JP3627604B2

JP3627604B2 - Front body structure of the vehicle

Info

Publication number: JP3627604B2
Application number: JP36068299A
Authority: JP
Inventors: 栄寺田; 雅規小川; 英治藤田; 隆行中前; 淳一柏田; 絵美幾野
Original assignee: Mazda Motor Corp
Current assignee: Mazda Motor Corp
Priority date: 1999-12-20
Filing date: 1999-12-20
Publication date: 2005-03-09
Anticipated expiration: 2019-12-20
Also published as: JP2001171448A

Description

【０００１】
【発明の属する技術分野】
本発明は、車両と障害物との衝突時において、障害物の衝撃を少なくするようにした車両の前部車体構造に関する。
【０００２】
【従来の技術】
車両の前部車体構造には、軽衝突時の衝撃吸収特性の改善と軽量化を図るべく、特開平１１−１１４９号公報に示すように、バンパとして、バンパフェースとバンパレインフォースメントとの間に、衝撃吸収材としての発泡材を配設するものや、特開平６−７２２８４号公報に示すように、障害物を保護すべく、フロントバンパにエアバッグを格納する一方、車両前方障害物を検知する車両前方障害物検知手段と車両の走行状態を検知する車両走行状態検知手段とを設け、この車両前方障害物検知手段と車両走行状態検出手段との両出力に基づいて車両と障害物との衝突を予測し、この衝突予測時にフロントバンパ内のエアバッグを車両進行方向に展開し、障害物と車両との直接接触を防止するものが提案されている。
【０００３】
【発明が解決しようとする課題】
しかし、前者に係る前部車体構造においては、障害物の衝撃を少なくする観点から十分ではなく、車両と障害物とが衝突すると、障害物は、その衝突により衝撃を受けるだけでなく、その後の二次衝撃を受けるおそれがある。
また後者に係る前部車体構造においては、障害物の衝撃を少なくすることができる利点があるものの、検知手段（センサ類）及びエアバッグが特別に必要となるばかりか、その構造が複雑となり、誤動作のおそれもある。
【０００４】
本発明は上記実情に鑑みてなされたもので、その技術的課題は、障害物の衝撃を少なくすることができると共に、構造が簡単で且つ誤動作のない車両の前部車体構造を提供することにある。
【０００５】
【課題を解決するための手段】
上記技術的課題を達成するために本発明（請求項１の発明）にあっては、
左右一対のフロントサイドフレーム上方に、ボンネットが車体前後方向に延びるようにして配設され、該ボンネットの前部下方にバンパを備えた車両の前部車体構造において、
前記バンパの主要強度部材の前面側に、衝突エネルギを吸収する第１のエネルギ吸収部材が取付けられ、
前記フロントサイドフレームに、前記バンパの主要強度部材の下方側において、突出部材が設けられ、
前記突出部材の前部に、該突出部材よりも小さい荷重をもって衝突エネルギを吸収する第２のエネルギ吸収部材が前記バンパの主要強度部材よりも前方に突出されるようにして設けられ、
前記第２のエネルギ吸収部材が、潰れ量当たりの動的潰れ荷重の立ち上がり勾配に関し、前記第１のエネルギ吸収部材よりも大きくされて、該第２のエネルギ吸収部材の硬さが該第１のエネルギ吸収部材の硬さに比べて相対的に硬くされている構成としてある。この請求項１の好ましい態様としては請求項２以下の記載の通りとなる。
【０００６】
【発明の効果】
請求項１の発明によれば、フロントサイドフレームに、バンパの主要強度部材の下方側において、突出部材が設けられ、その突出部材の前部に、該突出部材よりも小さい荷重をもって衝突エネルギを吸収する第２のエネルギ吸収部材がバンパの主要強度部材よりも前方に突出されるようにして設けられていることから、車両と障害物との衝突時に、バンパの主要強度部材に当接するに先立って、突出部材前部に設けられる第２のエネルギ吸収部材が、障害物の下部を払い、障害物を確実に衝撃の少ないボンネットに乗せることができることになる。
しかもこの場合、突出部材前部に設けられる第２のエネルギ吸収部材を用いて、障害物の下部を払うという極めて簡単な物理的作用を利用することから、構造を簡単にできると共に、センサ類等の特別の部品を用意することをなくして誤動作が発生する余地をなくすことができることになる。
さらに、障害物の下部を払う際、突出部材前部に設けられる第２のエネルギ吸収部材が用いられることから、障害物に作用する衝撃を少なくすることができることになる。
請求項２の発明によれば、突出部材が、一対のフロントサイドフレームにバンパの主要強度部材の下方側においてそれぞれ設けられる第１支持部材と、該両第１支持部材の前部に跨るようにして設けられ車幅方向略全長に亘って延びる第２支持部材とを備え、第２支持部材の前部に第２のエネルギ吸収部材が設けられていることから、具体的構造をもって前記請求項１と同様の作用効果を得ることができることになる。
【０００７】
請求項３の発明によれば、第２のエネルギ吸収部材が、少なくともリブが第２支持部材から前方に向けて起立しつつ車幅方向に間隔をあけて配列されるリブ構造により形成されていることから、各リブの座屈等を利用して、エネルギ吸収部材として、的確に衝突エネルギを吸収できることになる。
請求項４の発明によれば、第２のエネルギ吸収部材が樹脂をもって形成されていることから、樹脂の性質を利用して衝突エネルギを的確に吸収できるだけでなく、第２のエネルギ吸収部材が衝突エネルギを吸収するために複雑なリブ構造になる場合を含め該第２のエネルギ吸収部材を簡単に得る（成形する）ことができることになる。
【０００８】
請求項５の発明によれば、リブ構造は、変形するために要求される荷重としての要求変形荷重に関し、車幅方向において前記第１支持部材から離れるほど、前記リブの基端部が該リブの先端部に比べて大きくなるように設定されていることから、衝突時に、第１支持部材を支点として、第２支持部材が第１支持部材から離れるほど大きく撓み易くなるとしても、その撓みに相当する分が、リブの基端部における要求変形荷重が該リブの先端部における要求変形荷重に比べて大きいことに基づき、調整されることになり、衝突エネルギ吸収性能を、最適な状態をもって車幅方向全体に亘って略等しくすることができることになる。
請求項６の発明によれば、リブ構造は、車幅方向において両第１支持部材間中央部ほど、リブの基端部における要求変形荷重が該リブの先端部における要求変形荷重に比べて大きくなるように設定されていることから、最も撓み易い両第１支持部材間中央部において、リブの基端部における要求変形荷重が該リブの先端部における要求変形荷重に比べて大きいことに基づき、衝突時のエネルギ吸収特性の調整を図り、衝突エネルギ吸収性能を、最適な状態をもって車幅方向全体に亘って略等しくすることができることになる。
【０００９】
請求項７の発明によれば、リブの基端部における要求変形荷重が該リブの先端部における要求変形荷重に比べて大きいことが、該リブの基端部が二股状に分かれていることであることから、具体的に、リブ基端部の要求変形荷重を高めて、第２支持部材における撓み易い個所での衝突エネルギ吸収性能の調整を図り、衝突エネルギ吸収性能を、最適な状態をもって車幅方向全体に亘って略等しくすることができることになる。
請求項８の発明によれば、リブの基端部における要求変形荷重が該リブの先端部における要求変形荷重に比べて大きいことが、車体後方に向かうに従って車幅方向に厚くなることであることから、具体的に、リブ基端部の要求変形荷重を高めて、第２支持部材における撓み易い個所での衝突エネルギ吸収性能の調整を図り、衝突エネルギ吸収性能を、最適な状態をもって車幅方向全体に亘って略等しくすることができることになる。
【００１０】
請求項９の発明によれば、リブ構造は、リブの起立長さが車幅方向において第１支持部材に近いほど長くされていることから、第１支持部材に近い個所ほど剛性が高く変形しにくいけれども、リブの起立長さの増長に基づき衝突エネルギ吸収量を増やして、第１支持部材に近い個所での衝突エネルギ吸収性能の補正を図ることができ、衝突エネルギ吸収性能を、最適な状態をもって車幅方向全体に亘って略等しくすることができることになる。
請求項１０の発明によれば、第２支持部材が、車幅方向外方に向かうに従って車体後方に向かうように湾曲され、各リブが、第２支持部材の前面に対して略垂直に起立されていることから、第２支持部材が上記のように湾曲されたものであっても、リブの起立（取付け）強度を高めて、衝突時に、その衝突点を中心にして、各リブが車幅方向外側に向けて撓むようにしつつ座屈させることができることになり、衝突エネルギを効果的に吸収できることになる。
【００１１】
請求項１１の発明によれば、第１支持部材が中空構造とされると共に、該第１支持部材の前部が該第１支持部材の後部よりも縮径されていることから、衝突時に、第１支持部材を車体後方に向けて潰して、衝突エネルギを吸収できることになり、剛性が高い傾向にある第１支持部材に近い個所において、衝突エネルギ吸収性能の補正を図って、衝突エネルギ吸収性能を、最適な状態をもって車幅方向全体に亘って略等しくすることができることになる。
請求項１２の発明によれば、第１支持部材が、該第１支持部材の後部と該第１支持部材の前部との間に同心状の段差を有するように形成されていることから、具体的構造をもって、上記請求項１１と同様の作用効果を得ることができることになる。
【００１２】
請求項１３の発明によれば、第１支持部材が、該第１支持部材の後部側から該第１支持部材の前部側に向けて徐々に縮径されるように形成されていることから、具体的構造をもって、上記請求項１１と同様の作用効果を得ることができることになる。
請求項１４の発明によれば、バンパの主要強度部材がバンパレインフォースメントであることから、その場合においても、前記請求項１又は２と同様の作用効果を得ることができることになる。
【００１３】
【発明の実施の形態】
以下、本発明の実施形態について図面に基づいて説明する。
図１において、符号１は、第１実施形態に係る前部車体構造を示すものである。この前部車体構造１においては、左右一対のフロントサイドフレーム２が車体前後方向に延びており、そのフロントサイドフレーム２の上方に、ボンネット３が車体前後方向に延びるようにして配設され、そのボンネット３は、エンジンルーム４の上部を覆っている。このボンネット３は、その前部内面においてボンネットレインフォースメント５を有しており、そのボンネット３の前端下方側にはラジエータグリル６が配設されている。
【００１４】
前記ボンネット３の前部下方である前記ラジエータグリル６の下方には、バンパ７が設けられている。バンパ７は、バンパ主要強度部材としてのバンパレインフォースメント８と、エネルギ吸収部材９（第１のエネルギ吸収部材）と、バンパフェース１０とを備えている。
バンパレインフォースメント８は車幅方向略全体に亘って延びており、そのバンパレインフォースメント８は、前記一対のフロントサイドフレーム２の前端に跨るようにして取付けられている。
エネルギ吸収部材９は、バンパレインフォースメント８の前面に取付けられて車幅方向略全体に亘って延びている。このエネルギ吸収部材９は、本実施形態においては、図２に示すように、荷重（動的潰れ荷重）と変形量（潰れ量）とが比例する特性線となるように設定されている。
バンパフェース１０は、ラジエータグリル６よりも前方に張り出した状態をもって車幅方向略全体に亘って延び、その状態で垂下されている。このバンパフェース１０には、上下方向略中央部において空気導入孔１１が形成されており、その空気導入孔１１を基準として、バンパフェース１０の上下部に、上側フェース部１２と下側フェース部１３とが形成されている。このうち、上側フェース部１２は、上記エネルギ吸収部材９を覆うようにして内部に収納している。
【００１５】
前記各フロントサイドフレーム２には、図１，図３，図４に示すように、前記バンパレインフォースメント８の下方側において突出部材１４が配設されている。突出部材１４は、第１支持部材としてのクラッシュ管１５と、第２支持部材としてのサポート部材１６とを備えている。
クラッシュ管１５は、各フロントサイドフレーム２にブラケット１７を介してそれぞれ支持されており、その各クラッシュ管１５は、フロントサイドフレーム２の下側における同一高さ位置において車体前後方向に延びている。このクラッシュ管１５は、中空構造とされると共に、該クラッシュ管１５の前部１５ａが、同心状に段差１５ｃを形成しつつ該クラッシュ管１５の後部１５ｂよりも縮径されており、各クラッシュ管１５の前部１５ａに一定以上の衝突力が車体後方に向けて伝達されたときには、各クラッシュ管１５の前部１５ａが後部１５ｂ内に入り込んで塑性変形することになっている（図４中、仮想線参照）。
【００１６】
サポート部材１６は、図１，図３〜図７に示すように、上記両クラッシュ管１５の前端に跨るようにして取付けられている。このサポート部材１６は、略水平状態をもって車幅方向略全体に亘って延びており、本実施形態においては、このサポート部材１６は、車幅方向外方に向かうに従って車体後方に向かうようにやや湾曲されている。このサポート部材１６は、鋼板を用いて断面矩形状に形成されており、その前面１６ａは、その車幅方向全長に亘って、前方を向く平坦面とされている。
【００１７】
前記サポート部材１６の前面１６ａには、図１，図３〜図７に示すように、エネルギ吸収部材１８（第２のエネルギ吸収部材）が設けられている。このエネルギ吸収部材１８は、サポート部材１６と略同じ延び長さを有しており、エネルギ吸収部材１８は、サポート部材１６の全長に亘って該サポート部材１６の前面を覆っている。このエネルギ吸収部材１８は、前記サポート部材１６、クラッシュ管１５と共に、歩行者の膝よりも下の部分に相当する高さに位置させつつ、前記バンパレインフォースメント８よりも車体前方側に位置されており、そのエネルギ吸収部材１８は、前記下側フェース部１３に前方から覆われることになっている。これにより、歩行者と車両との衝突に際して、歩行者の膝にバンパレインフォースメント８が上側フェース部１２、エネルギ吸収部材９を介して衝突する前に、歩行者の膝よりも下部にエネルギ吸収部材１８が下側フェース部１３を介して衝突して（図１中、矢印参照）、歩行者の足を払って歩行者をボンネット３に乗せることができることになっている。
