JP2004263404A

JP2004263404A - Rolling bearing and anchor structure of structure

Info

Publication number: JP2004263404A
Application number: JP2003053784A
Authority: JP
Inventors: Tatsuji Matsumoto; 達治松本; Katsuyuki Tanaka; 克往田中; Tomoyuki Nishikawa; 知幸西川; Koji Marui; 浩司丸井
Original assignee: Sumitomo Rubber Industries Ltd; Mitsui Home Co Ltd
Current assignee: Sumitomo Rubber Industries Ltd; Mitsui Home Co Ltd
Priority date: 2003-02-28
Filing date: 2003-02-28
Publication date: 2004-09-24
Anticipated expiration: 2023-02-28
Also published as: JP4097198B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive compact support device allowing a hard spherical body to roll smoothly when an earthquake occurs, and provided with vibration absorbing performance and a function as a foundation packing member. <P>SOLUTION: This rolling support device 1 is provided with upper and lower hard plates 4, 5, a cylindrical positioning member 3 arranged between the upper and lower hard plates 4 and 5, and the hard spherical body 2 inscribing in the positioning member 3 and positioned in central parts of the upper and lower hard plates 4, 5. This device is arranged between an upper structure and a lower structure of a structure to support the upper structure of the structure. The positioning member 3 is bonded to either of the upper and lower hard plates 4, 5, and its outer peripheral side is bonded and its inner peripheral side is not bonded. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、構造物の上部構造と下部構造との間に装着され、下部構造の上に上部構造を固定する構造物のアンカー構造に用いる転がり支承装置に関するものである。
【０００２】
【従来の技術】
住宅などの軽量構造物は、一般に布基礎とも言われる基礎コンクリート１０１の上に建築されている。基礎コンクリート１０１（下部構造）の上に建築物（構造物）の土台１０３（上部構造）を固定する場合は、例えば、図６に示すように、Ｌ字状のアンカーボルト１０２の下部を基礎コンクリート１０１に埋設し、アンカーボルト１０２の上部を土台１０３に貫通させ、その土台１０３の上面に突出した部分をワッシャ１０４、ナット１０５で固定している。
【０００３】
しかし、単に土台１０３を基礎コンクリート１０１の上に固定しただけでは、大型車の通行により生じる交通振動が、基礎コンクリート１０１から土台１０３にそのまま伝わる。このため、図７に示すように、土台１０３と基礎コンクリート１０１の間にゴム板１００を挟んで、交通震動を緩和するものがあった。しかし、この場合でも、アンカーボルト１０２が土台１０３と基礎コンクリート１０１をしっかりと連結しており、アンカーボルト１０２を介して基礎コンクリート１０１から土台１０３に震動がそのまま伝わり、震動はさほど緩和されず、十分な免震効果は得られなかった。
【０００４】
なお、このようなゴム板１００は、住宅の基礎部の通気用の基礎パッキン材としての機能を備えている。すなわち、ゴム板１００を、基礎コンクリート１０１と住宅の土台１０３との間に所定の間隔を開けて複数配設することにより、土台１０３と基礎コンクリート１０１との間に生じた隙間から基礎コンクリート１０１の内部の換気が行え、基礎コンクリート１０１内の空気の流れが良くなり、湿気を低減させることができる。また、基礎コンクリート１０１と土台１０３との縁を切ることにより、基礎コンクリート１０１が吸った水分を土台１０３に伝えないという作用がある。
【０００５】
この種の基礎パッキン材の一般的な技術水準を示す公知文献としては、下記の特許文献１が知られている。
【０００６】
また、ダンプカーなどの大型の自動車や鉄道車両の通行に伴う交通振動や地震による振動を吸収する制振機能を兼ね備えた基礎パッキン材としては、上下の硬質板の間に円形の穴を有する復元用のゴム材を配設し、ゴム材の穴の中に硬球体を転動可能に配設した転がり支承構造を備えたものが下記の特許文献２に提案されている。
