目 录
摘要 ············································································································· 2 第一章 序 言 ······················································································· 3
1.1减振器的分类 ······················································································ 3
1.2筒式液阻减振器简介 ············································································· 3
第二章 减振器设计方案的确定 ·································································· 3
2.1减振器设计参数依据 ············································································· 3 2.2汽车振动系统对减振器特性的要求 ··························································· 4 2.3方案的确定 ························································································· 4
第三章 设计计算 ······················································································· 6
3.1载荷的确定 ························································································· 6 3.2减振器阻力与各腔压力的关系 ································································· 6 3.3主要性能参数的确定 ············································································· 6 3.3.1减振器的性能 ···················································································· 7 3.3.2相对阻尼系数Ψ ················································································· 7 3.3.3减振器阻尼系数δ的确定 ····································································· 7 3.3.4最大卸荷力Fs的确定 ·········································································· 8 3.3.5筒式减振器工作缸直径D的确定 ··························································· 8
第四章 阀体选用 ······················································································· 8 第五章 减振器的数学模型 ········································································· 9
5.1拉伸（复原行程）工况下的数学模型 ························································ 9 5.1.1开阀前 ····························································································· 9 5.1.2开阀后 ··························································································· 10 5.2压缩（压缩行程）工况下的数学模型 ······················································ 11 5.3 减振器的外特性模拟计算 ···································································· 13
第六章 减振器的行程与布置 ···································································· 14
6.1减振器的行程选取 ·············································································· 14 6.2减振器行程匹配 ················································································· 15 6.3减振器的行程校核 ·············································································· 16
结论 ··········································································································· 18 致谢 ··········································································································· 19 参考文献 ··································································································· 20
摘 要
本文旨在以一实例阐述筒式液阻减振器设计流程。先在筒式液阻减振器选取两种制造工艺相对成熟结构方案――单筒充气式液力减振器与双筒式液力减振器，进行对比。发现单筒充气式液力减振器相比之下有许多有点，但唯一不足之处在于安装尺寸不合要求，所以采用双筒式液力减振器。减振器设计计算的主要目的在于确定工作缸直径，其他尺寸的确定依赖于一些经验值。本文各项参数的选取和算法主要参照汽车设计手册，进行对减振器设计计算。然后根据前人的减振器数学建模成果，用MATLAB进行外特行计算，并绘制出F-V曲线。再根据曲线修改阀体尺寸及性能参数，再绘制曲线，直到满足设计要求为止。最后进行行程布置和校核计算，由于此项计算对悬架参数的选取依赖性很大，而本人没有找到合适的悬架参数，因此计算的结果意义不大，但这为以后的工作提供了一些资料。
关键词：减振器；数学模型；外特行计算
Abstract
The aim of this thesis is to explain the progress of design of the shock absorber. First, chose tow types of shock absorber which technics of product of is more mature——one solid bowl charged absorber and tow solid bowls absorber. Then compare one with the other one. Though the former have much advantage, it’ s size of assemblage is longer than the request of the design. So I chose the latter. According to the theory of automotive design, I chose the frame of the shock absorber and it’ s part, then calculate the most important parameter which was used to design. I make the F-V curves of the absorber with the mathematics model. At last I complete the calculation of the stroke by which the shock absorber works.
Key words: shock absorber; mathematics model; outer performance calculation
第一章 序 言
1.1减振器的分类
减振器的作用是缓和汽车的振动，提高汽车的行驶平顺性，保护货物，降低车身各部分的动应力，延长车身等部件的寿命。另外，还能增强车轮的附着性，有助于操纵性和稳定性，缓和由于路面不平引起的冲击。减振器从结构上可分为摇臂式减振器和筒式减振器两种。摇臂式减振器是早期产品，现代汽车上已很少用，基本上被淘汰；筒式减振器是主流，它分为被动式和可调式两种。被动式减振器又分为双筒式、单筒充气式、单筒非充气式三种，双筒式减振器按其作用又可分为单向作用式和双向作用式两种。可调式减振器有机械控制式、电子控制式、电流变和磁流变液体减振器四种。
1.2筒式液阻减振器简介
筒式液阻减振器在汽车上有着重要的作用，其阻尼力主要通过油液流经孔隙的节流作用产生。汽车上应用最多的该类减振器是悬架减振器，它能够有效地衰减悬挂质量与非悬挂质量的相对运动，提高汽车的乘坐舒适性、行驶平顺性和操纵稳定性。筒式液阻减振器还用作转向系减振器以及驾驶室、驾驶员座椅、发动机罩等部件的减振装置。随着汽车性能要求的不断提高，筒式液阻减振器的结构和性能亦不断得到改进和提高。在传统被动式减振器技术发展和完善的同时，能够适应不同行驶工况而调节其工作特性的机械控制式可调阻尼减振器、电子控制式减振器以及电流变液体、磁流变液体减振器技术也获得了快速发展。作为筒式液阻减振器技术的重要内容，其设计开发技术也正经历着由基于经验设计一实验修正的传统方法向基于CAD/CAE技术的现代设计开发方法的转变。随着硬件性能和计算分析能力的提高，在设计阶段预测减振器的性能并进行优化设计已成为可能，这对于提高汽车筒式液阻减振器产品的设计开发效率、缩短开发周期具有重要意义。
第二章 减振器设计方案的确定
2.1减振器设计参数依据
车型参数：整车质量1500kg