JP3726530B2

JP3726530B2 - Fluid filled active vibration isolator

Info

Publication number: JP3726530B2
Application number: JP3013399A
Authority: JP
Inventors: 勝久矢野; 勝博後藤; 吉彦萩野
Original assignee: Sumitomo Riko Co Ltd
Current assignee: Sumitomo Riko Co Ltd
Priority date: 1999-02-08
Filing date: 1999-02-08
Publication date: 2005-12-14
Anticipated expiration: 2019-02-08
Also published as: JP2000227136A

Description

【０００１】
【技術分野】
本発明は、非圧縮性流体が封入された受圧室の圧力を制御することにより能動的な防振効果を得ることの出来る流体封入式能動型防振装置に係り、特に受圧室に対してオリフィス通路を通じて連通された平衡室を備え、該オリフィス通路を通じて流動せしめられる流体の流動作用に基づく受動的な防振効果も、併せて得ることの出来る流体封入式能動型防振装置に関するものである。
【０００２】
【背景技術】
従来から、振動伝達系を構成する部材間に介装される防振連結体や防振支持体等の一種として、特開平５−１４９３６９号公報や特開平５−１４９３７２号公報，特開平１０−１８４７６９号公報等に記載されているように、第一の支持部材と第二の支持部材を本体ゴム弾性体で連結せしめて、該本体ゴム弾性体で壁部の一部が構成されて非圧縮性流体が封入された受圧室を形成すると共に、該受圧室の壁部の別の一部を、駆動手段により弾性変形を伴って加振変位せしめられるゴム弾性板等からなる加振部材によって構成し、加振部材を加振変位させて受圧室の圧力を制御することにより能動的な防振効果を得るようにした流体封入式能動型防振装置が知られている。また、このような防振装置においては、壁部の一部が可撓性膜で構成されて非圧縮性流体が封入された平衡室を、受圧室から独立して形成すると共に、それら受圧室と平衡室を連通するオリフィス通路を設けた構造も、好適に採用され得、それによって、オリフィス通路を流動せしめられる流体の共振作用等の流動作用を利用することが出来ることから、かかる流体の流動作用に基づく受動的な防振効果も併せて享受することが可能となる。
【０００３】
ところで、オリフィス通路を通じて流動せしめられる流体の流動作用に基づく受動的な防振効果を有効に得るためには、振動入力時に受圧室と平衡室の圧力差に基づくオリフィス通路を通じての流体流動量を十分に確保する必要がある。
【０００４】
ところが、上述の如き従来構造の能動型防振装置においては、振動入力時に受圧室に圧力変化が生ぜしめられると、かかる圧力の作用によって、受圧室の壁部の一部を構成する加振部材が弾性変形してしまい、この加振部材の弾性変形量に対応する分だけ、受圧室の圧力変化量、ひいては受圧室と平衡室の相対的な圧力変化量が小さくなって、オリフィス通路を流動せしめられる流体量を有効に確保することが難しくなるために、有効な受動的防振効果を得ることが困難であるという問題があった。
【０００５】
【解決課題】
ここにおいて、本発明は、上述の如き事情を背景として為されたものであって、その解決課題とするところは、オリフィス通路を通じての流体流動量が有利に確保され得て、加振部材の加振による受圧室の圧力制御に基づく能動的防振効果と、オリフィス通路を通じての流体流動に基づく受動的防振効果が、共に有効に発揮される、改良された構造の流体封入式能動型防振装置を提供することにある。
【０００６】
【解決手段】
以下、このような課題を解決するために為された本発明の態様を記載する。なお、以下に記載の各態様は、任意の組み合わせで採用可能である。また、本発明の態様乃至は技術的特徴は、以下に記載のものに限定されることなく、明細書全体および図面に記載の発明思想に基づいて認識されるものであることが理解されるべきである。
【０００７】
本発明の第一の態様は、第一の支持部材と第二の支持部材を本体ゴム弾性体で連結せしめて、該本体ゴム弾性体で壁部の一部が構成されて非圧縮性流体が封入された受圧室を形成すると共に、該受圧室の壁部の別の一部を、駆動手段により弾性変形を伴って加振変位せしめられる加振部材によって構成する一方、壁部の一部が可撓性膜で構成されて非圧縮性流体が封入された平衡室を、前記受圧室から独立して形成すると共に、該平衡室を該受圧室に連通するオリフィス通路を設けた流体封入式能動型防振装置において、前記加振部材の前記駆動手段による加振方向に対して直角な方向に広がるプレート部材を設けると共に、該プレート部材を前記駆動手段によって前記加振部材の加振方向一方の側に変位させて、該プレート部材の外周部分を該加振部材の外周支持部に密接させることにより、該プレート部材と該加振部材の間に閉塞領域が形成され得るようにし、該閉塞領域によって該加振部材の変位を規制するようにしたことを、特徴とする。
【０００８】
このような第一の態様に係る流体封入式能動型防振装置においては、プレート部材により、必要に応じて加振部材の変位を規制することが出来ることから、オリフィス通路による防振効果が要求される場合に加振部材の変位を規制することによって、加振部材の変位に起因する受圧室の圧力変動の逃げを防止して、オリフィス通路を通じての流体流動量を十分に確保することが出来るのであり、以て、流体の流動作用に基づく受動的な防振効果を有効に得ることが出来るのである。また、受圧室の能動的防振効果が要求される場合には、プレート部材を加振部材の外周支持部から離間させることにより、駆動手段による加振部材の加振変位が有利に生ぜしめられ得ることとなり、以て、受圧室の圧力制御に基づく能動的な防振効果を有効に得ることが出来るのである。
【０００９】
しかも、プレート部材は、加振部材を加振する駆動手段によって変位駆動されることから、プレート部材の変位のために特別な駆動手段が必要とされることがなく、簡単な構造によって目的とする能動型防振装置が有利に実現され得る。
【００１０】
なお、かかる第一の態様において、駆動手段としては、加振部材を目的とする周波数で加振すると共に、プレート部材に必要な変位ストロークを及ぼし得るものであれば良く、例えば、電磁力を利用した電磁式駆動手段や、負圧等を利用した空気圧式駆動手段等が、好適に採用され得る。また、プレート部材は、加振部材との間に、加振部材の変位を規制し得る閉塞領域を画成するものであれば良く、形状等は特に限定されるものでないが、加振部材との間に閉塞領域を形成することによって加振部材の変位を有利に規制し得るように、金属や樹脂等の剛性材で形成されることが望ましい。
【００１１】
また、本発明の第二の態様は、前記第一の態様に係る流体封入式能動型防振装置において、前記プレート部材が、その中央部分で加振部材に連結されて、該加振部材の加振方向に対して略直角に広がって配設されており、前記閉塞領域を形成しない状態下で、該プレート部材の少なくとも外周部分が、該加振部材から加振方向に離間して位置せしめられることにより、該加振部材の前記駆動手段による加振変位が許容され得るようにされていることを、特徴とする。このような本態様においては、プレート部材が簡単な構造で有利に構成され得る。
【００１２】
また、本発明の第三の態様は、前記第一又は第二の態様に係る流体封入式能動型防振装置において、前記プレート部材が前記受圧室内に配設されており、該プレート部材を前記加振部材の外周支持部へ密接させることによって、かかる受圧室が該プレート部材で流体密に仕切られて、前記閉塞領域に対する前記本体ゴム弾性体の弾性変形に伴う圧力伝達が阻止されることにより、該密閉領域によって該加振部材の変位が規制されるようにしたことを特徴とする。このような本態様においては、受圧室内で、本体ゴム弾性体と加振部材の間がプレート部材によって流体密に仕切られることにより、振動入力時に本体ゴム弾性体の弾性変形に伴って受圧室に圧力変動が生ぜしめられた際にも、その圧力変動が加振部材に及ぼされることがない。それ故、受圧室に有効な圧力変動が生ぜしめられて、オリフィス通路を通じての流体流動量が有利に確保されるのであり、かかる流体の流動作用に基づく受動的な防振効果が効果的に発揮されるのである。なお、能動的防振効果が要求される場合には、プレート部材を加振部材の外周支持部から離間させることにより、本体ゴム弾性体と加振部材によって壁部が協働して構成された一つの受圧室が形成されることから、加振部材の加振変位に基づく受圧室の圧力制御による能動的防振効果を有効に得ることが出来る。
【００１３】
しかも、上記第二の態様や第三の態様においては、加振部材に対してプレート部材を直接に当接させて拘束することなく、閉塞領域を介して加振部材の変位を有利に阻止し得ることから、プレート部材の加振部材への圧接等に起因する耐久性の問題等も、有利に回避され得るのである。
【００１４】
また、本発明の第四の態様は、前記第一乃至第三の何れかの態様に係る流体封入式能動型防振装置において、前記平衡室が前記加振部材を挟んで前記受圧室と反対側に形成されていると共に、前記プレート部材が該平衡室内に配設されており、該プレート部材を前記加振部材の外周支持部へ密接させることによって、該加振部材の前記受圧室とは反対側に前記閉塞領域が形成されて、該閉塞領域に充填された非圧縮性流体によって該加振部材の変位が規制されるようにしたことを、特徴とする。このような本態様においては、加振部材の背後（受圧室と反対側）に、平衡室の一部を利用して密閉された閉塞領域が形成されるのであり、しかも、この閉塞領域に非圧縮性流体が充填されて閉塞領域の容積変化が防止されていることから、かかる閉塞領域に空気等の圧縮性流体を封止した場合に比べて、非圧縮性流体で加振部材の変位が極めて有利に阻止されることとなる。それ故、かかる閉塞領域の形成状態下では、加振部材の変位による受圧室の圧力吸収が防止されて、受圧室に有効な圧力変動が生ぜしめられることにより、オリフィス通路を通じての流体の流動作用に基づく受動的な防振効果が有利に発揮される一方、閉塞領域が形成されていない状態下では、加振部材の変位が許容されて、加振部材の加振変位に基づく受圧室の圧力制御による能動的防振効果を有効に得ることが出来る。
【００１５】
なお、前記第一乃至第四の態様において、プレート部材の外周部分が当接される加振部材の外周支持部は、例えば、加振部材の外周縁部に沿って周方向に形成されて、プレート部材を加振部材側に変位させることによって該外周支持部に密接可能とされる。或いは、加振部材の外周側において加振部材の加振方向に向かって筒状に延び出し、先端部分が内向きのフランジ状に屈曲された密接部材を形成すると共に、この密接部材の内部に収容状態でプレート部材を配設して、該プレート部材を加振部材から離間する方向に変位させることによって、外周支持部としての該密接部材の内向きフランジ状部の内面に密接可能としても良い。
【００１６】
また、本発明の第五の態様は、前記第一乃至第四の何れかの態様に係る流体封入式能動型防振装置において、前記駆動手段による加振力が直接に及ぼされると共に、前記プレート部材が取り付けられる硬質の取付部材と、該取付部材から加振方向に対して略直角に広がって、外周縁部が前記第二の支持部材に固着されることにより、該取付部材を該第二の支持部材に対して弾性的に支持せしめる支持ゴム弾性体とを含んで、前記加振部材を構成したことを、特徴とする。このような本態様においては、取付部材によって、駆動手段による駆動力が、加振部材およびプレート部材に対して有利に伝達されると共に、支持ゴム弾性体によって、駆動手段による加振部材の変位が有利に生ぜしめられ得る。
【００１７】
更にまた、かかる第五の態様において、より好適には、前記プレート部材が、前記硬質の取付部材から加振方向に対して略直角に延び出して広がる構造とされて、該プレート部材の少なくとも外周部分が前記支持ゴム弾性体から加振方向に離間して配設されると共に、該プレート部材の外周部分が、前記加振部材の外周支持部に対して密接せしめられるようにされる。このようなプレート部材を採用すれば、加振部材の外周支持部に対する密接部の周方向長さを有利に確保することが出来ることから、密接部位における応力集中が軽減されると共に、プレート部材が加振部材の外周支持部から離間せしめられた状態下で、それらの対向面間に形成される狭窄領域の大きさを周方向で有利に確保することが可能となり、狭窄領域による流体流通抵抗が軽減されて、加振部材の加振効率や加振制御性の向上が図られ得る。
