JP2003275825A - Impact absorbing body and method for manufacturing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing body which is high in free volume, excellent in deformability, has structure in which strong dummy hollow metallic balls are continued and its stacked structure and a manufacturing method of it. <P>SOLUTION: In this manufacturing method of the impact absorbing body having very high strength and high absorption performance of impact energy, a layer structure in which the dummy hollow metallic balls are continued is manufactured by performing special deformation of a metallic sheet with a press die having a special shape and combining it with a member which is separately formed and, next, stacking them. The impact absorbing body is manufactured in this way. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallic shock absorbing porous element structure, and more specifically,
In particular, the present invention relates to a method for producing a hollow pseudo sphere that is applied when producing a porous element structure having a high porosity and exhibits suitable shock absorption properties, and a shock absorbing porous element structure. INDUSTRIAL APPLICABILITY The present invention is useful for realizing the production and use of a shock absorbing material having a hollow pseudo metal sphere having high deformability and high strength as an element.

[0002]

2. Description of the Related Art Conventionally, a structure used for absorbing shock is generally designed so that a predetermined space is filled with a hollow element and the shock energy is absorbed by the deformation characteristic of the structure. Many. For example, a metal structure such as a honeycomb panel is a good example. However, in such a structure, although a large impact absorption characteristic is obtained in a specific direction, if the direction is slightly deviated, only a very small impact absorption characteristic is obtained.

On the other hand, when it is desired to ensure shock absorption at a light weight and at a low cost under the condition that a large force is not applied, for example, a soft resin or a foaming resin is often used for this purpose. However, when this kind of material is used, there is a drawback that sufficient impact energy absorption is not performed due to the small deformability peculiar to the resin and the low deformation stress.

Therefore, in order to improve the problems of these materials, it is conceivable to use this kind of shock absorbing material as a metallic porous element structure. That is, this structure has a structure in which a predetermined space is filled with metal constituent elements such as hollow spheres, columnar materials, prismatic materials, laminated materials, and hollow box materials. At that time, it has been found that hollow spheres or pseudo spheres are most preferable for these components in terms of the filling factor of the elements and the strength thereof. As described above, when the shock absorbing material is a metal porous element structure composed of a hollow sphere or a pseudo sphere, the optimum deformation stress of the metal material and the large deformability derived from its toughness are obtained. Therefore, extremely large impact energy absorption performance can be realized. Further, by using such a porous element structure as the shock absorbing material, it is possible to realize an extremely light weight while using a metal material.

As described above, various advantages can be obtained by using the metal porous element structure as a shock absorbing material. However, this kind of metal porous element structure is derived from its porous structure. It can be used for various purposes such as the following. That is, this type of porous structure has a low thermal conductivity due to its porous structure, and therefore, as a material for applications requiring low thermal conductivity, or due to its porous structure. Since the elastic modulus is reduced, it can be suitably used as a material for applications where vibration suppression is required, and the like.

By the way, as a method for producing this kind of metal porous element, that is, a hollow metal sphere or a pseudo metal sphere, the following methods are conventionally known. The first method is to sprinkle a metal slurry around a flammable spherical polymeric material such as polyurethane foam, and after drying, burn out the polymeric material and simultaneously sinter the metal to produce a spherical hollow metal. Is the way.

The second method is to form a metal film around a flammable spherical polymeric material such as polyurethane foam by plating or spraying a molten metal, and then burn out the polymeric material. This is a method for producing a spherical hollow metal. A third method is a method of forming a hemispherical metal from a plate material by pressing or the like, and joining two hemispheres by welding, brazing, caulking or the like to form a hollow metal sphere.

However, in the case of the above-mentioned first method, that is, the method of using the metal slurry, it is necessary for the combustion gas of the polymer material to pass through the formed metal film, and the sintering is performed from the metal slurry. However, there is a problem that the metal film becomes extremely porous, and only a film having extremely low strength can be produced. Moreover, this method complicates the process and makes the manufacturing cost significantly higher.

On the other hand, in the case of the second method, that is, the method using plating or spraying, there is a problem that the hollow metal structure which can be produced is limited to nickel or a low melting point metal and the productivity is low. . Further, in this method, as in the first method, since it is necessary to discharge the combustion gas of the polymer material to the outside through the formed metal film, a hole through which gas has permeated is locally generated in the metal film, It is difficult to obtain a uniform metal film.

