Car shock absorber | Function, operation of the shock absorber
Roberto Magalhães
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Car shock absorber Function, shock absorber working
If only springs are used to absorb shocks, spring oscillations will continue even after the vehicle has experienced a bump. The wobbles cause the wheels to bounce up and fall until the wobbles disappear. Thus, shock absorbers or shock absorbers are used to stop the springs from wobbling after the vehicle passes over uneven road surfaces. Shock absorbers are required for use with coil springs. In the case of leaf springs, the friction between the leaves provides some damping effect. However, this is sometimes not enough, depending on the friction between the sheets. Consequently, shock absorbers are necessarily used as additional damping devices.
Function of shock absorbers
As explained previously, the function of the shock absorber is to dampen the vibrations of the helical and leaf springs used in the suspension system. These vibrations are generated when the vehicle passes an obstacle on the road.
Telescopic shock absorber operation
In modern cars, hydraulic shock absorbers are used. These absorbers use a piston and a cylinder where the cylinder is filled with suitable oil. Oil is used to dampen piston oscillations through suitable arrangement. The construction of a telescopic type shock absorber was shown in Figure
(a) Damper under compression
(b) Damper under Expansion
Sectional view of the telescopic shock absorber
The telescopic shock absorber mainly consists of a piston, a cylinder tube and a reservoir tube. The piston has been provided with holes or openings so that the fluid can pass from the top to the bottom or from the bottom to the top of the reservoir. The figure shows the condition when the absorber is compressed. This happens when the vehicle goes over a bump. In this condition, the length of the shock absorber becomes short. The piston rod forces the piston down the cylinder tube. Therefore, the fluid under the piston is compressed to high pressure. The fluid forcefully passes through small holes (in the piston) in the movements ahead of the bump or falls into a depression in the road, the shock absorber expands. In this condition the piston rises in the cylinder tube. Because of this, fluid is forced from the top of the cylinder tube to the bottom through the holes provided in the piston. In both cases i.e. expansion and compression, the fluid is forced through the holes. slowed down. This restricts the action of the spring and the vibrations of the structure are stopped in the shortest possible time. In this way, shocks (from bumps and depressions in the road) are absorbed by the shock absorber. It also prevents excessive wheel wobble when going over bumps and dips in the road. Shock absorbers are always provided along with the springs in the automobile suspension system to prevent spring oscillations.
Sectional view of the telescopic shock absorber
