Valve pin and nozzle configuration and method of control

Patent metadata

Field	Value
Publication number	US-2016288388-A1
Application number	US-201615181933-A
Country	US
Kind code	A1
Filing date	Jun 14, 2016
Priority date	Jan 8, 2014
Publication date	Oct 6, 2016
Grant date	—

Abstract

An injection molding apparatus comprising: a manifold, a nozzle, A distal tip of the nozzle being comprised of a highly heat conductive insert and an insulation cap that is substantially less heat conductive than the insert, the downstream end portion of the insulation cap being disposed between the gate and the downstream end portion of the highly heat conductive insert forming a fluid seal around the gate, a valve pin, wherein when the valve pin is in a gate closed position, an axially interior surface of a fluid exit aperture of the insulation cap surrounds a gap enabling circumferential surface of the valve pin forming a spatial gap immediately upstream of the gate between the interior surface of the fluid exit aperture of the insulation cap and the gap enabling circumferential surface of the valve pin.

First claim

What is claimed is:

1 . An injection molding apparatus comprising:
a manifold) having a manifold channel that receives an injection fluid, a nozzle having a nozzle channel having an axis receiving the injection fluid from the manifold channel, the nozzle having a distal tip in fluid communication with a gate to a mold cavity, the distal tip of the nozzle being comprised of a highly heat conductive insert and an insulation cap that is substantially less heat conductive than the insert, mounted coaxially within the nozzle channel in nested contact with each other, the highly heat conductive insert and the insulation cap each having a downstream end portion containing a fluid exit aperture that are aligned with each other enabling flow of injection fluid through the nozzle channel downstream into the mold cavity, the downstream end portion of the insulation cap being disposed between the gate and the downstream end portion of the highly heat conductive insert forming a fluid seal around the gate, a valve pin interconnected to an actuator adapted for controllably driven reciprocal movement of the valve pin coaxially through the nozzle flow channel, the valve pin having a distal end portion having a downstream-most circumferential surface complementary to an axially interior surface of the gate and a downstream surface portion immediately upstream of the downstream-most circumferential surface, the downstream surface portion having a gap enabling circumferential surface, the actuator being adapted to controllably drive the distal end portion of the valve pin along a drive path extending between one or more upstream positions where the injection fluid flows through the gate and a downstream gate closed position where the distal end portion of the valve pin mates with the axially interior surface of the gate to stop flow of injection fluid through the gate, wherein when the valve pin is in the gate closed position, an axially interior surface of the fluid exit aperture of the insulation cap surrounds the gap enabling circumferential surface of the valve pin forming a spatial gap immediately upstream of the gate between the interior surface of the fluid exit aperture of the insulation cap and the gap enabling circumferential surface of the valve pin.

2 . The apparatus of claim 1 wherein the actuator is interconnected to a controller that controllably instructs the actuator to drive the distal end portion of the valve pin continuously upstream starting from the gate closed position at one or more intermediate upstream velocities that are less than a predetermined high velocity and to subsequently further drive the valve pin upstream at the predetermined high velocity.

3 . The apparatus of claim 1 wherein the actuator comprises a hydraulically driven or pneumatically driven actuator or an electrically powered motor.

4 . The apparatus of claim 2 wherein the actuator comprises a hydraulically driven or pneumatically driven actuator or an electrically powered motor.

5 . The apparatus of claim 1 wherein the spatial gap is adapted to receive injection fluid that is forced upstream from the gate when the valve pin is moved downstream toward the gate closed position.

6 . The apparatus of claim 1 wherein axially interior surface of the gate comprises a surface of the mold.

7 . The apparatus of claim 1 wherein the nozzle channel has an axially interior surface disposed upstream of the fluid exit apertures that is complementary to and slidably engages with the gap enabling circumferential surface of the valve pin to align the axis of the valve pin with the gate during downstream movement of the valve pin toward the gate closed position.

8 . The apparatus of claim 1 wherein an axially inner surface of an upstream end portion of the insulation cap is engaged against an axially outer surface of a downstream end of the insert, the upstream end portion of the insulation cap being compressed between the insert and an axially inner surface of the distal tip of the nozzle to seal flow of the injection fluid to within the nozzle channel.

9 . The apparatus of claim 1 wherein the distal end portion of the valve pin is configured such that flow of injection fluid through the gate is restricted at one or positions of the valve pin that are intermediate the gate closed position and a fully upstream gate open position at which flow of the injection fluid is unrestricted.

10 . A method of performing an injection molding cycle comprising injecting the injection fluid from an injection molding machine into the manifold channel of the apparatus of claim 4 and using the apparatus of claim 4 to inject the injection fluid into the mold cavity during the course of an injection molding cycle.

11 . An injection molding apparatus comprising:
a manifold having a manifold channel receiving an injection fluid, a nozzle having a nozzle channel receiving injection fluid from the manifold channel, the nozzle having a distal tip in fluid communication with a gate to a cavity of a mold, the distal tip being comprised of a highly heat conductive insert mounted in contact with an insulation cap that is mounted between the insert and the gate, the insulation cap being substantially less heat conductive than the insert, the insulation cap forming a fluid seal around the gate such that a fluid sealed flow channel ( 54 ) is formed extending from an upstream end of the nozzle to the gate, a valve pin having a distal end portion having a circumferential surface, and a distal tip end, an actuator drivably interconnected to the valve pin adapted to drive the valve pin ( 90 ) along a drive path extending between a gate closed position, one or more intermediate upstream positions where the distal tip end of the valve pin restricts flow of the injection fluid through the gate and a third position upstream of the intermediate upstream positions where the injection fluid flows freely through the gate without restriction, wherein when the valve pin is in the gate closed position, the distal tip end of the valve pin seals the gate and a downstream circumferential surface of the distal end portion of the valve pin mates with a complementary axially interior surface of the gate, and,
wherein the insulation cap is configured to form a circumferential gap around an upstream circumferential surface of the distal end portion of the valve pin that is disposed immediately upstream of the complementary axially interior surface of the gate when the valve pin is in the gate closed position.

12 . The apparatus of claim 11 wherein the complementary internal surface of the gate comprises a surface of the mold.

13 . The apparatus of claim 11 wherein the upstream circumferential surface of the distal end portion of the valve pin slidably engages with an axially interior surface of the nozzle flow channel to align the axis of the pin with the gate during downstream movement of the pin toward the gate closed position.

14 . The apparatus of claim 11 wherein the actuator comprises a hydraulically driven or pneumatically driven actuator or an electrically powered motor.

15 . The apparatus of claim 11 wherein the actuator is interconnected to a controller that controllably instructs the actuator to drive the distal end portion of the valve pin continuously upstream starting from the gate closed position at one or more intermediate upstream velocities that are less than a predetermined high velocity and to subsequently further drive the valve pin upstream at the predetermined high velocity.

16 . A method of performing an injection mol

Assignees

• Synventive Molding Solutions Inc

Inventors

• Feng Ling
• Liquiao Li
• Henderson William
• Galati Vito

Classifications

• B29C2945/76568

  Position · CPC title

• B29C45/03

  Injection moulding apparatus (transfer moulding B29C45/02) · CPC title

• B29C2045/2787

  Nozzle tips made of at least 2 different materials · CPC title

• B29C45/7613

  the termination of flow of material into the mould · CPC title

• B29C45/278 Primary

  Nozzle tips (B29C45/2735 takes precedence) · CPC title