JP4373553B2

JP4373553B2 - Energy absorption member structure for car body

Info

Publication number: JP4373553B2
Application number: JP35604899A
Authority: JP
Inventors: 浩志狩集; 徹橋村
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 1999-12-15
Filing date: 1999-12-15
Publication date: 2009-11-25
Anticipated expiration: 2019-12-15
Also published as: JP2001171447A

Description

【０００１】
【発明の属する技術分野】
本発明は、特に車体衝突時のエネルギー吸収性能に優れたアルミニウム合金製（以下、アルミニウムを単にAlと言う）押出形材からなる車体用エネルギー吸収部材構造に関するものである。
【０００２】
【従来の技術】
自動車の車体には、バンパー補強材やドアビーム等の車体用エネルギー吸収部材が設けられている。この内、例えば、車体の前端および後端に取り付けられているバンパーの内部には、強度補強部材としてのバンパー補強材 (バンパーリインフォースメント、或いはバンパーレインフォースなどとも言う) が設けられている。このバンパー補強材は、周知の通り、バンパーステイなどの車体連結用部材を介して、フロントサイドメンバやリヤサイドメンバ等、車体前後方向の骨格部材の車体フレーム (車体メンバ) に連結、固定されて、車体用エネルギー吸収部材構造を構成している。また、前記ドアビームなどはブラケットやフレームなどの車体連結用部材を介して、車体としてのドアフレームに連結、固定されて、車体用エネルギー吸収部材構造を構成している。
【０００３】
今、バンパー補強材の場合を例にすると、より具体的には、例えば特開平4-31152 号公報等に開示されているように、車体長手方向に延在するフロントサイドメンバの前部に、断面形状が略矩形 (口形) の中空構造のバンパーステイーを介して、同じく中空構造のバンパー補強材を略車幅方向 (略水平方向) 固定、延在させる構造である。そして、このような構造とすることによって、車体の前方からの衝突に対し、バンパー補強材が横方向( 略水平方向) に圧壊、およびバンパーステイーが軸方向に圧壊して衝突エネルギーを吸収する。
【０００４】
したがって、これら車体用エネルギー吸収部材としてのバンパー補強材と、車体連結用部材としてのバンパーステイとの結合構造には、車体の衝突により加わった外力のエネルギー (衝突エネルギー) を、自らの塑性変形 (座屈変形) により吸収し、前記車体メンバ等を保護する性能が求められる。
【０００５】
近年、これらバンパー補強材やバンパーステイ、或いはフロントサイドメンバやリヤサイドメンバ等に、軽量化のために、従来使用されていた鋼材に代わって、5000系、6000系、7000系等の高強度Al合金製の押出形材 (長手方向に同一断面形状を有する形材) が使用され始めている。
【０００６】
Al合金は、鋼などに比して、前記エネルギー吸収性能に優れる。また、長手方向に同一断面形状を有するAl合金製押出形材は、バンパー補強材、バンパーステイなどに汎用されている、剛性に優れた断面形状が略矩形の中空構造を、効率的に、かつ大量に製造することが可能である。
【０００７】
【発明が解決しようとする課題】
しかし、このような断面形状が略矩形の中空構造を有し、Al合金製押出形材からなるバンパー補強材およびバンパーステイを結合した車体用エネルギー吸収部材の場合、バンパー補強部材に対する略水平方向からの荷重 (車両の衝突時の) に対し、衝突エネルギーの要求吸収性能が不足する場合があるという問題を生じる。
【０００８】
例えば、図16(a) に具体例を示す通り、従来のAl合金製押出形材からなるバンパー補強材101 は、前壁部104 と後壁部105 とを2 つのウエブ (側壁)103_a、103 _bにより接続した断面形状が口形の形状を有している。そして、図示しないフロントサイドメンバの前部に、同じくAl合金製押出形材からなる、断面形状が略矩形の中空構造のバンパーステイ102 を介して固定されている。なお、バンパー補強材101 とバンパーステイ102 とは、溶接あるいはボルト等の締結具107 等により互いに固定されている。
【０００９】
図16(b) に示す通り、車両の衝突時に、バンパー補強材101 に対し、略水平方向から大きな荷重F が加わった場合、バンパー補強材101 は横圧壊 (水平方向に変形) 状態となる。この時、バンパー補強材101 の中空構造におけるウエブ103 _a、103 _bには、ウエブの立脚方向 (水平方向) に力がかかる結果、通常、曲げ変形箇所107 を起点に、ウエブ103 _a、103 _bが中空構造の外側方向に変形、座屈する。この結果、バンパー補強材101 が衝突エネルギーの吸収を行い、フロントサイドメンバ等の車体メンバ類が圧壊するのを保護する。
【００１０】
ここにおいて、車両の衝突時に、バンパー補強材101 に対し、略水平方向から大きな荷重F が加わった場合、バンパー補強材101 は横圧壊状態となる。この時、バンパー補強材101 の中空構造におけるウエブ103 _a、103 _bには、ウエブの立脚方向 (水平方向) に力がかかる結果、通常、曲げ変形箇所107 を起点に、ウエブが中空構造の外側方向に変形乃至座屈する。そして、更にこの中空構造の外側方向への変形が進と、図16(b) に示す通り、ウエブ103 _a、103 _bと後壁部105 との接続箇所 (コーナー部)106や、曲げ変形箇所107 等で割れが生じる。
【００１１】
この結果、更に荷重F が加わっても、これより後では、バンパー補強材101 の変形が生じず、バンパー補強材101 によるエネルギー吸収が行われないことになる。したがって、車両の衝突時において、Al合金製押出形材からなるバンパー補強材では、車両の衝突エネルギー等の大きさによって、衝突のエネルギー吸収量が不足して、フロントサイドメンバ等の車体メンバ類に損傷を与えることにつながる。
【００１２】
また、更に大きな荷重F が加わって前記変形が進むと、図16(c) に示す通り、バンパー補強材101 を支持するバンパーステイ102 が、その前端部で接しているバンパー補強材101 の後壁部105 を突き抜けて、バンパー補強材101 の中空構造内に侵入する、いわゆるステイの打ち抜き現象が生じる可能性もある。
【００１３】
このステイの打ち抜き現象が生じた場合、これより後では、バンパー補強材101 の変形が生じず、バンパー補強材101 によるエネルギー吸収が行われないことになる。したがって、このステイの打ち抜き現象が生じた場合、車両の高速衝突時における、バンパー補強材101 のエネルギー吸収量が不足して、フロントサイドメンバ等の車体メンバ類に損傷を与えることにつながる。
【００１４】
これに対し、衝突のエネルギー吸収量を大きくするために、或いは、更にこれに加えてステイの打ち抜き現象を防止して衝突のエネルギー吸収量をより大きくするために、バンパー補強材101 を構成するAl合金自体を高強度化する、或いはウエブ103 _a、103 _bや後壁部105 のAl合金の厚みを厚くする、バンパー補強材に、断面形状が目形、日形、田形等の中リブを設けて補強する等の方法が考えられる。
【００１５】
しかし、Al合金材を高強度化した場合に、押出等の形材製造や曲げ等の形材の成形加工が難しくなるとともに、割れが生じやすく、却って、衝突のエネルギー吸収量を小さくしたり、ステイの打ち抜き現象を助長することにもつながる。また、単にAl合金材の厚みを厚くしたり、前記中リブを設けた場合、重量が増加して、Al合金による軽量化の利点が損なわれるとともに、バンパー補強材が塑性変形しにくくなり、却って、車両の衝突時におけるエネルギー吸収量が不足する。更に、単にAl合金材の厚みを厚くしたり、前記中リブを設けた場合、バンパー補強材圧壊時の最大荷重が、サイドメンバーの許容荷重以上に高くなり、却って、フロントサイドメンバ等の車体メンバ類に損傷を与える可能性も高い。
【００１６】
したがって、これまで以上に、バンパー補強材構造に対して、衝突エネルギー吸収量の増大およびステイの打ち抜き現象の防止が求められている。そして、これに対し、バンパー補強材構造の構造面や設計面からの改善が求められている (ドアビーム等の他のAl合金製車体用エネルギー部材でも同様) 。にも拘わらず、バンパー補強材の構造や設計を大幅に変更した場合には、他の車体メンバやバンパーステイ等の設計変更や車体自体の設計変更につながる可能性もあり、このような変更は許容できない。
【００１７】
この点、現行のバンパー補強材構造のデザインや設計条件を大幅に変更することなく、簡単な改善により、前記衝突エネルギー吸収量の増大、更に打ち抜き現象の防止をはかることができれば、それにこしたことはないが、効果的かつ効率的な改善策はこれまでに無かったのが実情である。
【００１８】
したがって、本発明の目的は、現行のバンパー補強材やドアビーム等のエネルギー吸収部材構造のデザインや設計条件を大幅に変更することなく、簡単な改善により、車両の衝突時のエネルギー吸収性能を高めることができ、好ましくは前記打ち抜き現象の防止も達成できる、断面形状が略矩形の中空構造を有するAl合金製押出形材からなるエネルギー吸収部材構造を提供しようとするものである。
【００１９】
【課題を解決するための手段】
この目的を達成するために、本発明の要旨は、略水平方向に延在して用いられる車体用エネルギー吸収部材と、その両端部に結合された車体連結用部材とからなる車体用エネルギー吸収部材構造であって、車体用エネルギー吸収部材と車体連結用部材とを、断面形状が略矩形の中空構造を有するアルミニウム(Al)合金製押出形材から各々構成し、車体結合用部材の前端に凸部を設け、かつ、前記車体連結用部材の前端に対応する車体用エネルギー吸収部材の後壁部面に、前記凸部に対応する部分的なスリットまたは凹部を設け、これらの部分的なスリットまたは凹部を通じて、前記凸部を車体用エネルギー吸収部材の中空構造空間内に突出させて、車体用エネルギー吸収部材と車体連結用部材とを結合したことである。
【００２０】
車体用エネルギー吸収部材と車体連結用部材とを、断面形状が略矩形の中空構造を有するAl合金製押出形材から各々構成し、車体結合用部材の前端に凸部を設け、該凸部を車体用エネルギー吸収部材の中空構造空間内に突出させて、車体用エネルギー吸収部材と車体連結用部材とを結合している。この結果、現行の車体用エネルギー吸収部材構造のデザインや設計条件を大幅に変更することなく、簡単な改善により、車体用エネルギー吸収部材構造に対する略水平方向からの荷重に対して、衝突エネルギーの吸収性能を高めることが可能となる。また、凸部の設け方により、バンパー補強材圧壊時の最大荷重の調節も可能となる。
【００２１】
