【０００１】
【発明の属する技術分野】
本発明は、車体前部構造に関する。
【０００２】
【従来の技術】
車体前部構造の中には、車幅方向両側のサイドメンバにマウントブラケットを介してパワーユニットを搭載支持するサブフレームを連結したものがあり、所定の第１の軸荷重が前方から加わった場合、サイドメンバの前方部分が圧縮変形する一方、サイドメンバの後方部分は変形しないようにするとともに、その後方部分は第１の軸荷重よりも大きな所定の第２の軸荷重が前方から加わることにより曲げ変形して、２段階のエネルギー吸収を可能としたものが知られている（例えば、特許文献１参照。）。
【０００３】
また、この車体前部構造では、前記サブフレームは車幅方向に対向した縦部材と、縦部材の車両前方部分間および車両後方部分間をそれぞれ繋ぐ前方横部材および後方横部材と、によって全体が矩形状に構成され、前記マウントブラケットは各縦部材の車両前方端部および車両後方端部に配置するようになっている。
【０００４】
【特許文献１】
特開２０００−１６３２７号公報（第３頁、第１図）
【０００５】
【発明が解決しようとする課題】
しかしながら、かかる従来の車体前部構造にあっては、正面衝突等のように前方から衝突荷重が入力する場合には、サブフレームの縦部材が圧縮変形してエネルギー吸収が可能であるが、オフセット衝突や斜め前方衝突あるいは前部側面衝突時には、サブフレームの前端部が非衝突側に荷重伝達する以前に、前方横部材が直状であるため途中で折れ曲がってしまったり、変形できずに突っ張り状態となってしまったりして、車体前部での衝突エネルギーの吸収効果が十分に発揮できない可能性がある。
【０００６】
そこで、本発明は車体前部にオフセット衝突や斜め前方衝突あるいは前部側面衝突時に入力される荷重を効率良く分散し、かつ、エネルギーを効率良く吸収することができる車体前部構造を提供するものである。
【０００７】
【課題を解決するための手段】
本発明の車体前部構造にあっては、サブフレームの縦部材から前方横部材に至る車両前方斜め部分に、車体外方に膨らむ前方円弧部分を設けるとともに、前記前方横部材にその車幅方向中央部で車両後方に滑らかに弯曲する凹設形状部を設けたことを特徴としている。
【０００８】
【発明の効果】
本発明によれば、車体前部にオフセット前方や斜め前方や横方向から荷重が入力した場合に、サブフレームの前方斜め方向部分に設けた前方円弧部分によって常に荷重を分散させることができ、このことはサブフレームの前方横部材に効率良く荷重を伝達し、ひいては、サブフレームの非衝突側への荷重分散を促進することができる。
【０００９】
また、衝突後半には凹設形状部を設けた前方横部材が効果的に変形し、また、前記前方円弧部分も変形するため、これら前方横部材および前方円弧部分の変形により、衝突形態のバラツキによっても安定してエネルギーを吸収することができる。
【００１０】
【発明の実施の形態】
以下、本発明の実施形態を図面と共に詳述する。
【００１１】
図１〜図４は本発明にかかる車体前部構造の第１実施形態を示し、図１は本発明の対象とする車体の全体斜視図、図２は車体前部右側の骨格構造を示す斜視図、図３は車体前部の側方衝突時の作用を順を追って示す車体前部骨格の平面図、図４はオフセット衝突時の作用を順を追って示す車体前部骨格の平面図である。
【００１２】
この第１実施形態の車体前部構造は、図１に示す車体１のフロントコンパートメント２に適用され、このフロントコンパートメント２は、図２に示すように車幅方向両側に対向して１対のサイドメンバ３が車体前後方向に延在しており、これらサイドメンバ３の前端に跨ってバンパーレインフォース４が連結されている。
【００１３】
また、サイドメンバ３の車両後方は、ダッシュパネル５に沿って下方に傾斜してフロアパネル６の下面に配置したエクステンションサイドメンバ７へと連続している。また、フロアパネル６の車幅方向外側縁には、エクステンションサイドメンバ７と略平行にサイドシル８が延在し、このサイドシル８の前端部にはフロントピラー９が立ち上がっている。
【００１４】
前記サイドメンバ３の下方にはサブフレーム１０を配置し、このサブフレーム１０に図外のパワーユニットを搭載支持するようになっており、このサブフレーム１０は図３にも示すように、車幅方向に対向した縦部材１１と、これら縦部材１１の前方部分間および後方部分間をそれぞれ繋ぐ前方横部材１２および後方横部材１３と、によって平面視して全体が閉じた構造となっている。
【００１５】
そして、この実施形態ではサブフレーム１０の形状を、縦部材１１から前方横部材１２に至る車両前方斜め部分に、車体外方に膨らむ前方円弧部分１４を設けるとともに、前方横部材１２にその車幅方向中央部で車両後方に滑らかに弯曲する凹設形状部１５を設けてある。
【００１６】
また、前方円弧部分１４に連なる縦部材１１の車両後方部分に、この前方円弧部分１４との間に、前方横部材１２と後方横部材１４とが略等長となる位置に設定した変曲点Ｋ１を境に、この前方円弧部分１４から同一方向に湾曲する後方円弧部分１６を設けてある。尚、この第１実施形態の後方横部材１３は車幅方向に直線的に延びている。
【００１７】
更に、前方円弧部分１４とこれに連続する縦部材１１との変曲点Ｋ１近傍に結合部Ｃ１を設けるとともに、前方横部材１２および後方横部材１３のそれぞれの車幅方向略中央部に結合部Ｃ２，Ｃ３を設け、結合部Ｃ１をサイドメンバ３の取付部Ｐ１に連結するとともに、結合部Ｃ２をバンパーレインフォース４の取付部Ｐ２に連結し、かつ、結合部Ｃ３をダッシュクロスメンバ５ａの取付部Ｐ３に連結することにより、サブフレーム１０の車体１への結合箇所を、左右一対の結合部Ｃ１，Ｃ１と前，後の結合部Ｃ２，Ｃ３の４箇所としてある。
【００１８】
また、この第１実施形態では図外のパワーユニットを支持するエンジンマウント部Ｅ１，Ｅ２は、左右一対の結合部Ｃ１の近傍および結合部Ｃ３の近傍の３箇所に設けている。
【００１９】
以上の構成によりこの第１実施形態の車体前部構造にあっては、図３（ｂ）に示すように前部側面衝突によって衝突荷重Ｆ１１が縦部材１１の側方から入力した場合、この衝突荷重Ｆ１１は、前方円弧部分１４から荷重ｆ３１，ｆ４１とバランス良く分散して前方横部材１２および後方横部材１３に伝達される。
【００２０】
一方、前方横部材１２の中央部近傍が結合部Ｃ２を介して車体側に拘束してあるため、変形が進むに伴ってその拘束部位も変形することによって、非衝突側、つまり、サブフレーム１０の図３（ｂ）中右側略半分への荷重伝達が行われる。
【００２１】
