The vehicle braking system (brake) is a vital part of driving safety. The soon-to-be-implemented "GB7258-2017" has made new provisions for the configuration of disc brakes on the front wheels of dangerous goods transport vehicles, semi-trailers for dangerous goods transport, and three-axle fence and barn-type trailers.

Although the new "GB7258" has been implemented on January 1, 2018, different regulations have given a transition period. Starting from January 1, 2019, new semi-trailers for the transportation of dangerous goods are equipped with disc brakes (disc brakes). Starting from January 1, 2020, newly produced fence-type and warehouse-type semi-trailers are equipped with disc brakes (disc brakes).

—The requirement that all wheels of dangerous goods transport semi-trailers, three-axle fence type and warehouse-type semi-trailers should be equipped with disc brakes (see 7.2.6) has been added.

The original text of 7.2.6 is as follows: All wheels of automobiles (except tricycles), motorcycles (except tricycles), trailers (except trailers with a total mass of not more than 750kg) should be equipped with brakes. Among them, the front wheels of all special school buses and dangerous goods transport trucks and the front wheels of other passenger cars with a length of more than 9m, as well as all wheels of dangerous goods transport semi-trailers, three-axle railing type and warehouse grid type semi-trailers, shall be equipped with trays. Type brake.

Dangerous goods transporter front wheel and trailer equipped with disc brake

This rule directly stipulates that the front axles and trailer axles of dangerous goods transportation tractors, as well as the front axles of bicycles, must be equipped with disc brakes. Compared with the well-known drum brakes, many card friends are skeptical of disc brakes.

Compared with drum brakes, the working surface of disc brakes is flat and has heat dissipation on both sides. In addition, there is a ventilation cavity in the middle. The disc is easy to cool when rotating, and it is not prone to major deformation. The braking performance is more stable; while the drum brake is single-sided transmission Due to heat, the large temperature difference between the inside and outside causes the brake drum to deform easily. At the same time, after a long time of braking, the brake drum will be carbonized at high temperature due to high temperature of the brake pads, the friction coefficient will be reduced, and the braking efficiency will be weakened.

Dangerous cargo trucks have high requirements for consistency between the tractor and the trailer because the cargo they carry is either flammable, explosive, or highly toxic and corrosive. The auxiliary brakes such as speed gear cooperate with each other to ensure the stability of the whole vehicle braking and improve the safety factor of the dangerous goods transport vehicle.

Although there are no clear regulations on the rear axle brakes of tractors and bicycles for dangerous goods transportation, the best way to solve the consistency of braking time and braking effect of the entire vehicle is to use disc brakes for the entire vehicle. This regulation will be implemented for new production vehicles from January 2019.