JP2004011692A - Damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping device that certainly positions a hard sphere and generates no vertical movement in an upper part of a structure. <P>SOLUTION: The damping device 1 comprises a cylindrical elastic body 2 made of rubber, a hard sphere 3 stored inside the cylindrical elastic body 2 while contacting with the inner surface of the cylindrical elastic body 2, upper and lower hard boards 4 and 5 mounted to respective upper and lower end surfaces of the cylindrical elastic body 2, and a positioning member 6. The damping device 1, in setting, positions the hard sphere 3 in the center of the cylindrical elastic body 2 with the positioning member 6. Thus, the positioning of the hard sphere is certainly performed and the upper and lower hard boards 4 and 5 have no uneven part, so that no vertical movement occurs in the upper part of the structure. In the damping device 1, a relation between the deformation amount and the reaction force in the shearing direction of the device, and damping performance are accurately predicted, and the practical application is easy. <P>COPYRIGHT: (C)2004,JPO

Description

【００２９】
次に、硬球体３は、所要の剛性を備えた球状体であり、例えば、鋼鉄製の鋼球を採用することができる。
【００３０】
硬球体３の滑らかな転動を確保するため、硬球体３と硬質板４、５は載荷時にそれぞれが変形しないように同程度の硬度を有する材料（例えば、ロックウェル硬度で±５以内、望ましくは同一材料）で形成することが望ましい。なお、同程度の硬度であれば、一方を金属、他方をプラスチックにしてもよい。ただし、硬質板４、５側に大きな凹状変形が生じると、水平せん断変位−水平反力の履歴曲線に負勾配を生じ、不安定な応答性能を示すため、硬質板４、５の硬度は硬球体３の硬度よりも高いことが望ましい。また、両者の材質をＳ４５Ｃに焼入れ・焼鈍しの熱処理を加えてロックウェル硬度を３０以上にすることにより、載荷時においてほとんど変形が生じないものとなる。
【００３１】
また、硬球体３が転動する上下の硬質板４、５の転動面は、凹凸のない平らな面で形成されている。
【００３２】
次に、位置決め部材６は、中心部に硬球体３が嵌まる穴７がある円板形状の部材である。位置決め部材６の内径は、硬球体３の直径よりも少し小さく、位置決め部材６の外径は筒状弾性体２の内径と略同じである。位置決め部材６は設置時に硬球体３を位置決めするのに必要な剛性を備えていればよく、地震時においては硬球体３の転動を妨げないものが良い。位置決め部材６の材質は、装置に変形が加わった場合に、位置決め部材６が筒状弾性体２を損傷させないように、筒状弾性体２よりも低硬度の材料を用いることが好ましい。例えば、多孔質でない弾性材料を用いる場合は、ＪＩＳＡ硬度１０〜８０程度にするとよく、より好ましくは、ＪＩＳＡ硬度２０〜５０程度にするのがよい。
【００３３】
また、位置決め部材６の材質は、装置に変形が加わった場合に、大きな反力値を示すことが無いよう、可撓性材料、弾性材料又は合成樹脂製の多孔質材（例えば、スポンジ）を採用するのがよい。
【００３４】
制振装置１は、例えば、下側の硬質板５に、筒状弾性体２を加硫接着し、硬球体３を位置決め部材６に嵌め、この状態で、硬球体３と位置決め部材６を筒状弾性体２の内部に入れ、位置決め部材６の外周縁を筒状弾性体２の内周面に嵌め、上側の硬質板４を筒状弾性体２の上端に加硫接着したものである。そして、下側の硬質板５を構造物の下部構造の上面に取り付け、上側の硬質板４を構造物の上部構造の下面に取り付ける。制振装置１の取り付けは、例えば、ボルト締結によって行う。この制振装置１は、制振装置１の位置決め部材６の穴７に硬球体３が嵌まっているので、制振装置１を設置する時に、硬球体３が筒状弾性体２の中央位置からずれることはない。これにより、常時は硬球体３が確実に筒状弾性体２の中央で荷重を受けることができるようになっている。
【００３５】
また、制振装置１は１ｋＮ以上の力で、構造物の上部構造と下部構造の間に挟んで設置する。これにより、硬球体３と上下の硬質板４、５の接触部分に十分に大きな摩擦力が作用し、硬球体３が上下の硬質板４、５の間で滑ることなく転動するようになる。なお、１ｋＮ以上の力で制振装置１を構造物の上部構造と下部構造の間に挟んで設置することにより、硬球体３と上下の硬質板４、５との間に滑りがなくなることは本発明者らが実験により見出した知見によるものである。このため、例えば、構造物の上部構造の重さに対し、一つの制振装置１が支持する荷重が１ｋＮ以上になるように、制振装置１の設置個数とその配置を定めるのがよい。
【００３６】
この制振装置１は、筒状弾性体２の内周面に嵌めた位置決め部材６の穴７に硬球体３が嵌まっており、風や交通振動などの軽微なせん断方向の外力が作用した場合は、位置決め部材６が硬球体３の転動を規制する。すなわち、位置決め部材６は制振機能を発揮させるトリガーとしての機能も備えている。これに対して、地震のような大きな揺れに対しては、地震による上側の硬質板４と下側の硬質板５の相対的な変位を受けて、硬球体３は図２に示すように転動する。このとき、図示は省略するが、硬球体３の転動する力が大きいため、位置決め部材６は硬球体３の転動に応じて変形または破損する。
【００３７】
