Development of a Composite Suspension with a Coil and Hydro-Pneumatic Spring

A new composite suspension is developed,where a coil spring and a hydro-pneumatic spring are used in order to improve the poor reliability of off-road vehicle with pure hydro-pneumatic suspension.According to road conditions,the two springs play different roles.The method for matching the composite suspension stiffness and distributing the load is proposed.The working pressure of hydro-pneumatic spring as well as the load and stiffness characteristics of composite suspension is compared with a pure hydro-pneumatic suspension.In addition,the ISO weighted vehicle body acceleration,suspension travel and relative dynamic load of the wheels between two kinds of suspension are analyzed with a quarter vehicle mode.The simulation result shows that the developed composite suspension is more suitable for off-road vehicle than the one hydro-pneumatic suspension,because the composite suspension can reduce the working pressure, improve the reliability and keep a similar ride cornfort with hydro-pneumatic suspension.