Controlled valve pin movement based on cavity sensor feedback
Apparatus for performing an injection molding cycle, comprising: a manifold routing injection fluid to two or more gates, an actuator associated with each gate, each gate having a downstream sensor that senses a selected condition of the injection fluid material, a controller, the downstream sensors establishing a standard elapsed time, the controller including instructions that compares the standard elapsed time with a calculated amount of elapsed time associated with each of the gates and that adjust the velocity or position of each of the actuators.
1. A method of performing an injection molding cycle in an injection molding apparatus comprised of:
a manifold that receives an injection fluid material, the manifold having or communicating with a delivery channel that delivers the injection fluid mold material under an injection pressure to two or more gates each leading to an associated mold cavity,
an actuator associated with each respective gate,
each actuator being drivably interconnected to a valve pin drivable upstream and downstream along a path of travel having a selected stroke length that extends between a gate closed position, a selected maximum flow position at which the injection fluid material flows at a maximum rate through the gate into the cavity and one or more selectable intermediate positions between the first position and the maximum flow position,
each actuator being controllably drivable to position an interconnected valve pin at the first, one or more selectable intermediate and maximum flow positions over the course of an injection cycle,
a downstream sensor that senses a selected physical condition of the injection fluid material at a position within a mold cavity that is downstream of an associated gate, the downstream sensor generating a signal corresponding to the sensed values,
the method comprising the steps of:
selecting and recording as a standard for a selected one of the gates, the amount of time elapsed between movement of the valve pin associated with the selected one of the gates out of the gate closed position and the time at which the downstream sensor first senses the selected condition of the injection fluid material flowing into the associated mold cavity,
performing a subsequent injection cycle and for each of the other gates and sensing the selected physical condition of the injection fluid material at the downstream position with the downstream sensor associated with each of the other gates, and,
recording the amount of time elapsed between movement of the valve pin associated with each of the other gates out of the gate closed position and the time at which the downstream sensor first senses the selected condition of the injection fluid material flowing into the associated cavities of each of the other gates,
comparing the recorded amounts of time elapsed associated with each of the other gates with the standard amount of time elapsed that is associated with the selected one of the gates,
adjusting position or velocity of the actuators or valve pins associated with each of the other gates during further subsequent injection cycles such that the amount of time elapsed between movement of the valve pins associated with each of the other gates of their gate closed position and the time at which the downstream sensor first senses the selected condition of the injection fluid material approaches or matches the selected standard amount of elapsed time,
wherein the step of selecting and recording comprises recording and establishing a standard profile of position of the actuator or valve pin versus time for the selected one of the gates and the step of adjusting can comprise recording and adjusting the position or drive rate of the actuators or valve pins associated with the other gates to approach or match the standard profile of position versus time.
2. The method of claim 1 wherein the steps of performing and adjusting are carried out automatically by an algorithm executed by a controller interconnected to and controllably driving or adjusting the drive of the actuators.
3. Apparatus for performing an injection molding cycle in an injection molding apparatus, the apparatus comprising:
a manifold that receives an injection fluid material, the manifold having or communicating with a delivery channel that delivers the injection fluid mold material under an injection pressure to two or more gates each leading to an associated mold cavity,
an actuator associated with each respective gate,
each actuator being drivably interconnected to a valve pin drivable upstream and downstream along a path of travel having a selected stroke length that extends between a gate closed position, a selected maximum flow position at which the injection fluid material flows at a maximum rate through the gate into the cavity and one or more selectable intermediate positions between the first position and the maximum flow position,
each actuator being controllably drivable to position an interconnected valve pin at the first, one or more selectable intermediate and maximum flow positions over the course of an injection cycle,
each gate having a downstream sensor that senses a selected condition of the injection fluid material at a position within each associated mold cavity that is downstream of each associated gate, the downstream sensor generating a response signal upon sensing the selected condition of the injection fluid material when the injection fluid material has flowed to the downstream position of the downstream sensor,
a controller containing predetermined data representing as a standard for a selected one of the gates, the amount of time elapsed between movement of the valve pin associated with the selected one of the gates out of the gate closed position and the time at which the downstream sensor associated with the selected one of the gates first senses the selected condition of the injection fluid material flowing into the associated mold cavity,
the downstream sensors of each of the gates other than the selected one of the gates sensing the selected condition of the injection fluid material and sending response signals to the controller on performance of each successive injection cycle by the apparatus,
the controller receiving the response signals from each downstream sensor associated with the other gates on performance of each successive injection cycle performed by the apparatus,
the controller including instructions that compares the amount of standard elapsed time with the calculated amount of elapsed time associated with each of the other gates,
the controller including instructions that adjust the velocity or position of each of the actuators associated with each of the other gates to drive the valve pins associated with each of the other gates at one or more velocities or to one or more positions during one or more successive injection cycles based on the compared amounts of time such that the amount of time elapsed between movement of the valve pins out of the gate closed position and the time that the downstream sensors associated with the other gates first sense the selected condition approaches or matches the standard amount of elapsed time, and
position sensors that sense position of the actuator or valve pin associated with each of the gates, the controller including data representing a standard profile of position of the actuator or valve pin versus time during an injection cycle for the selected one of the gates, the controller including instructions that compares position versus time of the actuators or valve pins for each of the gates during one or more successive injection cycles with the standard profile and directs the position or velocity of the actuators or valve pins associated with the other gates during the course of the one or more successive injection cycles such that the position versus time of the actuators or valve pins associated with the other gates approaches or matches the standard profile.
