汽车轮胎的发展趋势（三）

2.提高轮胎耐久性 为了增强轮胎的耐久性,主要着眼于轮胎帘线材料的变革,因而出现了各种不同帘线的轮胎。 1915年以后棉帘布广泛用于轮胎生产,1935年人造丝帘线开始被采用。 继人造丝之后,尼龙于1950年前后开始普遍使用于轿车轮胎。 1962年聚酯帘线投入工业生产,但因其耐冲击、耐疲劳强度不及尼龙帘线,故目前一般仅用作轿车轮胎。     

子午线轮胎简介

子午线轮胎是五十年代初期在欧洲发展起来的一种新型结构轮胎。由于它具有一系列突出的优点,深受各国重视,争相研究。1.子午线轮胎的结构特征普通斜交轮胎的帘布帘线是分层交叉排列的,有一定夹角,见图1。而子午线轮胎的帘线排列是零角度,其各层帘线相互平行。这种形式排列颇象地球子午线的径向方向,因而取名为子午线轮胎(radial—ply     

轮胎结构有限元分析应用于子午线轮胎帘线受力特性的研究

建立了195／60R14型子午线轮胎三维非线性有限元模型，研究了在静负荷作用下轮胎帘线的受力特征。结果表明，静负荷对轮胎接地区域内帘线受力影响显著；模型带束层结构为2层相交的帘线结构，不能构成力学上的对称；带束层角度的变化对帘线剪应力分布有一定的影响，对胎肩部位帘线剪应力影响较大。     

轮胎层级的选用

汽车轮胎是汽车行驶的主要部件,轮胎的消耗费用是汽车总消费支出中的重要部分。轮胎层级简释轮胎层级“PR”[ply rating]是指轮胎允许负荷的强度指标,并不一定是轮胎帘线层数。层级是根据帘线强力大小折合成棉帘线的层数。两层帘布的四层级轮胎,实际上只有两层帘布,但是其负荷和同样名义尺寸的四层级棉帘线标准轮胎相同。片面追求多层级轮胎的倾向与其危害一般说轮胎层级越多,负荷越大。但如果在     

GHK7060云雀轿车发动机机械异响的原因及排除

１前言 云雀微型轿车是从日本富士重工株式会社引进的车型，该车采用了前横置发动机及前轮驱动型式。其发动机采用了双平衡轴技术，使机体运转平稳，振动小，噪声低；配气机构采用齿形带传动，工作柔和，精度高。目前，云雀轿车已投放市场近１０年，随着使用时间的延长，发动机出现了一些各种不正常现象，如发动机出现异响。虽然导致异响的原因有很多，但主要原因是机械因素造成的。本文仅对其机械异响作一探讨。２活塞敲缸２．１异响现象 发动机怠速时，气缸体上部发出一种清脆而有节奏的“”金属敲击声，冷车时响声明显，随着发动机温度上…     

叉车轮胎的非正常磨损及预防

叉车轮胎在使用中的非正常磨损一般有六种情况：一是胎冠中部超常磨损;二是胎冠两肩超常磨损;三是转向轮的胎冠内侧(或外侧)超常偏磨损;四是胎冠呈锯齿状磨损;五是胎冠呈波浪状或蝶片状磨损;六是胎冠局部磨损。主要表现为胎面磨损不均匀、帘布层之间脱层、帘线松散和折断及由此引起的胎体破裂。     

轮胎使用及旧轮胎翻新与新胎辨别方法

轮胎的合理使用:①高速行驶保持车距,避免不必要或经常地制动,减少对轮胎的损害。同时注意轮胎的花纹深度,接近磨平的轮胎因为和路面的摩擦减少,制动距离长,不要高速行驶。②经常在超负荷下使用,轮胎的使用寿命会减少20%～50%。同时错误的装载方式也会造成轮胎负载不均匀,影响个别轮胎负载过高,寿命降低。③经常检查轮胎的气压。气压过高与不足都会产生异形磨损、花纹沟底龟裂、帘线折断、帘布层脱层、轮胎爆破等损坏。如果要持续高速行驶,气压宜在标准气压上提高5%～10%。     

汽车悬架减振器结构传递异响的试验研究

针对某型轿车减振器异响的特点,设计并进行了减振器整车道路试验,以找出减振器产生异响的成因.为进一步确认异响产生的部位,以及探索在减振器试验台上实现对此种异响的检测方法,设计了减振器单体台架试验.该试验采用单频率正弦信号对异响减振器进行激励.试验结果表明,该轿车减振器异响为活塞杆异常振动激发车身振动,并辐射到车内的结构传...     

