Brake Pads: Core Components of Automotive Brake Systems and Analysis of Their Key Functions
In an automotive brake system, brake pads are the core executive components that directly realize the "deceleration and parking" function. Their performance directly determines the safety, stability, and comfort of vehicle braking. Whether it is a traditional fuel-powered vehicle or a new energy vehicle, brake pads play a crucial role as the "first line of defense for vehicle safety".
Core Function: Convert Kinetic Energy into Braking Force to Achieve Vehicle Deceleration and Parking
The essential function of brake pads is to convert the vehicle's kinetic energy (or potential energy) into heat energy through "frictional energy consumption", which is then dissipated, ultimately achieving vehicle deceleration or stopping. Specifically, this can be broken down into three key functions:
Directly Provide Braking Friction Force
When the driver steps on the brake pedal, the master brake cylinder pushes the brake fluid to transmit pressure, causing the piston in the brake caliper to squeeze the brake pads, making the friction material of the brake pads closely fit the brake disc (or brake drum). At this time, the sliding friction force generated between the friction material and the brake disc directly hinders the rotational movement of the wheels and forces the vehicle speed to decrease. This is the core "braking force generation" function of brake pads, and the magnitude of the friction force directly determines the length of the braking distance.
Stably Maintain Braking Performance
High-quality brake pads need to maintain a stable friction coefficient (a key indicator for measuring the magnitude of friction force) under different working conditions. For example, in high-temperature environments (such as continuous downhill driving, frequent braking), low-temperature environments (severe cold in winter), and humid environments (wading in rainy days), the fluctuation of the friction coefficient must be controlled within a safe range (the national standard GB 5763-2018 requires that the fluctuation does not exceed ±0.15 within the commonly used temperature range). If the friction coefficient drops sharply (a phenomenon known as "thermal fade"), it will cause the brake pedal to become soft and the braking distance to be significantly extended. The material formula design of brake pads (such as ceramic-based, low-metal-based, and semi-metal-based) is precisely aimed at suppressing thermal fade and ensuring stable braking performance.
Protect Key Components of the Brake System
The friction material of brake pads has the characteristic of "priority wear of soft materials". Compared with the harder brake disc (mostly made of cast iron or carbon fiber ceramic material), the brake pads will be worn first due to friction, thereby preventing the brake disc from being scratched, deformed, or cracked prematurely. At the same time, some brake pads also add a buffer layer or noise-reducing coating on the surface of the friction material to reduce abnormal noise (such as "squealing") during braking, improve driving comfort, and indirectly extend the service life of components such as the brake disc and brake caliper.
