| 摘要 |
PURPOSE:To ensure that the shape of a tubular member with a smaller section can be changed as well as its thickness by driving a movable molding die forward and backward with respect to an extrusion opening, then allowing part of molding material to be discharged fro adjustment of its extruded quantity and at the same time, extruding the molding material, controlling the shape of the peripheral surface of a molded surface at the tip of a movable molding die. CONSTITUTION:When a movable molding die 8 leaves and extrusion opening 5 and stops up a material discharge path 7 formed on a mouthpiece 2, all the molding material B is extruded from the opening 5, and the first cylindrical tubular member A1 is extruded and molded. When the movable molding die 8 is moved toward the opening 5 to allow the material discharge path 7 to communicate with a material discharge hole 8c provided on the movable molding die 8, part of a molding material B is discharged to the exterior after passing through the material discharge path 7 and a material discharge hold 8c. The remaining molding material 13 is extruded from the extrusion molding orifice 5. Then part of the tubular member extruded from the extrusion molding orifice 5 of a die body 1 is forced to change its flow path by a guide surface 8b leading to a molding surface 8a at the tip of the movable molding die 8, and part of the peripheral surface of the second semi-cylindrical tubular member A2 is formed by a molding surface 8a. |