なお、位置決め部材６は、設置時に硬球体３の位置を筒状弾性体２の中央に位置決めすることを主目的としているので、設置後に位置決め部材６に塑性変形や破損が生じてもよい。また、位置決め部材６は、大きな地震が発生したときには、硬球体３の転動を妨げないことが重要であるので、破損時に破片が硬球体３の転動面に落ちるような脆い材料は適切でない。従って、位置決め部材６には、可撓性材料や、高弾性ゴムやエストラマーのような高弾性材料や、スポンジのように大きな変形を許容する合成樹脂（例えば、ポリエチレン、ポリプロピレン、ポリウレタン、ポリスチレン、ポリアクリルニトリルなど）の多孔質材料を用いるのがよい。
【００３８】
この制振装置１は、位置決め部材６によって、設置時に硬球体３を筒状弾性体２の中央に位置決めしている。そして、硬球体３は上下の硬質板４、５との間で滑ることなく転動するので、上下の硬質板４、５間の相対変位ｙは硬球体３の転動距離ｘの略２倍になる。これにより、この制振装置１は、装置のせん断方向への変形量とせん断方向の反力の関係、および、制振性能を正確に予測することができる。
【００３９】
また、地震が発生した時は、地震の揺れと慣性力による上下の硬質板４、５の水平方向の相対的な変位を受けて、硬球体３は、上下の硬質板４、５との間で滑ることなく転動する。このとき、上下の硬質板の転動面に凹凸がないので、構造物の上部構造に上下動が生じない。
【００４０】
地震が収まると、筒状弾性体２の弾性復元力を受けて、上下の硬質板４、５は相対的に元の位置に戻る。上下の硬質板４、５が元の位置に戻ると、硬球体３は上下の硬質板４、５との間で滑ることなく転動するので、再び筒状弾性体２の中央に戻る。
【００４１】
また、従来の免震工法では、図３に示すように、建物の固有周波数を長周期化させることにより、振動伝達率（地震周波数／固有振動数）を大きくし、これにより、優れた振動吸収性能を備えていた。これに対して、この制振装置１は、ｔａｎδが０．３以上（好ましくは、０．５以上）の高い減衰性を示す弾性材料からなる筒状弾性体２を用いて、共振ポイントにおける応答増幅倍率を低くすることにより、振動吸収性能を確保している。
【００４２】
また、この制振装置１は、免震工法のように建物の固有周波数の長周期化を意図しないので、小型で、かつ、安価である。このため、多くの制振装置１を使うことができ、上部構造をより多くの制振装置１で支持することができる。従って、通常の基礎パッキン材と同様に使えるので、上部構造の土台を補強する必要がない。また、上部構造と下部構造の相対的な変位も大きくはないので配管も上部構造と下部構造の間において大型のフレキシブルな継手を必要としない。この結果、従来の免震工法に比べて設置コスト総額が格段に安くなる。
【００４３】
すなわち、この制振装置１と従来の免震工法を比べると、振動吸収性能は、従来の免震工法の方が優れているのであるが、この制振装置１は、それ自体が安価であること、土台の補強が不要であること、配管の継手も変更が不要であることなどにより、設置コストを低コストにでき、また必要な振動吸収性能が得られるというメリットがある。
【００４４】
以上に説明したように、この制振装置１は、位置決め部材６によって、設置時に硬球体３を筒状弾性体２の中央に位置決めしたので、装置のせん断方向への変形量とせん断方向の反力の関係、および、制振性能を正確に予測することができる。
【００４５】
また、この制振装置１は、筒状弾性体２の内径を硬球体３の直径よりも大きくして、硬球体３の転動範囲を広く確保することができ、建物の固有周波数を長周期化させることもできる。
【００４６】
また、筒状弾性体２に高い減衰性を有する弾性材料を用いることにより、より好適な振動吸収性能が得られるようになる。
【００４７】
以上、本発明の一実施形態を説明したが、本発明は上記の実施形態に限定されるものではない。
【００４８】
位置決め部材６は、中心部に硬球体３が嵌まる穴７がある円板形状のものを挙げたが、これに限定されるものではない。例えば、図４（ａ）〜（ｄ）に示す６ａ〜６ｄのように、硬球体３が嵌まる穴７を備え、かつ、筒状弾性体２の内周面に嵌まる外形形状を備えるものであれば、様々な形状を採用することができる。そして、スペーサの形状を隙間の多い形状にしたり、硬球体３と筒状弾性体２の内周面に接触する比率を変えたりすることにより、硬球体３を支持する弾性を調節することができる。
【００４９】
また、位置決め部材６の厚さを変えることにより、硬球体３を支持する弾性を調節するようにしてもよい。位置決め部材６の厚さは、硬球体３の直径φｄの１／４０〜１、より好ましくは、１／５〜１／１０の厚さにするのがよく、通常は、１〜２０ｍｍにするのがよい。
【００５０】
また、位置決め部材６のトリガー作用を調節するには、位置決め部材６の応力歪み曲線を適当なものになるように設定すればよい。
【００５１】
また、特に住宅用の制振装置１については、図５に示すように、制振装置１の高さＨは、２０〜６０ｍｍにすると良い。高さＨが２０ｍｍよりも低いと、通気性能が不十分で基礎パッキン材としての機能が不十分になる。また、高さＨが６０ｍｍよりも高いと、せん断ばね定数が低く成り過ぎて不安定になり、制振装置１が大型化してコスト高になる。また、筒状弾性体の外径ｄ２は８０〜１３０ｍｍ、筒状弾性体２の内径ｄ１は硬球体３の直径ｄの１．１倍以上で３．５倍以下にするのが良い。これより大きいと制振装置１が大型化してコスト高になるからである。また、筒状弾性体２の厚さｄ３は、硬球体３の直径ｄの０．５倍より大きいのが良い。ゴムの厚さｄ３が小さいとせん断変形しにくくなるからである。
【００５２】
次に、本発明の他の実施形態に係る制振装置を説明する。
【００５３】
この制振装置１は、図６に示すように、位置決め部材６に代えて、筒状弾性体２の内周面から内径方向に一体的に延在した延在部８により、硬球体３を筒状弾性体２の内部空間の中央に位置決めしたものである。
【００５４】
図７に示すように、筒状弾性体２を成形する金型において、筒状弾性体２の内部空間を形成する中芯型を、上下に分割した分割型９、１０とし、この分割型９、１０の分割部の外周部分１１に延在部８に対応する成形材料充填空間を設けて、延在部８を筒状弾性体２と同時に成形するようにするとよい。
【００５５】
この延在部８の硬球体３を位置決めする作用は、位置決め部材６と同じであるので、その説明は省略する。
【００５６】
【発明の効果】
請求項１に記載の制振装置は、筒状弾性体の内周面と硬球体の外周面の間に充填した位置決め部材により、硬球体を筒状弾性体の内部空間の中央部に位置決めしたので、設置時に硬球体を確実に筒状弾性体の中央に位置決めすることができる。これにより、装置のせん断方向への変形量とせん断方向の反力の関係、および、制振性能を正確に予測することができ、実用化が容易である。また、上下の硬質板の転動面に凹凸がないので、構造物の上部構造に上下動が生じない。
【００５７】
請求項２に記載の制振装置は、位置決め部材が筒状弾性体の高さ方向の中央部、および、硬球体の高さ方向の中央部に接したプレート状の部材であるので、位置決め部材の厚さを変えることにより、硬球体を支持する弾性を調節することができる。