【００１８】
このエネルギ吸収部材１８は、その全長に亘って、リブ構造２０が基板部２１と支持板部２２とにより挟持される構造とされており、このような構造のエネルギ吸収部材１８は、樹脂（例えばポリプロピレン、ポリエチレン、ＡＢＳ樹脂等）をもって一体成形されている。
上記基板部２１は、サポート部材１６の前面１６ａに沿わせた状態で取付けるための取付け板部としての機能を有しており、該基板部２１は、サポート部材１６の湾曲した前面１６ａに対応した湾曲面をもって、該サポート部材１６の前面１６ａに留め具２３を介して取付けられている。
【００１９】
上記リブ構造２０は、本実施形態においては、基板部２１と支持板部２２とを跨ぐリブ１９が車幅方向に間隔をあけて配列される構造とされており、このエネルギ吸収部材１８（基板部２１）がサポート部材１６に取付けられると、各リブ１９はサポート部材１６（基板部２１）から車体前方に張り出されることになっている。このリブ構造２０における各リブ１９は、基本的には、図５、図６に示すように、板状のものが用いられているが、両クラッシュ管１５間の中央部位置（車幅方向中央部位置）においては、リブ１９として、図５、図７に示すように、基端部が二股状に分かれたものが用いられている。この構成上の意義については後述する。
【００２０】
このリブ構造２０における全てのリブ１９は、湾曲したサポート部材１６前面に対応して湾曲された基板部２１に対して略垂直状態をもって起立されている。これは、この状態において、基板部２１に対する各リブ１９の取付け強度が最も強くなることに着目し、これを利用して、衝突時に、その衝突点を中心にして、各リブ１９が車幅方向両外側に向けて撓むようにしつつ座屈させ易くし、これによって、衝突エネルギを効果的に吸収できるようにしているのである。
このような座屈特性は、車幅方向中央部におけるリブ１９だけでなく、車幅方向外方側に位置するリブ１９についても同様の効果が得られる。すなわち、車幅方向外方側に位置するリブ１９は、車体前方に向けて真っ直ぐに起立せず、やや斜め外側前方に向けて起立することになるが、この場合にも、リブ１９は、基板部１２に対して垂直状態であるので、この垂直方向の荷重に対して上記と同じ作用が生じることになる。
【００２１】
このリブ構造２０における各リブ１９の間隔は、障害物との衝突により衝突力が、車幅方向のいずれの場所によっても変わらないようにする観点から決められている。本実施形態においては、２０ｍｍ前後とされている。また、各リブ１９の起立長さ（基板部２１から前方への突出長さ）は、本実施形態においては、同一長さとされており、その起立長さも、他部材との関係を考慮しつつ、結果的に最適な状態（特性、エネルギ吸収量等）で衝突エネルギを吸収できるようにするための一要素として設定されている。
【００２２】
上記支持板部２２は、上記リブ構造２０におけるリブ１９の前方への起立長さが一定であることに基づき、上記基板部２１の湾曲面に対して平行関係をもって湾曲されており、サポート部材１６前面に基板部２１が取付けられたときには、支持板部２２は、リブ構造２０の前方に位置することになっている。このため、衝突時には、衝突荷重が支持板部２２を介して各リブ１９に的確に伝達されることになっている。
【００２３】
本実施形態においては、前記エネルギ吸収部材１８、前記サポート部材１６、クラッシュ管１５が有機的に連係させて、障害物と車両との衝突時に、障害物が車両の車幅方向のいずれの個所に衝突しても、できるだけ所望の衝突エネルギ吸収性能が得られるように設定されている。
すなわち、所望の衝突エネルギ吸収性能は、障害物にダメージを与えることなく、障害物の下部を払うのに最適な荷重が作用するようにする観点から定められており、具体的には、図８に示すように、横軸に変形量（潰れ量）、縦軸に荷重（動的潰れ荷重）をとった場合、衝突開始（零）から所定の短い変形量内において、荷重が所定の勾配をもって所定荷重ｃまで立ち上がり、その後、変形量が進んでも、荷重がその所定荷重ｃに維持される特性をもって表すことができる。
【００２４】
このため、本実施形態に係る前部車体構造においては、車幅方向のいずれの個所においても、上記所望の衝突エネルギ吸収性能が得られるようにすべく、基本的には、上記所望の衝突エネルギ吸収特性（荷重特性）に近い特性を示すエネルギ吸収部材１８をサポート部材１６に取付けることによって対処され、両クラッシュ管１５間の中央部位置（車幅方向中央部位置）及びクラッシュ管１５存在位置においては、特有の状況を考慮し、さらに特別な工夫が施されている。
【００２５】
両クラッシュ管１５間の中央部位置においては、前述の如く、リブ１９として、基端部が二股状に分かれたものが用いられて、そのようなリブ１９の先端部側から基端部側への荷重に関し、そのリブ１９の基端部における要求変形荷重が該リブ１９の先端部における要求変形荷重に比べて大きくなるように設定（圧縮強度ないしは剛性大に設定）されている。これは、車両前部１５ａに、両クラッシュ管１５間において衝突荷重が作用した場合、その両クラッシュ管１５の間においてサポート部材１６が撓む傾向にあることから、その撓み易い両クラッシュ管１５の間のサポート部材１６が撓み変形（塑性変形）してその撓み変形に基づき衝突エネルギが吸収されても、上記二股状のリブ１９の構成をもって衝突エネルギ吸収を補正し、そこの個所における衝突エネルギ吸収性能（特性）を、上記所望の衝突エネルギ吸収性能（特性）に近づけようとしているのである。
【００２６】
クラッシュ管１５存在位置においては、クラッシュ管１５が、そのクラッシュ管１５の前部１５ａに車体後方に向けて所定荷重ｃが作用すると、その前部１５ａがクラッシュ管１５後部１５ｂ内に入り込むように塑性変形されるように設定されている。これは、サポート部材１６をクラッシュ管１５ではない支持部材を用いて支持（連結）すると、その部分の剛性が他の部分に比して高いものとならざるを得ないことから、本実施形態においては、支持部材（第１支持部材）としてクラッシュ管１５を用い、そのクラッシュ管１５に車体後方に向けて所定荷重ｃが作用すると、クラッシュ管１５の前部１５ａがその後部１５ｂ内に入り込むように塑性変形させて、クラッシュ管１５の前部１５ａに近い個所におけるリブ１９の衝突エネルギ吸収性能を補完しようとしているのである。
【００２７】
このような構成の内容を裏付ける解析結果（荷重−変位量）を示すのが図９である。この図９において、ｆ１は、車幅方向において両クラッシュ管１５間の中央部位置（車幅方向中央部位置）における荷重特性、ｆ２は、車幅方向においてクラッシュ管１５が存在する位置における荷重特性、ｆ３は、上記両クラッシュ管１５間の中央部位置と上記クラッシュ管１５が存在する位置との間の中間位置における荷重特性を示すものである。
図９に示す解析結果によれば、各特性ｆ１、ｆ２、ｆ３は、略重なりつつ、前記図８における所望の衝突エネルギ吸収特性に近い特性を示し、車両前部１５ａにおける車幅方向のいずれの個所に衝突力が作用しても、好ましい結果が得られることを示した。
【００２８】
したがって、上記前部車体構造においては、車両と障害物との衝突時には、エネルギ吸収部材９、バンパレインフォースメント８に当接するに先立ち、サポート部材１６前面に取付けられるエネルギ吸収部材１８が、障害物下部を払い、障害物を確実に衝撃の少ないボンネット３に乗せることができることになる。
しかもこの場合、サポート部材１６前面に設けられるエネルギ吸収部材１８を用いて、障害物の下部を払うという極めて簡単な物理的作用を利用することから、構造を簡単にできると共に、センサ類等の特別の部品を用意することをなくして誤動作が発生する余地をなくすことができることになる。
また、障害物の下部を払う際、サポート部材１６前面に設けられるエネルギ吸収部材１８が用いられることから、そのサポート部材１６の剛性とエネルギ吸収部材１８の剛性との相互作用を有効に利用して（所望の衝突エネルギ吸収性能に近い吸収性能を実現）、障害物に作用する衝撃を少なく確保しつつ障害物の下部を払って（所定の作用力に調整すること）障害物をボンネット３に乗せことができることになる。
さらに、車幅方向において、クラッシュ管１５間の中央部位置におけるリブ１９として、その基端部が二股に分かれたものが用いられると共に、クラッシュ管１５が所定荷重ｃで潰れるように設定されていることから、クラッシュ管１５間の中央部位置、クラッシュ管１５に近い個所を含め、車両前部１５ａにおける車幅方向のいずれの個所でも、所望の衝突エネルギ吸収性能により近い性能を得る上において好ましいものとなる。
【００２９】
図１０は第２実施形態、図１１，図１２は第３実施形態、図１３は第４実施形態、図１４は第５実施形態を示す。この各実施形態において、前記第１実施形態と同一構成要素については同一符号を付してその説明を省略する。
【００３０】
図１０に示す第２実施形態においては、両クラッシュ管１５間の中央部に配設されるリブ１９が、車体後方に向かうに従って次第に車幅方向に厚くなるように設定されている。これにより、この場合にも、リブ１９の基端部における要求変形荷重が該リブ１９の先端部における要求変形荷重に比べて大きくなることになり、サポート部材１６の撓みを考慮に入れた衝突エネルギの吸収が行われることになる。
【００３１】
図１１，図１２に示す第３実施形態においては、第１支持部材として、後端部側から前端部側に徐々に縮径されるクラッシュ管１５が用いられており、その前端部の周縁部には、車体後方への荷重によって、潰れを促すための強度低下用ビード２４が形成されている。これにより、このクラッシュ管１５も所定荷重ｃが作用すると、車体後方に向けて潰れることになり、これを所望の衝突エネルギ吸収性能（特性）を得るための調整に利用できることになる。
【００３２】
図１３に示す第４実施形態においては、第１，第２支持部材の両機能を備える突出部材１４として、リブ構造２５を内蔵する樹脂構造体が用いられている。この突出部材１４としての樹脂構造体においては、内部リブの肉厚、密度、配列等により容易に荷重特性を設定することができ、エネルギ吸収部材１８と協働して所望の衝突エネルギ吸収特性に近づけることができることになる。
尚、この実施形態においては、樹脂構造体を突出部材１４に用いることを示したが、形状等を適宜変更して、このような樹脂構造体を第１支持部材、或いは第２支持部材として用いてもよい。
【００３３】
図１４に示す第５実施形態においては、クラッシュ管１５として、前部１５ａと後部１５ｂとの段差１５ｃが、前記第１実施形態よりも緩やかにされたものが用いられている。このクラッシュ管１５においても、前記第１実施形態に係るクラッシュ管１５と同様の機能を発揮することになる。
【００３４】
以上実施形態について説明したが本発明においては、クラッシュ管１５に代えて、通常の支持を目的とした支持部材を用い、その支持部材に近い個所におけるリブ１９の前方起立長さを他の個所のリブ１９に比して長くしてもよい。クラッシュ管１５を用いなくても、リブ１９の起立長さの増長に基づき、そのリブ１９により衝突エネルギの吸収量を増やすことができるからである。勿論、このようなリブ１９とクラッシュ管１５とを併用してもよい。
【００３５】
尚、本発明の目的は、明記されたものに限らず、実質的に好ましい或いは利点として載されたものに対応したものを提供することをも含むものである。
【図面の簡単な説明】
【図１】第１実施形態に係る前部車体構造を説明する説明図。
【図２】バンパレインフォースメントに設けられるエネルギ吸収部材の荷重特性を示す特性線図。
【図３】第１実施形態に係るフロントサイドフレーム、クラッシュ管、エネルギ吸収部材等の配設を示す斜視図。
【図４】第１実施形態に係るクラッシュ管の構造、作用を説明する説明図。
【図５】第１実施形態に係るサポート部材に設けられるエネルギ吸収部材のリブ構造を平面的に示す図。
【図６】第１実施形態に係るエネルギ吸収部材において、車幅方向外側にかけて用いられる板状のリブを備えるリブ構造を示す斜視図。
【図７】第１実施形態に係るエネルギ吸収部材において、車幅方向中央部で用いられる基端部二股状のリブを備えるリブ構造を示す斜視図。
【図８】障害物の下部を払うために好ましい所望の衝突エネルギ吸収特性を示す特性線図。
【図９】第１実施形態に係る前部車体構造における荷重特性を示す特性線図。
【図１０】第２実施形態に係るエネルギ吸収部材において、車幅方向中央部で用いられるリブ構造を示す斜視図。
【図１１】第３実施形態において用いられるクラッシュ管を示す斜視図。
【図１２】第３実施形態に係るクラッシュ管を示す縦断面図。
【図１３】第４実施形態に係る突出部材を示す斜視図。
【図１４】第５実施形態に係るクラッシュ管を示す縦断面図。
【符号の説明】
１前部車体構造
２フロントサイドフレーム
３ボンネット
７バンパ
８バンパレインフォースメント
９エネルギ吸収部材（第１のエネルギ吸収部材）
１４突出部材
１５クラッシュ管
１５ａ前部
１５ｂ後部
１５ｃ段差
１６サポート部材
１８エネルギ吸収部材（第２のエネルギ吸収部材）
１９リブ
２０リブ構造[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle front body structure that reduces the impact of an obstacle when the vehicle collides with an obstacle.
[0002]
[Prior art]
