WO2014073083A1 - Impact absorbing member - Google Patents

Impact absorbing member Download PDF

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Publication number
WO2014073083A1
WO2014073083A1 PCT/JP2012/079039 JP2012079039W WO2014073083A1 WO 2014073083 A1 WO2014073083 A1 WO 2014073083A1 JP 2012079039 W JP2012079039 W JP 2012079039W WO 2014073083 A1 WO2014073083 A1 WO 2014073083A1
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Prior art keywords
absorbing member
angle
cross
vertices
deformation
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PCT/JP2012/079039
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French (fr)
Japanese (ja)
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近藤　修
卓 角野
義崇 操上
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Ｊｆｅスチール株式会社
スズキ株式会社
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Priority to PCT/JP2012/079039 priority Critical patent/WO2014073083A1/en
Publication of WO2014073083A1 publication Critical patent/WO2014073083A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00—Vibration-dampers; Shock-absorbers
    • F16F7/12—Vibration-dampers; Shock-absorbers using plastic deformation of members

Definitions

  • the present invention relates to an impact absorbing member that absorbs impact energy.
  • the car is equipped with a member that absorbs energy in the event of a collision.
  • a member that absorbs energy in the event of a collision.
  • One such member is a crash box.
  • the crash box is generally formed in a cylindrical shape by one or several members, and absorbs impact energy by deforming in an accordion shape in the axial direction when an impact load is applied in the axial direction.
  • the performance required for the crash box includes a stable bellows deformation in the axial direction when an impact load is applied, and high energy absorption efficiency associated with the deformation.
  • Various proposals have been made to improve the performance required for crash boxes.
  • Patent Document 1 proposes a crush box whose cross-sectional shape is an octagon.
  • the crash box described in Patent Document 1 includes a stress concentration portion (bead forming portion) serving as a starting point of plastic deformation so that it can be stably deformed into a bellows shape.
  • the stress concentration portions are formed by convex portions formed inside the crash box, and are provided so as to alternate in the axial direction. By providing the stress concentration portion, deformation of the convex portion in the protruding direction is induced, and the crash box is stably deformed into a bellows shape.
  • FIG. 2 of Patent Document 1 shows a crash box having two stress concentration portions in the axial direction
  • FIG. 9 of the same document shows a crash box having seven stress concentration portions in the axial direction. It is shown in the figure.
  • Patent Document 2 discloses a crash box whose cross-sectional shape is a substantially cross-closed cross-sectional shape.
  • the crash box disclosed in Patent Document 2 is formed such that the angle formed by each side in the substantially cross-closed cross-sectional shape is substantially a right angle (90 °).
  • the cross-sectional shape of the crash box is an octagon like the crash box described in Patent Document 1
  • the cross-sectional shape is a regular octagon in relation to the shape of the end of the front side member where the crash box is installed. In many cases, it becomes a long octagon (an octagon having a long pair of opposing sides). In that case, a long side part remains, and axial force and energy absorption efficiency fall.
  • the peak impact load when the crash box receives an axial compression load may be small.
  • the reason why the peak impact load is required to be small is that when the peak impact load increases, it is necessary to increase the strength of the vehicle side member such as a bumper member that installs the crash box according to the peak impact load. is there.
  • the angle formed by each side in the substantially cross-closed cross-sectional shape is set to be substantially a right angle (90 °), so that the peak impact load increases.
  • the present invention has been made to solve the above problems, and provides an impact absorbing member that is stably deformed into a bellows shape, has high energy absorption efficiency, and does not have an excessive peak impact load. Objective.
  • the impact absorbing member according to the present invention is a cylindrical impact absorbing member that absorbs impact energy by plastic deformation in a bellows shape when subjected to an axial compression load, and the side wall induces bellows-like deformation.
  • the cross-sectional shape perpendicular to the axial direction is a substantially cross-shaped closed cross section having 12 vertices, and 8 vertices of the 12 vertices are straight lines.
  • An angle ⁇ formed by a straight line connecting the vertices at both ends of the hypotenuse and the vertices between them in the octagon formed by being connected is set in a range of 90 ° ⁇ ⁇ 150 °.
  • the impact absorbing member according to the present invention is stably deformed into an accordion shape, the energy absorption efficiency is increased, and the peak impact load is not excessive.
  • FIG. 1 is a perspective view of an impact absorbing member according to an embodiment of the present invention.
  • FIG. 2 is a cross-sectional view in the direction perpendicular to the axis of the impact absorbing member according to the embodiment of the present invention.
  • FIG. 3 is an explanatory diagram of a cross-sectional shape of an impact absorbing member according to an embodiment of the present invention.
  • FIG. 4 is an explanatory view of a deformation mode of the shock absorbing member according to the embodiment of the present invention.
  • FIG. 5 is an explanatory diagram of the shape used in the experiment for confirming the performance of the shock absorbing member according to the embodiment of the present invention.
  • FIG. 1 is a perspective view of an impact absorbing member according to an embodiment of the present invention.
  • FIG. 2 is a cross-sectional view in the direction perpendicular to the axis of the impact absorbing member according to the embodiment of the present invention.
