JP2000272448A - Impact energy absorbing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently absorb energy of external force applied to a body by providing not so large weight of an automobile. SOLUTION: An impact energy absorbing material 1, constituted by an aggregate pilling together kraft paper in outer/inner sides of a metal foil plate, for instance, iron foil and hard aluminum foil, is a flexible pipe having a quadrangular sectional shape to be provided with an irregular part spirally in an obverse/ reverse surface. The energy absorbing material is fixed by a bonding agent along an in-room side panel surface of an automobile body. When external force is applied to the energy absorbing material 1, it is plastically deformed, and energy of the external force can be absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact energy absorbing material for absorbing the energy of an external force applied to the body of an automobile.

[0002]

2. Description of the Related Art In order to ensure the safety of automobiles, body panels such as outer panels and inner panels have been reinforced. In order to reinforce the body panel, the thickness of the panel may be increased, but the weight of the body tends to increase by the increase in the thickness, which increases the material cost and increases the production cost, or completes the car After that, fuel efficiency also worsens. Therefore, the body panel is designed in consideration of the curvature and thickness of the panel so that the strength of the panel is sufficiently high.

[0003]

However, the body of an automobile may be different in shape, thickness of the body, etc. depending on the type of the vehicle, or the vehicle may not be reinforced by panels provided with accessory parts. Therefore, if the weight is reduced while the body is strengthened, it is difficult to strengthen all the parts, and some kind of reinforcing member is required. Further, even if the body is sufficiently reinforced in design, there is a case where the body is desired to be further strengthened by a simple method so as not to be so heavy. On the other hand, when an external force exceeding a certain level is applied to the vehicle body, plastic deformation occurs in the body panel. In such a case, if there is an absorbent capable of absorbing the energy of the external force, the load on the occupant of the vehicle due to the external force and the damage of other components can be reduced. The present invention has been made in view of the above problems, and an object of the present invention is to provide an impact energy absorbing material that can absorb the energy of an external force applied to a body without significantly increasing the weight of an automobile.

[0004]

In order to achieve the above object, an impact energy absorbing material according to the present invention is provided by attaching a flexible pipe having a rectangular cross section and having an uneven portion around the periphery to an automobile body, When it is applied to a pipe, it is plastically deformed to absorb the energy of external force.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an impact energy absorbing material according to an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show an impact energy absorbing material 1 according to the present invention. The energy absorbing material 1 is a flexible pipe having a substantially rectangular cross section. Regarding the square shape, any of a square shape and a rectangular shape can be used, and in this embodiment, a square shape is used as shown in FIG. Regarding the diameter of the pipe, there are various sizes suitable for the use condition.

FIG. 4 shows the energy absorbing material 1 shown in FIG.
It is an enlarged view of the arrow X section. As shown in the figure, the surface shape of the energy absorbing material 1 is a polymer composed of three layers of an outer layer material 2, an intermediate layer material 3 and an inner layer material 4 in order from the outside. Of these, the outer layer material 2 and the inner layer material 4 use kraft paper, and the intermediate layer material 3 uses a metal thin plate such as an iron foil or a hard aluminum foil.
Then, the concave portions 5 and the convex portions 6 are formed on these layer materials 2 to 4 in a continuous wave shape in the axial direction of the energy absorbing material 1, and the concave and convex portions 5 and 6 are shown in FIGS. 1 and 3. Thus, it is formed in a spiral shape. Table 1 shows details of preferred shapes for the energy absorbing material 1.

[0007]

[Table 1]

Next, the characteristics of the impact energy absorbing material 1 will be described. FIG. 5A shows a rectangular impact energy absorbing material 1 according to the present embodiment, and FIG. 5B shows a comparative example of a circular impact energy absorbing material 10 having a circular cross section. The circular energy absorbing material 10 is a flexible pipe having a cross section of a perfect circle, the outer diameter of which is the same as the external width of one side of the rectangular energy absorbing material 1, the axial length, and other intermediate layer materials. The same is true for the thickness, spiral pitch and number of turns.

These energy absorbing materials 1 and 10 were compressed by a compression tester at the tip of a hemisphere 11 having a diameter of 165 mm, and the length L of the inner diameter in FIG. The compression speed is 100 mm / min. FIG. 6 shows the result. In the figure, the solid line a shows the test result of the rectangular energy absorbing material 1, and the solid line b shows the circular energy absorbing material.
As is clear from the figure, the rectangular energy absorbing material 1
Compared with a circular one, the amount of deformation is small for a high load from the initial state, and the energy from external force is absorbed in the initial stage of deformation. Then, when a load equal to or more than a certain value is applied, the deformation amount rapidly increases. The other circular energy absorbing material 10 has a linear diagram in which the load and the deformation amount are proportional.

