JP4388306B2

JP4388306B2 - Protective structure for vehicle fuel tank

Info

Publication number: JP4388306B2
Application number: JP2003141960A
Authority: JP
Inventors: 恵三豊崎
Original assignee: Fuji Jukogyo KK
Current assignee: Subaru Corp
Priority date: 2003-05-20
Filing date: 2003-05-20
Publication date: 2009-12-24
Anticipated expiration: 2023-05-20
Also published as: JP2004345389A

Description

【０００１】
【発明の属する技術分野】
本発明は、車両用燃料タンクの保護構造に関し、特に車体フロアの下方に搭載される燃料タンクの保護構造に関する。
【０００２】
【従来の技術】
車両用燃料タンクは、車室内やトランクルームのスペースを確保すると共に、衝突時に車体に作用する衝撃荷重から保護するために車体フロアの下方に搭載する場合が多い。
【０００３】
車体フロアの下方に搭載される車両用燃料タンクの支持は、例えば、図９に示すように、車体フロア１０３の下方に配置した燃料タンク１０１を、前端が車体フロア１０３の段差部１０３ａの上端近傍にピンジョイント１０４を介して取り付けられ、かつ後端が車体フロア１０３にボルト１０５ａ及びナット１０５ｂによって取り付けられて燃料タンク１０１の下面に沿って前後に延びる複数のベルト１０２によって吊り下げ支持している。
【０００４】
しかし、衝突等によって車体に衝撃荷重Ｐが作用すると、慣性力Ｐａによって燃料タンク１０１が移動し、この移動する燃料タンク１０１によってベルト１０２が車体前方側に押されて、ピンジョイント１０４を中心に回動する。この結果、燃料タンク１０１が大きく移動して周辺部品と干渉して燃料タンク１０１の損傷や変形を誘発するおそれがある。
【０００５】
この対策として、車体に作用する衝撃荷重Ｐに対して燃料タンク１０１の移動を小さく抑え、かつ燃料タンク１０１の損傷や変形を抑制する車両用燃料タンク保護構造が種々提案されている。
【０００６】
この種の車両用燃料タンク保護構造は、例えば、図１０に示すように図９と対応する部分に同一符号を付して詳細な説明を省略するが、車体フロア１０３の段差部１０３ａの下端近傍に補強部材１０７の一端をボルト１０８によって固定して車体後方に向けて突設し、その補強部材１０７の他端をベルト１０２の外側に取り付けられたブラケット１０９にボルト１１０を介して固定する。これにより、車体に衝撃荷重Ｐが作用したときの慣性力Ｐａによって燃料タンク１０１が移動してベルト１０２がピンジョイント１０４を中心に回転しようとしても、この回転が補強部材１０７によって阻止されて燃料タンク１０１の移動が抑えられ、かつ燃料タンク１０１の慣性力Ｐａを補強部材１０７が受け止めて燃料タンク１０１の損傷や変形を抑制するものが知られている（例えば、特許文献１参照）。
【０００７】
【特許文献１】
実開昭６０−２４６２３号公報
【０００８】
【発明が解決しようとする課題】
上記特許文献１に記載の車両用燃料タンクの保護構造によると、車体フロア１０３の段差部１０３ａの下端近傍とベルト１０２の間に掛け渡された補強部材１０７によって、車体に衝撃荷重Ｐが作用したときの燃料タンク１０７の移動が抑制でき、かつ燃料タンク１０１の慣性力Ｐａを補強部材１０７によって受け止めることができる。
【０００９】
しかし、ベルト１０２の前端がピンジョイント１０４によって車体フロア１０３の段差部１０３ａの上端近傍に支持され、かつ車体フロア１０３の段差部１０３ａの下端近傍とベルト１０２との間に補強部材１０７が掛け渡されることから、車体に衝撃荷重Ｐが作用したときに慣性力Ｐａによって移動する燃料タンク１０１の前部が、補強部材１０７によって移動が抑制されたベルト１０２に沿って誘導されて迫り上がり、燃料タンク１０１が車体フロア１０３の下面に押圧或いは当接すると共に、ベルト１０２と車体フロア１０３とによって強く締め付けられて燃料タンク１０１の損傷や変形を誘発することが懸念される。また、燃料タンク１０１との干渉により車体フロア１０３の変形を招くおそれがある。
【００１０】
従って、かかる点に鑑みなされた本発明の目的は、車体に作用する衝撃荷重に対し燃料タンクの移動及び迫り上がりを抑制すると共に燃料タンクの破損や変形を抑える車両用燃料タンクの保護構造を提供することにある。
【００１１】
【課題を解決するための手段】
上記目的を達成する請求項１に記載の車両用燃料タンクの保護構造の発明は、車体フロアの下方に搭載された車両用燃料タンクの保護構造において、上記燃料タンクは、該燃料タンクの車体前方側の前面に車体前方方向に移行するに従って漸次下降する第１傾斜面が形成され、該第１傾斜面と対向し、かつ車体前方方向に移行するに従って漸次下降する第２傾斜面を備えた第１移動規制部と、上記燃料タンクの前面と対向する当接部を備えた第２移動規制部とを車体部材に設け、上記第２移動規制部は、上記車体部材と間隙を有して車体前後方向に延在する支持面及び該支持面の前端及び後端に連続形成されて上記車体部材にそれぞれ結合される前側取付部及び後側取付部を有する取付ブラケットと、該取付ブラケットの支持面に結合される上面部及び該上面部の両側縁に沿って折曲形成された側面部を有して車体前後方向に連続する断面略コ字状のベース部と、該ベース部の車体後方側端部に取り付けられて上記燃料タンクの前面と対向する上記当接部を備えたことを特徴とする。
【００１２】
請求項１の発明によると、衝突等によって前方から車体に衝撃荷重が作用したとき、慣性力により燃料タンクが車体前方方向に移動すると、燃料タンクの前面に形成された車体前方方向に移行するに従って漸次下降する第１傾斜面が、この第１傾斜面と対向しかつ車体前方方向に移行するに従って漸次下降する第１移動規制部の第２傾斜面に当接して受け止められると共に、傾斜する第２傾斜面に沿って燃料タンクの前部に形成された第１傾斜面が滑動して下方に誘導されて燃料タンクの迫り上がりが有効的に阻止できる。更に、燃料タンクの移動により燃料タンクの前面が第２移動規制部の当接部に当接して当接部を車体前方方向に押しやると、当接部を支持するベース部の上面部及び側面部が座屈変形し、かつこのベース部を車体部材に結合する取付ブラケットが座屈変形して燃料タンクへの衝撃を緩和する。これにより燃料タンクが車体フロアの下面に押圧或いは当接することが回避でき、燃料タンクの損傷や変形が抑制できる。
【００１３】
請求項２に記載の発明は、請求項１の車両用燃料タンクの保護構造において、上記第１移動規制部は、上記車体部材より車体後方側に位置する頂部から車体前方方向に移行するに従って漸次広くなる略三角形でかつ上記第１傾斜面と対向して車体前方方向に移行するに従って漸次下降する上記第２傾斜面と、該第２傾斜面の両側に稜線を介してそれぞれ連続すると共に上記頂部から車体前方方向に移行するに従って互いに漸次車幅方向に離間し、かつ広くなる略三角形の第３傾斜面及び第４傾斜面と、上記第３傾斜面及び第４傾斜面に稜線を介して連続すると共に上記頂部から車体前方方向に移行するに従って漸次広くなる略三角形の第５傾斜面とを有して上記車体部材側から車体後方方向に向かって突出する略四角錐状の膨出部を備えたことを特徴とする。
【００１４】
