In the suspension system, the vibration of the elastic element is caused by the shock, in order to improve the vehicle ride comfort, the suspension and the elastic element in parallel installation damper, for attenuation vibration, the automobile suspension system uses the shock absorber mostly is the hydraulic shock absorber, its working principle is when the frame (or body) and the vehicle bridge between the vibration appears relative movement, The piston in the shock absorber moves up and down, and the oil in the chamber of the shock absorber repeatedly flows from one cavity through different pores into another. At this time, the friction between the Combi and oil and the internal friction between the oil molecules forms the damping force of the vibration, which transforms the vibration energy into the oil heat energy, which is then absorbed into the atmosphere by the shock absorber.
When the Oil channel section and other factors are invariable, the resistance damping increases and decreases with the relative movement speed between the frame and the axle (or wheel), and is related to the viscosity of oil liquid. The shock absorber and the elastic element bear the task of slow impact and vibration reduction, and the damping force is too large, which will cause the suspension elasticity to become bad and even damage the connecting parts of the shock absorber.
The contradiction between the elastic element and the shock absorber should be adjusted by the plane. (1) in the compression stroke (vehicle bridge and frame close to each other), the damper damping force is small, in order to give full play to the elastic elements of elasticity, to mitigate the impact.
At this point, the elastic element plays a major role.
(2) in the suspension of the journey (car Bridge and frame away from each other), shock absorber damping force should be large, rapid vibration reduction.
(3) When the car Bridge (or wheel) and the car bridge between the relative speed is too large, the need for the damper can automatically increase the flow of liquid, so that the resistance damping always kept within a certain limit, to avoid too much impact load.
In the automotive suspension system is widely used in the cylinder damper, and in the compression and extension of the stroke can be used to reduce the rebound called two-way action damper, as well as the use of new shock absorber, which includes inflatable damper and drag-adjustable damper. Two-way action tube damper working principle explanation. When compressing the stroke, the vehicle wheel moves near the body, the shock absorber is compressed, and the piston 3 of the shock absorber moves downward. The volume of the lower chamber of the piston is reduced, the oil pressure is increased, and the fluid flows through the flow valve 8 to the chamber (upper cavity) above the piston. The upper chamber is taken up by the piston rod 1 part of the space, so the upper cavity increased volume is smaller than the lower cavity volume, part of the oil and then pushed away the compression valve 6, flow back to the oil storage tank 5. These valves conserve oil to form the damping force of the suspension by the compression movement. When the shock absorber is on the stroke, the wheel is away from the body and the shock absorber is stretched. Then the piston of the shock absorber moves upwards. The piston upper chamber oil pressure rises, the circulation valve 8 closes, the upper cavity oil liquid pushes the valve 4 to flow into the inferior cavity. Because of the presence of the piston rod, the oil from the upper chamber is not enough to fill the lower cavity of the increase in volume, the next cavity produces a vacuum, then the oil storage tank Open the compensation valve 7 flow into the lower cavity to complement.
Because of the throttle effect of these valves, the suspension plays a damping role in the campaign. Because of the stiffness of the valve spring and the design of the preload is greater than the compression valve, under the same pressure, the sum of the channel load area of the valve and the corresponding Changtong gap is less than that of the compression valve and the corresponding section of the usual gap channel.
This makes the damping force of the shock absorber more than the damping force of the compression stroke, and achieves the requirement of rapid vibration reduction. In order to accelerate the attenuation of the frame and the body vibration to improve the ride comfort of the vehicle, the shock absorber is installed in the suspension system of most automobiles.