Is the car wheel positioning related to the axle?

Automobiles have become an indispensable means of transportation for people in work and life in modern society. While it benefits mankind, it also brings problems such as traffic safety and environmental pollution. Since the car itself is a complex integrated system of light, machine and electricity, with the increase of driving distance and the continuation of use time, its technical status will inevitably change, with problems such as reduced power, poor economy and reduced safety. . Therefore, it is necessary to use various means to maintain the good technical status of the car. Among them, regular performance testing of the vehicle is a measure to control the running state of the vehicle axle. The detection of wheel positioning is one of the important detection contents. If the positioning deviation is too much after the vehicle is used for a long time, the direction of the steering will be heavy, trembling, deviation, misalignment, non-return or unilateral tire wear, wavy wear, Abnormal wear such as massive wear and partial wear. With the rapid development of modern automobile manufacturing and road transportation networks, the quality requirements for vehicle positioning are getting higher and higher. The traditional contact positioning method can not meet the requirements of on-line inspection of automobile manufacturing due to its complicated operation, time-consuming, labor-intensive and low working efficiency. Therefore, there is an urgent need to rely on modern multi-disciplinary technical research and manufacturing locators with fast speed, good accuracy, high reliability and low maintenance cost to achieve accurate detection of wheel positioning parameters. 

In order to ensure the steering stability of the car, the installation between the axle, the knuckle and the axle of the car has a certain relative position. This kind of installation with a certain relative position is called front wheel positioning. The front wheel positioning includes four contents: the main pin on the front axle of the car, the back tilt, the main pin inclination, the front wheel camber, and the front wheel toe. For the rear wheels on the two rear axle assemblies, there is also a relative position to the rear axle, called rear wheel positioning. Rear wheel positioning includes rear wheel camber and rear wheel toe. Front wheel positioning and rear wheel positioning are collectively referred to as four-wheel positioning. When the vehicle leaves the factory, the positioning angles of the front and rear axles are preset according to the design requirements. These positioning angles are used to jointly ensure the driving comfort and safety of the vehicle. However, after the vehicle has been driving for a period of time, these positioning angles may change due to traffic accidents, severe bumps caused by uneven roads, wear of chassis parts, replacement of chassis parts, tire replacement, etc. Once the positioning angle changes, it may cause failures such as abnormal tire wear, vehicle deviation, reduced safety, increased fuel consumption, accelerated wear of parts, and sinking of the steering wheel. Therefore, it is of great significance to improve the safety and economy of the car to carry out the four-wheel positioning parameter test to make it within a reasonable range. 

Foreign research on wheel positioning and detection technology was earlier, and corresponding detection and diagnosis equipment was developed in the 1950s, such as the United States, France, Germany, the Netherlands, Japan, and Italy. . China's research in this area started late, and the bench-type four-wheel locator was introduced in the 1960s. In the early 1980s, the Wuhan Automobile Research Institute successfully developed and put into production the GCD-I beam leveling front wheel locator, but It has a low degree of automation, complex measurement process, low accuracy and efficiency, and the instrument is not perfect. It can only measure the traditional four parameters: front axle toe, camber, kingpin inclination and kingpin backward.