Drum brake or disc brake for truck?

What kind of drum brake and disc brake is better? Since GB7258 was introduced, the discussion on this issue seems to have gone on forever. Many owners question whether it is necessary to force the installation of all trailer disc axle on the triaxial fence plate and triaxial warehouse grid semi-trailer.

Objectively speaking, in the total quantity of commercial vehicles in China, three-axle railboard and three-axle warehouse grid semi-trailer account for a relatively high proportion, and the goods transported by them are generally low value-added products. Therefore, many owners carry out transportation according to the upper load limit, and the situation of overload is relatively more. In addition, the price of this kind of vehicle is low, the technical safety configuration is relatively not high, forcing these vehicles to use disc brake and air bag suspension, to a certain extent can reduce the phenomenon of overload, improve the safety factor.

So why is the disc axle mandatory?

Disc axles are known to have less braking force than drum axles. Although the brake principle of disc axle and drum axle is similar, through the brake pad friction to slow down the vehicle, but the disc brake is through the caliper clamp brake disc, so that the brake pad inside the caliper and brake disc friction; Drum brake is not the same, it is through the top of the brake pad, so that the inner wall of the brake drum friction, friction area is larger, greater friction, braking force is naturally larger.

If the drum axle has more braking power, why don't you see it on high-end cars? In fact, it is also because of the structure of drum axle, although it gives it the advantage of braking force, but also produces some congenital shortcomings.

Such as poor heat dissipation. Brake pad and brake drum friction braking, will inevitably produce a lot of heat energy, at this time due to 360 degrees no dead Angle wrapped brake drum, resulting in heat dissipation.

If the brake drum and brake pad are in a high temperature state for a long time, the braking effect is easy to be affected, there are two main reasons: the brake drum and brake pad in a high temperature state hardness and other material performance thermal attenuation, affecting the friction brake; Secondly, under the principle of thermal expansion and cold contraction, the distance between the brake drum and the brake pad increases, resulting in insufficient fit degree between the brake pad and the brake drum during braking. In addition, the brake drum overheating also easily lead to smoke and even fire phenomenon, for driving safety is very unfavorable.

Therefore, the drum brake master will basically be equipped with water shower device, through the water to cool the brake drum.

However, water cooling is also a problem, after all, the brake drum is like a basin shape, the most easy water, once accidentally into the water, there will be brake drum, affect the braking effect is not said, but also may lead to tire lock, even if fortunately did not produce any serious consequences, long-term soak water is not clean up also easily lead to brake drum rust, the brake system is basically abandoned. This is also another shortcoming of the drum brake, in the rainstorm, the situation of puddles, need to be very careful.

For the northern region, the winter temperature is low, if the vehicle use water sprinkling device, water on the road is easy to produce ice phenomenon, affect traffic safety, therefore, many sections are not allowed to use water sprinkling device in winter.

In addition to poor heat dissipation and easy water, drum brake also has a big disadvantage, which also starts from its braking force. The use of drum axle vehicles, tires need to often brake adjustment, because it can not automatically adjust, if not adjusted for a long time, easy to lead to uneven distribution of the tire braking force, some because of the adjustment problem of excessive wear brake pad will lead to braking force is not unified, once there is a brake easy to lead to sideslip, offset or even out of control, very dangerous.

In addition, the drum brake brake response time is slower than the disc brake. When the owner steps on the brake, the drum brake needs to go through several mechanical transmission devices to push the brake pad to brake, but the disc brake can immediately drive the brake pad, friction brake. It is also because of the slow brake response of the drum brake, many auxiliary braking devices such as ABS, EBS can not play the maximum effect, or even counterproductive.

If replaced with a disc brake, there is no such trouble, heat dissipation performance is far ahead, after all, a big metal disk, exposed outside, the speed of the high minutes of natural cooling, water is not exist, vertical metal disk, water storage is impossible, wading through one or two braking, performance can be immediately restored.

For criticism, is the brake force of the disc brake is small, especially for the frequent transportation of heavy goods, or often run mountain road vehicles, installation trailer disc axle can realize the brake smoothly?

Actually, it can, as long as there are auxiliary braking devices, such as the main car hydraulic retarder. Hydraulic retarder light weight, large braking torque and soft braking, smooth, no impact, can also be a long time high-power braking, no thermal decay phenomenon, can make up for the disc brake on the shortage of braking power, but also can greatly reduce the disc brake wear, ensure driving safety. Relevant people introduce, in the legal nuclear load limit, the vehicle with hydraulic retarder in continuous long downhill, even if you do not brake, also can ensure the vehicle's speed is stable, but if it is overloaded it is very dangerous.

As mentioned above, ABS and EBS can also be used with disc axle, which can prevent wheel locking in the case of emergency braking, so that the vehicle can stop smoothly within the shortest braking distance. This is why the relevant departments promote disc axles.

Of course, trailer disc axle effect is not good, also depends on the owner of the axle quality and performance of the standard, if it is some shoddy products, once in heavy load or bumpy road conditions, the axle may not withstand pressure problems or even fracture. DARO disc axle is developed and manufactured by DARO Group, the first mass production of integrated axle enterprise in Liangshan special Vehicle production base. The shaft body and shaft head are polished and formed on the same high-strength alloy steel pipe, which is superior to the welded shaft head in heavy-duty performance. Fifteen production processes, such as hot spinning rolling at 1300℃, intermediate frequency quenching at 865℃, heat preservation treatment at 480℃ and precision grinding of CNC machine tools, are strictly in line with industry standards. With online and offline double quality inspection, product quality is strictly up to standard, fully meeting users' needs.