As shown in JP-A-11-1149, the front body structure of a vehicle has a bumper face between a bumper face and a bumper reinforcement as shown in Japanese Patent Application Laid-Open No. 11-1149 in order to improve shock absorption characteristics and light weight at the time of a light collision. In addition, as shown in Japanese Patent Laid-Open No. 6-72284, an airbag is stored in the front bumper, while an obstacle in front of the vehicle is disposed, as shown in Japanese Patent Laid-Open No. 6-72284. Vehicle front obstacle detecting means for detecting and vehicle running state detecting means for detecting the running state of the vehicle are provided, and the vehicle and the obstacle are detected based on both outputs of the vehicle front obstacle detecting means and the vehicle running state detecting means. It has been proposed to prevent a direct contact between an obstacle and a vehicle by predicting a collision of the vehicle and deploying an airbag in a front bumper in the vehicle traveling direction at the time of the collision prediction.
[0003]
[Problems to be solved by the invention]
However, in the front body structure according to the former, it is not sufficient from the viewpoint of reducing the impact of the obstacle. When the vehicle and the obstacle collide, the obstacle is not only affected by the collision, but also the subsequent There is a risk of secondary impact.
In addition, in the front body structure according to the latter, there is an advantage that the impact of the obstacle can be reduced, but not only a detection means (sensors) and an airbag are required, but the structure becomes complicated, There is also a risk of malfunction.
[0004]
The present invention has been made in view of the above circumstances, and a technical problem thereof is to provide a front vehicle body structure of a vehicle that can reduce the impact of an obstacle, has a simple structure, and does not malfunction. is there.
[0005]
[Means for Solving the Problems]
In order to achieve the above technical problem, the present invention (invention of claim 1)
In the front vehicle body structure of the vehicle, the bonnet is disposed above the pair of left and right front side frames so as to extend in the longitudinal direction of the vehicle body, and includes a bumper below the front portion of the bonnet.
A first energy absorbing member that absorbs collision energy is attached to the front side of the main strength member of the bumper,
On the lower side of the main strength member of the bumper, a protruding member is provided on the front side frame,
Absorbs collision energy at the front of the protruding member with a smaller load than the protruding member.SecondThe energy absorbing member protrudes forward from the main strength member of the bumper.Provided,
The second energy absorbing member is made larger than the first energy absorbing member with respect to the rising gradient of the dynamic crushing load per crushing amount, and the hardness of the second energy absorbing member is the first energy absorbing member. It is relatively hard compared to the hardness of the energy absorbing memberAs a configuration. The preferred embodiment of claim 1 is as described in claim 2 and the following.
[0006]
【The invention's effect】
According to the first aspect of the present invention, the front side frame is provided with a protruding member on the lower side of the main strength member of the bumper, and the front part of the protruding member absorbs collision energy with a smaller load than the protruding member. DoSecondSince the energy absorbing member is provided so as to protrude forward from the main strength member of the bumper, the front of the protruding member is brought into contact with the main strength member of the bumper at the time of collision between the vehicle and the obstacle. Provided in the departmentSecondThe energy absorbing member can wipe the lower part of the obstacle and reliably place the obstacle on the bonnet with less impact.
Moreover, in this case, it is provided at the front part of the protruding member.SecondUses an extremely simple physical action of removing the lower part of an obstacle using an energy absorbing member, so that the structure can be simplified and a malfunction occurs without preparing special parts such as sensors. It will be possible to eliminate the room to do.
Furthermore, when paying the lower part of the obstacle, it is provided in the front part of the protruding memberSecondSince the energy absorbing member is used, the impact acting on the obstacle can be reduced.
According to the second aspect of the present invention, the projecting member straddles the first support member provided on the pair of front side frames on the lower side of the main strength member of the bumper and the front portions of the first support members. And a second support member extending substantially over the entire length in the vehicle width direction, and at the front of the second support memberSecondSince the energy absorbing member is provided, the same effect as that of the first aspect can be obtained with a specific structure.
[0007]
According to the invention of claim 3,SecondSince the energy absorbing member is formed by a rib structure in which at least the ribs are erected forward from the second support member and arranged at intervals in the vehicle width direction, the buckling of each rib is utilized. Thus, the collision energy can be accurately absorbed as the energy absorbing member.
According to the invention of claim 4,SecondSince the energy absorbing member is made of resin, not only can the impact energy be absorbed accurately using the properties of the resin,SecondIncluding the case where the energy absorbing member has a complicated rib structure to absorb collision energy.SecondThe energy absorbing member can be easily obtained (molded).
[0008]
According to the invention of claim 5, the rib structure isRegarding the required deformation load as the load required to deform,The further away from the first support member in the vehicle width direction,The base end of the rib is at the tip of the ribSince it is set so as to be larger than the first support member at the time of a collision, even if the second support member is more easily bent as it is separated from the first support member, the amount corresponding to the bending is less. , The required deformation load at the base end of the rib is larger than the required deformation load at the distal end of the rib, and the collision energy absorption performance is optimized over the entire vehicle width direction. It can be made substantially equal throughout.
