【作者】 张谦；

【导师】 李凌丰；

【作者基本信息】 浙江大学 ， 机械设计及理论， 2004， 硕士

【摘要】 提高注塑机螺杆设计水平对提高注塑机加工质量具有重要的意义，而注塑机螺杆的复杂几何结构以及工作性能受众多工艺参数影响，导致其设计一直是个棘手的问题。本文对注塑机螺杆工作原理做了深入的分析．在塑化理论研究的基础上，利用固体输送理论推导出螺杆工作过程的数学模型，基于此数学模型，提出了螺杆优化设计的目标函数和约束条件。综合优化目标函数和约束条件构造了遗传算法的适应度函数，改进了遗传算法的选择算子运算规则，利用改进的遗传算法实现了注塑机螺杆优化设计。最后，给出了注塑机螺杆参数优化设计系统的应用实例。本文的工作克服了注塑机螺杆传统设计方法中的盲目性，为螺杆的设计改进提供了一种新方法。 第一章，首先介绍了注塑机系统和注塑机螺杆系统，讨论了注塑机螺杆优化设计项目研究背景和意义，综述了注塑机螺杆研究现状。分析螺杆设计中存在的问题与不足，最后阐述了本文的研究内容与总体框架。 第二章，以流变学理论为基础，从注塑机螺杆加工过程的特殊性出发，借鉴挤出机螺杆的模型，经过分析得出注塑机螺杆工作的物理模型——固体输送模型，为建立下一章的螺杆工作数学模型提供了理论依据。 第三章，根据螺杆固体输送模型，推导出机筒内熔膜厚度沿螺杆轴向的分布函数，并分析了塑料母料在螺杆中的停留时间，给出了塑料加工质量重要指标——纵向混合度和层状剪切混和度的表达式。综合分析纵向混合度和层状剪切混和度之后，构造出均匀度矢量。基于均匀度矢量，提出均匀度质量函数作为优化目标函数，确定了合理的优化约束条件。 第四章，首先分析了采用传统优化设计方法的工程设计中存在的若干缺陷，为尽量避免这些缺陷，提出采用遗传算法进行注塑机螺杆优化设计。改进了遗传算法中选择算子的运算规则，对遗传算法算子采用实数化编码。确定了遗传算法优化中各个参数，综合均匀度质量函数和优化约束条件，构造了遗传算法的适应度函数，并利用改进的遗传算法实现了典型注塑机螺杆的优化设计。实验对比结果表明，较之采用传统优化设计方法(网格法)，基于改进的遗传算法的螺杆优化设计显示了很大的优越性。 第五章，利用VB开发工具、SQL server2000数据库技术和改进的遗传算法实现了注塑机螺杆参数优化设计系统，并给出了其应用实例。 最后，对本文所做的工作进行了总结，并展望了本课题今后的发展。更多还原

【Abstract】 It is a very intractable problem to optimize injection molding machine (IM)’ screw for its complex geometrical structure and its performance influenced by plastic machining technique. After procedure of plastic machining by IM’ screw is studied theoretically, by means of the mold theory, several restrictions and an optimization object function - the quality uniformity function are proposed. Based on characteristic of issue, Genetic Algorithm (GA) is ameliorated. The improved GA is used to optimized of IM’ screw, aiming to minimize value of the uniformity function. So the typical design of IM’ screw becomes true. The test result shows the optimized design on IM’ screw using GA can accord with the standard of performance.In chapter 1, introducing the system of IM and the screw of IM, based on the backgroud of IM research, the Actuality of the screw of IM have been looked back to. After the means of the design of the IM’screw analysed, the deficiency is pointed out in them. At last the new ideas of way to design the screw are put forward, and the screw optimized design system is given.In chapter 2, in order to put forward the ideas of the question, the theory of the design is first introduced - theory of rheology, and educed the running of screw’ parameters. In virtue of the former of extrusion, the running IM’s screw of original model- Solid transportation theory is analyzed.In chapter 3, First, melted plastic’ distributing in three segment of screw was analyzed; Second, the time of melted plastic sticking around in Barrel is educed; Third, the radial degree of melted plastic’blending is discussed. Basing on them, the quality uniformity function is brought forward as optimization object function. At the same time, several restrictions are ascertained - the degree of melted plastic, efficient injection and High intensity of Screw.In chapter 4, the traditional means of design is introduced, considering the ravelling out the matters in screw of IM, I fall back on the Aritificial Intelligence (AI) -GA. Based on characteristic of issue, GA is ameliorated. The improved GA is used to optimize IM’ screw, aiming to minimum value of the uniformity function. So the typical design of IM’ Screw becomes true. The test result shows the optimized design on IM’ Screw using GA can accord with the standard of performance.In chapter 5, using the VB, SQL server 2000 and reformative Genetic algorithm, the Screw optimized design system is designed. And the Screw optimized design system is given.The remainder of this dissertation summarizes the research work and gives the future work of this research.更多还原