請求項２は、第１移動規制部の構成を具体的にしたもので、上記第２傾斜面を四角錐状の膨出部の一部として形成することによって第２傾斜面の剛性が向上し、車体前方方向に移動する燃料タンクを確実に受け止めかつ下方に誘導することができる。更に、車体前方方向に移行するに従って漸次車幅方向外側となるように車体前後方向に対して傾斜して第２傾斜面の両側に連続する第３傾斜面及び第４傾斜面によって、第１傾斜面に作用する第１移動規制部からの反力が車幅方向にも広く分散されて燃料タンクに及ぼす衝撃が大幅に緩和され、より確実に燃料タンクの損傷や変形が抑制できる。
【００１７】
請求項３に記載の発明は、請求項１または２の車両用燃料タンクの保護構造において、上記第１移動規制部は、上記車体部材の車幅方向のほぼ中央に設けられ、上記燃料タンクの前面と対向する当接部を備えた一対の上記第２移動規制部が上記第１移動規制部を隔てて上記車体部材に設けられたことを特徴とする。
【００１８】
請求項３の発明によると、第１移動規制部により燃料タンクに及ぼす衝撃を緩和してもなお残存する慣性力によって燃料タンクの移動が続行されるときには、その移動する燃料タンクの前面がそれぞれの第２移動規制部の当接部に当接して燃料タンクの移動が抑えられ、かつそれぞれの第２移動規制部の変形によって燃料タンクに及ぼす衝撃が更に緩和されて燃料タンクの損傷や変形を確実に防止することができる。
【００２１】
請求項４に記載の発明は、請求項１〜３のいずれか１項の車両用燃料タンクの保護構造において、上記車体部材は、車体側方に沿って前後方向に延在する左右のサイドシル間に上記燃料タンクの車体前方側で横架するクロスメンバであることを特徴とする。
【００２２】
請求項４の発明によると、第１移動規制部が左右のサイドシル間に掛け渡された剛性を有するクロスメンバに取り付けられて第１移動規制部の結合剛性が確保でき、第１移動規制部によって移動する燃料タンクをより有効的に受け止めると共に下方に誘導することができる。また、第２移動規制部を有する場合には、第２移動規制部による燃料タンクに及ぼす衝撃をより効率的に緩和することができる。
【００２３】
請求項５に記載の発明は、請求項４の車両用燃料タンクの保護構造において、上記クロスメンバは、車幅方向に延在するクロスメンバリンホースと協働して車幅方向に延在する中空の閉断面形状を形成することを特徴とする。
【００２４】
請求項５の発明によると、クロスメンバとクロスメンバリンホースによって車幅方向に延在する中空の閉断面形状を形成することによって、クロスメンバの剛性が更に向上し、請求項４に記載の効果をより効率的に達成することができる。
【００２５】
【発明の実施の形態】
以下、本発明による車両用燃料タンクの保護構造の実施の形態を図１乃至図８を参照して説明する。なお、各図において矢印Ｆは車体前方方向を示し、矢印Ｗは車幅方向を、ＵＰは上方方向を示している。
【００２６】
図１は、本実施の形態の概要を示す分解斜視図であって、図２は、各部材が結合された状態における図１のＩ−Ｉ線断面図、図３は図２のＩＩ−ＩＩ線断面図であり、図４は図１のＩＩＩ−ＩＩＩ線断面図である。
【００２７】
左右の車体側方に沿って車体前後方向に延在する図示しないサイドシルの間に配設される車体フロア１０は、低床なフロントフロア１１と、このフロントフロア１１の後方に高床なリヤフロア１５が左右のサイドシル間に横架する車体部材であるクロスメンバ２１を介して階段状に連続形成され、リヤフロア１５の下方に燃料タンク３１が搭載される。
【００２８】
フロントフロア１１は、左右に分離した一対のフロア部１２が、前後方向に連続して隆起するトンネル部１３を介して連結されている。
【００２９】
クロスメンバ２１は、前壁部２２と、前壁部２２の上端から後方に折曲形成された段部２３と、段部２３の後端から上方に折曲形成された後壁部２４とが階段状に連続形成されて車幅方向に延在し、前壁部２２及び段部２３の車幅方向中央部に前後方向に隆起してトンネル接続部２５が形成されている。更に、前壁部２２の下端縁からトンネル接続部２５の前縁に沿ってフロントフロア１１の後縁１１ａに結合する前側フランジ２２ａが形成され、後壁部２４の上端縁に沿って上側フランジ２４ａが後方に折曲形成されている。
【００３０】
クロスメンバ２１には、クロスメンバリンホース２６が設けられている。クロスメンバリンホース２６は、クロスメンバ２１の前壁部２２の上縁及びトンネル接続部２５の前縁に下縁２７ａが結合された前側部２７及びこの前側部２７の上縁から後方に折曲して形成されて後縁２８ａがクロスメンバ２１の上側フランジ２４ａに結合する上側部２８を有する断面略Ｌ字状で車幅方向に連続している。これらクロスメンバ２１及びクロスメンバリンホース２６の両端がそれぞれ左右のサイドシルに結合されて、左右のサイドシルの間にクロスメンバ２１の段部２３と後壁部２４及びクロスメンバリンホース２６の前側部２７と上側部２８によって車幅方向に連続する中空の閉断面形状を形成してクロスメンバ２１の剛性を確保すると共に、左右のサイドシルを強固に連結して車体剛性の向上を図っている。また、クロスメンバ２１の上側フランジ２４ａには、クロスメンバリンホース２６の上側部２８の後縁２８ａと共にリヤフロア１５の前縁１５ａが結合される。
【００３１】
燃料タンク３１は、平面視略矩形であって上ケース３２の外周に形成されたフランジ部３２ａと、下ケース３５の外周に形成されたフランジ部３５ａとを接合して形成された中空状であって、上ケース３２の車体前方側である前面３３の車幅方向中央部に車体前方方向に移行するに従って漸次下降する平面状の第１傾斜面３４が形成されている。この燃料タンク３１は、クロスメンバ２１の車体後方側に、クロスメンバ２１と隙間を介して上ケース３２及び下ケース３５の前面３３、３６が対向し、かつリヤフロア１５の下方にリヤフロア１５の下面との間に隙間を有して配置される。また、前端が取付ボルト３８によってクロスメンバ２１の段部２３に結合され、かつ後端が燃料タンク３１の車体後方側に配設された図示しないクロスメンバに取付ボルトによって結合されて燃料タンク３１の下面に沿って前後方向に延びる複数のベルト３７によってこの燃料タンク３１は吊り下げ支持されている。
【００３２】
クロスメンバ２１には、その車幅方向中央に燃料タンク３１の上ケース３２に形成された前下がりに傾斜する第１傾斜面３４に対向して第１移動規制部４１が設けられ、この第１移動規制部４１を隔てて車幅方向の対称位置に燃料タンク３３の下ケース３５の前面３６に対向する一対の第２移動規制部５２が設けられている。
【００３３】
第１移動規制部４１は、図５に斜視図を示し、かつ図６に図５のＡ矢視図を示すように、略矩形の本体部４２と、本体部４２の上縁に沿って後方に折曲形成された上側フランジ４２ａと、本体部４２の下縁４２ｂから前方に折曲形成された結合部５１が連続する板状材によって形成され、図２及び図３に示すように本体部４２、上側フランジ４２ａ、結合部５１がそれぞれクロスメンバ２１の後壁部２４の後面、上側フランジ２４ａの下面、トンネル接続部２５の下面にそれぞれ結合してクロスメンバ２１に取り付けられる。
【００３４】
本体部４２は、その上縁及び両側縁に沿ってクロスメンバ２１の後壁部２４に接合する上縁部４３ａ及び側縁部４３ｂ、４３ｃを備えたコ字状の接合面４３を有し、かつ接合面４３より車体後方側に位置する頂部４４から接合面４３の上縁部４３ａと側縁部４３ｂの隅部に連続する直線状の稜線４５ａ、頂部４４から上縁部４３ａと側縁部４３ｃの隅部に連続する直線状の稜線４５ｂ、頂部４４から側縁部４３ｂと本体部４２の下縁４２ｂの隅部に連続する直線状の稜線４５ｃ、頂部４４から側縁部４３ｃと本体部４２の下縁４２ｂの隅部に連続する直線状の稜線４５ｄを有し、各稜線４５ｃと４５ｄ、４５ａと４５ｃ、４５ｄと４５ｂ、４５ａと４５ｂとの間にそれぞれ頂部４４から車体前方方向に移行するに従って広くなる略三角形の第２傾斜面４７、第３傾斜面４８、第４傾斜面４９、第５傾斜面５０が形成された略四角錐状の膨出部４６が接合面４３から車体後方に向かって突出して形成されている。
