JP2004148955A - Collision energy absorbing member for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collision energy absorbing member for an automobile having high productivity capable of stably providing the amount of high absorbed collision energy. <P>SOLUTION: The collision energy absorbing member for the automobile made of metallic material is a hollow member having a rectangular cross section shape, and has at least one or more groove shapes (crushed beads 5) for promoting compression and deformation in absorbing the impact in each of four surfaces of the hollow member. In this member, the groove shapes are formed in the whole lateral width of each surface so that the groove shapes in two facing surfaces exist at mutually the same longitudinal positions and the groove shapes in two adjacent surfaces exist at mutually different longitudinal positions. <P>COPYRIGHT: (C)2004,JPO

Description

【００２２】
【発明の効果】
本発明によれば、従来部材に比べ、吸収エネルギーが大きく最大荷重が小さい衝撃吸収部材が得られるという効果を奏する。
【図面の簡単な説明】
【図１】本発明部材の１例を示す立体図である。
【図２】本発明部材例の潰れ具合を示す立体模式図である。
【図３】比較部材例の潰れ具合を示す立体模式図である。
【図４】フロントサイドフレームの役割の説明図である。
【図５】本発明例（ｂ）および比較例（ａ）の部材作製要領を示す模式図である。
【符号の説明】
１ フロントサイドフレーム
２ 衝突時の荷重を示す矢印
３ バンパ
４ キャビン
５ 潰れビード
６ 衝撃吸収部材
７ 長手方向
８ 断面長辺方向
９ 断面短辺方向
１０ 圧潰工具
１１ 圧潰（強制変位）
１２ スポット溶接点
１３，１４，１５，１６ 部材のパーツ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a collision energy absorbing member for a vehicle, that is, a member for absorbing collision energy at the time of a vehicle collision in a vehicle body frame or the like made of a metal material.
[0002]
[Prior art]
Among the frame structural parts of the vehicle body, the front side frame 1 and the rear side frame arranged at the rear of the vehicle as shown in FIG. 4 play an important role as an energy absorbing member at the time of collision of the vehicle. In general, when an automobile collides, the side frame is appropriately collapsed in a bellows shape to absorb energy at the time of the collision and secure a occupant survival space in the cabin. For example, in the front side frame 1 shown in FIG. 4, a load at the time of a collision indicated by an arrow 2 in the figure input at the time of a collision in the front is transmitted to the front side frame 1 via the bumper 3, and at this time, If the frame 1 is not properly crushed and cannot absorb energy, the load at the time of the collision is transmitted to the cabin 4 further rearward and damages the occupant.
[0003]
Against this background, members having a high energy absorption capability have been desired for the collision energy absorbing member such as the front side frame, and development has been promoted.
For example, in Patent Literature 1, a basic member extruded from a light metal into a closed cross-sectional structure and a compression-deformation promoting portion, preferably a notch, provided at least at the end, which are fitted into the basic member and have substantially the same length, are provided. A member having a double structure formed with a reinforcing member has been proposed. Patent Documents 2 and 3 also disclose a frame structure of an automobile body characterized in that a rib connected to the inner surface of the hollow material is provided on a surface passing through the center axis of the hollow material by extrusion of a light metal material. Has been proposed.
[0004]
The performance required of these members is that the total absorbed energy when absorbing shock due to compression deformation is as large as possible, and when compression deformation starts, it is easy to collapse and the maximum impact load is possible That is, the ratio is as small as possible, that is, the [average load / maximum load] ratio is increased. Therefore, it is generally used to provide a groove shape (hereinafter, also referred to as a crushed bead) for promoting compressive deformation on the surface of the member. However, if the crushed bead is improperly arranged, there is a problem that the compression deformation does not proceed properly.
[0005]
For example, Patent Literature 4 discloses that an aluminum alloy hollow member can be a starting point of bellows-like deformation of a profile when a compressive stress is applied to at least the longitudinal end of the profile in the longitudinal direction of the profile. A groove formed by bending the wall surface of the profile to the outer surface or the inner surface is formed in the lateral direction of the profile, and the pitch of the groove is [(vertical length of hollow portion + horizontal length of hollow portion) ) / 2], it is disclosed that it is preferable to arrange in parallel the length direction of each side portion of the profile within the range of ± 20%.
[0006]
In the groove disclosed in this technique, that is, in the method of attaching a bead, for example, when a crushed bead is formed in a rectangular shape, the crushed bead does not cover the entire lateral width direction due to one side surface or the like. In such a case, it is good that the shock input is applied perpendicularly to the length direction of the shock absorbing member.However, if the shock input is slightly deviated, the shock input may not be collapsed in a beautiful shape in a bellows shape. There is a problem that the absorbed energy is reduced. In addition, the absorbed energy differs depending on the positional relationship between the crushed beads, and it may not be possible to secure a sufficient total absorbed energy.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 4-310777 [Patent Document 2]
JP-A-11-29064 [Patent Document 3]
JP-A-11-208519 [Patent Document 4]
JP-A-7-145842 [0008]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a collision energy absorbing member for an automobile which has a high impact absorption energy amount, is stably obtained, and has excellent productivity.
[0009]
[Means for Solving the Problems]
The present invention relates to a collision energy absorbing member for automobiles composed of a metal material, wherein the hollow member has a rectangular cross section, and at least one impact is applied to each of four surfaces of the hollow member. It has a groove shape that promotes compressive deformation at the time of absorption, and the groove shape is such that two opposite surfaces are located at the same longitudinal position, and two adjacent surfaces are located at different longitudinal positions. A collision energy absorbing member for an automobile, which is formed over the entire lateral width of each surface.
[0010]
In the present invention, a rectangle refers to a rectangle or a square.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The collision energy absorbing member for a vehicle according to the present invention (member of the present invention) has a rectangular cross-section, that is, a rectangular cross-section having a hollow shape having four hollow surfaces, and at least one surface for each surface. As shown in FIG. 1, for example, as shown in FIG. 1, two opposing surfaces (: two opposing surfaces: surfaces parallel to the cross-section long-side direction 8 in the figure) The positions of the crushed beads 5 in the longitudinal direction 7 on the surfaces parallel to the sectional short side direction 9) are the same, and two adjacent surfaces (: two adjacent surfaces: surfaces parallel to the sectional long side direction 8 in the figure) 7 is different from each other in the longitudinal direction 7 of the crushed bead 5 on the surface parallel to the cross-sectional short side direction 9, and the length of the crushed bead 5 in the width direction covers the entire width of each surface. And
