The braking system includes the service brake system, parking brake system, emergency brake system and auxiliary brake system.
The service brake system, also known as the foot brake, is the main braking device. It is divided into pneumatic brake system and hydraulic brake system according to the working medium. Generally, family cars and small cars use hydraulic brakes, while large buses and trucks use pneumatic brakes. When working, the pedal force is converted into wheel braking force through the master brake cylinder and slave cylinder to slow down and stop the car. There is also a dual-circuit hydraulic brake system to improve braking reliability and safety. Later, brake auxiliary systems such as anti-lock braking system ABS and electronic brake force distribution EBD were added.
The parking brake system, that is, the handbrake, is used to stabilize the vehicle after the vehicle is parked. Small cars have mechanical handbrakes and electronic handbrakes that achieve braking by controlling the rear wheel brake calipers. Large vehicles use pneumatic brakes and use strong spring parking brakes to release the air pressure of the compressed strong spring when parking to achieve braking.
Emergency brake system The parking brake system also assumes the emergency braking function. For example, the mechanical handbrake can be pulled up at a low speed to stop the car, and it needs to be pulled up slowly at a high speed. The electronic handbrake has a dynamic emergency braking function. When the brake fails, hold the switch and do not release it for emergency braking. For large vehicles with air brakes, the rear wheel strong spring parking brake can achieve emergency braking by using the air-off braking function.
The auxiliary braking system mainly includes engine braking, electric turbine deceleration, hydraulic turbine deceleration, exhaust braking, etc. The function is to increase the resistance of the transmission system to prevent the car from sliding too fast. For example, engine braking uses the resistance generated by the engine compression stroke to restrain the drive wheel.