JP5661964B1 - Seismic isolation device and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a highly reliable seismic isolation device capable of freely setting the resistance force of a built-in core in a built-in damper type seismic isolation device and exhibiting stable energy absorption performance against severe seismic motion input. A damper core built in a laminated rubber is configured as a composite metal core combining two types of metal materials, and a material with high rigidity and strength in plastic deformation performance is applied to the outer metal. A metal material having low strength and high plastic deformation performance is disposed. By increasing the bending rigidity increase rate significantly higher than the shear rigidity increase rate of the composite metal core, the energy absorption performance by plastic deformation is further stabilized as a deformation mode in which shear deformation is excellent, and at the same time the horizontal shear average yield of the built-in metal core The strength level could be set to any strength level between the yield stress levels of the two metals. [Selection] Figure 2

Description

  The present invention relates to a seismic isolation device having a laminated rubber body with a built-in energy absorbing damper among seismic isolation devices capable of safely protecting a structure from an earthquake.

  Since the seismic isolation structure can reduce the shaking of the structure itself against strong ground motion during a large earthquake, it can improve the seismic safety of the entire building including internal structures such as furniture and equipment together with the structural framework of the building. Can be increased.

  The seismic isolation device for realizing a seismic isolation structure has both an isolator function that allows large horizontal deformation while supporting the weight of the structure, and a damper function that absorbs vibration energy input to the structure due to the earthquake. It is necessary to have. Examples of seismic isolation systems that have been put to practical use include 1) natural rubber-based laminated rubber + separate dampers, 2) high-damping laminated rubber, 3) laminated rubber-based seismic isolation systems such as lead-core laminated rubber. In addition, 4) sliding-base seismic isolation devices and 5) rolling-base seismic isolation devices have been put into practical use.

  Among these seismic isolation devices, “Laminated rubber seismic isolation device with lead core”, which was invented and developed in New Zealand, is one that has been highly evaluated worldwide and has many achievements (Patent Document 1 and Patents). Reference 2). This device has a lead core functioning as a damper (energy absorption mechanism) in one central part of the plane of a laminated rubber bearing as an isolator or in a plurality of locations in the plane. Japan and overseas (New Zealand, USA, Italy, (Taiwan, Turkey, China, South America, etc.)

  This seismic isolation device has both the isolator function and the damper function required for the seismic isolation structure in one device, and the seismic isolation structure is a combination of a lead core responsible for the damper function and laminated rubber responsible for the isolator function. Performance, that is, the restoring force characteristic of the seismic isolation device can be adjusted considerably freely.

  On the other hand, the social awareness of environmental issues has increased in recent years, and as a result of the growing social trend that dislikes the toxicity of lead as a material, superplastic metals with excellent plastic deformation performance as well as lead are incorporated. Proposals for use as a core material have been made. As specific materials, “laminated rubber with a tin plug” using tin and tin-bismuth alloy having a face-centered cubic lattice having the same crystal structure as lead (Patent Document 3), a zinc-aluminum alloy is used. A thing (patent document 4) etc. are also developed or proposed.

  In addition, as a core material for energy absorption, a material using a high-damping rubber or other polymer material having high damping performance, a material in which two types of plastic resin materials having different hardness are mixed and molded (Patent Documents 5 and 6), A material using an artificial damper material obtained by mixing and molding a polymer material such as rubber and a granular material such as iron powder or glass beads has also been proposed (Patent Document 7).

JP 59-62742 A Japanese Patent No. 30245562 JP 2008-082386 A JP 2007-139108 A Japanese Patent Laid-Open No. 2005-009558 Japanese Patent Laid-Open No. 2007-092818 JP-A-9-177368

FIG. 1 shows a basic configuration of a conventional damper (metal core) built-in seismic isolation device targeted by the present invention, wherein (1) is a longitudinal sectional view and (2) is a horizontal sectional view. A metal core 3 is built in the central portion of the laminated rubber body 1, a thick end steel plate 25 is provided near the upper and lower ends, and a flange steel plate 4 is provided on the outer side thereof. In this example, a built-in metal core 3 is provided at the center of the plane of the laminated rubber body 1 having a circular plane, and the plane shape of the metal core 3 is circular.
Seismic isolation devices with built-in metal cores such as laminated rubber with lead plug called “LRB” and laminated rubber with tin plug called “SnRB”, or man-made material cores by mixing rubber and iron powder, etc. As shown in FIG. 1, at least one or more inside a laminated rubber body 1 in which thin flat elastic materials 11 (usually rubber layers) and rigid materials 2 (usually steel plates) are alternately laminated in the vertical direction. It is set as the structure which incorporated the core material 3 which bears the energy absorption function accompanying plastic deformation. The core material 3 (built-in core) for energy absorption may be distributed in a plurality, but this is the case of a large apparatus having a very large plane of the laminated rubber body, and is usually the center of the plane of the laminated rubber body 1. Basically, one piece is arranged in each part.

  In order to improve the damping performance of the seismic isolation device, the built-in core responsible for energy absorption performance can be increased. However, if the built-in core diameter (planar dimension) becomes larger than a certain ratio to the laminated rubber diameter, Since the horizontal deformation mode of the laminated rubber body collapses or a problem arises in the stability and vertical load support capacity of the laminated rubber body when it is horizontally deformed, it is generally about 20% of the diameter of the laminated rubber. It is necessary to keep the core diameter below that.

  Therefore, from the viewpoint of adjusting the damping performance by selecting the core material, various materials as described above have been proposed as the damper material incorporated in the laminated rubber. Those using resin materials and granular materials are premised on seismic isolation devices for large heavy structures due to their low resistance (low shear resistance per unit cross-sectional area (stress level)). As a result, the core diameter must be very large, which is not a realistic dimension. The usable objects must be limited to lightweight and small-scale structures such as detached houses.

Therefore, if the seismic isolation device for a large heavy structure is a target, a metal material is suitable as a damper material for the built-in core from the viewpoint of the stress level of resistance.
Among metal materials, Patent Document 3 proposes a low melting point alloy material such as tin-bismuth, tin-indium and the like, and its melting point is 117 to 138 ° C. as shown in Table 1 and melts at an extremely low temperature.

