JP2011021644A

JP2011021644A - Shock absorbing member

Info

Publication number: JP2011021644A
Application number: JP2009165625A
Authority: JP
Inventors: Kenji Tamura; 憲司田村; Yoshiaki Nakazawa; 嘉明中澤
Original assignee: Sumitomo Metal Industries Ltd
Current assignee: Nippon Steel Corp
Priority date: 2009-07-14
Filing date: 2009-07-14
Publication date: 2011-02-03
Anticipated expiration: 2029-07-14
Also published as: JP5632142B2

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the shock absorbing performance of a shock absorbing member having a cylindrical body bent by an impact load applied in a collision to absorb impact energy. <P>SOLUTION: The shock absorbing member includes a first portion 3 formed of a cylindrical body having an outer wall 2a made of steel, a second portion 4 which is a bent part continuous with the outer wall 2a of the first portion 3 and formed bending to the outside, and a third portion 5 continuous with the second portion 4 and forming a support part of the second portion 4. Impact energy is absorbed by the continuous occurrence of bending deformation that increases the length L of a folded part 10 formed by folding the outer wall 3a of the first portion 3 by the impact load applied in the axial direction of the cylindrical body 2 from the end 3a of the first portion 3. The first portion 3 has a plurality of ridge lines 11 provided extending in the axial direction of the cylindrical body 2 at least in a range where bending deformation continuously occurs, out of the outer wall 2a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、衝撃吸収部材に関し、具体的には、自動車等の車両に装着されて、衝突時に負荷される衝撃荷重により曲げ変形を連続して生じることによって衝撃エネルギーを吸収する筒状体を有する衝撃吸収部材に関する。 The present invention relates to an impact absorbing member, and more specifically, has a cylindrical body that is mounted on a vehicle such as an automobile and absorbs impact energy by continuously generating bending deformation due to an impact load applied at the time of a collision. The present invention relates to an impact absorbing member.

近年、自動車の衝突時の衝突安全性の向上が、地球環境保護を目的とする燃費向上を図るための軽量化とともに、積極的に推進されている。衝突安全性の向上を図るため、車体各部の構造や各構造部材の見直しや適正化が推進されているとともに、衝突時に負荷される衝撃荷重により塑性変形を生じることによって衝撃エネルギーを効率的に吸収するための衝撃吸収部材が用いられている。 In recent years, improvement of collision safety at the time of automobile collision has been actively promoted together with weight reduction for improving fuel efficiency for the purpose of protecting the global environment. In order to improve collision safety, review and optimization of the structure of each part of the vehicle body and each structural member are promoted, and impact energy is efficiently absorbed by causing plastic deformation due to the impact load applied at the time of collision. An impact absorbing member is used for this purpose.

このような衝撃吸収部材として、旧来から用いられているサイドメンバーやバンパーレインフォースに加えて、近年にはクラッシュボックスも用いられる。クラッシュボックスは、バンパーレインフォースに固定されてサイドメンバーの長手方向の端部に装着され、バンパーレインフォースを介して負荷される衝撃荷重によりその軸方向への座屈を繰り返して蛇腹状に塑性変形することによって、サイドメンバーの損傷を防ぎながら衝撃エネルギーを吸収する筒状体を有する。本出願人も、先に特許文献１により、極めて高い衝撃吸収性能を有するクラッシュボックスに係る特許発明を開示した。 As such an impact absorbing member, in addition to the side members and bumper reinforcement that have been used conventionally, a crash box is also used in recent years. The crash box is fixed to the bumper reinforcement and attached to the end of the side member in the longitudinal direction. By the impact load applied through the bumper reinforcement, it is repeatedly buckled in the axial direction and plastically deformed into a bellows shape. By doing so, it has a cylindrical body that absorbs impact energy while preventing damage to the side members. The present applicant previously disclosed a patented invention related to a crash box having extremely high shock absorption performance according to Patent Document 1.

特許文献１に開示されたように、繰り返し座屈して蛇腹状に塑性変形することによって衝撃エネルギーを吸収する構造では、クラッシュボックスに蛇腹状の塑性変形を生じるために一定周期の反力変化（本明細書では「荷重振幅」という）が不可避的に繰り返し発生するので、その反力によって例えばロアークロスメンバー等の強度が小さい構造部材を損傷させるおそれがある。したがって、衝撃吸収部材を低強度の構造部材に装着するために、荷重振幅が小さく、衝撃エネルギーの吸収性能が衝突方向によらずに安定して高い衝撃吸収部材が求められている。 As disclosed in Patent Document 1, in a structure in which impact energy is absorbed by repeatedly buckling and plastically deforming into a bellows shape, a change in reaction force (constant period) is generated in order to cause a bellows-like plastic deformation in the crash box. In the specification, “load amplitude”) is inevitably repeated, and the reaction force may damage a structural member having a low strength such as a lower cross member. Therefore, in order to mount the shock absorbing member on a low-strength structural member, there is a demand for a shock absorbing member having a small load amplitude and a stable and high shock energy absorbing performance regardless of the collision direction.

特許文献２、３には、略述すると、小径部と、この小径部に連続して段差状に形成される大径部とを有する金属製の円筒体からなる衝撃吸収部材に係る発明が開示されている。この円筒体は、上述した特許文献１により開示される筒体のように衝撃荷重により座屈を繰り返して蛇腹状に塑性変形するのではなく、一方の端部から軸方向へ向けて負荷される衝撃荷重により小径部と大径部との間に形成される段差部を起点として、円筒体の外壁面の一部が折り返される曲げ変形を連続して発生することによって衝撃エネルギーを吸収する。特許文献２、３により開示された発明によれば、衝撃吸収部材の小型化を図りながら衝撃エネルギーを吸収することが可能であるとされている。 In brief, Patent Documents 2 and 3 disclose an invention relating to an impact absorbing member made of a metal cylindrical body having a small diameter portion and a large diameter portion formed in a step shape continuously from the small diameter portion. Has been. This cylindrical body is not plastically deformed into a bellows shape by repeatedly buckling due to an impact load like the cylindrical body disclosed in Patent Document 1 described above, but is loaded in the axial direction from one end. The impact energy is absorbed by continuously generating a bending deformation in which a part of the outer wall surface of the cylindrical body is folded back starting from a step portion formed between the small diameter portion and the large diameter portion due to the impact load. According to the invention disclosed in Patent Documents 2 and 3, it is said that it is possible to absorb impact energy while reducing the size of the impact absorbing member.

また、特許文献４には、塑性加工可能な直管を部分的に縮径または拡径して段差を介して繋がる小円筒体および大円筒体を形成してなり、段差は円弧角度９０°超の円弧状断面からなる小円筒体の折返縁および大円筒体の折返縁を連続して形成され、軸方向斜めから衝撃が加えられても、なお大円筒体に対する小円筒体の没入を確保して、塑性変形による衝撃エネルギーの吸収を達成できるバンパー支持型の衝撃吸収部材に係る発明が開示されている。 Further, Patent Document 4 includes a small cylinder and a large cylinder that are connected to each other through a step by partially reducing or expanding a straight pipe that can be plastically processed. The folding edge of the small cylinder and the folding edge of the large cylinder, which have an arc-shaped cross section, are continuously formed, and even if an impact is applied obliquely in the axial direction, the small cylinder can still be immersed in the large cylinder. Thus, there has been disclosed an invention relating to a bumper-supporting type impact absorbing member capable of achieving absorption of impact energy by plastic deformation.

特許文献５には、互いに径が異なる第１の円筒体および第２の円筒体が、それらの端部が合わされた状態で同軸的に一体化されてなり、軸方向の変形により、衝突時の反力が小さく、かつ部材変形時の反力変化が小さく、衝突する方向によらず安定した性能を発揮して衝突エネルギーを吸収する衝撃吸収部材に係る発明が開示されている。 In Patent Document 5, a first cylindrical body and a second cylindrical body having different diameters are coaxially integrated with their end portions being combined, and due to axial deformation, An invention relating to an impact absorbing member that has a small reaction force and a small change in reaction force when the member is deformed and that exhibits stable performance regardless of the direction of collision and absorbs collision energy is disclosed.

さらに、特許文献６には、塑性加工可能な直管を部分的に縮径または拡径し、互いに向かい合う中間端縁を環状段差部により結んだ外径の異なる小円筒体および大円筒体からなり、環状段差部は小円筒体の中間端縁から折り返した円弧状断面の小円筒体と、大円筒体の中間端縁から折り返した円弧状断面の大円筒体とを結んだ断面構造を有し、外径が大円筒体の内径よりも大きい圧入管部を小円筒体に設けることによって、車両の軽重、衝突時の速度の違いに基づいて適切な変位−荷重特性を設定できる塑性変形を利用した衝撃吸収部材に係る発明が開示されている。 Further, Patent Document 6 is composed of a small cylindrical body and a large cylindrical body having different outer diameters, in which a straight pipe that can be plastically processed is partially reduced or expanded, and intermediate edges facing each other are connected by an annular stepped portion. The annular step portion has a cross-sectional structure in which a small cylindrical body having an arc-shaped cross section folded from an intermediate end edge of a small cylindrical body and a large cylindrical body having an arc-shaped cross section folded from an intermediate end edge of the large cylindrical body are connected. Utilizing plastic deformation that can set the appropriate displacement-load characteristics based on the difference in vehicle weight and speed at the time of collision by providing a press-fit tube part with an outer diameter larger than the inner diameter of the large cylinder in the small cylinder An invention relating to the shock absorbing member is disclosed.

特許第３９１２４２２号明細書Japanese Patent No. 3912422 特開２００１−４７９５２号公報JP 2001-47952 A 特開２００１−１３８８４１号公報JP 2001-138841 A 特開２００４−５１０８４号公報JP 2004-51084 A 特開２００１−２４１４７８号公報JP 2001-241478 A 特開２００３−３２７０６２号公報JP 2003-327062 A

本発明者らの検討結果によれば、特許文献２〜６により開示された発明の衝撃吸収部材は、いずれも、反力の変化は小さいものの、衝撃吸収部材をなす円筒体の軸方向から偏った方向への衝撃荷重（本明細書では「偏荷重」という）が作用すると、衝撃吸収部材全体が大きく屈曲する曲がり変形が早期に発生し、衝撃エネルギーの吸収性能が著しく低下し易いことが判明した。 According to the examination results of the present inventors, the impact absorbing members of the inventions disclosed in Patent Documents 2 to 6 are all deviated from the axial direction of the cylindrical body forming the impact absorbing member, although the change in reaction force is small. It turns out that when the impact load in this direction (referred to as “unbalanced load” in this specification) is applied, the entire impact absorbing member will bend and bend significantly and the impact energy absorption performance will be significantly reduced. did.

