JP4688318B2

JP4688318B2 - Vehicle beam

Info

Publication number: JP4688318B2
Application number: JP2001066259A
Authority: JP
Inventors: 貴山中
Original assignee: Sankei Giken Kogyo Co Ltd
Current assignee: Sankei Giken Kogyo Co Ltd
Priority date: 2001-03-09
Filing date: 2001-03-09
Publication date: 2011-05-25
Anticipated expiration: 2021-03-09
Also published as: JP2002264740A

Description

【０００１】
【発明の属する技術分野】
本発明は自動車のバンパー構造等に用いられる車両用ビームに関する。
【０００２】
【従来の技術】
従来、追突時等の衝撃吸収を図るため自動車のバンパー構造に於いてバンパービームが用いられている。バンパービームには高度な耐衝撃性が要求されると共に、燃費向上の観点から軽量化が求められ、重量に対してより大きな強度を有することが重要となる。
【０００３】
バンパービームとしては、バンパービームをステーに取り付け、バンパーカバーとバンパービームの間にウレタン等の緩衝材を配設するバンパー構造で用いる、アルミニウム合金等からなる閉断面略長方形或いは開断面略コ字形等のバンパービームが提案されている。更にその改良として特開平５−８５２８６号には上壁と下壁とを第一中間壁にて連結すると共に前壁と後壁とを第二中間壁にて連結した閉断面略長方形のもので、車両衝突時の荷重による上壁及び下壁の座屈変形を抑制したものが開示されている。
【０００４】
そして、近年では特開平７−２４６８９４号等にようにハイテン鋼からなる閉断面略長方形或いは開断面略コ字形等のバンパービームも提案されている。
【０００５】
ハイテン鋼からなるバンパービームの例を図６に示す。図６に於けるバンパービーム１は開断面略コ字形で、中央に凸部１ａが形成されており、サイド部材４の先端に設けられているステー３に補助具２を介して溶接Ｗ等により取り付けられている。バンパー構造で用いる場合、取り付けられたバンパービーム１は図に省略したバンパーカバーで被覆されることになる。なお図６の矢印はバンパービーム１に対する荷重方向である。かようなバンパービームは軽量で且つ高度な強度を有し、高い耐衝撃性を発揮することが可能である。
【０００６】
【発明が解決しようとする課題】
しかし、上記閉断面略長方形や開断面略コ字形のバンパービームでは、未だその強度及び耐衝撃性に対する社会的要求に対して十分なものとは言えない。他方、例えば閉断面略長方形のバンパービームに上記のように第一中間壁や第二中間壁のような補強部を設けると軽量化の要請に逆行することになる。そのため、軽量化及び小型化の要請に応え、且つ高度な耐衝撃性を有するバンパービームなど車両用ビームが切望されていた。
【０００７】
本発明は上記問題点に鑑みなされたものであって、大幅な軽量化及び小型化を図ることができると共に低コストで製造可能で、高い強度及び耐衝撃性を有する車両用ビームを提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明の車両用ビームは、その断面形状が略三角形状を基本として構成されているものである。例えば本発明の車両用ビームは、略鉛直な取付側の一辺を有する略三角形の他の一辺と、略鉛直な圧壊側の一辺を有する略三角形の他の一辺が共有されている形状を、少なくとも断面形状に有することを特徴とし、複数の略三角形状を有する。
【０００９】
また、本発明の車両用ビームは、略鉛直な取付側の底辺を有する略二等辺三角形の等辺である一側辺と、略鉛直な圧壊側の底辺を有する略三角形の内側辺が、略二等辺三角形の両側辺で各々共有されている形状を、少なくとも断面形状に有することを特徴とする。
【００１０】
更に前記車両用ビームは、前記略二等辺三角形の底辺の両端近傍に各々両側端が位置していることを特徴とする。
【００１１】
更に上記車両用ビームは、支点対応位置が負荷方向に対して圧壊しやすい構成であることを特徴とする。
【００１２】
