JP3988298B2

JP3988298B2 - Damping structure for bolted joints

Info

Publication number: JP3988298B2
Application number: JP37101698A
Authority: JP
Inventors: 泰彦高橋; 康正鈴井; 嶽中村
Original assignee: Obayashi Corp
Current assignee: Obayashi Corp
Priority date: 1998-07-31
Filing date: 1998-12-25
Publication date: 2007-10-10
Anticipated expiration: 2018-12-25
Also published as: JP2000104338A

Description

【０００１】
【発明の属する技術分野】
本発明は、建物架構を構成する各鉄骨部材を結合する際に用いられるボルト接合部に適用して、地震や強風等により発生する建物架構の振動を効果的に制振するようにしたボルト接合部の制振構造に関する。
【０００２】
【従来の技術】
鉄骨柱および鉄骨梁を互いに結合して構成される建物架構は一般に多層階ビルディングに適用され、この鉄骨構造の建物架構ではブレースが地震や風等の水平力に対する抵抗要素として用いられる。これら鉄骨柱や鉄骨梁およびブレースなどの鉄骨部材は、溶接やボルトを介して接合してラーメン架構が構成されるが、特にボルト接合した場合には、大地震や強風などによって過大な水平力が作用すると、剛結構造となるラーメン架構にあっても接合した２部材の接合部分にズレを生ずる。すると、このズレによって大きな摩擦抵抗力が発生され、この摩擦抵抗力によって上記地震や風による振動エネルギーが消耗されて、建物架構の制振機能が発揮される。
【０００３】
図１１は上記ボルト接合部の一例を示し、互いに接合しようとする一方の鉄骨部材から一体に一対の外板１，１ａが突設されているとともに、他方の鉄骨部材から一体に中板２が突設されており、一対の外板１，１ａ間に中板２を挟み込み、これら外板１，１ａと中板２とをボルト３で貫通してナット３ａ締めされる。中板２のボルト挿通孔は長孔４として形成され、引っ張り方向あるいは圧縮方向に過大な相対変位力Ｐが入力された場合には外板１，１ａと中板２との相対移動が許容される。この相対移動時に発生される上記摩擦抵抗力Ｒは、ボルト３の軸力Ｎと、外板１，１ａと中板２との接触面の摩擦係数μとの積、Ｒ＝μ・Ｎによって決定される。尚、軸力Ｎはナット３ａの締付け力によって調節され、また、摩擦係数μは外板１，１ａと中板２との接触面の表面粗さによって調節される。
【０００４】
【発明が解決しようとする課題】
しかしながら従来のボルト接合部の制振構造にあっては、ボルト３の軸力Ｎは、単にナット３ａの締付け力により発生され、この軸力Ｎが直接外板１，１ａ間の締付け力として作用するようになっている。このため、所定の摩擦抵抗力Ｒを発生させるためにはナット３ａの締付け力調整が難しくなり、また、一旦締付け力を付加した場合にあっても、外板１，１ａと中板２とが幾度と無く滑りを生ずると、双方の滑動面が摩耗して摩擦係数μが徐々に小さくなってしまうとともに、摩耗された分だけ上記ナット３ａによる締付け力が減少し、延いては、ボルト３の軸力Ｎが小さくなってしまう。
【０００５】
このことにより、予め設定した摩擦抵抗力Ｒ（＝μ・Ｎ）が、μとＮとの双方の減少により大きく変動して、当初の制振効果が得られなくなってしまうという課題があった。
【０００６】
そこで、本発明はかかる従来の課題に鑑みて成されたものであり、外板と中板とが繰り返して滑りを生じた場合にも、常にほぼ一定した摩擦抵抗力を発生させて、安定した制振効果を得ることができるボルト接合部の制振構造を提供することを目的とする。
【０００７】
【課題を解決するための手段】
請求項１に係る発明は、互いに接合しようとする２つの鉄骨部材のうち、一方の鉄骨部材から第１圧接板を、かつ、他方の鉄骨部材から第２圧接板をそれぞれ一体に突設し、これら第１，第２圧接板を互いに重合するとともに、両圧接板間に相対移動を可能にしてボルト軸力を付加し、両圧接板間に入力される所定値以上の振動変位力により、これら両者の相対移動が許容され、このときに発生する摩擦抵抗力によって、上記２つの鉄骨部材間を制振するようにしたボルト接合部の制振構造において、上記第１圧接板と上記第２圧接板との間に、摩擦板が介在されており、前記摩擦板の摩擦抵抗力発生面に溝が設けられており、前記溝は、該溝内に取り込まれた摩耗粉が自重で落下排出されるように、鉛直方向に貫通して形成されていることを特徴とする。
【０００８】
また、本発明の請求項２に示すボルト接合部の制振構造にあっては、上記第１圧接板と上記第２圧接板との重合部分に上記ボルト軸力を付加する経路に、ボルトの軸方向変位に対して弾発力の変動が略一定となる非線形ばね領域を備えた付勢手段を介在し、該ボルトに所定の軸力を発生させた状態で、該付勢手段が上記非線形ばね領域内でたわみ変形するように設定する。
【０００９】
更に、本発明の請求項３に示すボルト接合部の制振構造にあっては、上記第１圧接板をボルト軸力の作用方向に対峙する一対の外板で形成するとともに、上記第２圧接板を上記一対の外板間に挟み込まれる中板で形成し、該中板のボルト挿通孔を長孔とする。
【００１８】
また、請求項１では、上記摩擦板がその摩擦抵抗力発生面に溝を有し、当該溝は該溝内に取り込まれた摩耗粉が自重で落下排出されるように、鉛直方向に貫通して形成されているから、摩擦ダンパ作動時に、前記溝内の空気への摩擦熱の放散により、摩擦板の表面温度の上昇を防止し、摩擦板表面の炭化、脱落による摩耗粉の発生を防止できる。また、摩耗粉が発生しても溝に取り込まれ、摩擦板と圧接板間の摩耗粉の滞留を防止できる。さらに溝内に取り込まれた摩耗粉は自重で落下排出される。このため、圧接板が傷つき難くなるとともに、摩耗粉の転がり滑りも生じ難くなり、摩擦板と圧接板間の摩擦抵抗力を一定に維持することができ、安定した制振効果を得ることが可能となる。更には、摩耗粉の滞留を防止できるので、摩擦板および圧接板との摺動面から、摩耗粉の噛込等に起因した異音が発生することを防止でき、制振時の騒音を著く低減することができる。
【００１９】
【発明の実施の形態】
以下、本発明の実施形態を添付図面を参照しつつ詳細に説明する。図１，図２は本発明にかかるボルト接合部の制振構造の一実施形態を示し、図１は要部の断面図、図２は要部の平面図である。
【００２０】
即ち、本発明の制振構造が適用されるボルト接合部は、図１に示すように第１圧接板としての上下一対の外板１０，１２と、該一対の外板１０，１２間に挟み込まれる第２圧接板としての中板１４とを備える。上記外板１０，１２および上記中板１４は、建物架構にあって、互いに接合される鉄骨部材の一方および他方からそれぞれ一体に突設される。
【００２１】
上記鉄骨部材としては鉄骨柱や鉄骨梁、更にはブレースなどがあり、垂直配置される鉄骨柱と水平配置される鉄骨梁とを、六面体の各辺を構成するように互いに接合して建物架構が構成される。上記ブレースは傾斜部分を備え、互いに隣設される鉄骨柱と鉄骨梁との間、または対向する上下鉄骨梁間に跨って接合される。なお、本発明のボルト接合部の制振構造を適用する箇所としての上記鉄骨柱と鉄骨梁との接合部構造の具体例、並びにブレース構造の具体例については、後に詳述する。
【００２２】