【００１８】
また、上述の如き各態様に係る流体封入式能動型防振装置においては、加振部材の加振に伴う受圧室内での流体流動が阻害されることなく、加振部材の加振による受圧室の圧力制御が効率的に為され得るように、以下の第六の態様や第七の態様が、好適に採用される。
【００１９】
すなわち、本発明の第六の態様は、前記第一乃至第五の何れかの態様に係る流体封入式能動型防振装置において、前記プレート部材が配設された前記受圧室または前記平衡室において該プレート部材の外周側に形成される環状の狭窄領域の開口面積を、前記加振部材の有効ピストン面積よりも大きく設定したことを、特徴とする。
【００２０】
また、本発明の第七の態様は、前記第一乃至第六の何れかの態様に係る流体封入式能動型防振装置において、前記プレート部材が配設された前記受圧室または前記平衡室において該プレート部材の外周側に形成される環状の狭窄領域が、前記加振部材の固有振動数よりも高周波数域において、流体流動の共振周波数を有していることを、特徴とする。
【００２１】
また、本発明の第八の態様は、前記第一乃至第七の何れかの態様、特に第六又は第七の態様に係る流体封入式防振装置において、前記プレート部材の外径寸法を、前記加振部材の外径寸法よりも大きくして、該プレート部材と前記外周支持部との密接部位を、該加振部材の外周縁部よりも更に外周側に位置して設けたことを、特徴とする。このような本態様においては、前記プレート部材が配設された前記受圧室または前記平衡室において該プレート部材の外周側に形成される環状の狭窄領域の開口面積を大きく設定することが容易となることから、狭窄領域による流体流動抵抗などの悪影響を容易に軽減乃至は回避することが可能となる。
【００２２】
さらに、本発明は、自動車用エンジンマウント等の防振連結体乃至は防振支持体の他、制振対象に取り付けられて振動を低減する制振器にも、適用可能である。具体的には、例えば、前記第一乃至第八の何れかの態様に係る流体封入式能動型防振装置において、第一の支持部材を、振動伝達部材（振動発生部材等）と被振動伝達部材（防振対象部材）の何れか一方に取り付けると共に、第二の支持部材を、それらの他方に取り付けることにより、本発明に従う構造とされたエンジンマウント等の防振連結体が有利に実現され得ることとなり、また、例えば、第一の支持部材と第二の支持部材の何れか一方を防振対象部材に取り付けて、それら第一の取付部材と第二の取付部材の他方を、防振対象部材に対して、本体ゴム弾性体で弾性支持せしめて一つの振動系を構成することにより、制振器が有利に構成され得る。
【００２３】
【発明の実施の形態】
以下、本発明を更に具体的に明らかにするために、本発明の実施形態について、図面を参照しつつ、詳細に説明する。
【００２４】
先ず、図１には、本発明の第一の実施態様としての自動車用のエンジンマウント１０が、示されている。このエンジンマウント１０は、互いに所定距離を隔てて配された第一の支持部材としての第一の支持金具１２と第二の支持部材としての第二の支持金具１４が、本体ゴム弾性体１６によって弾性的に連結されており、第一の支持金具１２がパワーユニット（図示せず）に固着されると共に、第二の支持金具１４がボデー（図示せず）に固着されることにより、パワーユニットをボデーに対して防振支持せしめるようになっている。なお、そのような自動車への装着状態下では、パワーユニットの重量が及ぼされることにより、本体ゴム弾性体１６が圧縮変形して、第一の支持金具１２と第二の支持金具１４が互いに接近方向に所定量だけ相対変位せしめられると共に、防振すべき主たる振動が、第一の支持金具１２と第二の支持金具１４の略対向方向（図中、略上下方向）に入力されることとなる。なお、以下の説明中、上下方向とは、原則として、マウント中心軸方向としての、図１中の上下方向をいう。
【００２５】
より詳細には、第一の支持金具１２は、略円形の平板形状を有しており、マウント中心軸に対して直交する方向に広がって配設されている。また、この第一の支持金具１２の下面中央には、下方に向かって小径化する保持金具１８が固着されており、この保持金具１８の下端部には、マウント軸直角方向に広がる略傘形状の傘金具２０が、ボルト固定されている。更に、保持金具１８の上端部には、第一の支持金具１２を貫通して上方に突出する第一の取付ボルト２２が立設されており、この第一の取付ボルト２２によって、第一の支持金具１２がパワーユニットに固定されるようになっている。
【００２６】
また一方、第二の支持金具１４は、それぞれ大径の略円筒形状を有する上筒金具２４と下筒金具２６から構成されており、それら上下筒金具２４，２６が軸方向に同軸的に重ね合わされ、上筒金具２４の下端開口部に設けられたかしめ部２８が、下筒金具２６の上端開口部に設けられたフランジ部３０にかしめ固定されることによって一体化されている。また、上筒金具２４の上側開口部分は、軸方向所定長さに亘って、開口部側に向かって次第に拡開するテーパ部３２とされており、このテーパ部３２が、第一の支持金具１２に固設された保持金具１８のテーパ状外周面に対して対向せしめられている。更に、下筒金具２６の下側開口部には、軸直角方向外方に広がる固定板部３４が一体形成されており、この固定板部３４が、図示しないボデーの取付面に重ね合わされてボルト固定されることによって、第二の支持金具１４がボデーに取り付けられるようになっている。
【００２７】
そして、第二の支持金具１４の上側開口部側に離間して、第一の支持金具１２が、略同一軸上で対向配置されており、これら第一の支持金具１２と第二の支持金具１４の間に本体ゴム弾性体１６が介装されている。この本体ゴム弾性体１６は、上方に向かって小径化する厚肉の略テーパ付円筒形状を有しており、小径側端面に第一の支持金具１２が重ね合わされて加硫接着されていると共に、中心孔に保持金具１８が貫通配置されて、該保持金具１８の外周面が中心孔の内周面に加硫接着されている。一方、本体ゴム弾性体１６の大径側端部の外周面には、第二の支持金具１４を構成する上筒金具２４のテーパ部３２が加硫接着されている。要するに、本体ゴム弾性体１６は、第一の支持金具１２および保持金具１８と上筒金具２４を備えた一体加硫成形品として形成されている。なお、本体ゴム弾性体１６の筒壁部には、軸方向中間部分において、上方に向かって拡径する薄肉の略テーパ筒状を有する補強金具３６が埋設状態で加硫接着されている。また、このようにして第一の支持金具１２と第二の支持金具１４が本体ゴム弾性体１６で連結されることによって、第二の支持金具１４（上筒金具２４）の上側開口部が、本体ゴム弾性体１６によって流体密に閉塞されている。
【００２８】
さらに、第二の支持金具１４を構成する下筒金具２６の中空内部には、内周面に沿って延びるオリフィス部材３８が配設されている。このオリフィス部材３８は、上方に向かって開口する凹形断面をもって周方向に連続して延びる円環形状の溝金具４０と、該溝金具４０の開口部に重ね合わされて覆蓋する円環板形状の蓋金具４２から構成されている。そして、溝金具４０の開口部が蓋金具４２で覆蓋されることにより、オリフィス部材３８の内部には、周方向に延びる環状のオリフィス通路４６が形成されている。また、これら溝金具４０および蓋金具４２の外周縁部には、それぞれ径方向外方に広がるフランジ状部４４が形成されており、両フランジ状部４４，４４が重ね合わされて、上筒金具２４と下筒金具２６のかしめ部間で一体的に挟持されることにより、第二の支持金具１４に対して固定されている。
【００２９】
また、オリフィス部材３８の中央透孔４８内には、加振部材５０が配設されており、この加振部材５０によって、オリフィス部材３８の中央透孔４８が流体密に閉塞されている。かかる加振部材５０は、オリフィス部材３８の中央透孔４８内の中央部分に配設された、中央透孔４８の孔径よりも小さな外径を有する取付部材としての逆カップ形状の第一の連結金具５２と、この第一の連結金具５２の外周面と溝金具４０の内周面との径方向対向面間に配設された円環板形状の支持ゴム弾性板５４を含んで構成されている。即ち、支持ゴム弾性板５４の内外周面が、第一の連結金具５２の外周面と溝金具４０の内周面にそれぞれ加硫接着されることによって、第一の連結金具５２が、溝金具４０、ひいては第二の支持金具１４にて弾性的に支持されており、支持ゴム弾性体５４の弾性変形に基づいて第一の連結金具５２の変位が許容されるようになっている。
【００３０】
更にまた、第一の連結金具５２の上底部は、支持ゴム弾性体５４よりもマウント軸方向上方に突出せしめられており、この上底部の上面に対して、プレート部材としての金属プレート５６が重ね合わされ、その中央において、リベットやボルト等の固定具５８により、第一の連結金具５２に固着されている。この金属プレート５６は、円形の平板形状を有しており、第一の連結金具５２から軸直角方向外方に突出して広がっていると共に、この第一の連結金具５２から突出して広がった部分が、支持ゴム弾性体５４から上方に離間して、支持ゴム弾性体５４上に翳されるように位置せしめられている。また、金属プレート５６は、その外径寸法が、オリフィス部材３８の中央透孔４８の孔径よりも大きく、且つ第二の支持金具１４の内径よりも十分に小さくされており、金属プレート５６の外周部分が、オリフィス部材３８の上方に離間して配設されている。これにより、オリフィス部材３８の内周縁部が、金属プレート５６の外周部分に対してマウント軸方向で離間して対向位置せしめられていると共に、このオリフィス部材３８の内周縁部において、オリフィス部材３８に向かって上方に突出し、山形断面をもって周方向に連続して延びる環状の緩衝突起６０が、支持ゴム弾性体５４と一体的に形成されている。なお、図示されているように、金属プレート５６は、この緩衝突起６０の先端部に対しても、マウント軸方向で所定距離：Ｌだけ離間して対向位置するように配設されている。
【００３１】
また、加振部材５０でオリフィス部材３８の中央透孔４８が流体密に覆蓋されることにより、第二の支持金具１４の内部には、本体ゴム弾性体１６と加振部材５０の対向面間において、内部に非圧縮性流体が封入された受圧室６２が形成されている。即ち、この受圧室６２は、壁部の一部が、本体ゴム弾性体１６と加振部材５０によって構成されており、振動入力時に、本体ゴム弾性体１６の弾性変形に伴って圧力変化が生ぜしめられるようになっているのである。なお、封入された非圧縮性流体としては、水やアルキレングリコール，ポリアルキレングリコール，シリコーン油等が好適に採用され、特に、流体の流動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以下の低粘性流体が望ましい。
【００３２】
更にまた、この受圧室６２には、第一の支持金具１２によって支持された傘金具２０と、第二の支持金具１４によって変位可能に支持された金属プレート５６が、それぞれマウント軸直角方向に広がる状態で、互いにマウント軸方向で離間位置して配設されている。また、マウント装着状態下では、パワーユニット重量の入力によって第一の支持金具１２と第二の支持金具１４が相対的に接近位置せしめられることにより、傘金具２０が受圧室６２内の略中央に位置せしめられ、以て、傘金具２０の外周面と上筒金具２４の内周面との間に、環状の狭窄流路が形成されるようになっている。
【００３３】
さらに、加振部材５０を挟んで受圧室６２と反対側には、可撓性膜としてのダイヤフラム６４が配設されている。このダイヤフラム６４は、変形容易な薄肉のゴム弾性膜で形成されており、中央部分には、深底の逆カップ形状を有する第二の連結金具６６が加硫接着されていると共に、外周縁部には、略大径円筒形状の取付筒金具６８が加硫接着されている。そして、取付筒金具６８の軸方向上端部に一体形成されたフランジ状部７０が、オリフィス部材３８のフランジ状部４４，４４と共に、上筒金具２４と下筒金具２６のかしめ部間で一体的に挟持されることにより、第二の支持金具１４に対して固定されている。また、第二の連結金具６６は、加振部材５０の第一の連結金具５２に対して圧入固定されて一体的に連結されている。
【００３４】
