I want to know whether the comprehensive performance of the automobile braking system is qualified

Whether the braking system is qualified or not needs to pass a professional test to be evaluated;

For example, one of the braking performance is when the vehicle speed reaches a certain level, the use of both feet brake, both hands release the steering wheel at the same time, when the car stops, measure the braking distance and check whether the car keeps sliding in a straight line when braking, this test needs a relatively spacious field, and the road surface (asphalt, cement), car weight (cooling water, gasoline weight, etc.), atmospheric temperature, wind speed, wind direction, driver weight, gear, speed have requirements, and carry a certain danger;

National standard requirements:

When the initial speed of a passenger car with no more than nine seats is 50km h, it does not exceed 19m;

Other total mass does not exceed the initial velocity of the car 50km h, not more than 21m;

For other cars, when the initial speed of the car train is 30km h, no more than 9m has tested an old Jetta car before, the braking distance has reached 17m, and there is a deviation phenomenon;

However, it was not strictly followed by standards at the time;

Remarks: The test is dangerous, do not imitate;

There are many conditions that affect the comprehensive performance of the automobile braking system, such as brake type drum brake, ventilated disc brake, disc brake... The width of the tires, the weight of the car ===, the assistance of electronic devices ====, the key is which car you want to know.

The stability evaluation index of automobile braking performance includes three aspects: braking efficiency, stability of braking efficiency and stability of braking direction

1. Braking deceleration speed refers to the change of braking time to the speed of the unit, which reflects the magnitude of ground power and is related to braking power and adhesion;

2. The greater the ground braking force of the vehicle, the greater the braking deceleration speed, and the shorter the braking distance, the ground power system first depends on the braking power, and is limited by the ground adhesion conditions;

3. Braking distance refers to the distance from the driver's right foot touching the brake pedal to the vehicle stopping at the specified speed in order to specify the pedal force of pressing the brake pedal.

Braking efficiency is the most important indicator of the braking performance of the car, and the main parameter to measure the braking efficiency of the car is the braking distance of the car per 100 kilometers, that is, the distance from the full braking of the car at a speed of 100 kilometers per hour to the stop of the car. We can also test it simply: on a wide field, good road adhesion and normal tire pressure are required.

We accelerate the car to more than 100 kilometers per hour, then let the car coast and slow down, and when the speed is reduced to 100 kilometers per hour, we press the brake pedal with all our might, and when the car comes to a complete stop, we measure the distance. In order to ensure the impartiality of the test, it is best to test it several times. The braking distance of the general car is excellent at 34 38 meters, 38 42 meters is good, 42 45 meters is qualified, and more than 45 meters means that the brakes of this car are too poor.

The brake performance of the automobile mainly refers to: braking efficiency (that is, braking distance and braking deceleration), the constancy of braking efficiency (thermal degradation resistance), and directional stability during braking.

What is the evaluation index of automobile braking performance What is the evaluation index of automobile braking performance The evaluation index of automobile braking performance stability includes three aspects: braking efficiency, stability of braking efficiency and high stability of braking direction: 1. Braking deceleration speed refers to the change of braking time to the speed of the unit, which reflects the size of the ground power and is related to braking power and adhesion; 2. The greater the ground braking force of the vehicle, the greater the braking deceleration speed, and the shorter the braking distance, the ground power system first depends on the braking power, and is limited by the ground attachment and erection conditions; 3. Braking distance refers to the distance from the driver's right foot touching the brake pedal to the vehicle stopping at the specified speed in order to specify the pedal force of pressing the brake pedal. @2019

Measuring the braking distance in 100 km: 100 km h braking distance is about 40 meters, 38 meters to 42 meters is enough! The longer the distance, the worse the braking performance, and more than 45 meters is not qualified.

At present, the Taiwan test method commonly used in domestic vehicle comprehensive performance test stations is simple, fast, safe and economical, but there are also some shortcomings. In view of this, if in the annual inspection, the vehicle braking performance test is not qualified, do not worry, the requirements of the national automobile braking safety standard, in addition to the braking power of the test bench, there is another indicator, is the speed of 50 kilometers per hour, the braking distance must be less than 20 meters.

Generally, whether the braking power performance of the car is qualified is measured by the braking distance of 100 kilometers: the braking distance of 100km h is about 40 meters, and 38 meters to 42 meters can be! The longer the distance, the worse the braking performance, and more than 45 meters is unqualified.

Automobile braking performance testing in accordance with the national standard, if the ratio of the total braking force of the automobile to the weight of the vehicle is greater than 60% when no-load and greater than 50% when fully loaded, the ratio of the braking force of the main bearing shaft to the axle load of the axle is greater than 60% when no-load and greater than 50% when fully loaded, and the braking performance of the tested vehicle is qualified.

At present, the test test method commonly used in domestic vehicle comprehensive performance testing stations is simple, rapid, safe and economical, but there are also some shortcomings. In view of this, if in the annual inspection, the vehicle braking performance is measured to be unqualified, do not worry, the national requirements for automobile braking safety, in addition to the bench test braking force, there is another indicator, that is, the speed of 50 kilometers per hour, the braking distance must be below 20 meters.

