导　　师： 郝启堂

学科专业： H0503

授予学位： 硕士

作　　者： ;

机构地区： 西北工业大学

摘　　要： 反重力铸造方法是生产大型优质构件的理想方法，反重力铸造液面加压控制系统是反重力铸造设备的核心，是获得优质铸件的关键。本文针对反重力铸造设备plc控制系统的特点和方案进行了研究，结合多功能大型反重力铸造装备的开发与应用项目，设计了电气控制、plc程序控制和计算机监控三个系统。 本文首先对反重力铸造加压工艺进行了分析。从控制角度对充型和凝固过程进行了定义，确定了实现过程控制所需的入口工艺参数，剖析了关键参数对成形加压工艺和铸件质量的影响，研究了不同情况下的加压工艺，为反重力铸造成形过程控制的实现提供了基础。 采用s7-200系列plc，运用与其配套的step7-micro/win编程软件，使用stl和lad两种编程语言编制了下位机的控制程序，从而使该系统可以按照工艺要求完成现场采样、数据处理和控制输出等过程。 在反重力铸造装备上位监控系统的设计中，利用组态软件设计了参数设置、过程监控、数据处理、故障定位和系统动画等具有windows风格的人性化动态操作画面，实现了现场数据实时监控与记录。 最后针对不同铸件的特点设计了反重力铸造装备的控制回路。在此基础上，采用pid+模糊控制算法实现了反重力铸造成形的过程控制。试验结果表明：系统运行可靠，跟踪性能好，控制精度高，调节方便。 Counter-gravity casting/(CGC/) technology is an ideal method of producing large-size high-quality parts .The pressurizing control system of the counter-gravity casting is the core of counter-gravity casting equipment, and also the key of obtaining qualified castings. Based on the research about the characteristics and methods of PLC control system in the CGC equipment, and combined with the project of the large and multifunction counter-gravity casting equipment, the paper presents the design of the electrical-pneumatic system, PLC system and the computer monitoring system. The pressurizing pattern of counter-gravity casting is analyzed. The filling process and solidification process are defined in the view of control. Inlet parameters used to realize process control are determined. The effect of key parameters on the casting quality is analyzed, and several pressurizing patterns under different conditions are researched, which is the foundation of the realization of the filling process control of counter-gravity casting. The paper uses STEP7-Micro//WIN, provided with two kinds of programming languages, STL and LAD, to build the program for Siemens PLC S7-200. The program can finish data acquisition, data processing and control according to the technological requirement. In the master system design of CGCE, InTouch is used to build dynamic operation pictures with Windows style, such as parameter setting frame, process monitor frame, data processing frame, fault location and system animation, etc.. According to the characteristics of different parts, the control loop of multifunctional CGC equipment is designed. And based on the control loop, this paper adopts PID+ Fuzzy controlling algorithm to implement the control system of CGC molten shaping process. Test results indicate that the system runs reliably with good tracing property, high accuracy and good usability.

关 键 词： 反重力铸造 加压工艺 控制技术 模糊化

分 类 号： [TG249.9 TG23]

领　　域： [金属学及工艺] [金属学及工艺]