Further, in the case of the third method, that is, the method of manufacturing each sphere by machining, a dense and high-strength coating can be formed, but the productivity is extremely low, and this method is used for shock absorbing materials. It is unsuitable when it is necessary to produce a large number of inexpensive spheres or pseudo spheres used as.

[0011]

Under these circumstances, the present inventor has, in view of the above-mentioned prior art, a new shock absorbing metal capable of drastically solving the problems of the above-mentioned prior art. In the process of conducting intensive research aiming to develop a method for producing a porous element structure easily and at low cost, the intended purpose is to be achieved by using a planar structural element in which pseudo hollow spheres of a specific structure are arranged. They have found that they can be achieved, and have reached the present invention. That is, the present invention is
An object of the present invention is to provide a metal porous element structure for impact absorption, which has large deformation performance and high strength. Another object of the present invention is to provide a method for producing the above-mentioned metal porous element structure, which enables the above-mentioned metal porous element structure to be produced simply and at low cost and with high efficiency.

[0012]

The present invention for solving the above-mentioned problems comprises the following technical means. (1) Using an upper die having a large number of protrusions and depressions having the same shape and a hemisphere tip and a lower die having a large number of similar protrusions and depressions facing the lower die, a metal plate material is formed from the upper and lower surfaces thereof. A method for forming a plate material having a large impact deformation amount, which comprises continuously and alternately forming hemispherical dome-shaped protrusions and depressions by applying a printing pressure. (2) The method for forming a plate material according to (1), wherein adjacent hemispherical dome-shaped projections and depressions occupy diagonal positions of a square, and the projections and depressions are in contact with each other. (3) A hemispherical dome-shaped depression occupies a position that is determined by forming two adjacent protrusions as the vertices of an equilateral triangle with respect to hemispherical dome-shaped protrusions that are arranged in contact with each other on a straight line. 1) The method for forming a plate material as described above. (4) A pseudo metal on a flat surface, characterized in that a hemispherical dome of a plate material separately formed by the same method is covered on the depression of the plate material formed by the method described in any one of (1) to (3) above. A method for manufacturing a porous structural element that absorbs impact deformation in which a large number of balls are arranged. (5) A method for manufacturing a shock absorber, characterized in that the structural element is laminated so that the pseudo metal sphere of the next component is placed directly above each pseudo metal sphere of the structural element described in (4) above. . (6) The method for manufacturing an impact absorber according to the above (5), characterized in that the pseudo metal spheres of the following constituents are placed in a valley formed by three or four pseudo metal spheres of the structural element. (7) The metal plate material is aluminum, magnesium,
The shock absorber manufacturing method according to (5) above, which is a simple substance or an alloy of any of titanium, iron, nickel, and copper. (8) The diameter of the formed pseudo metal sphere is 1 mm to 5
The method for producing an impact absorber according to (5) above, which is in the range of 0 mm. (9) The method for manufacturing an impact absorber according to the above (5), wherein the thickness of the formed pseudo metal sphere is in the range of 0.1 mm to 1 mm. (10) A shock absorber manufactured by the method according to any one of (5) to (9).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail. The method of the present invention realizes a metal porous element structure having high impact energy absorption performance by producing a constituent element in which pseudo hollow metal spheres are arranged on a plane and further stacking the constituent elements effectively. Is. That is, first, a metal plate material is press-molded using an upper die and a lower die whose cross-sectional view is schematically shown in FIG. 1 (a) to continuously form hemispherical projections and depressions on the metal plate material. To produce. At this time, since there is springback in the molding of the plate material, the outer diameter of the sphere where the outer diameter of the projection is formed on the upper surface of the plate material, and the sphere formed from the upper surface of the plate material to the upper end of the projection portion It is important and effective to dimension the mold so that it is equal to the radius. Similarly, the size of the mold should be equal to the outer diameter of the sphere where the outer diameter of the recess is formed on the lower surface of the plate material, and the radius of the sphere that is formed from the lower surface of the plate material to the lower end of the recess. Setting is important and effective.