また、前記車体連結用部材の前端に対応する車体用エネルギー吸収部材の後壁部面に、前記凸部に対応するスリット (後壁部に設けた貫通孔) または凹部を設けている。この結果、車体用エネルギー吸収部材と車体連結用部材との結合における位置決めや、結合自体も容易となって、バンパー補強構造の組み立てが容易となった上で、衝突エネルギーの吸収性能も高めることが可能となる。
【００２２】
更に、前記車体連結用部材の前端と結合される車体用エネルギー吸収部材の両端部分のウエブの両外壁面に、部分的な凹みを予め設け、車体用エネルギー吸収部材に対する略水平方向からの荷重に対して、前記部分的な凹みを起点に、前記両端部分のウエブが中空構造の内側に屈曲するように構成している。この結果、現行の車体用エネルギー吸収部材構造のデザインや設計条件を大幅に変更することなく、簡単な改善により、車体用エネルギー吸収部材構造に対する略水平方向からの荷重に対して、ステイの打ち抜き現象防止等による衝突エネルギーの吸収量が大きくなる効果や、衝突初期のピーク荷重を一定以下に抑制する効果を有し、衝突時に、フロントサイドメンバ等の車体メンバ類に損傷を与えることがなくなる。
【００２３】
また、ウエブの両外壁面に設けた部分的な前記凹みが、車体用エネルギー吸収部材の長手方向が長軸、車体用エネルギー吸収部材の幅方向が短軸となるような略楕円形の形状であるため、車体用エネルギー吸収部材構造に対する略水平方向からの荷重に対して、該凹みを起点に前記両端部分のウエブが中空構造の内側に、より屈曲しやすくすることができる。この結果、前記効果をより高めることができる。
【００２４】
更に、前記効果を得る凹みを、エンボス加工により、ウエブの両外壁面に、部分的に、かつ簡便に設けることが可能となる。
【００２５】
そして、Al合金として、AA乃至JIS 5000系、6000系、7000系から選択される、成形性が良くかつ高強度の規格Al合金を用いるので、押出加工等、車体用エネルギー吸収部材と車体連結用部材への製造がしやすく、かつ、衝突エネルギー吸収性能を高めることができる。
【００２６】
【発明の実施の形態】
以下、本発明の好適な実施形態について、バンパー補強部材構造の場合について、図面を用いて説明する。
【００２７】
本発明では、前記した通り、現行の車体用エネルギー吸収部材構造のデザインや設計条件を大幅に変更することなく、簡単な改善により、前記打ち抜き現象を防止し、車体の衝突時のエネルギー吸収性能を高める。このため、断面形状が略口形の中空構造を有するAl合金製押出形材からなるバンパー補強部材の基本的な構造は、前記した図16(a) の従来技術と、基本的に同じである。
【００２８】
即ち、図1 、図6 、図9 、図10に、本発明に係るバンパー補強部材1a〜1eの各実施態様を斜視図に示す。これら各図の通り、バンパー補強部材1a〜1eは、前壁部4 と後壁部5 とを、2 つのウエブ 3_a、3 _bにより接続した断面形状が略口形の中空一体構造を有している。そして、この中空一体構造は、Al合金製押出形材からなり、長手方向に渡って略口形の断面形状は同一である。本発明に係るバンパー補強部材の断面形状は、軽量化の点からは、口形の中空構造が好ましいし、口形の軽量中空構造で可能である。ただ、車種によって要求強度が異なり、また、軽量化よりも高強度が要求されるような場合もある。したがって、このような場合には、バンパー補強部材をより補強するために、例えば、中空構造内に補強用の中リブを入れて、断面形状を日形、田形、目形等にすることなども可能である。
【００２９】
また、本発明車体用エネルギー吸収部材構造を構成する、車体連結用部材としてのバンパーステイは、2a〜2kとして、図2 、図7 、図9(本発明バンパー補強構造を示す) 、図11に正面図で各実施態様を示す通り、バンパー補強部材と同様に、断面形状は基本的に、口形、日形等の、略矩形の中空一体構造を有している。断面形状はこの他、田形、目形等でも良い。そして、この中空一体構造は、Al合金製押出形材からなり、長手方向に渡って断面形状は同一である。そして、これらのバンパーステイ2a〜2kは、後述する通り、各々対応するバンパー補強部材1a〜1eと結合、固定されて、図3 、図8 、図9 、図12に正面図で各実施態様を示す、本発明バンパー補強構造を構成する。これらバンパーステイのいずれの態様でも、吸収すべき衝突エネルギー量に大きな相違はないため、主として、デザインや製造のし易さ等の問題から適宜選択される。
【００３０】
なお、図3 、図8 、図9 、図12の本発明車体用エネルギー吸収部材構造に係るバンパー補強構造は、バンパーステイを介して、各々のフロントサイドメンバ8 等の車体メンバ類の前端部にボルト等の適宜の締結具10により固定される。また、バンパー補強部材1 とバンパーステイ2 とは、従来と同じく、溶接あるいはボルト等の適宜の締結具等により互いに固定する。
【００３１】
次に、より具体的に、各図を用いて、本発明のバンパー補強構造を説明する。図1 は、バンパー補強部材1aの後壁部5 の面で、バンパーステイとの接続面にバンパー補強部材1aの長手方向で、かつ水平方向に延在するスリット6 (横スリット) を設けた例を示す斜視図である。このスリット6 は、バンパーステイの前端 (端部先端) の凸部を、バンパー補強部材の中空構造空間内に突出させるためのものである。この図1 のように、水平方向に延在する1 個のスリット6 を設けた例では、図2(a)か図2(d)、または図2(f)に正面図を示す、1 個の凸部7aか7d、または7fを有するバンパーステイ2a (断面日形、但し凸部以外の断面、以下同じ) か2d (断面口形) 、または2f (断面日形) を用いる。
【００３２】
前記スリット6 を通じて、バンパーステイの凸部をバンパー補強部材の中空構造空間内に突出させるように、バンパー補強部材とバンパーステイとを結合させるために、バンパーステイの凸部7a、7d、7fの大きさ (厚み×幅) と、スリット6 の大きさ (厚み×幅) 、更には、バンパー補強部材1aのウエブ3a、3bの長さとバンパーステイの凸部7a、7d、7fの長さ、そしてスリット6 の大きさと数、更には位置を調節して、各々対応させる。
【００３３】
ここにおいて、図2(b)か図2(e)、または図2(c)に正面図を示す、2 個の凸部7b、7e、または3 個の凸部7cを有するバンパーステイ2b (断面日形) か2e (断面口形) 、または2c( 断面日形) を用いる場合には、これに対応するバンパー補強部材のスリット6 を、2 個または3 個設けるように適宜調節する。そして、これらスリットおよびバンパーステイの凸部の大きさと形状は、後述するごとく、バンパーステイの凸部に負担させるべき、衝突荷重の大きさによって、基本的に定まる。
【００３４】
図3 に、バンパー補強部材とバンパーステイとを結合させた本発明のバンパー補強構造の正面図を示す。図3 は、前記バンパー補強部材1aを、スリット6 を通じて、図2 (a) のバンパーステイ2aを結合させた例である。本例では、バンパーステイ2aの凸部7aの先端を、バンパー補強部材1aの後壁部5 に設けたスリット6 を通じて、バンパー補強部材の中空構造空間内に突出させ、前壁部4 の内壁面に当接させている。バンパーステイ2aの凸部7aの先端は、後述するように、必ずしも、前壁部4 の内壁面に当接させる必要はなく、前壁部4 の内壁面に当接させず、中空構造空間内に臨ませるだけでも良い。
【００３５】
なお、バンパーステイ2aは、その係止片20を通じて、フロントサイドメンバ8 等の車体メンバ類の前端部にボルト等の適宜の締結具10により固定され、バンパー補強部材を車体メンバ類に連結する機能も有している。即ち、バンパー補強部材1aは、車体の前方のバンパーの態様を例に示すと、自動車の車幅方向に間隔を空けて、かつ車体の長手 (走行) 方向に延在する2 本のフロントサイドメンバ8 (図示は1 本) の各々の前端部に、各々バンパーステイ2aを介して、略水平方向 (車幅方向) に延在するように、その両端部において、固定されている。なお、車体後方のバンパーの態様も、基本的にはこれと同じである。
【００３６】
なお、この内壁面の当接部分には、バンパーステイ2aの凸部7aの先端を係り止める、凸部7aの先端の位置決めと固定のための係止部9aを、選択的に設けている。これら係止片の形状は、図4(a)〜(e) の正面図に示す、バンパーステイ2 の凸部7a〜7iの先端形状のバリエーションの選択に応じて適宜選択される。図5 は、バンパーステイの凸部の先端部形状と、前壁部4 の内壁面の係止部9 との関係を正面図で示したもので、図5(a)は、図4 (b) のT 字形凸部7gのT 字部分を前壁部4 の内壁面に係止部を設けずに当接させたもの、図5(b)は、図4 (c) のU 字形凸部7hのU 字部分を前壁部4 の内壁面に設けた係止部9bに当接させたものを示している。これら、前壁部4 の内壁面に係止部を設けるか否か、また設ける場合の形状は、バンパーステイの凸部の先端形状と、この先端の位置決めと固定のための必要性や必要条件から適宜選択される。
【００３７】
このような本発明のバンパー補強構造の作用について以下に説明する。図3 において、今、車両の衝突によって、矢印F1で示す水平方向の衝撃荷重が、バンパー補強部材1aの全面 (前壁部4)にかかった場合、バンパー補強部材1aの2 つのウエブ 3_a、3 _bに荷重がかかるとともに、前壁部4 の内壁面に当接しているバンパーステイ2aの凸部7aにも荷重がかかる。このことによりウエブ 3_a、3 _bの荷重負担が軽減され、割れ等の破壊を生じずに、変形して、エネルギー吸収が行われることになる。したがって、車両の高速衝突時において、Al合金製押出形材からなるバンパー補強部材でも、衝突のエネルギー吸収量が不足せず、フロントサイドメンバ等の車体メンバ類に損傷を与えることが防止できる。
【００３８】
このような作用は、前壁部4 の内壁面に当接させず、中空構造空間内に臨ませた場合も同様である。但し、この場合は、当初の水平方向の衝撃初期荷重はウエブ 3_a、3 _bのみで負担するものの、衝撃荷重によるバンパー補強部材1aの前壁部4 の後面側に向かう変形に伴って、前壁部4 がバンパーステイ2aの凸部7aに当接し、すぐに荷重を分担する。そして、これ以後は、前記の場合と同様の作用効果を有する。
【００３９】
また、一方、バンパーステイの凸部の個数や大きさ等の設け方により、バンパー補強部材の圧壊時の最大荷重を調節することができる。通常、断面形状が略矩形の中空構造のバンパー補強部材の前記圧壊時の最大荷重は必然的に高い。したがって、この最大荷重が、フロントサイドメンバ等の車体メンバ類の、車種等によって異なる、許容荷重 (強度) よりも高い場合には、車両の衝突時において、バンパー補強部材構造の変形による十分なエネルギー吸収が行われるよりも先に、フロントサイドメンバ等の車体メンバ類に衝突時の荷重がかかり、これら車体メンバ類に損傷を与えることにつながる。このため、バンパーステイの前記凸部の個数や大きさ等の設け方は、バンパー補強部材の前記スリットの設け方と合わせて、バンパー補強部材構造、特にバンパー補強部材の圧壊時の最大荷重を、フロントサイドメンバ等の車体メンバ類の許容荷重 (強度) よりも高くならないように設けることが好ましい。
【００４０】
