1 Introduction
modern commercial production and circulation areas, products are inseparable from the packaging. Such as milk boxes, fruit boxes, etc.. The cartons, boxes and attachment of Shengchan several million pieces of daily machine should be a very large production task, if not achieve Zi Donghua production, will consume a large amount of Lao Dongli, Erqiexiaoshuai and Zhiliang aspects are difficult to increase. The design is to apply paste box machine PLC system, so that the production of carton automation, their main task is how to cardboard processing molding, packaged in bundles, how to control the production process, it is the mechanical and electrical integration carton machinery. In short to ensure process control requirements in the circumstances, greatly improve the efficiency of production, there is a very promising market.
2, system control features and technological
2.1 Control requirements and characteristics
(1) absorption into the paper and cardboard to ensure the accurate location of absorption into the paper;
(2) Department of the upper and lower transmission folded cardboard with a clamping feed, so feed and operation of the adsorption chamber adsorption distinctive vertical sides of cardboard with a clamping feed each other, to ensure that no skew folding paper;
(3) about the distribution under the correction with increasing speed reducer, the friction force when folded around the cardboard rectifying effect is obvious, pulling;
(4) using a new device out of the sub-stack technology, than the advanced performance of similar devices is more stable and reliable, run more quickly. Time for Poor cardboard cardboard significantly reduced risk of confusion;
(5) man-machine interface technology, production speed can be displayed, the number of paper and related parameters;
(6) to achieve the A / M of control.
2.2 Process Description
PLC as the core of this system, since the load carried by the system is not, can one reach a 3.7kW inverter driving an asynchronous motor, the motor drag the main transfer device. When the materials ready, about to feed the clutch switch on the right and left motor stator carton size, measure the speed with speed detection devices, photoelectric sensors detect the location of the signal boxes, so that servo work. Can achieve a friendly touch screen interface, the monitoring system can be run online, and to modify the parameters accordingly. Material from the flat cardboard into the machine to complete the processing units to achieve full automation, the process diagram shown in Figure 1.
Figure 1 System technology sketch cardboard forming the track is the channel, determine the shape of the track the shape of cardboard cartons are processed, the following major components of each do a brief introduction.
(1) feeding device
because cardboard is the line processing, when the working platform placed enough when processing board, to enter the stable and continuous, non-overlapping work status, improved productivity;
(2) roll straightener
to allow passing cardboard perpendicular to the conveyor belt, and its close orbit to a more accurate molding board;
(3) Speed test
with strong anti-interference close to the switch as a sensor, and it generates the pulse signal to the PLC high speed counter;
(4) transmission equipment
driven by the motor, which controls the speed of the main production line by the inverter control;
(5) cardboard correction
mainly by the position signal sensor and servo system components, it is mainly formed of cardboard correct position in orbit shift, and the order of the carton packaging ready;
(6) count sensor
test track on the number of cartons in order to quantitatively Binding;
(7) boxes stacked units
to send the boxes to be stacked, the number set to launch;
(8) Binding
will be a good number of carton strapping.
3, control system design
cardboard processing molding process, a rigorous process, the control system to meet the requirements, using PLC, inverter, servo, high-performance human-machine interface and integration of sensors, effectively solve real problem. Also the composition of the system is simple, powerful, reliability, operability and visibility have increased.
3.1 hardware structure
the system with OMRON PLC s CPM1A-30CDT-A, 30 points I / O port, 18-point input, 12 output, and also left room for expansion. The models are Omron C series minicomputers, compact, functional, good cost performance. Inverters (VFD-B-5.5kW) and servo devices (AC servo HO series) and the touch screen (PWS717-STN) have adopted a more powerful functionality Delta products. The hardware structure shown in Figure 2, the hardware structure diagram.
Figure 2 Block diagram of system hardware 3.2 Inverter
The system uses a more advanced platform to speed up converter, it is convenient and reliable speed and speed with high accuracy. To accommodate this process load, need constant speed when the motor output torque, application V / F control characteristics of the frequency converter application in the fundamental frequency V / F control characteristics of the inverter in fundamental frequency (Delta A-type machine The parameter is the Pr04) The following speed. Application of this system of two Delta converter, which are master-slave relationship, from a given frequency of the inverter must be given following the primary inverter frequency changes, and ensure that the output from the inverter s frequency slightly higher than the main inverter output frequency.
3.3 Servo Correction Device
as cardboard send in orbit, they will appear position error, which may need to quickly correct the position of the device, while the servo motor possess such capabilities. It controls the input voltage signal into the output of the angular displacement or angular velocity, coupled with the control voltage, it will immediately rotate, remove it immediately stops and the control voltage, speed and control voltage proportional to the level. This device has a small moment of inertia, friction torque is small, smooth running and low noise characteristics. Here the main advantage of servo drive motion characteristics of the servo motor to set speed and location by using a combination of PID regulator, so that the location of boxes is well corrected.
4, software design
4.1 user interface settings
to be a very good control and monitoring system, you have to use touch screen. Former first determine the appropriate equipment and signals a good port address, and then use the touch screen programming software - ADP software interface settings. The figure of the master screen touch screen, it has a friendly exchange of machine. Through the touch screen operation, it is easy to understand and monitor the operation of the system, and can easily change the system s operating parameters. The design of the main menu shown in Figure 3.
Figure 3 the main menu interface diagram 4.2 PLC Programming
coordination of the various parts of the system to enable an orderly, safe and reliable operation of more optimization would have accompanied the software program. The software is modular programming method, easy to debug, modify and expand, it mainly includes three parts: common part of the agreement, set some parameters, and automatic operation control part, the program overall control block diagram shown in Figure 4. Figure 4 process flow chart 4.3 software reliability design
software reliability measures include three fault detection procedures:
(1) time fault detection process: the process execution time as the timing control of a time cushion of time, out the alarm and shutdown;
(2) compare the signal detection program: A failure scan clock to automatically type in the operation process can automatically detect sections of cells, which clear the fault;
(3) When the board is the main card or overlap, or slow down the alarm.
5, concluding remarks
cardboard forming process control, due to high-performance PLC and related equipment introduced to address the burdensome work of production to achieve a fully automated production, quality and quantity of its products have been significantly improved. In short in ensuring product quality process control requirements and circumstances, greatly improve the efficiency of production, there is a very promising market.