[0012]
FIG. 2 shows the state of collapse of the member example of the present invention, and FIG. 3 shows the state of collapse of a member (comparative member example) in which the longitudinal position of the collapse bead is the same on the two opposing surfaces and the two adjacent surfaces. As shown in FIG. 2, by changing the longitudinal position of the crushed bead on the two adjacent surfaces, the entire member is compressed and deformed, and as a result, the total absorbed energy is increased. In addition, since it is easy to be crushed in order from the tip during deformation, the maximum load is also reduced. The reason why the longitudinal position of the crushed bead on the surface of the opposing 2 is the same is to prevent the member of the present invention itself from being deformed. In addition, the input of the impact often shifts from the axial direction (longitudinal direction) as the actual parts, so that the shock absorbing member is crushed in a bellows shape in a clean form, and the [average load / maximum load] ratio is increased. Then, a crushed bead is formed so as to pass through the entire width direction of each surface.
[0013]
On the other hand, as shown in FIG. 3, when the longitudinal position of the crushed bead is the same on the two adjacent surfaces, only a part of the member is easily deformed by compression, and the total absorbed energy is not easily increased.
In forming the crushed bead, for example, a punch or the like may be used as conventionally performed, and a groove shape, that is, a bent shape inward or outward may be provided, and is not particularly limited. Therefore, it is excellent in productivity.
[0014]
At least one crushed bead may be provided on at least each surface. However, since a plurality of crushed beads can be stably crushed in a bellows state, two or more crushed beads are preferably formed. The arrangement of the crushed bead between the two adjacent surfaces is such that when at least one crushed bead is formed on one surface of the two adjacent surfaces, the pitch of the crushed bead on the other surface is equal to or greater than the two or more crushed bead. It is preferable to dispose by displacing by a half of the pitch between the crushed beads from the viewpoint of crushing into a beautiful bellows shape and increasing the [average load / maximum load] ratio.
[0015]
The hollow member having a rectangular cross section, which is a material of the member of the present invention, may be formed by joining a metal plate such as a steel plate by spot welding or the like to have a rectangular cross section, as is generally performed. May be used without any particular limitation.
[0016]
【Example】
As Example 1 of the present invention, the width (hereinafter referred to as a) of two facing surfaces is 60 mm, the width of two surfaces adjacent to these surfaces (hereinafter referred to as b) = 37.5 mm, and the longitudinal dimension (hereinafter referred to as L). Steel member having a rectangular cross-sectional shape of 100 mm 2, in which the longitudinally disposed position of the crushed bead is different on the long side and the short side of the cross section. As Example 2 of the present invention, a = 80 mm, b = 50 mm, L = 100 mm 2, a steel member having a rectangular cross-sectional shape and different longitudinally disposed positions of the crushed bead on the long side and the short side of the cross section. As Example 3 of the present invention, a = 100 mm, b = 62.5 mm, L = A steel member having a rectangular cross-sectional shape of 100 mm, in which the position of the crushed bead in the longitudinal direction is different on the long side and the short side of the cross section. The cross-sectional shape, the length of the collapsed bead As a steel member whose orientation is different on the long side and the short side of the cross section, the material and dimensions of the steel members are the same as those of the inventive examples 1 to 4, respectively. The same installation position was prepared on the long side and the short side, and a crush test was performed on each member.
[0017]
In these examples of the present invention and comparative examples, the positions of the crushed beads on the surfaces of the two facing surfaces were the same in the longitudinal direction. The thickness of the member was about 2 mm on average, and the number of crushed beads was three on each side. On the long side, a first crushed bead was provided at a position dividing the longitudinal direction into four equal parts, that is, at a position 25 mm from the end in the longitudinal direction, and a crushed bead was provided with an interval (pitch) between the crushed beads being 25 mm. In Examples 1 to 4 of the present invention, this arrangement is shifted by 1/2 pitch on the short side to the leading side of the crushing in the longitudinal direction, and the first bead is provided at a position 12.5 mm from the end in the longitudinal direction. The distance between the crushed beads was 25 mm, the crushed beads were provided, and the positions of the crushed beads in the longitudinal direction were different on the long side and the short side. In Comparative Examples 1 to 4, a crushed bead was provided on the short side at the same longitudinal position as the long side. In addition, the beads of each surface of the invention examples 1 to 4 and the comparative examples 1 to 4 were provided over the entire width direction of the surface.
[0018]
In Comparative Example 3, as in Comparative Example 3-2, the longitudinal position of the bead is arranged differently on the adjacent surface as in the present invention, but the length of the bead in the width direction is changed in the width direction. 90%, which is the result of not passing through the entire width direction. Further, although the cross-sectional shape of the rectangular material is described as rectangular or square, the corner has a shape having a radius of curvature (R) of 5 mm.
[0019]
As shown in the schematic diagram of FIG. 5, the members of the present invention and comparative examples were prepared by press-forming a steel plate having a thickness of 2 mm to produce two parts of each member for each example. The parts 13 and 14 and the parts 15 and 16) were spot-welded to complete a member (impact absorbing member 6).
In the crush test, the member was fixed, the member was pushed in from one end by a crushing tool and crushed, the data of tool stroke-load was measured, and the absorbed energy and the maximum load at the time of crushing 35 mm were measured. Table 1 shows the results. In the table, the length of each side is a and b, and the dimensions of the example are shown.
[0020]
As shown in Table 1, in the examples of the present invention, the maximum load was small, the absorbed energy was large, and excellent characteristics as a shock absorbing member were exhibited as compared with the comparative example.
[0021]
[Table 1]