更に上記車両用ビームは、一体形成されていることを特徴とする。また、本発明の車両用ビームは、略鉛直な取付側の底辺を有する略二等辺三角形の等辺である一側辺と、略鉛直な圧壊側の底辺を有する略三角形の内側辺が、略二等辺三角形の両側辺で各々共有されている形状を断面形状に有し、ハイテン鋼のロール成形若しくはプレス成形による一体形成で構成され、前記略二等辺三角形の底辺の両端に形成されている曲部の外側に、各々両側端が配置されて固着され、前記略二等辺三角形の両側辺にそれぞれ対応する前記略三角形の内側辺から底辺に至る曲部の外側が相互に固着されていることを特徴とする。また、本発明の車両用ビームは、略鉛直な取付側の底辺を有する略二等辺三角形の等辺である一側辺と、略鉛直な圧壊側の底辺を有する略三角形の内側辺が、略二等辺三角形の両側辺で各々共有されている形状を断面形状に有し、ハイテン鋼のロール成形若しくはプレス成形による一体形成で構成され、前記略二等辺三角形の底辺の両端に形成されている曲部の内側に接触して若しくは近傍に位置して、各々両側端が配置され、前記略二等辺三角形の両側辺にそれぞれ対応する前記略三角形の内側辺から底辺に至る曲部の外側が相互に固着されていることを特徴とする。
【００１３】
【発明の実施の形態】
以下、本発明の車両用ビームとして、図に於けるバンパービームの具体的な実施形態について説明する。なお本発明の車両用ビームはドアのビームなどバンパービーム以外にも適用可能である。図１は本発明によるバンパービームの縦断面図、図２は本発明によるバンパービームを用いたバンパー構造を示す縦断面図である。
【００１４】
図１に於いてバンパービーム１０は、略鉛直な取付側の底辺１１と等辺である二本の側辺１２・１２とからなる略二等辺三角形と、略鉛直な圧壊側の底辺１３と内側辺１４と外側辺１５とからなる略三角形を二つ有し、前記略二等辺三角形の両側辺１２・１２において、各側辺１２と前記各略三角形の内側辺１４が共有されている断面形状を有する閉断面であり、長手方向には弓形或いは直線形であって、バンパー構造で使用する際には図示矢印の方向から荷重が加わるものである。
【００１５】
バンパービーム１０は一体形成されてなり、前記略二等辺三角形の底辺１１から側辺１２に至る曲部１６、前記略三角形の内側辺１４（側辺１２）から底辺１３に至る曲部１７、前記略三角形の底辺１３から外側辺１５に至る曲部１８が各々例えば５ｍｍなど所定の曲率半径で形成されている。バンパービーム１０の両側端１９・１９は、各々前記略二等辺三角形の底辺１１の両端にある曲部１６・１６の外側の位置で底辺１１に到達する長さで形成され、各側端１９は曲部１６の外側に溶接Ｗ１等で固着されている。溶接Ｗ１はスポット溶接若しくはＭＩＧ溶接など適宜に行うことが可能であるが、例えばＭＩＧ溶接のｌ＝１５ｍｍ×５箇所（センター振り分け等ピッチ）とする。なお側端１９は底辺１１に到達しない長さ、例えば曲部１６に到達する長さとし、適宜固着してもよい。
【００１６】
前記各略三角形の各曲部１７・１７相互間には所定間隔の間隙ｄが設けられているが、間隙ｄを設けずに曲部１７・１７相互が当接するようにしてもよい。そして、バンパービーム１０に於いては更なる強度向上のため、各側端１９が各曲部１６の外側へ固着されることに加え、間隙ｄの両側に位置する曲部１７・１７の外側相互が溶接Ｗ２等で固着され、断面形状で三点の固着が行われる。溶接Ｗ２も溶接Ｗ１と同様に、例えばＭＩＧ溶接のｌ＝１５ｍｍ×７箇所（センター振り分け等ピッチ）とする。なお側端１９と曲部１６或いは曲部１７・１７相互は固着しない構成とすることも可能である。
【００１７】
バンパービーム１０の大きさや寸法は適宜のものとすることが可能である。また、本実施形態のバンパービーム１０はハイテン鋼からなるものであるが、アルミニウム合金若しくはマグネシウム合金で形成してもよく、その形成方法はハイテン鋼等のロール成形若しくはプレス成形する、或いはアルミニウム合金若しくはマグネシウム合金等を押出成形するなど適宜である。
【００１８】
バンパービーム１０をバンパー構造に用いる場合には、例えば図２に示すように、バンパービーム１０の底辺１１側の底面がサイド部材２１の先端に設けられているステー２１ａに固定して取り付けられ、バンパービーム１０はサイド部材２１に保持される。取り付けられているバンパービーム１０の前方にはウレタン等の吸収体である緩衝材２２が配設され、バンパービーム１０及び緩衝材２２はバンパーカバー２３で被覆される。
【００１９】
ここでバンパービーム１０の圧壊特性について説明する。図３は本発明によるバンパービームのバリア試験に於ける荷重と変位の関係を示すグラフ、図４は本発明によるバンパービームのペンデュラム試験に於けるペンデュラム侵入量と時間の関係を示すグラフである。
【００２０】
