JP4734777B2

JP4734777B2 - 3D vibration isolator

Info

Publication number: JP4734777B2
Application number: JP2001183534A
Authority: JP
Inventors: 明倫宮本; 譲安井
Original assignee: Obayashi Corp
Current assignee: Obayashi Corp
Priority date: 2001-06-18
Filing date: 2001-06-18
Publication date: 2011-07-27
Anticipated expiration: 2021-06-18
Also published as: JP2002371725A

Description

【０００１】
【発明の属する技術分野】
本発明は、水平方向および上下方向の免振機能を備えた三次元免振装置に関する。
【０００２】
【従来の技術】
原子力発電所等の重要施設は地震等による影響を極力無くす建築物として構築されるが、その重要施設を立地条件にかかわらず構築できる立地拡大を目指したサイトフリーと、設備の標準化によるコスト低減を目指した標準化プラント構築とを可能とする免振構造の採用が望まれる。
【０００３】
一般に、ビル等の建築物の免振は積層ゴム等を用いた水平免振構造が採用されるが、これに上下免振構造を併用することにより三次元免振を達成して地震から建築物を効率良く保護することができ、これを上記重要施設に適用することにより建築物の標準化が可能となる。
【０００４】
この種の三次元免振装置としては、例えば特開平８−２１８６７８号公報に開示されるものが提案されている。この三次元免振装置は、積層ゴム等の水平免振装置の下部または上部に上下免振機構を付加して構成されている。即ち、水平免振装置と上下免振機構とを上下方向に直列配置して構成されるようになっており、建築物の重量がこれら水平免振装置および上下免振機構に入力されるようになっている。
【０００５】
ところで、このような三次元免振装置にあっては、建築物が地震入力時の上下振動に共振するのを避けるべく、この建築物側の上下方向の固有振動数を長周期化することが望ましい。つまり、地震により入力される上下振動の卓越周期は０．５秒以下の範囲に存在するため、上下免振機構で決定される建築物側の上下方向の振動周期は少なくとも０．５秒以上、望ましくは３秒以上に長周期化して設定する必要があり、このように建築物を長周期化するためには、上下免振機構のバネ剛性を適切に設定する必要がある。
【０００６】
また、上下免振機構には、建築物の重量を確実に支持できること、並びに建築物のロッキング振動を防止できることも求められる。上下免振機構のバネ剛性の設定が不適当であると、建築物の上下振動周期が免振領域から短周期方向にずれて効果的に上下免振できなくなる虞がある。そして、このように免振領域からずれると建築物の上下振動が大きくなり、延いてはこの建築物に引抜き力が大きく作用して、積層ゴム等で構成される水平免振装置が損傷されてしまう虞もある。
【０００７】
さらに、建築物の荷重を支持するために上記上下免振機構のバネ剛性を大きくした場合には、この上下免振機構のバネ剛性に起因する上下変動荷重が水平免振装置の性能に大きな影響を与える。つまり、水平免振装置の上に直列に上下免振機構を設けて構成した三次元免振装置であると、水平免振装置には上下免振装置を介して上下変動荷重が作用することになるが、水平力により水平免振装置の積層ゴムに剪断力が発生しているときに、上下方向の変動荷重を受けるとその剪断抵抗力が上下変動力の影響を受けて変動してしまう。
【０００８】
これ故、上記特開平８−２１８６７８号公報に開示されるような従来の三次元免振装置では、水平免振装置自身が備える水平バネ剛性で本来達成されるべき水平免振性能に対して、上記上下免振機構の大きなバネ剛性に起因する上下変動荷重が影響し、水平免振装置単体を目的通りの性能で設計することが困難になる。
【０００９】
そこで、本願出願人は先に、特開２００１−８２５４２号公報にて示したように、支持構造物と免振構造物との間に、上下変動荷重を受けずに専ら水平免振を行う水平免振装置と、水平荷重を受けずに専ら上下免振を行う上下免振装置とを並設した三次元免振構造を提案した。即ち、当該特開２００１−８２５４２号公報の三次元免振装置にあっては、水平免振装置には積層ゴムを用いて、この積層ゴムには上下方向の相対変位を許容して水平変位のみを伝達する伝達機構を介在させて支持構造と免振構造との間に取り付ける一方、上下免振装置には免振構造体の荷重を確実に支持する必要性から皿バネ積層体を用い、この皿バネ積層体には水平方向の相対変位を許容する滑動機構を介在させて支持構造と免振構造との間に取り付けるようになっている。
【００１０】
【発明が解決しようとする課題】
しかしながら、係る提案の三次元免振装置では、上下免振装置に皿バネ積層体を用いているため、上下方向変位のストロークを十分に確保し得ず、現状では免振構造物の上下固有周期を未だ１秒以上に長周期化するのが困難で、望まれている３秒以上の長周期化を達成出来ないという課題がある。
【００１１】
ここで、水平免振の長周期化のみならず、上下ストロークをも十分に確保して上下固有周期を３秒以上に長周期化し得る三次元免振装置として、例えばゴム等の可撓性に富む材料にて単一気密構造の空気バネを作り、当該空気バネで三次元免振することも考えられ、このような単一気密構造の空気バネの研究開発も鋭意進められている。ところが、空気バネによって免振構造物を３秒以上の上下固有周期で支持するには、２０気圧（２０ｋｇ／ｂａｒ、１０１．３２５Pa）程度の内圧を確保する必要があって、ゴムなどの可撓性に富む材料で気密室を構成すると、その材質上、損傷を受け易いだけでなく経時劣化を生じる等、耐久信頼性の面で漏洩発生の虞が高い。そして、漏洩が生じると免振装置としての最も基本的な機能である免振構造物の支持機能を喪失してしまい、基礎版などの支持構造物の破壊や免振構造物の不等沈下をもたらす。
【００１２】
よって、以上の理由から、従来の三次元免振装置はいずれも、水平および上下の三次元方向の免振機能を共に長周期化を図りつつ、的確かつ十分に、しかも高い信頼性をもって発揮させ得ているとはいえず、従って、これを上記重要施設等に適用して建築物の標準化を達成することは、著しい困難を伴うという課題があった。
【００１３】
本発明は、以上のような事情に鑑みてなされたものであり、その目的は、専ら水平免振を行う水平免振装置と、専ら上下免振を行う上下免振装置とを並設する構成の三次元免振装置において、上下免振装置に耐久信頼性の高い鋼製ケース製の空気バネを用いて、水平免振装置による本来の水平免振機能を十分に確保しつつ、上下固有周期の３秒以上の長周期化を達成し得る三次元免振装置を提供することにある。
【００１４】
また、上記鋼製ケースで形成した空気バネを用いた場合、免振構造物下での配設位置が南北に異なると、それら各空気バネの周囲温度条件は四季や昼夜を通じて同等に変動することはない。このため、このような周囲温度条件の変動に差異が生じた場合に、各空気バネの内圧が相違して免振構造物に不等沈下や傾きが生じてしまう虞がある。そこで、本発明では、空気バネによる上下免振機能を損なうことなく外気温などの影響による空気バネの内圧変動を規定の一定範囲内に抑えて、免振構造物下に複数配設される空気バネ相互間の高さをほぼ一定に保ち得、もって免振構造物に不等沈下や傾きを生じさせることのない三次元免振装置を提供することを第２の目的とする。
【００１５】
【課題を解決するための手段】
上記第１の目的を達成するために本発明では、支持構造物と該支持構造物の上方に間隔を隔てて配置される免振構造物との間に設けられる三次元免振装置であって、これら両構造物間の水平方向の相対移動を許容する滑動機構を介して上下免振する上下免振装置と、両構造物間の上下方向の相対移動を許容する水平方向力伝達機構を介して水平方向免振する水平免振装置とからなり、該上下免振装置には、一端が閉塞された円筒状の鋼製ケースと該鋼製ケース内を摺動する摺動体とによって上下に拡縮するバネ室を形成した空気バネを用い、該空気バネの一端と該一端が当接する一方の構造物との間に前記滑動機構を介在させ、前記空気バネの鋼製ケースに径方向外方に延出させた支持ステーを一体形成し、該支持ステーに前記水平免振装置の一端を結合させて、前記上下免振装置と滑動機構とを前記水平方向力伝達機構として機能させる構成となし得る（請求項１）。
【００１７】
さらに、前記支持ステーは環状のフランジに形成し、該フランジに沿って前記鋼製ケースの周囲に、前記水平免振装置を複数並設する構成にもなし得る（請求項２）。
【００１８】
またさらに、前記支持ステーあるいはフランジと他方の構造物との間に、上下方向の振動減衰装置を設けた構成にもなし得る（請求項３）。
【００１９】
さらにまた、前記一方の構造物に、前記上下免振装置の他端を固定する固定台座を一体形成し、該固定台座と前記鋼製ケースの周壁部との間に水平方向の振動減衰装置を設けた構成にもなし得る（請求項４）。
【００２０】
ここで、前記滑動機構には転がり支承を用い得る（請求項５）。
また、前記水平免振装置には積層ゴムを用い得る（請求項６）。
【００２１】
一方、上記第２の目的を達成するために、本発明にあっては、前記上下免振装置の空気バネに、平常時における空気バネ室の内圧を一定範囲内に調圧するとともに、振動検知時に該調圧機能を強制停止させる定空気圧維持装置を取り付けたことを特徴とする（請求項７）。
【００２２】
ここで、前記定空気圧維持装置は、前記空気バネ室の内圧を検出する圧力センサと、該空気バネ室内の圧力を規定の上限値以下に保つリリーフ弁と、該リリーフ弁に直列接続されて該リリーフ弁による圧力解放機能を抑制する電磁開閉弁と、該空気バネ室内に圧搾空気を供給する圧気供給手段と、該圧力センサで検出した圧力値に基づいて該電磁開閉弁と該圧気供給手段との作動を制御する制御器とからなり、該制御器は該圧力センサで検出した圧力値が規定の下限値以下になると該圧気供給手段を作動させて空気バネ室の内圧を該下限値以上に保つ一方、該圧力センサで検出した圧力値の変動を監視して、該変動に基づいて振動を検知したときに該電磁開閉弁を閉じるとともに圧気供給手段の作動を停止させる構成となし得る（請求項８）。
【００２３】
【発明の実施の形態】
以下、本発明に係る三次元免振装置の好ましい実施形態について、添付図面を参照して詳細に説明する。
図１は本発明の基本形をなす第１実施形態を示すものである。図示するように、この三次元免振装置１０は、支持構造物１２とこの支持構造物１２の上方に間隔を隔てて配置される免振構造物１４との間に配設されて、これら両構造物１２，１４間の上下方向の相対移動を水平方向力伝達機構２０を介して許容しつつ水平免振する水平免振装置１６と、両構造物１２，１４間の水平方向の相対移動を滑動機構２８を介して許容しつつ上下免振する上下免振装置１８とからなる。