According to the invention of claim 6, in the rib structure, the required deformation load at the proximal end portion of the rib is larger than the required deformation load at the distal end portion of the rib at the central portion between both first support members in the vehicle width direction. Based on the fact that the required deformation load at the proximal end portion of the rib is larger than the required deformation load at the distal end portion of the rib at the center portion between both first support members that is most likely to be bent. Adjustment of the energy absorption characteristic at the time of collision can be achieved, and the collision energy absorption performance can be made substantially equal over the entire vehicle width direction in an optimum state.
[0009]
According to the seventh aspect of the invention, the required deformation load at the proximal end of the rib is larger than the required deformation load at the distal end of the rib because the proximal end of the rib is divided into two forks. Therefore, specifically, the required deformation load of the rib base end portion is increased to adjust the collision energy absorption performance at a position where the second support member is easily bent, and the collision energy absorption performance is adjusted to an optimal state. It can be made substantially equal over the entire width direction.
According to the eighth aspect of the present invention, the required deformation load at the base end portion of the rib is larger than the required deformation load at the tip end portion of the rib, which is to increase in thickness in the vehicle width direction toward the rear of the vehicle body. Specifically, the required deformation load at the rib base end portion is increased to adjust the collision energy absorption performance at the portion where the second support member is easily bent, and the collision energy absorption performance is optimized in the vehicle width direction. It can be made substantially equal throughout.
[0010]
According to the ninth aspect of the present invention, the rib structure has a longer standing length of the rib as it is closer to the first support member in the vehicle width direction. Therefore, the portion closer to the first support member is more rigid and deformed. Although it is difficult, the collision energy absorption amount can be increased based on the increase in the standing length of the rib to correct the collision energy absorption performance near the first support member. Therefore, it can be made substantially equal over the entire vehicle width direction.
According to the invention of claim 10, the second support member is curved so as to go to the rear of the vehicle body as going outward in the vehicle width direction, and each rib is erected substantially perpendicular to the front surface of the second support member. Therefore, even if the second support member is curved as described above, the rib standing height (attachment) strength is increased, and at the time of a collision, each rib has a vehicle width around the collision point. It will be possible to buckle while bending toward the outside in the direction, and collision energy can be absorbed effectively.
[0011]
According to the invention of claim 11, the first support member has a hollow structure, and the front part of the first support member is smaller in diameter than the rear part of the first support member. By collapsing the first support member toward the rear of the vehicle body and absorbing the collision energy, the collision energy absorption performance is corrected by correcting the collision energy absorption performance at a location close to the first support member that tends to have high rigidity. Can be made substantially equal over the entire vehicle width direction in an optimal state.
According to the invention of claim 12, the first support member is formed so as to have a concentric step between the rear portion of the first support member and the front portion of the first support member. With the specific structure, the same effect as that of the above-mentioned claim 11 can be obtained.
[0012]
According to the invention of claim 13, the first support member is formed so as to be gradually reduced in diameter from the rear side of the first support member toward the front side of the first support member. With the specific structure, the same effect as that of the above-mentioned claim 11 can be obtained.
According to the invention of claim 14, since the main strength member of the bumper is a bumper reinforcement, even in that case, the same effect as that of the invention of claim 1 or 2 can be obtained.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, the code | symbol 1 shows the front part vehicle body structure which concerns on 1st Embodiment. In the front body structure 1, a pair of left and right front side frames 2 extend in the longitudinal direction of the vehicle body, and a bonnet 3 is disposed above the front side frame 2 so as to extend in the longitudinal direction of the vehicle body. The bonnet 3 covers the upper part of the engine room 4. The bonnet 3 has a bonnet reinforcement 5 on the inner surface of the front portion thereof, and a radiator grill 6 is disposed below the front end of the bonnet 3.
[0014]
A bumper 7 is provided below the radiator grill 6 below the front of the bonnet 3. The bumper 7 includes a bumper reinforcement 8 as a bumper main strength member, and an energy absorbing member 9.(First energy absorbing member)And a bumper face 10.
The bumper reinforcement 8 extends substantially over the entire vehicle width direction, and the bumper reinforcement 8 is attached so as to straddle the front ends of the pair of front side frames 2.
The energy absorbing member 9 is attached to the front surface of the bumper reinforcement 8 and extends over substantially the entire vehicle width direction. In this embodiment, the energy absorbing member 9 is set so as to have a characteristic line in which a load (dynamic crushing load) and a deformation amount (crushing amount) are proportional to each other, as shown in FIG.