【００３５】
特に、第２傾斜面４７は、燃料タンク３１の上ケース３２の前面３３の車幅方向中央部に形成された第１傾斜面３４と略平行に対向して頂部４４側から下縁４２ｂ側に移行する従って漸次下降する前下がりに傾斜している。また、図３に示すように第２傾斜面４７の両側に稜線４５ｃ、４５ｄを介してそれぞれ連続する第３傾斜面４８及び第４傾斜面４９は、頂部４４側から側縁部４３ｂ、４３ｃ側、即ちクロスメンバ２１の後壁部２４側に移行するに従って互いに離反して漸次車幅方向外側に移行するように車体前後方向に対して傾斜している。
【００３６】
即ち、第１移動規制部４１は、クロスメンバリンホース２６及びフロントフロア１１のトンネル部１３の後端に結合されて剛性が確保されたクロスメンバ２１の後壁部２４に本体部４２の接合面４３が重合し、結合部５１がトンネル接続部２５に結合すると共に上側フランジ４２ａが上側フランジ２４ａに結合されてクロスメンバ２１に結合剛性が確保されて取り付けられる。かつ本体部４２に突出形成された膨出部４６が略三角形の第２傾斜面４７、第３傾斜面４８、第４傾斜面４９、第５傾斜面５０によって四角錐状に形成されてその剛性が確保される。特に第２傾斜面４７が四角錐状の膨出部４６の一部を形成することによって第２傾斜面４７の剛性が確保でき、車体後方側から第２傾斜面４７及び第３傾斜面４８、第４傾斜面４９に作用する荷重を接合面４３、結合部５１、上側フランジ４２ａからクロスメンバ２１の広範囲に分散して荷重伝達することができる。また、燃料タンク３１のフランジ部３２ａ、３５ａの先端は下縁４２ｂより若干下方に位置している。
【００３７】
一方、各第２移動規制部５２は、図７に分解斜視図を示し、かつ図８に組立状態を示すように、取付ブラケット５３と、本体部５６によって構成される。取付ブラケット５３は、略矩形の支持面５４と、支持面５４の後縁から上方に折曲形成された後側取付部５５ａと、支持部５４の前縁から下方に折曲形成された前側取付部５５ｂが一体に形成されている。支持面５４には、その略中央部にボルト挿通孔５４ｄが穿設され（図４参照）、かつボルト挿通孔５４ｄに対応してウエルディングナット５６が設けられると共に、前端近傍に車幅方向に延びる直線状の位置決め孔５４ｅが形成されている。この取付ブラケット５３は、図４に示すように後側取付部５５ａ及び前側取付部５５ｂをそれぞれクロスメンバ２１の後壁部２４と前壁部２２に結合することによって、段部２３と支持面５４との間に隙間をもって前後方向に延在してクロスメンバ２１に掛け渡されて取り付けられる。また、車幅方向に延びて開口する位置決め孔５４ｅによって、支持面５４に作用する荷重によって座屈変形し易い脆弱部が形成される。
【００３８】
本体部５６は、取付ブラケット５３の支持面５４の下面に接合可能な略矩形の支持面部５８ａと傾斜面部５８ｂと延設面部５８ｃが段差をもって前後方向に連続形成された上面部５８と、この上面部５８の左右両側から下方に折曲形成された側面部５９からなる前後方向に連続する断面略コ字状のベース部５７を有している。支持面部５８ａの略中央部に取付ブラケット５３のボルト挿通孔５４ｄに対応してボルト挿通孔５８ｄが穿設され、支持面５８ａの前縁から位置決め孔５４ｅに挿入可能な係止部５８ｅが上方に折曲形成されている。更に、側面部５９の下縁に沿ってフランジ５９ａが折曲形成され、かつ後縁に取付フランジ５９ｂが折曲形成され、この取付フランジ５９ｂを介して板状の当接部６０が取り付けられる。このベース部５７は下方が開放されたコ字形で比較的薄板によって形成されて、ベース部５７の剛性を抑制している。
【００３９】
この本体部５６は、図８に示すように取付ブラケット５３の支持面５４に穿設された位置決め孔５４ｅに係止部５８ｅが挿入し、かつボルト挿通孔５４ｄと５８ｄとが位置決めされた状態で支持面５４の下面に下方から支持面部５８ａが当接し、その状態でボルト挿入孔５８ｄ、５４ｄを貫通してウエルディングナット５５に螺合する取付ボルト６１によって取付ブラケット５３に結合される。この結合により、図４に示すように当接部６０が燃料タンク３１の下ケース３５の前面３６と対向した状態で本体部５６が取付ブラケット５３を介してクロスメンバ２１に取り付けられる。
【００４０】
このように構成された車両用燃料タンクの保護構造を備えた車両において、衝突等によって前方から車体に衝撃荷重Ｐが作用して、複数のベルト３７によってリヤフロア１５の下方に吊り下げ支持された燃料タンク３１が慣性力Ｐａによって車体前方方向に移動すると、燃料タンク３１の上ケース３２の前面３３に形成された第１傾斜面３４が、クロスメンバ２１に取り付けられた第１移動規制部４１の本体部４２に形成された膨出部４６の第２傾斜面４７に当接して受け止められる。
【００４１】
ここで、第１移動規制部４１は、剛性が確保されたクロスメンバ２１に取り付けられ、かつ本体部４２に剛性が確保された四角錐状に突出形成された膨出部４６に第２傾斜面４７が第１傾斜面３４と対向して平行に形成されることから、第２傾斜面４７のほぼ全面によって燃料タンク３１を強固に受け止めることができる。また、前下がりに傾斜する第２傾斜面４７に沿って第１傾斜面３４が滑動して、図２に二点差線３１ａで示すように燃料タンク３１の前部が下方に誘導されて燃料タンク３１の迫り上がりが有効的に阻止できる。更に、燃料タンク３１の第１傾斜面４７が第１移動規制部４１の第２傾斜面４７に当接して燃料タンク３１の移動が規制される際に、図３に示すように第２傾斜面４７に稜線４５ｃ、４５ｄを介して車体前方側に移行するに従って漸次車幅方向外側となるように燃料タンク３１の移動方向となる車体前後方向に対して車幅方向に傾斜して連続する第３傾斜面４８及び第４傾斜面４９によって、燃料タンク３１の第１傾斜面３４に入力される第１移動規制部４１からの反力が車幅方向にも広く分散伝達されて、燃料タンク３１に及ぼす衝撃が大幅に緩和されて燃料タンク３１の破損や変形が抑制できる。
【００４２】
従って、第１移動規制部４１によって燃料タンク３１の迫り上がりが確実に防止できてリヤフロア１５の下面に押圧或いは当接が回避できると共に、燃料タンク３１に及ぼす衝撃が大幅に減少して燃料タンク３１の損傷及び変形が抑制できる。
【００４３】
一方、第１移動規制部４１により燃料タンク３１に及ぼす衝撃を緩和してもなお残存する慣性力によって燃料タンク３１の移動が続行されたときは、その燃料タンク３１の移動により燃料タンク３１の下ケース３５の前面３６が第１移動規制部４１の左右に配置されたそれぞれの第２移動規制部５２の当接部６０に当接し、第２移動規制部５２の変形によって残存する慣性力が吸収されて受け止められる。即ち、燃料タンク３１の前面３６の左右部分がそれぞれの第２移動規制部５２の当接部６０に当接して、当接部６０を車体前方側に押しやると、当接部６０が取り付けられたベース部５７の支持面部５８ａ、傾斜面部５８ｂ、延設面部５８ｃによって屈曲形成された上面部５８が座屈変形し、かつ下方が開放された互いの側面部５９が座屈変形する。また、このベース部５７を結合する支持面５４がクロスメンバ２１の段部２３と間に隙間を有した状態でクロスメンバ２１に結合された取付ブラケット５２が、ベース部５７側からの荷重によって座屈変形する。これらベース部５７及び取付ブラケット５２の座屈変形によって残存する燃料タンク３１の慣性力を円滑に吸収して燃料タンク３１への衝撃を十分に緩和して燃料タンク３１の損傷及び変形を確実に回避することができる。
【００４４】