これにより、加振部材５０を挟んで受圧室６２と反対側には、加振部材５０とダイヤフラム６４の対向面間において、非圧縮性流体が封入された平衡室７２が形成されている。そして、この平衡室７２は、壁部の一部を構成するダイヤフラム６４の容易な変形に基づいて、容積変化が容易に許容されて内圧変動が可及的に軽減乃至は回避されるようになっている。また、受圧室６２と平衡室７２の隔壁部分に配されたオリフィス部材３８において、その内部に形成されたオリフィス通路４６が、連通孔７４，７６を通じて受圧室６２と平衡室７２にそれぞれ連通されており、以て、振動入力時に受圧室６２と平衡室７２の間に惹起される相対的な圧力差に基づいて、受圧室６２と平衡室７２の間で、所定長さのオリフィス通路４６を通じての流体流動が生ぜしめられるようになっている。特に、本実施形態では、オリフィス通路４６を通じて流動せしめられる流体の共振作用に基づいて、シェイク等の低周波振動に対して有効な防振効果（例えば減衰効果）が発揮されるように、受圧室６２および平衡室７２の壁ばね剛性や封入流体の比重等を考慮してオリフィス通路４６の通路長さや断面積が適当に設定されている。
【００３５】
なお、本実施形態では、振動入力時に第一の支持金具１２と第二の支持金具１４が相対変位することに伴い、受圧室６２内で傘金具２０が変位せしめられて、傘金具２０の外周側に形成された前記狭窄流路を通じての流体流動が生ぜしめられることとなる。それ故、この狭窄流路の流路長さや断面積等を適当に調節することによって、オリフィス通路４６による防振効果が発揮される振動よりも高周波数域の振動に対して、狭窄流路を流動せしめられる流体の共振作用に基づく防振効果を得ることが出来るのである。具体的には、例えば、かかる流体の共振作用に基づいてこもり音等の高周波振動に対して有効な防振効果（例えば振動絶縁効果）が発揮されるように、狭窄流路がチューニングされる。
【００３６】
さらに、平衡室７２を画成するダイヤフラム６４の下方には、駆動手段としての電磁式駆動装置８０が配設されており、第二の取付金具１４を構成する下筒金具２６に対してボルト等で固定されている。この電磁式駆動装置８０は、空芯コイル構造のコイル部材８２と、該コイル部材８２の空芯部に挿通配置された磁石部材８４が、軸方向に相対変位可能とされており、コイル部材８２への通電によってコイル部材８２と磁石部材８４の間に生ぜしめられる電磁力に基づいて、軸方向（図中、上下方向）の加振力を、前記加振部材５０に及ぼすようになっている。
【００３７】
より詳細には、コイル部材８２は、同軸上で互いに重ね合わされた第一のコイル８６と第二のコイル８８を備えており、それら両コイル８６，８８の重ね合わせ面間と軸方向両側に、それぞれ、強磁性材からなる複数枚の円環板９０が重ね合わされている。それによって、全体として実質的に一つの空芯構造のコイルが構成されている。そして、コイル８６，８８と複数枚の円環板９０の重ね合わせ体は、大径円筒形状のハウジング金具９２に嵌め込まれて相互に一体的に固着されており、更に、このハウジング金具９２が、円筒形状の支持ケース金具９４に圧入固定されている。かかる支持ケース金具９４は、大径円筒形状を有しており、軸方向下側開口部が薄肉ゴム膜からなるダストシール９６で覆蓋されている一方、軸方向上側開口部に一体形成されたフランジ状部９８において、第二の支持金具１４に重ね合わされてボルト等で固着されている。これにより、コイル部材８２が、支持ケース金具９４を介して、第二の支持金具１４によって固定的に支持されている。
【００３８】
また一方、磁石部材８４は、公知の永久磁石材で形成された円環板形状の磁石１００を備えており、この磁石１００の軸方向両側に、それぞれ強磁性材からなる円環ブロック形状の上下ヨーク１０２，１０４が重ね合わされている。そして、これら磁石１００と上下ヨーク１０２，１０４は、各中心孔に挿通されたロッド１０６に対して固着されることにより、ロッド１０６の軸方向中央部分に固定的に組み付けられている。ここにおいて、磁石１００は、軸方向両側に磁極が設定されており、磁石部材８４が、全体として、軸方向両端部に磁極を有する一つの磁石とされている。また、磁石１００と上下ヨーク１０２，１０４の重ね合わせ体は、コイル部材８２の空芯径よりも僅かに小さな外径寸法とされていると共に、コイル部材８２の空芯部よりも小さな軸方向長さとされており、磁石部材８４が、コイル部材８２の空芯部に対して略同軸的に収容され、軸方向に相対変位可能に配設されている。
【００３９】
また、磁石部材８４のロッド１０６は、コイル部材８２の空芯部から軸方向両側に突出して配設されており、コイル部材８２の軸方向両側の最外部に配設された円環板９０ａ，９０ｂに固着された摺動スリーブ１０８，１１０によって、軸直角方向に位置決めされて軸方向に摺動可能に支持されている。また、ロッド１０６の上端部には、略カップ形状の固着金具１１２がボルト固定されており、この固着金具１１２が、前記加振部材５０の第一の連結金具５２に固着された第二の連結金具６６に圧入固定されることにより、ロッド１０６の先端が、加振部材５０の第一の連結金具５２に固着されている。これにより、第一の連結金具５２を含む加振部材５０が、ロッド１０６を有する磁石部材８４と一体的に変位せしめられるようになっているのであり、加振部材５０が、ロッド１０６の軸方向に安定して変位せしめられるようになっている。なお、磁石部材８４の軸方向変位に対して、ハウジング金具９２内に存在する空気のばね作用が悪影響を及ぼさないように、円環板９０ａには、空気抜き孔１１４が形成されている。
【００４０】
このような構造とされたエンジンマウント１０においては、コイル部材８２のコイル８６，８８に通電すると、コイル部材８２の軸方向両側に磁極が形成されることにより、磁石部材８４に対して磁力による吸引乃至は反発力が及ぼされ、或いはまた、磁石部材８４による磁界中に配されたコイル８６，８８への通電電流に対してローレンツ力が及ぼされ、その結果、コイル部材８２と磁石部材８４の間に、軸方向の相対的な駆動力が及ぼされて、かかる駆動力がロッド１０６を通じて加振部材５０に及ぼされる。そして、ロッド１０６から加振部材５０に駆動力が伝達されることにより、支持ゴム弾性体５４の弾性変形に基づいて、第一の連結金具５２と支持ゴム弾性体５４が、上方または下方に変位せしめられるようになっている。ここにおいて、本実施形態では、給電制御装置１１６によって、コイル部材８２のコイル８６，８８に対してパルス状の駆動電流が給電されるようになっており、かかる給電制御装置１１６でコイル８６，８８への供給電流を制御することによって、加振部材５０の加振変位が制御されるようになっている。
【００４１】
そして、コイル８６，８８に対して、交番電流等を通電して加振部材５０を加振変位させることにより、受圧室６２に対して、加振部材５０の加振周波数と振幅に対応した周波数と圧力の内圧変動が生ぜしめられて、この内圧変動に対応した加振力が、防振対象部材たるボデーに伝達されるようになっている。それ故、点火パルス信号や走行信号等の振動に対応した電気信号を参照信号として採用して、給電制御装置１１６によって防振すべき振動に対応した周波数等でコイル８６，８８への通電制御を行い、例えば、自動車のボデーにおいて防振しようとする主たる振動に対応した周波数と振幅で加振部材５０を加振することにより、防振しようとする振動を打ち消すような加振力を及ぼして相殺的な能動的防振効果を得ることが出来るのであり、或いはまた、防振しようとする振動入力時における受圧室６２の圧力変化を積極的に解消せしめて、エンジンマウント１０のばね定数を０に近づけ、防振しようとする振動を積極的に吸収するような能動的防振効果を得ることが出来るのである。
【００４２】
そこにおいて、加振部材５０を加振した場合には、受圧室６２内において、オリフィス部材４６と金属プレート５６の対向面間に形成された環状の狭窄領域としての隙間１２０を通じて封入流体が流動せしめられることから、この隙間１２０による流体流動の制限作用によって大きな抵抗が発生しないように、かかる隙間１２０を十分に大きく設定することが望ましい。具体的には、下記（１式）および（２式）の少なくとも一方が成立するように、各部材の寸法やばね特性等を設定することが有効である。
【００４３】
Ｄ・Ｌ・π ≧ ｄ²・π ・・・（１式）
但し、Ｄは、環状の隙間１２０の径寸法（隙間１２０を挟んで緩衝突起６０に対向位置する金属プレート５６の外周部分の径寸法）であり、Ｌは、隙間１２０の大きさ（金属プレート５６と緩衝突起６０の対向面間距離）である。また、ｄは、加振部材５０の加振時における有効ピストン径であり、第一の連結金具５２の外径寸法より大きく、オリフィス部材３８の内径寸法より小さい値となる。即ち、この（１式）において、左辺は、環状の隙間１２０の開口面積であり、右辺は、加振部材５０の有効ピストン面積を表す。特に、本実施形態では、金属プレート５６の外径寸法が、加振部材５０の支持ゴム弾性体５４の外径寸法よりも大きく設定されていることから、Ｄ＞２ｄとなって、上記（１式）の条件が有利に実現可能とされる。
【００４４】
ｆ ≧ Ｆ・・・（２式）
但し、ｆは、加振部材５０を加振変位せしめた際に隙間１２０を通じて流動せしめられる流体の共振周波数であり、Ｆは、加振部材５０の固有振動数である。なお、加振部材５０の固有振動数：Ｆの値は、加振部材５０を含む一つの振動系を考えて、支持ゴム弾性体５４等をバネ系として考慮すると共に、第一，第二の連結金具５２，６６の他、金属プレート５６やロッド１０６等もマス系として考慮する必要がある。また、有効な防振効果を得るためには、加振部材５０の固有振動数：Ｆの値を、加振部材５０の加振変位に基づく能動的な防振効果が要求される振動周波数と略同じか、該防振効果が要求される振動周波数よりも高周波域に設定することが望ましい。
【００４５】
さらに、かかるエンジンマウント１０においては、電磁式駆動装置８０におけるロッド１０６の中立位置からの最大駆動ストローク量が、受圧室６２内でマウント軸方向で対向配置された金属プレート５６と緩衝突起６０との対向面間距離：Ｌよりも大きく設定されている。これにより、電磁式駆動装置８０に対して大きな直流駆動電流を給電してロッド１０６を下方に変位させることによって、図中に仮想線で示されているように、加振部材５０の第一の連結金具５２で固定的に支持された金属プレート５６が、マウント軸方向下方に変位し、その外周縁部が、オリフィス部材３８の内周縁部に突設された緩衝突起６０に対して、周方向全周に亘って圧接されるようになっている。
【００４６】
そして、金属プレート５６が、その外周部分の全周に亘って緩衝突起６０に密接されることにより、オリフィス部材３８における中央透孔４８の上側開口部が、金属プレート５６で流体密に閉塞されるようになっている。その結果、加振部材５０の支持ゴム弾性体５４と金属プレート５６の間に、密閉された環状の閉塞領域１１８が形成されるようになっている。換言すれば、金属プレート５６を緩衝突起６０に圧接することにより、受圧室６２が、金属プレート５６を挟んで、本体ゴム弾性体１６側と支持ゴム弾性体５４側とに流体密に二分されるようになっている。それ故、かかる状態下では、振動入力時に本体ゴム弾性体１６の弾性変形に伴って受圧室６２に惹起される圧力変化が、閉塞領域１１８には伝達され得ず、支持ゴム弾性体５４への伝達が回避されるのである。
【００４７】
従って、オリフィス通路４６がチューニングされた低周波振動の入力時には、金属プレート５６を緩衝突起６０に密接させて密閉領域１１８が形成された状態に保持されるように、給電制御装置１１６によるコイル８６，８８への通電を制御することにより、入力振動に伴って受圧室６２に生ぜしめられる圧力の支持ゴム弾性体５４への作用が回避されて、該受圧室６２の圧力変動が支持ゴム弾性体５４の弾性変形によって低減されることなく有効に生ぜしめられ得るのであり、その結果、受圧室６２と平衡室７２の間に大きな圧力差が生ぜしめられて、オリフィス通路４６を通じての流体流動が効率的に大きな流体流量をもって生ぜしめられることから、かかる流体の流動作用に基づく受動的な防振効果がより有効に発揮され得るのである。
【００４８】