【０００７】
【特許文献１】特開２００１−３５５３５０号公報
【特許文献２】特開２０００−１１０４０３号公報
【０００８】
【発明が解決しようとする課題】
上述した特許文献１に記載されている基礎パッキン材は、構造物の上部構造と下部構造の間にゴム材を挟んだだけであり、地震やダンプカーなどの大型の自動車による振動や鉄道車両の通行に伴う交通振動を吸収する制振機能が十分でなかった。
【０００９】
また、特許文献２に記載されている基礎パッキン材は、一定の制振効果は期待できるものの、構造上、設置時に硬球体がゴム材の穴の中央に位置していることが保証されていない。このため、硬球体がゴム材の穴の内周面に接した状態で配設されている可能性があり、このような場合には振動時に硬球体がすぐにゴム材に乗り上げてしまう。本発明者らの知見によれば、ゴム材に硬球体が乗り上げると、硬球体が乗り上げた位置でゴム材が破損する場合があるので、十分な制振効果を得ることができない。
【００１０】
また、積層ゴムとオイルダンパーを組み合わせた免震装置はよく知られているが、このような免震工法で用いられる積層ゴムやオイルダンパーは１基あたりの装置が負担する鉛直荷重や水平荷重が大きいため、また構造上小型化することが難しいために、装置が大きく、設置コストや設置スペースが嵩み、一般住宅などの比較的小さな構造物には不経済であり、あまり普及していない。
【００１１】
そこで、本発明者らは、地震時に硬球体が滑らかに転動する転がり支承装置の提供、及び、嵩張らず、安価で、振動吸収性能と基礎パッキン材としての機能を兼ね備えた構造物のアンカー構造の提供を目的としている。
【００１２】
【課題を解決するための手段】
本発明の転がり支承装置は、上下の硬質板と、上下の硬質板の間に配設した軟質弾性体からなる円筒状の位置決め部材と、位置決め部材に内接させて上下の硬質板の中央部に位置決めした硬球体とを備え、構造物の上部構造と下部構造との間に配設されて構造物の上部構造を支持する転がり支承装置において、位置決め部材は、上下の硬質板の何れか一方に接着されていることを特徴としている。さらに位置決め部材は外周側を接着し、内周側を接着しないようにするとよい。また、円滑な転動を確保するため、転がり支承装置の摩擦係数の基準値が０．０３以下にするとよい。また、長期間の性能を確保するため、クリープ歪みについても、２００μｍ以下にすることが好ましい。このクリープ歪みについては、住宅の耐用年数を考慮して、相当期間のクリープ歪みを考慮すると良い。
【００１３】
また、構造物のアンカー構造は、上述した転がり支承装置を、構造物の上部構造の鉛直荷重を支持するように、構造物の下部構造と上部構造との間に分散させて配設するとともに、高減衰ゴムの上下端面に硬質板をそれぞれ取り付けた複数の制振装置を、構造物の上部構造の捩じれ振動を抑制するように、構造物の下部構造と上部構造との間に分散させて配設したことを特徴としている。
【００１４】
【発明の実施の形態】
以下、本発明の一実施形態に係る転がり支承装置及び構造物のアンカー構造を図面に基づいて説明する。
【００１５】
転がり支承装置１は、図１に示すように、硬球体２と、硬球体２を内部に収容する円筒形状の位置決め部材３と、硬球体２及び位置決め部材３を上下に挟む硬質板４、５を備えている。
【００１６】
硬球体２は、所要の硬さと真球度を備えた球体であり、略球形に粗加工した鋼材に転動加工を施して製造したものである。転動加工は、略球形に粗加工した鋼材を研磨板で上下に挟み、研磨板間で転動させて鋼材の表面の歪を除去しながら、球形に整形するものである。硬球体２は、転動加工により加工硬化が生じて硬さが増す。この転動加工によれば、Ｓ１５Ｃなどの安価な鋼材を用いて、ＨＲＣ２０以上の硬さと、高度な真球度を備えた硬球体を得ることができ、硬球体２の部品コストを安くすることができる。なお、硬球体２には、例えば、ニッケルメッキなどの防錆処理を施しておくことが望ましい。
【００１７】
硬質板４、５は、所要の硬さと平面度を備えた略ひし形の板状部材であり、中央部に位置決め部材３を接着して硬球体２を中央に位置決めしている。硬質板４、５には、硬球体２を位置決めする位置を中心として、硬球体２の直径の２倍以上の距離を半径とする円を含む転動面を備えている。硬質板４、５の転動面もニッケルメッキなどの防錆処理を施しておくとよい。
【００１８】
この硬質板４、５は、板状素材に冷間圧延加工を施して製造している。冷間圧延加工は、板状素材を圧延ローラで挟みながら引き抜くものであり、熱処理を施すことがないので歪が生じることがなく、これにより所要の平面度を確保することができる。また加工硬化により所要の硬さを得ることができる。この冷間圧延加工によれば、ＳＵＳ３０４などの鋼材を用いて、ＨＲＣ２０以上、より好ましくはＨＲＣ２５以上の硬質板４、５を得ることができる。
【００１９】
また、硬質板４、５は、設置後、硬球体２から鉛直方向の荷重を受けるのでクリープ歪みにより、鉛直方向に窪みが生じる。地震時に硬球体２を滑らかに転動させるためには、このクリープ歪み量は小さければ小さいほど良い。上述したように冷間圧延加工により加工硬化させたものは、クリープ歪みが小さくなるので好適である。具体的には、６０年相当の鉛直沈み込み量が２００μｍ以下のものを用いることにより、硬球体２の円滑な転動を長期間（一般的な住宅の耐用年数期間）維持することができる。
【００２０】
位置決め部材３は、例えば、軟質ウレタンフォームやポリスチレン発泡体やポリエチレン発泡体などの軟質弾性材料を用いると良い。位置決め部材３の内径は、硬球体２の直径と同じか、硬球体２の直径よりも少し小さいものを用い、硬球体２の位置決めを確実に行えるようにすると良い。また、図１のように、硬球体２の周囲を位置決め部材３で覆うことにより、硬球体２の転動領域に塵や埃が入るのを防止することができる。