  • FIG. 3 is an explanatory diagram of a cross-sectional shape of an impact
  • FIG. 6 is a graph showing the relationship between the angle ⁇ formed by the inclined surface and the energy absorption efficiency in the shock absorbing member according to the embodiment of the present invention.
  • FIG. 7 is a graph showing the relationship between the impact load per unit weight and the stroke when the angle ⁇ formed by the inclined surface in the impact absorbing member according to one embodiment of the present invention is 90 ° and 135 °.
  • FIG. 8 is a graph in which the vertical axis of the graph shown in FIG. 7 is normalized by the unit peak impact load.
  • FIG. 9 is a graph showing the relationship between the angle ⁇ formed by the inclined surface and the energy absorption efficiency in the unit impact load in the impact absorbing member according to the embodiment of the present invention.
  • the impact absorbing member 1 is a cylindrical member that absorbs impact energy by plastic deformation in a bellows shape when subjected to an axial compression load.
  • the side wall of the shock absorbing member 1 is a flat surface that does not have a bead for inducing bellows-like deformation.
  • the cross-sectional shape orthogonal to the axial direction is a substantially cross-shaped closed cross section having 12 vertices.
  • the angle ⁇ formed by a straight line connecting the vertices at both ends of the hypotenuse in the octagon formed by connecting eight of the twelve vertices with a straight line is 90 ° ⁇ ⁇ 150 °. It is set within the range.
  • the shock absorbing member 1 is a cylindrical member, and the cross-sectional shape orthogonal to the axial direction is a substantially cross-shaped closed cross section having 12 vertices A to L as shown in FIG. .
  • the cross-sectional shape of the shock absorbing member 1 will be described in detail.
  • the eight vertices A, C, D, F, G, I, J, excluding the four vertices B, E, H, K near the center The shape formed by connecting L with a straight line (in FIG. 3, the straight line is indicated by a dotted line) is an octagon.
  • the angle ⁇ formed by the vertices at both ends of the hypotenuses AC, DF, GI, and JL in the octagon, for example, the straight lines AB and CB connecting the vertices A and C and the vertex B between them is within the range of 90 ° ⁇ ⁇ 150 °. (135 degrees in this example) is set.
  • the shock absorbing member 1 configured as described above is deformed into a bellows shape when the material moves inward and outward in the axial direction when receiving an axial compression load.
  • the direction of deformation is reversed inside and outside at each ridgeline, and adjacent surfaces are deformed in opposite directions inside and outside. For this reason, the energy absorbed with a deformation
  • the angle ⁇ is within the above range, it is possible to stably deform without providing a bead for inducing a bellows-like deformation, so there is no need to provide a bead and the shock absorbing member. 1 can be easily manufactured.
  • the direction of the arrow in FIG. 4 has shown the direction which deform
  • the angle ⁇ is set in the range of 90 ° ⁇ ⁇ 150 °.
  • the reason for this setting will be described based on experimental data.
  • FIG. 5 is an explanatory diagram of a cross-sectional shape of the shock absorbing member 1 used in the experiment.
  • the dimensions of each part are as follows.
  • the tensile strength of the used steel plate is 440 MPa.
  • a 90.9mm
  • b 104.3mm
  • c 42.6mm
  • d 30.6mm
  • R 5mm
  • ⁇ 135 °
  • the angle ⁇ is changed from the basic shape shown in FIG. 5 to 90 °, 105 °, 120 °, 135 °, 150 °, 165 °, and 180 °, and the absorbed energy when the shock absorbing member 1 is crushed by Smm in each case. Asked. The plate thickness of the steel plate as a raw material was adjusted so that the reaction force at the time of crushing would be equal to or less than the specified yield strength.
  • FIG. 6 is a graph showing the experimental results. The horizontal axis and the vertical axis indicate the value of the angle ⁇ and the absorbed energy at the time of Smm crushing, respectively.
  • the absorbed energy increases as the angle ⁇ decreases.
  • the shape is V-shaped (for example, the shape composed of vertices A, B, and C in FIG. 3)
  • the direction of deformation is reversed inside and outside at each ridgeline, and the adjacent surfaces are opposite to each other It was confirmed that it was deformed in the direction.
  • the greater the angle ⁇ the more unclear the range of inversion. Therefore, in the present invention, the range of the angle ⁇ at which the effect is obtained is set to 150 ° or less.
  • the reason why the lower limit value of the angle ⁇ is set to exceed 90 ° is that when the angle ⁇ is 90 ° or less, it is difficult to process the member and the peak impact load is increased.
  • FIG. 7 is a graph showing experimental results, where the vertical axis and the horizontal axis indicate the impact load and stroke per unit weight, respectively.
  • FIG. 8 is a graph in which the vertical axis of the graph shown in FIG. 7 is normalized by the peak impact load.
  • the absolute value of the peak impact load is larger when the angle ⁇ is 90 ° than when the angle ⁇ is 135 °. For this reason, when the angle ⁇ is 90 °, it is necessary to set the vehicle-side member strength in accordance with the peak impact load.
  • the impact load per unit weight relative to the unit peak impact load is larger when the angle ⁇ is 135 °, and the energy that can be absorbed is larger.
