JP4174081B2

JP4174081B2 - Synthetic resin bearing

Info

Publication number: JP4174081B2
Application number: JP22121595A
Authority: JP
Inventors: 鉄也相田
Original assignee: Oiles Corp
Current assignee: Oiles Corp
Priority date: 1995-08-08
Filing date: 1995-08-08
Publication date: 2008-10-29
Anticipated expiration: 2015-08-08
Also published as: JPH0949529A

Description

【０００１】
【発明の属する技術分野】
本発明は、四輪自動車におけるストラット型サスペンション（マクファーソン式）に組み込まれて好適な合成樹脂軸受に関する。
【０００２】
【従来の技術】
一般にストラット型サスペンションは、主として四輪自動車の前輪に用いられ、主軸と一体となった外筒の中に油圧式ショックアブソーバを内蔵したストラットアッセンブリにコイルバネを組合せた構造をもっている。斯かるサスペンションには、（１）ストラットの軸線に対してコイルバネの軸線を積極的にオフセットさせ、該ストラットに内蔵されたショックアブソーバのピストンロッドの摺動を円滑に行わせる構造と、（２）ストラットの軸線に対してコイルバネの軸線を同一軸線上に配置させる構造のものとがある。いずれの構造のサスペンションにおいても、ステアリング操作によりストラットアッセンブリがコイルバネとともに回転するさい、当該回転を円滑に許容すべく車体の取付部材とコイルバネの上部バネ座シートとの間に軸受が配置されている。
【０００３】
そして、この軸受には、車体荷重（スラスト荷重）を支持すると同時に前記サスペンション構造に起因するラジアル荷重、すなわち前者の構造においては、コイルバネの軸線がストラットの軸線に対してオフセットされているため、静止状態においてもコイルバネのストラットの軸線方向への復元力によって生じるラジアル荷重を、また後者の構造においては、ストラットの軸線とコイルバネの軸線とを同一軸線上に配置するという製作上の困難性に起因するミスアライメントによって生じるラジアル荷重を、円滑に許容する性能が要求される。而して、上述した性能を満足するべく従来より、当該軸受にはボールを使用したころがり軸受あるいは合成樹脂製すべり軸受が使用されている。
【０００４】
しかしながら、ころがり軸受は、微小揺動や振動荷重等によりボールに疲労破壊を生じる虞があり、円滑なステアリング操作を長期間にわたって維持し難いという問題がある。また、合成樹脂すべり軸受は、上記ころがり軸受に比べて摩擦係数が高くステアリング操作を重くするという問題がある。さらに、いずれの軸受においても軸受摺動面への塵埃等異物の混入を防止するべく装着されたゴム弾性体からなるダストシールの摩擦力が高いことに起因するステアリング操作を重くするという問題、特に合成樹脂すべり軸受においてはステアリング操作を一層重くするという問題がある。
【０００５】
上記従来技術における合成樹脂すべり軸受の問題点を解決するべく、本出願人は、先に、実願昭６１−１３３９３１号（実公平４−５２４８８号）において、ゴム弾性体からなるダストシールを使用することなく摺動面への塵埃等異物の侵入を防止し、ステアリング操作時の操舵力の増大を防止できる合成樹脂スラスト軸受を提案した。
【０００６】
ここで、実願昭６１−１３３９３１号（実公平４−５２４８８号）で提案した技術を図５に基づいて説明する。図５に示す合成樹脂スラスト軸受Ａは、合成樹脂下部ケースＢと合成樹脂上部ケースＣと円板状の合成樹脂軸受片Ｄとからなり、該合成樹脂下部ケースＢは、内面に挿通孔１を有する円筒部２と該円筒部２の外周面に該円筒部の一部２ａを突出させて一体に形成された環状幅広鍔部３と該円筒部の一部突出部と該鍔部上面とで環状凹部４を形成して該鍔部外周縁に突設された環状係合突出部５を備えており、該合成樹脂上部ケースＣは、円板状の平面部６と該平面部の中央部に形成された円孔７と該平面部６の外周縁に一体に形成された環状係合垂下部８を備えており、該軸受片Ｄは、該下部ケースＢの環状凹部４にその下面を摺接させて配され、該下部ケースＢには上部ケースＣがその環状係合垂下部８を該下部ケースＢの環状係合突出部５に弾性装着させ、該弾性装着部にラビリンス作用による密封部を形成して相対回転可能に組み合わされている。
【０００７】
【発明が解決しようとする課題】
上述した構成の合成樹脂スラスト軸受Ａは、図６に示すように、挿通孔１、円孔７にストラットのピストンロッドＲを挿通して下部ケースＢ及び上部ケースＣをピストンロッドＲの外周面に装着し、下部ケースＢの円筒部２外周面を上部バネ座シートＳの孔Ｓ１に嵌合固定させるとともに下部ケースＢの環状幅広鍔部３下面を上部バネ座シートＳの平面部Ｓ２に当接させ、上部ケースＣの円板状平面部６上面を車体取付部材Ｆの下面に当接させて、上部バネ座シートＳと車体取付部材Ｆとの間に配置される。
【０００８】
このように配置された合成樹脂スラスト軸受Ａは、上部バネ座シートＳと車体取付部材Ｆとの相対回転を円滑に許容し、ステアリング操作を円滑に行わせるものである。しかしながら、上部バネ座シートＳと車体取付部材Ｆとの間に配置された合成樹脂スラスト軸受Ａに、前述したラジアル荷重が作用した場合、当該ラジアル荷重は下部ケースＢの円筒部２の挿通孔１とこの挿通孔１を挿通するピストンロッドＲとの摺接、換言すれば合成樹脂と金属との摺接によって許容されることになるため、摺動抵抗が大きく、円滑に許容し難いという問題がある。
【０００９】
本発明は、前記諸点に鑑みてなされたものであって、その目的とするところは、スラスト荷重及びラジアル荷重を摺動摩擦抵抗の小さい合成樹脂同志の組合せによって円滑に許容でき、またゴム弾性体からなるダストシールを使用することなく軸受摺動面への塵埃等の侵入を防止できる合成樹脂軸受を提供することにある。
【００１０】
【課題を解決するための手段】
本発明によれば上記目的は、
車体の取付部材（Ｆ）とストラットアッセンブリの上部バネ座シート（Ｓ）との間に配される合成樹脂軸受（１０）であって、
