Motor-driven vertical type injection molding apparatus

A motor-driven vertical injection molding apparatus including;

• a screw holding member for rotatably holding a screw accommodated in a heated barrel, said screw extending in a vertical direction;
• a vertical driving mechanism for converting torque into a rectilinear force to rectilinearly move said screw,
• said vertical driving mechanism comprising;
• a ball screw integrally provided on said screw holding member and extending in the vertical direction;
• a ball nut rotatably provided internally in a molding apparatus body and screwed to said ball screw;
• and
• rotation transferring means, provided on an upper part of said ball nut and formed with a through-hole into which said ball screw is loosely fitted, for transferring the torque to said ball nut,
• wherein a length of said ball screw is set so that an upper end of said ball screw does not protrude from said rotation transferring means even when said ball screw rises up to an uppermost limit thereof;
• and
• an injection motor connected to said screw holding member through said vertical driving mechanism and providing torque thereto.