【００２４】
両免振装置１６，１８は両構造物１２，１４間に並列配置され、水平力伝達機構２０は水平免振装置１６とその上方の免振構造物１４との間に配置される一方、滑動機構２８は上下免振装置１８とその下方の支持構造物１２との間に配置され、上下免振装置１８によって免振構造物１４の鉛直荷重を支持するようになっている。これら水平免振装置１６と上下免振装置１８，水平力伝達機構２０及び滑動機構２８とは、同図に示すように、１つの三次元免振ユニットを構成し、このユニットが免振構造物１４の下面に複数個配置されて全体の三次元免振を行うようになっている。なお、水平免振装置１６と上下免振装置１８とは、これらを並列配置させてあれば必ずしもユニット化する必要はなく、個数も同数である必要はない。
【００２５】
上記水平免振装置１６は、ゴム層と鋼板とが交互に積層される積層ゴム２２で構成され、この積層ゴム２２には下方フランジ２２ａと上方フランジ２２ｂとが設けられる。この積層ゴム２２の設置部位には支持構造物１２から所定高さの鉄筋コンクリート造の固定台座２４が突設され、この固定台座２４上に下方フランジ２２ａを固定して積層ゴム２２が設置される。積層ゴム２２は、水平方向に等方性の復元性能および減衰性能を有し、水平方向全方位に対して的確な免振性能を発揮する。
【００２６】
この水平免振装置１６と免振構造物１４との間には、免振構造物１４の上下方向の相対移動を許容しつつ、水平方向の相対移動（水平方向力）を水平免振装置１６に伝達する水平方向力伝達機構２０が介在されており、この水平方向力伝達機構２０は、積層ゴム２２の上方フランジ２２ｂ上に立設された筒体３２と、免振構造物１４に固定される上方取付板３４から垂設されて筒体３２内に上下方向にスライド自在に挿入され、筒体３２に対して水平方向に係合する軸体３２ａとから構成される。これら筒体３２および軸体３２ａについては、図示例では上方フランジ２２ｂに筒体３２、上方取付板３４に軸体３２ａを設けたが、これらの配置関係は逆であってもよい。
【００２７】
そして互いに相対向する軸体３２ａの外周面と筒体３２の内周面との間には、僅かな隙間を設けることが好ましい。これら外周面と内周面とを常時摺接状態とすると、免振構造物１４と支持構造物１２との間に上下方向相対移動が生じたときに両者間に摩擦力が発生し、これが上下方向力として水平免振装置１６に作用するおそれがあるからである。他方、これら外周面と内周面との隙間が大きすぎると、免振構造物１４と支持構造物１２との間に水平方向相対移動が生じたときに水平免振装置１６や免振構造物１４に衝撃的な力が作用して好ましくないからである。
【００２８】
さらに、上下方向に相対向する軸体３２ａの下端と積層ゴム２２の上方フランジ２２ｂとの間、及び同じく上下方向に相対向する筒体３２の上端と上方取付板３４との間とには、許容すべき上下方向相対変位よりも大きな隙間が設定され、免振構造物１４と支持構造物１２との上下方向相対移動で軸体３２ａと上方フランジ２２ｂとが、また筒体３２と上方取付板３４とが干渉しないようになっている。ここで、筒体３２および軸体３２ａの断面形状は、上下方向スライドと水平方向の係合が維持されるならば、円形などどのような断面形状としてもよい。そして、これら軸体３２ａと筒体３２とが一対の係合部材を構成している。
【００２９】
上記上下免振装置１８には、空気バネ２６が用いられている。この空気バネ２６は、一端が平坦に閉塞された上下一対の有底円筒状の鋼製ケース２６ａ，２６ｂによって形成されており、下側鋼製ケース２６ａの方が上側鋼製ケース２６ｂよりも大径になっていて、上側鋼製ケース２６ｂの開放端側が下側鋼製ケース２６ａの開放端側に入り込んで相互に摺動自在に嵌合し、当該摺動部にはＯリング２７が介装されて、内部には２０気圧（２０ｋｇ／ｂａｒ、１０１．３２５Pa）程度の圧搾空気を収納する密封された空気バネ室２６ｃが上下に拡縮可能に画成されている。なお、ここで空気バネ２６は上記のように必ずしも一対の鋼製ケース２６ａ，２６ｂで構成する必要はなく、少なくとも一方を鋼製ケース２６ａで形成して他方はその鋼製ケース２６ａ内を上下に摺動するピストン様の摺動体としても良い。
【００３０】
そして、空気バネ２６の下側は、支持構造物１２に載置される滑動機構２８としての転がり支承２９上に搭載される。空気バネ２６の上側は、免振構造物１４に下方に突出されて一体形成された環状の上方取付座３０に上側鋼製ケース２６ｂの上端部が嵌合固定されて取り付けられる。
【００３１】
上記転がり支承２９は、下面が平坦となった支持基板２９ａと、この支持基板２９ａの周縁部を適宜隙間を設けて覆う外殻２９ｂと、これら支持基板２９ａと外殻２９ｂとの間の空間部に収納される多数の小球２９ｃとを備えて構成される。そして、上記支持基板２９ａは上記小球２９ｃを介在させた状態で支持構造物１２上面に敷設されるスライド基板３６に載置され、介在された小球２９ｃが転動することにより、この転がり支承２９と支持構造物１２とは極小さな滑動抵抗をもって滑動自在となっている。なお、滑動機構２８として本実施形態では転がり支障２９を用いているが、これに限らず、滑り支承を採用しても良い。
【００３２】
また、水平免振装置１６の上方取付板３４と上方フランジ２２ｂとの間には、これらに結合されて支持構造物１２と免振構造物１４との上下方向の相対振動のエネルギーを吸収して当該上下振動を減衰させるダンパー５０が別途設けられている。さらに、固定台座２４と空気バネ２６の下側鋼製ケース２６ａの周壁部との間には、これらの水平方向の相対変位方向に追従して回動するように両者にピンジョイント５１を介して回動自在に結合されて、支持構造物１２と免振構造物１４との水平方向の相対振動のエネルギーを吸収して当該水平振動を減衰させるダンパー５２が別途設けられている。これらの上下方向及び水平方向のバンパー５０，５２としては、例えば油圧式等の流体ダンパーあるいは摩擦ダンパー等を採用でき、ここでは油圧ダンパーが用いられている。
【００３３】
一方、前記上下免振装置１８の空気バネ２６には、平常時における空気バネ室２６ｃの内圧を一定範囲内に調圧するとともに、振動検知時にその調圧機能を強制停止させる定空気圧維持装置５４が取り付けられている。この定空気圧維持装置５４は、空気バネ室２６ｃの内圧を検出する圧力センサ５６と、この空気バネ室２６ｃ内の圧力を規定の上限値以下に保つリリーフ弁５８と、このリリーフ弁５８に直列接続されて当該リリーフ弁５８による圧力解放機能を抑制する電磁開閉弁６０と、空気バネ室２６ｃ内に圧搾空気を供給する圧気供給手段６２と、この圧力センサ５６で検出した圧力値に基づいて上記圧力解放抑制用の電磁開閉弁６０と圧気供給手段６２との作動を制御する制御器６４とからなる。
【００３４】
圧気供給手段６２はエアコンプレッサ６２ａと電磁開閉弁６２ｂとからなり、圧搾空気の供給時にはエアコンプレッサ６２ａの作動とともに電磁開閉弁６２ｂが開放され、供給停止時にはエアコンプレッサ６２ａが停止されるとともに電磁開閉弁６２ｂが閉じられるようになっている。
【００３５】
制御器６４はマイクロコンピュータにより構成され、圧力センサ５６で検出した圧力値が規定の下限値以下になると圧気供給手段６２を作動させて空気バネ室２６ｃの内圧をその下限値以上に保つ一方、圧力センサ５６で検出した圧力値の変動を常時監視して、この圧力変動の大きさ及び速さに基づいて振動を検知したときには電磁開閉弁６０を閉じるとともに圧気供給手段６２の作動を停止させるようになっており、振動が検知されない平常時にあっては圧力解放抑制用の電磁開閉弁６０は開放されている。なお、上記振動の検知は支持構造体側に設けた加速度センサによって行うようにしても良い。
【００３６】
以上の構成により本第１実施形態の三次元免振装置１０では、支持構造物１２と免振構造物１４との間に水平免振装置１６と上下免振装置１８とが並列配置されることにより、地震による振動が入力されると水平免振装置１６により水平振動エネルギーが吸収されて水平免振されるとともに、上下免振装置１８により上下振動エネルギーが吸収されて上下免振され、これら水平免振と上下免振とをもって三次元免振される。また、水平免振装置１６の上部に配置された水平力伝達機構２０は、上下振動に起因する軸力変動が水平免振装置１６に作用するのを阻止する機能を備える。
【００３７】
ここで、水平免振装置１６と上下免振装置１８とを並列配置し、かつ免振構造物１４の上下方向相対移動は許容し水平方向相対移動は水平免振装置１６に伝達する水平方向力伝達機構２０を設けることにより、鉛直方向に作用する免振構造物１４の重量Ｗを上下免振装置１８のみに支持させて、水平免振装置１６には免振構造物１４の重量Ｗが作用しないようにすることができる。このように水平免振装置１６で負担する鉛直荷重がなくなるため、積層ゴム２２のゴム層の面圧依存性を低下することができ、水平免振時のゴムの性状の不安定性を解消し得て、安定した性能を得ることができる。即ち、水平免振装置１６には水平力伝達機構２０を介して免振構造物１４と支持構造物１２間の水平方向の相対移動のみが伝達されるので、水平免振装置１６である積層ゴム２２は安定的にかつ十分な水平免振機能を発揮することができる。従ってまた、水平免振装置１６の設計も容易になる。
【００３８】
また、このように水平免振装置１６に鉛直荷重が作用しないので、免振構造物１４の下側に配置するこの水平免振装置１６の総個数を少なく、あるいは小型化することができ、これにより水平免振に関して長周期化を確保し易くなり、かつコストの低減をも達成することができる。
【００３９】
更に、水平力伝達機構２０によって地震時の上下変動荷重を、上下免振装置１８のみに負担させることができ、しかもこの上下免振装置１８には水平方向の剛性が強大な有底筒体状の鋼製ケース２６ａ，２６ｂで形成した空気バネ２６を用いているので、上下方向のバネ剛性をその空気バネ室２６ｃの内圧調整で任意に容易に設定し得る。このため、この上下免振装置１８にて支持される免振構造物１４の上下方向の振動周期を、例えば３．０秒以上の最適な値にチューニングして長周期化を図ることが容易になし得るとともに、支持荷重の調整範囲も広く確保することができるようになる。
【００４０】
また更に、この第１実施形態では上下免振装置１８の下側鋼製ケース２６ａの下端面に転がり支承２９を設けて、水平方向の自由な滑動が可能となっているため、支持構造物１２と免振構造物１４との間の水平振動が上下免振装置１８に入力されるのをこの転がり支承２９によって大幅に低減し得、もって、この上下免振装置１８のバネ剛性が水平免振装置１６に影響するのを極力防止することができる。この点からも、この水平免振装置１６による水平免振機能を、予期した設定通りに発揮させることができ、この水平免振装置１６の設計が容易になるとともに、上記転がり支承２９や滑り支承が滑動するときの摩擦抵抗を水平振動の減衰要素として機能させることもできる。
【００４１】