上記外板１０，１２および上記中板１４は互いに重合させた状態で、それぞれに形成したボルト挿通孔１０ａ，１２ａ，１４ａに高力ボルト１６を貫通させて、ナット１８締めするようになっている。このナット１８の締付けによりボルトの軸力Ｎが発生し、この軸力Ｎはワッシャ２０，２０ａを介して上記外板１０，１２に伝達され、中板１４の挟み込み力として作用する。上記中板１４のボルト挿通孔１４ａは、図２に示すように外板１０，１２と中板１４の延設方向に長軸となる長孔として形成され、この長孔となったボルト挿通孔１４ａの長軸方向に外板１０，１２と中板１４とは相対移動が許容される。
【００２３】
ここで、本実施形態では上記一対の外板１０，１２と上記中板１４の両面との間に、複合摩擦材料で形成され、中板１４との摺接面側に複数の溝２１を有する摩擦板２２をそれぞれ介在する。この摩擦板２２は、熱硬化型樹脂を結合材として、アラミド繊維，ガラス繊維，ビニロン繊維，カーボンファイバー，アスベストなどの繊維材料と、カシューダスト，鉛などの摩擦調整材と、硫酸バリュームなどの充填剤とからなる複合摩擦材料で形成される。上記熱硬化型樹脂としては、フェノール樹脂，メラミン樹脂，フラン樹脂，ポリイミド樹脂，ＤＦＫ樹脂，グアナミン樹脂，エポキシ樹脂，キシレン樹脂，シリコーン樹脂，ジアリルフタレーン樹脂，不飽和ポリエステル樹脂などがある。
【００２４】
上記摩擦板２２は、上述したように中板１４の両面に一対で配置されるとともに、これら一対の摩擦板２２は図２に示したように、上記ボルト挿通孔１４ａの短軸方向両側に対向するように分離して配置される。一方、上記中板１４の摩擦板２２が接触される両面を適切に磨き仕上げして円滑面１４ｂとし、この円滑面１４ｂに上記摩擦板２２を摺接させることにより、中板１４と摩擦板２２との間で所定の摩擦係数μをもって滑動させるようになっている。
【００２５】
即ち、外板１０，１２と中板１４、及び高力ボルト１６とナット１８、並びに摩擦板２２等によりボルト接合部は摩擦ダンパ８として構成されている。
【００２６】
以上の構成により本実施形態のボルト接合部の制振構造にあっては、一対の外板１０，１２間に中板１４を挟み込んで、これらに貫通した高力ボルト１６をナット１８締めするにあたって、これら外板１０，１２と中板１４との間に摩擦板２２を介在させてあるので、地震や風などの外力によって建物架構が振動する際に、この振動による変位力が所定値を超えると、外板１０，１２と中板１４とは中板１４両面の円滑面１４ｂと上記摩擦板２２との滑動を伴って相対移動する。このとき、中板１４と摩擦板２２との間は高力ボルト１６の軸力Ｎをもって圧接されるとともに、所定の摩擦係数μが作用しており、これら中板１４と摩擦板２２とが滑動される際には、振動エネルギーがμ×Ｎの摩擦抵抗力Ｒに変換されて振動減衰され、建物架構の制振に寄与するようになっている。
【００２７】
このとき、上記摩擦板２２は、フェノール樹脂，メラミン樹脂，フラン樹脂，ポリイミド樹脂，ＤＦＫ樹脂，グアナミン樹脂，エポキシ樹脂，キシレン樹脂，シリコーン樹脂，ジアリルフタレーン樹脂，不飽和ポリエステル樹脂などの熱硬化型樹脂を結合材として、アラミド繊維，ガラス繊維，ビニロン繊維，カーボンファイバー，アスベストなどの繊維材料と、カシューダスト，鉛などの摩擦調整材と、硫酸バリュームなどの充填剤とからなる複合摩擦材料で形成されるので、該摩擦板２２は硬度が高く、かつ、強度に富む材質となって、一定の摩擦係数を有する摩耗の著しく少ない部材として形成することができる。
【００２８】
従って、外板１０，１２と中板１４とが相対移動された際にも、中板１４と摩擦板２２との間の摩擦係数μは常時ほぼ一定に維持され、かつ、滑動部分の摩耗がほとんどないため高力ボルト１６の軸力Ｎもほぼ一定に維持される。このため、上記外板１０，１２と中板１４との間の相対移動時に、上記摩擦係数μと上記軸力Ｎとの積として発生する摩擦抵抗力Ｒをほぼ一定に維持することができる。従って、上記外板１０，１２および上記中板１４とそれぞれ一体の２つの鉄骨部材間の摩擦減衰力特性、延いては、建物架構の振動に対する制振特性が安定化され、当初設定した制振機能を長期に亘って維持することができる。
【００２９】
ただし、この摩擦板２２と前記中板１４との摺動により生じる摩擦熱が大きい場合は、摩擦板２２の表面温度が著く上昇し、摩擦板表面が炭化し、摩耗粉として脱落し、この摩耗粉が摺動境界面に滞留してしまうことがあり得る。この摩耗粉は炭化物であるため非常に硬度が高く、前記摺動により中板１４を傷つけたり、前記摺動境界面に摩耗粉が介在して転がる等して、摩擦係数を変動させる虞がある。このような現象を生じた場合には、摩擦抵抗力が大幅に変化し、前記制振構造の制振性能に大きな変動を生じてしまい、安定した制振効果を得難くなる懸念がある。
【００３０】
そこでこの対策として、図１、図２に示すように、前記摩擦板２２には、前記中板１４との摺接面側に凹部として直線状の溝２１を５本形成している。この溝２１は、前記摩擦板２２の摩擦抵抗力が発生する中板１４との摺接面に生じる摩擦熱を放散するとともに、摺接面の摩耗粉を取り込み排出する機能を持つ。すなわち、摩擦ダンパ作動時の摩擦板２２の摩擦熱を、前記溝２１内の空気へ放散することで、その表面温度の上昇を防止し、摩擦板表面の炭化、摩耗粉の脱落を防止する。また、万一摩耗粉が発生しても溝２１に取り込まれ、摩擦板２２と中板１４との摺接面の摩耗粉の滞留を防止する。このため、中板１４が傷つき難くなるとともに、摩耗粉の転がり滑りも生じ難くなり、摩擦板２２と中板１４間の摩擦抵抗力を一定に維持することができ、安定した制振効果を得ることが可能となる。更には、摩耗粉の滞留を防止できるので、摩擦板２２および圧接板１４との摺動面から、摩耗粉の噛込等に起因した異音が発生することを防止でき、制振時の騒音を著く低減することができる。
【００３１】
前記溝２１の深さ、幅、断面形状、本数は、発生する摩耗粉の予め想定される大きさや量、並びに摩擦板２２の表面温度等を勘案し設定される。すなわち、深さ、幅、断面形状は、主として摩耗粉を取り込める容積を有するように設定され、本数に関しては、前記表面温度が摩擦板２２の材料の使用限界温度以下となるように設定される。本実施形態の場合は、溝２１の断面形状は矩形で、その深さは摩擦板２２厚みの半分、またその本数は５本に設定されているが、前述の要件を満たすように自由に設定可能であり、断面形状は半円形状でも良く、更に深さについては貫通していても良い。
【００３２】
また、前記溝２１の平面形状も、摩擦熱の放散効率が大きく、摩耗粉を取り込み得る容積を有していれば、直線に限るものではなく、円形等どのような形状の凹部に形成しても良い。ただし、熱の放散効率の観点から、冷却媒体である空気が流通し易いように、大気開放空間と連通した溝２１とするのが望ましく、また摩耗粉排出の観点からは、取り込まれた溝２１内の摩耗粉が自重で落下排出されるように、前記溝２１は、鉛直方向に直線状に貫通して形成されていることが望ましい。
【００３３】
尚、本実施形態においては、摩擦抵抗力が発生する摺接面が中板１４側であったため、摩擦板２２の溝２１を中板１４側に形成したが、摺接面側であればこれに限るものではない。つまり、摩擦板２２が中板１４に固設され、外板１０，１２と摺動し、摩擦抵抗力が外板１０，１２側に発生する場合は、摩擦板２２の外板１０，１２側に溝２１を形成すれば良い。
【００３４】
また、本実施形態では第１圧接板を上記一対の外板１０，１２で形成するとともに、第２圧接板を上記中板１４で形成し、かつ、該中板１４のボルト挿通孔１４ａを長孔としたので、２つの鉄骨部材間に相対変位力が入力された際に、一対の外板１０，１２間に中板１４が挟まれた状態で相対移動するため、一対の外板１０，１２間にボルト１６の軸力Ｎ、つまり締付け力を付加した状態で両者が滑動する際に、ボルト１６が傾斜されるなどしてこじれを生ずることなく、スムーズに相対移動することができる。
【００３５】
