Is disc braking better than drum braking? Why?

Braking forms are mainly divided into drum type and disc type. Their principle is that the fixed non-rotating part (brake shoe or caliper) presses the part that rotates with the wheel (brake drum or brake disc) with a certain force, thus forcing the wheel to brake. The so-called drum braking means that the part that rotates with the wheel is like a drum; The so-called disc brake means that the part that rotates with the wheel looks like a plate, so it is named like this.

First, the advantages of disc brake

The disc brake has good heat dissipation performance and the braking system responds quickly. Can do high-frequency braking action. Compared with drum brake, disc brake has simple structure and easy maintenance. Under the same size, the braking force of the drum brake is also greater because the contact area between the brake pad and the braking bone of the drum brake is larger. The water stability is good because the unit pressure of the brake wheel block on the disc is high. It's easy to squeeze the water out. At the same time, under the action of centrifugal force, it is easy to spin dry after being wet. Coupled with the wiping effect of the pad on the disk, it takes 1~2 times to return to normal after the water comes out.

Second, the characteristics of drum braking

Disc brakes are cheap and conform to the traditional design. For heavy vehicles, the durability of brake shoes is higher than that of disc brakes because the speed is generally not very high. Moreover, under the condition of obtaining the same braking force, the diameter of the brake drum of the drum brake device is much smaller than that of the disc brake device. Therefore, many heavy vehicles still use the 4-drum design. In short, drum brakes are softer and more durable, and the braking effect is certainly better than that of disc brakes. But the cost is very high, so many cars choose the front plate and the rear drum.

Third, the economic cost.

Drum brake was first used in braking system, and its manufacturing technology is relatively mature, so the cost is due to disc brake. The quality of disc brake disc needs to be improved, and the cost of brake caliper, piston and brake pad is not equal to that of drum brake.