また、この第１実施形態の三次元免振装置１０では、水平免振装置１６の特性などを考慮せずに上下免振装置１８のバネ剛性を独自に適切に設定でき、このような独自設定の上下免振装置１８によって免振構造物１４全体を支持できることからロッキング振動を効果的に抑制することができる。
【００４２】
更に、上下免振装置１８は一対の鋼製ケース２６ａ，２６ｂによって空気バネ室２６ｃを画成した空気バネ２６で構成されるが、上下振動の入力により空気バネ室２６ｃが上下に拡縮変形して、相互に嵌合し合う一対の鋼製ケース２６ａ，２６ｂが互いに擦り合うため、このときの摩擦効果により上下振動に対する減衰効果も得ることができる。
【００４３】
また、水平免振装置１６の上方取付板３４と上方フランジ２２ｂとの間にダンパー５０を別途設けることにより、上下振動の入力によりこのダンパー５０が作動して上下振動エネルギーを吸収できるため、この構成によって必要な減衰を確保できるとともに、上下免振装置１８としての減衰量の設定が容易になる。また、上方取付板３４と上方フランジ２２ｂとは上下方向に相対変位するが、水平方向には相対変位が生じないので、ダンパー５０はその両端を上方取付板３４と上方フランジ２２ｂとのそれぞれに対して、ピンジョイント構造などを介さずに単に接続させるだけで良く、接続構造の簡略化が図れる。ここで、上下振動の入力に伴う減衰作用の発現に際し、若干の上下方向力が水平免振装置１６の積層バネ２２に加わることになるが、当該上下方向力はダンパー５０の抵抗力のみであって、積層バネ２２ｂの水平剛性に与える影響は殆ど無い。
【００４４】
加えて、固定台座２４と空気バネ２６の下側鋼製ケース２６ａの周壁部との間にダンパー５２を別途設けることにより、水平振動の入力によりこのダンパー５２が作動して水平振動を吸収できるため、この構成によって必要な減衰を確保できるとともに、水平免振装置１６としての減衰量の設定が容易になる。また、下側鋼製ケース２６ａと固定台座２４とには上下方向の相対変位が生じないので、ダンパー５２の両端はそれぞれ水平方向の回動のみを許容するピンジョイント５１を介して接続させれば良い。
【００４５】
一方、水平力伝達機構２０は筒体３２と軸体３２ａとから構成しており、これらによって水平方向の係合と上下方向の相対移動とを適切に確保でき、加えて構造が簡単であるとともに信頼性も高い。
【００４６】
また、上下免振装置の空気バネ２６には、平常時における空気バネ室２６ｃの内圧を一定範囲内に調圧するとともに、振動検知時に当該調圧機能を強制停止させる定空気圧維持装置５４を取り付けているので、上下振動入力時の免振機能を損なうことなく、温度変化に起因した各空気バネ相互間の膨張体積差を一定範囲内に維持し得る。
【００４７】
即ち、上下免振装置１８の空気バネ２６にはその内圧が規定の上限値を超えると内部の圧搾空気を外部にリリーフするリリーフ弁５８を設けているため、外気温の影響により内圧が高まってもその値を常に上限値以下に抑えることができる。一方、圧力センサ５６により内圧が規定の下限値を下回ったことを検出すると、制御器６４はエアコンプレッサ６２ａを作動させると共に電磁開閉弁６２ｂを開放させて空気バネ室２６ｃ内部に圧搾空気を供給するので、空気バネ室２６ｃの内圧を常時規定の一定値範囲内に保持することができる。このため、免振構造物１４の北側や南側等に複数配設される空気バネ２６の相互間に、大きな内圧差が生じることを防止でき、平常時において免振構造物を傾かせることなくその水平度を絶えず良好に維持することができる。
【００４８】
そして、地震時などに大きな振動が加わった場合には、圧力センサ５６で検出した空気バネ室２６ｃの内部圧力を絶えず制御器６４で監視することによって、その変動の大きさや速さから当該地震などの振動の入力を検知することができ、このような大きな振動を検知した際には、制御器６４は空気バネ室２６ｃ内の圧搾空気を外部にリリーフするリリーフ弁５８に直列接続させた電磁開閉弁６０を強制的に閉塞させて圧搾空気の解放を抑止するとともに、圧気供給手段６２の電磁開閉弁６２ｂも強制的に閉塞させる。このため、大きな上下振動が加わった際には、空気バネ室２６ｃは密閉状態に維持され、上下振動に伴って空気バネ室２６ｃの内圧が急激に大きく上昇しても圧搾空気は外部に解放されず、これ故、空気バネ２６による免振機能が損なわれることはない。
【００４９】
従って、この第１実施形態の三次元免振装置１０では、水平免振装置１６による水平免振機能を阻害することなく十分良好に確保しつつ、空気バネ２６でなる上下免振装置１８によって上下免振機能をも３秒以上の長周期化を図りながら十分に確保し得て、三次元方向に優れた免振機能を発揮することができる。
【００５０】
また、免振構造物１４下に複数配設される各々の空気バネ２６の平常時の内圧を、定空気圧維持装置５４により、その設置位置の南北などに起因する外気温条件のバラツキに左右されずに、絶えず規定の一定範囲内に保持することができ、もって四季や昼夜を通じて免振構造物１４の水平度を良好に維持して、不動沈下や傾きが生じることを防止できる。しかも、地震時などに大きな上下振動入力された場合には、当該振動を制御器６４が検知して定空気圧維持装置５４による調圧機能を強制的に停止させるから、空気バネ２６による所期の免振機能を損なわずに確保できる。
【００５１】
このため、この三次元免振装置１０を原子力発電所等の地震時の安全性が強く要求される重要施設の構造物等に適用することにより、この重要施設構造物の標準化、すなわち建物設備やプラント設備、例えば建物の骨組みや配管，サポート等の規格化を達成することができる。また、重要施設のサイトフリーを可能として立地条件の拡大を図ることができるとともに、他方、施設構造物の工費低減も達成することができる。
【００５２】
なお、本第１実施形態では水平免振装置１６を積層ゴム２２で構成したが、これに限ることなく水平免振を効果的に達成できる弾性部材であれば良い。更に、滑動機構として転がり支承２９を用いたが、勿論これに限ることはなく、滑らかな相対移動を許容する構造、例えば滑り支承やリニアレール等を用いることができる。
【００５３】
図２は、本発明の第２実施形態を示す。図示するように、この第２実施形態にあっても、上下免振装置１８をなす空気バネ２６と滑動機構の転がり支承２９及び水平免振装置１６は基本的に上記第１実施形態とほぼ同一構成であって、水平免振装置１６に対して水平力を伝達する水平力伝達機構２０の構成のみが異なっている。即ち、この第２実施形態では前記上下免振装置１８と滑動機構２８とを前記水平方向力伝達機構２０として機能させるようになっている。以下には、前記第１実施形態と同一構成の部材については同一の符号を付してその説明を省略し、構成の相違する部分に付いてのみ詳しく述べる。
【００５４】
本第２実施形態にあっては、前記空気バネ２６の下側鋼製ケース２６ａに径方向外方に延出させた支持ステー６６を一体形成し、この支持ステー６６に前記水平免振装置１６としての積層ゴム２２の上端を接合させて水平方向力伝達機構２０を構成している。この支持ステー６６は鋼製でなり、上側鋼製ケース２６ｂが摺動嵌合している下側鋼製ケース２６ａの上側部の外周に嵌着されて一体的に溶接接合されて設けられていて、下側鋼製ケース２６ａの当該部位の補強用リブとしても機能している。支持ステー６６の一端は水平免振装置１６の積層ゴム２２の上端に向けて水平に延び、当該積層ゴム２２の上方フランジ２２ｂを構成し、その下面に積層ゴム２２の上端部が接合されている。そして、この支持ステー６６と免振構造物の下面との間に上下振動を吸収するダンパー５０が設けられている。
【００５５】
従って、当該第２実施形態によれば、支持ステー６６によって下側鋼製ケース２６ａと積層バネ２２の上端部とを繋ぐだけという極めて簡単な構造で、上下免振装置１８と滑動機構２８とを水平方向力伝達機構２０として利用して機能させることができ、もって水平方向伝達機構を別途に設けずに済む。よって、部品点数の削減化が図れるばかりか、設置の手間も大幅に軽減できて、建設費の可及的な軽減が達成できる。
【００５６】
また、上下免振装置１６の下側鋼製ケース２６ａに一体的に設けられて径方向外方に延びる支持ステー６６と免振構造物１４の下面との間に上下振動を吸収するダンパー５０を別途設けることで、入力される上下振動により、このダンパー５０を作動させて上下振動エネルギーを吸収できるため、この構成によって必要な減衰を確保できるとともに、上下免振装置１８としての減衰量の設定が容易になる。また、支持ステー６６と免振構造物１４下面とは上下方向に相対変位するが、水平方向には相対変位が生じないので、ダンパー５０はその両端を免振構造物１４下面と支持ステー６６とのそれぞれに対して、ピンジョイント構造などを介さずに単に接続させるだけで良く、接続構造の簡略化が図れる。また、上下振動の入力に伴う減衰作用の発現に際して発生する上下方向力は、支持ステー６６と上下免振装置１８の下側ケース２６ａとを介して支持構造物１２に伝えることができ、水平免振装置１６の積層ゴム２２に上下方向力が加わるのを防止できる。
【００５７】
図３、図４は、本発明の第３実施形態を示す。図示するように、この第３実施形態にあっても、基本的には上下免振装置１８と滑動機構２８及び水平免振装置１６は、上記第１及び第２実施形態とほぼ同一構成であり、さらに水平免振装置１６に対して水平力を伝達する水平力伝達機構２０も第２実施形態と基本的に同様の構成となっていて、その相違する点は水平免振装置１６の積層ゴム２２が上下免振装置１８の空気バネ２６の周囲を取り巻いて複数設けらていることにある。
【００５８】
即ち、支持構造物１２に一体形成されて水平免振装置１６の積層ゴム２２が配設される固定台座２４は、上下免振装置１８を構成する空気バネ２６の外周囲に沿ってその下側鋼製ケース２６ａの下側部を囲繞するように、水平方向に所定距離を隔てて環状に設けられ、この固定台座２４の上面に８つの積層ゴム２２が等間隔で配設されている。一方、下側ケース２６ａの上端部には径方向外方に水平に延出されて各積層ゴム２２の上端部に至る環状フランジ６８が一体形成されていて、当該環状フランジ６８の下面に各積層ゴム２２の上端部が接合されている。つまり、この環状フランジ６８は前記第２実施形態における支持ステー６６並びに積層ゴム２２の上方フランジ２２ｂに相当する。
【００５９】
また、環状フランジ６８にはその上面と免振構造物１４とを繋いで、当該免振構造物１４の上下振動を減衰させるためのダンパー５０が等間隔に４つ設けられている。更に、固定台座２４と鋼製ケース２６ａの周壁部との間には、水平方向の振動を減衰させるダンパー５２を、水平方向の回動を許容させるピンジョイント５１を両端に介して接続させて放射状に４つ設けている。
【００６０】
従って、この第３実施形態によれば、水平免振装置１６の積層ゴム２２を複数に分割して配設することにより、個々の積層ゴム２２の小型化が図れるだけでなく、これらの積層ゴム２２や上下方向の振動を吸収するダンパー５０及び水平方向振動を吸収するダンパー５１を、上下免振装置１８の軸芯に対して容易に点対称に配置し得て、あらゆる方向への水平振動に対しても可及的に均等な免振性能を発揮させることができるようになる。
