JP4632572B2

JP4632572B2 - Vehicle suspension arm

Info

Publication number: JP4632572B2
Application number: JP2001147573A
Authority: JP
Inventors: 満井上
Original assignee: FTECH CO., LTD.
Current assignee: FTECH CO., LTD.
Priority date: 2001-05-17
Filing date: 2001-05-17
Publication date: 2011-02-16
Anticipated expiration: 2021-05-17
Also published as: JP2002337524A

Description

【０００１】
【発明の属する技術分野】
本発明は，サスペンションアーム，特に一端部が車体側に，他端部が車輪側にそれぞれ連結されるアーム本体と，このアーム本体の中間部を空隙を存して跨ぐダンパのフォーク状下端部に連結ピンを介して連結したブッシュを圧入，支持させるためのブッシュ支持部材とを備え，前記空隙にはドライブシャフトが通るようにした構造の車両用サスペンションアームに関する。
【０００２】
【従来の技術】
上記構造のサスペンションアームにおいて，アーム本体のダンパ支持部となる中間部の上側には，ドライブシャフトやその関節部を包囲する保護ブーツとの干渉を避けるためのスペースを，またその下側には，フル転舵又はフルバンプ状態の車輪との干渉を避けるためのスペースをそれぞれ確保する必要があるため，アーム本体中間部の設置スペースがかなり限定されており，しかも該アーム本体中間部は，これに大きなダンパ支持荷重が作用することから高強度，高剛性に構成する必要があるが，これらの要求を全て満たすために，従来では鍛造や鋳造によりサスペンションアームを製造することが一般的であった（図１０の（ａ）を参照）。
【０００３】
【発明が解決しようとする課題】
しかしながら鍛造や鋳造によるサスペンションアームは，重量大，高コストとなる等の欠点がある。
【０００４】
そこでこの欠点を解消するために，金属板をプレス成形してサスペンションアームを構成することも既に行われているが，このようなものでは，ダンパ支持部となるアーム本体中間部の横断面形状が大型化し易く，近年の車両ニーズの多様化（例えば車輪ホイール径のサイズアップ，エンジンの高出力化，ドライブシャフトのサイズアップ等々）への対応が困難となって適用車種に大きな制約を生じる等の不都合があった。
【０００５】
また上記板物のサスペンションアームの改良構造として，例えば図１０の（ｂ）に示すようにダンパ下端部支持用のブッシュをアーム本体中間部に支持させるためのブッシュ支持部材として円筒状のストレートカラーを用い，このカラーをアーム本体中間部の両側壁に溶接させる構造が提案されたが，この提案の構造では，カラーとアーム本体側壁間の溶接部の前後で急激な断面変化を生じてそこに応力集中が生じるため，該溶接部が疲労し易い等の問題がある。
【０００６】
また上記のカラー溶接構造では，アーム本体中間部の側壁より外方にカラー端部を少なからず張出（例えば７ｍｍ）させて溶接代を確保する必要があるため，アーム本体中間部周囲の前記限定されたスペースの中では，アーム本体自体に十分な幅断面を持たせる設計が困難であって，十分なアーム強度を確保できなくなるといった問題もある。
【０００７】
本発明は，上記事情に鑑み提案されたものであって，プレス成形した金属板よりアーム本体を構成しても，板物アームの上記従来の問題を簡単な構造で解決できるようにした車両用サスペンションアームを提供することを目的とする。
【０００８】
【課題を解決するための手段】
前記目的を達成するために，請求項１の発明は，プレス成形した金属板より構成されると共に一端部が車体側に，他端部が車輪側にそれぞれ連結されるアーム本体と，このアーム本体の中間部を空隙を存して跨ぐダンパのフォーク状下端部に連結ピンを介して連結したブッシュを圧入，支持させるためのブッシュ支持部材とを備え，前記空隙にはドライブシャフトが通るようにした車両用サスペンションアームにおいて，前記ブッシュ支持部材が，ブッシュ軸線方向に互いに並列する第１及び第２支持体より分割構成され，その各々の支持体が，前記アーム本体の中間部両側壁の貫通孔にそれぞれ挿入させる筒部と，該筒部の外端に一体に形成されて該両側壁にそれぞれ重合，溶接される外向きのフランジ部とを有しており，前記各フランジ部は，それが溶接されるアーム本体側壁部よりも上下に出っ張らないように，且つその各フランジ部の上下方向外径よりもアーム長手方向の外径が大きくなるように形成され，前記第１及び第２支持体の各筒部内周に前記ブッシュが圧入，嵌合されることを特徴とする。
【０００９】
上記特徴によれば，ブッシュ支持部材を構成する第１，第２支持体とアーム本体両側壁とをそれぞれ溶接しても，その溶接は，各支持体の筒部外端の外向きフランジ部でなされて，該フランジ部や溶接ビードがアーム本体側壁より外方に大きく張出すことはない。即ち，ブッシュ支持部材としてストレートカラーを使用した従来構造のように溶接代確保のために支持部材を該アーム本体側壁より外方に大きく張出させる必要はない（その張出量はフランジ部の板厚程度に止まる）ため，限られたスペースの中でアーム中間部自体に十分な幅断面を持たせる設計が可能となり，板物構造のアーム本体であっても十分な強度を確保できるようになる。しかも，各支持体とアーム本体間の溶接部の前後でのアーム横断面変化が極力抑えられて，該溶接部及びその周辺での応力集中が極力緩和される。併せて、各フランジ部は，それが溶接されるアーム本体側壁部よりも上下に出っ張らないように，且つその各フランジ部の上下方向外径よりもアーム長手方向の外径が大きくなるように形成されることにより、各支持体（フランジ部）の特設に伴うアーム中間部の上下幅拡大を回避しながら，各支持体（フランジ部）の溶接領域をアーム長手方向に延ばすことができて各支持体とアーム本体間の結合強度が一層高められる。
【００１１】