【００５８】
請求項３に記載の制振装置は、位置決め部材を筒状弾性体と硬球体を損傷させない材料で形成したので、地震発生時に、位置決め部材が硬球体の転動を妨げず、十分な制振性能を発揮することができる。
【００５９】
請求項４に記載の制振装置は、前記位置決め部材が、可撓性材料、弾性材料、又は、合成樹脂の多孔質体で構成したので、地震発生時に、筒状弾性体と硬球体を損傷させず、位置決め部材が硬球体の転動を妨げないので、十分な制振性能を発揮することができる。
【００６０】
請求項５に記載の制振装置は、筒状弾性体の内周面から内径方向に一体的に延在した延在部により、硬球体を筒状弾性体の内部空間の中央部に位置決めしたので、別途位置決め部材を設ける必要がなく、製造コストを低減させることができる。
【図面の簡単な説明】
【図１】（ａ）は、本発明の一実施形態に係る制振装置を示す縦断面図であり、（ｂ）はそのＡ−Ａ端面図である。
【図２】本発明の一実施形態に係る制振装置において、硬質板に変位が生じた状態を示す縦断面図である。
【図３】本発明の一実施形態に係る制振装置の建物の固有周波数と応答増幅倍率の関係を示す図。
【図４】（ａ）〜（ｄ）は、位置決め部材の変形例を示す図である。
【図５】本発明の一実施形態に係る制振装置の寸法例を説明する縦断面図である。
【図６】本発明の他の実施形態に係る制振装置の縦断面図である。
【図７】本発明の他の実施形態に係る制振装置の筒状弾性体の製造方法を示す図。
【図８】従来の基礎パッキン材を示す図。
【符号の説明】
１　制振装置
２　筒状弾性体
３　硬球体
４　上側の硬質板
５　下側の硬質板
６　位置決め部材
７　穴
８　延在部
９、１０　分割型[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vibration damping device mounted between an upper structure and a lower structure of a structure to alleviate shaking of the upper structure during an earthquake, and more particularly to a base packing material for ventilation of a base portion of a house. The present invention also relates to an apparatus which is not bulky, inexpensive, and has a high-performance vibration absorbing function, also serving as an anchor member.
[0002]
[Prior art]
A seismic isolation method in which the upper structure swings by inertia with respect to the lower structure of the structure is known as a method of reducing the shaking of the upper structure during an earthquake and imparting the structure with earthquake resistance. The seismic isolation method is an excellent method for improving the seismic resistance of a house, and includes, for example, a sliding bearing and an elastic bearing installed between an upper structure and a lower structure of a structure. In the seismic isolation method, the amplitude of the upper structure with respect to the lower structure is made as large as possible, and the vibration of the upper structure during an earthquake is made longer, so that the vibration during the earthquake can be more effectively mitigated. ing.
[0003]
However, the equipment used in the seismic isolation method is large and has a high unit price in order to increase the amplitude of the superstructure in order to extend the period of the building. In order to reduce the cost, many devices used for the seismic isolation method cannot be used, so that the superstructure cannot be supported by many devices. For this reason, it is necessary to reinforce the base in order to prevent the base from bending due to the concentrated load. In addition, in the seismic isolation method, since the amplitude of the upper structure is large, it is necessary to use a flexible joint between the lower structure and the upper structure for the piping, which also increases the cost. As described above, the seismic isolation method has excellent vibration absorption performance, but is not widely used in ordinary houses because it is large and expensive.
