638 Control of Dynamic Characteristics by Variable Stiffness Springs for Pantograph

The authors presented some simulation results that indicate that pantographs, which could change their stiffness depending on the train speed, are capable of reducing the fluctuations of their contact forces between pantographs and contact wires and a prototype of a variable stiffness spring ccmposed of two air springs. In this paper, we firstly investigated the basic characteristics of the improved variable stiffness spring. We then built the variable stiffness spring into a pantograph model and examined how the dynamic characteristics of the model varied with its stiffness.