また特に請求項２の発明は，請求項１の発明の前記特徴に加えて，各フランジ部の，アーム長手方向に延びる部分が，ブッシュから遠ざかるにつれて上下幅が漸減するように形成されることを特徴としている。この特徴によれば，各支持体（フランジ部）とアーム本体側壁間の溶接部の前後でのアーム横断面変化が効果的に抑えられて，該溶接部及びその周辺での応力集中が一層緩和される。
【００１２】
【発明の実施の形態】
本発明の実施の形態を，添付図面に例示した本発明の実施例に基づいて以下に具体的に説明する。
【００１３】
添付図面において，図１は，本発明の一実施例に係る自動車用サスペンションアームの車両取付状態を簡略的に示す斜視図，図２は，前記サスペンションアームの単体斜視図，図３は，前記サスペンションアームの単体平面図（図２の３矢視図），図４は図３の４−４線拡大断面図，図５は図３の５矢視拡大側面図，図６は図３の６−６線拡大断面図，図７は図３の７矢視拡大側面図，図８は図７の８−８線断面図，図９は，前記サスペンションアームのダンパ支持部の変形例を示す図８対応断面図である。
【００１４】
図１に示すように，車輪のホイールＷを回転自在に支持するナックルＮは，その下部がロアアームＡにより，またその上部が図示しないアッパアームによりそれぞれ車体又はこれに連結したサブフレーム（以下，単に車体Ｆという）に上下動可能に支持される。また車体重量を支持し且つナックルＮの上下動を緩衝するために車体ＦとロアアームＡの中間部との間には，コイルスプリングＳ付きのダンパＤが介装される。
【００１５】
前記ロアアームＡは，所謂Ａ型アームと呼ばれるもので，本発明のサスペンションアームを構成する。このロアアームＬＡの外端部はボールジョイントＢＪを介してナックルＮに首振り可能に連結されるとともに，二股状に分かれた第１及び第２内端部は，各前後一対のゴムブッシュＢ１，Ｂ２とそれらを貫通する連結ピンＪ１，Ｊ２とを介して車体Ｆに連結される。
【００１６】
図２，３を併せて参照して，ロアアームＬＡのアーム本体１は，鋼板を各々プレス加工して成形された上部板体２及び下部板体３を相互に一体的に結合して構成される。アーム本体１の前側の第１内端部には，第１ゴムブッシュＢ１を内周に圧入支持する第１ブッシュ圧入部Ｐ１が，また後側の第２内端部には，第２ゴムブッシュＢ２を内周に圧入支持する第２ブッシュ圧入部Ｐ２がそれぞれ連設され，更にアーム本体１の外端部には，前記ボールジョイントＢＪを支持するための取付孔４ａを有する支持ブラケット４が溶接される。
【００１７】
前記第１ブッシュ圧入部Ｐ１の軸線は略鉛直方向に，また前記第２ブッシュ圧入部Ｐ２は車体の略前後方向にそれぞれ設定されている。その第２ブッシュ圧入部Ｐ２は，図示例では円筒状の金属製カラーＣより構成されており，このカラーＣの外周部を前記上部板体２及び下部板体３の後側の各第２内端部に溶接ｗ′される。
【００１８】
前記上部板体２は，その外端及び前後一対の内端を除いて外周縁部が全周に亘り下方に比較的長く垂下しており，また前記下部板体３は，その外端及び前後一対の内端を除いて外周縁部が全周に亘り上方に比較的短く起立している。そして，その下部板体３の起立壁３ａの外側面と，これに対応する上部板体２の垂下壁２ａの内側面とがアーム本体１の全周に亘り密接，嵌合しており，その嵌合部はアーム本体１の外端及び前後一対の内端を除いてその全周に亘り溶接ｗされる。この溶接ｗによって，上，下部板体２，３より成るアーム本体１は頑丈な閉断面構造とされる。尚，上，下部板体２，３には，アーム本体１の略中央部においてそれぞれ窪み部ｇ，ｇがそれぞれ形成され，その上下の窪み部ｇ，ｇの相対向する底壁相互は直に接していて公知の適当な固着手段により結合される。
【００１９】
次に図４〜６を併せて参照して，前記ロアアームＬＡの第１ブッシュ圧入部Ｐ１の構造を説明する。
【００２０】
前記上部板体２及び下部板体３の前側の各第１内端部は，各々リング板状の上部端板５及び下部端板６が継ぎ目無く一体に形成される。これら上部端板５及び下部端板６の各内周部には，それぞれバーリング加工により内向きの（即ち先端が互いに向き合う）上部及び下部内周フランジ５ｉ，６ｉがそれぞれ形成されており，その上下の内周フランジ５ｉ，６ｉの各内周面は，第１ゴムブッシュＢ１を圧入嵌合させるブッシュ圧入面とされる。またその上下の内周フランジ５ｉ，６ｉは，各々の先端面５ｉｅ，６ｉｅ相互がその全周に亘り隙間なく当接している。
【００２１】
上，下部端板５，６の上，下面と上，下の内周フランジ５ｉ，６ｉの基端部外面との間は，それぞれ横断面円弧状の曲面（面取り）により滑らかに接続されており，該曲面が第１ゴムブッシュＢ１を該内周フランジ５ｉに圧入する際の案内面となる。また，上，下部端板５，６の上，下面と上，下の外周フランジ５ｏ，６ｏの基端部外面との間も，それぞれ横断面円弧状の曲面（面取り）により滑らかに接続されている。
【００２２】
而して前記上下の内周フランジ５ｉ，６ｉの内周面には第１ゴムブッシュＢ１の外周カラーＢ１ｃが軸方向一方側（図示例では上側）からの順次圧入により嵌合，保持される。この場合，上下の内周フランジ５ｉ，６ｉの内径公差は，第１ゴムブッシュＢ１の圧入による弾性変形量を見込み，圧入方向前側（図示例では下側）の内周フランジ６ｉの内径寸法を，圧入方向後側（図示例では上側）の内周フランジ５ｉのそれに対し若干小さく設定して，二度目（下側フランジ６ｉへ）の圧入でも十分な締代が確保されるようにすることで，上下の内周フランジ５ｉ，６ｉとも十分な圧入保持力が確保されるようにしている。
【００２３】
また上部端板５及び下部端板６の各外周部は，その内側の内周フランジ５ｉ，６ｉに略沿うようにそれぞれ内側に折曲げられていて上下一対の外周フランジ５ｏ，６ｏを形成しており，その両外周フランジ５ｏ，６ｏの先端面５ｏｅ，６ｏｅ相互がその全周に亘り小さな環状の間隙ｓを存して相対向している。
【００２４】
上記のような第１ブッシュ圧入部Ｐ１の構造によれば，該圧入部Ｐ１とアーム本体１との間が継ぎ目無く一体に接続されるため，強度アップを図る上，有利であり，部品点数も少なくできる。
【００２５】