[0004]
It is also desired for general houses to have seismic performance, and it is desired to provide devices with low cost and excellent seismic performance.
[0005]
On the other hand, as shown in FIG. 8, the base packing material 100 for ventilation of the base part of the house is a substantially rectangular member made of an elastic material. It is generally known that a plurality of concrete bodies 101 and a foundation 103 of a house are arranged at a predetermined interval. The inside of the basic concrete 101 can be ventilated by a gap provided by the basic packing material 100, and the flow of air in the basic concrete 101 is improved. In addition, the base packing material 100 has an effect of cutting off the edge between the base concrete 101 and the base 103 of the house so that the moisture absorbed by the base concrete 101 is not transmitted to the base.
[0006]
JP-A-2000-73616 and JP-A-2000-110403 disclose the above-mentioned base packing material and those having a function of absorbing vibration caused by large vehicles such as earthquakes and dump trucks and vibrations caused by the passage of railway vehicles. JP-A-2001-182366 and JP-A-9-242381. In both cases, the load of the structure is received by the hard sphere and transmitted to the foundation. In response to the shaking of the earthquake, the hard sphere rolls and transmits only a fraction of the sway of the foundation to the base (rolling). As the earthquake subsides, it is restored to its original position before the earthquake.
[0007]
Japanese Patent Application Laid-Open No. 2000-73616 discloses a system in which a cylindrical elastic body having a space in which a hard sphere can roll is fixed between a base metal fitting and a base metal fitting, and a hard sphere is accommodated in the cylindrical elastic body. A vibration device is described. In this vibration damping device, the inner diameter of the cylindrical elastic body is made larger than the diameter of the hard sphere, and a rolling space in which the hard sphere can roll is formed inside the cylindrical elastic body. The reason for providing such a rolling space is to allow the rolling of the hard sphere, to prolong the shaking of the building, and to function the seismic isolation function.
[0008]
Japanese Patent Application Laid-Open No. 2000-110403 further discloses a vibration damping device in which the height of the cylindrical elastic body is set to the same size as the diameter of the hard sphere so that the hard sphere is provided in each of the upper substrate and the lower substrate. Has been described.
[0009]
Japanese Patent Application Laid-Open No. 2001-182366 describes a vibration damping device in which hard spheres are provided between upper and lower dish-shaped steel plate members having vertically symmetric concave surfaces.
[0010]
Japanese Patent Application Laid-Open No. Hei 9-242381 discloses an arrangement in which a hard sphere is disposed at the center of a mortar-shaped recess formed on the upper surface of a lower support plate.
[0011]
By installing a plurality of such devices at predetermined intervals on the foundation of the structure, a ventilation gap can be formed between the devices, and a foundation for ensuring air permeability in the underfloor space can be formed. It also functions as a packing material.
[0012]
[Problems to be solved by the invention]
When a space in which a hard sphere can roll is provided, as in the vibration damping devices described in JP-A-2000-73616 and JP-A-2000-110403, the hard sphere can move freely. Unless a special structure is added at the time, the hard sphere is displaced from the center position of the internal space of the cylindrical elastic body during transportation or after assembly in a state where no vertical load is applied before construction, and the cylindrical elastic body May be in contact with the inner peripheral surface of the. In order to put the vibration damping device into practical use, the relationship between the amount of deformation of the device in the shear direction and the reaction force in the shear direction must be clear based on the Building Standards Law. In the vibration damping devices described in JP-A-2000-73616 and JP-A-2000-110403, since the position of the hard sphere in the cylindrical elastic body is indefinite, the movable range is small or indefinite. The relationship between the amount of deformation in the shear direction and the reaction force in the shear direction is not clear. Therefore, it could not be put to practical use. In addition, since the relationship between the amount of deformation of the device in the shear direction and the reaction force in the shear direction is unknown, there has been another problem that the vibration control performance cannot be accurately predicted.
[0013]
In contrast, in the vibration damping devices described in JP-A-2001-182366 and JP-A-9-242381, at least the lower support plate has a mortar-shaped recess, and the hard sphere has a mortar-shaped recess. It is located in the center. Therefore, the above problem does not occur. However, in this structure, the hard sphere rolls on the mortar-shaped recess when it shakes due to an actual earthquake, etc., and accordingly, the upper structure of the structure moves up and down, and the structure and the inside of it May damage furniture. Processing a mortar-shaped recess in the lower support plate is costly.
[0014]
Therefore, an object of the present invention is to provide a vibration damping device that can reliably position a hard sphere and does not cause vertical movement in the upper structure of a structure.
[0015]
[Means for Solving the Problems]
The vibration damping device according to claim 1, comprising: a cylindrical elastic body; hard spheres housed in the cylindrical elastic body; and upper and lower hard plates attached to upper and lower end surfaces of the cylindrical elastic body, respectively. In a vibration damping device mounted between an upper structure and a lower structure of an object, a positioning member filled between an inner peripheral surface of the cylindrical elastic body and an outer peripheral surface of the hard sphere causes the hard sphere to have a cylindrical elasticity. It is characterized by being positioned at the center of the internal space of the body. In this vibration damping device, since the hard sphere is positioned at the center of the cylindrical elastic body at the time of installation by the positioning member, the relationship between the amount of deformation of the device in the shear direction and the reaction force in the shear direction, and the vibration damping performance Can be accurately predicted, and practical application is easy. In addition, since the rolling surfaces of the upper and lower hard plates have no irregularities, no vertical movement occurs in the upper structure of the structure.
