JP3900057B2

JP3900057B2 - Liquid filled vibration isolator

Info

Publication number: JP3900057B2
Application number: JP2002283937A
Authority: JP
Inventors: 高伸南野
Original assignee: Sumitomo Riko Co Ltd
Current assignee: Sumitomo Riko Co Ltd
Priority date: 2002-09-27
Filing date: 2002-09-27
Publication date: 2007-04-04
Anticipated expiration: 2022-09-27
Also published as: JP2004116731A

Description

【０００１】
【発明の属する技術分野】
本発明は、車両のエンジンマウント等に用いられる液体封入式防振装置に関する。
【０００２】
【従来の技術】
従来、この種の液体封入式防振装置は、例えば特許文献１，２等に示すように、取付金具と、これに離間して配置された筒状金具と、取付金具と筒状金具の一端間を弾性的に連結するゴム弾性体部と、筒状金具の他端側に圧入固定されたオリフィス部材及びダイヤフラム部材とを設け、ゴム弾性体部とオリフィス部材とに囲まれた空間内が液体の封入された受圧室（主液室）になっており、オリフィス部材とダイヤフラム部材との間が平衡室（副液室）になっている。しかし、この液体封入式防振装置は、筒状金具の他端側にオリフィス部材及びダイヤフラム部材とを直列に配置しているため、軸方向の長さが長くなり、そのため装置の占有スペースが大きくなるという問題がある。さらに、この液体封入式防振装置は、ダイヤフラム部材を設けることにより部品点数が多くなり、そのため装置の重量が重くなると共に装置コストが高価になるという問題がある。
【０００３】
これに対する液体封入式防振装置として、特許文献３に示すように、第１取付部材を、略カップ形状の第２取付部材の開口部側に離隔配置すると共に、第１及び第２取付部材を本体ゴム弾性体で連結させて第２取付部材の開口部を流体密に覆蓋することにより、本体ゴム弾性体で壁部の一部が構成されて流体が封入された受圧室を第２取付部材内に形成する一方、第１取付部材と第２取付部材の開口周縁部との間に跨って広がるゴム弾性膜を本体ゴム弾性体の外方に離隔して配設し、本体ゴム弾性体を挟んで受圧室と反対側においてゴム弾性膜で壁部の一部が構成されて流体が封入された平衡室を形成すると共に、受圧室と平衡室を互いに連通するオリフィス通路を設けたものが知られている。この防振装置は、本体ゴム弾性体の外周面に円筒形状の外周筒金具を加硫接着させ、外周筒金具に円筒形状のオリフィス部材を外挿状態で組み付けると共に、外周筒金具とオリフィス部材を第２取付部材の筒壁部に内挿配置させて、オリフィス通路を外周筒金具と第２取付部材の筒壁部との間に形成している。一方、外周筒金具における第２取付部材の開口部側の端縁部に径方向外方に広がるフランジ状部を設けて、フランジ状部をオリフィス部材の軸方向端面に重ね合わせ、さらにゴム弾性膜の外周縁部にリング金具を加硫接着させて、リング金具をフランジ状部の軸方向外面に重ね合わせると共に、リング金具を第２取付部材の筒壁部によって嵌着固定している。
【０００４】
【特許文献１】
特開平１１−１９０３８２号公報（第２頁、図１、図８）
【特許文献２】
特開平１０−８９４０１号公報（第１頁、図１、図５）
【特許文献３】
特開２００２−１８１１１７号公報（第２頁、図１）
【０００５】
【発明が解決しようとする課題】
しかし、上記第３特許文献に記載の液体封入式防振装置は、第１取付部材と第２取付部材間にゴム弾性膜（ダイヤフラム部材）を設けなければならないため、外周側の構造が複雑になり、装置の組立作業も複雑で長時間を要するため、組付けコストが高価であった。また、ゴム弾性膜が必要なため部品点数も多くなり、そのために、防振装置のコストが高くなると共にその重量が重くなるという問題もある。
【０００６】
本発明は、上記した問題を解決しようとするもので、ダイヤフラム部材をなくすことによる組み付け作業の簡易さとコストの低減が可能で、かつ軸方向の占有スペースを短縮できると共に軽量化が可能な液体封入式防振装置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】
上記目的を達成するために、上記請求項１に係る発明の構成上の特徴は、取付部を有する取付金具と、取付金具から離間して配設された大径の中心穴を有する略板状の中間金具と、取付金具と中間金具との間を弾性的に連結して、中間金具の中心穴を閉塞すると共に中間金具の両面側に同軸状に延びるゴム弾性体部と、有底筒状であって、中間金具の取付部に対する反対側にてゴム弾性体部から離間した状態でゴム弾性体部に被せられると共にその開口端にて中間金具に固定された第２取付金具と、第２取付金具の底板部側に配設されて第２取付金具の内周面との間に周方向に沿ってオリフィス通路を形成すると共にゴム弾性体部に密着してゴム弾性体部との間に液体が満たされた受圧室を形成するオリフィス部材と、オリフィス部材と第２取付金具とゴム弾性体部及び中間金具とに囲まれて、オリフィス通路を通して受圧室に連通しており、オリフィス部材側の一部が液体で満たされると共にその他の部分が空気で満たされた空間部となっている筒状の平衡室とを設け、中間金具が、中心穴の周縁にて第２取付金具側に突出する環状の突出筒部を設けており、突出筒部にてゴム弾性体部の外周部にゴム弾性体部を圧縮した状態でかつ非接着で固定されており、さらに突出筒部の先端とオリフィス部材との間にゴム弾性体部の端部が介在すると共に突出筒部とオリフィス部材とにより液密状態で挟持されていることにある。
【０００８】
上記のように構成した請求項１に係る発明においては、取付金具と第２取付金具との間に振動入力が加えられたとき、ゴム弾性体部が弾性変形することにより受圧室内の液圧上昇が生じるが、平衡室に空気で満たされた空間部が設けられていることから、オリフィス通路を通して受圧室と平衡室の内圧差により液体が連通し、液柱共振が生じる。これにより、請求項１の発明においては、振動入力、特に低周波数の例えばエンジンシェイク等の振動を効果的に低減できる。
【０００９】
また、請求項１の発明によれば、空間部を設けた平衡室が、ダイヤフラムの機能も果たすようになっているため、ダイヤフラム部材を省くことができる。その結果、防振装置の部品点数を減らすことができ、部材コストを低減することができると共に装置の重量を低減することができる。また、軸方向の長さを短くすることができるため、防振装置の軸方向の占有スペースが削減される。また、この防振装置は、組立てにおいて金具の加締めを行う必要がないので、組立て作業が簡易にされると共に、液体封入も空中で簡易に行うことができ、液体封入装置が不要になる。
【００１０】
また、請求項１の発明においては、中間金具が、中心穴の周縁にて第２取付金具側に突出する環状の突出筒部を設けており、突出筒部にてゴム弾性体部の外周部にゴム弾性体部を圧縮した状態で固定されることにより、非接着でもゴム弾性体部に強固に固定される。さらに、突出筒部の先端とオリフィス部材との間にゴム弾性体部の端部が介在して突出筒部とオリフィス部材とにより強固に挟持されることにより、両者間に液密状態が保たれる。