本発明は、従来の技術が有するこの課題に鑑みてなされたものであり、荷重振幅が小さく、偏荷重が作用した場合にも衝撃吸収部材全体が大きく屈曲する曲がり変形の発生を抑制でき、衝突方向によらずに安定した高い衝撃エネルギーの吸収性能を維持することができる衝撃吸収部材を提供することを目的とする。 The present invention has been made in view of this problem of the prior art, and it is possible to suppress the occurrence of bending deformation in which the entire shock-absorbing member is bent greatly even when a load amplitude is small and an eccentric load is applied, An object of the present invention is to provide an impact absorbing member capable of maintaining a stable high impact energy absorbing performance regardless of the direction.

本発明は、金属材料からなる外壁を有する筒状体からなる第１の部分と、この第１の部分の外壁に連続するとともに外側に折れ曲がって形成される折れ曲がり部である第２の部分と、この第２の部分に連続するとともにこの第２の部分の支持部をなす第３の部分とを有し、第１の部分の端部から筒状体の軸方向へ向けて負荷される衝撃荷重によって、第１の部分の外壁が折り返されて形成される折り返し部の長さが増加する曲げ変形を連続して生じることにより衝撃エネルギーを吸収する衝撃吸収部材であって、第１の部分は、その外壁のうちで、少なくとも、曲げ変形を連続して生じる範囲に、筒状体の軸方向へ延びて設けられる複数の稜線を有することを特徴とする衝撃吸収部材である。 The present invention includes a first portion made of a cylindrical body having an outer wall made of a metal material, a second portion that is a bent portion that is continuous with the outer wall of the first portion and is bent outward. An impact load that is continuous with the second part and has a third part that forms a support part of the second part and is loaded from the end of the first part toward the axial direction of the cylindrical body The shock absorbing member that absorbs impact energy by continuously generating bending deformation in which the length of the folded portion formed by folding the outer wall of the first portion is increased, and the first portion is It is an impact-absorbing member characterized by having a plurality of ridge lines provided extending in the axial direction of the cylindrical body at least in a range where bending deformation is continuously generated among the outer walls.

この本発明では、第２の部分が筒状体であることが望ましく、また、第３の部分が筒状体であることが望ましい。
これらの本発明では、複数の稜線のうち筒状体の周方向に隣接する二本の稜線により区画される外壁が、平面、または、筒状体の外側または内側に向けて湾曲した曲面をなすことが望ましい。 In the present invention, the second portion is preferably a cylindrical body, and the third portion is preferably a cylindrical body.
In these aspects of the present invention, the outer wall defined by two ridge lines adjacent to each other in the circumferential direction of the cylindrical body among the plurality of ridge lines forms a flat surface or a curved surface curved toward the outer side or the inner side of the cylindrical body. It is desirable.

これらの本発明では、曲げ変形を連続して生じる外壁が、多角形の横断面形状を有することが望ましい。この場合に、多角形が、８角形から１２角形までのいずれかの多角形であることが望ましい。 In the present invention, it is desirable that the outer wall that continuously generates bending deformation has a polygonal cross-sectional shape. In this case, it is desirable that the polygon is any one of octagons to dodecagons.

これらの本発明では、第１の部分が一の金属材料からなるとともに、第３の部分がこの一の金属材料とは異なる他の一の金属材料からなることが望ましい。この場合に、一の金属材料と、他の一の金属材料とが、それぞれの板厚および／または材質が異なることがさらに望ましい。 In the present invention, it is desirable that the first portion is made of one metal material and the third portion is made of another metal material different from the one metal material. In this case, it is more desirable that one metal material and the other metal material have different plate thicknesses and / or materials.

これらの本発明では、さらに、第３の部分を支持するとともに折り返し部の外径よりも大きな径の穴を有する支持部材を備えることが望ましい。
また、これらの本発明では、第１の部分および第３の部分が、いずれも、筒状体の軸方向と略平行な方向へ延びて設けられることが望ましく、この場合に、筒状体の軸方向への第３の部分の長さが、この軸方向への第１の部分の長さ以上であることがさらに望ましい。 In the present invention, it is desirable to further include a support member that supports the third portion and has a hole having a diameter larger than the outer diameter of the folded portion.
In the present invention, the first part and the third part are preferably provided so as to extend in a direction substantially parallel to the axial direction of the cylindrical body. More preferably, the length of the third portion in the axial direction is equal to or longer than the length of the first portion in the axial direction.

本発明に係る衝撃吸収部材によれば、
（Ａ）折り返し量が増加するように折れ曲がり変形を連続して生じるので、荷重振幅が小さいこと、および
（Ｂ）外壁が軸方向へ延びる稜線を有するので、例えば特許文献２〜６により開示された円筒体を有する衝撃吸収部材よりも衝撃エネルギーの吸収性能が高く、また、偏荷重が作用した場合にも、衝撃吸収部材全体が大きく屈曲する曲がり変形の発生を抑制でき、衝突方向によらずに安定した高い衝撃エネルギーの吸収性能を維持できること
という優れた効果が奏される。 According to the shock absorbing member of the present invention,
(A) Since bending deformation continuously occurs so that the amount of folding increases, the load amplitude is small, and (B) the outer wall has a ridge line extending in the axial direction. Impact energy absorption performance is higher than that of a shock absorbing member having a cylindrical body, and even when an unbalanced load is applied, it is possible to suppress the occurrence of bending deformation that greatly bends the entire shock absorbing member, regardless of the collision direction. An excellent effect of maintaining stable high impact energy absorption performance is achieved.

特に、曲げ変形を連続して生じる外壁が、８角形から１２角形までのいずれかの多角形の横断面形状を有することが望ましく、特に正８角形から正１２角形までのいずれかの正多角形の横断面形状を有することがさらに望ましい。 In particular, it is desirable that the outer wall that continuously generates bending deformation has a polygonal cross-sectional shape of any one of octagons to dodecagons, and in particular, any regular polygon from regular octagons to regular dodecagons. It is further desirable to have the following cross-sectional shape.

このため、本発明によれば、例えば、ロアークロスメンバーに装着することができ、一台あたりの衝撃吸収部材の装着数を増やすことや、例えば軽自動車といったこれまでには衝撃吸収部材を装着できなかった小型の車両にも衝撃吸収部材を装着することが可能になり、これにより、衝撃エネルギーの吸収性能を高めることができる。 Therefore, according to the present invention, for example, it can be attached to the lower cross member, and the number of shock absorbing members per unit can be increased, or a shock absorbing member such as a light vehicle can be attached so far. It becomes possible to attach the impact absorbing member even to a small vehicle that has not been present, thereby improving the impact energy absorbing performance.

図１は、本発明に係る衝撃吸収部材の構造の一例を簡略化して示す分解斜視図である。FIG. 1 is an exploded perspective view showing a simplified example of the structure of an impact absorbing member according to the present invention. 図２（ａ）および図２（ｂ）は、いずれも、実施の形態１の衝撃吸収部材により衝撃エネルギーが吸収される状況を模式的に示す説明図であり、図２（ｃ）および図２（ｄ）は、いずれも、実施の形態２の衝撃吸収部材により衝撃エネルギーが吸収される状況を模式的に示す説明図であり、図２（ｅ）は、実施の形態３の衝撃吸収部材により衝撃エネルギーが吸収される状況を模式的に示す説明図である。2 (a) and 2 (b) are explanatory diagrams schematically showing a situation in which impact energy is absorbed by the impact absorbing member of Embodiment 1, and FIG. 2 (c) and FIG. (D) is explanatory drawing which shows typically the condition where an impact energy is absorbed by the impact-absorbing member of Embodiment 2, FIG.2 (e) is based on the impact-absorbing member of Embodiment 3. It is explanatory drawing which shows typically the condition where impact energy is absorbed. 図３は、円筒体を有する衝撃吸収部材に衝撃荷重が負荷された際の曲げ変形の発生状況を模式的に示す説明図であり、図３（ａ）は曲げ変形前を示し、図３（ｂ）は曲げ変形時を示し、図３（ｃ）は図３（ｂ）の円筒体をＡ−Ａ断面で切断して展開して示す。FIG. 3 is an explanatory view schematically showing the state of occurrence of bending deformation when an impact load is applied to an impact absorbing member having a cylindrical body. FIG. 3 (a) shows the state before bending deformation, and FIG. FIG. 3C shows a state of bending deformation, and FIG. 3C shows the cylindrical body of FIG. 図４（ａ）は、本発明に係る衝撃吸収部材の筒状体の折り返し変形開始時に折り返し部側からみた横断面の変化状況を示す説明図であり、図４（ｂ）は、筒状体の折り返し変形の進行中の横断面の変化状況を示す説明図であり、図４（ｃ）は、筒状体の稜線と稜線間の外壁とにおける折り返し変形の半径の違いを示す説明図である。FIG. 4A is an explanatory view showing a change state of a cross section viewed from the folded portion side at the start of folding deformation of the cylindrical body of the shock absorbing member according to the present invention, and FIG. 4B is a cylindrical body. FIG. 4C is an explanatory diagram illustrating a difference in radius of the folding deformation between the ridge line of the cylindrical body and the outer wall between the ridge lines. . 図５（ａ）および図５（ｂ）は、筒状体の折り返し部の近傍の断面の変形状況を経時的に示す説明図であり、図５（ａ）は曲げ変形開始前を示し、図５（ｂ）は曲げ変形中を示す。5 (a) and 5 (b) are explanatory views showing the deformation state of the cross section in the vicinity of the folded portion of the cylindrical body over time. FIG. 5 (a) shows the state before the start of bending deformation. 5 (b) shows the bending deformation. 図６は、金属板を素材として本発明に係る衝撃吸収部材を構成する筒状体を製造する方法を模式的に示す説明図である。FIG. 6 is an explanatory view schematically showing a method of manufacturing a cylindrical body constituting the shock absorbing member according to the present invention using a metal plate as a raw material. 図７は、多角形断面化加工の一例を示す説明図である。FIG. 7 is an explanatory diagram showing an example of polygonal cross-section processing. 図８は、多角形断面化加工の詳細を示す説明図である。FIG. 8 is an explanatory diagram showing details of polygon cross-section processing. 図９は、多角形断面化加工の他の一例を示す説明図である。FIG. 9 is an explanatory diagram showing another example of polygonal cross-section processing. 図１０は、金属管を素材として本発明に係る衝撃吸収部材を構成する筒状体を製造する方法を経時的に示す説明図である。FIG. 10 is an explanatory view showing a method of manufacturing a cylindrical body constituting the impact absorbing member according to the present invention using a metal tube as a material over time. 図１１は、実施の形態２の衝撃吸収部材の構造の一例を、簡略化して示す分解斜視図である。FIG. 11 is an exploded perspective view showing a simplified example of the structure of the shock absorbing member of the second embodiment. 実施例で行った、衝突試験を模擬した数値解析の条件を示す説明図である。It is explanatory drawing which shows the conditions of the numerical analysis which simulated the collision test performed in the Example. 実施例の結果を示すグラフである。It is a graph which shows the result of an Example.

