Abstract: This article describes the application of programmable controller on the square machine through PLC hardware configuration and software flow chart work process, and has a certain introduction to PLC.
Keywords: PLC control, square machine
Abstract:This paper introduces the application to electric controlled by PLC used for
Former .the composition of software and hardware in the system are presented.
Key words: PLC Control system Former
I. Overview Our company's barrel production has been for many years, and there are many barrel production lines. The technical process of the barrel production line is to roll the tinplate into a round barrel shape and then go through a square machine to make it into a rectangle, and then turn it through the flanging machine to turn the sky and floor. After testing into the finished barrel. In the square machine of the barrel line, due to the detection of whether there is a barrel, determine the location of the weld, lift the drum into a square, put down, transport and other processing processes. There are many machine actions and the control process is more complicated. Therefore, PLC is selected for control.
Second, the hardware configuration The square machine is under the control of the PLC system to achieve full automatic production, this set of control system is a central processing unit consisting of the Japanese company's C40P, the hardware connection shown in Figure 1
Figure 1 hardware connection diagram
Programmable Logic Controller, abbreviated as PLC; There are a large number of switch and analog control devices in the production equipment, such as: start and stop of the motor, opening and closing of the solenoid valve, counting of products, setting of temperature, pressure and flow rate And control and so on. Previously, the above controls were mainly implemented using relays or discrete components. But with the rapid development of production. People have put forward more general, changeable, easy-to-repair, reliable, and economical requirements for these automatic control devices. With the development of electronic technology, people have developed a variety of control devices that can meet the above requirements, including a programmable logic controller (PLC). PLC began to develop in 1969. According to the mature and effective concept and design concept of relay control, it uses the continuously developing new technologies and new electronic devices to form its own series of products. The OMRON C40P has the following features:
1. Complete functions: The basic functions of the PLC include digital inputs/outputs. Internal relays, delay ON/OFF relays, latch relays, master control relays, timers, counters, shift registers, arithmetic operations, comparisons, metric conversion, etc.
2. Flexible application: The standard modular hardware structure of the C40P and the modular software design make it not only adaptable to different size and versatility of control requirements, but also adapts to a variety of process changes. It is easy to install and field wiring. Because its logic and control functions are accomplished through software, it allows designers to perform “soft wiring†work before purchasing hardware equipment, thereby shortening the entire design, production, and debugging cycle.
3. Easy operation and easy maintenance: C40P uses the ladder programming and function mnemonic programming that electrical operators are accustomed to, so that the user can easily read the program and write and modify the program. The PLC has perfect monitoring and diagnostic functions, and it has a striking display of its internal working status, communication status, I/O point status and abnormal status. Therefore, the operator and maintenance personnel can understand the point of failure of the machine in a timely and accurate manner and use the alternative modules or plug-ins to quickly handle the failure.
4. Stable and reliable: All factories that produce PLCs are strictly inspected according to relevant technical standards. The C40P passes the JIS standard. Therefore, although the PLC has various models, it can be adapted to harsh industrial applications. In addition, due to its compact structure, heat, moisture, shock and other properties are also very good.
Third, the software structure OMRON Corporation C40P programmable controller used programming language ladder diagram.
Figure 2 flow chart
Due to the technical requirements of the squarer on the barrel production line, (1) the welding tank is changed from a round shape to a square shape. (2) Ensure that the position of the weld is in the middle of the tank edge. Therefore, in the software design, the first consideration is to align the can's weld position, fix it, pass it into the square station, make it into a square, and then send out the square machine to complete the work in the square.
The job of finding the weld is done by a vibration sensor and an amplifier. Because the weld seam is uneven, this can be detected by a vibration sensor, measured into the amplifier, the amplifier output and input to the programmable controller to inform the weld to find. The work of Cheng Fang is completed by two expansion blocks. When the circular tank goes into the expansion block, the expansion block expands outwards, making the circular tank a square and completing the work of the square.
Fourth, the control function In the automatic operating conditions, the automatic operation of the middle relay is energized, positioning valve normally closed, transport motor action. Then check whether the tank is in place. After being in position, the tank is positioned by the blocking rod to make the tank position correct. Then the detection, disk up, counting and other actions are performed. After the seam is detected, it is lowered, expanded to the expansion station, and then sent out of the tank Complete the work of the square machine to the next process. Under manual operating conditions, these actions can also be performed step by step.
In the weld inspection station, due to the fact that the rotating tank edge is to be stopped immediately after the weld is measured to ensure the correct weld position, a set of brake clutch is used here: when the motor drives the welding tank to rotate, the brake clutch With the rotation, when the weld is found, the brake clutch moves to accurately stop the welding tank and ensure the weld seam position.
V. Concluding remarks Although the PLC controller has a higher price, due to the presence of PLC's internal auxiliary relays and the output point can withstand large loads, it is possible to directly drive the general solenoid valves and signal lights. This saves all the original intermediate relays. The reduction of components reduces the size of the control cabinet. Moreover, PLC's reliability is higher and its functions are more complete. It is an ideal control device.
references
[1] Li Jinglin Application of PLC in Retrofit of Electric Control Circuits for Traveling Vehicles 200504
Author's introduction Yang Yonghong (1966-) Male Senior Engineer Mainly engaged in equipment maintenance and improvement.