REDUCED VELOCITY CONTROL BASED ON SENSED SYSTEM CONDITION

摘要

An injection molding system comprised of:
an injection machine having a barrel and a screw for injecting an injection fluid,a distribution manifold,a valve associated with a corresponding one of one or more downstream gates,a sensor adapted to sense and generate a signal indicative of pressure of the injection fluid in the barrel or an inlet that delivers injection fluid from the barrel to the manifold, anda controller receiving the signal generated from the sensor and including instructions that use the signal as a control value to adjust, during the course of an injection cycle, positioning or velocity of one or more of the valve pins.

主权项

1. An injection molding system comprised of:
an injection machine having a barrel and a screw for injecting an injection fluid to one or more downstream gates of one or more cavities of one or more molds during a first injection cycle and during a second injection cycle following the first injection cycle, a distribution manifold for receiving the molten injection fluid from the barrel and distributing the injection fluid through one or more fluid delivery channels in the manifold that deliver the injection fluid to one or more downstream fluid passages that mate with corresponding ones of the one or downstream gates to the one or more mold cavities, a valve associated with each downstream gate, each valve comprising an actuator interconnected to and reciprocally driving a corresponding valve pin at one or more selectable upstream travel velocities that include a maximum upstream travel velocity, the valve pins being driven between a gate closed position and a selected maximum upstream gate open position defining a complete upstream path of travel for each injection cycle, a sensor adapted to sense pressure of the injection fluid in the barrel or in an inlet that delivers injection fluid from the barrel to the manifold, the sensor sending a signal to a controller that is indicative of the sensed pressure in the barrel or the inlet, the controller receiving the signal and including instructions that use the signal as a control value to controllably drive one or more valve pins, during the second injection cycle, through an initial upstream path of travel beginning from the closed position through at least a portion of the complete upstream path of travel at one or more initial reduced upstream travel velocities during the second injection cycle that are less than the maximum upstream travel velocity, the instructions further using the control value as a variable in an algorithm that establishes an instruction value for the one or more initial reduced upstream velocities that operates to drive the one or more valve pins to effect a rate of flow of injection fluid through each gate corresponding to the one or more valve pins during the second injection cycle that is either reduced or is substantially constant relative to the rate of flow of injection fluid during the first injection cycle over at least the initial upstream path of travel of the one or more valve pins.