JP2004284532A

JP2004284532A - Vehicle body lower part structure

Info

Publication number: JP2004284532A
Application number: JP2003081128A
Authority: JP
Inventors: Hideji Saeki; 秀司佐伯
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2003-03-24
Filing date: 2003-03-24
Publication date: 2004-10-14
Anticipated expiration: 2023-03-24
Also published as: JP4123024B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body lower part structure capable of further improving load transmission efficiency of a tunnel part while restraining increase in weight. <P>SOLUTION: An upper panel 11 and a lower panel 12 are joined together to form the tunnel part 20, a U-shaped closed space part 23 is constituted between the upper panel 11 and the lower panel 12 of a portion corresponding to a ceiling part 21 and both vertical wall parts 22 in a vehicle front area of the tunnel part 20, and a rectangular closed space part 24 is provided between the upper panel 11 and the lower panel 12 of the portion corresponding to the ceiling part 21 of the tunnel part 20 in a vehicle rear area of the tunnel part 20. A height position of an upper face 12a of the lower panel 12 from the U-shaped closed space part 23 to the rectangular closed space part 24 is maintained in almost the same height to allow the tunnel part 20 with a closed space structure such as the U-shaped closed space part 23 and the rectangular closed space part 24 to function as a frame member of a floor panel 10 and the strength of a cabin is improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は自動車の車体下部構造に関する。
【０００２】
【従来の技術】
従来の自動車の車体下部構造の中には、断面台形状に形成したトンネル部の両側縦壁部の上部と下部に、それぞれ車両前後方向に延在する補強部材（アッパ，ロアリインフォースメント）を設け、前面衝突時にキャビン前方から入力する荷重の伝達分散効率を高められるようにしたものが知られている（例えば、特許文献１参照。）。
【０００３】
【特許文献１】
特開平８−１１９１５１号公報（第２−３頁、第１図）
【０００４】
【発明が解決しようとする課題】
しかしながら、かかる従来の車体下部構造は、前面衝突時の前方からの入力荷重を分散する補強部材がトンネル部の縦壁部の上下に大きくオフセットして配置しているため、この縦壁部にはモーメントが発生する。
【０００５】
このため、十分な荷重伝達能力を確保するためには、トンネル部の上側に沿って配置した台形状の補強板（シフトレバーリインフォースメント）の強度を高める必要があり、前記補強部材を設けたことによる重量増と相俟って車体重量の軽量化が困難になる。
【０００６】
そこで、本発明は重量の大幅な増大を抑制しつつ、トンネル部のより一層の荷重伝達効率を向上することができる車体下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】
本発明の車体下部構造にあっては、フロアパネルの車幅方向中央部に車両前後方向に延在するトンネル部を、アッパーパネルとロアーパネルの少なくとも２つのパネルを互いに接合して形成し、このトンネル部の車両前方領域には、トンネル部の天井部および両縦壁部に相当する部位にアッパーパネルとロアーパネルの間に断面逆Ｕ字状のＵ字状閉空間部を構成する一方、前記トンネル部の車両後方領域に、トンネル部の天井部に相当する部位にアッパーパネルとロアーパネルとの間に断面矩形状の矩形状閉空間部を設け、Ｕ字状閉空間部から矩形状閉空間部に至るロアーパネルの上面の高さ位置を略一致させるとともに、Ｕ字状閉空間部から矩形状閉空間部へとロアーパネルの両縦壁面を拡幅しつつ連続的に形状変化させたことを特徴としている。
【０００８】
【発明の効果】
本発明によれば、前面衝突等によってトンネル部前方から荷重が入力した場合に、Ｕ字状閉空間部や矩形状閉空間部等の閉空間構造を設けたトンネル部がフロアパネルの骨格部材として機能するため、キャビン強度を向上できるとともに、該トンネル部の車両前方領域のＵ字状閉空間部から車両後方領域の矩形状閉空間部へと連続的に形状変化するため、閉空間構造の連続性を確保して効率良く前後荷重を支持し、ひいては、重量の大幅な増大を抑制しつつ、前後方向の荷重伝達効率を向上することができる。
【０００９】
【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。
【００１０】
図１〜図５は本発明にかかる車体下部構造の第１実施形態を示し、図１は本発明の対象とする車両の全体斜視図、図２はキャビン内部のフロアパネル構造を示す斜視図、図３はフロアパネルの要部を示す側面図、図４（ａ）は図３中Ａ−Ａ線に沿った拡大断面図、図４（ｂ）は図３中Ｂ−Ｂ線に沿った拡大断面図、図５はフロアパネルの分解斜視図である。
【００１１】
この第１実施形態の車体下部構造は図１に示すような車両１に適用され、この車両１は、図２に示すようにフロアパネル１０の車幅方向中央部に車両前後方向に延在するトンネル部２０を形成してある。
【００１２】
車両１のフロントコンパートメント２にはパワーユニットＰを搭載してあり、このフロントコンパートメント２の車幅方向両側には車両前後方向に延在する１対のフロントサイドメンバ３を設けてある。
【００１３】
前記フロントサイドメンバ３は、その車両後方端部をダッシュパネル５に突当てて結合し、該ダッシュパネル５に沿って下方傾斜してフロアパネル１０の下側に廻り込んだエクステンションサイドメンバ４に連設してある。また、フロアパネル１０の車幅方向両外側には車両前後方向に延在するサイドシル６を設けてある。
【００１４】
左右のサイドシル６の前端部からは、図２に示すようにそれぞれフロントピラー７が立ち上がり、これらフロントピラー７間には、フロントサイドメンバ３の後端部を結合したダッシュクロスメンバ８を設けてある。
【００１５】
また、フロアパネル１０の車両前後方向略中央部には乗員座席としての前席Ｓを設置してあり、図３に示すように、この前席Ｓの車両後方には、車幅方向に延在するリアシートクロスメンバ９を左右両側のサイドシル６に亘って結合してある。
【００１６】
ここで、この第１実施形態では前記トンネル部２０を、図５に示すように、アッパーパネル１１とロアーパネル１２の２つのパネルを互いに接合して形成してある。
【００１７】
ロアーパネル１２はフロアパネル１０の全域を構成し、このロアーパネル１２の車幅方向中央部を断面台形状にプレス成形してトンネル部２０に相当する部分を突出形成する一方、アッパーパネル１１は全体を断面台形状にプレス成形して、このアッパーパネル１１を、ロアーパネル１２のトンネル部２０に相当する突設部分の上側を覆うことでトンネル部２０を構成してある。
【００１８】
また、図４（ａ）に示すようにこのトンネル部２０の車両前方領域には、トンネル部２０の天井部２１および両縦壁部２２に相当した部位にアッパーパネル１１とロアーパネル１２との間に断面逆Ｕ字状のＵ字状閉空間部２３を構成する一方、図４（ｂ）に示すように前記トンネル部２０の車両後方領域に、トンネル部２０の天井部２１に相当する部位にアッパーパネル１１とロアーパネル１２との間に断面矩形状の矩形状閉空間部２４を設けてある。
【００１９】
前記Ｕ字状閉空間部２３から矩形状閉空間部２４に至るロアーパネル１２の上面１２ａの高さ位置は略一致させてあるとともに、Ｕ字状閉空間部２３から矩形状閉空間部２４へとロアーパネル１２の両縦壁面１２ｂを拡幅しつつ連続的に形状変化させてある。
【００２０】
本実施形態ではトンネル部２０の車両後方領域の後端部分も断面逆Ｕ字状のＵ字状閉空間部２３として形成してあり、従って、ロアーパネル１２のトンネル形状部分はその前後方向中間部が拡幅成形されていて、該拡幅部の前後端部がスロープ状に形成されてＵ字状閉空間部２３と矩形状閉空間部２４とが連続的に形状変化するようにしてある。
【００２１】
また、アッパーパネル１１とロアーパネル１２は、車両前後方向に連続して形成してある。
【００２２】
前記トンネル部２０の矩形状閉空間部２４の車幅方向両側には、前記前席Ｓを設置してある。つまり、前席Ｓは運転席と助手席を備えており、運転席をトンネル部２０の片側に、助手席をトンネル部２０の他側に設置することになる。
【００２３】
また、アッパーパネル１１は、矩形状閉空間部２４の部分で図３，図５に示すように、その上面１１ａをＵ字状閉空間部２３よりも上方に突出させてある。
【００２４】
前記トンネル部２０はフロアパネル１０の車両前方端部から車両後方に向かって延在するが、このトンネル部２０の車両前方端部に設けた前記Ｕ字状閉空間部２３の天井部相当部分２１ａの高さ位置を、フロントサイドメンバ３の車両後方端部と略同位置に設定し、その天井部相当部分２１ａの車両前方端部をダッシュクロスメンバ８に結合してある。
【００２５】
また、トンネル部２０の車両後方領域の後端部分に設けたＵ字状閉空間部２３の後端部を、前記リアシートクロスメンバ９に結合してある。
【００２６】
以上の構成によりこの第１実施形態の車体下部構造にあっては、前面衝突等によってトンネル部２０の前方から荷重Ｆｆ（図２参照）が入力した場合に、Ｕ字状閉空間部２３や矩形状閉空間部２４等の閉空間構造を設けたトンネル部２０がフロアパネル１０の骨格部材として機能するため、キャビン強度を向上できるとともに、車両前方領域のＵ字状閉空間部２３から車両後方領域の矩形状閉空間部２４へと連続的に形状変化するため、閉空間構造の連続性を確保して効率良く前後荷重を支持し、ひいては、重量の大幅な増大を抑制しつつ、前後方向の荷重伝達効率を向上することができる。
【００２７】
また、トンネル部２０は、Ｕ字状閉空間部２３から矩形状閉空間部２４に至るロアーパネル１２の上面１２ａの高さ位置を略一致させてあるので、前後荷重に対してロアーパネル１２の上面１２ａ全体が剪断面として機能し、この点からもキャビン強度の更なる向上を図ることができる。
【００２８】
更に、トンネル部２０はＵ字状閉空間部２３から矩形状閉空間部２４へと連続的に形状変化させるにあたって、トンネル部２０を構成するロアーパネル１２の両縦壁面１２ｂを拡幅しつつ変化させたので、図４（ａ），（ｂ）に示すように、トンネル部２０の内側幅Ｗは車両前方領域から車両後方領域に向かって広がるため、車両前方領域には比較的細い排気管３０を配索し、車両後方領域には大型の触媒装置３１を効率良く配置できて、排気系の管路レイアウトを容易にすることができる。
【００２９】