また特に上下一対の内周フランジ５ｉ，６ｉと，それらの外側で重なり合う上下一対の外周フランジ５ｏ，６ｏとが上下で各々二重管構造をなし，その内、外周フランジ５ｉ，５ｏ（６ｉ，６ｏ）相互の補強効果や，上下の内周フランジ５ｉ，６ｉの先端面相互の突き合わせ効果によって，ブッシュ圧入部Ｐ１にカラーと同等の十分な剛性，強度を確保することができ，しかも上，下部端板５，６間が溶接（固着）されないため，その間に溶接のためのラップ代が不要となってアーム端部形状をコンパクト化でき，従ってロアアームＬＡ端部周辺の限られた車体空間（この空間には，図３からも明らかな如くサブフレームＦ，フル転舵状態の車輪のホイールＷ，ミッションケースＭＣ等が接近して狭小となっている）にもロアアームＬＡの端部を無理なくレイアウト可能となる。
【００２６】
また上部端板５及び下部端板６間を溶接しなくても，それらの内周フランジ５ｉ，６ｉの先端面５ｉｅ，６ｉｅ相互が当接していることから，これらフランジ５ｉ，６ｉへのブッシュＢ１の圧入荷重を無理なく受け止めることができる上，その上下の内周フランジ５ｉ，６ｉの締代を適宜設定することにより，ブッシュＢ１を介して両内周フランジ５ｉ，６ｉ間の必要な結合強度を確保可能である。更に加工誤差等に因りブッシュＢ１の圧入前に上下の内周フランジ５ｉ，６ｉ間に多少の芯ずれが生じたとしても，上部端板５及び下部端板６間は溶接（固着）されていないことから，ブッシュ圧入時に上下の内周フランジ５ｉ，６ｉを無理なく容易にセンタリングでき，その圧入保持力の安定化が図られる。
【００２７】
更に上下一対の外周フランジ５ｏ，６ｏの先端面５ｏｅ，６ｏｅ相互が間隙ｓを存して相対向しているため，この間隙ｓを，ロアアームＬＡに対する塗装工程では塗料の流通路に利用可能であり，従って，上下一対の内周フランジ５ｉ，６ｉの先端面５ｉｅ，６ｉｅ相互を当接させても，前記間隙ｓを通して内，外周フランジ５ｉ，５ｏ；６ｉ，６ｏ間の環状空間に塗料を万遍なく行き渡らせてフランジ５ｉ，５ｏ；６ｉ，６ｏ内面の塗装を的確に行うことができる。
【００２８】
次に図７，８を併せて参照して，前記ロアアームＬＡとダンパＤとの連結構造について説明する。
【００２９】
前記アーム本体１の，ダンパ支持部となる外端寄りの中間部１ｄには，これを空隙ｓ_Dを存して跨ぐダンパＤのフォーク状下端部７が，該下端部７に横架されて車体の略前後方向に延びる連結ピンＪ３と，該ピンＪ３を囲繞する第３ゴムブッシュＢ３とを介して連結される。そのアーム本体１の前記中間部１ｄには，第３ゴムブッシュＢ３を該中間部１ｄに圧入，支持させるためのブッシュ支持部材９が取付けられる。また前記空隙ｓ_Dには，車輪駆動用のドライブシャフト１０又は該シャフト１０の関節部を覆う保護ブーツＰＢが通るように配置されており，該シャフト１０の外端は，車輪のホイールＷに一体的に回転するように連結される。
【００３０】
前記ブッシュ支持部材９は，第３ゴムブッシュＢ３の軸線方向に並列する第１及び第２支持体１１，１２より分割構成されており，その各支持体１１，１２は鋼板等の金属板をそれぞれプレス成形して形成される。
【００３１】
その第１支持体１１は，アーム本体１（図示例では上部板体２）の前記中間部１ｄの一側壁Ｋ１に形成した貫通孔としての第１支持孔Ｈ１に挿入させる第１筒部１１ｐと，この第１筒部１１ｐの外端に一体に形成されて該一側壁Ｋ１に重合され且つ外周縁部全周が溶接ｗ″される外向きの第１フランジ部１１ｆとより構成される。また，第２支持体１２は，第１支持体１１と基本的に同様の構成を有するものであって，アーム本体１（図示例では上部板体２）の前記中間部１ｄの他側壁Ｋ２に形成した貫通孔としての第２支持孔Ｈ２に挿入させる第２筒部１２ｐと，この第２筒部１２ｐの外端に一体に形成されて該一側壁Ｋ２に重合され且つ外周縁部全周が溶接ｗ″される外向きの第２フランジ部１２ｆとより構成される。
【００３２】
前記第１，第２フランジ部１１ｆ，１２ｆは，互いに協働して第３ブッシュ圧入部Ｐ３を構成しており，その各筒部１１ｐ，１２ｐの内周面に，第３ゴムブッシュＢ３の外周カラーＢ３ｃが圧入嵌合される。また，第１及び第２筒部１１ｐ，１２ｐの相対向する内端相互は，一体に結合されることなく当接している。尚，その両筒部１１ｐ，１２ｐの相対向する内端の相互間に僅かな隙間を設定してもよい。
【００３３】
前記各フランジ部１１ｆ，１２ｆは，それが溶接されるアーム本体側壁部Ｋ１，Ｋ２よりも上下に出っ張らないように，且つその各フランジ部１１ｆ，１２ｆの上下方向外径よりもアーム長手方向の外径が大きくなるように，特に図示例では横長の概ね楕円形に形成され，従って各フランジ部１１ｆ，１２ｆの，アーム長手方向に延びる部分は，第３ゴムブッシュＢ３から遠ざかるにつれて上下幅が漸減する。
【００３４】
而して上記のようなアーム本体１のダンパ支持部となる中間部１ｄにおけるブッシュ支持構造によれば，ブッシュ支持部材９を構成する第１，第２支持体１１，１２とアーム本体両側壁Ｋ１，Ｋ２とを溶接ｗ″しているにも拘わらず，その溶接ｗ″は，各支持体１１，１２の筒部１１ｐ，１２ｐ外端の外向きフランジ部１１ｆ，１２ｆでなされていて，該フランジ部１１ｆ，１２ｆや溶接ビードがアーム本体側壁Ｋ１，Ｋ２より外方に大きく張出す心配がない。即ち，ブッシュ支持部材としてストレートカラーを使用した従来構造のように溶接代確保のためにブッシュ支持部材９を該アーム本体側壁Ｋ１，Ｋ２より外方に大きく張出させる必要はない（その張出量はフランジ部１１ｆ，１２ｆの板厚程度に止まる）ため，限られたスペースの中でロアアームＬＡ中間部自体に十分な幅断面を持たせる設計が可能となり，板物構造のアーム本体であっても十分な強度を確保できるようになる。しかも，各支持体１１，１２とアーム本体１間の溶接部ｗ″の前後でのアーム横断面変化が極力抑えられて，該溶接部及びその周辺での応力集中が極力緩和される。
【００３５】
また特に図示例では，上記第１，第２支持体１１，１２の各フランジ部１１ｆ，１２ｆは，それが溶接されるアーム本体側壁部Ｋ１，Ｋ２よりも上下に出っ張らないように，且つその各フランジ部１１ｆ，１２ｆの上下方向外径よりもアーム長手方向の外径が大きくなるように，横長の概ね楕円形に形成されているため，各支持体１１，１２（各フランジ部１１ｆ，１２ｆ）の特設に伴うロアアームＬＡ中間部の上下幅拡大を回避しながら，各支持体１１，１２（各フランジ部１１ｆ，１２ｆ）の溶接領域をアーム長手方向に極力長く延ばすことができて各支持体１１，１２とアーム本体１間の結合強度が一層高められる。しかも各フランジ部１１ｆ，１２ｆの，アーム長手方向に延びる部分が，ブッシュＢ３から遠ざかるにつれて上下幅が漸減しているから，各支持体１１，１２（各フランジ部１１ｆ，１２ｆ）とアーム本体側壁Ｋ１，Ｋ２間の溶接部の前後でのアーム横断面変化が効果的に抑えられて，該溶接部およびその周辺での応力集中が一層緩和される。
