First, according to the angle of damping material.
1, hydraulic type:
Hydraulic shock absorbers are widely used in automobile suspension systems. Its principle is that when the frame and axle move relatively back and forth and the piston moves back and forth in the cylinder of the shock absorber, the oil in the shock absorber shell repeatedly flows from one cavity to another through some narrow holes. At this time, the friction between the liquid and the inner wall and the internal friction of the liquid molecules form a damping force for vibration.
2. Pneumatic type:
Pneumatic shock absorber is a new type of shock absorber developed in 1960s. Its structural feature is that a floating piston is installed at 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. The floating piston is equipped with an O-ring with large cross section, which can completely separate oil from gas.
The working piston is equipped with a compression valve and a stretching valve, which change the cross-sectional area of the channel with the moving speed of the piston. When the wheel jumps up and down, the working piston of the shock absorber moves back and forth in the oil, which causes the oil pressure difference between the upper and lower cavities of the working piston, and the pressure oil pushes open the compression valve and the extension valve and flows back and forth. Because the damping force of the valve on the pressure oil is large, the vibration is attenuated.
Second, from the structural point of view.
1, double-tube shock absorber:
Composite shock absorber is also called double-tube shock absorber. The barrel has a dual structure. The piston part at the front end of the shaft and the assembly at the bottom of the pipeline are used to generate damping force.
The outer space of the pipeline becomes the oil storage chamber, and the oil equivalent to the shaft volume enters and exits the storage chamber. Atmospheric air or nitrogen is enclosed in it, and due to the compression and expansion of the gas, it will absorb the volume of oil coming in and out.
During the extension movement, the upper chamber of the piston is compressed, and the components on the extension side (the lower side of the piston) are compressed and bent, gradually generating attenuation force and flowing to the lower chamber of the piston. Because the shaft exits the oil in the cylinder at this time, the oil in the lower cavity of the piston is insufficient, and the insufficient oil is supplemented by the outflow of the oil storage cavity. At this time, the damping force of the fixed valve assembly hardly appears.
In the shortening movement, the lower chamber of the piston is compressed, and the components on the shortening side are bent under pressure and gradually generate attenuation force, which flows to the upper chamber of the piston. In addition, the oil under the pressurizing piston pushes open the fixed valve assembly and flows to the oil storage chamber, while reducing the attenuation force.
2. Single tube shock absorber:
Single tube shock absorber is called single tube, single tube, De carbon type and so on. High-pressure air is sealed under a single cylinder. In order to prevent air from mixing with oil, a free piston structure is designed between them.
The damping force is produced by the extension and shortening of the piston assembly installed in the piston part at the front end of the shaft, and the volume change of the shaft volume is absorbed by the expansion and compression of gas. The single cylinder is sealed with high-pressure nitrogen under the free piston, which is to prevent the upper cavity of the piston from becoming negative pressure during the shortening movement, so a very high value should be used.
Maintenance:
1. If the dust is serious, it is best to coat or crystallize the shock absorber of the vehicle, so that even if the shock absorber is scratched, it will not cause corrosion, and at the same time, it can ensure that the shock absorber of the vehicle will not be corroded. After coating or crystal plating, it can ensure that the paint surface of the original car is not damaged, and naturally it can also ensure the normal work of the vehicle shock absorber.
2. The corrosion and wear of vehicle shock absorbers are mainly sewage and dirt, so the shock absorbers should be treated in time after rainy days or after driving on roads with sewage. Wash the sewage and dirt on the shock absorber, and then wipe it clean. This can ensure that the shock absorber will not be corroded by sewage and dirt.