Injection molding nozzle with dynamic seal

摘要

A manifold, in a first pocket, defines a manifold orifice to supply material to a nozzle in a second pocket. A support ring in the second pocket maintains the nozzle stationary within the second pocket. A bushing extends between the pockets, fixedly attached to the manifold and laterally movable with respect to the pockets and the nozzle. At ambient temperature, the centers of the nozzle and manifold orifices are laterally offset from one another, a preload is defined between the nozzle and the bushing, another preload is defined between the manifold and the nozzle, and a gap is defined between the support ring and the pocket. In operation, when the various components thermally expand, the manifold moves laterally within the first pocket, and the nozzle remains substantially stationary within the second pocket, such that the centers of the nozzle and manifold orifices are laterally aligned, and the gap is closed.

主权项

1. An injection molding nozzle system, comprising:
a mold plate defining a first and a second pocket; a nozzle disposed in the second pocket, and defining a nozzle orifice extending in an axial direction and configured to inject molten material into a mold from a downstream end of the nozzle orifice, wherein an upstream end of the nozzle orifice defines a nozzle center when viewed in the axial direction; a manifold disposed in the first pocket, and defining a manifold orifice configured to supply the material to the nozzle orifice, wherein a downstream end of the manifold orifice is in fluid communication with the upstream end of the nozzle orifice, wherein the downstream end of the manifold orifice defines a manifold center when viewed in the axial direction; a centering support ring in the second pocket, configured to maintain the nozzle substantially stationary with respect to the second pocket; and a bushing extending between the first and second pockets, fixedly attached to the manifold and configured to move laterally with respect to the pockets and to the nozzle; wherein:
at an ambient temperature:
the nozzle center and the manifold center are offset from one another in a lateral direction substantially perpendicular to the axial direction;a first preload is defined between abutting surfaces of the nozzle and the bushing;a second preload is defined between abutting surfaces of the manifold and the nozzle; anda first gap is defined between the support ring and a shoulder at a downstream end of the second pocket; andin operation:
the manifold and the nozzle reach respective operating temperatures and thermally expand, such that the manifold moves laterally within the first pocket, and such that the nozzle remains substantially stationary within the second pocket, such that the nozzle center and the manifold center are substantially aligned in the lateral direction; andthe first gap is closed by thermal expansion of various components of the system.