ã€Abstract】In this paper, the application of Yonghong PLC's MA model in the reformation of equipment molding machine is introduced. It mainly involves the application of Yonghong PLC temperature PID, and the storage and transfer of PLC internal data through man-machine.
ã€Key Words】 Temperature PID Data Storage Data Call
1 Introduction
A factory has several vacuum forming machines purchased from Taiwan in the 1990s. It is mainly used to make bags for toys, hardware, instruments and other products. The control circuits of these devices are all controlled by traditional relays. The operation is complicated, the set-up time is inaccurate, the molding temperature is unstable, and the drift is severe. The internal wiring of the control cabinet is complex, which brings great inconvenience to equipment maintenance and troubleshooting. To this end, the factory is preparing to renovate the batch of equipment.
During the production process of the packaging bag, the molding temperature, heating and cooling time are very important links. It is required that the temperature be self-stabilized, the heating and cooling time can be set and displayed, and the molding time of various products can be stored.
In view of this situation, the plant uses PLC and touch screen as the core controller during the transformation of the equipment. Yonghong FBS series PLC has been widely used in industrial control because of its small size, high reliability, accurate NC positioning, and powerful communication features. FBS series PLC currently has 3 types of models: economical MA/MAT, high-functional MC/MCT, and NC-located MN/MNT. This article adopts FBS-40MA host + GP37W2 touch screen to realize the heating time, molding time, cooling time setting and display monitoring of the heating plate in the molding machine production process, and the storage and transfer of the required process time in different mold production processes. Molding machine automation.
2 Design and Implementation Process
The operating part of the control system adopts a touch screen, the core control part adopts FBS-40MA, and the controlled object includes a heating tube, a cylinder and a pull material motor. The control system group diagram is as follows:
Realization of temperature control part
The heating system of the forming machine is composed of 6 sets of heating pipes, which are controlled by a thermostat and a solid state relay.
Yonghong PLC according to the needs of the control process, with Yonghong other functional modules, flexible combination, can achieve a variety of control needs. A single host computer can realize 32-channel temperature measurement, and there are 5 kinds of temperature modules, including the most commonly used thermocouples and platinum resistors. Choose the 8EAT transistor output part of the macro and the temperature acquisition module TC6, and control the temperature via PID. FUN: TPCTL to achieve the thermostatic control of the molding machine.
The temperature PID control uses the temperature module and the temperature planning table to compare the current temperature in the heating plate of the forming machine with the set value, and converts the calculation result to the time ratio ON/OFF (based on the mathematical deviation of the software PID operation based on the existing deviation). PWM), the output point of the transistor output controls the heating circuit driven by the SSR so that the temperature inside the hot plate is maintained at SV±1°C.
The temperature of the TC module is collected by the temperature planning table, as shown below:
6-channel temperature acquisition is realized by K-type thermocouple and TC6 module. 6-channel temperature values ​​are stored in R30~R35, which are the current values ​​of 6 groups of heating tubes, and 6 groups of temperature settings are stored in R60~ R65 internal.
The program part is completed with the TPCTL instruction. The temperature setting values, deviation values, and P, I, and D of each way are set via the screen:
P, I, D in the internal execution of the PLC have default parameters that can be modified as needed:
Molding time storage and use
Different models require different molding times, so PLCs need to memorize different model times. It can be set and called through the screen. This function is implemented by the touch screen and PLC internal registers.
The screen interface is as follows:
The program part can be placed in the subprogram area. When the parameters need to be modified, the program in this part is called, which can save the PLC scan cycle time. The program storage, query, and calling programs of file No. 1 are as follows, and the program parts of other files are sequentially analogized. Yonghong PLC has nearly 7,000 ordinary R registers, more than 4000 ordinary D registers, and 8192 file buffers are available for use, so it is more than enough for data storage.
PLC I/O Bitmap
(1) Host FBS-40MA section
INPUT OUTPUT
X0 heating plate right limit Y0 brake
X1 heating plate left limit Y2 counter mode
X2 bottom mold lower limit Y3 on the bottom mold
X3 bottom mold upper Y4 under pressure
X4 pull material motor front limit Y5 press material
X5 pull material rear limit Y6 left hot plate
X6 press material lower limit Y7 right hot plate
X7 pressure upper limit Y8 vacuum suction
X8 press Y9 cooling blow
Pressing on X9 Y10 Cooling water spray
X10 Emergency Stop Y11 Blow Mold Release
Y12 feeding material
Y13 pull back
Y14 clip release
Y15 folder caught
(2) FBS-8EYT section
OUTPUT
Y1 1st heater
Y2 2nd heater
Y3 3rd heater
Y4 4th heater
Y5 5th heater
Y6 6th heater
(3) FBS-TC6
T0+/T0- No. 1 heater K type thermocouple
T1+/T1- 2nd heater K type thermocouple
T2+/T2- 3rd Heater Type K Thermocouple
T3+/T3- 4th heater K type thermocouple
T4+/T4- 5th heater K type thermocouple
T5+/T5- No.6 heater K type thermocouple
Based on the above core parts of temperature PID, temperature detection, parameter setting, storage, and call, the program is written.
3 Conclusion
After the transformation of this equipment, it has been put into production. The actual production shows that the FBS-40MA, the economical host of the Yonghong FBS series, has a good price/performance ratio and powerful functions, and can fully meet the requirements of the original transformation. The temperature can be maintained at SV±1°C, setting time is accurate, and the molding parameters of about 99 different products can be stored, which is convenient to call and greatly improves the quality and output of the product.
references:
[1]FATEK User Manual-1
[2] FATEK User's Manual-2
[3] GP Ergonomics Empty Software Operation Manual
Name: He Yanxiang
Position: Technical Engineer
Company: Xiamen Yonghong Yade Electromechanical Technology Co., Ltd.