Table 1 Composition and mechanical properties of low melting point alloy materials (according to Patent Document 3)

  The built-in core responsible for the damper function of the seismic isolation device aims to absorb the seismic input energy to the structure by its own plastic deformation accompanying the interlayer displacement of the seismic isolation layer. To do. It is known that the temperature rise easily exceeds 100 ° C. for severe earthquake motions by many experiments so far.

  Therefore, these low-melting-point alloy materials are likely to reach the melting point and melt when severe seismic motion is applied, the resistance decreases at high temperatures before melting, and the energy absorption performance decreases significantly. Will do. Therefore, although these low-melting-point alloy materials are plastic metal materials, it must be said that they are unsuitable as materials for the built-in core of seismic isolation devices for the purpose of absorbing energy associated with plastic deformation during a large earthquake. .

As metal materials considered to be excellent in plastic deformation performance that has been noticed and studied so far, use of lead, tin, aluminum, zinc, copper, and alloy materials thereof can be considered.
Table 2 shows basic characteristics (mechanical properties) of these representative superplastic metals as materials such as longitudinal elastic modulus E, shear elastic modulus G, bulk elastic modulus K, Poisson's ratio ν, melting point, room temperature, and density at the melting point. Shown in
Table 2 Mechanical properties of typical superplastic metals

  As is well known, among these materials, the metal material of the built-in core for seismic isolation devices, which has been most adopted so far, is pure lead with a purity of 99.99% or more. Although lead has excellent mechanical properties as a superplastic metal and has a very large plastic deformation capability, it is toxic to the human body, so its use is discouraged from the current situation of severe environmental health issues. Tend to be. Also, there is room for improvement in that the resistance is slightly lower for dampers.

  On the other hand, from the viewpoint of avoiding toxicity of lead, tin is attracting attention as a non-toxic superplastic metal. Laminated rubber with tin plug that uses tin as a built-in metal core material has been put into practical use, and its adoption has been steadily progressing, but the resistance of tin plugs is about twice as high as that of lead. For this reason, the resistance tends to be slightly too strong to be adopted for each laminated rubber. Its strength is linked to the hardness of the metal, but because of its hardness, the resistance in the plastic region is constant and lacks uniformity like lead that can be deformed, butterfly shape whose resistance increases with deformation The history shape is shown. That is, lead is superior in plastic deformation characteristics.

Moreover, the tin plug has the following fatal defects from the viewpoint of thermal characteristics.
Table 3 compares the thermal and mechanical properties of lead and tin. That is, tin has the characteristic that its resistance (shear yield stress) is about twice as strong as that of lead, but its melting point is nearly 100 ° C. lower than that of lead.

Table 3 Comparison of thermal and strength properties of lead and tin

Assuming that the most common (standard) laminated rubber for buildings is a laminated rubber with a diameter of 1000mmφ (core dimensions: diameter 200mmφxheight H400mm), and this is forced deformation of ± 300mm as a horizontal deformation during a large earthquake. When the number of vibration cycles until the metal plug reaches the melting point is calculated from the estimated temperature of 20 ° C before the earthquake, as shown in Table 3 (lower half), about 18 cycles for the lead plug On the other hand, with a tin plug, the melting point is reached in 7.6 cycles, which is about 1/3 of that.
This difference is characteristic of the tin plug, because its resistance is nearly twice as high as that of lead, so the absorbed energy amount per cycle, that is, the calorific value is nearly twice as high, but the melting point is 100 ° C lower than that of lead. This is due to the characteristics. Since the resistance decreases due to the temperature rise accompanying energy absorption, the actual number of excitation cycles that reach the melting point is expected to increase slightly, but in any case, the energy absorption performance decreases significantly early due to the decrease in resistance. It is clear that we will go.

  In particular, when a massive M9 level huge earthquake that is likely to occur near the 2011 off the Pacific coast of Tohoku Earthquake occurred along the Nankai Trough, many earthquakes with a larger amplitude than this assumption for a long time. Since it is highly likely to be subjected to repeated vibrations, it is necessary to say that the laminated rubber with tin plug has a serious problem against strong long-period, long-lasting seismic motion.

  The following is a summary of discussions and problems related to the built-in core for seismic isolation devices (laminated rubber). First, the use of a polymer material as the core material results in low performance as a damper function due to a low resistance level. If the core size is very large, the device itself will become unstable. As the performance is inferior. Further, among the metal cores, the low melting point alloy material (Table 1) has an excessively low melting point, and can easily reach the melting point by absorbed energy, and therefore is not suitable as a core material.

As for the metal material that is practical as the built-in core material, lead and tin, which have been proven so far, are promising. However, as shown in Table 2, the softest lead and the next tin are more than three times in elastic modulus. There is a nearly double difference in shear yield strength, with other materials having even greater differences. That is, although lead as a metal core is excellent in deformation performance, it is slightly softer in strength, and conversely, tin is too hard and its deformation characteristics are difficult compared to lead. Other metals such as aluminum, zinc, and copper have a tendency to be too strong as compared with a tin plug because they are more rigid than tin. Lead also has a problem of toxicity.
As described above, as a core material for the seismic isolation device, a metal core must be used from the viewpoint of strength level, but optimal strength, deformation characteristics, mechanical properties, environmental health and safety in handling ( From various viewpoints, such as “non-toxic”, it means that “there is no ideal metal core material that has all the requirements”.

The present invention adopts the following configuration in order to solve the above problems.
<Configuration 1>
Built-in damper with built-in plastic metal core as a damper mechanism responsible for energy absorption function accompanying at least one plastic deformation inside laminated rubber body with thin flat plate elastic material and rigid material alternately laminated in the vertical direction In the type of laminated rubber seismic isolation device,
The plastic metal core is configured by concentrically arranging an inner metal and an outer metal each having two types of plastic deformation capacities having different yield strength and elastic modulus in a horizontal section, and the inner metal And a composite metal core in which an outer metal whose yield strength and elastic modulus are higher than those of the inner metal is arranged on the outside of the inner metal, and both are in close contact with each other.
Deformation in which shear deformation is excellent by increasing the bending rigidity increase rate to a larger degree than the composite metal core's shear rigidity increase rate for a metal core composed of the inner metal alone with the entire cross section of a metal core having the same plane cross-sectional dimension. As a mode, energy absorption performance by plastic deformation is further stabilized,
When the horizontal shear resistance of the plastic metal core is compared with the same cross-sectional area, the horizontal shear resistance QA of the metal core A having the entire cross section made of the outer metal alone and the metal core having the entire cross section made of the inner metal alone The horizontal shear resistance QC of the composite metal core C is compared to the horizontal shear resistance QB of the metal core A and the horizontal shear resistance QB of the metal core B with respect to the horizontal shear resistance QB of B (QB <QA). A seismic isolation device characterized in that the horizontal shear resistance is of any strength between and is set as QB ≦ QC <QA.

