SX4257NR324-heavy Truck Braking System Performance Optimize

Braking performance is reflected in a car an important part of overall quality, braking performance will directly affect the personal safety of vehicles in particular. Adjusting the brake force distribution is an important manifestation of brake first.Braking force can be provided directly from the brake system, but limited by the adhesion of the ground, when the braking force is greater than the surface adhesion on locking wheel the tires leave the ground drag and slip, to increase the braking distance, braking effect is not good.When the braking force is sufficient, the braking process may occur in three cases:1Front wheels locking are dragged first, and then the rear wheels locking.2Rear wheels locking are dragged first, and then the front wheels locking.3Front and rear wheels locking are dragged at the same time.Whether it is the front wheels or the rear wheels that are dragged first, the ground adhesion have not been fully utilized. Case1is stable condition, but it loss the steering capability when braking car. In case2, the rear axle may spin and drift,it is an unstable condition. Case3can avoid sliding of the rear axle, and front wheels loss steering ability only at the maximum intensity braking.Compared to the previous two cases, the ground adhesion is better utilized.The purpose is to adjust the braking force to achieve front and rear wheels locking simultaneously, to maximize the use of surface adhesion.The condition of front and rear wheels locking simultaneously is:the total of front and rear braking force is equal to the total ground adhesion, and front and rear braking force is equal to their respective ground adhesion. With front and rear locking simultaneously, front and rear braking force curve is called I curve (that is the ideal front and rear brake-force distribution curve).With front and rear axle fixed ratio of braking force, the braking force distribution line is a straight line, referred to as β line. At the intersection of β line and I curve,the adhesion coefficient is synchronization adhesion coefficient. For the car with fixed ratio of the front and rear axle braking force, only when it is running on the road with synchronous adhesion coefficient,it can be achieved with the front and rear wheels locking simultaneously. At present,the scheme in that the ratio of front and rear axle braking force is fixed is adopted in more domestic automobile, the synchronous adhesion coefficient is generally taken to be common for the value of the dry asphalt road surface,other road conditions can not be achieved in synchronization locking. In fact, because road conditions and vehicle load conditions of complexity, combined with the braking force due to inertia caused by axle load transfer, in most cases can not achieve synchronization locking theory, as long as close to simultaneously locking is considered ideal. Therefore, the braking force should be adjusted so that it tends to synchronize front and rear wheels from locking,or you have to resort earlier in the rear wheel locking unavoidably.In foreign,heavy truck technology is advanced, braking force distribution is more mature, we also introduced a number of European trucks. In their localization they are adjusted by a big degree.We also absorb some experience, to make them suitable for China’s national conditions.