[0016]
According to a second aspect of the present invention, in the vibration damping device, the positioning member is a plate-shaped member that is in contact with the center of the cylindrical elastic body in the height direction and the center of the hard sphere in the height direction. And This vibration damping device can adjust the elasticity for supporting the hard sphere by changing the thickness of the positioning member and the shape of the plate. The thickness of the positioning member is, for example, preferably 1/5 to 1/10 of the diameter of the hard sphere.
[0017]
The vibration damping device according to claim 3 is characterized in that the positioning member is formed of a material that does not damage the cylindrical elastic body and the hard sphere. Thus, when an earthquake occurs, the positioning member does not hinder the rolling of the hard sphere, so that sufficient vibration damping performance can be exhibited. For example, the hardness of the positioning member is a hardness that does not damage the cylindrical elastic body, and is, for example, a JISA hardness of about 10 to 80, preferably a JISA hardness of 20 to 50.
[0018]
According to a fourth aspect of the present invention, in the vibration damping device, the positioning member is made of a porous body made of a flexible material, an elastic material, or a synthetic resin.
[0019]
The vibration damping device according to claim 5, comprising: a cylindrical elastic body; hard spheres housed in the cylindrical elastic body; and upper and lower hard plates attached to upper and lower end surfaces of the cylindrical elastic body, respectively. In a vibration damping device mounted between an upper structure and a lower structure of an object, a hard sphere is formed into a cylindrical elastic body by an extending portion integrally extending in an inner diameter direction from an inner peripheral surface of the cylindrical elastic body. It is characterized by being positioned at the center of the internal space of the body. According to this, since there is no need to provide a separate positioning member, manufacturing costs can be reduced.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a vibration damping device according to an embodiment of the present invention will be described with reference to the drawings.
[0021]
As shown in FIGS. 1A and 1B, the vibration damping device 1 includes a cylindrical elastic body 2 made of rubber and a cylindrical elastic body 2 in a state of being inscribed in an inner peripheral surface of the cylindrical elastic body 2. It comprises a hard sphere 3 housed therein, upper and lower hard plates 4 and 5 attached to upper and lower end surfaces of the cylindrical elastic body 2, respectively, and a positioning member 6.
[0022]
The cylindrical elastic body 2 is a substantially cylindrical member made of a highly damping elastic material. The inner diameter of the cylindrical elastic body 2 is larger than the diameter of the hard sphere 3. The height of the cylindrical elastic body 2 is the same as the diameter of the hard sphere 3 or slightly higher than the diameter of the hard sphere 3.
[0023]
The shear elastic modulus of the elastic material used for the cylindrical elastic body 2 is 80 N / cm ² or more, preferably 100 N / cm ² or more, and more preferably 200 N / cm ^{2 at a half} amplitude of 25% or less with respect to the height. It is preferable that it is above. Further, the loss coefficient tan δ of the elastic material used for the tubular elastic body 2 is preferably 0.3 or more, more preferably 0.5 or more, and further preferably 0.7 or more.
[0024]
Here, when the dynamic characteristics of the rubber material are expressed by complex elastic modulus, the real part is called storage elastic modulus G1, the imaginary part is called loss elastic modulus G2, and the ratio of storage elastic modulus G1 to loss elastic modulus G2 is the loss coefficient. It is called tan δ.
Loss coefficient tan δ = storage elastic modulus G1 / loss elastic modulus G2
[0025]
The loss coefficient tan δ is one of the evaluation indexes of the vibration damping characteristics of the vibration damping material. That is, when the vibration damping material has a damping in the vibration response system, its stress / strain diagram (or load / displacement diagram) draws a hysteresis loop (hysteresis loop). And is proportional to the ratio of the energy consumed to the maximum energy stored, corresponding to about twice the equivalent damping constant. The larger the loss coefficient tan δ, the higher the damping property of the material.
[0026]
Regarding the material of the cylindrical elastic body 2, it is preferable that the cylindrical elastic body 2 is made of NR high-attenuation compound rubber and coated with a weather-resistant material. Weather resistant materials include butyl rubber (IIR), ethylene propylene rubber (EPDM), and the like. The inner peripheral surface of the cylindrical elastic body 2 containing the hard spheres 3 is coated with a lubricant to smoothly roll the hard spheres 3 during an earthquake, or the cylindrical elastic body 2 containing the hard spheres 3 is coated with a lubricant. It is preferable that the inside is filled with a lubricant and the inner peripheral surface of the cylindrical elastic body 2 is covered with an oil-resistant material.
[0027]
Table 1 shows a preferred compounding example of the rubber material of the tubular elastic body 2. The cylindrical elastic body 2 may be coated with a weather-resistant material, for example, a rubber composition containing butyl rubber as a main component (for example, about 1 mm thick) in order to improve weather resistance. In addition, in Table 1, phr means the symbol used when the mass of a compounding agent is shown by the number of parts with respect to 100 parts of rubber.
[0028]
[Table 1]

[0029]
Next, the hard sphere 3 is a sphere having a required rigidity. For example, a steel ball made of steel can be adopted.
