客车发动机悬置软垫选型的计算与研究

客车发动机悬置软垫的合理设计与选择可有效地降低发动机的振动与噪声。本文结合6770G城市客车着重介绍客车发动机悬置软垫选型的相关计算方法。     

基于多动力总成的六点悬置匹配计算

发动机悬置系统性能的好坏是影响车辆乘坐舒适性的重要因素,而悬置软垫的刚度又是关键。本文以某新能源客车动力总成的悬置系统设计为例,介绍多动力总成的悬置系统的弯矩校核、系统解耦、软垫刚度计算,以及悬置系统设计的基本方法和步骤。     

压缩型低压剪比发动机悬置软垫的设计

在某车型发动机前悬置系统设计中，按照解耦隔振理论所计算的悬置软垫压剪比偏小，而普通的立方体压缩型软垫难以达到要求。介绍对悬置软垫结构改进以实现压缩型软垫低压剪比要求。     

汽车底盘悬置软垫的维护

汽车底盘上安装有各式各样的悬置软垫,它们不仅仅是简单的缓冲元件,同时起着不同寻常的重要作用。但是在日常维护作业中,车主和维修人员往往忽视对底盘悬置软垫的检查和维护。汽车底盘上的悬置软垫主要分布在发动机固定支架与车架之间、传动轴中间支承上和前钢板弹簧盖板上等。 发动机固定支架与车架之间、驾驶室总成下方四角与车架之间的橡胶垫块的作用主要是减缓车身、车厢的震动和保证万向传动装置的平稳运转。如果这类软垫失效(硬化、破损或者脱落),则无法吸收车辆行驶中的颠簸,发动机运转时将发生振抖,而且在汽车加速和制动时,发动     

汽车底盘悬置软垫的使用和维护

汽车底盘上安装有各式各样的悬置软垫，它们对减缓车辆的震动、提高行驶平顺性起着重要的作用。汽车底盘上的悬置软垫主要分布在发动机固定支架与车架之间、传动轴中间支承以及前钢板弹簧盖板等3个地方。     

基于能量解耦法的客车动力总成悬置隔振性能优化

针对某客车车身振动过大的问题,利用ADAMS对动力总成悬置系统进行解耦分析,得出车身振动过大的原因为动力总成悬置系统软垫刚度值不匹配,导致系统在六个振动模态方向上的能量分布相互耦合,使振动加剧。通过优化计算悬置软垫在不同方向上的刚度值,使系统在不同方向上的振动能量解耦,从而提高悬置系统隔振率,达到减振的目的,并经过测试验证。     

基于CAE技术的发动机悬置软垫设计

根据发动机悬置NVH分析的刚度要求,确定发动机悬置的初始结构并建立三维模型,利用ABAQUS软件对其进行静刚度/强度的仿真分析,并进行试验验证。结果表明,实测静刚度与仿真结果十分接近,从而探索出了一条利用CAE分析技术设计悬置软垫的方法。     

基于多目标优化设计的客车发动机悬置NVH分析

基于发动机悬置结构的动力学模型,合理选择设计变量、约束条件及优化目标,建立多目标优化模型,采用多岛遗传算法对其进行求解。根据优化结果进行悬置软垫试制及装车测试,结果表明,优化后的悬置系统在振动、噪声方面都有明显的改善。     

载货车悬置系统优化分析及改进

针对公司某款中型载货车发动机悬置隔振效果差的问题,提出了相对应的解决方案。根据现有车辆实验测定的振动数据和现有软垫的刚度参数,优化悬置系统的参数,应用ADAMS软件的分析优化,并通过振动试验的测定,最终达到优化悬置隔振的目标。为以后的载货车的悬置优化分析计算提供参考依据。     

