Author(s)

Y. Umehara, T. Oguro, S. Kamoshita, K. Nagashima, S. Sasaki, M. Kawai, T. Mitsumata

Abstract

In order to improve the curving performance of a railway vehicle, the authors have devised a steering system in which a magnetic elastomer is used for the elastic members such as a rubber bushing of the axle box suspension. This material is characterized by its hardness variation depending on the magnetic field. This steering system is capable of varying the longitudinal stiffness of the axle box suspension. In straight sections, the application of this system ensures running stability by increasing the longitudinal stiffness of the axle box suspension by means of applying a magnetic field. On the other hand, in curve sections, it improves curving performance by decreasing the longitudinal stiffness of the primary suspension by means of turning off the magnetic field. The authors made test pieces towards the development of the magnetic elastomer for the steering bogie. In a characteristic test, the authors confirmed that the Young’s modulus of the magnetic elastomer changed in the range of about five times depending on the presence or absence of the magnetic field. In addition, the authors simulated the 32-degrees-of-freedom vehicle running model by applying the stiffness change of the magnetic elastomer to the steering bogie. The authors confirmed that this steering bogie was capable of reducing the mean outer wheel lateral force in the circular curve section approximately by 20% compared to that of the normal bogie.

Keywords

magnetic elastomer, axle box suspension, steering bogie, lateral force, longitudinal stiffness