【００６１】
なお、図示した第１〜第３実施形態では、そのいずれもが空気バネ２６を免振構造物１４側に固定して、支持構造物１２に対して転がり支承を介して水平方向に相対移動可能となしているが、これらの配置関係は逆であってもよい。
【００６２】
【発明の効果】
以上説明したように本発明の三次元免振装置にあっては、次のような各種優れた効果を奏する。
【００６３】
（１）水平方向力を受けずに専ら上下振動を免振する上下免振装置に、水平方向の剛性が強大な有底筒体状の鋼製ケースで形成した空気バネを用いているので、上下方向のバネ剛性をその空気バネ室の内圧調整で任意に容易に設定することができる。このため、この上下免振装置にて支持される免振構造物の上下方向の振動周期を、例えば３．０秒以上の最適な値にチューニングして長周期化を図ることが容易になし得るとともに、支持荷重の調整範囲も広く確保することができるようになる。また、上下免振装置は鋼製ケースとこの鋼製ケース内を摺動する摺動体に空気バネ室が画成された空気バネで構成されるが、上下振動の入力により空気バネ室が上下に拡縮変形して、相互に嵌合し合う鋼製ケースと摺動体が擦り合うため、このときの摩擦効果により上下振動に対する減衰効果も得ることができる。
【００６４】
（２）上下免振装置の空気バネの鋼製ケースに径方向外方に延出させた支持ステーを一体形成し、この支持ステーに前記水平免振装置の一端を結合させるという極めて簡単な構造で、上下免振装置と滑動機構とを水平方向力伝達機構として利用して機能させることができ、水平方向伝達機構を別途に設けずに済む。よって、部品点数の削減化が図れるばかりか、設置の手間も大幅に軽減できて、建設費の可及的な軽減が達成できる。
【００６５】
（３）また、支持ステーと免振構造物の下面との間に上下振動を吸収するダンパーを別途設けることで、入力される上下振動により、このダンパーを作動させて上下振動エネルギーを吸収できるため、この構成によって必要な減衰を確保できるとともに、上下免振装置としての減衰量の設定が容易になる。また、支持ステーと免振構造物下面とは上下方向に相対変位するが、水平方向には相対変位が生じないので、ダンパーはその両端を免振構造物の下面と支持ステーとのそれぞれに対して、ピンジョイント構造などを介さずに単に接続させるだけで良く、接続構造の簡略化が図れる。また、上下振動の入力に伴う減衰作用の発現に際して発生する上下方向力は、支持ステーを介して上下免振装置の鋼製ケースに伝えることができるので、積層ゴムなどからなる水平免振装置に上下方向力が加わるのを防止できる。
【００６６】
（４）支持ステーを環状のフランジ状に形成することで、積層ゴムなどでなる水平免振装置や上下方向振動を吸収するダンパーを小型のものに複数に分割して上下免振装置の周囲に配設でき、個々の水平免振装置やダンパーの小型化が図れるだけでなく、これらを上下免振装置の軸芯に対して点対称に容易に配置し得て、あらゆる方向の水平振動に対しても可及的に均等な免振性能を発揮させることができるようになる。
【００６７】
（５）一方の構造物に、上下免振装置の他端を固定する固定台座を一体形成すれば、当該固定台座と鋼製ケースとには上下方向の相対変位が生じないから、水平方向振動を吸収するダンパーを当該固定台座と鋼製ケースの周壁部との間に、水平方向の回動のみを許容するピンジョイントを介して容易に設けることができる。また、水平振動の入力によりこのダンパーが作動して水平振動を吸収できるため、この構成によって必要な減衰を確保できるとともに、水平免振装置としての減衰量の設定が容易に行える。
【００６８】
更に、固定台座を上下免振装置の鋼製ケースの周囲を取り巻いて囲繞する様に形成すれば、水平方向の振動を吸収するダンパーも小型のものに複数に分割して上下免振装置の周囲に、上下免振装置の軸芯に対して点対称の放射状に容易に配置し得て、あらゆる方向の水平振動に対しても可及的に均等な減衰性能を発揮させることができるようになる。
【００６９】
（６）空気バネに、空気バネ室の内圧を規定の一定範囲内に保持する一方、振動検知時に該調圧機能を強制停止させる定空気圧維持装置を設けることにより、免振構造物下に複数配設される各々の空気バネの平常時の内圧を、それらの設置位置の南北の相違などに起因する外気温条件のバラツキに左右されずに、一定範囲内に保持することができ、もって四季や昼夜を通じて免振構造物の水平度を良好に維持して、不動沈下や傾きが生じることを防止でき、しかも、振動検知時には調圧機能を強制的に停止させるから、空気バネによる所期の免振機能を損なわずに確保できる。
【図面の簡単な説明】
【図１】本発明に係る三次元免振装置の基本形である第１実施形態の概略構成を示す一部を断面した側面図である。
【図２】本発明に係る三次元免振装置の第２実施形態の概略構成を示す一部を断面した側面図である。
【図３】本発明に係る三次元免振装置の第３実施形態の概略構成を示す一部を断面した側面図である。
【図４】図３中に示すIV−IV線矢視部の平断面図である。
【符号の説明】
１０三次元免振装置
１２支持構造物
１４免振構造物
１６水平免振装置
１８上下免振装置
２０水平方向力伝達手段
２２積層ゴム
２４固定台座
２６空気バネ
２６ａ，ｂ鋼製ケース
２６ｃ空気バネ室
２８滑動機構
２９転がり支承
５０，５２ダンパー
５４定空気圧維持装置
５６圧力センサー
５８リリーフ弁
６０電磁開閉弁
６２圧気供給手段
６４制御器
６６支持ステー
６８環状フランジ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional vibration isolator having a horizontal and vertical vibration isolation function.
[0002]
[Prior art]
Important facilities such as nuclear power plants are constructed as buildings that minimize the impact of earthquakes, etc., but site-free with the aim of expanding the location where the important facilities can be constructed regardless of location conditions, and cost reduction by standardization of facilities Adoption of a vibration isolation structure that enables the establishment of a standardized plant aimed at is desired.
[0003]
In general, horizontal vibration isolation structure using laminated rubber is adopted for vibration isolation of buildings such as buildings, but by using this together with top and bottom vibration isolation structure, 3D isolation is achieved and building from earthquake Can be efficiently protected, and it is possible to standardize buildings by applying it to the important facilities.
[0004]
As this type of three-dimensional vibration isolator, for example, a device disclosed in Japanese Patent Laid-Open No. 8-218678 has been proposed. This three-dimensional vibration isolator is configured by adding a vertical vibration isolator mechanism to the lower or upper part of a horizontal vibration isolator such as laminated rubber. That is, the horizontal vibration isolation device and the vertical vibration isolation mechanism are arranged in series in the vertical direction so that the weight of the building is input to the horizontal vibration isolation device and the vertical vibration isolation mechanism. It has become.
[0005]
By the way, in such a three-dimensional vibration isolator, it is possible to lengthen the natural frequency in the vertical direction on the building side in order to prevent the building from resonating with the vertical vibration at the time of earthquake input. desirable. In other words, since the dominant period of vertical vibration input by an earthquake exists in the range of 0.5 seconds or less, the vertical vibration period on the building side determined by the vertical vibration isolation mechanism is at least 0.5 seconds, Desirably, it is necessary to set the period longer than 3 seconds, and in order to increase the period of the building in this way, it is necessary to appropriately set the spring stiffness of the vertical vibration isolation mechanism.