【００２１】
この位置決め部材３は、硬球体２の転動に応じて変形し易くするため、下側の硬質板５に接着し、上側の硬質板４には接着していない。また、初動時の硬球体２の転動に対する抵抗を緩和するため、位置決め部材３の接着は、外周側を接着し、内周側は接着していない。例えば、外周側から位置決め部材３の半径方向の厚さの約半分程度を接着すると良い。
【００２２】
この硬質板４、５は、硬球体２を位置決めする位置を中心として、硬球体２の直径の２倍の距離（例えば、硬球体２の直径が４０ｍｍであれば８０ｍｍ）を半径とする円よりも大きい転動面を備えており、この転がり支承装置１は、硬球体２を位置決めする位置を中心として、硬球体２が直径の２倍以上の距離を転動することができるようになっている。
【００２３】
上下の硬質板４、５の両側には、アンカーボルト１３、１４（図２参照）を締結するボルト締結部１５、１６を設けている。片側の第１ボルト締結部１５には両側のボルト締結部１５、１６を結ぶ直線に沿って切欠き１７を形成しており、反対側の第２ボルト締結部１６には両側のボルト締結部１５、１６を結ぶ直線に直交する方向に沿って切欠き１８を形成している。第２ボルト締結部１６の切欠き１８は、詳しくは、第１ボルト締結部１５の所定の締結位置（例えば、設計上のボルト締結位置Ｏ）を中心とし、所定のボルトピッチ（例えば、設計上のボルトピッチＰ）を半径とする円弧Ｃに沿って形成している（図２参照）。
【００２４】
各ボルト締結部１５、１６の切欠き１７、１８の幅は、アンカーボルト１３、１４の直径よりも少し大きくなっており、切欠き１７、１８に沿ってアンカーボルト１３、１４を装着・離脱させることができるようになっている。また、切欠き１７、１８は、施工時の誤差を許容できるように、設計上のボルト締結位置よりも深く形成している。
【００２５】
この転がり支承装置１を施工するときは、図２に示すように、切欠き１７に沿って第１ボルト締結部１５に片側のアンカーボルト１３に装着し、図中の２点鎖線で示すように、転がり支承装置１を回動させて切欠き１８に沿って反対側のアンカーボルト１４を第２ボルト締結部１６に装着する。そして、ナットで転がり支承装置１を固定する（図示省略）。
【００２６】
この転がり支承装置１は、位置決め部材３を下側の硬質板５にだけ接着しており、位置決め部材３の上面は上側の硬質板４に接着していないので、地震時に硬球体２が転動すると、硬球体２の転動に応じて容易に変形する。このため、位置決め部材３が硬球体２の転動に対する抵抗となり難い。また、位置決め部材３は、外周側を接着しており、内周側は接着していないので、硬球体２の初動時の転がり抵抗を軽減することができる。これにより、硬球体２の転動に対し、硬球体２の可動範囲の全域において略均一な抵抗を示すようになる。
【００２７】
また、上下の硬質板４、５及び硬球体２を加工硬化により、ＨＲＣ２０以上の硬さにしたものを採用しているので、クリープ歪により硬質板４、５の転動面に生じる窪みが小さく、硬球体２の転動に対してほとんど無視できる。
【００２８】
この転がり支承装置１を住宅に設置した時と同等の鉛直荷重（約１５ｋＮ）を負荷して、上下の硬質板４、５を水平方向に相対移動させた水平変位−水平荷重の関係を図３に示す。
【００２９】
この転がり支承装置１は、上述したように、位置決め部材３が硬球体２の転動に対する抵抗となり難く、また、硬質板の転動面に生じるクリープ歪による窪みも硬球体の転動に対してほとんど無視できる。このため、硬球体２の転動時に生じる抵抗は水平に変位する間において略一定になり、水平変位―水平荷重の関係が剛塑性型のバイリニアループＢに良く一致する。このため設計時においては、転がり支承装置１の水平変位―水平荷重の関係を、近似した剛塑性型のバイリニアループＢに置き換えて設計することができ、設計業務を簡素化できる。
【００３０】
そして、転がり支承装置の摩擦係数の基準値を０．０３以下にすると良い。転がり支承装置の摩擦係数の基準値は、例えば、二軸載荷試験装置を用い、実大モデルによる試験体について、所定の鉛直荷重（例えば、住宅設置時と同等の鉛直荷重１４．７ｋＮ）を基準荷重として負荷し、この状態で正負の規定変形（例えば±４０ｍｍ）を生じさせることとなる力で水平変形を繰り返し行いことにより得られた３サイクル目の履歴における荷重−変形関係を用いて正方向及び負方向の切片荷重の平均値を基準荷重で除した値で求めたものである。この転がり支承装置の摩擦係数の基準値は、鉛直荷重を受けながら水平変形する際の硬質板４、５と硬球２の両部材の食い込み量が大きく影響する。摩擦係数の基準値が０．０３以下である場合には、硬質板４、５と硬球２の両部材の食い込み量が小さく、硬質板４、５に生じる轍もほとんど影響が生じない程度である。このため、地震時に硬球体２が轍を横切るように転動した場合でも、硬球体２の円滑な転動を妨げるほどの影響はなく、水平荷重−水平変位の履歴曲線（ヒステリシスループ）にも転がり支承装置の性能を不安定にさせるような負勾配は生じない。
【００３１】
次に、この転がり支承装置１を用いた構造物のアンカー構造Ａを説明する。
【００３２】
この構造物のアンカー構造Ａは、図４に示すように、住宅の土台６（構造物の上部構造）と基礎コンクリート７（下部構造）との間の制振層８において、各転がり支承装置３が略均等に上部構造の鉛直荷重を支持するように、基礎コンクリート７の上に複数の転がり支承装置３を分散させて配設するとともに、構造物の上部構造の捩じれ振動を抑制するように複数の制振装置２０を分散させて配設したものである。
【００３３】