（実施の形態１）
以下、本発明に係る衝撃吸収部材を実施するための形態を、添付図面を参照しながら説明する。なお、以降の説明では、本発明に係る衝撃吸収部材を構成する筒状体が鋼板からなる場合を例にとる。 (Embodiment 1)
EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the impact-absorbing member which concerns on this invention is demonstrated, referring an accompanying drawing. In the following description, the case where the cylindrical body constituting the shock absorbing member according to the present invention is made of a steel plate is taken as an example.

図１は、本発明に係る衝撃吸収部材１の構造の一例を、簡略化して示す分解斜視図である。
図１に示すように、この衝撃吸収部材１は、鋼板からなる外壁２ａを有する筒状体２を備える。この筒状体２は、図１中のＡ−Ａ断面図に示すように、その軸方向に関して、第１の部分３と、第２の部分４と、第３の部分５とを有する。 FIG. 1 is a simplified exploded perspective view showing an example of the structure of the shock absorbing member 1 according to the present invention.
As shown in FIG. 1, the impact absorbing member 1 includes a cylindrical body 2 having an outer wall 2a made of a steel plate. This cylindrical body 2 has a first portion 3, a second portion 4, and a third portion 5 in the axial direction as shown in the AA cross-sectional view in FIG. 1.

第１の部分３は、筒状体２の軸方向と略平行な方向へ真っ直ぐに延びて形成される部分である。第２の部分４は、第１の部分３に連続するとともに筒状体２の外壁２ａが筒状体２の外側に折れ曲がって形成される折れ曲がり部である。 The first part 3 is a part formed by extending straight in a direction substantially parallel to the axial direction of the cylindrical body 2. The second portion 4 is a bent portion that is continuous with the first portion 3 and is formed by bending the outer wall 2 a of the cylindrical body 2 to the outside of the cylindrical body 2.

さらに、第３の部分５は、第２の部分４に連続して筒状体２の軸方向へ延び、さらに、この軸方向と直交する方向であって筒状体２の外側へ延びて外向きフランジ状に形成される。第３の部分５は、第３の部分５を支持するための支持部材である取付け台座６に例えば溶接により接合される際における、筒状体２の支持部をなす部分である。 Further, the third portion 5 is continuous with the second portion 4 and extends in the axial direction of the cylindrical body 2, and further extends in the direction orthogonal to the axial direction and extends outside the cylindrical body 2. It is formed in a direction flange shape. The third portion 5 is a portion that forms a support portion of the cylindrical body 2 when being joined to the mounting base 6 that is a support member for supporting the third portion 5 by welding, for example.

図１に示す例では、第３の部分５に、筒状体２の軸方向と直交する方向であって筒状体２の外側へ延びる外向きフランジ部５ａを設けたが、外向きフランジ部５ａを設けずに、第３の部分５における筒状体２の軸方向へ延びる部分を介して、取付け台座６に例えば溶接により接合するようにしてもよい。いずれにしても、第３の部分５は、第２の部分４の支持部をなす部分である。 In the example illustrated in FIG. 1, the third portion 5 is provided with the outward flange portion 5 a extending in the direction orthogonal to the axial direction of the cylindrical body 2 and extending outward from the cylindrical body 2. You may make it join to the attachment base 6 by welding, for example through the part extended in the axial direction of the cylindrical body 2 in the 3rd part 5, without providing 5a. In any case, the third portion 5 is a portion that forms a support portion of the second portion 4.

第３の部分５を支持するための支持部材である取付け台座６には、ロアークロスメンバー７に取り付けるためのボルト８が貫通するための貫通穴６ａが設けられるとともに、後述する折り返し部１０の外径よりも大きな径の通過穴６ｂが設けられている。 A mounting base 6 serving as a support member for supporting the third portion 5 is provided with a through hole 6a through which a bolt 8 for mounting to the lower cross member 7 passes, and outside a folded portion 10 described later. A passage hole 6b having a diameter larger than the diameter is provided.

通過穴６ｂは、衝撃エネルギーの吸収時における筒状体２の折り返し部１０との干渉を防止するための当たり逃げとして、機能する。筒状体２は、外向きフランジ部５ａよりも第２の部分４の側に存在する部分を、この通過穴６ｂに挿入されることによって、外向きフランジ部５ａが取付け台座６の表面６ｃに突き当てられ、外向きフランジ部５ａを例えば溶接等の適当な接合手段によって接合することにより、取付け台座６に固定される。 The passage hole 6b functions as a contact relief for preventing interference with the folded portion 10 of the cylindrical body 2 when absorbing impact energy. The cylindrical body 2 is inserted into the passage hole 6b at a portion that is closer to the second portion 4 than the outward flange portion 5a, whereby the outward flange portion 5a is attached to the surface 6c of the mounting base 6. The outer flange portion 5a is abutted and joined to the mounting base 6 by joining with an appropriate joining means such as welding.

ロアークロスメンバー７には、貫通穴６ａが設けられる位置と一致するように同一ピッチでネジ穴７ａが設けられる。貫通穴６ａとネジ穴７ａとを一致させてから、ボルト８をネジ穴７ａにねじ込むことによって、取付け台座６がロアークロスメンバー７に脱着自在に締結固定される。取付け台座６のロアークロスメンバー７への取付けは、この締結に代表される機械的手段等の適宜手段により、脱着自在に取付けられていればよい。 The lower cross member 7 is provided with screw holes 7a at the same pitch so as to coincide with the positions where the through holes 6a are provided. The mounting base 6 is detachably fastened and fixed to the lower cross member 7 by aligning the through hole 6a and the screw hole 7a and then screwing the bolt 8 into the screw hole 7a. The attachment pedestal 6 may be attached to the lower cross member 7 so as to be detachable by appropriate means such as mechanical means represented by this fastening.

筒状体２の第１の部分３の先端３ａは、図１において図面を見易くするために二点鎖線により透視状態で示すバンパーレインフォースメント９の後面９ａに、例えば溶接等の適宜手段により接合される。なお、図１では、ロアークロスメンバー７およびバンパーレインフォースメント９はいずれも簡略化して示しており、それらの実際の形状を示すものではない。 The front end 3a of the first portion 3 of the cylindrical body 2 is joined to the rear surface 9a of the bumper reinforcement 9 shown in a transparent state by a two-dot chain line in order to make the drawing easier to see in FIG. 1 by appropriate means such as welding. Is done. In FIG. 1, the lower cross member 7 and the bumper reinforcement 9 are both shown in a simplified manner and do not show their actual shapes.

この衝撃吸収部材１は、特許文献２〜６により開示された衝撃吸収部材と同様に、バンパーレインフォースメント９を介して第１の部分３の端部３ａから筒状体２の軸方向へ向けて負荷される衝撃荷重によって、折れ曲がり部である第２の部分４を起点として、折れ曲がり部である第２の部分４の近傍の第１の部分３の外壁２ａが外側に折り返され、以後、第１の部分３の外壁２ａが順次折り返されて折り返し部１０の軸方向の長さＬが増加する曲げ変形を連続して生じることにより衝撃エネルギーを吸収するものである。 This shock absorbing member 1 is directed from the end 3a of the first portion 3 toward the axial direction of the tubular body 2 via the bumper reinforcement 9, similarly to the shock absorbing members disclosed in Patent Documents 2 to 6. The outer wall 2a of the first portion 3 in the vicinity of the second portion 4 that is the bent portion starts from the second portion 4 that is the bent portion by the impact load applied to the outside, and thereafter, The outer wall 2a of the first portion 3 is sequentially folded, and the bending energy in which the axial length L of the folded portion 10 is continuously generated is absorbed to absorb the impact energy.

本発明に係る衝撃吸収部材１の筒状体２は、その外壁２ａのうちで、少なくとも、曲げ変形を連続して生じる範囲に、筒状体２の軸方向へ延びて設けられる複数（図１に示す衝撃吸収部材１では８本）の稜線１１を有する。すなわち、筒状体２は八角形の横断面形状を有する。 The cylindrical body 2 of the impact-absorbing member 1 according to the present invention has a plurality (see FIG. 1) extending in the axial direction of the cylindrical body 2 at least in a range in which bending deformation continuously occurs in the outer wall 2a. The impact absorbing member 1 shown in FIG. That is, the cylindrical body 2 has an octagonal cross-sectional shape.

図１に示す衝撃吸収部材１は、筒状体２の周方向に隣接する２本の稜線１１、１１により区画される外壁２ａ−１、２ａ−２、２ａ−３、２ａ−４、２ａ−５、２ａ−６、２ａ−７、２ａ−８が平面をなしているが、これとは異なり筒状体２の外側または内側に向けて湾曲した曲面をなしていてもよい。 The impact absorbing member 1 shown in FIG. 1 has outer walls 2 a-1, 2 a-2, 2 a-3, 2 a-4, 2 a-defined by two ridge lines 11, 11 adjacent in the circumferential direction of the cylindrical body 2. 5, 2a-6, 2a-7, and 2a-8 form a plane, but unlike this, a curved surface that curves toward the outside or the inside of the cylindrical body 2 may be formed.

図１に示す衝撃吸収部材１は、筒状体２の軸方向の全域について外壁２ａが多角形の横断面形状を有しているが、これに限定されるものではなく、衝撃荷重を入力された際に曲げ変形を連続して生じることによって折り返し部１０を形成することとなる外壁２ａが、多角形をなしていればよく、折り返し部１０を形成することとはならない外壁２ａはこの多角形をなしていなくともよい。 In the impact absorbing member 1 shown in FIG. 1, the outer wall 2 a has a polygonal cross-sectional shape in the entire axial direction of the cylindrical body 2, but is not limited to this, and an impact load is input. The outer wall 2a that forms the folded portion 10 by continuously generating bending deformation when it is bent may be a polygon, and the outer wall 2a that does not form the folded portion 10 is the polygon. You don't have to.

例えば、第１の部分３の外壁２ａだけが多角形をなしているか、または第１の部分３の外壁２ａおよび第２の部分４の外壁２ａの双方だけが多角形をなしていればよい。第１の部分３の外壁２ａおよび第２の部分４の外壁２ａの双方が多角形をなしていることが望ましい。 For example, only the outer wall 2a of the first portion 3 has a polygonal shape, or only both the outer wall 2a of the first portion 3 and the outer wall 2a of the second portion 4 have to be polygonal. It is desirable that both the outer wall 2a of the first portion 3 and the outer wall 2a of the second portion 4 are polygonal.