提高185/70SR13轿车子午线轮胎动平衡的合格率

轿车轮胎“动平衡合格率”是一项重要的技术经济指标。动平衡不合格的轮胎在高速行驶时，影响车轮泪直线行驶，容易发生交通事故；同时还会产生剧烈震动，致使车辆机件辰报和轮胎疲劳。德国大众汽车公司标准规定：“185／70SR13轿车子午线轮胎动平衡双面不得超过729（包括轮同）”．“上海大众”最新规定：“动平衡不合格的轮胎一律不准安装在桑塔纳轿车上使用。”动平衡合格率的高低，直接影响到轮胎配套厂的生存与发展。1．帕累特分析185／70SR13轿车子午线轮胎动平衡合格率的提高，涉及到轮胎各个部件本身的质量分布均匀状况并与其所处…     

汽车悬架用空气弹簧的开发与设计

中介绍的SYS300型空气弹簧为自由膜式空气弹簧，其主要部件是橡胶囊，它一般由内橡胶层，帘布层和外橡胶层以及成型钢丝圈硫化而成，密封方式采用压力自密封，帘线布是橡胶囊的主要承载部件，帘线角是空气弹簧设计中的一个重要参数，帘线角的不同选择会导致橡胶囊充气后最大外径有较大的变化，同时也会对胶囊强度即铺层应力造成较大的影响，非线性有限元数值分析技术，可为空气弹簧的设计提供一种较为可靠的手段。     

A study on the effect of different tyre imperfections on steering wheel vibration

Multibody dynamics and tyre models have made possible detailed analysis not only for ride and handling, but also for determining their effects on tyre nonuniformities. The aim of this paper is to analyse the steering wheel vibration, both shimmy and shake, excited by different tyre imperfections by using the commercial simulation package ADAMS/car 2005R2 and FTire. Different settings with respect to imperfection locations, amount, and the combined effects of defects have been studied. An interesting beat phenomenon is observed when all the wheels have imperfections. A procedure to determine the type of imperfections in the tyre from the results of the test rig has also been proposed.     

Time-optimal control of the race car: influence of a thermodynamic tyre model

The robustness of an existing numerical method for the time-optimal control of the race car is demonstrated through its application to a model of a Formula 1 car equipped with a simplified thermodynamic tyre model. The tyre model includes a temperature- and frequency-dependent model of road/tyre friction. A lumped parameter approach is used to model the thermodynamics of the various parts of the tyre such as the tread, carcass and inflation gas. The influence of tyre, track surface and ambient temperatures on time-optimal manoeuvring is presented.     

三缸机传动系扭振引起的车内低频轰鸣声问题研究

传动系统扭振引起的车内低频轰鸣声,一直是汽车NVH领域的难点和热点问题.针对某型三缸机中型多用途汽车的中油门加速,在1 400-2 000 r/min发动机转速时的车内低频轰鸣声问题,基于半消声室转鼓试验研究,运用相关性分析方法,锁定了传动系扭振为该问题的激励源,并通过传递路径分析,识别了前风挡玻璃与一阶空腔模态的受迫...     