ところで、この実施形態では前述した作用効果に加えて、トンネル部２０の矩形状閉空間部２４の車幅方向両側に前席Ｓを設置したので、側面衝突等のように車両左右方向からの荷重入力によって、図４（ｂ）に示すように入力側の前席Ｓが車体中央側に変位して矩形状閉空間部２４に干渉することにより、この矩形状閉空間部２４が荷重伝達経路として機能するため、横方向の入力に対してもキャビン強度を向上することができる。
【００３０】
また、トンネル部２０を形成したアッパーパネル１２とロアーパネル１２を、車両前後方向に連続して形成してあるので、特別な部品を必要とすることなく、かつ、強度を確保しつつ合理的にトンネル部２０を構成できるとともに、キャビン内へのトンネル部２０の張出しを抑制できるため、キャビン内の空間効率を高めることができる。
【００３１】
更に、矩形状閉空間部２４の部分ではアッパーパネル１１は、その上面１１ａをＵ字状閉空間部２３よりも上方に突出させたので、この突出した矩形状閉空間部２４において矩形断面部の高さを大きくして、側方からの入力に対する前席Ｓと矩形状閉空間部２４との干渉面積を増大できるため、より確実な荷重伝達や荷重分散が可能となる。
【００３２】
更にまた、Ｕ字状閉空間部２３の天井部相当部分２１ａの高さ位置を、フロントサイドメンバ３の車両後方端部と略同位置に設定し、その天井部相当部分２１ａの車両前方端部をダッシュクロスメンバ８に結合したので、前面衝突等によって車両前方からフロントサイドメンバ３に入力した荷重を、ダッシュクロスメンバ８を介してトンネル部２０の閉空間構造部分で支持できるため、キャビン変形の抑制効果を更に高めることができる。
【００３３】
また、矩形状閉空間部２４の後方では閉空間構造の後端部を、前席Ｓの車両後方部分で左右両側のサイドシル６に車幅方向に結合したリアシートクロスメンバ９に結合したので、後面衝突等によって車両後方からサイドシル６やリアサイドメンバ等に入力した荷重を、リアシートクロスメンバ９を介してトンネル部２０の閉空間構造部分で支持できるため、この場合にあってもキャビン変形を抑制することができる。
【００３４】
図６〜図９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６はキャビン内部のフロアパネル構造を示す斜視図、図７はフロアパネルの成形工程を示す斜視図、図８はフロアパネルの要部を示す側面図、図９（ａ）は図８中Ｃ−Ｃ線に沿った拡大断面図、図９（ｂ）は図８中Ｄ−Ｄ線に沿った拡大断面図である。
【００３５】
この第２実施形態の車体下部構造は、図６に示すように、トンネル部２０とサイドシル６とを、アッパーパネル１１から一体に突設した車幅方向補強部材としての延設部分１３によって連結してある。
【００３６】
前記延設部分１３は、トンネル部２０の延在方向（車両前後方向）に対して直角に配置するとともに、この延設部分１３の車幅方向外側端部をフロントピラー７の基部７ａに連結して、フロアパネル１０の車両前端部に配置してある。
【００３７】
また、このように延設部分１３をフロアパネル１０の車両前端部に配置することにより、図８に示すように、この延設部分１３をパワーユニットＰを搭載支持したサブフレーム１４の取付部として兼ねている。
【００３８】
即ち、前記サブフレーム１４は、フロントコンパートメント２の下部に配置してあり、このサブフレーム１４の前端部をフロントサイドメンバ３の前端部下部に結合し、かつ、後端部を前記延設部分１３の下側部分に結合してある。
【００３９】
ところで、この第２実施形態では図７（ａ）に示すように、ロアーパネル１２はトンネル成形部分２５の板厚が最も厚くなるように複数枚、例えば３枚のパネルを接合して形成してある。
【００４０】
即ち、前記ロアーパネル１２は中央のパネル１２ｄをトンネル形成部分２５の面積として、その両側にパネル１２ｃをレーザー溶接等の連続溶接方法により一体に接合し、その後、図７（ｂ）に示すようにトンネル形成部分２５をプレス成形して、上面１２ａおよび両縦壁面１２ｂを形出し、その上からやはりプレス成形したアッパーパネル１１を被せて、図９（ａ），（ｂ）に示すように、Ｕ字状閉空間部２３および矩形状閉空間部２４の閉断面空間を形成して接合している。
【００４１】
ところで、図７（ｂ）に示すように前記延設部分１３は、アッパーパネル１２の両側壁部２２の下端部から図９（ａ）に示すようにロアーパネル１２との間に適宜間隔δをおいて一体に突設し、その前側縁を上方に折曲したフランジ部１３ａをダッシュパネル５に結合するとともに、後側縁を下方に折曲したフランジ部１３ｂをロアーパネル１２に結合してある。
【００４２】
従って、この第２実施形態の車体下部構造にあっては、トンネル部２０とサイドシル６とを延設部分１３によって連結したので、この延設部分１３を介してトンネル部２０とサイドシル６との間で荷重の伝達および分散が可能となるため、衝突時に入力した荷重の分散効率が向上し、これによって局部的な応力集中を抑制できるため、フロアパネル１０や各メンバの薄肉化を図って車体の軽量化を達成することができる。
【００４３】
また、前記延設部分１３をトンネル部２０の延在方向に対して直角に配置したので、延設部分１３の長さを最短として車体の軽量化に寄与するとともに、特に、側方からの入力に対して延設部分１３が軸部材として機能するため、側方から入力する荷重の支持効率が向上する。
【００４４】
更に、延設部分１３をフロントピラー７の基部に連結して、フロアパネル１０の車両前端部に配置したので、前面衝突時のタイヤ後退によるフロントピラー７若しくはフロントハホイールウジングとタイヤとの干渉による入力荷重を前記延設部分１３で支持するとともに、この入力荷重を延設部分１３を介してトンネル部２０に分散し、キャビン前方の局所的な変形を抑制することができる。
【００４５】
更にまた、前記延在部分１３はアッパーパネル１１から一体に突設したので、部品点数を削減して車体組付け性を向上し、ひいては車両生産性を高めることができる。
【００４６】
また、延設部分１３はサブフレーム１４の取付部を兼ねたので、前面衝突時にサブフレーム１４に作用する入力を延設部分１３を介してトンネル部２０とサイドシル６に伝達できるため、より効率良く車両前方からの入力荷重を支持および分散することができる。
【００４７】
更に、ロアーパネル１２はトンネル成形部分２５の板厚が最も厚くなるように複数枚のパネルを接合して形成したので、特別な補強部材を要することなく、容易かつ合理的にトンネル部２０およびこれに形成したＵ字状閉空間部２３や矩形状閉空間部２４等の閉空間構造部分の強度向上を図ることができ、これによって重量投資の抑制や生産性の向上を達成することができる。
【００４８】
図１０，図１１は本発明の第３実施形態を示し、前記第１，第２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１０はキャビン内部のフロアパネル構造を示す斜視図、図１１はフロアパネルの要部を示す側面図である。
【００４９】
この第３実施形態の車体下部構造は、図１０，図１１に示すように第２実施形態と同様にトンネル部２０とサイドシル６とを連結する延設部分１３をアッパーパネル１１から一体に突設してあり、この第３実施形態が第２実施形態と特に異なる点は、前記延設部分１３をトンネル部２０の延在方向（車両前後方向）に対して傾斜させて配置してあり、また、アッパーパネル１１はその上面１１ａをＵ字状閉空間部２３から矩形状閉空間部２４に亘って平坦に形成してある。
【００５０】
尚、この第３実施形態では延設部分１３の傾斜方向は、図１０に示すようにトンネル部２０側からセンターピラー７側に向かって車両前方に傾斜させてある。
【００５１】
従って、この第３実施形態の車体下部構造にあっては、前記第２実施形態と同様に傾斜部分１３によって衝突時に入力した荷重の分散効率を向上できるのは勿論のこと、この延設部分１３を傾斜させたことにより、前後方向および側方からの入力に対して引張り若しくは圧縮方向の入力荷重として延設部分１３に作用させることができるため、衝突方向に対する指向性を広げることができる。
【００５２】
また、アッパーパネル１１の前後方向中央部に上方突出部がないので、キャビン空間を狭めることがない。
【００５３】
尚、延設部分１３の傾斜方向は、この実施形態とは逆にトンネル部２０側からセンターピラー７側に向かって車両後方に傾斜させてもよい。
【００５４】
図１２〜図１５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１２はフロアパネルの要部を示す側面図、図１３は図１２中Ｅ−Ｅ線に沿った拡大断面図、図１４は矩形状閉空間部内に結合する内部補強部材の拡大斜視図、図１５は内部補強部材の取付け状態を示す分解斜視図である。
【００５５】
この第４実施形態の車体下部構造は、図１２に示すように第１実施形態と同様にトンネル部２０の矩形状閉空間部２４の車幅方向両側に前席Ｓを設置してあり、この第４実施形態では図１３に示すように、その矩形状閉空間部２４内に、ロアーパネル１２の上面１２ａに結合したボックス状の内部補強部材１５を設け、この内部補強部材１５にトンネル部２０の車幅方向両側に設置した前記前席Ｓを連結してある。
【００５６】
内部補強部材１５は、図１４に示すように、平板を車両前後方向に向かって上方に突出する台形状に折曲するとともに、その車幅方向両端を端板１５ａで閉止して形成し、前後方向両端部に設けたフランジ部１５ｂを、図１５に示すように、ロアーパネル１２の上面１２ａの上側にボルト固定している。
【００５７】
前記端板１５ａにはボルト挿通穴１５ｃが形成されるとともに、その裏面にウエルドナット１５ｄを設けてある。
【００５８】
そして、前記内部補強部材１５は、図１５に示すように前席Ｓの配置部分の前後両側に位置して２つを設け、それら内部補強部材１５の外側をアッパーパネル１１で覆うことにより、図１３に示すように矩形状閉空間部２４内に内部補強部材１５がロアーパネル１２の上面１２ａにボルト固定された状態で収納される。
【００５９】
前記２つの内部補強部材１５のウエルドナット１５ｄには、トンネル部２０の両縦壁部２２に、図１３に示すようにアッパーパネル１１の外側から車両前後方向に配置したレール１６をボルト１７結合し、このレール１６に左，右の前席Ｓ、つまり、助手席と運転席とを結合するようになっている。
【００６０】
従って、この第４実施形態の車体下部構造にあっては、左，右の前席Ｓが内部補強部材１５を介して互いに連結されるため、これら左，右前席Ｓと内部補強部材１５が車幅方向の骨格部材若しくは荷重伝達経路として機能し、側面衝突時の入力荷重に対してキャビンの強度を高めることができる。
【００６１】
また、前席Ｓは矩形状閉空間部２４において、内部補強部材１５を介してロアーパネル１２の上面１２ａに結合してあるので、前面衝突時に前席Ｓおよびこれに着座した前席乗員Ｍに作用する慣性力を、矩形状閉空間部２４の剛性が大きくなったロアーパネル１２の上面１２ａで支持でき、特に高速での衝突時に矩形状閉空間部２４における高い支持効率を発揮することができる。
【００６２】
ところで、本発明の車体下部構造は前記第１〜第４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両の全体斜視図。
【図２】本発明の第１実施形態におけるキャビン内部のフロアパネル構造を示す斜視図。
【図３】本発明の第１実施形態におけるフロアパネルの要部を示す側面図。
【図４】（ａ）は図３中Ａ−Ａ線に沿った拡大断面図、（ｂ）は図３中Ｂ−Ｂ線に沿った拡大断面図。
【図５】本発明の第１実施形態におけるフロアパネルの分解斜視図。
【図６】本発明の第２実施形態におけるキャビン内部のフロアパネル構造を示す斜視図。
【図７】本発明の第２実施形態におけるフロアパネルの成形工程を（ａ），（ｂ）によって示す斜視図。
【図８】本発明の第２実施形態におけるフロアパネルの要部を示す側面図。
【図９】（ａ）は図８中Ｃ−Ｃ線に沿った拡大断面図、（ｂ）は図８中Ｄ−Ｄ線に沿った拡大断面図。
【図１０】本発明の第３実施形態におけるキャビン内部のフロアパネル構造を示す斜視図。
【図１１】本発明の第３実施形態におけるフロアパネルの要部を示す側面図。
【図１２】本発明の第４実施形態におけるフロアパネルの要部を示す側面図。
【図１３】図１２中Ｅ−Ｅ線に沿った拡大断面図。
【図１４】本発明の第４実施形態における矩形状閉空間部内に結合する内部補強部材の拡大斜視図。
【図１５】本発明の第４実施形態における内部補強部材の取付け状態を示す分解斜視図。
【符号の説明】
１車両
３フロントサイドメンバ
６サイドシル
７フロントピラー
８ダッシュクロスメンバ
９リアシートクロスメンバ