The bumper face 10 extends over substantially the entire vehicle width direction with a state protruding forward from the radiator grill 6 and is suspended in that state. An air introduction hole 11 is formed in the bumper face 10 at a substantially central portion in the vertical direction. The upper face portion 12 and the lower face portion 13 are formed at the upper and lower portions of the bumper face 10 with the air introduction hole 11 as a reference. And are formed. Among these, the upper face portion 12 is housed inside so as to cover the energy absorbing member 9.
[0015]
As shown in FIGS. 1, 3, and 4, each front side frame 2 is provided with a protruding member 14 on the lower side of the bumper reinforcement 8. The protruding member 14 includes a crush tube 15 as a first support member and a support member 16 as a second support member.
The crash pipes 15 are respectively supported by the front side frames 2 via brackets 17, and the crash pipes 15 extend in the longitudinal direction of the vehicle body at the same height position on the lower side of the front side frames 2. The crush tube 15 has a hollow structure, and the front portion 15a of the crush tube 15 is concentrically formed with a step 15c and is reduced in diameter than the rear portion 15b of the crush tube 15. When a collision force of a certain level or more is transmitted to the front portion 15a of the vehicle 15 toward the rear of the vehicle body, the front portion 15a of each crash tube 15 enters the rear portion 15b and is plastically deformed (in FIG. 4, Virtual line reference).
[0016]
As shown in FIGS. 1 and 3 to 7, the support member 16 is attached so as to straddle the front ends of the two crash pipes 15. The support member 16 extends substantially over the entire vehicle width direction in a substantially horizontal state. In the present embodiment, the support member 16 is slightly curved toward the rear of the vehicle body as it goes outward in the vehicle width direction. Has been. The support member 16 is formed in a rectangular cross section using a steel plate, and the front surface 16a is a flat surface facing the front over the entire length in the vehicle width direction.
[0017]
As shown in FIGS. 1 and 3 to 7, an energy absorbing member 18 is provided on the front surface 16 a of the support member 16.(Second energy absorbing member)Is provided. The energy absorbing member 18 has substantially the same length as the support member 16, and the energy absorbing member 18 covers the front surface of the support member 16 over the entire length of the support member 16. The energy absorbing member 18, together with the support member 16 and the crash tube 15, is positioned at a height corresponding to a portion below the knee of the pedestrian, and is positioned on the front side of the vehicle body relative to the bumper reinforcement 8. The energy absorbing member 18 is covered with the lower face portion 13 from the front. Thus, when the pedestrian collides with the vehicle, before the bumper reinforcement 8 collides with the pedestrian's knee via the upper face portion 12 and the energy absorbing member 9, energy is absorbed below the pedestrian's knee. The member 18 collides via the lower face portion 13 (see the arrow in FIG. 1), and the pedestrian can be put on the hood 3 by paying the pedestrian's foot.
[0018]
The energy absorbing member 18 has a structure in which the rib structure 20 is sandwiched between the substrate portion 21 and the support plate portion 22 over the entire length thereof. The energy absorbing member 18 having such a structure is made of resin (for example, Polypropylene, polyethylene, ABS resin, etc.).
The substrate portion 21 has a function as a mounting plate portion for mounting in a state along the front surface 16 a of the support member 16, and the substrate portion 21 corresponds to the curved front surface 16 a of the support member 16. A curved surface is attached to the front surface 16 a of the support member 16 via a fastener 23.
[0019]
In the present embodiment, the rib structure 20 has a structure in which ribs 19 straddling the substrate portion 21 and the support plate portion 22 are arranged at intervals in the vehicle width direction. The energy absorbing member 18 (substrate When the portion 21) is attached to the support member 16, the ribs 19 are projected from the support member 16 (substrate portion 21) to the front of the vehicle body. As shown in FIGS. 5 and 6, each rib 19 in the rib structure 20 is basically a plate-like one. However, the center position between the crash pipes 15 (the center in the vehicle width direction) is used. As shown in FIGS. 5 and 7, a rib 19 having a base end portion divided into two forks is used. The significance of this configuration will be described later.
[0020]
All the ribs 19 in the rib structure 20 are erected in a substantially vertical state with respect to the curved substrate portion 21 corresponding to the front surface of the curved support member 16. In this state, attention is paid to the fact that the mounting strength of each rib 19 with respect to the base plate portion 21 is the strongest. Using this, each rib 19 is centered on the collision point in the vehicle width direction at the time of collision. It is easy to buckle while being bent toward both outer sides, so that collision energy can be effectively absorbed.
Such a buckling characteristic has the same effect not only on the rib 19 at the center in the vehicle width direction but also on the rib 19 located on the outer side in the vehicle width direction. That is, the rib 19 positioned on the outer side in the vehicle width direction does not stand straight toward the front of the vehicle body, but rises slightly diagonally forward and forward. Since it is in a state perpendicular to the portion 12, the same action as described above occurs with respect to the load in the vertical direction.
[0021]
The interval between the ribs 19 in the rib structure 20 is determined from the viewpoint of preventing the collision force from changing in any position in the vehicle width direction due to the collision with the obstacle. In this embodiment, it is about 20 mm. In addition, the standing length of each rib 19 (the length protruding forward from the substrate portion 21) is the same length in the present embodiment, and the standing length also takes into account the relationship with other members. As a result, it is set as one element for enabling collision energy to be absorbed in an optimal state (characteristics, energy absorption amount, etc.).
