内蒙古工业大学硕士学位论文
Abstract
With the implementation of "made in China 2025" strategic goal, the demand for
thin-walled alloy castings in manufacturing industry is increasing. Low pressure casting is
widely used in the industry because of its advantages of high efficiency, light weight and
high compactness. At present, the domestic low-pressure casting industry still has the
phenomenon of field manual operation, low degree of automation, imperfect control
function and bad working environment, especially the gap between the low-pressure
casting production control technology and foreign countries is large. Therefore, to speed up
the research and development of low-pressure casting production control system is of great
significance for the further development of low-pressure casting industry in China. In this
paper, an intelligent automatic production line is designed, which consists of gantry device,
material conveyor belt and several low-pressure cantilever casting machines, and the
corresponding casting control system is developed. The production control system of
low-pressure cantilever casting machine developed in this paper improves the batch
efficiency of low-pressure casting and realizes the unattended automatic production.
First of all, based on the analysis of the existing casting mode, the paper establishes
the mathematical model of job scheduling and Optimization in the low-pressure casting
workshop. Through the modeling and calculation based on discrete events, the production
beat of each station, the station layout of the production line, and the station service ability
are determined. Through the ProModel simulation, the optimal number of work stations,
the layout of work stations and the material transportation mode are determined, which
provides the basis for the development of the production control system of low-pressure
cantilever casting.
Secondly, the programming and control function integration of the casting control
system are completed. The hardware of the control system adopts Siemens s7-1200 PLC,
which collects the field process data through sensors to realize the field control. The
software of the control system is Kingview, which is programmed according to the
requirements of safety production and production process to realize the real-time
monitoring and control of production process. At the same time, in order to ensure the
rotation accuracy and positioning in the process of cantilever movement, a computational
control model is established for the servo motor of low-pressure cantilever casting machine,
and a current loop control strategy based on finite time is proposed. The speed control loop