従って、衝突等によって車体に衝撃荷重Ｐが作用して、リヤフロア１５の下方に搭載された燃料タンク３１が慣性力Ｐａによって車体前方方向に移動すると、燃料タンク３１に形成された第１傾斜面３４が第１移動規制部４１の第２傾斜面４７に当接して受け止められると共に、燃料タンク３１の前部が下方に誘導されて燃料タンク３１の迫り上がりが有効的に阻止でき、燃料タンク３１とリヤフロア１５との当接が回避されて燃料タンク３１に及ぼす衝撃が緩和されて燃料タンク３１の損傷や変形が抑制できる。更に、残存する慣性力で燃料タンク３１が更に移動するときには、移動する燃料タンク３１の前面３６が第２移動規制部５２の当接部６０に当接し、ベース部５７及び取付ブラケット５２が座屈変形して燃料タンク３１への衝撃を有効的に緩和して燃料タンク３１の損傷及び変形を確実に防止することができ、衝突等の衝撃から燃料タンク３１を保護することができ安全性が向上する。
【００４５】
なお、本発明は上記実施の形態に限定されることなく、発明の趣旨を逸脱しない範囲で種々変更可能である。例えば、第１移動規制部４１及びリヤフロア１５と燃料タンク３１の間にクッション材を介在させて、燃料タンク３１とリヤフロア１５との干渉を抑制すると共に、車体に衝撃荷重が作用したときの第１移動規制部４１と燃料タンク３１の当接による燃料タンク３１への衝撃をより緩和することもできる。また、上記実施の形態では、第１移動規制部４１の膨出部４６を第２傾斜面４７を有する四角錐状に形成したが、燃料タンク３１の第１傾斜面３４と対向して車体前方方向に移行するに従って漸次下降する第２傾斜面４７を含む五角錐状等他の多角錐状に形成することもできる。更に、上記実施の形態では第１移動規制部４１の第２傾斜面４７を平面状に形成したが、燃料タンク３１の第１傾斜面３４と対向して車体前方方向に移行するに従って漸次下降して傾斜する円錐面等に形成することもできる。また、第２移動規制部５２の本体部５６や取付ブラケット５３にビードや開口部等を形成して第２移動規制部５２の剛性を変えて座屈変形特性を調整することもできる。
【００４６】
【発明の効果】
以上説明した本発明の車両用燃料タンクの保護構造によると、車体フロアの下方に搭載された燃料タンクの車体前方側の前面に車体前方側に車体前方方向に移行するに従って漸次下降する第１傾斜面を形成すると共に、この第１傾斜面と対向して車体前方方向に移行するに従って漸次下降する第２傾斜面を備えた第１移動規制部を車体部材に設けることによって、衝突等によって車体に作用する衝撃荷重によって燃料タンクが移動した際に、第１傾斜面が第１移動規制部の第２傾斜面に当接して燃料タンクの移動が抑制される。更に、燃料タンクの移動により燃料タンクの前面が第２移動規制部の当接部に当接して当接部を車体前方方向に押しやると、当接部を支持するベース部の上面部及び側面部が座屈変形し、かつこのベース部を車体部材に結合する取付ブラケットが座屈変形して燃料タンクへの衝撃を緩和する。これにより燃料タンクが車体フロアの下面に押圧或いは当接することが回避でき、燃料タンクの損傷や変形が抑制できる。
【図面の簡単な説明】
【図１】本発明による車両用燃料タンクの保護構造の実施の形態の概要を示す分解斜視図である。
【図２】同じく、各部材が結合された状態における図１のＩ−Ｉ線断面図である。
【図３】同じく、図２のＩＩ−ＩＩ線断面図である。
【図４】同じく、各部材が結合された状態における図１のＩＩＩ−ＩＩＩ線断面図である。
【図５】同じく、第１移動規制部の斜視図である。
【図６】同じく、図５のＡ矢視図である。
【図７】同じく、第２移動規制部の分解斜視図である。
【図８】同じく、第２移動規制部の斜視図である。
【図９】従来の車両用燃料タンク支持構造の説明図である。
【図１０】従来の車両用燃料タンクの保護構造の説明図である。
【符号の説明】
１０車体フロア
１１フロントフロア
１５リヤフロア
２１クロスメンバ（車体部材）
２２前壁部
２３段部
２４後壁部
２４ａ上側フランジ
２６クロスメンバリンホース
３１燃料タンク
３２上ケース
３３前面
３４第１傾斜面
３５下ケース
３６前面
４１第１移動規制部
４２本体部
４２ａ上側フランジ
４３接合面
４４頂部
４５ａ、４５ｂ、４５ｃ、４５ｄ稜線
４６膨出部
４７第２傾斜面
４８第３傾斜面
４９第４傾斜面
５０第５傾斜面
５１結合部
５２第２移動規制部
５３取付ブラケット
５４支持面
５５ａ後側取付部
５５ｂ前側取付部
５６本体部
５７ベース部
５８上面部
５９側面部
６０当接部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle fuel tank protection structure, and more particularly to a fuel tank protection structure mounted below a vehicle body floor.
[0002]
[Prior art]
In many cases, a vehicle fuel tank is mounted below a vehicle body floor in order to secure space in a vehicle compartment and a trunk room and to protect it from an impact load acting on the vehicle body at the time of a collision.
[0003]
For example, as shown in FIG. 9, the fuel tank 101 for the vehicle mounted on the lower side of the vehicle body floor is supported by the fuel tank 101 arranged below the vehicle body floor 103, and the front end is in the vicinity of the upper end of the stepped portion 103 a of the vehicle body floor 103. Are attached to the vehicle body floor 103 by bolts 105a and nuts 105b, and are suspended and supported by a plurality of belts 102 extending forward and backward along the lower surface of the fuel tank 101.
[0004]
However, when an impact load P is applied to the vehicle body due to a collision or the like, the fuel tank 101 is moved by the inertial force Pa, and the belt 102 is pushed forward by the moving fuel tank 101 to rotate around the pin joint 104. Move. As a result, there is a possibility that the fuel tank 101 moves greatly and interferes with peripheral components, thereby causing damage or deformation of the fuel tank 101.
