This paper presents the curving performance of railway vehicles with air suspensions. Air suspensions sometimes cause reduction of wheel load at transition curve. In previous studies it was found that the air suspensions have non-linear characteristics at low speed and that the performance is influenced by the initial condition, the entrance transition curve condition and so on, by computer simulation and experiments using one-car-modeled test bench. Proposed new concept devices have functions to make the link rod of air suspension systems extend or shorten. These proposed control methods were examined by the experiments using one-car-modeled test bench and simulations. In this study, a new type of Leveling Valve (LV) with two-step characteristic was proposed to enhance the control performance to prevent Wheel Load reduction, and at the same time, the control device was sure of fail-safe. Wheel Load reduction of 1st axle outside was prevented further more experimentally, and derailment coefficient reduction effect was convinced by full car tight curve passing simulation using multi-body dynamics analysis software.
