Leaf spring is one of the most widely used elastic elements in automobile suspension, also known as leaf spring. It is composed of several alloy spring pieces of equal width but different length. It generally presents a symmetrical sectional structure, and the thickness of each spring piece can be the same or different.

Compared with other types of elastic elements, leaf spring has a simple structure, low cost of construction and maintenance, strong rigidity, and can bear loads. It can not only play the role of shock absorption and buffer, but also have a guiding function, transmitting forces and moments in all directions, and can also show linear or nonlinear elastic characteristics through certain combinations. Therefore, leaf spring is widely used in trucks, trailers and other freight vehicles, as well as in some passenger vehicles, off-road vehicles, vans and pickups.

In daily use, some car owners believe that the leaf springs are stacked together and should not be too fragile, so they neglect the standardized use and maintenance of the leaf springs. Some leaf springs are normal to break due to being used for too long and exceeding their service life, while others are damaged early in use due to improper use and maintenance.

Here, the Darong axle summarizes some common reasons that can easily cause damage to leaf springs:

1. Long term overloading of vehicles

Vehicle accessories are generally designed based on the load capacity of the vehicle, and leaf springs are no exception. If the vehicle frequently transports goods exceeding the rated load or there are often cases of partial loading, the leaf springs will experience excessive bending stress during use, greatly reducing their fatigue strength.

Therefore, in the daily use of vehicles, it is essential to extend the service life of leaf springs through compliant and legal transportation and uniform loading. If the vehicle is often in a heavy or biased state, it is necessary to consider modifying the original vehicle with leaf springs to enhance their load-bearing capacity and extend their service life.

2. Driving speed too fast

When the driving speed of the vehicle is too high, the inertia of the vehicle body and goods will increase, especially on the rough road conditions. Too fast speed will lead to accelerated fatigue of the leaf spring, which will inevitably accelerate the damage of the leaf spring in the long run.

Developing good driving habits, appropriately controlling driving speed, and maintaining different economic speeds for vehicles based on different road conditions not only ensures driving safety, but also saves fuel and reduces component wear and tear.

3. Excessive bending speed

When a vehicle passes through a turning section, it will generate outward centrifugal force, and the load pressure of the outer leaf spring will be stronger than on a straight section. The faster the vehicle speed, the greater the load borne by the leaf spring, which is more likely to cause damage to the leaf spring.

It is recommended that car owners slow down when turning, as this is not only safe but also reduces the wear and tear of vehicle accessories and faults. It can also protect goods, reduce damage, and improve operational profits.

4. Frequent emergency braking

Frequent emergency braking is also one of the reasons for premature damage to the leaf spring. When the vehicle brakes urgently, the body and cargo will continue to move forward under the inertia, causing excessive bending and tensile stress to the front leaf spring. Once the stress exceeds its range, it may cause the leaf spring to break and damage.

It is recommended that car owners develop a habit of anticipatory driving, do not drive too fast in normal times, and apply oil brakes early. If conditions permit, auxiliary braking devices can be used in conjunction.

5. Poor lubrication of the spring

The leaf spring also needs to be well lubricated. When the leaf spring undergoes bending deformation under stress load, there will be squeezing, stretching, and friction between adjacent springs. The two friction surfaces will generate forces in two different directions, causing the temperature of the leaf spring to rise and surface damage to occur. As the load increases, the friction force also increases. Once the stress concentration point reaches the fatigue limit, single or multilateral fracture will occur.

When installing the leaf spring, it is necessary to evenly apply lubricating grease on both sides of the spring, and pay more attention to maintenance and regular lubrication. This not only prevents the spring surface from being pulled, helps the spring dissipate heat and cool down, but also reduces abnormal noise, allows the leaf spring to cope with changes in friction coefficient more calmly, and reduces the possibility of spring fracture. In addition, it can also reduce the erosion of dust, soil, and rainwater on the spring blades and prevent rusting.

In addition, pay more attention to the fastening of riding bolts and central bolts during maintenance to avoid damage to the leaf spring caused by bolt looseness. The lifting lug must be greased, and the upper limit of auxiliary steel also needs to be greased.

If one or several springs are replaced separately, in order to reduce or avoid inconsistent strength between the new and old springs, gaps after installation, uneven force on the springs, and increased wear of the springs, it is also necessary to adjust the old springs appropriately.

The most important thing is to try to choose leaf spring produced by regular manufacturers. After all, it is related to driving safety. You should be careful when selecting products. If the quality of products is unqualified, no amount of follow-up and meticulous maintenance can change their inherent shortcomings. The leaf springs sold by Darong Group are specially designed and manufactured for freight vehicles, using silicon manganese spring steel and adding high-strength heat treatment process. The strength, elasticity, and hardenability are stable and reliable, and the surface is treated with rust prevention, isolation, moisture resistance, oxidation resistance, and corrosion resistance, extending the service life and improving protection.