JP2022101298A - Energy absorbing component - Google Patents

Abstract

To provide an energy absorbing component that is light in weight, has small initial reaction force, starts to be crushed from the front of the component, and has good energy absorbing performance.SOLUTION: An energy absorbing component 1 includes an outer shell portion 2 and a reinforcement component 3 located inside the outer shell portion. The outer shell portion is a cylindrical member in which a portion having the shortest outer peripheral length is located in one half in a longitudinal direction. The reinforcement component is a cylindrical component. The reinforcement component has a structure in three or more minimum units, each of which is a polygonal column having a diagonal fold line on a side surface sandwiched between an imaginary upper bottom surface and an imaginary lower bottom surface of a polygon. The three or more minimum units are formed in a direction perpendicular to the imaginary upper bottom surface or the lower bottom surface. Alternatively, the reinforcement component has a structure in which an outer shape has a recessed portion and a projecting portion alternately formed in a longitudinal direction, and has a cross-sectional shape connecting points set in sections inside a rectangular edge from an edge of an ellipse, along a plurality of imaginary line segments extending toward a rectangular edge at a predetermined angle around a center of the rectangle, with respect to the rectangle and the ellipse inscribed in the rectangle.SELECTED DRAWING: Figure 1A

Description

The present invention relates to an energy absorbing component, particularly an energy absorbing component that can be suitably used for a crash box used in an automobile body.

As a component that absorbs energy such as when an automobile collides, a structure that absorbs energy by crushing the component itself by a load is generally used. For example, the crash box is arranged between the bumper and the side member of the vehicle body, and is crushed in a bellows shape in the axial direction of the crash box by the load in the front-rear direction at the time of a collision to absorb the collision energy.

If the crash box can be crushed during a collision to prevent damage to the side members, the vehicle body can be easily repaired by replacing the bumper and the crash box.

The performance required for a crash box is that it absorbs a large amount of energy, and in order to reduce damage to the side members, it is in front of the parts (for example, in the case of a crash box on the front of the vehicle, it is in front of the vehicle, and in the case of a crash box on the rear of the vehicle. Is crushed and deformed from the rear of the vehicle), the initial reaction force (deformation load) is small in order to reduce the impact on the occupants, and weight reduction is also required from the viewpoint of improving fuel efficiency. ..

Many studies have been made on the structure of such a crash box. For example, in Patent Document 1, a pair of corner portions arranged to face each other and a line connecting the pair of corner portions are 80. It is composed of a metal cylinder having a cross-sectional shape having a basic cross-sectional shape of a quadrangle, and having another pair of corners arranged intersecting at an angle of ° or more and 100 ° or less. It is a crash box in which an impact load is input from one end in the axial direction of the body toward the other end, and the angle (α) formed by the pair of corners is 90 ° or more and 150 ° or less. The angle (β) formed by the other pair of corners is 30 ° or more and 90 ° or less, and extends in the longitudinal direction provided on each of the two sides sandwiching at least one of the corners of the pair of corners. It has one or more grooves that are convex toward the inside, and the cross-sectional circumference of the cylinder on the side of one end is larger than the cross-sectional circumference of the cylinder on the side of the other end. A crash box characterized by being small is disclosed.

Further, Patent Document 2 discloses a crash box, which comprises a middle plate extending horizontally so as to partition the hollow region up and down near the center in the vertical direction of the hollow cross section.

From the viewpoint of reducing the initial peak load, Patent Document 3 describes an energy absorption structure using an inverted spiral origami structure, and the energy absorption structure is a polygonal virtual upper bottom surface and virtual lower bottom surface. The smallest unit consisting of an inverted spiral origami structure of polygonal columns having diagonal fold lines on the side surface sandwiched between the two is provided with a cylindrical metal body formed in three or more stages in a direction perpendicular to the virtual upper bottom surface or virtual lower bottom surface. An energy absorbing structure characterized by doing so is disclosed.

Japanese Unexamined Patent Publication No. 2011-55181 Japanese Unexamined Patent Publication No. 2007-30778 Japanese Unexamined Patent Publication No. 2011-58579

It is preferable that the energy absorbing parts have high energy absorbing performance, and particularly in a vehicle type such as a truck, the weight of the vehicle body is large and the kinetic energy is also large. Therefore, the energy absorbing parts are required to have higher energy absorbing performance. Therefore, in the case of energy absorbing parts used for a crash box, it is conceivable to secure the absorbed energy by increasing the plate thickness or increasing the total length of the parts. However, if the plate thickness is simply increased, there is a problem that the initial reaction force becomes large and the impact on the occupant and the vehicle body becomes large. Therefore, it is preferable to increase the total length of the parts. However, when the total length of the component is long, the entire component is easily bent at the time of crushing deformation, and if the entire component is bent, there is a problem that sufficient absorbed energy cannot be obtained.

The techniques described in Patent Document 1 and Patent Document 2 are intended for a crash box having a short overall component length, and have a problem that it is difficult to apply to a crash box having a long overall component length. Further, in the inverted spiral origami structure described in Patent Document 3, even if the total length of the component is long, the entire component can be stably crushed without bending, but there is a problem that it is difficult to control the crushing start position. was there.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an energy absorbing component which is lightweight, has a small initial reaction force, starts crushing from the front of the component, and has good energy absorption performance. ..

The gist structure of the present invention is as follows.
(1) An energy absorbing component that can absorb collision energy.
The outer shell and
With a reinforcing component located inside the outer shell portion,
The outer shell portion is a cylindrical member in which the portion having the minimum outer peripheral length is located in one half portion in the longitudinal direction.
The reinforcing part is a cylindrical part and is a tubular part.
The reinforcing parts are
A structure in which the smallest unit of a polygonal prism having diagonal fold lines on the side surfaces sandwiched between the virtual upper bottom surface and the virtual lower bottom surface of a polygon is formed in three or more stages in a direction perpendicular to the virtual upper bottom surface or the virtual lower bottom surface. Or,
Concave and convex parts are formed alternately in the longitudinal direction, and in a cross section perpendicular to the longitudinal axis, the rectangle and the ellipse inscribed in the rectangle are centered on the center of the rectangle. A cross-sectional shape connecting points set in a section inside the edge of the ellipse from the edge of the ellipse along a plurality of virtual line segments extending toward the edge of the rectangle at a predetermined angle. An energy absorbing component characterized by having a structure having a structure.
Here, the "half portion" is a half portion when the outer shell portion is divided into two in the longitudinal direction.

