JP4174637B2

JP4174637B2 - Energy absorption structure of automobile

Info

Publication number: JP4174637B2
Application number: JP22152498A
Authority: JP
Inventors: 誠一安藤
Original assignee: Mazda Motor Corp
Current assignee: Mazda Motor Corp
Priority date: 1998-08-05
Filing date: 1998-08-05
Publication date: 2008-11-05
Anticipated expiration: 2018-08-05
Also published as: JP2000053017A

Description

【０００１】
【発明の属する技術分野】
本発明は自動車のエネルギー吸収構造に関し、特に、衝突時に衝撃吸収部材の外周壁を車体フレームの内部に折返しながら没入させるようにしたエネルギー吸収構造に関する。
【０００２】
【従来の技術】
従来、自動車の衝突エネルギーを吸収する構造として、車体のフロントサイドフレームの前端部にプレート部材を固着し、そのプレート部材に前方程細くなるテーパー状の外周壁を有するバンパーステイ（衝撃吸収部材）の基端部側を固着し、衝突時、バンパーステイを座屈させることにより、衝突エネルギーを吸収するエネルギー吸収構造が実用に供されている（例えば、特開平７−４０８５８号公報参照）。
【０００３】
一方、特開平１０−７０２５号公報には、筒状の第１部材と、第１部材よりも外形が大きく且つ高強度の筒状の第２部材と、同心状に配置した第１部材の後端部と第２部材の前端部を部分的に連結するトリガー部を備え、衝突時、先ずトリガー部を第２部材の内面側へ変形させることにより、第１部材をトリガー部から曲げ変形させて第２部材内に侵入させ、衝突エネルギーを吸収するエネルギー吸収構造が記載されている。
【０００４】
【発明が解決しようとする課題】
特開平７−４０８５８号公報のエネルギー吸収構造では、プレート部材にバンパーステイの基端部側全体を支持し固着しているので、衝突直後、実施形態に係る図７のエネルギー吸収特性図の荷重曲線ｂからも分かるように、バンパーステイが略座屈を開始する迄の間に衝突荷重が急激に高くなり、自動車乗員への衝撃が大きくなるという問題がある。
【０００５】
衝突荷重によりバンパーステイが座屈する際、外周壁が全体的に崩壊するけれども、外周壁全体が効果的にエネルギー吸収を行う訳ではなく、外周壁の複数の崩壊個所の座屈によるエネルギー吸収が生じるため、また、バンパーステイの座屈開始後には支持可能な荷重（又は、衝突荷重に抵抗する力）が極端に低下するため、衝突エネルギー吸収性能を十分に高めることが難しいという問題がある。
【０００６】
しかも、バンパーステイの座屈した部分はフレームの前側に塊状に積み重なるため、バンパーステイが衝撃吸収ストローク分座屈した後には、エネルギー吸収機能が殆どなくなり、バンパーステイの長さ（例えば、約100mm ）よりも短い衝撃吸収ストローク（例えば、約80mm）しか確保できなくなるため、エネルギー吸収性を高めることができないし、衝撃吸収ストロークを大きくするとバンパーステイが大型化するという問題がある。
【０００７】
一方、特開平１０−７０２５号公報のエネルギー吸収構造では、衝突直後、トリガー部は第２部材の内面側へ容易に変形するものの、第１部材がストレート状の筒状に構成されているため、実施形態に係る図９のエネルギー吸収特性図の荷重曲線ｄからも分かるように、第１部材の一部が第２部材の前端側に積み重なり易く、衝撃吸収ストロークがバンパーステイの長さ（例えば、約100mm ）よりも短いストローク（例えば、約87mm）になり、前記同様エネルギー吸収性を高めることが難しいという問題がある。
【０００８】
しかも、第１部材がストレート状の筒状に構成されているため、第１部材にその長さ方向に対して傾いた角度で衝突荷重が入力した場合、第２部材に対して第１部材が傾き、第１部材が第２筒部材内に円滑に没入しにくくなり、エネルギー吸収性が低下する虞がある。
【０００９】
本発明の目的は、自動車のエネルギー吸収構造において、衝突直後の乗員への衝撃を緩和すること、エネルギー吸収性を高めること、衝撃吸収ストロークを大きくすること、衝撃吸収部材が機能可能な衝突荷重入力方向を拡大すること、等である。
【００１０】
【課題を解決するための手段】
請求項１の自動車のエネルギー吸収構造は、自動車の衝突エネルギーを吸収する構造において、車体フレームの車両前後方向の外方側の端部に、車両前後方向の外方程細くなるテーパー状の外周壁とこの外周壁の基端に折曲状に連なる連結壁部とを有する基端開放状の衝撃吸収部材を、連結壁部を介して車両前後方向の外方へ突出する状態に固着し、前記車体フレームの車両前後方向の外方側の端部に衝撃吸収部材の外周壁の基端よりも大きな開口部を形成し、衝突時に外周壁を前記開口部から車体フレームの内部に折返しながら没入させることで、衝突エネルギー吸収を行うように構成したことを特徴とするものである。
【００１１】
このエネルギー吸収構造では、衝突時、衝撃吸収部材に車両前後方向の外方側から衝突荷重が入力すると、車両前後方向の外方程細くなるテーパー状の外周壁にはその外周壁を内方へ曲げる曲げモーメント（この曲げモーメントは外周壁の基端側程大きくなる）が作用するとともに、連結壁部にも曲げモーメントが作用する。衝突後最初に、連結壁部の曲げ変形を介して外周壁の基端部分が、車体フレームの開口部から車体フレームの内部へ折り返し状に座屈変形し、その座屈変形が外周壁の基端部から外端側へ向かって連続的に発生し、最終的に衝撃吸収部材の全部が開口部から車体フレームの内部へ折り返し状に没入する。こうして、衝撃吸収部材の外周壁の全部が確実に塑性変形して衝突エネルギーが効果的に吸収される。
【００１２】
衝撃吸収部材の外周壁を車両前後方向の外方程細くなるテーパー状に形成し、外周壁の基端に折曲状に連なる連結壁部を介して衝撃吸収部材を車体フレームに固着し、車体フレームの車両前後方向の外方側の端部に衝撃吸収部材の外周壁の基端よりも大きな開口部を形成したので、衝突直後から連結壁部と外周壁の基端部分が崩壊し易くなるから、衝突直後の乗員への衝撃を緩和できる。
【００１３】