4. A method of performing an injection molding cycle in an injection molding apparatus comprised of:
a manifold that receives an injection fluid material, the manifold having or communicating with a delivery channel that delivers the injection fluid mold material under an injection pressure to two or more gates each leading to an associated mold cavity,
an actuator associated with each respective gate,
each actuator being drivably interconnected to a valve pin drivable upstream and downstream along a path of travel having a selected stroke length that extends between a gate closed position, a selected maximum flow position at which the injection fluid material flows at a maximum rate through the gate into the cavity and one or more selectable intermediate positions between the first position and the maximum flow position,
each actuator being controllably drivable to position an interconnected valve pin at the first, one or more selectable intermediate and maximum flow positions over the course of an injection cycle,
a downstream sensor that senses a selected physical condition of the injection fluid material at a position within a mold cavity that is downstream of an associated gate, the downstream sensor generating a signal corresponding to the sensed values,
the method comprising the steps of:
selecting as a standard for each of the gates, the amount of time elapsed between movement of the valve pin associated with the selected one of the gates out of the gate closed position and the time at which the downstream sensor first senses the selected condition of the injection fluid material flowing into the associated mold cavity,
performing a subsequent injection cycle and, for each of the gates, sensing the selected physical condition of the injection fluid material at the downstream position with the downstream sensor associated with each of the gates, and,
recording the amount of time elapsed between movement of the valve pin associated with each of the gates out of the gate closed position and the time at which the downstream sensor first senses the selected condition of the injection fluid material flowing into the associated cavities of each of the gates,
comparing the recorded amounts of time elapsed associated with each of the gates with the standard amount of time elapsed for one or more subsequent injection cycles,
adjusting position or velocity of the actuators or valve pins associated with each of the gates during one or more subsequent injection cycles such that the amount of time elapsed between movement of the valve pins associated with each of the other gates of their gate closed position and the time at which the downstream sensor first senses the selected condition of the injection fluid material approaches or matches the selected standard amount of elapsed time,
wherein the step of selecting and recording comprises recording and establishing a standard profile of position of the actuator or valve pin versus time for the selected one of the gates and the step of adjusting can comprise recording and adjusting the position or drive rate of the actuators or valve pins associated with the other gates to approach or match the standard profile of position versus time.
5. The method of claim 4 wherein the steps of performing and adjusting are carried out automatically by an algorithm executed by a controller interconnected to and controllably driving or adjusting the drive of the actuators.
6. An apparatus for performing an injection molding cycle in an injection molding apparatus, the apparatus comprising:
a manifold that receives an injection fluid material, the manifold having or communicating with a delivery channel that delivers the injection fluid mold material under an injection pressure to two or more gates each leading to an associated mold cavity,
an actuator associated with each respective gate,
each actuator being drivably interconnected to a valve pin drivable upstream and downstream along a path of travel having a selected stroke length that extends between a gate closed position, a selected maximum flow position at which the injection fluid material flows at a maximum rate through the gate into the cavity and one or more selectable intermediate positions between the first position and the maximum flow position,
each actuator being controllably drivable to position an interconnected valve pin at the first, one or more selectable intermediate and maximum flow positions over the course of an injection cycle,
each gate having a downstream sensor that senses a selected condition of the injection fluid material at a position within each associated mold cavity that is downstream of each associated gate, the downstream sensor generating a response signal upon sensing the selected condition of the injection fluid material when the injection fluid material has flowed to the downstream position of the downstream sensor,
a controller containing predetermined data representing as a standard for all gates, the amount of time elapsed between movement of the valve pin associated with a gate out of the gate closed position and the time at which the downstream sensor associated with a gate first senses the selected condition of the injection fluid material flowing into the associated mold cavity,
the downstream sensors of each of the gates sensing the selected condition of the injection fluid material and sending response signals to the controller on performance of each successive injection cycle by the apparatus,
the controller receiving the response signals from each downstream sensor associated with each of the gates on performance of each successive injection cycle performed by the apparatus,
the controller including instructions that compares the amount of standard elapsed time with the calculated amount of elapsed time associated with each of the gates,
the controller including instructions that adjust the velocity or position of each of the actuators associated with each of the gates to drive the valve pins associated with each of the gates at one or more velocities or to one or more positions during one or more successive injection cycles based on the compared amounts of time such that the amount of time elapsed between movement of the valve pins out of the gate closed position and the time that the downstream sensors associated with each of the gates first sense the selected condition approaches or matches the standard amount of elapsed time, and
position sensors that sense position of the actuator or valve pin associated with each of the gates, the controller including data representing a standard profile of position of the actuator or valve pin versus time during an injection cycle for the selected one of the gates, the controller including instructions that compares position versus time of the actuators or valve pins for each of the gates during one or more successive injection cycles with the standard profile and directs the position or velocity of the actuators or valve pins associated with the other gates during the course of the one or more successive injection cycles such that the position versus time of the actuators or valve pins associated with the other gates approaches or matches the standard profile.
7. The apparatus of claim 6 wherein corresponding cavities are associated with each of the individual two or more gates the cavities comprising either separate individual cavities or wherein two or more gates enter into a single cavity.