【０００１】
【発明の属する技術分野】
本発明は、例えば各種建築物の免震構造体あるいは橋梁等の土木構築物の支承体として用いられる鉛芯材入り積層ゴム支承装置に関する。詳しくは、地震等によって加わる振動エネルギーを、弾性ゴム層のせん断変形特性及び鉛の減衰特性を利用して吸収し減衰するように、複数の弾性ゴム層と薄肉剛性板とを交互に積層し、その積層方向の両端に厚肉剛性板を接着配置してなる積層ゴム本体の中央部またはその周辺部に、厚肉剛性板を含めて積層方向に貫通する孔を形成し、この貫通孔に柱状の鉛芯材を挿入して構成される鉛芯材入り積層ゴム支承装置に関するものである。
【０００２】
【従来の技術】
この種の鉛芯材入り積層ゴム支承装置においては、地震等によって積層ゴム本体が繰り返して水平変形したとき、この積層ゴム本体を構成する鋼板等の薄肉剛性板が鉛芯材に食い込んで鉛芯材または薄肉剛性板が局部変形したり、鉛芯材が積層ゴム本体の弾性ゴム層に食い込んで弾性ゴム層を損傷したりして、せん断変形特性あるいは減衰特性が損なわれて長期に亘って所期の振動エネルギー吸収・減衰性能を保持することができないという問題がある。
【０００３】
かかる問題を解消する手段として、従来、薄肉剛性板間の弾性ゴム層内に柱状鉛芯材の外周辺部を取り囲んで該鉛芯材を拘束するように中間補強プレートをリング状に配置したものが知られている（例えば、特許文献１参照）。
【０００４】
【特許文献１】
特開２００１−３５５６７７号公報（図１〜図４）
【０００５】
【発明が解決しようとする課題】
上記のような構成の従来の鉛芯材入り積層ゴム支承装置では、せん断変形試験や実設置使用状態での水平変形時に薄肉剛性板が鉛芯材に食い込んだり、鉛芯材が弾性ゴム層に食い込んだりすることをリング状中間補強プレートによって防止して、所期の振動エネルギー吸収・減衰性能の低下を抑制することが可能である。
【０００６】
しかしながら、リング状中間補強プレートによる鉛芯材の拘束能力を超えるような大きな水平変形力が加わった場合、図８に明示するように、積層された複数の薄肉剛性板２よりも剛性が大きい積層方向両端の厚肉剛性板４とそれに接する弾性ゴム層１との接着界面ｂに応力が集中して鉛芯材８の一部分８ａが先尖り状態で食い込み、この食い込んだ先尖り鉛部分８ａの楔作用によって、その食い込み部が起点となって矢印ｘで示す装置外側に向けて破断が急速に進行するといった内部破壊が起こりやすく、したがって、装置全体としての破断変形能力が乏しく、強大な水平変形力を繰り返し受ける条件下で設置使用される、この種の装置の耐久性の面で大きな問題が残されていた。
【０００７】
本発明は上記実情に鑑みてなされたもので、鉛芯材の拘束能力を超えるような大きな水平変形力が加わって鉛芯材の一部分が接着界面に食い込んだとしても、その食い込み部からの破断の進行を食い止めて全体の破断変形能力、ひいては耐久性の著しい向上を図ることができる鉛芯材入り積層ゴム支承装置を提供することを目的としている。
【０００８】
【課題を解決するための手段】
上記目的を達成するために、本発明に係る鉛芯材入り積層ゴム支承装置は、複数の弾性ゴム層と薄肉剛性板とを交互に積層し、その積層方向の両端に厚肉剛性板を接着配置してなる積層ゴム本体の中央部またはその周辺部に、厚肉剛性板を含めて積層方向に貫通する孔が形成され、この貫通孔に柱状の鉛芯材を挿入して構成される鉛芯材入り積層ゴム支承装置であって、上記厚肉剛性板の弾性ゴム層との接着界面で柱状鉛芯材の周辺部に座ぐり加工により環状段差を形成していることを特徴とするものである。
【０００９】
上記のごとき構成を有する本発明によれば、せん断変形試験や実設置使用状態で鉛芯材の拘束能力を超えるような大きな水平変形力が加わった時、その水平変形に伴い鉛芯材がせん断塑性変形して最も剛性の高い厚肉剛性板とこれに接する弾性ゴム層との接着界面に鉛芯材の一部分が食い込むことになるが、この際、その食い込み鉛部分が環状段差の内周面で受け止められてそれ以上の食い込みが阻止されるとともに、食い込み鉛部分の楔作用による破断の進行方向が接着界面に対して直交する方向に切り替えられることになる。したがって、食い込みに伴う破断が装置外側に向けて急速に進行するといった内部破壊を抑制して装置全体の破断変形能力の向上が図れ、鉛芯材入り積層ゴム支承装置の耐久性を高めて所期の振動エネルギー吸収・減衰性能を長期に亘って安定よく保持することが可能である。
【００１０】
本発明に係る鉛芯材入り積層ゴム支承装置における上記環状段差として、その内径が柱状鉛芯材の外径の１．０２倍未満で、かつ、深さが薄肉剛性板の厚みの０．１倍未満の場合は、大変形時に接着界面への食い込み鉛部分を十分に受け止めることができず、また、その内径が柱状鉛芯材の外径の１．２倍を超え、かつ、深さが薄肉剛性板の２．０倍を超える場合は、食い込みに伴って界面に沿って急速に進行する破断力を止めることができない。かかる観点からみて上記環状段差としては、その内径が柱状鉛芯材の外径の１．０２〜１．２倍、深さが薄肉剛性板の厚みの０．１〜２．０倍の大きさに設定されていることが好ましい。
【００１１】