(2) The energy absorbing component according to (1) above, wherein one half in the longitudinal direction is a half that can be positioned as the front side of the vehicle body.

(3) The outer peripheral length of the outer shell portion according to (1) or (2) above, wherein the outer peripheral length at the end of the one half portion in the longitudinal direction is smaller than the outer peripheral length at the end of the other half portion in the longitudinal direction. Energy absorbing parts.

(4) The energy absorbing component according to any one of (1) to (3) above, wherein the reinforcing component is made of a steel plate having a plate thickness of 1.0 m or less.

(5) The total length L of the outer shell portion, the minimum value of the outer cross-sectional area in the one half portion in the longitudinal direction of the outer shell portion, and the maximum value of the outer cross-sectional area in the other half portion in the longitudinal direction. The energy absorbing component according to any one of (1) to (4) above, wherein the average value A satisfies the following formula (1).
L ≧ 2 × √A (1)
Here, the outer cross-sectional area is the cross-sectional area when the outer shell portion is a solid part having the same outer shape.

(6) The outer peripheral length Lf at the end of the half portion on one side in the longitudinal direction of the outer shell portion and the outer peripheral length Lr at the end of the half portion on the other side in the longitudinal direction satisfy the following equation (2). Energy absorbing component according to any one of (1) to (5) above Lf ≦ 0.9 × Lr (2)

(7) The energy absorbing component according to (2) above, wherein the yield strength (YP) of the steel sheet is 150 to 650 MPa.
Here, the "yield strength" is measured by the metal material tensile test method shown in "JIS Z 2241", and in the stress-strain curve measured in the tensile test, the steel plate having an upper yield point The yield strength is defined as the upper yield point, and the yield strength is 0.2% proof stress (offset method) for a steel plate having no upper yield point.

According to the present invention, it is possible to provide an energy absorbing component which is lightweight, has a small initial reaction force, starts crushing from the front of the component, and has good energy absorbing performance.

It is a transmission perspective view of the energy absorption component which concerns on 1st Embodiment of this invention. It is a perspective view which shows the outer shell part of the energy absorption component of FIG. 1A. It is a perspective view which shows the reinforcement component of the energy absorption component of FIG. 1A. It is a perspective view of a reinforcing part. It is a perspective view of the minimum unit when the rotation angle θ is 0 degree. It is explanatory drawing for defining a rotation angle θ. It is a figure for demonstrating the minimum unit after the virtual upper bottom surface is rotated by the rotation angle θ. It is a transmission perspective view of the energy absorption component which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the outer shell part of the energy absorption component of 2nd Embodiment. It is a perspective view which shows the outer shell part of the energy absorption component of 2nd Embodiment in detail. It is explanatory drawing of the rectangular cross section. It is explanatory drawing of the ellipse inscribed in a rectangular cross section. It is explanatory drawing of the virtual line segment extending radially from the center of a rectangular cross section. It is explanatory drawing of the node of the outer shape. It is explanatory drawing of the outer shape which connected the node. It is explanatory drawing of the outer shape of the odd-numbered stage. It is a transmission perspective view of the energy absorption component which concerns on 3rd Embodiment of this invention. It is a perspective view which shows the reinforcement component of the energy absorption component of 3rd Embodiment. It is a perspective view of the energy absorption component which concerns on a comparative example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment)
FIG. 1A is a transmission perspective view of an energy absorbing component according to a first embodiment of the present invention. As shown in FIG. 1A, the energy absorbing component 1 of the present embodiment includes an outer shell portion 2 and a reinforcing component 3 located inside the outer shell portion 2. The energy absorbing component 1 is a component composed of a cylindrical outer shell portion 2 and a tubular reinforcing component, and one side of the extending direction (longitudinal direction) of the cylinder is the front side of the vehicle body or the rear side of the rear side (rear side). That is, it can be used as a crash box by arranging it between the bumper (front bumper or rear bumper) of the vehicle body and the side member so as to be located in the direction in which the force at the time of collision enters). The energy absorbing component 1 is capable of absorbing collision energy (for example, of a vehicle body) as follows. Hereinafter, the outer shell portion 2 and the reinforcing component 3, which are the constituent elements of the energy absorbing component 1, will be described.

FIG. 1B is a perspective view showing an outer shell portion of the energy absorbing component of FIG. 1A. As shown in FIG. 1B, the outer shell portion 2 is a cylindrical member having a hollow cross section. As a specific cylindrical shape, in the illustrated example, the outer shell portion 2 has a substantially elliptical cross section. This makes it possible to further improve the energy absorption performance. However, the cross-sectional shape of the outer shell portion 2 can be various other shapes such as a polygon such as a circle or a rectangle. Further, in the total length L of the outer shell portion 2 in the longitudinal direction and one half portion of the outer shell portion 2 in the longitudinal direction (a half portion that can be positioned as the front side of the front side or the rear side of the vehicle body). It is preferable that the average value A of the minimum value of the external cross-sectional area and the maximum value of the external cross-sectional area in the other half in the longitudinal direction satisfies the following equation (1).
L ≧ 2 × √A (1)
This is because by satisfying the above formula (1), the total length of the component can be lengthened and a large amount of absorbed energy can be secured. As a result, it can be suitably used as a crash box of a vehicle body that generates a large amount of energy when a truck or the like collides.
For the same reason, it is more preferable that the total length L and the average value A satisfy the following equation (1').
L ≧ 3.5 × √A (1')
Although it is not particularly limited because it depends on the target (vehicle type and the like) to be applied, L is preferably 30 cm or more, and more preferably 45 cm or more for the same reason as described above.
The outer shell portion 2 is not particularly limited, but may be made of a metal plate, for example, a steel plate. The steel sheet in this case can be, for example, a hot-rolled steel sheet, a cold-rolled steel sheet, or the like. The steel sheet preferably has a constant thickness in view of ease of processing and the like, but may have a portion where the thickness changes. The plate thickness of the outer shell portion 2 is preferably 1.4 to 5.0 mm. By setting the plate thickness of the outer shell portion 2 to 1.4 mm or more, rigidity is ensured and the energy absorption performance is further improved, while by setting the plate thickness of the outer shell portion 2 to 5.0 mm or less, the plate thickness is set to 5.0 mm or less. This is because the weight of the energy absorbing component 1 can be reduced.