図３から図５は他の実施形態を示し、上記実施形態と同一構成部分に同一符号を付して重複する説明を省略して述べる。尚、図３は要部の断面図、図４は要部の平面図、図５はこの実施形態で用いられる付勢手段のばね特性図である。
【００３６】
この実施形態が上記実施形態と主に異なる点は、高力ボルト１６の軸力Ｎを外板１０，１２に付加する経路に、ボルトの軸方向変位に対して弾発力の変動が略一定となる非線形ばね領域を備えた付勢手段を介装して摩擦ダンパ８として構成したものである。
【００３７】
即ち、この実施形態のボルト接合部の制振構造は、上記実施形態と同様に一対の外板１０，１２間に中板１４を挟み込んでボルト１６，ナット１８締めする際に、外板１０，１２と中板１４との間に摩擦板２２が介在されるようになっており、このように構成されたボルト接合部にあって、高力ボルト１６の頭部１６ａと一方の外板１０との間に、付勢手段としての皿ばね３０を介装するようになっている。
【００３８】
上記皿ばね３０のばね特性Ａは、図５に示すように高力ボルト１６の中心軸方向の変形量（見込み変化量）σに対して、荷重（弾発力）ｗの変動がほぼ一定となる非線形ばね領域Ｐを備えており、該皿ばね３０は上記高力ボルト１６に所定の軸力Ｎを付加した状態で上記非線形ばね領域Ｐ内に設定される。また、本実施形態では上記皿ばね３０は、複数枚の皿ばね単体を同一方向に積層して構成したものが用いられる。
【００３９】
従って、この実施形態では高力ボルト１６の頭部１６ａ側の大径ワッシャ３２と一方の外板１０との間に皿ばね３０を介在したので、外板１０，１２と中板１４との間の隙間の変動を該皿ばね３０によって吸収することができる。そして、このときの変動吸収によって皿ばね３０のたわみ量が変化した場合にあっても、該皿ばね３０が非線形ばね領域Ｐ内に設定されているため、弾発力つまり高力ボルト１６の軸力をほぼ一定に維持することができる。
【００４０】
つまり、振動入力が無い状態では上記外板１０，１２と上記中板１０とは、大きな静摩擦力をもって固定状態が維持されるが、振動入力によりこの固定状態から小さな動摩擦力を伴う相対移動状態に移行する際に、それぞれの接触面間に大きな反発力が発生し、これが大きな音や衝撃として現れる。しかし、上記皿ばね３０を設けたことにより、このときの反発力を上記皿ばね３０の弾性により高力ボルト１６の軸力Ｎを変化させることなく吸収できる。従って、過大振動力が入力された場合にも、皿ばね３０の緩衝作用により音や衝撃の発生を抑制しつつ建物架構の制振機能を十分に発揮することができる。
【００４１】
また、上記皿ばね３０が非線形ばね領域Ｐに設定されていることにより、該皿ばね３０の弾発力は外板１０，１２と中板１４とが相対移動する際の滑動面、つまり、摩擦板２２と中板１４との間の接触面にたとえ摩耗が生じたとしても、弾発力をほぼ一定に維持して摩擦抵抗力Ｒが低下するのを防止できる。従って、外板１０，１２と中板１４との接合部における当初の制振機能を永続して発揮することができる。
【００４２】
また、この実施形態では上記皿ばね３０を、一方の外板１０と高力ボルト１６の頭部１６ａ側の大径ワッシャ３２との間、つまり、外板１０，１２の一方側に介在させた場合を開示したが、これに限ることなく図６に示すように外板１０，１２の両方側、つまり、両外板１０，１２と高力ボルト１６の頭部１６ａ側およびナット１８側の大径ワッシャ３２，３２ａとの間にそれぞれ皿ばね３０を介装させることもできる。また、図示は省略したが皿ばね３０を、他方の外板１２とナット１８側の大径ワッシャ３２ａとの間のみに介装させることもできる。
【００４３】
更に、皿ばね３０を構成する皿ばね単体の組み合わせ配置構成は、本実施形態に示したように同一方向に複数枚を積層したものに限ることなく、これ以外にも本発明の皿ばね３０に求められる設定が可能である限り種々に変更して組み合わせて構成することができ、例えば、皿ばね単体を単数で用いたり、複数枚を並列に積層したり、その積層方向を正逆交互に向けたりすることができる。
【００４４】
更にまた、この実施形態では付勢手段として皿ばね３０を用いた場合を開示したが、これに限ることなくボルトの軸方向変位に対して弾発力の変動が略一定となる非線形ばね領域を備えたばねであればよい。
【００４５】
ところで、上記各実施形態では中板１４の両面を円滑面１４ｂとして、これに摩擦板２２を摺接させたが、このように円滑面１４ｂを形成することなく、表面が滑らかなステンレス板などの図外の滑動板を取り付けて、この滑動板と上記摩擦板２２との間で滑動させても良い。また、摩擦板２２と中板１４との間で滑動させるようにした場合を開示したが、これに限ることなく摩擦板２２と外板１０，１２との間、若しくは、これら摩擦板２２と中板１４との間および摩擦板２２と外板１０，１２との間の両方で滑動させることもできる。
【００４６】
図７は上記本発明のボルト接合部の制振構造の適用対象の１つである鉄骨柱と鉄骨梁との接合部分を示す。図示するように、一般的に鉄骨柱５２と鉄骨梁５４とはＨ型鋼によって形成されて架構を構成する。鉄骨柱５２の梁接続部分には、鉄骨梁５４と同じＨ型鋼を短尺に切断したブラケット材５５を溶接して一体化し、このブラケット材５５に上記鉄骨梁５４の接続端部が結合される。図示例では上記ブラケット材５５は鉄骨柱５２のフランジ５２ａ面に溶接されるとともに、該ブラケット材５５の上下フランジ５５ａ，５５ｂ位置に対応して、鉄骨柱５２の両側フランジ５２ａ，５２ｂ間に跨って補剛材５７が溶接されている。
【００４７】
上記鉄骨梁５４の接続端は上記ブラケット材５５の先端に突き合わされ、これら鉄骨梁５４とブラケット材５５の互いに対応される上方フランジ５４ａと５５ａ、および下方フランジ５４ｂと５５ｂ、そして、ウェブ５４ｃと５５ｃとの各部に両部材間に跨ってその両面に添え板５８、５９が配置され、これらを貫通する高力ボルト１６にナット１８を螺合して締め付けることにより、上記鉄骨梁５４と上記ブラケット材５５つまり鉄骨柱５２とが結合される。
【００４８】
ここで、当該鉄骨柱５２と鉄骨梁５４との接合部において、本発明の制振構造は、上方フランジ５４ａと５５ａ、および下方フランジ５４ｂと５５ｂ、並びにウェブ５４ｃと５５ｃとのボルト接合部に組み込まれる。即ち、上記添え板５８，５９が外板１０，１２に該当し、鉄骨梁５４の上下フランジ５４ａ，５４ｂおよびウェブ５４ｃが中板１４に該当して、この各接合部が摩擦ダンパ８として構成され、この摩擦ダンパ８によって建物架構に入力される水平方向の振動を減衰する機能が付加される。
【００４９】
図８はその上方フランジ５４ａと５５ａとの接合部を例にして前記本発明の第２実施例にかかる制振構造を組み込んだ状態を示している。図示するように、上記添え板５８，５９はブラケット材５５側に高力ボルト１６，ナット１８を介して確実に締め付け固定（この部分は溶接でも良い）された上で、該添え板５８，５９と上方フランジ５４ａとの間に摩擦板２２，２２を介在させて摺動自在とし、これら三者間に高力ボルト１６の軸力をもって摩擦力を発生させるようになっている。
【００５０】
即ち、上記摩擦ダンパ８は、鉄骨梁５４の上方フランジ５４ａ端部を滑り板とし、この滑り板となった上方フランジ５４ａには、高力ボルト１６の貫通部分に水平方向に長孔となるボルト挿通孔１４ａが形成され、これによって鉄骨梁５４とブラケット材５５との水平方向の相対移動が許容される。また、上記高力ボルト１６には添え板５８，５９と摩擦板２２，２２と上方フランジ５４ａとの間に圧接力を付加するための付勢手段としての皿ばね３０が設けられる。
【００５１】
図９と図１０は、本発明にかかるボルト接合部の制振構造をブレースに適用する場合の一例を示すもので、摩擦ダンパ８をブレース６０の途中を分断した間に介装するようにしたものである。また、この図示例にあっても上記摩擦ダンパ８は、一対の外板１０，１２と摩擦板２２，２２と中板１４、および付勢手段としての皿ばね３０とによって構成される。