具体例としては、基礎コンクリート７の幅が２０ｃｍ程度である場合には、転がり支承装置３は、転動加工により真球度と２０ＨＲＣ以上の表面硬さを確保した直径が４０ｍｍの硬球体と、冷間圧延加工により平面度と２０ＨＲＣ以上の硬さを確保し、厚さ５ｍｍで半径８０ｍｍの転動面を備えた硬質板を用いる。この転がり支承装置１は、少なくとも一つで約１．５ｔｏｎｆ（約１５ｋＮ）の荷重を支持することが可能であり、住宅の総重量、重量分布を考慮して、基礎コンクリート７の上に分散させて配設するとよい。
【００３４】
制振装置２０は、例えば、図５に示すように、高減衰ゴムからなる円柱形状の制振部材２１と、制振部材２１を上下に挟む硬質板２２、２３と、ゴム製の被覆材２４を備え、制振部材２１の上端及び下端にそれぞれ硬質板２２、２３を加硫接着し、制振部材２１の外周面をゴム製の被覆材２４で被覆したものを用い、制振層８の偏心率が小さくなるように（例えば、制振層８の偏心率が３％以下になるように）制振装置を分散させて配設する。偏心率は、後記する式１に基づいて算出されるものであり、剛心と重心の偏りを示すものである。この制振装置２０には、転がり支承装置１と同様の切り欠き２８、２９を形成したボルト締結部２６、２７があり、転がり支承装置１と同じように基礎コンクリート７に取り付けることができる（図２参照）。
【００３５】
制振部材２１は、詳しくは、せん断弾性率が、制振部材２１の高さに対して±２５％以下の振幅領域において１００Ｎ／ｃｍ^２以上で、かつ、高減衰ゴムの高さに対して±１５０％以上の振幅領域において４０Ｎ／ｃｍ^２以下のものであることが望ましい。制振部材２１に、このような特性を有する弾性材料を用いることにより、風や交通振動などの微小な振動に対しては、制振部材２１のせん断変形を抑制することができ、かつ、地震のように大きな加速度（慣性力）を伴う大きな揺れに対しては、制振部材２１が大きなせん断変形を行うようになる。すなわち、制振装置２０が、それ自体、風や交通振動に対するトリガーとして機能を備えたものになる。
【００３６】
また、制振装置２０に用いられている高減衰の弾性材料は、損失係数ｔａｎδが０．３以上、より好ましくは０．５以上であることが望ましい。ここで、ゴム材料の動的特性を複素弾性率で表現した場合、実数部分を貯蔵弾性率Ｇ１、虚数部分を損失弾性率Ｇ２といい、貯蔵弾性率Ｇ１と損失弾性率Ｇ２の比を損失係数ｔａｎδという（損失係数ｔａｎδ＝貯蔵弾性率Ｇ１／損失弾性率Ｇ２）。
【００３７】
損失係数ｔａｎδは、制振材料の制振特性の評価指標の一つである。すなわち、制振材料は、振動応答系に減衰があると、その応力・歪み線図（あるいは荷重・変位線図）は履歴曲線（ヒステリシスループ）を描くのであるが、損失係数ｔａｎδは、１サイクルで消費されるエネルギと貯蔵される最大エネルギの比に比例する量で、等価減衰定数の約２倍の値に対応する。従って、損失係数ｔａｎδが大きいほど減衰性の高い材料になる。
【００３８】
また、制振部材２１には、６０年相当の熱老化促進による劣化を与えた後、周波数２Ｈｚで実験を行った際に、せん断弾性率Ｇおよび／又は損失係数ｔａｎδの変化率が３０％以内であるゴム材料を用いると良い。すなわち、一般住宅の耐用年数は５０年〜６０年程度であるから、少なくともその間、制振装置２０に必要な性能を確保することができる。後記表１に、制振部材２１に用いるゴム材料の好適な配合例を示す。なお、表１中、ｐｈｒは、配合剤の質量をゴム１００部に対する部数で示すときに用いる記号である。
【００３９】
この構造物のアンカー構造Ａは、転がり支承装置１と制振装置２０を別々にしているので、それぞれの設置位置に自由度があり、制振装置２０については、地震の揺れ方向に対して、構造物の上部構造が捩じれ方向に揺れるのを抑制するように設置することができる。例えば、制振装置２０の設置位置については、制振層８の偏心率を３％以下に設定するとよい。また、特許文献２に記載したもののように、硬球体２が転動するときに、高減衰ゴムに乗り上げるというような不具合も生じない。
【００４０】
また、この転がり支承装置１は、位置決め部材３の外周側が硬質板５に接着しており、内周側が硬質板５に接着していないので、硬球体２の初動時の転がり抵抗を軽減することができる。また、位置決め部材３を下側の硬質板５にだけ接着しており、位置決め部材３の上面は上側の硬質板４に接着していないので、地震時に硬球体２が転動すると、位置決め部材３は硬球体２の転動に応じて容易に変形する。このため、硬球体２の可動範囲の全域においても安定した摩擦係数を示すようになる。
【００４１】
これにより、この転がり支承装置１を用いた構造物のアンカー構造Ａによれば、地震時において、構造物の上部構造を下部構造に対して円滑に挙動させることができ、制振装置２０の減衰作用も十分に発揮されるので、地震の揺れを極めて効率良く減衰させることができる。
【００４２】
また、転がり支承装置１及び制振装置２０は共に、５０ｍｍ以下の厚さにすることができるので、基礎コンクリート７と住宅の土台６との間に設置しても嵩張らず、しかも、製造コストも低コストであり、また各装置はそれぞれ軽量であり、かつ、設置作業も簡便であるから設置コストも従来の免震構造に比べて極めて低コストである。従って、一般住宅のような軽量構造物においても、安価に制振機能を備えたアンカー構造を提供することができる。
【００４３】
以上、本発明に係る転がり支承装置及び構造物のアンカー構造を説明したが、本発明に係る転がり支承装置及び構造物のアンカー構造は、上述した実施形態に限定されるものではない。
【００４４】
例えば、転がり支承装置の位置決め部材について、下側の硬質板に接着し、上側の硬質板には接着していないものを例示したが、位置決め部材は、上下の硬質板の何れか一方に接着されていれば、同様の作用効果を得ることができるので、上側の硬質板に接着し、下側の硬質板に接着していないものにしても良い。
【００４５】
【式１】

