【作者】 邓建新；

【导师】 邵明；

【作者基本信息】 华南理工大学 ， 机械设计及理论， 2010， 博士

【摘要】 挤压铸造因具有提高铸件性能、减少铸件缺陷等优势近年获得了较快发展,也越来越受到各国的青睐和重视,挤压铸造的生产竞争也随之变得激烈。挤压铸造的成形过程涉及到设备、模具、工艺参数等多个支持工具或影响因素。因此,为有效地实现挤压铸造生产的竞争力目标,有必要对这些支持其成形过程的技术和工具进行系统性地研究。为此,论文主要结合广东省教育部产学研重大专项项目“大型挤压铸造成形技术及装备研发及产业化(2009A090100026)”的研究工作,从系统工程角度出发,对挤压铸造成形过程涉及的硬件和软件的组合即挤压铸造成形系统进行了研究。在分析挤压铸造工艺研究现状及挤压铸造成形过程的基础上,提出了研究挤压铸造成形系统,阐述了挤压铸造成形系统的内涵;然后对挤压铸造成形系统进行了总体设计,规划了系统的功能,分析了系统的信息结构,提出了一种总体结构。该总体结构将整个成形系统划分为模具设计子系统、工艺参数设计管理子系统和挤压铸造设备子系统三大部分,其中设备子系统是核心。分析了挤压铸造设备的多种属性,将公理设计理论引入其设计过程中,介绍了公理设计理论。针对现行公理设计缺乏保证满足独立公理的功能分解支持理论,提出了基于连接关系的功能分解设计方法,阐述了该方法的思想、操作原则。在此基础上,建立了挤压铸造设备的公理设计框架,完成了2 500kN挤压铸造设备的公理设计,并提出了一种零部件的设计顺序。之后对设计的设备机械系统的整机部分进行了有限元分析,验证和进一步保证了设计的合理性。为评价该设备的生产性能,提出了从物流角度评价它性能的方法。揭示了挤压铸造设备与物流的关系,构建了挤压铸造设备的物流性能的评价体系,该体系包括空行程时间、总循环时间、浇注合模时间、设备部件(装置)利用率和处理的实体数5个指标。在此基础上还研究了挤压铸造设备的物流仿真问题,提出了运用Flexsim仿真软件来进行挤压铸造设备物流仿真的策略,构建了仿真模型和实例,并对仿真结果进行了分析。总结了挤压铸造工艺参数的常规设计方法,基于铸件材料成分与其铸造工艺性能之间的相关性及知识管理、铸造模拟的应用趋势,提出了运用工艺知识管理系统进行铸件工艺参数初值设计,基于该初值运用铸造模拟软件进行优化的工艺参数设计方法。为建立挤压铸造的工艺知识管理系统,分析了挤压铸造工艺知识的结构,提出了计算材料相似度的算法,介绍了挤压铸造工艺知识管理系统的体系结构和开发实现效果。然后划分了挤压铸造成形系统的运行过程,总结了各阶段的主要任务。就运行时出现的合模故障问题进行了分析,建立了故障判定模型,提出了处理控制策略。最后对设计的2500kN设备进行了试制,并以它和开发的工艺知识管理系统为基础按提出的总体结构构建成形系统,通过一个阶梯薄壁零件的成形实验,进一步说明挤压铸造成形系统的运行过程,验证了提出的挤压铸造设备方案的合理性和及相关方法的可行性、有效性和实用性。更多还原

【Abstract】 Squeeze casting (SC) recently commercialized has been attached more importance bymore countries in the world, due to its major advantanges such as improving componentmechanical properties, decreasing casting defects.This also makes the production competetionof squeeze casting more serious. Since equipment, moulds, process parameters and othersfactors affect the forming process of squeeze casting, research and development efforts in thestragetic areas of these support techniques and tools to reduce production lead-time and costand to enhance quality and productivity, are very much needed.Under the funding ofGuangdong&Education Ministry IAR project (Grant 2009A090100026), this thesis studiesthe forming system for squeeze casting constructed by the hardware and software related tosqueeze casting forming process from the view of system engineering.On the basis of the analyses about the recent studies and the forming process of squeezecasting, this thesis puts forword the forming system for squeeze casting, at the same timeillustrates the features of this system. Following this, the general functions and theinformation architecture of this forming system are discussed, and then a general structure forit is presented, which is composed of the mould design system, the process parameter designsystem and the core, squeeze casting equipment system.During designing the squeeze casting equipment, axomatic design (AD) theory isintroduced and the method for functional design of axiomatic design based on connections ispresented, in order to actively avoid functional coupling of axiomatic design. The basicprinciples and rules about this method are emphasized. After that, the AD framework forsqueeze casting equipments is constructed and the squeeze casting with the locking force of2500kN is designed based on this framework. The FEM analysis on the general structure ofsqueeze casting equipment designed is also conducted to verify and keep the design resultsmore rational. Then, the paper puts forward the method to evaluate the production permanceof squeeze casting equipment in the view of logistics. The relations of squeeze castingequipment and logistics is illustrated, and the evaluation system made of five indexes issuggested, which are idle loop time, production cycle time, metal feeding and locking time,utilization rate, the number of logistic entities handled. Meanwhile, the logistic simulation ofsqueeze casting equipment in Flexsim software is discussed; the simulation model, cases andresults are included.After summarizing the conventional design methods of squeeze casting process parameters, on the basis of the relations between material composition and processpropertiesof casts, simultaneously considering the application trends of knowledge management andcasting simulation, the paper proposes the new process parameter design method, whichincludes two steps: i) getting initial values of process parameters from process knowledgemanagement system ; ii) input these values into casting simulation software as boundaryconditions to optimize. The process knowledge structure and the algorithm for getting initialvalues of process parameters by material similarity are constructed. The SC processknowledge management system is developed.The operation process for the forming system of squeeze casting is analysed, where maintasks about each operation stage are discussed. At the same time, the thesis analyses clampingfaults which will happen during running in the forming system. The determinant model aboutclamping faults is built; the control algorithms are proposed to control two main clampingfaults and the control module is illustrated too.Finally, the forming experiments of a thin step component are conducted in the formingsystem for squeeze casting mainly composed of the manufactured 2500kN squeeze castingequipment based on the design above and the process knowledge management systemdeveloped. It indicates that the design of the squeeze casting equipment is rational and theproposed methods are feasible and effective.更多还原