<Configuration 2>
In the seismic isolation device described in Configuration 1, as a combination of the material of the outer metal and the inner metal constituting the composite metal core, a combination 1 (the outer metal is tin and the inner metal is lead), a combination 2 (the above Outer metal as aluminum, inner metal as lead or tin, combination 3 (outer metal as zinc, inner metal as lead, tin, or aluminum), combination 4 (outer metal as copper, inner metal as One of lead, tin, aluminum, and zinc (however, each material includes the respective alloy).

<Configuration 3>
In the seismic isolation device according to Configuration 1 or Configuration 2, the vertical cross-sectional shape of the composite metal core is a tapered columnar body having a plane dimension from the upper end to the lower end that is substantially the same or slightly different, and the outer metal And when the planar cross-sectional shape of the inner metal is any one of a circle, an approximate square, or an approximately regular polygon less than an octagon, and the planar shape is a circle, both the outer surface of the outer metal and the inner and outer metals A seismic isolation device, wherein two or more vertical ribs having a concave shape or a convex shape are provided on the boundary surface of the base plate.

<Configuration 4>
In the seismic isolation device described in any one of Configuration 1 to Configuration 3,
The material of the outer metal constituting the composite metal core is tin or an alloy thereof, and the material of the inner metal is lead or an alloy thereof,
The cross-sectional shape of the outer metal and the inner metal is either a circle, a square, or a regular regular polygon less than an octagon,
A seismic isolation device characterized in that the thickness t1 of the outer metal is 0.35 or less (t1 / dp ≦ 0.35) with respect to the outer dimension dp of the composite metal core.

<Configuration 5>
In the seismic isolation device according to any one of Configurations 1 to 4, a core fixing lid member in which a center portion of a plane is twisted is embedded in an upper end portion, a lower end portion, or upper and lower end portions of the composite metal core. A seismic isolation device, wherein the core fixing lid member is made of copper or a copper alloy.

<Configuration 6>
A method of manufacturing a seismic isolation device including the composite metal core according to any one of Configurations 1 to 5,
Utilizing the difference in melting point of the metal material used for the outer metal and the inner metal,
When the melting point of the outer metal is higher than the melting point of the inner metal, the inner metal that has been melted at a temperature equal to or lower than the melting point of the outer metal is inserted into the inner cavity of the outer metal that has been shaped to a predetermined size and shape in advance. Producing the composite metal core by pouring, or
When the melting point of the outer metal is lower than the melting point of the inner metal, a mold having an inner surface shape equal to the outer surface shape of the outer metal is created, and the inner metal shaped in advance is placed inside the mold, A method of manufacturing a seismic isolation device, wherein the composite metal core is manufactured by injecting the outer metal in a molten state at a temperature lower than the melting point of the inner metal into the gap.

<Configuration 7>
A method of manufacturing a seismic isolation device including the composite metal core according to any one of Configurations 1 to 5,
The composite is obtained by shaping the inner metal into a predetermined size and shape in advance, immersing the outer metal in a molten bath, and forming a surface plating layer of the outer metal on the outer surface of the inner metal. Manufacture metal cores, or
The composite metal core is manufactured by spraying the outer metal on at least a side surface of the inner metal shaped in advance into a predetermined size and shape to form a thin film of the outer metal. A method of manufacturing a seismic isolation device incorporating a metal core.

The first effect of the present invention is that the horizontal shear resistance of the metal core can be set arbitrarily.
In the present invention, in order to configure the metal core incorporated in the laminated rubber as a hybrid core in which two kinds of metal materials are combined, both horizontal shear resistances of the metal core are constituted by two kinds of metal cores alone. Any horizontal shear resistance can be freely set within the intermediate range of the horizontal shear resistance.
That is, when the horizontal shear resistance of the plastic metal core is compared with the same cross-sectional area, the horizontal shear resistance QA of the metal core A in which the entire cross section is constituted by the outer metal alone and the metal core B in which the entire cross section is constituted by the inner metal alone. The horizontal shear resistance QC of the composite metal core C is an arbitrary value between the horizontal shear resistance QA of the metal core A and the horizontal shear resistance QB of the metal core B with respect to the horizontal shear resistance QB (QB <QA). It is possible to set the horizontal shear resistance of the strength of QB ≦ QC <QA.
In the above description, QC = QB is included when the outer metal A is formed as a thin film by plating or thermal spraying in the configuration 7, and the resistance QC is approximately close to QB (QC≈QB). ing.

The second effect of the present invention is the same effect as the first point, but the strength (horizontal shear resistance per unit area) of the metal core can be freely adjusted.
When the horizontal shear resistance of the metal core is expressed as the average shear stress per unit area, the yield shear stress of the outer metal is τ1, the yield shear stress of the inner metal is τ2 (τ2 <τ1), When the ratio of the cross-sectional area A1 of the outer metal to the cross-sectional area A0 is RA1 (= A1 / A0), the average yield shear stress degree τ3 per unit area of the composite metal core is τ3 = τ1 × RA1 + τ2 (1-RA1). The average shear yield stress degree τ3 (τ2 ≦ τ3 <τ1) having an arbitrary strength between τ1 and τ2 can be set according to the area ratio of the two kinds of metals combined.

  Next, as the third point of the effect of the present invention, the bending rigidity EI3 and shear rigidity GA3 of the composite metal core adopting a material having a higher elastic modulus than the inner metal as the outer metal, and the bending rigidity EI2 and shear of the inner metal core alone are used. When compared with the rigidity GA2, the contribution of the secondary moment I, which determines the bending rigidity of the metal core, to the outside of the cross section of the core is higher The rate of increase CEI = EI3 / EI2 and CGA = GA3 / GA2 with respect to the latter (cross-sectional performance of the inner metal core alone) of the former (cross-sectional performance of the composite metal core) and the latter (cross-sectional performance of the inner metal core alone). In general, CEI> CGA. Therefore, in the composite metal core of the present invention, the rate of increase in bending stiffness is higher than the rate of increase in shear stiffness, so bending deformation is less likely to occur as a deformation mode when a horizontal force is applied to the composite metal core. That is, since the composite metal core of the present invention is less likely to bend and deform, it becomes a shear deformation-dominant deformation mode, generates more stable shear deformation, and exhibits stable energy absorption characteristics.

