内燃机气门弹簧结构分析与参数优化.doc

摘 要 气门弹簧是内燃机配气机构中气门组件的重要组成部分，它可保证气门关闭时,依靠弹力使气门与阀座保持闭合密封。而气门弹簧受强度、刚度、稳定性等约束条件较多，使其尺寸也受到限制,导致其应力状态严重。因此，对气门弹簧进行结构分析与其参数的优化就变的尤为重要。 本文分析了弹簧的结构参数，得出设计公式。然后基于实体建模进行分析，得到变形量与应力分布图。再基于梁单元对弹簧进行分析，并于设计公式得到的结果进行比较。最后，通过分析内燃机气门弹簧优化设计的设计变量、目标函数和约束条件,建立起以内燃机气门弹簧的质量、高度为目标函数的多目标优化设计数学模型,利用理想点法统一目标函数，并给出了设计实例。算例结果表明该方法具有工程实用价值；并通过MATLAB提供的可视化界面设计，设计出了可视化界面程序。 本文对弹簧进行了有限元分析得出变形量与应力分布图。而对弹簧的优化设计方法，能够准确优化出弹簧的参数，能缩短气门弹簧优化的时间，具有实用价值。 关键词：气门弹簧，多目标，优化设计，可视化界面，有限元 Abstract Valve spring is an important part of the valve mechanism. It can ensure that valve is closed .There are more sectors that restrict the valve spring such as the strength, stiffness, stability constraints, leading to severe stress. Therefore, structural analysis of the valve spring and its optimization parameters is particularly important. Starting from the structure of spring in this paper, then we can get the formula of spring. Then, based on the spring beam element analysis, we can get the figure of deformation and stress distribution. Further analysis based on real modeling and was designed to compare the results of the formula. Finally, through analysis the designing variables, target functions and related constraints of valve spring in Internal Combustion Engines, it set up the optimum design math model of multi-objective. The optimum design multiple of multi-objective was explore. The designing example was offered, the result showed that method is the more engineering practical. MATLAB provides GUI, we can design of the program of visual interface. This method of optimization, can accurately optimize the parameters of the spring. We can shorten the optimization time and it has practical value. Keywords: valve spring; multi-objective ; optimal design; visual interface ;finite element 目 录 摘 要 I Abstract II 目 录 III 第一章 绪论 1 1.1 课题的背景和意义 1 1.2 国内外研究现状 1 1.3 本文的主要研究内容 4 第二章 圆柱螺旋弹簧设计计算方法 5 2.1圆柱螺旋弹簧的几何参数 5 2.2圆柱螺旋压缩弹簧的稳定性与自振频率 6 2.3圆柱螺旋压缩弹簧的结构与设计计算 7 2.4本章小结 9 第三章 基于有限元的圆柱螺旋弹簧分析 10 3.1基于实体单元的圆柱螺旋弹簧的分析 10 3.2 基于梁单元的圆柱螺旋