Automobile knowledge sharing-the internal structure of the shock absorber by Asiautos Auto Parts(CHINA CAR Aftermarket Parts Expert)

Shock absorbers are used to suppress the shock caused by the rebound of springs after absorbing shock and the impact from the road surface. They are widely used in automobiles to accelerate the attenuation of frame and body vibrations to improve the driving smoothness of the car. When passing through uneven roads, although the shock-absorbing spring can filter the vibration of the road surface, the spring itself will still have reciprocating motion, and the shock absorber is used to suppress this spring jump.

Double acting :

Double-acting type : damping force is generated when the vehicle rebounds and compresses (most shock absorbers belong to this category. At present, the most common type for passenger cars is double-acting type, which is divided into single-tube and double-tube shock absorbers according to the structure.

Single acting :

Single-acting type : It generates damping force when the vehicle starts in one direction (mainly generates damping force when extending, suitable for off-road vehicles

Internal structure and component functions :

Mono-tube shock absorber : There is only one cylinder, which is generally filled with high-pressure ammonia (about 2.5Mpa). There are two pistons in the cylinder. The piston installed on the connecting rod is used to generate damping force, and the piston below is a floating piston used to separate the shock absorber fluid and high-pressure gas.

Advantages : The shock absorber can be installed upside down without affecting its performance, and its light weight can reduce the unsprung mass. In addition, since the shock absorber is only separated from the outside world by a layer of cylinder, the heat dissipation performance is better.

Disadvantages : It requires a longer size and is difficult to use in general vehicles; the high-pressure gas inside can easily damage parts and requires high sealing properties.

Twin-tube shock absorber : This is the most common and typical shock absorber at present. It generally has restoring resistance and compression resistance, and is also called a two-way shock absorber. The so-called twin-tube refers to the working cylinder and the oil storage cylinder. The piston moves in the working cylinder. The oil storage cylinder is used to store the shock absorber oil. In most cases, it has a restoring valve and a compression valve.

Advantages : Due to its relatively simple manufacturing, compact structure, stable performance, and ability to meet a wide range of damping force requirements, it is widely used in the automotive field.

Disadvantages : On poor road surfaces, if the shock absorber oil is not fully replenished during the recovery process, it will cause oil shortage during the compression process, resulting in abnormal noise, reduced comfort and other defects. In order to solve this problem, a double-tube pneumatic shock absorber was developed. Nitrogen (about 0.5~1Mpa) is filled into the shock absorber, so that the shock absorber oil can be fully replenished during the recovery process to solve the above defects.

Independent ignition mode : Each cylinder is equipped with an ignition coil, which is suitable for multi-cylinder engines and can improve ignition efficiency and engine performance.

Simultaneous ignition mode : multiple cylinders share one ignition coil, which is suitable for engines with few cylinders, but the ignition efficiency is low.

Classification by cooling method :

Oil-immersed ignition coil : cooled by oil, suitable for traditional ignition systems, but with large magnetic leakage and low efficiency.

Dry ignition coil : air cooling, better heat dissipation performance and higher conversion efficiency.

Classification by connection method :

Three-terminal type : An additional resistor is installed on the housing to improve ignition performance.

Two-terminal type : no additional resistance, simple structure.