[0006]
The vertical vibration isolation mechanism is also required to be able to reliably support the weight of the building and to prevent rocking vibration of the building. If the setting of the spring rigidity of the vertical vibration isolation mechanism is inappropriate, the vertical vibration period of the building may deviate from the vibration isolation region in the short period direction, making it impossible to effectively perform vertical vibration isolation. And if it deviates from an isolation region in this way, the vertical vibration of a building will become large, and the pulling-out force will act on this building greatly, and the horizontal isolation device which consists of laminated rubber etc. will be damaged. There is also a risk of it.
[0007]
Furthermore, when the spring stiffness of the vertical vibration isolation mechanism is increased to support the building load, the vertical fluctuation load due to the spring stiffness of the vertical vibration isolation mechanism has a significant effect on the performance of the horizontal vibration isolation device. give. In other words, if it is a three-dimensional vibration isolator constructed by providing a vertical vibration isolator mechanism in series on the horizontal vibration isolator, a vertically variable load acts on the horizontal vibration isolator via the vertical vibration isolator. However, when a shearing force is generated in the laminated rubber of the horizontal vibration isolator due to a horizontal force, the shear resistance force fluctuates due to the influence of the up-and-down fluctuation force when subjected to a fluctuating load in the vertical direction.
[0008]
Therefore, in the conventional three-dimensional vibration isolator as disclosed in the above-mentioned JP-A-8-218678, with respect to the horizontal vibration isolation performance that should be originally achieved by the horizontal spring rigidity provided in the horizontal vibration isolation device itself, The vertical fluctuation load due to the large spring rigidity of the vertical vibration isolation mechanism is affected, making it difficult to design the horizontal vibration isolation device with the desired performance.
[0009]
Therefore, the applicant of the present application previously described horizontal horizontal vibration isolation between the support structure and the vibration isolation structure without any vertical fluctuation load, as described in JP-A-2001-82542. A three-dimensional vibration isolation structure was proposed in which a vibration isolation device and a vertical vibration isolation device that exclusively performs vertical vibration isolation without receiving a horizontal load. That is, in the three-dimensional vibration isolator disclosed in Japanese Patent Application Laid-Open No. 2001-82542, a laminated rubber is used for the horizontal vibration isolator, and the horizontal displacement of the laminated rubber is allowed only in the horizontal direction. Is installed between the support structure and the vibration isolation structure with a transmission mechanism for transmitting the vibration, while the vertical vibration isolation device uses a disc spring laminated body because it is necessary to securely support the load of the vibration isolation structure. The disc spring laminated body is attached between the support structure and the vibration isolation structure with a sliding mechanism allowing a relative displacement in the horizontal direction interposed therebetween.
[0010]
[Problems to be solved by the invention]
However, since the proposed three-dimensional vibration isolator uses a disc spring laminated body for the vertical vibration isolator, the vertical displacement stroke cannot be secured sufficiently, and at present the vertical natural period of the vibration isolation structure However, it is still difficult to make the period longer than 1 second, and the desired period longer than 3 seconds cannot be achieved.
[0011]
Here, as a three-dimensional vibration isolator capable of ensuring not only a long period of horizontal vibration isolation but also a sufficiently long vertical stroke and a long natural period of 3 seconds or more, for example, flexibility such as rubber It is conceivable that a single airtight structure air spring is made of a rich material, and that the air spring is used for three-dimensional vibration isolation, and research and development of such a single airtight structure air spring has been intensively advanced. However, in order to support the vibration-isolating structure with an air spring by an upper and lower natural period of 3 seconds or more, it is necessary to secure an internal pressure of about 20 atm (20 kg / bar, 101.325 Pa), and a flexible material such as rubber. If the airtight chamber is made of a material rich in properties, the material is not only easily damaged but also deteriorated with time, and there is a high risk of leakage in terms of durability and reliability. If leakage occurs, the support function of the vibration isolation structure, which is the most basic function of the vibration isolation device, will be lost, resulting in the destruction of the support structure such as the base plate and the uneven settlement of the vibration isolation structure. Bring.
[0012]
Therefore, for the above reasons, all of the conventional three-dimensional vibration isolators exhibit both the horizontal and vertical three-dimensional vibration isolation functions with a long period of time, with sufficient accuracy and high reliability. Therefore, it has been a problem that it is extremely difficult to achieve standardization of buildings by applying it to the above important facilities.
[0013]
The present invention has been made in view of the circumstances as described above, and an object thereof is a configuration in which a horizontal vibration isolation device that exclusively performs horizontal vibration isolation and a vertical vibration isolation device that exclusively performs vertical vibration isolation are arranged in parallel. In the three-dimensional vibration isolator, the vertical vibration isolator uses an air spring made of a steel case with high durability and reliability, while ensuring the original horizontal vibration isolating function of the horizontal vibration isolator sufficiently, It is an object of the present invention to provide a three-dimensional vibration isolator capable of achieving a long period of 3 seconds or more.
[0014]
In addition, when air springs formed with the steel case are used, the ambient temperature conditions of these air springs will change equally throughout the seasons and day and night if the disposition position under the vibration isolation structure differs from north to south. There is no. For this reason, when there is a difference in the variation of the ambient temperature condition, there is a possibility that the internal pressure of each air spring is different and the vibration isolation structure is unevenly subsidized or tilted. Therefore, in the present invention, a plurality of air disposed under the vibration-isolating structure by suppressing the fluctuation of the internal pressure of the air spring due to the influence of the outside air temperature and the like within a specified range without impairing the vertical vibration isolation function by the air spring. It is a second object of the present invention to provide a three-dimensional vibration isolator that can keep the height between the springs substantially constant and that does not cause uneven subsidence or inclination of the vibration isolation structure.
[0015]
[Means for Solving the Problems]
  In order to achieve the first object, according to the present invention, there is provided a three-dimensional vibration isolator provided between a support structure and a vibration isolation structure disposed above the support structure with a space therebetween. A vertical vibration isolator that vertically isolates the structure via a sliding mechanism that allows horizontal relative movement between the two structures, and a horizontal force transmission mechanism that permits vertical relative movement between the two structures. The vertical vibration isolator is vertically expanded and contracted by a cylindrical steel case closed at one end and a sliding body that slides in the steel case. An air spring having a spring chamber is formed, and the sliding mechanism is interposed between one end of the air spring and one structure with which the one end abuts.And a support stay extended radially outwardly in the steel case of the air spring, and one end of the horizontal vibration isolator is coupled to the support stay, and the vertical vibration isolator and the sliding mechanism Can be configured to function as the horizontal force transmission mechanism (claim 1).
[0017]
  Further, the support stay is formed in an annular flange, and around the steel case along the flange, the support stayHorizontalCan be configured to have multiple vibration isolator(Claim 2).
[0018]
  Still further, a configuration in which a vertical vibration damping device is provided between the support stay or the flange and the other structure can be realized.(Claim 3).
[0019]
  Furthermore, a fixed pedestal for fixing the other end of the vertical vibration isolator is integrally formed on the one structure, and a horizontal vibration damping device is provided between the fixed pedestal and the peripheral wall portion of the steel case. Can also be configured(Claim 4).
[0020]
  Here, a rolling bearing can be used for the sliding mechanism.(Claim 5).
  In addition,HorizontalLaminated rubber can be used for the vibration isolator(Claim 6).
[0021]
  On the other hand, in order to achieve the second object, according to the present invention, the air spring of the upper and lower vibration isolator is adjusted to the normal pressure of the air spring chamber in a normal range, and at the time of vibration detection. A constant air pressure maintenance device for forcibly stopping the pressure regulating function is attached.(Claim 7).
[0022]
  Here, the constant air pressure maintaining device includes a pressure sensor that detects an internal pressure of the air spring chamber, a relief valve that keeps the pressure in the air spring chamber below a predetermined upper limit value, and is connected in series to the relief valve. An electromagnetic on-off valve that suppresses a pressure release function by a relief valve, a pressurized air supply means for supplying compressed air into the air spring chamber, and the electromagnetic on-off valve and the pressurized air supply means based on a pressure value detected by the pressure sensor; A controller that controls the operation of the air spring, and when the pressure value detected by the pressure sensor falls below a specified lower limit value, the controller operates the pressurized air supply means to increase the internal pressure of the air spring chamber above the lower limit value. While maintaining, the fluctuation of the pressure value detected by the pressure sensor is monitored, and when the vibration is detected based on the fluctuation, the electromagnetic on-off valve is closed and the operation of the pressure supply means is stopped(Claim 8).
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a three-dimensional vibration isolator according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a first embodiment forming the basic form of the present invention. As shown in the figure, the three-dimensional vibration isolator 10 is disposed between a support structure 12 and a vibration isolation structure 14 disposed above the support structure 12 with a space therebetween. The horizontal vibration isolator 16 that horizontally isolates the structure 12 and 14 while allowing the vertical relative movement between the structures 12 and 14 via the horizontal force transmission mechanism 20 and the horizontal relative movement between the structures 12 and 14. It consists of a vertical vibration isolator 18 that performs vertical vibration isolation while allowing it via a sliding mechanism 28.
[0024]
Both the vibration isolation devices 16 and 18 are arranged in parallel between the two structures 12 and 14, and the horizontal force transmission mechanism 20 is arranged between the horizontal vibration isolation device 16 and the vibration isolation structure 14 thereabove, while sliding. The mechanism 28 is disposed between the vertical vibration isolator 18 and the support structure 12 below the vertical vibration isolator 18, and supports the vertical load of the vibration isolation structure 14 by the vertical vibration isolator 18. The horizontal vibration isolator 16, the vertical vibration isolator 18, the horizontal force transmission mechanism 20, and the sliding mechanism 28 constitute one three-dimensional vibration isolation unit as shown in FIG. A plurality of them are arranged on the lower surface of 14 to perform the entire three-dimensional vibration isolation. The horizontal vibration isolator 16 and the vertical vibration isolator 18 do not necessarily need to be unitized as long as they are arranged in parallel, and the number need not be the same.