  The fourth point of the effect of the present invention is that when lead is used for the inner metal of the composite metal core and a material other than lead, such as tin, is used for the outer metal, lead that is toxic to the human body is toxic. Therefore, the safety in handling during the manufacturing process and the safety and hygiene issues for workers are improved.

  As a method of combining the composite metal core of the present invention, when lead is used for the inner metal and the thickness of the outer metal is reduced to a thin film by plating or thermal spraying, the mechanical properties of the composite metal core are those of the inner metal (lead). It is possible to realize a metal core that almost matches the characteristics and that the surface has no toxicity in handling.

The fifth point of the effect of the present invention is the effect of eliminating the weak point of the laminated rubber containing a tin plug.
As a laminated rubber seismic isolation device with a metal core other than lead, there is a laminated rubber with a tin plug, and its adoption has been increasing in recent years. This device is a thermal material pointed out in paragraphs [0018] to [0021]. Has weaknesses. On the other hand, in the device of the present invention in which tin is used for the outer metal and lead is used for the inner metal, the heat generated in the tin portion can be transferred to the lead portion having a large heat capacity and a low calorific value. Temperature rise, and the heat capacity of the entire core is increased, and lead with a high melting temperature covers the thermal degradation of tin. It is improved and the thermal problem of the laminated rubber with tin plug can be solved.

  As a sixth effect, in the present invention, the planar shape of the composite metal core is also devised. That is, when the plane is a polygon such as a square, the rib may be omitted. However, when the plane shape of the composite metal core is circular, two or more vertical surfaces are formed on the outer side surface of the metal core and the boundary surface between the outer metal and the inner metal. Ribs are to be provided. As a result, when the seismic isolation device is forced to deform in two horizontal directions at the same time, especially when the device upper surface is subjected to vibration that rotates the upper surface of the device in a plane, It is impossible to cause rotation around the vertical axis, and energy absorption performance by stable plastic deformation can be exhibited in any vibration mode, particularly circular vibration.

  Further, when a square (side length D) is adopted as the planar shape of the metal core, when the same planar dimension (D = d) is adopted as compared with the conventional circular section (diameter dφ), the cross-sectional area of the core is 1.27. Since it is doubled (= 4 / π), there is an effect that the device has a higher attenuation performance (energy absorption performance).

Furthermore, there is an effect from an economic viewpoint. One of the issues with tin plug-containing laminated rubber at present is the problem of cost. That is, since the material cost of tin used for the core is extremely high, the price of the laminated rubber containing a tin plug is extremely high. As the composite metal core of the present invention, lead is used for the inner metal, tin is used for the outer metal, and the thickness of the outer metal tin is appropriately restricted, thereby eliminating the toxicity and improving the strength. It becomes possible to suppress to the level.

It is a figure which shows the basic composition of the conventional damper built-in type seismic isolation device, (1) The longitudinal cross-sectional view which shows having a core in the center of a laminated rubber body, (2) A circular core in the plane center of a laminated rubber body It is a horizontal sectional view showing that it is built. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows Example 1 of this invention, and shows the basic composition of the whole seismic isolation apparatus which incorporates a composite metal core, (1) The longitudinal cross-section which shows having a composite metal core in the center of a laminated rubber body (2) It is a horizontal sectional view showing that a square plane composite metal core is built in the center of the plane of the laminated rubber body. It is explanatory drawing which shows Example 2 (Structure 3) of this invention, (1A) It is a composite metal core with a circular planar shape, and has four vertical ribs on the outer peripheral side surface and the boundary surface between the outer metal and the inner metal. (2A) Elevated view of the composite metal core, (3A) Longitudinal cross section showing a case where a suspension connecting member is built in the upper and lower ends of the composite metal core, 1B) A horizontal sectional view showing a composite metal core having a substantially square planar shape, (2B) an elevation view of the composite metal core, and (3A) a core fixing lid member is built in the upper and lower ends of the composite metal core. FIG. It is a figure which shows Example 3 (metal core manufactured by the structure 7) of this invention, (1A) It is a figure which shows the composite metal core with a circular planar shape, and is vertical to the side surface and the boundary surface of an outer side metal and an inner side metal. Horizontal cross-sectional view showing a situation in which the outer metal is a thin film formed by plating or thermal spraying, and the cross section of the composite metal core is mostly composed of the inner metal in the case of having four ribs. (2A) Standing of the composite metal core (1B) Horizontal sectional view showing a state in which the cross section of the composite metal core is mostly composed of the inner metal because the outer metal is a thin film formed by plating or spraying. (2B) Elevated view of the composite metal core. It is a figure which shows Example 4 of the composite metal core of this invention, In the case where the planar shape of a composite metal core is circular or square, and the material of an outer metal is tin, and the material of an inner metal is lead, It is explanatory drawing which shows the change of the average shear yield stress degree (tau) of a composite metal core by the ratio of the thickness of an outer side metal. It is a figure which shows Example 5 of this invention, The planar dimension (diameter) of a composite metal core when the planar shape of a composite metal core is circular, the material of an outer metal is tin, and the material of an inner metal is lead, and an outer side It is explanatory drawing which shows the change of the horizontal shearing resistance force Qd of the composite metal core by the thickness of a metal. It is a figure which shows Example 6 of this invention, The planar dimension (diameter) of a composite metal core when the planar shape of a composite metal core is square, the material of an outer metal is tin, and the material of an inner metal is lead, and an outer side It is explanatory drawing which shows the change of the horizontal shearing resistance force Qd of the composite metal core by the thickness of a metal. It is a figure which shows Example 7 of this invention, The material of a composite metal core by the area ratio (A1 / A0) of an outer metal and the whole composite metal core when the material of an outer metal is tin and the material of an inner metal is lead. It is explanatory drawing which shows the raise rate (with respect to the core which comprised the whole core with lead) of bending rigidity EI and shear rigidity GA. FIG. 10 is a diagram showing Example 8 of the present invention, where the outer metal material is tin and the inner metal material is lead, and the bending stiffness EI of the composite metal core according to the thickness ratio (2t1 / dp) of the outer metal. It is explanatory drawing which shows the increase rate (with respect to the core which comprised the whole core with lead) of shear rigidity GA. Regardless of whether the planar shape of the core is circular or square, the increase rate curve is common (common if the outer peripheral shape and the inner metal are the same planar shape and the outer metal has a uniform thickness t1). It is a figure for demonstrating the 6th effect of this invention, (1) The longitudinal cross-sectional view which shows the state which the laminated rubber which has a core in the center of a laminated rubber body received the forced deformation in the horizontal direction (5 direction) (2) After being deformed in the above 5 direction, when deformed in the orthogonal direction (6 direction), that is, the upper end surface of the laminated rubber body is 7 as compared to the lower end surface fixed to the base side. Isometric view showing the possibility that the built-in circular plane core may rotate around the vertical axis like 8 in the conventional device when subjected to forced deformation in the rotating direction. (3) Same as 2 above It is an isometric view showing that the core of the square plane (or circular plane with vertical ribs) of the present invention cannot be rotated about the vertical axis even when subjected to forced deformation.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the part which is common in each Example.