Here, in the outer shell portion 2, the portion having the minimum outer peripheral length is located in one half portion in the longitudinal direction. In particular, in this example, the outer peripheral length of the outer shell portion 2 at the end of one half portion in the longitudinal direction is smaller than the outer peripheral length at the end of the other half portion in the longitudinal direction. In this example, the outer peripheral length at the end of one half in the longitudinal direction is the smallest, from which the outer circumference gradually increases toward the end of the other half in the longitudinal direction, and the outer circumference at the end of the other half The length is the maximum.
In particular, it is preferable that the outer peripheral length Lf at the end of one half of the outer shell portion 2 in the longitudinal direction and the outer peripheral length Lr at the end of the other half of the longitudinal direction satisfy the following equation (2). .. This is because the control of the crushing start position, which will be described later, can be made more reliable.
Lf ≤ 0.9 × Lr (2)
Further, for the same reason, it is more preferable that the above Lf and Lr satisfy the following equation (2').
Lf ≤ 0.88 x Lr (2')
On the other hand, it is preferable to satisfy the following equation (2 ′ ′) in order to secure a certain degree of rigidity near the end on one side and enhance the energy absorption performance.
Lf ≧ 0.7 × Lr (2 ″)
Further, the Lf can be, for example, 300 to 400 mm for the same reason as described above, although it is not particularly limited because it depends on the applicable target (vehicle type, etc.).

Next, FIG. 1C is a perspective view showing a reinforcing component of the energy absorbing component of FIG. 1A. The reinforcing component 3 is a tubular component having an inverted spiral structure. The reinforcing component 3 is made of a metal plate, and is preferably a steel plate. The thickness of the steel plate is preferably 1.0 mm or less. This is because the energy absorbing component 1 can be reduced in weight. On the other hand, from the viewpoint of ensuring a certain degree of rigidity and improving the energy absorption performance, the thickness of the steel sheet is preferably 0.2 mm or more. In this case, the yield strength (YP) of the steel sheet is preferably 150 to 650 MPa. This is because the energy absorption performance can be improved by setting the yield strength of the steel sheet to 150 MPa or more, while the initial reaction force can be reduced by setting it to 650 MPa or less. Hereinafter, the inverted spiral structure will be described in detail with reference to FIG. 2.

As shown in FIG. 2, the inverted spiral structure is a minimum unit composed of an inverted spiral origami structure of a polygonal column having a fold line of a diagonal line 38 on a side surface 36 sandwiched between a virtual upper bottom surface 32 and a virtual lower bottom surface 34 of a polygon. 30 is a structure in which three or more steps are formed in a direction perpendicular to the virtual upper bottom surface 32 or the virtual lower bottom surface 34.

The minimum unit 30 has a structure in which the virtual upper bottom surface 32 and the virtual lower bottom surface 34 are spirally inverted and crushed at the time of crushing. The inverted spiral origami structure of the minimum unit 30 is a polygonal column having a diagonal line 38 on the side surface 36 sandwiched between the virtual upper bottom surface 32 and the virtual lower bottom surface 34 of the polygon. In the illustrated example, a configuration in which a minimum unit 30 composed of a regular hexagonal virtual upper bottom surface 32 and a virtual lower bottom surface 34 is connected in a series of four stages is shown. However, the polygon is not limited to the hexagon, and may be an equilateral polygon. Further, the number of stages of the minimum unit may be 3 or more, and is not limited to 4 stages. In addition, in order to simplify the explanation, in FIG. 2, the number of stages is smaller than that in FIG. 1C.

Here, regarding the fold lines of each side of the side surface 36 of the minimum unit 30 and the fold lines of the diagonal line 38, the tubular metal body is preliminarily creases, cutouts, or thinned. It may be configured so that it can be folded at the position of the fold line.

Further, in the illustrated example, the shape of the side surface 36 of the minimum unit 30 and the diagonal line 38 are configured so that the directions are reversed for each of the minimum units 30. More specifically, each stage of the minimum unit 30 is configured to be plane-symmetrical with the virtual upper bottom surface 32 or the virtual lower bottom surface 34 of the other stages.

Next, the operation when the reinforcing component 3 is crushed will be described. When the reinforcing component 3 receives the crushing energy from the virtual upper bottom surface 32 side of the minimum unit 30 in the uppermost stage, the reinforcing component 3 bends along the diagonal line 38 provided on the side surface 36, and at the same time, the joint of the adjacent side surfaces 36 and the upper and lower parts are formed. The joint of the minimum unit 30 is bent, and the side surface 36 is closely folded. That is, the joint between the side surfaces 36 is bent at a mountain fold, and the diagonal line 38 is bent at a valley fold. Then, the joint between the minimum units 30, that is, the side around the virtual upper bottom surface 32 or the virtual lower bottom surface 34 is bent by a mountain fold.

Since the minimum unit 30 has an inverted spiral origami structure, the virtual upper bottom surface 232 and the virtual lower bottom surface 34 are spirally inverted, that is, twisted and crushed at the time of crushing. Therefore, in each minimum unit 30, rotation occurs relatively between the virtual upper bottom surface 32 and the virtual lower bottom surface 34. Here, when the minimum unit 30 has an even number of stages in the axial direction, that is, four stages as shown in the illustrated example, and each stage is configured to be plane-symmetrical with the virtual upper bottom surface 32 or the virtual lower bottom surface 34 of the other stages. The rotation of the minimum unit 30 in the uppermost stage is offset by the rotation of the minimum unit 30 in the next stage, and this is repeated thereafter. Therefore, in order to prevent rotational twisting from occurring in the virtual upper bottom surface of the uppermost stage and the virtual lower bottom surface of the lowermost stage, the virtual upper bottom surface may be configured to have an even number of stages and plane symmetry.

The reinforcing component 3 absorbs the crushing energy from the virtual upper bottom surface side of the minimum unit 30 in the uppermost stage by the operation as described above. In order to maximize the amount of energy absorbed at this time, the rotation angle θ of the virtual upper and lower bottom surfaces that determine the shape of the side surface 36, the chamfered shape of each side of the side surface 36 and the diagonal line 38, the virtual upper bottom surface 32 or the virtual lower bottom surface 34. The aspect ratio of the height h of the minimum unit 30 with respect to the peripheral length of the above may be determined as follows.

