Why do they say disc brakes are better?

2019-03-14

Why do they say disc brakes are better?

Disc brake is also known as disc brake, as the name suggests is to take its shape. The brake disc is made of alloy steel and fixed to the wheel, which rotates with it. Nowadays, most of the household cars use disc brakes. Do you know the advantages and disadvantages of disc brakes?


Advantages of disc brakes


1. The braking torque has nothing to do with the forward and backward running of the car.


2. Good thermal stability. Because the size of the brake friction liner is not long, the area of its working surface is only 12% ~ 6% of the area of the brake disc, so the heat dissipation is better.


3. The thermal expansion of the brake disc will not cause the travel loss of the brake pedal as the thermal expansion of the brake drum, which also simplifies the design of the automatic clearance adjustment device.


4. Good water stability. Because the brake pad for disc unit pressure is high, easy to squeeze out the water, after touching water in under the action of centrifugal force at the same time also is easy to get rid of, coupled with the liner for disk wiping effect, therefore, only after the water by the primary and secondary braking can be back to normal, and drum brakes is required to pass through more than ten times braking can resume normal braking efficiency.


5, disc type friction liner is easier to replace than drum type friction liner after wear, the structure is also simple, easy maintenance.


6. The clearance between the brake disc and the friction liner is small (0.05 ~ 0.15mm), which shortens the operating time of the piston of the oil cylinder and increases the force transmission ratio of the braking driving mechanism.


Disadvantages of disc brakes


1, brake and brake pipe manufacturing requirements are high, the friction of the loss of large, expensive cost.


2, due to the small area of the friction sheet, relative to the friction of the working face is also small, the need for high brake hydraulic, must have a booster device in order to use the vehicle, the general use of servo device.


3, the brake is relatively rough. Two friction disks with friction liner can slide back and forth on the spline shaft, which is the rotating part of the brake. When braking, it can stop the vehicle in a very short time. Plus the pressure plate on the ball groove inclination can not be infinite, so the brake is not smooth.


Today, disc brakes have been widely used in household vehicles, most of the wheels; A few are used only for the front wheel brake, with the rear wheel drum brake. In addition, disc brakes are gradually adopted in new models and high-end models.