FIG. 2 shows Example 1 of Configuration 1 and Configuration 2 of the present invention. 2 (1) is a longitudinal sectional view, and FIG. 2 (2) is a horizontal sectional view.
The seismic isolation device of Example 1 includes at least one plastic in the laminated rubber body 1 in which thin flat rubber layers 11 (elastic material) and internal steel plates 2 (rigid material) are alternately laminated in the vertical direction. This is a damper built-in laminated rubber seismic isolation device including a plastic metal core 30 as a damper mechanism that bears an energy absorbing function accompanying deformation.
The plastic metal core 30 is configured by concentrically arranging an inner metal 32 and an outer metal 31 each having two types of plastic deformation capacities having different yield strength and elastic modulus in a horizontal section. Further, as a combination condition of both, an outer metal 31 having an elastic modulus and a yield strength higher than that of the inner metal 32 is arranged outside the inner metal 32, and the both are brought into close contact with each other to form a composite metal core 30. As shown in FIG. 2 (2), the composite metal core 30 is formed in a substantially square planar shape.
By arranging a material having a higher longitudinal elastic modulus and higher yield strength than the inner metal 32 on the outer metal 31, the shear of the composite metal core can be reduced with respect to the metal core constituted by the inner metal 32 alone having the same plane cross-sectional dimension. It is possible to greatly increase the bending rigidity increasing rate than the rigidity increasing rate. As a result, the bending deformation of the metal core is reduced, and the shear deformation can be made excellent as a deformation mode, the shear plastic deformation is stabilized, and the energy absorption performance by the plastic deformation is further stabilized.

A thick end steel plate 25 is provided near the upper and lower ends of the composite metal core 30, and the flange steel plate 4 is provided on the outside thereof.
As specific combinations of the materials of the outer metal 31 and the inner metal 32, there are the following four combinations. That is, in the combination 1, the outer metal 31 is tin and the inner metal 32 is lead. In the combination 2, the outer metal 31 is aluminum and the inner metal 32 is lead or tin. In the combination 3, the outer metal 31 is zinc, and the inner metal 32 is any one of lead, tin, and aluminum. In the combination 4, the outer metal 31 is copper, and the inner metal 32 is any one of lead, tin, aluminum, and zinc.
Any of these combinations (however, each material includes an alloy thereof) can be adopted. However, as a typical example, the outer metal 31 is tin and the inner metal 32 is lead (including each alloy). ) Combination.
With the above configuration, in the present invention, when the horizontal shear resistance force of the plastic metal core (composite metal core) 30 is compared with the same cross-sectional area, the horizontal shear resistance force of the metal core A having the entire cross section composed of the outer metal 31 alone. The horizontal shear resistance QC of the composite metal core C is equal to the horizontal shear resistance QC of the metal core A with respect to the horizontal shear resistance QB (QB <QA) of the metal core B that is configured by QA and the inner metal 32 alone. It is possible to set the horizontal shear resistance of any strength between QA and the horizontal shear resistance QB of the metal core B, that is, QB ≦ QC <QA.

FIG. 3 shows an embodiment of the configuration 3 of the present invention, and shows a specific shape of a built-in composite metal core. 3 (1A) to (3A) are cases where the planar shape of the composite metal core is circular, and FIG. 3 (1A) is a horizontal sectional view of the composite metal core 30. FIG. FIG. 3 (2A) is an elevational view of the composite metal core 0, and the vertical ribs 33 on the outer peripheral portion can be seen. FIG. 3 (3 </ b> A) is an example of a longitudinal sectional view of the composite metal core 0.
The vertical cross-sectional shape of the composite metal core 30 is a columnar body with a taper having slightly the same or slightly different planar dimensions from the upper end to the lower end. The horizontal cross-sectional shape of the outer metal 31 and the inner metal 32 is any one of a circular shape, a substantially square shape, or an approximately regular polygon shape having an octagon or less. Further, when the planar shape is circular, four (two or more) vertical ribs 33 are provided on the outer surface of the outer metal 31, and four vertical grooves ( (Vertical unevenness shape) 34 is fitted and integrated.
FIG. 3 (3A) also shows a core fixing lid member 36 used for hanging work or the like at the time of manufacturing laminated rubber at the upper and lower ends of the core. The lid member 36 has a “confinement function” that encloses the outflow of the core metal to the upper part due to the deformation of the core metal at the time of earthquake, and residual deformation occurs by configuring the lid member with copper or a copper alloy. "Residual deformation release function" that makes it easy to release the residual deformation by heating and raising the temperature of the core metal after energization, and recrystallizing the metal crystals caused by plastic deformation by the temperature rise and cooling It has a “metal structure regenerating function” for urging and thereby recovering the structure of the metal core by eliminating plastic strain.