また、本発明に係る鉛芯材入り積層ゴム支承装置において、請求項３に記載のように、上記柱状鉛芯材の外周面と貫通孔の内周面との間の環状空間部内に、積層ゴム本体のせん断変形時に鉛芯材を拘束する筒形の拘束部材が介在され、この筒形拘束部材の周辺部に上記環状段差が形成された構成とすることが望ましい。この場合は、大きな水平変形力が加わって鉛芯材がせん断塑性変形するとき、その鉛芯材の全外周面が筒形拘束部材で常時拘束されたままであるため、複数の薄肉剛性板が鉛芯材に食い込んだり、鉛芯材が複数の弾性ゴム層に食い込んだりすることを防止できるのはもとより、厚肉剛性板とこれに接する弾性ゴム層との接着界面に鉛芯材の一部分及びその部分を覆う拘束部材の一部分が食い込むことがあってもそれ以上の食い込み及び食い込み部分の楔作用による破断の進行を環状段差で防止でき、これら食い込み防止作用と接着界面での破断の進行防止作用との相乗によって、装置の破断変形能力、ひいては、耐久性を一段と向上することができる。
【００１２】
特に、上記の筒形拘束部材が介在されている鉛芯材入り積層ゴム支承装置における筒形拘束部材として、請求項４に記載のように、互いに密に隣接させて螺旋状に巻き付けたスチールコードとこの螺旋状のスチールコードの内外周面に配置され該スチールコードに加硫接着により一体化された内外周ゴム層とから構成されたものを用いることによって、螺旋状スチールコードが有する水平方向への大きな変形能力により履歴復元特性を良好に維持しつつ、破断せん断ひずみ及び破断水平変位を大きく確保することができるとともに、大きな水平変形時における鉛芯材の拘束性を十分に発揮させることができて、振動エネルギー吸収・減衰性能の一層の安定保持性を高めることができる。
【００１３】
【発明の実施の形態】
以下、本発明の実施例を図面にもとづいて説明する。
図１は本発明に係る鉛芯材入り積層ゴム支承装置の第１実施例を示す全体縦断面図、図２は図１のＸ−Ｘ線に沿った横断面図であり、この第１実施例の鉛芯材入り積層ゴム支承装置２０は、複数の弾性ゴム層１…と薄鋼板からなる複数枚の薄肉剛性板２…及び上下の厚肉剛性板（フランジ）４，４とを上下交互に配置して積層し、かつ、それら積層物（弾性ゴム層１…、薄肉剛性板２…及び厚肉剛性板４，４）の全外周に被覆ゴム１Ａを配置し、これらを加硫接着により一体化してなる積層ゴム本体３の上下厚肉剛性板４，４の外面に、上部構造物Ａ及び下部構造物ＢにアンカーＣ，Ｃ等を介して固定支持可能な取付板５，５がせん断キー６，６により固定接合されて構成されている。
【００１４】
上記積層ゴム本体３の中央部には、上下の厚肉剛性板４，４を含めて積層方向に貫通する貫通孔７が形成されており、この貫通孔７内の全域に円柱状の鉛芯材８が挿入されているとともに、この円柱状鉛芯材８の上下両端の外周面が厚肉剛性板４，４の貫通孔７部分の内周面に接着固定されている。
【００１５】
上記構成の鉛芯材入り積層ゴム支承装置２０において、上記厚肉剛性板４，４のそれらに接する上下端の弾性ゴム層１，１との接着界面ｂで柱状鉛芯材８の外周辺部には、図３及び図４に明示するように、座ぐり加工によって環状段差９，９が形成されており、この環状段差９，９内には、上下端の弾性ゴム層１，１の一部１ａ，１ａを入り込ませて接着している。また、各環状段差９，９は、その内径ｄ１が柱状鉛芯材８の外径ｄの１．０２〜１．２倍で、かつ、その深さｔ１が薄肉剛性板２…の厚みｔの０．１〜２．０倍の範囲内の大きさに設定されている。なお、図３及び図４は積層方向の一端側のみを示しており、以下の説明ではその一端側についてのみ記述するが、両端共に同様な構成を有し、同様に変形動作するものである。
【００１６】
上記のように構成された鉛芯材入り積層ゴム支承装置２０は、図１に示すように、上部構造物Ａと下部構造物Ｂの間に介在された状態で設置使用され、この実設置使用状態で、地震の発生等によって下部構造体Ｂに振動力が入力されると、上部構造体Ａが相対的に水平方向に変位し、これに伴って、積層ゴム本体３が弾性せん断変形することで振動エネルギーを吸収して上部構造物Ａに伝達するといったような免震作用を発揮する。一方、積層ゴム本体３のせん断変形に伴って鉛芯材８もせん断塑性変形し、その塑性変形によって振動エネルギーが減衰されることになる。
【００１７】
このような振動エネルギー吸収・減衰機能を発揮する鉛芯材入り積層ゴム支承装置２０において、通常時、つまり、非変形時には、図３に示すように、厚肉剛性板４に形成されている環状段差９内にその厚肉剛性板４に接する弾性ゴム層１の一部１ａが入り込んでおり、鉛芯材８は複数の弾性ゴム層１…により拘束されている。そして、製品（鉛芯材入り積層ゴム支承装置２０）のせん断変形試験や実設置使用状態で鉛芯材８の拘束能力を超えるような大きな水平変形力が加わり、これに伴い鉛芯材８が大きくせん断塑性変形した時には、図４に示すように、厚肉剛性板４とこれに接する弾性ゴム層１との接着界面ｂに鉛芯材８の一部分８ａが食い込むことになる。
【００１８】
