| 摘要 |
<p>An apparatus for injection molding comprises an injection unit (14) comprising a plunger (64), the plunger (64) being translated with accumulation of plasticized material in preparation for injection and being advanced to inject the accumulated plasticized material into mold cavities (23). At least one electric motor (134) is engaged with the plunger (64) to resist translation as melt is accumulated and to inject plasticized material into the mold cavities (23). At least one hydraulic actuator (97) selectably operates the plunger (64) during a pack and hold interval to supply supplemental force when force supplied by the electric motors (134) is limited to maintain the operation of the motors (134) within the applicable continuous duty rating thereof. The electric motors (134) are advantageously selectably operatively engaged with the plunger (64) to inject plasticized material into the mold cavities (23) and the hydraulic actuators (97) are operated to inject plasticized material into the mold cavities (23) when the motors (134) are not engaged therefore.</p> |
