Control System for Monitoring Plastics Injection Molding Machines

1) A control system (1) for monitoring plastics injection molding machines (2) comprising a plastic material injection device (4) having a number of electric heating units appropriately arranged in the body of the injection device (4);

• each heating unit comprising at least one resistor located in the body of said injection device (4), and at least one temperature sensor located close to said resistor to measure the temperature of the portion of the injection device (4) around the resistor;
• said plastics injection molding machines (2) also comprising an electric power unit (7) which, on command, supplies electric energy independently to the individual resistors of the heating units, and an electronic central control unit (8) connected to the temperature sensors of said heating units, and which controls said electric power unit (7) as a function of signals from said temperature sensors;
• said electric power unit (7) and said electronic central control unit (8) being two distinct, separate electric devices;
• and said plastics injection molding machines (2) also comprising a multiwire electric cable (10) connecting the electronic central control unit (8) to both said electric power unit (7) and the temperature sensors of said heating units;
• said control system (1) being characterized by comprising a data processing unit (11), which is completely separate from and independent of said electronic central control unit (8), and processes the signals travelling along the multiwire electric cable (10) of at least one said plastics injection molding machine (2) to determine any malfunctioning of the machine (2);
• and at least one data acquisition device (12, 12′) connected to said multiwire electric cable (10) to intercept the signals travelling along said multiwire electric cable (10), and to send copies of them directly to the data processing unit (11) without interfering in any way with operation of said electronic central control unit (8).