| 摘要 |
PURPOSE:To enable always extrusion molding in uniform thickness, by a method wherein a mandrel having magnetism on the surface is used, an extruding machine is provided with a moving device moving an outer die, and a thickness measuring device is arranged in front of the extruding machine. CONSTITUTION:A long-sized mandrel 61 having magnetism on the surface is inserted through an insertion hole 29 for the mandrel of an inner die holder 31, the tip part is projected through an extrusion port 41, then extruded from the extrusion port 41 by passing through a material feed port 25 and extrusion passage 39 with a screw 23 and a rubber layer is molded. An extrusion-molded rubber layer is moved forward and passes through the inside of a thickness measuring device 55. In this instance, since the surface of the long-sized mandrel 61 possesses the magnetism, a thickness is measured by a sensor part 60. A measured result is operated by the central treatment device and in the case where the same is different from a predetermined fixed thickness value, a control device of a hydraulic cylinder 45 is controlled by sending out a signal to the hydraulic cylinder 45 so that the thickness becomes uniform. |