【００１１】
また、上記請求項２に係る発明の構成上の特徴は、前記請求項１に記載の液体封入式防振装置において、受圧室に接する底部側に、受圧室と外部とを仕切るゴム弾性体製の可動膜を設けたことにある。このように、底部側に受圧室に接するとともに外部とを仕切る可動膜を設けたことにより、振動入力を受けたときの液体の移動に伴って、可動膜が振動させられる。このような可動膜の振動により、上記オリフィス通路における液体の循環による液柱共振作用により減衰される低周波数の振動に対して、さらに高い周波数域の振動例えば車両のアイドル振動や低速こもり音等を低減させることができる。
【００１２】
また、上記請求項３に係る発明の構成上の特徴は、前記請求項１又は２に記載の液体封入式防振装置において、取付金具が長尺部を有しており、長尺部が中心穴に対して同軸状に配置されており、かつ長尺部の少なくとも一部が突出筒部内に挿入配置されていることにある。このように、取付金具の長尺部の少なくとも一部突出筒部内に挿入配置されていることにより、取付金具と突出筒部間に入力される水平方向の振動成分が両者間で適正に受けとめられ、その間に設けられたゴム弾性体部の弾性変形により、水平方向の振動入力が効果的に減衰させられる。
【００１３】
【発明の実施の形態】
以下、本発明の一実施形態を図面を用いて説明する。図１及び図２は、第１実施形態である自動車用エンジンマウントとして使用される液体封入式防振装置（以下、防振装置と記す）を断面図及び平面図により示したものである。
【００１４】
防振装置１０は、上下に離間して配置された取付金具１１及び中間金具２１と、取付金具１１と中間金具２１との間を弾性的に連結するゴム弾性体部１５と、ゴム弾性体部１５に被せられて中間金具２１の下側に固定された第２取付金具２６と、第２取付金具２６の底板部とゴム弾性体部１５下端間に配置固定されたオリフィス部材３１とを備えている。オリフィス部材３１は、第２取付金具２６の内周面に沿って環状のオリフィス通路３５を形成し、ゴム弾性体部１５との間に液体が満たされた受圧室Ｒ１を形成すると共に、オリフィス通路３５の上部に第２取付金具２６と中間金具２１及びゴム弾性体部１５に囲まれた平衡室Ｒ２を形成している。なお、防振装置１０の上下については、図１及び図２の上下に合せるものとする。
【００１５】
取付金具１１は、長尺部である縦長の厚板製の板部１２と、板部１２の上端部に板厚方向に貫通して一体で固定された取付部である円筒形のパイプ製の円筒金具１３とを設けている。板部１２は、幅方向中間を中心とした対称形状であり、上端側が略長方形になっており、長方形状の下端が幅の狭められた段部１２ａになっており、さらに段部１２ａの下側が下端に向けて幅が狭くなるように傾斜した台形状になっている。板部１２は、上端側長方形部分の中心に厚さ方向に貫通した貫通穴１２ｂを設けており、貫通穴１２ｂには円筒金具１３が圧入により挿通固定されている。
【００１６】
ゴム弾性体部１５は、取付金具１１の外周側に加硫接着により形成されており、取付金具１１の段部１２ａに対応する部分を境界として、上側部１６と下側部１８に分けられており、両者の境界が薄肉の連結部１７になっている。上側部１６は、板部１２の長方形部分を囲むと共に、円筒金具１３外周の軸方向両端近傍までの範囲を囲んで配設されている。下側部１８は、上下が略平面になった円柱形状であって、板部１２の下端よりわずかに下側まで延設されている。すなわち、板部１２は、ゴム弾性体部１５内に埋設されている。下側部１８は、その外周面において上下端から軸方向の所定長さ部分が径方向にわずかに突出した環状の上及び下環状突部１８ａ，１８ｂになっており、上及び下環状突部１８ａ，１８ｂの間が、軸心方向に凹んだ中間凹部１９になっている。連結部１７は、幅方向の凹側で凹むと共に、円筒金具１３の長手方向においてもその下側で板部１２近傍まで凹んでいる。
【００１７】
中間金具２１は、略円形でその中央に大径の中心穴２３を設けた円板部２２と、中心穴２３の周縁に沿って下方に向けて垂直にわずかに延びた円筒形の突出筒部２４とを設けている。円板部２２は、径方向の対向する２箇所にて径方向外方に突出した半円状の取付片２２ａを有しており、取付片２２ａの中心には取付穴２２ｂを設けている。突出筒部２４は、その長さがゴム弾性体部１５の中間凹部１９の軸方向長さと略同一であり、その内径が中間凹部１９の外径よりわずかに小さくされている。中間金具２１は、突出筒部２４を中間凹部１９の外周部に圧入することにより、突出筒部２４が中間凹部１９から押圧力を受けると共に、突出筒部２４の上下端が上及び下環状突部１８ａ，１８ｂに挟まれた状態となるため、非接着ではあるがゴム弾性体部１５に非常に強固に固定されている。また、ゴム弾性体部１５に固定された取付金具１１の下端は、突出筒部２４の下端よりわずかに下方に配置されている。
【００１８】
第２取付金具２６は、円筒形の筒部２７と、筒部２７の下端を塞ぐ底板部２８と、筒部２７の上端にて径方向外方にわずかに延びた環状のフランジ部２９とを一体で設けた容器形状の金具である。筒部２７の内径は、中間金具２１の突出筒部２４及びゴム弾性体部１５の下環状突部１８ｂの外径より大きく、両者間に所定幅の筒状の隙間が設けられている。また、筒部２７の軸方向長さは、突出筒部２４と下環状突部１８ｂとを合せた軸方向長さより長く、底板部２８とゴム弾性体部１５の下端との間に隙間を設けている。フランジ部２９の外径は、中間金具２１の取付片２２ａを除いた部分の外径と略同一である。さらに、第２取付金具２６は、図３に示すように、周方向の１箇所にて、筒部２７下端側と底板部２８とに跨って軸方向及び径方向に略直方体形状に凹んだ係合凹部２６ａを設けている。
【００１９】
第２取付金具２６の内部には、オリフィス部材３１が底板部２８とゴム弾性体部１５の下端面に挟まれて配置されている。オリフィス部材３１は、図３に示すように、樹脂成形あるいは金属板加工により一体で形成された偏平な円形の容器であって、底の浅い容器部３２と、容器部３２の開口端から径方向外方に延びた円環状のフランジ部３３とを設けている。容器部３２は、底板３２ａと、底板３２ａから開口端に向けてわずかに傾斜して拡径された側壁部３２ｂとを有しており、開口端の外径が中間金具２１の突出筒部２４の内径より小さくなっている。また、側壁部３２ｂの高さは、上記底板部２８とゴム弾性体部１５の下端間の隙間よりわずかに大きくなっている。さらに、フランジ部３３の外径は、筒部２７の内径と同一にされている。オリフィス部材３１は、側壁部３２ｂの周方向の一部に第１開口部３４ａを設けており、またフランジ部３３の周方向の第１開口部３４ａと中心角で略４５°をなす位置に第２開口部３４ｂを設けている。
【００２０】
第２取付金具２６は、中間金具２１の円板部２２の下面側にて中心穴２３を囲んでフランジ部２９が重ね合せれて、溶接により円板部２２に固定されている。ここで、オリフィス部材３１は、上記第１開口部３４ａ位置と第２開口部３４ｂ位置とが、第２取付金具２６の上記係合凹部２６ａを鋭角で挟んだ位置に合せて配設されており、これにより後述するオリフィス通路３５が所望長さに確保される。また、オリフィス部材３１は、フランジ部３３がゴム弾性体部１５の下環状突部１８ｂに圧接されており、中間金具２１の突出筒部２４とによって、下環状突部１８ｂを強固に挟持しており、下環状突部１８ｂに対して液密状態で接触している。これにより、オリフィス部材３１は、側壁部３２ｂ外周面及びフランジ部３３の下側面とにより第２取付金具２６内壁を挟んで、環状のオリフィス通路３５を形成している。