基于偏相干分析的大型客车振动源识别试验研究

针对某客车在实际运行和怠速工况下振动较大的问题,采用偏相干分析方法进行了理论分析和试验研究。介绍了偏相干分析的基本原理和计算方法,编制了计算程序。在该车辆的发动机前悬置上下侧、发动机后悬置上下侧、变速器悬置左右侧和最后排座椅地板等处设置了6个测点,通过对6个测点数据的偏相干分析,找出了发动机前悬置振动是该客车在怠速工况下地板振动较大的主要振源,为实际降振提供了理论依据。     

Effect of temperature- and frequency-dependent dynamic properties of rail pads on high-speed vehicle–track coupled vibrations

The soft under baseplate pad of WJ-8 rail fastener frequently used in China’s high-speed railways was taken as the study subject, and a laboratory test was performed to measure its temperature and frequency-dependent dynamic performance at 0.3?Hz and at ?60°C to 20°C with intervals of 2.5°C. Its higher frequency-dependent results at different temperatures were then further predicted based on the time–temperature superposition (TTS) and Williams–Landel–Ferry (WLF) formula. The fractional derivative Kelvin–Voigt (FDKV) model was used to represent the temperature- and frequency-dependent dynamic properties of the tested rail pad. By means of the FDKV model for rail pads and vehicle–track coupled dynamic theory, high-speed vehicle–track coupled vibrations due to temperature- and frequency-dependent dynamic properties of rail pads was investigated. Finally, further combining with the measured frequency-dependent dynamic performance of vehicle’s rubber primary suspension, the high-speed vehicle–track coupled vibration responses were discussed. It is found that the storage stiffness and loss factor of the tested rail pad are sensitive to low temperatures or high frequencies. The proposed FDKV model for the frequency-dependent storage stiffness and loss factors of the tested rail pad can basically meet the fitting precision, especially at ordinary temperatures. The numerical simulation results indicate that the vertical vibration levels of high-speed vehicle–track coupled systems calculated with the FDKV model for rail pads in time domain are higher than those calculated with the ordinary Kelvin–Voigt (KV) model for rail pads. Additionally, the temperature- and frequency-dependent dynamic properties of the tested rail pads would alter the vertical vibration acceleration levels (VALs) of the car body and bogie in 1/3 octave frequencies above 31.5?Hz, especially enlarge the vertical VALs of the wheel set and rail in 1/3 octave frequencies of 31.5–100?Hz and above 315?Hz, which are the dominant frequencies of ground vibration acceleration and rolling noise (or bridge noise) caused by high-speed railways respectively. Since the fractional derivative value of the adopted rubber primary suspension, unlike the tested rail pad, is very close to 1, its frequency-dependent dynamic performance has little effect on high-speed vehicle–track coupled vibration responses.     

超大重型货车半金属制动块的研制

本文介绍了新研制的超大重型货车半金属制动埠的配方、生产工艺以及它与进口制动块的性能比较。     

The effect of spring pads in the secondary suspension of railway vehicles on bogie yaw resistance

This paper deals with properties of bogie yaw resistance of an electric locomotive with secondary suspension consisting of flexi-coil springs supplemented with tilting spring pads. Transversal stiffness of a sample of a spring/pad assembly was measured on a dynamic test stand of the University of Pardubice (Czech Republic) and the results were applied into a multi-body model of the locomotive created in the simulation tool ‘SJKV’. On the basis of the simulation results, a detailed analysis of the bogie yaw resistance was performed in order to explain the effect in dynamic behaviour of the locomotive when the moment against bogie rotation (and therefore the distribution of guiding forces on individual wheels, as well) is influenced with the vehicle speed in a certain curve. Results of this analysis show that the application of suspension elements with strongly directionally dependent transversal stiffness into the secondary suspension can just lead to a dependency of the bogie yaw resistance on cant deficiency, i.e. on the vehicle speed in curve. This fact has wide consequences on the vehicle dynamics (especially on the guiding behaviour of the vehicle in curves) and it also points out that the current method of evaluation of the bogie yaw resistance according to relevant standards, which is related with assessment of the quasistatic safety of a railway vehicle against derailment, is not objective enough.     