その後、更に変形が進むことにより、図３（ｃ）に示すように前方円弧部分１４が結合部Ｃ１近傍の変曲点Ｋ１から曲げ変形をし、曲げモーメントＭ１１の伝達により前方横部材１２の変曲点Ｋ２近傍で曲げ変形が発生するため、非衝突側部材への荷重伝達を実現し、反力を発生しつつ部材の曲げ変形によりエネルギー吸収が行われる。
【００２２】
また、図４（ａ）に示すようにオフセット衝突の場合、前方円弧部分１４の前端から入力が縦部材１１と前方横部材１２にバランス良く荷重ｆ３２，ｆ４２として分散され、次に前方円弧部分１４が正面から押し込まれ、前方横部材１２が中央の結合部Ｃ２を基点に曲げられることにより、図４（ｂ）に示すように、軸力ｆ３２と曲げモーメントＭ１２がサブフレーム１０の図中右方の非衝突側にも伝達される。
【００２３】
そして、前方横部材１２の変曲点Ｋ２と縦部材１１の結合部Ｃ１を基点に曲げ変形を行い、また、縦部材１１の後部の変曲点Ｋ３によっても曲げ変形を行うことにより、エネルギーの吸収効率を高めることができる。
【００２４】
即ち、この第１実施形態では、車体前部にオフセット前方あるいは斜め前方や横方向から荷重が入力した場合に、サブフレーム１０の前方斜め方向部分に設けた前方円弧部分１４によって常に荷重を分散させることができ、このことはサブフレーム１０の前方横部材１２に効率良く荷重を伝達し、ひいては、サブフレーム１０の非衝突側への荷重分散を促進することができる。
【００２５】
また、衝突後半には凹設形状部１５を設けた前方横部材１２が変形し、また、前記前方円弧部分１４も変形するため、これら前方横部材１２および前方円弧部分１４の変形により、衝突形態のバラツキによっても安定してエネルギーを吸収することができる。
【００２６】
従って、オフセット衝突や斜め前方衝突あるいは前部側方衝突の場合に、衝突側と反対の方向への荷重分散および変形によるエネルギー吸収を効率良く行うことができるため、キャビンへの入力を低減してキャビン変形を小さく抑制することができる。尚、正面衝突時にはサブフレーム１０は縦部材１１が曲げ変形するとともに、前方横部材１２は図外のパワーユニットとの干渉により圧潰することになる。
【００２７】
また、この第１実施形態では前述した作用効果に加えて、サブフレーム１０の車体への結合箇所を、前方円弧部分１４とこれに連続する縦部材１１との変曲点Ｋ１近傍と、前方横部材１２および後方横部材１３それぞれの車幅方向略中央部との４箇所としたことにより、斜め前方および横方向から荷重が入力する場合、前方横部材１２は変曲点近傍が拘束されていることで、衝突初期には荷重を非衝突側に伝達し易くなる。そして、入力の増加に伴って曲げ変形を行い、その動きに追従して反対側の縦部材と横部材１２，１３の変曲点周辺の変形を誘発する。
【００２８】
更に、縦部材１１と前方横部材１２の変曲点近傍が拘束されていることにより衝突初期に前方円弧状部分１４で荷重を受け、その後、結合部Ｃ１よりも後方への荷重伝達が行われて曲げ変形等によりエネルギーの吸収効率を高めることができる。
【００２９】
尚、正面から荷重が作用する場合、後方横部材１３の結合によりサブフレーム１０前部の変形後、結合部Ｃ１を支点にサブフレーム１０の曲げ変形によりエネルギーを吸収することができる。
【００３０】
つまり、衝突初期に前方横部材１２から非衝突側に荷重伝達を行い、前方横部材１２の変曲点の拘束部分よりも前方部分で曲げ変形して、後方部分の変形によりエネルギー吸収を行う。また、縦部材１１は変曲点近傍よりも前方部分で圧潰や曲げ変形してエネルギー吸収し、衝突後半は後方部分の変形により確実にエネルギーを吸収できる。
【００３１】
図５，図６は本発明の第２実施形態を示し、前記第１実施形態と同一構成部分に同一符号を付して重複する説明を省略して述べるものとし、図５は車体前部右側の骨格構造を示す斜視図、図６は車体前部の斜め前方衝突時の作用を順を追って示す車体前部骨格の平面図である。
【００３２】
この第２実施形態の車体前部構造は、図５，図６（ａ）に示すように、第１実施形態と同様にサブフレーム１０の形状を、縦部材１１から前方横部材１２に至る車両前方斜め部分に、車体外方に膨らむ前方円弧部分１４を設けるとともに、前方横部材１２にその車幅方向中央部で車両後方に滑らかに弯曲する凹設形状部１５を設けてある。
【００３３】
そして、第１実施形態と主に異なる点は、前方円弧部分１４に連なる縦部材１１の車両後方部分に、この前方円弧部分１４との間に、前方横部材１２が後方横部材１３よりも長くなる位置に変曲点Ｋ１を備えて、この前方円弧部分１４から直線状に連なる後方直線部分１７を設けてある。
【００３４】
尚、この第２実施形態の後方横部材１３は、第１実施形態と同様に車幅方向に直線的に延びている。
【００３５】
また、前方横部材１２の凹設形状部１５近傍に結合部Ｃ４を設けるとともに、縦部材１１と後方横部材１３との変曲点Ｋ３近傍に結合部Ｃ５を設け、結合部Ｃ４をバンパーレインフォース４の車幅方向略中央部に設けた取付部Ｐ４に連結し、結合部Ｃ５をサイドメンバ３の取付部Ｐ５に連結することにより、サブフレーム１０の車体１への取付箇所を３箇所としてある。
【００３６】
更に、この第２実施形態では、パワーユニットを支持するエンジンマウント部Ｅ３，Ｅ４は前記結合部Ｃ４，Ｃ５の近傍に配置してある。
【００３７】
従って、この第２実施形態の車体前部構造にあっては、図６（ｂ）に示すように斜め前方衝突により斜め前方から衝突荷重Ｆ２が入力すると、前方円弧部分１４によって縦部材１１と前方横部材１２に荷重ｆ５，ｆ６としてバランス良く分散される。また、衝突初期では前方円弧部分１４は前側の結合部Ｃ４を基点に曲げ変形を行い、その後、その変形部が押し込まれるとともに、非衝突側への荷重伝達を増加させる。
【００３８】
更に変形が進み、図６（ｃ）に示すように縦部材１１は車両後方部分が後方直線部分１７によって斜め方向に直線的に形成されているため、その軸力で荷重を受け、かつ、その後方直線部分１７は結合部Ｃ５によって車体に連結されているため、一定以上の荷重による変形が行われる。このため、前方円弧部分１４の曲げ変形後に後方直線部分１７の前端部が圧潰することにより、エネルギーの吸収効率を高めることができる。
【００３９】
即ち、この第２実施形態では斜め前方衝突に限ることなく、オフセット衝突の場合に衝突荷重が前方の片側に作用する場合、前方円弧部分１４で受けた荷重の横方向成分を前方横部材１２に効率良く伝達するとともに、前後方向の荷重を車体前方外側から後方内側に向かって直線状に延びる後方直線部分１７によって効率良く軸力として伝達でき、その際に前方円弧部分１４と前方横部材１２は変曲点Ｋ２周辺の曲げ変形によってエネルギーの吸収効率を高めることができる。
【００４０】