１０フロアパネル
１１アッパーパネル
１１ａアッパーパネルの上面
１２ロアーパネル
１２ａロアーパネルの上面
１２ｂロアーパネルの縦壁面
１３延設部分（車幅方向補強部材）
１４サブフレーム
１５内部補強部材
２０トンネル部
２１天井部
２２縦壁部
２３Ｕ字状閉空間部
２４矩形状閉空間部
２５トンネル成形部分
Ｓ前席（乗員座席）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lower structure of a vehicle body.
[0002]
[Prior art]
In a conventional vehicle underbody structure, reinforcing members (upper and lower reinforcements) extending in the vehicle front-rear direction are provided at upper and lower portions of both side vertical walls of a tunnel portion having a trapezoidal cross section. There has been known a configuration in which the transmission dispersion efficiency of a load input from the front of the cabin at the time of a frontal collision can be enhanced (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-8-119151 (page 2-3, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in such a conventional lower body structure, a reinforcing member for dispersing an input load from the front at the time of a frontal collision is disposed at a large offset above and below the vertical wall portion of the tunnel portion. A moment is generated.
[0005]
For this reason, in order to ensure sufficient load transmission capacity, it is necessary to increase the strength of the trapezoidal reinforcing plate (shift lever reinforcement) disposed along the upper side of the tunnel portion, and the reinforcing member is provided. Combined with the increase in weight, it is difficult to reduce the weight of the vehicle body.
[0006]
Accordingly, the present invention provides a vehicle body lower structure capable of further improving the load transmission efficiency of a tunnel portion while suppressing a significant increase in weight.
[0007]
[Means for Solving the Problems]
In the vehicle body lower structure of the present invention, a tunnel portion extending in the vehicle front-rear direction is formed at the center portion of the floor panel in the vehicle width direction by joining at least two panels of the upper panel and the lower panel to each other. In the vehicle front region of the tunnel portion, a U-shaped closed space portion having an inverted U-shaped cross section is formed between an upper panel and a lower panel at a portion corresponding to a ceiling portion and both vertical wall portions of the tunnel portion, A rectangular closed space having a rectangular cross section is provided between the upper panel and the lower panel at a portion corresponding to a ceiling of the tunnel in a vehicle rear region of the tunnel, and a rectangular closed space is formed from the U-shaped closed space. The height position of the upper surface of the lower panel reaching the upper part is made substantially the same, and both vertical wall surfaces of the lower panel are continuously changed in shape from the U-shaped closed space to the rectangular closed space while widening. Features There.
[0008]
【The invention's effect】
According to the present invention, when a load is input from the front of the tunnel portion due to a frontal collision or the like, the tunnel portion provided with a closed space structure such as a U-shaped closed space portion or a rectangular closed space portion serves as a frame member of the floor panel. In order to function, the strength of the cabin can be improved, and the shape of the tunnel changes continuously from the U-shaped closed space in the front area of the vehicle to the rectangular closed space in the rear area of the vehicle, so that the closed space structure Thus, the load transfer efficiency in the front-rear direction can be improved while efficiently supporting the front-rear load while suppressing a significant increase in weight.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
1 to 5 show a first embodiment of a vehicle body lower structure according to the present invention, FIG. 1 is an overall perspective view of a vehicle to which the present invention is applied, FIG. 2 is a perspective view showing a floor panel structure inside a cabin, 3 is a side view showing a main part of the floor panel, FIG. 4 (a) is an enlarged sectional view taken along line AA in FIG. 3, and FIG. 4 (b) is an enlarged view taken along line BB in FIG. FIG. 5 is an exploded perspective view of the floor panel.
[0011]
The lower body structure of the first embodiment is applied to a vehicle 1 as shown in FIG. 1, and this vehicle 1 extends in the vehicle front-rear direction at the center of the floor panel 10 in the vehicle width direction as shown in FIG. A tunnel portion 20 is formed.
[0012]
A power unit P is mounted on the front compartment 2 of the vehicle 1, and a pair of front side members 3 extending in the vehicle front-rear direction are provided on both sides of the front compartment 2 in the vehicle width direction.
[0013]
The front side member 3 is connected to the dash panel 5 by abutting the rear end of the vehicle against the dash panel 5, and is connected to the extension side member 4 sloping downward along the dash panel 5 and going under the floor panel 10. It is set up. Side sills 6 extending in the vehicle front-rear direction are provided on both outer sides of the floor panel 10 in the vehicle width direction.
[0014]
Front pillars 7 stand up from the front ends of the left and right side sills 6 as shown in FIG. 2, and a dash cross member 8 is provided between the front pillars 7 to connect the rear ends of the front side members 3. .
[0015]