【００２１】
また、オリフィス部材３１の容器部３２とゴム弾性体部１５下端との間の空間は、液体で満たされた受圧室Ｒ１に形成されている。受圧室Ｒ１には、オリフィス部材３１の第１開口部３４ａが開口している。さらに、第２取付金具２６の内周面と、中間金具２１及びゴム弾性体部１５の下環状突部１８ｂの外側面とによって挟まれた円環状の空間部分が、オリフィス部材３１のフランジ部３３に仕切られて、平衡室Ｒ２にされている。平衡室Ｒ２は、下側半分程度が液体で満たされており、上側半分が空気で満たされた空気部Ｋになっている。また、オリフィス部材３１のフランジ部３３に設けた第２開口部３４ｂは、平衡室Ｒ２に開口している。
【００２２】
中間金具２１の上面側には、ストッパ金具３６が被せられている。ストッパ金具３６は、長尺状の金属板を折り曲げて形成されたもので、水平板部３７と、その長手方向両端で下方に同一角度でわずかに広げた状態に曲げられた一対の側板部３８と、各側板部３８から外方にかつ水平板部３７に平行に延びた一対の取付板部３９とを一体で備えており、長手方向長さが中間金具２１の取付片２２ａを含めた長さと同一長さにされている。水平板部３７の長手方向長さは、第２取付金具２６の筒部２７外径と略同一であり、側板部３８の下端間の長さは、第２取付金具２６のフランジ部２９の外径長さと略同一になっている。取付板部３９には中間金具２１の取付穴２２ｂに合せて取付穴３９ａが設けられている。ストッパ金具３６は、中間金具２１の取付片２２ａ上側面に取付板部３９を重ね合せて配設されており、取付穴２２ｂに取付穴３９ａを重ね合わせてボルトナット等により固定して取り付けることができる。また、ストッパ金具３６の水平板部３７は、ゴム弾性体部１５の上側部１６の上面との間にわずかの隙間を設けている。
【００２３】
上記防振装置１０の製造については、まず取付金具１１を、所定の成形金型（図示しない）に装着し、ゴム弾性体材料を注入して加硫成形を行うことにより、ゴム弾性体部１５が取付金具１１に一体で接着形成される。つぎに、オリフィス部材３１が装着された第２取付金具２６の内部に所定量の液体が収容され、この状態で第２取付金具２６が、中間金具２１が圧入により固定されたゴム弾性体部１５に、中間金具２１の裏面側から同軸状に被せられる。そして、フランジ部２９が、中間金具２１に同軸状態で溶接等により固定される。さらに、中間金具２１の上面にストッパ部材３６を中間金具２１から突出した円筒金具１３を包んだゴム弾性体部１５側に被せて、中間金具２１の取付片２２ａに固定することにより、防振装置１０が得られる。なお、受圧室Ｒ１及び平衡室Ｒ２内に封入される液体としては、非圧縮性液体が封入されており、例えば水やアルキレングリコール、ポリアルキレングリコール、シリコーン油等が何れも採用可能であり、特に流体の共振作用に基づく防振効果を有効に得るためには、粘度が０．１Ｐａ・ｓ以下の低粘性液体が好適に採用される。
【００２４】
上記のように形成された防振装置１０の車両への組付けは、円筒金具１３がエンジン側ブラケットに固定され、中間金具２１及びストッパ金具３６がの取付穴２２ｂ，３９ａを介してボルト等による締付けによりにて車体側ブラケットに固定される。ただし、場合によっては、逆に円筒金具１３が車体側ブラケットに固定され、中間金具２１及びストッパ金具３６がエンジン側ブラケットに固定されることも行われる。
【００２５】
上記実施形態においては、防振装置１０の取付金具１１と第２取付金具２６との間に上下方向の振動入力が加えられたとき、ゴム弾性体部１５が弾性変形することで、受圧室Ｒ１内で液圧上昇が生じるが、平衡室Ｒ２内に圧力緩衝を行う空気で満たされた空間部Ｋが設けられていることから、オリフィス通路３５を通して受圧室Ｒ１と平衡室Ｒ２に生じた内圧差により、液体が連通し、液柱共振が生じる。これにより、防振装置１０は振動入力を低減できる。特に、オリフィス通路３５の長さを適正に調整することにより、特に低周波数の例えばエンジンシェイク等の振動に対して効果的に低減できる。また、車体側から過大な振動入力が加えられたり、車両の発進時や急加減速時にエンジンの動きが大きくなったりすると、ゴム弾性体部１５の上側部１６が、ストッパ部材３６の水平板部３７に当接することによって、エンジン側と車体側の過大な相対変位が抑えられる。
【００２６】
また、防振装置１０は、空間部Ｋを設けた平衡室Ｒ２が、ダイヤフラムの機能を果たすようになっているため、ダイヤフラム部材が省かれている。そのため、防振装置１０の部品点数が減らされ、その結果、防振装置１０において、部材コストを低減することができると共に装置の重量が低減される。また、ダイヤフラム部材が省かれることにより、防振装置１０の軸方向の長さが短くされるため、防振装置１０の軸方向の占有スペースが縮小される。また、防振装置１０は、組立てにおいて金具の加締めを行う必要がないので、組立てが簡易にされ組み立てコストが削減される。さらに、防振装置１０の液体封入も空中で簡易に行うことができ、液体封入のための装置が不要になるため、液体封入のコストも削減される。
【００２７】
なお、防振装置１０の車体側への取付については、上記実施形態に代えて、図４に示すように、第２取付金具２６の筒部２７に縦長の取付ブラケット４１を固定し、この取付ブラケット４１によって車体側ブラケットに固定してもよい。取付ブラケット４１は、縦長でＬ字形状の本体４２と、その側面に取り付けられた補強用のリブ４３とを設けており、本体４２の上端側で筒部２７に固定されており、底板に設けた取付穴４２ａを介してボルト等により車体側ブラケットに固定される。この場合、中間金具２１及びストッパ金具３６は、取付穴２２ｂ，３９ａを介してボルト及びナット４４により固定されている。特に、この取付形態は、エンジン側部材と車体側ブラケットとの距離が大きく離れている場合に有効である。
【００２８】
つぎに、第２の実施形態について説明する。
第２の実施形態の防振装置１０Ａは、図５に示すように、第２取付金具２６Ａ及びオリフィス部材３１Ａが変更されており、その底板部にゴム弾性体製で薄肉の可動膜４６を設けたものである。第２取付金具２６Ａは、その底板部２８Ａの中心に取付穴２８ａを設けると共に、その周縁部に沿って所定幅で外側にわずかに突出した取付凸部２８ｂを設けている。オリフィス部材３１Ａは、容器部３２Ａの底板部３２Ｂの中心に上記取付穴２８ａと同一径の取付穴３２Ｃを設けると共にその周縁部に沿って、所定幅で内側にわずかに突出した取付凸部３２Ｄを設けている。そして、取付凸部２８ｂと取付凸部３２Ｄの間に、可動膜４６が圧縮されて挟まれるか、もしくは接着剤にて固定されている。可動膜４６は、受圧室Ｒ１に接すると共に、防振装置１０Ａの内部と外部とを仕切っている。その他の構成については、上記第１実施形態に示した防振装置と同一である。
【００２９】
