What are the types of automobile shock absorbers?
The main function of automobile shock absorbers is to suppress the shock when the spring rebounds after shock absorption and the impact from the road, thereby improving the smoothness of the vehicle's driving and reducing the vibration of the frame and body when the vehicle accelerates.

Types of automobile shock absorbers
Division from the perspective of materials:
Hydraulic shock absorbers: widely used in automobile suspension systems. The principle is that when the frame and axle reciprocate and the piston reciprocates in the cylinder of the shock absorber, the oil in the shock absorber housing repeatedly flows from one inner cavity to another through some narrow holes. At this time, the friction between the liquid and the inner wall and the friction between the liquid molecules will form a damping force on the vibration. Hydraulic shock absorbers can be divided into two structures: single-tube and double-tube.

Pneumatic shock absorbers: a new type of shock absorber developed since the 1960s. Its structural feature is that a floating piston is installed at the bottom of the cylinder, and a closed air chamber formed by the floating piston and one end of the cylinder is filled with high-pressure nitrogen. A large-section O-ring is installed on the floating piston to completely separate the oil and gas. The working piston is equipped with a compression valve and an extension valve that change the cross-sectional area of ??the channel with the speed of its movement. When the wheel bounces up and down, the working piston of the shock absorber reciprocates in the oil, causing an oil pressure difference between the upper and lower chambers of the working piston, and the pressure oil pushes the compression valve and the extension valve to flow back and forth. Since the valve exerts a large damping force on the pressure oil, the vibration is attenuated.

Variable damping shock absorber: It is also a type of shock absorber classified from the material perspective.

Classification from the structural perspective:
Single-tube type: simple structure, reducing a set of valve systems. A floating piston is installed at the bottom of the cylinder (the so-called floating means that there is no piston rod to control its movement), and a closed air chamber is formed under the floating piston, which is filled with high-pressure nitrogen. The above-mentioned changes in the liquid level caused by the piston rod entering and exiting the oil are automatically adapted through the floating of the floating piston.

Double-tube type: refers to the shock absorber with two inner and outer tubes. The piston moves in the inner tube. As the piston rod enters and withdraws, the volume of oil in the inner tube increases and contracts accordingly. Therefore, the oil balance in the inner tube must be maintained by exchanging with the outer tube. Therefore, there must be four valves in the double-tube shock absorber, that is, in addition to the two throttle valves on the piston mentioned above, there are also flow valves and compensation valves installed between the inner and outer tubes to complete the exchange function.