合成樹脂製の下部ケース（２０）と、この下部ケースに組合わされた合成樹脂製の上部ケース（３０）と、上部ケースと下部ケースとの間に配された合成樹脂製の環状スラスト軸受体（４１）とを具備しており、
該下部ケース（２０）は、円筒部（２１）と該円筒部の上端部外周面に延設された環状幅広鍔部（２２）と該円筒部の上端部端面（２１ａ）と連なって該環状幅広鍔部（２２）の上面に立設された環状突出部（２３）と該環状突出部（２３）と環状幅広鍔部（２２）の上面とで環状凹部（２４）を形成して該環状幅広鍔部の外周縁に立設された環状係合突出部（２５）と該円筒部（２１）の下端部内周面に径方向内側に延設された環状鍔部（２７）と該環状鍔部（２７）の内面に形成された環状係合段部（２７ａ）とを備えており、
該上部ケース（３０）は、内周面（３１）を挿通孔とした円筒部（３２）と該円筒部（３２）の上端部外周面に延設された環状幅広鍔部（３３）と該環状幅広鍔部（３３）の外周縁に垂下した環状係合垂下部（３４）と該円筒部（３２）の下端部外周面に形成された環状切欠き部（３６）とを備えており、
該上部ケース（３０）は、円筒部（３２）の外周面と該下部ケース（２０）の円筒部（２１）の内周面との間に軸受隙間を保持して該円筒部（３２）の外周面と該下部ケース（２０）の円筒部（２１）の内周面との合成樹脂同志の摺動によるラジアル軸受部を形成し、かつ環状係合垂下部（３４）を該下部ケース（２０）の環状係合突出部（２５）に弾性装着させるとともに、該円筒部（３２）の環状切欠き部（３６）を該下部ケース（２０）の円筒部（２１）の環状係合段部（２７ａ）に係合させて該下部ケース（２０）に組合わされており、
環状スラスト軸受体（４１）は、下部ケース（２０）の環状凹部（２４）と該環状凹部（２４）に対面する上部ケース（３０）の環状幅広鍔部（３３）の下面との間の空間に配されていることを特徴とする合成樹脂軸受、
によって達成される。
【００１１】
また、上記構成からなる合成樹脂軸受において、
下部ケース（２０）は、環状幅広鍔部（２２）の上面に、該環状係合突出部（２５）と径方向内側に環状深溝（２８）を形成して立設されるとともに該環状突出部（２３）と環状幅広鍔部（２２）の上面とで環状凹部（２４）を形成する外側環状突出部（２９）をさらに備えており、
該上部ケース（３０）は、環状幅広鍔部（３３）の下面に、該環状係合垂下部（３４）と径方向内側に環状溝（３７）を形成して垂下した環状垂下部（３８）をさらに備えており、
該上部ケース（３０）は、円筒部（３２）の外周面と該下部ケース（２０）の円筒部（２１）の内周面との間に軸受隙間を保持して該円筒部（３２）の外周面と該下部ケース（２０）の円筒部（２１）の内周面との合成樹脂同志の摺動によるラジアル軸受部を形成し、かつ環状垂下部（３８）の端部を該下部ケース（２０）の外側環状突出部（２９）の端部とその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成し環状係合垂下部（３４）を該下部ケース（２０）の環状係合突出部（２５）に弾性装着させるとともに、該円筒部（３２）の環状切欠き部（３６）を該下部ケース（２０）の円筒部（２１）の環状係合段部（２７ａ）に係合させて該下部ケース（２０）に組合わされてなる、
合成樹脂軸受とすることもできる。
【００１２】
本発明の合成樹脂軸受における上部ケース及び下部ケースを形成する合成樹脂は、耐摩耗性、耐衝撃性、耐クリープ性等の摺動特性及び機械的特性に優れていることが好ましく、また、上部ケースと下部ケースとの間に配される環状スラスト軸受体を形成する合成樹脂は、とくに自己潤滑性を有することが好ましく、例えばポリアセタール樹脂、ポリアミド樹脂、ポリブチレンテレフタレート樹脂（ＰＢＴ）等の熱可塑性ポリエステル樹脂、ポリエチレン樹脂、ポリプロピレン樹脂等のポリオレフィン樹脂等が使用される。
【００１３】
上部ケース及び下部ケースには、環状スラスト軸受体を形成する合成樹脂と同様の合成樹脂が使用されるが、特に環状スラスト軸受体に使用される合成樹脂と摺動摩擦特性の良好な組合せであって、しかも比較的剛性の高い合成樹脂であることが望ましい。その望ましい組合せについて例示すると、上部ケースにポリアセタール樹脂を、下部ケースにポリアミド樹脂を、環状スラスト軸受体にポリオレフィン樹脂を使用する組合せである。
【００１４】
本発明の合成樹脂軸受は、四輪自動車におけるストラット型サスペンション（マクファーソン式）に組込まれ、車体の取付部材とストラットアッセンブリの上部バネ座シートとの間に配されて使用される。そして、ステアリング操作によりストラットアッセンブリが回動されると、上部ケースに対して下部ケースが回転され、この下部ケースの回転は、上部ケース及び下部ケース間に配される合成樹脂製の環状スラスト軸受体によって円滑に許容され、ステアリング操作が円滑に行われる。また、合成樹脂軸受にラジアル荷重が作用した場合でも、当該ラジアル荷重は、上部ケースの円筒部外周面と下部ケースの円筒部内周面との間に軸受隙間を保持して形成されたラジアル軸受部における合成樹脂同志の摺動によって円滑に許容される。
【００１５】
【発明の実施の形態】
つぎに本発明の実施の形態を、図に示す好ましい実施例に基づいてさらに詳細に説明する。なお、本発明はこれら実施例に何ら限定されないのである。
【００１６】
図１において、本例の合成樹脂軸受１０は、合成樹脂製の下部ケース２０と、この下部ケース２０に組合わされた合成樹脂製の上部ケース３０と、下部ケース２０と上部ケース３０との間に配された合成樹脂製の環状スラスト軸受体４１とを具備している。
【００１７】
下部ケース２０は、円筒部２１と該円筒部２１の上端部外周面に延設された環状幅広鍔部２２と該円筒部２１の上端部端面２１ａと連なって該環状幅広鍔部２２の上面に立設された環状突出部２３と該環状突出部２３と該環状幅広鍔部２２の上面とで環状凹部２４を形成して該環状幅広鍔部２２の外周縁に立設された環状係合突出部２５と該環状係合突出部２５の外周面に形成された係合部２６を備えている。該係合部２６は、該環状係合突出部２５の端部から外方に向けて傾斜するテーパ面部と該テーパ面部と連続し、環状凸角部を形成して該環状幅広鍔部２２の外周面に連なるテーパ面部とからなっている。
【００１８】
上端部に環状幅広鍔部２２を備えた円筒部２１の下端部内周面には、径方向内側に延設された環状鍔部２７が形成されているとともに該環状鍔部２７の内面には環状係合段部２７ａが形成されている。
【００１９】