また、後方横部材１３を前方横部材１２よりも短くすることにより、斜め方向の入力に対して軸力の伝達効率を高めて変形荷重を増加させることができる。
【００４１】
図７，図８は本発明の第３実施形態を示し、前記第１実施形態と同一構成部分に同一符号を付して重複する説明を省略して述べるものとし、図７は車体前部右側の骨格構造を示す斜視図、図８は車体前部の斜め前方衝突時の作用を順を追って示す車体前部骨格の平面図である。
【００４２】
この第３実施形態の車体前部構造は、図７，図８（ａ）に示すように、第１実施形態と同様にサブフレーム１０の形状を、縦部材１１から前方横部材１２に至る車両前方斜め部分に、車体外方に膨らむ前方円弧部分１４を設けるとともに、前方横部材１２にその車幅方向中央部で車両後方に滑らかに弯曲する凹設形状部１５を設けてある。
【００４３】
そして、第１実施形態と主に異なる点は、前方円弧部分１４に連なる縦部材１１の車両後方部分に、この前方円弧部分１４よりも大きな曲率半径をもって車体内方に膨らむ内方円弧部分１８を設けてある。
【００４４】
尚、この第２実施形態の後方横部材１３は、第１実施形態と同様に車幅方向に直線的に延びている。
【００４５】
また、前方円弧部分１４とこれに連続する前方横部材１２との変曲点Ｋ２近傍に結合部Ｃ６を設けるとともに、縦部材１１と後方横部材１３との変曲点Ｋ３近傍に結合部Ｃ７を設け、結合部Ｃ６をサイドメンバ３の取付部Ｐ６に連結し、結合部Ｃ７をサイドメンバ３の取付部Ｐ７に連結することにより、サブフレーム４の車体１への結合箇所を４箇所としてある。
【００４６】
更に、この第３実施形態では、図外のパワーユニットを支持するエンジンマウント部Ｅ５，Ｅ６は前記結合部Ｃ６，Ｃ７の近傍に配置してある。
【００４７】
従って、この第３実施形態の車体前部構造にあっては、図８（ｂ）に示すように斜め前方衝突により斜め前方から衝突荷重Ｆ３が入力すると、前方円弧部分１４からの入力によって縦部材１１と前方横部材１２の変曲点Ｋ２近傍に設けた結合部Ｃ６を基点として曲げ変形を行い、図８（ｃ）に示すようにその動きにより発生した曲げモーメントＭ５が非衝突側に伝達される。
【００４８】
そして、図８（ｂ）に示すように前方横部材１２の曲げ変形によりエネルギー吸収を行い、前後方向の荷重ｆ８は車体前方外側から後方内側に向かって配置した内方円弧部分１８に軸力ｆ８とモーメントＭ４によって伝達する。そのとき、前方円弧部分１４よりも後方に配置した内方円弧部分１８の曲率半径が大きくなっており、その後端部は結合部Ｃ７によって車体１に連結されることで、前方円弧部分１４が変形した後に縦部材１１が内方円弧部分１８から曲げ変形することにより、高いエネルギー吸収を確保することができる。
【００４９】
即ち、この第３実施形態では斜め前方衝突に限ることなく、オフセット衝突の場合に衝突荷重が前方の片側に作用する場合、前方円弧部分１４で受けた荷重の横方向成分を前方横部材１２に効率良く伝達するとともに、前方横部材１２の曲げ変形によりエネルギー吸収する一方、前後方向荷重を車体前方外側から後方内側に向かって配置される内方円弧部分１８に軸力とモーメントとによって伝達する。
【００５０】
そのとき、前方円弧部分１４よりも後方の内方円弧部分１８の曲率半径が大きいので、前方円弧部分１４が変形した後に内方円弧部分１８が変形するため、この内方円弧部分１８の変形によりエネルギーの吸収効率を高めることができる。
【００５１】
また、この第３実施形態では前述した作用効果に加えて、サブフレーム１０の車体への結合箇所を、前方円弧部分１４とこれに連続する前方横部材１２との変曲点Ｋ２近傍と、縦部材１１と後方横部材１３との変曲点Ｋ３近傍との４箇所としたことにより、斜め前方および横方向から荷重が入力する場合、横方向荷重を前方円弧部分１４と前方横部材１２とが一体として動くことにより、非衝突側に荷重伝達することができる。そして、衝突後半には前方横部材１２および縦部材１１が変曲点をきっかけに曲げ変形を行ってエネルギー吸収する。
【００５２】
更に、後方の変曲点Ｋ３近傍が拘束されることにより、正面から荷重が入力する場合、前後方向の荷重によりサブフレーム１０が圧潰および曲げ変形によりエネルギー吸収を行うことができる。
【００５３】
つまり、前方横部材１２からの非衝突側への荷重伝達後に曲げ変形によるエネルギー吸収ができるため、縦部材１１は後端部の支持により前端部が確実に圧潰し、また曲げ変形してエネルギー吸収することができる。
【００５４】
図９，図１０は本発明の第４実施形態を示し、前記第１実施形態と同一構成部分に同一符号を付して重複する説明を省略して述べるものとし、図９は車体前部右側の骨格構造を示す斜視図、図１０は車体前部の側方衝突時の作用を順を追って示す車体前部骨格の平面図である。
【００５５】
この第４実施形態の車体前部構造は、図９，図１０（ａ）に示すように、第１実施形態と同様にサブフレーム１０の形状を、縦部材１１から前方横部材１２に至る車両前方斜め部分に、車体外方に膨らむ前方円弧部分１４を設けるとともに、前方横部材１２にその車幅方向中央部で車両後方に滑らかに弯曲する凹設形状部１５を設けてある。
【００５６】
そして、第１実施形態と主に異なる点は、前方円弧部分１４に縦部材１１の車両後方部分を滑らかに連続させるとともに、後方横部材１３を車体後方に膨らむ平面半円弧状に湾曲して、この後方横部材１３を前記縦部材１１に滑らかに連続させてある。
【００５７】
また、第１実施形態と同様に前方円弧部分１４とこれに連続する縦部材１１との変曲点Ｋ１近傍に結合部Ｃ１を設けるとともに、前方横部材１２および後方横部材１３それぞれの車幅方向略中央部に結合部Ｃ２，Ｃ３を設け、結合部Ｃ１をサイドメンバ３の取付部Ｐ１に連結するとともに、結合部Ｃ２をバンパーレインフォース４の取付部Ｐ２に連結し、かつ、結合部Ｃ３をダッシュクロスメンバ５ａの取付部Ｐ３に連結することにより、サブフレーム１０の車体１への結合箇所を、左右一対の結合部Ｃ１，Ｃ１と前，後の結合部Ｃ２，Ｃ３の４箇所としてある。
【００５８】
更に、この第４実施形態ではパワーユニットを支持するエンジンマウント部Ｅ８，Ｅ９，Ｅ１０は、左右一対の結合部Ｃ１の近傍および結合部Ｃ２，Ｃ３の近傍の４箇所に設けている。
【００５９】
従って、この第４実施形態の車体前部構造にあっては、図１０（ｂ）に示すように前部側方衝突によって横方向から衝突荷重Ｆ４が入力した場合、後方横部材１３を半円弧状に形成したことにより、前方円弧部分１４で分散した軸力ｆ９，ｆ１０の反力を増加させるとともに、前方横部材１２および後方横部材１３がそれぞれの中央部に設けた結合部Ｃ２，Ｃ３を基点として曲げ変形するため、よりバランスの良い荷重分散と変形分散を行うことができる。