  • the angle ⁇ is preferably more than 90 ° from the viewpoint of suppressing the peak impact load.
  • the angle ⁇ is 90 °, 105 °, 120 °, 135 °, 150 °, 165 ° from the basic shape shown in FIG.
  • the absorbed energy per unit weight at the time of Smm crushing with respect to the unit peak impact load in each case was determined.
  • the results are shown in the graph of FIG.
  • the vertical axis and the horizontal axis indicate the absorbed energy per unit weight and the value of the angle ⁇ at the time of Smm crushing with respect to the unit peak impact load, respectively.
  • the absorbed energy per unit weight at the time of Smm crushing with respect to the unit peak impact load is large when the value of the angle ⁇ is in the range of 90 ° ⁇ ⁇ 150 °.
  • the absorbed energy per unit weight at the time of Smm collapse with respect to the unit peak impact load increases rapidly when the value of the angle ⁇ is between 90 ° and 105 °. For this reason, it is presumed that there is a preferable value of the angle ⁇ between 90 ° and 105 °. From this, it can be said that it is more preferable if the value of the angle ⁇ is in the range of 95 ° ⁇ ⁇ ⁇ 150 °. From the graph of FIG. 9, when the value of the angle ⁇ is 105 °, the absorbed energy per unit weight at the time of Smm collapse against the unit peak impact load is high, so the value of the angle ⁇ is 105 ° ⁇ ⁇ ⁇ 150 °. It can be said that it is more preferable if it is within the range.
  • the shock absorbing member 1 is formed by joining two press-formed products.
  • the present invention is not limited to this, and one plate material is formed by bending. You can also Moreover, in the said embodiment, although the case where the end part is overlap
  • the impact absorbing member according to the present invention can be applied to a member that absorbs energy at the time of a collision installed in an automobile or the like.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Vibration Dampers (AREA)

Abstract

A cylindrical impact absorbing member (1) that absorbs impact energy by plastically deforming in a bellows shape when an axial compression load has been received, and having side walls that comprise a planar surface that does not have beads for inducing bellows-shaped deformation. In this impact absorbing member (1), a cross-sectional shape orthogonal to the axial direction has a substantially cross-shaped closed cross-section having 12 apexes, and an angle (α) is set within the range of 90°<α≤150°, said angle (α) being formed by straight lines that join apexes at both ends of an oblique side of an octagon formed by using straight lines to connect 8 of the 12 apexes, to an apex therebetween.

Description

衝撃吸収部材Shock absorbing member
　本発明は、衝撃エネルギーを吸収する衝撃吸収部材に関する。 The present invention relates to an impact absorbing member that absorbs impact energy.
　自動車には衝突時のエネルギーを吸収する部材が搭載されている。このような部材の一つにクラッシュボックスがある。クラッシュボックスは、一般的には一つ又は幾つかの部材によって筒状に形成され、軸方向に衝撃荷重が付加されたときに軸方向に蛇腹状に変形することによって衝撃エネルギーを吸収する。クラッシュボックスに要求される性能としては、衝撃荷重が付加されたときに軸方向に安定して蛇腹状に変形すること、及び変形に伴うエネルギー吸収効率が高いことが挙げられる。クラッシュボックスに要求される性能を向上するために種々の提案がなされている。 The car is equipped with a member that absorbs energy in the event of a collision. One such member is a crash box. The crash box is generally formed in a cylindrical shape by one or several members, and absorbs impact energy by deforming in an accordion shape in the axial direction when an impact load is applied in the axial direction. The performance required for the crash box includes a stable bellows deformation in the axial direction when an impact load is applied, and high energy absorption efficiency associated with the deformation. Various proposals have been made to improve the performance required for crash boxes.
　断面形状が四角形や六角形であるクラッシュボックスでは、軸方向に伸びる稜線の数が少なく、一辺の長さが長くなるために、衝撃吸収に際してエネルギー吸収効率が悪くなる。このため、特許文献１には、断面形状が八角形であるクラッシュボックスが提案されている。特許文献１記載のクラッシュボックスは、安定して蛇腹状に変形可能なように塑性変形の起点となる応力集中部（ビード形成部）を備えている。応力集中部は、クラッシュボックスの内側に形成された凸部によって構成され、軸方向で互い違いになるように設けられている。応力集中部を設けることにより、凸部の突出方向への変形が誘発され、クラッシュボックスは安定して蛇腹状に変形する。 In a crash box having a square or hexagonal cross-sectional shape, the number of ridge lines extending in the axial direction is small and the length of one side is long, so that the energy absorption efficiency is deteriorated when absorbing the impact. For this reason, Patent Document 1 proposes a crush box whose cross-sectional shape is an octagon. The crash box described in Patent Document 1 includes a stress concentration portion (bead forming portion) serving as a starting point of plastic deformation so that it can be stably deformed into a bellows shape. The stress concentration portions are formed by convex portions formed inside the crash box, and are provided so as to alternate in the axial direction. By providing the stress concentration portion, deformation of the convex portion in the protruding direction is induced, and the crash box is stably deformed into a bellows shape.
