Injection molding apparatus

An injection molding apparatus comprising:

• an injection unit having a plurality of injection nozzles having respective distal end portions that move back and forth between a first position and a second position spaced therefrom by a predetermined distance by movement of the injection unit, and a molten resin is injected from an injection opening arranged at a vertex portion of the distal end portion of said plurality of injection nozzles when the respective distal end portions of said injection nozzles are at said second position,
• a mold clamp unit comprising a first mold clamp unit having a first frame body and an upper mold mounted on the first frame body, a second mold clamp unit having a second frame body and a lower mold mounted on the second frame body, wherein a plurality of nozzle reception portions to which said distal end portions of the injection nozzles fit respectively are formed in one of said first and second frame bodies and a resin introduction passage is formed for introducing molten resin from central portions of the plurality of nozzle reception portions to a plurality of cavities formed between said upper mold and lower mold as they are clamped is formed,
• wherein said respective distal end portions of the plurality of injection nozzles move to said second position when respective distal end portions of the plurality of injection nozzles are fitted and fixed to a corresponding one of said nozzle reception portions so as to inject the molten resin from said injection openings to said resin introduction passage,
• wherein a manifold having a plurality of cylindrical holes to accommodate said plurality of injection nozzles, and a molten resin passage formed to communicate with one side thereof is provided, and
• wherein said injection nozzles are inserted into said cylindrical holes so that distal end portions thereof project outside said manifold and distal end portions of said plurality of injection nozzles are mounted by providing first and second ring-shaped elastic members outside said plurality of injection nozzles and inside said plurality of cylindrical holes to permit the respective distal end portions to move loosely in any direction in response to an external force applied thereto.