[0005]
As countermeasures, various vehicle fuel tank protection structures for suppressing the movement of the fuel tank 101 with respect to the impact load P acting on the vehicle body and suppressing the damage and deformation of the fuel tank 101 have been proposed.
[0006]
In this type of vehicle fuel tank protection structure, for example, as shown in FIG. 10, parts corresponding to those in FIG. One end of the reinforcing member 107 is fixed with a bolt 108 and protrudes toward the rear of the vehicle body, and the other end of the reinforcing member 107 is fixed to a bracket 109 attached to the outside of the belt 102 via a bolt 110. Thus, even if the fuel tank 101 moves due to the inertial force Pa when the impact load P acts on the vehicle body and the belt 102 tries to rotate around the pin joint 104, this rotation is prevented by the reinforcing member 107 and the fuel tank. It is known that the movement of the fuel tank 101 is suppressed and the reinforcing member 107 receives the inertial force Pa of the fuel tank 101 to suppress damage and deformation of the fuel tank 101 (for example, see Patent Document 1).
[0007]
[Patent Document 1]
Japanese Utility Model Publication No. 60-24623
[0008]
[Problems to be solved by the invention]
According to the protection structure for a vehicle fuel tank described in Patent Document 1, an impact load P is applied to the vehicle body by the reinforcing member 107 spanned between the vicinity of the lower end of the stepped portion 103a of the vehicle body floor 103 and the belt 102. The movement of the fuel tank 107 at the time can be suppressed, and the inertial force Pa of the fuel tank 101 can be received by the reinforcing member 107.
[0009]
However, the front end of the belt 102 is supported by the pin joint 104 in the vicinity of the upper end of the stepped portion 103a of the vehicle body floor 103, and the reinforcing member 107 is stretched between the belt 102 and the vicinity of the lower end of the stepped portion 103a of the vehicle body floor 103. Therefore, the front portion of the fuel tank 101 that moves by the inertial force Pa when the impact load P is applied to the vehicle body is guided along the belt 102 whose movement is suppressed by the reinforcing member 107 and rushes up. Is pressed or brought into contact with the lower surface of the vehicle body floor 103 and is strongly tightened by the belt 102 and the vehicle body floor 103 to cause damage or deformation of the fuel tank 101. In addition, the vehicle body floor 103 may be deformed due to interference with the fuel tank 101.
[0010]
Accordingly, an object of the present invention made in view of such points is to provide a fuel tank protection structure for a vehicle that suppresses the movement and rushing of the fuel tank against an impact load acting on the vehicle body and also prevents the fuel tank from being damaged or deformed. There is to do.
[0011]
[Means for Solving the Problems]
The vehicle fuel tank protection structure invention according to claim 1, which achieves the above object, is a vehicle fuel tank protection structure mounted below a vehicle body floor, wherein the fuel tank is located in front of the vehicle body of the fuel tank. A first inclined surface that gradually descends as the vehicle moves forward is formed on the front side of the vehicle, and a second inclined surface that faces the first inclined surface and gradually descends as the vehicle moves forward is provided. 1 movement restriction part; A second movement restricting portion having a contact portion facing the front surface of the fuel tank On the body member, The second movement restricting portion has a support surface extending in the longitudinal direction of the vehicle body with a gap from the vehicle body member, and a front side attachment formed continuously at the front end and the rear end of the support surface and coupled to the vehicle body member, respectively. A mounting bracket having a mounting portion and a rear mounting portion; an upper surface portion coupled to a support surface of the mounting bracket; and a side surface portion bent along both side edges of the upper surface portion to be continuous in the longitudinal direction of the vehicle body A base portion having a substantially U-shaped cross section, and the abutting portion attached to the vehicle body rear side end portion of the base portion and facing the front surface of the fuel tank. It is characterized by that.
[0012]
According to the first aspect of the present invention, when an impact load is applied to the vehicle body from the front due to a collision or the like, when the fuel tank moves in the vehicle body forward direction due to inertial force, the fuel tank moves in the vehicle body forward direction formed on the front surface of the fuel tank. The first inclined surface that gradually descends is opposed to and received by the second inclined surface of the first movement restricting portion that faces the first inclined surface and gradually descends as it moves in the forward direction of the vehicle body, and the second inclined surface is inclined. The first inclined surface formed at the front portion of the fuel tank is slid along the inclined surface and is guided downward to effectively prevent the fuel tank from being pushed up. Further, when the front surface of the fuel tank comes into contact with the contact portion of the second movement restricting portion by the movement of the fuel tank and pushes the contact portion in the vehicle body front direction, the upper surface portion and the side surface portion of the base portion that supports the contact portion Is buckled and the mounting bracket connecting the base part to the vehicle body member buckles and reduces the impact on the fuel tank. As a result, the fuel tank can be prevented from being pressed or brought into contact with the lower surface of the vehicle body floor, and damage or deformation of the fuel tank can be suppressed.
[0013]
According to a second aspect of the present invention, in the vehicle fuel tank protection structure according to the first aspect, the first movement restricting portion gradually moves from the top located on the vehicle rear side of the vehicle body member toward the vehicle front direction. The substantially inclined triangle and the second inclined surface that gradually descends as it moves in the front direction of the vehicle body facing the first inclined surface, and continues to both sides of the second inclined surface via ridge lines, and the top portion. The third inclined surface and the fourth inclined surface, which are gradually spaced apart from each other in the vehicle width direction and become wider as they move from the vehicle forward direction to the vehicle body direction, and continue to the third inclined surface and the fourth inclined surface via a ridge line. And having a substantially triangular fifth inclined surface that gradually increases from the top to the front of the vehicle body and has a substantially quadrangular pyramidal bulge protruding from the vehicle body member toward the rear of the vehicle body. Octopus The features.
[0014]
A second aspect of the present invention is a specific configuration of the first movement restricting portion, and the rigidity of the second inclined surface is improved by forming the second inclined surface as a part of the quadrangular pyramid-shaped bulging portion. The fuel tank moving in the forward direction of the vehicle body can be reliably received and guided downward. Further, the first inclined surface is formed by the third inclined surface and the fourth inclined surface that are inclined with respect to the longitudinal direction of the vehicle body so as to gradually become the outer side in the vehicle width direction as the vehicle moves forward, and are continuous on both sides of the second inclined surface. The reaction force from the first movement restricting portion acting on the surface is widely dispersed also in the vehicle width direction, so that the impact on the fuel tank is greatly relieved, and damage and deformation of the fuel tank can be more reliably suppressed.
[0017]
Claim 3 The vehicle fuel tank protection structure according to claim 1 or 2, wherein the first movement restricting portion is provided at substantially the center in the vehicle width direction of the vehicle body member and faces the front surface of the fuel tank. A pair of abutting parts the above A second movement restricting portion is provided on the vehicle body member across the first movement restricting portion.
[0018]
Claim 3 According to the invention, when the movement of the fuel tank is continued by the remaining inertia force even after the impact on the fuel tank is mitigated by the first movement restricting portion, the front surface of the moving fuel tank is moved to the second movement. The movement of the fuel tank is suppressed by abutting against the abutment portion of the restriction portion, and the impact on the fuel tank is further mitigated by the deformation of each second movement restriction portion, thereby reliably preventing damage and deformation of the fuel tank. be able to.
[0021]
Claim 4 The invention described in claim 1 3 One of 1 item In the vehicle fuel tank protective structure, the vehicle body member is a cross member that lies horizontally on the vehicle body front side of the fuel tank between left and right side sills extending in the front-rear direction along the side of the vehicle body. And
[0022]
Claim 4 According to the invention, the first movement restricting portion is attached to the cross member having rigidity spanned between the left and right side sills so that the coupling rigidity of the first movement restricting portion can be secured, and the fuel moves by the first movement restricting portion. The tank can be received more effectively and guided downward. Moreover, when it has a 2nd movement control part, the impact on the fuel tank by a 2nd movement control part can be relieve | moderated more efficiently.