The use of road test method to test braking performance is indeed closer to the actual situation of driving. But this test method to a large area of open field, may not have a lot of vehicle testing station does not have this condition, on the contrary, the test has an advantage in this regard, it takes a short time, safe, affected by external factors is small, in addition, the test object of the test is the braking force, it can record the braking force of each wheel in the braking process, can accurately find out which link is the problem of the vehicle with poor braking performance.

The evaluation index of automobile braking performance stability includes three aspects: braking efficiency, the constancy of braking efficiency, and the directional stability during braking

1. Braking efficiency.

Braking efficiency refers to the ability of the car to quickly reduce its driving speed until it stops, or to maintain a certain speed and park on the ramp when going downhill, which is the most basic evaluation index of braking performance. Generally, it is evaluated by braking deceleration, braking force, braking distance, etc.

1. Braking deceleration.

It refers to the amount of change in the speed of the vehicle per unit time when braking. It reflects the magnitude of the braking force on the ground, which is related to the braking force and adhesion of the brakes.

2. Braking force.

1) Ground braking power.

2) Braking power.

3) The relationship between ground braking force, brake braking force and adhesion.

The greater the ground braking force of the car, the greater the braking deceleration and the shorter the braking distance; The braking force on the ground depends first on the braking force of the brakes, and at the same time is limited by the adhesion conditions on the ground. Therefore, sufficient braking power can only be obtained if the car has sufficient braking power and the ground can provide high adhesion.

3. Braking distance.

It refers to the distance made by the vehicle from the driver's right foot touching the brake pedal to the vehicle stopping when the vehicle is pressed the brake pedal with the specified pedal at the specified speed.

The main factors that affect the braking distance: the time the brake is in action, the maximum braking deceleration (determined by adhesion and brake braking force), and the braking speed. Therefore, timely maintenance of the vehicle can shorten the brake action time and stabilize the braking performance.

It mainly includes three aspects: braking efficiency, braking thermal degradation resistance and directional stability during braking.

The concepts of these two words are different.

Brake system safety wisdom includes technical unqualified: refers to the safety performance of the entire braking system does not meet the specified standards or requirements. The braking system is a crucial system in the vehicle to control the deceleration and stopping of the vehicle.

If the safety technology of the pre-production laughing system is not up to standard, it means that the system is designed, manufactured or maintained to be defective, which may cause the braking system to not work reliably and increase the risk of accidents for the driver and passengers while driving.

Brake failure: refers to a part or component of the braking system itself that does not meet the specified performance parameters or loses its normal function. For example, problems such as heavy wear of brake pads, leakage of brake fluid, and deformation of brake discs can all lead to poor brakes.

Unqualified braking may affect the braking effect of the vehicle, prolong the braking distance of the vehicle, and increase the risk of an accident.

The brake pedal of the car is under the steering wheel, and when the brake pedal is pressed, the brake bar is pressurized and transmitted to the brake pad on the brake drum to jam the brake wheel, so that the car slows down or stops running. The manual brake of the car is next to the gear shift and is connected to the brake bar. Bicycle brakes are also common, which are decelerated by rod brakes fixed to the frame or disc brakes.

The brakes are accomplished by the intense friction between the brake pads and the brake drums.

The principle of braking is to convert the kinetic energy of the car into heat energy and consume it, and the kinetic energy comes from the power provided by the engine, which needs to be provided by the work of fuel combustion, which means that if you step on the brakes once, it means that your gasoline will be wasted. Therefore, please remember the first rule: drive the car to brake as little as possible, and the brakes are only for comfort or in case of emergency.

Many brakes are emergency brakes as a last resort, so you must pay attention to the braking skills. There are two situations discussed here, one is the vehicle without the ABS anti-lock braking system, and the old vehicles are basically like this. When this kind of vehicle encounters emergency braking, if the braking force is too large, it may make the car tires lock (the tires do not rotate at all), we can often see two black brake marks that drag a long time on the road, which is the traces of friction between the tires and the ground when the car brakes without ABS, the tires will no longer rotate after the tires are locked due to emergency braking, but the huge inertia will make the tires of the car rub against the ground and continue to slide forward, The violent friction between the tire and the ground caused a black mark on the rubber particles that had been rubbed off on the tire.

At this time, if you force the direction, it will often have serious consequences such as deviation, side slippage, tail flicking, or even rollover out of control.

What are the evaluation indicators of automobile braking performance? What are the evaluation indicators of automobile braking performance? The dynamics of the car are mainly evaluated by three indicators:

The ability to accelerate a car, also known as the ability to react, has a great impact on the average speed of the car, especially for cars, which is more important for the acceleration time. It is often used to express the acceleration time of starting on the spot, taking the short and overtaking acceleration time. 3. The climbing ability of the car:

The maximum incline that a fully loaded car can climb. @2019