一方、オリフィス通路４６のチューニング周波数よりも高周波数域の振動（例えば、アイドリング振動等）の入力時には、コイル８６，８８への直流電流の通電を解除して、金属プレート５６をオリフィス部材３８から離間した中立位置（図１参照）に保持せしめた状態下で、給電制御装置１１６によるコイル８６，８８への通電を制御して防振すべき振動に対応した通電を行って加振部材５０を加振変位させることにより、受圧室６２に圧力変動を生ぜしめて能動的な防振効果を有効に得ることが出来るのである。なお、オリフィス通路３８は、常時、連通状態にあるが、加振部材５０の加振による能動的防振効果が発揮される周波数よりも低周波数域にオリフィス通路３８がチューニングされていることから、能動的防振効果を得ようとする周波数域では、オリフィス通路３８を通じての流体流動が十分に抑えられて、受圧室６２の内圧変動、ひいては能動的防振効果が有効に発揮され得ることとなる。
【００４９】
しかも、上述の如きエンジンマウント１０においては、金属プレート５６を変位させて閉塞領域１１８を形成するための駆動手段と、金属プレート５６を加振して受圧室６２に圧力変化を生ぜしめるための駆動手段とが、一つの電磁式駆動装置８０によって構成されていることから、構造とその制御が簡単となる。
【００５０】
次に、図２及び図３には、本発明の第二及び第三の実施形態としての自動車用エンジンマウント１２２，１２４が示されている。なお、これら図２及び図３においては、第一の実施形態と同様な構造とされた部材および部位に対して、それぞれ、図中に、第一の実施形態と同一の符号を付することにより、それらの詳細な説明を省略する。
【００５１】
すなわち、図２に示された第二の実施形態としてのエンジンマウント１２２においては、オリフィス部材３８を構成する蓋金具４２に対して、その内周縁部から軸方向上方に向かって延び出す密接部材としての円筒部１２６が一体形成されている。また、この円筒部１２６の突出先端部は、所定幅で径方向内方に屈曲されたフランジ状の環状当接部１２８とされている。
【００５２】
そして、加振部材５０に取り付けられた金属プレート５６が、円筒部１２６の内径寸法よりも小さな外径寸法とされており、円筒部１２６内の軸方向中間部分に位置せしめられている。即ち、本実施形態では、金属プレート５６の外径寸法が、加振部材５０における第一の連結金具５２の外径寸法および円筒部１２６の環状当接部１２８の内径寸法よりは大きく、支持ゴム弾性体５４およびオリフィス部材３８の外径寸法よりは小さく設定されている。また、金属プレート５６の外周部分には、上方に向かって突出するゴム製の緩衝突起１３０が、周方向に連続して形成されており、この緩衝突起１３０が形成された金属プレート５６の外周部分が、円筒部１２６の環状当接部１２８に対して、加振部材５０の変位方向となるマウント軸方向で離間して対向位置せしめられている。
【００５３】
このような構造とされた本実施形態のエンジンマウント１２２では、図中に仮想線で示されているように、電磁式駆動装置８０によって加振部材５０を上方に変位させて金属プレート５６を、緩衝突起１３０を介して、環状当接部１２８に当接させることにより、円筒部１２６の開口部が金属プレート５６で流体密に覆蓋され、以て、該円筒部１２６内に閉塞領域１１８が形成される。
【００５４】
従って、本実施形態のエンジンマウント１２２においても、金属プレート５６を環状当接部１２８から離隔位置させた状態下で、加振部材５０を加振変位させることにより、受圧室６２に圧力変化が生ぜしめて能動的な防振効果を得ることが出来ると共に、金属プレート５６を環状当接部１２８に当接させた状態下では、本体ゴム弾性体１６の弾性変形に伴う受圧室６２の圧力変化による加振部材５０（支持ゴム弾性体５４）の変位が防止されて、振動入力によって受圧室６２に有効な圧力変化が生ぜしめられることから、オリフィス通路４６を通じての流体の流動作用に基づく受動的な防振効果を有効に得ることが可能となるのであり、第一の実施形態としてのエンジンマウントと同様な効果が、何れも有効に発揮され得るのである。
【００５５】
また、図３に示された第三の実施形態としてのエンジンマウント１２４においては、加振部材５０との間に密閉領域を形成するプレート部材としてのプレート部１３２が、加振部材５０の下方に配設されている。
【００５６】
より詳細には、加振部材５０を構成する第一の連結金具５２において、その開口部から径方向外方に向かって広がる円環板形状のプレート部１３２が一体形成されている。そして、このプレート部１３２が、平衡室７２内において、該平衡室７２の内周壁を構成する第二の連結金具６６の外周面から加振方向に対して直角な方向に広がる状態で、加振部材５０の支持ゴム弾性体５４に対して下方に離間して配設されている。また、プレート部１３２は、加振部材５０の支持ゴム弾性体５４の外径寸法よりも大きく、且つ平衡室７２の外径寸法よりも小さな外径寸法を有しており、その外周部分が、加振部材の外周支持部としてのオリフィス部材３８（溝金具４０）の内周縁部に対して、軸方向下方に離間して対向位置せしめられている。なお、オリフィス部材３８の内周縁部には、軸方向下方に向かって突出するゴム製の緩衝突起１３４が、周方向に連続して環状に形成されて、プレート部１３２の外周部分に対して対向位置せしめられている。
【００５７】
このような構造とされた本実施形態のエンジンマウント１２４では、図中に仮想線で示されているように、電磁式駆動装置８０によって加振部材５０を上方に変位させてプレート部１３２を、緩衝突起１３４を介して、オリフィス部材３８の内周縁部に当接させることにより、オリフィス部材３８の中央透孔４８の下側開口部がプレート部１３２で流体密に覆蓋され、以て、加振部材５０の背後（受圧室６２と反対側）において、加振部材５０とプレート部１３２の間に閉塞領域１３６が形成される。換言すれば、平衡室７２がプレート部１３２で流体密に仕切られることにより、加振部材５０とプレート部１３２の間に、非圧縮性流体が充填された閉塞領域１３６が形成されるのである。それにより、加振部材５０（支持ゴム弾性体５４）は、その背後に形成された閉塞領域１３６による補強作用を受けて変形および変位が阻止されるのであり、特に閉塞領域１３６に非圧縮性流体が封入されていることから、受圧室６２の容積変化を伴うような加振部材５０の変形および変位が極めて有利に防止されることとなる。
【００５８】
従って、本実施形態のエンジンマウント１２４においても、プレート部１３２をオリフィス部材３８から下方に離隔位置させた状態下で、加振部材５０を加振変位させることにより、受圧室６２に圧力変化を生ぜしめて能動的な防振効果を得ることが出来ると共に、プレート部１３２を上方に駆動変位させてオリフィス部材３８に当接させた状態下では、本体ゴム弾性体１６の弾性変形に伴う受圧室６２の圧力変化による加振部材５０（支持ゴム弾性体５４）の変位が防止されて、振動入力によって受圧室６２に有効な圧力変化が生ぜしめられることから、オリフィス通路４６を通じての流体の流動作用に基づく受動的な防振効果を有効に得ることが出来るのであり、以て、第一の実施形態としてのエンジンマウントと同様な効果が、何れも有効に発揮され得るのである。
【００５９】
以上、本発明の実施形態について詳述してきたが、これらはあくまでも例示であって、本発明は、これらの実施形態における具体的な記載によって、何等、限定的に解釈されるものでない。
【００６０】
例えば、受圧室内にプレート部材を配設する場合にも、プレート部材を、加振部材によって構成することも可能である。具体的には、例えば、第二の実施形態としてのエンジンマウント１２２においては、環状当接部１２８の内径寸法を、加振部材５０を構成する第一の連結金具５２の上底部の外径寸法よりも小さくして、該第一の連結金具５２の上底部の外周縁部を環状当接部１２８に対向位置せしめることにより、第一の連結金具５２の上底部によって、プレート部材を構成することが可能である。
【００６１】
また、プレート部材は、加振部材の外周支持部への密接時に、加振部材との間に閉塞領域を安定して形成し得るものであれば良く、例えば、前記第一の実施形態において、金属プレート５６を、加振部材５０の第一の連結金具５２に対して、ガタツキ程度の相対変位が許容される状態で取り付けることにより、緩衝突起６０に対しては強固に圧接可能であるが、緩衝突起６０から離間位置せしめられた状態下では、加振部材５０の加振変位に際して、第一の連結金具５２との間の相対変位が許容されることによって、金属プレート５６の変位が軽減され得るようにしても良い。このように、加振部材５０の加振変位に際して金属プレート５６が略静止状態に維持されるようにすれば、金属プレート５６の変位に伴う抵抗を回避することが出来、加振部材５０を効率的に且つ容易に加振変位させることが可能となる。
【００６２】
さらに、前記実施形態では、何れも、第一の支持金具１２と第二の支持金具１４が、主たる振動入力方向たるマウント軸方向で対向配置された構造の防振装置に対して、本発明を適用したものを示したが、その他、互いに径方向に離間配置された第一及び第二の支持部材としての軸部材と外筒部材を、それらの間に介装された本体ゴム弾性体で連結すると共に、それら軸部材と外筒部材の間に非圧縮性流体が封入された受圧室と平衡室を形成した筒型構造の防振装置にも、本発明は、同様に適用可能である。
【００６３】
加えて、本発明は、自動車用エンジンマウントの他、自動車用のボデーマウントやデフマウント、或いは自動車以外の装置に用いられる各種の流体封入式能動型防振装置（制振器を含む）に対して、何れも適用可能である。
【００６４】
その他、一々列挙はしないが、本発明は、当業者の知識に基づいて種々なる変更，修正，改良等を加えた態様において実施され得るものであり、また、そのような実施態様が、本発明の趣旨を逸脱しない限り、何れも、本発明の範囲内に含まれるものであることは、言うまでもない。
【００６５】
【発明の効果】
上述の説明から明らかなように、本発明に従う構造とされた流体封入式能動型防振装置においては、加振部材を加振変位させる駆動手段によって変位せしめられるプレート部材を設け、該プレート部材を変位させることによって加振部材の変位を規制する閉塞領域を必要に応じて形成可能としたことにより、閉塞領域が形成されていない状態下において、加振部材の加振変位に基づく能動的な防振効果を有効に得ることが出来ると共に、閉塞領域を形成することによって、オリフィス通路を流動せしめられる流体の流動作用に基づく受動的な防振効果を有効に得ることが出来るのである。
【図面の簡単な説明】
【図１】本発明の第一の実施形態としての自動車用エンジンマウントを示す縦断面図である。
【図２】本発明の第二の実施形態としての自動車用エンジンマウントを示す縦断面図である。
【図３】本発明の第三の実施形態としての自動車用エンジンマウントを示す縦断面図である。
【符号の説明】
１０エンジンマウント
１２第一の支持金具
１４第二の支持金具
１６本体ゴム弾性体
３８オリフィス部材
４６オリフィス通路
５０加振部材
５２第一の連結金具
５４支持ゴム弾性体
５６金属プレート
６０緩衝突起
６２受圧室
６４ダイヤフラム
６６第二の連結金具
７２平衡室
８０電磁式駆動装置[0001]
【Technical field】
The present invention relates to a fluid-filled active vibration isolator capable of obtaining an active vibration isolation effect by controlling the pressure of a pressure receiving chamber in which an incompressible fluid is sealed, and in particular, an orifice for the pressure receiving chamber. The present invention also relates to a fluid-filled active vibration isolator that includes an equilibrium chamber communicated through a passage and can also obtain a passive vibration isolation effect based on a fluid action of a fluid that flows through the orifice passage.