【００６０】
即ち、この第４実施形態では斜め前方衝突に限ることなく前部側方衝突の場合に、衝突荷重が斜め前方および横方向から作用する場合、前方円弧部分１４でバランス良く均等に荷重を分散し、横方向成分は衝突部位が前方であれば主に前方横部材１２が荷重を受け、後方であれば主に後方横部材１３が荷重を受けて、幅広い衝突範囲にも対応できる。
【００６１】
また、横方向の荷重は非衝突側へ伝達することができるとともに、前，後方横部材１２，１３それぞれの中央部に変曲点Ｋ４，Ｋ５が形成されていることにより、変形の進行に伴って前，後方横部材１２，１３が曲げ変形してエネルギー吸収できるため、サブフレーム１０の耐力を向上させるとともに変形によるエネルギー吸収量も増加することができる。
【００６２】
図１１，図１２は本発明の第５実施形態を示し、前記第１実施形態と同一構成部分に同一符号を付して重複する説明を省略して述べるものとし、図１１は車体前部右側の骨格構造を示す斜視図、図１２は車体前部の斜め前方衝突時の作用を順を追って示す車体前部骨格の平面図である。
【００６３】
この第５実施形態の車体前部構造は、図１１，図１２（ａ）に示すように、第１実施形態と同様にサブフレーム１０の形状を、縦部材１１から前方横部材１２に至る車両前方斜め部分に、車体外方に膨らむ前方円弧部分１４を設けるとともに、前方横部材１２にその車幅方向中央部で車両後方に滑らかに弯曲する凹設形状部１５を設けてある。
【００６４】
そして、第１実施形態と主に異なる点は、前方円弧部分１４とこれに連続する縦部材１１との変曲点Ｋ１近傍と、前方円弧部分１４とこれに連続する前方横部材１２との変曲点Ｋ２近傍と、を連結する取付ブラケット２０を設け、この取付ブラケット２０に車体への結合部Ｃ８を設けてある。
【００６５】
従って、この実施形態では取付ブラケット２０に結合部Ｃ８を設けたことにより、取付ブラケット２０が結合した前記変曲点Ｋ２近傍を支持することになり、この場合のサブフレーム１０の車体への結合箇所は、前方円弧部分１４とこれに連続する前方横部材１２との変曲点Ｋ２近傍であり、後方横部材１３の車幅方向略中央部に結合部Ｃ３を設け、結合部Ｃ８をサイドメンバ３の取付部Ｐ８に連結するとともに、結合部Ｃ３をダッシュクロスメンバ５ａの取付部Ｐ３に連結することにより、サブフレーム４の車体１への結合箇所を３箇所としてある。
【００６６】
更に、この第５実施形態では、パワーユニットを支持するエンジンマウント部Ｅ１１，Ｅ１２は前記取付ブラケット２０および結合部Ｃ３の近傍に配置してある。
【００６７】
ところで、この第５実施形態のサブフレーム１０は、第４実施形態と同様に前方円弧部分１４に縦部材１１の車両後方部分を滑らかに連続させるとともに、後方横部材１３を車体後方に膨らむ平面半円弧状に湾曲して、この後方横部材１３を前記縦部材１１に滑らかに連続させてあるが、これに限ることなく第１〜第３実施形態のサブフレーム１０の構造、若しくはそれ以外の構造を採ることができる。
【００６８】
従って、この第５実施形態の車体前部構造にあっては、図１２（ｂ）に示すように斜め前方衝突等によって斜め前方から荷重Ｆ５が入力すると、前方円弧部分１４と取付ブラケット２０とによって閉じた構造となり、この閉じた構造部分の変形およびその変形によって前方横部材１２の中央部を基点にする曲げ変形が誘発される。また、縦部材１１の後方部分も後方横部材１３の中央部の結合部Ｃ３を基点に曲げ変形することによりエネルギーの吸収効果をより高めることができる。
【００６９】
即ち、この実施形態では斜め前方衝突に限ることなく、前部側方衝突やオフセット衝突によって衝突荷重が前方の片側に作用する場合、前方円弧部分１４と取付ブラケット２０とにより形成された閉じ構造部分の変形により、正面衝突と同様のエネルギー吸収を行うことができる。
【００７０】
また、サブフレーム１０の車体への結合箇所を、前方円弧部分１４とこれに連続する前方横部材１２との変曲点Ｋ２近傍と、後方横部材１３の車幅方向略中央部の３箇所としたので、斜め前方や前部横方向から荷重が入力する場合、前部円弧部１４から続く縦部材１１の部分で湾曲した部分が伸びるような変形を行う。
【００７１】
その際に、前方部の連結箇所は近接しているので拘束が十分に行われており、前方円弧部分１４の断面変形を積極的に促進することができる。また、その後、縦部材１１の曲げ変形によりエネルギー吸収を行う。
【００７２】
オフセット衝突の場合、衝突初期は前端の圧潰による変形、後半部分は締結部分までの湾曲若しくは変曲点を有するメンバの曲げ変形により、エネルギーの吸収効率を高めることができる。
【００７３】
ところで、本発明の車体前部構造は前記第１〜第５実施形態に例をとって説明したが、これら実施形態に限ることなく本発明の要旨を逸脱しない範囲で他の実施形態を各種採ることができる。
【図面の簡単な説明】
【図１】本発明の対象とする車体の斜視図。
【図２】本発明の第１実施形態における車体前部右側の骨格構造を示す斜視図。
【図３】本発明の第１実施形態における車体前部の側方衝突時の作用を順を追って示す車体前部骨格の平面図。
【図４】本発明の第１実施形態におけるオフセット衝突時の作用を順を追って示す車体前部骨格の平面図。
【図５】本発明の第２実施形態における車体前部右側の骨格構造を示す斜視図。
【図６】本発明の第２実施形態における車体前部の斜め前方衝突時の作用を順を追って示す車体前部骨格の平面図。
【図７】本発明の第３実施形態における車体前部右側の骨格構造を示す斜視図。
【図８】本発明の第３実施形態における車体前部の斜め前方衝突時の作用を順を追って示す車体前部骨格の平面図。
【図９】本発明の第４実施形態における車体前部右側の骨格構造を示す斜視図。
【図１０】本発明の第４実施形態における車体前部の側方衝突時の作用を順を追って示す車体前部骨格の平面図。
【図１１】本発明の第５実施形態における車体前部右側の骨格構造を示す斜視図。
【図１２】本発明の第５実施形態における車体前部の斜め前方衝突時の作用を順を追って示す車体前部骨格の平面図。
【符号の説明】
１ 車体
３ サイドメンバ
１０ サブフレーム
１１ 縦部材
１２ 前方横部材
１３ 後方横部材
１４ 前方円弧部分
１５ 凹設形状部
１６ 後方円弧部分
１７ 後方直線部分
１８ 内方円弧部分
２０ 取付ブラケット
Ｋ１〜Ｋ５ 変曲点
Ｃ１〜Ｃ８ 結合部
Ｐ１〜Ｐ８ 取付部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle body front structure.