この場合、上記接着界面ｂへの食い込み鉛部分８ａは環状段差９の内周面で受け止められてそれ以上の食い込みが防止されるとともに、食い込み鉛部分８ａの楔作用による破断の進行方向が図４の矢印ｙで示すごとく接着界面ｂに対して直交する方向に切り替えられることになる。したがって、大きな水平変形力に伴って鉛芯材８の一部分８ａが接着界面ｂに食い込んだとしても、それ以上の食い込み及び破断が装置外側に向けて急速に進行することに起因する内部破壊が抑制されることになり、装置全体の破断変形能力の向上により鉛芯材入り積層ゴム支承装置２０の耐久性を高めて所期の振動エネルギー吸収・減衰性能を長期に亘って安定よく保持することができる。
【００１９】
図５は本発明に係る鉛芯材入り積層ゴム支承装置の第２実施例を示す全体縦断面図である。この第２実施例の鉛芯材入り積層ゴム支承装置２０は、積層ゴム本体３の中央部に上下の厚肉剛性板４，４を含めて積層方向に貫通形成した貫通孔７の内周面とこの貫通孔７内の全域に挿入した柱状鉛芯材８の外周面との間の環状空間１０内に、積層ゴム本体３が地震等によって水平力を受けてせん断変形する時に鉛芯材８を拘束して該鉛芯材８が弾性ゴム層１…に食い込んだり、薄肉剛性板２…が鉛芯材８に食い込んだりすることを防止するための筒形拘束部材１１を介在させ、この筒形拘束部材１１の外周辺部に上記第１実施例と同様に、座ぐり加工によって環状段差９，９を形成したものであり、その他の構成は第１実施例と同一であるため、該当部材及び該当部位に同一の符号を付してそれらの説明を省略する。
【００２０】
この第２実施例で用いる筒形拘束部材１１としては、図７に明示するように、ゴム１２でトッピングされた二束の撚線１３，１３を単位構成幅２Ｗとするスチールコード１４を積層ゴム本体３の内外方向で互いに密接させて二列に配置（二プライ）した上、内外二列のスチールコード１４ｉ，１４ｏのそれぞれを、図６に示すように、互いに隙間なく密に隣接させて螺旋状に巻き付け、そのうち内側列の螺旋状スチールコード１４ｉの内周面に、鉛芯材８の外径と等しい内径を有する内周ゴム層１５を、かつ、外側列の螺旋状スチールコード１４ｏの外周面に、貫通孔７の内径と等しい外径を有する外周ゴム層１６をそれぞれ配置するとともに、これら内周ゴム層１５及び外周ゴム層１６を螺旋状スチールコード１４ｉ，１４ｏのトッピングゴム１２に加硫接着することにより、それら内，外ゴム層１５，１６と螺旋状スチールコード１４ｉ，１４ｏとを一体化して作製されている。また、このように作製された筒形拘束部材１１は、上記環状空間１０内に挿入してその外周ゴム層１６を積層ゴム本体３の弾性ゴム層１…に加硫接着している。なお、各螺旋状スチールコード１４（１４ｉ，１４ｏ）の単位構成となる撚線１３は、直径が約０．１５ｍｍ程度の数十本の金属細線１３ａ…を撚ったものである。
【００２１】
上記のように構成された第２実施例の鉛芯材入り積層ゴム支承装置２０も、上記第１実施例と同様に、上部構造物Ａと下部構造物Ｂの間に介在された状態で設置使用され、積層ゴム本体３の弾性せん断変形による振動エネルギーの吸収機能及び鉛芯材８のせん断塑性変形による振動エネルギーの減衰機能を発揮する。
【００２２】
このとき、大きな水平変形力が加わって鉛芯材８がせん断塑性変形した場合もその鉛芯材８の全外周面が筒形拘束部材１１で常時拘束されたままであるため、複数の薄肉剛性板２…が鉛芯材８に食い込んだり、鉛芯材８が複数の弾性ゴム層１…に食い込んだりすることを防止できるだけでなく、厚肉剛性板４とこれに接する弾性ゴム層１との接着界面ｂに鉛芯材８の一部分８ａ及びその部分８ａを覆う筒形拘束部材１１の一部分１１ａが食い込むことがあってもそれ以上の食い込み及び食い込み部分の楔作用による破断の進行も防止できるのであり、それらの相乗によって、装置の破断変形能力、ひいては、耐久性を一段と向上することができる。
【００２３】
特に、筒形拘束部材１１として、互いに密に隣接させて螺旋状に巻き付けたスチールコード１４ｉ，１４ｏとそれら螺旋状スチールコード１４ｉ，１４ｏの内外周面にゴム層１５，１６を加硫接着により一体化したものを使用することによって、螺旋状スチチールコード１４が有する水平方向への大きな変形能力により履歴復元特性を良好に維持しつつ、破断せん断ひずみ及び破断水平変位を大きく確保することができるとともに、大きな水平変形時における鉛芯材８の拘束性を十分に発揮させることができ、振動エネルギー吸収・減衰性能を一層安定保持することができる。
【００２４】
なお、上記第２実施例では、筒形拘束部材１１として、積層ゴム本体３の内外方向で互いに密接させて二列に配置した内外のスチールコード１４ｉ，１４ｏをそれぞれ互いに隙間なく密に隣接させて螺旋状に巻き付けてなる二プライ構成のものを用いたが、ゴム１２でトッピングされた二束の撚線１３，１３を単位構成幅２Ｗとする一列のスチールコード１４のみを互いに隙間なく密に隣接させて螺旋状に巻き付け、この螺旋状スチールコード１４の内外周面に内，外ゴム層１５，１６を加硫接着してなる一プライ構成のものであってもよい。
【００２５】
また、上記の第１，第２実施例では、柱状の鉛芯材８を挿入するための貫通孔７が積層ゴム本体３の中央部に形成されたもので説明したが、積層ゴム本体３の全体を四角柱形状とし、この積層ゴム本体３の中央部の周辺に円周方向に等間隔で複数の貫通孔７を形成し、これら貫通孔７内にそれぞれ鉛芯材８を挿入するとともに、各鉛芯材８の外周辺部に対応する厚肉剛性板４の複数箇所にそれぞれ環状段差９を形成したものであってもよい。