[0002]
[Background]
Conventionally, as a type of a vibration proof coupling body or a vibration proof support body interposed between members constituting a vibration transmission system, Japanese Patent Laid-Open Nos. 5-149369, 5-149372, and 10- As described in Japanese Patent No. 184769, etc., the first support member and the second support member are connected by a main rubber elastic body, and a part of the wall portion is configured by the main rubber elastic body so that it is not compressed. Forming a pressure receiving chamber filled with a neutral fluid, and another part of the wall of the pressure receiving chamber is constituted by a vibration member made of a rubber elastic plate or the like that is displaced by vibration by an elastic deformation by a driving means. A fluid-filled active vibration isolator is known in which an active vibration isolation effect is obtained by controlling the pressure in the pressure receiving chamber by oscillating and displacing the vibration member. In addition, in such a vibration isolator, an equilibrium chamber in which a part of the wall portion is formed of a flexible film and in which an incompressible fluid is sealed is formed independently from the pressure receiving chamber, and the pressure receiving chambers A structure provided with an orifice passage that communicates with the equilibrium chamber can also be suitably employed, whereby a fluid action such as a resonance action of a fluid that is caused to flow through the orifice passage can be utilized, and the flow of such fluid It is also possible to enjoy a passive vibration isolation effect based on the action.
[0003]
By the way, in order to effectively obtain the passive vibration isolation effect based on the flow action of the fluid that flows through the orifice passage, the fluid flow amount through the orifice passage based on the pressure difference between the pressure receiving chamber and the equilibrium chamber is sufficient when vibration is input. It is necessary to secure it.
[0004]
However, in the active vibration isolator having the conventional structure as described above, when a pressure change occurs in the pressure receiving chamber at the time of vibration input, the vibration member that constitutes a part of the wall portion of the pressure receiving chamber by the action of the pressure. Is elastically deformed, and the amount of pressure change in the pressure receiving chamber, and consequently the amount of relative pressure change between the pressure receiving chamber and the equilibrium chamber, decreases by an amount corresponding to the amount of elastic deformation of the vibration member, and flows through the orifice passage. There has been a problem that it is difficult to obtain an effective passive vibration-proofing effect because it is difficult to effectively secure the amount of fluid to be squeezed.
[0005]
[Solution]
Here, the present invention has been made in the background as described above, and the problem to be solved is that the amount of fluid flow through the orifice passage can be advantageously ensured, and the vibration member is added. An improved structure with fluid-filled active vibration isolation that effectively demonstrates both the active vibration isolation effect based on the pressure control of the pressure-receiving chamber by vibration and the passive vibration isolation effect based on fluid flow through the orifice passage To provide an apparatus.
[0006]
[Solution]
Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, each aspect described below can be employed in any combination. In addition, it should be understood that the aspects and technical features of the present invention are not limited to those described below, but are recognized based on the inventive concept described in the entire specification and drawings. It is.
[0007]
In the first aspect of the present invention, the first support member and the second support member are connected by the main rubber elastic body, and a part of the wall portion is configured by the main rubber elastic body so that the incompressible fluid is While forming the enclosed pressure receiving chamber, another part of the wall portion of the pressure receiving chamber is constituted by a vibration member that is subjected to vibration displacement with elastic deformation by the driving means, while part of the wall portion is A fluid-filled active type comprising a flexible membrane and forming an equilibrium chamber in which an incompressible fluid is enclosed, independently of the pressure receiving chamber, and an orifice passage communicating the equilibrium chamber with the pressure receiving chamber In the mold vibration isolator, a plate member extending in a direction perpendicular to the direction of vibration of the vibration member by the driving means is provided, and the plate member is moved in one direction of vibration of the vibration member by the driving means. The outer periphery of the plate member A closed region can be formed between the plate member and the vibrating member by being in close contact with the outer peripheral support portion of the vibrating member, and the displacement of the vibrating member is regulated by the closed region. This is a feature.
[0008]
In such a fluid-filled active vibration isolator according to the first aspect, the plate member can regulate the displacement of the vibration member as necessary, so that the vibration isolation effect by the orifice passage is required. In such a case, by restricting the displacement of the vibration member, it is possible to prevent the pressure variation in the pressure receiving chamber from escaping due to the displacement of the vibration member, and to sufficiently secure the fluid flow amount through the orifice passage. Therefore, a passive vibration isolation effect based on the fluid flow action can be obtained effectively. Further, when an active vibration isolation effect of the pressure receiving chamber is required, the vibration displacement of the vibration member by the driving means is advantageously generated by separating the plate member from the outer peripheral support portion of the vibration member. Therefore, the active vibration isolation effect based on the pressure control of the pressure receiving chamber can be effectively obtained.
[0009]
Moreover, since the plate member is driven to be displaced by the drive means for exciting the vibration member, no special drive means is required for the displacement of the plate member, and the plate member is intended to have a simple structure. An active vibration isolator can be advantageously realized.
[0010]
In the first aspect, the drive means may be any drive means that can vibrate the vibration member at a target frequency and can exert a necessary displacement stroke on the plate member. For example, an electromagnetic force is used. The electromagnetic driving means, the pneumatic driving means using negative pressure or the like can be suitably employed. Further, the plate member may be any member as long as it defines a closed region that can restrict displacement of the vibration member between the vibration member and the shape is not particularly limited. In order to advantageously restrict the displacement of the vibration member by forming a closed region between the two, it is desirable that the member be formed of a rigid material such as metal or resin.
[0011]
A second aspect of the present invention is the fluid-filled active vibration isolator according to the first aspect, wherein the plate member is connected to the vibration member at a central portion thereof, and the vibration member The plate member is disposed so as to extend substantially at right angles to the excitation direction, and at least the outer peripheral portion of the plate member is positioned away from the excitation member in the excitation direction without forming the closed region. Thus, the vibration displacement of the vibration member by the driving means can be allowed. In this embodiment, the plate member can be advantageously configured with a simple structure.
[0012]
According to a third aspect of the present invention, in the fluid-filled active vibration isolator according to the first or second aspect, the plate member is disposed in the pressure receiving chamber. By closely contacting the outer peripheral support portion of the vibration member, the pressure receiving chamber is fluid-tightly partitioned by the plate member, and pressure transmission due to elastic deformation of the main rubber elastic body with respect to the closed region is prevented. The displacement of the vibrating member is regulated by the sealed region. In such a mode, the body rubber elastic body and the vibration member are partitioned fluid-tightly by the plate member in the pressure receiving chamber, so that the body rubber elastic body is elastically deformed at the time of vibration input. Even when a pressure fluctuation is generated, the pressure fluctuation is not exerted on the vibration member. Therefore, effective pressure fluctuation is generated in the pressure receiving chamber, and the amount of fluid flow through the orifice passage is advantageously ensured, and the passive vibration isolation effect based on the fluid flow action is effectively exhibited. It is done. In addition, when an active vibration isolation effect is required, the wall portion is configured by the body rubber elastic body and the vibration member in cooperation by separating the plate member from the outer peripheral support portion of the vibration member. Since one pressure receiving chamber is formed, it is possible to effectively obtain an active vibration isolation effect by pressure control of the pressure receiving chamber based on the vibration displacement of the vibration member.
[0013]
Moreover, in the second and third aspects, the displacement of the vibration member is advantageously prevented via the closed region without restraining the plate member by directly contacting the vibration member. Therefore, the durability problem caused by the press contact of the plate member to the vibration member and the like can be advantageously avoided.
[0014]
According to a fourth aspect of the present invention, in the fluid-filled active vibration isolator according to any one of the first to third aspects, the equilibrium chamber is opposite to the pressure receiving chamber with the vibration member interposed therebetween. The plate member is disposed in the equilibrium chamber, and the pressure receiving chamber of the vibration member is defined by bringing the plate member into close contact with the outer peripheral support portion of the vibration member. The closed region is formed on the opposite side, and the displacement of the excitation member is regulated by the incompressible fluid filled in the closed region. In such a mode, a closed region that is sealed by using a part of the equilibrium chamber is formed behind the vibration member (on the side opposite to the pressure receiving chamber). Since the volume change in the closed area is prevented by filling with the compressible fluid, the displacement of the vibration member with the incompressible fluid is less than when the compressible fluid such as air is sealed in the closed area. It will be blocked very advantageously. Therefore, under such a closed region formation state, pressure absorption of the pressure receiving chamber due to displacement of the excitation member is prevented, and effective pressure fluctuation is generated in the pressure receiving chamber, so that the fluid flow action through the orifice passage On the other hand, the passive vibration-proofing effect based on the pressure is advantageously exerted, while in the state where the closed region is not formed, the displacement of the vibration member is allowed and the pressure in the pressure receiving chamber based on the vibration displacement of the vibration member The active vibration isolation effect by the control can be obtained effectively.
[0015]
In the first to fourth aspects, the outer peripheral support portion of the vibration member with which the outer peripheral portion of the plate member abuts is formed in the circumferential direction along the outer peripheral edge portion of the vibration member, for example, By displacing the plate member toward the vibration member side, the plate member can be brought into close contact with the outer peripheral support portion. Alternatively, on the outer peripheral side of the vibration member, a close contact member is formed which extends in a cylindrical shape toward the vibration direction of the vibration member, and a tip portion is bent in an inward flange shape. By disposing the plate member in the accommodated state and displacing the plate member in a direction away from the vibration member, the plate member may be brought into close contact with the inner surface of the inward flange-like portion of the close contact member as the outer peripheral support portion. .
[0016]
According to a fifth aspect of the present invention, in the fluid-filled active vibration isolator according to any one of the first to fourth aspects, an excitation force is directly exerted by the driving means, and the plate A hard mounting member to which the member is mounted, and an outer peripheral edge portion fixed to the second support member so as to spread from the mounting member at a substantially right angle with respect to the excitation direction. The vibration member is configured to include a support rubber elastic body that is elastically supported with respect to the support member. In this aspect, the mounting member advantageously transmits the driving force by the driving means to the vibration member and the plate member, and the support rubber elastic body allows the displacement of the vibration member by the driving means. Can be advantageously produced.
[0017]
Furthermore, in the fifth aspect, more preferably, the plate member has a structure that extends from the hard mounting member so as to extend substantially at right angles to the excitation direction, and at least the outer periphery of the plate member. The portion is disposed away from the support rubber elastic body in the vibration direction, and the outer peripheral portion of the plate member is brought into close contact with the outer peripheral support portion of the vibration member. By adopting such a plate member, it is possible to advantageously secure the circumferential length of the close contact portion with respect to the outer periphery support portion of the vibration member, so that stress concentration at the close contact portion is reduced and the plate member is Under the state of being separated from the outer peripheral support portion of the vibration member, it is possible to advantageously ensure the size of the constricted region formed between the opposing surfaces in the circumferential direction, and the fluid flow resistance due to the constricted region is reduced. As a result, the vibration efficiency and vibration controllability of the vibration member can be improved.
[0018]
In the fluid-filled active vibration isolator according to each aspect as described above, the pressure receiving chamber by the vibration of the vibration member is not hindered by the fluid flow in the pressure receiving chamber accompanying the vibration of the vibration member. The following sixth and seventh aspects are preferably employed so that the pressure control can be efficiently performed.
[0019]
That is, a sixth aspect of the present invention is the fluid-filled active vibration isolator according to any one of the first to fifth aspects, wherein the pressure receiving chamber or the equilibrium chamber in which the plate member is disposed. The opening area of the annular constriction region formed on the outer peripheral side of the plate member is set larger than the effective piston area of the vibration member.
[0020]
According to a seventh aspect of the present invention, in the fluid filled active vibration isolator according to any one of the first to sixth aspects, the pressure receiving chamber or the equilibrium chamber in which the plate member is disposed. An annular constriction region formed on the outer peripheral side of the plate member has a resonance frequency of fluid flow in a frequency region higher than the natural frequency of the vibration member.
[0021]
Further, an eighth aspect of the present invention is the fluid-filled vibration isolator according to any one of the first to seventh aspects, particularly the sixth or seventh aspect, wherein the outer diameter dimension of the plate member is It is larger than the outer diameter dimension of the vibration member, and the close contact portion between the plate member and the outer peripheral support portion is provided on the outer peripheral side further than the outer peripheral edge portion of the vibration member. Features. In this aspect, it is easy to set a large opening area of the annular constriction region formed on the outer peripheral side of the plate member in the pressure receiving chamber or the equilibrium chamber in which the plate member is disposed. Therefore, it is possible to easily reduce or avoid adverse effects such as fluid flow resistance due to the constriction region.