【００５２】
即ち、上記外板１０，１２は上記ブレース６０を切断した一方の端部６０ａに取り付けられるとともに、ブレース６０を切断した他方の端部６０ｂが上記中板１４とされ、一対の外板１０，１２間に摩擦板２２，２２を介して中板１４としてのブレース端部６０ｂが挟み込まれる。このとき、この図示例では外板１０，１２はブレース６０より若干幅狭に形成されて上記端部６０ａにボルト，ナット結合（溶接でも良い）されている。また、中板１４のボルト挿通孔（長孔）１４ａを通って外板１０，１２を貫通する締付け用の高力ボルト１６の外周に、皿ばね３０が挿通されて大径ワッシャ３２と外板１０との間に挟圧されて設けられる。
【００５３】
【発明の効果】
以上説明したように本発明の請求項１に示すボルト接合部の制振構造にあっては、摩擦板がその摩擦抵抗力発生面に溝を有し、当該溝は該溝内に取り込まれた摩耗粉が自重で落下排出されるように、鉛直方向に貫通して形成されているから、摩擦ダンパ作動時に、前記溝内の空気への摩擦熱の放散により、摩擦板の表面温度の上昇を防止し、摩擦板表面の炭化、脱落による摩耗粉の発生を防止できる。また、摩耗粉が発生しても溝に取り込まれ、摩擦板と圧接板間の摩耗粉の滞留を防止できる。さらに溝内に取り込まれた摩耗粉は自重で落下排出される。このため、圧接板が傷つき難くなるとともに、摩耗粉の転がり滑りも生じ難くなり、摩擦板と圧接板間の摩擦抵抗力を一定に維持することができ、安定した制振効果を得ることが可能となる。更には、摩耗粉の滞留を防止できるので、摩擦板および圧接板との摺動面から、摩耗粉の噛込等に起因した異音が発生することを防止でき、制振時の騒音を著く低減することができる。
【００５５】
また、本発明の請求項２に示すボルト接合部の制振構造にあっては、上記第１圧接板と上記第２圧接板との重合部分に上記ボルト軸力を付加する経路に、ボルトの軸方向変位に対して弾発力の変動が略一定となる非線形ばね領域を備えた付勢手段を介在し、該ボルトに所定の軸力を発生させた状態で、該付勢手段が上記非線形ばね領域内でたわみ変形するように設定したので、第１，第２圧接板間の隙間の変動を上記付勢手段によって吸収することができ、このときの変動吸収によって付勢手段のたわみ量が変化した場合にあっても、該付勢手段が非線形ばね領域内に設定されているため、弾発力つまりボルトの軸力をほぼ一定に維持することができる。
【００５６】
従って、所定値以上の振動変位力の入力により上記第１圧接板と第２圧接板とが相対移動する際の反発力を、上記付勢手段によりボルト軸力を変化することなく吸収し、音や衝撃の発生を抑制しつつ制振機能を十分に発揮することができる。また、上記付勢手段の弾発力は、第１，第２圧接板が相対移動する際の滑動面が摩耗された場合にも弾発力をほぼ一定に維持できるため、摩擦抵抗力が低下するのを防止して当初の制振機能を永続して発揮させることができる。
【００５７】
更に、本発明の請求項３に示すボルト接合部の制振構造にあっては、上記第１圧接板をボルト軸力の作用方向に対峙する一対の外板で形成するとともに、上記第２圧接板を上記一対の外板間に挟み込まれる中板で形成し、該中板のボルト挿通孔を長孔としたので、２つの鉄骨部材間に相対変位力が入力された際に、一対の外板間に中板が挟まれた状態で相対移動するため、一対の外板間にボルトの軸力つまり締付け力を付加した状態で両者が滑動する際に、ボルトが傾斜されるなどしてこじれを生ずるのを防止できる。このため、外板と中板とをスムーズに相対移動することができ、延いては、制振機能を効果的に発揮することができるという優れた効果を奏する。
【図面の簡単な説明】
【図１】本発明のボルト接合部の制振構造の一実施形態を示す要部の断面図である。
【図２】本発明のボルト接合部の制振構造の一実施形態を示す要部の平面図である。
【図３】本発明のボルト接合部の制振構造の他の実施形態を示す要部の断面図である。
【図４】本発明のボルト接合部の制振構造の他の実施形態を示す要部の平面図である。
【図５】本発明のボルト接合部の制振構造の他の実施形態に用いられる付勢手段のばね特性図である。
【図６】本発明のボルト接合部の制振構造の更に他の実施形態を示す要部の断面図である。
【図７】本発明のボルト接合部の制振構造を鉄骨柱と鉄骨梁との接合部に適用する場合の一例を示す正面図である。
【図８】図７の要部を示す断面図である。
【図９】本発明のボルト接合部の制振構造を分断形成したブレースの途中に介在させて適用した例を示す正面図である。
【図１０】図９の側面図である。
【図１１】従来のボルト接合部を示す断面図である。
【符号の説明】
８摩擦ダンパ
１０，１２外板（第１圧接板）
１４中板（第２圧接板）
１６高力ボルト
１８ナット
２０摩擦ダンパ
２１溝（凹部）
２２摩擦板
３０皿ばね（付勢手段）
３２，３２ａ大径ワッシャ（締付け部）
５２鉄骨柱
５４鉄骨梁[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a bolt joint used when joining each steel member constituting a building frame, and is a bolt joint that effectively suppresses vibration of the building frame caused by an earthquake or a strong wind. This relates to the vibration control structure of the department.
[0002]
[Prior art]
Building structures constructed by connecting steel columns and steel beams to each other are generally applied to multi-story buildings, and braces are used as resistance elements against horizontal forces such as earthquakes and winds. Steel members such as steel columns, steel beams, and braces are joined together by welding or bolts to form a rigid frame structure. Especially when bolted, excessive horizontal force is caused by large earthquakes or strong winds. If it acts, even if it exists in the rigid frame structure used as a rigid connection structure, a shift | offset | difference arises in the joined part of the joined 2 members. As a result, a large frictional resistance force is generated by this displacement, and the vibrational energy due to the earthquake and wind is consumed by the frictional resistance force, and the vibration control function of the building frame is exhibited.
