Flexible tube production apparatus

A flexible tube production apparatus for extrusion molding a flexible tube, the flexible tube production apparatus comprising:

• a first extruder that extrudes a first resin;
• a second extruder that extrudes a second resin more flexible than the first resin;
• a third extruder that extrudes a third resin more flexible than the first resin and the second resin;
• a die that has a first penetrating hole through which a braded wire is inserted, an extrusion port extruding the resins onto a surface of the braded wire passing through the first penetrating hole, and a flow passage in communication with the extrusion port;
• a first valve that is switchable between a state in which the first extruder and the flow passage of the die are in communication and a state in which the first extruder and the flow passage of the die are interrupted from each other;
• a second valve that is switchable between a state in which the second extruder and the flow passage of the die are in communication and a state in which the second extruder and the flow passage of the die are interrupted from each other;
• and
• a third valve that is switchable between a state in which the third extruder and the flow passage of the die are in communication and a state in which the third extruder and the flow passage of the die are interrupted from each other;
• and
• wherein a first supply passage connecting the first valve and the flow passage, a second supply passage connecting the second valve and the flow passage, and a third supply passage connecting the third valve and the flow passage are provided inside the die,
• the die has:
• an inner die that has a straight portion of circular columnar outer shape and a convergent tapered portion provided closer to the extrusion port side than the straight portion;
• and
• an outer die that has a hollow portion and houses the inner die in the hollow portion with there being a predetermined interval, serving as the flow passage, from an outer surface of the inner die, and
• downstream side end portions of the first supply passage and the second supply passage are connected to a portion of the flow passage formed between the straight portion and the outer die, and a downstream side end portion of the third supply passage is connected to a portion of the flow passage formed between the tapered portion and the outer die.