【作者】 黄恒；

【导师】 邓楚南；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2005， 硕士

【摘要】 减振器是悬架系统中的重要部件之一,它影响着整车的舒适性、操作稳定性、安全性等重要性能。双简液压减振器作为减振器中主流产品,改善其设计方法及预测其性能一直是汽车减振器技术发展的主要课题。 传统的设计方法主要是根据经验确定设计参数,然后进行实验修正。这种完全依赖于样机实验的设计开发方法不但周期长、消耗大,而且较难获得最优的减振器特性。为克服上述方法的缺点,并缩短开发周期,利用CAD/CAE技术进行减振器的设计开发已经成为必然的趋势。其基本过程是:基于减振器的结构建立数学模型,并经模拟分析得到其阻尼力特性,将此特性用于汽车系统的动力学和振动分析,以评价汽车的操纵稳定性和乘坐舒适性/平顺性等性能,在此基础上对减振器的特性和结构进行优化设计。该过程的核心问题是在设计阶段能够准确地预测减振器的特性,也就是建立能够准确反映减振器特性的数学模型,并在此基础上进行CAD设计。 目前,国内很多学者已经对减振器的建模工作做了大量的研究,但几乎都是将减振器的节流形式视为薄壁小孔节流形式,从而忽略了温度对减振器外特性造成的影响。而在实际考察中发现,很多减振器并非是薄壁小孔节流,而是以管嘴节流,缝隙节流或管嘴和缝隙相叠加的节流方式来产生阻尼力的,因此温度的变化对减振器外特性产生了直接的影响。本文从减振器的结构原理开始,对某种管嘴和缝隙相叠加的节流方式来产生阻尼力的减振器进行数学建模,然后运用传热学理论提出了减振器热平衡的计算方案,并在此基础上分析减振器的外特性和温度间存在的定性的关系。最后通过计算机仿真计算出该减振器的速度特性曲线和示功图,其结果与试验结果基本吻合。这表明,理论计算结果是可信的,所建立的数学模型是正确的,从而为减振器的设计和性能预测提供一定的理论依据。更多还原

【Abstract】 The shock absorber is a important part of the suspension system, it is affecting the important performance, such as the entire vehicle comfortableness, the operation stability, secure and so on. The double barrelled hydraulic shock absorber is the mainstream product of the shock absorber, improves its design method and forecast its performance always is the automobile shock absorber technological development main topic.The traditional design method determined the design variable mainly according to experiences, then relies on the experiment to revise them. This kind of design method which total depend on the tests in the prototype not only the cycle long, consumes in a big way, moreover is difficult to obtain the most superior shock absorber characteristic. In order to overcome the shortcoming of the above method, and reduces the development cycle, uses CAD/CAE technology in the shock absorber design is becoming the inevitable tendency. Its unit process is mathematical model-setting which based on the shock absorber structure, and obtains its damping force characteristic after the simulation analysis, uses this characteristic in the dynamics of automobile system and the vibration analysis, by appraises the automobile the operation stability and rides comfortableness/ smoothness performance and so on, then carries on the optimized design in the shock absorber characteristic and the structure base on this foundation. This process’s core question is accurately forecast the shock absorber’s characteristic in the design stage, also is the mathematical model can accurately reflect the shock absorber characteristic, and carries on the CAD design on this foundation.Up to the present, many scholars at home have done lots of work on the research of the absorbers’ analytical models, and almost all ofmodels are based on the precondition that the absorbers’ throttle is laminal pinhole, consequently they ignore the influence of temperature to the absorbers. However, through the observation we found that many absorbers’ throttle is not based on laminal pinhole, but based on tube or combine tube with gap. So the temperature is effecting the outer performance of shock absorber directly. The paper derived the damping formula of shock absorber which throttle is based on tube and gap associative with the theory of hydraulics and material mechanics, and brought forward the solution of how to calculate the caloric balance of absorber. Based on that, the paper analysed the qualitative relationship between temperature and the outer performance of absorber. Last, the working performance of one kind of vehicle’s shock absorber is also simulated with computer and compared the theoretical values with the test results. The outcome displayed the model is reasonable. Therefore, the paper supplies the base of a theory for designing shock absorbers and predicting their characteristics.更多还原