[0025]
The horizontal vibration isolator 16 includes a laminated rubber 22 in which rubber layers and steel plates are alternately laminated. The laminated rubber 22 is provided with a lower flange 22a and an upper flange 22b. A fixed base 24 made of reinforced concrete having a predetermined height protrudes from the support structure 12 at an installation site of the laminated rubber 22, and the laminated rubber 22 is installed by fixing a lower flange 22 a on the fixed base 24. The laminated rubber 22 has isotropic restoration performance and damping performance in the horizontal direction, and exhibits accurate vibration isolation performance in all horizontal directions.
[0026]
Between the horizontal vibration isolator 16 and the vibration isolation structure 14, the horizontal relative movement (horizontal force) is allowed to move in the horizontal direction while allowing the relative movement of the vibration isolation structure 14 in the vertical direction. A horizontal force transmission mechanism 20 is interposed between the cylindrical body 32 erected on the upper flange 22 b of the laminated rubber 22 and the vibration isolation structure 14. And a shaft body 32a that is vertically slidably inserted into the cylindrical body 32 and engages with the cylindrical body 32 in the horizontal direction. In the illustrated example, the cylindrical body 32 and the shaft body 32a are provided with the cylindrical body 32 on the upper flange 22b and the shaft body 32a on the upper mounting plate 34. However, the arrangement relationship may be reversed.
[0027]
A slight gap is preferably provided between the outer peripheral surface of the shaft body 32 a and the inner peripheral surface of the cylindrical body 32 that face each other. If these outer peripheral surface and inner peripheral surface are always in sliding contact, when a vertical relative movement occurs between the vibration isolation structure 14 and the support structure 12, a frictional force is generated between them, This is because the directional force may act on the horizontal vibration isolator 16. On the other hand, if the gap between the outer peripheral surface and the inner peripheral surface is too large, the horizontal vibration isolator 16 or the vibration isolator structure is generated when a horizontal relative movement occurs between the vibration isolator structure 14 and the support structure 12. This is because a shocking force acts on 14.
[0028]
Further, between the lower end of the shaft body 32a opposed to the vertical direction and the upper flange 22b of the laminated rubber 22, and between the upper end of the cylindrical body 32 opposite to the vertical direction and the upper mounting plate 34, A gap larger than the vertical relative displacement to be allowed is set, and the shaft body 32a and the upper flange 22b are moved in the vertical direction relative movement between the vibration-isolating structure 14 and the support structure 12, and the cylinder 32 and the upper mounting plate. 34 does not interfere. Here, the cross-sectional shape of the cylindrical body 32 and the shaft body 32a may be any cross-sectional shape such as a circle as long as the vertical sliding and the horizontal engagement are maintained. The shaft body 32a and the cylinder body 32 constitute a pair of engaging members.
[0029]
An air spring 26 is used in the vertical vibration isolator 18. The air spring 26 is formed by a pair of upper and lower bottomed cylindrical steel cases 26a, 26b whose ends are closed flat, and the lower steel case 26a is larger than the upper steel case 26b. The open end side of the upper steel case 26b enters the open end side of the lower steel case 26a and is slidably fitted to each other, and an O-ring 27 is interposed in the sliding portion. In addition, a sealed air spring chamber 26c that accommodates compressed air of about 20 atm (20 kg / bar, 101.325 Pa) is defined in the inside so as to be able to expand and contract vertically. Here, the air spring 26 is not necessarily constituted by the pair of steel cases 26a and 26b as described above, at least one is formed by the steel case 26a and the other is vertically moved in the steel case 26a. A sliding piston-like sliding body may be used.
[0030]
The lower side of the air spring 26 is mounted on a rolling bearing 29 as a sliding mechanism 28 placed on the support structure 12. The upper side of the air spring 26 is attached by fitting and fixing the upper end portion of the upper steel case 26b to an annular upper mounting seat 30 that protrudes downward from the vibration isolation structure 14 and is integrally formed.
[0031]
The rolling support 29 includes a support substrate 29a having a flat bottom surface, an outer shell 29b that covers the periphery of the support substrate 29a with an appropriate gap, and a space between the support substrate 29a and the outer shell 29b. And a large number of small spheres 29c housed in the storage. The support substrate 29a is placed on the slide substrate 36 laid on the upper surface of the support structure 12 with the small spheres 29c interposed therebetween, and the rolling spheres 29c roll so that the rolling support is supported. 29 and the support structure 12 are slidable with a very small sliding resistance. Although the rolling obstacle 29 is used as the sliding mechanism 28 in the present embodiment, the present invention is not limited to this, and a sliding bearing may be adopted.
[0032]
Further, between the upper mounting plate 34 and the upper flange 22b of the horizontal vibration isolator 16, the energy of the relative vibration in the vertical direction between the support structure 12 and the vibration isolation structure 14 is absorbed by these. A damper 50 for damping the vertical vibration is separately provided. Further, between the fixed base 24 and the peripheral wall portion of the lower steel case 26a of the air spring 26, a pin joint 51 is interposed between the two so as to follow the horizontal relative displacement direction. A damper 52 that is rotatably coupled and absorbs the energy of horizontal relative vibration between the support structure 12 and the vibration isolation structure 14 and attenuates the horizontal vibration is separately provided. As the bumpers 50 and 52 in the vertical direction and the horizontal direction, for example, a hydraulic fluid damper or a friction damper can be employed, and a hydraulic damper is used here.
[0033]
On the other hand, the air spring 26 of the vertical vibration isolator 18 has a constant air pressure maintaining device 54 that regulates the internal pressure of the air spring chamber 26c in a normal range within a certain range and forcibly stops the pressure regulating function when vibration is detected. It is attached. The constant air pressure maintaining device 54 is connected in series to a pressure sensor 56 that detects the internal pressure of the air spring chamber 26c, a relief valve 58 that keeps the pressure in the air spring chamber 26c below a specified upper limit value, and the relief valve 58. The pressure on the basis of the pressure value detected by this pressure sensor 56, the electromagnetic on-off valve 60 that suppresses the pressure release function by the relief valve 58, the pressurized air supply means 62 that supplies the compressed air into the air spring chamber 26c. It comprises a controller 64 for controlling the operation of the electromagnetic on-off valve 60 for suppressing release and the pressurized air supply means 62.
[0034]
The pressurized air supply means 62 comprises an air compressor 62a and an electromagnetic on-off valve 62b. When compressed air is supplied, the electromagnetic on-off valve 62b is opened along with the operation of the air compressor 62a, and when the supply is stopped, the air compressor 62a is stopped and an electromagnetic on-off valve 62b is closed.
[0035]
The controller 64 is constituted by a microcomputer, and when the pressure value detected by the pressure sensor 56 is below a specified lower limit value, the pressure air supply means 62 is operated to keep the internal pressure of the air spring chamber 26c above the lower limit value. The fluctuation of the pressure value detected by the sensor 56 is constantly monitored, and when vibration is detected based on the magnitude and speed of the pressure fluctuation, the electromagnetic on-off valve 60 is closed and the operation of the pressurized air supply means 62 is stopped. In the normal state where no vibration is detected, the electromagnetic on / off valve 60 for suppressing pressure release is opened. In addition, you may make it detect the said vibration with the acceleration sensor provided in the support structure side.
[0036]
With the above configuration, in the three-dimensional vibration isolation device 10 of the first embodiment, the horizontal vibration isolation device 16 and the vertical vibration isolation device 18 are arranged in parallel between the support structure 12 and the vibration isolation structure 14. When the vibration due to the earthquake is input, the horizontal vibration isolator 16 absorbs the horizontal vibration energy and is subjected to horizontal vibration isolation, and the vertical vibration isolator 18 absorbs the vertical vibration energy and is subjected to vertical vibration isolation. Three-dimensional isolation is provided with isolation and vertical isolation. Further, the horizontal force transmission mechanism 20 disposed at the upper part of the horizontal vibration isolator 16 has a function of preventing the axial force fluctuation caused by the vertical vibration from acting on the horizontal vibration isolator 16.
[0037]
Here, the horizontal vibration isolator 16 and the vertical vibration isolator 18 are arranged in parallel, and the vertical relative movement of the vibration isolation structure 14 is allowed and the horizontal relative movement is transmitted to the horizontal vibration isolator 16. By providing the transmission mechanism 20, the weight W of the vibration isolation structure 14 acting in the vertical direction is supported only by the vertical vibration isolation device 18, and the weight W of the vibration isolation structure 14 acts on the horizontal vibration isolation device 16. You can avoid it. Thus, since the vertical load borne by the horizontal vibration isolator 16 is eliminated, the surface pressure dependence of the rubber layer of the laminated rubber 22 can be reduced, and the instability of the rubber properties during horizontal vibration isolation can be eliminated. Thus, stable performance can be obtained. That is, only the horizontal relative movement between the vibration isolation structure 14 and the support structure 12 is transmitted to the horizontal vibration isolation device 16 via the horizontal force transmission mechanism 20, so that the laminated rubber which is the horizontal vibration isolation device 16 is used. 22 can exhibit a stable and sufficient horizontal vibration isolation function. Therefore, the design of the horizontal vibration isolator 16 is also facilitated.
[0038]
Further, since the vertical load does not act on the horizontal vibration isolator 16 in this way, the total number of the horizontal vibration isolator 16 disposed below the vibration isolation structure 14 can be reduced or downsized. As a result, it is easy to ensure a longer period for horizontal vibration isolation, and cost reduction can also be achieved.
[0039]
Further, the horizontal force transmission mechanism 20 can load the vertical fluctuation load at the time of the earthquake only on the vertical vibration isolator 18, and the vertical vibration isolator 18 has a bottomed cylindrical shape with great horizontal rigidity. Since the air spring 26 formed by the steel cases 26a, 26b is used, the spring rigidity in the vertical direction can be arbitrarily set easily by adjusting the internal pressure of the air spring chamber 26c. For this reason, it is easy to tune the vibration period in the vertical direction of the vibration isolation structure 14 supported by the vertical vibration isolation device 18 to an optimum value of, for example, 3.0 seconds or longer to increase the period. In addition, a wide adjustment range of the support load can be secured.