[0003]
FIG. 11 shows an example of the above-described bolt joint portion, and a pair of outer plates 1 and 1a project integrally from one steel member to be joined to each other, and an intermediate plate 2 is integrally joined from the other steel member. The intermediate plate 2 is sandwiched between the pair of outer plates 1 and 1 a, and the outer plate 1, 1 a and the intermediate plate 2 are penetrated by the bolt 3 and tightened with the nut 3 a. The bolt insertion hole of the intermediate plate 2 is formed as a long hole 4, and relative movement between the outer plates 1, 1 a and the intermediate plate 2 is allowed when an excessive relative displacement force P is input in the pulling direction or the compression direction. The The frictional resistance R generated during the relative movement is determined by the product of the axial force N of the bolt 3 and the friction coefficient μ of the contact surface between the outer plates 1, 1 a and the intermediate plate 2, R = μ · N. Is done. The axial force N is adjusted by the tightening force of the nut 3a, and the friction coefficient μ is adjusted by the surface roughness of the contact surface between the outer plates 1 and 1a and the intermediate plate 2.
[0004]
[Problems to be solved by the invention]
However, in the conventional vibration damping structure of the bolt joint, the axial force N of the bolt 3 is simply generated by the tightening force of the nut 3a, and this axial force N acts directly as the tightening force between the outer plates 1 and 1a. It is supposed to be. For this reason, it is difficult to adjust the tightening force of the nut 3a in order to generate the predetermined frictional resistance force R. Even if the tightening force is once applied, the outer plates 1, 1a and the intermediate plate 2 are not connected. If slipping occurs several times, both sliding surfaces wear and the friction coefficient μ gradually decreases, and the tightening force by the nut 3a is reduced by the amount of wear. The axial force N becomes small.
[0005]
As a result, the preset frictional resistance R (= μ · N) fluctuates greatly due to a decrease in both μ and N, and the original vibration damping effect cannot be obtained.
[0006]
Therefore, the present invention has been made in view of such a conventional problem, and even when the outer plate and the intermediate plate repeatedly slip, a substantially constant frictional resistance force is always generated and stable. An object of the present invention is to provide a vibration damping structure for a bolt joint that can obtain a vibration damping effect.
[0007]
[Means for Solving the Problems]
  The invention according to claim 1 is provided by integrally projecting the first press contact plate from one steel member and the second press contact plate from the other steel member of the two steel members to be joined to each other, These first and second pressure plates are overlapped with each other, and are capable of relative movement between both pressure plates and applied with a bolt axial force. Relative movement of both is allowed, and in the vibration suppression structure of the bolt joint portion that suppresses vibration between the two steel members by the frictional resistance generated at this time, the first pressure contact plate and the second pressure contact A friction plate is interposed between the friction plate, and a groove is provided on the frictional resistance generating surface of the friction plate, and the wear powder taken into the groove is dropped and discharged by its own weight. So as to penetrate vertically And it features.
[0008]
Further, in the vibration damping structure of the bolt joint portion according to claim 2 of the present invention, a bolt is provided in a path for applying the bolt axial force to the overlapping portion of the first pressure contact plate and the second pressure contact plate. An urging means having a non-linear spring region in which the variation of the elastic force is substantially constant with respect to the axial displacement is interposed, and the urging means is in the non-linear state in a state where a predetermined axial force is generated on the bolt. Set to bend and deform in the spring region.
[0009]
Furthermore, in the vibration damping structure for a bolt joint portion according to claim 3 of the present invention, the first pressure contact plate is formed of a pair of outer plates facing the direction of the bolt axial force, and the second pressure contact is formed. The plate is formed of an intermediate plate sandwiched between the pair of outer plates, and the bolt insertion hole of the intermediate plate is a long hole.
[0018]
    Also,Claim 1Then, the friction plate is on the frictional resistance generating surface.Since the groove has a groove, the groove is formed so as to penetrate in the vertical direction so that the wear powder taken into the groove is dropped and discharged by its own weight.When the friction damper is activated,grooveBy dissipating frictional heat to the air inside, an increase in the surface temperature of the friction plate can be prevented, and generation of wear powder due to carbonization and falling off of the friction plate surface can be prevented. Even if wear powder is generatedgrooveIt is possible to prevent the accumulation of wear powder between the friction plate and the pressure contact plate.Further, the wear powder taken into the groove is dropped and discharged by its own weight.For this reason, the pressure contact plate is less likely to be damaged, and wear powder is less likely to roll and slip, and the frictional resistance force between the friction plate and the pressure contact plate can be maintained constant, and a stable damping effect can be obtained. It becomes. Furthermore, since the accumulation of wear powder can be prevented, it is possible to prevent the generation of noise caused by wear powder from the sliding surface between the friction plate and the pressure contact plate, and the noise during vibration suppression is significant. Can be reduced.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a vibration damping structure for a bolt joint according to the present invention, FIG. 1 is a cross-sectional view of the main part, and FIG. 2 is a plan view of the main part.
[0020]
That is, the bolt joint to which the vibration damping structure of the present invention is applied is sandwiched between a pair of upper and lower outer plates 10 and 12 as a first pressure contact plate and the pair of outer plates 10 and 12 as shown in FIG. And a middle plate 14 as a second pressure contact plate. The outer plates 10 and 12 and the intermediate plate 14 are provided integrally with each other from one and the other of the steel members to be joined to each other in the building frame.
[0021]
The steel members include steel columns, steel beams, and braces.The building frame is constructed by joining vertically arranged steel columns and horizontally arranged steel beams to each other so as to form each side of the hexahedron. Composed. The brace has an inclined portion and is joined between a steel column and a steel beam adjacent to each other, or straddling between upper and lower steel beams facing each other. In addition, the specific example of the junction part structure of the said steel column and steel beam as a location which applies the damping structure of the bolt junction part of this invention and the specific example of a brace structure are explained in full detail later.
[0022]
In the state where the outer plates 10 and 12 and the intermediate plate 14 are superposed with each other, the high-strength bolts 16 are passed through the bolt insertion holes 10a, 12a and 14a formed therein, and the nuts 18 are tightened. . By tightening the nut 18, an axial force N of the bolt is generated. This axial force N is transmitted to the outer plates 10 and 12 through washers 20 and 20a, and acts as a pinching force for the intermediate plate 14. The bolt insertion hole 14a of the intermediate plate 14 is formed as a long hole having a long axis in the extending direction of the outer plates 10 and 12 and the intermediate plate 14, as shown in FIG. The outer plates 10 and 12 and the middle plate 14 are allowed to move relative to each other in the major axis direction of 14a.
[0023]
Here, in the present embodiment, a composite friction material is formed between the pair of outer plates 10 and 12 and both surfaces of the intermediate plate 14, and a plurality of grooves 21 are provided on the sliding contact surface side with the intermediate plate 14. A friction plate 22 is interposed. The friction plate 22 is made of a thermosetting resin as a binder, a fiber material such as aramid fiber, glass fiber, vinylon fiber, carbon fiber or asbestos, a friction adjusting material such as cashew dust or lead, and a filling such as sulfate sulfate. It is formed of a composite friction material comprising an agent. Examples of the thermosetting resin include phenol resin, melamine resin, furan resin, polyimide resin, DFK resin, guanamine resin, epoxy resin, xylene resin, silicone resin, diallyl phthalene resin, and unsaturated polyester resin.
[0024]
As described above, the friction plates 22 are disposed as a pair on both surfaces of the intermediate plate 14, and the pair of friction plates 22 are opposed to both sides in the short axis direction of the bolt insertion hole 14a as shown in FIG. To be separated. On the other hand, both surfaces of the intermediate plate 14 with which the friction plate 22 is brought into contact are appropriately polished to form a smooth surface 14b, and the friction plate 22 is brought into sliding contact with the smooth surface 14b. And a predetermined friction coefficient μ.