[0002]
[Prior art]
In the vehicle body front structure, there is a structure in which a subframe for mounting and supporting the power unit is connected to side members on both sides in the vehicle width direction via a mount bracket, and when a predetermined first axial load is applied from the front, While the front portion of the side member is compressed and deformed, the rear portion of the side member is not deformed, and the rear portion is bent by applying a predetermined second axial load larger than the first axial load from the front. It is known that it is deformed to enable two-stage energy absorption (for example, see Patent Document 1).
[0003]
Further, in the vehicle body front structure, the subframe is entirely formed by a vertical member facing the vehicle width direction, and a front horizontal member and a rear horizontal member connecting the vertical member between the vehicle front part and the vehicle rear part, respectively. The mount brackets are formed in a rectangular shape, and the mount brackets are arranged at a vehicle front end and a vehicle rear end of each vertical member.
[0004]
[Patent Document 1]
JP-A-2000-16327 (page 3, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, in such a conventional vehicle body front structure, when a collision load is input from the front such as a head-on collision, the vertical members of the sub-frame can be compressed and deformed to absorb energy. In the event of a collision, oblique forward collision, or front side collision, before the front end of the subframe transmits the load to the non-collision side, the front transverse member is straight, so it is bent in the middle and it is in a stretched state without being deformed And the effect of absorbing the collision energy at the front of the vehicle body may not be sufficiently exhibited.
[0006]
Therefore, the present invention provides a vehicle body front structure capable of efficiently dispersing a load input at the time of an offset collision, an oblique forward collision, or a front side collision at the vehicle body front and absorbing energy efficiently. It is.
[0007]
[Means for Solving the Problems]
In the vehicle body front structure of the present invention, a front arc portion swelling outward from the vehicle body is provided in a diagonally forward portion of the vehicle from the vertical member of the subframe to the front horizontal member, and the front horizontal member is provided in the vehicle width direction. It is characterized in that a recessed portion that smoothly curves in the rear of the vehicle is provided at the center.
[0008]
【The invention's effect】
According to the present invention, when a load is input to the front of the vehicle body from an offset front, diagonally forward, or lateral direction, the load can always be dispersed by the front arc portion provided in the front diagonal portion of the subframe. This effectively transmits the load to the front lateral member of the sub-frame, and thus can promote load distribution to the non-collision side of the sub-frame.
[0009]
Further, in the latter half of the collision, the front transverse member provided with the concave shape portion is effectively deformed, and the front arc portion is also deformed. Therefore, the deformation of the front transverse member and the front arc portion causes variations in the collision form. Energy can be stably absorbed.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
1 to 4 show a first embodiment of a vehicle body front structure according to the present invention, FIG. 1 is an overall perspective view of a vehicle body to which the present invention is applied, and FIG. FIG. 3 is a plan view of the vehicle body front skeleton showing the action at the time of a side collision of the vehicle body front part in order, and FIG. 4 is a plan view of the vehicle body front skeleton showing the action at the time of the offset collision in order. .
[0012]
The vehicle body front structure of the first embodiment is applied to a front compartment 2 of a vehicle body 1 shown in FIG. 1, and the front compartment 2 has a pair of side The members 3 extend in the front-rear direction of the vehicle body, and a bumper reinforce 4 is connected across the front ends of the side members 3.
[0013]
Further, the rear of the side member 3 in the vehicle is inclined downward along the dash panel 5 and continues to an extension side member 7 arranged on the lower surface of the floor panel 6. A side sill 8 extends substantially parallel to the extension side member 7 on the outer edge of the floor panel 6 in the vehicle width direction, and a front pillar 9 stands at a front end of the side sill 8.
[0014]
A sub-frame 10 is arranged below the side member 3, and a power unit (not shown) is mounted and supported on the sub-frame 10. As shown in FIG. , And a front horizontal member 12 and a rear horizontal member 13 connecting the front portion and the rear portion of the vertical member 11, respectively.
[0015]
In this embodiment, the shape of the sub-frame 10 is such that a front arc portion 14 swelling outward from the vehicle body is provided in a diagonally forward portion of the vehicle from the vertical member 11 to the front horizontal member 12, and the vehicle width is provided on the front horizontal member 12. At the center in the direction, there is provided a recessed portion 15 that smoothly curves toward the rear of the vehicle.
[0016]
Also, an inflection point set at a position where the front horizontal member 12 and the rear horizontal member 14 are substantially equal in length between the front circular arc 14 and the rear side of the vertical member 11 connected to the front circular arc 14. A rear arc portion 16 that curves in the same direction from the front arc portion 14 is provided with K1 as a boundary. The rear lateral member 13 of the first embodiment extends linearly in the vehicle width direction.
[0017]
Further, a connecting portion C1 is provided near the inflection point K1 between the front circular arc portion 14 and the longitudinal member 11 continuing thereto, and a connecting portion is provided at a substantially central portion of each of the front lateral member 12 and the rear lateral member 13 in the vehicle width direction. C2 and C3 are provided to connect the connecting portion C1 to the mounting portion P1 of the side member 3, connect the connecting portion C2 to the mounting portion P2 of the bumper reinforcement 4, and connect the connecting portion C3 to the dash cross member 5a. By connecting to the portion P3, the connecting portions of the subframe 10 to the vehicle body 1 are four places of a pair of right and left connecting portions C1, C1 and front and rear connecting portions C2, C3.
[0018]
In the first embodiment, engine mounts E1 and E2 for supporting a power unit (not shown) are provided at three locations near a pair of left and right connecting portions C1 and near the connecting portion C3.
[0019]
With the above structure, in the vehicle body front structure of the first embodiment, when the collision load F11 is input from the side of the vertical member 11 due to the front side collision as shown in FIG. The load F11 is distributed to the front lateral member 12 and the rear lateral member 13 from the front arc portion 14 in a well-balanced manner with the loads f31 and f41.
[0020]
On the other hand, since the vicinity of the center of the front lateral member 12 is restrained toward the vehicle body via the coupling portion C2, the restrained portion is also deformed as the deformation proceeds, so that the non-collision side, that is, the sub-frame 10 3 (b), the load is transmitted to substantially the right half.