次に、図6 は、バンパー補強部材1bの後壁部5 の面で、バンパーステイとの接続面に、バンパー補強部材1bの幅方向で、かつ垂直方向に延在するスリット9 (縦スリット) を3 本設けた例を示す斜視図である。このスリット9 も、バンパーステイの前端の凸部を、バンパー補強部材の中空構造空間内に突出させるためのものである。図6 のように、垂直方向に延在する3 個のスリット9 を設けた例では、図7(c)に示す、3 個の凸部7lを有するバンパーステイ2i (断面日形) を用いる。スリット9 を1 本、または2 本設ける場合には、図7(a)か図7(b)に正面図を示す、2 個、または3 個の凸部7jか7hを有するバンパーステイ2h (断面日形) か2k (断面口形) を用いる。
【００４１】
前記スリット9 を通じて、図1 の横スリットの場合と同様に、バンパーステイの凸部をバンパー補強部材の中空構造空間内に突出させるように、バンパーステイの凸部とスリット9 の大きさと数、更には位置を調節して、バンパー補強部材とバンパーステイとを結合させる。そして、これらスリットおよびバンパーステイの凸部の大きさと形状は、前記したごとく、バンパーステイの凸部に負担させるべき、衝突荷重の大きさによって、基本的に定まる。
【００４２】
図8 に、前記縦スリット9 を通じて、バンパー補強部材とバンパーステイとを結合させた本発明のバンパー補強構造の正面図を示す。図8 は、前記バンパー補強部材1bを、スリット9 を通じて、図7 (a) のバンパーステイ2gを結合させた例である。本例では、バンパーステイ2gの凸部7jの先端を、バンパー補強部材1bの後壁部5 に設けたスリット9 を通じて、バンパー補強部材の中空構造空間内に突出させ、前壁部4 の内壁面に当接させている。この場合も、バンパーステイ2gの凸部7jの先端を必ずしも、前壁部4 の内壁面に当接させる必要はないのは、前記した通りである。なお、バンパーステイ2gは、その係止片19を通じて、フロントサイドメンバ8 等の車体メンバ類の前端部にボルト等の適宜の締結具10により固定され、バンパー補強部材を車体メンバ類に連結する機能も有している。
【００４３】
このような縦スリットタイプの本発明のバンパー補強構造の作用は、前記横スリットタイプの本発明のバンパー補強構造の作用と全く同じである。
【００４４】
図9 (a) は、縦スリット11を用いた例を示す平面図であるが、図1 や図6 のようなバンパー補強部材が真っ直ぐな場合ではなく、両端部が内側に湾曲したタイプのバンパー補強部材の屈曲部とバンパーステイとを結合させた本発明のバンパー補強構造を示す。本例では、バンパーステイ2jの凸部7mの先端を、前記図8 と同様に、バンパー補強部材1cの後壁部5 に設けた1 本の縦スリット11を通じて、バンパー補強部材の中空構造空間内に突出させ、前壁部4 の内壁面に当接させている。この場合、バンパーステイ2jの前面13は、バンパー補強部材の後壁部5 の傾斜面に対応した傾斜面を有している。
【００４５】
これに対して、図9 (b) は、前記図9 (a) の場合と同じく、両端部が内側に湾曲したタイプのバンパー補強部材の屈曲部とバンパーステイとを結合させた本発明のバンパー補強構造の平面図を示している。ただ図9 (b) の場合には、横 (水平) スリット14を用いた例であり、バンパーステイ2kの凸部7nの先端を、前記図9 (a) と同様に、バンパー補強部材1dの後壁部5 に設けた1 本の横スリット14を通じて、バンパー補強部材の中空構造空間内に突出させ、前壁部4 の内壁面に当接させている。しかし、このような形状のバンパーステイ2kは押出により一体に製造することができず、切削等によって形状を出す必要があるので、本発明では不適である。したがって、両端部が内側に湾曲したタイプのバンパー補強部材では、バンパーステイを押出加工により効率的に製造使用とすると、前記図9 (a) で示した縦スリット9 を用いる必要があることが分かる。
【００４６】
更に、図10は、バンパー補強部材1eの後壁部5 の面で、バンパーステイとの接続面に、凹部15を設けた例を示す斜視図である。この凹部15も、バンパーステイの前端の凸部を、バンパー補強部材の中空構造空間内に突出させるためのものである。図10のように、凹部15を設けた例では、図11(a) 、(b) に示す、前記凹部15に対応する形状を有する凸部2dや2fを有するバンパーステイ2d (断面口形) 、か2f (断面日形) を用いる。
【００４７】
図12に、前記凹部15を通じて、バンパー補強部材とバンパーステイとを結合させた本発明のバンパー補強構造の正面図を示す。本例では、バンパーステイ2dや2fの凸部2dや2fを、凹部15の空間内に嵌め合わせて、バンパー補強部材とバンパーステイとを結合させる。
【００４８】
このような凹部タイプの本発明のバンパー補強構造の作用は、前記スリットタイプの本発明のバンパー補強構造の作用と全く同様に、凹部と凹部内に収容されたバンパーステイの凸部が、衝撃荷重を分担して負担することにより、衝撃エネルギーの吸収量を大きくするものである。
【００４９】
更に、大きな衝撃荷重が加わった場合の前記ステイの打ち抜き現象を防止するための、また、バンパー補強部材の圧壊時の最大荷重を、フロントサイドメンバ等の車体メンバ類の許容荷重 (強度) よりも高くならないように下げるための、本発明の好ましい実施態様を以下に説明する。
【００５０】
図13は、前記ステイの打ち抜き現象を防止するための部分的な凹み16a 、16b を、バンパー補強部材1aのウエブ3 _a、3 _bの、ステイと連結される両端部分のウエブの両外壁面 (スリット6 に対応して) に予め設けた状態を示す斜視図である。この凹み16_a、16_bは、バンパー補強部材1 に対する略水平方向からの荷重に対して、前記凹み6 _a、6 _bを起点に、前記両端部分のウエブ3 _a、3 _bのみが部分的に中空構造の内側に屈曲するようにするもので、凹み6 _a、6 _bのウエブ3 _a、3 _bに設ける位置、その大きさ (幅と長さ) と深さ等は、車種等によって決まる、バンパー補強材圧壊時の要求最大荷重量 (最大荷重の低減度合い) や、衝突エネルギー吸収量の要求程度、そして、打ち抜き現象の防止に必要な中空構造の内側への屈曲程度等の観点から、適宜選択される。
【００５１】
なお、本実施態様では、凹み6 _a、6 _bは、ウエブ3 _a、3 _bの両外壁面のうちの、ステイ側後方に、バンパー補強部材1 の長手方向に延在するように設けている。この方が、外壁面の前方側に設けるよりも、ウエブ3 _a、3 _bを中空構造の内側に屈曲させやすい。
【００５２】
そして、凹み6 _a、6 _bは、バンパー補強部材1 の長手方向の径L₁が長軸、バンパー補強部材1 の幅方向の径L₂が短軸となるような略楕円形に設けている。凹み6 _a、6 _bをこのような略楕円形とすることにより、まず、凹み6 _a、6 _bの深さとともに凹み6 _a、6 _bの幅方向の径L₂の大きさによって、バンパー補強部材1 への略水平方向からの荷重に対する、ウエブ3 _a、3 _bの中空構造の内側への屈曲の起点となることを確保する。凹み6 _a、6 _bの深さと幅方向の径L₂があまり小さすぎると、略水平方向からの荷重の大きさにもよるが、前記屈曲の起点となり得ず、結果として、前記バンパー補強材圧壊時の最大荷重量の低減やエネルギー吸収量の向上およびステイの打ち抜き防止効果が弱まる。
【００５３】
また、凹み6 _a、6 _bの深さとともに、凹み6 _a、6 _bの長手方向の径L₁や幅方向の径L₂の大きさによって、バンパー補強部材1 への略水平方向からの荷重に対する、ウエブ3 _a、3 _bの中空構造の内側へ屈曲する部分の、バンパー補強部材1 における長手方向の長さを規定できる。この凹み6 _a、6 _bの深さ、長手方向の径L₁や幅方向の径L₂があまり小さすぎると、ウエブ3 _a、3 _bの中空構造の内側へ屈曲する効果を発揮できないで、従来技術のように、ウエブ3 _a、3 _bが中空構造の外側方向に変形乃至座屈する。また、ウエブ3 _a、3 _bが中空構造の内側へ屈曲する部分を十分確保できず、前記バンパー補強材圧壊時の最大荷重量やエネルギー吸収量の向上およびステイの打ち抜き防止効果が弱まる。
【００５４】
この点は、凹みが楕円形でなくても、円形等の他の形状を有していても同じであり、要は、凹みを予め設けるに際しては、バンパー補強部材に対する略水平方向からの荷重に対して、前記部分的な凹みを起点に、前記両端部分のウエブが中空構造の内側に屈曲するように設けることが重要となる。
【００５５】
なお、凹み6 _a、6 _bの他の設け方として、前記凹みの効果を阻害しない範囲で、前記図13の通り、凹みをウエブの両外壁面に1 個ずつ、また凹みの長さL₁をバンパーステイの幅と同じ長さとせずとも、凹みの長さL₁をバンパーステイの幅より多少長くしても、或いは短くしても、更には、バンパー補強部材の長手方向に分割して、2 個以上設けても良い。
【００５６】
(凹みの作用)
図14(a) 、(b) に、上記に説明した本発明における凹み6 _a、6 _bの作用を示す。なお、図14(a) 、(b) は、図13に示した本発明バンパー補強部材の実施態様の正面図である。
【００５７】
今、バンパー補強部材1 _aに対し、略水平方向からの衝突荷重F が加わった場合、凹み16_a、16_bを起点として、前記両端部分のウエブ3 _a、3 _bを中空構造の内側に屈曲しやすくする。この結果、前記バンパー補強材圧壊時の最大荷重量の低減が図れる。また、更に、変形が進んだとしても、ウエブと後壁部5 との接続箇所 (コーナー部) や、曲げ変形箇所等で割れが生じる可能性が少ない。この結果、エネルギー吸収量の向上が図れる。
【００５８】
そして、前記箇所に割れが生じない場合でも、あるいは割れが生じた場合でも、このウエブが内側に座屈した部分17_a、17_bによって後壁部5 を保持することによって、或いは、ウエブが内側に座屈した部分17_a、17_bと後壁部5 との干渉作用によって、バンパーステイ2 による後壁部5 の突き抜けを防止して、ステイの打ち抜き現象を防止する。
【００５９】
この結果は、前記割れやステイの打ち抜き現象による衝突エネルギー吸収量の低下を防止し、ウエブの内側への座屈後も、バンパー補強部材1 の変形による、エネルギー吸収が継続して行われ、衝突エネルギーの吸収量が大きくなる効果をもたらす。したがって、本発明における好ましい要件である前記凹みは、バンパー補強部材の荷重変位特性における、衝突初期のピーク荷重を一定以下に抑制する効果、ステイの打ち抜き現象防止等による衝突エネルギーの吸収量が大きくなる効果を有し、衝突時に、フロントサイドメンバ等の車体メンバ類に損傷を与えることがなくなる。
【００６０】
(適用Al合金)
次に、本発明で用いるAl合金について説明する。本発明で用いるAl合金自体は、前記した通り、本発明の目的が、特殊なAl合金を用いず、汎用 (規格)Al 合金材を用いることであるから、使用するAl合金の種類は、通常、この種構造部材用途に汎用される、AA乃至JIS 5000系、6000系、7000系等の耐力の比較的高いAl合金の適用が好適に用いられる。特に、これら7000系 (Al-Zn-Mg系) Al合金や6000系(Al-Mg-Si 系)Al 合金を、押出加工後人工時効処理したT5や押出加工後更に溶体化処理した後に人工時効硬化処理したT6等の調質処理材が好ましい。