[0022]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the shock absorption member with a large absorption energy and a small maximum load is obtained compared with a conventional member.
[Brief description of the drawings]
FIG. 1 is a three-dimensional view showing one example of a member of the present invention.
FIG. 2 is a schematic three-dimensional view showing how a member example of the present invention is crushed.
FIG. 3 is a schematic three-dimensional view showing a collapse state of a comparative member example.
FIG. 4 is an explanatory diagram of a role of a front side frame.
FIG. 5 is a schematic view showing the procedure for producing members of the present invention example (b) and comparative example (a).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front side frame 2 Arrow indicating load at the time of collision 3 Bumper 4 Cabin 5 Collapse bead 6 Shock absorbing member 7 Longitudinal direction 8 Cross section long side direction 9 Cross section short side direction 10 Crushing tool 11 Crush (forced displacement)
12 spot welding points 13, 14, 15, 16 parts of parts

Claims (1)

In a vehicle collision energy absorbing member made of a metal material, a cross-sectional shape is a hollow member having a rectangular shape, and at least one or more of each of four surfaces of the hollow member is used to absorb an impact. It has a groove shape that promotes compressive deformation, and the groove shape is such that those of the two opposing surfaces are at the same longitudinal position and those of the two adjacent surfaces are at different longitudinal positions. A collision energy absorbing member for an automobile, which is formed over the entire width.

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