【００３６】
また図９には，ブッシュ支持部材９の変形例が示される。即ち，前記実施例では，第１及び第２支持体１１，１２の筒部１１ｐ，１２ｐの内端相互が当接するように筒部１１ｐ，１２ｐの軸方向長さを十分長く形成して，第１ゴムブッシュＢ１に対する支持強度を高めたものを示したが，本変形例では，図９に示すように第１及び第２支持体１１，１２の各筒部１１ｐ，１２ｐの軸方向長さを第１ゴムブッシュＢ１の支持に必要最小限の長さに留め，その両筒部１１ｐ，１２ｐの内端相互間に比較的大きな間隙ｓ_Pを設定している。この場合には，各支持体１１，１２の軸方向短縮化により，それらのプレス成形性が良好となり且つ材料の歩留り効率も高くなって，コスト節減や軽量化が図られる。
【００３７】
以上，本発明の実施例を詳述したが，本発明は前記実施例に限定されるものでなく，種々の小設計変更を行うことが可能である。例えば，前記実施例では，アーム本体１を，上部板体２及び下部板体３を結合一体化して閉断面構造としたものを示したが，本発明では，アーム本体１を開放断面，例えば断面Ｕ字状や逆Ｕ字状に形成してもよい。
【００３８】
また前記実施例では，アーム本体１を構成する上部板体２及び下部板体３を溶接により結合するようにしたものを示したが，本発明では，その上部板体２及び下部板体３を溶接以外の固着手段により結合するようにしてもよい。
【００３９】
また前記実施例では，サスペンションアームとしてＡ型のロアアームＬＡを示したが，Ａ型以外，例えばＩ型アームに本発明を実施するようにしてもよい。
【００４０】
以上のように本発明によれば，プレス成形した金属板よりアーム本体を構成した軽量且つ低コストのサスペンションアームにおいて，ブッシュ支持部材は，ブッシュ軸線方向に互いに並列する第１及び第２支持体より分割構成され，その各々の支持体が，アーム本体の中間部両側壁の貫通孔にそれぞれ挿入させる筒部と，該筒部の外端に一体に形成されて該両側壁にそれぞれ重合，溶接される外向きのフランジ部とを有しており，その第１及び第２支持体の各筒部内周にブッシュが圧入，保持されるので，各支持体とアーム本体側壁とを溶接するにも拘わらず，その溶接代確保のために各支持体を該アーム本体側壁より外方に大きく張出させる必要はなくなり，従って，限られたスペースの中でアーム中間部自体に十分な幅断面を持たせる設計が可能となるため，板物構造のアーム本体であっても十分な強度を確保でき，しかも，各支持体とアーム本体間の溶接部の前後でのアーム横断面変化を極力抑えて，該溶接部及びその周辺での応力集中を極力緩和することができるため，それら部位の耐疲労性を高めることができる。併せて、各フランジ部は，それが溶接されるアーム本体側壁部よりも上下に出っ張らないように，且つその各フランジ部の上下方向外径よりもアーム長手方向の外径が大きくなるように形成されることにより、各支持体（フランジ部）の特設に伴うアーム中間部の上下幅拡大を回避しながら，各支持体（フランジ部）の溶接領域をアーム長手方向に延ばすことができて各支持体とアーム本体間の結合強度が一層高められる。
【００４２】
また特に請求項２の発明によれば，第１，第２支持体の各フランジ部の，アーム長手方向に延びる部分は，ブッシュから遠ざかるにつれて上下幅が漸減するように形成されるので，各支持体とアーム本体間の溶接部の前後でのアーム横断面変化を効果的に抑えることができ，これにより，該溶接部及びその周辺での応力集中を一層緩和できるため，それら部位の耐疲労性が一層向上する。
【図面の簡単な説明】
【図１】本発明の一実施例に係る自動車用サスペンションアームの車両取付状態を簡略的に示す斜視図
【図２】前記サスペンションアームの単体斜視図
【図３】前記サスペンションアームの単体平面図（図２の３矢視図）
【図４】図３の４−４線拡大断面図
【図５】図３の５矢視拡大側面図
【図６】図３の６−６線拡大断面図
【図７】図３の７矢視拡大側面図
【図８】図７の８−８線断面図
【図９】前記サスペンションアームのダンパ支持部の変形例を示す図８対応断面図
【図１０】従来のサスペンションアームを示す概略斜視図
【符号の説明】
Ｂ３第３ゴムブッシュ（ブッシュ）
Ｄダンパ
Ｆ車体又はサブフレーム
Ｈ１，Ｈ２第１，第２支持孔（貫通孔）
Ｊ３連結ピン
Ｋ１一側壁
Ｋ２他側壁
ＬＡロアアーム（サスペンションアーム）
Ｐ３第３ブッシュ圧入部（ブッシュ圧入部）
ｓ_D 空隙
Ｗホイール（車輪）
ｗ″ 溶接
１アーム本体
１ｄ中間部
２，３上，下部板体（金属板）
７フォーク状下端部
９ブッシュ支持部材
１０ドライブシャフト
１１，１２第１，第２支持体
１１ｆ，１２ｆ第１，第２フランジ部
１１ｐ，１２ｐ第１，第２筒部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a suspension arm, particularly an arm main body having one end connected to the vehicle body and the other end connected to the wheel, and a fork-like lower end of a damper straddling an intermediate portion of the arm main body with a gap. The present invention relates to a vehicle suspension arm having a structure in which a bush support member for press-fitting and supporting a bush connected via a connection pin is provided, and a drive shaft passes through the gap.