上部ケース３０は、内周面３１を挿通孔とした円筒部３２と該円筒部３２の上端部外周面に延設された環状幅広鍔部３３と該環状幅広鍔部３３の外周縁に垂下した環状係合垂下部３４と該環状係合垂下部３４の内周面に形成された係合フック部３５を備えている。該係合フック部３５は、その内周面の基部から外方に向けて傾斜するテーパ面部と該テーパ面部と連続し、環状凹角部を形成して該環状係合垂下部３４の下端に連なるテーパ面部とからなっている。
【００２０】
上端部に環状幅広鍔部３３を備えた円筒部３２の下端部外周面には、環状切欠き部３６が形成されている。
【００２１】
該上部ケース３０は、円筒部３２の外周面と下部ケース２０の円筒部２１の内周面との間に軸受隙間を保持して該円筒部３２の外周面と該下部ケース２０の円筒部２１の内周面との合成樹脂同志の摺動によるラジアル軸受部を形成し、環状係合垂下部３４の内周面の係合フック部３５を該下部ケース２０の環状係合突出部２５の外周面の係合部２６に弾性装着させ、該円筒部３２の端部の環状切欠き部３６を該下部ケース２０の円筒部２１の端部に形成された環状係合段部２７ａに係合させて該下部ケース２０に組合わされている。このように組合わされた上部ケース３０と下部ケース２０との間には外周側の弾性装着部と内周側の環状切欠き部３６と環状係合段部２７ａとの係合部に、外部から軸受摺動面への塵埃等異物の侵入を防止する密封部が形成されている。
【００２２】
環状スラスト軸受体４１は、下部ケース２０の環状凹部２４と該環状凹部２４に対面する上部ケース３０の環状幅広鍔部３３の下面との間の空間に、該環状凹部２４の底面と環状幅広鍔部３３の下面に対して摺動自在に配される。該環状スラスト軸受体４１は、該環状凹部２４を形成する環状突出部２３の外径よりも大きい内径を有し、環状係合突出部２５の内径よりも小さい外径を有しているとともに該環状スラスト軸受体４１の両端面には、その内径側の周縁にリング溝４２と該リング溝４２から外径側に開口する複数個の放射状溝４３が円周方向に等間隔に、かつ３０度の位相差をもって形成されている。該リング溝４２及び放射状溝４３は、グリースなどの潤滑剤の溜り部となる。
【００２３】
このように構成された合成樹脂軸受１０は、図３に示すストラットアッセンブリに組込まれる。すなわち、合成樹脂軸受１０は、上部ケース３０の円筒部３２の内周面３１にストラットアッセンブリのピストンロッドＲを、当該ピストンロッドＲの外周面と内周面（挿通孔）３１との間に軸受隙間（クリアランス）を保持させて挿通し、下部ケース２０の円筒部２１の外周面を、上部バネ座シートＳの平面部Ｓ１に形成された孔Ｓ２と該平面部Ｓ１の上面に固定された円板状座板Ｓ３の孔Ｓ４に嵌合固定させるとともに環状幅広鍔部２２の下面を該円板状座板Ｓ３の上面に当接させ、上部ケース３０の環状幅広鍔部３３の上面を車体側取付部材Ｆの下面に当接させて上部バネ座シートＳと車体側取付部材Ｆとの間に配置される。
【００２４】
上部バネ座シートＳと車体取付部材Ｆとの間に配置された合成樹脂軸受１０に、サスペンションの構造に起因するラジアル荷重が作用した場合は、当該ラジアル荷重は上部ケース３０の円筒部３２の外周面と下部ケース２０の円筒部２１の内周面との間に軸受隙間を保持して形成されたラジアル軸受部における上部ケース３０の円筒部３２の外周面と下部ケース２０の円筒部２１の内周面との合成樹脂同志の摺動によって円滑に許容される。また、車体重量は、下部ケース２０の環状凹部２４と該環状凹部２４に対面する上部ケース３０の環状幅広鍔部３３の下面とこれら環状凹部２４の底面と環状幅広鍔部３３の下面に対して摺動自在に配された環状スラスト軸受体４１とで支持するとともにスラスト荷重はこれら下部ケース２０の環状凹部２４と環状スラスト軸受体４１と上部ケース３０の環状幅広鍔部３３の下面との合成樹脂同志の摺動によって円滑に許容される。
【００２５】
図４は合成樹脂軸受１０の他の具体例を示すもので、図４において、本例の合成樹脂軸受１０は、前述した合成樹脂軸受１０における下部ケース２０の環状幅広鍔部２２の上面に、該環状係合突出部２５と径方向内側に環状深溝２８を形成して立設された外側環状突出部２９をさらに備えており、該上部ケース３０は環状幅広鍔部３３の下面に、該環状係合垂下部３４と径方向内側に環状溝３７を形成して垂下した環状垂下部３８をさらに備えている。該上部ケース３０は円筒部３２の外周面と該下部ケース２０の円筒部２１の内周面との間に軸受隙間を保持して該円筒部３２の外周面と該下部ケース２０の円筒部２１の内周面との合成樹脂同志の摺動によるラジアル軸受部を形成し、かつ環状垂下部３８の端部を該下部ケース２０の外側環状突出部２９の端部とその径方向に重畳させて該重畳部にラビリンス作用による密封部を形成するとともに環状係合垂下部３４の内周面の係合フック部３５を下部ケース２０の環状係合突出部２５の外周面の係合部２６に弾性装着させ、該円筒部３２の端部の環状切欠き部３６を該下部ケース２０の円筒部２１の端部の環状係合段部２７ａに係合させて該下部ケース２０に組合わされている。
【００２６】
このように組合わされた上部ケース３０と下部ケース２０との間には、外周側の弾性装着部と環状垂下部３８の端部と下部ケース２０の外側環状突出部２９の端部との重畳部に形成されたラビリンス作用による密封部と内周側の環状切欠き部３６と環状係合段部２７ａとの係合部に密封部が形成されているので、外部から軸受摺動面への塵埃等異物の侵入が防止される。
【００２７】
環状スラスト軸受体４１は、下部ケース２０の環状凹部２４と該環状凹部２４に対面する上部ケース３０の環状幅広鍔部３３の下面との間の空間に、該環状凹部２４の底面と環状幅広鍔部３３の下面に対して摺動自在に配される。該環状スラスト軸受体４１は、該環状凹部２４を形成する環状突出部２３の外径よりも大きい内径を有し、外側環状突出部２９の内径よりも小さい外径を有している。
【００２８】
【発明の効果】
本発明の合成樹脂軸受では、サスペンションの構造に起因するラジアル荷重が作用した場合でも、当該ラジアル荷重は上部ケースの円筒部の外周面と下部ケースの円筒部の内周面との間に軸受隙間を保持して形成されたラジアル軸受部における上部ケース３０の円筒部３２の外周面と下部ケース２０の円筒部２１の内周面との合成樹脂同志の摺動によって円滑に許容される。
【図面の簡単な説明】
【図１】本発明の合成樹脂軸受の断面図である。
【図２】図１に示す合成樹脂軸受における環状スラスト軸受体の平面図である。