【００６１】
しかし、一方で、前記した材料側から種々提案されている成分や組織を制御した特殊なAl合金であっても、本発明の構成をとることによって、当然エネルギー吸収性能も優れたものとなる。したがって、コスト的には、従来の汎用 (規格)Al 合金材が有望であるものの、従来の特殊なAl合金であっても、勿論、本発明のバンパーステイには使用可能である。
【００６２】
(Al合金製中空形材の製造)
また、本発明に係る断面が略矩形形状のAl合金製中空形材の製造自体は、鋳造、均質化熱処理、熱間押出、調質熱処理等を、主要工程とする常法により製造される。
【００６３】
【実施例】
次に、本発明の実施例を説明する。図1 に示した断面形状が口形の中空構造の、JIS 6N01Al合金押出形材のT5材 (耐力240N/mm²) 製のバンパー補強部材1aを準備した。また、図2(a)に示した断面形状が口形の中空構造の、JIS 6N01Al合金押出形材のT5材 (耐力240N/mm²) 製のバンパーステイ2aを準備した。なお、この6N01Al合金押出形材のT5材は、車体用のエネルギー吸収材として汎用されており、同じく汎用されているJIS 7003Al合金等の7000系Al合金に比べると、衝突荷重時に割れやすいという特性を有する。したがって、本実施例における6N01Al合金押出形材での良好な結果は、JIS 7003Al合金等の7000系Al合金押出形材の結果にも反映させることが可能である。
【００６４】
ここにおいて、バンパー補強部材1aとバンパーステイ2aの両者に貫通穴を設けて、図16(a) に示すように、ボルト、ナット (但し、本実施例では凸部7aを挟んだ2 箇所) により結合し、図3 に各々示した断面形状を有する本発明のバンパー補強構造を製作し、発明例1 とした。
【００６５】
発明例1 のバンパー補強部材1aの仕様は、前壁部と後壁部の幅を50mm、ウエブ3 _a、3 _bの高さを40mm、これら各肉厚を1.5mm とした。そして、発明例1 は、バンパー補強部材の両端部から水平方向に50 mm 内側で、高さ25 mm の位置の後壁部5 の箇所各々2 箇所に、長さ方向の中心がくるように、中空構造内に貫通する横スリットを設けた。横スリットの長さは後述するバンパーステイの凸部7aの幅より、また、横スリットの幅は後述するバンパーステイの凸部7aの厚みより、若干大きめとした。
【００６６】
また、バンパーステイ2aの仕様は、前壁部と後壁部の幅を60mm、ウエブ3 _a、3 _bの高さを35mm、これら各肉厚を2.5mm とした。そして、バンパーステイの凸部7aの長さ (水平方向の長さ) はウエブ3 _a、3 _bの高さに対応させて40mmとし、前記スリットを介して装入された先端部がバンパー補強部材の前壁部4 の内面壁に当接するようにした。また、バンパーステイの凸部7aの幅 (図における奥行き) は60mm、バンパーステイの凸部7aの厚みは1.5mm とした。
【００６７】
更に、発明例1 において、ウエブ3 _a、3 _bの両外壁面のうちの、バンパー補強部材の前端部から27.5 mm ステイ側後方の位置に、バンパー補強部材の長手方向に延在するように凹みをエンポス加工により2 箇所設けた例を、発明例2 とした。凹みの条件は、バンパー補強部材の長手方向の径L₁が70 mm 、バンパー補強部材の幅方向の径L₂が 15mm 、中心深さが5mm となるような楕円形とした。
【００６８】
また、比較のために、本発明1 のバンパー補強部材のスリットと、バンパーステイの凸部を設けない、或いはウエブの凹みを設けない以外は、全て発明例1 に各々対応して同じ条件とした比較例を準備した。
【００６９】
そして、これら発明例1 、2 と比較例バンパー補強部材とバンパーステイの構造体の衝突時のエネルギー吸収性を評価した。
【００７０】
評価方法は、これら組み立て体中空材のバリア試験を行い、車両の衝突時を想定して、バンパー補強部材を略水平方向に配置した前記組み立て体を固定壁に衝突させ、この際の衝突時のエネルギー吸収性とステイの打ち抜き性を調査した。衝突は、固定壁に対し、組み立て体をバンパー補強部材の前面全てが均一に固定壁に当たるように、軽衝突のカナダ等の規格である、2.22m/sec (8km/hr)の速度で衝突させ、バンパー補強部材の前面に、また略水平方向に衝撃力 (衝突荷重) が加わるようにした。
【００７１】
この結果、まず、バリア試験を行ったバンパー補強部材の目視観察を行った結果、比較例の方は、ウエブが中空構造の外側方向に変形、座屈しており、ウエブと後壁部との接続箇所や、曲げ変形箇所等で割れが生じているとともに、ステイがその前端部で接しているバンパー補強部材の後壁部を突き抜けて、バンパー補強部材の中空構造内に侵入しており、ステイの打ち抜きが生じていた。
【００７２】
これに対し、発明例1 は、比較例と同様に、ウエブが中空構造の外側方向に変形、座屈しているものの、ウエブと後壁部との接続箇所や、曲げ変形箇所等での割れは生じておらず、ステイの打ち抜きも生じていなかった。
また、発明例2 の方は、予めウエブに設けた凹みを起点として、バンパー補強部材の、ステイの前端部に対応する、両端部分のウエブが中空構造の内側に屈曲しており、ウエブと後壁部との接続箇所や、曲げ変形箇所等での割れや、ステイの打ち抜きは生じていなかった。
【００７３】
バリア試験における、発明例1 、2 と比較例の衝突時のエネルギー吸収性を図15に荷重変位特性として示す。図15から分かる通り、細かい点線で示す比較例は、横軸の変位が約1 〜2mm 部分の衝突初期のピーク荷重が高い。また、ウエブと後壁部との接続箇所や、曲げ変形箇所等での割れにより、横軸の変位が約14mm部分を越えるあたりから荷重 (エネルギー吸収量) が低下し、更に、横軸の変位が約16〜18mmの部分で、ステイの打ち抜きが生じた結果、これより後では、バンパー補強部材の変形が生じず、バンパー補強部材によるエネルギー吸収が行われず、荷重 (エネルギー吸収量) が著しく低下している。
【００７４】
これに対し、太い点線で示す発明例1 は、横軸の変位が約1 〜2mm 部分の衝突初期のピーク荷重が、比較例に比して、著しく高くなっている。また、比較例でウエブと後壁部との接続箇所や曲げ変形箇所等での割れが生じた、横軸の変位が約14mm部分を越えるあたりでも荷重 (エネルギー吸収量) は低下していない。更に、比較例でステイの打ち抜きが生じた、横軸の変位が約16〜18mm部分以降の荷重 (エネルギー吸収量) も高い。
【００７５】
更に、実線で示す発明例2 は、横軸の変位が約1 〜2mm 部分の衝突初期のピーク荷重が、比較例や発明例1 に比して、著しく低い。また、比較例でウエブと後壁部との接続箇所や曲げ変形箇所等での割れが生じた、横軸の変位が約14mm部分を越えるあたりでも荷重 (エネルギー吸収量) は低下していない。更に、比較例でステイの打ち抜きが生じた、横軸の変位が約16〜18mm部分以降の荷重 (エネルギー吸収量) も、発明例1 よりも高い。したがって、これら荷重変位特性の結果は、前記目視観察結果と良く対応している。また、本発明構造の効果と、更に凹みを設けた効果が裏付けられる。
【００７６】
以上の結果から、本発明車体用エネルギー吸収部材構造により、衝突初期の最大荷重を制御することが可能であり、かつ衝突エネルギーの吸収量も大きくなることの効果が裏付けられる。また、好ましい態様におけるバンパーステイの打ち抜き現象を防止効果が裏付けられる。これらの結果は、他のドアビームとブラケットやフレームなどの、車体エネルギー吸収部材構造にも同様に言える。
【００７７】
【発明の効果】
本発明によれば、現行のバンパー補強材やドアビーム等のエネルギー吸収部材構造のデザインや設計条件を大幅に変更することなく、簡単な改善により、前記打ち抜き現象の防止も達成でき、車両の衝突時のエネルギー吸収性能を高めることができる、断面形状が略矩形の中空構造を有するAl合金製押出形材からなるエネルギー吸収部材構造を提供することができる。このため、バンパー補強部材やバンパーステイ、ドアビームとブラケットやフレームなどの、車体用エネルギー吸収部材構造用に、Al合金材の用途を大きく拡大するものであり、工業的な価値が大きい。
【図面の簡単な説明】
【図１】本発明に係る車体用エネルギー吸収部材構造の一実施態様を示す斜視図である。
【図２】本発明に係る車体用エネルギー吸収部材構造の一実施態様を示す正面図である。
【図３】本発明に係る車体用エネルギー吸収部材構造の一実施態様を示す、一部断面正面図である。
【図４】本発明に係る車体用エネルギー吸収部材構造のバンパーステイの凸部の他の実施態様を示す正面図である。
【図５】本発明に係る車体用エネルギー吸収部材構造の、バンパーステイの凸部の先端部と、バンパー補強材の前壁部内壁面との関係を示す正面図である。
【図６】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す斜視図である。
【図７】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す正面図である。
【図８】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す、一部断面正面図である。
【図９】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す正面図である。
【図１０】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す斜視図である。
【図１１】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す正面図である。
【図１２】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す正面図である。
【図１３】本発明に係る車体用エネルギー吸収部材構造の他の実施態様を示す斜視図である。
【図１４】本発明に係る車体用エネルギー吸収部材構造の作用を示す正面図である。
【図１５】本発明に係る車体用エネルギー吸収部材構造の荷重変位曲線を示す説明図である。
【図１６】従来の車体用エネルギー吸収部材構造を示す説明図である。
【符号の説明】
1:バンパー補強材、2:バンパーステイ、3:ウエブ、4:前壁部、5:後壁部、6:スリット、7:凸部、8:フロントサイドメンバ、[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an energy absorbing member structure for a vehicle body made of an extruded product made of an aluminum alloy (hereinafter, aluminum is simply referred to as “Al”) excellent in energy absorption performance especially in a vehicle collision.