  3 (1B) to (3B) are cases where the planar shape of the composite metal core is an approximate square, FIG. 3 (1B) is a horizontal sectional view of the composite metal core 30, and FIG. 3 (2B) is an elevation view. FIG. 3 (3B) is a longitudinal sectional view. When the planar shape is square or polygonal, there is no possibility that the flange 4 meshes with each other depending on the outer shape of the metal core outer shape and the inner steel plate 2 and end steel plate 25 of the laminated rubber, and causes a rotational deviation around the vertical axis. Vertical ribs on the outer periphery are not required. Further, since the outer metal 31 and the inner metal 32 mesh with each other and there is no possibility of causing a rotational shift around the vertical axis, the vertical concave and convex grooves at the boundary between the two metals are unnecessary.

The role of the core fixing lid members at the upper and lower ends of the core in FIG. 3 (3B) is as described in the description of FIG. 3 (3A).
3 (3A) and FIG. 3 (3B) show a circumferential groove (horizontal uneven shape) 35 at the boundary between the outer metal 31 and the inner metal 32. FIG. This is a vertical misalignment prevention between both metals to prevent vertical slip between the two metals when the composite metal core is forced to deform in the horizontal direction. The metal core in which two kinds of metals are combined generates strain as a whole, so that plastic deformation becomes uniform and stable energy absorption performance can be exhibited.

The configuration 6 defines a method for manufacturing the composite metal core 30 shown in FIG. 3 by utilizing the difference in melting points of the metal materials used for the outer metal 31 and the inner metal 32. That is, when the melting point of the outer metal 31 is higher than the melting point of the inner metal 32, the inner side of the outer metal 31 shaped into a predetermined size and shape is melted at a temperature lower than the melting point of the outer metal 31. The composite metal core 30 can be manufactured by injecting the metal 32.
Conversely, if the melting point of the outer metal 31 is lower than the melting point of the inner metal 32, a mold having an inner surface shape equal to the outer surface shape of the outer metal 31 is created, and the preshaped inner metal 32 is placed inside the mold. Thus, the composite metal core 30 can be manufactured by injecting the outer metal 31 in a molten state at a temperature lower than the melting point of the inner metal 32 into the gap between them.

FIG. 4 shows an embodiment of the configuration 7 of the present invention. FIGS. 4 (1A) to (2A) show that when the planar shape of the composite metal core is circular, FIGS. 4 (1B) to (2B) This is a case where the planar shape of the composite metal core is approximately square.
4 (1A) and (1B) are horizontal sectional views of the composite metal core 30, and FIGS. 4 (2A) and (2B) are elevation views of the composite metal core 30. FIG.
In the seismic isolation device of the present embodiment, the inner metal 32 is shaped in advance to have a predetermined size and shape, and the outer metal is immersed in a molten tank so that the outer metal 31 surface is placed on the outer surface of the inner metal 32. The composite metal core 30 is manufactured by forming a plating layer, or the outer metal 31 is sprayed on at least the side surface of the inner metal 32 shaped in advance to a predetermined size and shape to form a thin film of the outer metal. The composite metal core 30 is manufactured by forming.
Since the outer metal 31 is formed as a thin film by plating or spraying, it is only displayed as an outline 311 in the drawing, and the inner metal 32 occupies most of the core. At this time, the inner metal 32 is made of lead, and the outer metal 31 (311) is made of tin, aluminum, or other non-toxic metal and is coated and coated, so that the mechanical performance of the metal core exhibits the characteristics of lead. In addition, the seismic isolation device has been realized that is free from sanitary and environmental problems. By this example, the problem of toxicity of the laminated rubber containing lead plugs was solved and solved.
In the present embodiment, since the outer metal is configured as a thin film, the resistance force by the outer metal is extremely small, and the resistance force QC of the composite metal core C is a value that is substantially close to the resistance force QB of the inner metal B (QC≈ QB).

FIG. 5 specifically shows the combined effect of two kinds of metals according to configurations 1 and 2 of the present invention. The average shear stress τ of the composite metal core 30 when the outer metal 31 of the composite metal core 30 is combined with tin and the inner metal 32 is lead is the ratio 2t1 of the composite metal core 30 diameter dp and the thickness t1 of the outer metal 31. It shows how it changes according to / dp.
That is, when the horizontal axis 2t1 / dp = 0, the horizontal shear resistance (average shear stress) τ matches the shear yield stress τ of lead of the inner metal 32 = 8 (N / mm 2). When the outer metal 31 of Example 3 is formed as a thin film by plating or thermal spraying, it substantially corresponds to this state.
As shown in FIG. 5, as the thickness of the outer metal 31 increases, the horizontal shear resistance of the composite metal core 30 increases. When the horizontal axis becomes 2t1 / dp = 1, the horizontal shear resistance of the composite metal core 30 increases. (Average shear stress degree) τ corresponds to the outer metal 31, that is, the shear yield stress degree ττ15 (N / mm 2) when the entire cross section is made of tin. As shown in the figure, in the present invention, the average shear stress can be adjusted to an arbitrary strength as long as it is between the horizontal shear resistances of the two metals by combining the two kinds of metals. This graph shows the same curve whether the planar shape of the composite metal core 30 is circular or square in the combination of tin and lead, and the outer metal 31 and the inner metal 32 have the same shape even in the case of a polygon. If the thickness t1 is uniform, it agrees with this curve.

FIG. 6 shows the relationship between the actual dimension (composite metal core (plug) diameter dp) of the composite metal core 30 and the horizontal shear resistance Qd when the outer metal 31 shown in FIG. 5 is tin and the inner metal 32 is lead. Is shown. The planar shape of the metal core is a circular shape.
The plug diameter dp is in the range of φ100 mm to φ300 mm, and among the plurality of curves, the horizontal shear resistance in the case where the lowermost line is made of lead in all cross sections and the uppermost line is made of tin in all cross sections It is power. It can be seen that the horizontal shear resistance Qd can be increased very efficiently by setting the thickness of the tin of the outer metal 31 to about 50 mm even when the thickness of the tin is only from t1 = 10 mm to 300 mmφ.

FIG. 7 shows the side length dp and horizontal shear resistance of the composite metal core 30 (plug) when the planar shape of the composite metal core 30 in which the outer metal 31 is tin and the inner metal 32 is lead is square, as in FIG. The relationship of force Qd is shown.
The dimension of the square plug is that the side length dp is in the range of 100 mm to 300 mm. When the lowermost line is composed of lead in all cross sections, the uppermost line is the horizontal shear resistance when the entire cross section is composed of tin. is there. Similar to FIG. 6, the horizontal shear resistance Qd can be raised very efficiently by making the thickness of the tin of the outer metal 31 as small as t1 = 10 mm to 50 mm. This shows that the horizontal shear resistance Qd is considerably larger than that of a circular plane.

