With the continuous development of domestic transportation industry, the requirements for vehicle production technology are becoming more and more strict. According to GB7258, dangerous goods transport vehicles, three axle rail cars and three axle warehouse grid cars must be equipped with disc brakes. Many trailer manufacturers said that if the trailer is required to be equipped with disc brake, the main vehicle must be equipped with hydraulic retarder.

This is because although the braking reaction speed, heat dissipation, heat attenuation resistance and water attenuation resistance of the disc brake are better than the drum brake, the braking force is small, which can not meet the braking requirements of medium and heavy trailers or vehicles in the process of long downhill. In addition, the disc brake can not use the water shower device to cool down, otherwise the brake disc will crack and affect the driving safety.

Hydraulic retarder is a kind of vehicle retarder that reduces the driving speed of vehicles through hydraulic device, also known as hydraulic retarder. It can realize deceleration braking under non emergency braking that can be predicted in advance, such as long downhill, instead of stepping on the brake. Therefore, it can greatly reduce the use of brake and avoid safety problems such as brake failure caused by long-term braking.

As for the advantages of hydraulic retarder, it is also very obvious:

1. Braking is safer. The hydraulic retarder has the function of constant speed control. 90% of the braking is carried out through the wear-free state during the driving of the vehicle, which can maximally ensure that the braking system is in the cold state and reduce the braking failure caused by braking overheating.

2. Braking is more stable. The hydraulic retarder has large braking torque, stable braking without impact, and keeps the vehicle speed stable.

3. Prolong the service life of friction plate and tire. After installing the hydraulic retarder, it can reduce the friction loss of the friction plate and tire, prolong its service life, reduce the replacement frequency and save the cost of comprehensive vehicles.

4. Reduce the dead weight of the vehicle. Compared with the general drenching device of drum brake, the liquid buffer has smaller volume and lighter weight, which can reduce the dead weight of the vehicle and let the owner load more goods.

In fact, the Ministry of Communications issued relevant regulations in the first two years, according to JT / t1178 2. It is required that from September 1, 2020, newly produced tractors need to be equipped with hydraulic retarders or other auxiliary braking devices. It can be seen that Trailer disc brake + hydraulic brake may become a general trend of the industry.

Although the combination of disc brake and hydraulic brake is more worry-free and safer, in practice, many car owners are still unwilling to install hydraulic brake. The reasons are as follows:

1. Liquid retarder is expensive. Under normal circumstances, the price for the owner to install the liquid buffer is about 10000 yuan. If it is better, it can even reach about 30000 yuan. If the conductor installs the liquid buffer when selling the car, the cost is higher, which is not a small expense for the owners.

2. It is considered that the cost performance of liquid retarder is not high. In the concept of many car owners, the hydraulic buffer is specially developed for long downhill or steep mountain routes. There are no steep mountain routes for their own transportation, so they feel that the cost performance is not high after installation. It's not. Under many road conditions, such as toll stations, traffic lights or traffic jams, the hydraulic brake can play the function of predictive braking and deceleration, not just on mountain roads.

3. There is no long-term return. Although the installation price of the liquid buffer is indeed very high, the long-term return rate is relatively high. Compared with the water drenching device, the liquid buffer can weigh about 900 kg and 1500 kg. These are used for loading, and the extra freight is also considerable. In addition, the watering device needs to add water, and the average cost of adding water is about 5000 a year. After using liquid buffer, the loss of tire and friction plate can also be reduced. In the long run, the cost recovery is relatively fast.

Based on the above conditions, whether in terms of economic benefits or safety performance, the combination of hydraulic buffer + disc brake has great advantages, especially the stable braking effect. Of course, in order to give full play to the advantages of hydraulic retarder, it also needs to be matched with disc brakes with higher cost performance. Darong disc axle adopts domestic advanced "one-piece" heat treatment molding technology, combined with medium frequency quenching treatment, which improves the bending, torsion and deformation resistance. At the same time, it takes into account the lightweight design, which is about 15% less than traditional products, which can fully help car owners save energy, reduce consumption and improve comprehensive operating income.