Injection molding flow control apparatus and method

• US 10,160,150 B2
• Filed: 03/08/2017
• Issued: 12/25/2018
• Est. Priority Date: 11/23/2010
• Status: Active Grant

• Current Assignee: Synventive Molding Solutions Incorporated
• Original Assignee: Synventive Molding Solutions Incorporated
• Inventors: Galati, Vito, de Oliveira Antunes, Sergio Ribeiro, Lopez, J. Andres
• Primary Examiner(s): Sanders, James
• Application Number:
  US15/453,019
• Publication Number:
  US 20170173836A1
• Time in Patent Office: 657 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 mold material to a mold cavity, the apparatus comprising: an injection molding machine and a manifold; an actuator interconnected to a valve pin having a tip end; a valve system in fluid communication with the actuator to drive the actuator at one or more rates of travel, the valve system having a start position, one or more intermediate drive rate positions and a high drive rate position, the start position holding the valve pin in a gate closed position; a controller that instructs the valve system to move from the start position to the one or more intermediate drive rate positions and to remain in the one or more intermediate drive rate positions for one or more corresponding predetermined amounts of time.

Claims

1. 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, upstream to a second position upstream of the gate where the mold material flows at a maximum rate through the gate and continuously 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, first adjusting the drive system to drive the tip end of the valve pin upstream from the first position through all or a portion of the intermediate positions for a preselected period of time at the one or more intermediate velocities,

subsequently adjusting the drive system to drive the tip end of the valve pin upstream at the one or more high velocities after the step of first adjusting.

2. The method of claim 1 wherein the drive system is adjusted to drive the actuator at a single intermediate velocity for a single selected length of time.

3. The method of claim 1 wherein the drive system is interconnected to an electrical signal generating device operable to generate electrical signals of controllably variable degree of output, the drive system being adjustable in drive rate to adjust velocity to a degree that is proportional to the degree of output of the electrical signals, the steps of first adjusting and subsequently adjusting the drive system comprising operating the electrical signal generating device to generate electrical signals that proportionally adjust the drive rate of the drive system according to electrical signals having one or more selected degrees of output.

4. The method of claim 1 wherein the length of travel between the first position and the one or more intermediate positions along the drive path is between about 1 mm and about 5 mm.

5. An apparatus for controlling the rate of flow of mold material to a mold cavity, the apparatus comprising:

an injection molding machine and a manifold that receives the injected mold material from the machine, the manifold having a delivery channel that delivers the mold material at one or more flow rates through a gate to the mold cavity,

an actuator interconnected to a valve pin having a tip end, the actuator being drivable to move the valve pin along a path of travel starting from a downstream gate closed position upstream to and through a series of successively upstream intermediate gate open positions and further upstream to a high upstream gate open position,

a drive system connected to the actuator, the drive system being adapted to drive the actuator upstream beginning from the gate closed position at one or more preselected intermediate velocities for a preselected period of time through one or more of the successively upstream intermediate gate open positions,

wherein a controller includes instructions that instruct the actuator to further subsequently drive the actuator upstream from the one or more upstream intermediate gate open positions at one or more high velocities that are higher than the intermediate velocities.

6. The apparatus of claim 5 further comprising

a controller interconnected to the drive system, the controller being adapted to control operation of the drive system between the start position, the one or more intermediate upstream gate open positions and the high upstream gate open position,

the controller including an electrical signal generator that outputs electrical signals of controllably variable degree of output, the drive system being adjustable in drive rate to adjust velocity of the actuator and the valve pin to a degree that is proportional to the degree of output of the electrical signals,

the controller including instructions that operate the electrical signal generating device to generate electrical signals of one or more preselected degrees of output that drive the actuator upstream at one or more of the intermediate upstream velocities through the one or more upstream intermediate gate open positions and that further drive the actuator at the one or more high velocities subsequent to the valve pin being driven through the one or more intermediate upstream gate open positions.

7. The apparatus of claim 6 wherein the output of the electrical signal is one or more of electrical energy, electrical power, voltage, current or amperage.

8. The apparatus of claim 5 wherein

the tip end of the valve pin obstructs the gate to prevent the mold material from flowing into the cavity when the actuator is in the downstream gate closed position, the mold material flows at a maximum rate through the gate when the actuator is in the high upstream gate open position and the tip end of the valve pin restricts the flow of the mold material to less than the maximum rate when the actuator is in the one or more intermediate upstream gate open positions, and wherein

the valve pin is in one or more of the intermediate upstream gate open positions restricting flow of the mold material to less than the maximum rate when the drive system is driving the actuator at the one or more intermediate velocities.

9. The apparatus of claim 5 wherein the rate of travel of the actuator when the actuator is driven at the highest of the one or more intermediate velocities is less than about 75% of the rate of travel of the actuator when the actuator is driven at the lowest of the one or more high velocities.

10. The apparatus of claim 5 wherein the length of travel between the downstream gate closed position and the furthest upstream of the one or more intermediate upstream gate open positions is between about 1 mm and about 5 mm.

11. A method of performing an injection molding cycle comprising injecting a mold material into a cavity of a mold employing the injection molding apparatus of claim 5.