[0023]
Claim 5 The invention described in claim 4 In the vehicular fuel tank protective structure, the cross member forms a hollow closed cross-sectional shape extending in the vehicle width direction in cooperation with a cross member ring hose extending in the vehicle width direction. To do.
[0024]
Claim 5 According to the present invention, the cross member and the cross member ring hose form a hollow closed cross-sectional shape extending in the vehicle width direction, thereby further improving the rigidity of the cross member. 4 The effect described in (1) can be achieved more efficiently.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a vehicle fuel tank protection structure according to the present invention will be described below with reference to FIGS. In each figure, the arrow F indicates the vehicle body front direction, the arrow W indicates the vehicle width direction, and UP indicates the upward direction.
[0026]
1 is an exploded perspective view showing an outline of the present embodiment. FIG. 2 is a cross-sectional view taken along the line II of FIG. 1 in a state where the respective members are coupled together, and FIG. 3 is a cross-sectional view taken along the line II-II of FIG. FIG. 4 is a sectional view taken along line III-III of FIG.
[0027]
A vehicle body floor 10 disposed between side sills (not shown) extending in the longitudinal direction of the vehicle body along the left and right sides of the vehicle body includes a low floor front floor 11 and a high floor rear floor 15 behind the front floor 11. A fuel tank 31 is mounted below the rear floor 15 and is formed continuously in a stepped manner via a cross member 21 that is a vehicle body member that is horizontally mounted between the left and right side sills.
[0028]
The front floor 11 is connected to a pair of floor portions 12 separated left and right via a tunnel portion 13 that continuously rises in the front-rear direction.
[0029]
The cross member 21 includes a front wall portion 22, a step portion 23 bent backward from the upper end of the front wall portion 22, and a rear wall portion 24 bent upward from the rear end of the step portion 23. A tunnel connection portion 25 is formed by being continuously formed in a staircase shape and extending in the vehicle width direction and protruding in the vehicle width direction center of the front wall portion 22 and the step portion 23 in the front-rear direction. Further, a front flange 22a is formed to be coupled to the rear edge 11a of the front floor 11 from the lower end edge of the front wall portion 22 along the front edge of the tunnel connecting portion 25, and the upper flange 24a is formed along the upper end edge of the rear wall portion 24. Is bent backwards.
[0030]
The cross member 21 is provided with a cross member ring hose 26. The cross member phosphorus hose 26 is bent rearward from the upper edge of the front wall portion 22 of the cross member 21 and the front side portion 27 in which the lower edge 27a is coupled to the front edge of the tunnel connection portion 25 and from the upper edge of the front side portion 27. The rear edge 28a is formed in this manner and has a substantially L-shaped cross section having an upper portion 28 coupled to the upper flange 24a of the cross member 21 and is continuous in the vehicle width direction. Both ends of the cross member 21 and the cross member phosphorus hose 26 are respectively coupled to the left and right side sills, and the step portion 23 and the rear wall portion 24 of the cross member 21 and the front side portion 27 of the cross member phosphorus hose 26 are interposed between the left and right side sills. The upper portion 28 forms a hollow closed cross-sectional shape continuous in the vehicle width direction to ensure the rigidity of the cross member 21 and to firmly connect the left and right side sills to improve the rigidity of the vehicle body. The front edge 15 a of the rear floor 15 is coupled to the upper flange 24 a of the cross member 21 together with the rear edge 28 a of the upper portion 28 of the cross member ring hose 26.
[0031]
The fuel tank 31 is substantially rectangular in plan view and has a hollow shape formed by joining a flange portion 32 a formed on the outer periphery of the upper case 32 and a flange portion 35 a formed on the outer periphery of the lower case 35. Thus, a flat first inclined surface 34 that gradually descends as it moves in the vehicle body front direction is formed at the vehicle width direction center portion of the front surface 33 on the vehicle body front side of the upper case 32. The fuel tank 31 has a front surface 33 and 36 of the upper case 32 and the lower case 35 facing the cross member 21 through a gap on the vehicle body rear side of the cross member 21, and a lower surface of the rear floor 15 below the rear floor 15. Are arranged with a gap between them. Further, the front end is coupled to the step portion 23 of the cross member 21 by the mounting bolt 38 and the rear end is coupled to the cross member (not shown) disposed on the rear side of the vehicle body of the fuel tank 31 by the mounting bolt. The fuel tank 31 is suspended and supported by a plurality of belts 37 extending in the front-rear direction along the lower surface.
[0032]
The cross member 21 is provided with a first movement restricting portion 41 at the center in the vehicle width direction so as to face a first inclined surface 34 that is formed in the upper case 32 of the fuel tank 31 and is inclined downward. A pair of second movement restricting portions 52 that are opposed to the front surface 36 of the lower case 35 of the fuel tank 33 are provided at symmetrical positions in the vehicle width direction across the movement restricting portion 41.
[0033]
The first movement restricting portion 41 is rearward along the substantially rectangular main body portion 42 and the upper edge of the main body portion 42 as shown in the perspective view of FIG. 2 and 3, the upper flange 42a formed by bending and the connecting portion 51 formed by bending forward from the lower edge 42b of the main body 42 are formed of a continuous plate-like material. 42, the upper flange 42 a, and the coupling portion 51 are respectively coupled to the rear surface of the rear wall 24 of the cross member 21, the lower surface of the upper flange 24 a, and the lower surface of the tunnel connection portion 25.
[0034]
The main body portion 42 has a U-shaped joining surface 43 including an upper edge portion 43a and side edge portions 43b and 43c that are joined to the rear wall portion 24 of the cross member 21 along the upper edge and both side edges thereof. Further, a linear ridge line 45a continuous from the top portion 44 located on the vehicle body rear side with respect to the joint surface 43 to the corners of the upper edge portion 43a and the side edge portion 43b of the joint surface 43, and from the top portion 44 to the upper edge portion 43a and the side edge portion. 43c, a straight ridge 45b continuous from the corner 44, a straight edge 45c from the top 44 to the corner of the side edge 43b and the lower edge 42b of the main body 42, a side edge 43c and the main body from the top 44 42 has a straight ridge line 45d at the corner of the lower edge 42b, and transitions from the top 44 to the front of the vehicle body between the ridge lines 45c and 45d, 45a and 45c, 45d and 45b, and 45a and 45b, respectively. The third of the approximately triangle that becomes wider as A substantially quadrangular pyramidal bulging portion 46 formed with the inclined surface 47, the third inclined surface 48, the fourth inclined surface 49, and the fifth inclined surface 50 is formed so as to protrude from the joint surface 43 toward the rear of the vehicle body. .
[0035]
In particular, the second inclined surface 47 faces the first inclined surface 34 formed in the vehicle width direction central portion of the front surface 33 of the upper case 32 of the fuel tank 31 substantially in parallel to the top edge 44 side to the lower edge 42b side. As it shifts, it slopes down before it gradually descends. Further, as shown in FIG. 3, the third inclined surface 48 and the fourth inclined surface 49, which are continuous to both sides of the second inclined surface 47 via the ridge lines 45c and 45d, respectively, are from the top portion 44 side to the side edge portions 43b and 43c side. That is, the vehicle is inclined with respect to the longitudinal direction of the vehicle body so as to move toward the rear wall 24 side of the cross member 21 and gradually move outward in the vehicle width direction.
