Injection molding controller with machine modeling
AssigneeRockwell Technologies, LLC
InventorsJeffrey A. Shearer, David M. Fort, Robert E. Davitt, Jr., Robert B. Meeker
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Abstract
An industrial controller for injection molding machines models the injection molding machine by observing ram state in response to control variables to alert the user when a control profile may be physically unrealizable and to inhibit a learning process to avoid extreme actuation of the controlled components such as may be detrimental to later control accuracy. Simultaneous velocity and pressure control of the ram, with separate profiles, may be obtained by open-loop control of either pressure or velocity and continuous closed-loop control of the other control variable.
Claims15
A controller for use with an injection molding machine having a ram to inject plastic material into a mold cavity during at least one injection molding cycle, the injection molding machine accepting a ram control variable signal to control the ram and providing at least one process variable signal indicating the operation of the ram, the controller comprising:
- (a) input circuitry receiving the process variable signal;
- (b) output circuitry providing a ram control variable signal to the injection molding machine;
- (c) an electronic memory storing a user defined control profile;
- (d) an electronic computer receiving the control profile from the electronic memory, the process variable signal from the input circuitry and executing a stored program to:
- (i) monitor the process variable signal during operation of the injection molding machine to model the operation of the injection molding machine;
- and
- (ii) evaluating the control profile against the modeled machine to generate an indication to the user as to whether the control profile is physically achievable with the injection molding machine.
A controller for use with an injection molding machine having a ram to inject plastic material into a mold cavity during at least one injection molding cycle, the injection molding machine accepting a control signal controlling the ram and producing a process variable signal, the controller comprising:
- (a) input circuitry receiving the process variable signal;
- (b) output circuitry providing a control signal to the injection molding machine;
- (c) an electronic memory storing a user defined control profile;
- (d) an electronic computer receiving the control profile from the electronic memory, the process variable signal from the input circuitry and executing a stored program to:
- (i) determine control variable signals corresponding to multiple segments in a control profile;
- and
- (ii) correct the control variable signals for a subsequent cycle of the injection molding machine based on the operation of the injection molding machine in a current cycle;
- and
- (iii) generate an indication to the user if the corrected control signal exceeds a predetermined deviation from a baseline control signal.
A controller for use with an injection molding machine having a ram to inject plastic material into a mold cavity during at least one injection molding cycle, the injection molding machine accepting a control variable signal controlling the ram and producing a process variable signal, the controller comprising:
- (a) input circuitry receiving the process variable signal;
- (b) output circuitry providing the control variable signal to the injection molding machine;
- (c) an electronic memory storing a user defined control profile;
- (d) an electronic computer receiving the control profile from the electronic memory, the process variable signal from the input circuitry and executing a stored program to:
- (i) monitor the process variable to evaluate a transient time between a providing of the injection molding machine with a control signal and a response by the injection molding machine;
- (ii) determine control signals corresponding to multiple segments in a control profile;
- and
- (iii) correct the control variable signals for a subsequent cycle of the injection molding machine based on the operation of the injection molding machine in a current cycle during each segment but after the transient time.
A controller for use with an injection molding machine having a ram to inject plastic material into a mold cavity during at least one stage of an injection molding cycle, the injection molding machine accepting a pressure control signal and a velocity control signal controlling the ram and producing a pressure sensor signal and a position sensor signal indicating the operation of the ram, the controller comprising:
- (a) input circuitry receiving the pressure sensor signal and position sensor signal;
- (b) output circuitry providing the pressure control signal and the velocity control signals to the injection molding machine;
- (c) an electronic memory storing a user defined pressure profile and user defined velocity profile each having multiple corresponding segments defining a sequence of independent pressures and velocities;
- (d) an electronic computer receiving the pressure profile and velocity profile from the electronic memory, and receiving the pressure sensor signal and position sensor signal from the input circuitry and executing a stored program to:
- (i) simultaneously read the segments of the pressure profile and the velocity profile and output corresponding pressure control signals and velocity control signals to the injection molding machine based on the read segments;
- whereby the pressure on the ram may be changed as its velocity is controlled.
Dependencies are inferred from the claim text.