SEISMIC ISOLATOR

To provide a seismic isolator having a restoring force using a magnet.SOLUTION: In place of a conventional seismic isolator, a seismic isolator comprises an axial force pivot mechanism and a horizontal restoring force acting mechanism, and the horizontal restoring acting mechanism has a plurality of upper permanent magnets and a plurality of lower permanent magnets, and a permanent magnet holding member for holding a pair of the upper and lower permanent magnets along a magnet virtual circle with a pair of upper and lower virtual vertical axes as centers when viewed from above with intervals between lower parts of the plurality of upper permanent magnets and upper parts of the lower permanent magnets. When a pair of upper and lower magnet virtual vertical axes are made coincide with each other when viewed from above, positions of the plurality of upper permanent magnets arranged along the magnet virtual circle and positions of the plurality of lower permanent magnets are superimposed on each other, and a magnetic field is generated so that the plurality of upper permanent magnets and the plurality of lower permanent magnets which are different in positions when viewed from above are attracted to each other.SELECTED DRAWING: Figure 3 【課題】 磁石を利用した復元力をもつ免震装置を提供しようとする。【解決手段】従来の免震装置に換えて、軸力支承機構と水平復元力作用機構とを備え、前記水平復元力作用機構が、複数の上部永久磁石と複数の下部永久磁石と、上下一対の複数の永久磁石を複数の上部永久磁石の下部と複数の下部永久磁石の上部との間に隙間を設けて上から見て上下一対の磁石仮想垂直軸を中心とする磁石仮想円に沿って保持する永久磁石保持材とを有し、上から見て上下一対の前記磁石仮想垂直軸を一致させたとき前記磁石仮想円に沿って配置される複数の前記上部永久磁石の位置と複数の前記下部永久磁石との位置とが互いに重なり、上から見て位置が重なる複数の前記上部永久磁石と複数の下部永久磁石とが互いに引き合う様に磁界を発生する、ものとした。【選択図】 図３