The protrusions and depressions formed by press molding may be arranged in a square shape as schematically shown in FIG. 2 (a) or an equilateral triangle as schematically shown in FIG. 2 (a). Arrangement of shape is desirable. Here, T is a protrusion and D is a depression. However, it is not limited to these. next,
A hemisphere having the same shape as the projections and depressions produced by the above method is separately produced from a sheet material of the same type and the same thickness as the formed sheet material, and the hemisphere is schematically shown in FIG. Such shock absorber components are made.

An example of an embodiment of the present invention is shown in FIGS.
Shown in. The above-mentioned constituent elements of the present invention greatly vary depending on the site where they are used, load stress, load energy supply rate, amount of energy to be absorbed, and the like. Therefore, the illustrated example is a simplified and easy-to-understand example, and does not directly reflect the actual shape.

That is, the size, shape, and
The number of spheres can be appropriately selected depending on the purpose of use, conditions of use, and the like. The same applies to the method of laminating the above-mentioned constituent elements. As an example of the present invention,
A method for producing a shock absorber by laminating the components of the shock absorber thus produced will be specifically described below.

When the shock absorbing spheres are arranged in a square shape on a plane, as shown in FIG. 4 (a), the quasi metal spheres of the following constituents are provided immediately above the quasi metal spheres. It is desirable to place them in a simple cubic shape, or as shown in FIG. 4 (a), place the pseudo metal balls of the next component in a body-centered cubic shape in a valley formed by four pseudo metal balls. . However, it is not limited to these.

On the other hand, in the case where two adjacent protrusions are arranged in a regular triangle on a plane, as shown in FIG. 4A, the pseudo metal spheres of the following constituents are immediately above each pseudo metal sphere. It may be placed or placed in a face-centered cubic or close-packed hexagonal shape where the pseudo metal balls of the next component are placed in a valley formed by three pseudo metal balls as shown in FIG. 4 (a). desirable. However, it is not limited to these.

By the method of the present invention, a hollow metal sphere-filled type metallic porous structure can be produced. This structure has a uniform shape of the hollow spheres as compared with a hollow metal sphere-filled metallic porous material produced by another method, and since the filling method can be controlled extremely well, the deformability is high. Since it is large and the strength can be increased, and the manufacturing cost can be remarkably reduced, it can be used as a particularly suitable material for impact absorption.

In the present invention, as the material of the metal plate material, aluminum, magnesium, titanium, iron,
Either nickel or copper alone or an alloy can be preferably used. However, it is not limited to these. In particular, when used as a shock absorbing material, an aluminum plate material is preferably used in terms of its light weight and material cost.

Further, in the present invention, it is possible to preferably use a pseudo metal ball having a diameter in the range of 1 mm to 50 mm. Further, in the present invention, the pseudo metal spheres formed as described above having a thickness in the range of 0.1 mm to 1 mm can be preferably used. However, it is not limited to these.

[0022]

According to the method of manufacturing the shock absorber of the present invention, the pseudo metal spheres of the following constituents are placed directly above each pseudo metal material of the planar structural element in which the pseudo hollow spheres formed by combining two plate materials are arranged. It is characterized in that the above-mentioned components are laminated as described above. That is, in the method of the present invention, first, a constituent element in which pseudo hollow metal spheres are lined up on a plane is prepared, and further, by optimizing the constituent element and effectively stacking the constituent elements, a metal porous element having a high impact energy absorption performance. Create a construct.
The present invention, the size, shape of the pseudo metal sphere of the above components,
By arbitrarily adjusting the number of spheres, the filling method, and their arrangement method, various types of shock absorbers with various deformation performances and strengths corresponding to the purpose of use, conditions of use, etc. can be produced arbitrarily. It is possible. As a result, in the present invention, it is possible to highly efficiently produce, as the shock absorbing material, a metal porous element constituent having any shock absorbing characteristic and any form, and the present invention is simple and low cost. As a method of producing a shock absorber and a product thereof, it can be used in various fields in a wide variety of technical fields.

[0023]

EXAMPLES Next, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples. Example (1) Manufacture of shock absorber A square type SKD steel upper mold having a thickness of 0.5 mm and using 3000 series aluminum alloy plates in which five recesses and five protrusions are alternately arranged in both vertical and horizontal directions. Then, by loading about 10 tons with the lower mold, a structure as shown in FIG. The outer shape of the depression is about 1
It was set to 0 mm. 100 hemispherical domes made of a 3000 series aluminum alloy plate having a plate thickness of 0.5 mm were similarly prepared on the molded body obtained by this press molding process, and the hemispherical domes were covered on the respective recesses to give an impact. It was used as a constituent element of the absorber.

