| 摘要 |
An injection molding apparatus comprises a manifold having a manifold channel for receiving a melt stream of moldable material under pressure and delivering the melt stream to a nozzle channel of a nozzle. A mold cavity is in communication with the nozzle channel of the nozzle and receives melt through a mold gate. A valve pin is axially movable through the nozzle channel of the nozzle to selectively open the mold gate. The mold gate is open when the valve pin is in an extended position and a portion of the valve pin is received in the mold cavity. At least one groove is provided in an outer surface of the valve pin and at least a portion of the outer surface of the valve pin is in continuous engagement with the mold gate to align the valve pin relative to the mold gate. When the valve pin is in the extended position, the groove is aligned with the mold gate to allow melt to flow between the nozzle channel and the mold cavity. When the valve pin is in the retracted position, the valve pin is seated in the mold gate to block melt flow between the nozzle channel and the mold cavity.
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