Composite-molding method and injection-molding machine of different material resin

A composite-molding method of different material resins, comprising the steps of:

• juxtaposing a primary cavity mold and a secondary cavity mold at symmetrical positions of a fixed plate;
• juxtaposing core molds closing alternately with both the primary cavity mold and the secondary cavity mold on a rotary table installed on a movable platen, for transferring a primary molding which is injection-molded by the primary cavity mold and the core mold to the secondary cavity mold through displacement of the core mold by the rotary table;
• installing a holding pin for the primary molding and a resin pushing pin in said core mold in a way to appear and disappear with respect to a cavity of the primary cavity mold and secondary cavity mold, when composite-molding integrally by the second cavity mold the primary molding and a secondary molding of different material resin which is injection-molded;
• injection molding a primary molding;
• holding the primary molding in contact with a surface of the secondary cavity mold by the holding pin and forming a pin hole to be opened on a surface of the core mold for refilling the different material resin by retracting the pushing pin;
• injecting and refilling with the different material resin into the secondary cavity including the pin hole, retracting the holding pin to sink in the surface of core mold and moving the pushing pin forward to press the resin for refilling from the pin hole into the resin in the secondary cavity;
• and refilling with the resin an unfilled region formed by retracting the holding pin.