Insert molding die, insert molding apparatus and insert molding method

An insert molding method:

• wherein an insert part is supported in the molten resin material extruded in the shape of pipe by an extrusion die, and while sucking the air, the molten resin material with the insert part is shaped by at least a top set of die halves closest to the extrusion die, a middle set of die halves, and a bottom set of die halves furthest from the extrusion die, the top, middle and bottom sets of die halves being separable from each other to permit independent clamping by each of the top, middle and bottom sets of die halves;
• wherein the molten resin material extruded in the shape of pipe is clamped by the bottom set of die halves, and the molten resin material is pressed against the support side of the insert part thereby to seal the open forward end of the molten resin material;
• wherein at the same time as the air is sucked with the open forward end of the molten resin material having been sealed, a clamping operation is performed by the middle set of die halves to cover and shape the molten resin material around the insert part;
• and
• wherein a clamping operation is performed by the top set of die halves so that the molten resin material extruded in the shape of pipe is cut off thereby to eject the molded part covered with the molten resin material.