A front seat S as an occupant seat is installed substantially at the center of the floor panel 10 in the vehicle front-rear direction, and extends in the vehicle width direction behind the front seat S as shown in FIG. The rear seat cross member 9 is connected to the left and right side sills 6.
[0016]
Here, in the first embodiment, the tunnel section 20 is formed by joining two panels, an upper panel 11 and a lower panel 12, to each other as shown in FIG.
[0017]
The lower panel 12 constitutes the entire area of the floor panel 10, and the center of the lower panel 12 in the vehicle width direction is press-formed into a trapezoidal cross section to form a portion corresponding to the tunnel portion 20 while the upper panel 11 is formed as a whole. Is press-formed into a trapezoidal cross section, and the upper panel 11 covers the upper side of a protruding portion corresponding to the tunnel portion 20 of the lower panel 12 to form the tunnel portion 20.
[0018]
In addition, as shown in FIG. 4 (a), in a region in front of the vehicle of the tunnel portion 20, a portion corresponding to the ceiling portion 21 and both vertical wall portions 22 of the tunnel portion 20 is provided between the upper panel 11 and the lower panel 12. A U-shaped closed space 23 having an inverted U-shaped cross section is formed on the other hand, as shown in FIG. 4B, in a region behind the vehicle of the tunnel portion 20 and at a portion corresponding to the ceiling portion 21 of the tunnel portion 20. A rectangular closed space 24 having a rectangular cross section is provided between the upper panel 11 and the lower panel 12.
[0019]
The height position of the upper surface 12a of the lower panel 12 from the U-shaped closed space portion 23 to the rectangular closed space portion 24 is substantially matched, and from the U-shaped closed space portion 23 to the rectangular closed space portion 24. The shape is continuously changed while the width of both vertical wall surfaces 12b of the lower panel 12 is increased.
[0020]
In this embodiment, the rear end portion of the vehicle rear area of the tunnel portion 20 is also formed as a U-shaped closed space portion 23 having an inverted U-shaped cross section. Is widened, and the front and rear ends of the widened portion are formed in a slope shape so that the U-shaped closed space portion 23 and the rectangular closed space portion 24 are continuously changed in shape.
[0021]
The upper panel 11 and the lower panel 12 are formed continuously in the vehicle longitudinal direction.
[0022]
The front seats S are installed on both sides in the vehicle width direction of the rectangular closed space portion 24 of the tunnel portion 20. That is, the front seat S has a driver's seat and a passenger seat, and the driver's seat is installed on one side of the tunnel section 20 and the passenger seat is installed on the other side of the tunnel section 20.
[0023]
As shown in FIGS. 3 and 5, the upper panel 11 has an upper surface 11 a protruding above the U-shaped closed space 23 in the rectangular closed space 24 as shown in FIGS. 3 and 5.
[0024]
The tunnel portion 20 extends from the front end of the floor panel 10 toward the rear of the vehicle. The U-shaped closed space 23 provided at the front end of the tunnel portion 20 corresponds to a ceiling portion 21a. Is set at substantially the same position as the rear end of the vehicle of the front side member 3, and the front end of the vehicle corresponding to the ceiling portion 21 a is connected to the dash cross member 8.
[0025]
A rear end portion of a U-shaped closed space portion 23 provided at a rear end portion of the tunnel portion 20 at the rear side of the vehicle is connected to the rear seat cross member 9.
[0026]
With the above configuration, in the vehicle body lower structure of the first embodiment, when the load Ff (see FIG. 2) is input from the front of the tunnel section 20 due to a frontal collision or the like, the U-shaped closed space section 23 or the rectangular Since the tunnel portion 20 provided with the closed space structure such as the shape closed space portion 24 functions as a frame member of the floor panel 10, the strength of the cabin can be improved, and the U-shaped closed space portion 23 in the front region of the vehicle and the rear region of the vehicle. The shape changes continuously to the rectangular closed space portion 24, so that the continuity of the closed space structure is ensured and the front-rear load is efficiently supported, and thus the weight in the front-rear direction is suppressed. Load transmission efficiency can be improved.
[0027]
In addition, since the height of the upper surface 12a of the lower panel 12 extending from the U-shaped closed space 23 to the rectangular closed space 24 is substantially matched, the tunnel portion 20 has a lower position with respect to the front-rear load. The entire upper surface 12a functions as a shear plane, and from this point, the strength of the cabin can be further improved.
[0028]
Further, in continuously changing the shape of the tunnel portion 20 from the U-shaped closed space portion 23 to the rectangular closed space portion 24, both the vertical wall surfaces 12b of the lower panel 12 constituting the tunnel portion 20 are changed while being widened. Therefore, as shown in FIGS. 4A and 4B, since the inner width W of the tunnel portion 20 increases from the vehicle front region toward the vehicle rear region, a relatively thin exhaust pipe 30 is provided in the vehicle front region. The large catalyst device 31 can be efficiently arranged in the rear area of the vehicle by wiring, and the layout of the exhaust system pipeline can be facilitated.
