Abstract
This study discusses the vibration characteristics of the magnetic spring vibration-isolating bed which is used in ambulances. Ambulances can operate at a maximum speed of 80 km/h, and often accelerate and decelerate at various speeds. These driving conditions cause blood pressure fluctuation and resonance of internal organs of patients riding in ambulances. Therefore, vibration isolation is needed to prevent patients from experiencing the vibration caused by ambulances. In this bed, both a nonlinear magnetic spring and linear springs (torsion bars) are set between the mount and the bed in parallel, and achieve the nonlinear Duffing-type restoring force characteristics of the springs. By setting the spring constant of the magnetic spring as negative, the total spring constant becomes approximately zero, which can isolate patients from the vibration of an ambulance. In this research, an experimental and analytical evaluation of the vibration-isolating bed for ambulance was performed, and the optimum design for the suspension system is proposed.
