Injection molding flow control apparatus and method

• US 10,173,356 B2
• Filed: 04/06/2017
• Issued: 01/08/2019
• Est. Priority Date: 11/23/2010
• Status: Active Grant

• Current Assignee: Synventive Molding Solutions Incorporated
• Original Assignee: Synventive Molding Solutions Incorporated
• Inventors: de Oliveira Antunes, Sergio Ribeiro, Gotz, Christian, Emich, Juergen Wilhelm
• Primary Examiner(s): Sanders, James
• Application Number:
  US15/480,447
• Publication Number:
  US 20170210048A1
• Time in Patent Office: 642 Days
• CPC Class Codes: B29C 2045/1792 Machine parts driven by an electric motor, e.g. electric servomotor
• CPC Class Codes: B29C 2045/2712 Serial gates for moulding articles in successively filled serial mould cavities
• CPC Class Codes: B29C 2045/2824 Needle valves driven by an electric motor
• CPC Class Codes: B29C 2045/2865 having position detecting means
• CPC Class Codes: B29C 2045/2872 with at least three positions, e.g. two different open positions to control the melt flow
• CPC Class Codes: B29C 2945/76006 Pressure
• CPC Class Codes: B29C 2945/76076 duration
• CPC Class Codes: B29C 2945/76083 Position
• CPC Class Codes: B29C 2945/76277 nozzles
• CPC Class Codes: B29C 2945/7628 manifolds
• CPC Class Codes: B29C 2945/76381 Injection
• CPC Class Codes: B29C 2945/76545 Flow rate
• CPC Class Codes: B29C 2945/76568 Position
• CPC Class Codes: B29C 2945/76598 linear movement
• CPC Class Codes: B29C 2945/76602 derivative, change thereof
• CPC Class Codes: B29C 2945/76755 nozzles
• CPC Class Codes: B29C 2945/76859 Injection
• CPC Class Codes: B29C 2945/76933 The operating conditions are corrected immediately, during the same phase or cycle
• CPC Class Codes: B29C 2945/76936 The operating conditions are corrected in the next phase or cycle
• CPC Class Codes: B29C 2945/76939 Using stored or historical data sets
• CPC Class Codes: B29C 2945/76993 : Remote, e.g. LAN, wireless LAN
• CPC Class Codes: B29C 45/03 : Injection moulding apparatus transfer moulding B29C45/02
• CPC Class Codes: B29C 45/2703 : Means for controlling the runner flow, e.g. runner switches, adjustable runners or gates
• CPC Class Codes: B29C 45/2708 : Gates B29C45/2703 takes precedence
• CPC Class Codes: B29C 45/2806 : consisting of needle valve systems B29C45/2896 takes precedence
• CPC Class Codes: B29C 45/281 : Drive means therefor
• CPC Class Codes: B29C 45/76 : Measuring, controlling or regulating measuring in general G01; controlling or regulating in general G05
• CPC Class Codes: B29C 45/7613 : the termination of flow of material into the mould
• CPC Class Codes: B29C 45/77 : of velocity or pressure of moulding material
• CPC Class Codes: B29C 45/80 : of relative position of mould parts
• CPC Class Codes: B29K 2105/0067 : Melt
• CPC Class Codes: G05B 15/02 : electric
• CPC Class Codes: G05D 7/0635 : by action on throttling means G05D7/0688, G05D7/0694 take precedence

Abstract

An apparatus for controlling the rate of flow of a fluid mold material comprising:

• • a manifold,
  • an actuator interconnected to a valve pin,
  • a position sensor that senses position of the valve pin,
  • a controller that controls movement of the actuator according to instructions that instruct the actuator to drive the valve pin upstream at one or more selected intermediate velocities in response to receipt by the controller of a signal from the position sensor that the valve pin is disposed in the one or more intermediate upstream gate open positions.

Claims

1. An apparatus for controlling the rate of flow of a fluid mold material from an injection molding machine to a cavity of a mold, the apparatus comprising:

a manifold receiving the injected fluid mold material, the manifold having a delivery channel that delivers the fluid mold material to a gate to the mold cavity;

an actuator interconnected to a valve pin having a tip end, the actuator moving the valve pin upstream along a path of travel between a downstream gate closed position and one or more intermediate upstream gate open positions, the downstream gate closed position being a position wherein the tip end of the valve pin obstructs the gate to prevent fluid material from flowing into the mold cavity, the one or more intermediate upstream gate open positions being predetermined positions between the downstream gate closed position and a fully open, end of stroke position upstream of the intermediate upstream gate open positions at which the fluid mold material flows at a maximum rate through the gate, wherein the gate is partially open when the valve pin is in the one or more intermediate upstream gate open positions;

a position sensor that senses position of the valve pin,

a controller interconnected to the actuator and to the position sensor that controls movement of the actuator at least in part according to instructions that instruct the actuator to drive the valve pin upstream at one or more selected intermediate velocities over the course of travel of the valve pin through the one or more intermediate upstream gate open positions in response to receipt by the controller of a signal from the position sensor that the valve pin is disposed in the one or more intermediate upstream gate open positions,

the valve pin being drivable at a maximum upstream velocity, the one or more selected intermediate velocities being less than the maximum velocity.

2. The apparatus of claim 1 wherein the actuator is driven by a drive fluid having a maximum rate of flow into or out of the actuator to drive the valve pin at a maximum upstream velocity, the one or more selected velocities being selected by selecting a rate of flow of drive fluid to or from the actuator that is a selected fraction of the maximum rate of flow.