[0002]
[Prior art]
In the suspension arm having the above structure, a space for avoiding interference with the drive boot and the protective boot surrounding the joint portion is provided above the intermediate portion serving as a damper support portion of the arm body, and below that, Since it is necessary to secure a space for avoiding interference with a fully steered wheel or a fully bumped wheel, the space for installing the middle part of the arm body is considerably limited, and the middle part of the arm body is large. Since the damper support load acts, it is necessary to configure it with high strength and high rigidity, but in order to satisfy all of these requirements, conventionally, suspension arms were generally manufactured by forging or casting (Fig. 10 (see a)).
[0003]
[Problems to be solved by the invention]
However, forging and casting suspension arms have disadvantages such as high weight and high cost.
[0004]
In order to eliminate this drawback, a suspension arm is already formed by press-molding a metal plate, but in such a case, the cross-sectional shape of the middle part of the arm main body that becomes the damper support part is reduced. It is easy to increase the size, and it becomes difficult to cope with the diversification of vehicle needs in recent years (for example, increasing the wheel wheel diameter, increasing the engine output, increasing the drive shaft size, etc.). There was an inconvenience.
[0005]
Further, as an improved structure of the suspension arm of the plate, for example, as shown in FIG. 10B, a cylindrical straight collar is used as a bush support member for supporting a bush for supporting the lower end of the damper on the middle part of the arm body. A structure has been proposed in which this collar is welded to both side walls of the middle part of the arm body. However, in this proposed structure, a sudden cross-sectional change occurs before and after the weld between the collar and the side wall of the arm body. Since concentration occurs, there is a problem that the welded portion is easily fatigued.
[0006]
Further, in the above-mentioned collar welding structure, since it is necessary to secure the welding allowance by extending the collar end portion outward (for example, 7 mm) from the side wall of the arm main body intermediate portion, the above-mentioned limitation around the arm main body intermediate portion is required. In such a space, it is difficult to design the arm body itself to have a sufficient width section, and there is a problem that sufficient arm strength cannot be secured.
[0007]
The present invention has been proposed in view of the above circumstances, and can be used for a vehicle that can solve the above-mentioned conventional problems of a plate arm with a simple structure even if the arm body is constituted by a press-formed metal plate. An object is to provide a suspension arm.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 comprises an arm main body constituted by a press-molded metal plate and having one end connected to the vehicle body side and the other end connected to the wheel side, and the arm main body. A bush support member for press-fitting and supporting a bush connected via a connecting pin to a fork-like lower end of a damper straddling an intermediate portion of the damper with a gap, and a drive shaft passes through the gap. In the suspension arm for a vehicle, the bush support member is divided into first and second support members that are parallel to each other in the bush axis direction, and each support member is formed in a through-hole on both side walls of the intermediate portion of the arm body. a cylindrical portion for insertion respectively, each polymerization the both side walls are formed integrally with the outer end of the cylindrical portion, and a flange portion outwardly to be welded, each flange Is such that it is does not project vertically than the arm body sidewall portion to be welded, is formed and so that the outer diameter of the arm longitudinal direction than the vertical outer diameter of the flange portion is increased, the first and The bush is press-fitted and fitted to the inner periphery of each cylindrical portion of the second support.
[0009]
According to the above feature, even if the first and second supports constituting the bush support member are welded to both side walls of the arm body, the welding is performed at the outward flange portion at the outer end of the cylindrical portion of each support. Thus, the flange portion and the weld bead do not protrude greatly outward from the side wall of the arm body. In other words, unlike the conventional structure using a straight collar as the bushing support member, it is not necessary to extend the support member greatly outward from the side wall of the arm body in order to secure the welding allowance (the amount of protrusion is the plate of the flange portion). Therefore, it is possible to design the middle part of the arm itself to have a sufficient width cross section in a limited space, and it is possible to secure sufficient strength even with a plate structure arm body. . In addition, the change in the arm cross section before and after the welded portion between each support and the arm main body is suppressed as much as possible, and the stress concentration at the welded portion and its surroundings is alleviated as much as possible. In addition, each flange portion is formed so that it does not protrude above and below the arm body side wall portion to be welded, and the outer diameter in the arm longitudinal direction is larger than the outer diameter in the vertical direction of each flange portion. As a result, the welded area of each support (flange) can be extended in the longitudinal direction of the arm while avoiding the increase in the vertical width of the middle part of the arm accompanying the special provision of each support (flange). The bond strength between the body and the arm body is further increased.
[0011]
In addition, the invention of claim 2 is characterized in that, in addition to the above feature of the invention of claim 1 , the portion of each flange portion extending in the arm longitudinal direction is formed such that the vertical width gradually decreases as the distance from the bush increases. It is a feature. According to this feature, the change in the arm cross section before and after the weld between each support (flange) and the arm body side wall is effectively suppressed, and the stress concentration at and around the weld is further reduced. Is done.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings.
[0013]
In the accompanying drawings, FIG. 1 is a perspective view schematically showing a vehicle mounting state of an automobile suspension arm according to an embodiment of the present invention, FIG. 2 is a perspective view of the suspension arm, and FIG. FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 3, FIG. 5 is an enlarged side view taken along arrow 5 in FIG. 3, and FIG. FIG. 7 is an enlarged side view taken along arrow 7 in FIG. 3, FIG. 8 is a sectional view taken along line 8-8 in FIG. 7, and FIG. 9 is a view showing a modification of the damper support portion of the suspension arm. FIG.
[0014]
As shown in FIG. 1, a knuckle N that rotatably supports a wheel W of a wheel has a lower portion connected by a lower arm A and an upper portion connected by an upper arm (not shown) to a vehicle body or a subframe (hereinafter simply referred to as a vehicle body). F) and is supported so as to be movable up and down. In addition, a damper D with a coil spring S is interposed between the vehicle body F and the lower arm A in order to support the vehicle body weight and buffer the vertical movement of the knuckle N.
[0015]
The lower arm A is a so-called A-type arm and constitutes the suspension arm of the present invention. The outer end of the lower arm LA is connected to the knuckle N via a ball joint BJ so as to be able to swing, and the first and second inner ends divided into two forks are formed of a pair of front and rear rubber bushes B1, B2. And the connecting pins J1 and J2 penetrating them are connected to the vehicle body F.
