Shut-off nozzle, injection device, and injection molding machine

An injection device comprising:

• a heating cylinder;
• a screw inserted in the heating cylinder;
• and
• a shut-off nozzle provided in the heating cylinder,
• wherein the shut-off nozzle comprises:
• a nozzle body portion having an in-nozzle flow path formed therein;
• and
• a needle valve that is inserted into the nozzle body portion coaxially with the nozzle body portion and is configured to open and close an outlet of the in-nozzle flow path,
• wherein a cylindrical portion is formed in the vicinity of a tip of the needle valve,
• wherein a cylindrical hole portion is formed in the vicinity of a tip of the in-nozzle flow path, the cylindrical hole portion being a cylindrical hole, and
• wherein in a case where the needle valve is driven in a forward direction, the cylindrical portion is fitted into the cylindrical hole portion.

An injection molding machine comprising:

• an injection device configured to inject resin;
• and
• a mold clamping device configured to clamp a mold,
• wherein the injection device comprises:
• a heating cylinder;
• a screw inserted in the heating cylinder;
• and
• a shut-off nozzle provided in the heating cylinder,
• wherein the shut-off nozzle comprises:
• a nozzle body portion having an in-nozzle flow path formed therein;
• and
• a needle valve that is inserted into the nozzle body portion coaxially with the nozzle body portion and is configured to open and close an outlet of the in-nozzle flow path,
• wherein a cylindrical portion is formed in the vicinity of a tip portion of the needle valve,
• wherein a cylindrical hole portion is formed in the vicinity of a tip portion of the in-nozzle flow path, the cylindrical hole portion being a cylindrical hole, and
• wherein the cylindrical portion is configured to be fitted into the cylindrical hole portion in a case where the needle valve is driven in a forward direction.