【図３】図１に示す合成樹脂軸受をストラットアッセンブリに組込んだ状態の断面図である。
【図４】本発明の合成樹脂軸受の他の具体例を示す断面図である。
【図５】従来技術の合成樹脂軸受の断面図である。
【図６】図５に示す合成樹脂軸受をストラットアッセンブリに組込んだ状態の断面図である。
【符号の説明】
１０合成樹脂軸受
２０下部ケース
２１円筒部
２２環状幅広鍔部
２３環状突出部
２４環状凹部
２５環状係合突出部
３０上部ケース
３１内周面
３２円筒部
３３環状幅広鍔部
３４環状係合垂下部
４１環状スラスト軸受体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin bearing suitable for being incorporated in a strut type suspension (McPherson type) in a four-wheeled vehicle.
[0002]
[Prior art]
In general, a strut suspension is mainly used for a front wheel of a four-wheeled vehicle, and has a structure in which a coil spring is combined with a strut assembly in which a hydraulic shock absorber is incorporated in an outer cylinder integrated with a main shaft. Such a suspension includes (1) a structure in which the axis of the coil spring is positively offset with respect to the axis of the strut, and the piston rod of the shock absorber built in the strut smoothly slides. There is a structure in which the axis of the coil spring is arranged on the same axis with respect to the axis of the strut. In any suspension structure, when the strut assembly is rotated together with the coil spring by a steering operation, a bearing is disposed between the mounting member of the vehicle body and the upper spring seat of the coil spring so as to allow the rotation smoothly.
[0003]
This bearing supports the vehicle body load (thrust load) and at the same time the radial load resulting from the suspension structure, that is, in the former structure, the axis of the coil spring is offset with respect to the axis of the strut. The radial load caused by the restoring force of the coil spring in the axial direction of the strut even in the state, and in the latter structure, the strut axis and the coil spring axis are arranged on the same axis. Performance that smoothly allows radial loads caused by misalignment is required. Thus, in order to satisfy the above-described performance, conventionally, a rolling bearing using a ball or a synthetic resin sliding bearing has been used as the bearing.
[0004]
However, the rolling bearing may cause fatigue damage to the ball due to minute swing or vibration load, and there is a problem that it is difficult to maintain a smooth steering operation over a long period of time. Further, the synthetic resin sliding bearing has a problem that it has a higher coefficient of friction and makes the steering operation heavier than the above rolling bearing. Furthermore, in any bearing, there is a problem that the steering operation becomes heavy due to the high frictional force of the dust seal made of a rubber elastic body that is mounted to prevent foreign matters such as dust from entering the sliding surface of the bearing. The resin sliding bearing has a problem that the steering operation becomes heavier.