上記のように構成した第２実施形態においては、上記第１実施形態と同様の効果が得られると共に、このように、底板部２８Ａ，３２Ｂ側に受圧室Ｒ１に接するとともに外部とを仕切る可動膜４６を設けたことにより、防振装置１０Ａが上下方向の振動入力を受けたときに、受圧室Ｒ１内の液体が圧縮を受けることに伴って、可動膜４６が振動する。このような可動膜４６の振動により、上記オリフィス通路３５における液体の循環による液柱共振作用により減衰される低周波数の振動に対して、さらに高い周波数域の振動例えば車両のアイドル振動や低速こもり音等を減衰させることができる。
【００３０】
なお、本発明の防振装置の具体的外形等については、上記実施形態に示したものに限られるものではない。例えば、取付金具については、平坦な板部とすることに限らず、棒状、ブロック状であってもよい。また、取付金具は、水平方向の振動減衰効果が損なわれるが、中間金具の突出筒部内に挿入されていないような配置であってもよい。また、取付金具の取付部については、円筒金具に限らず、取付金具に設けた取付穴にボルト等の取付具を組み合わせることによる取付部とすることもできる。また、中間金具については、突出筒部を設けない形状とすることも可能である。オリフィス部材についても、部材の軽量化のために、底板の一部を除くこともできる。また、可動膜については、オリフィス部材の底板、あるいは第２取付金具の底板部のいずれかに固定されるものであってもよい。その他、上記実施形態に示したものは一例であり、本発明の主旨を逸脱しない範囲で、種々変更して実施することが可能である。
【００３１】
【発明の効果】
上記請求項１の発明によれば、防振装置側面側の平衡室内に設けた空間部が、ダイヤフラムの機能を果たすようになっているため、ダイヤフラム部材を省くことができる。その結果、請求項１の発明においては、部品点数を減らすことができるため、部材コストを低減できると共に装置の重量を低減することができる。また、ダイヤフラム部材を省けることにより装置の軸方向長さを短くすることができるため、装置の軸方向の占有スペースが削減される。また、この防振装置は、金具の加締めを行う必要がないので、組立てが簡易にされると共に、液体封入も空中で簡易に行うことができ液体封入装置が不要になるため、組立てのコストが大幅に削減される。また、中間金具が、突出筒部にてゴム弾性体部の外周部にゴム弾性体部を圧縮した状態で固定されることにより、非接着でもゴム弾性体部に強固に固定される。さらに、突出筒部の先端とオリフィス部材との間にゴム弾性体部の端部が介在して突出筒部とオリフィス部材とにより強固に挟持されることにより、両者間に液密状態が確保される。
【００３２】
また、底部側に可動膜を設けたことにより、オリフィス通路における液柱共振作用により振動の低周波成分に対してより高周波数の振動成分を有効に減衰させることができる（請求項２の発明の効果）。また、取付金具の長尺部の少なくとも一部が、突出筒部内に挿入配置されていることにより、この長尺部によって水平方向の振動入力を効果的に減衰させることができる（請求項３の発明の効果）。
【図面の簡単な説明】
【図１】本発明の第１実施形態である液体封入式防振装置を示す図２のＩ−Ｉ線方向の断面図である。
【図２】同防振装置を示す平面図である。
【図３】同防振装置のオリフィス部材装着部分を示す図４のＩＩＩｂ−ＩＩＩｂ線方向及びＩＩＩａ−ＩＩＩａ線方向の断面図である。
【図４】同防振装置の第２取付金具に取付金具を取り付けたものを示す断面図である。
【図５】第２実施形態である液体封入式防振装置を示す断面図である。
【符号の説明】
１０…液体封入式防振装置、１１…取付金具、１２…板部、１３…円筒金具、１５…ゴム弾性体部、１８ａ…上環状突部、１８ｂ…下環状突部、１９…中間凹部、２１…中間金具、２２…円板部、２３…中心穴、２４…突出筒部、２６…第２取付金具、２７…筒部、２８…底板部、２９…フランジ部、３１…オリフィス部材、３２…容器部、３３…フランジ部、３４ａ…第１開口部、３４ｂ…第２開口部、３５…オリフィス通路、３６…ストッパ金具、４１…取付ブラケット、４６…可動膜、Ｋ…空間部、Ｒ１…受圧室、Ｒ２…平衡室。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a liquid filled type vibration isolator used for an engine mount of a vehicle.
[0002]
[Prior art]
  Conventionally, this type of liquid-filled vibration isolator is, for example, as shown in Patent Documents 1 and 2 and the like, a mounting bracket, a cylindrical bracket spaced apart from the mounting bracket, and one end of the mounting bracket and the cylindrical bracket. A rubber elastic body portion that elastically connects between each other, and an orifice member and a diaphragm member that are press-fitted and fixed to the other end of the cylindrical metal fitting are provided, and the space surrounded by the rubber elastic body portion and the orifice member is liquid. The pressure receiving chamber (main liquid chamber) is sealed, and the space between the orifice member and the diaphragm member is an equilibrium chamber (sub liquid chamber). However, since this liquid-filled vibration isolator has an orifice member and a diaphragm member arranged in series on the other end side of the cylindrical metal fitting, the axial length becomes long, and therefore the occupied space of the device is large. There is a problem of becoming. Furthermore, this liquid-filled vibration isolator has a problem that the number of parts is increased by providing a diaphragm member, which increases the weight of the device and increases the cost of the device.