[0016]
2 and 3 together, the arm body 1 of the lower arm LA is configured by integrally joining an upper plate 2 and a lower plate 3 formed by pressing each steel plate. . A first bush press-fit portion P1 for press-fitting and supporting the first rubber bush B1 to the inner periphery is provided at the first inner end portion on the front side of the arm body 1, and a second rubber bush is provided at the second inner end portion on the rear side. A second bush press-fit portion P2 for press-fitting and supporting B2 on the inner periphery is connected to each other, and a support bracket 4 having a mounting hole 4a for supporting the ball joint BJ is welded to the outer end portion of the arm body 1. Is done.
[0017]
The axis of the first bush press-fit portion P1 is set in a substantially vertical direction, and the second bush press-fit portion P2 is set in a substantially front-rear direction of the vehicle body. The second bush press-fit portion P2 is formed of a cylindrical metal collar C in the illustrated example, and the outer periphery of the collar C is connected to each second inner side of the rear side of the upper plate 2 and the lower plate 3. Welded to the end.
[0018]
The upper plate 2 has an outer peripheral edge that hangs down relatively long over the entire circumference except for its outer end and a pair of front and rear inner ends, and the lower plate 3 has its outer end and front and rear Except for the pair of inner ends, the outer peripheral edge stands up relatively short over the entire circumference. The outer surface of the upright wall 3a of the lower plate 3 and the inner surface of the hanging wall 2a of the upper plate 2 corresponding thereto are closely fitted over the entire circumference of the arm body 1, The fitting portion is welded over the entire circumference except for the outer end of the arm body 1 and the pair of front and rear inner ends. By this welding w, the arm body 1 composed of the upper and lower plate bodies 2 and 3 has a sturdy closed cross-sectional structure. The upper and lower plate bodies 2 and 3 are respectively formed with depressions g and g at the substantially central part of the arm body 1, and the bottom walls facing each other at the upper and lower depressions g and g are directly connected to each other. They are in contact with each other and are bonded by a suitable known fixing means.
[0019]
Next, the structure of the first bush press-fit portion P1 of the lower arm LA will be described with reference to FIGS.
[0020]
Each of the first inner end portions on the front side of the upper plate body 2 and the lower plate body 3 is formed integrally with a ring plate-like upper end plate 5 and lower end plate 6 seamlessly. The inner peripheral portions of the upper end plate 5 and the lower end plate 6 are respectively formed with upper and lower inner peripheral flanges 5i, 6i that are inward (that is, the tips face each other) by burring. The inner peripheral surfaces of the inner peripheral flanges 5i and 6i are bush press-fitting surfaces into which the first rubber bush B1 is press-fitted. Further, the upper and lower inner peripheral flanges 5i, 6i are in contact with each other without gaps over the entire circumference thereof.
[0021]
The upper and lower end plates 5 and 6 are smoothly connected to the upper and lower surfaces of the upper and lower inner peripheral flanges 5i and 6i by the curved surfaces (chamfered) having a circular cross section. The curved surface becomes a guide surface when the first rubber bush B1 is press-fitted into the inner peripheral flange 5i. In addition, the upper and lower end plates 5 and 6 are smoothly connected to the upper and lower surfaces of the upper and lower outer peripheral flanges 5o and 6o by the curved surfaces (chamfered) having a circular cross section. Yes.
[0022]
Thus, the outer peripheral collar B1c of the first rubber bush B1 is fitted and held on the inner peripheral surfaces of the upper and lower inner peripheral flanges 5i, 6i by sequential press-fitting from one side in the axial direction (the upper side in the illustrated example). In this case, the inner diameter tolerance of the upper and lower inner peripheral flanges 5i, 6i is expected to be the amount of elastic deformation due to the press-fitting of the first rubber bush B1, and the inner diameter dimension of the inner peripheral flange 6i on the front side in the press-fitting direction (lower side in the illustrated example) By setting it slightly smaller than that of the inner peripheral flange 5i on the rear side in the press-fitting direction (upper side in the illustrated example), a sufficient tightening margin is ensured even by the second press-fitting (to the lower flange 6i). A sufficient press-fit holding force is ensured for the upper and lower inner peripheral flanges 5i, 6i.
[0023]
Further, the outer peripheral portions of the upper end plate 5 and the lower end plate 6 are bent inward so as to substantially follow the inner peripheral flanges 5i, 6i on the inner end plate 5 to form a pair of upper and lower outer peripheral flanges 5o, 6o. The front end surfaces 5oe and 6oe of the outer peripheral flanges 5o and 6o are opposed to each other with a small annular gap s over the entire circumference.
[0024]
According to the structure of the first bush press-fitting part P1 as described above, the press-fitting part P1 and the arm body 1 are connected together seamlessly, which is advantageous in increasing the strength and the number of parts. Less.
[0025]
In particular, a pair of upper and lower inner peripheral flanges 5i and 6i and a pair of upper and lower outer peripheral flanges 5o and 6o overlapping each other form a double pipe structure in the upper and lower sides, and among them, outer peripheral flanges 5i and 5o (6i and 6o) ) Due to the mutual reinforcing effect and the abutting effect between the top end surfaces of the upper and lower inner peripheral flanges 5i, 6i, the bush press-fit portion P1 can have sufficient rigidity and strength equivalent to the collar, and the upper and lower ends Since the plates 5 and 6 are not welded (fixed), there is no need for welding laps between them, and the arm end shape can be made compact, and therefore the limited vehicle body space around the lower arm LA end (this space) As shown in FIG. 3, the subframe F, the wheel W of the fully steered wheel, the transmission case MC, etc. are close and narrow. It is possible layout without difficulty.
[0026]
Even if the upper end plate 5 and the lower end plate 6 are not welded, the front end surfaces 5ie and 6ie of the inner peripheral flanges 5i and 6i are in contact with each other, so that the bush B1 to these flanges 5i and 6i Can be received without difficulty, and the necessary coupling strength between the inner peripheral flanges 5i and 6i can be obtained via the bush B1 by appropriately setting the tightening allowance of the upper and lower inner peripheral flanges 5i and 6i. It can be secured. Further, even if a slight misalignment occurs between the upper and lower inner peripheral flanges 5i and 6i before press-fitting the bush B1 due to processing errors, the upper end plate 5 and the lower end plate 6 are not welded (fixed). Therefore, the upper and lower inner peripheral flanges 5i and 6i can be easily centered without difficulty when the bush is press-fitted, and the press-fitting holding force can be stabilized.
[0027]
Furthermore, since the tip surfaces 5oe and 6oe of the pair of upper and lower outer peripheral flanges 5o and 6o are opposed to each other with a gap s, the gap s can be used as a paint flow path in the painting process for the lower arm LA. Therefore, even if the front end surfaces 5ie and 6ie of the pair of upper and lower inner peripheral flanges 5i and 6i are brought into contact with each other, the paint is universally provided in the annular space between the inner and outer peripheral flanges 5i and 5o; 6i and 6o through the gap s. The inner surfaces of the flanges 5i and 5o; 6i and 6o can be accurately painted.