【００４６】
【表１】

【００４７】
【発明の効果】
本発明に係る転がり支承装置は、上下の硬質板と、上下の硬質板の間に配設した軟質弾性体からなる円筒状の位置決め部材と、前記位置決め部材に内接させて上下の硬質板の中央部に位置決めした硬球体とを備え、構造物の上部構造と下部構造との間に配設されて構造物の上部構造を支持する転がり支承装置において、位置決め部材を、上下の硬質板の何れか一方に接着したので、地震時に硬球体が転動すると、位置決め部材は硬球体の転動に応じて容易に変形する。これにより、地震時に硬球体の滑らかな転動を確保することができる。
【００４８】
また、位置決め部材を、外周側で接着し、内周側を接着しないことにより、硬球体の転動の初動時に対する抵抗を小さくすることができる。これにより転がり支承装置は、硬球体の可動範囲の全域において略均一な抵抗を示すようになり、地震時に硬球体のより滑らかな転動を確保することができる。
【００４９】
本発明に係る構造物のアンカー構造は、これらの転がり支承装置を、構造物の上部構造の鉛直荷重を支持するように、構造物の下部構造と上部構造との間に分散させて配設するとともに、高減衰ゴムの上下端面に硬質板をそれぞれ取り付けた複数の制振装置を、前記構造物の上部構造の捩じれ振動を抑制するように、構造物の下部構造と上部構造との間に分散させて配設したので、地震時において、構造物の上部構造を下部構造に対して円滑に挙動させることができ、制振装置の減衰作用も十分に発揮されるので、地震の揺れを極めて効率良く減衰させることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る転がり支承装置を示す斜視図。
【図２】本発明の一実施形態に係る転がり支承装置の施工工程を示す平面図。
【図３】本発明の一実施形態に係る転がり支承装置の水平変位―水平荷重の関係を示す図。
【図４】本発明の一実施形態に係る構造物のアンカー構造の設置例を示す平面図。
【図５】制振装置を示す斜視図。
【図６】従来の住宅の上部構造のアンカー構造を示す図。
【図７】基礎パッキン材を示す図。
【符号の説明】
１転がり支承装置
２硬球体
３位置決め部材
４、５硬質板
６住宅の土台
７基礎コンクリート
８制振層
２０制振装置
２１制振部材
２２、２３硬質板
２４被覆材
Ａ構造物のアンカー構造[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a rolling bearing device used for an anchor structure of a structure which is mounted between an upper structure and a lower structure of a structure and fixes the upper structure on the lower structure.
[0002]
[Prior art]
A lightweight structure such as a house is constructed on a basic concrete 101 generally called a cloth foundation. When the base 103 (upper structure) of a building (structure) is fixed on the basic concrete 101 (lower structure), for example, as shown in FIG. The base is buried in the base 101, the upper part of the anchor bolt 102 is penetrated through the base 103, and the portion protruding from the upper surface of the base 103 is fixed with the washer 104 and the nut 105.
[0003]
However, if the base 103 is simply fixed on the foundation concrete 101, traffic vibration generated by the traffic of a large vehicle is transmitted from the foundation concrete 101 to the foundation 103 as it is. For this reason, as shown in FIG. 7, there is a type in which a rubber plate 100 is interposed between a base 103 and a foundation concrete 101 to mitigate traffic vibration. However, even in this case, the anchor bolt 102 firmly connects the foundation 103 and the foundation concrete 101, and the vibration is transmitted from the foundation concrete 101 to the foundation 103 via the anchor bolt 102 as it is, and the vibration is not reduced so much. No seismic isolation effect was obtained.
[0004]
In addition, such a rubber plate 100 has a function as a base packing material for ventilation of a base part of a house. That is, by arranging a plurality of rubber plates 100 at predetermined intervals between the foundation concrete 101 and the base 103 of the house, the gap between the foundation 103 and the foundation concrete 101 causes Ventilation of the inside can be performed, the flow of air in the foundation concrete 101 is improved, and moisture can be reduced. Further, by cutting the edge between the base concrete 101 and the base 103, there is an effect that the moisture absorbed by the base concrete 101 is not transmitted to the base 103.
[0005]
As a known document indicating the general technical level of this type of basic packing material, the following Patent Document 1 is known.
[0006]
In addition, as a basic packing material that also has a vibration damping function that absorbs vibration caused by traffic and earthquake caused by the traffic of large vehicles such as dump trucks and railway cars, rubber for restoration with circular holes between upper and lower hard plates Japanese Patent Application Laid-Open Publication No. HEI 10-163566 proposes a structure in which a rolling material is provided and a hard sphere is rollably disposed in a hole of a rubber material.
[0007]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-355350 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-110403
[Problems to be solved by the invention]
The base packing material described in Patent Document 1 described above merely sandwiches a rubber material between the upper structure and the lower structure of a structure, and is used for vibrations caused by large vehicles such as earthquakes and dump trucks, and traffic of railway vehicles. Insufficient vibration damping function to absorb traffic vibrations caused by traffic.
[0009]
Further, although the base packing material described in Patent Document 2 can be expected to have a certain vibration damping effect, it is not guaranteed that the hard sphere is located at the center of the hole of the rubber material at the time of installation due to its structure. . For this reason, there is a possibility that the hard sphere is disposed in contact with the inner peripheral surface of the hole of the rubber material, and in such a case, the hard sphere immediately rides on the rubber material during vibration. According to the knowledge of the present inventors, when a hard sphere rides on a rubber material, the rubber material may be damaged at a position where the hard sphere rides, so that a sufficient vibration damping effect cannot be obtained.
[0010]
Also, seismic isolation devices using a combination of laminated rubber and oil dampers are well known, but the laminated rubber and oil dampers used in such seismic isolation methods are limited by the vertical load and horizontal load that one device bears. Because of its large size and its difficulty in reducing its size in terms of structure, the device is large, the installation cost and the installation space are increased, and it is uneconomical for relatively small structures such as ordinary houses, and is not widely used.
[0011]
Therefore, the present inventors provide a rolling bearing device in which a hard sphere smoothly rolls during an earthquake, and an anchor structure of a structure that is not bulky, inexpensive, and has both vibration absorption performance and a function as a base packing material. The purpose is to provide.
[0012]
[Means for Solving the Problems]
The rolling bearing device of the present invention comprises an upper and lower hard plate, a cylindrical positioning member made of a soft elastic body disposed between the upper and lower hard plates, and a positioning member which is inscribed in the positioning member and positioned at a central portion of the upper and lower hard plates. The rolling bearing device is provided between the upper structure and the lower structure of the structure and supports the upper structure of the structure, wherein the positioning member is bonded to one of the upper and lower hard plates. It is characterized by being. Further, it is preferable that the positioning member be bonded on the outer peripheral side and not on the inner peripheral side. In order to ensure smooth rolling, the reference value of the coefficient of friction of the rolling bearing device may be set to 0.03 or less. Further, in order to secure long-term performance, it is preferable that the creep strain is also 200 μm or less. Regarding the creep strain, it is preferable to consider the creep strain for a considerable period in consideration of the service life of the house.
[0013]
Further, the anchor structure of the structure, the rolling bearing device described above, while supporting the vertical load of the upper structure of the structure, while dispersing and disposed between the lower structure and the upper structure of the structure, A plurality of vibration damping devices each having a hard plate attached to the upper and lower end surfaces of the high damping rubber are distributed between the lower structure and the upper structure of the structure so as to suppress torsional vibration of the upper structure of the structure. It is characterized by having been established.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a rolling bearing device and an anchor structure of a structure according to an embodiment of the present invention will be described with reference to the drawings.
[0015]
As shown in FIG. 1, the rolling bearing device 1 includes a hard sphere 2, a cylindrical positioning member 3 that houses the hard sphere 2, and

