According to the type, they can be divided into: disc
BRAKE PADS and drum brake shoes
Basic knowledge sharing of automobile brake pads-Youjia
Disc brake pads are generally used for small cars and cars
Basic knowledge sharing of automobile brake pads-Youjia
Drum brake shoes are mostly used for medium and large trucks and buses, and a small number of cars have drum-type rear brakes
Basic knowledge sharing of automobile brake pads-Youjia
Braking principle of brake pads: The way brake pads exert their braking effect comes from friction. The friction between the brake pads and the brake disc (or brake drum) is used to convert the kinetic energy of the vehicle's movement into friction heat energy, so that the car slows down/stops.
Fixed caliper disc brake: The characteristic is that there are two pistons
Floating caliper disc brake: The characteristic is that there is only one piston
Drum brake
What is the power of the friction material of the brake pad?
In December, it was winter, and two identical new cars were shipped at the same time. The first car was transported to Harbin, where ice and snow were flying. The car was parked outdoors at -30 degrees. The owner wanted the brake system to work perfectly, smooth, no noise, no vibration. The second car was sent to Hainan. The owner decided to take his family on vacation. The car was heavily loaded and driving on a country road. The brake temperature reached at least 650°C. He also expected good braking, smooth, no noise, no vibration, and emergency braking. Of course, they both wanted the brake pads to have a life of 80,000 km.
This is a big challenge!
The same friction material must be used in extremely cold and extremely hot conditions.
The driving speed will vary from 5km/h to 250km/h
The driving habits range from an old man to a sports driver, and the car has different loads.
Brake pad formula classification:
Friction materials for automotive brakes are classified according to materials:
Brake pads are divided into organic brake pads (cars, light rail, subways), sintered brake pads (high-speed rail), carbon-carbon brake pads (racing cars), etc.
Among them, organic (referring to resin as adhesive) automotive brake pads are divided into:
Asbestos-based: asbestos is used as a reinforcing material (reinforced fiber), which has been banned because asbestos materials are carcinogenic.
Non-asbestos metal type:
Semi-metal: iron content exceeds 50%
Low metal: iron content is less than 15%
Non-asbestos NAO type (called ceramic formula in the aftermarket): the biggest feature is that it does not contain iron
Traditional NAO: copper content is greater than 5%
Low copper NAO: copper content is less than 5%, greater than 0.5%
Copper-free NAO: copper content is less than 0.5%
1. Why are new brake pads and old discs "softer" when braking, and the braking distance is longer?
A: The surface of the old brake disc has many potholes and uneven places, while the surface of the new brake pad is very smooth, resulting in a smaller direct contact surface between the new pad and the old disc than before the replacement, which means a reduction in friction area, and the braking force is not as good as the original. This is why the new brake pad is softer after replacement. To solve this problem, the brake pad must be "skinned".
Usually we see repairmen test driving after replacing brake pads. During the test driving, they often brake suddenly several times. This is the simplest way to break the skin. Generally speaking, brake suddenly several times at 40 horsepower, then brake evenly at 80 horsepower to stop several times, and finally brake suddenly several times at 80 horsepower to stop. It's basically OK!
2. Brake pad noise
Answer: 1. Noise during initial installation: new pads and new discs, new pads and old discs, improper installation
2. Noise during use: Is there any foreign matter between the pads and discs
Is the friction material uneven and has hard particles
Continuous and frequent braking, high temperature causes surface sintering
3. Noise at the end of use: The brake pad alarm and the brake disc rub and emit an alarm
Abnormal noise caused by the friction between the brake pad steel back and the brake disc
Braking is completed by the caliper, pads, discs, and brake fluid system. Each factor may cause abnormal noise.
3. Brake pads are dusty?
Answer: Cause: Friction will cause dust to fall off, and friction materials are prone to static electricity
Phenomenon: Adsorbed on the wheel hub, black ash appears
Explanation: a. Brake materials with strong braking force are prone to static electricity (original Mercedes-Benz and BMW pads)
b. Adsorbing on the wheel hub is more environmentally friendly, and dust will not be scattered in the air
Dust falling from the brake pad has no effect on braking performance
DONGYING BORUI BRAKE SYSTEM CO.,LTD.