First, the rotation angle θ will be described. FIG. 3 is a perspective view for explaining the rotation angle θ in the minimum unit 30, FIG. 3A is a perspective view of the minimum unit 30 when the rotation angle θ is 0 degrees, and FIG. 3B defines a rotation angle θ. FIG. 3C is a diagram for explaining the minimum unit 30 after rotating the virtual upper bottom surface 32 at the rotation angle θ. In the figure, the parts with the same reference numerals as those in FIG. 2 represent the same objects.

但し、ｈは最小ユニット３０の高さ、Ｌは仮想上底面３２又は仮想下底面３４の周辺長、Ｒは仮想上底面３２の頂点での回転直径である。 As shown in FIG. 3A, the shape of the side surface 36 of the minimum unit 30 is a virtual shape when the virtual upper bottom surface 32 is rotated at the center point O of the virtual upper bottom surface 32 in the direction of the arrow in FIG. 3A at a rotation angle θ. It is determined by the side shape that connects each side of the upper bottom surface and each side of the virtual lower bottom surface. More specifically, the relationship between the angle of rotation θ shown in FIG. 3B and the angle α and the angle β is expressed by the following equation.

However, h is the height of the minimum unit 30, L is the peripheral length of the virtual upper bottom surface 32 or the virtual lower bottom surface 34, and R is the rotation diameter at the apex of the virtual upper bottom surface 32.

As shown in FIG. 3B, the shape of the parallel quadrilateral of the side surface 36 on the developed view of the polygonal prism is determined according to the rotation angle θ, and the diagonal line 38 thereof is also determined. It should be noted that the point A shown in FIG. 3A moves to the point A'shown in FIG. 3C by rotation. Here, the rotation angle θ may be preferably 10 degrees or less. When the rotation angle θ is 10 degrees or less, the energy absorption amount is maximum, and when the rotation angle θ is 28 degrees or more, it is about 70% of the energy absorption amount when the rotation angle θ is 0 degrees. In the above illustrated example, the shapes of the side surface 36 and the diagonal line 38 are determined by rotating the virtual upper bottom surface 32, but since the virtual upper bottom surface 32 and the virtual lower bottom surface 34 may be relatively rotated, it is sufficient. Of course, the shape of the side surface 36 and the diagonal line 38 may be determined by rotating the virtual lower bottom surface 34.

Here, the rotation angle θ of at least one minimum unit 30 may be different from that of the other minimum unit 30. As the angle of rotation θ increases, the inverted spiral origami structure tends to collapse. Therefore, for example, by reducing the rotation angle θ of each minimum unit 30 in order from the direction in which the crushing energy acts, it is possible to configure the reaction force to gradually increase when the crushing energy acts. For example, by making the rotation angle of the reinforcing component in one half of the longitudinal direction larger than the rotation angle of the reinforcing component in the other half of the longitudinal direction, the crushing start position is further set to the one side. Can be ensured. For example, the position having the maximum rotation angle may be set to one half of the longitudinal direction of the reinforcing component, or the average rotation angle of the one half of the longitudinal direction of the reinforcing component may be set. It can be larger than the average angle of rotation in the other half of the longitudinal direction of the reinforcement, or as described above, from the direction in which the crushing energy acts (one side in the longitudinal direction), each of the smallest units 30. It is also possible to reduce the rotation angle θ in order.

Next, the chamfered shape of the fold line will be described. In the minimum unit 30 formed as described above, chamfering (rounding) may be performed on each side of the side surface 36 of the minimum unit 30, the fold line of the diagonal line 38, and the joint between the minimum units 30. By chamfering, it is possible to increase the amount of absorbed energy.

Next, the aspect ratio will be described. In the above illustrated example, the aspect ratio of the height h of the minimum unit 30 to the peripheral length L of the virtual upper bottom surface 32 or the virtual lower bottom surface 34 of the minimum unit 30 is the same as the aspect ratio of the other minimum unit 30. However, the aspect ratio of at least one minimum unit may be configured to be different from the other minimum units. For example, when the peripheral lengths of the virtual upper bottom surface 32 and the virtual lower bottom surface 34 of all the minimum units 30 are constant, the heights may be different for each minimum unit in each stage. Thereby, it is possible to make the energy absorption amount of the minimum unit 30 of each stage different. For example, by increasing the height of each minimum unit 30 in order from the direction in which the crushing energy acts, it is possible to configure the reaction force to gradually increase when the crushing energy acts. For example, further crushing can be initiated by making the height of the smallest unit in one half of the longitudinal direction of the reinforcement part smaller than the height of the smallest unit in the other half of the longitudinal direction of the reinforcement. It is possible to ensure that the position is on one side of the above. For example, the smallest unit with the minimum height may be one half of the longitudinal direction of the reinforcement, or the average minimum unit in one half of the longitudinal direction of the reinforcement. The height can be less than the height of the average minimum unit in the other half of the longitudinal direction of the reinforcement, or from the direction in which the crushing energy acts (one side in the longitudinal direction), as described above. , The height of each minimum unit 30 can be increased in order.

Here, the reinforcing component 3 located inside the outer shell portion 2 can be attached to the inner peripheral surface of the outer shell portion 2 by welding or the like. Further, flanges are provided at the ends of the reinforcing component 3 and the outer shell portion 2 in the longitudinal direction, and the flanges of the reinforcing component 3 and the outer shell portion 2 are joined to each other for attachment, or the respective flanges are joined to the flat plate-shaped component. It can also be attached.

Hereinafter, the action and effect of the energy absorbing component of the first embodiment will be described. Hereinafter, a case where one half of the outer shell portion 2 in the longitudinal direction is arranged so as to be in front of the front side of the vehicle body will be described as an example. Since the energy absorbing component 1 of the first embodiment includes an outer shell portion 2 and a reinforcing component 3 located inside the outer shell portion 2, the reinforcing component 3 has a cylindrical inverted spiral structure. It is possible to perform stable crushing by rotating and crushing the virtual upper bottom surface 32 and the virtual lower bottom surface 34 while spirally reversing each of the above-mentioned virtual upper bottom surface 32 and virtual lower bottom surface 34 against the collision energy from the front side of the vehicle body. It can absorb a large amount of energy compared to the case where the crushing is unstable and the entire part is bent. Further, since the outer shell portion 2 is provided, the rigidity is higher than that without the outer shell portion 2, and a larger amount of energy can be absorbed. Since the outer shell portion 2 is a cylindrical member in which the portion having the minimum outer peripheral length is located in one half portion in the longitudinal direction, the rigidity of the one side thereof is relatively low and the outer shell portion 2 is easily crushed. The crushing start position of the reinforcing component 3 of the above can also be controlled to the one side. As a result, the crushing can proceed stably from one side to the other side, so that a larger amount of energy can be absorbed in this respect as well. Further, since it is not necessary to use a reinforcing member having a weight other than the outer shell portion 2 and the reinforcing component 3, or to increase the thickness of the outer shell portion 2 and the reinforcing component 3 more than necessary, the weight is reduced. It is also possible to reduce the initial reaction force.
As described above, according to the energy absorbing component of the first embodiment, the energy absorbing component is lightweight, the initial reaction force is small, the crushing starts from the front of the component, and the energy absorbing performance can be improved.
In addition, for example, even when one half of the outer shell portion 2 in the longitudinal direction is arranged so as to be behind the rear side of the vehicle body, the same action and effect as described above can be obtained against a collision from the rear of the vehicle body. It is clear that you can get it.