[0002]
[Prior art]
A vehicle body is provided with a vehicle body energy absorbing member such as a bumper reinforcement or a door beam. Among these, for example, a bumper reinforcing material (also referred to as bumper reinforcement or bumper reinforcement) as a strength reinforcing member is provided inside the bumper attached to the front end and the rear end of the vehicle body. As is well known, this bumper reinforcement is connected and fixed to a vehicle body frame (vehicle body member) of a skeleton member in the longitudinal direction of the vehicle body such as a front side member and a rear side member via a vehicle body connection member such as a bumper stay. An energy absorbing member structure for a vehicle body is configured. Further, the door beam or the like is connected and fixed to a door frame as a vehicle body via a vehicle body connecting member such as a bracket or a frame to constitute a vehicle body energy absorbing member structure.
[0003]
Now, taking the case of a bumper reinforcement as an example, more specifically, for example, as disclosed in Japanese Patent Laid-Open No. 4-31152, etc., at the front part of the front side member extending in the longitudinal direction of the vehicle body, It is a structure in which a bumper reinforcing material having the same hollow structure is fixed and extended in a substantially vehicle width direction (substantially horizontal direction) through a hollow bumper stay having a substantially rectangular (mouth shape) cross section. With such a structure, the bumper reinforcement material is crushed in the lateral direction (substantially horizontal direction) and the bumper stay is crushed in the axial direction to absorb the collision energy against the collision from the front of the vehicle body. .
[0004]
Therefore, in the joint structure of the bumper reinforcement as the vehicle body energy absorbing member and the bumper stay as the vehicle body connection member, the external force energy (collision energy) applied by the collision of the vehicle body is transformed into its own plastic deformation ( It is required to have a performance of absorbing the body member by buckling deformation) and protecting the vehicle body member and the like.
[0005]
In recent years, high-strength Al alloys such as 5000 series, 6000 series, and 7000 series have been used in place of steel materials that have been used to reduce the weight of these bumper reinforcements, bumper stays, or front side members and rear side members. Extruded profiles (made with the same cross-sectional shape in the longitudinal direction) are starting to be used.
[0006]
The Al alloy is excellent in the energy absorption performance as compared with steel and the like. In addition, the extruded shape made of Al alloy having the same cross-sectional shape in the longitudinal direction is a hollow structure that is generally used for bumper reinforcement, bumper stays, etc. It can be manufactured in large quantities.
[0007]
[Problems to be solved by the invention]
However, in the case of a vehicle body energy absorbing member having a hollow structure having a substantially rectangular cross section and an aluminum alloy extruded shape member and a bumper stay coupled to the bumper reinforcement member, the bumper reinforcement member is viewed from a substantially horizontal direction. There is a problem that the required absorption performance of the collision energy may be insufficient with respect to the load (during vehicle collision).
[0008]
For example, as shown in a specific example in FIG. 16 (a), a bumper reinforcing member 101 made of a conventional Al alloy extruded profile has a front wall portion 104 and a rear wall portion 105, which have two webs (side walls) 103. _a , 103 _b The cross-sectional shape connected by the above has a mouth shape. The front side member (not shown) is fixed to a front portion of a bumper stay 102 having a hollow structure having a substantially rectangular cross section, which is also made of an extruded product made of an Al alloy. The bumper reinforcement 101 and the bumper stay 102 are fixed to each other by welding or a fastener 107 such as a bolt.
[0009]
As shown in FIG. 16 (b), when a large load F is applied to the bumper reinforcing member 101 from a substantially horizontal direction at the time of a vehicle collision, the bumper reinforcing member 101 is in a lateral crushing state (deformed in the horizontal direction). At this time, the web 103 in the hollow structure of the bumper reinforcement 101 _a , 103 _b Therefore, as a result of applying a force in the stance direction (horizontal direction) of the web, the web 103 usually starts from the bending deformation point 107. _a , 103 _b Deforms and buckles in the outward direction of the hollow structure. As a result, the bumper reinforcement member 101 absorbs the collision energy and protects the body members such as the front side member from being crushed.
[0010]
Here, when a large load F is applied to the bumper reinforcing material 101 from a substantially horizontal direction at the time of a vehicle collision, the bumper reinforcing material 101 is in a lateral crushing state. At this time, the web 103 in the hollow structure of the bumper reinforcement 101 _a , 103 _b As a result, a force is applied in the stance direction (horizontal direction) of the web. As a result, the web is usually deformed or buckled in the outward direction of the hollow structure starting from the bending deformation portion 107. Further, when the hollow structure is further deformed outwardly, as shown in FIG. _a , 103 _b And cracks occur at the connecting portion (corner portion) 106 between the rear wall portion 105 and the bending deformation portion 107.
[0011]
As a result, even if a load F is further applied, the bumper reinforcing material 101 is not deformed after this, and energy absorption by the bumper reinforcing material 101 is not performed. Therefore, at the time of a vehicle collision, the bumper reinforcement made of an extruded product made of an Al alloy has a shortage of energy absorption of the collision due to the size of the vehicle's collision energy, etc. It leads to damage.
[0012]
Further, when the deformation is advanced by applying a larger load F, as shown in FIG. 16 (c), the bumper stay 102 that supports the bumper reinforcement 101 is in contact with the rear wall of the bumper reinforcement 101 that is in contact with the front end portion thereof. There is also a possibility that a so-called stay punching phenomenon that penetrates through the portion 105 and enters the hollow structure of the bumper reinforcing material 101 may occur.
[0013]
When the stay punching phenomenon occurs, the bumper reinforcing material 101 is not deformed after this, and the energy absorption by the bumper reinforcing material 101 is not performed. Therefore, when this stay punching phenomenon occurs, the amount of energy absorbed by the bumper reinforcing member 101 at the time of high-speed collision of the vehicle is insufficient, leading to damage to vehicle body members such as the front side member.
[0014]
On the other hand, in order to increase the energy absorption amount of the collision, or in addition to this, in order to prevent the stay punching phenomenon and increase the energy absorption amount of the collision, the Al constituting the bumper reinforcement 101 Strengthen the alloy itself, or use web 103 _a , 103 _b Alternatively, a method of increasing the thickness of the Al alloy of the rear wall portion 105 or reinforcing the bumper reinforcing material by providing a medium rib having a cross-sectional shape such as an eye shape, a date shape, or a tabular shape can be considered.
[0015]
However, when the strength of the Al alloy material is increased, it becomes difficult to produce a shape material such as extrusion and the shape processing of the shape material such as bending, and cracking easily occurs, on the contrary, the energy absorption amount of the collision is reduced, It also helps to promote the stay punching phenomenon. In addition, when the thickness of the Al alloy material is simply increased or the above-mentioned middle rib is provided, the weight increases, and the advantage of weight reduction by the Al alloy is impaired, and the bumper reinforcing material becomes difficult to be plastically deformed. Insufficient energy absorption during a vehicle collision. Furthermore, when the thickness of the Al alloy material is simply increased or the above-mentioned middle rib is provided, the maximum load when the bumper reinforcing material is crushed becomes higher than the allowable load of the side member. There is also a high possibility of damaging the species.
[0016]
Therefore, more than ever, there is a demand for a bumper reinforcement structure that increases the amount of collision energy absorption and prevents the stay punching phenomenon. On the other hand, there is a demand for improvements in the structure and design of the bumper reinforcement structure (the same applies to other Al alloy body energy members such as door beams). Nevertheless, if the structure or design of the bumper reinforcement is significantly changed, it may lead to changes in the design of other body members, bumper stays, etc., and the design of the body itself. Unacceptable.
[0017]
In this respect, if it was possible to increase the amount of collision energy absorption and prevent the punching phenomenon through simple improvements without significantly changing the design and design conditions of the current bumper reinforcement structure, However, there are no effective and efficient improvement measures so far.
[0018]
Therefore, the object of the present invention is to improve the energy absorption performance at the time of vehicle collision by making a simple improvement without significantly changing the design and design conditions of the energy absorbing member structure such as the current bumper reinforcement material and door beam. It is desirable to provide an energy absorbing member structure made of an Al alloy extruded profile having a hollow structure with a substantially rectangular cross-sectional shape, which can preferably prevent the punching phenomenon.
[0019]
[Means for Solving the Problems]
In order to achieve this object, the gist of the present invention is that a vehicle body energy absorbing member comprising a vehicle body energy absorbing member used extending substantially in the horizontal direction and a vehicle body connecting member coupled to both ends thereof. The vehicle body energy absorbing member and the vehicle body connecting member are each made of an extruded aluminum (Al) alloy member having a hollow structure with a substantially rectangular cross-sectional shape, and protruded from the front end of the vehicle body coupling member. Set up a section, And, on the rear wall portion surface of the vehicle body energy absorbing member corresponding to the front end of the vehicle body connecting member, a partial slit or concave portion corresponding to the convex portion is provided, and through the partial slit or concave portion, the The projecting portion protrudes into the hollow structure space of the vehicle body energy absorbing member, and the vehicle body energy absorbing member and the vehicle body connecting member are coupled.
[0020]
Body The energy absorbing member for vehicle use and the member for connecting the vehicle body are each made of an extruded product made of an Al alloy having a hollow structure with a substantially rectangular cross-sectional shape, and a convex portion is provided at the front end of the vehicle body coupling member. The vehicle body energy absorbing member and the vehicle body connecting member are coupled to each other by projecting into the hollow structure space of the vehicle energy absorbing member. As a result, it is possible to absorb collision energy with respect to the load from the substantially horizontal direction on the energy absorption member structure for the vehicle body by a simple improvement without significantly changing the design and design conditions of the current energy absorption member structure for the vehicle body. It becomes possible to improve performance. Further, the maximum load when the bumper reinforcing material is crushed can be adjusted by the way of providing the convex portion.
[0021]
Also, the above A slit (through hole provided in the rear wall) or a concave portion corresponding to the convex portion is provided on the rear wall surface of the vehicle body energy absorbing member corresponding to the front end of the vehicle body coupling member. As a result, positioning and coupling of the vehicle body energy absorbing member and the vehicle body coupling member are facilitated, and the bumper reinforcement structure can be easily assembled, and the impact energy absorption performance can be improved. It becomes possible.
[0022]
Furthermore, the Partial recesses are provided in advance on both outer wall surfaces of the web at both ends of the vehicle body energy absorbing member coupled to the front end of the vehicle body connecting member, and the load from the substantially horizontal direction on the vehicle body energy absorbing member is Starting from the partial recess, the webs at both end portions are configured to bend inward of the hollow structure. As a result, the stay punching phenomenon with respect to the load from the substantially horizontal direction on the energy absorbing member structure for the vehicle body can be achieved by simple improvement without significantly changing the design and design conditions of the current energy absorbing member structure for the vehicle body. It has the effect of increasing the amount of collision energy absorbed due to prevention and the like, and the effect of suppressing the peak load at the initial stage of the collision to a certain level or less, so that the vehicle body members such as the front side member are not damaged during the collision.
