Seismic isolation device and manufacturing method of the same

Abstract

A composite metal core 30 incorporated in a laminated rubber bearing for damper having two different kinds of metal material. An outer metal 31 includes a material having a high rigidity and an excellent plastic deformability. An inner metal 32 includes a material having low rigidity and an excellent plastic deformability. By making a rising rate of a bending rigidity of the composite metal core higher than a rising rate of a shear rigidity of the composite core, the composite metal core enters a deformation mode in which a superior shear deformability is created. In that deformation mode, the performance of absorbing energy generated in a process of plastic deformation is stabilized. And at the same time, an average horizontal shear yield stress degree of the composite metal core can be set at an arbitral level between the horizontal shear yield stress degrees of the two kinds of metal.

1 - 15 . (canceled) 
     
     
         16 . A seismic isolation device comprising:
 a laminated rubber body formed by alternately laminating a plurality of elastic materials and a plurality of rigid materials in a vertical direction, each elastic material and each rigid material having a thin plate shape; and   a composite metal core disposed inside the laminated rubber body and plastically deformable to absorb energy,   wherein the composite metal core includes an inner metal and an outer metal, the outer metal concentrically surrounding the inner metal in a horizontal cross-sectional view, the inner metal and the outer metal being disposed in close adherence with each other, the outer metal having an elastic modulus and an yield rigidity greater than the inner metal so that a shear deformability of the composite metal core becomes greater than a bending deformability of the composite metal core, and   wherein a horizontal shear resistance force QC of the composite metal core in a predetermined cross-sectional area is set to satisfy an equation: QB≦QC<QA, the QA being a horizontal shear resistance force in the predetermined cross-sectional area of a metal core A composed of the single outer metal, the QB being a horizontal shear resistance force in the predetermined cross-sectional area of a metal core B composed of the single inner metal.   wherein any one of Combinations 1 to 4 (Combination 1: tin for the outer metal and lead for the inner metal, Combination 2: aluminum for the outer metal and lead or tin for the inner metal, Combination 3: zinc for the outer metal and any one of lead, tin and aluminum for the inner metal, Combination 4: copper for the outer metal and any one of lead, tin, aluminum and zinc for the inner metal) is employed as a combination of a material composing the outer metal and a material composing the inner metal.   
     
     
         17 . The seismic isolation device according to  claim 16 , wherein the composite metal core has a rectangular shape or a slightly tapered rectangular shape in a vertical cross-section, and
 wherein both the outer metal and the inner metal have one of a circular shape, an approximately quadrate shape, and an approximately polygonal shape having fewer angles than octagon in the horizontal cross-sectional,   wherein, when the outer metal has a circular shape in the plane view, two or more longitudinal ribs extending in the vertical direction are formed on the outer peripheral surface of the outer metal, and   wherein, when the inner metal has a circular shape in the plane view, two or more longitudinal engaging members are formed on the inner peripheral surface of the outer metal and the outer peripheral surface of the inner metal to be engaged with each other.   
     
     
         18 . The seismic isolation devise according to  claim 16 , wherein the outer metal is composed of tin or tin alloy and the inner metal is composed of lead or lead alloy,
 wherein both the outer metal and the inner metal have one of a circular shape, an approximately quadrate shape, and an approximately polygonal shape having fewer angles than octagon in the horizontal cross-sectional view, and   wherein a thickness t 1  of the outer metal in the cross-sectional plane view is set to satisfy an equation t 1 /dp≦0.35, the dp being a size of the composite metal core in the horizontal cross-sectional view.   
     
     
         19 . The seismic isolation devise according to  claim 17 , wherein the outer metal is composed of tin or tin alloy and the inner metal is composed of lead or lead alloy,
 wherein both the outer metal and the inner metal have one of a circular shape, an approximately quadrate shape, and an approximately polygonal shape having fewer angles than octagon in the horizontal cross-sectional view, and   wherein a thickness t 1  of the outer metal in the cross-sectional plane view is set to satisfy an equation t 1 /dp≦0.35, the dp being a size of the composite metal core in the horizontal cross-sectional view.   
     
     
         20 . The seismic isolation devise according to  claim 16 , wherein one or two lid member, which is screw-cut, for fixing a core is incorporated at a plane center part of an upper end and/or a lower end of the composite metal core, and
 wherein the lid member is composed of copper or copper alloy.   
     
     
         21 . The seismic isolation devise according to  claim 17 , wherein one or two lid member, which is screw-cut, for fixing a core is incorporated at a plane center part of an upper end and/or a lower end of the composite metal core, and
 wherein the lid member is composed of copper or copper alloy.   
     
