In order to improve the ride comfort of the vehicle, the shock absorber is installed in parallel with the elastic element in the suspension system. In order to attenuate the vibration, the shock absorber in the automobile suspension system is mostly hydraulic shock absorber. , The working principle is that when the frame (or body) and the vibration between the car and the relative movement, the shock absorber piston up and down, shock absorber cavity of the oil will repeatedly from a cavity through a different The pores flow into the other cavity. At this point between the wall and the oil friction between the oil molecules and the internal friction between the vibration to form a damping force, the car vibration energy into oil heat, and then absorbed by the shock absorber to the atmosphere. In the oil channel cross-section and other factors unchanged, the damping force with the car and the axle (or wheel) between the relative movement speed increase and decrease, and the viscosity of the oil.

Shock absorbers and elastic components bear the task of cushioning and damping, damping force is too large, will make the suspension elastic deterioration, and even damage to the shock absorber connector. So to adjust the elastic components and shock absorbers this contradiction.

(1) in the compression stroke (axle and frame close to each other), shock absorber damping force is small, in order to give full play to the elastic elements of elasticity, ease the impact. At this time, the elastic components play a major role.

(2) in the suspension of the trip (axle and frame away from each other), shock absorber damping force should be large, rapid shock absorption.

(3) When the relative speed between the axle (or wheel) and the axle is too large, it is required that the shock absorber automatically increase the flow rate so that the damping force is always kept within a certain limit to avoid excessive impact Load.

In the car suspension system is widely used in the cylinder shock absorber, and in the compression and stretching process can play a role in the shock absorber called two-way shock absorber, as well as the use of new shock absorbers, which includes inflatable reduction Shock absorbers and resistance adjustable shock absorbers.