　なお、特許文献１の図２には、応力集中部を軸方向に２段設けたクラッシュボックスが図示され、同文献の図９には、応力集中部を軸方向に７段設けたクラッシュボックスが図示されている。また、クラッシュボックスの他の例として、特許文献２には断面形状が略十字閉断面形状であるクラッシュボックスが開示されている。特許文献２に開示されたクラッシュボックスは、略十字閉断面形状における各辺の成す角度がほぼ直角（９０°）になるように形成されている。 FIG. 2 of Patent Document 1 shows a crash box having two stress concentration portions in the axial direction, and FIG. 9 of the same document shows a crash box having seven stress concentration portions in the axial direction. It is shown in the figure. As another example of a crash box, Patent Document 2 discloses a crash box whose cross-sectional shape is a substantially cross-closed cross-sectional shape. The crash box disclosed in Patent Document 2 is formed such that the angle formed by each side in the substantially cross-closed cross-sectional shape is substantially a right angle (90 °).
特開２００６－１２３８８７号公報JP 2006-123887 A 特開２００９－８３６８６号公報JP 2009-83686 A
　しかしながら、特許文献１記載のクラッシュボックスであっても、安定して蛇腹状に変形すること、及び変形に伴うエネルギー吸収効率が高いこと、というクラッシュボックスに要求される性能を十分に満足しているとは言えない。 However, even the crash box described in Patent Document 1 sufficiently satisfies the performance required for the crash box that is stably deformed into a bellows shape and that the energy absorption efficiency associated with the deformation is high. It can not be said.
　すなわち、特許文献１記載のクラッシュボックスのようにクラッシュボックスの断面形状を八角形にしたとしても、クラッシュボックスが設置されるフロントサイドメンバの端部の形状との関係で、断面形状が正八角形ではなく長八角形（対向する一対の辺部が長い八角形）になる場合が多い。その場合には、長い辺部が残存することになり、軸力やエネルギー吸収効率が低下する。 That is, even if the cross-sectional shape of the crash box is an octagon like the crash box described in Patent Document 1, the cross-sectional shape is a regular octagon in relation to the shape of the end of the front side member where the crash box is installed. In many cases, it becomes a long octagon (an octagon having a long pair of opposing sides). In that case, a long side part remains, and axial force and energy absorption efficiency fall.
　また、特許文献１記載のクラッシュボックスによれば、同一断面では全ての応力集中部が内側方向に突出しており、同一断面で同一方向への変形を誘発するようにしている。しかしながら、同一断面で同一方向への変形では、エネルギー吸収効率に限界があり、必ずしも十分なエネルギー吸収を行うことができない。 Also, according to the crash box described in Patent Document 1, all the stress concentration portions protrude inward in the same cross section, and induce deformation in the same direction in the same cross section. However, deformation in the same direction in the same cross section has a limit in energy absorption efficiency, and sufficient energy absorption cannot always be performed.
　さらに、クラッシュボックスに要求される性能として、吸収エネルギーが大きいことの他に、クラッシュボックスが軸圧縮荷重を受けたときのピーク衝撃荷重が小さいことがある。ピーク衝撃荷重が小さいことが要求される理由は、ピーク衝撃荷重が大きくなると、ピーク衝撃荷重に合わせてクラッシュボックスを設置する例えばバンパメンバー等の車体側の部材の強度を高くする必要があるからである。この点、特許文献２に開示されたクラッシュボックスでは、略十字閉断面形状における各辺の成す角度がほぼ直角（９０°）になるようにしているため、ピーク衝撃荷重が大きくなる。 Furthermore, as performance required for the crash box, in addition to the large absorbed energy, the peak impact load when the crash box receives an axial compression load may be small. The reason why the peak impact load is required to be small is that when the peak impact load increases, it is necessary to increase the strength of the vehicle side member such as a bumper member that installs the crash box according to the peak impact load. is there. In this regard, in the crash box disclosed in Patent Document 2, the angle formed by each side in the substantially cross-closed cross-sectional shape is set to be substantially a right angle (90 °), so that the peak impact load increases.
　本発明は、上記の課題を解決するためになされたものであり、安定して蛇腹状に変形し、エネルギー吸収効率が高く、且つ、ピーク衝撃荷重が過大にならない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 to solve the above problems, and provides an impact absorbing member that is stably deformed into a bellows shape, has high energy absorption efficiency, and does not have an excessive peak impact load. Objective.
　本発明に係る衝撃吸収部材は、軸圧縮荷重を受けたときに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筒状の衝撃吸収部材であって、側壁が蛇腹状の変形を誘発させるためのビードを有していない平坦面からなり、軸方向に直交する断面形状が１２個の頂点を有する略十字状の閉断面であり、前記１２個の頂点のうちの８個の頂点を直線で連結して形成される八角形における斜辺の両端の頂点とその間にある頂点とを結ぶ直線の成す角度αが９０°＜α≦１５０°の範囲内に設定されていることを特徴とする。 The impact absorbing member according to the present invention is a cylindrical impact absorbing member that absorbs impact energy by plastic deformation in a bellows shape when subjected to an axial compression load, and the side wall induces bellows-like deformation. The cross-sectional shape perpendicular to the axial direction is a substantially cross-shaped closed cross section having 12 vertices, and 8 vertices of the 12 vertices are straight lines. An angle α formed by a straight line connecting the vertices at both ends of the hypotenuse and the vertices between them in the octagon formed by being connected is set in a range of 90 ° <α ≦ 150 °.