     
         22 . The seismic isolation devise according to  claim 18 , wherein one or two lid member, which is screw-cut, for fixing a core is incorporated at a plane center part of an upper end and/or a lower end of the composite metal core, and
 wherein the lid member is composed of copper or copper alloy.   
     
     
         23 . A manufacturing method of the composite metal core of the seismic isolation device according to  claim 16 , wherein, when the outer metal has a melting point higher than the inner metal, the composite metal core is manufactured by injecting the inner metal, which is in a molten state at a temperature lower than the melting point of the outer metal, into a hollow formed by an inner surface of the outer metal formed in a prescribed size and shape, or
 wherein, when the outer metal has a melting point lower than the inner metal, the composite metal is manufactured by injecting the outer metal, which is in a molten state at a temperature lower than the melting point of the inner metal, into a hollow formed between a metal mold having an internal shape equal to an outer surface of the outer metal, and the internal metal which is formed in advance and disposed inside the hollow.   
     
     
         24 . A manufacturing method of the composite metal core of the seismic isolation device according to  claim 17 , wherein, when the outer metal has a melting point higher than the inner metal, the composite metal core is manufactured by injecting the inner metal, which is in a molten state at a temperature lower than the melting point of the outer metal, into a hollow formed by an inner surface of the outer metal formed in a prescribed size and shape, or
 wherein, when the outer metal has a melting point lower than the inner metal, the composite metal is manufactured by injecting the outer metal, which is in a molten state at a temperature lower than the melting point of the inner metal, into a hollow formed between a metal mold having an internal shape equal to an outer surface of the outer metal, and the internal metal which is formed in advance and disposed inside the hollow.   
     
     
         25 . A manufacturing method of the composite metal core of the seismic isolation device according to  claim 18 , wherein, when the outer metal has a melting point higher than the inner metal, the composite metal core is manufactured by injecting the inner metal, which is in a molten state at a temperature lower than the melting point of the outer metal, into a hollow formed by an inner surface of the outer metal formed in a prescribed size and shape, or
 wherein, when the outer metal has a melting point lower than the inner metal, the composite metal is manufactured by injecting the outer metal, which is in a molten state at a temperature lower than the melting point of the inner metal, into a hollow formed between a metal mold having an internal shape equal to an outer surface of the outer metal, and the internal metal which is formed in advance and disposed inside the hollow.   
     
     
         26 . A manufacturing method of the composite metal core of the seismic isolation device according to  claim 20 , wherein, when the outer metal has a melting point higher than the inner metal, the composite metal core is manufactured by injecting the inner metal, which is in a molten state at a temperature lower than the melting point of the outer metal, into a hollow formed by an inner surface of the outer metal formed in a prescribed size and shape, or
 wherein, when the outer metal has a melting point lower than the inner metal, the composite metal is manufactured by injecting the outer metal, which is in a molten state at a temperature lower than the melting point of the inner metal, into a hollow formed between a metal mold having an internal shape equal to an outer surface of the outer metal, and the internal metal which is formed in advance and disposed inside the hollow.   
     
     
         27 . The manufacturing method according to  claim 16 , wherein the composite metal core is manufactured as a metallic skin by immersing the inner metal, which is formed in a prescribed size and shape in advance, into a container in which the outer metal is in a molten state, or
 wherein the composite metal core is manufactured as a thin film by thermal-splaying the outer metal, which is in a molten state, on at least a side surface of the inner metal, which is formed in a prescribed size and shape in advance.   
     
     
         28 . The manufacturing method according to  claim 17 , wherein the composite metal core is manufactured as a metallic skin by immersing the inner metal, which is formed in a prescribed size and shape in advance, into a container in which the outer metal is in a molten state, or
 wherein the composite metal core is manufactured as a thin film by thermal-splaying the outer metal, which is in a molten state, on at least a side surface of the inner metal, which is formed in a prescribed size and shape in advance.   
     
     
         29 . The manufacturing method according to  claim 18 , wherein the composite metal core is manufactured as a metallic skin by immersing the inner metal, which is formed in a prescribed size and shape in advance, into a container in which the outer metal is in a molten state, or
 wherein the composite metal core is manufactured as a thin film by thermal-splaying the outer metal, which is in a molten state, on at least a side surface of the inner metal, which is formed in a prescribed size and shape in advance.   
     
     
         30 . The manufacturing method according to  claim 20 , wherein the composite metal core is manufactured as a metallic skin by immersing the inner metal, which is formed in a prescribed size and shape in advance, into a container in which the outer metal is in a molten state, or
 wherein the composite metal core is manufactured as a thin film by thermal-splaying the outer metal, which is in a molten state, on at least a side surface of the inner metal, which is formed in a prescribed size and shape in advance.