[0025]
That is, the bolt joint portion is configured as the friction damper 8 by the outer plates 10 and 12 and the intermediate plate 14, the high-strength bolt 16 and the nut 18, the friction plate 22, and the like.
[0026]
With the above-described structure of the bolt joint vibration damping structure of the present embodiment, the intermediate plate 14 is sandwiched between the pair of outer plates 10 and 12, and the high-strength bolt 16 penetrating them is tightened with the nut 18. Since the friction plate 22 is interposed between the outer plates 10 and 12 and the intermediate plate 14, when the building frame vibrates due to an external force such as an earthquake or wind, the displacement force due to this vibration exceeds a predetermined value. The outer plates 10 and 12 and the intermediate plate 14 move relative to each other with the sliding of the smooth surface 14b on both sides of the intermediate plate 14 and the friction plate 22. At this time, the intermediate plate 14 and the friction plate 22 are pressed against each other with the axial force N of the high-strength bolt 16 and a predetermined coefficient of friction μ is applied. The intermediate plate 14 and the friction plate 22 slide. In this case, the vibration energy is converted to a frictional resistance force R of μ × N and is attenuated, thereby contributing to vibration control of the building frame.
[0027]
At this time, the friction plate 22 is a thermosetting type such as phenol resin, melamine resin, furan resin, polyimide resin, DFK resin, guanamine resin, epoxy resin, xylene resin, silicone resin, diallyl phthalene resin, and unsaturated polyester resin. Made of composite friction material consisting of fiber materials such as aramid fiber, glass fiber, vinylon fiber, carbon fiber, asbestos, friction modifiers such as cashew dust and lead, and fillers such as sulfate sulfate, using resin as a binder. Therefore, the friction plate 22 is made of a material having high hardness and high strength, and can be formed as a member having a constant friction coefficient and extremely low wear.
[0028]
Therefore, even when the outer plates 10 and 12 and the intermediate plate 14 are relatively moved, the friction coefficient μ between the intermediate plate 14 and the friction plate 22 is always kept substantially constant, and wear of the sliding portion is reduced. Since there is almost no, the axial force N of the high-strength bolt 16 is also maintained substantially constant. Therefore, the frictional resistance R generated as a product of the friction coefficient μ and the axial force N during the relative movement between the outer plates 10 and 12 and the intermediate plate 14 can be maintained substantially constant. Therefore, the frictional damping force characteristics between the two steel members integrated with the outer plates 10 and 12 and the middle plate 14, respectively, and hence the vibration damping characteristics against vibration of the building frame are stabilized, and the initially set vibration damping is stabilized. The function can be maintained for a long time.
[0029]
However, when the frictional heat generated by sliding between the friction plate 22 and the intermediate plate 14 is large, the surface temperature of the friction plate 22 rises significantly, the surface of the friction plate carbonizes, and falls off as wear powder. The wear powder may stay on the sliding interface. Since the wear powder is a carbide, the hardness is very high, and the friction coefficient may be changed by damaging the intermediate plate 14 due to the sliding or rolling with the wear powder interposed on the sliding boundary surface. . When such a phenomenon occurs, there is a concern that the frictional resistance will change drastically, resulting in large fluctuations in the damping performance of the damping structure, making it difficult to obtain a stable damping effect.
[0030]
Therefore, as a countermeasure, as shown in FIGS. 1 and 2, the friction plate 22 is formed with five linear grooves 21 as concave portions on the sliding contact surface side with the intermediate plate 14. The groove 21 has a function of dissipating frictional heat generated on the sliding contact surface with the intermediate plate 14 where the frictional resistance of the friction plate 22 is generated, and taking in and discharging wear powder on the sliding contact surface. That is, by dissipating the frictional heat of the friction plate 22 during the operation of the friction damper to the air in the groove 21, the surface temperature is prevented from rising, and the friction plate surface is prevented from being carbonized and the wear powder falling off. Further, even if wear powder is generated, it is taken into the groove 21 and prevents the wear powder from staying on the sliding contact surface between the friction plate 22 and the intermediate plate 14. For this reason, the intermediate plate 14 is less likely to be damaged and rolling of the wear powder is less likely to occur, and the frictional resistance force between the friction plate 22 and the intermediate plate 14 can be maintained constant, and a stable vibration damping effect is obtained. It becomes possible. Furthermore, since the accumulation of wear powder can be prevented, it is possible to prevent the generation of noise caused by the wear powder and the like from the sliding surfaces of the friction plate 22 and the pressure contact plate 14, and noise during vibration suppression. Can be significantly reduced.
[0031]
The depth, width, cross-sectional shape, and number of the grooves 21 are set in consideration of the size and amount of wear powder generated in advance, the surface temperature of the friction plate 22, and the like. That is, the depth, width, and cross-sectional shape are set so as to mainly have a volume capable of taking in the wear powder, and the number of the sets is set so that the surface temperature is equal to or lower than the use limit temperature of the material of the friction plate 22. In the case of the present embodiment, the cross-sectional shape of the groove 21 is rectangular, the depth thereof is set to half the thickness of the friction plate 22, and the number thereof is set to five, but can be freely set so as to satisfy the above-mentioned requirements. The cross-sectional shape may be a semicircular shape, and the depth may be penetrated.
[0032]
Further, the planar shape of the groove 21 is not limited to a straight line as long as it has a large frictional heat dissipation efficiency and a volume capable of taking in wear powder. Also good. However, from the viewpoint of heat dissipation efficiency, it is desirable that the groove 21 communicates with the open air space so that air as a cooling medium can easily flow. It is desirable that the groove 21 is formed so as to penetrate linearly in the vertical direction so that the inner wear powder falls and is discharged by its own weight.
[0033]
In this embodiment, since the sliding contact surface on which the frictional resistance is generated is on the intermediate plate 14 side, the groove 21 of the friction plate 22 is formed on the intermediate plate 14 side. It is not limited to. That is, when the friction plate 22 is fixed to the intermediate plate 14 and slides with the outer plates 10 and 12, and frictional resistance is generated on the outer plates 10 and 12 side, the outer plate 10 and 12 side of the friction plate 22. The groove 21 may be formed in the groove.
[0034]
In the present embodiment, the first pressure contact plate is formed by the pair of outer plates 10 and 12, the second pressure contact plate is formed by the intermediate plate 14, and the bolt insertion hole 14 a of the intermediate plate 14 is long. Since the holes are holes, when a relative displacement force is input between the two steel members, the pair of outer plates 10, 12 move relative to each other with the intermediate plate 14 sandwiched between them. When both of them slide in a state where an axial force N of the bolt 16, that is, a tightening force is applied between the bolts 12, the bolts 16 can be smoothly moved relative to each other without causing twisting or the like.
[0035]
3 to 5 show other embodiments, and the same components as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. 3 is a cross-sectional view of the main part, FIG. 4 is a plan view of the main part, and FIG. 5 is a spring characteristic diagram of the biasing means used in this embodiment.
[0036]
This embodiment is mainly different from the above-described embodiment in that the variation in the elastic force is substantially constant with respect to the axial displacement of the bolt in the path for applying the axial force N of the high strength bolt 16 to the outer plates 10 and 12. The friction damper 8 is configured by interposing an urging means having a non-linear spring region.
[0037]
That is, the vibration damping structure of the bolt joint portion of this embodiment is similar to the above embodiment in that the outer plate 10, when the intermediate plate 14 is sandwiched between the pair of outer plates 10, 12 and the bolts 16 and nuts 18 are tightened. The friction plate 22 is interposed between the intermediate plate 14 and the intermediate plate 14. In the bolt joint portion thus configured, the head 16 a of the high strength bolt 16 and the one outer plate 10 In between, the disc spring 30 as an urging | biasing means is interposed.