(Second embodiment)
Next, a second embodiment of the present invention will be described. FIG. 4 is a transmission perspective view of the energy absorbing component according to the second embodiment of the present invention. As shown in FIG. 4, the energy absorbing component 4 of the second embodiment is also an energy absorbing component capable of absorbing the collision energy of the vehicle body, and is a reinforcement located inside the outer shell portion 5 and the outer shell portion 5. It is equipped with a component 3. The outer shell portion 5 shown in FIG. 5 is similar to the first embodiment in that the portion having the minimum outer peripheral length is a tubular member located in one half portion in the longitudinal direction, but is polygonal. It differs from the first embodiment in that it has an origami structure. Since the reinforcing component 3 is the same as that of the first embodiment, the description thereof will be omitted. Hereinafter, the polygonal origami structure of the outer shell portion 5 will be described in detail.

FIG. 6 is a perspective view of an example of the outer shell portion 5 of the energy absorbing component 4 according to the second embodiment. As shown in FIG. 6, the outer shell portion 5 is a tubular member, and a step portion 51 forming a portion having a minimum outer peripheral length is formed in a half portion on one side in the longitudinal direction. In the illustrated example, the outer shell portion 5 has two step portions 51 and 52. The step portion 51 has a concave outer shape from the outside to the inside, and the step portion 52 has a convex outer shape from the inside to the outside. In this example, the outer peripheral length gradually decreases from the end of one half of the outer shell portion 5 in the longitudinal direction to the step portion 51, the outer peripheral length gradually increases from the step portion 51 to the step portion 52, and the outer peripheral length gradually increases from the step portion 52. The outer peripheral length gradually decreases to the end of the other half in the longitudinal direction. In this example, the outer shell portion 5 has the minimum outer peripheral length in the stepped portion 51 and the maximum outer peripheral length in the stepped portion 52. The outer shell portion 5 may have a portion having a minimum outer peripheral length formed in one half portion in the longitudinal direction, and as in this example, the outer peripheral length of the end of one half portion may be formed. May be minimized, or various shapes other than this example are possible. For example, the number of stepped portions is not particularly limited, and may include a portion where the outer peripheral length does not change in the longitudinal direction, and the position where the outer peripheral length is maximized is on one half side in the longitudinal direction. It may be positioned, and the outer peripheral length of the end of the other half may be maximized as in this example. When having three or more stepped portions, as an example, a portion where the outer peripheral length gradually decreases and a portion where the outer peripheral length gradually increases from the end of one half portion in the longitudinal direction of the outer shell portion 5 to the end of the other half portion. By alternately arranging and in the longitudinal direction, it is possible to configure the concave stepped portion and the convex stepped portion to be alternately formed in the longitudinal direction. For example, the outer peripheral length at the step portion forming the portion having the minimum outer peripheral length is preferably 70 to 90% of the outer peripheral length of the portion having the maximum outer peripheral length in the longitudinal direction. By setting it to 70% or more, it is possible to secure a certain degree of rigidity and increase the absorbed energy, while by setting it to 90% or less, it is possible to more reliably control the crushing start position described later. Is. When there are three or more steps, it is preferable that the step having the second smallest outer peripheral length is also located in one half of the longitudinal direction from the viewpoint of more reliable control of the crushing start position described later. .. The optimum number of steps varies depending on the total length L and the like, but when the total length L is 35 cm or more, it is preferably 3 to 7. Although not particularly limited, from the viewpoint of controlling the crushing start position, the length (separation distance) in the longitudinal direction between the steps is preferably within ± 10% of the total length L / (number of steps + 1).

Next, the cross-sectional shape of the outer shell portion 5 will be described. The outer shell portion 5 has a predetermined angle centered on the center of the rectangle (rectangular cross section) with respect to the rectangle (rectangular cross section) and the ellipse inscribed in the rectangle (rectangular cross section) in the cross section perpendicular to the axis in the longitudinal direction. Has a cross-sectional shape connecting points set in the section inside the edge of the rectangle (rectangular cross section) from the edge of the ellipse along a plurality of virtual line segments extending toward the edge of the rectangle (rectangular cross section). ing. 7A is an explanatory diagram of a rectangular cross section, FIG. 7B is an explanatory diagram of an ellipse inscribed in the rectangular cross section, FIG. 7C is an explanatory diagram of a virtual line segment extending radially from the center of the rectangular cross section, and FIG. 7D is an external diagram. 7E is an explanatory diagram of the outer shape connecting the nodes, and FIG. 7F is an explanatory diagram of the outer shape of the odd-sized stage.

First, in FIG. 7A, an ellipse inscribed in a quadrangular pyramid-shaped pipe having a rectangular cross section before processing is derived as shown in FIG. 7B. Next, in FIG. 7C, the X-axis direction (width direction) and the Y-axis direction (height direction) with the center of the rectangular cross section as the origin are assumed, and the region corresponding to the first quadrant of the XY plane is targeted. In the region of the first quadrant, the 90-degree angle range between the X-axis and the Y-axis is divided into 6 as an example of a predetermined angle interval. The number of divisions can be arbitrarily changed according to the design, specifications, etc., but if it is too large, processing becomes difficult, and if it is too small, the strength is insufficient, so the range of 5 divisions to 8 divisions is preferable. Is.

Then, a radial virtual line segment that divides 90 degrees into 6 is derived from the center of the rectangular cross section. That is, as an example of a predetermined angle, virtual line segments are derived at intervals of 15 degrees. Then, the points where each virtual line segment intersects the ellipse are designated as the first nodes a1 to a5. Further, the points where each virtual line segment intersects the edge of the rectangular cross section are defined as the second nodes b1 to b5.