[0022]
The support plate portion 22 is curved in a parallel relationship with the curved surface of the substrate portion 21 based on the fact that the standing length of the rib 19 in the rib structure 20 in the forward direction is constant, and the support member 16. When the substrate portion 21 is attached to the front surface, the support plate portion 22 is positioned in front of the rib structure 20. For this reason, at the time of a collision, the collision load is accurately transmitted to each rib 19 via the support plate portion 22.
[0023]
In the present embodiment, the energy absorbing member 18, the support member 16, and the crash tube 15 are organically linked so that the obstacle is located at any position in the vehicle width direction of the vehicle when the obstacle collides with the vehicle. Even if a collision occurs, the desired collision energy absorption performance is set as much as possible.
In other words, the desired collision energy absorption performance is determined from the viewpoint of applying an optimum load to pay the lower part of the obstacle without damaging the obstacle. Specifically, FIG. As shown in Fig. 2, when the deformation amount (collapse amount) is taken on the horizontal axis and the load (dynamic crush load) is taken on the vertical axis, the load has a predetermined gradient within a predetermined short deformation amount from the start of collision (zero). Even if the amount of deformation rises up to a predetermined load c and then the deformation amount advances, the load can be expressed with a characteristic that is maintained at the predetermined load c.
[0024]
Therefore, in the front vehicle body structure according to the present embodiment, basically, the desired collision energy is obtained so that the desired collision energy absorption performance can be obtained at any location in the vehicle width direction. It is dealt with by attaching to the support member 16 an energy absorbing member 18 exhibiting characteristics close to absorption characteristics (load characteristics), and at the center position between the crash pipes 15 (the center position in the vehicle width direction) and the position where the crash pipe 15 exists. Has been devised in consideration of the specific situation.
[0025]
As described above, a rib 19 having a base end divided into two forks is used as the rib 19 at the central position between the two crash pipes 15. From the tip end side of the rib 19 to the base end side, as described above. Is set so that the required deformation load at the base end portion of the rib 19 is larger than the required deformation load at the distal end portion of the rib 19 (set to compressive strength or high rigidity). This is because the support member 16 tends to bend between the two crash pipes 15 when a collision load acts between the two crash pipes 15 on the vehicle front portion 15a. Even if the support member 16 between the two is bent and deformed (plastically deformed) and the collision energy is absorbed based on the deformation, the collision energy absorption is corrected by the structure of the bifurcated ribs 19 and the collision energy is absorbed at the location. The performance (characteristic) is being brought close to the desired collision energy absorption performance (characteristic).
[0026]
When the crash tube 15 is present, the crash tube 15 is plastic so that when a predetermined load c is applied to the front portion 15a of the crash tube 15 toward the rear of the vehicle body, the front portion 15a enters the rear portion 15b of the crash tube 15. It is set to be deformed. This is because, when the support member 16 is supported (connected) using a support member other than the crash tube 15, the rigidity of the portion must be higher than that of the other portions. The crush tube 15 is used as a support member (first support member), and when a predetermined load c acts on the crush tube 15 toward the rear of the vehicle body, the front portion 15a of the crush tube 15 enters the rear portion 15b. It is intended to complement the collision energy absorption performance of the rib 19 at a location close to the front portion 15a of the crash tube 15 by plastic deformation.
[0027]
FIG. 9 shows an analysis result (load-displacement amount) that supports the contents of such a configuration. In FIG. 9, f1 is a load characteristic at the center position (the center position in the vehicle width direction) between the two crash pipes 15 in the vehicle width direction, and f2 is a load characteristic at a position where the crash pipe 15 is present in the vehicle width direction. , F3 indicate load characteristics at an intermediate position between the center position between the two crash pipes 15 and the position where the crash pipe 15 exists.
According to the analysis result shown in FIG. 9, the characteristics f1, f2, and f3 are substantially overlapped and exhibit characteristics close to the desired collision energy absorption characteristics in FIG. 8, and any of the vehicle width direction in the vehicle front portion 15a is shown. It has been shown that favorable results can be obtained even if a collision force acts on a part.
[0028]
Therefore, in the front body structure, when the vehicle collides with the obstacle, the energy absorbing member 18 attached to the front surface of the support member 16 before the abutting against the energy absorbing member 9 and the bumper reinforcement 8 is provided with the obstacle. By removing the lower part, the obstacle can be surely placed on the bonnet 3 with less impact.
Moreover, in this case, since the energy absorbing member 18 provided on the front surface of the support member 16 is used and the extremely simple physical action of removing the lower part of the obstacle is used, the structure can be simplified and special sensors such as sensors can be used. It is possible to eliminate the possibility of malfunction by eliminating the preparation of these parts.