なお、稜線１１は、多角形を構成する頂点に相当するが、実際の衝撃吸収部材１は鋼板の折り曲げ成形やプレス成形等の適宜手段で成形されるため、この頂点に相当する稜線１１は横断面で見れば、稜線以外の他の部分に比べて相当程度小さな曲率半径を有する部分である。 The ridge line 11 corresponds to a vertex constituting a polygon. However, since the actual shock absorbing member 1 is formed by appropriate means such as bending and press forming of a steel plate, the ridge line 11 corresponding to the vertex is transverse. In terms of the surface, it is a portion having a radius of curvature that is considerably smaller than other portions other than the ridgeline.

衝撃吸収部材１を構成する筒状体２は、バンパーレインフォースメント９を介してその一方の端部３ａから衝撃荷重Ｆを筒状体２の軸方向へ負荷されると、折り返し部１０の折り返し量（図１における長さＬ）が増加するように、第１の部分３の外壁２ａに曲げ変形を連続して生じることによって、衝撃エネルギーを吸収する。 When the impact load F is applied to the tubular body 2 constituting the impact absorbing member 1 in the axial direction of the tubular body 2 through the bumper reinforcement 9, the tubular body 2 is folded back. The impact energy is absorbed by continuously generating bending deformation on the outer wall 2a of the first portion 3 so that the amount (length L in FIG. 1) increases.

図２（ａ）および図２（ｂ）は、いずれも、本発明に係る衝撃吸収部材１により衝撃エネルギーが吸収される状況を、模式的に示す説明図である。図２（ａ）および図２（ｂ）における左図は正面図、中央図は曲げ変形開始時の断面図、右図は曲げ変形終了時の断面図である。 2 (a) and 2 (b) are explanatory views schematically showing a situation where impact energy is absorbed by the impact absorbing member 1 according to the present invention. 2A and 2B, the left figure is a front view, the central figure is a sectional view at the start of bending deformation, and the right figure is a sectional view at the end of bending deformation.

図１、図２（ａ）および図２（ｂ）に示すように、筒状体２は、バンパーレインフォースメント９を介して端部３ａから衝撃荷重Ｆを筒状体２の軸方向（図１および図２（ａ）における矢印方向）へ負荷されると、筒状体２は、折り返し部１０の折り返し量（図１における長さＬ）が増加するように、第１の部分３の外壁２ａが折り返される曲げ変形（圧縮変形）を連続して生じることによって衝撃エネルギーを吸収する。 As shown in FIGS. 1, 2 (a) and 2 (b), the cylindrical body 2 applies an impact load F from the end portion 3 a via the bumper reinforcement 9 in the axial direction of the cylindrical body 2 (FIG. 1 and the outer wall of the first portion 3 so that the amount of folding of the folded portion 10 (length L in FIG. 1) increases. The impact energy is absorbed by continuously generating bending deformation (compression deformation) in which 2a is folded.

このように、本発明に係る衝撃吸収部材１による衝撃エネルギーの吸収は、筒状体２の折り返し部１０の折り返し量（図１における長さＬ）が変化するように、筒状体２の第１の部分３の外壁２ａに曲げ変形を連続して生じることにより、行われる。このため、本発明に係る衝撃吸収部材１では、筒状体２の折り返し部１０をなす外壁２ａの部分を、異なる複数種の材料により構成すれば、折り返し部４に発生する曲げ変形の挙動を制御することも可能になる。 As described above, the impact energy is absorbed by the impact absorbing member 1 according to the present invention so that the folding amount (length L in FIG. 1) of the folded portion 10 of the cylindrical body 2 changes. This is done by continuously producing a bending deformation in the outer wall 2a of the portion 3 of 1. For this reason, in the shock absorbing member 1 according to the present invention, if the portion of the outer wall 2a that forms the folded portion 10 of the cylindrical body 2 is made of a plurality of different materials, the behavior of the bending deformation that occurs in the folded portion 4 is achieved. It is also possible to control.

例えば、第１の部分３が一の鋼板からなるとともに、第３の部分５が、例えば板厚および材質の少なくとも一つが異なることによってこの一の鋼板とは相違する他の一の鋼板からなることが望ましい。 For example, the first portion 3 is made of one steel plate, and the third portion 5 is made of another steel plate that is different from the one steel plate due to, for example, at least one of the thickness and material being different. Is desirable.

図２（ｂ）は、図２（ａ）に示す場合において、筒状体２が、第１の部分３および第２の部分４を構成する一の鋼製材料Ｓ１と、第３の部分を構成する他の一の鋼製材料Ｓ２と、外壁２ａにおける曲げ変形を連続して生じる部分に形成され、一の材料Ｓ１および他の一の材料Ｓ２を接合する接合部１２とを有する場合を示す説明図である。 FIG. 2B shows a case where the cylindrical body 2 includes the first steel material S1 constituting the first part 3 and the second part 4 and the third part in the case shown in FIG. The case where it has the joining part 12 which joins one other material S2 formed in the part which produces the other one steel material S2 to comprise, and the bending deformation in the outer wall 2a continuously is shown. It is explanatory drawing.

図２（ｂ）に示す場合は、図２（ａ）に示す場合と同様に、筒状体２は、バンパーレインフォースメント９を介して端部３ａから衝撃荷重Ｆを筒状体２の軸方向（図１および図２（ｂ）における矢印方向）へ負荷されると、筒状体２は、折り返し部１０の折り返し量（図１における長さＬ）が増加するように、外壁２ａが折り返される曲げ変形（圧縮変形）を連続して生じることによって衝撃エネルギーを吸収する。 In the case shown in FIG. 2B, the cylindrical body 2 applies the impact load F from the end portion 3a via the bumper reinforcement 9 as in the case shown in FIG. When loaded in the direction (the arrow direction in FIGS. 1 and 2B), the outer wall 2a of the cylindrical body 2 is folded so that the amount of folding of the folded portion 10 (length L in FIG. 1) increases. It absorbs impact energy by continuously producing bending deformation (compression deformation).

図２（ｂ）に示す場合には、筒状体２が、一の材料Ｓ１と他の一の材料Ｓ２と接合部１２とを有するので、一の材料Ｓ１および他の一の材料Ｓ２それぞれの板厚や強度を異ならせて設定することにより、折り返し部１０における曲げ変形の変形挙動を所望のように制御することができる。 In the case shown in FIG. 2 (b), the cylindrical body 2 has one material S1, another one material S2, and a joint portion 12. Therefore, each of the one material S1 and the other one material S2 By setting the plate thickness and strength to be different, the deformation behavior of the bending deformation in the folded portion 10 can be controlled as desired.

例えば、材料Ｓ２の板厚を材料Ｓ１の板厚よりも大きく設定すること、あるいは材料Ｓ２の強度を材料Ｓ１の強度より大きく設定することによって、折り返し部１０の折り返し変形が継続している間は、材料Ｓ２の変形が抑制されるため、より安定して衝撃エネルギーを吸収することが可能になる。このように、折れ曲がり変形を受けない部分（例えば第３の部分５）には、板厚が大きい材料を用いるか、あるいは強度が高い材料を用いることが望ましい。 For example, by setting the plate thickness of the material S2 to be greater than the plate thickness of the material S1, or by setting the strength of the material S2 to be greater than the strength of the material S1, the folding portion 10 continues to be folded back. Since the deformation of the material S2 is suppressed, the impact energy can be absorbed more stably. As described above, it is desirable to use a material having a large plate thickness or a material having a high strength for a portion that is not bent and deformed (for example, the third portion 5).

この筒状体２は、図１、図２（ａ）および図２（ｂ）に示すように、多角形の横断面形状（図１、図２（ａ）および図２（ｂ）では八角形の横断面形状）を有する。すなわち、この筒状体２はその外壁２ａに軸方向へ延びる複数本（８本）の稜線１１を備える。 As shown in FIGS. 1, 2 (a) and 2 (b), this cylindrical body 2 has a polygonal cross-sectional shape (an octagon in FIGS. 1, 2 (a) and 2 (b)). Of the cross-sectional shape). That is, the cylindrical body 2 includes a plurality of (eight) ridge lines 11 extending in the axial direction on the outer wall 2a.

筒状体２が複数本の稜線１１を備え、多角形の横断面形状を有することによって、筒状体２が円形の横断面形状を有する場合に較べて、折り返し部１０において生じる繰り返し変形荷重を高めることができるので、この筒状体２を有する衝撃吸収部材１の衝撃吸収性能を高めること、すなわち衝撃エネルギーの吸収量を増加することができる。 Since the cylindrical body 2 includes a plurality of ridge lines 11 and has a polygonal cross-sectional shape, the repeated deformation load generated in the folded portion 10 can be reduced as compared with the case where the cylindrical body 2 has a circular cross-sectional shape. Therefore, the impact absorbing performance of the impact absorbing member 1 having the tubular body 2 can be increased, that is, the amount of impact energy absorbed can be increased.

また、筒状体２は、多角形の横断面形状を有するので、円形の横断面形状を有する円筒体に比較して、衝突方向によらずに安定した高い衝突エネルギーの吸収性能を発揮することが可能である。 In addition, since the cylindrical body 2 has a polygonal cross-sectional shape, the cylindrical body 2 exhibits stable high collision energy absorption performance regardless of the collision direction, compared to a cylindrical body having a circular cross-sectional shape. Is possible.

図３は、円筒体１３を有する衝撃吸収部材に衝撃荷重が負荷された際の曲げ変形の発生状況を模式的に示す説明図であり、図３（ａ）は曲げ変形前を示し、図３（ｂ）は曲げ変形時を示し、図３（ｃ）は図３（ｂ）の円筒体１３をＡ−Ａ断面で切断して展開して示す。 FIG. 3 is an explanatory view schematically showing the state of occurrence of bending deformation when an impact load is applied to the impact absorbing member having the cylindrical body 13, and FIG. 3 (a) shows the state before bending deformation, and FIG. FIG. 3C shows a state of bending deformation, and FIG. 3C shows the cylindrical body 13 of FIG.

円筒体１３の一端１３ａから衝撃荷重Ｆが負荷された後、円筒体１３は以下に列記するように曲げ変形を生じる。
（ｉ）最初に折り返し部である第２の部分１３−２を起点として、第２の部分１３−２の近傍の第１の部分１３−１の外壁が外側に折り返され、以後、第１の部分１３−１の外壁が順次裏返しに折り返される。 After the impact load F is applied from the one end 13a of the cylindrical body 13, the cylindrical body 13 undergoes bending deformation as listed below.
(I) First, the outer wall of the first portion 13-1 in the vicinity of the second portion 13-2 is folded outward from the second portion 13-2 that is the folded portion as a starting point. The outer wall of the portion 13-1 is turned upside down sequentially.