[0003]
  As a liquid-filled vibration isolator for this, as shown in Patent Document 3, the first mounting member is spaced apart from the opening side of the substantially cup-shaped second mounting member, and the first and second mounting members are arranged. By connecting the opening portion of the second mounting member fluid-tightly by connecting with the main rubber elastic body, the pressure-receiving chamber in which a part of the wall portion is configured by the main rubber elastic body and the fluid is sealed is formed in the second mounting member. On the other hand, a rubber elastic film that extends between the first mounting member and the opening peripheral edge of the second mounting member is disposed apart from the main rubber elastic body, A part of the wall portion is formed of a rubber elastic film on the opposite side of the pressure receiving chamber to form an equilibrium chamber filled with fluid, and an orifice passage that communicates the pressure receiving chamber and the equilibrium chamber is known. It has been. In this vibration isolator, a cylindrical outer cylindrical fitting is vulcanized and bonded to the outer peripheral surface of the main rubber elastic body, and a cylindrical orifice member is assembled to the outer cylindrical fitting in an extrapolated state. The orifice passage is formed between the outer peripheral cylindrical fitting and the cylindrical wall portion of the second mounting member by being inserted into the cylindrical wall portion of the second mounting member. On the other hand, a flange-like portion that spreads radially outward is provided at the edge of the second mounting member on the opening side of the outer cylindrical metal fitting, and the flange-like portion is overlapped with the axial end surface of the orifice member, and a rubber elastic film A ring metal fitting is vulcanized and bonded to the outer peripheral edge portion of the ring fitting, and the ring metal fitting is overlapped on the outer surface in the axial direction of the flange-like portion, and the ring metal fitting is fitted and fixed by the cylindrical wall portion of the second mounting member.
[0004]
[Patent Document 1]
          JP-A-11-190382 (2nd page, FIG. 1, FIG. 8)
[Patent Document 2]
          Japanese Patent Laid-Open No. 10-89401 (first page, FIGS. 1 and 5)
[Patent Document 3]
          JP 2002-181117 (second page, FIG. 1)
[0005]
[Problems to be solved by the invention]
  However, in the liquid-filled vibration isolator described in the third patent document, since a rubber elastic film (diaphragm member) must be provided between the first mounting member and the second mounting member, the structure on the outer peripheral side is complicated. Therefore, the assembly work of the apparatus is complicated and requires a long time, so that the assembling cost is expensive. In addition, since a rubber elastic film is required, the number of parts is increased, and thus there is a problem that the cost of the vibration isolator increases and its weight increases.
[0006]
  The present invention is intended to solve the above-described problems, and can eliminate the diaphragm member, simplify the assembly work and reduce the cost, reduce the occupied space in the axial direction, and reduce the weight. Anti-vibrationEquipmentThe purpose is to provide.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, the structural feature of the invention according to claim 1 is a substantially plate-like shape having a mounting bracket having a mounting portion and a large-diameter center hole disposed away from the mounting bracket. The intermediate metal fitting, the mounting metal fitting and the intermediate metal fitting are elastically connected, the center hole of the intermediate metal fitting is closed and the rubber elastic body portion extending coaxially on both sides of the intermediate fitting, and the bottomed cylindrical shape A second mounting bracket that is placed on the rubber elastic body portion in a state of being separated from the rubber elastic body portion on the side opposite to the mounting portion of the intermediate metal fitting and is fixed to the intermediate metal fitting at the opening end thereof; An orifice passage is formed along the circumferential direction between the mounting bracket and the inner peripheral surface of the second mounting bracket, and is in close contact with the rubber elastic body and between the rubber elastic body and the rubber elastic body. An orifice member forming a pressure receiving chamber filled with liquid; an orifice member; A space that is surrounded by a metal fitting, a rubber elastic body part, and an intermediate metal part, communicates with the pressure receiving chamber through an orifice passage, and is filled with a liquid on the orifice member side and filled with air on the other part. And the cylindrical equilibrium chamberThe intermediate metal fitting is provided with an annular protruding cylindrical portion protruding toward the second mounting bracket at the periphery of the center hole, and the rubber elastic body portion is compressed to the outer peripheral portion of the rubber elastic body portion by the protruding cylindrical portion. The rubber elastic body portion is interposed between the tip of the protruding cylindrical portion and the orifice member, and is sandwiched between the protruding cylindrical portion and the orifice member in a liquid-tight state. HaveThere is.
[0008]
  In the invention according to Claim 1 configured as described above, when a vibration input is applied between the mounting bracket and the second mounting bracket, the rubber elastic body portion is elastically deformed to increase the hydraulic pressure in the pressure receiving chamber. However, since the space portion filled with air is provided in the equilibrium chamber, the liquid communicates through the orifice passage due to the internal pressure difference between the pressure receiving chamber and the equilibrium chamber, and liquid column resonance occurs. Thus, in the first aspect of the invention, vibration input, particularly low frequency vibration such as engine shake can be effectively reduced.
[0009]
  According to the first aspect of the present invention, since the equilibrium chamber provided with the space portion also functions as a diaphragm, the diaphragm member can be omitted. As a result, the number of parts of the vibration isolator can be reduced, the member cost can be reduced, and the weight of the apparatus can be reduced. Moreover, since the axial length can be shortened, the axial occupation space of the vibration isolator is reduced. In addition, since the vibration isolator does not require caulking of the metal fittings during assembly, the assembling work is simplified, and the liquid filling can be easily performed in the air, so that the liquid filling apparatus becomes unnecessary.
[0010]
  In the first aspect of the invention, the intermediate fitting is provided with an annular protruding cylindrical portion protruding toward the second mounting bracket at the periphery of the center hole, and the outer peripheral portion of the rubber elastic body portion at the protruding cylindrical portion. By fixing the rubber elastic body portion in a compressed state, the rubber elastic body portion is firmly fixed to the rubber elastic body portion even if it is not bonded. Further, the end portion of the rubber elastic body portion is interposed between the tip of the protruding cylindrical portion and the orifice member, and is firmly held between the protruding cylindrical portion and the orifice member, thereby maintaining a liquid-tight state therebetween. Be.
[0011]
  Further, the structural feature of the invention according to claim 2 is that the liquid-filled vibration isolator according to claim 1 is made of a rubber elastic body that partitions the pressure receiving chamber and the outside on the bottom side in contact with the pressure receiving chamber. The movable film is provided. Thus, by providing the movable film which contacts the pressure receiving chamber and separates the outside from the bottom side, the movable film is vibrated with the movement of the liquid when receiving the vibration input. Due to such vibration of the movable membrane, vibrations in a higher frequency range, such as idle vibrations of vehicles and low-speed booming noises, are generated against the low-frequency vibrations damped by the liquid column resonance caused by the circulation of the liquid in the orifice passage. Can be reduced.
[0012]
  Further, the structural feature of the invention according to claim 3 is the liquid-filled vibration isolator according to claim 1 or 2,The mounting bracket has a long portion, the long portion is disposed coaxially with respect to the center hole, and at least a part of the long portion is inserted and disposed in the protruding cylindrical portion. . In this way, by being inserted and disposed in at least a part of the protruding cylindrical portion of the long portion of the mounting bracket, the horizontal vibration component input between the mounting bracket and the protruding cylindrical portion can be properly received between the two. The horizontal vibration input is effectively attenuated by the elastic deformation of the rubber elastic body provided between them..
[0013]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 are a cross-sectional view and a plan view of a liquid-filled vibration isolator (hereinafter referred to as a vibration isolator) used as an automobile engine mount according to a first embodiment..