[0028]
Next, a connection structure between the lower arm LA and the damper D will be described with reference to FIGS.
[0029]
A fork-like lower end portion 7 of the damper D straddling the gap s _D across the intermediate portion 1d near the outer end serving as a damper support portion of the arm body 1 is horizontally mounted on the lower end portion 7. The connection is made through a connection pin J3 extending substantially in the front-rear direction of the vehicle body and a third rubber bush B3 surrounding the pin J3. A bush support member 9 for press-fitting and supporting the third rubber bush B3 in the intermediate portion 1d is attached to the intermediate portion 1d of the arm body 1. Further, a drive shaft 10 for driving the wheel or a protective boot PB covering the joint portion of the shaft 10 passes through the gap s _D , and the outer end of the shaft 10 is integrated with the wheel W of the wheel. Connected so as to rotate.
[0030]
The bush support member 9 is divided into first and second supports 11 and 12 arranged in parallel in the axial direction of the third rubber bush B3, and each of the supports 11 and 12 is a metal plate such as a steel plate. It is formed by press molding.
[0031]
The first support 11 is inserted into a first support hole H1 as a through hole formed in one side wall K1 of the intermediate part 1d of the arm body 1 (upper plate 2 in the illustrated example), The first cylindrical portion 11p is formed integrally with the outer end of the first cylindrical portion 11p, overlapped with the one side wall K1 and welded to the entire periphery of the outer peripheral edge portion. The second support 12 has basically the same configuration as the first support 11 and is formed on the other side wall K2 of the intermediate portion 1d of the arm body 1 (upper plate 2 in the illustrated example). A second cylindrical portion 12p that is inserted into the second support hole H2 as a through hole, and is formed integrally with the outer end of the second cylindrical portion 12p and overlapped with the one side wall K2, and the entire circumference of the outer peripheral portion is welded. The second flange portion 12f facing outward is formed.
[0032]
The first and second flange portions 11f and 12f cooperate with each other to form a third bush press-fit portion P3, and the outer periphery of the third rubber bush B3 is formed on the inner peripheral surface of each of the cylindrical portions 11p and 12p. The collar B3c is press-fitted. Moreover, the mutually opposing inner ends of the first and second cylindrical portions 11p, 12p are in contact with each other without being integrally coupled. A slight gap may be set between the inner ends of the cylindrical portions 11p, 12p facing each other.
[0033]
The flange portions 11f and 12f are arranged so as not to protrude above and below the arm body side wall portions K1 and K2 to which the flange portions 11f and 12f are welded, and outside the longitudinal direction outer diameter of the flange portions 11f and 12f. In order to increase the diameter, in particular in the example shown in the figure, it is formed in an oblong shape that is oblong, and therefore the vertical width of the flange portions 11f, 12f extending in the longitudinal direction of the arm gradually decreases as the distance from the third rubber bush B3 increases. .
[0034]
Thus, according to the bush support structure in the intermediate portion 1d serving as the damper support portion of the arm body 1 as described above, the first and second supports 11 and 12 constituting the bush support member 9 and the arm body side walls K1. , K2 is welded to the flanges 11f and 12f of the outer ends of the cylindrical portions 11p and 12p of the supports 11 and 12, respectively. There is no concern that the portions 11f and 12f and the weld bead project beyond the arm body side walls K1 and K2. That is, it is not necessary to project the bush support member 9 outwardly from the arm body side walls K1 and K2 in order to secure the welding allowance as in the conventional structure using a straight collar as the bush support member (the amount of the projection) Can be designed to have a sufficient width cross section in the lower arm LA itself in a limited space, even if the arm body has a plate structure. Sufficient strength can be secured. In addition, the change in the cross section of the arm before and after the welded portion w ″ between the supports 11 and 12 and the arm body 1 is suppressed as much as possible, and the stress concentration in the welded portion and its surroundings is alleviated as much as possible.
[0035]
In the illustrated example, the flange portions 11f and 12f of the first and second support bodies 11 and 12 do not protrude above and below the arm main body side wall portions K1 and K2 to which the flange portions 11f and 12f are welded. Since the outer diameter in the arm longitudinal direction is larger than the outer diameter in the vertical direction of the flange portions 11f and 12f, each support body 11 and 12 (each flange portion 11f and 12f) is formed in a substantially elliptical shape. The welded area of each support 11, 12 (each flange 11f, 12f) can be extended as long as possible in the longitudinal direction of the arm while avoiding an increase in the vertical width of the intermediate portion of the lower arm LA due to the special arrangement of each support 11. , 12 and the arm body 1 are further enhanced in bonding strength. Moreover, since the vertical widths of the flange portions 11f and 12f extending in the arm longitudinal direction gradually decrease as they move away from the bush B3, the support bodies 11 and 12 (the flange portions 11f and 12f) and the arm body side wall K1. , K2 is effectively restrained from changing the cross section of the arm before and after the welded portion, and the stress concentration at and around the welded portion is further relaxed.
[0036]
FIG. 9 shows a modified example of the bush support member 9. That is, in the above embodiment, the axial lengths of the cylindrical portions 11p and 12p are sufficiently long so that the inner ends of the cylindrical portions 11p and 12p of the first and second supports 11 and 12 are in contact with each other. In the present modification, the axial lengths of the cylindrical portions 11p and 12p of the first and second support bodies 11 and 12 are set as shown in FIG. The length is kept to the minimum necessary for supporting the first rubber bush B1, and a relatively large gap s _P is set between the inner ends of both the cylindrical portions 11p and 12p. In this case, shortening the axial direction of the supports 11 and 12 improves their press formability and increases the material yield efficiency, thereby reducing cost and weight.
[0037]
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various small design changes can be made. For example, in the above-described embodiment, the arm main body 1 is shown as a closed cross-section structure in which the upper plate body 2 and the lower plate body 3 are combined and integrated. However, in the present invention, the arm main body 1 has an open cross-section, for example, a cross-section. It may be formed in a U shape or an inverted U shape.
[0038]
In the above embodiment, the upper plate 2 and the lower plate 3 constituting the arm body 1 are connected by welding. However, in the present invention, the upper plate 2 and the lower plate 3 are connected to each other. You may make it couple | bond by fixing means other than welding.
[0039]
In the above embodiment, the A-type lower arm LA is shown as the suspension arm. However, the present invention may be applied to an I-type arm other than the A-type.
