| 摘要 |
PURPOSE:To prevent thin wall parts from occurring partially in a gutter manufactured by deforming a resin covered sheet so as to separate each edge surface from an annular pipe prior to the solidification of molten resin covering the inner peripheral surface and outer peripheral surface of a metallic sheet which is formed into an annular pipe. CONSTITUTION:A cross-head die 40 which serves to extrusion-cover the inner peripheral surface and outer peripheral surface of an annular pipe sheet 12 has a cylindrical inner surface resin covering mold 41 and cylindrical outer surface resin covering mold 43 which is externally fitted in an inner surface resin covered mold 41 in order to form an annular clearance 42 on the outer surface side of its tip end part. The inner surface resin covered mold 41 has a support part 411 positioned within a groove-shaped sheet 11 being placed immediately before the molding into the annular pipe sheet 12 on the upstream side of advancing direction of the annular pipe 12, a cylindrical molding part 412 projecting from the support part 411 to the downstream side of the transfer direction of the groove-shaped sheet 11, and a core part 414 inserted in the molding part 412 so as to form a cylindrical resin passage 413 on the inner surface side of the molding part 412. The tip part of the resin passage 413 is made widening in diameter gradually to the tip end. The tip end of the resin passage 413 is opened toward the cylindrical clearance 42. |