試験対象のバンパービーム１０は、高さ方向略８０ｍｍ、荷重方向略５０ｍｍの所定寸法で上述した断面形状に形成されていると共に、長手方向にはキャンバーを有する弓形に形成され、所定箇所を固着されている。その素材は降伏応力ＹＰ：１０６０Ｎ／ｍｍ^２、引張強さＴＳ：１２０５Ｎ／ｍｍ^２の材料特性を有するハイテン鋼であって、負荷方向幅２０ｍｍ程度のステーに取り付けられている。また比較対象のバンパービーム１は、高さ方向略９０ｍｍ、荷重方向略７０ｍｍの所定寸法で図６に示す断面形状に形成されていると共に、長手方向にはキャンバーを有する弓形に形成され、所定箇所を固着されている。その素材は降伏応力ＹＰ：７８０Ｎ／ｍｍ^２、引張強さＴＳ：１０１０Ｎ／ｍｍ^２の材料特性を有するハイテン鋼であって、負荷方向幅２０ｍｍ程度のステーに取り付けられている。なお試験対象及び比較対象の長さ及び厚さは略同一である。
【００２１】
バリア試験ではバンパービーム１０、１の両端を自由支持して平板で荷重を負荷して圧壊し、その際の荷重−変位関係を測定して測定値を取得した。ペンデュラム試験では質量１５００ｋｇのペンデュラムを速度８．０４６５ｋｍ／ｈでバンパービーム１０、１に衝突させ、ペンデュラム侵入量を最大値まで測定して測定値を取得した。
【００２２】
図３のバリア試験のグラフに於いて、横軸は負荷方向のバンパービーム１０、１の変位（ｍｍ）で、縦軸は負荷した荷重（ｋＮ）であり、実線は試験対象のバンパービーム１０、破線は比較対象のバンパービーム１を示す。その結果として、試験対象のバンパービーム１０も比較対象のバンパービーム１も、変位４０ｍｍ程度までの荷重に大きな相違はないが、変位４０ｍｍ程度を越えると同一変位に対する荷重が急激に増加しており、その強度特性は非常に優れている。
【００２３】
図４のペンデュラム試験のグラフに於いて、横軸は測定時間（ｓ）で、縦軸はペンデュラム侵入量（ｍ）であり、実線は試験対象のバンパービーム１０、破線は比較対象のバンパービーム１を示している。その結果として、試験対象のペンデュラムの最大侵入量は比較対象に比して明らかに小さく、さらには変形量自体も少ないことが時間経過に伴って明らかになっている。従って、高い強度と衝撃吸収性を有し圧壊特性に優れていることが理解される。
【００２４】
次に本発明によるバンパービームの他の実施形態について説明する。図５はバンパービームの他の実施形態を示す縦断面図である。
【００２５】
図５に於いてバンパービーム３０は、略鉛直な取付側の底辺３１と等辺である二本の側辺３２・３２とからなる略二等辺三角形と、略鉛直な圧壊側の底辺３３と内側辺３４と外側辺３５とからなる略三角形を二つ有し、前記略二等辺三角形の両側辺３２・３２において、各側辺３２と前記略三角形の内側辺３４が共有されている断面形状を有するものであり、長手方向には弓形或いは直線形であって、バンパー構造で使用する際には図示矢印の方向から荷重が加わるものである。
【００２６】
バンパービーム３０は一体形成されてなり、前記略二等辺三角形の底辺３１から前記略三角形の外側辺３５に至る曲部３６、前記略三角形の外側辺３５から底辺３３に至る曲部３７、前記略三角形の底辺３３から内側辺３４（側辺３２）に至る曲部３８が各々例えば５ｍｍなど所定の曲率半径で形成されている。バンパービーム３０の両側端３９・３９は、各々前記略二等辺三角形の底辺３１の両端にある曲部３６・３６に接触して或いは近傍に位置して形成されており、必要に応じて側端３９を曲部３６の内側にＭＩＧ溶接等で固着することが可能である。
【００２７】
前記略三角形の両曲部３８・３８相互間には所定間隔の間隙ｊが設けられているが、間隙ｊを設けずに両曲部３８・３８相互が当接するようにしてもよい。間隙ｊの両側に位置する曲部３８・３８は、例えばＭＩＧ溶接のｌ＝１５ｍｍ×７箇所（センター振り分け等ピッチ）など溶接Ｗ３で必要に応じて固着されているが、曲部３８・３８相互を固着しない構成にすることも可能である。
【００２８】
バンパービーム３０の大きさや寸法は適宜のものとすることが可能である。また、バンパービーム３０はハイテン鋼からなるものであるが、アルミニウム合金若しくはマグネシウム合金で形成してもよく、その形成方法はハイテン鋼等のロール成形若しくはプレス成形する、或いはアルミニウム合金若しくはマグネシウム合金等を押出成形するなど適宜である。
【００２９】
尚、図３に於いて、本発明のバンパービーム１０の強度特性の高さが示されているが、採用される車両により、図２のサイド部材２１の耐荷重を超えてしまう場合がある。その場合、サイド部材２１との締結部分であるステー２１ａの対応位置に適宜加工を加えることにより、サイド部材２１の耐荷重のオーバーを抑制することが可能である。これにより、幅広い種類の車両に対応することも可能である。その実施形態を以下に示す。図７は図５のバンパービームの加工例を示す斜視図、図８は図５のバンパービームの他の加工例を示す斜視図である。