[0036]
That is, the first movement restricting portion 41 is joined to the cross member ring hose 26 and the rear end of the tunnel portion 13 of the front floor 11, and the joining surface of the main body portion 42 to the rear wall portion 24 of the cross member 21 secured with rigidity. 43 is superposed, the coupling portion 51 is coupled to the tunnel connection portion 25, and the upper flange 42a is coupled to the upper flange 24a so that the coupling rigidity is secured to the cross member 21. Further, the bulging portion 46 formed to project from the main body portion 42 is formed into a quadrangular pyramid shape by a substantially triangular second inclined surface 47, third inclined surface 48, fourth inclined surface 49, and fifth inclined surface 50, and its rigidity. Is secured. In particular, the second inclined surface 47 forms part of the quadrangular pyramidal bulging portion 46, whereby the rigidity of the second inclined surface 47 can be secured, and the second inclined surface 47 and the third inclined surface 48, The load acting on the fourth inclined surface 49 can be dispersed and transmitted over a wide range of the cross member 21 from the joint surface 43, the coupling portion 51, and the upper flange 42a. The tips of the flange portions 32a and 35a of the fuel tank 31 are located slightly below the lower edge 42b.
[0037]
On the other hand, each 2nd movement control part 52 is comprised by the attachment bracket 53 and the main-body part 56 so that an exploded perspective view may be shown in FIG. The mounting bracket 53 includes a substantially rectangular support surface 54, a rear attachment portion 55 a bent upward from the rear edge of the support surface 54, and a front attachment bent downward from the front edge of the support portion 54. The part 55b is integrally formed. The support surface 54 is provided with a bolt insertion hole 54d at substantially the center thereof (see FIG. 4), and a welding nut 56 is provided corresponding to the bolt insertion hole 54d, and in the vehicle width direction near the front end. An extending linear positioning hole 54e is formed. As shown in FIG. 4, the mounting bracket 53 includes a stepped portion 23 and a support surface 54 by connecting the rear mounting portion 55 a and the front mounting portion 55 b to the rear wall portion 24 and the front wall portion 22 of the cross member 21, respectively. And extending in the front-rear direction with a gap between the two and the cross member 21 to be attached. Further, the positioning hole 54e that extends and opens in the vehicle width direction forms a fragile portion that is easily buckled and deformed by a load acting on the support surface 54.
[0038]
The main body portion 56 includes a substantially rectangular support surface portion 58a that can be joined to the lower surface of the support surface 54 of the mounting bracket 53, an inclined surface portion 58b, and an extended surface portion 58c that are continuously formed in the front-rear direction with steps. It has a base portion 57 having a substantially U-shaped cross section that is continuous in the front-rear direction, and includes a side portion 59 that is bent downward from the left and right sides of the portion 58. A bolt insertion hole 58d is formed in a substantially central portion of the support surface portion 58a corresponding to the bolt insertion hole 54d of the mounting bracket 53, and a locking portion 58e that can be inserted into the positioning hole 54e from the front edge of the support surface 58a is formed upward. It is bent. Further, a flange 59a is bent along the lower edge of the side surface portion 59, and a mounting flange 59b is bent at the rear edge, and the plate-like contact portion 60 is attached via the mounting flange 59b. The base portion 57 is formed in a U shape with a lower portion open and formed by a relatively thin plate, and suppresses the rigidity of the base portion 57.
[0039]
As shown in FIG. 8, the main body portion 56 is in a state where the locking portion 58e is inserted into the positioning hole 54e formed in the support surface 54 of the mounting bracket 53 and the bolt insertion holes 54d and 58d are positioned. The support surface portion 58a comes into contact with the lower surface of the support surface 54 from below, and is connected to the mounting bracket 53 by mounting bolts 61 that pass through the bolt insertion holes 58d and 54d and are screwed into the welding nut 55 in this state. As a result of this connection, the main body 56 is attached to the cross member 21 via the attachment bracket 53 with the contact portion 60 facing the front surface 36 of the lower case 35 of the fuel tank 31 as shown in FIG.
[0040]
In a vehicle having a vehicle fuel tank protection structure configured as described above, an impact load P acts on the vehicle body from the front due to a collision or the like, and the fuel is suspended and supported below the rear floor 15 by a plurality of belts 37. When the tank 31 moves in the front direction of the vehicle body by the inertial force Pa, the first inclined surface 34 formed on the front surface 33 of the upper case 32 of the fuel tank 31 is the main body of the first movement restricting portion 41 attached to the cross member 21. The bulging part 46 formed in the part 42 is in contact with and received by the second inclined surface 47 of the bulging part 46.
[0041]
Here, the first movement restricting portion 41 is attached to the cross member 21 with which rigidity is ensured, and the second inclined surface is formed on the bulging portion 46 formed to protrude from the main body portion 42 in the shape of a quadrangular pyramid. Since 47 is formed parallel to the first inclined surface 34, the fuel tank 31 can be firmly received by almost the entire second inclined surface 47. Further, the first inclined surface 34 slides along the second inclined surface 47 inclined downward, and the front portion of the fuel tank 31 is guided downward as indicated by a two-dot chain line 31a in FIG. 31 jumps can be effectively prevented. Further, when the first inclined surface 47 of the fuel tank 31 abuts on the second inclined surface 47 of the first movement restricting portion 41 and the movement of the fuel tank 31 is restricted, the second inclined surface as shown in FIG. As shown in FIG. 47, a third continuous vehicle is inclined in the vehicle width direction with respect to the longitudinal direction of the vehicle body as the moving direction of the fuel tank 31 so as to gradually move outward in the vehicle width direction as it shifts to the vehicle body front side via the ridges 45c and 45d. By the inclined surface 48 and the fourth inclined surface 49, the reaction force from the first movement restricting portion 41 input to the first inclined surface 34 of the fuel tank 31 is widely dispersed and transmitted also in the vehicle width direction, and is transmitted to the fuel tank 31. The impact exerted is greatly relieved, and damage and deformation of the fuel tank 31 can be suppressed.
[0042]
Accordingly, the first movement restricting portion 41 can surely prevent the fuel tank 31 from being pushed up, can avoid pressing or abutting against the lower surface of the rear floor 15, and can greatly reduce the impact on the fuel tank 31, thereby reducing the fuel tank 31. Damage and deformation can be suppressed.
[0043]
On the other hand, when the movement of the fuel tank 31 is continued by the remaining inertia force even after the impact on the fuel tank 31 is alleviated by the first movement restricting portion 41, the movement of the fuel tank 31 causes the bottom of the fuel tank 31 to move. The front surface 36 of the case 35 comes into contact with the contact portions 60 of the second movement restriction portions 52 arranged on the left and right sides of the first movement restriction portion 41, and the inertial force remaining due to the deformation of the second movement restriction portion 52 is absorbed. Received. That is, when the left and right portions of the front surface 36 of the fuel tank 31 are in contact with the contact portions 60 of the respective second movement restricting portions 52 and the contact portions 60 are pushed to the front side of the vehicle body, the contact portions 60 are attached. The upper surface portion 58 formed by bending by the support surface portion 58a, the inclined surface portion 58b, and the extended surface portion 58c of the base portion 57 is buckled and deformed, and the side surface portions 59 whose lower sides are opened are buckled and deformed. Further, the mounting bracket 52 coupled to the cross member 21 with the support surface 54 for coupling the base portion 57 having a gap between the stepped portion 23 of the cross member 21 is seated by a load from the base portion 57 side. Bends and deforms. The inertia force of the fuel tank 31 remaining due to the buckling deformation of the base portion 57 and the mounting bracket 52 is smoothly absorbed, and the impact on the fuel tank 31 is sufficiently mitigated, so that the damage and deformation of the fuel tank 31 are surely avoided. can do.
