JP2012154475A - Impact energy absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact energy absorber for increasing its stroke in a plateau region when subjected to an impact load, while securing its supporting rigidity.SOLUTION: The impact energy absorber 1 includes a metal cylindrical body 3 and a metal bulk body 2. The cross section of the metal cylindrical body 3 is set to be shaped uniformly uneven along the axial direction 4 of the metal cylindrical body 3. The metal bulk body 2, in which a plurality of cavities exist and which is shaped uneven along an inner peripheral face 3c of the metal cylindrical body 3, approaches or contacts the inner peripheral face 3c of the metal cylindrical body 3.

Description

  The present invention relates to an impact energy absorber that absorbs an impact load by deformation at the time of a vehicle collision, for example.

  Patent Document 1 describes an impact energy absorber in which a side surface of an assembly of hollow metal spheres formed by adhering or joining adjacent hollow metal spheres is covered with a thin metal plate having a plurality of slit portions. Yes.

JP 2009-121599 A

  In the conventional impact energy absorber described above, the metal thin plate having a plurality of slit portions allows the hollow metal sphere to expand in the radial direction when the impact load acts to crush. For this reason, the stroke of the plateau region where a relatively plateau load is generated with respect to the stroke can be increased, and the impact energy can be absorbed in the plateau region below the load that does not damage the vehicle body.

  However, since the above conventional impact energy absorber is obtained by covering the side surface of the assembly of hollow metal spheres with a thin metal plate having a plurality of slit portions, a desired support rigidity cannot be obtained. Is difficult to support on the vehicle body side by the impact energy absorber.

  Therefore, an object of the present invention is to provide an impact energy absorber capable of increasing the stroke of a plateau region when an impact load is applied while ensuring support rigidity.

  In order to achieve the above object, the impact energy absorber of the present invention comprises a metal cylindrical body and a metal bulk body. The metal cylindrical body extends linearly along a predetermined direction, and the cross-sectional shape of the metal cylindrical body orthogonal to the predetermined direction is set to a uniform uneven shape along the predetermined direction. The metal bulk body is disposed inside the metal cylindrical body and has a plurality of voids. The outer peripheral surface of the metal bulk body has a concavo-convex shape along the inner peripheral surface of the metal cylindrical body, and is close to or in contact with the inner peripheral surface of the metal cylindrical body.

  The impact energy absorber having the above configuration is arranged so that an impact load acts along a predetermined direction of the metal cylindrical body. When an impact load is applied to the impact energy absorber, the metal bulk body is crushed in the direction of load application (predetermined direction) and tries to spread outward in the direction intersecting with the predetermined direction. Press the surface. Since the cross-sectional shape of the metal cylindrical body is set to a uniform uneven shape along a predetermined direction, when a pressing force in a direction crossing the predetermined direction acts on the inner peripheral surface of the metal cylindrical body, the concave portion The metal cylindrical body is deformed so that the concave portion is pushed out and approaches the cylindrical shape in which the uneven shape is relaxed, and the cross-sectional area in the cylinder of the metal cylindrical body increases. For this reason, the expansion behavior at the time of crushing of a metal bulk body is permitted by the increase in the cross-sectional area in the cylinder of the metal cylinder due to the relief of the uneven shape. In addition, such an increase in the cross-sectional area due to the relief of the concavo-convex shape is more efficiently generated with a lower pressing force than in the case where the cross-sectional area is increased by the elongation of the metal cylindrical body itself. Therefore, the stroke of the plateau region where a relatively plateau load is generated with respect to the stroke can be increased, and impact energy can be absorbed in the plateau region below the load that does not damage the vehicle body.

  Moreover, the strength of the metal cylindrical body can be set arbitrarily within a range that does not prevent the collapse of the metal bulk body due to the impact load applied to the impact energy absorber, so the metal cylindrical body is set to a desired strength. By doing so, the support rigidity of the impact energy absorber can be ensured.

  According to the present invention, it is possible to increase the stroke of the plateau region when an impact load is applied while ensuring the support rigidity of the impact energy absorber.

It is a perspective view which shows the impact energy absorber concerning embodiment of this invention. It is a perspective view which shows the state before accommodating the metal bulk body of FIG. 1 in a metal cylindrical body. FIG. 2 is a side view schematically showing a state in which the front bumper is supported on the vehicle body side by the impact energy absorber shown in FIG. 1. FIG. 4 is a cross-sectional view taken along arrow IV-IV in FIG. 3.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the impact energy absorber 1 of this embodiment includes a metal cylindrical body 3 and a metal bulk body 2.

  The metal cylindrical body 3 has a thin cylindrical shape that opens at both ends, extends linearly along an axial direction (predetermined direction) 4 from one end of the cylindrical shape toward the other end, and is formed of a metal such as stainless steel. The The cross-sectional shape orthogonal to the axial direction 4 of the metal cylindrical body 3 is set to a uniform uneven shape along the axial direction 4. The cross-sectional shape of the present embodiment is set to a substantially cross shape in which four concave portions 3a and four convex portions 3b are alternately continued. The four convex portions 3b extend from the central portion of the metal cylindrical body 3 so as to protrude in four directions orthogonal to each other. The recessed part 3a is located between the adjacent convex parts 3b, and curves toward the center part of the metal cylindrical body 3 rather than the surface which connects the front-end | tips of the adjacent convex part 3b linearly. Note that the material and dimensions of the metal cylindrical body 3 are set so that desired support rigidity is ensured within a range in which the metal bulk body 2 is not prevented from being crushed by an impact load applied to the impact energy absorber 1. .