【００３０】
図７に於けるバンパービーム３０は、上方及び下方に位置する側辺３２（内側辺３４）の両端が、横辺３２ａ（３４ａ）と斜辺３２ｂ（３４ｂ）からなる略く形の所定形状にカットされている。なお前記所定形状のカットは必要に応じて上方位置の側辺３２のみ若しくは下方位置の側辺３２のみに形成し、或いはこれらのカットをバンパービーム３０の片側のみに形成することも可能である。
【００３１】
図８に於けるバンパービーム３０は、側辺３２（内側辺３４）及び外側辺３５の両端にそれぞれ各２箇所のピアス孔４０が穿設されている。なお前記ピアス孔４０を設ける辺、位置、数は上記に限定されず、例えば上方の側辺３２のみ、上方の外側辺３５のみ、若しくは上方の側辺３２及び外側辺３５のみ、或いは下方の側辺３２、外側辺３５のみに設けるなど本発明の趣旨の範囲内で適宜である。
【００３２】
上記加工例のバンパービーム３０のように、上記実施形態で支点対応位置となるバンパービームの両端を略く形にカットする或いは両端にピアス孔を設ける等所定形状に加工すること等で、バンパービームの支点対応位置を負荷方向に対して圧壊しやすい構造にすることにより、バンパービームの支点対応位置の反力が減少し、前記支点対応位置はより潰れやすくなる。これにより、同一断面形状のバンパービームで、大型車や中型車だけではなく、小型車等に於いても衝突時に車体へかかる負荷を極力軽減することができて、幅広い車種への対応が可能となり、更なるコスト低減が期待できる。
【００３３】
上記のようにバンパービーム１０、３０等は、略三角形状を基本にするので荷重の分散を図ることができ、高い強度を有し衝撃吸収性に非常に優れている。例えば断面略四角形及び断面略円形のバンパービームでは、圧壊時に圧壊方向の縦壁を外側に開く力が作用するので縦壁が倒れて座屈し易い。これに対して例えば図１のバンパービーム１０では、圧壊時に内側の曲部１８が外側に膨らむのを側端１９が防止すると共に、圧壊時に間隙ｄ等の部分で支持する際に曲部１７・１７相互が両側から押され両者が当接する方向の力が加わり、縦壁である側辺１２・１２同士が突っ張る。このように各辺の端部等で突っ張ることで縦壁が倒れにくくなり、変形が防止されて荷重に対する圧壊強度が向上する。
【００３４】
さらに、バンパービーム１０等の断面形状は略三角形状を基本にすることから、例えば略四角形状のバンパービームでは圧壊方向に対する縦壁が二つであるのに対し略三角形状のバンパービーム１０等では四つであるなど、圧壊方向に対する縦壁の数を容易に多くすることが可能で強度を向上できる。
【００３５】
また、バンパービーム１０等は、断面形状が円形や四角形等のバンパービームは延長を図るのが困難であるのに対し、略三角形状を断面形状の基本にすることで、連続して略三角形状を形成して容易に延長し、簡単に大型化を図ることができる。
【００３６】
また同一の大きさではより高い強度及び衝撃吸収性を発揮でき、同一強度では小型化して軽量化を図ることができるので、例えば小スペースでも小型化することで設置できる。さらには圧壊方向のバンパービームの寸法を最小限にできるので、緩衝材等の設置も容易に行える。
【００３７】
【発明の効果】
本発明によるバンパービームなど車両用ビームは上記構成であるから、車両用ビーム及びこれを用いるバンパー構造等の大幅な軽量化及び小型化を図ることができると共に、高い強度及び耐衝撃性を発揮することができる効果がある。さらには低コストで製造することが可能である。
【図面の簡単な説明】
【図１】本発明によるバンパービームの縦断面図。
【図２】本発明によるバンパービームを用いたバンパー構造を示す縦断面図。
【図３】本発明によるバンパービームのバリア試験に於ける荷重と変位の関係を示すグラフ。
【図４】本発明によるバンパービームのペンデュラム試験に於けるペンデュラム侵入量と時間の関係を示すグラフ。
【図５】バンパービームの他の実施形態を示す縦断面図。
【図６】従来のハイテン鋼からなるバンパービームを示す縦断面図。
【図７】図５のバンパービームの変形例を示す斜視図。
【図８】図５のバンパービームの他の変形例を示す斜視図。
【符号の説明】
１０、３０バンパービーム
１１、１３、３１、３３底辺
１２、３２側辺
１４、３４内側辺
１５、３５外側辺
１６、１７、１８、３６、３７、３８曲部
１９、３９側端
２１サイド部材
２２緩衝材
２３バンパーカバー
２１ａステー
ｄ、ｊ間隙
Ｗ１、Ｗ２、Ｗ３溶接[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle beam used for a bumper structure of an automobile.