そして、外周壁の基端部分から外端側へ向かって順々に連続的に座屈変形させていくことができるから、外周壁の全体を衝突エネルギー吸収に寄与させることができる。外周壁の変形した部分が車体フレームの車両前後方向の外端側に塊状に積み重なることがなく、衝撃吸収部材のほぼ全長に等しい衝撃吸収ストロークを確保することができるため、エネルギー吸収性を格段に高めることができる。
【００１４】
外周壁を車両前後方向の外方程細くなるテーパー状に形成したので、衝突時、衝撃吸収部材にその長さ方向に対して少々傾いた角度で衝突荷重が入力しても、衝撃吸収部材の前記の衝撃吸収機能を確保することができる。
【００１５】
請求項２の自動車のエネルギー吸収構造は、自動車の衝突エネルギーを吸収する構造において、車体のフロントサイドフレームの前端部に、前方程細くなるテーパー状の外周壁とこの外周壁の後端に折曲状に連なる連結壁部とを有する後端開放状の衝撃吸収部材を、連結壁部を介して前方へ突出する状態に固着し、前記フロントサイドフレームの前端部に衝撃吸収部材の外周壁の後端よりも大きな開口部を形成し、衝突時に外周壁を前記開口部からフロントサイドフレームの内部に折返しながら没入させることで、衝突エネルギー吸収を行うように構成したことを特徴とするものである。
【００１６】
従って、自動車が正面衝突した場合、請求項１の作用と同様に、衝突直後の衝撃を抑制して乗員への衝撃を緩和でき、外周壁の全体を衝突エネルギー吸収に寄与させることができ、衝撃吸収部材の略全長に等しい衝撃吸収ストロークを確保して衝突エネルギー吸収性を格段に高めることができる。フロントサイドフレームの前端部付近はスペース的に余裕がないが、衝撃吸収部材の全長を増すことなく、衝撃吸収ストロークを大きくし得るので非常に有利である。
【００１７】
請求項３の自動車のエネルギー吸収構造は、請求項１又は２の発明において、前記衝撃吸収部材の車両前後方向の車両外方側の端が閉じられていることを特徴とするものである。従って、衝突荷重を衝撃吸収部材の外周壁にほぼ一様に伝達させ、外周壁をほぼ一様に座屈変形させることができる。
【００１８】
請求項４の自動車のエネルギー吸収構造は、請求項１又は３の発明において、前記車体フレームに衝撃吸収部材を取付ける為の取付けプレートを固着し、その取付けプレートに前記開口部を形成したことを特徴とするものである。従って、衝撃吸収部材を取付けプレートを介して車体フレームの外端部に簡単且つ確実に取付けることができる。
【００１９】
請求項５の自動車のエネルギー吸収構造は、請求項４の発明において、前記取付けプレートの開口部の内縁部分に、車体フレームの内部側へ折り曲げた折り曲げフランジ部を設けたことを特徴とするものである。従って、取付けプレートの開口部の内縁部分の強度を高め、しかも、折り曲げフランジ部により外周壁をガイドして車体フレームの内部に円滑に折返して没入させることができる。
【００２０】
請求項６の自動車のエネルギー吸収構造は、請求項４又は５の発明において、前記車体フレームはフロントサイドフレームであることを特徴とするものである。従って、基本的に請求項２とは同様の作用を奏するうえ、請求項４又は５と同様の作用を奏する。
【００２１】
請求項７の自動車のエネルギー吸収構造は、請求項６の発明において、前記衝撃吸収部材の付近において、フロントサイドフレームにタイダウンフックを設けたことを特徴とするものである。従って、フロントサイドフレームの前端部分は強度が高まり変形しない部位となり、そのフロントサイドフレームの前端部分の内部に、外周壁を確実に折返して没入させることができる。
【００２２】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照しながら説明する。本実施形態は、自動車の衝突エネルギーを吸収する構造に本発明を適用した場合の一例である。
【００２３】
図１〜図５に示すように、自動車１の車体２は、閉断面フレームである前方開放状のフロントサイドフレーム３と、左右１対のフロントサイドフレーム３の前端部分を連結するフロントクロスメンバ４を有し、エネルギー吸収構造として、各フロントサイドフレーム３の前端部に、フロントサイドフレーム３の閉断面よりも大きな矩形板状の取付けプレート１０が固着され、その取付けプレート１０に衝撃吸収部材２０が取付けられている。
【００２４】
フロントサイドフレーム３の左右両面の前端にはブラケット５，６が溶接等で夫々固着され、取付けプレート１０は、その後面部をフロントサイドフレーム３及びブラケット５，６の前端面に当接させた状態で、取付けプレート１０のボルト孔１０ａ〜１０ｃとブラケット５，６のボルト孔５ａ，６ｂ，６ｃに夫々装着されるボルト（図示略）により締結されている。
【００２５】
図２、図３に示すように、フロントサイドフレーム３の前端部分にはタイダウンフック７が設けられ、そのタイダウンフック７にワイヤ（図示略）を引っ掛けて、例えば、自動車１を牽引できるようになっている。尚、タイダウンフック７の上端部分がフロントサイドフレーム３の外面に接合され、更に、中段部分がフロントクロスメンバ４の外側面に接合される。
【００２６】
ここで、通常、フロントサイドフレーム３は、衝突時に座屈変形することでエネルギー吸収可能に構成されるが、フロントサイドフレーム３の前端部分は、タイダウンフック７の他フロントクロスメンバ４やブラケット５，６を固着する関係上強度が高まり変形しない部位となるため、フロントサイドフレーム３の前端部に設けられた衝撃吸収部材２０を確実に機能させることができる。
【００２７】
取付けプレート１０には、その中央部分にフロントサイドフレーム３の前端の開口よりも小さな開口部１１が形成され、開口部１１の内縁部分に、フロントサイドフレーム３の内部側（後側）へ少し折り曲げた折り曲げフランジ部１２が設けられている。尚、折り曲げフランジ部１２は取付けプレート１０に一体形成されているが、取付けプレート１０に開口部１１だけを形成し、折り曲げフランジ部１２に相当するフランジ部材を別途固着し設けてもよい。
【００２８】
衝撃吸収部材２０は、前方程細くなるテーパー状の外周壁２１、外周壁２１の前端部に繋がり衝撃吸収部材２０の前端を閉じる前壁２２、外周壁２１の後端部に折曲状に連なり外側へ広がる環状のフランジ２３（これが、連結壁部に相当する）を一体形成して後端開放状に構成され、フロントサイドフレーム３の前端部に前方へ突出する状態に設けられている。
【００２９】