[0044]
Accordingly, when an impact load P acts on the vehicle body due to a collision or the like and the fuel tank 31 mounted below the rear floor 15 moves in the vehicle body forward direction by the inertial force Pa, the first inclined surface 34 formed on the fuel tank 31 is formed. In contact with the second inclined surface 47 of the first movement restricting portion 41 and the front portion of the fuel tank 31 is guided downward to effectively prevent the fuel tank 31 from being pushed up. The contact with the rear floor 15 is avoided, the impact on the fuel tank 31 is alleviated, and damage and deformation of the fuel tank 31 can be suppressed. Further, when the fuel tank 31 further moves due to the remaining inertia force, the front surface 36 of the moving fuel tank 31 abuts against the abutting portion 60 of the second movement restricting portion 52, and the base portion 57 and the mounting bracket 52 are buckled. The deformation can effectively mitigate the impact on the fuel tank 31 to reliably prevent the fuel tank 31 from being damaged and deformed, and can protect the fuel tank 31 from the impact such as a collision, thereby improving safety. To do.
[0045]
In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, a cushioning material is interposed between the first movement restricting portion 41 and the rear floor 15 and the fuel tank 31 to suppress interference between the fuel tank 31 and the rear floor 15 and the first when an impact load is applied to the vehicle body. The impact on the fuel tank 31 due to the contact between the movement restricting portion 41 and the fuel tank 31 can be further alleviated. Further, in the above embodiment, the bulging portion 46 of the first movement restricting portion 41 is formed in a quadrangular pyramid shape having the second inclined surface 47, but facing the first inclined surface 34 of the fuel tank 31 and the front of the vehicle body It can also be formed in other polygonal pyramids such as a pentagonal pyramid including the second inclined surface 47 that gradually descends as it moves in the direction. Furthermore, in the above-described embodiment, the second inclined surface 47 of the first movement restricting portion 41 is formed in a flat shape. However, the second inclined surface 47 faces the first inclined surface 34 of the fuel tank 31 and gradually descends as the vehicle moves forward. It can also be formed on a conical surface that is inclined. Further, a buckling deformation characteristic can be adjusted by changing the rigidity of the second movement restricting portion 52 by forming a bead, an opening or the like in the main body portion 56 or the mounting bracket 53 of the second movement restricting portion 52.
[0046]
【The invention's effect】
According to the vehicle fuel tank protection structure of the present invention described above, the first slope gradually descends as the vehicle tank moves forward in the front direction of the vehicle body on the front surface of the fuel tank mounted on the lower side of the vehicle body floor. The vehicle body member is provided with a first movement restricting portion provided with a second inclined surface that forms a surface and gradually descends as the vehicle moves forward in a direction opposite to the first inclined surface. When the fuel tank moves due to the acting impact load, the first inclined surface comes into contact with the second inclined surface of the first movement restricting portion, and the movement of the fuel tank is suppressed. Further, when the front surface of the fuel tank comes into contact with the contact portion of the second movement restricting portion by the movement of the fuel tank and pushes the contact portion in the vehicle body front direction, the upper surface portion and the side surface portion of the base portion that supports the contact portion Is buckled and the mounting bracket connecting the base part to the vehicle body member buckles and reduces the impact on the fuel tank. As a result, the fuel tank can be prevented from being pressed or brought into contact with the lower surface of the vehicle body floor, and damage or deformation of the fuel tank can be suppressed.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an outline of an embodiment of a protection structure for a vehicle fuel tank according to the present invention.
2 is a cross-sectional view taken along the line II of FIG. 1 in a state where the members are coupled together. FIG.
3 is a cross-sectional view taken along the line II-II in FIG.
4 is a cross-sectional view taken along the line III-III of FIG. 1 in a state where the members are coupled together. FIG.
FIG. 5 is a perspective view of the first movement restricting portion in the same manner.
6 is a view taken along arrow A in FIG.
FIG. 7 is an exploded perspective view of the second movement restricting portion.
FIG. 8 is a perspective view of the second movement restricting portion in the same manner.
FIG. 9 is an explanatory view of a conventional vehicle fuel tank support structure.
FIG. 10 is an explanatory diagram of a conventional protective structure for a vehicle fuel tank.
[Explanation of symbols]
10 body floor
11 Front floor
15 Rear floor
21 Cross member (body member)
22 Front wall
23 steps
24 Rear wall
24a Upper flange
26 Cross member phosphorus hose
31 Fuel tank
32 Upper case
33 Front
34 First inclined surface
35 Lower case
36 Front
41 1st movement control part
42 Body
42a Upper flange
43 Joint surface
44 Top
45a, 45b, 45c, 45d Ridge line
46 bulge
47 Second inclined surface
48 3rd inclined surface
49 4th inclined surface
50 5th inclined surface
51 joint
52 Second Movement Restriction Unit
53 Mounting bracket
54 Support surface
55a Rear mounting part
55b Front mounting part
56 Body
57 Base part
58 Upper surface
59 Side
60 Contact part

Claims

In the protection structure of the vehicle fuel tank mounted below the vehicle body floor,
In the fuel tank, a first inclined surface that gradually descends as the vehicle tank moves forward is formed on the front surface of the fuel tank on the front side of the vehicle body.
A first movement restricting portion provided with a second inclined surface facing the first inclined surface and gradually descending as it moves in the front direction of the vehicle body, and a second provided with a contact portion facing the front surface of the fuel tank. A movement restricting portion is provided on the body member,
The second movement restriction unit is
A support surface that extends in the longitudinal direction of the vehicle body with a gap from the vehicle body member, and a front attachment portion and a rear attachment portion that are continuously formed at the front end and the rear end of the support surface and are respectively coupled to the vehicle body member. A mounting bracket;
A base portion having a substantially U-shaped cross section having a top surface portion coupled to the support surface of the mounting bracket and side portions bent along both side edges of the top surface portion and continuing in the longitudinal direction of the vehicle body;
A protective structure for a fuel tank for a vehicle, comprising: the abutting portion that is attached to an end portion on the vehicle body rear side of the base portion and faces the front surface of the fuel tank.

The first movement restriction unit is
The second inclined surface that is a substantially triangular shape that gradually increases as it moves in the vehicle body front direction from the top portion located on the vehicle body rear side from the vehicle body member, and that gradually decreases as it moves in the vehicle body front direction so as to face the first inclined surface. When,
A substantially triangular third inclined surface and a fourth inclined surface that are continuous with both sides of the second inclined surface via a ridge line and are gradually separated from each other in the vehicle width direction and become wider from the top to the vehicle body front direction. When,
The third inclined surface and the fourth inclined surface are connected via a ridge line, and have a substantially triangular fifth inclined surface that gradually increases from the top to the front of the vehicle body, and from the vehicle body member side to the rear of the vehicle body 2. The vehicular fuel tank protection structure according to claim 1, further comprising a substantially quadrangular pyramidal bulging portion projecting in a direction.

The first movement restriction unit is
It is provided at the approximate center in the vehicle width direction of the vehicle body member,
To claim 1 or 2, characterized in that the pair of the second movement restricting portion having a contact portion to the front facing of the fuel tank is provided on the vehicle body member separates the first movement restricting portion The vehicle fuel tank protective structure as described.

The vehicle body member is
According to any one of claims 1 to 3, characterized in that a cross member laterally bridged in the vehicle body front side of the fuel tank between the left and right side sills extending in the front-rear direction along the side of the vehicle Protective structure for vehicle fuel tank.

The cross member is
5. The vehicle fuel tank protection structure according to claim 4, wherein a hollow closed cross-sectional shape extending in the vehicle width direction is formed in cooperation with a cross member ring hose extending in the vehicle width direction.