INJECTION MOLDING FLOW CONTROL APPARATUS AND METHOD

摘要

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 and further drives the valve system to move from the one or more intermediate drive rate positions to the high drive rate position on expiration of the one or more predetermined amounts of time.

主权项

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 mold material to one or more rates less than the maximum rate, a valve system for controllably driving the valve pin, the valve system being controllably movable from a start position to one or more intermediate drive rate positions and a high drive rate position, the high drive rate position driving the pin upstream at a high rate of travel, the intermediate drive rate positions driving the pin upstream at one or more intermediate rates of travel that are less than the high rate of travel, the method comprising: selecting one or more lengths of time for the valve system to operate or reside in corresponding ones of the one or more intermediate drive rate positions, beginning an injection cycle with the tip end of the valve pin in the first position and the valve system in the start position, adjusting the valve system to operate at the one or more of the intermediate drive rate positions for the one or more selected lengths of time to drive the valve pin continuously upstream, and, adjusting the valve system to operate at the high drive rate position to drive the tip end of the valve in continuously upstream at the high rate of travel upon expiration of the one or more selected lengths of time.