Divided from material
From the perspective of generating damping materials, shock absorbers mainly include hydraulic and pneumatic shock absorbers, and there is also a variable damping shock absorber.
1. Hydraulic type
Hydraulic shock absorbers are widely used in automobile suspension systems. The principle is that when the frame and the axle reciprocate and the piston reciprocates in the cylinder of the shock absorber, the oil in the shock absorber shell will repeatedly flow from the inner cavity through some narrow pores into the other. An inner cavity. At this time, the friction between the liquid and the inner wall and the internal friction of the liquid molecules form a damping force against vibration.
2. Inflatable
Inflatable shock absorber is a new type of shock absorber developed since the 1960s. Its structural feature is that a floating piston is installed in the lower part 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 seal is installed on the floating piston, which completely separates the oil and gas. The working piston is equipped with a compression valve and an expansion valve that change the cross-sectional area of the channel according to its moving speed. 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 cavity and the lower cavity of the working piston, and the pressure oil pushes the compression valve and the expansion valve to flow back and forth. Because the valve produces a relatively large damping force on the pressure oil, the vibration is attenuated.
Divided from the structure
According to its structure, shock absorbers are divided into two types: single tube and double tube. It can be further divided into: 1. Single cylinder air pressure shock absorber; 2. Double cylinder oil pressure shock absorber; 3. Double cylinder oil and gas shock absorber.
1. Double barrel type
Refers to the shock absorber has two inner and outer cylinders. The piston moves in the inner cylinder. Due to the entry and withdrawal of the piston rod, the volume of oil in the inner cylinder increases and shrinks. Therefore, the oil in the inner cylinder must be exchanged with the outer cylinder to maintain the oil in the inner cylinder. balance. Therefore, there are four valves in the double-cylinder shock absorber, that is, in addition to the two throttle valves on the piston mentioned above, there are also a flow valve and a compensation valve installed between the inner and outer cylinders to complete the exchange function.
2. Monocular
Compared with the double-tube type, the single-tube type shock absorber has a simple structure and reduces a set of valve systems. It is equipped with a floating piston in the lower part 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, filled with high-pressure nitrogen