[0040]
Furthermore, in the first embodiment, the rolling support 29 is provided on the lower end surface of the lower steel case 26a of the vertical vibration isolator 18 so that free sliding in the horizontal direction is possible. The horizontal vibration between the vertical vibration isolator 18 and the vertical vibration isolator 18 can be greatly reduced by the rolling bearing 29 so that the spring rigidity of the vertical vibration isolator 18 is horizontal. It is possible to prevent the influence on the device 16 as much as possible. Also in this respect, the horizontal vibration isolation function by the horizontal vibration isolation device 16 can be exhibited as expected, and the design of the horizontal vibration isolation device 16 is facilitated, and the rolling bearing 29 and the sliding bearing are The frictional resistance at the time of sliding can also function as a damping element for horizontal vibration.
[0041]
Further, in the three-dimensional vibration isolator 10 of the first embodiment, the spring rigidity of the vertical vibration isolator 18 can be appropriately set independently without considering the characteristics of the horizontal vibration isolator 16, and such unique setting is possible. Since the vertical vibration isolator 18 can support the vibration isolation structure 14 as a whole, rocking vibration can be effectively suppressed.
[0042]
Further, the vertical vibration isolator 18 is constituted by an air spring 26 that defines an air spring chamber 26c by a pair of steel cases 26a and 26b, but the air spring chamber 26c is expanded and contracted vertically by the input of vertical vibration. Since the pair of steel cases 26a and 26b fitted to each other rub against each other, a damping effect against vertical vibration can be obtained by the friction effect at this time.
[0043]
Further, by separately providing a damper 50 between the upper mounting plate 34 of the horizontal vibration isolator 16 and the upper flange 22b, this damper 50 can be operated by the input of vertical vibration to absorb the vertical vibration energy. Thus, the necessary attenuation can be ensured, and the attenuation amount as the vertical vibration isolator 18 can be easily set. Further, although the upper mounting plate 34 and the upper flange 22b are relatively displaced in the vertical direction, relative displacement does not occur in the horizontal direction, so that the damper 50 has both ends thereof relative to the upper mounting plate 34 and the upper flange 22b. Thus, it is sufficient to simply connect without using a pin joint structure or the like, and the connection structure can be simplified. Here, when the damping action due to the input of the vertical vibration is developed, a slight vertical force is applied to the laminated spring 22 of the horizontal vibration isolator 16, but the vertical force is only the resistance force of the damper 50. Thus, there is almost no influence on the horizontal rigidity of the laminated spring 22b.
[0044]
In addition, since the damper 52 is separately provided between the fixed base 24 and the peripheral wall portion of the lower steel case 26a of the air spring 26, the damper 52 is activated by the input of the horizontal vibration to absorb the horizontal vibration. With this configuration, necessary attenuation can be ensured, and the amount of attenuation as the horizontal vibration isolator 16 can be easily set. Further, since the relative displacement in the vertical direction does not occur between the lower steel case 26a and the fixed pedestal 24, both ends of the damper 52 can be connected via pin joints 51 that allow only horizontal rotation. good.
[0045]
On the other hand, the horizontal force transmission mechanism 20 is composed of a cylindrical body 32 and a shaft body 32a. With these, the horizontal engagement and the relative movement in the vertical direction can be appropriately secured, and in addition, the structure is simple. High reliability.
[0046]
The air spring 26 of the vertical vibration isolator is attached with a constant air pressure maintaining device 54 for adjusting the internal pressure of the air spring chamber 26c in a normal range within a certain range and forcibly stopping the pressure adjusting function when vibration is detected. Therefore, the expansion volume difference between the air springs due to the temperature change can be maintained within a certain range without impairing the vibration isolating function when inputting vertical vibration.
[0047]
That is, since the air spring 26 of the vertical vibration isolator 18 is provided with a relief valve 58 that relieves the compressed air inside when the internal pressure exceeds a predetermined upper limit value, the internal pressure increases due to the influence of the outside air temperature. This value can always be kept below the upper limit. On the other hand, when the pressure sensor 56 detects that the internal pressure has fallen below the prescribed lower limit value, the controller 64 operates the air compressor 62a and opens the electromagnetic on-off valve 62b to supply compressed air into the air spring chamber 26c. As a result, the internal pressure of the air spring chamber 26c can always be maintained within a specified constant value range. For this reason, it is possible to prevent a large internal pressure difference from being generated between the plurality of air springs 26 disposed on the north side, the south side, or the like of the vibration isolation structure 14. The levelness can be constantly kept good.
[0048]
When a large vibration is applied at the time of an earthquake or the like, the internal pressure of the air spring chamber 26c detected by the pressure sensor 56 is continuously monitored by the controller 64, so that the earthquake or the like can be determined from the magnitude and speed of the fluctuation. When such a large vibration is detected, the controller 64 is connected in series with a relief valve 58 for relief of the compressed air in the air spring chamber 26c to the outside. The valve 60 is forcibly closed to prevent the compressed air from being released, and the electromagnetic open / close valve 62b of the compressed air supply means 62 is also forcibly closed. For this reason, when a large vertical vibration is applied, the air spring chamber 26c is maintained in a hermetically sealed state, and the compressed air is released to the outside even if the internal pressure of the air spring chamber 26c increases drastically with the vertical vibration. Therefore, the vibration isolation function by the air spring 26 is not impaired.
[0049]
Therefore, in the three-dimensional vibration isolator 10 according to the first embodiment, the vertical vibration isolator 18 composed of the air springs 26 is moved up and down while ensuring sufficiently well without hindering the horizontal vibration isolation function of the horizontal vibration isolator 16. The vibration isolation function can be sufficiently secured while achieving a period of 3 seconds or longer, and an excellent vibration isolation function in the three-dimensional direction can be exhibited.
[0050]
Further, the normal internal pressure of each of the plurality of air springs 26 disposed under the vibration isolation structure 14 is affected by variations in outside air temperature conditions caused by the north and south of the installation position by the constant air pressure maintaining device 54. Therefore, it is possible to keep the vibration isolating structure 14 at a good level throughout the four seasons and day and night, thereby preventing immobile subsidence and tilting. In addition, when a large vertical vibration is input during an earthquake or the like, the controller 64 detects the vibration and forcibly stops the pressure regulation function by the constant air pressure maintaining device 54. It can be secured without impairing the isolation function.
[0051]
For this reason, by applying this three-dimensional vibration isolator 10 to the structure of an important facility where safety at the time of an earthquake such as a nuclear power plant is strongly required, standardization of this important facility structure, that is, building equipment or Standardization of plant equipment, such as building frameworks, piping, supports, etc., can be achieved. In addition, the site conditions of the important facilities can be made free and the location conditions can be expanded. On the other hand, the construction cost of the facility structure can be reduced.
[0052]
In the first embodiment, the horizontal vibration isolator 16 is composed of the laminated rubber 22. However, the elastic member is not limited to this and may be an elastic member that can effectively achieve horizontal vibration isolation. Furthermore, although the rolling bearing 29 is used as the sliding mechanism, it is of course not limited to this, and a structure that allows smooth relative movement, such as a sliding bearing or a linear rail, can be used.
[0053]
FIG. 2 shows a second embodiment of the present invention. As shown in the figure, even in the second embodiment, the air spring 26, the rolling support 29 of the sliding mechanism, and the horizontal vibration isolator 16 constituting the vertical vibration isolator 18 are basically the same as those in the first embodiment. Only the configuration of the horizontal force transmission mechanism 20 that transmits a horizontal force to the horizontal vibration isolator 16 is different. That is, in the second embodiment, the vertical vibration isolator 18 and the sliding mechanism 28 function as the horizontal force transmission mechanism 20. In the following, members having the same configurations as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only portions having different configurations are described in detail.
[0054]
In the second embodiment, a support stay 66 extending radially outward is integrally formed on the lower steel case 26a of the air spring 26, and the horizontal vibration isolator 16 is formed on the support stay 66. The horizontal force transmission mechanism 20 is configured by joining the upper ends of the laminated rubbers 22. The support stay 66 is made of steel, and is provided by being welded and integrally joined to the outer periphery of the upper portion of the lower steel case 26a in which the upper steel case 26b is slidably fitted. Also, it functions as a reinforcing rib for the part of the lower steel case 26a. One end of the support stay 66 extends horizontally toward the upper end of the laminated rubber 22 of the horizontal vibration isolator 16, constitutes an upper flange 22b of the laminated rubber 22, and the upper end of the laminated rubber 22 is joined to the lower surface thereof. . A damper 50 for absorbing vertical vibration is provided between the support stay 66 and the lower surface of the vibration isolation structure.
[0055]
Therefore, according to the second embodiment, the vertical vibration isolator 18 and the sliding mechanism 28 are provided with an extremely simple structure in which the lower steel case 26a and the upper end of the laminated spring 22 are simply connected by the support stay 66. The horizontal direction force transmission mechanism 20 can be used and functioned, so that it is not necessary to provide a separate horizontal direction transmission mechanism. Therefore, not only the number of parts can be reduced, but also the labor for installation can be greatly reduced, and the construction cost can be reduced as much as possible.
[0056]
Further, a damper 50 that is provided integrally with the lower steel case 26 a of the vertical vibration isolator 16 and that absorbs vertical vibration between a support stay 66 extending radially outward and the lower surface of the vibration isolation structure 14 is provided. By providing it separately, the damper 50 can be operated by the input vertical vibration to absorb the vertical vibration energy, so that this structure can secure the necessary attenuation and set the attenuation amount as the vertical vibration isolator 18. It becomes easy. Further, although the support stay 66 and the bottom surface of the vibration isolation structure 14 are relatively displaced in the vertical direction, no relative displacement is generated in the horizontal direction, so that the damper 50 has both ends thereof at the bottom surface of the vibration isolation structure 14 and the support stay 66. It is only necessary to connect each of them without using a pin joint structure or the like, and the connection structure can be simplified. In addition, the vertical force generated when the damping action due to the input of the vertical vibration is generated can be transmitted to the support structure 12 via the support stay 66 and the lower case 26a of the vertical vibration isolator 18, and the horizontal immunity can be transmitted. It is possible to prevent vertical force from being applied to the laminated rubber 22 of the vibration device 16.
[0057]
3 and 4 show a third embodiment of the present invention. As shown in the figure, even in the third embodiment, the vertical vibration isolator 18, the sliding mechanism 28, and the horizontal vibration isolator 16 basically have the same configuration as the first and second embodiments. Further, the horizontal force transmission mechanism 20 for transmitting a horizontal force to the horizontal vibration isolator 16 has basically the same configuration as that of the second embodiment, and the difference is the laminated rubber of the horizontal vibration isolator 16. 22 is provided around the air spring 26 of the vertical vibration isolator 18.
