The braking effect on automobiles can only be caused by external forces acting on automobiles in opposite directions to the driving direction of automobiles. The magnitude of these external forces is random and uncontrollable. Therefore, a series of special devices must be installed on automobiles to achieve the above functions.
Vehicle braking system refers to the installation of special braking mechanism on the vehicle in order to ensure the safe driving of the vehicle and improve the average speed of the vehicle. Generally speaking, the automobile brake system consists of two sets of independent devices, the driving brake system and the parking brake system. The driving brake device is operated by the driver's foot, so it is also called foot brake device. Parking brake device is operated by the driver by hand, so it is also called hand brake device.
The function of the driving brake is to slow down the moving car or stop it in the shortest distance. The function of the parking brake is to keep the cars parked on various roads still. However, sometimes in emergencies, two kinds of brake devices can be used at the same time to increase the effect of vehicle braking. Long-term and frequent braking will lead to overheating of braking devices for some special purpose vehicles and those often driving in mountainous areas. Therefore, various types of auxiliary braking devices are often added to these vehicles in order to stabilize vehicle speed during downhill.
According to the braking energy situation, the braking system can also be divided into three kinds: manpower braking system, power braking system and servo braking system. Manpower braking system uses driver's physical strength as braking energy, power braking system uses air pressure or hydraulic pressure transformed by engine power as braking energy, and servo braking system uses both manpower and engine power as braking energy. In addition, according to the transmission mode of braking energy, braking system can be divided into mechanical, hydraulic, pneumatic and electromagnetic.
In all kinds of automobile brake systems, brake is a component of automobile brake system to produce force to prevent the movement or trend of the vehicle. At present, all kinds of brakes used in automobiles are friction brakes. That is to say, the braking moment that prevents the movement of automobiles comes from the friction between fixed components and rotating working surfaces.
