Stopping Distance (mm): braking distance is one of the key parameters to measure the braking performance of a vehicle. It means the distance traveled by a vehicle from the start of braking to complete standstill when the vehicle is at a certain speed.It means that when the car is at a certain initial speed, the driver suddenly steps on itbrake pedalAt first, the distance traveled until the car came to a complete stop.The smaller the braking distance, the better the braking performance of the car.Because it is relatively intuitive, it has become a widely used indicator to evaluate braking efficiency.It is very important to know the braking distance correctly to ensure driving safety.
Chinese name
braking distance
Foreign name
StoppingDistance
Pronunciation
zhì dòng jù lí
Properties
Performance parameters of automobiles and motor vehicles
When the driver finds an emergency when the car is running, he can step downbrake pedalThe time before the braking action is called the reaction time, and the distance traveled by the vehicle within the reaction time is called the reaction distance.The length of this distance depends on the driving speed and reaction time. The higher the driving speed or the longer the reaction time, the longer the reaction distance.The reaction time is directly related to the driver's sensitivity and technical proficiency.The usual reaction time is 0.75 to 1 second. If the vehicle speed is 30 km/h, the reaction time is 1 second, and the reaction distance is 8.33 meters.
Braking distance refers to the distance from the driver stepping on the brake pedal to the complete stop of the car, when the tire appears obvious drag marks on the road.The length of braking distance is related to driving speed, braking force and adhesion coefficient.The higher the driving speed is, the longer the braking distance is. The driving speed is proportional to the square of the braking distance.The braking force refers to the force that blocks and forces the wheels to stop rotating after the driver steps on the brake pedal.The braking force is not only related to the stroke of stepping on the brake pedal, but also depends on the adhesion coefficient between the wheel and the ground. The smoother the road (such as icy road), the smaller the adhesion coefficient, and the longer the braking distance.The experiment proves that the braking distance is different when the motor vehicle runs on different roads at the same speed.For example, the braking distance is 5.9 meters when driving on the asphalt road at the speed of 30 km/h, 17.7 meters when driving on the floating snow road, and 35.4 meters when driving on the icy road.[1]
requirement
Announce
edit
The braking distance of various vehicle types at the specified initial speed is specified in the braking regulations of various countries.Vehicles exceeding this distance are unqualified vehicles and cannot run on the road. One of the most important indicators of the traffic management department when conducting vehicle inspection is the braking distance.The requirements for braking distance of vehicles (no-load) in China are:
When the initial speed of the passenger car with no more than nine seats is 50Km/h, it shall not exceed 19m;
otherTotal massWhen the initial speed of the vehicle not exceeding 4.5t is 50Km/h, it shall not exceed 21m;
For other vehicles, when the initial speed of the vehicle train is 30Km/h, it shall not exceed 9m.
The braking distance should be measured by professionals using special instruments. The old method of stepping on the brake and tugboat tire marks is neither scientific nor accurate.If the braking distance cannot meet the requirements, the braking system shall be overhauled in time to prevent accidents.[2]
influence factor
Announce
edit
The length of braking distance is an important factor to judge whether the braking system of this car works normally.Generally speaking, the heavier the car is, the more inertia it has, and the braking system it is equipped with should be more powerful. Of course, because some super sports cars are extremely powerful, the braking system is also first-class.It usually takes about 3 seconds for a family car to go from 100 km/h to standstill, but the distance is as long as 40 meters.According to the test, the braking distance of BMW 530i is the most prominent among the cars sold in the market, reaching 37.8 meters.Some cars need 46 meters from 100 km/h to 0. Although they meet the national safety standards, don't underestimate the gap of more than 8 meters. In a critical moment, a car with excellent braking distance can save your property and even your life.[3]
inspect
Announce
edit
There are many factors affecting the braking distance, such asBrake disc(hub), shoe, tire treadBrake fluidConsumption degree of, braking caused by frequent brakingThermal attenuation, the load of the car, etc.Brake discs (hubs) have a service life. When they are worn to a certain extent, they must be replaced. In normal use in urban driving, their service life is about 50000 km, and the service life of brake shoes is about 30000 km. However, the specific situation depends on the service condition of the vehicle owner. It is better to check every 10000 km.
Tires have a considerable impact on the braking distance. Each tire has a wear mark that must be replaced when exposed. In addition, the service life of the tire is only 3 years. Even new tires must be replaced after 3 years.[3]
Accident prevention methods
Announce
edit
stayskyline driveWhen driving on the road, it is not allowed to slip in neutral gear and brake frequently. It is necessary to slip in low gear and use the traction force of the engine to assist braking, otherwise the brake discs will overheat and lead to brake failure,Jingchang ExpresswayThe altitude of the tail section drops rapidly, and many large cars adopt neutral gear to save fuelCar slidingAnd brake frequently, and finally brake failure and turn into the valley, "Death Valley" is so named.Also, remember not to coast off. Without the vacuum assistance of the engine, the braking system is "disabled".
Many motorists like to drive on weekends. Before that, in order to ensure the safety of long-distance driving, you must thoroughly check your car, especially the working condition of the brake system.Many young friends choose to rent cars for an outing. You don't know about the car of the rental company. A thorough inspection of the whole car is more necessary. Otherwise, when we go to the countryside, the car will have problems. It is secondary to not finding a repair shop. The key is to spend money but not enjoy it.
The friend who just bought a new car doesn't have nothing to do with it. The first 1000 km of the new car is crucial. The braking system is also neededrunning-inIt is better not to have emergency braking.In order to run in smoothly, you need to step down the clutch before stepping on the brake, but this is only an emergency measure. After 1000 kilometers, in order to extend the life of the clutch, you still need to "brake first and then leave".[3]
