I believe you will not be very familiar with the very conspicuous disc brake, but before the car disc brake system has not been popularized, disc brakes are mostly used on the wheels of trains. It is necessary to clamp the disc with calipers from both sides to make the disc brake more than tens of tons of trains. After the development of Automotive technology to high-performance vehicles, the disc brake system will be used at that time. Advanced technology has been introduced into sports cars, and even small cars have been equipped with four-wheel disc brakes, which is one of the examples to witness the popularization of high-tech.
There are also opposite disc brakes with double pistons. Fixed calipers directly clamp both sides of the disc. Not only can the braking force be evenly distributed, the reaction is faster, but also the rigidity is strong.
The operation of disc brake is very simple. The piston in the caliper is used to drive the disc to clamp the rotating disc. The pressure of the piston comes from the Pascal principle produced by the main brake pump. For the disc brakes of most original cars, when the piston on one side contacts the disc and pushes it to the disc, the opposite side of the disc will automatically push to the disc to achieve the clamping effect. The structure is simple, there is no need to adjust the clearance, and the left and right are almost synchronized. It is called "floating calipers".
Many rear disc brakes contain drum brakes for hand brakes, which are based on solid discs.
Although the floating calipers with single piston can propel the two sides of the disc are a great advantage, they also result in insufficient average and rigidity of the clamping force on the disc (the contact surface between the disc and the disc is insufficient, and the friction force is insufficient). They are suitable for general passenger cars, and if they are racing cars on the track, they may not be able to keep up with them. At speeds of more than 160 km/h, pistons will be installed on both sides of the calipers of the racing car to push the shield to the disc with balanced clamping force. The configuration of the opposite piston (four pistons, six pistons and even more commonly heard) can also improve the braking reaction speed.
In addition to the perforated surface, there are several kinds of ventilation rib design in the dish. Among them, the whirlwind design has good heat dissipation ability. If there are ducts, it will have better heat dissipation effect than other designs.
In order to maintain high efficiency of braking force, heat dissipation has become an important knowledge of the braking system. Heat transfer will gradually increase the temperature of the disc and the incoming shield, and overheating will cause the decline of material quality and lead to the decrease of braking force. Most of the structure of disc brake is exposed, which can take away heat energy by using the driving wind. Its heat dissipation ability is better than drum brake. Although there are few opportunities to drive fiercely, the temperature of disc will rise several Baidu on the mountain road or on the track. In order to prevent heat recession, vents will be opened in the disc to increase ventilation efficiency. It is suitable for front wheels with heavy braking load (although many models have been equipped with four-wheel disc brakes).
High temperature brake with high horsepower is no longer suitable for steel disc, so carbon fiber ceramic composite disc with better heat dissipation is adopted.