[0030]
In order to ensure smooth rolling of the hard sphere 3, the hard sphere 3 and the hard plates 4, 5 are made of a material having the same degree of hardness so that they are not deformed during loading (for example, Rockwell hardness within ± 5, preferably Are preferably formed of the same material). In addition, if it is about the same hardness, one may be metal and the other may be plastic. However, when a large concave deformation occurs on the hard plates 4 and 5 side, a negative gradient is generated in a hysteresis curve of horizontal shear displacement-horizontal reaction force and unstable response performance is exhibited. It is desirable that the hardness is higher than the hardness of the sphere 3. In addition, when both materials are subjected to heat treatment of quenching and annealing to S45C to have a Rockwell hardness of 30 or more, almost no deformation occurs at the time of loading.
[0031]
The rolling surfaces of the upper and lower hard plates 4 and 5 on which the hard sphere 3 rolls are formed as flat surfaces without irregularities.
[0032]
Next, the positioning member 6 is a disk-shaped member having a hole 7 in the center portion into which the hard sphere 3 fits. The inner diameter of the positioning member 6 is slightly smaller than the diameter of the hard sphere 3, and the outer diameter of the positioning member 6 is substantially the same as the inner diameter of the cylindrical elastic body 2. The positioning member 6 only needs to have the rigidity necessary for positioning the hard sphere 3 at the time of installation, and preferably does not hinder the rolling of the hard sphere 3 during an earthquake. The material of the positioning member 6 is preferably a material having a lower hardness than the cylindrical elastic body 2 so that the positioning member 6 does not damage the cylindrical elastic body 2 when the device is deformed. For example, when a non-porous elastic material is used, the JIS hardness is preferably about 10 to 80, more preferably about 20 to 50.
[0033]
The material of the positioning member 6 is a porous material (for example, sponge) made of a flexible material, an elastic material, or a synthetic resin so as not to show a large reaction force value when the device is deformed. Good to adopt.
[0034]
For example, the vibration damping device 1 is configured such that the cylindrical elastic body 2 is vulcanized and bonded to the lower hard plate 5 and the hard sphere 3 is fitted to the positioning member 6. The positioning member 6 is fitted inside the cylindrical elastic body 2, the outer peripheral edge of the positioning member 6 is fitted to the inner peripheral surface of the cylindrical elastic body 2, and the upper hard plate 4 is vulcanized and bonded to the upper end of the cylindrical elastic body 2. Then, the lower hard plate 5 is attached to the upper surface of the lower structure of the structure, and the upper hard plate 4 is attached to the lower surface of the upper structure of the structure. The vibration damping device 1 is attached by, for example, bolting. In the vibration damping device 1, the hard sphere 3 is fitted into the hole 7 of the positioning member 6 of the vibration damping device 1. Therefore, when the vibration damping device 1 is installed, the hard sphere 3 is positioned at the center of the cylindrical elastic body 2. There is no deviation. This ensures that the hard sphere 3 can always receive the load at the center of the tubular elastic body 2 at all times.
[0035]
The vibration damping device 1 is installed between the upper structure and the lower structure of the structure with a force of 1 kN or more. Thereby, a sufficiently large frictional force acts on the contact portion between the hard sphere 3 and the upper and lower hard plates 4, 5, and the hard sphere 3 rolls without sliding between the upper and lower hard plates 4, 5. . By installing the vibration damping device 1 between the upper structure and the lower structure of the structure with a force of 1 kN or more, slippage between the hard sphere 3 and the upper and lower hard plates 4 and 5 can be eliminated. This is based on the findings that the present inventors have found through experiments. For this reason, for example, it is preferable to determine the number of vibration damping devices 1 and the arrangement thereof so that the load supported by one vibration damping device 1 is 1 kN or more with respect to the weight of the upper structure of the structure.
[0036]
In this vibration damping device 1, the hard sphere 3 is fitted in the hole 7 of the positioning member 6 fitted on the inner peripheral surface of the cylindrical elastic body 2, and a small external force in the shear direction such as wind or traffic vibration acts. In this case, the positioning member 6 regulates the rolling of the hard sphere 3. That is, the positioning member 6 also has a function as a trigger for exerting a vibration damping function. On the other hand, for a large shake such as an earthquake, the hard sphere 3 is rolled as shown in FIG. 2 due to the relative displacement of the upper hard plate 4 and the lower hard plate 5 due to the earthquake. Move. At this time, although not shown, since the rolling force of the hard sphere 3 is large, the positioning member 6 is deformed or damaged in accordance with the rolling of the hard sphere 3.
[0037]
In addition, since the positioning member 6 mainly aims at positioning the position of the hard sphere 3 at the center of the cylindrical elastic body 2 at the time of installation, the positioning member 6 may undergo plastic deformation or breakage after installation. Since it is important that the positioning member 6 does not hinder the rolling of the hard sphere 3 when a large earthquake occurs, a brittle material that causes fragments to fall on the rolling surface of the hard sphere 3 when damaged is not appropriate. . Therefore, the positioning member 6 is made of a flexible material, a highly elastic material such as a highly elastic rubber or an elastomer, or a synthetic resin such as a sponge that allows a large deformation (for example, polyethylene, polypropylene, polyurethane, polystyrene, polystyrene). It is preferable to use a porous material such as acrylonitrile.