[0022]
Furthermore, the present invention can be applied to a vibration damping device that is attached to a vibration damping object and reduces vibration in addition to a vibration damping coupling body or vibration damping support body such as an automobile engine mount. Specifically, for example, in the fluid-filled active vibration isolator according to any one of the first to eighth aspects, the first support member is a vibration transmission member (vibration generating member or the like) and a vibration transmission. By attaching to one of the members (vibration isolation target members) and attaching the second support member to the other of them, an anti-vibration coupling body such as an engine mount structured according to the present invention is advantageously realized. In addition, for example, either one of the first support member and the second support member is attached to the vibration isolation target member, and the other of the first attachment member and the second attachment member is anti-vibration. A vibration damping device can be advantageously configured by elastically supporting the target member with the main rubber elastic body to form one vibration system.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.
[0024]
First, FIG. 1 shows an automobile engine mount 10 as a first embodiment of the present invention. The engine mount 10 includes a first support member 12 as a first support member and a second support member 14 as a second support member, which are arranged at a predetermined distance from each other, by a main rubber elastic body 16. The first support fitting 12 is fixed to a power unit (not shown) and the second support fitting 14 is fixed to a body (not shown). Against vibration. Note that, in such a state where the vehicle is mounted on the automobile, the weight of the power unit is exerted, whereby the main rubber elastic body 16 is compressed and deformed, and the first support fitting 12 and the second support fitting 14 approach each other. The main vibration to be vibrated is input in a substantially opposing direction (substantially up and down in the drawing) of the first support fitting 12 and the second support fitting 14. . In the following description, the vertical direction means, in principle, the vertical direction in FIG. 1 as the mount central axis direction.
[0025]
More specifically, the first support fitting 12 has a substantially circular flat plate shape, and is disposed so as to spread in a direction orthogonal to the mount center axis. Further, a holding metal fitting 18 whose diameter is reduced downward is fixed to the center of the lower surface of the first support metal fitting 12, and a substantially umbrella shape extending in a direction perpendicular to the mount axis is formed at the lower end portion of the holding metal fitting 18. The umbrella bracket 20 is fixed with bolts. Furthermore, a first mounting bolt 22 that protrudes upward through the first support bracket 12 is erected on the upper end portion of the holding bracket 18. The support fitting 12 is fixed to the power unit.
[0026]
On the other hand, the second support fitting 14 is composed of an upper cylindrical fitting 24 and a lower cylindrical fitting 26 each having a large cylindrical shape, and the upper and lower cylindrical fittings 24 and 26 are coaxially overlapped in the axial direction. The caulking portion 28 provided at the lower end opening of the upper tube fitting 24 is integrated by being caulked and fixed to the flange portion 30 provided at the upper end opening of the lower tube fitting 26. Moreover, the upper opening part of the upper cylinder metal fitting 24 is made into the taper part 32 which expands gradually toward the opening part side over the axial direction predetermined length, and this taper part 32 is the 1st support metal fitting. 12 is opposed to the tapered outer peripheral surface of the holding metal fitting 18 fixed to the base plate 12. Further, a fixing plate portion 34 that extends outward in a direction perpendicular to the axis is integrally formed in the lower opening of the lower cylindrical metal fitting 26, and this fixing plate portion 34 is overlapped with a mounting surface of a body (not shown) to be bolted. By being fixed, the second support fitting 14 is attached to the body.
[0027]
The first support fitting 12 is disposed on the substantially same axis so as to be spaced apart from the upper opening side of the second support fitting 14, and the first support fitting 12 and the second support fitting are disposed. 14, a main rubber elastic body 16 is interposed. The main rubber elastic body 16 has a thick, substantially tapered cylindrical shape whose diameter decreases upward, and the first support fitting 12 is superimposed on the end surface on the small diameter side and vulcanized and bonded. The holding metal fitting 18 is disposed through the center hole, and the outer peripheral surface of the holding metal fitting 18 is vulcanized and bonded to the inner peripheral surface of the center hole. On the other hand, on the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16, the taper portion 32 of the upper tube fitting 24 constituting the second support fitting 14 is vulcanized and bonded. In short, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first support fitting 12, the holding fitting 18 and the upper tube fitting 24. A reinforcing metal fitting 36 having a thin, substantially tapered cylindrical shape whose diameter is increased upward is vulcanized and bonded to the cylindrical wall portion of the main rubber elastic body 16 in the axially intermediate portion. In addition, by connecting the first support fitting 12 and the second support fitting 14 with the main rubber elastic body 16 in this way, the upper opening of the second support fitting 14 (upper tube fitting 24) is The main rubber elastic body 16 is closed fluid-tightly.
[0028]
Further, an orifice member 38 extending along the inner peripheral surface is disposed in the hollow interior of the lower cylindrical metal fitting 26 constituting the second support metal fitting 14. The orifice member 38 has an annular groove metal fitting 40 that extends continuously in the circumferential direction with a concave cross section that opens upward, and an annular plate shape that overlaps and covers the opening of the groove metal fitting 40. It is comprised from the lid metal fitting 42. Then, the opening of the groove fitting 40 is covered with the lid fitting 42, whereby an annular orifice passage 46 extending in the circumferential direction is formed inside the orifice member 38. Further, flange-shaped portions 44 that extend radially outward are formed on the outer peripheral edge portions of the groove metal fitting 40 and the cover metal fitting 42, respectively, and both the flange-shaped portions 44, 44 are overlapped to form the upper tube metal fitting 24. And is fixed to the second support fitting 14 by being integrally sandwiched between the caulking portions of the lower tubular fitting 26.
[0029]
In addition, a vibration member 50 is disposed in the central through hole 48 of the orifice member 38, and the central through hole 48 of the orifice member 38 is closed fluid-tightly by the vibration member 50. Such a vibrating member 50 is disposed in the central portion of the central through hole 48 of the orifice member 38 and is a first connection in the shape of an inverted cup as an attachment member having an outer diameter smaller than the diameter of the central through hole 48. The metal fitting 52 includes an annular plate-shaped support rubber elastic plate 54 disposed between radially outer surfaces of the outer peripheral surface of the first connecting metal fitting 52 and the inner peripheral surface of the groove metal fitting 40. Yes. That is, the inner and outer peripheral surfaces of the support rubber elastic plate 54 are vulcanized and bonded to the outer peripheral surface of the first connecting fitting 52 and the inner peripheral surface of the groove fitting 40, respectively. 40 and by extension, the second support fitting 14 is elastically supported, and the displacement of the first connection fitting 52 is allowed based on the elastic deformation of the support rubber elastic body 54.
[0030]
Furthermore, the upper bottom portion of the first connecting fitting 52 is projected upward in the mount axis direction from the support rubber elastic body 54, and a metal plate 56 as a plate member is superimposed on the upper surface of the upper bottom portion. At the center, the first connecting fitting 52 is fixed by a fixing tool 58 such as a rivet or a bolt. The metal plate 56 has a circular flat plate shape. The metal plate 56 protrudes outward from the first connecting fitting 52 in the direction perpendicular to the axis, and a portion protruding from the first connecting fitting 52 extends. The support rubber elastic body 54 is spaced from the support rubber elastic body 54 and positioned on the support rubber elastic body 54. Further, the outer diameter of the metal plate 56 is larger than the hole diameter of the central through hole 48 of the orifice member 38 and sufficiently smaller than the inner diameter of the second support fitting 14. The portions are spaced apart above the orifice member 38. As a result, the inner peripheral edge of the orifice member 38 is spaced from and opposed to the outer peripheral portion of the metal plate 56 in the mount axis direction, and at the inner peripheral edge of the orifice member 38, An annular buffer protrusion 60 that protrudes upward and extends continuously in the circumferential direction with a chevron-shaped cross section is formed integrally with the support rubber elastic body 54. As shown in the figure, the metal plate 56 is also disposed so as to be opposed to the tip end portion of the buffer projection 60 by a predetermined distance L in the mount axis direction.
[0031]
Further, the center through hole 48 of the orifice member 38 is fluid-tightly covered with the vibration member 50, so that the second support fitting 14 is provided between the opposing surfaces of the main rubber elastic body 16 and the vibration member 50. , A pressure receiving chamber 62 in which an incompressible fluid is sealed is formed. That is, the pressure receiving chamber 62 is partly composed of the main rubber elastic body 16 and the vibration member 50, and a pressure change occurs due to elastic deformation of the main rubber elastic body 16 when vibration is input. It can be tightened. As the enclosed incompressible fluid, water, alkylene glycol, polyalkylene glycol, silicone oil or the like is preferably employed. In particular, in order to effectively obtain a vibration-proofing effect based on the fluid flow action, the viscosity is Is preferably a low-viscosity fluid having a viscosity of 0.1 Pa · s or less.
[0032]
Furthermore, in the pressure receiving chamber 62, the umbrella metal 20 supported by the first support metal 12 and the metal plate 56 supported by the second support metal 14 so as to be displaceable spread in the direction perpendicular to the mount axis. In the state, they are arranged apart from each other in the mount axis direction. Also, under the mounted state, the first support fitting 12 and the second support fitting 14 are positioned relatively close by the input of the power unit weight, so that the umbrella fitting 20 is positioned at the approximate center in the pressure receiving chamber 62. As a result, an annular constricted flow path is formed between the outer peripheral surface of the umbrella bracket 20 and the inner peripheral surface of the upper tube bracket 24.
[0033]
Further, a diaphragm 64 as a flexible film is disposed on the side opposite to the pressure receiving chamber 62 with the vibration member 50 interposed therebetween. The diaphragm 64 is formed of a thin rubber elastic film that can be easily deformed, and a second connecting fitting 66 having a deep-bottomed reverse cup shape is vulcanized and bonded to the center portion, and an outer peripheral edge portion. An attachment cylinder fitting 68 having a substantially large diameter cylindrical shape is vulcanized and bonded. The flange-shaped portion 70 formed integrally with the upper end portion in the axial direction of the mounting cylinder fitting 68 is integrated with the flange-shaped portions 44, 44 of the orifice member 38 between the caulking portions of the upper cylinder fitting 24 and the lower cylinder fitting 26. By being sandwiched between the two, the second support fitting 14 is fixed. The second connection fitting 66 is press-fitted and fixed integrally with the first connection fitting 52 of the vibration member 50.
[0034]
As a result, an equilibrium chamber 72 filled with an incompressible fluid is formed between the opposing surfaces of the vibration member 50 and the diaphragm 64 on the opposite side of the pressure receiving chamber 62 with the vibration member 50 interposed therebetween. In the equilibrium chamber 72, the volume change is easily allowed based on the easy deformation of the diaphragm 64 constituting a part of the wall portion, and the internal pressure fluctuation is reduced or avoided as much as possible. ing. Further, in the orifice member 38 disposed in the partition wall portions of the pressure receiving chamber 62 and the equilibrium chamber 72, the orifice passage 46 formed therein is communicated with the pressure receiving chamber 62 and the equilibrium chamber 72 through the communication holes 74 and 76, respectively. Therefore, based on the relative pressure difference induced between the pressure receiving chamber 62 and the equilibrium chamber 72 at the time of vibration input, between the pressure receiving chamber 62 and the equilibrium chamber 72 through the orifice passage 46 having a predetermined length. Fluid flow is generated. In particular, in the present embodiment, the pressure receiving chamber is designed so that an effective anti-vibration effect (for example, a damping effect) is exhibited against low-frequency vibration such as a shake based on the resonance action of the fluid flowing through the orifice passage 46. The passage length and cross-sectional area of the orifice passage 46 are appropriately set in consideration of the rigidity of the wall springs 62 and the equilibrium chamber 72 and the specific gravity of the sealed fluid.
