| 摘要 |
PROBLEM TO BE SOLVED: To provide a pressure-proof hose enabling weight reduction while securing required pressure capacity, and to provide its manufacturing method. SOLUTION: In molding a spiral core portion of the pressure-proof hose, a mold 15 is used with an air passage arranged at the approximate center of a cylindrical resin passage. Molten resin and pressure controlled air are supplied to the corresponding passages to extrusion-mold a hollow hard synthetic resin core material 3. The hard synthetic resin core material 3 extrusion-molded in a semi-melted condition is sealed at its front end to keep pressure in the core material constant. The hard synthetic resin core material 3 is spirally wound on a synthetic resin tube 2 at selective pitches to form the spiral core portion Sp. COPYRIGHT: (C)2007,JPO&INPIT
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