（ｉｉ）この際、第１の部分１３−１の各断面は拡大する。すなわち、第１の部分１３−１の周長が増大する方向に変形する。
（ｉｉｉ）したがって、この周長の増大によって折り返された部分には周方向への引張力が作用する。 (Ii) At this time, each cross section of the first portion 13-1 is enlarged. That is, the first portion 13-1 is deformed in the direction in which the circumferential length increases.
(Iii) Accordingly, a tensile force in the circumferential direction acts on the portion folded by the increase in the circumferential length.

（ｉｖ）この反力により、折り返し部の内側の折り返し予定部（曲げ変形を生じていない第１の部分１３−１）には周方向への圧縮力が作用する。
（ｖ）曲げ変形を生じていない第１の部分１３−１は、この周方向の圧縮力によって、初期断面よりも折り返し部近傍において縮径変形を生じる。 (Iv) Due to this reaction force, a compressive force in the circumferential direction acts on a portion to be folded inside the folded portion (the first portion 13-1 in which no bending deformation has occurred).
(V) The first portion 13-1 that has not undergone bending deformation undergoes diameter-reducing deformation in the vicinity of the folded portion rather than the initial cross section due to the compressive force in the circumferential direction.

このように、特許文献２〜６により開示された発明のような円筒体を有する衝撃吸収部材では、衝撃荷重を負荷されて円筒体の軸方向へ圧縮荷重が負荷されると、折り返し部の横断面に一様に圧縮荷重が作用し、折り返し変形は周方向に一様となる。 As described above, in the impact absorbing member having the cylindrical body as disclosed in Patent Documents 2 to 6, when the impact load is applied and the compressive load is applied in the axial direction of the cylindrical body, the crossing of the folded portion is performed. A compressive load acts uniformly on the surface, and the folding back deformation becomes uniform in the circumferential direction.

これに対し、稜線１１を有する、多角形の横断面を有する筒状体２を有する本発明に係る衝撃吸収部材１は、折り返し変形の状況が、稜線と稜線間とでは異なる。
図４（ａ）は、本発明に係る衝撃吸収部材１の筒状体２の折り返し変形開始時に折り返し部側からみた横断面の変化状況を示す説明図であり、図４（ｂ）は、この筒状体２の折り返し変形の進行中の横断面の変化状況を示す説明図であり、図４（ｃ）は、筒状体２の稜線１１と稜線間の外壁２ａとにおける折り返し変形の半径の違いを示す説明図である。 On the other hand, the impact-absorbing member 1 according to the present invention having the cylindrical body 2 having a polygonal cross section having the ridge line 11 is different in the state of the folding deformation between the ridge line and the ridge line.
FIG. 4 (a) is an explanatory view showing a change state of a cross section viewed from the folded portion side at the start of folding deformation of the cylindrical body 2 of the shock absorbing member 1 according to the present invention, and FIG. FIG. 4C is an explanatory view showing a change state of the cross section during the folding deformation of the cylindrical body 2, and FIG. 4C is a diagram showing the radius of the folding deformation at the ridge line 11 of the cylindrical body 2 and the outer wall 2 a between the ridge lines. It is explanatory drawing which shows a difference.

図４（ａ）に示すように、本発明に係る衝撃吸収部材１の筒状体２に衝撃荷重Ｆが負荷されると、図４（ｂ）に示すように、上記（ｖ）項に示す周方向の圧縮力によって外壁２ａ−１〜２ａ−８はいずれも断面内側へたわむとともに、８本の稜線１１はいずれも鋭角化して尖る。 As shown in FIG. 4A, when an impact load F is applied to the cylindrical body 2 of the impact absorbing member 1 according to the present invention, as shown in FIG. The outer walls 2a-1 to 2a-8 are all deflected inward by the circumferential compressive force, and the eight ridge lines 11 are all sharpened and sharpened.

このため、図４（ｃ）に示すように、稜線１１では曲率半径が小さい曲げ変形となるために折り返し変形時に非常に大きな曲げひずみが発生する。一方、外壁２ａ−１〜２ａ−８の平面部は大きな曲率半径での曲げとなり、曲げ変形により生じるひずみは、従来の衝撃吸収部材の円筒体１３よりも小さくなる。しかし、断面全体では稜線１１での大きなひずみ発生の効果が外壁２ａ−１〜２ａ−８でのひずみ縮小の影響を上回るため、本発明のように多角形断面化によって円形断面よりもより高い変形荷重が得ることができる。 For this reason, as shown in FIG.4 (c), in the ridgeline 11, since it becomes a bending deformation with a small curvature radius, a very big bending distortion generate | occur | produces at the time of a folding deformation. On the other hand, the flat portions of the outer walls 2a-1 to 2a-8 are bent with a large curvature radius, and the strain caused by the bending deformation is smaller than that of the cylindrical body 13 of the conventional shock absorbing member. However, since the effect of large strain generation at the ridge line 11 exceeds the influence of strain reduction at the outer walls 2a-1 to 2a-8 in the entire cross section, the deformation is higher than that of the circular cross section by the polygonal cross section as in the present invention. A load can be obtained.

また、多角形断面として稜線１１が存在することによって、偏荷重が作用した場合においても、稜線１１の剛性が高く、稜線１１が存在せず全周に曲面のみを有する円筒体に比べて、偏荷重による曲げ変形時の倒れ込みが生じ難くなる。 Further, since the ridge line 11 exists as a polygonal cross section, even when a biased load is applied, the rigidity of the ridge line 11 is high, and the ridge line 11 is not present, and the ridge line 11 is not present. It becomes difficult for the body to collapse during bending deformation due to the load.

ただし、筒状体２の横断面をなす多角形は、８角形から１２角形までのいずれかの多角形であることが望ましい。角数が８角形よりも少ないと、稜線１１が曲げ変形前に鋭角に尖り過ぎ、折り返し変形が生じずに座屈および軸圧壊に移行し易いとともに、偏荷重に対して稜線が過度に突っ張った後に折れ曲がりが生じ易い。一方、角数が１２角形よりも多いと、稜線１１のひずみの集中効果が薄れるとともに、偏荷重に対して稜線１１の剛性向上効果が薄れる。 However, it is desirable that the polygon forming the cross section of the cylindrical body 2 is any polygon from octagon to dodecagon. When the number of corners is less than the octagon, the ridge line 11 is too sharply sharp before bending deformation, and it is easy to shift to buckling and axial crushing without causing folding-back deformation, and the ridge line is excessively stretched against uneven load. Later bending is likely to occur. On the other hand, when the number of corners is larger than that of the dodecagon, the effect of strain concentration of the ridge line 11 is reduced, and the rigidity improvement effect of the ridge line 11 is reduced with respect to the uneven load.

図５（ａ）および図５（ｂ）は、筒状体２の折り返し部１０の近傍の断面の変形状況を経時的に示す説明図であり、図５（ａ）は曲げ変形開始前を示し、図５（ｂ）は曲げ変形中を示す。 5 (a) and 5 (b) are explanatory views showing the deformation state of the cross section in the vicinity of the folded portion 10 of the cylindrical body 2 over time, and FIG. 5 (a) shows before the start of bending deformation. FIG. 5B shows the bending deformation.

第２の部分４は、図５（ａ）に示すように曲げ変形の開始と同時に折り返されて、図５（ｂ）に示すように変形する。ただし、以後は第１の部分３のみの折り返し変形が進行する。したがって、多角形化の上述した効果を得るためには、少なくとも第１の部分３が多角形断面であればよい。 As shown in FIG. 5A, the second portion 4 is folded simultaneously with the start of the bending deformation, and deformed as shown in FIG. 5B. However, after that, the folding deformation of only the first portion 3 proceeds. Therefore, in order to obtain the above-described effect of polygonalization, it is sufficient that at least the first portion 3 has a polygonal cross section.

このように、本発明に係る衝撃吸収部材１の筒状体２は、特許文献２〜６により開示された衝撃吸収部材には存在しない稜線１１を有する。この稜線１１は、平面や曲面により構成される外壁２ａ−１〜２ａ−８よりも曲率半径が極めて小さく、高い剛性を有するため、折り返し部１０の繰り返し曲げ変形時にこの稜線１１に塑性変形が集中し、これにより、特許文献２〜６により開示された衝撃吸収部材に比較して折り返し曲げ変形時の強度が上昇するので、特許文献２〜６により開示された衝撃吸収部材よりも衝撃エネルギーの吸収量が増加する。 Thus, the cylindrical body 2 of the impact absorbing member 1 according to the present invention has the ridge line 11 that does not exist in the impact absorbing member disclosed in Patent Documents 2 to 6. Since the ridge line 11 has an extremely small radius of curvature and higher rigidity than the outer walls 2a-1 to 2a-8 configured by a plane or a curved surface, plastic deformation concentrates on the ridge line 11 when the folded portion 10 is repeatedly bent. As a result, the strength at the time of bending bending deformation is increased as compared with the impact absorbing members disclosed in Patent Documents 2 to 6, so that the impact energy is absorbed more than the impact absorbing members disclosed in Patent Documents 2 to 6. The amount increases.

また、この筒状体２は、稜線１１を有するので、衝撃エネルギーの吸収量が増加し、かつ偏荷重が作用した場合にも、筒状体２全体が屈曲する曲げ変形が抑制され、衝突方向によらずに安定した高い衝撃エネルギーの吸収性能を維持することができる。 Moreover, since this cylindrical body 2 has the ridgeline 11, even when the amount of absorption of impact energy increases and an unbalanced load acts, the bending deformation which the whole cylindrical body 2 bends is suppressed, and a collision direction Regardless of this, it is possible to maintain stable high impact energy absorption performance.

さらに、筒状体２の横断面形状は、正８角形から正１２角形のいずれか正多角形の横断面形状を有することが望ましい。これにより、筒状体２の軸方向と平行な方向へ負荷される衝撃荷重によってより確実に折り返し部１０に折り返しによる曲げ変形を生じることが可能になるとともに、偏荷重が作用した場合に部材全体が屈曲する変形の抑制効果が大きい。なお、ここで「正多角形」とは、数学的な正多角形を基準として、内角が１５％以内のばらつき、辺の長さが１５％以内のばらつきを有する多角形を含む。 Further, it is desirable that the cross-sectional shape of the cylindrical body 2 has a cross-sectional shape of any regular polygon from a regular octagon to a regular dodecagon. As a result, it is possible to cause the bending portion 10 to bend more reliably by the folding portion 10 due to the impact load applied in the direction parallel to the axial direction of the cylindrical body 2, and the entire member when an unbalanced load is applied. The effect of suppressing deformation of bending is great. Here, the “regular polygon” includes a polygon having an inner angle variation of 15% or less and a side length variation of 15% or less on the basis of a mathematical regular polygon.