[0014]
  The vibration isolator 10 includes a mounting bracket 11 and an intermediate bracket 21 that are spaced apart from each other, a rubber elastic body portion 15 that elastically connects the mounting bracket 11 and the intermediate bracket 21, and a rubber elastic body portion. 15 and a second mounting bracket 26 fixed to the lower side of the intermediate bracket 21, and an orifice member 31 disposed and fixed between the bottom plate portion of the second mounting bracket 26 and the lower end of the rubber elastic body portion 15. Yes. The orifice member 31 forms an annular orifice passage 35 along the inner peripheral surface of the second mounting bracket 26, forms a pressure receiving chamber R1 filled with a liquid between the rubber elastic body portion 15, and the orifice passage. An equilibrium chamber R <b> 2 surrounded by the second mounting bracket 26, the intermediate bracket 21, and the rubber elastic body portion 15 is formed in the upper portion of 35. In addition, about the upper and lower sides of the vibration isolator 10, it shall match with the upper and lower sides of FIG.1 and FIG.2.
[0015]
  The mounting bracket 11 is made of a long and long plate portion 12 made of a thick plate, and a cylindrical pipe that is an attachment portion that penetrates the upper end portion of the plate portion 12 in the plate thickness direction and is integrally fixed. A cylindrical fitting 13 is provided. The plate portion 12 has a symmetrical shape centering on the middle in the width direction, the upper end side is substantially rectangular, the lower end of the rectangular shape is a stepped portion 12a having a narrowed width, and further below the stepped portion 12a. It has a trapezoidal shape that is inclined so that the width becomes narrower toward the lower end. The plate portion 12 is provided with a through hole 12b penetrating in the thickness direction at the center of the upper end side rectangular portion, and a cylindrical fitting 13 is inserted and fixed to the through hole 12b by press fitting.
[0016]
  The rubber elastic body portion 15 is formed by vulcanization adhesion on the outer peripheral side of the mounting bracket 11 and is divided into an upper portion 16 and a lower portion 18 with a portion corresponding to the stepped portion 12a of the mounting bracket 11 as a boundary. The boundary between the two is a thin connecting portion 17. The upper portion 16 surrounds the rectangular portion of the plate portion 12 and is disposed so as to surround a range up to the vicinity of both ends in the axial direction of the outer periphery of the cylindrical metal fitting 13. The lower side portion 18 has a cylindrical shape whose upper and lower sides are substantially flat, and extends slightly below the lower end of the plate portion 12. That is, the plate part 12 is embedded in the rubber elastic body part 15. The lower side portion 18 has annular upper and lower annular protrusions 18a and 18b whose predetermined length portions in the axial direction slightly protrude in the radial direction from the upper and lower ends on the outer peripheral surface thereof, and the upper and lower annular protrusions. Between 18a and 18b is an intermediate recess 19 that is recessed in the axial direction. The connecting portion 17 is recessed on the concave side in the width direction, and is recessed to the vicinity of the plate portion 12 on the lower side in the longitudinal direction of the cylindrical metal fitting 13.
[0017]
  The intermediate fitting 21 has a substantially circular circular plate portion 22 having a large-diameter center hole 23 at the center thereof, and a cylindrical projecting cylinder portion slightly extending vertically downward along the periphery of the center hole 23. 24. The disc part 22 has a semicircular mounting piece 22a that protrudes radially outward at two opposing positions in the radial direction, and a mounting hole 22b is provided at the center of the mounting piece 22a. The length of the protruding cylindrical portion 24 is substantially the same as the axial length of the intermediate recess 19 of the rubber elastic body portion 15, and the inner diameter thereof is slightly smaller than the outer diameter of the intermediate recess 19. The intermediate fitting 21 presses the protruding cylindrical portion 24 into the outer peripheral portion of the intermediate concave portion 19, so that the protruding cylindrical portion 24 receives a pressing force from the intermediate concave portion 19, and the upper and lower ends of the protruding cylindrical portion 24 have upper and lower annular protrusions. Since it is sandwiched between the portions 18a and 18b, the rubber elastic body portion 15 is very firmly fixed although it is not bonded. In addition, the lower end of the mounting bracket 11 fixed to the rubber elastic body portion 15 is disposed slightly below the lower end of the protruding cylinder portion 24.
[0018]
  The second mounting bracket 26 includes a cylindrical tube portion 27, a bottom plate portion 28 that closes the lower end of the tube portion 27, and an annular flange portion 29 that slightly extends radially outward at the upper end of the tube portion 27. It is a container-shaped metal fitting provided integrally. The inner diameter of the cylindrical portion 27 is larger than the outer diameter of the protruding cylindrical portion 24 of the intermediate fitting 21 and the lower annular protrusion 18b of the rubber elastic body portion 15, and a cylindrical gap having a predetermined width is provided therebetween. The axial length of the cylindrical portion 27 is longer than the combined axial length of the protruding cylindrical portion 24 and the lower annular protruding portion 18b, and a gap is provided between the bottom plate portion 28 and the lower end of the rubber elastic body portion 15. ing. The outer diameter of the flange portion 29 is substantially the same as the outer diameter of the portion excluding the attachment piece 22a of the intermediate fitting 21. Further, as shown in FIG. 3, the second mounting bracket 26 is a member that is recessed in a substantially rectangular parallelepiped shape in the axial direction and the radial direction across the lower end side of the cylindrical portion 27 and the bottom plate portion 28 at one place in the circumferential direction. A concavity 26a is provided.
[0019]
  Inside the second mounting bracket 26, the orifice member 31 is disposed between the bottom plate portion 28 and the lower end surface of the rubber elastic body portion 15. As shown in FIG. 3, the orifice member 31 is a flat circular container integrally formed by resin molding or metal plate processing, and has a shallow container part 32 and a radial direction from the opening end of the container part 32. An annular flange portion 33 extending outward is provided. The container part 32 has a bottom plate 32a and a side wall part 32b whose diameter is slightly inclined from the bottom plate 32a toward the opening end, and the outer diameter of the opening end is the protruding cylinder part 24 of the intermediate fitting 21. It is smaller than the inner diameter. Further, the height of the side wall portion 32 b is slightly larger than the gap between the bottom plate portion 28 and the lower end of the rubber elastic body portion 15. Further, the outer diameter of the flange portion 33 is the same as the inner diameter of the cylindrical portion 27. The orifice member 31 is provided with a first opening 34a in a part of the side wall portion 32b in the circumferential direction, and the first opening portion 34a is formed at a position that forms a substantially 45 ° central angle with the circumferential first opening portion 34a of the flange portion 33. Two openings 34b are provided.
[0020]
  The second mounting bracket 26 is fixed to the disc portion 22 by welding by surrounding the center hole 23 on the lower surface side of the disc portion 22 of the intermediate fitting 21 and overlapping the flange portion 29. Here, the orifice member 31 is arranged so that the position of the first opening 34a and the position of the second opening 34b is aligned with the position where the engaging recess 26a of the second mounting bracket 26 is sandwiched at an acute angle. Thereby, an orifice passage 35 described later is secured to a desired length. The orifice member 31 has a flange portion 33 that is pressed against the lower annular protrusion 18 b of the rubber elastic body portion 15, and the lower annular protrusion 18 b is firmly held by the protruding cylindrical portion 24 of the intermediate fitting 21. And is in liquid-tight contact with the lower annular protrusion 18b. Accordingly, the orifice member 31 forms an annular orifice passage 35 with the inner wall of the second mounting bracket 26 sandwiched between the outer peripheral surface of the side wall portion 32b and the lower side surface of the flange portion 33.