[0002]
[Prior art]
Conventionally, a bumper beam is used in a bumper structure of an automobile in order to absorb an impact during a rear-end collision. Bumper beams are required to have high impact resistance and are also required to be light in weight from the viewpoint of improving fuel efficiency, and it is important to have greater strength with respect to weight.
[0003]
As the bumper beam, a bumper beam is attached to the stay, and a bumper structure in which a cushioning material such as urethane is disposed between the bumper cover and the bumper beam is used. Bumper beams have been proposed. As a further improvement, Japanese Patent Application Laid-Open No. 5-85286 discloses a substantially rectangular closed section in which the upper wall and the lower wall are connected by a first intermediate wall and the front wall and the rear wall are connected by a second intermediate wall. In addition, there is disclosed one in which buckling deformation of an upper wall and a lower wall due to a load at the time of a vehicle collision is suppressed.
[0004]
In recent years, a bumper beam made of high-tensile steel, such as a substantially rectangular closed cross section or a substantially U-shaped open cross section, has been proposed as disclosed in JP-A-7-246894.
[0005]
An example of a bumper beam made of high-tensile steel is shown in FIG. The bumper beam 1 shown in FIG. 6 has an approximately U-shaped open cross section, and a convex portion 1a is formed at the center. It is attached. When used in a bumper structure, the mounted bumper beam 1 is covered with a bumper cover not shown in the figure. Note that the arrow in FIG. 6 indicates the load direction with respect to the bumper beam 1. Such a bumper beam is lightweight and has high strength, and can exhibit high impact resistance.
[0006]
[Problems to be solved by the invention]
However, the bumper beam having the substantially closed cross-section and the open cross-section substantially U-shaped is still not sufficient for the social demand for its strength and impact resistance. On the other hand, for example, when a reinforcing portion such as the first intermediate wall or the second intermediate wall is provided on the bumper beam having a substantially rectangular closed cross section as described above, it goes against the demand for weight reduction. Therefore, a beam for a vehicle such as a bumper beam which meets the demand for weight reduction and miniaturization and has high impact resistance has been desired.
[0007]
The present invention has been made in view of the above problems, and provides a vehicle beam that can be significantly reduced in weight and size, can be manufactured at low cost, and has high strength and impact resistance. With the goal.
[0008]
[Means for Solving the Problems]
The vehicular beam according to the present invention has a substantially triangular cross-sectional shape. For example, the vehicle beam of the present invention has at least a shape in which the other side of the substantially triangular shape having one side of the substantially vertical mounting side and the other side of the substantially triangular shape having one side of the substantially vertical crushing side are shared. It has a cross-sectional shape and has a plurality of substantially triangular shapes.
[0009]
Further, the vehicle beam of the present invention has approximately one side that is an isosceles side of a substantially isosceles triangle having a bottom on the substantially vertical mounting side and an inner side of a substantially triangle that has a bottom on the substantially vertical crushing side. A shape shared by both sides of the equilateral triangle is at least a cross-sectional shape.
[0010]
Further, the vehicle beam is characterized in that both side ends are located in the vicinity of both ends of the base of the substantially isosceles triangle.
[0011]
Further, the vehicle beam is characterized in that the fulcrum corresponding position is easily collapsed in the load direction.
[0012]
Further, the vehicle beam is integrally formed. Further, the vehicle beam of the present invention has approximately one side that is an isosceles side of a substantially isosceles triangle having a bottom on the substantially vertical mounting side and an inner side of a substantially triangle that has a bottom on the substantially vertical crushing side. A curved portion that has a shape shared by both sides of the equilateral triangle in cross-sectional shape, is formed by integral formation by roll forming or press forming of high-tensile steel, and is formed at both ends of the base of the substantially isosceles triangle The outer sides of the curved portions extending from the inner side to the base of the substantially triangular shape respectively corresponding to the both sides of the approximately isosceles triangle are fixed to each other. And Further, the vehicle beam of the present invention has approximately one side that is an isosceles side of a substantially isosceles triangle having a bottom on the substantially vertical mounting side and an inner side of a substantially triangle that has a bottom on the substantially vertical crushing side. A curved portion that has a shape shared by both sides of the equilateral triangle in cross-sectional shape, is formed by integral formation by roll forming or press forming of high-tensile steel, and is formed at both ends of the base of the substantially isosceles triangle Are located in contact with or in the vicinity of the inner side of each of the two sides, and the outer sides of the curved portions extending from the inner side to the base side of the substantially triangular shape respectively corresponding to the both sides of the substantially isosceles triangle are fixed to each other. It is characterized by being.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the bumper beam in the drawings will be described as the vehicle beam of the present invention. The vehicle beam according to the present invention can be applied to other than a bumper beam such as a door beam. FIG. 1 is a longitudinal sectional view of a bumper beam according to the present invention, and FIG. 2 is a longitudinal sectional view showing a bumper structure using the bumper beam according to the present invention.
