【作者】 胡佩俊；

【导师】 应济；

【作者基本信息】 浙江大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 高精度二板式注塑机作为精密注塑机的一个发展方向,越来越为注塑机制造企业所关注。液压控制系统是注塑机的核心技术之一,直接决定注塑机的性能。开发具有高响应速度、高精度、低超调等性能的液压系统是目前急需解决的问题,具有较大的经济效益。本文在总结国内外注塑机液压系统相关研究的基础上,以宁波海天集团HT1600二板机型为研究对象,结合国家科技支撑计划项目“注塑机高效、节能的高精度液压控制系统研制”,分析了二板式注塑机液压控制系统的设计过程,对开关模、注射保压及顶出等典型工作过程进行数学建模及动态特性仿真分析。针对系统动态性能存在的不足,结合遗传算法,进行了控制策略的优化研究,达到改善系统响应特性的目的。本文具体研究内容如下:1.基于二板注塑机的工作原理,分析了压力流量总液压控制系统及开关模、锁模、注射、顶出等过程模块液压控制系统的设计过程,并给出相应液压元件的选用原则。2.对控制开关模和注射过程的大流量电液比例阀及控制顶出过程的三通比例阀等关键元件进行等效数学模型的建立工作,并分析了液流经过的各管道对系统性能的影响因素。3.利用MATLAB/SIMULINK的仿真平台,对各典型工作过程进行仿真研究,分析了开关模、注射过程保压及顶出过程中系统的动态特性。4.对于开关模及注塑等过程系统响应特性存在的不足,考虑到注射工艺对于注塑机工作过程中速度、压力、位置等参数的控制要求,控制过程中采取了双反馈闭环控制的策略,注塑保压过程采用流量压力切换控制,结合遗传算法,得到了高速、高精度、低超调量的系统响应特性曲线,改善了液压控制系统的性能。更多还原

【Abstract】 As one development trend of high-precision injection molding machine, two-plate plastic injection molding machine has been paid more and more attention to by manufacturers. The design of its hydraulic control system, which has excellent dynamic characteristics of fast response speed, high precision and low overshoot, is one of the most sophisticated problems needed to be solved and a successfully developed hydraulic system with high performance will make big economic profits. Research presented in the paper plays an important role in the accomplishment of the national supporting project named ’Research on Precision Injection Molding Machine with High Efficiency and Low Energy Consumption’.On summarizing researches related to hydraulic system at home and abroad, the design principles of electro-hydraulic system is presented by taking the two-plate injection molding machine ’HT1600’ of Ningbo Haitian Co., Ltd as a research object. After analyzing the systems, mathematical models are built for the machine’s typical working processes of which dynamic characteristics are simulated on the platform of MATLAB/SIMLINK6.0. Then an optimal control method adopting the idea of GA(Genetic Algorithms) is introduced to overcome shortages of the system’s dynamic properties shown in the above simulation results. The main research contents go as follows:1. According to the operating principles of two-plate injection molding machine, the design process of the hydraulic control system is presented which includes the plate open-close module, plate locking module, injecting module and pushing-out module.2. An equivalent mathematical model of the electro-hydraulic valve which controls the process of open-close plate and injection as well as the tee proportional valve which controls the pushing-out action is established respectively, meanwhile, the influencing factors of each pipeline flowed through by fluid stream are analyzed.3. On the basis of the modeling, operation processes of open-close plate, push-out action and injection are simulated on the platform of MATLAB/SIMLINK6.0 and their dynamic property curves are shown and analyzed.4. To cope with the deficiencies of the system response, a double feedback closed-loop control is adopted, which meets the requirements of speed, pressure and position during machine’s operating process. In the process of pressure maintaining, pressure and flow control switchover method combined with GA was adopted and thus, a satisfying response curve with fast speed, high degree of accuracy and low overshoot is got.更多还原