The shock absorber is used to suppress the shock and the impact from the road surface when the spring rebounds after shock absorption. Widely used in automobiles, in order to accelerate the attenuation of the vibration of the frame and the body to improve the ride comfort of the car. When passing through an uneven road, 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 suppress this spring jump. In the suspension system, the elastic element vibrates due to the impact. In order to improve the ride comfort of the car, a shock absorber is installed in parallel with the elastic element in the suspension to dampen the vibration. The working principle is that when the frame (or body) and the axle vibrate and there is relative movement, the piston in the shock absorber moves up and down, and the oil in the shock absorber cavity repeatedly passes through a different cavity. The pores flow into another cavity. At this time, the friction between the hole wall and the oil and the internal friction between the oil molecules form a damping force on the vibration, so that the vibration energy of the car is converted into the heat energy of the oil, which is then absorbed by the shock absorber and released into the atmosphere. When the oil channel section and other factors remain unchanged, the damping force increases or decreases with the relative movement speed between the frame and the axle (or wheel), and is related to the oil viscosity.
The shock absorber and the elastic element undertake the task of buffering shock and shock absorption. If the damping force is too large, the elasticity of the suspension will be deteriorated, and even the shock absorber connection will be damaged. Therefore, it is necessary to adjust the contradiction between the elastic element and the shock absorber.
(1) During the compression stroke (the axle and the frame are close to each other), the damping force of the shock absorber is small, so that the elastic effect of the elastic element can be fully exerted to ease the impact. At this time, the elastic element plays a major role.
(2) During the extension stroke of the suspension (the axle and the frame are far away from each other), the damping force of the shock absorber should be large, and the shock absorber should be quickly damped.
(3) When the relative speed between the axle (or wheel) and the axle is too large, the shock absorber is required to automatically increase the fluid flow, so that the damping force is always kept within a certain limit to avoid excessive impact load.
Cartridge shock absorbers are widely used in automobile suspension systems, and they can act as shock absorbers in both compression and extension strokes. They are called double-acting shock absorbers, and new shock absorbers are used. shock absorbers and adjustable resistance shock absorbers.