Influence of long-wavelength track irregularities on the motion of a high-speed train

Vertical track irregularities over viaducts in high-speed rail systems could be possibly caused by concrete creep if pre-stressed concrete bridges are used. For bridge spans that are almost uniformly distributed, track irregularity exhibits a near-regular wave profile that excites car bodies as a high-speed train moves over the bridge system. A long-wavelength irregularity induces low-frequency excitation that may be close to the natural frequencies of the train suspension system, thereby causing significant vibration of the car body. This paper investigates the relationship between the levels of car vibration, bridge vibration, track irregularity, and the train speed. First, this study investigates the vibration levels of a high-speed train and bridge system using 3D finite-element (FE) transient dynamic analysis, before and after adjustment of vertical track irregularities by means of installing shimming plates under rail pads. The analysis models are validated by in situ measurements and on-board measurement. Parametric studies of car body vibration and bridge vibration under three different levels of track irregularity at five train speeds and over two bridge span lengths are conducted using the FE model. Finally, a discontinuous shimming pattern is proposed to avoid vehicle suspension resonance.     

关于悬挂点焊机焊点过烧的分析

在汽车的制造生产过程中,白车身总成的焊接通常使用悬挂点焊机进行驾驶室的焊接,点焊属于压力焊的一种,然而在焊接过程中易出现焊点过烧(俗称炸点)的现象,对焊接质量造成一定的影响,也会对人身安全造成一定的伤害。本文主要介绍在悬挂电焊机出现过烧问题时的分析与故障排查。     

汽车制动摩擦衬片道路试验研究

在现行国家标准基础上研究并设计了乘用车制动摩擦衬片道路试验方法，对所得试验数据应用拉格郎日插值法进行处理并取得了理想效果。试验结果表明，该试验具有较高的仿真度和稳定性，试验方法可行，且可移植性强，适用于综合评价高性能摩擦衬片的实际安装性能，对摩擦衬片的研发具有较高的应用价值。     

浅析悬浮桩在公路软基处理中的应用

悬浮桩在软弱地基处理中的应用日益广泛,国内工程界对悬浮桩理论从不同角度上进行了研究,但鲜有文章对悬浮桩设计的整体过程进行论述。该文对悬浮桩的设计步骤进行了详细说明,并指出了其设计过程中的一些重点环节。     

机械式汽车悬架性能检测试验台闭环控制系统的开发

开发了机械式汽车悬架装置试验台闭环控制系统，设计了闭环控制算法，使试验过程中，保证加速度恒定，并通过实验验证了本系统的可行性和正确性，从而使新系统进一步满足汽车悬架特性测试的要求，又降低了研究成本。在软件的开发中，采用VC＋＋6.0语言编制控制系统，使得开发出的系统界面友好，操作方便，功能强大。     

挂车液压悬架系统的结构分析与改进设计

在拼接式重型多轴挂车满载匀速直线行驶工况下,对其液压悬架系统举升过程仿真,得到悬架构件的最大受力,建立其Pro/E三维实体模型,进行有限元计算和结构分析,提出改进措施。结构改进后,悬架构件的最大受力明显减小,应力分布更加均匀、合理。     

虚拟样机技术在空气悬架系统设计中的应用

应用MSC.ADAMS及ANSYS软件,在ADAMS/Car[1]中建立了中型客车前空气悬架系统刚柔体耦合的动力学模型。模型的各类参数主要通过试验和Solidworks软件获得。在ADAMS/Car中,利用虚拟仿真试验对单纵臂式非独立悬架进行了多种性能分析,并结合空气悬架在设计及使用过程中出现的主要问题进行了探讨,提出了相应的解决办法。通过模型参数化分析及不同方案的仿真试验对比表明,利用基于ADAMS/Car软件建立的空气悬架系统模型可对悬架性能做出正确预测,对空气悬架系统的设计具有工程指导意义。