[0021]
Thereafter, as the deformation further proceeds, the front arc portion 14 bends and deforms from the inflection point K1 near the joint C1 as shown in FIG. 3C, and the front transverse member 12 is deformed by transmitting the bending moment M11. Since bending deformation occurs near the bending point K2, load transmission to the non-collision-side member is realized, and energy absorption is performed by bending deformation of the member while generating a reaction force.
[0022]
As shown in FIG. 4A, in the case of an offset collision, the input is distributed from the front end of the front circular arc portion 14 to the vertical member 11 and the front horizontal member 12 as loads f32 and f42 in a well-balanced manner. Is pushed in from the front, and the front horizontal member 12 is bent around the center joint portion C2, so that the axial force f32 and the bending moment M12 are shifted rightward in the drawing of the sub-frame 10 as shown in FIG. Is transmitted to the non-collision side of the vehicle.
[0023]
The bending deformation is performed based on the inflection point K2 of the front horizontal member 12 and the coupling portion C1 of the vertical member 11, and the bending deformation is also performed at the rear inflection point K3 of the vertical member 11, thereby achieving energy saving. Absorption efficiency can be increased.
[0024]
That is, in the first embodiment, when a load is input to the front portion of the vehicle body from an offset front, diagonally forward, or lateral direction, the load is always dispersed by the front arc portion 14 provided in the front diagonal portion of the subframe 10. As a result, the load can be efficiently transmitted to the front cross member 12 of the sub-frame 10, and thus, the load distribution to the non-collision side of the sub-frame 10 can be promoted.
[0025]
Further, in the latter half of the collision, the front transverse member 12 provided with the concave-shaped portion 15 is deformed, and the front arc portion 14 is also deformed. The energy can be stably absorbed even by the variation of.
[0026]
Therefore, in the case of an offset collision, an oblique forward collision, or a front side collision, energy can be efficiently absorbed by dispersing a load in the direction opposite to the collision side and deforming, thereby reducing input to the cabin. Cabin deformation can be suppressed small. At the time of a frontal collision, the vertical member 11 of the sub-frame 10 is bent and deformed, and the front horizontal member 12 is crushed by interference with a power unit (not shown).
[0027]
In addition, in the first embodiment, in addition to the above-described functions and effects, the connecting portion of the sub-frame 10 to the vehicle body is located near the inflection point K1 between the front circular arc portion 14 and the vertical member 11 connected thereto, and When the load is input from obliquely forward and lateral directions, the front lateral member 12 is restrained in the vicinity of the inflection point by having four portions, that is, the substantially central portion in the vehicle width direction of the member 12 and the rear lateral member 13. This makes it easier to transmit the load to the non-collision side at the beginning of the collision. Then, bending deformation is performed with an increase in the input, and the deformation is induced around the inflection point of the opposite vertical members and horizontal members 12 and 13 following the movement.
[0028]
Further, since the vicinity of the inflection point between the vertical member 11 and the front horizontal member 12 is restrained, a load is received at the front arc-shaped portion 14 at the initial stage of the collision, and thereafter, the load is transmitted to the rear of the joint C1. Thus, the energy absorption efficiency can be increased by bending deformation or the like.
[0029]
When a load is applied from the front, energy can be absorbed by bending deformation of the sub-frame 10 with the joint C1 serving as a fulcrum after deformation of the front portion of the sub-frame 10 by the connection of the rear transverse member 13.
[0030]
That is, a load is transmitted from the front lateral member 12 to the non-collision side at the initial stage of the collision, and the front lateral member 12 bends and deforms at a portion in front of the restrained portion at the inflection point, and absorbs energy by deforming the rear portion. Further, the vertical member 11 absorbs energy by crushing or bending deformation in a portion ahead of the vicinity of the inflection point, and can surely absorb energy in the latter half of the collision by deformation of the rear portion.
[0031]
5 and 6 show a second embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof will not be repeated. FIG. 6 is a plan view of the vehicle body front skeleton, showing the action of the vehicle body front at the time of an oblique forward collision in order.
[0032]
As shown in FIGS. 5 and 6 (a), the vehicle body front structure according to the second embodiment changes the shape of the subframe 10 from the vertical member 11 to the front horizontal member 12 as in the first embodiment. A front arc portion 14 bulging outward from the vehicle body is provided in the front diagonal portion, and a concave shape portion 15 is provided in the front transverse member 12 so as to smoothly curve toward the rear of the vehicle at the center in the vehicle width direction.
[0033]
The main difference from the first embodiment is that the front horizontal member 12 is longer than the rear horizontal member 13 between the front arc portion 14 and the vehicle rear portion of the vertical member 11 connected to the front arc portion 14. An inflection point K1 is provided at a certain position, and a rear straight line portion 17 that is linearly continued from the front circular arc portion 14 is provided.
[0034]
The rear lateral member 13 of the second embodiment extends linearly in the vehicle width direction as in the first embodiment.
[0035]
In addition, a connecting portion C4 is provided near the concave shape portion 15 of the front horizontal member 12, and a connecting portion C5 is provided near the inflection point K3 between the vertical member 11 and the rear horizontal member 13, so that the connecting portion C4 is connected to the bumper reinforcement. 4, the sub-frame 10 is attached to the vehicle body 1 by connecting the sub-frame 10 to the vehicle body 1 by connecting the sub-frame 10 to the mounting portion P4 provided substantially at the center in the vehicle width direction and connecting the connecting portion C5 to the mounting portion P5 of the side member 3. .
[0036]
Further, in the second embodiment, the engine mounts E3 and E4 supporting the power unit are arranged near the coupling portions C4 and C5.
[0037]
Therefore, in the vehicle body front structure according to the second embodiment, when the collision load F2 is input from an oblique front due to an oblique front collision as shown in FIG. Loads f5 and f6 are distributed to the horizontal member 12 in a well-balanced manner. Further, in the initial stage of the collision, the front arc portion 14 bends and deforms with the front joint portion C4 as a base point. Thereafter, the deformed portion is pushed in and the load transmission to the non-collision side is increased.
[0038]
As the deformation progresses further, as shown in FIG. 6 (c), the vertical member 11 receives the load by its axial force because the rear portion of the vehicle is linearly formed in the oblique direction by the rear straight portion 17. Since the straight line portion 17 is connected to the vehicle body by the connecting portion C5, the deformation is performed by a load equal to or more than a certain value. Therefore, the front end of the rear straight portion 17 is crushed after the front arc portion 14 is bent and deformed, so that the energy absorption efficiency can be increased.
[0039]
That is, in the second embodiment, the horizontal component of the load received by the front arc portion 14 is applied to the front cross member 12 when the collision load acts on one side in the front in the case of the offset collision, without being limited to the oblique front collision. In addition to efficiently transmitting the load, the load in the front-rear direction can be efficiently transmitted as axial force by the rear straight portion 17 extending linearly from the front outer side to the rear inner side. At this time, the front arc portion 14 and the front cross member 12 Energy absorption efficiency can be increased by bending deformation around the inflection point K2.
