The shock absorber is used to suppress the vibration and shock from the road surface when the spring rebounds after shock absorption. It is widely used in automobiles to accelerate the attenuation of frame and body vibrations to improve the ride comfort of automobiles. When passing through uneven roads, although the shock-absorbing spring can filter the vibration of the road, the spring itself will have a reciprocating motion, and the shock absorber is used to inhibit the spring from jumping.
Material angle division Divided from the perspective of generating damping materials, shock absorbers are mainly hydraulic and pneumatic, and there is a variable damping shock absorber.
Hydraulic Hydraulic shock absorbers are widely used in automotive suspension systems. The principle is that when the frame and the axle make relative reciprocal movements and the piston reciprocates in the cylinder of the shock absorber, the oil in the shock absorber housing repeatedly flows from the inner cavity through some narrow pores into another 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 on the vibration.
Inflatable 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. A large-section O-ring is installed on the floating piston, which completely separates 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 according to 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 back and forth. Because the valve produces a large damping force on the pressure oil, the vibration is attenuated.
Structural angle division The structure of the shock absorber is that a piston rod with a piston is inserted into the barrel, and the barrel is filled with oil. The piston has throttle holes so that the oil in the two parts of the space separated by the piston can complement each other. Damping occurs when viscous oil passes through the orifice. The smaller the orifice, the greater the damping force, the greater the viscosity of the oil, and the greater the damping force. If the size of the orifice is unchanged, when the shock absorber works fast, excessive damping will affect the absorption of shock. Therefore, a disc-shaped leaf spring valve is set at the outlet of the orifice. When the pressure becomes larger, the valve is pushed open, the orifice opening becomes larger, and the damping becomes smaller. Because the piston moves in both directions, leaf spring valves are installed on both sides of the piston, which are called compression valves and extension valves, respectively.
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 pneumatic shock absorber; 2. Double-cylinder hydraulic shock absorber; 3. Double-cylinder oil and gas shock absorber.
Double barrel The shock absorber has two inner and outer cylinders. The piston moves in the inner cylinder. As the piston rod enters and withdraws, the volume of oil in the inner cylinder increases and contracts accordingly. Therefore, the oil in the inner cylinder must be maintained by exchange with the outer cylinder balance. Therefore, there must be 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.
Monocylinder Compared with the double-cylinder type, the single-cylinder 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, which is filled with high-pressure nitrogen. The above-mentioned changes in the liquid level caused by the piston rod entering and leaving the oil are automatically adapted by the floating piston floating. In addition to the two types of shock absorbers described above, there are also adjustable resistance shock absorbers. It can change the size of the orifice through external operation. Recent cars have electronically controlled shock absorbers as standard equipment, which uses sensors to detect driving conditions, and the computer calculates the optimal damping force to make the damping force adjustment mechanism on the shock absorber work automatically.
In order to accelerate the attenuation of the frame and body vibration to improve the ride comfort (comfort) of the car, shock absorbers are installed inside the suspension system of most cars.
The car’s shock absorption system is composed of springs and shock absorbers. The shock absorber is not used to support the weight of the vehicle body, but to suppress the vibration when the spring rebounds after absorbing shock and absorb the energy of the road impact. The spring plays a role of easing the impact, changing “a single impact with large energy” into “multiple impacts with small energy”, and the shock absorber gradually reduces “multiple impacts with small energy”. If you have driven a car with a broken shock absorber, you can experience the bouncing of the car after each undulation and the undulating after waves, and the shock absorber is used to suppress this bouncing. Without the shock absorber, the spring rebound cannot be controlled. When the car encounters rough roads, it will have a serious bounce. When cornering, it will also cause the tire’s grip and tracking loss due to the vibration of the spring.