OO control for injection molding machine

A method for controlling the operation of an injection molding machine having a screw axially translatable in a barrel by a screw injector to cause injection of a shot of melt into a mold and a clamp operable to open, close and clamp said mold contained therein by clamp hardware associated with said clamp, said method comprising the steps of:

• generating an object oriented, computerized, programmed routine in source code controlling the sequence and implementation of injection and clamping functions of said machine by command signals produced during run time, said object oriented routine including i) a master sequence class defining behavior of said machine through the machine cycle in accordance with a machine control law, ii) a clamp class defining behavior and attributes of said clamp mechanism and owning a plurality of constituent classes and iii) a base screw injector class defining screw attributes and behavior of said screw during injection and owning a plurality of constituent classes;
• instantiating said classes when said routine is run to produce from said source code at any instance i) a base clamp object having attributes and defining behavior of said clamp hardware and ii) a screw injector object having attributes and defining behavior of said screw hardware;
• and,
• compiling and linking or interpreting or assembling said source code from said base clamp object and said screw inject object into object code processed by the microprocessor in said control system to produce command signals outputted by said system to actuators associated with said screw and said clamp and controlling the behavior thereof.

In a plastic injection molding machine having hardware and associated actuators permitting said machine to mold parts in a sequenced cycle including clamp, inject, hold, recover and eject and having a microprocessor control system controlling the operation of said actuators to produce a molding cycle meeting set points established by an operator of said machine, said microprocessor control system including at least one controller regulating specific machine hardware to meet the set points for a sequence in the cycle, the improvement comprising:

• said controller being programmed as an object-oriented programmed sequence having a controller class instantiated as a controller object with behavior transitioning from at least a first state to a second state in advance of the time a state transition is to occur and said controller class having attributes related to the hardware and machine actuator controlled by said controller, wherein said controller object is an aggregated object owning a plurality of constituent objects, each constituent object having behavior for preparing the transition of said controller object from one state to the other in advance of the time at which said transition occurs, said object oriented program sequence further includes an actuator class in relationship to said controller class and instantiated to produce an actuator object controlling the behavior of said actuator regulated by said controller in accordance with state instructions from said controller object, said object oriented program sequence further includes an observer class in relationship to at least said actuator class and instantiated to produce an observer object indicative of the behavior of the machine hardware and its associated actuator(s), said observer class and said actuator classes are aggregations of a plurality of constituent classes, one of said constituent classes of said observer class including a digital filter class for producing, as an instance thereof, a digital filter object indicative of the current motion of the hardware being controlled by said controller.

A method for controlling molding of parts by an injection molding machine having hardware performing a sequence of clamp, inject, hold, recover and eject through a computerized control system having an operator station setting set points for the sequence and including at least one controller generating control signals for regulating performance of machine hardware through a machine actuator(s) for performing at least one of said sequences pursuant to sequence instructions received from said control system, said method comprising the steps of:

• generating i) an object-oriented controller class having behavioral characteristics of said machine hardware performing one of said controlled sequences, said behavior characteristics including transitioning said controller from a first state to a second state and ii) an object oriented actuator class in relationship with said controller class and having behavioral characteristics indicative of move instructions for said machine actuator to implement for controlling said machine hardware performing one of said controlled sequences;
• instantiating said controller class to produce a controller object and said actuator class to produce an actuator object, said controller object sending messages to said actuator object and said actuator object containing source code for generating move commands to its associated machine actuator(s);
• and,
• compiling and linking or assembling or interpreting said source code to produce object code acted upon by said microprocessor to produce command signals for controlling said machine actuator(s) of said machine hardware performing one of said controlled sequences.

A modeling method for assembling source code into an object oriented programmed routine for controlling any specific injection molding machine having hardware actuators controlling hardware machine components performing an interrelated machine molding cycle of close, inject, hold, recover and eject pursuant to a general, sequence control law common to all injection molding machines, said method comprising the steps of:

• a) building an object oriented class library collection by modeling as general classes therein a class corresponding to attributes and behavior of major machine components necessary to perform each step of said molding cycle including at least the general, abstract classes of a clamp class, an inject class, a rotate class and an eject class and relations therebetween;
• specifying for each general class a plurality of more specific child classes, each child class inheriting the attributes and behavior of its parent class and adding thereto additional attributes and behavior more specific to different hardware components used in injection molding machines for performing the function controlled by said general abstract class and optionally specifying additional descendants until all different types of molding machine hardware performing the behavior of the realizable descendants have been modeled, principally by difference;
• b) building a component library including i) a collection of primitive components corresponding to the assembled classes including usage relations, associations and aggregations for the realizable and selective abstract classes, ii) a subsystem collection of related primitive components is specified and iii) a machine variant component in which desired subsystems for a specific machine and making up the control system for a desired machine are selected;
• and,
• c) adding additional objects of classes depending from classes in said subsystem for any specific machine, principally by difference, to account for any specific requirements of the specific machine not accounted for in the subsystem collection whereby any injection molding machine using existing hardware components can be programmed to produce a molding machine cycle.