Leaf spring suspension and air suspension are usually used in trucks. The most commonly seen truck suspension is leaf spring suspension because of its simple structure, low cost and reliable operation. However, since January 1, 2020, the newly produced and licensed three axle rail plate and cage type semi-trailer will be compulsorily installed with disc brake and air suspension. What are the advantages of disc brake and air suspension?
1、 First, air suspension
Air suspension is commonly said to replace steel plate damping with air bag, and control the charging and discharging of compressed air in the air bag through the control system, so as to realize the adjustment of vehicle bearing capacity and height. Vehicles equipped with air suspension are generally equipped with a controller under the driver's seat. Compared with the traditional leaf spring suspension, the air suspension can keep the chassis height unchanged, the natural frequency almost unchanged, and the vehicle center of gravity almost unchanged when driving.
Therefore, it has good comfort and safety, which can effectively protect goods, reduce the transport loss rate of goods during transportation, and also reduce the impact of vehicles on the road. The airbag can be adjusted by the controller to improve loading and unloading efficiency, reduce fuel consumption, reduce tire wear, etc. At the same time, the air suspension also has the characteristics of smaller space and lighter weight.
The tractor equipped with air suspension can be quickly uncoupled and hitched by adjusting the height of the air bag during the throw off and hitching transportation, which improves the transportation efficiency. In addition, when the vehicle docks with the loading platform, the air suspension can more conveniently adjust the chassis height, so as to realize the rapid loading and unloading of goods.
However, because the air bag suspension of the trailer is affected by the air circuit of the trailer, when the vehicle is parked or backed up for braking, due to the inertia factor of the vehicle, the rear of the vehicle will stretch upward at the moment of braking. When the handbrake is applied at the same time, the rear of the vehicle will not fall back. The height control valve is in the exhaust state at this time, and the air pressure of the air bag will be discharged. When the brake is released again, The whole vehicle will fall instantly or cause airbag wrinkles.
Therefore, for trailers equipped with airbag suspension, when parking or backing up, the vehicle shall be slowly stopped and then the handbrake shall be pulled up.
2、 Let's talk about disc brake
Disc brake is officially called disc brake. In structure, it is mainly divided into two parts: brake disc and brake pad. The brake disc rotates with the wheel. When decelerating, the brake pad clamps the brake disc to decelerate the wheel. Thanks to its structural advantages, it is not easy for the brake to fade. It can also ensure the deceleration effect under high temperature, which will undoubtedly improve the driving safety.
The fit clearance between the brake pad and the brake disc of the disc brake is very small, and the piston only needs a small stroke to generate braking force. Therefore, the brake response speed of the disc brake is faster than that of the drum brake, and it can complete high-frequency braking actions. The effect is better with the ABS anti lock brake system or EBS system.
However, if the trailer is equipped with disc brake, the tractor shall be equipped with hydraulic retarder. Finally, it should be noted that the brake disc may be damaged under severe working conditions because the disc brake disc is exposed. Therefore, if the brake disc is transported in a gravel plant, a mine or other environment for a long time, it is necessary to check the brake disc.