[0023]
In addition, The partial recesses provided on both outer wall surfaces of the hub have a substantially elliptical shape in which the longitudinal direction of the energy absorbing member for the vehicle body is the long axis and the width direction of the energy absorbing member for the vehicle body is the short axis. With respect to the load from the substantially horizontal direction with respect to the energy absorbing member structure for the vehicle body, the webs at the both end portions can be bent more easily inside the hollow structure starting from the dent. As a result, The effect Can be further enhanced.
[0024]
Furthermore, the It becomes possible to provide the recess which obtains an effect partially and simply on both outer wall surfaces of the web by embossing.
[0025]
And Al The alloy is selected from AA to JIS 5000 series, 6000 series, and 7000 series, and uses a standard Al alloy with good formability and high strength. It is easy to manufacture and can improve the collision energy absorption performance.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings in the case of a bumper reinforcing member structure.
[0027]
In the present invention, as described above, the punching phenomenon is prevented by a simple improvement without significantly changing the design and design conditions of the current energy absorption member structure for a vehicle body, and the energy absorption performance at the time of vehicle collision is improved. Increase. For this reason, the basic structure of a bumper reinforcing member made of an Al alloy extruded profile having a hollow structure with a substantially mouth-shaped cross-section is basically the same as the prior art of FIG. 16 (a) described above.
[0028]
That is, FIG. 1, FIG. 6, FIG. 9, and FIG. 10 are perspective views showing respective embodiments of the bumper reinforcing members 1a to 1e according to the present invention. As shown in these drawings, the bumper reinforcing members 1a to 1e are formed by connecting the front wall portion 4 and the rear wall portion 5 with two webs 3. _a , 3 _b Have a hollow integrated structure having a substantially mouth-shaped cross-section. This hollow integrated structure is made of an extruded product made of an Al alloy, and has a substantially mouth-like cross-sectional shape in the longitudinal direction. The sectional shape of the bumper reinforcing member according to the present invention is preferably a mouth-shaped hollow structure from the viewpoint of weight reduction, and can be a mouth-shaped light-weight hollow structure. However, the required strength differs depending on the vehicle type, and there are cases where higher strength is required than weight reduction. Therefore, in such a case, in order to further reinforce the bumper reinforcing member, for example, a reinforcing middle rib may be inserted in the hollow structure so that the cross-sectional shape is a day shape, a square shape, an eye shape, etc. Is possible.
[0029]
Further, the bumper stay as the vehicle body connecting member constituting the energy absorption member structure for the vehicle body of the present invention is shown as 2a to 2k in FIGS. 2, 7, 9 (showing the bumper reinforcement structure of the present invention), FIG. As each embodiment is shown in the front view, like the bumper reinforcing member, the cross-sectional shape basically has a substantially rectangular hollow integrated structure such as a mouth shape and a date shape. In addition to this, the cross-sectional shape may be a square shape, an eye shape or the like. The hollow integrated structure is made of an extruded product made of an Al alloy and has the same cross-sectional shape in the longitudinal direction. These bumper stays 2a to 2k are coupled and fixed to the corresponding bumper reinforcing members 1a to 1e, as will be described later, and the respective embodiments are shown in front views in FIGS. 3, 8, 9, and 12. The present invention bumper reinforcement structure is shown. In any aspect of these bumper stays, there is no significant difference in the amount of collision energy to be absorbed, and therefore, it is appropriately selected mainly from problems such as design and ease of manufacture.
[0030]
The bumper reinforcing structure according to the energy absorbing member structure for a vehicle body of the present invention shown in FIGS. 3, 8, 9 and 12 is provided at the front end of each vehicle body member such as the front side member 8 via a bumper stay. It is fixed by an appropriate fastener 10 such as a bolt. Further, the bumper reinforcing member 1 and the bumper stay 2 are fixed to each other by appropriate fasteners such as welding or bolts as in the conventional case.
[0031]
Next, the bumper reinforcement structure of the present invention will be described more specifically with reference to the drawings. FIG. 1 shows an example in which a slit 6 (lateral slit) extending in the longitudinal direction and in the horizontal direction of the bumper reinforcing member 1a is provided on the surface of the rear wall portion 5 of the bumper reinforcing member 1a on the connection surface with the bumper stay. FIG. This slit 6 is for projecting the convex portion at the front end (end tip) of the bumper stay into the hollow structure space of the bumper reinforcing member. As shown in Fig. 1, in the example with one slit 6 extending in the horizontal direction, the front view is shown in Fig. 2 (a), Fig. 2 (d), or Fig. 2 (f). A bumper stay 2a having a convex portion 7a, 7d, or 7f (a cross-sectional shape, but a cross section other than the convex portion, the same applies hereinafter), 2d (a cross-sectional shape), or 2f (a cross-sectional shape) is used.
[0032]
The bumper stay protrusions 7a, 7d, and 7f are large in size so that the bumper stay member and the bumper stay are coupled with each other so that the bumper stay protrusion protrudes into the hollow structure space of the bumper reinforcement member through the slit 6. The thickness (thickness x width), the size of the slit 6 (thickness x width), the length of the webs 3a, 3b of the bumper reinforcing member 1a, the length of the bumper stay projections 7a, 7d, 7f, and the slit Adjust the size, number and position of 6 to correspond to each.
[0033]
Here, a bumper stay 2b having two convex portions 7b, 7e, or three convex portions 7c (cross-section) shown in a front view in FIG. 2 (b), FIG. 2 (e), or FIG. In the case of using (day shape), 2e (cross-section mouth shape), or 2c (cross-section shape), the slit 6 of the bumper reinforcing member corresponding to this is appropriately adjusted so as to provide two or three. The sizes and shapes of the slits and bumper stay projections are basically determined by the magnitude of the collision load to be borne by the bumper stay projections, as will be described later.
[0034]
FIG. 3 shows a front view of the bumper reinforcing structure of the present invention in which the bumper reinforcing member and the bumper stay are combined. FIG. 3 shows an example in which the bumper reinforcing member 1a is coupled to the bumper stay 2a of FIG. In this example, the tip of the convex portion 7a of the bumper stay 2a is projected into the hollow structure space of the bumper reinforcing member through the slit 6 provided in the rear wall portion 5 of the bumper reinforcing member 1a, and the inner wall surface of the front wall portion 4 is It is made to contact. As will be described later, the tip of the convex portion 7a of the bumper stay 2a does not necessarily abut on the inner wall surface of the front wall portion 4, and does not necessarily abut on the inner wall surface of the front wall portion 4. You can just let them face you.
[0035]
The bumper stay 2a is fixed to the front end portion of the vehicle body members such as the front side member 8 by an appropriate fastener 10 such as a bolt through the locking piece 20, and connects the bumper reinforcing member to the vehicle body members. Also have. In other words, the bumper reinforcing member 1a includes two front side members extending in the longitudinal (running) direction of the vehicle body and spaced apart from each other in the vehicle width direction. 8 (one in the figure) is fixed at both ends so as to extend in a substantially horizontal direction (vehicle width direction) via a bumper stay 2a. The aspect of the bumper behind the vehicle body is basically the same as this.
[0036]
Note that the contact portion of the inner wall surface is selectively provided with a locking portion 9a for positioning and fixing the tip of the convex portion 7a, which locks the tip of the convex portion 7a of the bumper stay 2a. The shapes of these locking pieces are appropriately selected according to the selection of the tip shape variations of the convex portions 7a to 7i of the bumper stay 2 shown in the front views of FIGS. 4 (a) to (e). FIG. 5 is a front view showing the relationship between the shape of the tip of the convex part of the bumper stay and the engaging part 9 of the inner wall surface of the front wall part 4, and FIG. ) In which the T-shaped portion of the T-shaped convex portion 7g is brought into contact with the inner wall surface of the front wall portion 4 without providing a locking portion, FIG. 5 (b) is a U-shaped convex portion in FIG. 4 (c). The U-shaped portion of 7h is brought into contact with a locking portion 9b provided on the inner wall surface of the front wall portion 4. Whether or not to provide a locking portion on the inner wall surface of the front wall portion 4 and the shape when it is provided are the tip shape of the bumper stay's convex portion, and the necessity and requirements for positioning and fixing the tip. Is appropriately selected.
[0037]
The operation of the bumper reinforcement structure of the present invention will be described below. In FIG. 3, when the impact load in the horizontal direction indicated by the arrow F1 is applied to the entire surface (front wall portion 4) of the bumper reinforcing member 1a due to the collision of the vehicle, the two webs 3 of the bumper reinforcing member 1a 3 _a , 3 _b A load is also applied to the convex portion 7a of the bumper stay 2a that is in contact with the inner wall surface of the front wall portion 4. This makes the web 3 _a , 3 _b The load is reduced and the energy is absorbed without being deformed without causing breakage such as cracking. Therefore, even at the time of high-speed collision of the vehicle, even the bumper reinforcing member made of the Al alloy extruded profile does not have a sufficient amount of collision energy absorption, and can prevent the vehicle body members such as the front side member from being damaged.
[0038]
Such an action is the same when the front wall portion 4 is not brought into contact with the inner wall surface and is exposed to the hollow structure space. However, in this case, the initial initial impact in the horizontal direction is 3 _a , 3 _b However, the front wall 4 comes into contact with the convex portion 7a of the bumper stay 2a as the deformation toward the rear surface side of the front wall 4 of the bumper reinforcement member 1a due to impact load occurs, and the load is immediately shared. . Thereafter, the same effects as those in the above case are obtained.
[0039]
On the other hand, the maximum load at the time of crushing of the bumper reinforcing member can be adjusted depending on how the bumper stays are provided with the number of protrusions and the size. Usually, the maximum load at the time of the crushing of the bumper reinforcing member having a hollow structure having a substantially rectangular cross section is inevitably high. Therefore, if this maximum load is higher than the permissible load (strength), which varies depending on the type of vehicle body members such as the front side member, sufficient energy due to deformation of the bumper reinforcement member structure at the time of vehicle collision Prior to the absorption, the vehicle body members such as the front side member are subjected to a load at the time of collision, which leads to damage to these vehicle body members. For this reason, the number of bumps, the number of protrusions, the size, etc. of the bumper stay, together with the way of providing the slit of the bumper reinforcement member, the bumper reinforcement member structure, in particular, the maximum load when the bumper reinforcement member is crushed, It is preferably provided so as not to exceed the allowable load (strength) of the body members such as the front side member.
[0040]
Next, FIG. 6 shows a slit 9 (longitudinal slit) extending in the width direction of the bumper reinforcing member 1b and in the vertical direction on the surface of the rear wall portion 5 of the bumper reinforcing member 1b and on the connection surface with the bumper stay. It is a perspective view which shows the example which provided three. This slit 9 is also for projecting the convex portion at the front end of the bumper stay into the hollow structure space of the bumper reinforcing member. As shown in FIG. 6, in an example in which three slits 9 extending in the vertical direction are provided, a bumper stay 2i (cross-sectional day shape) having three convex portions 7l shown in FIG. 7 (c) is used. When one or two slits 9 are provided, a bumper stay 2h (cross section) having two or three convex portions 7j or 7h, as shown in the front view in FIG. 7 (a) or FIG. (Day shape) or 2k (section mouth shape).