取付けプレート１０の開口部１１は、外周壁２１の後端よりも大きく形成され、その開口部１１の前側に外周壁２１の後端が位置する状態で、取付けプレート１０の前面にフランジ２３の後面を溶接して、衝撃吸収部材２０が取付けられている。フランジ２３の開口部１１の前側に位置する部分は、取付けプレート１０に当接していないため、衝突荷重が作用したときに曲がり易い変形促進部２３ａになっている。
【００３０】
ここで、例えば、衝撃吸収部材２０の前後長さＬ＝100mm 、厚さｔ＝1.6mm 、外周壁２１のテーパ角度θ＝１０度、開口１１の内縁部から内側へ張り出した変形促進部２３ａの長さβ＝５mmに形成されている。尚、衝撃吸収部材２０の前後長さＬ、厚さｔ、外周壁２１のテーパ角度θ、変形促進部２３ａの長さβは、前記の値に限定される訳ではないが、変形促進部２３ａの長さβは少なくとも５mm位の大きさに設定することが望ましい。
【００３１】
衝突時、衝撃吸収部材２０に略正面側から衝突荷重が入力すると、外周壁２１にその外周壁２１を内側へ曲げようとする曲げモーメントが作用し、その曲げモーメントは後方程大きくなる。そして、フランジ２３の変形促進部２３ａにも曲げモーメントが作用する。衝突直後に、図４に示すように、最初に変形促進部２３ａが取付けプレート１０の開口部１１の内縁側へ変形するとともに、この変形促進部２３ａの変形に連動して、外周壁２１の後端部が座屈変形してフロントサイドフレーム３の内部へ折り返されていく。このとき、変形促進部２３ａと外周壁２１の後端部が取付けプレート１０の折り曲げフランジ部１２にガイドされる。
【００３２】
その後、図５に示すように、外周壁２１の全体が、後端側から前端側に向かって順々に連続的に座屈変形して、開口部１１からフロントサイドフレーム３の内部に折り返し状に変形していき、最終的には、衝撃吸収部材２０の前端が取付けプレート１０と一致するような状態まで崩壊が進行する。
【００３３】
次に、衝撃吸収部材２０のエネルギー吸収特性について本願発明者等が行った実験の結果について、図６〜図９を参照して説明する。図６、図８は夫々従来技術におけるエネルギー吸収構造（比較例）、図７は図６の衝撃吸収部材２０Ａと衝撃吸収部材２０のエネルギー吸収特性の線図、図９は図８の衝撃吸収部材２０Ｂと衝撃吸収部材２０のエネルギー吸収特性の線図である。図７、図９の横軸は衝撃吸収部材の変形量（潰れ量）、縦軸は衝撃吸収部材に作用する衝突荷重を示す。
【００３４】
図６のエネルギー吸収構造は、前記衝撃吸収部材２０と同じ構造の衝撃吸収部材２０Ａ（外周壁２１Ａ、前壁２２Ａ、フランジ２３Ａを有する）を、フロントサイドフレーム３の前端部に固着の開口部を形成していない取付けプレート３０に前方突出状に取付けたものである。
【００３５】
図６のエネルギー吸収構造では、図７の荷重曲線ｂに示すように、衝突直後、衝撃吸収部材２０Ａが座屈を開始する迄の間に衝突荷重が 100ＫＮ近くまで急激に高くなり、その後、衝撃吸収部材２０Ａの座屈崩壊が始まると、衝突荷重が40ＫＮ以下に低下し維持される。衝撃吸収部材２０Ａの座屈した部分は取付けプレート３０の前側に塊状に積み重なるため、衝撃吸収ストロークは約80mmしか確保できず、変形量が約80mmを越えるとエネルギー吸収機能が殆どなくなり、衝突荷重が著しく上昇する。
【００３６】
一方、本案のエネルギー吸収構造では、図７の荷重曲線ａに示すように、衝突直後、衝撃吸収部材２０が変形を開始する迄の間に衝突荷重が70ＫＮ以下に抑えられ、その外周壁２１の座屈崩壊の開始後にも衝突荷重があまり低下せず約50〜60ＫＮに維持される。しかも、衝撃吸収部材２０はフロントサイドフレーム３の内部に折返しながら没入するため、衝撃吸収ストロークは略衝撃吸収部材２０の長さ分の 100mm確保することができ、変形量が 100mm近くになる迄衝突荷重が約50〜60ＫＮに維持される。
【００３７】
つまり、本案のエネルギー吸収構造では、図６のエネルギー吸収構造に比べると、衝突直後の衝撃を緩和でき、図の面積（Ａ＋Ｂ−α）に相当する分だけエネルギー吸収性能が向上する。
【００３８】
次に、図８のエネルギー吸収構造は、円筒状の外周壁３５と前壁３６とフランジ３７を有する衝撃吸収部材２０Ｂを、フロントサイドフレーム３の前端部に固着の前記取付けプレート１０と同様の取付けプレート１０Ｂ（開口部１１Ｂ，折り曲げフランジ部１２Ｂを有する）に前方突出状に取付けたものである。
【００３９】
図８のエネルギー吸収構造では、図９の荷重曲線ｄに示すように、衝撃吸収部材２０Ｂの変形量が約15mm〜40mmのとき衝撃荷重は60ＫＮ前後で略一定に維持されるが、衝撃吸収部材２０Ｂの変形量が約43mm〜80mmのとき衝撃荷重がかなり低下し、しかも、変形量が約80mmを越えると衝突荷重が急激に上昇してエネルギー吸収機能が殆どなくなり、衝撃吸収ストロークは約87mmしか確保することができない。
【００４０】
つまり、本案のエネルギー吸収構造では、図８のエネルギー吸収構造に比べると、エネルギー吸収量が、略斜線で示した面積Ｄ，Ｆと逆斜線で示した面積Ｃ，Ｅの差（Ｄ＋Ｆ−Ｃ−Ｅ）の分だけ多くなる。特に、エネルギー吸収ストロークの増加による面積Ｆ分が大きいため、エネルギー吸収性能が大幅に高まる。尚、図９の荷重曲線ｃは図７の荷重曲線ａと若干異なるが、これは構造等が若干異なる為である。
【００４１】
このように、上記エネルギー吸収構造によれば、前方開放状のフロントサイドフレーム３の前端部に、取付けプレート１０を介して、前方程細くなるテーパー状の外周壁２１とフランジ２３とを有する後端開放状の衝撃吸収部材２０を、フランジ２３を介して前方へ突出する状態に設け、取付けプレート１０に衝撃吸収部材２０の外周壁２１の後端よりも大きな開口部１１を形成したので、衝突直後の最初に外周壁２１の後端部とフランジ２３の変形促進部１２ａを開口部１１側へ変形させ、その後、外周壁２１の全体を、その後端部から順々に前方へ向かって座屈変形させて、開口部１１からフロントサイドフレーム３の内部にその後端部から前方へ向かって順々に折返しながら没入させることができる。
【００４２】
その結果、衝突直後に衝突荷重が急激に高くなるのを抑制し、乗員への衝撃を緩和できるとともに、外周壁２１の全体をエネルギー吸収に寄与させることができ、しかも、外周壁２１の変形した部分がフロントサイドフレーム３の前側に塊状に積み重なることがなく、衝撃吸収部材２０の略全長Ｌ分の衝撃吸収ストロークを確保できるため、エネルギー吸収性を格段に高めることができる。
【００４３】