【００２６】
【発明の効果】
以上のように、本発明によれば、積層ゴム本体の積層方向両端に接着配置される厚肉剛性板のこれに接する弾性ゴム層との接着界面で柱状鉛芯材の周辺部に座ぐり加工によって環状段差を形成するといった簡単な構造改良を施すだけで、せん断変形試験や実設置使用状態で鉛芯材の拘束能力を超えるような大きな水平変形力が加わって鉛芯材の一部分が剛性の高い厚肉剛性板とこれに接する弾性ゴム層との接着界面に食い込んだ際、その食い込み鉛部分を環状段差の内周面で受け止めてそれ以上の食い込み並びにその食い込み鉛部分の楔作用による装置外側に向けての急速な破断進行を防止して内部破壊を極力回避することが可能であり、これによって、装置全体の破断変形能力の著しい向上が図れ、鉛芯材入り積層ゴム支承装置全体の耐久性を高めて所期の振動エネルギー吸収・減衰性能を長期に亘って安定よく保持することができるという効果を奏する。
【００２７】
特に、請求項３に記載の構成を併用することによって、大きな水平変形時における薄肉剛性板の鉛芯材への食い込み及び鉛芯材の弾性ゴム層への食い込み防止機能と、環状段差による接着界面での破断防止機能との相乗によって、装置全体の破断変形能力、ひいては、耐久性の一段の向上を図ることができる。
【００２８】
また、食い込み防止に用いる筒形拘束部材として、請求項４に記載のような構成を採用することによって、螺旋状スチチールコードが有する水平方向への大きな変形能力により履歴復元特性を良好に維持しつつ、破断せん断ひずみ及び破断水平変位を大きく確保することができるとともに、大きな水平変形時における鉛芯材の拘束性を十分に発揮させることができて、振動エネルギー吸収・減衰性能の一層の安定保持性を高めることができる。
【図面の簡単な説明】
【図１】本発明に係る鉛芯材入り積層ゴム支承装置の第１実施例を示す全体縦断面図である。
【図２】図１のＸ−Ｘ線に沿った横断面図である。
【図３】同上第１実施例の鉛芯材入り積層ゴム支承装置の非変形時における要部の拡大縦断面図である。
【図４】同上第１実施例の鉛芯材入り積層ゴム支承装置の水平変形時における要部の拡大縦断面図である。
【図５】本発明に係る鉛芯材入り積層ゴム支承装置の第２実施例を示す全体縦断面図である。
【図６】同上第２実施例の鉛芯材入り積層ゴム支承装置の主要部である筒形拘束部材の拡大縦断面図である。
【図７】同上筒形拘束部材を構成するスチールコード単位体の拡大断面図である。
【図８】従来の鉛芯材入り積層ゴム支承装置の水平変形時における問題点を説明する要部の拡大縦断面図である。
【符号の説明】
１ 弾性ゴム層
２ 薄肉剛性板
３ 積層ゴム本体
４ 厚肉剛性板
７ 貫通孔
８ 円柱状鉛芯材
９ 環状段差
１０ 環状空間
１１ 筒形拘束部材
１１ トッピングゴム
１４，１４ｉ，１４ｏ 螺旋状スチールコード
１５ 内周ゴム層
１６ 外周ゴム層
２０ 鉛芯材入り積層ゴム支承装置[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated rubber bearing device containing a lead core material, which is used as a bearing member of civil engineering structures such as seismic isolation structures of various buildings or bridges. Specifically, a plurality of elastic rubber layers and thin rigid plates are alternately laminated so that vibration energy applied by an earthquake or the like is absorbed and attenuated using the shear deformation characteristics of the elastic rubber layers and the damping characteristics of lead, At the center or at the periphery of the laminated rubber body, a thick rigid plate is adhered and arranged at both ends in the laminating direction, a hole is formed in the laminating direction including the thick rigid plate, and a columnar shape is formed in this through hole. The present invention relates to a laminated rubber bearing device containing a lead core material formed by inserting a lead core material.
