Design analysis of bogie with self-attenuation of air spring

The self-damping property of the air spring and the bogie with no bolster spring up and down damping are shown in Figure 10. An orifice is provided between the main body of the air spring and the auxiliary air chamber, and the air flow resistance is given to produce a spring effect on the air spring. At the same time, it can also give a damping effect. This was known at the beginning of the development of the air spring bogie. On the other hand, it is also known that the flow characteristics of the air passing through the orifice are non-linear. Moreover, if the diameter of the orifice is reduced, if the flow resistance is increased, the spring constant of the air spring will increase.

Because I don’t understand how much attenuation can be given by only relying on the orifice, for this reason, in the initial stage of the air spring bogie, the oil damper was installed in parallel with the air spring, just like the traditional bogie. Sumitomo Metal Co., Ltd. considered a bogie design that only uses air springs to dampen itself, and produced an air spring bogie without upper and lower hydraulic dampers.

The air spring bogie has a running vibration test to determine the size of the throttle aperture. In the operating vibration test, the pressure changes of the air spring and the auxiliary air chamber were also measured at the same time. From the analysis results of the data, the linear spring-damper model of the self-damping air spring was deduced. As shown in this model, if If the orifice diameter is reduced, the attenuation constant of the shock absorber will increase, and the spring constant k1 of the air spring will increase.

On the other hand, if the aperture is made to an appropriate size and the attenuation value of the shock absorber becomes an appropriate size, the spring constant of the air spring can become a low spring constant that adds the internal volume of the auxiliary air chamber. It is sufficient for analyzing the up and down vibration of actual air spring vehicles. Based on this result, the air spring was designed, and it was understood that even without the upper and lower shock absorbers of the air spring bogie, the necessary spring and damping characteristics can be given. The bogies without bolster booms that were born after that were all air spring bogies without upper and lower shock absorbers.

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