Abstract: A plastic injection molding machine has an object oriented programmed routine to control the molding cycle of the machine. The programmed routine implements the inter-related molding cycle of clamp, inject, hold, eject and recover by development of classes corresponding to machine structure performing basic molding cycle steps. The basic classes use object oriented concepts of data encapsulation, inheritance, polymorphism, abstraction and the like that are linked together to produce objects during run time. The classes in turn include controller, observer and actuators classes. The controller class functions as a state machine. The observer class functions to determine the current state and the actuator class produces command signals controlling class related machine hardware. A modeling system is also disclosed for constructing the OO programmed routine for any injection molding machine using existing classes, principally by difference.

Abstract: An injection molding machine with a vertically operating clamp mechanism is provided with a pair of locking devices on the upper movable platen to lock the locking rods for high tonnage clamping forces. Each locking device uses spring biased actuating rods to simultaneously lock two locking rods to the movable platen in an always “on” arrangement. A power on actuator is provided to release the locking device for raising and lowering the movable platen. A vertical ladder frame is provided for guiding the movable platen when it is raised or lowered. Additionally, a lift mechanism is provided for a rotary table carrying the lower mold halves.

Abstract: Electric injection molding machines and systems are disclosed in which a melt pressure value is provided without pressure sensing through solving one or more state equations using measured motor performance parameters such as position or velocity, and torque or current. The pressure value may be used to control melt pressure during an injection step, or may be used for monitoring. Methods and computer-readable media are also disclosed for providing or estimating melt pressure in an injection molding machine without a melt pressure sensor.

Abstract: Methods and apparatus are disclosed for controlling an injection molding machine, wherein a control law estimates future machine states according to a proposed control output vector, the current machine state and a model of the machine, and recursively refines the control output vector using an error function and an adjustment rule in order to reduce the error between the estimated future machine states and desired future machine states. One or more control outputs are provided to actuators associated with the machine according to the refined control output vector.

Abstract: An injection molding machine with a vertically oriented clamp is equipped with a rotatable table for sequentially processing a plurality of bottom mold halves mounted thereon. An aligning device insures accurate positioning of a bottom mold half in molding relation to a top mold half in the clamp by insuring seating of a locating pin in a locating hole in the table after the table has been rotatably indexed to bring a bottom mold half into alignment with a movable top half. The locating pin is secured to an actuator mounted by a guide rail and runner block to the machine's stationary platen. As the pin is pushed into the locating hole by the actuator, the aligning device linearly moves along the guide rail and the table slightly rotates to allow seating of the locating pin into the locating hole.

Abstract: An energy efficient general purpose injection molding employs a hydraulic drive for injection and clamp machine functions and an electric drive for screw recovery. Both drives use AC “squirrel cage” induction motors under vector control. Speed command signals for the vector controls are generated by the machine's controller utilizing state transition and predictive signal techniques to account for motor and motor/pump response latencies. Hydraulic drive efficiency is improved by varying motor speed/pump output to match cycle requirements to retain hydraulic drive advantages for mold clamp and injection functions while improving the electric drive performance for screw recovery.

Abstract: An energy efficient general purpose injection molding employs a hydraulic drive for injection and clamp machine functions and an electric drive for screw recovery. Both drives use AC "squirrel cage" induction motors under vector control. Speed command signals for the vector controls are generated by the machine's controller utilizing state transition and predictive signal techniques to account for motor and motor/pump response latencies. Hydraulic drive efficiency is improved by varying motor speed/pump output to match cycle requirements to retain hydraulic drive advantages for mold clamp and injection functions while improving the electric drive performance for screw recovery.

Abstract: An injection molding machine uses a summed, multi-term control law to control ram velocity during the injection stroke of a molding cycle to emulate a user set velocity profile. An automatic calibration method sets no load ram speeds to duplicate user set ram speeds. Finite impulse response filters produce open loop, no load control signals at advanced positions on the velocity profile to account for lag in system response. An adaptive, error term indicative of load disturbance, observed from a preceding cycle is added at the advanced travel position predicted by the finite impulse response filter to produce a predictive open loop, load compensated control signal. Finally, an auto tuned PID controller develops a real time, feedback load disturbance signal summed with the open loop control signal to produce a drive signal for the machine's proportioning valve.

Abstract: A control system utilizing a programmable controller for an injection molding machine in which the controller is periodically scanned in response to input signals to produce output control signals is provided with an impulse response filter arrangement. The impulse response filter senses a plurality of current and past sensor input signals to accurately predict the occurrence of a variable triggering event which will in fact be sensed by a sensor. A predictive sensor signal is then generated which is inputted to the controller in advance of the occurrence of the triggering event and at a time which corresponds to the processor scan time so that the controller generates the desired output at the precise time the triggering event occurs thus eliminating controller response latency from the control system.

Abstract: A control system utilizing a programmable controller for an injection molding machine in which the controller is periodically scanned in response to input signals to produce output control signals is provided with an impulse response filter arrangement. The impulse response filter senses a plurality of current and past sensor input signals to accurately predict the occurrence of a variable triggering event which will in fact be sensed by a sensor. A predictive sensor signal is then generated which is inputted to the controller in advance of the occurrence of the triggering event and at a time which corresponds to the processor scan time so that the controller generates the desired output at the precise time the triggering event occurs thus eliminating controller response latency from the control system.

Abstract: An improved temperature control system using a state controller with two degrees of freedom to regulate the temperature of the barrel of an injection molding machine is disclosed. The control system divides the temperature of the barrel into longitudinally-extending zones and radially extending layers within each zone. Heat transfer calculations which include the effects of heat transfer between all the layers within the zones are performed for a set time in the future to accurately determine the heat needed from the heater band to reach the operator set point temperature. The duty cycle for the heater bands is thus accurately set to give a more responsive and accurate control than heretofore possible. The controller additionally includes factors for accounting for heat disturbances present in the injection molding process. In addition each system is calibrated for each machine to insure accurate formulation of machine specific parameters such as heat transfer co-efficients used in the control.