Abstract
Carbody elastic vibration of railway vehicles negatively affects the ride comfort of passengers. One of the sources of the vibration is excitation force induced by the longitudinal vibration of the bogies. The purpose of this study is to develop a longitudinal vibration isolator between carbody and bogies for railway vehicles. Since the vibration isolator possibly affects running stability of the vehicle, we need to develop a device which copes with both the vibration reduction and running stability. To confirm the vibration isolation performance and also to evaluate the running stability, we construct a simulation model of a test vehicle equipped with rubber bushes in the traction links and yaw dampers using multi-body dynamics software. As a result, we confirm that the elastic vibration can be reduced by equipped with displacement-dependent rubber bushes to the traction links. It is also verified that the device affects the critical hunting speed, especially under the condition where a yaw damper is attached to one side of the bogie, which simulates the failure of another damper. Then, using the simulation model, we investigate the desirable characteristics of the device in order to reduce the carbody elastic vibration and to improve the running stability simultaneously. As a result, we confirm that it is possible to cope with both the vibration reduction and running stability by changing the characteristics of the device.