[0035]
In the present embodiment, when the first support fitting 12 and the second support fitting 14 are relatively displaced at the time of vibration input, the umbrella fitting 20 is displaced in the pressure receiving chamber 62, and the outer circumference of the umbrella fitting 20 is changed. Fluid flow through the constricted flow path formed on the side is generated. Therefore, by appropriately adjusting the channel length, the cross-sectional area, etc. of this constricted channel, the constricted channel can be prevented against vibrations in a higher frequency range than the vibration that exhibits the vibration isolation effect by the orifice channel 46. It is possible to obtain a vibration isolation effect based on the resonance action of the fluid to be flowed. Specifically, for example, the constricted flow path is tuned so as to exhibit an effective anti-vibration effect (for example, a vibration insulation effect) against high-frequency vibration such as a booming sound based on the resonance action of the fluid.
[0036]
Further, an electromagnetic drive device 80 as drive means is disposed below the diaphragm 64 that defines the equilibrium chamber 72, and bolts or the like are provided with respect to the lower cylinder fitting 26 constituting the second mounting fitting 14. It is fixed with. In the electromagnetic drive device 80, a coil member 82 having an air core coil structure and a magnet member 84 inserted and disposed in the air core portion of the coil member 82 are capable of relative displacement in the axial direction. Based on the electromagnetic force generated between the coil member 82 and the magnet member 84 by energization of the coil, an exciting force in the axial direction (vertical direction in the figure) is exerted on the exciting member 50. .
[0037]
More specifically, the coil member 82 includes a first coil 86 and a second coil 88 that are coaxially overlapped with each other, and between the overlapping surfaces of both the coils 86 and 88 and on both sides in the axial direction. A plurality of annular plates 90 each made of a ferromagnetic material are superposed on each other. Thereby, substantially one air core structure coil is constituted as a whole. The superposed body of the coils 86 and 88 and the plurality of annular plates 90 is fitted into a large-diameter cylindrical housing fitting 92 and is integrally fixed to each other. A cylindrical support case fitting 94 is press-fitted and fixed. The support case fitting 94 has a large-diameter cylindrical shape, and its axially lower opening is covered with a dust seal 96 made of a thin rubber film, while being integrally formed with the axially upper opening. In the portion 98, the second support fitting 14 is overlaid and fixed with a bolt or the like. As a result, the coil member 82 is fixedly supported by the second support fitting 14 via the support case fitting 94.
[0038]
On the other hand, the magnet member 84 includes an annular plate-shaped magnet 100 formed of a known permanent magnet material. On the both sides in the axial direction of the magnet 100, an annular block-shaped upper and lower made of a ferromagnetic material is provided. The yokes 102 and 104 are overlapped. The magnet 100 and the upper and lower yokes 102 and 104 are fixedly attached to the central portion in the axial direction of the rod 106 by being fixed to the rod 106 inserted into each center hole. Here, the magnet 100 has magnetic poles set on both sides in the axial direction, and the magnet member 84 is a single magnet having magnetic poles at both ends in the axial direction as a whole. The superposed body of the magnet 100 and the upper and lower yokes 102 and 104 has an outer diameter slightly smaller than the air core diameter of the coil member 82 and an axial length smaller than the air core portion of the coil member 82. The magnet member 84 is accommodated substantially coaxially with respect to the air core portion of the coil member 82 and is disposed so as to be relatively displaceable in the axial direction.
[0039]
Further, the rod 106 of the magnet member 84 is disposed so as to protrude from the air core portion of the coil member 82 to both sides in the axial direction, and the annular plates 90 a, The sliding sleeves 108 and 110 fixed to 90b are positioned in a direction perpendicular to the axis and supported so as to be slidable in the axial direction. Further, a substantially cup-shaped fixing bracket 112 is bolted to the upper end portion of the rod 106, and the fixing bracket 112 is fixed to the first connecting bracket 52 of the vibration member 50. By being press-fitted and fixed to the metal fitting 66, the tip of the rod 106 is fixed to the first connection metal fitting 52 of the vibration member 50. As a result, the vibration member 50 including the first connecting fitting 52 can be displaced integrally with the magnet member 84 having the rod 106, and the vibration member 50 can be moved in the axial direction of the rod 106. Can be displaced stably. An air vent hole 114 is formed in the annular plate 90a so that the spring action of air existing in the housing fitting 92 does not adversely affect the axial displacement of the magnet member 84.
[0040]
In the engine mount 10 having such a structure, when the coils 86 and 88 of the coil member 82 are energized, magnetic poles are formed on both sides in the axial direction of the coil member 82, thereby attracting the magnet member 84 by magnetic force. Or a repulsive force is exerted, or a Lorentz force is exerted on an electric current applied to the coils 86 and 88 disposed in the magnetic field by the magnet member 84, and as a result, the coil member 82 and the magnet member 84 are In addition, a relative driving force in the axial direction is applied, and the driving force is applied to the vibration member 50 through the rod 106. Then, when the driving force is transmitted from the rod 106 to the vibration member 50, the first coupling fitting 52 and the support rubber elastic body 54 are displaced upward or downward based on the elastic deformation of the support rubber elastic body 54. It is supposed to be squeezed. Here, in the present embodiment, a pulsed drive current is supplied to the coils 86 and 88 of the coil member 82 by the power supply control device 116, and the coils 86 and 88 are supplied by the power supply control device 116. The vibration displacement of the vibration member 50 is controlled by controlling the current supplied to the vibration member.
[0041]
Then, by applying an alternating current or the like to the coils 86 and 88 to vibrate and displace the vibration member 50, the frequency corresponding to the vibration frequency and amplitude of the vibration member 50 with respect to the pressure receiving chamber 62. Thus, an internal pressure fluctuation of the pressure is generated, and an excitation force corresponding to the internal pressure fluctuation is transmitted to the body which is a vibration-proof target member. Therefore, the electric signal corresponding to the vibration such as the ignition pulse signal and the traveling signal is adopted as the reference signal, and the energization control to the coils 86 and 88 is performed by the power supply control device 116 at the frequency corresponding to the vibration to be isolated. For example, by exciting the vibration member 50 with a frequency and amplitude corresponding to the main vibration to be vibration-isolated in the body of an automobile, an excitation force that cancels the vibration to be anti-vibration is exerted and canceled. Active vibration isolation effect can be obtained, or the change in pressure in the pressure receiving chamber 62 at the time of vibration input to prevent vibration is positively eliminated, and the spring constant of the engine mount 10 is reduced to zero. It is possible to obtain an active anti-vibration effect that actively absorbs vibrations that are close and anti-vibration.
[0042]
In this case, when the vibration member 50 is vibrated, the sealed fluid flows in the pressure receiving chamber 62 through the gap 120 as an annular constriction region formed between the opposed surfaces of the orifice member 46 and the metal plate 56. Therefore, it is desirable to set the gap 120 sufficiently large so that a large resistance is not generated by the fluid flow restricting action of the gap 120. Specifically, it is effective to set the dimensions and spring characteristics of each member so that at least one of the following (formula 1) and (formula 2) is satisfied.
[0043]
D ・ L ・ π ≧ d ² ・ Π (1 set)
However, D is the diameter dimension of the annular gap 120 (the diameter dimension of the outer peripheral portion of the metal plate 56 positioned opposite the buffer protrusion 60 across the gap 120), and L is the size of the gap 120 (metal plate 56). And the distance between the opposing surfaces of the buffer protrusion 60). Further, d is an effective piston diameter when the vibration member 50 is vibrated, and is larger than the outer diameter dimension of the first connecting fitting 52 and smaller than the inner diameter dimension of the orifice member 38. That is, in this (1 type), the left side is the opening area of the annular gap 120, and the right side represents the effective piston area of the vibration member 50. In particular, in the present embodiment, the outer diameter dimension of the metal plate 56 is set to be larger than the outer diameter dimension of the support rubber elastic body 54 of the vibration member 50, so that D> 2d and the above (1 The condition of (formula) is advantageously realized.
[0044]
f ≧ F (2 formulas)
However, f is the resonance frequency of the fluid that is caused to flow through the gap 120 when the vibration member 50 is displaced by vibration, and F is the natural frequency of the vibration member 50. Note that the value of the natural frequency F of the vibration member 50 is determined by considering one vibration system including the vibration member 50 and considering the support rubber elastic body 54 and the like as a spring system, and the first and second values. In addition to the connection fittings 52 and 66, the metal plate 56, the rod 106, and the like need to be considered as a mass system. Further, in order to obtain an effective vibration isolation effect, the value of the natural frequency F of the vibration member 50 is set to a vibration frequency that requires an active vibration isolation effect based on the vibration displacement of the vibration member 50. It is desirable that the frequency is set to be substantially the same or higher than the vibration frequency at which the vibration isolation effect is required.
[0045]
Further, in such an engine mount 10, the maximum drive stroke amount from the neutral position of the rod 106 in the electromagnetic drive device 80 is such that the metal plate 56 and the buffer protrusion 60 that are opposed to each other in the mount axis direction within the pressure receiving chamber 62. The distance between the opposing surfaces is set larger than L. As a result, by feeding a large DC drive current to the electromagnetic drive device 80 and displacing the rod 106 downward, as shown by the phantom line in the drawing, The metal plate 56 fixedly supported by the connection fitting 52 is displaced downward in the mount axial direction, and the outer peripheral edge portion thereof is circumferential with respect to the buffer protrusion 60 provided on the inner peripheral edge portion of the orifice member 38. It is designed to be pressed over the entire circumference.
[0046]
Then, the metal plate 56 is brought into close contact with the buffer protrusion 60 over the entire outer periphery of the metal plate 56, whereby the upper opening of the central through hole 48 in the orifice member 38 is fluid-tightly closed with the metal plate 56. It is like that. As a result, a sealed annular closed region 118 is formed between the support rubber elastic body 54 of the vibration member 50 and the metal plate 56. In other words, by pressing the metal plate 56 against the buffer protrusion 60, the pressure receiving chamber 62 is fluid-divided into the main rubber elastic body 16 side and the support rubber elastic body 54 side with the metal plate 56 interposed therebetween. It is like that. Therefore, under such a state, the pressure change caused in the pressure receiving chamber 62 due to the elastic deformation of the main rubber elastic body 16 at the time of vibration input cannot be transmitted to the closed region 118, and the Transmission is avoided.
[0047]
Therefore, at the time of inputting low-frequency vibration with the orifice passage 46 tuned, the coils 86, the power supply controller 116 keep the metal plate 56 in close contact with the buffer protrusion 60 and the sealed region 118 is formed. By controlling the energization to 88, the action of the pressure generated in the pressure receiving chamber 62 due to the input vibration on the support rubber elastic body 54 is avoided, and the pressure fluctuation in the pressure receiving chamber 62 is changed to the support rubber elastic body 54. As a result, a large pressure difference is generated between the pressure receiving chamber 62 and the equilibrium chamber 72, and the fluid flow through the orifice passage 46 is efficiently performed. Therefore, the passive vibration isolation effect based on the fluid flow action of the fluid can be more effectively exhibited.
[0048]
On the other hand, when a vibration in a frequency range higher than the tuning frequency of the orifice passage 46 (for example, idling vibration or the like) is input, the direct current is not supplied to the coils 86 and 88 and the metal plate 56 is separated from the orifice member 38. In the state of being held in the neutral position (see FIG. 1), the energizing member 50 is energized by controlling energization of the coils 86 and 88 by the power feeding control device 116 and conducting energization corresponding to the vibration to be isolated. By oscillating and displacing, an active vibration isolation effect can be effectively obtained by causing a pressure fluctuation in the pressure receiving chamber 62. Although the orifice passage 38 is always in communication, the orifice passage 38 is tuned to a frequency range lower than the frequency at which the active vibration isolation effect due to the vibration of the vibration member 50 is exhibited. In the frequency range in which an active vibration isolation effect is to be obtained, the fluid flow through the orifice passage 38 is sufficiently suppressed, and the internal pressure fluctuation of the pressure receiving chamber 62 and thus the active vibration isolation effect can be effectively exhibited. .
[0049]
Moreover, in the engine mount 10 as described above, driving means for displacing the metal plate 56 to form the closed region 118 and driving for causing the metal plate 56 to vibrate and causing a pressure change in the pressure receiving chamber 62. Since the means is constituted by one electromagnetic driving device 80, the structure and its control are simplified.