　本発明に係る衝撃吸収部材によれば、安定して蛇腹状に変形し、エネルギー吸収効率が高くなり、ピーク衝撃荷重が過大になることがない。 The impact absorbing member according to the present invention is stably deformed into an accordion shape, the energy absorption efficiency is increased, and the peak impact load is not excessive.
図１は、本発明の一実施形態に係る衝撃吸収部材の斜視図である。FIG. 1 is a perspective view of an impact absorbing member according to an embodiment of the present invention. 図２は、本発明の一実施形態に係る衝撃吸収部材の軸直交方向の断面図である。FIG. 2 is a cross-sectional view in the direction perpendicular to the axis of the impact absorbing member according to the embodiment of the present invention. 図３は、本発明の一実施形態に係る衝撃吸収部材の断面形状の説明図である。FIG. 3 is an explanatory diagram of a cross-sectional shape of an impact absorbing member according to an embodiment of the present invention. 図４は、本発明の一実施形態に係る衝撃吸収部材の変形の態様の説明図である。FIG. 4 is an explanatory view of a deformation mode of the shock absorbing member according to the embodiment of the present invention. 図５は、本発明の一実施形態に係る衝撃吸収部材の性能を確認する実験に用いた形状の説明図である。FIG. 5 is an explanatory diagram of the shape used in the experiment for confirming the performance of the shock absorbing member according to the embodiment of the present invention. 図６は、本発明の一実施形態に係る衝撃吸収部材における傾斜面の成す角度αとエネルギー吸収効率との関係を示すグラフである。FIG. 6 is a graph showing the relationship between the angle α formed by the inclined surface and the energy absorption efficiency in the shock absorbing member according to the embodiment of the present invention. 図７は、本発明の一実施形態に係る衝撃吸収部材における傾斜面の成す角度αが９０°及び１３５°であるときの単位重量当たりの衝撃荷重とストロークとの関係を示すグラフである。FIG. 7 is a graph showing the relationship between the impact load per unit weight and the stroke when the angle α formed by the inclined surface in the impact absorbing member according to one embodiment of the present invention is 90 ° and 135 °. 図８は、図７に示すグラフの縦軸を単位ピーク衝撃荷重で正規化したグラフである。FIG. 8 is a graph in which the vertical axis of the graph shown in FIG. 7 is normalized by the unit peak impact load. 図９は、本発明の一実施形態に係る衝撃吸収部材における傾斜面の成す角度αと単位衝撃荷重におけるエネルギー吸収効率との関係を示すグラフである。FIG. 9 is a graph showing the relationship between the angle α formed by the inclined surface and the energy absorption efficiency in the unit impact load in the impact absorbing member according to the embodiment of the present invention.
　本発明の一実施形態を図１乃至図９に基づいて説明する。 An embodiment of the present invention will be described with reference to FIGS.
　本実施形態に係る衝撃吸収部材１は、軸圧縮荷重を受けたときに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筒状の部材である。衝撃吸収部材１の側壁は、蛇腹状の変形を誘発させるためのビードを有していない平坦面からなる。この衝撃吸収部材１においては、軸方向に直交する断面形状が１２個の頂点を有する略十字状の閉断面になっている。１２個の頂点のうちの８個の頂点を直線で連結して形成される八角形における斜辺の両端の頂点とその間にある頂点とを結ぶ直線の成す角度αは９０°＜α≦１５０°の範囲内に設定されている。 The impact absorbing member 1 according to the present embodiment is a cylindrical member that absorbs impact energy by plastic deformation in a bellows shape when subjected to an axial compression load. The side wall of the shock absorbing member 1 is a flat surface that does not have a bead for inducing bellows-like deformation. In the shock absorbing member 1, the cross-sectional shape orthogonal to the axial direction is a substantially cross-shaped closed cross section having 12 vertices. The angle α formed by a straight line connecting the vertices at both ends of the hypotenuse in the octagon formed by connecting eight of the twelve vertices with a straight line is 90 ° <α ≦ 150 °. It is set within the range.