次に、本発明に係る衝撃吸収部材１の製造方法を説明する。本発明に係る衝撃吸収部材１は、特定の製造方法には限定されず、上述した特徴を満足する衝撃吸収部材１を製造することができる方法により適宜製造されるが、生産性等の観点から好適な製造方法を説明する。 Next, a method for manufacturing the impact absorbing member 1 according to the present invention will be described. The impact absorbing member 1 according to the present invention is not limited to a specific manufacturing method, and is appropriately manufactured by a method capable of manufacturing the impact absorbing member 1 satisfying the above-described characteristics, but from the viewpoint of productivity and the like. A suitable manufacturing method will be described.

図６は、金属板を素材として本発明に係る衝撃吸収部材を構成する筒状体２を製造する方法を模式的に示す説明図である。
図６に示すように、薄鋼板や薄アルミニウム合金板等の素材１４に、段階的な深絞り加工（多段絞り加工）を行って円筒状の深絞り成形品１５を製造する。その後、この深絞り成形品１５に対して、多角形断面化加工を行う。 FIG. 6 is an explanatory view schematically showing a method of manufacturing the cylindrical body 2 constituting the impact absorbing member according to the present invention using a metal plate as a raw material.
As shown in FIG. 6, a cylindrical deep-drawn molded product 15 is manufactured by performing stepwise deep-drawing (multi-stage drawing) on a material 14 such as a thin steel plate or a thin aluminum alloy plate. Thereafter, polygonal cross-section processing is performed on the deep-drawn molded product 15.

図７は、この多角形断面化加工の一例を示す説明図である。また、図８は、この多角形断面化加工の詳細を示す説明図である。なお、図８では、図７における上押え治具１６および下押え治具１７は省略してある。 FIG. 7 is an explanatory view showing an example of this polygonal cross-section processing. Moreover, FIG. 8 is explanatory drawing which shows the detail of this polygonal cross-section process. In FIG. 8, the upper presser jig 16 and the lower presser jig 17 in FIG. 7 are omitted.

図７に示すように、円筒状の深絞り成形品１５のフランジ部１５ａを、上押え治具１６および下押え治具１７によりホールドし、多角形断面の内面を有する外周成形工具１９を下降することにより深絞り成形品１５の外面を成形するとともに、多角形断面の外面を有する内面成形工具１９を上昇することにより深絞り成形品１５の内面を成形することによって、深絞り成形品１５に多角形断面化加工を行う。この多角形断面化加工の際に、図８に示すように、適宜折り返し部４も含めて成形することにより、筒状体２を製造する。 As shown in FIG. 7, the flange portion 15a of the cylindrical deep-drawn molded product 15 is held by the upper presser jig 16 and the lower presser jig 17, and the outer peripheral molding tool 19 having the polygonal cross section is lowered. In this way, the outer surface of the deep-drawn molded product 15 is molded, and the inner surface of the deep-drawn molded product 15 is molded by raising the inner surface forming tool 19 having an outer surface with a polygonal cross section. Perform square sectioning. At the time of this polygonal cross-section processing, as shown in FIG. 8, the cylindrical body 2 is manufactured by appropriately forming the folded portion 4.

図９は、多角形断面化加工の他の一例を示す説明図である。図９に示す例では、段階的な深絞り加工（多段絞り加工）を行って円筒状の深絞り成形品を製造する際の後段の加工により、多角形断面化を行い、多角形断面化された深絞り成形品１５−１に内面成形工具１９−１を挿入して深絞り成形品１５−１を固定し、外周成形工具１８−１を下降することによって、折り返し部４を成形して、筒状体２を製造する。 FIG. 9 is an explanatory diagram showing another example of polygonal cross-section processing. In the example shown in FIG. 9, the polygonal cross section is formed by the subsequent processing when a cylindrical deep drawing product is manufactured by performing stepwise deep drawing (multistage drawing). The inner surface forming tool 19-1 is inserted into the deep drawn molded product 15-1, the deep drawn molded product 15-1 is fixed, and the outer peripheral forming tool 18-1 is lowered to form the folded portion 4, The cylindrical body 2 is manufactured.

図１０は、金属管２０を素材として本発明に係る衝撃吸収部材を構成する筒状体２を製造する方法を経時的に示す説明図であって、金属管１０の管端の曲げ加工方法を示す。図１０（ａ）は初期状態を示し、図１０（ｂ）は中間状態を示し、図１０（ｃ）はつば拡げを示し、図１０（ｄ）は折り返しを示す。 FIG. 10 is an explanatory view showing, over time, a method of manufacturing the cylindrical body 2 constituting the shock absorbing member according to the present invention using the metal tube 20 as a raw material, and shows a method for bending the tube end of the metal tube 10. Show. FIG. 10A shows the initial state, FIG. 10B shows the intermediate state, FIG. 10C shows the widened collar, and FIG. 10D shows the folding.

図１０（ａ）および図１０（ｂ）に示すように、初期状態から中間状態において第１の工具２１によって１回または複数回に分けて金属管２０の管端を折り曲げ、その後、図１０（ｃ）に示すように第２の工具２２を用いてつば拡げまで完了させて、中間品２４とする。 As shown in FIGS. 10 (a) and 10 (b), the tube end of the metal tube 20 is bent one or more times by the first tool 21 from the initial state to the intermediate state. As shown in c), the second tool 22 is used to complete the expansion of the collar, and the intermediate product 24 is obtained.

この中間品２４を、図７（ａ）により示す工程に投入して筒状体２を製造してもよいし、あるいは、さらに図１０（ｄ）に示すように第３の工具２３によって中間品２４の管端を折り曲げることによって筒状体２を製造してもよい。 The intermediate product 24 may be put into the process shown in FIG. 7A to manufacture the cylindrical body 2, or may be further processed by a third tool 23 as shown in FIG. 10D. The cylindrical body 2 may be manufactured by bending the 24 tube ends.

このように、金属管２０の管端の曲げ加工の後に多角形断面化加工を行い、筒状体２が製造される。
このようにして、本発明に係る衝撃吸収部材１を構成する筒状体２を製造する。そして、この筒状体２を、例えば溶接等の適当な接合手段によって取付け台座６に接合することによって、本発明に係る衝撃吸収部材１が製造される。 Thus, the polygonal cross-section processing is performed after the bending process of the pipe end of the metal pipe 20, and the cylindrical body 2 is manufactured.
Thus, the cylindrical body 2 constituting the shock absorbing member 1 according to the present invention is manufactured. And the impact-absorbing member 1 which concerns on this invention is manufactured by joining this cylindrical body 2 to the mounting base 6 by suitable joining means, such as welding, for example.

本発明に係る衝撃吸収部材１によれば、
（ａ）筒状体２が曲げ変形を継続して生じることにより衝撃エネルギーを吸収するため、軸方向への座屈を繰り返して蛇腹状に塑性変形することにより衝撃エネルギーを吸収する公知のクラッシュボックスに比較して、周期的な荷重変化（荷重振幅）が小さい衝撃吸収性能を得ることができ、衝撃吸収部材を低強度の部材（例えばロアークロスメンバー）等に装着しても、この部材の損傷に起因した補修費の上昇を、できるだけ抑制することが可能になること、
（ｂ）筒状体２が複数本の稜線１１を有し、多角形の横断面形状を有するので、衝撃エネルギーの吸収量を高め、かつ、衝突方向によらず曲げ変形を安定的に継続して発生することができ、安定した高い衝撃エネルギーの吸収性能を発揮できること、および。 According to the shock absorbing member 1 according to the present invention,
(A) A known crush box that absorbs impact energy by repeatedly buckling in the axial direction and plastically deforming into a bellows shape because the cylindrical body 2 absorbs impact energy by continuously bending deformation. Compared to the above, it is possible to obtain shock absorbing performance with a small periodic load change (load amplitude). Even if the shock absorbing member is mounted on a low-strength member (for example, a lower cross member), the member is damaged. It will be possible to suppress the increase in repair costs caused by
(B) Since the cylindrical body 2 has a plurality of ridge lines 11 and has a polygonal cross-sectional shape, the impact energy absorption amount is increased, and bending deformation is stably continued regardless of the collision direction. It can be generated in a stable manner, and can exhibit stable high impact energy absorption performance.

（ｃ）筒状体２に形成される折り返し部１０は、折り返し変形の際に、取付け台座６の通過穴６ｂに収容されるため、衝突方向が多少変化する場合であっても、変形状態の変化が小さく安定した吸収性能を発揮することが可能になること
という、極めて優れた効果を奏することができる。 (C) Since the folded portion 10 formed in the cylindrical body 2 is accommodated in the passage hole 6b of the mounting base 6 at the time of folding deformation, the folded portion 10 is in a deformed state even when the collision direction changes somewhat. It is possible to obtain an extremely excellent effect that it is possible to exhibit stable absorption performance with little change.

このようにして、本発明によれば、小さな荷重振幅で衝撃エネルギーの吸収性能を高め、特に偏荷重が作用した場合であっても部材全体が大きく屈曲する曲げ変形が抑制され、衝突方向によらず安定した高い衝撃エネルギーの吸収性能を発揮できる。 In this way, according to the present invention, the impact energy absorption performance is improved with a small load amplitude, and even when an uneven load is applied, bending deformation that greatly bends the entire member is suppressed. Stable and high impact energy absorption performance can be demonstrated.

このため、本発明に係る衝撃吸収部材は、例えば、ロアークロスメンバー等の低強度の構造部材に装着することが可能となり、衝撃エネルギーの吸収性能を高めて乗員の安全性を一層高めることができる。 For this reason, the impact absorbing member according to the present invention can be attached to a low-strength structural member such as a lower cross member, for example, and the impact energy absorbing performance can be enhanced to further increase the safety of the occupant. .

また、本発明によれば、この衝撃吸収部材の衝撃エネルギーの吸収効率を高めることができるので、目標とする衝撃エネルギーの値に応じて、筒状体２を構成する外壁２ａをなす鋼板の板厚を低減することができ、軽量化を図ることもできる。 Further, according to the present invention, since the impact energy absorption efficiency of the impact absorbing member can be increased, the steel plate plate forming the outer wall 2a constituting the cylindrical body 2 according to the target impact energy value. The thickness can be reduced and the weight can be reduced.

本発明に係る衝撃吸収部材は、ロアークロスメンバーに取り付けることができることは当然であるが、ロッカーレインフォース、センタピラー、各種ピラー、ルーフレールサイド、サイドシルさらにはサイドメンバー等の自動車の各種構造部材に取り付けることができる。 Naturally, the impact absorbing member according to the present invention can be attached to the lower cross member, but it is attached to various structural members of the automobile such as rocker reinforcement, center pillar, various pillars, roof rail side, side sill and side members. be able to.

（実施の形態２）
次に、実施の形態２に係る衝撃吸収部材を説明する。以降の説明では、上述した実施の形態１と相違する部分を説明し、同一の部分については同一の符合を付することにより重複する説明は適宜省略する。 (Embodiment 2)
Next, the impact absorbing member according to Embodiment 2 will be described. In the following description, portions that are different from the above-described first embodiment will be described, and the same portions will be denoted by the same reference numerals, and redundant description will be appropriately omitted.