[0038]
As shown in FIG. 5, the spring characteristic A of the disc spring 30 is such that the fluctuation of the load (elastic force) w is substantially constant with respect to the deformation amount (expected change amount) σ of the high-strength bolt 16 in the central axis direction. The disc spring 30 is set in the nonlinear spring region P in a state where a predetermined axial force N is applied to the high-strength bolt 16. In the present embodiment, the disc spring 30 is formed by laminating a plurality of disc springs in the same direction.
[0039]
Therefore, in this embodiment, since the disc spring 30 is interposed between the large-diameter washer 32 on the head 16a side of the high-strength bolt 16 and the one outer plate 10, the space between the outer plates 10 and 12 and the intermediate plate 14 is increased. The disc spring 30 can absorb the fluctuation of the gap. Even when the amount of deflection of the disc spring 30 changes due to fluctuation absorption at this time, since the disc spring 30 is set in the nonlinear spring region P, the elastic force, that is, the axis of the high-strength bolt 16 is used. The force can be kept almost constant.
[0040]
That is, in the state where there is no vibration input, the outer plates 10 and 12 and the middle plate 10 are maintained in a fixed state with a large static frictional force. However, the vibrational input changes from this fixed state to a relative moving state with a small dynamic frictional force. When moving, a large repulsive force is generated between the contact surfaces, and this appears as a loud sound or impact. However, by providing the disc spring 30, the repulsive force at this time can be absorbed by the elasticity of the disc spring 30 without changing the axial force N of the high-strength bolt 16. Therefore, even when an excessive vibration force is input, the vibration control function of the building frame can be sufficiently exhibited while suppressing the generation of sound and impact by the buffering action of the disc spring 30.
[0041]
Further, since the disc spring 30 is set in the non-linear spring region P, the elastic force of the disc spring 30 is a sliding surface when the outer plates 10 and 12 and the middle plate 14 move relative to each other, that is, friction. Even if wear occurs on the contact surface between the plate 22 and the intermediate plate 14, the elastic force can be maintained substantially constant and the frictional resistance R can be prevented from decreasing. Therefore, the initial damping function at the joint between the outer plates 10 and 12 and the middle plate 14 can be exhibited permanently.
[0042]
In this embodiment, the disc spring 30 is interposed between one outer plate 10 and the large-diameter washer 32 on the head 16a side of the high-strength bolt 16, that is, on one side of the outer plates 10 and 12. Although the case has been disclosed, the present invention is not limited to this, and as shown in FIG. A disc spring 30 may be interposed between the diameter washers 32 and 32a. Although not shown, the disc spring 30 can be interposed only between the other outer plate 12 and the large-diameter washer 32a on the nut 18 side.
[0043]
Furthermore, the combination arrangement configuration of the single disc springs constituting the disc spring 30 is not limited to the one in which a plurality of disc springs are stacked in the same direction as shown in the present embodiment, but other than this, the disc spring 30 of the present invention is also provided. As long as the required setting is possible, it can be configured with various changes and combinations.For example, a single disc spring can be used, a plurality of disc springs can be stacked in parallel, and the stacking direction can be alternately reversed. Can be.
[0044]
Furthermore, in this embodiment, the case where the disc spring 30 is used as the biasing means has been disclosed. However, the present invention is not limited to this. Any spring provided may be used.
[0045]
By the way, in each said embodiment, although both surfaces of the intermediate | middle board 14 were made into the smooth surface 14b and the friction board 22 was slidably contacted with this, stainless steel board etc. where the surface is smooth, without forming the smooth surface 14b in this way. A sliding plate (not shown) may be attached and slid between the sliding plate and the friction plate 22. Moreover, although the case where it was made to slide between the friction board 22 and the intermediate | middle board 14 was disclosed, it is not restricted to this, Between the friction board 22 and the outer plates 10 and 12, or these friction board 22 and intermediate | middle It is also possible to slide both between the plate 14 and between the friction plate 22 and the outer plates 10, 12.
[0046]
FIG. 7 shows a joint portion between a steel column and a steel beam, which is one of the application targets of the vibration damping structure for a bolt joint portion of the present invention. As shown in the figure, the steel column 52 and the steel beam 54 are generally formed of H-shaped steel to constitute a frame. A bracket member 55 obtained by cutting the same H-shaped steel as the steel beam 54 in a short length is welded and integrated to the beam connecting portion of the steel column 52, and the connecting end portion of the steel beam 54 is coupled to the bracket member 55. In the illustrated example, the bracket material 55 is welded to the surface of the flange 52a of the steel column 52, and straddles between the flanges 52a and 52b of the steel column 52 corresponding to the positions of the upper and lower flanges 55a and 55b of the bracket material 55. A stiffener 57 is welded.
[0047]
The connection end of the steel beam 54 is abutted against the tip of the bracket member 55, and the upper flanges 54a and 55a, the lower flanges 54b and 55b of the steel beam 54 and the bracket member 55, and the webs 54c and 55c. Are attached to both sides of each member, and the nut 18 is screwed onto the high-strength bolt 16 penetrating them to fasten the steel beam 54 and the bracket material. 55, that is, the steel column 52 is coupled.
[0048]
Here, in the joint portion between the steel column 52 and the steel beam 54, the vibration damping structure of the present invention is incorporated in the bolt joint portion between the upper flanges 54a and 55a, the lower flanges 54b and 55b, and the webs 54c and 55c. It is. That is, the attachment plates 58 and 59 correspond to the outer plates 10 and 12, the upper and lower flanges 54 a and 54 b and the web 54 c of the steel beam 54 correspond to the intermediate plate 14, and each joint portion is configured as the friction damper 8. A function of attenuating horizontal vibration input to the building frame by the friction damper 8 is added.
[0049]
FIG. 8 shows a state in which the vibration damping structure according to the second embodiment of the present invention is incorporated, taking the joint portion between the upper flanges 54a and 55a as an example. As shown in the drawing, the attachment plates 58 and 59 are securely fastened and fixed to the bracket material 55 side via the high-strength bolts 16 and nuts 18 (this portion may be welded), and then the attachment plates 58 and 59. The upper and lower flanges 54a are made slidable by interposing friction plates 22 and 22, and a frictional force is generated by the axial force of the high-strength bolt 16 between these three members.
[0050]
That is, the friction damper 8 has a sliding plate at the end of the upper flange 54 a of the steel beam 54, and the upper flange 54 a that is the sliding plate has a bolt that is a long hole in the horizontal direction in the through portion of the high-strength bolt 16. The insertion hole 14a is formed, and thereby the horizontal relative movement between the steel beam 54 and the bracket material 55 is allowed. The high-strength bolt 16 is provided with a disc spring 30 as an urging means for applying a pressing force between the attachment plates 58 and 59, the friction plates 22 and 22, and the upper flange 54a.
[0051]
FIG. 9 and FIG. 10 show an example in which the vibration damping structure of the bolt joint portion according to the present invention is applied to the brace, and the friction damper 8 is interposed while the middle of the brace 60 is divided. Is. Further, even in this illustrated example, the friction damper 8 includes a pair of outer plates 10 and 12, friction plates 22 and 22, an intermediate plate 14, and a disc spring 30 as an urging means.
[0052]
That is, the outer plates 10 and 12 are attached to one end portion 60a obtained by cutting the brace 60, and the other end portion 60b obtained by cutting the brace 60 is used as the intermediate plate 14 so that a pair of outer plates 10 and 12 are provided. A brace end 60b as the intermediate plate 14 is sandwiched between the friction plates 22 and 22 therebetween. At this time, in the illustrated example, the outer plates 10 and 12 are formed to be slightly narrower than the brace 60 and are joined to the end 60a by bolts and nuts (may be welded). Further, a disc spring 30 is inserted into the outer periphery of the high-strength bolt 16 for tightening that passes through the outer plates 10 and 12 through the bolt insertion hole (long hole) 14a of the intermediate plate 14, and the large-diameter washer 32 and the outer plate. 10 to be sandwiched between the two.
