抄録
Japan is frequently suffered from giant earthquake. Representative giant earthquakes are Great Hanshin-Awaji and Tohoku Earthquake and Tsunami. Several research institutions estimate the scale of damage occurred in Nankai Trough Earthquake in the future. Some methods which protect buildings from these earthquakes are earthquake resistant, seismic isolation system, and vibration control. We have developed oil dampers as vibration control devices. The developed oil damper using valves and silicone oil have fixed characteristics. Variable damping force damper which adjusts damping force to vibrational strength is expected that the damper efficiently controls vibration includes random waves such as earthquakes. Magneto Rheological Fluid (MR Fluid) significantly changes the characteristics when magnet field is applied. MR damper which is used the typical property has been developed as variable damping force damper. And, taking advantage of MR Fluid’s characteristics of being heavier than ordinary oil, MR damper using MR Fluid as the operating fluid has been developed. This report introduces these developed products.