図１１は、実施の形態２の衝撃吸収部材１−１の構造の一例を、簡略化して示す分解斜視図である。また、図２（ｃ）および図２（ｄ）は、いずれも、実施の形態２の衝撃吸収部材１−１により衝撃エネルギーが吸収される状況を、模式的に示す説明図であり、図２（ｃ）および図２（ｄ）における左図は正面図、中央図は曲げ変形開始時の断面図、右図は曲げ変形終了時の断面図である。 FIG. 11 is a simplified exploded perspective view showing an example of the structure of the shock absorbing member 1-1 according to the second embodiment. 2 (c) and 2 (d) are explanatory diagrams schematically showing the situation in which impact energy is absorbed by the impact absorbing member 1-1 of the second embodiment. The left figure in (c) and FIG. 2 (d) is a front view, the central figure is a sectional view at the start of bending deformation, and the right figure is a sectional view at the end of bending deformation.

この衝撃吸収部材１−１が実施の形態１の衝撃吸収部材１と相違するのは、衝撃吸収部材１のように、第３の部分５が筒状体２の軸方向と直交する方向へ延びて設けられ、かつこの第３の部分５を支持するための支持部材である取付け台座６に、折り返し部１０との干渉を防止するための通過穴６ｂが設けられているのではなく、第３の部分５が第１の部分３と同様に筒状体２の軸方向と略平行な方向へ延びて設けられ、かつ折り返し部１０はこの第３の部分５の内部に収容されるために取付け台座６−１に通過穴６ｂを設ける必要がない点である。 The shock absorbing member 1-1 is different from the shock absorbing member 1 of the first embodiment in that the third portion 5 extends in a direction perpendicular to the axial direction of the cylindrical body 2 like the shock absorbing member 1. The mounting base 6 is a support member for supporting the third portion 5 and is not provided with a passage hole 6b for preventing interference with the folded portion 10; The portion 5 is provided so as to extend in a direction substantially parallel to the axial direction of the cylindrical body 2 in the same manner as the first portion 3, and the folded portion 10 is attached to be accommodated inside the third portion 5. It is a point which does not need to provide the passage hole 6b in the base 6-1.

図１１に示すように、この衝撃吸収部材１−１における第２の部分４は、第１の部分３に連続するとともに筒状体２の外壁２ａが筒状体２の外側に折れ曲がって形成される折れ曲がり部である。そして、第３の部分５は、第２の部分４に連続するとともに筒状体２の軸方向と略平行な方向へ延びて設けられる。第３の部分５の端部５ａは、取付け台座６−１の表面６ｃに突き当てられて、例えば溶接等の適当な接合手段によって取付け台座６に接合される。 As shown in FIG. 11, the second portion 4 of the shock absorbing member 1-1 is continuous with the first portion 3 and is formed by bending the outer wall 2 a of the tubular body 2 to the outside of the tubular body 2. It is a bent part. The third portion 5 is provided so as to be continuous with the second portion 4 and to extend in a direction substantially parallel to the axial direction of the cylindrical body 2. The end portion 5a of the third portion 5 is abutted against the surface 6c of the mounting base 6-1 and joined to the mounting base 6 by appropriate joining means such as welding.

筒状体２の軸方向への第３の部分５の長さは、筒状体２の軸方向への折り返し部１０の長さの最大値よりも大きく設定されているので、折り返し部１０が取付け台座６−１と干渉することがない。このため、取付け台座６−１には通過穴６ｂが設けられていない。 Since the length of the third portion 5 in the axial direction of the tubular body 2 is set to be larger than the maximum value of the length of the folded-back portion 10 in the axial direction of the tubular body 2, There is no interference with the mounting base 6-1. For this reason, the mounting base 6-1 is not provided with the passage hole 6b.

図２（ｃ）に示すように、この衝撃吸収部材１−１は、上述した衝撃吸収部材１と同様に、バンパーレインフォースメント９を介して第１の部分３の端部３ａから筒状体２の軸方向へ向けて負荷される衝撃荷重によって、最初に折れ曲がり部である第２の部分４を起点として、第２の部分４の近傍の第１の部分３の外壁２ａが順次折り返されて形成される折り返し部１０の軸方向の長さＬが増加する曲げ変形を連続して生じることにより衝撃エネルギーを吸収するものである。 As shown in FIG. 2C, the shock absorbing member 1-1 is a cylindrical body from the end portion 3a of the first portion 3 via the bumper reinforcement 9, similarly to the shock absorbing member 1 described above. 2, the outer wall 2a of the first portion 3 in the vicinity of the second portion 4 is sequentially folded back starting from the second portion 4 that is the bent portion. The impact energy is absorbed by continuously generating a bending deformation in which the axial length L of the folded portion 10 to be formed increases.

衝撃吸収部材１を構成する筒状体２は、バンパーレインフォースメント９を介してその他方の端部３ｂから衝撃荷重Ｆを筒状体２の軸方向へ負荷されると、折り返し部１０の折り返し量（図１１における長さＬ）が増加するように、外壁２ａに曲げ変形を連続して生じることによって、衝撃エネルギーを吸収する。 When the impact load F is applied in the axial direction of the tubular body 2 via the bumper reinforcement 9, the tubular body 2 constituting the impact absorbing member 1 is folded back. The impact energy is absorbed by continuously generating bending deformation in the outer wall 2a so that the amount (length L in FIG. 11) increases.

この衝撃吸収部材１−１による衝撃エネルギーの吸収は、筒状体２の折り返し部１０の折り返し量（図１１における長さＬ）が変化するように、筒状体２の外壁２ａに曲げ変形を連続して生じることにより、行われる。このため、この衝撃吸収部材１−１においても、筒状体２の折り返し部１０をなす外壁２ａの部分を、異なる複数種の材料により構成すれば、折り返し部４に発生する曲げ変形の挙動を制御することができる。 Absorption of the impact energy by the impact absorbing member 1-1 causes the outer wall 2a of the cylindrical body 2 to be bent and deformed so that the amount of folding (the length L in FIG. 11) of the folded portion 10 of the cylindrical body 2 changes. This is done by occurring continuously. For this reason, also in this shock absorbing member 1-1, if the portion of the outer wall 2a that forms the folded portion 10 of the cylindrical body 2 is made of a plurality of different materials, the behavior of the bending deformation that occurs in the folded portion 4 can be achieved. Can be controlled.

例えば、第１の部分３が一の鋼板からなるとともに、第３の部分５が、例えばこの一の鋼板とは板厚および材質の少なくとも一つが異なることによってこの一の鋼板とは相違する他の一の鋼板からなることが望ましい。 For example, the first portion 3 is made of a single steel plate, and the third portion 5 is different from the one steel plate because, for example, at least one of the thickness and material is different from the one steel plate. It is desirable to consist of one steel plate.

図２（ｄ）は、図２（ｃ）に示す場合において、筒状体２が、第１の部分３および第２の部分４を構成する一の鋼製材料Ｓ１と、第３の部分５を構成する他の一の鋼製材料Ｓ２と、外壁２ａにおける曲げ変形を連続して生じる部分に形成され、一の材料Ｓ１および他の一の材料Ｓ２を接合する接合部１２とを有する場合を示す説明図である。 FIG. 2 (d) shows a case where the cylindrical body 2 is composed of one steel material S1 constituting the first portion 3 and the second portion 4 and the third portion 5 in the case shown in FIG. 2 (c). And a joint portion 12 that is formed in a portion that continuously causes bending deformation in the outer wall 2a and joins the one material S1 and the other one material S2. It is explanatory drawing shown.

図２（ｄ）に示す場合には、筒状体２が、一の材料Ｓ１と他の一の材料Ｓ２と接合部１２とを有するので、一の材料Ｓ１および他の一の材料Ｓ２それぞれの板厚や強度を異ならせて設定することにより、折り返し部１０における曲げ変形の変形挙動を所望のように制御することができる。例えば、材料Ｓ２の板厚を材料Ｓ１の板厚よりも大きく設定すること、あるいは材料Ｓ２の強度を材料Ｓ１の強度より大きく設定することによって、折り返し部１０の折り返し変形が継続している間は、材料Ｓ２の変形が抑制されるため、より安定して衝撃エネルギーを吸収することが可能になる。 In the case shown in FIG. 2 (d), the cylindrical body 2 has one material S1, another one material S2, and a joint portion 12. Therefore, each of the one material S1 and the other one material S2 is provided. By setting the plate thickness and strength to be different, the deformation behavior of the bending deformation in the folded portion 10 can be controlled as desired. For example, by setting the plate thickness of the material S2 to be greater than the plate thickness of the material S1, or by setting the strength of the material S2 to be greater than the strength of the material S1, the folding portion 10 continues to be folded back. Since the deformation of the material S2 is suppressed, the impact energy can be absorbed more stably.

本発明に係る衝撃吸収部材１−１によれば、上述した衝撃吸収部材１と同様の効果を奏することができるとともに、取付け台座６−１に通過穴６ｂを設ける必要がないため、衝撃吸収部材１−１の取付け部付近の剛性の低下を抑制することができるとともに、取付け台座６−１の製造コストを低下することができる。 According to the impact absorbing member 1-1 according to the present invention, the same effect as the impact absorbing member 1 described above can be obtained, and it is not necessary to provide the passage hole 6b in the mounting base 6-1. While being able to suppress a decrease in rigidity in the vicinity of the mounting portion 1-1, the manufacturing cost of the mounting base 6-1 can be reduced.

（実施の形態３）
次に、実施の形態３に係る衝撃吸収部材を説明する。図２（ｅ）は、実施の形態３の衝撃吸収部材１−２により衝撃エネルギーが吸収される状況を、模式的に示す説明図であり、図２（ｅ）における左図は正面図、中央図は曲げ変形開始時の断面図、右図は曲げ変形終了時の断面図である。 (Embodiment 3)
Next, an impact absorbing member according to Embodiment 3 will be described. FIG. 2 (e) is an explanatory view schematically showing a situation where impact energy is absorbed by the impact absorbing member 1-2 of Embodiment 3, and the left figure in FIG. 2 (e) is a front view and a center. The figure is a sectional view at the start of bending deformation, and the right figure is a sectional view at the end of bending deformation.

この衝撃吸収部材１−２は、実施の形態１の衝撃吸収部材１の変形例として位置付けられるものであって、図２（ｅ）に示すように、第２の部分４の構造を簡素化し、Ｌ字状に屈曲する曲げ部として第２の部分４を構成するものである。 This shock absorbing member 1-2 is positioned as a modified example of the shock absorbing member 1 of the first embodiment, and as shown in FIG. 2 (e), the structure of the second portion 4 is simplified, The 2nd part 4 is comprised as a bending part bent in L shape.