[0014]
In FIG. 1, a bumper beam 10 includes a substantially isosceles triangle composed of a base 11 on a substantially vertical mounting side and two side edges 12 and 12 which are equilateral, a base 13 and an inner side on a substantially vertical crushing side. 14 and two outer sides 15, each of the sides 12 and 12 of the substantially isosceles triangle has a sectional shape in which each side 12 and the inner side 14 of each of the substantially triangles are shared. The closed section has an arcuate shape or a straight shape in the longitudinal direction, and a load is applied from the direction of the arrow in the figure when used in a bumper structure.
[0015]
The bumper beam 10 is integrally formed, a curved portion 16 extending from the base 11 to the side 12 of the substantially isosceles triangle, a curved portion 17 extending from the inner side 14 (side 12) of the substantially triangular to the base 13, The curved portions 18 extending from the base 13 of the substantially triangular shape to the outer side 15 are each formed with a predetermined radius of curvature such as 5 mm. Both side ends 19 and 19 of the bumper beam 10 are formed to reach the base 11 at positions outside the curved portions 16 and 16 at both ends of the base 11 of the substantially isosceles triangle, respectively, It is fixed to the outside of the curved portion 16 by welding W1 or the like. Welding W1 can be appropriately performed, such as spot welding or MIG welding. For example, MIG welding is set to l = 15 mm × 5 locations (pitch of center distribution, etc.). The side end 19 has a length that does not reach the bottom 11, for example, a length that reaches the curved portion 16, and may be fixed as appropriate.
[0016]
A gap d having a predetermined interval is provided between the curved portions 17 and 17 of the substantially triangular shapes. However, the curved portions 17 and 17 may contact each other without providing the gap d. In the bumper beam 10, in order to further improve the strength, each side end 19 is fixed to the outside of each curved portion 16, and the curved portions 17, 17 located on both sides of the gap d are mutually outside. Are fixed by welding W2 or the like, and three points are fixed in a cross-sectional shape. Similarly to the welding W1, the welding W2 is, for example, 1 = 15 mm × 7 places (pitch of center distribution, etc.) of MIG welding. Note that the side end 19 and the curved portion 16 or the curved portions 17 and 17 may not be fixed to each other.
[0017]
The size and dimensions of the bumper beam 10 can be set appropriately. The bumper beam 10 of the present embodiment is made of high-tensile steel, but may be formed of aluminum alloy or magnesium alloy, and the forming method is roll forming or press forming of high-tensile steel or the like, or aluminum alloy or It is appropriate to extrude a magnesium alloy or the like.
[0018]
When the bumper beam 10 is used in a bumper structure, for example, as shown in FIG. 2, the bottom surface of the bumper beam 10 on the bottom side 11 side is fixedly attached to a stay 21 a provided at the tip of the side member 21. The beam 10 is held by the side member 21. A shock absorbing material 22 that is an absorber such as urethane is disposed in front of the mounted bumper beam 10, and the bumper beam 10 and the shock absorbing material 22 are covered with a bumper cover 23.
[0019]
Here, the crushing characteristic of the bumper beam 10 will be described. FIG. 3 is a graph showing the relationship between load and displacement in the bumper beam barrier test according to the present invention, and FIG. 4 is a graph showing the relationship between pendulum penetration and time in the bumper beam pendulum test according to the present invention.
[0020]
The bumper beam 10 to be tested is formed in the above-mentioned cross-sectional shape with predetermined dimensions of approximately 80 mm in the height direction and approximately 50 mm in the load direction, and is formed in an arc shape having a camber in the longitudinal direction, and a predetermined portion is fixed. ing. The material is high-tensile steel having material characteristics of yield stress YP: 1060 N / mm ² and tensile strength TS: 1205 N / mm ² , and is attached to a stay having a load direction width of about 20 mm. Further, the bumper beam 1 to be compared is formed in a cross-sectional shape shown in FIG. 6 with a predetermined dimension of approximately 90 mm in the height direction and approximately 70 mm in the load direction, and is formed in an arc shape having a camber in the longitudinal direction. Is fixed. The material is high-tensile steel having material characteristics of yield stress YP: 780 N / mm ² and tensile strength TS: 1010 N / mm ² , and is attached to a stay having a load direction width of about 20 mm. Note that the length and thickness of the test object and the comparison object are substantially the same.
[0021]
In the barrier test, both ends of the bumper beams 10 and 1 were supported freely, and a flat plate was loaded with a load to be crushed. The load-displacement relationship at that time was measured to obtain a measured value. In the pendulum test, a pendulum having a mass of 1500 kg was made to collide with the bumper beams 10 and 1 at a speed of 8.0465 km / h, and the pendulum penetration amount was measured to the maximum value to obtain a measured value.