FIG. 8 shows the extent to which the bending rigidity EI and shear rigidity GA of the metal core are increased by compounding the metal core. The composite metal is shown as the ratio of rigidity to the case where the outer metal 31 is combined with tin and the inner metal 32 is lead as in the previous example, and the entire cross section is made of lead.
The planar shape of the composite metal core 30 is circular, and the diameter dp of the composite metal core 30 (plug) is in the range of φ100 mm to φ300 mm, but this graph does not depend on the core dimensions, and is the same for all dimensions.
Among the plurality of lines, the lowermost line (A1 / A0 = 0) is a case where the entire cross section is made of lead, and this rigidity is set to a reference value = 1. The uppermost line (A1 / A0 = 1) is the rigidity when the entire cross section is made of tin. The rate of increase in bending rigidity EI is the ratio of the longitudinal elastic modulus of tin and lead, and the rate of increase in shear rigidity GA is tin. And the ratio of shear modulus of lead. The plurality of intermediate lines indicate the value of the ratio A1 / A0 of the area A1 of the outer metal 31 (tin) with respect to the total cross-sectional area A0 of the core as a parameter.
As can be seen from the comparison of both figures, it can be clearly seen that when the area ratio of the outer metal 31 is the same, the increase rate of the bending stiffness is larger than the increase rate of the shear stiffness. It is one of the important points of the present invention that the rate of increase in bending stiffness is higher than the rate of increase in shear stiffness.

FIG. 9 shows the rate of increase of the bending rigidity EI and shear rigidity GA in the composite metal core 30 as the ratio 2t1 / dp of the thickness t1 of the outer metal 31 to the diameter dp of the circular core on the horizontal axis. The composite metal is shown as the rate of increase in rigidity with respect to the rigidity (reference value = 1) when the outer metal 31 is combined with tin and the inner metal 32 is combined with lead as in the previous example, and the entire cross section is composed of lead. .
As can be seen from this graph, the rate of increase in stiffness of the composite metal core 30 is in the range of 2t1 / dp = 0 to 0.7, and the rate of increase in bending stiffness exceeds the rate of increase in shear stiffness. 2t1 / dp≈0.7 Reverses at That is, when the composite metal core 30 is composed of the outer metal 31 as tin and the inner metal 32 as lead, the thickness of the outer metal 31 (tin) should be in the range of t1 / dp = 0 to 0.35. is there.
Within the range of this condition, the composite metal core 30 of the present invention becomes a metal core in a deformation mode in which shear deformation is easy to be excellent, and it can be expected to exhibit stable energy absorption performance.
This graph shows the same curve whether the planar shape of the composite metal core 30 is circular or square in the combination of tin and lead, and the outer metal 31 and the inner metal 32 have the same shape even in the case of a polygon. If the thickness t1 is uniform and symmetric with respect to the central axis (neutral axis) of the cross section, it coincides with this curve.

  Considering the above FIG. 6, FIG. 7, and FIG. 9 simultaneously, it can be seen that the present invention has the following excellent effects. That is, in the case where the composite metal core 30 is constituted by using the outer metal 31 as tin and the inner metal 32 as lead, the horizontal shear resistance of the core can be obtained only by setting the thickness of the tin of the outer metal 31 to about 10 to 20 mm. While the force can be increased considerably, the bending rigidity of the core is greatly increased (2 t1 / dp≈0.1 to 0.2 for the average core dimension dp = 200 mm), and the shear deformation is excellent. It becomes the deformation mode of the mold and can exhibit stable energy absorption characteristics.

  At this time, a large heat capacity is secured for the entire core due to the effect of the lead of the inner metal 32 (the lead area is 90 to 81% of the whole), so that the temperature rising at the tin portion is quickly transmitted to the lead portion. The temperature rise of the entire core is suppressed. As a result, in the case of a laminated rubber with a tin plug in which the entire core is made of tin, in the case of a severe earthquake input in which a large deformation is repeated many times, the horizontal shear resistance is drastically reduced due to the temperature rise of the tin plug. In some cases, the composite metal core 30 of the present invention greatly improves and eliminates the risk of lowering the horizontal shear resistance due to the temperature rise and the risk of melting the core itself.

FIG. 10 is an embodiment showing one of the effects of the laminated rubber seismic isolation device incorporating the composite metal core 30 of the present invention.
FIG. 10A is a longitudinal sectional view showing a state (deformation 1) in which the laminated rubber body 1 is subjected to horizontal shear deformation in the direction of arrow 5. The built-in core 3 is deformed as shown in the figure in accordance with the horizontal deformation of the laminated rubber body 1, and the upper end portion 38 of the core is parallel to the horizontal deformation amount of the laminated rubber with respect to the lower end portion 37 of the core. The position is shifted.
After this state, when the deformation of the laminated rubber upper end 38 proceeds in the orthogonal direction 6 different from the direction of the arrow 5 (deformation 1) by 90 °, the force acting in the direction of the arrow 6 in FIG. The center arrow) is a moment (torsional force) for rotating the core 3 with respect to the lower end portion 37 of the core, and the core 3 tends to rotate around the vertical axis as indicated by the arrow 8. When the core 3 follows the horizontal deformation of the laminated rubber body by the rotational deformation around the vertical axis, the plastic shear deformation does not occur in the core itself, and as a result, the energy absorption performance of the core is not exhibited.

  In the present invention, when the planar shape of the composite metal core 30 is a polygon such as a square, or the planar shape is a circle, two or more vertical ribs are provided on the outer side surface of the metal core and the boundary surface between the outer metal and the inner metal. I have to. As a result, even when the seismic isolation device is forced to deform in two horizontal directions at the same time, particularly when subjected to vibration such as arrow 7 in which the upper surface of the device rotates in a plane with respect to the lower surface of the device, In this case, the metal core 30 cannot rotate around the vertical axis, and can exhibit an energy absorbing performance by stable plastic deformation against any vibration, particularly circular vibration. It has.