[0021]
  A space between the container portion 32 of the orifice member 31 and the lower end of the rubber elastic body portion 15 is formed in a pressure receiving chamber R1 filled with a liquid. A first opening 34a of the orifice member 31 is opened in the pressure receiving chamber R1. Furthermore, an annular space portion sandwiched between the inner peripheral surface of the second mounting bracket 26 and the outer surface of the lower annular projection 18 b of the intermediate bracket 21 and the rubber elastic body portion 15 is a flange portion 33 of the orifice member 31. And is made into an equilibrium chamber R2. The equilibrium chamber R2 is an air portion K in which the lower half is filled with liquid and the upper half is filled with air. Further, the second opening 34b provided in the flange portion 33 of the orifice member 31 opens into the equilibrium chamber R2.
[0022]
  A stopper fitting 36 is put on the upper surface side of the intermediate fitting 21. The stopper fitting 36 is formed by bending a long metal plate, and a horizontal plate portion 37 and a pair of side plate portions 38 bent in a slightly widened state at the same angle downward at both longitudinal ends thereof. And a pair of attachment plate portions 39 extending outwardly from each side plate portion 38 and parallel to the horizontal plate portion 37, and the length in the longitudinal direction including the attachment piece 22 a of the intermediate fitting 21. And the same length. The length in the longitudinal direction of the horizontal plate portion 37 is substantially the same as the outer diameter of the cylindrical portion 27 of the second mounting bracket 26, and the length between the lower ends of the side plate portions 38 is outside the flange portion 29 of the second mounting bracket 26. It is almost the same as the diameter. A mounting hole 39 a is provided in the mounting plate portion 39 so as to match the mounting hole 22 b of the intermediate fitting 21. The stopper fitting 36 is disposed by superimposing an attachment plate 39 on the upper side surface of the attachment piece 22a of the intermediate fitting 21, and the attachment hole 39a is overlaid on the attachment hole 22b and fixed by a bolt nut or the like. it can. Further, a slight gap is provided between the horizontal plate portion 37 of the stopper fitting 36 and the upper surface of the upper portion 16 of the rubber elastic body portion 15.
[0023]
  Regarding the manufacture of the vibration isolator 10, first, the mounting bracket 11 is attached to a predetermined molding die (not shown), and rubber elastic body material is injected to perform vulcanization molding, whereby the rubber elastic body portion 15 is obtained. Are integrally bonded to the mounting bracket 11. Next, a predetermined amount of liquid is accommodated in the second mounting bracket 26 to which the orifice member 31 is mounted, and in this state, the second mounting bracket 26 and the rubber elastic body portion 15 to which the intermediate bracket 21 is fixed by press-fitting. The intermediate metal fitting 21 is covered coaxially from the back side. And the flange part 29 is fixed to the intermediate | middle metal fitting 21 by a coaxial etc. by welding. Further, the stopper member 36 is placed on the upper surface of the intermediate fitting 21 on the rubber elastic body portion 15 side that wraps the cylindrical fitting 13 protruding from the intermediate fitting 21, and is fixed to the attachment piece 22a of the intermediate fitting 21, thereby providing a vibration isolator. 10 is obtained. In addition, as the liquid sealed in the pressure receiving chamber R1 and the equilibrium chamber R2, an incompressible liquid is sealed, and for example, water, alkylene glycol, polyalkylene glycol, silicone oil or the like can be used. In order to effectively obtain the vibration isolation effect based on the resonance action of the fluid, a low viscosity liquid having a viscosity of 0.1 Pa · s or less is preferably employed.
[0024]
  The vibration isolator 10 formed as described above is assembled to the vehicle by fixing the cylindrical fitting 13 to the engine-side bracket and using bolts or the like via the attachment holes 22b and 39a of the intermediate fitting 21 and the stopper fitting 36. It is fixed to the body side bracket by tightening. However, in some cases, the cylindrical fitting 13 is fixed to the vehicle body side bracket, and the intermediate fitting 21 and the stopper fitting 36 are fixed to the engine side bracket.
[0025]
  In the above embodiment, when a vertical vibration input is applied between the mounting bracket 11 and the second mounting bracket 26 of the vibration isolator 10, the rubber elastic body portion 15 is elastically deformed, so that the pressure receiving chamber R1. However, since a space K filled with air for pressure buffering is provided in the equilibrium chamber R2, an internal pressure difference generated in the pressure receiving chamber R1 and the equilibrium chamber R2 through the orifice passage 35. Therefore, the liquid communicates and liquid column resonance occurs. Thereby, the vibration isolator 10 can reduce vibration input. In particular, by appropriately adjusting the length of the orifice passage 35, it is possible to effectively reduce particularly low frequency vibration such as engine shake. Further, when an excessive vibration input is applied from the vehicle body side, or when the movement of the engine increases when the vehicle starts or suddenly accelerates or decelerates, the upper portion 16 of the rubber elastic body portion 15 becomes the horizontal plate portion of the stopper member 36. By abutting on 37, excessive relative displacement between the engine side and the vehicle body side is suppressed.
[0026]
  Further, in the vibration isolator 10, since the equilibrium chamber R2 provided with the space portion K functions as a diaphragm, a diaphragm member is omitted. Therefore, the number of parts of the vibration isolator 10 is reduced. As a result, in the vibration isolator 10, the member cost can be reduced and the weight of the apparatus is reduced. Further, since the diaphragm member is omitted, the axial length of the vibration isolator 10 is shortened, so that the space occupied in the axial direction of the vibration isolator 10 is reduced. Further, since the vibration isolator 10 does not need to be caulked with metal fittings during assembly, the assembly is simplified and the assembly cost is reduced. Furthermore, the liquid filling of the vibration isolator 10 can be easily performed in the air, and the device for filling the liquid becomes unnecessary, so that the cost of filling the liquid is reduced.
[0027]
  For mounting the vibration isolator 10 on the vehicle body side, instead of the above embodiment, as shown in FIG. 4, a vertically long mounting bracket 41 is fixed to the cylindrical portion 27 of the second mounting bracket 26, and this mounting is performed. The bracket 41 may be fixed to the vehicle body side bracket. The mounting bracket 41 is provided with a vertically long and L-shaped main body 42 and reinforcing ribs 43 attached to the side surfaces thereof. The mounting bracket 41 is fixed to the cylindrical portion 27 on the upper end side of the main body 42 and is provided on the bottom plate. It is fixed to the vehicle body side bracket with a bolt or the like through the mounting hole 42a. In this case, the intermediate fitting 21 and the stopper fitting 36 are fixed by bolts and nuts 44 through the mounting holes 22b and 39a. In particular, this attachment form is effective when the distance between the engine side member and the vehicle body side bracket is largely separated.
[0028]
  Next, a second embodiment will be described.