hard plates

4, 5 that vertically sandwich the hard sphere 2 and the positioning member 3. It has.
[0016]
The hard sphere 2 is a sphere having a required hardness and sphericity, and is manufactured by rolling a steel material roughly processed into a roughly spherical shape. In the rolling process, a steel material roughly processed into a roughly spherical shape is vertically sandwiched between polishing plates, and is rolled between the polishing plates to form a spherical shape while removing distortion on the surface of the steel material. The hard sphere 2 is hardened by work hardening due to the rolling process, and the hardness increases. According to this rolling process, it is possible to obtain a hard sphere having hardness equal to or higher than HRC20 and a high sphericity using an inexpensive steel material such as S15C, and to reduce the cost of parts of the hard sphere 2. Can be. It is desirable that the hard sphere 2 be subjected to a rust prevention treatment such as nickel plating.
[0017]
The

hard plates

4 and 5 are substantially rhombic plate-shaped members having required hardness and flatness, and a positioning member 3 is adhered to a central portion to position the hard sphere 2 at the center. The

hard plates

4, 5 are provided with rolling surfaces including a circle having a radius that is at least twice the diameter of the hard sphere 2 around the position where the hard sphere 2 is positioned. The rolling surfaces of the

hard plates

4 and 5 are also preferably subjected to a rust prevention treatment such as nickel plating.
[0018]
The

hard plates

4 and 5 are manufactured by subjecting a plate-shaped material to cold rolling. In the cold rolling, the plate-shaped material is drawn while being sandwiched between rolling rollers. Since no heat treatment is performed, no distortion occurs, and a required flatness can be secured. The required hardness can be obtained by work hardening. According to this cold rolling,

hard plates

4 and 5 having an HRC of 20 or more, more preferably an HRC of 25 or more can be obtained using a steel material such as SUS304.
[0019]
Further, the

hard plates

4 and 5 receive a load in the vertical direction from the hard sphere 2 after being installed, so that a depression occurs in the vertical direction due to creep strain. In order to smoothly roll the hard sphere 2 during an earthquake, the smaller the amount of creep strain, the better. As described above, a material that is work-hardened by cold rolling is preferable because creep distortion is reduced. More specifically, by using a material having a vertical subsidence amount of 200 μm or less corresponding to 60 years, the smooth rolling of the hard sphere 2 can be maintained for a long period of time (the service life of a general house).
[0020]
The positioning member 3 is preferably made of a soft elastic material such as a soft urethane foam, a polystyrene foam, or a polyethylene foam. It is preferable that the inner diameter of the positioning member 3 is the same as or slightly smaller than the diameter of the hard sphere 2, so that the positioning of the hard sphere 2 can be surely performed. In addition, as shown in FIG. 1, by covering the periphery of the hard sphere 2 with the positioning member 3, it is possible to prevent dust and dirt from entering the rolling region of the hard sphere 2.
[0021]
The positioning member 3 is bonded to the lower hard plate 5 and is not bonded to the upper hard plate 4 in order to be easily deformed in accordance with the rolling of the hard sphere 2. Further, in order to reduce the resistance to rolling of the hard sphere 2 at the time of initial movement, the positioning member 3 is bonded on the outer peripheral side and not on the inner peripheral side. For example, approximately half of the thickness of the positioning member 3 in the radial direction from the outer peripheral side may be bonded.
[0022]
The

hard plates

4 and 5 are formed from a circle having a radius of a distance twice the diameter of the hard sphere 2 (for example, 80 mm if the diameter of the hard sphere 2 is 40 mm) with the center of the position at which the hard sphere 2 is positioned. This rolling bearing device 1 is capable of rolling the hard sphere 2 over a distance of at least twice the diameter around the position where the hard sphere 2 is positioned. I have.
[0023]
On both sides of the upper and lower

hard plates

4, 5,

bolt fastening portions

15, 16 for fastening anchor bolts 13, 14 (see FIG. 2) are provided. A notch 17 is formed in the first bolt fastening portion 15 on one side along a straight line connecting the

bolt fastening portions

15 and 16 on both sides, and the second bolt fastening portion 16 on the opposite side is formed with the bolt fastening portions 15 on both sides. , 16 are formed along a direction perpendicular to a straight line connecting the notches 18. More specifically, the notch 18 of the second bolt fastening portion 16 is centered on a predetermined fastening position (for example, a designed bolt fastening position O) of the first bolt fastening portion 15 and has a predetermined bolt pitch (for example, a design bolted position). Are formed along an arc C having a radius of the bolt pitch P) (see FIG. 2).
[0024]
The width of the

notches

17, 18 of each

bolt fastening portion

15, 16 is slightly larger than the diameter of the

anchor bolts

13, 14, and the

anchor bolts

13, 14 are attached and detached along the

notches

17, 18. You can do it. In addition, the

notches

17 and 18 are formed deeper than designed bolt fastening positions so as to allow for errors during construction.
[0025]
When this rolling bearing device 1 is constructed, as shown in FIG. 2, one of the anchor bolts 13 is attached to the first bolt fastening portion 15 along the notch 17, and as shown by a two-dot chain line in the drawing. Then, the rolling bearing device 1 is rotated, and the opposite anchor bolt 14 is attached to the second bolt fastening portion 16 along the notch 18. Then, the rolling bearing device 1 is fixed with a nut (not shown).
[0026]
In this rolling bearing device 1, the positioning member 3 is bonded only to the lower hard plate 5, and the upper surface of the positioning member 3 is not bonded to the upper hard plate 4, so that the hard sphere 2 rolls during an earthquake. Then, it is easily deformed in accordance with the rolling of the hard sphere 2. For this reason, the positioning member 3 hardly becomes a resistance against the rolling of the hard sphere 2. Further, since the positioning member 3 has the outer peripheral side adhered and the inner peripheral side not adhered, the rolling resistance of the hard sphere 2 at the initial movement can be reduced. As a result, substantially uniform resistance to the rolling of the hard sphere 2 is exhibited in the entire movable range of the hard sphere 2.
[0027]
In addition, since the upper and lower

hard plates

4 and 5 and the hard spheres 2 are made to have a hardness of HRC 20 or more by work hardening, the dents generated on the rolling surfaces of the