As described above, in the laminated rubber containing the composite metal core 30 according to the present invention, the horizontal shear resistance of the core that cannot be achieved by a single metal can be set to an appropriate level, and at the same time, stable energy absorption performance can be exhibited. As a result, it has become possible to greatly improve the performance and reliability of laminated rubber with built-in dampers so far.
In particular, after experiencing the 2011 Tohoku-Pacific Ocean Earthquake (M9.0) in 2011, the M9-level super-large earthquake has come to be recognized as a realistic thing in Japan, and it is a severe period that lasts for a long period and continues for a long time. When assuming strong ground motions in two horizontal directions, it is expected that the seismic isolation device of the present invention will play a significant role.

1: Laminated rubber body 11: Rubber layer 2: Internal steel plate
21: Central hole of the inner steel plate 23: Recessed notch at the end of the central hole of the inner steel plate 25: Upper and lower end steel plates of the laminated rubber body 3: Built-in metal core 30: Composite metal core 31: Outer metal 311: Thin film Outer metal (by plating or spraying)
32: Inner metal 33: Convex-shaped vertical rib on the outer periphery of the composite metal core 34: Vertical groove (vertical uneven shape of the metal boundary of the composite metal core)
35: Circumferential groove (horizontal uneven shape at the metal boundary of the composite metal core)
36: Core fixing lid members above and below the composite metal core 37: Lower end and lower end surface of the built-in core 38: Upper end and upper end surface of the built-in core 4: Flange steel plates above and below the laminated rubber body 5: Deformation 1 of the seismic isolation device Arrow indicating direction 6: Arrow indicating the direction of deformation 2 of the seismic isolation device (direction perpendicular to deformation 1) 7: Arrow indicating the rotational direction deformation of the seismic isolation device 8: Direction of rotational deformation around the vertical axis of the built-in core Showing arrow

Claims (6)

Built-in damper with built-in plastic metal core as a damper mechanism responsible for energy absorbing function accompanying at least one plastic deformation inside laminated rubber body with thin flat plate elastic material and rigid material alternately laminated in the vertical direction Type laminated rubber seismic isolation device ,
The plastic metal core is configured by concentrically arranging an inner metal and an outer metal each having two types of plastic deformation capacities having different yield strength and elastic modulus in a horizontal section, and the inner metal And a composite metal core in which an outer metal whose yield strength and elastic modulus are higher than those of the inner metal is arranged on the outside of the inner metal, and both are in close contact with each other.
Deformation in which shear deformation is excellent by increasing the bending rigidity increase rate to a larger degree than the composite metal core's shear rigidity increase rate for a metal core composed of the inner metal alone with the entire cross section of a metal core having the same plane cross-sectional dimension. As a mode, energy absorption performance by plastic deformation is further stabilized,
When the horizontal shear resistance of the plastic metal core is compared with the same cross-sectional area, the horizontal shear resistance QA of the metal core A having the entire cross section made of the outer metal alone and the metal core having the entire cross section made of the inner metal alone The horizontal shear resistance QC of the composite metal core C is compared to the horizontal shear resistance QB of the metal core A and the horizontal shear resistance QB of the metal core B with respect to the horizontal shear resistance QB of B (QB <QA). In the seismic isolation device set as horizontal shear resistance of arbitrary strength between QB ≦ QC <QA ,
As a combination of materials of the outer metal and the inner metal constituting the composite metal core, a combination 1 (the outer metal is tin and the inner metal is lead), a combination 2 (the outer metal is aluminum and the inner metal is lead) Or tin), combination 3 (the outer metal is zinc, the inner metal is any of lead, tin, and aluminum), and combination 4 (the outer metal is copper, and the inner metal is any of lead, tin, aluminum, and zinc) ) (Where each material includes its respective alloy) . In the seismic isolation device according to claim 1,
The vertical cross-sectional shape of the composite metal core is a columnar body with a taper having a slightly different planar dimension from the upper end to the lower end, or slightly different,
The cross-sectional shape of the outer metal and the inner metal is either a circle, a square, or a regular regular polygon less than an octagon,
In addition, when the planar shape is circular, two or more vertical ribs having a concave shape or a convex shape are provided on the outer surface of the outer metal and the boundary surface between the inner and outer metals . In the seismic isolation device according to claim 1 or claim 2,
The material of the outer metal constituting the composite metal core is tin or an alloy thereof, and the material of the inner metal is lead or an alloy thereof,
The cross-sectional shape of the outer metal and the inner metal is either a circle, a square, or a regular regular polygon less than an octagon,
A seismic isolation device characterized in that the thickness t1 of the outer metal is 0.35 or less (t1 / dp ≦ 0.35) with respect to the outer dimension dp of the composite metal core . In the seismic isolation apparatus according to any one of claims 1 to 3,
A core fixing lid member in which the center portion of the plane is twisted is embedded in the upper end portion or lower end portion of the composite metal core, or both upper and lower end portions,
A seismic isolation device, wherein the core fixing lid member is made of copper or a copper alloy . A method of manufacturing a seismic isolation device incorporating the composite metal core according to any one of claims 1 to 4 ,
Utilizing the difference in melting point of the metal material used for the outer metal and the inner metal,
When the melting point of the outer metal is higher than the melting point of the inner metal, the inner metal that has been melted at a temperature equal to or lower than the melting point of the outer metal is inserted into the inner cavity of the outer metal that has been shaped to a predetermined size and shape in advance. Producing the composite metal core by pouring, or
When the melting point of the outer metal is lower than the melting point of the inner metal, a mold having an inner surface shape equal to the outer surface shape of the outer metal is created, and the inner metal shaped in advance is placed inside the mold, A method of manufacturing a seismic isolation device, wherein the composite metal core is manufactured by injecting the outer metal in a molten state at a temperature lower than the melting point of the inner metal into the gap. A method of manufacturing a seismic isolation device incorporating the composite metal core according to any one of claims 1 to 4 ,
The composite is obtained by shaping the inner metal into a predetermined size and shape in advance, immersing the outer metal in a molten bath, and forming a surface plating layer of the outer metal on the outer surface of the inner metal. Manufacture metal cores, or
The composite metal core is manufactured by spraying the outer metal on at least a side surface of the inner metal shaped in advance into a predetermined size and shape to form a thin film of the outer metal. A method of manufacturing a seismic isolation device incorporating a metal core.