In FIG. 7D, [| ai-bi | / 20] as an example of a predetermined distance from the second node side with respect to the distance between the first node and the second node along each virtual line segment. A third node ci (i = 1 to 5) is set at the position of. That is, the third node ci is a point set in the section inside the edge of the ellipse and the edge of the rectangular cross section in the virtual line segment. If the position of the third node ci is too close to the second node bi, it approaches the one having a rectangular cross section, and if the position of the third node ci is too close to the first node ai, it is processed from the base material of the rectangular cross section. Since the amount of deformation at the time of processing increases and processing becomes difficult, it is possible to select between a rectangular cross section and an ellipse depending on the performance, the material of the base material, the processing method, and the like.

In FIG. 7E, the intersection A of the X-axis and the rectangular cross section, the third node ci derived in FIG. 7D, and the intersection B of the Y-axis and the rectangular cross section are connected. In FIG. 7F, the above-mentioned third node ci is also derived for the second to fourth quadrants. The polygonal shape connecting the intersections of the third node ci and the X-axis, the Y-axis, and the rectangular cross section derived in this way is defined as the cross-sectional shape (outer shape) of the outer shell portion 5.

It should be noted that such a polygonal origami structure can be formed by embossing from a state in which the base material is filled with a liquid and removing unnecessary portions.

Hereinafter, the action and effect of the energy absorbing component of the second embodiment will be described. Hereinafter, a case where one half of the outer shell portion 5 in the longitudinal direction is arranged so as to be in front of the front side of the vehicle body will be described as an example. Hereinafter, only the differences from the first embodiment will be described. In the second embodiment, the portion having the minimum outer peripheral length is the step portion 51, and since the step portion 51 is a concave portion, crushing is likely to start from the portion and its vicinity, and crushing is performed. The control of the start position can be further ensured. Further, in the above example, the portion having the maximum outer peripheral length is the step portion 52, which is located in the other half portion, and the step portion 52 has a convex shape. Therefore, in the other half portion. Crushing is difficult to start, which also further ensures that crushing starts in one half. Further, in the above example, since the outer shell portion 5 has the above-mentioned cross-sectional shape (polygonal cross-sectional shape close to an ellipse), rigidity is ensured as compared with the case where the cross-sectional shape is rectangular. Greater energy absorption performance can be achieved.
As described above, the energy absorbing component of the second embodiment is also lightweight, has a small initial reaction force, starts crushing from the front of the component, and can improve the energy absorbing performance.
The second embodiment is particularly advantageous in that the crushing start position of the reinforcing member can be controlled more reliably. It is also advantageous in terms of absorbed energy per weight.
In addition, for example, even when one half of the outer shell portion 5 in the longitudinal direction is arranged so as to be behind the rear side of the vehicle body, the same action and effect as described above can be obtained against a collision from the rear of the vehicle body. It is clear that you can get it.

(Third embodiment)
Next, a third embodiment of the present invention will be described. FIG. 8 is a transmission perspective view of the energy absorbing component according to the third embodiment of the present invention. As shown in FIG. 8, the energy absorbing component 6 of the third embodiment is also an energy absorbing component capable of absorbing the collision energy of the vehicle body, and is a reinforcement located inside the outer shell portion 2 and the outer shell portion 2. It is equipped with a component 7. Since the outer shell portion 2 shown in FIG. 8 is the same as that of the first embodiment, the description thereof will be omitted. The reinforcing component 7 shown in FIG. 9 is different from the first embodiment in that it has a polygonal origami structure. Hereinafter, the polygonal origami structure of the reinforcing component 7 will be described.

The polygonal origami structure of the reinforcing component 7 also has a configuration similar to that described in the second embodiment of the polygonal origami structure of the outer shell portion 5, as described below. However, since the crushing start position is controlled by the outer shell portion 2, the reinforcing component 7 is formed with a stepped portion forming a portion having the minimum outer peripheral length in one half portion in the longitudinal direction. It is not necessary, and a step portion forming a portion having the minimum outer peripheral length may be formed in the other half portion. Of course, a step portion may be formed on one half portion in the longitudinal direction to form a portion having the minimum outer peripheral length. Further, as an example, in the reinforcing component 5, a portion where the outer peripheral length gradually decreases and a portion where the outer peripheral length gradually increases from the end of one half portion in the longitudinal direction to the end of the other half portion alternate in the longitudinal direction. By arranging them, it is possible to configure the concave portion and the convex portion of the outer shape to be alternately formed in the longitudinal direction. As a result, it becomes easy to crush the concave portion sandwiched between the convex portions in the longitudinal direction as the starting point, and stable crushing becomes possible. When there are a plurality of recesses, the outer peripheral length of the recesses may be different between the recesses depending on the position in the longitudinal direction, or may be the same. Further, when there are a plurality of convex portions, the outer peripheral length of the convex portions may be different between the convex portions depending on the position in the longitudinal direction, or may be the same. For example, the outer peripheral length of the step portion forming the concave portion is preferably 70 to 90% of the outer peripheral length of the step portion forming the convex portion. This is because when it is 70% or more, a certain degree of rigidity can be secured and the absorbed energy can be increased, while when it is 90% or less, it becomes easy to be appropriately crushed. The optimum number of steps varies depending on the total length L and the like, but when the total length L is 35 cm or more, it is preferably 3 to 7. Although not particularly limited, from the viewpoint of controlling the crushing start position, the length (separation distance) in the longitudinal direction between the steps is preferably within ± 10% of the total length L / (number of steps + 1).

The cross-sectional shape of the polygonal origami structure of the reinforcing component 7 has the same configuration as that described for the polygonal origami structure of the outer shell portion 5 in the second embodiment (however, the reinforcing component is arranged inside the outer shell portion). Therefore, the cross-sectional area and the like are smaller than the cross-sectional area and the like of the polygonal origami structure of the outer shell portion), so the description thereof will be omitted.