3. The apparatus of claim 2 wherein the drive fluid is liquid or gaseous.

4. The apparatus of claim 1 wherein the tip end of the valve pin and the gate are adapted to cooperate with each other to restrict and continuously increase rate of flow of the fluid material through the gate over the course of at least a portion of the continuous upstream travel of the valve pin from the downstream gate closed position to the intermediate upstream gate open position.

5. The apparatus of claim 1 further comprising a sensor that generates one or more signals indicative of the position of the valve pin, the controller carrying out instructions to cause the valve pin to move continuously upstream at the one or more selected intermediate velocities and to adjust upstream velocity of the valve pin based on one or more of the signals generated by the sensor.

6. The apparatus of claim 5 wherein the instructions cause the velocity of the valve pin to be adjusted to a selected higher velocity in response to a signal generated by the sensor having detected and indicating the valve pin has reached the intermediate upstream gate open position.

7. The apparatus of claim 6 wherein the selected higher velocity is a maximum velocity at which the actuator is capable of driving the valve pin.

8. The apparatus of claim 7 wherein the tip end of the valve pin and the gate are adapted to cooperate with each other to restrict to less than the maximum flow rate and continuously increase the rate of flow of the fluid material through the gate over the course of at least a portion of the continuous upstream travel of the valve pin from the downstream gate closed position to the intermediate upstream gate open position.

9. The apparatus of claim 1 wherein the one or more selected intermediate velocities are less than about 75% of the higher velocities.

10. The apparatus of claim 1 wherein the one or more selected intermediate velocities are a single selected velocity.

11. The apparatus of claim 5 wherein the instructions of the controller utilize the signals received from the sensor to calculate real time velocity of the valve pin and compare the calculated real time velocity to one or more predetermined velocities for the pin during the course of travel of the tip end of the pin from at least the downstream gate closed position to the intermediate upstream gate open position.

12. The apparatus of claim 11 wherein the controller compares the calculated real time velocity to the predetermined velocities and sends a signal instructing the actuator to match the velocity of the pin to the predetermined velocities based on the comparison at any given position of the valve pin.

13. The apparatus of claim 11 wherein the controller calculates real time velocity based a value corresponding to the position of the pin signal received in real time from the sensor.

14. The apparatus of claim 1 wherein the actuator is driven by a fluid flowing through a flow valve that opens and closes to a controllably variable degree to vary velocity of the valve pin in response to an electronic or electric signal received from the controller that is controllably variable.

15. The apparatus of claim 14 further comprising a position sensor that sends signals to the controller indicative of the position of the fluid driven actuator at least during movement of the valve pin from the downstream gate closed position to the intermediate upstream gate open position, the controller carrying out the instructions to move the valve pin at the one or more selected velocities based on the signals received from the sensor.

16. The apparatus of claim 14 wherein the valve opens and closes to a degree that is proportional to the strength or degree of output of the controllably variable electric or electronic signal.

17. The apparatus of claim 1 wherein the actuator comprises an electrically driven motor interconnected to the valve pin that moves the valve pin at a controllably variable rate in response to an electric or electronic signal received from the controller that is controllably variable.

18. The apparatus of claim 17 further comprising a position sensor that sends signals to the controller indicative of the position of the electrically driven motor at least during movement of the valve pin from the downstream gate closed position to the intermediate upstream gate open position, the controller carrying out the instructions to move the valve pin at the one or more selected velocities based on the signals received from the sensor.

19. The apparatus of claim 5 wherein the controller, in response to the one or more signals received from the sensor, instructs the actuator to move the valve pin upstream of the one or more intermediate upstream gate open positions to a fully open, end of stroke position at one or more velocities that are higher than the one or more velocities of the valve pin during travel from the downstream gate closed position to the intermediate upstream gate open position.

23. A method of performing an injection molding cycle comprising operating the apparatus of claim 1 to inject the fluid mold material into the cavity of the mold during the course of an injection molding cycle.

20. A method of performing an injection molding cycle in an injection molding apparatus comprising:

an injection molding machine and a manifold that receives an injected mold material from the injection molding machine, the manifold having a delivery channel that delivers the mold material under an injection pressure to a first gate of a mold cavity, an actuator interconnected to a valve pin driving the valve pin from a first position where the tip end of the valve pin obstructs the gate to prevent the injection fluid material from flowing into the cavity, the actuator further driving the valve pin upstream to a second position upstream of the gate where the mold material flows at a maximum rate through the gate and upstream from the start position through one or more intermediate positions between the first position and the second position wherein the tip end of the valve pin restricts flow of the injection fluid to one or more rates less than the maximum rate,

a drive system for controllably driving the actuator and the valve pin upstream at one or more selected intermediate velocities and at one or more high velocities that are higher than the intermediate velocities,

the method comprising;

beginning an injection cycle with the tip end of the valve pin in the first position,

sensing the position of the valve pin,

adjusting the drive system to drive the actuator at the one or more intermediate velocities upstream to and through one or more of the intermediate positions at the one or more selected intermediate velocities in response to sensing of the position of the valve pin in the one or more of the intermediate positions.

21. The method of claim 20 wherein the actuator comprises an electrically driven motor.

22. The method of claim 20 wherein the actuator comprises a hydraulically or pneumatically driven actuator.