Further, when the lower part of the obstacle is paid, the energy absorbing member 18 provided on the front surface of the support member 16 is used. Therefore, the interaction between the rigidity of the support member 16 and the rigidity of the energy absorbing member 18 is effectively used. (Achieving absorption performance close to the desired collision energy absorption performance) Paying the lower part of the obstacle (adjusting it to a predetermined action force) while ensuring a small impact acting on the obstacle, put the obstacle on the bonnet 3 Will be able to.
Further, in the vehicle width direction, as the rib 19 at the center portion position between the crash pipes 15, a rib 19 whose base end is divided into two is used, and the crash pipe 15 is set to be crushed with a predetermined load c. Therefore, it is preferable to obtain performance closer to the desired collision energy absorption performance at any location in the vehicle width direction in the vehicle front portion 15a including the location near the crash tube 15 and the location near the crash tube 15. It becomes.
[0029]
10 shows the second embodiment, FIGS. 11 and 12 show the third embodiment, FIG. 13 shows the fourth embodiment, and FIG. 14 shows the fifth embodiment. In each of the embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0030]
In the second embodiment shown in FIG. 10, the rib 19 disposed in the central portion between the two crash pipes 15 is set so as to gradually increase in the vehicle width direction toward the rear of the vehicle body. Accordingly, in this case as well, the required deformation load at the proximal end portion of the rib 19 becomes larger than the required deformation load at the distal end portion of the rib 19, and the collision energy considering the bending of the support member 16 is taken into account. Will be absorbed.
[0031]
In the third embodiment shown in FIGS. 11 and 12, a crush tube 15 that is gradually reduced in diameter from the rear end portion side to the front end portion side is used as the first support member, and the peripheral portion of the front end portion thereof. A strength reducing bead 24 is formed to promote crushing by a load applied to the rear of the vehicle body. As a result, when the predetermined load c is applied to the crush tube 15, the crush tube 15 is crushed toward the rear of the vehicle body, and this can be used for adjustment for obtaining a desired collision energy absorption performance (characteristic).
[0032]
In the fourth embodiment shown in FIG. 13, a resin structure containing a rib structure 25 is used as the protruding member 14 having both functions of the first and second support members. In the resin structure as the projecting member 14, the load characteristics can be easily set by the thickness, density, arrangement, etc. of the internal ribs, and the desired energy absorption characteristics can be obtained in cooperation with the energy absorbing member 18. You can get closer.
In this embodiment, it is shown that the resin structure is used for the projecting member 14, but the resin structure is used as the first support member or the second support member by appropriately changing the shape or the like. May be.
[0033]
In the fifth embodiment shown in FIG. 14, a crush tube 15 is used in which the step 15 c between the front portion 15 a and the rear portion 15 b is made gentler than that in the first embodiment. The crash tube 15 also exhibits the same function as the crash tube 15 according to the first embodiment.
[0034]
Although the embodiment has been described above, in the present invention, instead of the crush tube 15, a support member intended for normal support is used, and the front standing length of the rib 19 at a location close to the support member is set at other locations. The length may be longer than that of the rib 19. This is because the amount of collision energy absorbed by the rib 19 can be increased based on the increase in the standing length of the rib 19 without using the crash tube 15. Of course, the rib 19 and the crush tube 15 may be used in combination.
[0035]
It should be noted that the object of the present invention is not limited to what is explicitly described, but includes provision of what is substantially preferable or corresponding to what is listed as an advantage.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a front vehicle body structure according to a first embodiment.
FIG. 2 is a characteristic diagram showing a load characteristic of an energy absorbing member provided in a bumper reinforcement.
FIG. 3 is a perspective view showing the arrangement of a front side frame, a crash tube, an energy absorbing member, and the like according to the first embodiment.
FIG. 4 is an explanatory diagram for explaining the structure and operation of a crush tube according to the first embodiment.
FIG. 5 is a plan view showing a rib structure of an energy absorbing member provided in the support member according to the first embodiment.
FIG. 6 is a perspective view showing a rib structure including a plate-like rib used on the outer side in the vehicle width direction in the energy absorbing member according to the first embodiment.
FIG. 7 is a perspective view showing a rib structure including a base end portion bifurcated rib used in the vehicle width direction central portion in the energy absorbing member according to the first embodiment.
FIG. 8 is a characteristic diagram showing a desired collision energy absorption characteristic preferable for removing the lower part of the obstacle.
FIG. 9 is a characteristic diagram showing load characteristics in the front body structure according to the first embodiment.
FIG. 10 is a perspective view showing a rib structure used at the center in the vehicle width direction in the energy absorbing member according to the second embodiment.
FIG. 11 is a perspective view showing a crush tube used in the third embodiment.
FIG. 12 is a longitudinal sectional view showing a crush tube according to a third embodiment.
FIG. 13 is a perspective view showing a protruding member according to a fourth embodiment.
FIG. 14 is a longitudinal sectional view showing a crush tube according to a fifth embodiment.
[Explanation of symbols]
1 Front body structure
2 Front side frame
3 Bonnet
7 Bumper
8 Bumper reinforcement
9 Energy absorbing member (first energy absorbing member)
14 Protruding member
15 Crash tube
15a front
15b rear
15c step
16 Support material
18 Energy absorbing member(Second energy absorbing member)
19 Ribs
20 Rib structure

