Dump semi-trailer refers to a semi-trailer whose carriage can automatically tip over at a certain angle during unloading. Its market coverage is relatively high. With the advantages of transportation efficiency and transportation cycle, it plays an irreplaceable role in the transportation of loose goods such as sand and gravel, soil, coal, etc.

Compared with ordinary semi-trailer, the operating conditions of dump semi-trailer are more complex. If the product quality is not up to standard, it is easy to have problems, most of which are cracks.

Specific manifestations of dump truck cracking:

1. Cracking of welds between turnover beam and web

During the use of dump semi-trailer, the torque is relatively large, especially for the lower wing plate. The torque acts on the overturning beam through the diagonal brace of the overturning beam, resulting in high stress at the welding point between the overturning beam and the web, and the weld is easy to crack.

2. Cracking of suspension rib plate

Generally speaking, the arc angle at the change of variable section of the suspension rib plate of the dump semi-trailer is small, so the stress is too concentrated. At the same time, the strength of the plate rib plate section is greatly reduced due to the existence of the weight reduction hole, so it is easy to fracture. Especially when the vehicle passes through complex road conditions, the web will crack due to torsion.

3. Cracking of suspension diagonal brace and suspension big brace

The suspension is an area with large torsion. Especially when the frame turns quickly, the lateral force on the tire will act on the frame through the axle, leaf spring, suspension, etc., so the torque on the frame is large, especially at the lower wing plate, which is more likely to twist and cause cracking of the inner and outer support plates.

4. Cracking of suspension diagonal brace

Some dump semi-trailer suspension upper webs are not reinforced by steel plate support, and the suspension diagonal brace is not welded with the connecting pipe. During the use of the vehicle, the torque borne by the suspension is very large, and the stress of the diagonal brace plate is too concentrated, resulting in the cracking of the suspension diagonal brace.

5. Cracking of reinforcing diagonal brace of subframe turnover beam

There are generally two reasons for the cracking of the diagonal brace of the subframe turnover beam: the longitudinal beam of the subframe is cross jointed with the turnover beam, and the strength is weak. When the vehicle is overturned for unloading, the turnover beam is deformed; If the front and rear cylinders are not synchronized when the dump truck is discharging, the subframe is prone to torsion cracking.

As for the reason for the cracking of the dump truck, the main problem is whether the design is reasonable and the production process is not up to standard.

Some manufacturers manufacture dump trucks according to the design idea of ordinary semi trailers. In fact, in addition to the general bearing force, the design of dump semi trailers should also comprehensively consider the stress conditions of different parts of the body, frame, suspension, etc. when the dump hydraulic support lifts goods. In addition, whether the material selection is standard, whether the welding seam is firm, and whether the selection of components is up to the standard are the key factors affecting the vehicle quality.

So, when choosing a car, what aspects should we choose?

The design shall be reasonable and the lightweight shall be appropriate. The chassis should be stable and the center of gravity should be relatively low. Of course, systematic planning should also be carried out in combination with load, cargo type, road conditions, driving habits, etc. Nowadays, the trend of trailer lightweight is prevailing, and the dump truck can also consider lightweight treatment in terms of materials, but due to the particularity of the operating conditions of the dump truck, we must not blindly sacrifice strength to pursue lightweight.

Pay attention to the selection of materials for vehicles. The steel can be divided into high-strength steel, manganese steel and ordinary steel. Different types of steel can be divided into different models. For example, high-strength steel can be divided into 700, 900, 980 and other models. Its durability will gradually increase with the increase of the model, but the weight of the car body will gradually decrease, and of course, the cost will also increase.

The production process needs to pass the standard. Nowadays, the production automation of large trailer plants is gradually popularized. Processes such as welding and painting have achieved automatic operation, and the processing quality has also been improved to a certain extent. Sand blasting and rust removal shall not be less, paint spraying shall be uniform, and electrophoresis coating is certainly better. Paint can also be divided into alkyd paint and polyurethane paint, the latter is more high-end.

The hydraulic lifting system should be stable, for example, the oil circuit design should be reasonable, the cylinder lifting should be synchronized, and so on. After all, the hydraulic system is the power source of dump truck tipping unloading, and the stable operation of the hydraulic system can ensure the normal unloading.

The key parts must be reliable. For example, there are many axle brands on the market, with a large difference in price, quality and performance. Try to choose brands with independent factories, customized production capacity, early launch, and market validation. These products are more reliable to use, and have more after-sales protection. Although the cost is relatively high, long-term use at one time can help owners reduce many subsequent unnecessary troubles.