hard plates

4 and 5 due to creep strain are small. The rolling of the hard sphere 2 is almost negligible.
[0028]
FIG. 3 shows a horizontal displacement-horizontal load relationship in which a vertical load (about 15 kN) equivalent to that when the rolling bearing device 1 is installed in a house is applied and the upper and lower

hard plates

4 and 5 are relatively moved in the horizontal direction. Shown in
[0029]
In the rolling bearing device 1, as described above, the positioning member 3 hardly becomes a resistance against the rolling of the hard sphere 2, and the depression due to the creep strain generated on the rolling surface of the hard plate also prevents the rolling of the hard sphere. Almost negligible. Therefore, the resistance generated when the hard sphere 2 rolls becomes substantially constant during the horizontal displacement, and the relationship between the horizontal displacement and the horizontal load matches well with the rigid-plastic type bilinear loop B. For this reason, at the time of design, the relationship between the horizontal displacement and the horizontal load of the rolling bearing device 1 can be replaced with an approximate rigid-plastic type bilinear loop B, and the design work can be simplified.
[0030]
The reference value of the coefficient of friction of the rolling bearing device is preferably set to 0.03 or less. The reference value of the friction coefficient of the rolling bearing device is, for example, a predetermined vertical load (for example, a vertical load of 14.7 kN equivalent to that at the time of installation of a house) for a test sample of a full-scale model using a biaxial loading test device. A load is applied as a load, and in this state, positive and negative prescribed deformations (for example, ± 40 mm) are generated, and horizontal deformation is repeatedly performed with a force that causes the positive and negative prescribed deformations. And the value obtained by dividing the average value of the intercept load in the negative direction by the reference load. The reference value of the friction coefficient of the rolling bearing device is greatly affected by the amount of biting between the

hard plates

4 and 5 and the hard ball 2 during horizontal deformation while receiving a vertical load. When the reference value of the friction coefficient is equal to or less than 0.03, the bite amount of both the

hard plates

4 and 5 and the hard ball 2 is small, and the rut generated on the

hard plates

4 and 5 has almost no influence. . For this reason, even if the hard sphere 2 rolls across the rut during an earthquake, there is no effect that hinders the smooth rolling of the hard sphere 2, and the horizontal load-horizontal displacement hysteresis loop (hysteresis loop) does not occur. There is no negative gradient that would destabilize the performance of the rolling bearing.
[0031]
Next, an anchor structure A of a structure using the rolling bearing device 1 will be described.
[0032]
As shown in FIG. 4, the anchor structure A of this structure includes, as shown in FIG. 4, each rolling bearing device 3 in a vibration damping layer 8 between a base 6 (upper structure of the structure) and a foundation concrete 7 (lower structure). A plurality of rolling bearings 3 are dispersed and arranged on the foundation concrete 7 so as to support the vertical load of the superstructure almost equally, and a plurality of rolling bearings 3 are arranged so as to suppress the torsional vibration of the superstructure of the structure. Are arranged in a dispersed manner.
[0033]
As a specific example, when the width of the base concrete 7 is about 20 cm, the rolling bearing device 3 is a hard sphere having a diameter of 40 mm, which has secured sphericity and a surface hardness of 20 HRC or more by rolling, A flat plate and a hard plate having a rolling surface with a radius of 80 mm having a flatness and a hardness of 20 HRC or more are used by cold rolling. This rolling bearing device 1 can support a load of about 1.5 tonf (about 15 kN) by at least one, and is dispersed on the foundation concrete 7 in consideration of the total weight and weight distribution of the house. It is good to arrange.
[0034]
As shown in FIG. 5, for example, the vibration damping device 20 includes a cylindrical vibration damping member 21 made of high-damping rubber, hard plates 22 and 23 sandwiching the vibration damping member 21 vertically, and a rubber covering material 24. The hard plates 22 and 23 are respectively vulcanized and bonded to the upper end and the lower end of the damping member 21, and the outer peripheral surface of the damping member 21 is covered with a rubber covering material 24. The vibration damping devices are dispersed and arranged so that the eccentricity becomes small (for example, the eccentricity of the vibration damping layer 8 becomes 3% or less). The eccentricity is calculated based on Expression 1 described later, and indicates the deviation between the rigidity and the center of gravity. The vibration damping device 20 has