Hereinafter, the action and effect of the energy absorbing component of the third embodiment will be described. Hereinafter, a case where one half of the outer shell portion 2 in the longitudinal direction is arranged so as to be in front of the front side of the vehicle body will be described as an example. Hereinafter, only the differences from the first embodiment will be described. In the third embodiment, the reinforcing component 7 has the above-mentioned polygonal origami structure, but is concave because the concave and convex outer shapes are alternately formed in the longitudinal direction. The location is likely to be the starting point of crushing, and stable crushing is possible, and the energy absorption performance is better than when the entire part is bent due to unstable crushing. Further, since the reinforcing component 7 has a polygonal cross-sectional shape close to the elliptical shape described above, it is possible to secure rigidity and achieve greater energy absorption performance as compared with the case where the cross-sectional shape is rectangular. can. Therefore, even with the reinforcing component 7 having such a polygonal origami structure, the reinforcing component 7 is stably crushed and the energy absorption performance is improved.
As described above, the energy absorbing component of the third embodiment is also lightweight, has a small initial reaction force, starts crushing from the front of the component, and can improve the energy absorbing performance.
In addition, for example, even when one half of the outer shell portion 5 in the longitudinal direction is arranged so as to be behind the rear side of the vehicle body, the same action and effect as described above can be obtained against a collision from the rear of the vehicle body. It is clear that you can get it.

(Fourth Embodiment)
Although not shown, the energy absorbing component of the fourth embodiment is also an energy absorbing component capable of absorbing the collision energy of the vehicle body, and includes an outer shell portion and a reinforcing component located inside the outer shell portion. ing. The outer shell portion in the fourth embodiment is the same as the outer shell portion in the second embodiment, and the reinforcing component in the fourth embodiment is the same as the reinforcing component in the third embodiment. That is, in the fourth embodiment, the outer shell portion and the reinforcing component have the respective polygonal origami structures described above in the second and third embodiments, respectively.
The energy absorbing component of the fourth embodiment is also lightweight and has a small initial reaction force for the same reason as described for the outer shell portion of the second embodiment and the reinforcing component of the third embodiment, respectively. The crushing starts from the front of the part, and the energy absorption performance can be improved.

The energy absorbing component of the present disclosure can be suitably used for a crash box of a vehicle body, and can be particularly preferably used as a crash box of a vehicle body having a heavy load such as a truck. The energy absorbing component of the present disclosure can be used as a crash box on the front side of the vehicle body, or can be used as a crash box on the rear side.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples. In order to confirm the effect of the present invention, the energy absorbing components of Comparative Examples and Invention Examples 1 to 3 were evaluated in a simulation experiment.

As a comparative example, a hollow cylindrical energy absorbing component as shown in FIG. 10 was created. In the comparative example, the outer peripheral length (minimum) at the end of one half portion on the front side of the front side of the vehicle body was set to 359 mm, and the outer peripheral length (maximum) at the end of the other half portion was set to 414 mm. It was assumed that the outer peripheral length gradually increased from the end of the half on one side to the end of the half on the other side. The total length in the longitudinal direction was 576 mm. This member was made of a steel plate having a plate thickness of 3.5 mm.

As an example of the invention 1, an energy absorbing component having a structure in which a reinforcing component having an inverted spiral structure is arranged inside a cylindrical outer shell portion as shown in FIG. 1 was created. Regarding the outer shell portion, the outer peripheral length (minimum) at the end of one half portion on the front side of the front side of the vehicle body was set to 359 mm, and the outer peripheral length (maximum) at the end of the other half portion was set to 414 mm. It was assumed that the outer peripheral length gradually increased from the end of the half on one side to the end of the half on the other side. The total length in the longitudinal direction is 576 mm. This member was made of a steel plate having a plate thickness of 3.0 mm. The reinforcing parts consisted of 10 minimum units, each having a height of 57.6 mm, with an angle of rotation of 10 ° and a cross-sectional shape of a regular hexagon with a side length of 28.87 mm. This member was made of a steel plate having a plate thickness of 0.5 mm.

As Example 2 of the invention, an energy absorbing component having a structure in which a reinforcing component having an inverted spiral structure is arranged inside a tubular outer shell portion having a polygonal origami structure as shown in FIG. 6 was created. Regarding the outer shell portion, the outer peripheral length at the end of one half portion, which is the front side of the front side of the vehicle body, was set to 366.38 mm, and the outer peripheral length at the end of the other half portion was set to 420.94 mm. The total length in the longitudinal direction was 576 mm. The number of stepped portions was 6, and the stepped portions having a convex outer shape and the stepped portions having a concave outer shape were alternately arranged in the longitudinal direction. With respect to the virtual surface connecting the front end and the other end with a straight line, a step of 5 mm was given to the convex step. In the cross-sectional shape, the points where the radial virtual line segment that divides the 90-degree angle range from the X-axis to the Y-axis into six equal parts intersects the ellipse are defined as the first nodes a1 to a5, and each virtual line is defined. The points where the minute intersects the edge of the rectangular cross section are set as the second nodes b1 to b5, and the third node ci (i = 1 to 5) is set at the position of [| ai-bi | / 20], and X is set. The intersection of the axis and the rectangular cross section, the third node ci, and the intersection B of the Y axis and the rectangular cross section were connected, and the same was performed in the other quadrants to determine the determination. This member was made of a steel plate having a plate thickness of 2.7 mm. As the reinforcing parts, the same ones as in Invention Example 1 were used.

As Example 3 of the invention, an energy absorbing component having a structure in which a reinforcing component having a polygonal origami structure is arranged inside a cylindrical outer shell portion was created. As the outer shell portion, the same one as in Invention Example 1 was used. The number of stepped parts of the reinforcing parts is 6, and the stepped parts having a convex outer shape and the stepped parts having a concave shape are alternately formed in the longitudinal direction. The outer peripheral length at the end of the other half was 293.1 mm, and the outer peripheral length at the other half end was 336.75 mm. With respect to the virtual surface connecting the front end and the other end with a straight line, a step of 4 mm was given to the convex step. In the cross-sectional shape, the points where the radial virtual line segment that divides the 90-degree angle range from the X-axis to the Y-axis into six equal parts intersects the ellipse are defined as the first nodes a1 to a5, and each virtual line is defined. The points where the minute intersects the edge of the rectangular cross section are set as the second nodes b1 to b5, and the third node ci (i = 1 to 5) is set at the position of [| ai-bi | / 20], and X is set. The intersection of the axis and the rectangular cross section, the third node ci, and the intersection B of the Y axis and the rectangular cross section were connected, and the same was performed in the other quadrants to determine the determination. This member was made of a steel plate having a plate thickness of 0.5 mm.

As Comparative Example 2, an energy absorbing component composed of only a reinforcing component having an inverted spiral structure described in Invention Example 1 was created. However, the thickness of the steel plate was set to 3.0 mm. Other shapes are the same as the reinforcing parts of Invention Example 1.