  The metal bulk body 2 is an aggregate of a plurality of hollow metal spheres formed in a columnar shape by adhering or joining adjacent hollow metal spheres, and includes a large number of voids. The hollow metal sphere is made of, for example, iron or an iron-based alloy, and has a diameter of about 1 to 10 mm and a thickness of about 0.05 to 0.2 mm. Adjacent hollow metal spheres are made of resin. It is bonded or bonded by an adhesive, a low melting point adhesive, solid phase diffusion bonding, or the like. The outer peripheral surface 2 c of the metal bulk body 2 has a concave portion 2 a and a convex portion 2 b along the inner peripheral surface 3 c of the metal cylindrical body 3, and is in contact with the inner peripheral surface 3 c of the metal cylindrical body 3. The material and dimensions of the hollow metal sphere are determined according to the energy absorption performance required for the impact energy absorber 1 and are not particularly limited to the above.

  The impact energy absorber 1 is arranged so that an impact load (compression load) acts along the axial direction 4 of the metal cylindrical body 3. 3 and 4 are examples in which the front bumper 11 is supported on the vehicle body side by the impact energy absorber 1. The front end and the rear end of the impact energy absorber 1 are respectively joined to the rear surface of the front bumper 11 and the front surface of the front side member 12 on the vehicle body side, and the impact energy absorber 1 extends in the front-rear direction of the vehicle. Further, the impact energy absorber 1 is supported by the flange 13 so that the cross-sectional shape of the metal cylindrical body 3 can be deformed from an uneven shape to a cylindrical shape described later.

  When an impact load is applied to the impact energy absorber 1 due to a vehicle collision or the like, the metal bulk body (hollow metal sphere) 2 is crushed in the acting direction of the load, and is outside (substantially orthogonal to the acting direction of the load). The inner circumferential surface 3c of the metal cylindrical body 3 is pressed to increase the cross-sectional area of the metal cylindrical body 3 in the cylinder. For example, when the metal cylindrical body has a cross-sectional shape (cylindrical shape or the like) that does not have an uneven shape, it is necessary to extend the metal cylindrical body itself in order to increase the cross-sectional area. However, there is a limit to the extension of the metal cylindrical body itself, and the pressing force necessary for the extension is excessive, so that the outward spreading behavior of the metal bulk body is restricted. For this reason, stacking up in which the load increases to the right shoulder occurs early, and the stroke of the plateau region where the load that is relatively plateau with respect to the stroke is generated tends to be shortened.

  On the other hand, the cross-sectional shape of the metal cylindrical body 3 of the present embodiment is set to a uniform uneven shape along the axial direction. When the metal bulk body 2 that is crushed and expands outward presses the inner peripheral surface 3 c of the metal cylindrical body 3, the four recesses 3 a set in a cross-sectional shape are pushed out toward the outer side of the metal cylindrical body 3. The uneven shape is relaxed, and the metal cylindrical body 3 is deformed so as to approach a cylindrical shape having the same peripheral length as the metal cylindrical body 3. As a result, the cross-sectional area in the cylinder of the metal cylindrical body 3 is increased, and the spreading behavior when the metal bulk body 2 is crushed is allowed. In addition, as described above, the increase in the cross-sectional area due to the relief of the uneven shape is efficiently generated with a low pressing force as compared with the case where the cross-sectional area is increased due to the elongation of the metal cylindrical body itself. Therefore, since the occurrence of stack-up is delayed while the cross-sectional shape of the metal cylindrical body 3 is deformed by the low pressing force from the concavo-convex shape toward the cylindrical shape, the stroke of the plateau region can be increased and the impact energy can be increased. Can be absorbed in a plateau region below a load that does not damage the vehicle body.

  In addition, the strength of the metal cylindrical body 3 can be arbitrarily set within a range that does not prevent the metal bulk body 2 from being crushed by the impact load applied to the impact energy absorber 1. Therefore, by setting the metal cylindrical body 3 to a desired strength, it is possible to secure the support rigidity of the impact energy absorber 1 and to support the front bumper 11 on the vehicle body side by the impact energy absorber 1. .

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  For example, in the present embodiment, the metal cylindrical body 3 has four recesses 3a, but it is only necessary to have at least one recess. Moreover, the uneven | corrugated shape set to the cross-sectional shape of the metal cylindrical body 3 is not limited to the shape of this embodiment, What is necessary is just the shape which can relieve the uneven | corrugated shape and approximate circular shape.

  In the present embodiment, the outer peripheral surface 2 c of the metal bulk body 2 is in contact with the inner peripheral surface 3 c of the metal cylindrical body 3, but even if it is close to the inner peripheral surface 3 c of the metal cylindrical body 3. Good.

  Moreover, the metal bulk body 2 is not limited to an aggregate of hollow metal spheres, and may be foamed aluminum or the like. Further, instead of the metal bulk body 2, a plurality of independent hollow metal spheres that are not bonded or joined may be filled in the cylinder of the metal cylindrical body 3.

DESCRIPTION OF SYMBOLS 1 Impact energy absorber 2 Metal bulk body 2c Outer peripheral surface of metal bulk body 3 Metal cylindrical body 3a Recessed portion of metal cylindrical body 3b Convex portion of metal cylindrical body 3c Inner peripheral surface of metal cylindrical body

Claims (1)

A metal cylinder extending linearly along a predetermined direction;
A metal bulk body disposed inside the metal cylindrical body and including a plurality of voids,
The cross-sectional shape of the metal cylindrical body perpendicular to the predetermined direction is set to a uniform uneven shape along the predetermined direction,
The outer peripheral surface of the metal bulk body has a concavo-convex shape along the inner peripheral surface of the metal cylindrical body, and is close to or in contact with the inner peripheral surface of the metal cylindrical body. .

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