しかも、外周壁２１を前方程細くなるテーパー状に形成したので、衝突時、衝撃吸収部材２０にその長さ方向に対して傾いた方向から衝突荷重が入力しても、その傾き角度が所定角度以下の場合には、外周壁２１をフロントサイドフレーム３の内部に確実に没入させることができ、衝撃吸収部材２０が機能可能な衝突荷重入力方向を拡大することができる。衝撃吸収部材２０の前端が前壁２２により閉じられているので、衝突荷重を衝撃吸収部材２０の外周壁にほぼ一様に伝達させ、外周壁２１をほぼ一様に座屈変形させることができる。
【００４４】
フロントサイドフレーム３に取付けプレート１０を固着し、その取付けプレート１０に開口部１１を形成したので、衝撃吸収部材２０を取付けプレート１０を介してフロントサイドフレーム３に簡単且つ確実に取付けることができ、しかも、取付けプレート１０の開口部１１の内縁部分に、フロントサイドフレーム３の内部側へ折り曲げた折り曲げフランジ部１２を設けたので、その内縁部分の強度を高めるとともに、折り曲げフランジ部１２により、外周壁１１をガイドしてフロントサイドフレーム３の内部に円滑に折返して没入させることができる。
【００４５】
衝撃吸収部材２０の付近において、フロントサイドフレーム３にタイダウンフック７を設けたので、フロントサイドフレーム３の前端部分は強度が高まり変形しない部位となり、そのフロントサイドフレーム３の前端部分の内部に、外周壁２１を確実に折返して没入させることができるようになる。尚、前記実施形態では、衝撃吸収部材２０の外周壁２１を断面角筒状に構成したが、外周壁を断面円筒状に構成してもよい。
【００４６】
尚、前記実施形態のエネルギー吸収構造は一例を示すものに過ぎず、本発明の趣旨を逸脱しない範囲において種々の変更を付加し、前記フロントサイドフレーム以外の車体フレームの外端部（例えば、リヤサイドフレームの後端部等）に衝撃吸収部材２０を固着した構造のエネルギー吸収構造にも本発明を同様に適用することができる。
【００４７】
【発明の効果】
請求項１の自動車のエネルギー吸収構造によれば、前記の作用の欄で説明したように、衝突直後から連結壁部と外周壁の基端部分が崩壊し易くなるから、衝突直後の乗員への衝撃を緩和できる。そして、外周壁の基端部分から外端側へ向かって順々に連続的に座屈変形させていくことができるから、外周壁の全体を衝突エネルギー吸収に寄与させることができる。
【００４８】
外周壁の変形した部分が車体フレームの車両前後方向の外端側に塊状に積み重なることがなく、衝撃吸収部材のほぼ全長に等しい衝撃吸収ストロークを確保することができるため、エネルギー吸収性を格段に高めることができる。外周壁を車両前後方向の外方程細くなるテーパー状に形成したので、衝突時、衝撃吸収部材にその長さ方向に対して少々傾いた角度で衝突荷重が入力しても、衝撃吸収部材の前記の衝撃吸収機能を確保することができる。
【００４９】
請求項２の自動車のエネルギー吸収構造によれば、基本的に請求項１と同様の効果が得られるうえ、自動車の正面衝突時の衝突エネルギーを吸収できるエネルギー吸収構造がえられる。特に、フロントサイドフレームの前端部付近はスペース的に余裕がないが、衝撃吸収部材の全長を増すことなく、衝撃吸収ストロークを大きくし得るので非常に有利である。
【００５０】
請求項３の自動車のエネルギー吸収構造によれば、請求項１又は２と同様の効果を奏するが、衝撃吸収部材の車両前後方向の車両外方側の端が閉じられているので、衝突荷重を衝撃吸収部材の外周壁にほぼ一様に伝達させ、外周壁をほぼ一様に座屈変形させることができる。
【００５１】
請求項４の自動車のエネルギー吸収構造によれば、請求項１又は３と同様の効果を奏するが、車体フレームに衝撃吸収部材を取付ける為の取付けプレートを固着し、その取付けプレートに前記開口部を形成したので、衝撃吸収部材を取付けプレートを介して車体フレームの外端部に簡単且つ確実に取付けることができ、しかも、衝撃吸収部材のエネルギー吸収機能を確保することができる。
【００５２】
請求項５の自動車のエネルギー吸収構造によれば、請求項４と同様の効果を奏するが、取付けプレートの開口部の内縁部分に、車体フレームの内部側へ折り曲げた折り曲げフランジ部を設けたので、取付けプレートの開口部の内縁部分の強度を高めるとともに、折り曲げフランジ部により外周壁をガイドして車体フレームの内部にスムースに折返して没入させることができる。
【００５３】
請求項６の自動車のエネルギー吸収構造によれば、請求項２と同様の効果を奏する上、請求項４又は５と同様の効果を奏する。
【００５４】
請求項７の自動車のエネルギー吸収構造によれば、請求項６と同様の効果を奏するが、衝撃吸収部材の付近において、フロントサイドフレームにタイダウンフックを設けたので、フロントサイドフレームの前端部分は強度が高まり変形しない部位となり、そのフロントサイドフレームの前端部分の内部に、外周壁を確実に折返して没入させることができる。
【図面の簡単な説明】
【図１】本発明の実施形態に係る車体右側のフロントサイドフレームとその衝撃吸収部材の分解斜視図である。
【図２】前記フロントサイドフレームとエネルギー吸収構造の斜視図である。
【図３】図２のIII −III 線断面図である。
【図４】エネルギー吸収構造（衝突直後状態）の縦断面図である。
【図５】エネルギー吸収構造（衝突後座屈変形途中状態）の縦断面図である。
【図６】従来技術におけるエネルギー吸収構造の縦断面図である。
【図７】図３と図６のエネルギー吸収構造のエネルギー吸収特性図である。
【図８】従来技術におけるエネルギー吸収構造の縦断面図である。
【図９】図３と図９のエネルギー吸収構造のエネルギー吸収特性図である。
【符号の説明】
１自動車
２車体
３フロントサイドフレーム
７タイダウンフック
１０取付けプレート
１１開口部
１２折り曲げフランジ部
２０衝撃吸収部材
２１外周壁
２３フランジ
２３ａ変形促進部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an energy absorbing structure for an automobile, and more particularly, to an energy absorbing structure in which an outer peripheral wall of an impact absorbing member is folded back into a body frame at the time of a collision.
