Injection molding nozzle

Abstract

The invention relates to a nozzle (100) for use with injection molding systems, comprising a nozzle housing (112) defining a melt channel (114) and having a first preload engagement surface (171); a tip insert (116) having a tip channel (122) and at least one outlet aperture (120) communicated with the tip channel (122); a tip retainer (124) abutting against the nozzle housing (112) and retaining the tip insert (116) so as to communicate the tip channel (122) and the melt channel (114), the tip retainer (124) having a second preload engagement surface (172); and a preload limiter gap (170) between the tip retainer (124) and the nozzle housing (112) and comprising a spaced distance between the first preload engagement surface (171) and the second preload engagement surface (172) when the nozzle (100) is in a first partially assembled position and a second fully assembled position, and the spaced distance creating a desired amount of preload force P when the nozzle (100) is in the second fully assembled position, wherein the preload limiter gap (170) is defined as the distance between the first preload engagement surface (171) of the nozzle housing (112) and the first preload engagement surface (172) of the tip retainer (124) and configured that: in the first partially assembled position, a nip inert flange (150) initially substantially contacts both a flange engagement portion (151) of the tip retainer (124) and a nozzle seal engagement portion (154) of the nozzle housing (112), and in the second fully assembled position, the first preload engagement surface (171) of the nozzle housing (112) substantially abuts against the first preload engagement surface (172) of the tip retainer (124) and creates the desired amount of preload force P.

Description

technical field [0001] The present invention relates to molding systems, and more particularly to nozzles for injection molding systems. Background technique [0002] The current state of the art includes various nozzles and nozzle tips for molding systems including, but not limited to, hot runner injection molding systems. Hot runner nozzles can generally include valve gated or hot tip nozzles. In a valve-gated nozzle, a separate rod moves into the nozzle and the tip acts as a valve to selectively start and stop the flow of resin through the nozzle. In a hot tip nozzle, a small gate area at the tip of the nozzle freezes off to thereby stop the flow of resin through the nozzle. The invention can be applied to valve gated and / or hot tip nozzles. [0003] For details, see figure 1 and 2 , showing two exemplary hot runner nozzle tips 1 . The nozzle tip 1 may comprise a nozzle housing 2 comprising a melt channel 6, and a tip insert 3 comprising a tip channel 7 in fluid com...

AI Technical Summary

Problems solved by technology

Since the tip holder 4 and / or the nozzle tip 2 may be constructed of a higher strength material than the tip insert flange 17, high stress concentrations along the tip insert 17 may exceed the tip insert flange. The yield strength limit of the material of the flange 17, resulting in damage to the pointed insert flange 17

[0009] In addition, the perpendicular arrangement of the tip insert flange 17 and the surfaces 27, 28 of the tip holder 4 can lead to an uneven distribution of force along the seal 21 between the tip insert 3 and the nozzle housing 2

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