Today we talk about automotive shock absorbers. It should be said that we attach great importance to this component when using the car, because it is related to the comfort of our vehicle. If the chassis makes a "dump" sound on uneven roads, we know that the shock absorber may have failed. So what the hell is this shock absorber? How does it reduce vibration? What types are there? TEAHO will answer your questions one by one:
The role of shock absorbers
The shock absorber is mainly used to suppress the shock when the spring rebounds after shock absorption and the impact from the road surface. When passing through uneven roads, although the shock-absorbing spring can filter the vibration of the road, the spring itself will reciprocate, and the shock absorber is used to suppress this spring jump.
Here everyone must pay attention: the shock absorber is to damp the spring, not the body. Why is this?
In the car suspension, the shock absorber is always used in conjunction with the spring. When we press down a corner of the body, the actual compression is the spring, and the corresponding swing arm swings. When the body is released, the body should rebound under the force of the spring. At this time, the shock absorber dampens the spring's rebound, that is, it stabilizes after the rebound. If there is no shock absorber, the spring will be compressed and rebound again after rebounding, showing that the body tends to stabilize after multiple rebounds. So the shock absorber is for the spring of the car suspension to dampen the shock when rebounding.
If the shock absorber is too soft, the body will jump up and down, and if the shock absorber is too hard, it will bring too much resistance and prevent the spring from working properly.
Who is the shock absorber of the car?
The function principle of the hydraulic shock absorber is: when the frame and the axle reciprocate relative movement, the piston in the shock absorber also reciprocates in the cylinder tube, and the oil in the shock absorber shell repeatedly from a The inner cavity flows into another inner cavity through some narrow pores. The friction between the hole wall and the oil and the friction within the liquid molecules form a damping force on the vibration, so that the vibration energy of the body and the frame is converted into heat energy, which is absorbed by the oil and the shock absorber shell and dispersed into the atmosphere in.
The shock absorbers commonly used in our cars are two-way cylinder shock absorbers. In some high-end cars, inflatable shock absorbers, adjustable resistance shock absorbers, electromagnetic shock absorbers, etc. are used in order to improve Car ride comfort and improve car maneuverability.
Working principle of two-way cylinder shock absorber
The automotive hydraulic shock absorber is filled with special oil for shock absorber. The interior is divided into two cylinders: oil storage cylinder and working cylinder, and the piston divides the working cylinder into an upper cavity and a lower cavity. An extension valve and a flow valve are provided on the piston to control the flow of oil between the upper cavity and the lower cavity; and the compression valve and the compensation valve between the lower cavity of the working cylinder and the oil storage cylinder are used for the oil in the lower cavity and the storage Flow between cylinders.
When the shock absorber is compressed, the piston goes down, the volume of the upper cavity increases, the volume of the lower cavity decreases, the flow valve opens, and the oil in the lower cavity enters the upper cavity through the flow valve; at the same time, part of the oil opens the compression valve and enters the oil storage cylinder. The throttling effect of these two valves on the oil causes the damper to produce a damping effect during the compression movement.
When the shock absorber is extended, the piston moves upward, the volume of the upper cavity decreases and the volume of the lower cavity increases, the expansion valve opens, and the oil in the upper cavity enters the lower cavity through the expansion valve; at the same time, a part of the oil opens to compensate and enters from the oil storage cylinder Lower cavity. The throttling effect of the two valves on the oil causes the damper to produce a damping effect during the extension movement.
Because the spring force of the expansion valve is greater than that of the flow valve, and the flow area of the valve hole of the expansion valve is smaller than that of the flow valve, the damping force generated by the expansion stroke of the shock absorber is greater than the damping force of the compression stroke, which can quickly reduce the spring shock.