[0005]
In order to solve the problems of the synthetic resin plain bearing in the above-mentioned prior art, the present applicant previously uses a dust seal made of a rubber elastic body in Japanese Utility Model Application No. 61-133931 (Japanese Utility Model Publication No. 4-52488). We proposed a synthetic resin thrust bearing that prevents foreign matter such as dust from entering the sliding surface and prevents an increase in steering force during steering operation.
[0006]
Here, the technique proposed in Japanese Utility Model Application No. 61-133931 (Japanese Utility Model Publication No. 4-52488) will be described with reference to FIG. The synthetic resin thrust bearing A shown in FIG. 5 includes a synthetic resin lower case B, a synthetic resin upper case C, and a disc-shaped synthetic resin bearing piece D. The synthetic resin lower case B has an insertion hole 1 on its inner surface. A cylindrical portion 2 having an annular wide flange 3 integrally formed by projecting a portion 2a of the cylindrical portion on the outer peripheral surface of the cylindrical portion 2, a partial protruding portion of the cylindrical portion, and an upper surface of the flange portion. An annular engagement protrusion 5 is provided that forms an annular recess 4 and projects from the outer periphery of the flange, and the synthetic resin upper case C includes a disk-shaped flat portion 6 and a central portion of the flat portion. And the annular engagement hanging portion 8 formed integrally with the outer peripheral edge of the flat portion 6, and the bearing piece D has its lower surface in the annular recess 4 of the lower case B. The lower case B is arranged in sliding contact with the upper case C, and the annular engagement hanging portion 8 is connected to the annular engagement protrusion of the lower case B. The elastic is attached, it is combined to be relatively rotated to form a seal by the labyrinth effect the elastic mounting unit.
[0007]
[Problems to be solved by the invention]
As shown in FIG. 6, the synthetic resin thrust bearing A having the above-described configuration is configured such that the piston rod R of the strut is inserted into the insertion hole 1 and the circular hole 7 so that the lower case B and the upper case C are placed on the outer peripheral surface of the piston rod R. Attach and fix the outer peripheral surface of the cylindrical portion 2 of the lower case B to the hole S1 of the upper spring seat S, and contact the lower surface of the annular wide flange portion 3 of the lower case B with the flat portion S2 of the upper spring seat S Then, the upper surface of the disc-shaped flat portion 6 of the upper case C is disposed between the upper spring seat S and the vehicle body mounting member F with the lower surface of the vehicle body mounting member F being in contact therewith.
[0008]
The synthetic resin thrust bearing A arranged in this manner smoothly allows relative rotation between the upper spring seat S and the vehicle body attachment member F, and smoothly performs the steering operation. However, when the aforementioned radial load is applied to the synthetic resin thrust bearing A disposed between the upper spring seat S and the vehicle body attachment member F, the radial load is inserted into the insertion hole 1 of the cylindrical portion 2 of the lower case B. And the piston rod R that is inserted through the insertion hole 1, in other words, is allowed by sliding contact between the synthetic resin and the metal, so that there is a problem that the sliding resistance is large and it is difficult to allow it smoothly. is there.
[0009]
The present invention has been made in view of the above points, and the object of the present invention is to allow a thrust load and a radial load smoothly by a combination of synthetic resins having a small sliding friction resistance, and from a rubber elastic body. It is an object of the present invention to provide a synthetic resin bearing capable of preventing dust and the like from entering the bearing sliding surface without using a dust seal.
[0010]
[Means for Solving the Problems]
According to the present invention, the object is
A synthetic resin bearing (10) disposed between a mounting member (F) of a vehicle body and an upper spring seat (S) of a strut assembly,
A synthetic resin lower case (20), a synthetic resin upper case (30) combined with the lower case, and a synthetic resin annular thrust bearing body (between the upper case and the lower case) 41) and
The lower case (20) is connected to the cylindrical portion (21), the annular wide flange portion (22) extending on the outer peripheral surface of the upper end portion of the cylindrical portion, and the end surface (21a) of the upper end portion of the cylindrical portion. An annular recess (24) is formed by the annular protrusion (23) standing on the upper surface of the wide flange (22), the annular protrusion (23), and the upper surface of the annular wide flange (22). An annular engagement protrusion (25) erected on the outer peripheral edge of the wide collar, an annular collar (27) extending radially inward on the inner peripheral surface of the lower end of the cylindrical part (21), and the annular collar An annular engagement step portion (27a) formed on the inner surface of the portion (27),
The upper case (30) includes a cylindrical portion (32) having an inner peripheral surface (31) as an insertion hole, an annular wide flange portion (33) extending on the outer peripheral surface of the upper end portion of the cylindrical portion (32), and the upper case (30). An annular engagement hanging portion (34) suspended from the outer peripheral edge of the annular wide flange portion (33), and an annular notch portion (36) formed on the outer peripheral surface of the lower end portion of the cylindrical portion (32);
The upper case (30) retains a bearing gap between the outer peripheral surface of the cylindrical portion (32) and the inner peripheral surface of the cylindrical portion (21) of the lower case (20). A radial bearing portion is formed by sliding of the synthetic resin between the outer peripheral surface and the inner peripheral surface of the cylindrical portion (21) of the lower case (20), and the annular engagement hanging portion (34) is connected to the lower case (20). ) Is elastically attached to the annular engagement protrusion (25), and the annular notch (36) of the cylindrical portion (32) is connected to the annular engagement step portion (21) of the cylindrical portion (21) of the lower case (20). 27a) is engaged with the lower case (20),
The annular thrust bearing body (41) is a space between the annular recess (24) of the lower case (20) and the lower surface of the annular wide flange (33) of the upper case (30) facing the annular recess (24). Synthetic resin bearings, characterized in that
Achieved by:
[0011]
In the synthetic resin bearing having the above-described configuration,
The lower case (20) is erected on the upper surface of the annular wide flange (22) by forming the annular engagement protrusion (25) and an annular deep groove (28) radially inward, and the annular protrusion An outer annular protrusion (29) that forms an annular recess (24) with (23) and the upper surface of the annular wide flange (22);
The upper case (30) has an annular hanging portion (38) that is suspended by forming an annular groove (37) radially inward of the annular engagement hanging portion (34) on the lower surface of the annular wide flange portion (33). Further comprising
The upper case (30) retains a bearing gap between the outer peripheral surface of the cylindrical portion (32) and the inner peripheral surface of the cylindrical portion (21) of the lower case (20). A radial bearing portion is formed by sliding of synthetic resin between the outer peripheral surface and the inner peripheral surface of the cylindrical portion (21) of the lower case (20), and the end of the annular hanging portion (38) is connected to the lower case ( 20) and an end portion of the outer annular protrusion (29) which is overlapped with the radial direction thereof to form a sealing portion by labyrinth action on the overlapping portion, and the annular engagement hanging portion (34) is formed in the annular shape of the lower case (20). The engagement protrusion (25) is elastically mounted, and the annular notch (36) of the cylindrical portion (32) is connected to the annular engagement step (27a) of the cylindrical portion (21) of the lower case (20). Engaged and combined with the lower case (20),
It can also be a synthetic resin bearing.