[0022]
In the graph of the barrier test of FIG. 3, the horizontal axis is the displacement (mm) of the bumper beams 10 and 1 in the load direction, the vertical axis is the applied load (kN), and the solid line is the bumper beam 10 to be tested. A broken line indicates the bumper beam 1 to be compared. As a result, the bumper beam 10 to be tested and the bumper beam 1 to be compared do not have much difference in load up to about 40 mm, but when the displacement exceeds about 40 mm, the load for the same displacement increases rapidly. Its strength characteristics are very good.
[0023]
In the graph of the pendulum test of FIG. 4, the horizontal axis is the measurement time (s), the vertical axis is the pendulum penetration amount (m), the solid line is the bumper beam 10 to be tested, and the broken line is the bumper beam 1 to be compared. Is shown. As a result, it has become clear over time that the maximum penetration amount of the pendulum to be tested is obviously smaller than that of the comparison subject, and further, the deformation amount itself is small. Therefore, it is understood that it has high strength and shock absorption and has excellent crush characteristics.
[0024]
Next, another embodiment of the bumper beam according to the present invention will be described. FIG. 5 is a longitudinal sectional view showing another embodiment of the bumper beam.
[0025]
In FIG. 5, the bumper beam 30 includes a substantially isosceles triangle composed of a base 31 on a substantially vertical mounting side and two sides 32 and 32 that are equilateral, and a base 33 and an inner side on a substantially vertical crushing side. 34 and two outer sides 35, and both sides 32 and 32 of the substantially isosceles triangle have a cross-sectional shape in which each side 32 and the inner side 34 of the substantially triangle are shared. In the longitudinal direction, it has an arcuate shape or a linear shape, and when used in a bumper structure, a load is applied from the direction of the arrow shown in the figure.
[0026]
The bumper beam 30 is integrally formed, a curved portion 36 extending from the base 31 of the substantially isosceles triangle to the outer side 35 of the substantially triangular shape, a curved portion 37 extending from the outer side 35 of the substantially triangular shape to the base 33, and the approximately Curved portions 38 extending from the bottom 33 of the triangle to the inner side 34 (side 32) are each formed with a predetermined radius of curvature, such as 5 mm. Both side ends 39 and 39 of the bumper beam 30 are formed in contact with or near the curved portions 36 and 36 on both ends of the base 31 of the substantially isosceles triangle, respectively, 39 can be fixed inside the curved portion 36 by MIG welding or the like.
[0027]
A gap j having a predetermined interval is provided between the curved portions 38 and 38 of the substantially triangular shape. However, the curved portions 38 and 38 may contact each other without providing the gap j. The curved portions 38 and 38 positioned on both sides of the gap j are fixed as necessary by welding W3 such as 1 = 15 mm × 7 locations (center distribution pitch, etc.) of MIG welding, but the curved portions 38 and 38 are mutually connected. It is also possible to adopt a configuration that does not stick.
[0028]
The size and dimensions of the bumper beam 30 can be set appropriately. The bumper beam 30 is made of high-tensile steel, but may be formed of aluminum alloy or magnesium alloy, and the forming method is roll forming or press forming of high-tensile steel, or aluminum alloy or magnesium alloy. Extrusion molding is appropriate.
[0029]
Although FIG. 3 shows the high strength characteristics of the bumper beam 10 of the present invention, the load capacity of the side member 21 of FIG. 2 may be exceeded depending on the vehicle employed. In that case, it is possible to suppress overload resistance of the side member 21 by appropriately processing the corresponding position of the stay 21a that is the fastening portion with the side member 21. Thereby, it is also possible to deal with a wide variety of vehicles. The embodiment is shown below. FIG. 7 is a perspective view showing a processing example of the bumper beam of FIG. 5, and FIG. 8 is a perspective view showing another processing example of the bumper beam of FIG.
[0030]
The bumper beam 30 in FIG. 7 is cut into a substantially rectangular predetermined shape in which both ends of the side 32 (inner side 34) located above and below are composed of a lateral side 32a (34a) and a hypotenuse 32b (34b). Has been. It is also possible to form the cut of the predetermined shape only on the upper side 32 or the lower side 32 as necessary, or to form these cuts only on one side of the bumper beam 30.
[0031]
The bumper beam 30 shown in FIG. 8 has two pierce holes 40 formed at both ends of the side 32 (inner side 34) and the outer side 35, respectively. The side, position, and number of the pierced holes 40 are not limited to the above. For example, only the upper side 32, only the upper outer side 35, only the upper side 32 and the outer side 35, or the lower side. It is appropriate within the scope of the present invention, such as being provided only on the side 32 and the outer side 35.
