The working principle of brake is mainly from friction, the use of brake pads and brake disc (drum) and tires and the ground friction, the kinetic energy of the vehicle will be converted into the heat energy after friction, the car will stop. A good and efficient braking system must provide stable, sufficient and controllable braking force, and have good hydraulic transmission and heat dissipation capacity to ensure that the force exerted by the driver from the brake pedal can be fully and effectively transmitted to the main pump and the sub-pumps, and avoid hydraulic failure and brake decay caused by high heat. There are disc brakes and drum brakes, but in addition to the cost advantage, drum brakes are far less efficient than disc brakes.
friction
"Friction" refers to the resistance of motion between the contact surfaces of two objects in relative motion. The size of the friction force (F) is proportional to the product of the friction coefficient (μ) and the vertical positive pressure (N) on the friction force surface, expressed by the physical formula: F=μN. For the brake system: (μ) refers to the friction coefficient between the brake pad and the brake disc, and N is the Pedal Force exerted by the brake caliper piston on the brake pad. The greater the friction coefficient produced by the greater the friction, but the friction coefficient between the brake pad and the disc will change because of the high heat produced by the friction, that is to say, the friction coefficient (μ) is changed with the temperature, each kind of brake pad because of different materials and different friction coefficient curve, so different brake pads will have different optimal working temperature, And the applicable working temperature range, this is everyone must know when buying brake pads.
Transfer of braking force
The Force exerted by the brake caliper piston on the brake pad is called Pedal Force. After the force of the driver stepping on the brake pedal is amplified by the lever of the pedal mechanism, the force is amplified by the vacuum power boost using the principle of vacuum pressure difference to push the brake master pump. The liquid pressure issued by the brake master pump utilizes the liquid incompressible power transmission effect, which is transmitted to each sub-pump through the brake tubing, and the "PASCAL principle" is used to amplify the pressure and push the piston of the sub-pump to exert force on the brake pad. Pascal's Law refers to the fact that liquid pressure is the same everywhere in a closed container.
The pressure is obtained by dividing the applied force by the stressed area. When the pressure is equal, we can achieve the effect of power amplification by changing the proportion of the applied and stressed area (P1=F1/A1=F2/A2=P2). For braking systems, the ratio of the total pump to the sub-pump pressure is the ratio of the piston area of the total pump to the piston area of the sub-pump.