[0012]
The synthetic resin forming the upper case and the lower case in the synthetic resin bearing of the present invention preferably has excellent sliding characteristics and mechanical characteristics such as wear resistance, impact resistance, and creep resistance. The synthetic resin forming the annular thrust bearing body disposed between the case and the lower case is particularly preferably self-lubricating, for example, thermoplastic such as polyacetal resin, polyamide resin, polybutylene terephthalate resin (PBT). Polyolefin resins such as polyester resin, polyethylene resin, and polypropylene resin are used.
[0013]
The upper case and the lower case are made of a synthetic resin similar to the synthetic resin that forms the annular thrust bearing body. In particular, the synthetic resin used for the annular thrust bearing body and a good combination of sliding friction characteristics are used. Moreover, it is desirable that the synthetic resin is relatively high in rigidity. As an example of the desirable combination, a polyacetal resin is used for the upper case, a polyamide resin is used for the lower case, and a polyolefin resin is used for the annular thrust bearing body.
[0014]
The synthetic resin bearing of the present invention is incorporated in a strut type suspension (McPherson type) in a four-wheeled vehicle, and is used by being disposed between a mounting member of a vehicle body and an upper spring seat of a strut assembly. When the strut assembly is rotated by the steering operation, the lower case is rotated with respect to the upper case, and the rotation of the lower case is an annular thrust bearing body made of synthetic resin disposed between the upper case and the lower case. Therefore, the steering operation is smoothly performed. In addition, even when a radial load is applied to the synthetic resin bearing, the radial load is formed by holding a bearing gap between the outer peripheral surface of the cylindrical portion of the upper case and the inner peripheral surface of the cylindrical portion of the lower case. Is allowed smoothly by sliding between synthetic resins.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in more detail based on preferred examples shown in the drawings. In addition, this invention is not limited to these Examples at all.
[0016]
In FIG. 1, a synthetic resin bearing 10 of this example includes a lower case 20 made of synthetic resin, an upper case 30 made of synthetic resin combined with the lower case 20, and between the lower case 20 and the upper case 30. An annular thrust bearing body 41 made of synthetic resin is provided.
[0017]
The lower case 20 is connected to the upper surface of the annular wide flange portion 22 by connecting the cylindrical portion 21, the annular wide flange portion 22 extending on the outer peripheral surface of the upper end portion of the cylindrical portion 21, and the upper end surface 21 a of the cylindrical portion 21. An annular recess 24 is formed by the upright annular protrusion 23, the annular protrusion 23, and the upper surface of the annular wide flange 22, and an annular engagement protrusion that is provided upright on the outer peripheral edge of the annular wide flange 22. An engagement portion 26 formed on the outer peripheral surface of the portion 25 and the annular engagement protrusion 25 is provided. The engaging portion 26 is continuous with the tapered surface portion that is inclined outward from the end portion of the annular engaging protrusion 25 and the tapered surface portion, and forms an annular convex corner portion to form the annular wide flange portion 22. It consists of the taper surface part which continues to an outer peripheral surface.
[0018]
An annular flange 27 extending radially inward is formed on the inner peripheral surface of the lower end portion of the cylindrical portion 21 having the annular wide flange portion 22 at the upper end portion, and an annular surface is formed on the inner surface of the annular flange portion 27. An engagement step portion 27a is formed.
[0019]
The upper case 30 hangs down on a cylindrical portion 32 having an inner peripheral surface 31 as an insertion hole, an annular wide flange portion 33 extending on the outer peripheral surface of the upper end portion of the cylindrical portion 32, and an outer peripheral edge of the annular wide flange portion 33. An annular engagement hanging portion 34 and an engagement hook portion 35 formed on the inner peripheral surface of the annular engagement hanging portion 34 are provided. The engagement hook portion 35 is continuous with the tapered surface portion inclined outward from the base portion of the inner peripheral surface thereof, forms an annular concave corner portion, and continues to the lower end of the annular engagement hanging portion 34. It consists of a tapered surface.
[0020]
An annular notch 36 is formed on the outer peripheral surface of the lower end portion of the cylindrical portion 32 having the annular wide flange portion 33 at the upper end portion.