[0002]
[Prior art]
Conventionally, as a structure for absorbing the collision energy of an automobile, a plate member is fixed to a front end portion of a front side frame of a vehicle body, and a bumper stay (shock absorbing member) having a tapered outer peripheral wall that becomes thinner toward the front of the plate member. An energy absorbing structure that absorbs collision energy by fixing the base end side and buckling the bumper stay at the time of collision has been put to practical use (see, for example, Japanese Patent Laid-Open No. 7-40858).
[0003]
On the other hand, Japanese Patent Laid-Open No. 10-7025 discloses a cylindrical first member, a cylindrical second member having a larger outer shape and higher strength than the first member, and a first member disposed concentrically. A trigger portion that partially connects the end portion and the front end portion of the second member is provided, and at the time of collision, the first member is bent and deformed from the trigger portion by first deforming the trigger portion toward the inner surface side of the second member. An energy absorption structure is described that penetrates into the second member and absorbs collision energy.
[0004]
[Problems to be solved by the invention]
In the energy absorption structure disclosed in Japanese Patent Laid-Open No. 7-40858, the entire base end side of the bumper stay is supported and fixed to the plate member. Therefore, immediately after the collision, the load curve of the energy absorption characteristic diagram of FIG. As can be seen from b, there is a problem that the impact load suddenly increases until the bumper stay starts substantially buckling, and the impact on the vehicle occupant increases.
[0005]
When the bumper stay buckles due to a collision load, the outer peripheral wall collapses as a whole, but the entire outer peripheral wall does not absorb energy effectively, but energy absorption occurs due to buckling of multiple collapse points on the outer peripheral wall. For this reason, since the load that can be supported (or the force that resists the collision load) is extremely reduced after the start of buckling of the bumper stay, it is difficult to sufficiently improve the collision energy absorption performance.
[0006]
Moreover, since the bumper stay buckled part is piled up in front of the frame, after the bumper stay is buckled by the shock absorbing stroke, the energy absorbing function is almost lost, and the length of the bumper stay (for example, about 100mm) Since it is possible to ensure only a shorter shock absorption stroke (for example, about 80 mm) than that, there is a problem that the energy absorption cannot be increased, and if the shock absorption stroke is increased, the bumper stay is enlarged.
[0007]
On the other hand, in the energy absorption structure of Japanese Patent Laid-Open No. 10-7025, immediately after the collision, the trigger portion is easily deformed to the inner surface side of the second member, but the first member is configured in a straight cylindrical shape, As can be seen from the load curve d in the energy absorption characteristic diagram of FIG. 9 according to the embodiment, a part of the first member is easily stacked on the front end side of the second member, and the shock absorption stroke is the length of the bumper stay (for example, The stroke becomes shorter than about 100 mm) (for example, about 87 mm), and there is a problem that it is difficult to improve the energy absorption as described above.
[0008]
Moreover, since the first member is configured in a straight cylindrical shape, when a collision load is input to the first member at an angle inclined with respect to the length direction, the first member is Inclination, the first member is less likely to be smoothly immersed in the second cylindrical member, and energy absorption may be reduced.
[0009]
The object of the present invention is to reduce the impact on the occupant immediately after the collision, increase the energy absorption, increase the shock absorption stroke, and input the collision load that the shock absorbing member can function in the energy absorption structure of the automobile. Expanding directions, etc.
[0010]
[Means for Solving the Problems]
Energy absorber for a vehicle in accordance with claim 1, in the structure to absorb the impact energy of the automobile, the end of the longitudinal direction of the vehicle outer side of the vehicle body frame, a tapered outer peripheral wall becomes thinner as the outside of the vehicle longitudinal direction A base end open shock absorbing member having a connecting wall portion connected in a bent shape at the base end of the outer peripheral wall is fixed in a state of projecting outward in the vehicle front-rear direction via the connecting wall portion. the end of the longitudinal direction of the vehicle outer side of the frame to form a large opening than the proximal end of the outer peripheral wall of the shock absorbing member, thereby retracted while folding the outer peripheral wall into the interior of the vehicle body frame through the opening at the time of a collision Thus, it is configured to perform collision energy absorption.
[0011]
In this energy absorbing structure, when a collision load is input to the shock absorbing member from the outside in the vehicle longitudinal direction at the time of a collision, the outer circumferential wall is bent inward to the tapered outer circumferential wall that becomes narrower outward in the vehicle longitudinal direction. A bending moment (this bending moment increases toward the base end side of the outer peripheral wall) acts, and a bending moment also acts on the connecting wall portion. First after the collision, the proximal portion of the outer peripheral wall via a bending deformation of the connecting wall portion, and buckling deformation inside the folding-back shape of the vehicle body frame through the opening of the vehicle body frame, the buckling deformation of the outer peripheral wall continuously occurs toward the outer end side from the proximal end, eventually all of the impact-absorbing member is retracted into form-back folding into the interior of the vehicle body frame through the opening. Thus, the entire outer peripheral wall of the shock absorbing member is reliably plastically deformed and the collision energy is effectively absorbed.
[0012]
The outer peripheral wall of the shock absorbing member is formed in a tapered shape that becomes thinner outward in the vehicle front-rear direction, and the shock absorbing member is fixed to the vehicle body frame via a connecting wall portion that is bent at the base end of the outer peripheral wall. since the formation of the larger opening than the proximal end of the outer peripheral wall of the vehicle longitudinal direction of the shock absorbing member to the end portion of the outer side, since the base end portion of the connecting wall portion and the outer peripheral wall is likely to collapse immediately after the collision , Can reduce the impact on passengers immediately after the collision.
[0013]
And since it can be continuously buckled and deformed in order from the base end portion of the outer peripheral wall toward the outer end side, the entire outer peripheral wall can contribute to the collision energy absorption. Since the deformed portion of the outer peripheral wall does not pile up on the outer end side of the vehicle body frame in the longitudinal direction of the vehicle body, it is possible to secure a shock absorption stroke that is almost the same as the entire length of the shock absorbing member, so that energy absorption is markedly improved. Can be increased.
[0014]
Since the outer peripheral wall is formed in a taper shape that becomes thinner outward in the vehicle front-rear direction, even if a collision load is input to the shock absorbing member at a slightly inclined angle with respect to its length direction at the time of collision, the shock absorbing member The shock absorbing function can be ensured.
[0015]
According to a second aspect of the present invention, there is provided an automobile energy absorbing structure that absorbs collision energy of an automobile, and is bent at a front end portion of a front side frame of a vehicle body at a tapered outer peripheral wall that becomes thinner toward the front and a rear end of the outer peripheral wall. A shock absorbing member having an open rear end having a connecting wall portion connected in a shape is fixed in a state of protruding forward through the connecting wall portion, and the rear end of the outer peripheral wall of the shock absorbing member is attached to the front end portion of the front side frame. An opening larger than the end is formed, and the outer wall is retracted from the opening to the inside of the front side frame at the time of collision, so that the collision energy is absorbed.