Claims

In the front vehicle body structure of the vehicle, the bonnet is disposed above the pair of left and right front side frames so as to extend in the longitudinal direction of the vehicle body, and includes a bumper below the front portion of the bonnet.
A first energy absorbing member that absorbs collision energy is attached to the front side of the main strength member of the bumper,
On the lower side of the main strength member of the bumper, a protruding member is provided on the front side frame,
A second energy absorbing member that absorbs collision energy with a smaller load than the protruding member is provided at the front of the protruding member so as to protrude forward from the main strength member of the bumper ,
The second energy absorbing member is made larger than the first energy absorbing member with respect to the rising gradient of the dynamic crushing load per crushing amount, and the hardness of the second energy absorbing member is the first energy absorbing member. It is relatively hard compared to the hardness of the energy absorbing member,
A vehicle front body structure characterized by that.

In claim 1,
The projecting members are provided on the pair of front side frames on the lower side of the main strength member of the bumper, and are provided so as to straddle the front portions of the first support members. A second support member extending over substantially the entire length,
The second energy absorbing member is provided on a front portion of the second support member,
A vehicle front body structure characterized by that.

In claim 2,
The second energy absorbing member is formed by a rib structure in which at least ribs are arranged at intervals in the vehicle width direction while standing forward from the second support member.
A vehicle front body structure characterized by that.

In claim 3,
The second energy absorbing member is formed of resin;
A vehicle front body structure characterized by that.

In claim 3,
The rib structure is related to a required deformation load as a load required for deformation , and the base end portion of the rib becomes larger than the tip end portion of the rib as the distance from the first support member increases in the vehicle width direction. Is set to
A vehicle front body structure characterized by that.

In claim 5,
The rib structure, as the central portion between both the first support member in the vehicle width direction, set such that the required deformation load at the proximal end of the rib is greater than that of the required deformation load at the tip of the rib Being
A vehicle front body structure characterized by that.

In claim 5 or 6,
It is that the proximal ends of the ribs are divided into bifurcated said request deformation load at the proximal end of the rib is greater than that of the required deformation load at the tip of the rib,
A vehicle front body structure characterized by that.

In claim 5 or 6,
It is to be thicker in the vehicle width direction toward the rear of the vehicle body the required deformation load at the proximal end of the rib is greater than that of the required deformation load at the tip of the rib,
A vehicle front body structure characterized by that.

In claim 3,
The rib structure is lengthened as the standing length of the rib is closer to the first support member in the vehicle width direction.
A vehicle front body structure characterized by that.

In claim 3,
The second support member is curved so as to go to the rear of the vehicle body as it goes outward in the vehicle width direction;
The ribs are erected substantially perpendicular to the front surface of the second support member;
A vehicle front body structure characterized by that.

In claim 2,
The first support member has a hollow structure, and the front portion of the first support member has a smaller diameter than the rear portion of the first support member.
A vehicle front body structure characterized by that.

In claim 11,
The first support member is formed to have a concentric step between a rear portion of the first support member and a front portion of the first support member.
A vehicle front body structure characterized by that.

In claim 11,
The first support member is formed so as to be gradually reduced in diameter from the rear side of the first support member toward the front side of the first support member.
A vehicle front body structure characterized by that.

In claim 1 or 2,
The main strength member of the bumper is a bumper reinforcement.
A vehicle front body structure characterized by that.