| abstract |
(57) [Summary] [Purpose] When manufacturing resin pipe fittings by the casting method, By using an inner mold with a simple structure that is easy to assemble and demold, productivity is improved and cost is reduced. [Structure] A tubular fiber woven fabric 2 as an outer peripheral material of an inner mold A is prepared, and an inflatable tube 3 is placed in the tubular fiber woven fabric 2. Is inserted, the tube 3 is expanded by press-fitting of a fluid to assemble the inner mold A, the inner mold A is incorporated into the outer mold 4, and the outer mold 4 is held while maintaining the expanded state of the tubular fiber woven fabric 2. After injecting the resin material into the inside and solidifying the injected resin, after removing the outer mold 4, The tube 3 and the tubular fiber woven fabric 2 are removed. |