Injection molding flow control apparatus and method
First Claim
1. A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
- drivably interconnecting the valve pin to an actuator comprising an electric motor in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin closes the gate to prevent the injection fluid from flowing into the cavity, a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate at a maximum flow velocity, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve pin restricts flow of the injection fluid through the gate to a rate that is less than the maximum flow velocity along at least a portion of the length of the drive path extending between the first closed position and the intermediate position, and,controllably operating the actuator to drive the valve pin to be held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity, and,controllably operating the actuator to drive the valve pin at an upstream velocity of travel that is reduced relative to a high velocity during the course of the injection cycle.
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Abstract
Injection molding apparatuses and methods wherein a valve pin is controllably driven upstream and downstream along an axis between a first closed position where the tip end of the valve pin obstructs the gate to prevent the injection fluid from flowing into the cavity, a full open position and one or more intermediate positions,
- wherein the valve pin is drivable to be disposed or held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity.
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Citations
20 Claims
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1. A method of performing an injection molding cycle in an injection molding apparatus comprising a manifold that receives an injection fluid, the manifold distributing injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel, the method comprising:
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drivably interconnecting the valve pin to an actuator comprising an electric motor in an arrangement wherein the actuator drives the valve pin upstream and downstream along the axis and drives the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin closes the gate to prevent the injection fluid from flowing into the cavity, a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate at a maximum flow velocity, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve pin restricts flow of the injection fluid through the gate to a rate that is less than the maximum flow velocity along at least a portion of the length of the drive path extending between the first closed position and the intermediate position, and, controllably operating the actuator to drive the valve pin to be held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity, and, controllably operating the actuator to drive the valve pin at an upstream velocity of travel that is reduced relative to a high velocity during the course of the injection cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An injection molding apparatus comprising a manifold that receives an injection fluid from an injection molding machine, the manifold distributing the injection fluid to a fluid delivery channel that delivers the injection fluid under an injection pressure to a gate of a mold cavity and a valve pin having an axis and a tip end, the valve pin being slidably mounted for movement along the axis within the fluid delivery channel,
wherein the valve pin is interconnected to an actuator comprising an electric motor in an arrangement wherein the actuator is adapted to drive the valve pin upstream and downstream along the axis and to drive the tip end of the valve pin upstream and downstream between a first closed position where the tip end of the valve pin closes the gate to prevent the injection fluid from flowing into the cavity, a full open position where the injection fluid material flows freely without restriction from the tip end of the valve pin through the gate at a maximum flow velocity, and one or more intermediate positions between the first position and the full open position wherein the tip end of the valve restricts flow of the injection fluid through the gate to a rate that is less than the maximum flow velocity along at least a portion of the length of the drive path extending between the first closed position and the intermediate position, the apparatus including a controller that contains instructions that instruct the actuator to controllably drive the valve pin to be held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity, and to controllably operate the actuator to drive the valve pin at an upstream velocity of travel that is reduced relative to a high velocity.
Specification