| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a flexible tube that has high flexibility, a large pressure resisting value and less internal pressure-based torsion and elongation. SOLUTION: The flexible tube 21 comprises an inner tube layer 11 of a soft resin, an inner reinforcement 1 of a hard resin wound helically on the inner tube layer 11, an intermediate tube layer 12 of a soft resin enclosing the periphery of the inner reinforcement 1, and an outer reinforcement 4 of a hard resin wound helically on the intermediate tube layer 12 in the opposite direction to the inner reinforcement 1. The opposite helix directions of the inner and outer reinforcements 1 and 4 cause internal pressure-based forces trying to twist the helices to counteract each other.</p> |