[0040]
As described above, according to the present invention, in the lightweight and low-cost suspension arm in which the arm body is configured by the press-molded metal plate, the bush support member is formed by the first and second support bodies parallel to each other in the bush axis direction. Each of the supports is divided into a cylindrical part to be inserted into the through-holes on both side walls of the middle part of the arm body, and formed integrally with the outer end of the cylindrical part, and is superposed and welded to the both side walls. Since the bushing is press-fitted and held on the inner periphery of each cylindrical portion of the first and second support members, the support member and the arm body side wall are welded. In order to secure the welding allowance, it is not necessary to extend each support body outwardly from the side wall of the arm body, so that the arm intermediate portion itself has a sufficient width section in a limited space. Setting Therefore, even with an arm body with a plate structure, sufficient strength can be secured, and the cross-sectional change of the arm before and after the weld between each support and the arm body can be suppressed as much as possible. Since the stress concentration at the part and its periphery can be alleviated as much as possible, the fatigue resistance of those parts can be improved. In addition, each flange portion is formed so that it does not protrude above and below the arm body side wall portion to be welded, and the outer diameter in the arm longitudinal direction is larger than the outer diameter in the vertical direction of each flange portion. As a result, the welded area of each support (flange) can be extended in the longitudinal direction of the arm while avoiding the increase in the vertical width of the middle part of the arm accompanying the special provision of each support (flange). The bond strength between the body and the arm body is further increased.
[0042]
In particular, according to the invention of claim 2 , the portions extending in the arm longitudinal direction of the flange portions of the first and second support members are formed so that the vertical width gradually decreases as the distance from the bush increases. It is possible to effectively suppress changes in the cross section of the arm before and after the weld between the body and the arm body, thereby further reducing the stress concentration at the weld and its surroundings. Is further improved.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a vehicle mounting state of an automobile suspension arm according to an embodiment of the present invention. FIG. 2 is a perspective view of the suspension arm. FIG. 3 is a plan view of the suspension arm. (3 arrow view of FIG. 2)
4 is an enlarged sectional view taken along line 4-4 in FIG. 3. FIG. 5 is an enlarged side view taken along arrow 5 in FIG. 3. FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG. FIG. 8 is a sectional view taken along line 8-8 in FIG. 7. FIG. 9 is a sectional view corresponding to FIG. 8 showing a modification of the damper support portion of the suspension arm. FIG. 10 is a schematic perspective view showing a conventional suspension arm. Figure [Explanation of symbols]
B3 3rd rubber bush (bush)
D Damper F Car body or subframe H1, H2 First and second support holes (through holes)
J3 Connecting pin K1 One side wall K2 Other side wall LA Lower arm (suspension arm)
P3 3rd bush press-fit part (bush press-fit part)
s _D gap W wheel (wheel)
w ″ Welding 1 Arm body 1d Middle part 2, 3 Upper, lower plate (metal plate)
7 Fork-shaped lower end portion 9 Bush support member 10 Drive shafts 11 and 12 First and second support members 11f and 12f First and second flange portions 11p and 12p First and second tube portions

Claims

プレス成形した金属板（２，３）より構成されると共に一端部が車体（Ｆ）側に，他端部が車輪（Ｗ）側にそれぞれ連結されるアーム本体（１）と，このアーム本体（１）の中間部（１ｄ）を空隙（ｓ_Ｄ）を存して跨ぐダンパ（Ｄ）のフォーク状下端部（７）に連結ピン（Ｊ３）を介して連結したブッシュ（Ｂ３）を圧入，支持させるためのブッシュ支持部材（９）とを備え，前記空隙（ｓ_Ｄ）にはドライブシャフト（１０）が通るようにした車両用サスペンションアームにおいて，前記ブッシュ支持部材（９）は，ブッシュ軸線方向に互いに並列する第１及び第２支持体（１１，１２）より分割構成され，その各々の支持体（１１，１２）は，前記アーム本体（１）の中間部両側壁（Ｋ１，Ｋ２）の貫通孔（Ｈ１，Ｈ２）にそれぞれ挿入させる筒部（１１ｐ，１２ｐ）と，該筒部（１１ｐ，１２ｐ）の外端に一体に形成されて該両側壁（Ｋ１，Ｋ２）にそれぞれ重合，溶接（ｗ″）される外向きのフランジ部（１１ｆ，１２ｆ）とを有しており，前記各フランジ部（１１ｆ，１２ｆ）は，それが溶接されるアーム本体側壁部（Ｋ１，Ｋ２）よりも上下に出っ張らないように，且つその各フランジ部（１１ｆ，１２ｆ）の上下方向外径よりもアーム長手方向の外径が大きくなるように形成され，前記第１及び第２支持体（１１，１２）の各筒部（１１ｐ，１２ｐ）内周に前記ブッシュ（Ｂ３）が圧入，嵌合されることを特徴とする，車両用サスペンションアーム。An arm body (1) which is composed of a press-formed metal plate (2, 3) and has one end connected to the vehicle body (F) side and the other end connected to the wheel (W) side; The bush (B3) connected via the connecting pin (J3) to the fork-like lower end (7) of the damper (D) straddling the intermediate part (1d) of 1) with a gap (s _D ) interposed therebetween and supported A suspension arm for a vehicle having a drive shaft (10) passing through the gap (s _D ), wherein the bush support member (9) is arranged in the bush axis direction. The first and second supports (11, 12) arranged in parallel with each other are divided and each of the supports (11, 12) penetrates the both side walls (K1, K2) of the intermediate portion of the arm body (1). Insert into holes (H1, H2) respectively Cylinder part (11p, 12p) to be formed, and outward flange formed integrally with the outer end of the cylinder part (11p, 12p) and superposed and welded (w ″) to both side walls (K1, K2), respectively Each flange portion (11f, 12f) does not protrude above and below the arm body side wall portion (K1, K2) to which the flange portion (11f, 12f) is welded. Each of the cylindrical portions (11p, 12p) of the first and second supports (11, 12) is formed so that the outer diameter in the arm longitudinal direction is larger than the outer diameter in the vertical direction of the flange portions (11f, 12f ). A suspension arm for a vehicle, wherein the bush (B3) is press-fitted and fitted to an inner periphery.

前記各フランジ部（１１ｆ，１２ｆ）の，アーム長手方向に延びる部分は，ブッシュ（Ｂ３）から遠ざかるにつれて上下幅が漸減するように形成されることを特徴とする，請求項１に記載の車両用サスペンションアーム。2. The vehicle according to claim 1, wherein a portion extending in the arm longitudinal direction of each flange portion (11 f, 12 f) is formed such that the vertical width gradually decreases as the distance from the bush (B <b> 3) increases . Suspension arm.