Mitsubishi FX2N-PLC and the application of inverter in rubber extruding machine

1, the system FX2N-PLC inverter rubber machine application Mitsubishi overview

 

The FX2N-PLC inverter rubber machine application Mitsubishi extruder of developed countries has been widely used modern electronic and computer control technology, the process parameters of the extrusion process such as melt pressure and temperature, paragraphs body temperature, the main screw and feed screw speed, feed rate of the proportion of all kinds of raw materials, such as current voltage of the motor parameters online testing, and USES the microcomputer closed-loop control. Some companies have used online process monitoring, diagnosis and control, network control was carried out on the extrusion molding line. This to ensure stability in the process conditions, to improve the precision of the product is very good.

 

As composite extrusion machine, its mechanical performance will be more complex, matching with complicated control system, control precision is also higher. Therefore, how to design a suitable control system to ensure its economic, safe and reliable to run, and not be eliminated in a short time or transitional product, is our engineering designers must consider the question. In multiple composite extrusion machine control, bus technology, simple network structure, technical performance is stable, not only greatly reduces the amount of wiring, easy installation and maintenance, and greatly enhanced the flexibility and reliability of the system, the guarantee system with advanced, and achieved good social and economic benefits.

 

Contraction deformation of small, high dimensional accuracy and extrusion speed precise extruder screw extruder and development, new composite co-extrusion technology matures, in recent years, the rapid development of rubber industry, China rubber plastic extrusion technology of rapid ascension. The radial tire compound co-extrusion technology is a typical representative of the rubber extrusion technology.

 

2, process characteristics,

 

General according to the type of polymer and the shape of the products or semi-finished products, selected extruder, the nose and mouth mold, and finalize the design and drawing the corresponding auxiliary device, and then determine the extrusion processing conditions such as screw speed, head pressure, material temperature, and finalize the design temperature, pulling speed, etc. In extrusion process, the material is typically through plasticate, but to finalize the design method is different. Plastic extrusion, for example, often need cooling finalize the design, make its curing, and extruding rubber semi-finished products, it still needs further sulfide. Adopt different extrusion equipment and process, can get different products.

 

3, the control system

 

Extruder has been widely used modern electronic instrument and PLC control technology, the process parameters of the extrusion process such as melt pressure and temperature, paragraphs body temperature, the main screw and feed screw speed, feed feed rate, the proportion of all kinds of raw materials, such as current voltage of the motor parameters online testing, and USES the inverter closed loop control. PLC monitoring, diagnosis and control of extrusion production line for automatic control of motor speed control. This to ensure stability in the process conditions, to improve the precision of the product is very good.

 

As composite extrusion machine, its mechanical performance will be more complex, matching with complicated control system, control precision is also higher. Therefore, how to design a suitable control system to ensure its economic, safe and reliable to run, and not be eliminated in a short time or transitional product, is our engineering designers must consider the question.

 

Contraction deformation of small, high dimensional accuracy and extrusion speed precise extruder screw extruder and development, new composite co-extrusion technology matures, in recent years, the rapid development of rubber industry, China rubber plastic extrusion technology of rapid ascension.

 

Extrusion machine, the main function of control system is implemented in the process of extrusion of screw speed, barrel temperature and melt process parameters such as pressure control. At present, the instrument control system, PLC control system as the main choice. Both functions are: temperature control instrument in the control system can realize two control switch, also can use ratio control, easy to implement intelligent instruments and PLC control system can realize PID through analog communication (ratio - integro-differential control) control; The former pressure control show that the melt pressure, while the latter shows the melt pressure and achieve closed-loop control; Test only display of the former, while the latter can realize serial communication test unit. Extruder control system is mainly composed of electrical, instrumentation and actuator, its main function is

 

(1) the control of main, auxiliary engine, drag the motor rotation speed and power required by meet the technological requirements, and ensure the main, auxiliary engine can run harmoniously.

(2) the control of main, auxiliary engine temperature, pressure, flow rate and the quality of products.

(3) realize the automatic control of the unit.

(4) for data acquisition and processing, to realize closed loop control.

 

 

The extruder is through the FX2N series programmable controller and GT1045 - QSBD man-machine interface circuit system as the core of all the motor and to control the extruder temperature setting, automatic stop switch input, thermal relay, sensor and encoder, PLC control the running speed of the motor and the process parameters. Touch screen is used to set and display of extrusion speed, pressure, regional temperature control, through the PLC will switch signal sent to the inverter, such as start-stop control frequency converter. Frequency converter and motor alarm signal sent to the screen the failure, etc. With 235 communication between PLC and touch screen, the process parameters and operating through 235 to send the signals to PLC, after data processing, analysis and calculation, by PLC through 485 communication signal, to control the inverter speed accordingly.

 

4 system debugging

 

1 FX2N PLC man-machine interface and 1, two GT1045 - QSBD man-machine interface control motor speed regulation control, temperature, pressure and other work.

 

FR - E740-90 k - CHT encoder feedback, precise control of motor speed, realize closed loop control of motor speed, stop work. As long as there is fault, at the same time GT1045 - jump to fault QSBD man-machine interface display screen, the screen can see the cause of the problem of corresponding part of the extruder, the fault section has a detailed description. Human-machine interface for users to provide 4 pictures, respectively "boot", "parameter setting", "manual adjustments", "running".

 

Frequency conversion speed is adjustable, through encoder feedback signal control feeding frequency conversion speed. So as to realize closed loop control, achieve accurate speed control.

 

The velocity of the frequency conversion and compensation by the user input through the touch screen, PLC after receiving touch screen input data, through processing, through the communication module to the inverter. Temperature control is through the instrument control, PLC through 485 communication and instrument, at the touch screen can see temperature and set temperature.

 

4.2.2 the operation of variable frequency speed regulation system

 

(1) the operation of the inverter frequency, set the touch screen, through the communication transmission to PLC, again through the communication module to frequency converter.

(2) the inverter start, stop, speed switch, such as instruction, issued by the operating personnel in the industrial type touch screen, and by the output of the PLC will this switch signal is transmitted to the corresponding input terminal of the inverter.

(3) inverter, after receiving the above instructions according to the requirements of directive began to run. In running, and motor encoder coaxial connection will actually detected pulse feedback to PLC, the PLC to carry on the processing.

(4) inverter, such as failure alarm, the open collector output will send the signals to the PLC input point. Frequency conversion system immediately stop running, and touch screen immediately shows failure type and elimination method, the response speed is very fast.

 

In the process of debugging, will encounter many problems, and a lot of problems is not very good, need step by step, step by step, if there is an alarm, to check the related books.

 

5, the system advantages

 

5.1, the extrusion machine adopts PLC and man-machine interface to the whole control system, greatly improving the extruder production stability reliability, susceptible to interference, low failure rate;

5.2, operation more convenient, for more accurate speed control, easy to adjust;

5.3, improve the efficiency of the extruder, simplify operation, reduce consumption, reduce labor intensity.

 

 

 

6, summary

 

The extrusion machine controlled by mitsubishi programmable controller as the core, combining variable frequency closed loop control, touch screen debugging, solve the existing potentiometer control of motor speed, operation inconvenient, poor stability, the control of the whole electric control system level had the very big enhancement, reflects the current domestic squeeze out the development direction of the electric control. Mitsubishi FA products through years of use, cost performance is good, has been more and more customers approval.