Injection molding flow control apparatus and method

Abstract

An injection molding system for implementing a molding process, comprising: a mold, a controller, a position sensor, wherein during an injection cycle, the system feeds the fluid material to one or more nozzles at one or more predetermined times, the controller being configured to receive and process the output signal from the position sensor to determine one or more actual flow rate indicative parameters, a user interface that displays one or more pin positions and one or more flow rate indicative parameters by which a user of the system can track the one or more pin positions and flow rate indicative parameters in real time during the injection cycle.

What is claimed is: 
     
         1 . An injection molding system for implementing a molding process, comprising:
 a mold having one or more gates and one or more associated nozzles through which an injection fluid material is injected into a cavity of the mold during an injection cycle, each nozzle having an associated valve pin driven by an associated actuator between a gate closed position and an upstream end of stroke position,   a controller that controls movement of the valve pins over the course of the injection cycle in accordance with a set of predetermined flow rate indicative parameters,   a position sensor associated with each valve pin for monitoring pin position with respect to an associated gate and generating an output signal indicative of actual pin positions as the valve pin moves between the gate closed and gate open positions,   wherein during an injection cycle, the system feeds the fluid material to the one or more nozzles at one or more predetermined times, starting by opening the valve pin of a respective nozzle at an opening time and allowing the fluid material to flow into the cavity to form a molded part in the cavity,   the controller being configured to receive and process the output signal from the position sensor to determine one or more actual flow rate indicative parameters,   a user interface that receives information from the controller indicative of one or more pin positions in real time and displays the one or more pin positions and one or more flow rate indicative parameters by which a user of the system can track the one or more pin positions and flow rate indicative parameters in real time during the injection cycle.   
     
     
         2 . The system of  claim 1  wherein the one or more pin positions and flow rate indicative parameters include one or more of pin opening time, pin opening position, pin closed position and pin velocity. 
     
     
         3 . The system of  claim 1  wherein the controller processes the sensor output signal to generate a control signal to control the pin position. 
     
     
         4 . The system of  claim 3  wherein the controller includes a user interface for receiving user input for adjusting the control signal to control the pin position. 
     
     
         5 . The system of  claim 1  wherein the user interface comprises a display of pin position, based on the sensor output signal, which includes pin open and closed positions and positions between the pin open and closed positions. 
     
     
         6 . The system of  claim 1  wherein the output signal from the sensor provides continuous monitoring of the pin position. 
     
     
         7 . The system of  claim 1  wherein the actuator comprises an electric motor comprising a rotatably drivable component interconnected to the valve pin in an arrangement wherein the pin is drivable along a linear path of travel between a gate closed position and an upstream end of stroke position. 
     
     
         8 . The system of  claim 1  wherein the mold has a center nozzle and one or more lateral nozzles routing the injection fluid into a common cavity,
 wherein during an injection cycle, the system feeds the fluid material to the center and one or more lateral nozzles at one or more predetermined times, starting by opening the valve pin of the center nozzle at a first selected opening time and allowing the fluid material to flow into the common cavity and opening the one or more lateral nozzles at one or more second selected opening times that is subsequent to the first selected opening time such that the fluid material is injected sequentially from the center nozzle and the one or more lateral nozzles such that the injection fluid material joins together to form a single molded part in a common cavity. 
 
     
     
         9 . A method of performing an injection molding cycle comprising operating the system of  claim 1 . 
     
     
         10 . An injection molding system for controlling the rate of flow of a fluid mold material from an injection molding machine to a cavity of a mold, the system 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 an end of stroke position upstream of the intermediate upstream gate open position at which the fluid mold material flows at a selected 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 and generates signals indicative of position of the valve pin, 
 a controller interconnected to the actuator and to the position sensor, the controller receiving the signals indicative of position of the valve pin and controlling movement of the actuator at least in part according to instructions that utilize the signals indicative of position of the valve pin to instruct the actuator to drive the valve pin upstream at one or more selected intermediate velocities over the course of a selected portion of the travel of the valve pin between the downstream gate closed position and the end of stroke position, 
 the valve pin being drivable at a selected maximum upstream velocity, the one or more selected intermediate velocities being less than the selected maximum velocity, 
 a user interface that receives information from the controller indicative of one or more pin positions in real time and displays the one or more pin positions and one or more flow rate indicative parameters by which a user of the system can track the one or more pin positions and flow rate indicative parameters in real time during the injection cycle. 
   
     
     
         11 . The system of  claim 10  wherein the one or more pin positions and flow rate indicative parameters include one or more of pin opening time, pin opening position, pin closed position and pin velocity. 
     
     
         12 . The system of  claim 10  wherein the controller processes the sensor output signal to generate a control signal to control the pin position. 
     
     
         13 . The system of  claim 12  wherein the controller includes a user interface for receiving user input for adjusting the control signal to control the pin position. 
     
     
         14 . The system of  claim 10  wherein the user interface comprises a display of pin position, based on the sensor output signal, which includes pin open and closed positions and positions between the pin open and closed positions. 
     
     
         15 . The system of  claim 10  wherein the output signal from the sensor provides continuous monitoring of the pin position. 
     
     
         16 . The system of  claim 10  wherein the actuator comprises an electric motor comprising a rotatably drivable component interconnected to the valve pin in an arrangement wherein the pin is drivable along a linear path of travel between a gate closed position and an upstream end of stroke position. 
     
     
         17 . The system of  claim 10  wherein the mold has a center nozzle and one or more lateral nozzles routing the injection fluid into a common cavity,
 wherein during an injection cycle, the system feeds the fluid material to the center and one or more lateral nozzles at one or more predetermined times, starting by opening the valve pin of the center nozzle at a first selected opening time and allowing the fluid material to flow into the common cavity and opening the one or more lateral nozzles at one or more second selected opening times that is subsequent to the first selected opening time such that the fluid material is injected sequentially from the center nozzle and the one or more lateral nozzles such that the injection fluid material joins together to form a single molded part in a common cavity. 
 
     
     
         18 . A method of performing an injection molding cycle comprising operating the system of  claim 10 . 
     
     
         19 . 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.   
     
     
         20 . The method of  claim 19  wherein the actuator comprises an electrically driven motor. 
     
     
         21 . The method of  claim 19  wherein the actuator comprises a hydraulically or pneumatically driven actuator. 
     
     
         22 . 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.