[0040]
Further, by making the rear horizontal member 13 shorter than the front horizontal member 12, it is possible to increase the transmission efficiency of the axial force with respect to the input in the oblique direction and increase the deformation load.
[0041]
7 and 8 show a third embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. FIG. FIG. 8 is a plan view of the vehicle body front skeleton showing the operation of the vehicle body front part at the time of an oblique forward collision in order.
[0042]
As shown in FIGS. 7 and 8A, the vehicle body front structure according to the third embodiment is similar to the first embodiment in that the shape of the subframe 10 is changed from the vertical member 11 to the front horizontal member 12 as shown in FIG. A front arc portion 14 bulging outward from the vehicle body is provided in the front diagonal portion, and a concave shape portion 15 is provided in the front transverse member 12 so as to smoothly curve toward the rear of the vehicle at the center in the vehicle width direction.
[0043]
The main difference from the first embodiment is that an inwardly arcuate portion 18 bulging inward with a larger radius of curvature than the forwardly arcuate portion 14 is provided on the vehicle rear portion of the vertical member 11 connected to the forwardly arcuate portion 14. It is provided.
[0044]
The rear lateral member 13 of the second embodiment extends linearly in the vehicle width direction as in the first embodiment.
[0045]
A connecting portion C6 is provided near the inflection point K2 between the front circular arc portion 14 and the front horizontal member 12 continuous thereto, and a connecting portion C7 is provided near the inflection point K3 between the vertical member 11 and the rear horizontal member 13. By connecting the connecting portion C6 to the mounting portion P6 of the side member 3 and connecting the connecting portion C7 to the mounting portion P7 of the side member 3, the subframe 4 is connected to the vehicle body 1 in four places.
[0046]
Further, in the third embodiment, engine mounts E5 and E6 supporting a power unit (not shown) are arranged near the coupling portions C6 and C7.
[0047]
Therefore, in the vehicle body front structure according to the third embodiment, when a collision load F3 is input from an oblique front due to an oblique front collision as shown in FIG. Bending deformation is performed with the joint portion C6 provided near the inflection point K2 of the front transverse member 11 and the front transverse member 12 as shown in FIG. 8C, and the bending moment M5 generated by the movement is transmitted to the non-collision side as shown in FIG. You.
[0048]
As shown in FIG. 8B, energy is absorbed by bending deformation of the front horizontal member 12, and the load f8 in the front-rear direction is applied to the inner arc portion 18 arranged from the front outer side to the rear inner side by the axial force f8. And the moment M4. At this time, the radius of curvature of the inner circular arc portion 18 arranged rearward of the front circular arc portion 14 is large, and the rear end portion is connected to the vehicle body 1 by the coupling portion C7, so that the front circular arc portion 14 is deformed. After this, the vertical member 11 bends and deforms from the inner circular arc portion 18, so that high energy absorption can be secured.
[0049]
That is, in the third embodiment, the horizontal component of the load received by the front circular arc portion 14 is applied to the front cross member 12 when the collision load acts on one side in the front in the case of the offset collision without being limited to the oblique front collision. While efficiently transmitting the energy, the energy is absorbed by the bending deformation of the front transverse member 12, and the longitudinal load is transmitted by the axial force and the moment to the inner arc portion 18 arranged from the front outer side to the rear inner side of the vehicle body.
[0050]
At this time, since the radius of curvature of the inner arc portion 18 behind the front arc portion 14 is large, the inner arc portion 18 is deformed after the front arc portion 14 is deformed. Energy absorption efficiency can be increased.
[0051]
In the third embodiment, in addition to the above-described functions and effects, the connecting portion of the sub-frame 10 to the vehicle body is located near the inflection point K2 between the front circular arc portion 14 and the front horizontal member 12 continuous therewith, By providing four points near the inflection point K3 between the member 11 and the rear lateral member 13, when a load is input from diagonally forward and lateral directions, the lateral load is applied by the front arc portion 14 and the front lateral member 12. By moving together, the load can be transmitted to the non-collision side. Then, in the latter half of the collision, the front horizontal member 12 and the vertical member 11 perform bending deformation triggered by the inflection point to absorb energy.
[0052]
Furthermore, when a load is input from the front by constraining the vicinity of the rear inflection point K3, the sub-frame 10 can absorb energy by crushing and bending deformation due to the load in the front-rear direction.
[0053]
In other words, since energy can be absorbed by bending after the load is transmitted from the front horizontal member 12 to the non-collision side, the front end of the vertical member 11 is securely crushed by the support of the rear end, and the energy is absorbed by bending. can do.
[0054]
9 and 10 show a fourth embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. FIG. 9 shows a vehicle body front right side. FIG. 10 is a plan view of the vehicle body front skeleton showing the operation of the vehicle body front part at the time of a side collision in order.
[0055]
As shown in FIGS. 9 and 10 (a), the vehicle body front structure according to the fourth embodiment changes the shape of the subframe 10 from the vertical member 11 to the front horizontal member 12 as in the first embodiment. A front arc portion 14 bulging outward from the vehicle body is provided in the front diagonal portion, and a concave shape portion 15 is provided in the front transverse member 12 so as to smoothly curve toward the rear of the vehicle at the center in the vehicle width direction.
[0056]
The main difference from the first embodiment is that the front arc portion 14 smoothly connects the vehicle rear portion of the vertical member 11 to the vehicle, and the rear transverse member 13 is curved into a plane semicircular shape bulging rearward of the vehicle body. The rear horizontal member 13 is smoothly connected to the vertical member 11.
[0057]
Further, as in the first embodiment, a coupling portion C1 is provided near the inflection point K1 between the front circular arc portion 14 and the vertical member 11 connected thereto, and the vehicle width direction of each of the front horizontal member 12 and the rear horizontal member 13 is set. Connecting portions C2 and C3 are provided substantially at the center, and the connecting portion C1 is connected to the mounting portion P1 of the side member 3, and the connecting portion C2 is connected to the mounting portion P2 of the bumper reinforce 4, and the connecting portion C3 is connected. By connecting to the mounting portion P3 of the dash cross member 5a, the connecting portions of the sub-frame 10 to the vehicle body 1 are four portions of a pair of right and left connecting portions C1, C1 and front and rear connecting portions C2, C3.
[0058]
Further, in the fourth embodiment, engine mounts E8, E9, and E10 that support the power unit are provided at four locations near the pair of left and right coupling portions C1 and near the coupling portions C2 and C3.
[0059]
Therefore, in the vehicle body front structure according to the fourth embodiment, as shown in FIG. 10B, when the collision load F4 is input from the lateral direction due to the front side collision, the rear horizontal member 13 is semicircular. Due to the formation of the arc shape, the reaction force of the axial forces f9 and f10 dispersed in the front arc portion 14 is increased, and the connecting portions C2 and C3 provided at the central portions of the front transverse member 12 and the rear transverse member 13 are provided. Since the bending deformation is performed as a base point, a more balanced load distribution and deformation distribution can be performed.