[0002]
[Prior art]
In this type of laminated rubber bearing device containing a lead core, when the laminated rubber main body is repeatedly and horizontally deformed due to an earthquake or the like, a thin rigid plate such as a steel plate constituting the laminated rubber main body cuts into the lead core material and the lead core is formed. The material or the thin rigid plate is locally deformed, or the lead core material cuts into the elastic rubber layer of the laminated rubber body and damages the elastic rubber layer, resulting in deterioration of the shear deformation characteristics or damping characteristics, resulting in long-term failure. However, there is a problem that the vibration energy absorption / damping performance of the period cannot be maintained.
[0003]
As means for solving such a problem, conventionally, an intermediate reinforcing plate is arranged in a ring shape so as to surround an outer peripheral portion of a columnar lead core material in an elastic rubber layer between thin rigid plates and restrain the lead core material. Is known (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-355677 A (FIGS. 1 to 4)
[0005]
[Problems to be solved by the invention]
In the conventional lead-core-containing laminated rubber bearing device with the above configuration, the thin rigid plate digs into the lead core during the horizontal deformation in the shear deformation test or actual installation condition, or the lead core becomes the elastic rubber layer. It is possible to prevent digging in by the ring-shaped intermediate reinforcing plate and to suppress the expected decrease in vibration energy absorption / damping performance.
[0006]
However, when a large horizontal deformation force exceeding the binding capacity of the lead core material by the ring-shaped intermediate reinforcing plate is applied, as shown in FIG. 8, as shown in FIG. Stress concentrates on the adhesive interface b between the thick rigid plate 4 at both ends in the direction and the elastic rubber layer 1 in contact therewith, and a portion 8a of the lead core material 8 bites in a pointed state, and the wedge of the biting lead portion 8a is cut. By the action, internal destruction such that the biting portion becomes a starting point and the rupture rapidly progresses toward the outside of the device indicated by the arrow x is likely to occur, and therefore, the rupture deformation capability of the entire device is poor, and a strong horizontal deformation force A major problem remains in terms of the durability of this type of device installed and used under conditions that are repeatedly subjected to the following.
[0007]
The present invention has been made in view of the above circumstances, and even if a part of the lead core material digs into the bonding interface by applying a large horizontal deformation force exceeding the restraining ability of the lead core material, breakage from the bite portion It is an object of the present invention to provide a laminated rubber bearing device containing a lead core material, which can prevent the progress of cracking and can significantly improve the entire breaking deformation capability and, consequently, the durability.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a laminated rubber bearing device containing a lead core material according to the present invention is configured by alternately laminating a plurality of elastic rubber layers and thin rigid plates, and bonding thick rigid plates to both ends in the laminating direction. A hole is formed in the central portion or the peripheral portion of the laminated rubber body that is disposed and penetrates in the laminating direction including the thick rigid plate, and a lead formed by inserting a columnar lead core material into the through hole. A laminated rubber bearing device containing a core material, wherein an annular step is formed in the peripheral portion of the columnar lead core material at a bonding interface with the elastic rubber layer of the thick rigid plate by counterbore processing. It is.
[0009]
According to the present invention having the above-described configuration, when a large horizontal deformation force that exceeds the restraining capacity of the lead core material is applied in a shear deformation test or actual installation use state, the lead core material is sheared due to the horizontal deformation. A part of the lead core material will bite into the adhesive interface between the thickest rigid plate, which is the most rigid due to plastic deformation, and the elastic rubber layer in contact with the thick plate, and the biting lead portion will be the inner peripheral surface of the annular step. And the further biting is prevented, and the direction of progress of the break due to the wedge action of the biting lead portion is switched to a direction orthogonal to the bonding interface. Therefore, it is possible to suppress the internal destruction such that the rupture accompanying the bite proceeds rapidly toward the outside of the device, improve the rupture deformation capacity of the entire device, and improve the durability of the laminated rubber bearing device containing lead core material. It is possible to stably maintain the vibration energy absorption / damping performance of the device over a long period of time.