bolt fastening portions

26 and 27 formed with

notches

28 and 29 similar to the rolling bearing device 1 and can be attached to the foundation concrete 7 in the same manner as the rolling bearing device 1 (FIG. 2).
[0035]
More specifically, the damping member 21 has a shear modulus of 100 N / cm ² or more in an amplitude range of ± 25% or less with respect to the height of the damping member 21 and a height of the high damping rubber. It is desirable that the amplitude is 40 N / cm ² or less in an amplitude range of ± 150% or more. By using an elastic material having such characteristics for the vibration damping member 21, it is possible to suppress the shear deformation of the vibration damping member 21 against minute vibrations such as wind and traffic vibration, and In response to a large vibration accompanied by a large acceleration (inertial force), the vibration damping member 21 undergoes a large shear deformation. That is, the vibration damping device 20 itself has a function as a trigger for wind and traffic vibration.
[0036]
In addition, the high damping elastic material used for the vibration damping device 20 preferably has a loss coefficient tan δ of 0.3 or more, more preferably 0.5 or more. 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 referred to as tan δ (loss coefficient tan δ = storage elastic modulus G1 / loss elastic modulus G2).
[0037]
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. Therefore, the larger the loss coefficient tan δ, the higher the damping property of the material.
[0038]
Further, after the vibration damping member 21 is deteriorated by accelerating thermal aging equivalent to 60 years, when an experiment is performed at a frequency of 2 Hz, the rate of change of the shear modulus G and / or the loss coefficient tan δ is within 30%. It is good to use a rubber material that is as follows. That is, since the useful life of a general house is about 50 to 60 years, the performance required for the vibration damping device 20 can be secured at least during that time. Table 1 below shows a preferred compounding example of the rubber material used for the vibration damping member 21. In Table 1, phr is a symbol used when indicating the mass of the compounding agent by the number of parts with respect to 100 parts of rubber.
[0039]
In the anchor structure A of this structure, since the rolling bearing device 1 and the vibration damping device 20 are separated, there is a degree of freedom in the respective installation positions. The structure can be installed so as to suppress the upper structure of the structure from swaying in the twisting direction. For example, as for the installation position of the vibration damping device 20, the eccentricity of the vibration damping layer 8 may be set to 3% or less. Further, there is no such a problem that the hard sphere 2 runs on the high damping rubber when the hard sphere 2 rolls as described in Patent Document 2.
[0040]
Further, in the rolling bearing device 1, since the outer peripheral side of the positioning member 3 is bonded to the hard plate 5 and the inner peripheral side is not bonded to the hard plate 5, the rolling resistance of the hard sphere 2 at the time of initial movement can be reduced. Can be. Also, since the positioning member 3 is bonded only to the lower hard plate 5 and the upper surface of the positioning member 3 is not bonded to the upper hard plate 4, when the hard sphere 2 rolls during an earthquake, the positioning member 3 Are easily deformed according to the rolling of the hard sphere 2. Therefore, a stable coefficient of friction is exhibited even in the entire movable range of the hard sphere 2.
[0041]
Accordingly, according to the anchor structure A of the structure using the rolling bearing device 1, the upper structure of the structure can behave smoothly with respect to the lower structure during an earthquake, and the damping of the vibration damping device 20 can be achieved. Since the effect is sufficiently exhibited, the shaking of the earthquake can be attenuated extremely efficiently.
[0042]
Further, since both the rolling bearing device 1 and the vibration damping device 20 can have a thickness of 50 mm or less, even if they are installed between the foundation concrete 7 and the base 6 of the house, they are not bulky and the manufacturing cost is low. The cost is low, and each device is lightweight and the installation work is simple, so that the installation cost is extremely low as compared with the conventional seismic isolation structure. Therefore, even in a lightweight structure such as a general house, an anchor structure having a vibration damping function can be provided at low cost.
[0043]
Although the rolling bearing device and the anchor structure of the structure according to the present invention have been described above, the rolling bearing device and the anchor structure of the structure according to the present invention are not limited to the above-described embodiment.
[0044]
For example, although the positioning member of the rolling bearing device is illustrated as being bonded to the lower hard plate and not bonded to the upper hard plate, the positioning member is bonded to one of the upper and lower hard plates. Therefore, the same function and effect can be obtained, so that it may be bonded to the upper hard plate and not bonded to the lower hard plate.
[0045]
(Equation 1)

[0046]
[Table 1]

[0047]
【The invention's effect】
The rolling bearing device according to the present invention includes an upper and lower hard plate, a cylindrical positioning member made of a soft elastic body disposed between the upper and lower hard plates, and a central portion of the upper and lower hard plates in contact with the positioning member. In a rolling bearing device which is provided between the upper structure and the lower structure of the structure and supports the upper structure of the structure, the positioning member is provided with one of the upper and lower hard plates. When the hard sphere rolls during an earthquake, the positioning member easily deforms in accordance with the rolling of the hard sphere. As a result, smooth rolling of the hard sphere can be ensured during an earthquake.
[0048]
Further, by adhering the positioning member on the outer peripheral side and not on the inner peripheral side, the resistance of the hard sphere against the initial movement of the rolling can be reduced. As a result, the rolling bearing device exhibits substantially uniform resistance over the entire movable range of the hard sphere, and can ensure smoother rolling of the hard sphere during an earthquake.
[0049]
In the anchor structure for a structure according to the present invention, these rolling bearing devices are dispersed and arranged between the lower structure and the upper structure of the structure so as to support the vertical load of the upper structure of the structure. At the same time, a plurality of vibration damping devices each having a hard plate attached to the upper and lower end surfaces of the high damping rubber are distributed between the lower structure and the upper structure of the structure so as to suppress the torsional vibration of the upper structure of the structure. The upper structure of the structure can behave smoothly with respect to the lower structure in the event of an earthquake, and the damping effect of the vibration damping device is fully exhibited, so that the vibration of the earthquake is extremely efficient It can be attenuated well.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a rolling bearing device according to an embodiment of the present invention.
FIG. 2 is a plan view showing a construction process of the rolling bearing device according to one embodiment of the present invention.
FIG. 3 is a diagram showing a relationship between horizontal displacement and horizontal load of the rolling bearing device according to one embodiment of the present invention.
FIG. 4 is a plan view showing an installation example of an anchor structure of a structure according to an embodiment of the present invention.
FIG. 5 is a perspective view showing a vibration damping device.
FIG. 6 is a diagram showing an anchor structure of a conventional superstructure of a house.
FIG. 7 is a view showing a basic packing material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolling bearing device 2 Hard sphere 3

Positioning member

4, 5 Hard plate 6 Base of house 7 Foundation concrete 8 Damping layer 20 Damping device 21 Damping member 22, 23 Hard plate 24 Coating material A Anchor structure of structure

Claims

Upper and lower hard plates, a cylindrical positioning member made of a soft elastic body disposed between the upper and lower hard plates, and a hard sphere positioned in the center of the upper and lower hard plates in contact with the positioning member, In a rolling bearing device disposed between an upper structure and a lower structure of a structure to support the upper structure of the structure,
The rolling bearing device, wherein the positioning member is bonded to one of the upper and lower hard plates.

2. The rolling bearing device according to claim 1, wherein the positioning member is adhered on an outer peripheral side and is not adhered on an inner peripheral side. 3.

The rolling bearing device according to claim 1, wherein a reference value of a coefficient of friction of the rolling bearing device is 0.03 or less.

The rolling bearing device according to any one of claims 1 to 3, wherein a vertical sinking amount due to creep strain is 200 µm or less.

The rolling bearing device according to any one of claims 1 to 4, which is dispersed and disposed between the lower structure and the upper structure of the structure so as to support the vertical load of the upper structure of the structure.
A plurality of vibration damping devices each having a hard plate attached to the upper and lower end surfaces of the high damping rubber are dispersed between the lower structure and the upper structure of the structure so as to suppress the torsional vibration of the upper structure of the structure. An anchor structure for a structure, which is provided.