[0060]
That is, in the fourth embodiment, when the collision load is applied not only to the diagonally forward collision but also to the front side collision and from the diagonally forward and side directions, the load is uniformly distributed in a well-balanced manner at the front arc portion 14. In the lateral direction component, if the collision site is forward, the front horizontal member 12 is mainly loaded, and if it is behind, the rear horizontal member 13 is mainly loaded, so that a wide collision range can be handled.
[0061]
Further, the load in the lateral direction can be transmitted to the non-collision side, and the inflection points K4 and K5 are formed at the center portions of the front and rear transverse members 12 and 13, respectively, so that the deformation can progress as the deformation progresses. Since the front and rear transverse members 12 and 13 can bend and deform to absorb energy, the strength of the subframe 10 can be improved and the amount of energy absorbed by the deformation can be increased.
[0062]
11 and 12 show a fifth embodiment of the present invention, in which the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. FIG. 12 is a plan view of the vehicle body front skeleton showing the action of the vehicle body front part in an oblique forward collision in order.
[0063]
As shown in FIGS. 11 and 12A, the vehicle body front structure according to the fifth embodiment changes the shape of the subframe 10 from the vertical member 11 to the front horizontal member 12 as in the first embodiment. A front arc portion 14 bulging outward from the vehicle body is provided in the front diagonal portion, and a recessed portion 15 that smoothly curves rearward in the vehicle width direction at the center in the vehicle width direction is provided in the front transverse member 12.
[0064]
The first embodiment differs from the first embodiment mainly in the vicinity of the inflection point K1 between the front circular arc portion 14 and the vertical member 11 continuous therewith, and the change between the front circular arc portion 14 and the front horizontal member 12 continuous therewith. A mounting bracket 20 is provided for connecting the vicinity of the curved point K2, and a connecting portion C8 to the vehicle body is provided on the mounting bracket 20.
[0065]
Therefore, in this embodiment, by providing the connecting portion C8 to the mounting bracket 20, the vicinity of the inflection point K2 to which the mounting bracket 20 is connected is supported. In this case, the connecting portion of the subframe 10 to the vehicle body Is located near the inflection point K2 between the front circular arc portion 14 and the front horizontal member 12 continuous therewith, provided with a coupling portion C3 substantially at the center of the rear lateral member 13 in the vehicle width direction, and connected the coupling portion C8 to the side member 3 By connecting the connecting portion C3 to the mounting portion P3 of the dash cross member 5a, the subframe 4 is connected to the vehicle body 1 at three locations.
[0066]
Further, in the fifth embodiment, the engine mounts E11 and E12 for supporting the power unit are arranged near the mounting bracket 20 and the joint C3.
[0067]
By the way, the sub-frame 10 of the fifth embodiment is similar to the fourth embodiment in that the front arc portion 14 smoothly connects the rear portion of the vertical member 11 to the vehicle, and the rear cross member 13 extends in the plane half which swells to the rear of the vehicle body. The rear horizontal member 13 is smoothly connected to the vertical member 11 by being curved in an arc shape. However, the present invention is not limited to this. The structure of the subframe 10 according to the first to third embodiments, or another structure Can be adopted.
[0068]
Therefore, in the vehicle body front structure according to the fifth embodiment, when the load F5 is input from an oblique front due to an oblique front collision or the like as shown in FIG. The closed structure is deformed, and the deformation of the closed structure and the deformation induce bending deformation centered on the center of the front cross member 12. In addition, the rear part of the vertical member 11 is also bent and deformed with the joint C3 at the center of the rear horizontal member 13 as a base point, so that the energy absorbing effect can be further enhanced.
[0069]
That is, in this embodiment, not limited to the oblique forward collision, when the collision load acts on one side in the front due to the front side collision or the offset collision, the closed structure portion formed by the front arc portion 14 and the mounting bracket 20 Can absorb the same energy as in a head-on collision.
[0070]
In addition, the connection points of the sub-frame 10 to the vehicle body are three places near the inflection point K2 between the front circular arc portion 14 and the front horizontal member 12 continuous therewith, and approximately at the center of the rear horizontal member 13 in the vehicle width direction. Therefore, when a load is input diagonally forward or in the front lateral direction, a deformation is performed such that a curved portion is extended in a portion of the vertical member 11 continuing from the front circular arc portion 14.
[0071]
At this time, since the connecting portion of the front portion is close to the connecting portion, the restraint is sufficiently performed, and the cross-sectional deformation of the front circular arc portion 14 can be positively promoted. After that, energy absorption is performed by bending deformation of the vertical member 11.
[0072]
In the case of an offset collision, the energy absorption efficiency can be increased by the deformation due to the crushing of the front end in the initial stage of the collision and the bending deformation of the member having the curve or inflection point up to the fastening portion in the latter half.
[0073]
By the way, the vehicle body front structure of the present invention has been described by taking the first to fifth embodiments as examples. However, the present invention is not limited to these embodiments, and various other embodiments may be adopted without departing from the gist of the present invention. be able to.
[Brief description of the drawings]
FIG. 1 is a perspective view of a vehicle body to which the present invention is applied.
FIG. 2 is a perspective view showing a skeletal structure of a vehicle body front right side in the first embodiment of the present invention.
FIG. 3 is a plan view of a vehicle body front skeleton sequentially showing an action at the time of a side collision of the vehicle body front in the first embodiment of the present invention.
FIG. 4 is a plan view of the vehicle body front skeleton showing the operation at the time of an offset collision in the first embodiment of the present invention in order.
FIG. 5 is a perspective view showing a skeletal structure of a vehicle body front right side according to a second embodiment of the present invention.
FIG. 6 is a plan view of a vehicle body front skeleton showing in order a function of a vehicle body front portion in a diagonal forward collision according to a second embodiment of the present invention.
FIG. 7 is a perspective view showing a skeletal structure of a vehicle body front right side according to a third embodiment of the present invention.
FIG. 8 is a plan view of a vehicle body front skeleton showing in order a function of a vehicle body front portion in a diagonally forward collision according to a third embodiment of the present invention.
FIG. 9 is a perspective view showing a skeletal structure of a vehicle body front right side according to a fourth embodiment of the present invention.
FIG. 10 is a plan view of a vehicle body front skeleton showing in order a function of a vehicle body front in a side collision according to a fourth embodiment of the present invention.
FIG. 11 is a perspective view showing a skeletal structure of a vehicle body front right side according to a fifth embodiment of the present invention.
FIG. 12 is a plan view of a vehicle body front skeleton showing in order a function of a vehicle body front in a diagonal forward collision in a fifth embodiment of the present invention.
[Explanation of symbols]
1 Body
3 Side member
10 subframes
11 vertical members
12 Front horizontal member
13 Rear transverse member
14 Forward arc
15 Recessed shape
16 Back arc part
17 Rear straight section
18 Inner arc
20 Mounting bracket
K1-K5 inflection point
C1-C8 joint
P1 to P8 Mounting part