[0029]
By the way, in this embodiment, in addition to the above-described functions and effects, the front seats S are installed on both sides in the vehicle width direction of the rectangular closed space portion 24 of the tunnel portion 20, so that the load from the left and right direction of the vehicle such as a side collision. By the input, the front seat S on the input side is displaced toward the center of the vehicle body and interferes with the rectangular closed space 24 as shown in FIG. 4B, so that the rectangular closed space 24 serves as a load transmission path. Since it functions, the cabin strength can be improved even for a lateral input.
[0030]
Further, since the upper panel 12 and the lower panel 12 forming the tunnel section 20 are formed continuously in the vehicle front-rear direction, no special parts are required, and the strength is assured while securing the strength. Since the tunnel section 20 can be configured and the protrusion of the tunnel section 20 into the cabin can be suppressed, the space efficiency in the cabin can be increased.
[0031]
Further, since the upper panel 11 has the upper surface 11a protruding above the U-shaped closed space portion 23 in the rectangular closed space portion 24, the upper panel 11 has a rectangular cross section in the protruding rectangular closed space portion 24. By increasing the height and increasing the interference area between the front seat S and the rectangular closed space 24 with respect to input from the side, more secure load transmission and load distribution can be achieved.
[0032]
Furthermore, the height position of the ceiling portion 21a of the U-shaped closed space 23 is set to substantially the same position as the vehicle rear end of the front side member 3, and the vehicle front end of the ceiling portion 21a. Is connected to the dash cross member 8, so that the load input to the front side member 3 from the front of the vehicle due to a frontal collision or the like can be supported by the closed space structure portion of the tunnel portion 20 via the dash cross member 8, so that the cabin deforms. The suppression effect can be further enhanced.
[0033]
Further, the rear end of the closed space structure behind the rectangular closed space portion 24 is connected to the rear seat cross member 9 which is connected to the left and right side sills 6 in the vehicle width direction at the vehicle rear portion of the front seat S, so that the rear surface is provided. Since the load input to the side sill 6 and the rear side member from the rear of the vehicle due to a collision or the like can be supported by the closed space structure portion of the tunnel section 20 via the rear seat cross member 9, even in this case, the cabin deformation is suppressed. Can be.
[0034]
FIGS. 6 to 9 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 redundant description will be omitted. FIG. 6 shows a floor inside a cabin. FIG. 7 is a perspective view showing a molding process of the floor panel, FIG. 8 is a side view showing a main part of the floor panel, and FIG. 9A is an enlarged view taken along line CC in FIG. FIG. 9B is an enlarged sectional view taken along line DD in FIG.
[0035]
In the vehicle body lower part structure of the second embodiment, as shown in FIG. 6, the tunnel portion 20 and the side sill 6 are connected by an extended portion 13 as a vehicle width direction reinforcing member integrally projecting from the upper panel 11. It is.
[0036]
The extending portion 13 is disposed at right angles to the extending direction of the tunnel portion 20 (vehicle longitudinal direction), and connects the outer end of the extending portion 13 in the vehicle width direction to the base 7a of the front pillar 7. And is arranged at the front end of the floor panel 10 in the vehicle.
[0037]
By arranging the extended portion 13 at the vehicle front end of the floor panel 10 in this way, as shown in FIG. 8, the extended portion 13 also serves as a mounting portion for the subframe 14 on which the power unit P is mounted and supported. ing.
[0038]
That is, the sub-frame 14 is disposed below the front compartment 2, the front end of the sub-frame 14 is connected to the lower front end of the front side member 3, and the rear end is connected to the extended portion 13. It is connected to the lower part.
[0039]
By the way, in the second embodiment, as shown in FIG. 7A, the lower panel 12 is formed by joining a plurality of panels, for example, three panels, so that the plate thickness of the tunnel forming part 25 is the largest. is there.
[0040]
That is, the lower panel 12 is formed such that the center panel 12d is the area of the tunnel forming portion 25 and the panels 12c are integrally joined to both sides thereof by a continuous welding method such as laser welding, and thereafter, as shown in FIG. The tunnel forming portion 25 is press-molded to form the upper surface 12a and both vertical wall surfaces 12b, and the upper panel 11 which has also been press-molded thereon is put thereon, as shown in FIGS. 9 (a) and 9 (b). A closed cross-sectional space of the character-shaped closed space 23 and the rectangular closed space 24 is formed and joined.
[0041]
