Injection molding unit

An injection molding unit, comprising:

• an injection molding machine for injecting plasticized molten resin, said injection molding machine including a screw cylinder having a tip, a nozzle at said tip and a screw advanceable in said screw cylinder for injecting molten resin from said nozzle;
• an injection mold comprising a cavity mold and a core mold forming a hollow therebetween for forming an injection molded product therein;
• a resin passage extending from inside said screw cylinder to a terminal end of said hollow;
• and
• a pressure relief means for releasing molten resin from said resin passage at a pressure of the molten resin in said resin passage greater than a predetermined value;
• wherein said cavity mold comprises a plurality of cavity mold segments defining respective wall portions of said hollow.

An injection molding unit, comprising:

• an injection molding machine for injecting plasticized molten resin, said injection molding machine including a screw cylinder having a tip, a nozzle at said tip and a screw advanceable in said screw cylinder for injecting molten resin from said nozzle;
• an injection mold comprising a cavity mold and a core mold forming a hollow therebetween for forming an injection molded product therein;
• a resin passage extending from inside said screw cylinder to a terminal end of said hollow;
• and
• a pressure relief valve located on said resin passage and adapted to release molten resin from said resin passage at a pressure of the molten resin in said resin passage greater than a predetermined value;
• wherein said cavity mold comprises plurality of cavity mold segments defining respective wall portions of said hollow.