Further, 10 sets of these constituent elements were produced, and 10 layers were laminated in a structure in which the sphere was located on the sphere, and the inner diameter was 100 mm × 100 mm, the wall thickness was 1 mm, and the height was 120 mm.
It was housed in a rectangular cross-section container to be used as a shock absorber.

(2) Impact absorption characteristics When impact energy is applied to this impact absorber at a speed of 20 m / sec until it is deformed by 50%, about 4 MJ /
Energy absorption of m ³ was realized. This is extremely large compared to the impact energy absorption amount of 2 to ³ MJ / m ³ which can be obtained with a normal hollow body-filled impact energy absorber. As described above, according to the present invention, a high-strength and high-absorption-energy-impact absorber can be obtained as compared with the conventional method. Although one example of the present invention has been described above, when a shock absorber is manufactured in the same manner as the above method by changing materials and conditions, the same result is obtained.

[0026]

As described above in detail, the present invention relates to a high-performance shock absorber and a method for manufacturing the same, and the present invention has the following special effects. (1) It is possible to manufacture a shock absorber made of a metal hollow pseudosphere by a simple method and at low cost. (2) An impact absorber having high strength and high absorbed energy performance can be obtained as compared with the conventional method. (3) It is useful as an impact absorbing material having high deformability and high strength. (4) Light weight and low price can be realized. (5) It is possible to provide a method of producing a hollow hollow sphere made of metal with high efficiency. (6) Impact energy from all directions can be efficiently absorbed.

[Brief description of drawings]

FIG. 1 is a schematic view of a method for processing a plate material according to the present invention and an explanatory view showing a partial structure of a pseudo hollow metal sphere.

FIG. 2 is a schematic diagram showing a positional relationship between protrusions and depressions.

FIG. 3 is a schematic diagram showing a structure in which pseudo hollow metal spheres are continuous in a plate shape.

FIG. 4 is a schematic diagram showing a method of stacking shock absorbing elements.

Claims (10)

[Claims] 1. A metal plate material is formed on a metal plate material by using an upper mold having a large number of protrusions and depressions having the same shape and a hemispherical tip and a lower mold having a plurality of similar protrusions and depressions facing the upper mold. A method for forming a plate material having a large impact deformation amount, characterized in that hemispherical dome-shaped projections and depressions are continuously and alternately formed by applying pressure from the lower surface. 2. The method for forming a plate material according to claim 1, wherein adjacent hemispherical dome-shaped projections and depressions occupy diagonal positions of a square, and the projections and depressions are in contact with each other. 3. A hemispherical dome-shaped depression occupies a position determined by forming two adjacent protrusions as the vertices of an equilateral triangle with respect to hemispherical dome-shaped protrusions arranged in contact with each other on a straight line. The method for forming a plate material according to claim 1. 4. A pseudo metal sphere on a flat surface, characterized in that a hemispherical dome of a plate separately formed by the same method is covered on the depression of the plate formed by the method according to any one of claims 1 to 3. A method for manufacturing a porous structural element that absorbs impact deformation in which a large number of elements are arranged. 5. A shock absorber characterized in that the structural element is laminated so that the pseudo metallic sphere of the next component is placed directly above each pseudo metallic sphere of the structural element according to claim 4. Method. 6. The method of manufacturing a shock absorber according to claim 5, wherein a pseudo metal sphere of the next component is placed in a valley formed by three or four pseudo metal spheres of the structural element. . 7. The method of manufacturing an impact absorber according to claim 5, wherein the metal plate material is a simple substance or an alloy of any of aluminum, magnesium, titanium, iron, nickel, and copper. 8. The diameter of the pseudo metal sphere formed is 1 mm.
The method for manufacturing an impact absorber according to claim 5, wherein the impact absorber is in the range of 50 mm to 50 mm. 9. The thickness of the pseudo metal sphere formed is 0.1.
The method for manufacturing an impact absorber according to claim 5, which is in the range of mm to 1 mm. 10. A shock absorber produced by the method according to any one of claims 5 to 9.