By the way, as shown in FIG. 7 (b), the extending portion 13 has an appropriate distance δ between the lower end portions of both side wall portions 22 of the upper panel 12 and the lower panel 12 as shown in FIG. 9 (a). And a flange 13 a having a front edge bent upward is connected to the dash panel 5, and a flange 13 b having a rear edge bent downward is connected to the lower panel 12. .
[0042]
Therefore, in the lower body structure of the second embodiment, since the tunnel portion 20 and the side sill 6 are connected by the extension portion 13, the tunnel portion 20 and the side sill 6 are connected via the extension portion 13. Since the load can be transmitted and dispersed in the vehicle, the efficiency of dispersing the load input at the time of collision is improved, and local stress concentration can be suppressed. Therefore, the thickness of the floor panel 10 and each member can be reduced to reduce the thickness of the vehicle body. Lightening can be achieved.
[0043]
Further, since the extending portion 13 is arranged at right angles to the extending direction of the tunnel portion 20, the length of the extending portion 13 is minimized, which contributes to the weight reduction of the vehicle body, and particularly, the input from the side. In contrast, since the extended portion 13 functions as a shaft member, the efficiency of supporting a load input from the side is improved.
[0044]
Furthermore, since the extending portion 13 is connected to the base of the front pillar 7 and is disposed at the front end of the vehicle on the floor panel 10, interference between the tire and the front pillar 7 or the front wheelwheel housing due to the tire retreating at the time of a frontal collision is caused. The input load is supported by the extending portion 13, and the input load is dispersed to the tunnel portion 20 via the extending portion 13, so that local deformation in front of the cabin can be suppressed.
[0045]
Furthermore, since the extending portion 13 is integrally protruded from the upper panel 11, the number of parts can be reduced, the vehicle body assemblability can be improved, and the vehicle productivity can be improved.
[0046]
Further, since the extending portion 13 also serves as a mounting portion of the sub-frame 14, an input acting on the sub-frame 14 at the time of a frontal collision can be transmitted to the tunnel portion 20 and the side sill 6 via the extending portion 13, so that the efficiency is improved more efficiently. The input load from the front of the vehicle can be supported and dispersed.
[0047]
Further, since the lower panel 12 is formed by joining a plurality of panels so that the thickness of the tunnel molding portion 25 is the largest, the lower panel 12 can be easily and rationally formed without any special reinforcing member. The strength of the closed space structural parts such as the U-shaped closed space portion 23 and the rectangular closed space portion 24 formed in the above can be improved, thereby suppressing weight investment and improving productivity.
[0048]
10 and 11 show a third embodiment of the present invention, in which the same components as those in the first and second embodiments are denoted by the same reference numerals, and redundant description will be omitted. FIG. 11 is a perspective view showing an internal floor panel structure, and FIG. 11 is a side view showing a main part of the floor panel.
[0049]
In the lower body structure of the third embodiment, as shown in FIGS. 10 and 11, similarly to the second embodiment, an extended portion 13 connecting the tunnel portion 20 and the side sill 6 is integrally protruded from the upper panel 11. The third embodiment is particularly different from the second embodiment in that the extending portion 13 is arranged to be inclined with respect to the extending direction of the tunnel portion 20 (vehicle longitudinal direction). The upper panel 11 has its upper surface 11a formed flat from the U-shaped closed space 23 to the rectangular closed space 24.
[0050]
In the third embodiment, the direction of inclination of the extending portion 13 is inclined forward of the vehicle from the tunnel portion 20 toward the center pillar 7 as shown in FIG.
[0051]
Therefore, in the vehicle body lower structure according to the third embodiment, the dispersing efficiency of the load input at the time of the collision can be improved by the inclined portion 13 as in the second embodiment, as well as the extension portion 13. Can be applied to the extended portion 13 as an input load in the tension or compression direction with respect to the input from the front and rear direction and from the side, so that the directivity in the collision direction can be expanded.
[0052]
In addition, since there is no upper protruding portion at the center in the front-rear direction of the upper panel 11, the cabin space is not narrowed.
[0053]
In addition, the inclination direction of the extension portion 13 may be inclined rearward of the vehicle from the tunnel portion 20 side toward the center pillar 7 opposite to this embodiment.
[0054]
12 to 15 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. FIG. 13 is an enlarged sectional view taken along line EE in FIG. 12, FIG. 14 is an enlarged perspective view of an internal reinforcing member connected to a rectangular closed space, and FIG. It is an exploded perspective view showing a state.
[0055]