[0010]
As the annular step in the laminated rubber bearing device containing a lead core material according to the present invention, the inner diameter is less than 1.02 times the outer diameter of the columnar lead core material, and the depth is 0.1% of the thickness of the thin rigid plate. If it is less than twice, it is not possible to sufficiently receive the lead portion digging into the bonding interface during large deformation, and its inner diameter exceeds 1.2 times the outer diameter of the columnar lead core material, and its depth is If the thickness exceeds 2.0 times that of the thin rigid plate, the breaking force that rapidly progresses along the interface with the bite cannot be stopped. From this viewpoint, the annular step has an inner diameter of 1.02 to 1.2 times the outer diameter of the columnar lead core material and a depth of 0.1 to 2.0 times the thickness of the thin rigid plate. Is preferably set to.
[0011]
Further, in the laminated rubber bearing device containing a lead core material according to the present invention, as described in claim 3, the laminated rubber bearing device is provided in an annular space between the outer peripheral surface of the columnar lead core material and the inner peripheral surface of the through hole. It is preferable that a cylindrical restraining member that restrains the lead core material be interposed when the rubber body is sheared and deformed, and the annular step be formed around the cylindrical restraining member. In this case, when a large horizontal deformation force is applied and the lead core material undergoes shear plastic deformation, the entire outer peripheral surface of the lead core material is always restrained by the cylindrical restraining member. In addition to being able to prevent the core material from digging into the core material and the lead core material from digging into the plurality of elastic rubber layers, a part of the lead core material and its Even if a part of the restraining member that covers the part may bite, further digging and the progress of rupture due to the wedge action of the digging part can be prevented by the annular step, and these digging prevention action and the rupture progression preventing action at the adhesive interface By synergistically, the breaking deformation capability of the device and, consequently, the durability can be further improved.
[0012]
In particular, as a cylindrical restraining member in a laminated rubber bearing device containing a lead core material in which the above-described cylindrical restraining member is interposed, a steel cord spirally wound closely adjacent to each other as described in claim 4. And the inner and outer peripheral rubber layers which are arranged on the inner and outer peripheral surfaces of the spiral steel cord and are integrated with the steel cord by vulcanization bonding, thereby allowing the spiral steel cord to have a horizontal direction. While maintaining the hysteresis restoration characteristics satisfactorily due to the large deformation capacity, it is possible to secure large breaking shear strain and breaking horizontal displacement, and to fully exert the restraint of the lead core material during large horizontal deformation. As a result, the stability of vibration energy absorption / damping performance can be further improved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall longitudinal sectional view showing a first embodiment of a laminated rubber bearing device containing a lead core material according to the present invention, and FIG. 2 is a transverse sectional view taken along line XX of FIG. In the example of the laminated rubber bearing device 20 containing a lead core, a plurality of elastic rubber layers 1, a plurality of thin rigid plates 2 made of a thin steel plate, and upper and lower thick rigid plates (flanges) 4, 4 are alternately arranged vertically. And the laminated rubber (elastic rubber layers 1, thin rigid plates 2, and thick rigid plates 4, 4) is covered with a coating rubber 1 </ b> A on the entire periphery thereof, and these are vulcanized and adhered. On the outer surfaces of the upper and lower thick rigid plates 4 and 4 of the integrated laminated rubber main body 3, mounting plates 5 and 5 which can be fixedly supported on the upper structure A and the lower structure B via anchors C and C are sheared. The keys 6 and 6 are fixedly joined.
[0014]
A through hole 7 is formed in the center of the laminated rubber body 3 including the upper and lower thick rigid plates 4 and 4 in the laminating direction, and a cylindrical lead core is formed in the entire area of the through hole 7. The material 8 is inserted, and the outer peripheral surfaces of the upper and lower ends of the columnar lead core material 8 are bonded and fixed to the inner peripheral surfaces of the through holes 7 of the thick rigid plates 4, 4.
[0015]
In the laminated rubber bearing device 20 including the lead core material having the above-described configuration, the outer peripheral portion of the columnar lead core material 8 at the adhesive interface b between the thick rigid plates 4 and 4 and the upper and lower elastic rubber layers 1 and 1 in contact with them. As shown in FIGS. 3 and 4, annular steps 9, 9 are formed by counterbore processing. In the annular steps 9, one of the upper and lower elastic rubber layers 1, 1 is formed. The parts 1a, 1a are inserted and bonded. Each of the annular steps 9, 9 has an inner diameter d1 of 1.02 to 1.2 times the outer diameter d of the columnar lead core material 8 and a depth t1 of the thickness t of the thin rigid plate 2. The size is set within a range of 0.1 to 2.0 times. 3 and 4 show only one end side in the stacking direction. In the following description, only the one end side will be described. However, both ends have the same configuration and similarly deform.
[0016]
As shown in FIG. 1, the lead-core-containing laminated rubber bearing device 20 configured as described above is installed and used while being interposed between the upper structure A and the lower structure B. In this state, when a vibration force is input to the lower structure B due to an earthquake or the like, the upper structure A is relatively displaced in the horizontal direction, and accordingly, the laminated rubber body 3 is elastically sheared. Thus, a seismic isolation action such as absorbing vibration energy and transmitting the vibration energy to the upper structure A is exhibited. On the other hand, with the shear deformation of the laminated rubber main body 3, the lead core material 8 also undergoes shear plastic deformation, and vibration energy is attenuated by the plastic deformation.
