| 摘要 |
A method for processing a tube equipped with an inward flange portion in a hole formed at an end portion of a thin tube from a thin tube made of a thermoplastic resin, and an apparatus used in this method. The thin tube is fitted to a tube holder equipped with a male mold for forming the flange portion in the hole and an open portion inside the flange portion into predetermined shapes, in such a way that the distal end of the thin tube protrudes by a predetermined length from the distal end of the tube holder. Heated air is blown to an inner wall surface at the end portion of the thin tube and the outer wall surface of this end portion is cooled so as to generate a temperature difference between the inside and the outside of the thin tube and to cause radial deformation of the end portion of the thin tube. When the inner wall surface is heated to a temperature lower than the melting point of the inner layer, the end portion of the thin tube undergoes inward deformation; when the inner wall surface is heated to a temperature higher than the melting point, the end portion of the thin tube undergoes outward deformation. The end portion of the thin tube so deformed is shaped into the flange portion having a predetermined shape and to the open portion inside the flange portion having a predetermined shape by using a female mold cooperating with the male mold described above.
|
