Understand the introduction and function of Spring post assy

Introduction to Spring post assy

Spring post assy

The truck suspension system spring is an elastic element in the truck suspension system, which makes the elastic connection between the axle and the frame or body, bears and transmits the vertical load, and alleviates and suppresses the impact caused by uneven roads.

Truck suspension system is the general term for all power transmission connection devices between the frame (or load-bearing body) and the axle (or wheels). The main function of the truck suspension system is to transmit the vertical reaction force (support force), longitudinal reaction force (driving force and braking force) and lateral reaction force acting on the wheels of the road surface and the moment formed by these reaction forces to the frame (Or load-bearing body) to ensure the normal driving of the car.

The elastic element makes the truck suspension system and the axle make an elastic connection, bears and transmits the vertical load, alleviates and suppresses the impact caused by the uneven road; the guide device is used to transmit the longitudinal force, the lateral force and its moment, and ensure the wheels Relative to the frame or body, there is a certain law of motion; the shock absorber is used to accelerate the attenuation of vibration and limit the vibration of the body and wheels. It can be seen that the above three components play the role of buffering, guiding and damping respectively, and the three jointly play the role of common force transmission. In order to prevent excessive lateral inclination of the body when driving or turning on uneven roads, some cars are also equipped with auxiliary elastic elements-lateral stabilizers and balance bars.

The elastic elements used in common truck suspension systems mainly include steel spring post assy, coil springs, torsion bar springs, air springs and rubber springs.

Steel plate Spring post assy

Steel plate Spring post assy is the most widely used elastic element in truck suspension systems. It is an elastic beam of approximately equal strength, which is composed of several alloy spring sheets of equal width but unequal length (the thickness can be equal or unequal).

The first piece (the longest piece) of the spring post assy of steel plate is called the main piece. The two ends of the spring post assy are bent into rolling ears, and bushings made of bronze or plastic, rubber, powder metallurgy, etc. are installed in it, so that they can be fixed with spring pins. A hinge connection is formed on the bracket or ear seat on the frame. The middle part of the steel spring post assy is generally fixed on the axle with U-shaped bolts.

The main film roll ears are severely stressed, which is a weak point. In order to improve the force of the main film rolling ears, the end of the second sheet is often also bent into rolling ears and wrapped around the main film rolling ears, which is called wrapping ears. In order to make it possible for each piece to slide relatively when the spring is deformed, a large gap is left between the main piece rolling ears and the second piece wrapping ears. The spring post assy steel plate in some suspensions is not made into curling ears at both ends, but uses other support connections.

When the steel plate Spring post assy deforms under load, friction occurs between the plates due to relative sliding, which can promote the attenuation of frame vibration. The dry friction between the individual plates will transmit the impact of the wheels to the frame to a large extent, that is, it reduces the ability of the suspension to mitigate the impact and accelerates the wear of the spring plates, which is unfavorable. In order to reduce the wear of the friction plate, when the spring post assy is installed on the steel plate, a thicker lubricant (graphite grease) must be applied between the plates, and regular maintenance should be carried out. In order to store grease for a long time during use and prevent contamination, sometimes steel plate Spring post assy is installed in the sheath.

In recent years, more and more automobiles at home and abroad have adopted variable-section steel Spring post assy, which is composed of a single piece or 2~3 pieces of spring with variable thickness section.

The cross-sectional size of the spring sheet changes along the length direction, and the sheet width remains unchanged. This kind of small-piece variable cross-section steel plate Spring post assy overcomes the shortcomings of multi-piece steel plate Spring post assy of high quality and poor performance (due to the existence of friction between the plates, it affects the smoothness of the car). According to statistics, when the life of the two springs is equal, a few pieces of variable cross-section steel spring post assy can reduce the mass by 40%~50%. Therefore, this kind of spring is very beneficial to the realization of vehicle weight reduction, energy saving, and saving alloy spring steel materials, so it is increasingly widely used.

Spiral Spring post assy

Spiral Spring post assy is widely used in independent truck suspension systems, especially front wheel independent truck suspension systems. However, in the rear wheel non-independent truck suspension system of some cars, the elastic element also uses spiral Spring post assy. Spiral Spring post assy and steel plate Spring post assy have the following advantages: no need for lubrication, no mud, it requires little longitudinal installation space; the quality of the spring itself is small.

The spiral Spring post assy itself has no damping effect, so an additional shock absorber must be installed in the spiral Spring post assy. In addition, the spiral Spring post assy can only bear vertical loads, so a guiding mechanism must be installed to transmit various forces and moments other than the vertical force. Spiral Spring post assy is rolled from spring steel bar material and can be made into equal pitch or variable pitch. The stiffness of the former is constant, and the stiffness of the latter is variable.