[0053]
【The invention's effect】
    As described above, in the vibration damping structure for a bolt joint shown in claim 1 of the present invention,The friction plate has a groove on its frictional resistance generation surface, and the groove is formed so as to penetrate in the vertical direction so that the wear powder taken into the groove is dropped and discharged by its own weight. When the friction damper is activated, the frictional heat is dissipated into the air in the groove, thereby preventing the surface temperature of the friction plate from rising and the generation of wear powder due to carbonization and dropping of the friction plate surface. Moreover, even if abrasion powder is generated, it is taken into the groove, and the accumulation of abrasion powder between the friction plate and the pressure contact plate can be prevented. Further, the wear powder taken into the groove is dropped and discharged by its own weight. For this reason, the pressure contact plate is less likely to be damaged, and wear powder is less likely to roll and slip, and the frictional resistance force between the friction plate and the pressure contact plate can be maintained constant, and a stable damping effect can be obtained. It becomes. Furthermore, since the accumulation of wear powder can be prevented, it is possible to prevent the generation of noise caused by wear powder from the sliding surface between the friction plate and the pressure contact plate, and the noise during vibration suppression is significant. Can be reduced.
[0055]
Further, in the vibration damping structure of the bolt joint portion according to claim 2 of the present invention, a bolt is provided in a path for applying the bolt axial force to the overlapping portion of the first pressure contact plate and the second pressure contact plate. An urging means having a non-linear spring region in which the variation of the elastic force is substantially constant with respect to the axial displacement is interposed, and the urging means is in the non-linear state in a state where a predetermined axial force is generated on the bolt. Since it is set so as to bend and deform within the spring region, fluctuations in the gap between the first and second pressure plates can be absorbed by the biasing means, and the deflection amount of the biasing means can be reduced by absorbing the fluctuations at this time. Even in the case of a change, since the biasing means is set in the non-linear spring region, the elastic force, that is, the axial force of the bolt can be maintained almost constant.
[0056]
Therefore, the repulsive force when the first pressure contact plate and the second pressure contact plate move relative to each other by the input of the vibration displacement force of a predetermined value or more is absorbed by the biasing means without changing the bolt axial force, The vibration control function can be sufficiently exhibited while suppressing the occurrence of shock. In addition, the elastic force of the urging means can be maintained substantially constant even when the sliding surface is worn when the first and second pressure contact plates are relatively moved, so that the frictional resistance is reduced. It is possible to prevent this from happening and to make the original damping function permanent.
[0057]
Furthermore, in the vibration damping structure for a bolt joint portion according to claim 3 of the present invention, the first pressure contact plate is formed of a pair of outer plates facing the direction of the bolt axial force, and the second pressure contact is formed. Since the plate is formed by an intermediate plate sandwiched between the pair of outer plates and the bolt insertion hole of the intermediate plate is a long hole, when a relative displacement force is input between the two steel members, the pair of outer plates Since they move relative to each other with the intermediate plate sandwiched between the plates, the bolts are twisted when they are slid with the axial force or tightening force of the bolt between the pair of outer plates. Can be prevented. For this reason, the outer plate and the middle plate can be smoothly moved relative to each other, and as a result, the excellent effect of effectively exhibiting the vibration damping function can be achieved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing an embodiment of a vibration damping structure for a bolt joint according to the present invention.
FIG. 2 is a plan view of a main part showing an embodiment of a vibration damping structure for a bolt joint according to the present invention.
FIG. 3 is a cross-sectional view of a main part showing another embodiment of a vibration damping structure for a bolt joint according to the present invention.
FIG. 4 is a plan view of a main part showing another embodiment of a vibration damping structure for a bolt joint according to the present invention.
FIG. 5 is a spring characteristic diagram of an urging means used in another embodiment of the vibration damping structure for a bolt joint according to the present invention.
FIG. 6 is a cross-sectional view of a main part showing still another embodiment of a vibration damping structure for a bolt joint according to the present invention.
FIG. 7 is a front view showing an example in which the vibration suppression structure for a bolt joint portion according to the present invention is applied to a joint portion between a steel column and a steel beam.
8 is a cross-sectional view showing a main part of FIG.
FIG. 9 is a front view showing an example in which the vibration damping structure of the bolt joint portion according to the present invention is applied in the middle of a parted brace.
10 is a side view of FIG. 9. FIG.
FIG. 11 is a cross-sectional view showing a conventional bolt joint.
[Explanation of symbols]
8 Friction damper
10, 12 Outer plate (first pressure contact plate)
14 Middle plate (second pressure plate)
16 High strength bolt
18 nuts
20 Friction damper
21 Groove (concave)
22 Friction plate
30 Disc spring (biasing means)
32, 32a Large diameter washer (tightening part)
52 Steel Column
54 Steel beam

Claims

互いに接合しようとする２つの鉄骨部材のうち、一方の鉄骨部材から第１圧接板を、かつ、他方の鉄骨部材から第２圧接板をそれぞれ一体に突設し、これら第１，第２圧接板を互いに重合するとともに、両圧接板間に相対移動を可能にしてボルト軸力を付加し、両圧接板間に入力される所定値以上の振動変位力により、これら両者の相対移動が許容され、このときに発生する摩擦抵抗力によって、上記２つの鉄骨部材間を制振するようにしたボルト接合部の制振構造において、
上記第１圧接板と上記第２圧接板との間に、摩擦板が介在されており、
前記摩擦板の摩擦抵抗力発生面に溝が設けられており、
前記溝は、該溝内に取り込まれた摩耗粉が自重で落下排出されるように、鉛直方向に貫通して形成されていることを特徴とするボルト接合部の制振構造。Of the two steel members to be joined to each other, the first pressure plate is integrally projected from one steel member and the second pressure plate is integrally projected from the other steel member. And the bolt axial force is applied by allowing relative movement between the two pressure plates, and the relative displacement between the two is allowed by the vibration displacement force of a predetermined value or more input between the two pressure plates, In the vibration suppression structure of the bolt joint that is configured to suppress vibration between the two steel members by the frictional resistance generated at this time,
A friction plate is interposed between the first pressure contact plate and the second pressure contact plate ,
A groove is provided on the frictional resistance generating surface of the friction plate,
The damping structure for a bolt joint , wherein the groove is formed so as to penetrate in the vertical direction so that the wear powder taken into the groove is dropped and discharged by its own weight .

上記第１圧接板と上記第２圧接板との重合部分に上記ボルト軸力を付加する経路に、ボルトの軸方向変位に対して弾発力の変動が略一定となる非線形ばね領域を備えた付勢手段を介在し、該ボルトに所定の軸力を発生させた状態で、該付勢手段が上記非線形ばね領域内でたわみ変形するように設定したことを特徴とする請求項１に記載のボルト接合部の制振構造。 A path for applying the bolt axial force to the overlapping portion of the first pressure contact plate and the second pressure contact plate is provided with a non-linear spring region in which the variation in elastic force is substantially constant with respect to the axial displacement of the bolt. 2. The biasing means is set so as to bend and deform within the non-linear spring region in a state where a predetermined axial force is generated on the bolt via the biasing means. Damping structure for bolted joints.

上記第１圧接板をボルト軸力の作用方向に対峙する一対の外板で形成するとともに、上記第２圧接板を上記一対の外板間に挟み込まれる中板で形成し、該中板のボルト挿通孔を長孔としたことを特徴とする請求項１または２に記載のボルト接合部の制振構造。 The first pressure contact plate is formed by a pair of outer plates facing each other in the direction in which the bolt axial force acts, and the second pressure contact plate is formed by an intermediate plate sandwiched between the pair of outer plates, and the bolt of the intermediate plate The damping structure for a bolt joint according to claim 1 or 2, wherein the insertion hole is a long hole.