＜衝撃吸収部材の全体形状＞
　衝撃吸収部材１は、筒状の部材であって、軸方向に直交する断面形状が、図３に示すように、Ａ乃至Ｌの１２個の頂点を有する略十字状の閉断面になっている。衝撃吸収部材１の断面形状を詳細に説明する。衝撃吸収部材１の断面における１２個の頂点のうち、中心寄りにある４個の頂点Ｂ、Ｅ、Ｈ、Ｋを除いた８個の頂点Ａ、Ｃ、Ｄ、Ｆ、Ｇ、Ｉ、Ｊ、Ｌを直線（図３では直線を点線で表示）で連結して形成される形状が八角形になっている。八角形における斜辺ＡＣ、ＤＦ、ＧＩ、ＪＬの両端にある頂点、例えば頂点Ａ、Ｃとその間にある頂点Ｂとを結ぶ直線ＡＢ、ＣＢの成す角度αは９０°＜α≦１５０°の範囲内（本例では１３５°）に設定されている。 <Overall shape of impact absorbing member>
The shock absorbing member 1 is a cylindrical member, and the cross-sectional shape orthogonal to the axial direction is a substantially cross-shaped closed cross section having 12 vertices A to L as shown in FIG. . The cross-sectional shape of the shock absorbing member 1 will be described in detail. Of the twelve vertices in the cross section of the shock absorbing member 1, the eight vertices A, C, D, F, G, I, J, excluding the four vertices B, E, H, K near the center, The shape formed by connecting L with a straight line (in FIG. 3, the straight line is indicated by a dotted line) is an octagon. The angle α formed by the vertices at both ends of the hypotenuses AC, DF, GI, and JL in the octagon, for example, the straight lines AB and CB connecting the vertices A and C and the vertex B between them is within the range of 90 ° <α ≦ 150 °. (135 degrees in this example) is set.
　上記のように構成された本実施形態に係る衝撃吸収部材１は、軸圧縮荷重を受けると軸方向で内外方向に材料が移動することによって蛇腹状に変形する。そして、軸直交方向の一断面に着目すると、図４に示すように、各稜線で変形の向きが内外反転し、隣接する面が内外反対方向に変形する。このため、変形に伴って吸収されるエネルギーが増し、エネルギー吸収効率が高くなる。また、角度αが上記の範囲内にあることで、蛇腹状の変形を誘発させるためのビードを設けることなく、安定的に変形が可能になるので、ビードを設ける手間等がなく、衝撃吸収部材１を容易に製造することができる。なお、図４における矢印の向きは凸側に変形する方向を示している。 The shock absorbing member 1 according to the present embodiment configured as described above is deformed into a bellows shape when the material moves inward and outward in the axial direction when receiving an axial compression load. When attention is paid to one cross section in the direction perpendicular to the axis, as shown in FIG. 4, the direction of deformation is reversed inside and outside at each ridgeline, and adjacent surfaces are deformed in opposite directions inside and outside. For this reason, the energy absorbed with a deformation | transformation increases and energy absorption efficiency becomes high. Further, since the angle α is within the above range, it is possible to stably deform without providing a bead for inducing a bellows-like deformation, so there is no need to provide a bead and the shock absorbing member. 1 can be easily manufactured. In addition, the direction of the arrow in FIG. 4 has shown the direction which deform | transforms into a convex side.
　上述のように、本実施形態に係る衝撃吸収部材１においては、角度αが９０°＜α≦１５０°の範囲内に設定されている。以下、このように設定した理由を実験データに基づいて説明する。 As described above, in the shock absorbing member 1 according to the present embodiment, the angle α is set in the range of 90 ° <α ≦ 150 °. Hereinafter, the reason for this setting will be described based on experimental data.
　図５は、実験に用いた衝撃吸収部材１の断面形状の説明図である。各部の寸法は以下の通りである。使用した鋼板の引張り強度は４４０ＭＰａである。a=90.9mm、b=104.3mm、c=42.6mm、d=30.6mm、R=5mm、α=135° FIG. 5 is an explanatory diagram of a cross-sectional shape of the shock absorbing member 1 used in the experiment. The dimensions of each part are as follows. The tensile strength of the used steel plate is 440 MPa. a = 90.9mm, b = 104.3mm, c = 42.6mm, d = 30.6mm, R = 5mm, α = 135 °
　図５に示した基本形状から角度αを９０°、１０５°、１２０°、１３５°、１５０°、１６５°、１８０°に変化させ、それぞれの場合における衝撃吸収部材１のＳｍｍ圧潰時の吸収エネルギーを求めた。素材としての鋼板の板厚は圧潰時の反力が規定の耐力以下となるように調整した。図６は実験結果を示すグラフであり、横軸及び縦軸はそれぞれ角度αの値及びＳｍｍ圧潰時の吸収エネルギーを示している。 The angle α is changed from the basic shape shown in FIG. 5 to 90 °, 105 °, 120 °, 135 °, 150 °, 165 °, and 180 °, and the absorbed energy when the shock absorbing member 1 is crushed by Smm in each case. Asked. The plate thickness of the steel plate as a raw material was adjusted so that the reaction force at the time of crushing would be equal to or less than the specified yield strength. FIG. 6 is a graph showing the experimental results. The horizontal axis and the vertical axis indicate the value of the angle α and the absorbed energy at the time of Smm crushing, respectively.