Straight-ahead running of road vehicles – analytical formulae including full tyre characteristics

ABSTRACT

During straight-ahead running, the longitudinal axis of road vehicles, notably cars, is not parallel to road axis. This occurrence is general and is due both to road cross slope (road banking) and to tyre characteristics, particularly ply-steer and conicity. In order to describe such a phenomenon, the paper develops a new and relatively simple analytical model. Despite the model is linear, the solution which is provided is exact, since straight-ahead motion occurs with small angles and both the elastokinematics of suspension system and tyre characteristics can be modelled by linearised equations. The Handling Diagram theory is updated and completed by introducing the actual shifts of tyre characteristics. The validation of the analytical expressions is performed by using a MSC Adams^TM full model of a car. A subjective-objective experimental test campaign provides preliminary substantiation of the ability of the derived formulae to describe tyre performance. By means of the unreferenced analytical formulae developed in the paper, we allow, given the vehicle, the proper tyre design specification and vice-versa. In particular, a formula is given to make null the steering torque during straight-ahead driving. The derived analytical formulae may provide a sound understanding of the straight-ahead running of road vehicles.     

轮胎径向尺寸对加速行驶车外噪声的影响

为了准确获取轮胎径向尺寸变化对加速行驶车外噪声试验的影响,文章采用同一辆乘用车换装2种型号轮胎,依据GB1495—2002《汽车加速行驶车外噪声限值及测量方法》进行对比试验。结果显示,轮胎径向尺寸变化会对加速行驶车外噪声试验结果产生影响,并指出采用径向尺寸较小的轮胎,加速行驶车外噪声试验过程中汽车发动机转速越高,噪声试验最终结果也越大。文章建议将轮胎尺寸的差异列为车型判定的条件。     

燃料电池轿车车内噪声特性试验分析

在半自由场消声室内四轮转毂试验台上对燃料电池轿车进行了声振特性测试,采集了不同车速工况下车内噪声信号及运动部件的振动加速度信号。分析了不同车速工况下车内噪声的分布状况及主要频率成分。通过信号分析表明,车内噪声来源于驱动电机总成和燃料电池系统中的氢泵、风机,产生的噪声通过空气直接传到车内,同时引起车身板件振动并向车内辐射噪声。根据样车的结构特点提出了减振降噪措施。     

抗滑水轮胎技术的新发展

轮胎在湿路面上的行驶性能关系到汽车的安全性。阐述了国外开发的三种新型抗滑水轿车轮胎的设计思想，结构特点以及主要性能，介绍了提高轮胎在潮湿带水路面上行驶性能的新技术及其新发展，对开发国产高性能轿车轮肥具有现实的参考借鉴意义。     

汽车空调压缩机引起的车内噪声试验研究

针对某汽车空调用斜盘式压缩机在怠速工况下运转时引起的车内噪声的问题进行了试验研究，研究分为台架试验和整车试验两部分。通过试验，不仅了解了压缩机单机振动和噪声特性，而且对压缩机振动引起的车内噪声特性，以及影响车内噪声的机理也得到了一些有意义的初步结论。这些结论对于解决压缩机，乃至汽至汽车空调系统的减振降噪问题极具参考价值。     

Analysis of lateral tyre friction dynamics1

The tyre friction model is a key part of the overall multi-body tyre dynamics model. The LuGre dynamic tyre friction model is analytically linearised for pure cornering conditions. The linearised model parameters are conveniently expressed as functions of static curve slope parameters. The linearised lateral force and self-aligning torque submodels are described by equivalent mechanical systems. The linearised model and equivalent system parameters are analysed for different slip angle and wheel centre speed operating points. An example of the application of linearised tyre friction model to tyre vibration analysis is presented as well.     

Noise,vibration, harshness model of a rotating tyre

ABSTRACT

The tyre plays a fundamental role in the generation of acoustically perceptible driving noise and vibrations inside the vehicle. An essential part of these vibrations is induced by the road excitation and transferred via the tyre into the vehicle. There are two basic ways to study noise, vibration, harshness (NVH) behaviour: Simulations in time and frequency domains. Modelling the tyre transfer behaviour in frequency domain requires special attention to the rotation of the tyre. This paper shows the approach taken by the authors to include the transfer behaviour in the frequency range up to 250?Hz from geometric road excitations to resulting spindle forces in frequency domain. This paper validates the derived NVH tyre model by comparison with appropriate transient simulations of the base transient model.