Detailed description of the blow molding machine control system

2019-04-30 17:19:50

Blow molding machines can be divided into three categories: extrusion blow molding machine, injection blow molding machine and special structure blow molding machine. Stretch blow molding machines can be assigned to each of the above categories. The extrusion blow molding machine is a combination of an extruder and a blow molding machine and a mold clamping mechanism, and is composed of an extruder and a parison die, an inflation device, a mold clamping mechanism, a parison thickness control system, and a transmission mechanism. The parison die is one of the important components that determine the quality of the blow molded product, typically a side feed die and a center feed die. The storage cylinder type blank die is often used for blow molding of large products. The storage tank has a minimum volume of 1kg and a maximum capacity of 240kg. The parison thickness control device is used to control the parison wall thickness, and the control point is up to 128 points, generally 20 to 30 points. The extrusion blow molding machine can produce hollow articles having a volume ranging from 2.5 ml to 104 l.

The automatic wind ring is an online real-time control system. The system is controlled by several motors distributed on the wind ring. The cooling airflow sent by the fan is distributed to each air channel through the constant pressure of the air ring air chamber, and the motor drives the valve to open and close to adjust the size of the air outlet and the air volume, and change the cooling effect of the film blank at the die discharge. Therefore, the thickness of the film is controlled. From the control process, there is no clear relationship between the thickness variation of the film and the amount of motor control. The thickness and thickness of the film and the different positions of the valve vary nonlinearly with the control amount, and each valve is adjusted. The influence on the adjacent points is very large, and the adjustment has hysteresis, which makes the different moments related to each other. For this highly nonlinear, strong coupling, time-varying and control uncertainty system, the exact mathematical model is almost impossible. Establishing, even if a mathematical model can be established, it is very complicated and difficult to solve, so that it has no practical value, while the traditional control has better control effect on the determined control model, but the control effect is highly poor for highly nonlinear, uncertain, and complex feedback information. Even powerless. In view of this we have chosen the fuzzy control algorithm. At the same time, the method of changing the fuzzy quantization factor is adopted to better adapt to the change of system parameters.