[0038]
In the vibration damping device 1, the positioning member 6 positions the hard sphere 3 at the center of the tubular elastic body 2 at the time of installation. Since the hard sphere 3 rolls without slipping between the upper and lower hard plates 4 and 5, the relative displacement y between the upper and lower hard plates 4 and 5 is approximately twice the rolling distance x of the hard sphere 3. become. Accordingly, the vibration damping device 1 can accurately predict the relationship between the amount of deformation of the device in the shear direction and the reaction force in the shear direction, and the vibration damping performance.
[0039]
When an earthquake occurs, the hard sphere 3 receives a relative displacement between the upper and lower hard plates 4 and 5 due to the horizontal displacement of the upper and lower hard plates 4 and 5 due to the shaking of the earthquake and the inertial force. Rolls without slipping. At this time, since the rolling surfaces of the upper and lower hard plates have no irregularities, no vertical movement occurs in the upper structure of the structure.
[0040]
When the earthquake stops, the upper and lower hard plates 4 and 5 relatively return to their original positions by receiving the elastic restoring force of the tubular elastic body 2. When the upper and lower hard plates 4 and 5 return to their original positions, the hard spheres 3 roll without sliding between the upper and lower hard plates 4 and 5 and thus return to the center of the tubular elastic body 2 again.
[0041]
In addition, in the conventional seismic isolation method, as shown in FIG. 3, the natural frequency of a building is made longer to increase the vibration transmissibility (earthquake frequency / natural frequency), thereby providing excellent vibration absorption. It had performance. On the other hand, the vibration damping device 1 uses the cylindrical elastic body 2 made of an elastic material having a high damping property with a tan δ of 0.3 or more (preferably 0.5 or more), and a response at a resonance point. The vibration absorption performance is secured by lowering the amplification factor.
[0042]
Further, since the vibration damping device 1 is not intended to increase the natural frequency of the building as in the seismic isolation method, it is small and inexpensive. Therefore, many damping devices 1 can be used, and the upper structure can be supported by more damping devices 1. Therefore, since it can be used in the same manner as a normal base packing material, there is no need to reinforce the base of the upper structure. Further, since the relative displacement between the upper structure and the lower structure is not large, the piping does not require a large-sized flexible joint between the upper structure and the lower structure. As a result, the total installation cost is significantly lower than the conventional seismic isolation method.
[0043]
That is, when comparing the vibration damping device 1 with the conventional seismic isolation method, the vibration absorption performance of the conventional seismic isolation method is superior, but the vibration damping device 1 itself is inexpensive. Since there is no need to reinforce the base and no need to change the joints of the pipes, there is an advantage that the installation cost can be reduced and the required vibration absorption performance can be obtained.
[0044]
As described above, in the vibration damping device 1, the positioning member 6 positions the hard sphere 3 at the center of the cylindrical elastic body 2 at the time of installation. It is possible to accurately predict the relationship between the forces and the damping performance.
[0045]
In addition, the vibration damping device 1 can secure the wide rolling range of the hard sphere 3 by making the inner diameter of the cylindrical elastic body 2 larger than the diameter of the hard sphere 3, and increase the natural frequency of the building to a long period. It can also be converted.
[0046]
Further, by using an elastic material having a high damping property for the tubular elastic body 2, more suitable vibration absorbing performance can be obtained.
[0047]
As described above, one embodiment of the present invention has been described, but the present invention is not limited to the above embodiment.
[0048]
The positioning member 6 is a disk-shaped member having a hole 7 in the center where the hard sphere 3 fits, but the positioning member 6 is not limited to this. For example, as shown in 6a to 6d shown in FIGS. 4 (a) to 4 (d), those having a hole 7 into which the hard sphere 3 fits and having an outer shape fitting into the inner peripheral surface of the cylindrical elastic body 2 If so, various shapes can be adopted. Then, the elasticity for supporting the hard sphere 3 can be adjusted by changing the shape of the spacer to a shape having a large gap or changing the ratio of the hard sphere 3 to the inner peripheral surface of the cylindrical elastic body 2. .
[0049]
Further, the elasticity for supporting the hard sphere 3 may be adjusted by changing the thickness of the positioning member 6. The thickness of the positioning member 6 is preferably 1/40 to 1 of the diameter φd of the hard sphere 3, more preferably 1/5 to 1/10, and usually 1 to 20 mm. Is good.
[0050]
Further, in order to adjust the triggering action of the positioning member 6, the stress-strain curve of the positioning member 6 may be set to an appropriate one.
[0051]
In particular, as for the vibration damping device 1 for a house, as shown in FIG. 5, the height H of the vibration damping device 1 is preferably set to 20 to 60 mm. When the height H is lower than 20 mm, the ventilation performance is insufficient and the function as a basic packing material is insufficient. On the other hand, if the height H is higher than 60 mm, the shear spring constant becomes too low and becomes unstable, resulting in an increase in the size of the vibration damping device 1 and an increase in cost. Further, the outer diameter d2 of the cylindrical elastic body is preferably 80 to 130 mm, and the inner diameter d1 of the cylindrical elastic body 2 is preferably not less than 1.1 times and not more than 3.5 times the diameter d of the hard sphere 3. If it is larger than this, the vibration damping device 1 becomes large and the cost increases. The thickness d3 of the cylindrical elastic body 2 is preferably larger than 0.5 times the diameter d of the hard sphere 3. This is because if the thickness d3 of the rubber is small, it is difficult to cause shear deformation.