[0032]
Like the bumper beam 30 in the above processing example, the bumper beam can be formed by cutting the both ends of the bumper beam that corresponds to the fulcrum-corresponding position in the above embodiment into a substantially rectangular shape or by processing the bumper beam into a predetermined shape such as providing pierce holes at both ends By making the fulcrum corresponding position easy to collapse in the load direction, the reaction force at the fulcrum corresponding position of the bumper beam is reduced, and the fulcrum corresponding position is more easily crushed. As a result, the bumper beam with the same cross-sectional shape can reduce the load on the vehicle body at the time of collision not only in large cars and medium-sized cars, but also in small cars as much as possible, making it possible to handle a wide range of vehicles. Further cost reduction can be expected.
[0033]
As described above, the bumper beams 10, 30 and the like are based on a substantially triangular shape, so that the load can be dispersed, the strength is high, and the shock absorption is very excellent. For example, in a bumper beam having a substantially square cross section and a substantially circular cross section, a force that opens the vertical wall in the crushing direction to the outside acts during crushing, so that the vertical wall tends to collapse and buckle easily. On the other hand, in the bumper beam 10 of FIG. 1, for example, the side end 19 prevents the inner curved portion 18 from expanding outward during crushing, and the curved portion 17. 17 is pushed from both sides, and a force is applied in the direction in which the two come into contact with each other, so that the side walls 12 and 12 which are vertical walls are stretched. In this way, the vertical wall is not easily tilted by stretching at the end of each side or the like, the deformation is prevented, and the crushing strength against the load is improved.
[0034]
Further, since the cross-sectional shape of the bumper beam 10 and the like is basically a triangular shape, for example, a substantially rectangular bumper beam has two vertical walls in the crushing direction, whereas a substantially triangular bumper beam 10 and the like It is possible to easily increase the number of vertical walls with respect to the crushing direction, such as four, and the strength can be improved.
[0035]
In addition, the bumper beam 10 or the like is difficult to extend for a bumper beam having a circular or quadrangular cross-sectional shape. Can be easily extended and can be easily enlarged.
[0036]
In addition, since the same size can provide higher strength and shock absorption, and the same strength can reduce the size and weight, for example, it can be installed by reducing the size even in a small space. Furthermore, since the size of the bumper beam in the crushing direction can be minimized, it is possible to easily install a cushioning material or the like.
[0037]
【The invention's effect】
Since the vehicular beam such as the bumper beam according to the present invention has the above-described configuration, the vehicular beam and the bumper structure using the vehicular beam can be significantly reduced in weight and size, and exhibit high strength and impact resistance. There is an effect that can. Furthermore, it can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a bumper beam according to the present invention.
FIG. 2 is a longitudinal sectional view showing a bumper structure using a bumper beam according to the present invention.
FIG. 3 is a graph showing the relationship between load and displacement in a bumper beam barrier test according to the present invention.
FIG. 4 is a graph showing the relationship between pendulum penetration and time in a pendulum test of a bumper beam according to the present invention.
FIG. 5 is a longitudinal sectional view showing another embodiment of the bumper beam.
FIG. 6 is a longitudinal sectional view showing a conventional bumper beam made of high-tensile steel.
7 is a perspective view showing a modified example of the bumper beam of FIG. 5. FIG.
8 is a perspective view showing another modification of the bumper beam shown in FIG.
[Explanation of symbols]
10, 30 Bumper beam 11, 13, 31, 33 Base 12 and 32 Side 14 and 34 Inner side 15 and 35 Outer side 16, 17, 18, 36, 37, 38 Bend 19 and 39 Side end 21 Side member 22 Buffer material 23 Bumper cover 21a Stay d, j Gap W1, W2, W3 Welding

Claims

One side which is an isosceles side of a substantially isosceles triangle having a base on the substantially vertical mounting side and an inner side of the substantially triangle having a base on the substantially vertical crushing side are shared by both sides of the substantially isosceles triangle. Have a cross-sectional shape
Consists of one-piece high-tensile steel roll forming or press forming,
Outside the curved portion formed at both ends of the base of the approximately isosceles triangle, each side end is disposed and fixed,
The vehicular beam, wherein the outer sides of the curved portions from the inner side to the bottom side of the substantially triangular shape respectively corresponding to both sides of the substantially isosceles triangle are fixed to each other.

One side which is an isosceles side of a substantially isosceles triangle having a base on the substantially vertical mounting side and an inner side of the substantially triangle having a base on the substantially vertical crushing side are shared by both sides of the substantially isosceles triangle. Have a cross-sectional shape
Consists of one-piece high-tensile steel roll forming or press forming,
In contact with or in the vicinity of the inside of the curved portion formed at both ends of the base of the approximately isosceles triangle, both side ends are arranged,
The vehicular beam, wherein the outer sides of the curved portions from the inner side to the bottom side of the substantially triangular shape respectively corresponding to both sides of the substantially isosceles triangle are fixed to each other.