What are the types of common car shock absorbers? What are the characteristics?(2)

- Apr 27, 2019-

What are the types of common car shock absorbers? What are the characteristics?

2, according to the structural angle


Double cylinder shock absorber:


The double-tube shock absorber is also called the Twin Tube Damper. The barrel is a double construction. The piston portion of the shaft tip end, and the assembly provided at the bottom of the tube, the damping force occurs. (The former is the main piston assembly, the latter is called the fixed valve assembly.) The space outside the tube becomes the oil reservoir chamber (sub tank = auxiliary tank), and the oil entering and leaving the volume of the shaft enters and exits the reservoir chamber. The reservoir chamber is such that atmospheric pressure air or nitrogen gas (Nitrogen) gas is enclosed therein, and the volume of oil in and out is absorbed by the compression and expansion of the gas therein.


During the extension movement, the upper chamber of the piston is pressurized, and the oil causes the assembly on the extension side (the lower side of the piston) to be pressurized and bent, and gradually reduces the fading force, and flows toward the lower chamber of the piston. Since the shaft is withdrawn from the oil in the cylinder at this time, the amount of oil in the lower chamber of the piston corresponding to the shaft is insufficient, and the insufficient amount of oil is replenished by the reservoir chamber. At this time, the fixed valve assembly hardly has a reducing force.


When the movement is shortened, the lower chamber of the piston is pressurized, and the oil is pressed by the assembly on the shortening side (upper side of the piston) to be bent and gradually degraded, and flows toward the upper chamber of the piston. In addition, the oil under the pressurized piston pushes the fixed valve assembly open, and flows to the reservoir chamber while reducing the damping force.


Features of the double-tube shock absorber:


advantage:

. Cheaper manufacturing costs

. Because it is a double structure, it can allow a little deformation of the outer cylinder.

. The construction is of sufficient length so that sufficient stroke is ensured.

Disadvantages:

. Cannot be used when over-tilted.

. The volume of the upper air chamber is small, and the volume change (pressure change) of the air chamber is large, and it is easy to exceed the pressure resistance of the oil seal.

. The gas and oil are not separated, and it is prone to aeration (in the case of air mixed in the liquid). In order to improve the performance of the exercise and improve the attenuation, it is prone to cavitation (decompression boiling), so it is not easy to have a stable attenuation.

. There is no way to increase the piston diameter, so it is not easy to make minor reductions.

Because of the relationship between cost and production cost performance, the double-cylinder shock absorbers use this structure for the original vehicle shock absorbers.


Single-tube shock absorber:


The single-tube type shock absorber is called a single tube, a mono tube, a De Carbon (inventor) type or the like. High-pressure air is sealed under a single cylinder, and in order to prevent air from being mixed with oil, a free piston structure is designed between them. The fading force is generated by the elongation and the shortening of both the elongation and the shortening of the piston assembly disposed at the tip end of the shaft, and the volume change of the shaft volume is absorbed by the expansion and compression of the gas. The single-cylinder type is filled with a high-pressure nitrogen gas (Nitrogen) gas under the free piston. This is to use a very high value so that the upper chamber of the piston does not become a negative pressure when the movement is shortened.


Single-tube shock absorber features


advantage:

. The relationship between gas and oil separation does not cause cavitation, aeration, and can produce stable attenuation.

. Free configuration (can be inverted)

. The strut type can be inverted. In order to increase the damping force, the air pressure is also smaller than the gas pressure of the double cylinder, and the ride comfort is better.

. The piston diameter can be increased, so that the damping force can be finely adjusted.


The spring acts as a gentle shock and changes the "big energy one impact" into "small energy multiple impact", and the shock absorber gradually reduces the "small energy multiple impact". If you drive a broken car with a damper, you can experience the bounce of the car through every hole and after the undulation, and the damper is used to suppress this bounce. Without the damper, there is no way to control the rebound of the spring. When the car encounters a rough road, it will produce a serious bounce. When the car is bent, the tire grip and tracking loss will be caused by the shock of the spring.