[0052]
Next, a vibration damping device according to another embodiment of the present invention will be described.
[0053]
As shown in FIG. 6, this vibration damping device 1 is configured such that, instead of the positioning member 6, the hard sphere 3 is extended by the extending portion 8 integrally extending from the inner peripheral surface of the cylindrical elastic body 2 in the inner diameter direction. It is positioned at the center of the internal space of the tubular elastic body 2.
[0054]
As shown in FIG. 7, in the mold for molding the cylindrical elastic body 2, the core mold forming the internal space of the cylindrical elastic body 2 is divided into upper and lower divided molds 9 and 10. It is preferable to provide a molding material filling space corresponding to the extending portion 8 in the outer peripheral portion 11 of the ten divided portions so that the extending portion 8 is molded simultaneously with the cylindrical elastic body 2.
[0055]
The operation of positioning the hard sphere 3 of the extending portion 8 is the same as that of the positioning member 6, and therefore the description thereof is omitted.
[0056]
【The invention's effect】
In the vibration damping device according to the first aspect, the hard sphere is positioned at the center of the internal space of the cylindrical elastic body by the positioning member filled between the inner peripheral surface of the cylindrical elastic body and the outer peripheral surface of the hard sphere. Therefore, at the time of installation, the hard sphere can be reliably positioned at the center of the cylindrical elastic body. This makes it possible to accurately predict the relationship between the amount of deformation of the device in the shear direction and the reaction force in the shear direction and the vibration damping performance, and facilitates practical application. In addition, since the rolling surfaces of the upper and lower hard plates have no irregularities, no vertical movement occurs in the upper structure of the structure.
[0057]
In the vibration damping device according to the second aspect, the positioning member is a plate-shaped member that is in contact with the central portion in the height direction of the cylindrical elastic body and the central portion in the height direction of the hard sphere. By changing the thickness, the elasticity for supporting the hard sphere can be adjusted.
[0058]
In the vibration damping device according to the third aspect, since the positioning member is formed of a material that does not damage the cylindrical elastic body and the hard sphere, the positioning member does not hinder the rolling of the hard sphere when an earthquake occurs, and sufficient vibration damping is achieved. Performance can be demonstrated.
[0059]
In the vibration damping device according to the fourth aspect, since the positioning member is formed of a porous material made of a flexible material, an elastic material, or a synthetic resin, the cylindrical elastic body and the hard sphere are damaged when an earthquake occurs. Since the positioning member does not hinder the rolling of the hard sphere, sufficient vibration damping performance can be exhibited.
[0060]
In the vibration damping device according to the fifth aspect, the hard sphere is positioned at the center of the internal space of the cylindrical elastic body by the extending portion integrally extending in the radial direction from the inner peripheral surface of the cylindrical elastic body. Therefore, there is no need to provide a separate positioning member, and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view showing a vibration damping device according to an embodiment of the present invention, and FIG. 1B is an AA end view thereof.
FIG. 2 is a longitudinal sectional view showing a state in which a hard plate is displaced in the vibration damping device according to one embodiment of the present invention.
FIG. 3 is a diagram showing a relationship between a natural frequency of a building and a response amplification factor of the vibration damping device according to the embodiment of the present invention.
FIGS. 4A to 4D are diagrams showing modified examples of a positioning member.
FIG. 5 is a longitudinal sectional view for explaining an example of dimensions of the vibration damping device according to one embodiment of the present invention.
FIG. 6 is a longitudinal sectional view of a vibration damping device according to another embodiment of the present invention.
FIG. 7 is a view showing a method of manufacturing a cylindrical elastic body of a vibration damping device according to another embodiment of the present invention.
FIG. 8 is a view showing a conventional base packing material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vibration suppression device 2 Cylindrical elastic body 3 Hard sphere 4 Upper hard plate 5 Lower hard plate 6 Positioning member 7 Hole 8 Extension part 9, 10 Split type

Claims (5)

A tubular elastic body, a hard sphere housed in the tubular elastic body, and upper and lower hard plates attached to upper and lower end surfaces of the tubular elastic body, respectively, between an upper structure and a lower structure of the structure. In a vibration damping device that is mounted between
A vibration damping device, wherein the hard sphere is positioned at the center of the internal space of the cylindrical elastic body by a positioning member filled between the inner peripheral surface of the cylindrical elastic body and the outer peripheral surface of the hard sphere. 2. The vibration damping device according to claim 1, wherein the positioning member is a plate-shaped member that is in contact with the center of the cylindrical elastic body in the height direction and the center of the hard sphere in the height direction. 3. . 2. The vibration damping device according to claim 1, wherein the positioning member is formed of a material that does not damage the cylindrical elastic body and the hard sphere. 2. The vibration damping device according to claim 1, wherein the positioning member is formed of a flexible material, an elastic material, or a synthetic resin porous body. 3. A tubular elastic body, a hard sphere housed in the tubular elastic body, and upper and lower hard plates attached to upper and lower end surfaces of the tubular elastic body, respectively, between an upper structure and a lower structure of the structure. In a vibration damping device that is mounted between
A vibration damping device, wherein a hard sphere is positioned at a central portion of an internal space of the cylindrical elastic body by an extending portion integrally extending in an inner diameter direction from an inner peripheral surface of the cylindrical elastic body.

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