loses its rotational symmetry. The wall of the cylindrical tube (12) has local thickness reinforcements on its inner surface which are designed so as to restore the rotational symmetry of the connection pipe (10) during its cooling off. <IMAGE> |