[0016]
Therefore, when the automobile collides head-on, the impact immediately after the collision can be suppressed and the impact on the occupant can be mitigated, and the entire outer peripheral wall can contribute to the collision energy absorption. A shock absorption stroke equal to substantially the entire length of the absorbing member can be ensured, and the impact energy absorption can be remarkably enhanced. Although there is no space in the vicinity of the front end portion of the front side frame, it is very advantageous because the shock absorbing stroke can be increased without increasing the overall length of the shock absorbing member.
[0017]
According to a third aspect of the present invention, there is provided an automobile energy absorbing structure according to the first or second aspect, wherein the end of the shock absorbing member on the vehicle outer side in the vehicle front-rear direction is closed. Therefore, the collision load can be transmitted almost uniformly to the outer peripheral wall of the shock absorbing member, and the outer peripheral wall can be buckled and deformed substantially uniformly.
[0018]
According to a fourth aspect of the present invention, there is provided an energy absorption structure for an automobile, wherein, in the first or third aspect of the invention, a mounting plate for mounting an impact absorbing member is fixed to the body frame, and the opening is formed in the mounting plate. It is what. Therefore, the shock absorbing member can be easily and reliably attached to the outer end portion of the vehicle body frame via the attachment plate.
[0019]
According to a fifth aspect of the present invention, there is provided an automobile energy absorbing structure according to the fourth aspect of the invention, wherein a bent flange portion bent toward the inner side of the body frame is provided at an inner edge portion of the opening of the mounting plate. is there. Therefore, the strength of the inner edge portion of the opening portion of the mounting plate can be increased, and the outer peripheral wall can be guided by the bent flange portion so that it can be smoothly folded back into the body frame.
[0020]
According to a sixth aspect of the present invention, there is provided an automobile energy absorbing structure according to the fourth or fifth aspect, wherein the body frame is a front side frame. Therefore, basically the same effect as that of claim 2 is obtained, and the same effect as that of claim 4 or 5 is obtained.
[0021]
According to a seventh aspect of the present invention, there is provided an energy absorption structure for an automobile according to the sixth aspect, wherein a tie-down hook is provided on a front side frame in the vicinity of the shock absorbing member. Therefore, the front end portion of the front side frame becomes a portion where the strength is increased and does not deform, and the outer peripheral wall can be reliably folded and immersed inside the front end portion of the front side frame.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment is an example when the present invention is applied to a structure that absorbs collision energy of an automobile.
[0023]
As shown in FIGS. 1 to 5, a vehicle body 2 of an automobile 1 includes a front cross frame 4 that connects a front open front side frame 3 that is a closed cross section frame and a front end portion of a pair of left and right front side frames 3. As an energy absorbing structure, a rectangular plate-shaped mounting plate 10 larger than the closed cross section of the front side frame 3 is fixed to the front end portion of each front side frame 3, and the shock absorbing member 20 is attached to the mounting plate 10. Installed.
[0024]
The brackets 5 and 6 are fixed to the front ends of the left and right sides of the front side frame 3 by welding or the like, respectively, and the mounting plate 10 is in a state in which the rear surface portion is in contact with the front end surfaces of the front side frame 3 and the brackets 5 and 6. The bolt holes 10a to 10c of the mounting plate 10 and the bolt holes 5a, 6b and 6c of the brackets 5 and 6 are fastened by bolts (not shown).
[0025]
As shown in FIGS. 2 and 3, a tie-down hook 7 is provided at the front end portion of the front side frame 3, and a wire (not shown) is hooked on the tie-down hook 7 so that, for example, the automobile 1 can be pulled. It has become. The upper end portion of the tie-down hook 7 is joined to the outer surface of the front side frame 3, and the middle portion is joined to the outer surface of the front cross member 4.
[0026]
Here, the front side frame 3 is normally configured to be able to absorb energy by being buckled and deformed at the time of collision, but the front end portion of the front side frame 3 has a front cross member 4 and a bracket 5 in addition to the tie-down hook 7. , 6 are fixed and the portion is not deformed and is not deformed. Therefore, the shock absorbing member 20 provided at the front end portion of the front side frame 3 can function reliably.
[0027]
The attachment plate 10 is formed with an opening 11 smaller than the opening at the front end of the front side frame 3 at the center thereof, and is bent slightly toward the inner side (rear side) of the front side frame 3 at the inner edge of the opening 11. A bent flange 12 is provided. Although the bent flange portion 12 is integrally formed with the mounting plate 10, only the opening 11 may be formed in the mounting plate 10, and a flange member corresponding to the bent flange portion 12 may be separately fixed.
[0028]
The shock absorbing member 20 is connected to the tapered outer peripheral wall 21 that becomes thinner toward the front, the front wall 22 that is connected to the front end of the outer peripheral wall 21 and closes the front end of the shock absorbing member 20, and the rear end of the outer peripheral wall 21 in a bent shape. An annular flange 23 (which corresponds to a connecting wall portion) that extends outward is integrally formed to be open at the rear end, and is provided in a state of protruding forward from the front end portion of the front side frame 3.
[0029]
The opening 11 of the mounting plate 10 is formed larger than the rear end of the outer peripheral wall 21, and the rear surface of the flange 23 is placed on the front surface of the mounting plate 10 with the rear end of the outer peripheral wall 21 positioned on the front side of the opening 11. And the shock absorbing member 20 is attached. Since the portion of the flange 23 located on the front side of the opening 11 is not in contact with the mounting plate 10, it is a deformation promoting portion 23 a that is easily bent when a collision load is applied.
[0030]
Here, for example, the longitudinal length L of the shock absorbing member 20 is 100 mm, the thickness is t = 1.6 mm, the taper angle θ of the outer peripheral wall 21 is 10 degrees, and the deformation promoting portion 23 a that protrudes inward from the inner edge of the opening 11 is formed. The length β is 5 mm. The longitudinal length L, the thickness t, the taper angle θ of the outer peripheral wall 21, and the length β of the deformation promoting portion 23a are not limited to the above values, but the deformation promoting portion 23a. It is desirable to set the length β of at least about 5 mm.
[0031]
When a collision load is input to the shock absorbing member 20 from the substantially front side during a collision, a bending moment is applied to the outer peripheral wall 21 to bend the outer peripheral wall 21 inward, and the bending moment increases toward the rear. A bending moment also acts on the deformation promoting portion 23 a of the flange 23. Immediately after the collision, as shown in FIG. 4, the deformation promoting portion 23a is first deformed to the inner edge side of the opening 11 of the mounting plate 10, and in conjunction with the deformation of the deformation promoting portion 23a, end is gradually returned folded to the inside of the front side frame 3 is deformed buckling. At this time, the deformation promoting portion 23 a and the rear end portion of the outer peripheral wall 21 are guided by the bending flange portion 12 of the mounting plate 10.
