【作者】 钱德猛；

【导师】 赵韩；

【作者基本信息】 合肥工业大学 ， 车辆工程， 2005， 博士

【摘要】 空气悬架可以减少整车的振动噪声,车轮动载荷小,安装有空气悬架的车辆可以获得理想的固有频率,可以获得更好的行驶平顺性、操纵稳定性和行驶安全性,因而有着广阔的发展应用前景。本论文主要针对空气悬架涉及的两项关键技术——空气弹簧的设计与空气悬架导向机构及各种安装支架的设计技术及悬架的设计理论进行了系统的理论分析、仿真及试验研究。 论文在查阅了大量空气弹簧和空气悬架的研究文献和对国内相关企业作了广泛地调研的基础上系统地综合分析了国内外对空气悬架的研究现状、空气悬架的设计方法及其在汽车上的使用情况。进一步详细介绍了空气悬架系统的主要元件和空气悬架导向机构的不同结构型式,阐述了空气悬架与钢板弹簧悬架相比所具有的独特的优点。应用多体动力学理论的Langrage方法对一种空气悬架的导向机构作了理论分析,并基于国际上流行的虚拟样机技术对其作了刚体运动学和弹性运动学的分析,得到了该型空气悬架定位参数随车轮跳动的变化规律。自行设计了适用于一种非承载式大客车的空气悬架系统(包括转向传动机构),在对系统作了运动分析的基础上建立了以转向轮接地点的侧向滑移量最小为目标函数的结构参数优化设计模型,基于遗传算法对该空气悬架的导向机构的特性参数进行了优化设计,得到了该型空气悬架的结构参数的较为合理的优化设计方案。 论文应用有限元理论与方法,研究分析了空气悬架的关键元件——空气弹簧和弹簧支架。在对参考车型的空气悬架系统的弹簧支架进行了力学特性的分析基础上,为了适用于新车型,进一步作了改型设计,探索了一种动力学分析和有限元分析相结合的方法,参照非独立悬架中车桥的寿命计算所采用的方法计算了该结构件的疲劳寿命问题,并对其作了疲劳寿命的分析计算。从理论上推导分析了空气弹簧的刚度特性、频率特性和阻尼特性;考虑了空气弹簧的材料非线性和几何非线性,采用非线性有限元分析技术建立了空气弹簧有限元模型,分析了由复合材料构成的空气弹簧的非线性特性,得到了不同初始压力和不同帘线角等结构参数和使用参数对空气弹簧的轴向和横向特性的影响,为空气弹簧的设计提供了一定的依据。 论文采用虚拟样机技术将研究对象分解为多个子系统,建立了自行设计的空气悬架客车的整车多体动力学模型,编制了路面谱文件,进行了平顺性仿真分析,并与参考客车的道路试验的结果和安装非空气悬架的车辆进行了比较。比较发现:该车车身上相应位置的加速度值与参考客车接近,而整体小于非空气悬架的车辆上相应位置的加速度值,说明安装有空气悬架的汽车相对于未安装空气悬架的汽车具有更好的乘坐舒适性。该方法可以在整车开发的设计阶段、试制之前对其性能进行有效的预测,从而在试制样车之前最大限度的发现问题。 论文利用相似工程学理论建立了一种大型客车的空气悬架系统的主要功能部件的几何和力学的相似关系,分别按照一定的缩尺比建立了悬架导向机构、弹簧支架、减振器和空气弹簧的相似模型,最后在虚拟环境中建立了多体动力学相似模型,进行了相似系统的试验,并与原型悬架的虚拟样机试验进行了结果比较,证明了相似建模在悬架设计中的可行性。 本文关于空气悬架关键技术和相关汽车设计理论与方法的研究对于增强自主开发能力,有效缩短汽车产品的研发周期具有重要的指导意义和可操作价值。更多还原

【Abstract】 Air suspension system can reduce not only the vibration and noises of vehicles but also the dynamic loads of wheels. The vehicles which are equipped with air suspension system can get perfect connatural frequency and better comfortable performance when they are running, better stability when being controlled, better safety performance when they are running. So air suspension has wide application and development foreground. The dissertation progresses the theory analysis by the numbers and simulation research in allusion to two kinds of pivotal technology of the air suspension, the design method of air suspension and the design technology and theory of the direction framework and all kinds of bracket fixed on air suspension.The dissertation synthetically by the numbers analyzes the research actuality on air suspension in our country and foreign countries, the design method and application instance of air suspension based on reading a number of research papers on air spring and air suspension and investigating widely correlative factories in our country. Then ulteriorly the main components of air suspension and the different structure of the direction framework are introduced and the strongpoint of air suspension compared with armor plate spring suspension is expounded. The theory analysis in allusion to the direction framework of a kind of air suspension is processed taking use of Langrate method of the multi-body dynamics theory. At the same time the kinematics analysis of rigid body and elasticity is also processed based on Virtual Prototype Technique which is popular in the world and the changing orderliness of wheel alignment parameters along with wheel jumpiness is got. The air suspension system including turning system that is fit to a kind of passenger car whose body doesn’t bear the weight of load directly is design independently. Then based on kinematics analysis the structure optimal design model is established with considering the side way displacement of the wheel’s contacting ground point as the goal function and the optimization in allusion to the parameters of the direction structure of air suspension is carried based on genetic arithmetic. Finally the relative reasonable project for the air suspension system is got.The dissertation analyses the air spring and spring bracket which belong to the air suspension system as pivotal components taking use of the finite element theory and method. The remodeling design fit to a kind of new passenger car is carried based on the mechanical characteristic analysis in allusion to the spring bracket of the air suspension system of the referenced passenger car. And the fatigue life of the spring bracket is calculated referencing the fatigue life calculation method of vehicle bridge used in the independent suspension. The stiffness characteristics, frequency characteristics and damper characteristics of air spring are analyzed. Considering the nonlinear features of the air springs in materials and geometry, the nonlinear finite elements analysis technology is used to build the finite element model of air spring and analyze the characteristics of air springs which are composed of composite materials. The deformation characteristics under different loads of air springs and different curtain-line angles are obtained. This provides some basis for the design of air spring.The dissertation divides the research object into several subsystems based on virtual prototype technique, builds the multi-body dynamics model of the whole vehicle which is designedindependently, designs the road characteristic files, carries the simulation of comfortable capability and compares the experiment results with the referenced passenger car and the vehicle which isn’t equipped with air suspension. Through comparison the acceleration value of the relevant locations of the body is near to the referenced passenger car while less than the vehicle which isn’t equipped with air suspension. This result indicates the vehicles equipped with air suspension has better comfortable characteristics than the vehicles not equipped with air suspension. The method can forecast the performance of the vehicles effectively during the process design moment and before manufacture. So most problems will be discovered before manufacture.The dissertation builds the geometrical and mechanical relationship of the main functional parts of the air spring suspension system of a kind of passenger car taking use of the similarity theory. Then the similarity models of the direction structure, the spring bracket, the damper equipment and air spring are built according to respective scale. Finally the multi-body dynamics similarity model is established under virtual environment and experiments are carried in allusion to the similarity system. The results are compared between the similarity model and former suspension model. The comparison result proves the feasibility of similarity modeling of suspension design.In the dissertation the research on the pivotal technology of air suspension and the theory and design method of vehicles has important guidance significance and practicality value to strengthen the independent exploitation capability and shorten exploitation cycle of the vehicles effectively.更多还原