汽车四轮定位的探讨.doc

摘要　随着中国汽车市场的成长，汽车技术迅速发展并走向成熟，私家车数量的增加，行车安全性及舒适性的要求也随之增高。现今发动机和变速器的维修量逐渐减少，四轮定位及底盘的检测服务将成为汽车维修业的重要项目。车辆在出厂时，其悬架定位角度都是根据设计要求预先设定好的，用来保证车辆驾驶的舒适性和安全性。车辆在使用中，这些定位角度会由于悬架系统零件的磨损、路面颠簸、交通事故、更换相关零件以及更换轮胎等原因而发生变化。改变定位角度，就有可能产生轮胎异常磨损、油耗增加、转向沉重、转向盘不正或抖动、行车漂移、偏向行驶等现象。良好的四轮定位能够使车辆保持相对稳定的直线行驶，并且能转向轻便，减少轮胎与转向机构的磨损，降低油耗，增加车辆的高速稳定性能、操纵性能，减少驾驶疲劳，提高驾驶安全性能。那么汽车在设计时为什么要预先设定车轮定位角度呢？实际上，在绝大多数维修厂做四轮定位测量时采用的是静态测量方式。也就是说，在测量时汽车车体处于相对静止状态。由于汽车的自重、载重范围、用途、使用区域不同，各汽车悬架系统构造和软硬程度也有所不同。为了行驶的安全性、轮胎磨损最小化，汽车在运动（直行和转向）时，要保证车轮平面与车辆行进方向一致（直行时平行、转向时同心），且车轮相对于地面处于垂直状态。汽车在设计时，通过对样车的行进状态进行反复预算，计算出车辆在静态时的各个定位角度值区间，即我们所说的汽车四轮定位规范值。由于车辆设计不同，因此有的车轮定位角度可调，有的车轮定位角度不可调。做四轮定位就是通过四轮定位仪，检测出被测车辆的各车轮定位角度值是否符合原厂标准。如果不符合规范，可作随机调整。只有车辆的定位数据准确，它的操控性能、稳定性能才能达到最佳状态，轮胎的寿命才能达到最长。四轮定位的作用就是要使汽车保持稳定的直线行驶和转向轻便，并减少汽车在行驶中轮胎和转向机件的磨损。

【关键词】汽车 四轮定位 检测 调整 故障分析

 
Abstract With the growth of China's auto market, the rapid development of automotive technology and to mature, increase in the number of private cars, driving safety and comfort requirements also will be increased. Maintenance of the current engine and transmission was gradually reduced, wheel alignment and chassis testing services will be the automotive repair industry, an important part. Vehicle at the factory, the suspension orientation angle are pre-configured according to design requirements, to ensure that vehicles driving comfort and safety. Vehicles in use, the orientation angle due to wear of suspension parts, road bumps, traffic accidents, replacement parts and replacement tires and other related reasons to change. Change the orientation angle, it may produce abnormal tire wear, increased fuel consumption, steering heavy, the steering wheel is not correct, or jitter, lane drift and tend to travel and so on. Good wheel alignment can make the vehicle maintain a relatively stable straight, and can turn to light, reducing tire wear and steering, lower fuel consumption, increased vehicle speed stability, handling performance, reduce fatigue, improve driving safety. So why in the design of vehicle pre-set wheel alignment angle it? In fact, most of the repair station to do wheel alignment measurements using a static measurement. In other words, when the vehicle body measurements in a relatively quiescent state. As the car weight, load range, uses, use of regional differences, the construction and automotive suspension systems at different levels of hardness. For driving safety, to minimize tire wear, vehicle in motion (straight and turning), to ensure that the wheels of vehicles traveling the same direction plane (parallel to straight time, steering concentric), and the wheels relative to the ground in a vertical state. Car design, like cars moving through the state budget again, to calculate the vehicle positioning in a static point of view when the value of each interval, that is what we call the value of a car wheel alignment specifications. The vehicle designs, so some wheel alignment angle adjustable, and some wheel alignment angle is not adjustable. To do wheel alignment wheel alignment is through the detection of all the tested vehicle wheel alignment angle values are consistent with the original standards. If you do not meet specifications, can be randomly adjusted. Accurate vehicle location data only, its handling and stability in order to achieve the best condition to achieve the longest life of the tire. The role of wheel alignment is to make the cars drive a straight line stability and steering light and reduce the car is moving in the tire wear and steering parts.

Key words adjustment of automobile wheel alignment testing failure analysis

 
目  录
1 车轮定位几何 1
•1.1 主销纵倾角 1
•1.2 车轮外倾角 1
•1.3 车轮前束 1
•1.4 主销内倾角 2
2 四轮定位系统简介 4
•2.1 地沟式定位系统 4
•2.2 举升器式定位系统 4
3车轮定位几何的测量原理 6
•3.1车轮前束和推力角的测量原理 6
•3.2主销后倾角和主销内倾角的测量原理 7
•3.3 转向20°时前张角的测量原理 10
4汽车四轮定位测试系统的安装与使用 12
•4.1 做四轮定位时的注意事项 12
•4.2 汽车四轮定位的步骤 12
•4.3 汽车四轮定位仪的正确使用 13
•4.3.1 上车前的准备工作 13
4.3.2进行车轮定位 14
总结 18
参考文献 19
致谢 19