この場合、第２の部分４の内法Ｒ１よりも、取付け台座６の通過穴６ｂよりも若干大きい適正な寸法に設定することにより、衝撃吸収部材１と同様の曲げ変形を継続して発生することができる。 In this case, the bending deformation similar to that of the shock absorbing member 1 is continuously generated by setting an appropriate dimension slightly larger than the passing hole 6b of the mounting base 6 than the inner method R1 of the second portion 4. be able to.

本発明を、実施例を参照しながら、さらに具体的に説明する。
本実施例では、本発明に係る衝撃吸収部材の効果をさらに説明するため、下記の要領で衝突試験を模擬した数値解析を行った。 The present invention will be described more specifically with reference to examples.
In this example, in order to further explain the effect of the shock absorbing member according to the present invention, a numerical analysis simulating a collision test was performed in the following manner.

図１および図２（ａ）を参照しながら説明した本発明に係る衝撃吸収部材であって筒状体２の横断面形状が正１２角形（内角：１５０°）である本発明例の衝撃吸収部材１と、横断面形状が円形であること以外は本発明例の衝撃吸収部材１と同じ構成を有する比較例の衝撃吸収部材とに、図１２に示すように、筒状体２の端部３ａに剛体壁２５を筒状体２の軸方向へ１６ｋｍ／ｈの速度で衝突させた場合の変形挙動を、ＦＥＭ数値解析を行うことにより解析し、筒状体２の変位量が８０ｍｍとなるまでに筒状体２に負荷される荷重の履歴を求めた。 The shock absorbing member according to the present invention described with reference to FIG. 1 and FIG. 2 (a), wherein the cylindrical body 2 has a regular dodecagon (inner angle: 150 °). As shown in FIG. 12, the end portion of the cylindrical body 2 is formed on the member 1 and a shock absorbing member of a comparative example having the same configuration as the shock absorbing member 1 of the present invention except that the cross-sectional shape is circular. The deformation behavior when the rigid wall 25 is caused to collide with the axial direction of the cylindrical body 2 at a speed of 16 km / h in 3a is analyzed by FEM numerical analysis, and the displacement amount of the cylindrical body 2 becomes 80 mm. The history of the load applied to the cylindrical body 2 was obtained up to now.

また、剛体壁（バリア）２５の傾斜角度θを０度とした、筒状体２の軸方向に対して垂直な場合と、剛体壁２５の傾斜角度θを１０度とした場合とを検討した。
なお、この解析では、筒状体２に取付け台座６を固定し、取付け台座６の位置は常に不変であるとするとともに、取付け台座６は常に回転しないものとした。 In addition, the case where the inclination angle θ of the rigid wall (barrier) 25 is set to 0 degree and is perpendicular to the axial direction of the cylindrical body 2 and the case where the inclination angle θ of the rigid body wall 25 is set to 10 degrees were examined. .
In this analysis, it is assumed that the mounting base 6 is fixed to the cylindrical body 2, the position of the mounting base 6 is always unchanged, and the mounting base 6 does not always rotate.

それぞれの筒状体２は、外壁が２７０ＭＰａ級の１．２ｍｍ厚の鋼板からなる外壁２ａにより構成されるとともに、その全長が１００ｍｍであるとした。さらに、本発明に係る衝撃吸収部材１の筒状体２の外径（多角形に外接する円の直径）は４５ｍｍとし、比較例の衝撃吸収部材の筒状体の外径は４５ｍｍとした。 Each cylindrical body 2 is composed of an outer wall 2a made of a 270 MPa class 1.2 mm thick steel plate and has an overall length of 100 mm. Furthermore, the outer diameter (diameter of a circle circumscribing the polygon) of the cylindrical body 2 of the shock absorbing member 1 according to the present invention was 45 mm, and the outer diameter of the cylindrical body of the shock absorbing member of the comparative example was 45 mm.

結果を、図１３と表１にまとめて示す。
図１３は、荷重の変化を示すグラフであり、図１３（ａ）には、傾斜角度θが０度である剛体壁２５を用いた場合（正突）で、横断面形状が円形である比較例と、横断面形状が１２角形である本発明例とを対比して示し、図１３（ｂ）には、傾斜角度が１０度である剛体壁２５を用いた場合（斜突）で、横断面形状が円形である比較例と、横断面形状が１２角形である本発明例とを対比して示す。 The results are summarized in FIG. 13 and Table 1.
FIG. 13 is a graph showing a change in load. FIG. 13A shows a comparison in which the cross-sectional shape is circular when the rigid wall 25 having an inclination angle θ of 0 degrees is used (front projection). An example and a cross-sectional shape of the present invention having a dodecagonal cross-sectional shape are shown in contrast, and FIG. 13 (b) shows a cross section when a rigid wall 25 having an inclination angle of 10 degrees is used (oblique projection). A comparative example in which the surface shape is circular is shown in comparison with an example of the present invention in which the cross-sectional shape is dodecagon.

また、表１には、単位質量当たりの吸収エネルギーＥＡを比較して示す。 Table 1 shows a comparison of absorbed energy EA per unit mass.

図１３（ａ）のグラフから、本発明例は、比較例に比べ、荷重が大きくなり、衝撃エネルギの吸収量が増大することがわかる。
また、表１に示すように、正突の場合、本発明例の単位質量当たりの吸収エネルギは、比較例に比べ７％程度増大する。 From the graph of FIG. 13A, it can be seen that the load of the example of the present invention increases and the amount of absorption of impact energy increases compared to the comparative example.
Moreover, as shown in Table 1, in the case of a collision, the absorbed energy per unit mass of the example of the present invention is increased by about 7% compared to the comparative example.

さらに、図１３（ｂ）は、傾斜角度が１０度の斜突において、比較例の円形部材が大きく倒れた６０ｍｍ圧下までの荷重変化を比較したグラフであるが、このグラフから、１２角形の横断面形状を有する筒状体２を備える衝撃吸収部材１では、１０度傾斜した剛体壁２５による偏荷重が作用した場合において、円形の横断面形状を有する筒状体２を備える衝撃吸収部材１よりも倒れが生じ難く、優れた衝撃エネルギーの吸収特性を維持できることがわかる。なお、表１に示すように、角度１０°の斜突の場合、本発明例の単位質量当たりの吸収エネルギーは、比較例に比べて２２％程度増大する。 Further, FIG. 13B is a graph comparing the load change up to 60 mm reduction in which the circular member of the comparative example collapsed greatly in the oblique projection with the inclination angle of 10 degrees. In the impact absorbing member 1 including the cylindrical body 2 having a planar shape, the impact absorbing member 1 including the cylindrical body 2 having a circular cross-sectional shape is applied when an unbalanced load is applied by the rigid wall 25 inclined by 10 degrees. It can be seen that it is difficult to fall down and can maintain excellent shock energy absorption characteristics. As shown in Table 1, in the case of an oblique projection with an angle of 10 °, the absorbed energy per unit mass of the example of the present invention is increased by about 22% compared to the comparative example.

１、１−１、１−２本発明に係る衝撃吸収部材
２筒状体
２ａ、２ａ−１、２ａ−２、２ａ−３、２ａ−４、２ａ−５、２ａ−６、２ａ−７、２ａ−８外壁
３第１の部分
３ａ先端
４第２の部分
５第３の部分
５ａ外向きフランジ部
６、６−１取付け台座
６ａ貫通穴
６ｂ通過穴
６ｃ表面
７ロアークロスメンバー
７ａネジ穴
８ボルト
９バンパーレインフォースメント
９ａ後面
１０折り返し部
１１稜線
１２接合部
１３円筒体
１３ａ一端
１３−１第１の部分
１３−２第２の部分
１４素材
１５，１５−１深絞り成形品
１５ａフランジ部
１６上押え治具
１７下押え治具
１８、１８−１外周成形工具
１９、１９−１内面成形工具
２０金属管
２１第１の工具
２２第２の工具
２３第３の工具
２４中間品
２５剛体壁 1, 1-1, 1-2 Shock absorbing member 2 according to the present invention Tubular body 2a, 2a-1, 2a-2, 2a-3, 2a-4, 2a-5, 2a-6, 2a-7, 2a-8 outer wall 3 first part 3a tip 4 second part 5 third part 5a outward flange parts 6, 6-1 mounting base 6a through hole 6b through hole 6c surface 7 lower cross member 7a screw hole 8 bolt 9 Bumper reinforcement 9a Rear surface 10 Folded portion 11 Ridge line 12 Joint portion 13 Cylindrical body 13a One end 13-1 First portion 13-2 Second portion 14 Material 15, 15-1 Deep-drawn molded product 15a Flange portion 16 Presser jig 17 Lower presser jigs 18, 18-1 Outer peripheral forming tools 19, 19-1 Inner surface forming tool 20 Metal tube 21 First tool 22 Second tool 23 Third tool 24 Intermediate product 25 Rigid wall

Claims

A first portion made of a cylindrical body having an outer wall made of a metal material; a second portion which is a bent portion formed by being bent outward and continuous with the outer wall of the first portion; A third portion that is continuous with the portion and that forms the support portion of the second portion, and by an impact load that is loaded in the axial direction of the cylindrical body from the end portion of the first portion, An impact absorbing member that absorbs impact energy by continuously generating a bending deformation in which the length of the folded portion formed by folding the outer wall of the first portion increases,
The first part has a plurality of ridge lines extending in the axial direction of the cylindrical body at least in a range where the bending deformation is continuously generated in the outer wall. Element.

The impact absorbing member according to claim 1, wherein the second portion is a cylindrical body.

The impact absorbing member according to claim 1, wherein the third portion is a cylindrical body.

The outer wall defined by two ridge lines adjacent to each other in the circumferential direction of the cylindrical body among the plurality of ridge lines forms a flat surface or a curved surface curved toward the outer side or the inner side of the cylindrical body. The impact-absorbing member according to any one of claims 1 to 3.

The impact absorbing member according to any one of claims 1 to 4, wherein the outer wall that continuously generates the bending deformation has a polygonal cross-sectional shape.

The impact absorbing member according to claim 5, wherein the polygon is any one of octagons to dodecagons.

7. The device according to claim 1, wherein the first portion is made of one metal material, and the third portion is made of another metal material different from the one metal material. The described shock absorbing member.

The shock absorbing member according to claim 7, wherein the one metal material and the other metal material are different in thickness and / or material.

The impact absorbing member according to any one of claims 1 to 8, further comprising a supporting member that supports the third portion and has a hole having a diameter larger than an outer diameter of the folded portion.

The first part and the third part are both provided in any one of claims 1 to 8 provided to extend in a direction substantially parallel to the axial direction of the cylindrical body. Shock absorbing member.

The impact absorbing member according to claim 10, wherein a length of the third portion in the axial direction of the cylindrical body is equal to or longer than a length of the first portion in the axial direction.