Systems and Approaches for Controlling an Injection Molding Machine

Abstract

Systems and approaches for controlling an injection molding machine having a mold forming a mold cavity and being controlled according to an injection cycle include obtaining a pattern for the injection cycle, operating the injection molding machine to inject a molten material into the mold cavity , and measuring a cavity pressure value of the mold cavity during the mold cycle. Upon measuring a nominal cavity pressure value, a pattern recognition portion of the injection cycle that is at least partially dependent on the obtained pattern commences where a driving force being exerted on the molten material is adjusted such that the measured cavity pressure matches the obtained pattern for the injection cycle.

What is claimed is: 
     
         1 . An injection molding machine comprising:
 an injection unit and a mold forming a mold cavity, the injection unit adapted to receive and inject a molten plastic material into the mold cavity to form a molded part;   a controller adapted to control operation of the injection molding machine according to an injection cycle having a first portion and a second portion;   a first sensor coupled to the injection molding machine and the controller;   a second sensor coupled to the injection molding machine and the controller, the second sensor adapted to measure a different characteristic than the first sensor;   wherein in the first portion of the injection cycle, the controller controls the injection unit at least partially based on measurements obtained from the first sensor, and upon an event occurring, the second portion of the injection cycle commences, and the controller further controls the injection unit at least partially based on measurements obtained from the second sensor.   
     
     
         2 . The injection molding machine of  claim 1 , wherein the first sensor is adapted to measure a melt pressure value of the injection unit. 
     
     
         3 . The injection molding machine of  claim 1 , wherein the second sensor is adapted to measure a cavity pressure value of the injection unit. 
     
     
         4 . The injection molding machine of  claim 1 , wherein the event comprises a measured nominal cavity pressure value. 
     
     
         5 . The injection molding machine of  claim 4 , wherein the nominal cavity pressure value is approximately 50 psi. 
     
     
         6 . The injection molding machine of  claim 1 , wherein the controller controls the injection unit at least partially based on measurements obtained from the second sensor and a previously-captured pattern. 
     
     
         7 . The injection molding machine of  claim 6 , wherein the previously-captured pattern comprises an ideal cavity pressure setpoint curve. 
     
     
         8 . The injection molding machine of  claim 1 , wherein the second sensor comprises a virtual sensor and a series of parameters are generated that indicate a flow front position of the molten material and a corresponding pressure at the flow front of the molten material. 
     
     
         9 . The injection molding machine of  claim 1 , wherein during the first portion of the injection cycle, the controller adjusts a driving force being exerted on the molten material according to a melt pressure profile where an input is obtained from the first sensor. 
     
     
         10 . The injection molding machine of  claim 1 , wherein during the second portion of the injection cycle, the controller adjusts a driving force being exerted on the molten material according to a cavity pressure control-based and an input is obtained from the second sensor.