【作者】 李艳聪；

【导师】 张连洪；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2010， 博士

【摘要】 液压机是制造业的一种基础制造装备。液压机主机的刚度对压制件的精度具有显著影响。现行的液压机设计中,主机刚度指标的制订依据主要源自经验类比,缺乏压制件精度方面的考虑,可能导致所设计的液压机刚度不足,不能满足压制件的成形精度要求;或导致刚度储备过大,降低产品的性价比。为此,本文对计及压制件精度的液压机主机结构设计方法进行了研究。论文主要研究内容和成果如下:1.通过对液压机-模具系统分析,得出了液压机主机诸结构部件中,下横梁弯曲变形是影响压制件成形精度的主要因素的结论,进而建立了压制件成形精度与液压机下横梁刚度间的映射关系模型,将压制件成形精度映射为液压机下横梁刚度性能要求。2.构建了液压机概念设计方法。该方法采用材料力学方法,建立液压机主要结构部件的力学模型及概念设计模型;基于液压机各部件概念设计模型,依据液压机的公称载荷、工作空间等技术规格及各部件的刚度性能要求,确定各部件截面的惯性矩和抗剪切截面面积或抗拉压界面面积,得到液压机主机的概念设计原型,进而得到液压机主机结构设计原型。3.提出了基于灵敏度分析与近似建模技术的液压机主机结构优化策略。即:基于液压机主机结构设计原型,建立主机部件的有限元模型,进行部件结构性能灵敏度分析,进而提取影响液压机主机部件性能的关键结构参数作为主机结构优化的候选设计变量;基于正交数值模拟试验,以主机结构轻量化/高刚度为优化目标,建立主机结构近似优化模型;求解优化模型,获得液压机主机结构优化设计方案。4.基于上述研究成果,提出了以压制件成形精度作为设计约束,计及压制件精度的液压机主机结构设计方法。该方法基于压制件成形精度与液压机下横梁刚度的映射关系模型,将压制件成形精度映射为液压机下横梁刚度性能要求;基于液压机概念设计模型和液压机技术规格与各部件刚度性能约束,设计液压机主机结构概念原型;进而得到液压机主机结构设计原型;以该原型设计为基础,进行主机部件结构性能灵敏度分析及主机结构优化设计。5.将所提出的计及压制件精度的液压机主机结构设计方法应用于THP10-10000型100MN等温锻造液压机主机结构设计,实现了该液压机主机结构的概念原型设计、原型结构设计及优化设计。得到了该液压机主机结构轻量化最优解和轻量化/高刚度化Pareto优化解。其中,轻量化最优解在满足了液压机刚度要求同时,较原型设计质量优化率2.044%,较样机质量优化率5.774%。轻量化/高刚度化Pareto优化解为液压机设计决策提供了多个可行解。本文研究的计及压制件成形精度的液压机主机结构设计方法,虽然其具体对象是液压机,但就其理念和原理而言,也适用于其它成形制造装备设计,具有一般性意义。更多还原

【Abstract】 Hydraulic press is fundamental to manufacturing industry. Though stiffness of hydraulic press has direct impact on the forming precision of mouldings, as there is less knowledge about the forming precision of mouldings versus the stiffness of hydraulic press, design indexes of the stiffness performance of hydraulic press are mainly determined by experience in current hydraulic press design, which may result in stiffness shortage and low forming precision of mouldings, or stiffness overage and high cost of the press. To resolve the above issue, a design method for mainframe of hydraulic press considering forming precision of mouldings is proposed and studied in this thesis. Main research works and results of the thesis are as follows.1. By analysis of the hydraulic press-mould system, it was concluded that the stiffness of lower beam of hydraulic press is the major factor affecting the forming precision of mouldings. And a mapping model between the forming precision of mouldings and the deflection of the lower beam is established, with which the forming precision of mouldings can be mapped to the design index of the lower beam stiffness.2. A method for conceptual design of mainframe of hydraulic press is constructed. The method consists of setting up mechanical models and conceptual design models of structural components of the mainframe with mechanics of material theory, designing the conceptual prototypes of the structural components by calculating initial moment of bending and cross section area of shearing of the structural components based on the conceptual design models according to the technical specifications and the design indexes of stiffness of the mainframe of the hydraulic press, and finally designing the structural prototype of the mainframe based on the conceptual prototypes. The structural prototype of the mainframe can be a starting point for optimization of the mainframe of hydraulic press.3. A sensitivity analysis and approximate modeling based strategy for mainframe optimization of hydraulic press is put forward. The optimization strategy includes two steps: step 1, stiffness and mass sensitivity analysis of the structural components with FEA (finite element analysis), by which key dimension parameters can be filtrated as candidates of optimization variables of the mainframe; step 2, setting up the approximate optimization model for the mainframe by means of DOE (design of experiments) and FEA with light weight or light weight and high stiffness as object of optimization, and solving the model by appropriate optimization algorithm to obtain optimized design schemes for the mainframe of hydraulic press.4. A design method for mainframe of hydraulic press considering forming precision of mouldings is proposed. In this method, the design process of the mainframe is as follows: firstly, the forming precision of mouldings is mapped to the design index of the lower beam stiffness via the mapping model between the forming precision of mouldings and the deflection of the lower beam; secondly, the conceptual prototype and structural prototype of the mainframe is designed with the conceptual design models of the structural components according to the technical specifications and the design indexes of stiffness of the mainframe; thirdly, the sensitivity analysis and optimization is carried out to acquire optimized design schemes of the mainframe of hydraulic press based on the structural prototype.5.The design method is applied to the mainframe design of Model THP10-10000 100MN isothermal forging hydraulic press. Conceptual prototype design, structural prototype design and optimization of the mainframe of the hydraulic press are realized by the method. Optimized design scheme for light weight and Pareto optimized design schemes for light weight and high stiffness are obtained of the mainframe of the hydraulic press. The light weight optimized design scheme provides a light weight rate of 2.044% and 5.774% in comparison with the structural prototype and the engineering mockup respectively while satisfying the design indexes of stiffness of the mainframe. The Pareto optimized design schemes for light weight and high stiffness provides multi feasible solutions for the mainframe of the hydraulic press.Although the object of this thesis is hydraulic press, the ideas and principles proposed in the thesis are applicable and general to the design of other forming equipment.更多还原