　図６に示すように、吸収エネルギーは角度αが小さくなるほど増大している。また、変形状態を確認したところ、Ｖ字の形状（例えば図３における頂点Ａ、Ｂ、Ｃからなる形状）がついていれば、各稜線で変形の向きが内外反転し、隣接する面が内外反対方向に変形していることが確認された。しかしながら、角度αが大きくなるほど、反転する範囲が不明瞭になった。そこで、本発明においては、効果が得られる角度αの範囲を１５０°以下とした。また、角度αの下限値を９０°超とした理由は、角度αが９０°以下になると部材の加工が難しくなり、且つ、ピーク衝撃荷重が大きくなるからである。 As shown in FIG. 6, the absorbed energy increases as the angle α decreases. In addition, when the deformation state is confirmed, if the shape is V-shaped (for example, the shape composed of vertices A, B, and C in FIG. 3), the direction of deformation is reversed inside and outside at each ridgeline, and the adjacent surfaces are opposite to each other It was confirmed that it was deformed in the direction. However, the greater the angle α, the more unclear the range of inversion. Therefore, in the present invention, the range of the angle α at which the effect is obtained is set to 150 ° or less. The reason why the lower limit value of the angle α is set to exceed 90 ° is that when the angle α is 90 ° or less, it is difficult to process the member and the peak impact load is increased.
　前述した図５に示す衝撃吸収部材１を用いて、角度αを９０°及び１３５°にした場合の単位重量当たりの衝撃荷重とストロークとの関係を実験により求めた。図７は、実験結果を示すグラフであり、縦軸及び横軸はそれぞれ単位重量当たりの衝撃荷重及びストロークを示している。また、図８は、図７に示したグラフについて、縦軸をピーク衝撃荷重で正規化したグラフである。 Using the impact absorbing member 1 shown in FIG. 5 described above, the relationship between the impact load per unit weight and the stroke when the angle α was 90 ° and 135 ° was obtained by experiments. FIG. 7 is a graph showing experimental results, where the vertical axis and the horizontal axis indicate the impact load and stroke per unit weight, respectively. FIG. 8 is a graph in which the vertical axis of the graph shown in FIG. 7 is normalized by the peak impact load.
　図７に示すように、角度αが９０°である場合の方が角度αが１３５°である場合よりもピーク衝撃荷重の絶対値が大きくなっている。このため、角度αを９０°とする場合には、ピーク衝撃荷重に合わせて車両側の部材強度を設定する必要がある。他方、図８を見ると、単位ピーク衝撃荷重に対する単位重量当たりの衝撃荷重は、角度αが１３５°である場合の方が大きく、吸収できるエネルギーが大きい。このように、角度αが９０°である場合と角度αが１３５°である場合との比較から、角度αを９０°超とすることがピーク衝撃荷重を抑制するという観点から好ましいと言える。 As shown in FIG. 7, the absolute value of the peak impact load is larger when the angle α is 90 ° than when the angle α is 135 °. For this reason, when the angle α is 90 °, it is necessary to set the vehicle-side member strength in accordance with the peak impact load. On the other hand, referring to FIG. 8, the impact load per unit weight relative to the unit peak impact load is larger when the angle α is 135 °, and the energy that can be absorbed is larger. Thus, comparing the case where the angle α is 90 ° and the case where the angle α is 135 °, it can be said that the angle α is preferably more than 90 ° from the viewpoint of suppressing the peak impact load.
　次に、角度αの値と単位ピーク衝撃荷重に対する吸収エネルギーとの関係を求めるため、図５に示した基本形状から角度αを９０°、１０５°、１２０°、１３５°、１５０°、１６５°に変化させ、それぞれの場合における単位ピーク衝撃荷重に対するＳｍｍ圧壊時の単位重量当たりの吸収エネルギーを求めた。結果を図９のグラフに示す。図９においては、縦軸及び横軸がそれぞれ単位ピーク衝撃荷重に対するＳｍｍ圧壊時の単位重量当たりの吸収エネルギー及び角度αの値を示している。図９に示すように、角度αの値が９０°＜α≦１５０°の範囲内において、単位ピーク衝撃荷重に対するＳｍｍ圧壊時の単位重量当たりの吸収エネルギーが大きくなっていることが分かる。 Next, in order to obtain the relationship between the value of the angle α and the absorbed energy with respect to the unit peak impact load, the angle α is 90 °, 105 °, 120 °, 135 °, 150 °, 165 ° from the basic shape shown in FIG. The absorbed energy per unit weight at the time of Smm crushing with respect to the unit peak impact load in each case was determined. The results are shown in the graph of FIG. In FIG. 9, the vertical axis and the horizontal axis indicate the absorbed energy per unit weight and the value of the angle α at the time of Smm crushing with respect to the unit peak impact load, respectively. As shown in FIG. 9, it can be seen that the absorbed energy per unit weight at the time of Smm crushing with respect to the unit peak impact load is large when the value of the angle α is in the range of 90 ° <α ≦ 150 °.
　また、図９に示されるように、角度αの値が９０°と１０５°との間で単位ピーク衝撃荷重に対するＳｍｍ圧壊時の単位重量当たりの吸収エネルギーが急増している。このため、９０°と１０５°との間に角度αの好ましい値があると推認され、このことから角度αの値が９５°≦α≦１５０°の範囲内にあればより好ましいと言える。また、図９のグラフから角度αの値が１０５°であるときには単位ピーク衝撃荷重に対するＳｍｍ圧壊時の単位重量当たりの吸収エネルギーが高いことから、角度αの値は１０５°≦α≦１５０°の範囲内にあればさらに好ましいと言える。 Also, as shown in FIG. 9, the absorbed energy per unit weight at the time of Smm collapse with respect to the unit peak impact load increases rapidly when the value of the angle α is between 90 ° and 105 °. For this reason, it is presumed that there is a preferable value of the angle α between 90 ° and 105 °. From this, it can be said that it is more preferable if the value of the angle α is in the range of 95 ° ≦ α ≦ 150 °. From the graph of FIG. 9, when the value of the angle α is 105 °, the absorbed energy per unit weight at the time of Smm collapse against the unit peak impact load is high, so the value of the angle α is 105 ° ≦ α ≦ 150 °. It can be said that it is more preferable if it is within the range.