[0021]
The upper case 30 holds a bearing gap between the outer peripheral surface of the cylindrical portion 32 and the inner peripheral surface of the cylindrical portion 21 of the lower case 20, and the outer peripheral surface of the cylindrical portion 32 and the cylindrical portion 21 of the lower case 20. A radial bearing portion is formed by the sliding of synthetic resin with the inner peripheral surface of the inner peripheral surface of the lower case 20, and the engaging hook portion 35 on the inner peripheral surface of the annular engaging hanging portion 34 is connected to the outer periphery of the annular engaging protruding portion 25 of the lower case 20. It is elastically attached to the engaging portion 26 of the surface, and the annular notch 36 at the end of the cylindrical portion 32 is engaged with the annular engaging step portion 27 a formed at the end of the cylindrical portion 21 of the lower case 20. And combined with the lower case 20. Between the upper case 30 and the lower case 20 combined in this manner, an outer peripheral elastic mounting portion, an inner peripheral annular cutout portion 36, and an annular engagement step portion 27a are engaged from the outside. A sealing portion is formed to prevent foreign matters such as dust from entering the bearing sliding surface.
[0022]
The annular thrust bearing body 41 is formed in a space between the annular recess 24 of the lower case 20 and the lower surface of the annular wide flange portion 33 of the upper case 30 facing the annular recess 24. It is slidably arranged on the lower surface of the portion 33. The annular thrust bearing body 41 has an inner diameter that is larger than the outer diameter of the annular protrusion 23 that forms the annular recess 24, and has an outer diameter that is smaller than the inner diameter of the annular engagement protrusion 25. On both end faces of the annular thrust bearing body 41, a ring groove 42 and a plurality of radial grooves 43 opened from the ring groove 42 to the outer diameter side are formed at equal intervals in the circumferential direction and 30 degrees on the inner periphery. The phase difference is formed. The ring groove 42 and the radial groove 43 serve as a reservoir for a lubricant such as grease.
[0023]
The synthetic resin bearing 10 configured as described above is assembled in the strut assembly shown in FIG. That is, the synthetic resin bearing 10 has a piston rod R of a strut assembly on the inner peripheral surface 31 of the cylindrical portion 32 of the upper case 30 and a bearing between the outer peripheral surface of the piston rod R and the inner peripheral surface (insertion hole) 31. A circle that is inserted while holding a gap (clearance), and the outer peripheral surface of the cylindrical portion 21 of the lower case 20 is fixed to the hole S2 formed in the flat portion S1 of the upper spring seat S and the upper surface of the flat portion S1. The plate-shaped seat plate S3 is fitted and fixed in the hole S4, and the lower surface of the annular wide collar portion 22 is brought into contact with the upper surface of the disk-shaped seat plate S3, so that the upper surface of the annular wide collar portion 33 of the upper case 30 is It is disposed between the upper spring seat S and the vehicle body side mounting member F in contact with the lower surface of the mounting member F.
[0024]
When a radial load due to the suspension structure is applied to the synthetic resin bearing 10 disposed between the upper spring seat S and the vehicle body attachment member F, the radial load is applied to the outer periphery of the cylindrical portion 32 of the upper case 30. The outer peripheral surface of the cylindrical portion 32 of the upper case 30 and the inner portion of the cylindrical portion 21 of the lower case 20 in a radial bearing portion formed by holding a bearing gap between the surface and the inner peripheral surface of the cylindrical portion 21 of the lower case 20. It is smoothly allowed by the sliding of the synthetic resin with the peripheral surface. The vehicle body weight is relative to the annular recess 24 of the lower case 20, the lower surface of the annular wide flange portion 33 of the upper case 30 facing the annular recess 24, the bottom surface of these annular recesses 24, and the lower surface of the annular wide flange portion 33. A synthetic resin is supported by the annular thrust bearing body 41 slidably disposed and the thrust load is formed by the annular recess 24 of the lower case 20, the annular thrust bearing body 41, and the lower surface of the annular wide flange portion 33 of the upper case 30. Smoothly allowed by comrade sliding.
[0025]
FIG. 4 shows another specific example of the synthetic resin bearing 10. In FIG. 4, the synthetic resin bearing 10 of this example is formed on the upper surface of the annular wide flange portion 22 of the lower case 20 in the synthetic resin bearing 10 described above. The ring-shaped engagement protrusion 25 is further provided with an outer ring-shaped protrusion 29 erected by forming an annular deep groove 28 on the radially inner side. It further includes an engagement hanging portion 34 and an annular hanging portion 38 that is suspended by forming an annular groove 37 radially inward. The upper case 30 holds a bearing gap between the outer peripheral surface of the cylindrical portion 32 and the inner peripheral surface of the cylindrical portion 21 of the lower case 20, and the outer peripheral surface of the cylindrical portion 32 and the cylindrical portion 21 of the lower case 20. A radial bearing portion is formed by sliding on the inner peripheral surface of the synthetic resin, and the end portion of the annular hanging portion 38 is overlapped with the end portion of the outer annular projecting portion 29 of the lower case 20 in the radial direction thereof. A sealing portion by labyrinth action is formed in the overlapping portion, and the engagement hook portion 35 on the inner peripheral surface of the annular engagement hanging portion 34 is elastically engaged with the engagement portion 26 on the outer peripheral surface of the annular engagement protrusion 25 of the lower case 20. The annular notch 36 at the end of the cylindrical portion 32 is engaged with the annular engagement step portion 27 a at the end of the cylindrical portion 21 of the lower case 20 so as to be combined with the lower case 20.
[0026]
Between the upper case 30 and the lower case 20 combined in this manner, an overlapping portion of the elastic mounting portion on the outer peripheral side, the end portion of the annular hanging portion 38, and the end portion of the outer annular projecting portion 29 of the lower case 20. Since a sealing portion is formed in the sealing portion formed by the labyrinth action, the engaging portion of the inner circumferential annular notch portion 36 and the annular engaging step portion 27a, dust from the outside to the bearing sliding surface is formed. Intrusion of foreign matter such as is prevented.