[0041]
As in the case of the horizontal slit in FIG. 1, through the slit 9, the size and number of bumper stay protrusions and slits 9 are further increased so that the bumper stay protrusions protrude into the hollow structure space of the bumper reinforcement member. Adjusts the position to couple the bumper reinforcing member and the bumper stay. The sizes and shapes of the slits and bumper stay projections are basically determined by the magnitude of the collision load to be borne by the bumper stay projections as described above.
[0042]
FIG. 8 shows a front view of a bumper reinforcing structure of the present invention in which a bumper reinforcing member and a bumper stay are coupled through the vertical slit 9. FIG. 8 shows an example in which the bumper reinforcing member 1b is coupled to the bumper stay 2g of FIG. In this example, the tip of the convex portion 7j of the bumper stay 2g protrudes into the hollow structure space of the bumper reinforcing member through the slit 9 provided in the rear wall portion 5 of the bumper reinforcing member 1b, and the inner wall surface of the front wall portion 4 It is made to contact. Also in this case, as described above, it is not always necessary to bring the tip of the convex portion 7j of the bumper stay 2g into contact with the inner wall surface of the front wall portion 4. The bumper stay 2g is fixed to the front end portion of the vehicle body members such as the front side member 8 by an appropriate fastener 10 such as a bolt through the locking piece 19, and connects the bumper reinforcing member to the vehicle body members. Also have.
[0043]
The operation of such a vertical slit type bumper reinforcing structure of the present invention is exactly the same as the operation of the lateral slit type bumper reinforcing structure of the present invention.
[0044]
FIG. 9 (a) is a plan view showing an example in which the vertical slit 11 is used, but the bumper reinforcing member shown in FIG. 1 and FIG. The bumper reinforcement structure of this invention which combined the bending part and bumper stay of the reinforcement member is shown. In this example, the tip of the convex portion 7m of the bumper stay 2j is passed through one vertical slit 11 provided in the rear wall portion 5 of the bumper reinforcing member 1c, as in FIG. Projecting to the inner wall surface of the front wall portion 4. In this case, the front surface 13 of the bumper stay 2j has an inclined surface corresponding to the inclined surface of the rear wall portion 5 of the bumper reinforcing member.
[0045]
On the other hand, FIG. 9 (b) shows the bumper of the present invention in which the bent portion of the bumper reinforcing member of which the both ends are curved inward and the bumper stay are combined as in the case of FIG. 9 (a). The top view of the reinforcement structure is shown. However, in the case of FIG. 9 (b), the horizontal (horizontal) slit 14 is used, and the tip of the convex portion 7n of the bumper stay 2k is connected to the bumper reinforcing member 1d as in FIG. 9 (a). Through one horizontal slit 14 provided in the rear wall portion 5, the bumper reinforcing member protrudes into the hollow structure space and is brought into contact with the inner wall surface of the front wall portion 4. However, the bumper stay 2k having such a shape cannot be manufactured integrally by extrusion and needs to be formed by cutting or the like, and thus is not suitable in the present invention. Therefore, in the bumper reinforcing member of the type in which both ends are curved inward, it is understood that the vertical slit 9 shown in FIG. 9 (a) needs to be used when the bumper stay is efficiently manufactured and used by extrusion. .
[0046]
Further, FIG. 10 is a perspective view showing an example in which the concave portion 15 is provided on the surface of the rear wall portion 5 of the bumper reinforcing member 1e on the connection surface with the bumper stay. The concave portion 15 is also for projecting the convex portion at the front end of the bumper stay into the hollow structure space of the bumper reinforcing member. As shown in FIG. 10, in the example in which the recess 15 is provided, a bumper stay 2d having a convex portion 2d or 2f having a shape corresponding to the recess 15 shown in FIGS. 11 (a) and 11 (b) (cross-sectional mouth shape), Or 2f (Circular section).
[0047]
FIG. 12 shows a front view of the bumper reinforcing structure of the present invention in which the bumper reinforcing member and the bumper stay are coupled through the recess 15. In this example, the bumper stays 2d and 2f are fitted with the convex portions 2d and 2f in the space of the concave portion 15, and the bumper reinforcing member and the bumper stay are coupled.
[0048]
The function of the bumper reinforcing structure of the present invention of the concave type is exactly the same as the function of the bumper reinforcing structure of the present invention of the slit type, so that the convex part of the bumper stay accommodated in the concave part and the concave part has an impact load. This increases the amount of absorption of impact energy.
[0049]
Furthermore, in order to prevent the stay punching phenomenon when a large impact load is applied, the maximum load when the bumper reinforcement member is crushed is larger than the allowable load (strength) of the body members such as the front side member. A preferred embodiment of the present invention for lowering so as not to increase is described below.
[0050]
FIG. 13 shows partial recesses 16a and 16b for preventing the stay punching phenomenon from being formed on the web 3 of the bumper reinforcing member 1a. _a , 3 _b FIG. 6 is a perspective view showing a state in which the web is provided in advance on both outer wall surfaces (corresponding to the slits 6) of both ends connected to the stay. This dent 16 _a , 16 _b Is applied to the bumper reinforcing member 1 with respect to the load from the substantially horizontal direction. _a , 6 _b Starting from the web 3 _a , 3 _b Only the part that bends inside the hollow structure is a dent 6 _a , 6 _b The web 3 _a , 3 _b Position, size (width and length) and depth, etc. determined by the vehicle type, etc., required maximum load when crushing bumper reinforcement (maximum load reduction degree), and required level of impact energy absorption And, it is appropriately selected from the viewpoint of the degree of inward bending of the hollow structure necessary for preventing the punching phenomenon.
[0051]
In this embodiment, the dent 6 _a , 6 _b The web 3 _a , 3 _b The bumper reinforcing member 1 is provided so as to extend in the longitudinal direction of the bumper reinforcing member 1 on the rear side of the both outer wall surfaces. This is the web 3 rather than the front side of the outer wall. _a , 3 _b Is easily bent inside the hollow structure.
[0052]
And dent 6 _a , 6 _b Is the diameter L in the longitudinal direction of the bumper reinforcing member 1 ₁ Is the long axis, the diameter L of the bumper reinforcement member 1 in the width direction ₂ Is provided in a substantially elliptical shape with a short axis. Dent 6 _a , 6 _b First, the dent 6 _a , 6 _b Recess with depth of 6 _a , 6 _b Diameter in the width direction L ₂ Depending on the size of the web 3 against the load from the substantially horizontal direction on the bumper reinforcement member 1 _a , 3 _b It is ensured that it becomes the starting point of the inward bending of the hollow structure. Dent 6 _a , 6 _b Depth and diameter L in the width direction ₂ If it is too small, although it depends on the magnitude of the load from the substantially horizontal direction, it cannot be the starting point of the bending, and as a result, the maximum load amount when the bumper reinforcing material is crushed and the energy absorption amount is improved. The effect of stay punching prevention is weakened.
[0053]
Also dent 6 _a , 6 _b With depth of dent 6 _a , 6 _b Longitudinal diameter L ₁ Diameter L in the width direction ₂ Depending on the size of the web 3 against the load from the substantially horizontal direction on the bumper reinforcement member 1 _a , 3 _b The length in the longitudinal direction of the bumper reinforcing member 1 of the portion bent inward of the hollow structure can be defined. This dent 6 _a , 6 _b Depth, longitudinal diameter L ₁ Diameter L in the width direction ₂ Is too small, web 3 _a , 3 _b In the conventional structure, the web 3 _a , 3 _b Is deformed or buckled in the outer direction of the hollow structure. Web 3 _a , 3 _b However, it is not possible to secure a sufficient portion to bend inward of the hollow structure, so that the maximum load amount and energy absorption amount at the time of collapse of the bumper reinforcement and the effect of stay punching prevention are weakened.
[0054]
This point is the same regardless of whether the dent is not elliptical or has other shapes such as a circle. On the other hand, it is important to provide the webs at both end portions so as to bend inward of the hollow structure starting from the partial dent.
[0055]
Recess 6 _a , 6 _b As another method of providing the dent, as long as the effect of the dent is not obstructed, as shown in FIG. 13, one dent is provided on each of the outer wall surfaces of the web, and the length L of the dent. ₁ The length of the recess L is not the same as the width of the bumper stay. ₁ The width of the bumper stay may be slightly longer or shorter than the width of the bumper stay, or two or more may be provided by being divided in the longitudinal direction of the bumper reinforcing member.
[0056]
(Indentation action)
FIGS. 14 (a) and 14 (b) show the dent 6 in the present invention described above. _a , 6 _b The effect of 14 (a) and 14 (b) are front views of the embodiment of the bumper reinforcing member of the present invention shown in FIG.
[0057]
Now bumper reinforcement 1 _a On the other hand, when a collision load F from a substantially horizontal direction is applied, _a , 16 _b Starting from the web 3 _a , 3 _b To bend easily inside the hollow structure. As a result, it is possible to reduce the maximum load amount when the bumper reinforcing material is crushed. Further, even if the deformation further progresses, there is little possibility that a crack will occur at a connection portion (corner portion) between the web and the rear wall portion 5, a bending deformation portion, or the like. As a result, the amount of energy absorption can be improved.
[0058]
Even if no crack occurs in the portion, or even if a crack occurs, the portion where the web is buckled inwardly 17 _a , 17 _b By holding the rear wall part 5 by the _a , 17 _b And the rear wall portion 5 prevent the bumper stay 2 from penetrating the rear wall portion 5 to prevent the stay punching phenomenon.
[0059]
This result prevents a decrease in the amount of collision energy absorption due to the cracking and stay punching phenomenon, and after the buckling to the inside of the web, the energy absorption is continued due to the deformation of the bumper reinforcement member 1, and the collision This has the effect of increasing the amount of energy absorbed. Therefore, the dent, which is a preferable requirement in the present invention, has an effect of suppressing the peak load at the initial stage of the collision to a certain level or less in the load displacement characteristic of the bumper reinforcing member, and the amount of collision energy absorbed by preventing the stay punching phenomenon is increased. It has an effect, and the vehicle body members such as the front side member are not damaged at the time of collision.
[0060]
(Applicable Al alloy)
Next, the Al alloy used in the present invention will be described. Since the Al alloy itself used in the present invention is, as described above, the purpose of the present invention is to use a general-purpose (standard) Al alloy material without using a special Al alloy, the type of Al alloy to be used is usually Application of Al alloys having a relatively high yield strength such as AA to JIS 5000 series, 6000 series, and 7000 series, which are widely used for this kind of structural member application, is preferably used. In particular, these 7000-series (Al-Zn-Mg-series) Al alloys and 6000-series (Al-Mg-Si-series) Al alloys were artificially aged after T5 which was subjected to artificial aging treatment after extrusion and further solution treatment after extrusion. A tempered material such as T6 that has been cured is preferred.
[0061]
However, on the other hand, even the special Al alloy in which various components and structures are proposed from the above-described material side, the energy absorption performance is naturally excellent by adopting the configuration of the present invention. Therefore, although a conventional general-purpose (standard) Al alloy material is promising in terms of cost, a conventional special Al alloy can of course be used for the bumper stay of the present invention.