[0050]
Next, FIGS. 2 and 3 show automobile engine mounts 122 and 124 as second and third embodiments of the present invention. 2 and 3, the same reference numerals as those in the first embodiment are given to the members and parts having the same structure as in the first embodiment. Detailed description thereof will be omitted.
[0051]
That is, in the engine mount 122 as the second embodiment shown in FIG. 2, as a close member that extends upward in the axial direction from the inner peripheral edge of the lid fitting 42 constituting the orifice member 38. The cylindrical portion 126 is integrally formed. The projecting tip of the cylindrical portion 126 is a flange-shaped annular contact portion 128 that is bent inward in the radial direction with a predetermined width.
[0052]
The metal plate 56 attached to the vibration member 50 has an outer diameter smaller than the inner diameter of the cylindrical portion 126 and is positioned at an intermediate portion in the axial direction in the cylindrical portion 126. That is, in the present embodiment, the outer diameter of the metal plate 56 is larger than the outer diameter of the first coupling fitting 52 and the inner diameter of the annular contact portion 128 of the cylindrical portion 126 in the vibration member 50, and the support rubber. The outer diameter of the elastic body 54 and the orifice member 38 is set to be smaller. Further, a rubber-made buffer protrusion 130 protruding upward is continuously formed on the outer peripheral portion of the metal plate 56 in the circumferential direction, and the outer peripheral portion of the metal plate 56 on which the buffer protrusion 130 is formed. Is opposed to the annular contact portion 128 of the cylindrical portion 126 while being spaced apart in the mount axis direction, which is the displacement direction of the vibration member 50.
[0053]
In the engine mount 122 of the present embodiment having such a structure, as shown by the phantom line in the drawing, the vibration member 50 is displaced upward by the electromagnetic drive device 80 and the metal plate 56 is moved. By contacting the annular contact portion 128 via the buffer protrusion 130, the opening of the cylindrical portion 126 is fluid-tightly covered with the metal plate 56, and thus a closed region 118 is formed in the cylindrical portion 126. Is done.
[0054]
Therefore, also in the engine mount 122 of the present embodiment, a pressure change occurs in the pressure receiving chamber 62 by oscillating and displacing the oscillating member 50 in a state where the metal plate 56 is separated from the annular contact portion 128. At the same time, an active vibration isolating effect can be obtained, and under the condition that the metal plate 56 is in contact with the annular contact portion 128, the pressure is applied by the pressure change in the pressure receiving chamber 62 due to elastic deformation of the main rubber elastic body 16. Since the displacement of the vibration member 50 (support rubber elastic body 54) is prevented and an effective pressure change is generated in the pressure receiving chamber 62 by the vibration input, the passive prevention based on the fluid flow action through the orifice passage 46 is performed. The vibration effect can be effectively obtained, and the same effects as those of the engine mount as the first embodiment can be effectively exhibited.
[0055]
Further, in the engine mount 124 as the third embodiment shown in FIG. 3, a plate portion 132 as a plate member that forms a sealed region between the vibration member 50 and the vibration member 50 is provided below the vibration member 50. It is arranged.
[0056]
More specifically, in the first coupling fitting 52 that constitutes the vibration member 50, an annular plate-shaped plate portion 132 that extends radially outward from the opening is integrally formed. The plate portion 132 is vibrated in a state where the plate portion 132 spreads in a direction perpendicular to the vibration direction from the outer peripheral surface of the second connecting fitting 66 constituting the inner peripheral wall of the balance chamber 72 in the balance chamber 72. The member 50 is disposed so as to be spaced downward from the support rubber elastic body 54. Further, the plate portion 132 has an outer diameter that is larger than the outer diameter of the support rubber elastic body 54 of the vibration member 50 and smaller than the outer diameter of the equilibrium chamber 72. The orifice member 38 (groove fitting 40) as the outer peripheral support portion of the vibration member is opposed to the inner peripheral edge of the vibration member in a manner spaced apart downward in the axial direction. A rubber cushioning protrusion 134 that protrudes downward in the axial direction is formed on the inner peripheral edge of the orifice member 38 in an annular shape continuously in the circumferential direction and faces the outer peripheral portion of the plate portion 132. It is positioned.
[0057]
In the engine mount 124 of this embodiment having such a structure, as shown by the phantom line in the drawing, the vibration member 50 is displaced upward by the electromagnetic driving device 80 to displace the plate portion 132. By contacting the inner peripheral edge of the orifice member 38 via the buffer protrusion 134, the lower opening of the central through hole 48 of the orifice member 38 is covered with the plate portion 132 in a fluid-tight manner. A closed region 136 is formed between the vibration member 50 and the plate portion 132 behind the member 50 (opposite to the pressure receiving chamber 62). In other words, the equilibrium chamber 72 is partitioned fluid-tightly by the plate portion 132, so that a closed region 136 filled with an incompressible fluid is formed between the vibration member 50 and the plate portion 132. As a result, the vibration member 50 (support rubber elastic body 54) is prevented from being deformed and displaced by the reinforcing action by the closed region 136 formed behind it, and in particular, the closed region 136 is incompressible fluid. Therefore, deformation and displacement of the vibration member 50 that accompanies a change in the volume of the pressure receiving chamber 62 are extremely advantageously prevented.
[0058]
Therefore, also in the engine mount 124 of the present embodiment, the pressure change in the pressure receiving chamber 62 is achieved by oscillating and displacing the oscillating member 50 in a state where the plate portion 132 is spaced apart from the orifice member 38. The As a result, an active vibration isolating effect can be obtained, and the pressure receiving chamber 62 accompanying the elastic deformation of the main rubber elastic body 16 can be obtained when the plate portion 132 is driven and displaced upward to come into contact with the orifice member 38. The displacement of the vibration member 50 (support rubber elastic body 54) due to the pressure change is prevented, and an effective pressure change is generated in the pressure receiving chamber 62 by the vibration input, so that the fluid flows through the orifice passage 46. The passive vibration isolation effect based on this can be effectively obtained, and therefore the same effects as those of the engine mount as the first embodiment can be effectively exhibited.
[0059]
As mentioned above, although embodiment of this invention was explained in full detail, these are illustrations to the last, Comprising: This invention is not limited at all by the specific description in these embodiment.
[0060]
For example, even when the plate member is disposed in the pressure receiving chamber, the plate member can be constituted by a vibration member. Specifically, for example, in the engine mount 122 as the second embodiment, the inner diameter dimension of the annular contact portion 128 is set to the outer diameter dimension of the upper bottom portion of the first connecting fitting 52 that constitutes the vibration member 50. The plate member is constituted by the upper bottom portion of the first connection fitting 52 by making the outer peripheral edge of the upper bottom portion of the first connection fitting 52 opposite the annular contact portion 128. Is possible.
[0061]
In addition, the plate member may be any member that can stably form a closed region between the vibration member and the vibration support member when closely contacting the vibration support member. For example, in the first embodiment, The metal plate 56 can be firmly pressed against the buffer protrusion 60 by attaching the metal plate 56 to the first coupling fitting 52 of the vibration member 50 in a state in which a relative displacement of about rattling is allowed. Under the state of being spaced apart from the buffer protrusion 60, the displacement of the metal plate 56 is reduced by allowing the relative displacement between the vibration member 50 and the first coupling fitting 52 when the vibration member 50 is subjected to vibration displacement. You may make it get. As described above, if the metal plate 56 is maintained in a substantially stationary state when the vibration member 50 is subjected to the vibration displacement, it is possible to avoid the resistance due to the displacement of the metal plate 56 and to make the vibration member 50 efficient. Therefore, the vibration displacement can be easily and easily performed.
[0062]
Furthermore, in the above embodiment, the present invention is applied to the vibration isolator having a structure in which the first support fitting 12 and the second support fitting 14 are opposed to each other in the mount axis direction which is the main vibration input direction. In addition to the above, the shaft member and the outer cylinder member as the first and second support members, which are spaced apart from each other in the radial direction, are connected by the main rubber elastic body interposed between them. In addition, the present invention is also applicable to a vibration isolator having a cylindrical structure in which a pressure receiving chamber in which an incompressible fluid is sealed between the shaft member and the outer cylinder member and an equilibrium chamber are formed.
[0063]
In addition, the present invention relates to various types of fluid-filled active vibration isolators (including vibration dampers) used in automobile body mounts, differential mounts, and other devices than automobiles in addition to automobile engine mounts. Any of these can be applied.
[0064]
In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.
[0065]
【The invention's effect】
As is apparent from the above description, in the fluid-filled active vibration isolator having the structure according to the present invention, a plate member that is displaced by a driving means that vibrates and displaces the vibration member is provided. By making it possible to form a closed region that restricts the displacement of the vibrating member by displacing it as necessary, active prevention based on the vibration displacement of the vibrating member can be performed in a state where the closed region is not formed. A vibration effect can be obtained effectively, and by forming the closed region, a passive vibration isolation effect based on the fluid action of the fluid that can flow through the orifice passage can be obtained effectively.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an automobile engine mount as a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing an automobile engine mount as a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing an automobile engine mount as a third embodiment of the present invention.
[Explanation of symbols]
10 Engine mount
12 First support bracket
14 Second support bracket
16 Body rubber elastic body
38 Orifice member
46 Orifice passage
50 Excitation member
52 First connecting bracket
54 Support rubber elastic body
56 Metal plate
60 Buffer protrusion
62 Pressure receiving chamber
64 Diaphragm
66 Second coupling bracket
72 equilibrium room
80 Electromagnetic drive

Claims

The first support member and the second support member are connected by a main rubber elastic body, and a part of the wall portion is formed by the main rubber elastic body to form a pressure receiving chamber in which an incompressible fluid is enclosed. In addition, another part of the wall portion of the pressure receiving chamber is constituted by a vibration member that is vibrated and displaced with elastic deformation by the driving means, while a part of the wall portion is constituted by a flexible film. In the fluid-filled active vibration isolator, an equilibrium chamber in which a compressive fluid is sealed is formed independently of the pressure receiving chamber, and an orifice passage is provided that communicates the balance chamber with the pressure receiving chamber.
While providing a plate member that spreads in a direction perpendicular to the excitation direction of the excitation member by the drive means, the plate member is displaced by the drive means to one side of the excitation direction of the excitation member, By bringing the outer peripheral portion of the plate member into close contact with the outer peripheral support portion of the vibration member, a closed region can be formed between the plate member and the vibration member, and the vibration member A fluid-filled active vibration isolator characterized by regulating displacement.

The equilibrium chamber is formed on the opposite side of the pressure receiving chamber with the vibration member interposed therebetween, and the plate member is disposed in the equilibrium chamber, and the plate member is disposed on the outer peripheral support portion of the vibration member. The closed region is formed on the side of the vibration member opposite to the pressure receiving chamber, and the displacement of the vibration member is regulated by the incompressible fluid filled in the closed region. The fluid-filled active vibration isolator according to claim 1 .

Exciting force is directly exerted by the driving means, a hard mounting member to which the plate member is mounted, and an outer peripheral edge extending from the mounting member at a substantially right angle with respect to the excitation direction, by being fixed to the support member, and a supporting rubber elastic allowed to elastically support the mounting member relative to said second support member, the claim vibrating member is constituted 1 or 2 A fluid-filled active vibration isolator as described in 1.

The opening area of an annular constriction region formed by an outer peripheral portion of the plate member in the pressure receiving chamber or the equilibrium chamber in which the plate member is disposed is set larger than an effective piston area of the vibration member. The fluid-filled active vibration isolator according to any one of 1 to 3 .

An annular constriction region formed by the outer peripheral portion of the plate member in the pressure receiving chamber or the equilibrium chamber in which the plate member is disposed has a fluid flow in a frequency range higher than the natural frequency of the excitation member. The fluid-filled active vibration isolator according to any one of claims 1 to 4 , having a resonance frequency.

The outer diameter dimension of the plate member is made larger than the outer diameter dimension of the vibration member, and the close contact portion between the plate member and the outer peripheral support portion is further on the outer peripheral side than the outer peripheral edge portion of the vibration member. The fluid-filled active vibration isolator according to any one of claims 1 to 5 , wherein