　なお、上記実施形態においては、衝撃吸収部材１を２つのプレス成形品を接合して形成する場合を示したが、本発明はこれに限られるものではなく、１枚の板材を折り曲げ加工によって形成することもできる。また、上記実施形態においては、２枚のプレス成形品の接合形態として、端部を重ね合わせてスポット溶接する場合を示しているが、本発明はこれに限られるものではなく、端部を突合せ溶接（レーザー溶接等）するようにしてもよい。この点は、衝撃吸収部材１を１枚の板材で形成する場合であっても同様である。なお、衝撃吸収部材１を２枚のプレス成形品を接合して形成する場合や１枚の板材を折り曲げ加工して端部を接合して形成する場合のいずれの場合であっても、接合箇所を突合せ溶接することで衝撃吸収部材１の重量を最も軽くできるので好ましい。 In the above embodiment, the shock absorbing member 1 is formed by joining two press-formed products. However, the present invention is not limited to this, and one plate material is formed by bending. You can also Moreover, in the said embodiment, although the case where the end part is overlap | superposed and spot-welded is shown as a joining form of two press molded products, this invention is not limited to this, Abutting an end part You may make it weld (laser welding etc.). This is the same even when the shock absorbing member 1 is formed of a single plate. It should be noted that in any case where the shock absorbing member 1 is formed by joining two press-formed products or when one plate material is bent and joined at the end, Is preferable because the weight of the shock absorbing member 1 can be minimized.
　本発明に係る衝撃吸収部材は、自動車等に設置される衝突時のエネルギーを吸収する部材に適用することができる。 The impact absorbing member according to the present invention can be applied to a member that absorbs energy at the time of a collision installed in an automobile or the like.
　１　衝撃吸収部材 1 Shock absorbing member

Claims (1)

  1. 　軸圧縮荷重を受けたときに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筒状の衝撃吸収部材であって、
    　側壁が蛇腹状の変形を誘発させるためのビードを有していない平坦面からなり、
    　軸方向に直交する断面形状が１２個の頂点を有する略十字状の閉断面であり、
    　前記１２個の頂点のうちの８個の頂点を直線で連結して形成される八角形における斜辺の両端の頂点とその間にある頂点とを結ぶ直線の成す角度αが９０°＜α≦１５０°の範囲内に設定されている
    　ことを特徴とする衝撃吸収部材。     A cylindrical impact absorbing member that absorbs impact energy by plastic deformation in a bellows shape when subjected to an axial compression load,
    The side wall consists of a flat surface without a bead for inducing bellows-like deformation,
    The cross-sectional shape orthogonal to the axial direction is a substantially cross-shaped closed cross section having 12 vertices,
    The angle α formed by a straight line connecting the vertices at both ends of the hypotenuse in the octagon formed by connecting eight of the twelve vertices with a straight line is 90 ° <α ≦ 150 °. The shock absorbing member is characterized by being set within the range.
PCT/JP2012/079039 2012-11-08 2012-11-08 Impact absorbing member WO2014073083A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3051714A1 (en) * 2016-05-31 2017-12-01 Faurecia Sieges D'automobile ANTI-VIBRATION PIECE AND METHOD OF MANUFACTURING THE SAME
WO2024011998A1 (en) * 2022-07-14 2024-01-18 一汽奔腾轿车有限公司 Integrated cross-shaped hydroformed crash box structure for electric vehicle subframe

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002284033A (en) * 2001-03-27 2002-10-03 Nippon Steel Corp Strength member for automobile
JP2009083686A (en) * 2007-10-01 2009-04-23 Mazda Motor Corp Vehicle body structure of automobile
US20100072788A1 (en) * 2008-09-19 2010-03-25 Tau Tyan Twelve-cornered strengthening member

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002284033A (en) * 2001-03-27 2002-10-03 Nippon Steel Corp Strength member for automobile
JP2009083686A (en) * 2007-10-01 2009-04-23 Mazda Motor Corp Vehicle body structure of automobile
US20100072788A1 (en) * 2008-09-19 2010-03-25 Tau Tyan Twelve-cornered strengthening member

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3051714A1 (en) * 2016-05-31 2017-12-01 Faurecia Sieges D'automobile ANTI-VIBRATION PIECE AND METHOD OF MANUFACTURING THE SAME
WO2024011998A1 (en) * 2022-07-14 2024-01-18 一汽奔腾轿车有限公司 Integrated cross-shaped hydroformed crash box structure for electric vehicle subframe

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