[0032]
Thereafter, as shown in FIG. 5, the entire outer peripheral wall 21 is continuously buckled and deformed in order from the rear end side toward the front end side, and is folded back from the opening 11 into the front side frame 3. Finally, the collapse proceeds until the front end of the shock absorbing member 20 coincides with the mounting plate 10.
[0033]
Next, the results of experiments conducted by the inventors of the present invention on the energy absorption characteristics of the shock absorbing member 20 will be described with reference to FIGS. 6 and 8 are energy absorption structures in the prior art (comparative example), FIG. 7 is a diagram of energy absorption characteristics of the shock absorbing member 20A and the shock absorbing member 20 in FIG. 6, and FIG. 9 is a shock absorbing member in FIG. It is a diagram of the energy absorption characteristic of 20B and the impact-absorbing member 20. FIG. 7 and 9, the horizontal axis represents the deformation amount (crush amount) of the shock absorbing member, and the vertical axis represents the collision load acting on the shock absorbing member.
[0034]
The energy absorbing structure shown in FIG. 6 has an impact absorbing member 20A (having an outer peripheral wall 21A, a front wall 22A, and a flange 23A) having the same structure as that of the shock absorbing member 20, and a fixed opening at the front end of the front side frame 3. It is attached to a mounting plate 30 that is not formed in a forward protruding manner.
[0035]
In the energy absorbing structure of FIG. 6, as shown by the load curve b of FIG. 7, the impact load increases rapidly to near 100 KN immediately after the impact and before the impact absorbing member 20A starts buckling, and then the impact is increased. When the buckling collapse of the absorbing member 20A starts, the collision load is reduced to 40KN or less and maintained. Since the buckled portion of the shock absorbing member 20A is piled up in front of the mounting plate 30, the shock absorbing stroke can be secured only about 80mm. If the deformation exceeds about 80mm, the energy absorbing function is almost lost and the impact load is reduced. It rises remarkably.
[0036]
On the other hand, in the energy absorbing structure of the present plan, as shown by a load curve a in FIG. 7, the collision load is suppressed to 70 KN or less immediately after the collision and before the shock absorbing member 20 starts to be deformed. Even after the start of buckling collapse, the collision load does not decrease so much and is maintained at about 50-60 KN. In addition, since the shock absorbing member 20 is immersed inside the front side frame 3, the shock absorbing stroke can be ensured to be approximately 100 mm as much as the length of the shock absorbing member 20, and the collision occurs until the deformation amount is close to 100 mm. The load is maintained at about 50-60KN.
[0037]
That is, in the energy absorption structure of the present proposal, compared with the energy absorption structure of FIG. 6, the impact immediately after the collision can be mitigated, and the energy absorption performance is improved by an amount corresponding to the area (A + B−α) in the figure.
[0038]
Next, in the energy absorbing structure of FIG. 8, a shock absorbing member 20B having a cylindrical outer peripheral wall 35, a front wall 36, and a flange 37 is attached in the same manner as the attachment plate 10 fixed to the front end portion of the front side frame 3. It is attached to the plate 10B (having the opening 11B and the bent flange portion 12B) so as to protrude forward.
[0039]
In the energy absorbing structure of FIG. 8, as shown by the load curve d of FIG. 9, when the deformation amount of the impact absorbing member 20B is about 15 mm to 40 mm, the impact load is maintained substantially constant at around 60 KN. When the deformation amount of 20B is about 43mm to 80mm, the impact load drops considerably, and when the deformation amount exceeds about 80mm, the impact load increases rapidly and the energy absorption function is almost lost, and the shock absorption stroke is only about 87mm. It cannot be secured.
[0040]
That is, in the energy absorption structure of the present proposal, the energy absorption amount is the difference between the areas D and F indicated by the oblique lines and the areas C and E indicated by the oblique lines (D + F−C−) as compared with the energy absorption structure of FIG. E) is increased by the amount. In particular, since the area F due to the increase in the energy absorption stroke is large, the energy absorption performance is greatly improved. Note that the load curve c in FIG. 9 is slightly different from the load curve a in FIG. 7 because the structure and the like are slightly different.
[0041]
Thus, according to the energy absorbing structure, the rear end having the tapered outer peripheral wall 21 and the flange 23 that become thinner toward the front through the mounting plate 10 at the front end of the front side frame 3 that is open front. Since the open shock absorbing member 20 is provided so as to protrude forward through the flange 23 and the opening 11 larger than the rear end of the outer peripheral wall 21 of the shock absorbing member 20 is formed in the mounting plate 10, First, the rear end portion of the outer peripheral wall 21 and the deformation promoting portion 12a of the flange 23 are deformed to the opening 11 side, and then the entire outer peripheral wall 21 is buckled and deformed in order from the rear end portion to the front. Thus, it is possible to immerse into the inside of the front side frame 3 from the opening 11 while turning back in order from the rear end.
[0042]
As a result, it is possible to suppress a sudden increase in the collision load immediately after the collision, to reduce the impact on the occupant, to contribute to the energy absorption of the entire outer peripheral wall 21, and to deform the outer peripheral wall 21. Since the portion does not pile up in a lump on the front side of the front side frame 3 and the shock absorbing stroke for substantially the entire length L of the shock absorbing member 20 can be secured, the energy absorption can be remarkably improved.
[0043]
Moreover, since the outer peripheral wall 21 is formed in a taper shape that becomes thinner toward the front, even when a collision load is input to the shock absorbing member 20 from the direction inclined with respect to the length direction at the time of collision, the inclination angle is a predetermined angle. In the following cases, the outer peripheral wall 21 can be reliably immersed inside the front side frame 3, and the collision load input direction in which the shock absorbing member 20 can function can be expanded. Since the front end of the shock absorbing member 20 is closed by the front wall 22, the collision load can be transmitted almost uniformly to the outer peripheral wall of the shock absorbing member 20, and the outer peripheral wall 21 can be buckled and deformed substantially uniformly. .
[0044]
Since the attachment plate 10 is fixed to the front side frame 3 and the opening 11 is formed in the attachment plate 10, the shock absorbing member 20 can be easily and reliably attached to the front side frame 3 via the attachment plate 10. In addition, since the bent flange portion 12 that is bent toward the inner side of the front side frame 3 is provided at the inner edge portion of the opening 11 of the mounting plate 10, the strength of the inner edge portion is increased, and the outer peripheral wall is improved by the bent flange portion 12. 11 can be guided and smoothly folded back into the interior of the front side frame 3.