[0027]
The annular thrust bearing body 41 is formed in a space between the annular recess 24 of the lower case 20 and the lower surface of the annular wide flange portion 33 of the upper case 30 facing the annular recess 24. It is slidably arranged on the lower surface of the portion 33. The annular thrust bearing body 41 has an inner diameter that is larger than the outer diameter of the annular protrusion 23 that forms the annular recess 24, and an outer diameter that is smaller than the inner diameter of the outer annular protrusion 29.
[0028]
【The invention's effect】
In the synthetic resin bearing of the present invention, even when a radial load due to the suspension structure is applied, the radial load is generated between the outer peripheral surface of the cylindrical portion of the upper case and the inner peripheral surface of the cylindrical portion of the lower case. Is smoothly allowed by the sliding of the synthetic resin between the outer peripheral surface of the cylindrical portion 32 of the upper case 30 and the inner peripheral surface of the cylindrical portion 21 of the lower case 20 in the radial bearing portion formed by holding.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a synthetic resin bearing of the present invention.
FIG. 2 is a plan view of an annular thrust bearing body in the synthetic resin bearing shown in FIG.
3 is a cross-sectional view showing a state in which the synthetic resin bearing shown in FIG. 1 is assembled in a strut assembly.
FIG. 4 is a cross-sectional view showing another specific example of the synthetic resin bearing of the present invention.
FIG. 5 is a cross-sectional view of a conventional synthetic resin bearing.
6 is a cross-sectional view showing a state in which the synthetic resin bearing shown in FIG. 5 is assembled in a strut assembly.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Synthetic resin bearing 20 Lower case 21 Cylindrical part 22 Annular wide collar part 23 Annular protrusion part 24 Annular recessed part 25 Annular engagement protrusion part 30 Upper case 31 Inner peripheral surface 32 Cylindrical part 33 Annular wide collar part 34 Annular engagement drooping part 41 Annular thrust bearing body

Claims

A synthetic resin bearing (10) disposed between a mounting member (F) of a vehicle body and an upper spring seat (S) of a strut assembly,
Synthetic resin-made lower casing (20), and combined synthetic resin upper case to the lower case (30), distribution synthetic resin annular thrust bearing member between the upper case and the lower case ( 41) and
Said lower casing (20) is continuous cylindrical portion (21) and the annular wide collar portion extending to an end portion outer peripheral faces of the cylindrical portion (22) upper end face of the cylindrical portion (21a) said An annular recess (24) is formed by the annular protrusion (23) standing on the upper surface of the annular wide flange (22), the annular protrusion (23), and the upper surface of the annular wide flange (22). An annular engagement protrusion (25) erected on the outer peripheral edge of the annular wide flange portion, an annular flange portion (27) extending radially inward on the inner peripheral surface of the lower end portion of the cylindrical portion (21), and the annular shape An annular engagement step portion (27a) formed on the inner surface of the flange portion (27) ,
Upper case (30) includes a cylindrical portion the inner circumferential surface (31) and the insertion hole (32) and the annular wide collar portion extending to an end portion outer peripheral faces of the cylindrical portion (32) and (33) An annular engagement hanging portion (34) hanging from the outer peripheral edge of the annular wide flange portion (33) and an annular notch portion (36) formed on the outer peripheral surface of the lower end portion of the cylindrical portion (32) are provided. ,
The upper case (30) retains a bearing gap between the outer peripheral surface of the cylindrical portion (32) and the inner peripheral surface of the cylindrical portion (21) of the lower case (20 ). A radial bearing portion is formed by sliding of the synthetic resin between the outer peripheral surface and the inner peripheral surface of the cylindrical portion (21) of the lower case (20) , and the annular engagement hanging portion (34) is connected to the lower case (20). annular engagement protrusion (25) and the resiliently mounted Rutotomoni of), the annular engagement Godan portion of the cylindrical portion (cylindrical portion of the lower casing annular notch (36) of 32) (20) (21) (27a) is engaged with the lower case (20),
The annular thrust bearing body (41) is a space between the annular recess (24) of the lower case (20) and the lower surface of the annular wide flange (33) of the upper case (30) facing the annular recess (24). synthetic resin bearing which is characterized by being distribution to.

Lower case (20) is the upper surface of the annular wide collar portion (22), the annular engaging projecting portion (25) and erected to form a cyclic deep groove radially inwardly (28) Rutotomoni annular protrusion An outer annular protrusion (29) that forms an annular recess (24) with (23) and the upper surface of the annular wide flange (22) ;
The upper case (30) has an annular hanging portion (38) that is suspended by forming an annular groove (37) radially inward of the annular engagement hanging portion (34) on the lower surface of the annular wide flange portion (33). Further comprising
The upper case (30) retains a bearing gap between the outer peripheral surface of the cylindrical portion (32) and the inner peripheral surface of the cylindrical portion (21) of the lower case (20 ). A radial bearing portion is formed by sliding of synthetic resin between the outer peripheral surface and the inner peripheral surface of the cylindrical portion (21) of the lower case (20) , and the end of the annular hanging portion (38) is connected to the lower case ( 20) and an end portion of the outer annular protrusion (29) which is overlapped with the radial direction thereof to form a sealing portion by labyrinth action on the overlapping portion, and the annular engagement hanging portion (34) is formed in the annular shape of the lower case (20). cylindrical portion of the Rutotomoni elastic is attached to the engaging projection (25), an annular notch (36) of said lower casing of the cylindrical portion (32) (20) annular engagement Godan portion (21) (27a) The synthetic resin bearing according to claim 1, wherein the synthetic resin bearing is engaged with the lower case (20).