Injection flow control apparatus and method

Patent metadata

Field	Value
Publication number	US-2018015652-A1
Application number	US-201715715906-A
Country	US
Kind code	A1
Filing date	Sep 26, 2017
Priority date	Nov 23, 2010
Publication date	Jan 18, 2018
Grant date	—

Abstract

An actuator assembly comprising a piston interconnected to a valve pin, the piston being driven by drive fluid controlled by a restriction valve,
a pressure sensor adapted to sense pressure of the drive fluid disposed within an upstream drive chamber or within an upstream drive fluid channel connecting the drive chamber and the restriction valve, the pressure sensor sending and a controller receiving a signal indicative of the sensed pressure, the controller operating to execute a display of a visually recognizable format corresponding to the sensed pressure or an algorithm to control movement of the piston.

First claim

1 . In an apparatus for controlling flow of fluid injection material from an injection molding machine to a mold cavity, wherein the apparatus comprises: a manifold receiving the injected fluid mold material, the manifold having one or more fluid delivery channels that delivers the injected fluid material through a gate to the mold cavity;
a pressure sensing assembly comprising: an actuator comprising a piston interconnected to a valve pin drivable along a drive path that extends between a gate closed position where a distal end of the valve pin stops flow through the gate and an upstream open position where the distal end of the valve pin is withdrawn upstream to enable injection fluid material to flow through the gate, the piston being housed within a piston housing in an arrangement that forms an upstream drive chamber and a downstream drive chamber, the upstream drive chamber having a drive fluid port fluid sealably interconnected via an upstream drive fluid channel to a restriction valve, the piston being drivable upstream and downstream by drive fluid ( 14 ) pumped into and out of the upstream drive chamber through the drive fluid port, drive fluid channel and restriction valve, a pressure sensor adapted to sense pressure of the drive fluid disposed within the upstream drive chamber or within the upstream drive fluid channel, a controller that includes a program that instructs the restriction valve to close for a first portion of an injection cycle to prevent flow of the drive fluid such that the piston is held or stopped in a first position where drive fluid resides and remains within the upstream drive chamber or within the upstream drive fluid channel without flow through the restriction valve during the first portion of the injection cycle, the pressure sensor sensing pressure of the drive fluid resident and remaining within either the upstream drive chamber or the upstream drive fluid channel during the first portion of the injection cycle, the pressure sensor sending and the controller receiving a signal indicative of the sensed pressure, wherein the controller operates to execute a display of a visually recognizable format corresponding to the sensed pressure or uses the received signal in an algorithm to control movement of the piston.

2 . The pressure sensor assembly according to claim 1 wherein the controller includes instructions that operate to display a visually recognizable format of the sensed pressure as either sensed pressure of the drive fluid or pressure of the injection fluid that correlates to the sensed pressure of the drive fluid.

3 . The pressure sensor assembly according to claim 1 wherein the controller includes instructions that instruct the piston to travel to a selected maximum upstream position during the course of the injection cycle that leaves a space or volume within which drive fluid resides during the first portion of the injection cycle.

4 . The pressure sensor assembly according to claim 3 wherein the selected maximum upstream position of the piston is selected such that an upstream end surface of the piston is spaced an axial distance of between 0.1 and 2.0 mm from an opposing undersurface of an upstream wall of the upstream drive chamber.

5 . The pressure sensor assembly according to claim 3 wherein the selected maximum upstream position of the piston is selected such that an upstream end surface of the piston is spaced an axial distance of between 0.25 and 1.0 mm from an opposing undersurface of an upstream wall of the upstream drive chamber.

6 . The pressure sensor assembly according to claim 1 wherein an upstream surface of the piston is spaced a selected axial distance of 0.1 mm or greater away from an undersurface of the housing or upstream drive chamber during the entire course of the injection cycle.

7 . The pressure sensor assembly according to claim 1 further including a source of drive fluid that is drivable into and out of the upper drive chamber through the restriction valve and upstream drive fluid channel, the restriction valve being controllably openable by the controller to a selected degree to enable flow of drive fluid into and out of the upstream drive chamber at a selectable rate of flow to control rate of travel of the piston, the restriction valve being controllably closable to controllably stop flow of drive fluid into and out of the upstream drive chamber and to stop movement of the piston.

8 . The pressure sensor assembly according to claim 1 wherein the controller includes instructions that instruct the piston to travel, subsequent to the first portion of the injection cycle, to a second position for a second portion of the injection cycle where a distal end of the valve pin is positioned relative to the gate such that rate of flow of injection fluid is selectively controlled.

9 . The pressure sensor assembly according to claim 8 wherein the instructions of the controller operate to drive the piston to the second position in response to receipt of a first trigger signal from the pressure sensor corresponding to a first selected target pressure.

10 . The pressure sensor assembly according to claim 8 wherein the controller includes instructions that instruct the piston to travel, subsequent to the second portion of the injection cycle, to a third position for a third portion of the injection cycle where a distal end of the valve pin is positioned relative to the gate such that rate of flow of injection fluid is selectively controlled.

11 . The pressure sensor assembly according to claim 10 wherein the instructions of the controller operate to drive the piston to the third position in response to receipt of a second trigger signal from the pressure sensor corresponding to a second selected target pressure.

12 . The pressure sensor assembly according to claim 8 wherein the first position is a position where a distal end of the valve pin is positioned relative to the gate such that flow of injection fluid is not significantly restricted and injection fluid flows at a maximum speed or a relatively high speed or velocity or pressure at and through the gate and wherein the second position is a position wherein the distal end of the valve pin is disposed axially intermediate a gate closed and a fully gate open position such that the end of the valve pin restricts or reduces rate or velocity of flow or pressure of the injection fluid flowing through or exerted at the gate to a selected reduced velocity or pressure that is less than a maximum rate of flow or pressure.

13 . The pressure sensor assembly according to claim 8 wherein the second position is a position where a distal end of the valve pin is positioned relative to the gate such that flow of injection fluid is (a) not significantly restricted and injection fluid flows at a relatively high speed or velocity or pressure at and through the gate or (b) such that the distal end of the valve pin is disposed axially intermediate a gate closed and a fully gate open position such that the end of the valve pin restricts or reduces rate or velocity of flow or pressure of the injection fluid flowing through or exerted at the gate to a selected reduced velocity or pressure that is less than a maximum velocity or pressure.

14 . The pressure sensor assembly according to claim 1 wherein the controller includes instructions that instruct the actuator to drive the valve pin upstream beginning from the gate closed position to the first position for the first portion of the injection cycle and subsequently to one or more different subsequent positions for one or more different subsequent portions of the injection cycle in respon

Assignees

• Synventive Molding Solutions Inc

Inventors

• Galati Vito

Classifications

• B29C2945/76859

  Injection · CPC title

• B29C2945/76598

  linear movement · CPC title

• B29C2045/2712

  Serial gates for moulding articles in successively filled serial mould cavities · CPC title

• B29C45/2703

  Means for controlling the runner flow, e.g. runner switches, adjustable runners or gates · CPC title

• B29C2945/76545

  Flow rate · CPC title