[0017]
In the case of the laminated rubber bearing device 20 containing a lead core material exhibiting such vibration energy absorbing and damping functions, at normal times, that is, at the time of non-deformation, as shown in FIG. A part 1a of the elastic rubber layer 1 which is in contact with the thick rigid plate 4 enters the step 9, and the lead core 8 is restrained by the plurality of elastic rubber layers 1. Then, a large horizontal deformation force exceeding the restraining ability of the lead core material 8 is applied in the shear deformation test of the product (the laminated rubber bearing device 20 containing the lead core material) or in actual installation and use, and the lead core material 8 When a large shear plastic deformation occurs, as shown in FIG. 4, a portion 8a of the lead core material 8 bites into the bonding interface b between the thick rigid plate 4 and the elastic rubber layer 1 in contact therewith.
[0018]
In this case, the lead portion 8a biting into the bonding interface b is received by the inner peripheral surface of the annular step 9 so that further biting is prevented, and the direction in which the lead portion 8a breaks due to the wedge action is shown in FIG. Is switched in a direction orthogonal to the bonding interface b as shown by the arrow y. Therefore, even if a part 8a of the lead core material 8 bites into the bonding interface b due to a large horizontal deformation force, the internal destruction caused by the further biting and rupture progressing rapidly toward the outside of the device is suppressed. As a result, the durability of the laminated rubber bearing device 20 containing a lead core is enhanced by improving the breaking deformation capability of the entire device, and the expected vibration energy absorption / damping performance can be stably maintained over a long period of time. it can.
[0019]
FIG. 5 is an overall vertical sectional view showing a second embodiment of the laminated rubber bearing device containing a lead core material according to the present invention. In the laminated rubber bearing device 20 containing a lead core material of the second embodiment, the inner peripheral surface of a through hole 7 formed in the center of the laminated rubber body 3 including the upper and lower thick rigid plates 4 and 4 in the laminating direction. When the laminated rubber main body 3 undergoes a horizontal force due to an earthquake or the like and undergoes shear deformation in an annular space 10 between the lead core material 8 and the outer peripheral surface of the columnar lead core material 8 inserted into the entire area of the through hole 7, And a cylindrical restraining member 11 for preventing the lead core material 8 from biting into the elastic rubber layer 1 and the thin rigid plate 2 from biting into the lead core material 8 is interposed. As in the first embodiment, the annular steps 9, 9 are formed in the outer peripheral portion of the shape-restraining member 11 by counterbore processing, and the other configurations are the same as those in the first embodiment. The same reference numerals are given to the corresponding parts and the description thereof is omitted.
[0020]
As shown in FIG. 7, as the cylindrical restraining member 11 used in the second embodiment, a steel cord 14 having two bundles of twisted wires 13, 13 topped with rubber 12 and having a unit configuration width of 2 W is a laminated rubber. After being arranged in two rows (two plies) in close contact with each other in the inner and outer directions of the main body 3, the steel cords 14i and 14o in the two inner and outer rows are spirally arranged closely adjacent to each other as shown in FIG. The inner circumferential rubber layer 15 having an inner diameter equal to the outer diameter of the lead core material 8 is provided on the inner circumferential surface of the spiral steel cords 14i in the inner row, and the outer circumference of the spiral steel cords 14o in the outer row. Outer rubber layers 16 each having an outer diameter equal to the inner diameter of the through-hole 7 are arranged on the surface, and the inner rubber layer 15 and the outer rubber layer 16 are topped by spiral steel cords 14i and 14o. By vulcanization bonded to arm 12, in those, the outer rubber layers 15, 16 and the spiral steel cord 14i, have been produced by integrating the 14o. The cylindrical restraining member 11 thus manufactured is inserted into the annular space 10 and the outer peripheral rubber layer 16 is vulcanized and bonded to the elastic rubber layers 1 of the laminated rubber body 3. The stranded wire 13 as a unit configuration of each spiral steel cord 14 (14i, 14o) is formed by twisting several tens of fine metal wires 13a having a diameter of about 0.15 mm.
[0021]
The laminated rubber bearing device 20 containing a lead core material of the second embodiment configured as described above is also installed in a state interposed between the upper structure A and the lower structure B, similarly to the first embodiment. It is used and exhibits a function of absorbing vibration energy due to elastic shear deformation of the laminated rubber body 3 and a function of attenuating vibration energy due to shear plastic deformation of the lead core material 8.
[0022]
At this time, even when a large horizontal deformation force is applied and the lead core material 8 undergoes shear plastic deformation, the entire outer peripheral surface of the lead core material 8 is always restrained by the cylindrical restraining member 11, so that a plurality of thin rigid plates are provided. Can prevent the lead core material 8 from digging into the lead core material 8 and the lead core material 8 from digging into the plurality of elastic rubber layers 1, as well as the adhesion between the thick rigid plate 4 and the elastic rubber layer 1 in contact therewith. Even if the portion 8a of the lead core material 8 and the portion 11a of the cylindrical restraint member 11 covering the portion 8a bite into the interface b, further biting and breakage of the biting portion due to wedge action can be prevented. The synergistic combination thereof can further improve the breaking deformation capability of the device and, consequently, the durability.