The energy absorbing members of Comparative Examples 1 and 2 and Invention Examples 1 to 3 are applied to the vehicle body with a weight of 3000 kg on the rear end side of the energy absorbing component assuming the front side, and are attached to a rigid wall at an initial speed of 56 km / h. A collision simulation was performed to evaluate the initial peak load, crushing start position, and absorbed energy. The outer shell and the reinforcing parts were made of steel plate, and the yield strength was 215 MPa. Moreover, the weight was calculated assuming that the density of the used steel plate was 7.85 g / cm ³ . The evaluation results are shown in Table 1 below. In addition, in Table 1, "◯" of the crushing mode means that it was crushed from the front half part of the front side of the vehicle body. The target value of mass was 5.04 kg or less, the target value of absorption energy was 65 kJ or more, and the target value of initial peak load was 335 kN or less.

As shown in Table 1, according to Invention Examples 1 to 3, it can be seen that the weight was light, the crushing was stable, the energy absorption performance was good, and the initial reaction force could be reduced.

1: Energy absorbing part 2: Outer shell part 3: Reinforcing part 4: Energy absorbing part 5: Outer shell part 6: Energy absorbing part 7: Reinforcing part

Since the minimum unit 30 has an inverted spiral origami structure, the virtual upper bottom surface 32 and the virtual lower bottom surface 34 are spirally inverted, that is, twisted and crushed at the time of crushing. Therefore, in each minimum unit 30, rotation occurs relatively between the virtual upper bottom surface 32 and the virtual lower bottom surface 34. Here, when the minimum unit 30 has an even number of stages in the axial direction, that is, four stages as shown in the illustrated example, and each stage is configured to be plane-symmetrical with the virtual upper bottom surface 32 or the virtual lower bottom surface 34 of the other stages. The rotation of the minimum unit 30 in the uppermost stage is offset by the rotation of the minimum unit 30 in the next stage, and this is repeated thereafter. Therefore, in order to prevent rotational twisting from occurring in the virtual upper bottom surface of the uppermost stage and the virtual lower bottom surface of the lowermost stage, the virtual upper bottom surface may be configured to have an even number of stages and plane symmetry.

The polygonal origami structure of the reinforcing component 7 also has a configuration similar to that described in the second embodiment of the polygonal origami structure of the outer shell portion 5, as described below. However, since the crushing start position is controlled by the outer shell portion 2, the reinforcing component 7 is formed with a stepped portion forming a portion having the minimum outer peripheral length in one half portion in the longitudinal direction. It is not necessary, and a step portion forming a portion having the minimum outer peripheral length may be formed in the other half portion. Of course, a step portion may be formed on one half portion in the longitudinal direction to form a portion having the minimum outer peripheral length. Further, as an example, in the reinforcing component 7 , from the end of the half portion on one side in the longitudinal direction to the end of the half portion on the other side, a portion where the outer peripheral length gradually decreases and a portion where the outer peripheral length gradually increases alternate in the longitudinal direction. By arranging them, it is possible to configure the concave portion and the convex portion of the outer shape to be alternately formed in the longitudinal direction. As a result, it becomes easy to crush the concave portion sandwiched between the convex portions in the longitudinal direction as the starting point, and stable crushing becomes possible. When there are a plurality of recesses, the outer peripheral length of the recesses may be different between the recesses depending on the position in the longitudinal direction, or may be the same. Further, when there are a plurality of convex portions, the outer peripheral length of the convex portions may be different between the convex portions depending on the position in the longitudinal direction, or may be the same. For example, the outer peripheral length of the step portion forming the concave portion is preferably 70 to 90% of the outer peripheral length of the step portion forming the convex portion. This is because when it is 70% or more, a certain degree of rigidity can be secured and the absorbed energy can be increased, while when it is 90% or less, it becomes easy to be appropriately crushed. The optimum number of steps varies depending on the total length L and the like, but when the total length L is 35 cm or more, it is preferably 3 to 7. Although not particularly limited, from the viewpoint of controlling the crushing start position, the length (separation distance) in the longitudinal direction between the steps is preferably within ± 10% of the total length L / (number of steps + 1).

Claims (7)

It is an energy absorbing component that can absorb collision energy.
The outer shell and
With a reinforcing component located inside the outer shell portion,
The outer shell portion is a cylindrical member in which the portion having the minimum outer peripheral length is located in one half portion in the longitudinal direction.
The reinforcing part is a cylindrical part and is a tubular part.
The reinforcing parts are
A structure in which the smallest unit of a polygonal prism having diagonal fold lines on the side surfaces sandwiched between the virtual upper bottom surface and the virtual lower bottom surface of a polygon is formed in three or more stages in a direction perpendicular to the virtual upper bottom surface or the virtual lower bottom surface. Or,
Concave and convex parts are formed alternately in the longitudinal direction, and in a cross section perpendicular to the longitudinal axis, the rectangle and the ellipse inscribed in the rectangle are centered on the center of the rectangle. A structure having a cross-sectional shape connecting points set in a section inside the edge of the rectangle from the edge of the ellipse along a plurality of virtual line segments extending toward the edge of the rectangle at a predetermined angle. An energy absorbing component characterized by having. The energy absorbing component according to claim 1, wherein one half portion in the longitudinal direction is a half portion that can be positioned as the front side of the vehicle body. The energy absorbing component according to claim 1 or 2, wherein the outer shell portion has an outer peripheral length at the end of the one half portion in the longitudinal direction smaller than the outer peripheral length at the end of the other half portion in the longitudinal direction. The energy absorbing component according to any one of claims 1 to 3, wherein the reinforcing component is made of a steel plate having a plate thickness of 1.0 m or less. The average value A of the total length L of the outer shell portion, the minimum value of the outer cross-sectional area in the one half portion in the longitudinal direction of the outer shell portion, and the maximum value of the outer cross-sectional area in the other half portion in the longitudinal direction. The energy absorbing component according to any one of claims 1 to 4, which satisfies the following formula (1).
L ≧ 2 × √A (1) Claim 1 that the outer peripheral length Lf at the end of the one half portion in the longitudinal direction and the outer peripheral length Lr at the end of the other half portion in the longitudinal direction satisfy the following equation (2). Energy absorbing component according to any one of 5 to Lf ≦ 0.9 × Lr (2) The energy absorbing component according to claim 2, wherein the steel sheet has a yield strength (YP) of 150 to 650 MPa.

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