In the lower body structure of the fourth embodiment, front seats S are installed on both sides in the vehicle width direction of the rectangular closed space portion 24 of the tunnel portion 20 as shown in FIG. In the fourth embodiment, as shown in FIG. 13, a box-shaped internal reinforcing member 15 connected to the upper surface 12a of the lower panel 12 is provided in the rectangular closed space portion 24, and the internal reinforcing member 15 The front seats S installed on both sides in the vehicle width direction are connected.
[0056]
As shown in FIG. 14, the internal reinforcing member 15 is formed by bending a flat plate into a trapezoidal shape protruding upward in the vehicle front-rear direction and closing both ends in the vehicle width direction with end plates 15a. Flanges 15b provided at both ends in the direction are bolted to the upper side of the upper surface 12a of the lower panel 12, as shown in FIG.
[0057]
A bolt insertion hole 15c is formed in the end plate 15a, and a weld nut 15d is provided on the back surface thereof.
[0058]
As shown in FIG. 15, two internal reinforcing members 15 are provided on both front and rear sides of the portion where the front seat S is disposed, and the outside of the internal reinforcing members 15 is covered with the upper panel 11. As shown in FIG. 13, the internal reinforcing member 15 is housed in the rectangular closed space portion 24 while being bolted to the upper surface 12 a of the lower panel 12.
[0059]
As shown in FIG. 13, bolts 17 are connected to weld nuts 15d of the two internal reinforcing members 15 on both vertical wall portions 22 of the tunnel portion 20 from outside the upper panel 11 in the vehicle front-rear direction as shown in FIG. The left and right front seats S, that is, a passenger seat and a driver seat are connected to the rail 16.
[0060]
Therefore, in the lower body structure of the fourth embodiment, the left and right front seats S are connected to each other through the internal reinforcing member 15, so that the left and right front seats S and the internal reinforcing member 15 are connected to each other. It functions as a frame member or a load transmission path in the width direction, and can increase the strength of the cabin against an input load at the time of a side collision.
[0061]
Further, since the front seat S is coupled to the upper surface 12a of the lower panel 12 via the internal reinforcing member 15 in the rectangular closed space 24, the front seat S and the front seat occupant M seated thereon at the time of a frontal collision. The acting inertial force can be supported by the upper surface 12a of the lower panel 12 in which the rigidity of the rectangular closed space portion 24 is increased, and high supporting efficiency in the rectangular closed space portion 24 can be exhibited particularly at the time of high-speed collision. .
[0062]
By the way, the lower body structure of the present invention has been described by taking the first to fourth 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. Can be.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a vehicle to which the present invention is applied.
FIG. 2 is a perspective view showing a floor panel structure inside the cabin according to the first embodiment of the present invention.
FIG. 3 is a side view showing a main part of the floor panel according to the first embodiment of the present invention.
4A is an enlarged sectional view taken along line AA in FIG. 3, and FIG. 4B is an enlarged sectional view taken along line BB in FIG.
FIG. 5 is an exploded perspective view of the floor panel according to the first embodiment of the present invention.
FIG. 6 is a perspective view showing a floor panel structure inside a cabin according to a second embodiment of the present invention.
FIGS. 7A and 7B are perspective views showing a molding process of a floor panel according to a second embodiment of the present invention, using FIGS.
FIG. 8 is a side view showing a main part of a floor panel according to a second embodiment of the present invention.
9A is an enlarged sectional view taken along line CC in FIG. 8, and FIG. 9B is an enlarged sectional view taken along line DD in FIG.
FIG. 10 is a perspective view showing a floor panel structure inside a cabin according to a third embodiment of the present invention.
FIG. 11 is a side view showing a main part of a floor panel according to a third embodiment of the present invention.
FIG. 12 is a side view showing a main part of a floor panel according to a fourth embodiment of the present invention.
FIG. 13 is an enlarged sectional view taken along line EE in FIG. 12;
FIG. 14 is an enlarged perspective view of an internal reinforcing member coupled to a rectangular closed space according to a fourth embodiment of the present invention.
FIG. 15 is an exploded perspective view showing an attached state of an internal reinforcing member according to a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle 3 Front side member 6 Side sill 7 Front pillar 8 Dash cross member 9 Rear seat cross member 10 Floor panel 11 Upper panel 11a Upper panel upper surface 12 Lower panel 12a Lower panel upper surface 12b Lower panel vertical wall surface 13 Extension part (car) Width direction reinforcing member)
14 Sub Frame 15 Internal Reinforcement Member 20 Tunnel 21 Ceiling 22 Vertical Wall 23 U-Shaped Closed Space 24 Rectangular Closed Space 25 Tunnel Forming Part S Front Seat (Passenger Seat)