[0023]
In particular, as the cylindrical restraining member 11, the steel cords 14i, 14o spirally wound closely adjacent to each other and the rubber layers 15, 16 integrally formed on the inner and outer peripheral surfaces of the spiral steel cords 14i, 14o by vulcanization bonding. By using the reinforced steel cord, it is possible to secure large breaking shear strain and breaking horizontal displacement while maintaining good hysteresis restoration characteristics by a large deformation capability in the horizontal direction of the spiral steel cord 14. In addition, the restraint of the lead core material 8 at the time of large horizontal deformation can be sufficiently exhibited, and the vibration energy absorption / damping performance can be more stably maintained.
[0024]
In the second embodiment, as the cylindrical restraining member 11, inner and outer steel cords 14i and 14o arranged in two rows in close contact with each other in the inner and outer directions of the laminated rubber body 3 are closely adjacent to each other without any gap. Although a two-ply structure wound spirally was used, only a single line of steel cords 14 having a unit configuration width of two bundles of stranded wires 13 and 13 topped with rubber 12 was closely adjacent to each other without gaps. Then, the helical steel cord 14 may be spirally wound, and the inner and outer rubber layers 15 and 16 may be vulcanized and adhered to the inner and outer peripheral surfaces of the helical steel cord 14 to form a single ply.
[0025]
In the first and second embodiments, the through hole 7 for inserting the columnar lead core material 8 is described as being formed in the central portion of the laminated rubber main body 3. The whole is in the shape of a quadrangular prism, and a plurality of through holes 7 are formed at equal intervals in the circumferential direction around the center of the laminated rubber body 3, and a lead core material 8 is inserted into each of the through holes 7, An annular step 9 may be formed at a plurality of locations on the thick rigid plate 4 corresponding to the outer peripheral portion of each lead core 8.
[0026]
【The invention's effect】
As described above, according to the present invention, the peripheral portion of the columnar lead core material is counterbored at the bonding interface between the thick rigid plate adhered to both ends of the laminated rubber body in the laminating direction and the elastic rubber layer in contact with the thick rigid plate. A simple structural improvement such as the formation of an annular step is applied, and a large horizontal deformation force that exceeds the restraining capacity of the lead core material in a shear deformation test or actual installation condition is applied, and a part of the lead core material becomes rigid. When biting into the adhesive interface between the high-thick rigid plate and the elastic rubber layer in contact with it, the biting lead portion is received by the inner peripheral surface of the annular step and further biting, and the outside of the device due to the wedge action of the biting lead portion It is possible to prevent the internal fracture as much as possible by preventing rapid rupture progression toward, and thereby remarkably improve the rupture deformation capacity of the entire device and the durability of the entire laminated rubber bearing device containing lead core material. Expected vibration energy absorption and damping performance to enhance the over long advantageously possible to stably well maintained.
[0027]
In particular, by using the configuration according to claim 3 together, the function of preventing the thin rigid plate from biting into the lead core material and the lead core material from biting into the elastic rubber layer at the time of large horizontal deformation, and the bonding interface due to the annular step In combination with the rupture prevention function described above, the rupture deformation capability of the entire device, and furthermore, the durability can be further improved.
[0028]
In addition, by adopting a configuration as described in claim 4 as the cylindrical restraining member used for preventing biting, the history restoring characteristic is favorably maintained due to the large horizontal deformation capability of the spiral steel cord. In addition, the breaking shear strain and the breaking horizontal displacement can be secured large, and the restraint of the lead core material at the time of large horizontal deformation can be sufficiently exhibited, and the vibration energy absorption and damping performance can be more stably maintained. Can be enhanced.
[Brief description of the drawings]
FIG. 1 is an overall vertical sectional view showing a first embodiment of a laminated rubber bearing device containing a lead core material according to the present invention.
FIG. 2 is a cross-sectional view taken along line XX of FIG.
FIG. 3 is an enlarged longitudinal sectional view of a main part of the laminated rubber bearing device containing a lead core material of the first embodiment when it is not deformed.
FIG. 4 is an enlarged vertical sectional view of a main part of the laminated rubber bearing device containing a lead core material of the first embodiment during horizontal deformation.
FIG. 5 is an overall vertical sectional view showing a second embodiment of a laminated rubber bearing device containing a lead core material according to the present invention.
FIG. 6 is an enlarged vertical sectional view of a cylindrical restraining member which is a main part of the laminated rubber bearing device containing a lead core material of the second embodiment.
FIG. 7 is an enlarged cross-sectional view of a steel cord unit constituting the above cylindrical restraining member.
FIG. 8 is an enlarged vertical sectional view of a main part for explaining a problem at the time of horizontal deformation of a conventional laminated rubber bearing device containing a lead core material.
[Explanation of symbols]
Reference Signs List 1 elastic rubber layer 2 thin rigid plate 3 laminated rubber main body 4 thick rigid plate 7 through hole 8 cylindrical lead core material 9 annular step 10 annular space 11 cylindrical restraining member 11 topping rubber 14, 14i, 14o spiral steel cord 15 Inner circumference rubber layer 16 Outer circumference rubber layer 20 Laminated rubber bearing device containing lead core material