  In the vibration isolator 10A of the second embodiment, as shown in FIG. 5, the second mounting bracket 26A and the orifice member 31A are changed, and a thin movable film 46 made of a rubber elastic body is provided on the bottom plate portion. It is a thing. The second mounting bracket 26A is provided with a mounting hole 28a at the center of the bottom plate portion 28A, and with a mounting protrusion 28b slightly protruding outward with a predetermined width along the peripheral edge. The orifice member 31A is provided with a mounting hole 32C having the same diameter as the mounting hole 28a in the center of the bottom plate portion 32B of the container portion 32A and a mounting protrusion 32D that slightly protrudes inward with a predetermined width along its peripheral edge. Provided. And the movable film | membrane 46 is compressed and pinched | interposed between the attachment convex part 28b and the attachment convex part 32D, or is fixed with the adhesive agent. The movable film 46 is in contact with the pressure receiving chamber R1 and partitions the inside and outside of the vibration isolator 10A. About another structure, it is the same as the vibration isolator shown in the said 1st Embodiment.
[0029]
  In the second embodiment configured as described above, the same effect as in the first embodiment can be obtained, and in this way, the movable film that contacts the pressure receiving chamber R1 on the side of the bottom plate portions 28A and 32B and partitions the outside. By providing 46, when the vibration isolator 10A receives vertical vibration input, the movable film 46 vibrates as the liquid in the pressure receiving chamber R1 is compressed. Due to such vibration of the movable film 46, vibrations in a higher frequency range, such as idle vibrations of a vehicle and low-speed booming noise, are reduced with respect to low-frequency vibrations damped by the liquid column resonance effect caused by the circulation of the liquid in the orifice passage 35. Etc. can be attenuated.
[0030]
  In addition, about the specific external shape etc. of the vibration isolator of this invention, it is not restricted to what was shown in the said embodiment. For example, the mounting bracket is not limited to a flat plate portion, but may be a rod shape or a block shape. Further, the mounting bracket may be arranged so that the vibration damping effect in the horizontal direction is impaired, but is not inserted into the protruding cylindrical portion of the intermediate bracket. Moreover, about the attachment part of an attachment metal fitting, it can also be set as the attachment part by combining attachment tools, such as a volt | bolt, with the attachment hole provided in the attachment metal fittings not only in a cylindrical metal fitting. In addition, the intermediate metal fitting can be formed in a shape that does not include the protruding cylindrical portion. As for the orifice member, a part of the bottom plate can be removed to reduce the weight of the member. The movable film may be fixed to either the bottom plate of the orifice member or the bottom plate portion of the second mounting bracket. In addition, what was shown to the said embodiment is an example, and can be implemented in various changes in the range which does not deviate from the main point of this invention.
[0031]
【The invention's effect】
  According to the first aspect of the present invention, since the space provided in the equilibrium chamber on the side of the vibration isolator side functions as a diaphragm, the diaphragm member can be omitted. As a result, in the invention of claim 1, since the number of parts can be reduced, the member cost can be reduced and the weight of the apparatus can be reduced. Moreover, since the axial length of the apparatus can be shortened by omitting the diaphragm member, the space occupied in the axial direction of the apparatus is reduced. In addition, since the vibration isolator does not require caulking of the metal fittings, the assembling is simplified and the liquid sealing can be easily performed in the air. Is greatly reduced.Further, the intermediate metal fitting is fixed to the rubber elastic body portion even if it is not adhered by fixing the rubber elastic body portion to the outer peripheral portion of the rubber elastic body portion with the protruding cylinder portion in a compressed state. Furthermore, the end of the rubber elastic body portion is interposed between the tip of the protruding cylindrical portion and the orifice member, and is firmly sandwiched between the protruding cylindrical portion and the orifice member, so that a liquid-tight state is secured between the two. Ru.
[0032]
  Also, by providing a movable membrane on the bottom side, the liquid column in the orifice passageresonanceBy the action, the vibration component having a higher frequency can be effectively damped with respect to the low frequency component of the vibration (effect of the invention of claim 2). Also,Since at least a part of the long part of the mounting bracket is inserted and disposed in the protruding cylinder part, the vibration input in the horizontal direction can be effectively damped by the long part (invention of claim 3). effect).
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along the line II of FIG. 2, showing a liquid-filled vibration isolator according to a first embodiment of the present invention.
FIG. 2 is a plan view showing the vibration isolator.
3 is a cross-sectional view taken along the line IIIb-IIIb and the line IIIa-IIIa in FIG. 4 showing the orifice member mounting portion of the vibration isolator.
FIG. 4 is a cross-sectional view showing a mounting bracket attached to a second mounting bracket of the vibration isolator.
FIG. 5 is a cross-sectional view showing a liquid filled type vibration damping device according to a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Liquid enclosure type vibration isolator, 11 ... Mounting bracket, 12 ... Plate part, 13 ... Cylindrical metal fitting, 15 ... Rubber elastic body part, 18a ... Upper annular protrusion, 18b ... Lower annular protrusion, 19 ... Middle recessed part, 21 ... Intermediate metal fitting, 22 ... Disc part, 23 ... Center hole, 24 ... Projection cylinder part, 26 ... Second mounting metal part, 27 ... Cylinder part, 28 ... Bottom plate part, 29 ... Flange part, 31 ... Orifice member, 32 ... container part, 33 ... flange part, 34a ... first opening part, 34b ... second opening part, 35 ... orifice passage, 36 ... stopper metal fitting, 41 ... mounting bracket, 46 ... movable film, K ... space part, R1 ... Pressure receiving chamber, R2 ... equilibrium chamber.

Claims

A mounting bracket having a mounting portion;
A substantially plate-shaped intermediate bracket having a large-diameter center hole disposed away from the mounting bracket;
A rubber elastic body portion that elastically connects between the mounting bracket and the intermediate bracket, closes the central hole of the intermediate bracket, and extends coaxially on both sides of the intermediate bracket;
It has a bottomed cylindrical shape, and is placed on the rubber elastic body portion in a state of being separated from the rubber elastic body portion on the side opposite to the mounting portion of the intermediate metal fitting, and is fixed to the intermediate metal fitting at the opening end thereof. A second mounting bracket,
An orifice passage is formed along the circumferential direction between the second mounting bracket and the inner peripheral surface of the second mounting bracket, and is in close contact with the rubber elastic body portion to provide the rubber elasticity. An orifice member forming a pressure receiving chamber filled with liquid between the body part;
Surrounded by the orifice member, the second mounting bracket, the rubber elastic body portion, and the intermediate bracket, and communicates with the pressure receiving chamber through the orifice passage, and a portion on the orifice member side is filled with liquid. A cylindrical equilibrium chamber whose other part is a space filled with air,
Provided ,
The intermediate fitting is provided with an annular projecting cylindrical portion projecting toward the second mounting bracket at the periphery of the center hole, and the rubber elastic body is provided on the outer peripheral portion of the rubber elastic body portion at the projecting cylindrical portion. And the end of the rubber elastic body is interposed between the tip of the projecting cylinder and the orifice member, and the projecting cylinder and the orifice member A liquid-sealed vibration isolator characterized by being held in a liquid-tight state by

2. The liquid filled type vibration damping device according to claim 1, wherein a movable film made of a rubber elastic body that partitions the pressure receiving chamber and the outside is provided on a bottom side that is in contact with the pressure receiving chamber.

The mounting bracket has a long part, the long part is arranged coaxially with respect to the center hole, and at least a part of the long part is inserted and arranged in the protruding cylinder part. liquid-filled vibration damping device according to claim 1 or 2, characterized in that is.