JPS6414005A - Manufacture of extrusion molded pipe - Google Patents

Abstract

PURPOSE:To prevent deterioration in the strength of a molded pipe by molding an extruded pipe without distributing a reinforcing material unevenly by making a supporting member fixing a molding core to a molding cylinder unnecessary, by a method wherein the molding core is made movable in an extruding direction by connecting the molding core with an extruding member by interlocking with the extruding member and a molding matrix is extruded between an external circumference of the molding core and an internal circumference of an outlet of the molding cylinder. CONSTITUTION:A thick molding matrix 7 is fitted over a molding core 4 at a base end 2b side of a molding cylinder 2, an extruding member 3 is extruded toward the outlet of the molding cylinder 2 by a hydraulic cylinder 5 and the molding core 4 also moved together with the extruding member 3 in the same direction as that of the extruding member 3. The molding matrix 7 is tapered gradually at a tapered pipe 2c part, extruded through a space between an internal circumference of an outlet of the molding cylinder 2 and the external circumference of the molding core 4 and a molded pipe 8 of a desired thickness is completed. In this instance, when the molding matrix 7 is set at a temperature suitable for extrusion by a heater 6 of a molding core 4 and extrusion is continued further, as the rate of the extrusion of the molding matrix 7 is faster than that of the extruding member 3, the molded pipe 8 is pulled out of the molding core 4. The molding core 4 is moved backward, the molded pipe 8 is taken out by removing the tapered cylinder 2c, the molding matrix 7 is fitted over the molding core 4 again and the next extrusion is performed.