Claims

In a vehicle body lower structure in which a tunnel portion extending in a vehicle front-rear direction is formed at a center portion of a floor panel in a vehicle width direction,
A tunnel portion is formed by joining at least two panels of an upper panel and a lower panel to each other, and an upper panel is provided at a portion corresponding to a ceiling portion and both vertical wall portions of the tunnel portion in a vehicle forward region of the tunnel portion. A U-shaped closed space having an inverted U-shaped cross section is formed between the lower panel and the lower panel, and a portion corresponding to the ceiling of the tunnel is provided between the upper panel and the lower panel in the vehicle rear area of the tunnel. A rectangular closed space portion having a rectangular cross section is provided on the lower panel, and the height positions of the upper surfaces of the lower panels from the U-shaped closed space portion to the rectangular closed space portion substantially match, and the U-shaped closed space portion has a rectangular shape. A lower body structure in which both vertical wall surfaces of the lower panel are continuously changed in shape while being widened into a closed space.

The vehicle body lower part structure according to claim 1, wherein an occupant seat is provided on both sides in a vehicle width direction of the rectangular closed space portion of the tunnel portion.

The lower body structure according to claim 1 or 2, wherein the upper panel and the lower panel each having the tunnel portion are formed continuously in the vehicle longitudinal direction.

The vehicle body lower structure according to any one of claims 1 to 3, wherein the upper panel has a rectangular closed space part whose upper surface protrudes above the U-shaped closed space part.

The vehicle according to any one of claims 1 to 4, wherein the tunnel portion and a side sill extending in the vehicle front-rear direction at both end portions in the vehicle width direction of the floor panel are connected by a vehicle width direction reinforcing member. Lower body structure.

The vehicle body lower structure according to claim 5, wherein the vehicle width direction reinforcing member is disposed at right angles to an extending direction of the tunnel portion.

The vehicle body lower structure according to claim 5, wherein the vehicle width direction reinforcing member is disposed so as to be inclined with respect to a direction in which the tunnel portion extends.

The vehicle body lower structure according to any one of claims 5 to 7, wherein the vehicle width direction reinforcing member is an extended portion integrally protruded from the upper panel.

The vehicle width direction reinforcing member has a vehicle width direction outer end connected to a base of a front pillar and arranged at a vehicle front end of a floor panel. Lower body structure.

The vehicle body lower part structure according to claim 9, wherein the vehicle width direction reinforcing member also serves as a mounting part of a subframe disposed below the front compartment.

The lower body structure according to any one of claims 1 to 10, wherein the lower panel is formed by joining a plurality of panels so that the thickness of the tunnel forming portion is the largest.

The height position of the ceiling equivalent portion of the U-shaped closed space is set to substantially the same position as the vehicle rear end that abuts against the dash panel of the front side member, and the ceiling equivalent of the U-shaped closed space is set. The vehicle body lower structure according to any one of claims 1 to 11, wherein the vehicle front end portion is connected to a dash cross member.

13. The rear seat cross member which is connected to the left and right side sills in the vehicle width direction at the vehicle rear part of the occupant seat at the vehicle rear end of the closed space structure of the tunnel portion. The underbody structure of one of the above.

A box-shaped internal reinforcing member connected to the upper surface of the lower panel is provided in the rectangular closed space, and passenger seats installed on both sides of the tunnel in the vehicle width direction are connected to the internal reinforcing member. Item 14. The vehicle body lower structure according to any one of Items 2 to 13.