[0058]
That is, the fixed base 24 integrally formed with the support structure 12 and provided with the laminated rubber 22 of the horizontal vibration isolator 16 is disposed along the outer periphery of the air spring 26 constituting the vertical vibration isolator 18. In order to surround the lower side portion of the steel case 26a, it is provided in an annular shape with a predetermined distance in the horizontal direction, and eight laminated rubbers 22 are arranged on the upper surface of the fixed base 24 at equal intervals. On the other hand, an annular flange 68 that extends horizontally outward in the radial direction and reaches the upper end of each laminated rubber 22 is integrally formed at the upper end portion of the lower case 26 a, and each laminated layer is formed on the lower surface of the annular flange 68. The upper end of the rubber 22 is joined. That is, the annular flange 68 corresponds to the support stay 66 and the upper flange 22b of the laminated rubber 22 in the second embodiment.
[0059]
The annular flange 68 is provided with four dampers 50 at equal intervals for connecting the upper surface thereof to the vibration isolation structure 14 and attenuating the vertical vibration of the vibration isolation structure 14. Further, between the fixed base 24 and the peripheral wall portion of the steel case 26a, a damper 52 that attenuates horizontal vibration is connected to both ends via pin joints 51 that allow horizontal rotation, and the radial direction is reduced. There are four.
[0060]
Therefore, according to the third embodiment, the laminated rubber 22 of the horizontal vibration isolator 16 is divided into a plurality of parts, so that not only the individual laminated rubber 22 can be downsized but also these laminated rubbers. 22 and the damper 50 that absorbs the vibration in the vertical direction and the damper 51 that absorbs the vibration in the horizontal direction can be easily arranged point-symmetrically with respect to the axis of the vertical vibration isolator 18 for horizontal vibration in all directions. Even in this case, it is possible to exhibit as much vibration isolation performance as possible.
[0061]
In each of the illustrated first to third embodiments, the air spring 26 is fixed to the vibration isolation structure 14 side, and can be relatively moved in the horizontal direction with respect to the support structure 12 via the rolling support. However, these arrangement relationships may be reversed.
[0062]
【The invention's effect】
As described above, the three-dimensional vibration isolator of the present invention has the following various excellent effects.
[0063]
(1) Since an air spring formed of a bottomed cylindrical steel case with great horizontal rigidity is used for the vertical vibration isolator that exclusively isolates vertical vibration without receiving horizontal force, The spring rigidity in the vertical direction can be arbitrarily set easily by adjusting the internal pressure of the air spring chamber. For this reason, it is easy to tune the vertical vibration period of the vibration isolation structure supported by the vertical vibration isolation device to an optimum value of, for example, 3.0 seconds or longer to increase the period. In addition, a wide adjustment range of the support load can be secured. The vertical vibration isolator is composed of a steel case and an air spring in which an air spring chamber is defined on a sliding body that slides in the steel case. Since the steel case and the sliding body, which are expanded and contracted and fitted to each other, rub against each other, a damping effect against vertical vibration can be obtained by the friction effect at this time.
[0064]
(2) An extremely simple structure in which a support stay extended radially outward is integrally formed on a steel case of an air spring of a vertical vibration isolator, and one end of the horizontal vibration isolator is coupled to the support stay. Thus, the vertical vibration isolator and the sliding mechanism can be functioned using the horizontal direction force transmission mechanism, and it is not necessary to provide a horizontal direction transmission mechanism separately. Therefore, not only the number of parts can be reduced, but also the labor for installation can be greatly reduced, and the construction cost can be reduced as much as possible.
[0065]
(3) Since a damper for absorbing vertical vibration is separately provided between the support stay and the lower surface of the vibration-isolating structure, the vertical vibration energy can be absorbed by the input vertical vibration to absorb the vertical vibration energy. With this configuration, it is possible to ensure the necessary attenuation and to easily set the attenuation amount as the vertical vibration isolator. In addition, although the support stay and the bottom surface of the vibration-isolating structure are relatively displaced in the vertical direction, relative displacement does not occur in the horizontal direction. Thus, it is sufficient to simply connect without using a pin joint structure or the like, and the connection structure can be simplified. In addition, since the vertical force generated when the damping effect is generated due to the input of vertical vibration can be transmitted to the steel case of the vertical vibration isolator via the support stay, the horizontal vibration isolator made of laminated rubber or the like can be used. It is possible to prevent vertical force from being applied.
[0066]
(4) By forming the support stay in the shape of an annular flange, the horizontal vibration isolator made of laminated rubber or the like and the damper that absorbs the vertical vibration are divided into a plurality of small ones around the vertical vibration isolator. Not only can the individual horizontal vibration isolation devices and dampers be reduced in size, but they can also be easily placed point-symmetrically with respect to the axis of the vertical vibration isolation device to prevent horizontal vibrations in all directions. Even so, it will be possible to exert as even isolation performance as possible.
[0067]
(5) If a fixed pedestal for fixing the other end of the vertical vibration isolator is integrally formed on one structure, there is no vertical displacement between the fixed pedestal and the steel case. Can be easily provided between the fixed base and the peripheral wall portion of the steel case via a pin joint that allows only horizontal rotation. Further, since this damper can be actuated by the input of horizontal vibration to absorb the horizontal vibration, this configuration can ensure the necessary attenuation and can easily set the amount of attenuation as the horizontal vibration isolator.
[0068]
Furthermore, if the fixed pedestal is formed so as to surround and surround the steel case of the vertical vibration isolator, the damper that absorbs horizontal vibration is divided into a plurality of small ones to surround the vertical vibration isolator. In addition, it can be easily arranged in a point-symmetric radial manner with respect to the axis of the vertical vibration isolator, so that evenly uniform damping performance can be exhibited even with respect to horizontal vibration in all directions. .
[0069]
(6) The air spring is provided with a constant air pressure maintaining device that keeps the internal pressure of the air spring chamber within a predetermined fixed range and forcibly stops the pressure adjusting function when vibration is detected. The normal internal pressure of each installed air spring can be maintained within a certain range regardless of variations in the outside air temperature conditions due to the difference between the north and south of the installation position. In addition, the leveling of the isolation structure can be maintained well throughout the day and night to prevent improper settlement and tilting, and the pressure adjustment function is forcibly stopped when vibration is detected. It can be secured without impairing the isolation function.
[Brief description of the drawings]
FIG. 1 is a partially sectional side view showing a schematic configuration of a first embodiment which is a basic form of a three-dimensional vibration isolator according to the present invention.
FIG. 2 is a partially sectional side view showing a schematic configuration of a second embodiment of the three-dimensional vibration isolator according to the present invention.
FIG. 3 is a partial cross-sectional side view showing a schematic configuration of a third embodiment of the three-dimensional vibration isolator according to the present invention.
4 is a cross-sectional plan view taken along the line IV-IV in FIG.
[Explanation of symbols]
10 Three-dimensional vibration isolator
12 Support structure
14 Isolation structure
16 Horizontal vibration isolator
18 Vertical vibration isolator
20 Horizontal force transmission means
22 Laminated rubber
24 fixed base
26 Air spring
26a, b Steel case
26c Air spring chamber
28 Sliding mechanism
29 Rolling support
50, 52 damper
54 Constant air pressure maintenance device
56 Pressure sensor
58 relief valve
60 solenoid valve
62 Pressure supply means
64 controller
66 Support Stay
68 Annular flange

Claims

A three-dimensional vibration isolator provided between a support structure and a vibration isolation structure that is spaced above the support structure, and allows relative movement in the horizontal direction between the two structures. A vertical vibration isolation device that performs vertical vibration isolation through a sliding mechanism, and a horizontal vibration isolation device that performs horizontal vibration isolation through a horizontal force transmission mechanism that allows relative movement in the vertical direction between the two structures. The vertical vibration isolator uses an air spring in which a cylindrical steel case whose one end is closed and a sliding body which slides in the case forms a spring chamber which expands and contracts vertically. The sliding mechanism is interposed between one end of the two and one structure with which the one end abuts ,
A support stay extended radially outward is integrally formed on the steel case of the air spring, and one end of the horizontal vibration isolator is coupled to the support stay to connect the vertical vibration isolator and the sliding mechanism to the air stay. A three-dimensional vibration isolator characterized by functioning as a horizontal force transmission mechanism.

2. The three-dimensional vibration isolator according to claim 1 , wherein the support stay is formed in an annular flange, and a plurality of the horizontal vibration isolator is arranged around the steel case along the flange. .

The three-dimensional vibration isolator according to claim 1 or 2 , wherein a vertical vibration damping device is provided between the support stay or flange and the other structure.

A fixed pedestal for fixing the other end of the vertical vibration isolator is integrally formed on the one structure, and a horizontal vibration damping device is provided between the fixed pedestal and the peripheral wall portion of the steel case. The three-dimensional vibration isolator according to any one of claims 1 to 3 .

The three-dimensional vibration isolator according to any one of claims 1 to 4 , wherein the sliding mechanism is a rolling bearing.

The three-dimensional vibration isolator according to any one of claims 1 to 5 , wherein the horizontal vibration isolator is a laminated rubber.

A constant air pressure maintaining device is attached to the air spring of the vertical vibration isolator to adjust the internal pressure of the air spring chamber in a normal range within a certain range and forcibly stop the pressure adjusting function when vibration is detected. The three-dimensional vibration isolator according to any one of claims 1 to 6 .

The constant air pressure maintaining device includes a pressure sensor that detects an internal pressure of the air spring chamber, a relief valve that keeps the pressure in the air spring chamber below a predetermined upper limit, and a relief valve that is connected in series to the relief valve. An electromagnetic on-off valve that suppresses the pressure release function, pressure air supply means for supplying compressed air into the air spring chamber, and operation of the electromagnetic on-off valve and the pressure air supply means based on a pressure value detected by the pressure sensor A controller for controlling, and when the pressure value detected by the pressure sensor falls below a specified lower limit value, the controller operates the pressurized air supply means to keep the internal pressure of the air spring chamber above the lower limit value, the variation of pressure values detected by the pressure sensor monitors to claim 7, characterized in that stops the operation of the gas supply means is closed the solenoid valve when the detecting vibration on the basis of the displacement movement Three described Motomenfu apparatus.