[0045]
Since the tie-down hook 7 is provided on the front side frame 3 in the vicinity of the shock absorbing member 20, the front end portion of the front side frame 3 becomes a portion that is not increased in strength and deformed, and inside the front end portion of the front side frame 3, The outer peripheral wall 21 can be reliably folded and immersed. In the above-described embodiment, the outer peripheral wall 21 of the shock absorbing member 20 is configured in a square tube shape, but the outer peripheral wall may be configured in a cylindrical shape in cross section.
[0046]
It should be noted that the energy absorbing structure of the above embodiment is merely an example, and various modifications are made without departing from the spirit of the present invention, and the outer end portion of the vehicle body frame other than the front side frame (for example, the rear side The present invention can be similarly applied to an energy absorbing structure having a structure in which the shock absorbing member 20 is fixed to the rear end portion or the like of the frame.
[0047]
【The invention's effect】
According to the vehicle energy absorption structure of the first aspect, as described in the section of the action, the connection wall portion and the base end portion of the outer peripheral wall easily collapse immediately after the collision. Shock can be mitigated. And since it can be continuously buckled and deformed in order from the base end portion of the outer peripheral wall toward the outer end side, the entire outer peripheral wall can contribute to the collision energy absorption.
[0048]
Since the deformed portion of the outer peripheral wall does not pile up on the outer end side of the vehicle body frame in the longitudinal direction of the vehicle body, it is possible to secure a shock absorption stroke that is almost the same as the entire length of the shock absorbing member, so that energy absorption is markedly improved. Can be increased. Since the outer peripheral wall is formed in a taper shape that becomes thinner outward in the vehicle front-rear direction, even if a collision load is input to the shock absorbing member at a slightly inclined angle with respect to its length direction at the time of collision, the shock absorbing member The shock absorbing function can be ensured.
[0049]
According to the energy absorption structure for a vehicle of claim 2, an energy absorption structure capable of absorbing basically the same effect as that of claim 1 and absorbing the collision energy at the time of a frontal collision of the vehicle is obtained. In particular, there is no space in the vicinity of the front end portion of the front side frame, but it is very advantageous because the shock absorbing stroke can be increased without increasing the total length of the shock absorbing member.
[0050]
According to the energy absorption structure for a vehicle of claim 3, the same effect as that of claim 1 or 2 can be obtained, but since the end of the shock absorbing member on the vehicle outer side in the vehicle front-rear direction is closed, the collision load is reduced. It can be transmitted almost uniformly to the outer peripheral wall of the shock absorbing member, and the outer peripheral wall can be buckled and deformed substantially uniformly.
[0051]
According to the automobile energy absorbing structure of claim 4, the same effect as that of claim 1 or 3 is obtained, but a mounting plate for mounting the shock absorbing member is fixed to the body frame, and the opening is formed in the mounting plate. Since it is formed, the shock absorbing member can be easily and reliably attached to the outer end portion of the vehicle body frame via the mounting plate, and the energy absorbing function of the shock absorbing member can be ensured.
[0052]
According to the automobile energy absorption structure of claim 5, the same effect as that of claim 4 is obtained, but the bent flange portion bent toward the inner side of the body frame is provided at the inner edge portion of the opening of the mounting plate. The strength of the inner edge portion of the opening portion of the mounting plate can be increased, and the outer peripheral wall can be guided by the bent flange portion so that it can be smoothly folded back into the body frame.
[0053]
According to the automobile energy absorption structure of claim 6, the same effect as that of claim 2 is obtained and the same effect as that of claim 4 or 5 is obtained.
[0054]
According to the energy absorption structure for an automobile of claim 7, the same effect as that of claim 6 is obtained, but since the front side frame is provided with a tie-down hook in the vicinity of the impact absorbing member, the front end portion of the front side frame is The strength increases and the portion is not deformed, and the outer peripheral wall can be reliably folded and immersed inside the front end portion of the front side frame.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a front side frame on the right side of a vehicle body and an impact absorbing member thereof according to an embodiment of the present invention.
FIG. 2 is a perspective view of the front side frame and an energy absorbing structure.
3 is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is a longitudinal sectional view of an energy absorption structure (a state immediately after a collision).
FIG. 5 is a longitudinal sectional view of an energy absorption structure (in the middle of buckling deformation after a collision).
FIG. 6 is a longitudinal sectional view of an energy absorption structure in the prior art.
7 is an energy absorption characteristic diagram of the energy absorption structure of FIGS. 3 and 6. FIG.
FIG. 8 is a longitudinal sectional view of an energy absorption structure in the prior art.
9 is an energy absorption characteristic diagram of the energy absorption structure of FIGS. 3 and 9. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Car 2 Car body 3 Front side frame 7 Tie-down hook 10 Mounting plate 11 Opening part 12 Bending flange part 20 Shock absorbing member 21 Outer peripheral wall 23 Flange 23a Deformation promotion part

Claims

In the structure that absorbs automobile collision energy,
The end portion of the outer side the longitudinal direction of the vehicle body frame, a proximal opening and a connecting wall portion continuous to the bent shape to the proximal end of the outer peripheral wall and tapered outer peripheral wall becomes thinner as the outside of the vehicle longitudinal direction the Jo shock absorbing member, via the connecting wall fixed in a state of projecting in the vehicle longitudinal direction of the outer, peripheral wall of the base of the shock absorbing member to the end portion in the vehicle longitudinal direction of the outer side of the body frame Forming an opening larger than the end,
An automobile energy absorbing structure configured to absorb collision energy by immersing the outer peripheral wall by folding it back into the body frame from the opening during a collision.

In the structure that absorbs automobile collision energy,
A shock absorbing member with an open rear end having a tapered outer peripheral wall that becomes thinner toward the front and a connecting wall portion that is bent at the rear end of the outer peripheral wall is connected to the front end of the front side frame of the vehicle body. Fixed in a state of projecting forward through the part, forming an opening larger than the rear end of the outer peripheral wall of the shock absorbing member at the front end of the front side frame ,
An automobile energy absorption structure configured to absorb collision energy by immersing the outer peripheral wall while being folded back into the front side frame from the opening during a collision.

The energy absorbing structure for an automobile according to claim 1 or 2, wherein an end of the shock absorbing member on the vehicle outer side in the vehicle front-rear direction is closed.

4. The vehicle energy absorption structure according to claim 1, wherein a mounting plate for mounting an impact absorbing member is fixed to the vehicle body frame, and the opening is formed in the mounting plate.

5. The energy absorbing structure for an automobile according to claim 4, wherein a bent flange portion bent toward the inner side of the vehicle body frame is provided at an inner edge portion of the opening portion of the mounting plate.

6. The automobile energy absorbing structure according to claim 4, wherein the vehicle body frame is a front side frame.

7. The energy absorbing structure for an automobile according to claim 6, wherein a tie-down hook is provided on the front side frame in the vicinity of the shock absorbing member.