[0062]
(Manufacture of aluminum alloy hollow profile)
In addition, the Al alloy hollow section having a substantially rectangular cross section according to the present invention is manufactured by a conventional method including casting, homogenization heat treatment, hot extrusion, tempering heat treatment, and the like as main processes.
[0063]
【Example】
Next, examples of the present invention will be described. T5 material with JIS 6N01Al alloy extruded shape (with a proof stress of 240 N / mm) with a hollow structure with a mouth-shaped cross section shown in Fig. 1 ² ) A bumper reinforcing member 1a made of was prepared. In addition, JIS 6N01Al alloy extruded shape T5 material (with a yield strength of 240 N / mm) with a hollow structure with a mouth-shaped cross section shown in Fig. ² ) Bumper stay 2a made was prepared. In addition, T5 material of this 6N01Al alloy extruded profile is widely used as an energy absorbing material for car bodies, and is more susceptible to cracking during impact loads than 7000 series Al alloys such as JIS 7003Al alloy, which is also widely used. Have Therefore, the good result with the 6N01Al alloy extruded shape in this example can be reflected in the result of the 7000 series Al alloy extruded shape such as JIS 7003Al alloy.
[0064]
Here, through-holes are provided in both the bumper reinforcing member 1a and the bumper stay 2a, and as shown in FIG. 16 (a), bolts and nuts (however, in this embodiment, two places sandwiching the convex portion 7a) The bumper reinforcing structure of the present invention having the cross-sectional shapes shown in FIG.
[0065]
The specification of the bumper reinforcing member 1a of the invention example 1 is that the width of the front wall portion and the rear wall portion is 50 mm, and the web 3 _a , 3 _b The height of each was 40 mm, and the thickness of each of these was 1.5 mm. And, Invention Example 1 is such that the center in the length direction comes to the two locations of the rear wall portion 5 at a position of 25 mm inside, 50 mm inside in the horizontal direction from both ends of the bumper reinforcing member. A transverse slit penetrating the hollow structure was provided. The length of the lateral slit was made slightly larger than the width of the bumper stay convex portion 7a described later, and the width of the horizontal slit was slightly larger than the thickness of the bumper stay convex portion 7a described later.
[0066]
The specifications of the bumper stay 2a are as follows: the width of the front and rear walls is 60mm, and the web 3 _a , 3 _b The height was 35 mm, and the thickness of each of these was 2.5 mm. The length of the bumper stay projection 7a (the length in the horizontal direction) is the web 3 _a , 3 _b The front end portion inserted through the slit is in contact with the inner wall of the front wall portion 4 of the bumper reinforcing member. The width (depth in the figure) of the bumper stay convex portion 7a was 60 mm, and the thickness of the bumper stay convex portion 7a was 1.5 mm.
[0067]
Furthermore, in Invention Example 1, the web 3 _a , 3 _b An example in which two dents are provided by embossing at both ends of the outer wall of the bumper reinforcement member at a position 27.5 mm behind the bumper reinforcement member so as to extend in the longitudinal direction of the bumper reinforcement member. 2. The condition of the dent is the length L of the bumper reinforcement member in the longitudinal direction. ₁ Is 70 mm, the width L of the bumper reinforcement member in the width direction ₂ The oval shape is 15mm and the center depth is 5mm.
[0068]
For comparison, all the conditions were the same as in Example 1 except that the bumper reinforcing member slit of the present invention 1 and the bumper stay convex part were not provided or the web concave part was not provided. A comparative example was prepared.
[0069]
Then, the energy absorption at the time of collision between these invention examples 1 and 2 and the comparative example bumper reinforcing member and the bumper stay structure was evaluated.
[0070]
In the evaluation method, a barrier test of these assembly hollow materials is performed, and assuming that the vehicle collides, the assembly in which the bumper reinforcing member is arranged in a substantially horizontal direction is caused to collide with the fixed wall. The energy absorption and stay punchability were investigated. The collision is performed with a fixed wall at a speed of 2.22m / sec (8km / hr), which is the standard of light collision Canada, etc., so that the entire front surface of the bumper reinforcement member uniformly hits the fixed wall. In addition, an impact force (collision load) is applied to the front surface of the bumper reinforcement member in a substantially horizontal direction.
[0071]
As a result, first, as a result of visual observation of the bumper reinforcing member subjected to the barrier test, in the comparative example, the web is deformed and buckled in the outer direction of the hollow structure, and the connection between the web and the rear wall portion Cracks have occurred at locations, bending deformation locations, etc., and the stay has penetrated the rear wall portion of the bumper reinforcing member that is in contact with the front end of the stay, and has entered the hollow structure of the bumper reinforcing member. Punching has occurred.
[0072]
On the other hand, in the invention example 1, as in the comparative example, although the web is deformed and buckled in the outer direction of the hollow structure, cracks at the connection portion between the web and the rear wall, the bending deformation portion, etc. It did not occur, and there was no punching out of the stay.
Further, in the case of the invention example 2, the web at both ends corresponding to the front end of the stay of the bumper reinforcing member is bent toward the inside of the hollow structure starting from the depression provided in the web in advance. There were no cracks at the connection with the wall, bending deformation, or the like, or stay punching.
[0073]
In the barrier test, energy absorption at the time of collision between Invention Examples 1 and 2 and the comparative example is shown as load displacement characteristics in FIG. As can be seen from FIG. 15, the comparative example indicated by the fine dotted line has a high peak load at the beginning of the collision when the displacement on the horizontal axis is about 1 to 2 mm. In addition, due to cracks at the connection between the web and the rear wall, bending deformation, etc., the load (energy absorption) decreases when the displacement of the horizontal axis exceeds about 14 mm, and further the displacement of the horizontal axis As a result of stay punching at a portion of about 16 to 18 mm, the bumper reinforcement member does not deform after this, energy absorption by the bumper reinforcement member is not performed, and the load (energy absorption amount) is significantly reduced is doing.
[0074]
On the other hand, in the invention example 1 indicated by the thick dotted line, the peak load at the initial stage of collision when the displacement on the horizontal axis is about 1 to 2 mm is significantly higher than that in the comparative example. Further, in the comparative example, the load (energy absorption amount) does not decrease even when the displacement of the horizontal axis exceeds about 14 mm where cracks occur at the connection between the web and the rear wall, the bending deformation, or the like. Furthermore, the load (energy absorption amount) after the portion where the horizontal axis displacement is about 16 to 18 mm, where the stay was punched in the comparative example, is high.
[0075]
Further, in Invention Example 2 indicated by a solid line, the peak load at the initial stage of collision when the displacement on the horizontal axis is about 1 to 2 mm is significantly lower than that in Comparative Example and Invention Example 1. Further, in the comparative example, the load (energy absorption amount) does not decrease even when the displacement of the horizontal axis exceeds about 14 mm where cracks occur at the connection between the web and the rear wall, the bending deformation, or the like. Further, the load (energy absorption amount) after the portion where the horizontal axis displacement is about 16 to 18 mm where the stay was punched in the comparative example is also higher than that of the invention example 1. Therefore, the results of these load displacement characteristics correspond well with the visual observation results. Further, the effect of the structure of the present invention and the effect of further providing the recess are supported.
[0076]
From the above results, it is possible to control the maximum load at the initial stage of collision and increase the amount of collision energy absorbed by the vehicle body energy absorbing member structure of the present invention. Further, the effect of preventing the bumper stay punching phenomenon in the preferred embodiment is supported. These results can be similarly applied to vehicle body energy absorbing member structures such as other door beams and brackets and frames.
[0077]
【The invention's effect】
According to the present invention, the punching phenomenon can be prevented by a simple improvement without significantly changing the design and design conditions of an energy absorbing member structure such as a current bumper reinforcement or door beam. It is possible to provide an energy absorbing member structure made of an extruded product made of an Al alloy having a hollow structure with a substantially rectangular cross-sectional shape that can improve the energy absorbing performance. For this reason, the use of the Al alloy material is greatly expanded for the energy absorbing member structure for the vehicle body such as the bumper reinforcing member, the bumper stay, the door beam, the bracket, and the frame, and the industrial value is great.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a vehicle body energy absorbing member structure according to the present invention.
FIG. 2 is a front view showing an embodiment of a vehicle body energy absorbing member structure according to the present invention.
FIG. 3 is a partially sectional front view showing an embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 4 is a front view showing another embodiment of the convex portion of the bumper stay of the vehicle body energy absorbing member structure according to the present invention.
FIG. 5 is a front view showing a relationship between a front end portion of a bumper stay convex portion and a front wall portion inner wall surface of a bumper reinforcement member in the vehicle body energy absorbing member structure according to the present invention.
FIG. 6 is a perspective view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 7 is a front view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 8 is a partial cross-sectional front view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 9 is a front view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 10 is a perspective view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 11 is a front view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 12 is a front view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 13 is a perspective view showing another embodiment of the vehicle body energy absorbing member structure according to the present invention.
FIG. 14 is a front view showing the operation of the vehicle body energy absorbing member structure according to the present invention.
FIG. 15 is an explanatory diagram showing a load displacement curve of the vehicle body energy absorbing member structure according to the present invention.
FIG. 16 is an explanatory view showing a conventional vehicle body energy absorbing member structure.
[Explanation of symbols]
1: Bumper reinforcement, 2: Bumper stay, 3: Web, 4: Front wall, 5: Rear wall, 6: Slit, 7: Convex, 8: Front side member,

Claims

A vehicle body energy absorption member structure comprising a vehicle body energy absorption member used extending in a substantially horizontal direction and a vehicle body connection member coupled to both ends thereof. And a vehicle body corresponding to the front end of the vehicle body coupling member, each of which is made of an extruded product made of an aluminum alloy having a hollow structure with a substantially rectangular cross-sectional shape. A partial slit or concave portion corresponding to the convex portion is provided on the rear wall surface of the energy absorbing member for a vehicle , and the convex portion is passed through the partial slit or concave portion in the hollow structure space of the energy absorbing member for a vehicle body. The vehicle body energy absorbing member structure is characterized in that the vehicle body energy absorbing member and the vehicle body coupling member are coupled to each other.

Partial recesses are provided in advance on both outer wall surfaces of the web at both ends of the vehicle body energy absorbing member that is coupled to the front end of the vehicle body connecting member, so that the load from the substantially horizontal direction to the vehicle body energy absorbing member is reduced. 2. The energy absorbing member structure for a vehicle body according to claim 1 , wherein the web at both end portions is bent inward of the hollow structure starting from the partial recess .

The vehicle body energy absorbing member structure according to claim 2, wherein the recess has a substantially elliptical shape in which a longitudinal direction of the energy absorbing member for vehicle body is a major axis and a width direction of the energy absorbing member for vehicle body is a minor axis .

The vehicle body energy absorbing member structure according to claim 2 or 3 , wherein the recess is provided by embossing .

The energy absorbing member structure for a vehicle body according to any one of claims 1 to 4, wherein a standard aluminum alloy selected from AA to JIS 5000 series, 6000 series, and 7000 series is used as the aluminum alloy .