Gas spring classification and characteristics
In the suspension system, the elastic element is vibrated due to the shock. In order to improve the riding comfort of the automobile, the shock absorber is installed in parallel with the elastic element in the suspension. In order to attenuate the vibration, the shock absorber used in the automobile suspension system is mostly hydraulic damping , Its working principle is that when the frame (or body) and the bridge between the relative movement by vibration, the piston within the shock absorber moves up and down, the shock absorber cavity fluid will repeatedly from a cavity through a different Pores flow into the other chamber. At this moment, the friction between hole wall and oil and the internal friction between oil molecules form a damping force on the vibration, so that the vibration energy of automobile is transformed into the heat energy of the oil, which is then absorbed by the absorber and dissipated into the atmosphere. When the oil passage cross-section and other factors remain unchanged, the damping force increases or decreases with the relative speed between the frame and the axle (or wheel), and is related to the oil viscosity.
Shock absorber and elastic components bear the task of shock and vibration damping, damping force is too large, will make the suspension elastic deterioration, or even damage to the shock absorber connector. Due to the surface to adjust the contradiction between the elastic element and shock absorber.
(1) In the compression stroke (axle and frame close to each other), damper damping force is smaller, in order to give full play to the elastic role of elastic elements to ease the impact. At this point, the elastic element plays a major role.
(2) Stretch in the suspension trip (the bridge and the frame away from each other), damping force damping force should be large, rapid damping.
(3) When the relative speed between the axle (or wheel) and the axle is too large, it is required that the shock absorber can automatically increase the liquid flow to keep the damping force within a certain limit to avoid excessive impact Load.
Widely used in the automotive suspension system is a tube shock absorber, and in the compression and extension stroke can play a role in vibration damping two-way shock absorber, as well as the use of new shock absorber, which includes inflatable minus Shock absorbers and resistance adjustable shock absorbers.
Two-way effect tube shock absorber working principle instructions. In the compression stroke, refers to the car wheel closer to the body, the shock absorber is compressed, then the shock absorber piston 3 moves down. The volume of the lower chamber of the piston is reduced and the hydraulic pressure is increased. Oil flows through the flow valve 8 to the chamber (upper chamber) above the piston. The upper chamber is partially occupied by the piston rod 1, so that the volume of the upper chamber is smaller than the volume of the lower chamber. A portion of the oil then pushes the compression valve 6 back to the reservoir 5. The savings of these valves on the oil form the damping force of the suspension under compression. Shock absorber in the stretch stroke, the wheel is equivalent to stay away from the body, shock absorber by stretching. The damper's piston moves upward at this moment. Piston oil pressure on the rise, the flow valve 8 is closed, the upper chamber of the oil pushed open stretch valve 4 into the lower chamber. Due to the existence of the piston rod, the oil flowing from the upper chamber is not enough to fill the volume of the lower chamber to increase, so that the lower chamber generates a vacuum. At this time, the oil in the storage cylinder pushes the compensation valve 7 to flow into the lower chamber supplement. The throttling effect of these valves dampens the suspension during extension.
Due to the stiffness and preload of the extended valve spring, the sum of the load carrying area of the expansion valve and the corresponding normally open slit is smaller than the sum of the cross-sectional area of the compression valve and the corresponding normally open slit under the same pressure. This makes the damping force generated by the stretching stroke of the shock absorber is greater than the damping force of the compression stroke to achieve the requirement of rapid vibration damping.
In order to speed up the attenuation of the frame and the body vibration to improve the riding comfort (comfort) of the car, a shock absorber is installed inside the suspension system of most automobiles.