Table 2 shows details of the shapes of the energy absorbing materials of different types. As a result of performing the above-mentioned tests on these energy absorbing materials, type 1 has a bottom (the length L of the internal width becomes 0). In this case, the load was about 220 Kgf, and that of Type 2 was 460 Kgf.

[0011]

[Table 2]

With respect to the strength of the impact energy absorbing material 1, the amount of deformation with respect to the load can be changed by providing a rounded corner, and the larger the radius of the roundness, the greater the amount of deformation with respect to the load. In addition, the thickness of the material,
Tuning is possible by changing the width and the pitch of the projections.

The energy absorbing material 1 absorbs the energy of the external force when the external force is applied to the body of the automobile. As shown in FIG. 7, the energy absorber 1 is disposed at a front pillar 12, a center pillar 13, shoulder portions 14 and 15 of the front and rear doors, waist portions 16 and 17, a front roof rail 18, and a side roof rail 19 of an automobile 11. When a sliding roof is attached to the rear header rail 20 or the like, it can be disposed around the sliding roof 21.

Since the energy absorbing material 1 is rectangular, it can be easily attached directly to the panel with an adhesive. Also,
Since the energy absorbing material 1 has flexibility, even if there is a slight curvature in the arrangement place, the energy absorbing material 1 can be mounted correspondingly. As described above, when the external force is applied to the body of the automobile 11, the energy absorbing material according to the embodiment of the present invention absorbs the energy of the external force by deforming the energy absorbing material 1, and the load applied to other parts. And impact can be reduced. In particular, even when a large initial load is applied, the impact can be reduced with a small deformation amount as compared with a circular cross section. In addition, it is versatile in that it can be mounted even if it has some curvature, and the workability of mounting is good. As shown in Table 1, the weight is light and the weight of the vehicle body is not burdened.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical concept of the present invention.

For example, according to the above embodiment, the energy absorbing material 1 is arranged at the position as shown in FIG.
For example, it can be arranged on an apron side panel or a front panel of an engine room, and has a similar effect. Further, in order to make the energy absorbing material 1 flexible, the concavo-convex portions 5, 6 are formed in a spiral shape, but the concavo-convex portions may be arranged in a ring shape to have flexibility. When attaching the energy absorbing material 1 to each part, not only a method of attaching with an adhesive, but also a clip may be attached to the energy absorbing material 1 and attached to a panel, or may be attached with a clip band.

[0017]

As described above, according to the present invention, the energy of the external force applied to the body can be absorbed without increasing the weight of the automobile so much that the load on the occupant due to the external force and other factors can be improved. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of an impact energy absorbing material of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a partially broken side view of the same.

FIG. 4 is an enlarged cross-sectional view of a portion X in FIG. 3;

FIG. 5A is a schematic diagram of a characteristic test of an impact energy absorbing material according to an embodiment of the present invention. B is a schematic diagram of a characteristic test of the impact energy absorbing material of the comparative example.

FIG. 6 is a schematic graph showing the results of a characteristic test.

FIG. 7 is a perspective view of the automobile showing a place where the impact energy absorbing material according to the present embodiment is provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impact energy absorbing material 2 Outer layer material 3 Intermediate layer material 4 Inner layer material 5 Concave part 6 Convex part 11 Automobile

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Claims (14)

[Claims] 1. A flexible pipe having a rectangular cross-sectional shape and having irregularities on its periphery is attached to an automobile body,
An impact energy absorbing material characterized in that when an external force is applied to a pipe, the pipe is plastically deformed to absorb the energy of the external force. 2. The impact energy absorbing material according to claim 1, wherein the concave and convex portions of the flexible pipe are spirally provided. 3. The impact energy absorbing material according to claim 1, wherein the concave and convex portions of the flexible pipe are arranged in a ring. 4. The impact energy absorbing material according to claim 1, wherein said flexible pipe is disposed to be curved. 5. The impact energy absorbing material according to claim 1, wherein said flexible pipe is formed by laminating an inner layer material and an outer layer material. 6. The impact energy absorbing material according to claim 1, wherein the flexible pipe is attached to the body with an adhesive or a fastening member. 7. The impact energy absorbing material according to claim 1, wherein the body is a front pillar. 8. The impact energy absorbing material according to claim 1, wherein said body is a center pillar. 9. The impact energy absorbing material according to claim 1, wherein the body is a shoulder portion of a front door. 10. The impact energy absorbing material according to claim 1, wherein the body is a shoulder portion of a rear door. 11. The impact energy absorbing material according to claim 1, wherein the body is a front roof rail. 12. The impact energy absorbing material according to claim 1, wherein the body is a side roof rail. 13. The impact energy absorbing material according to claim 1, wherein said body is a rear header roof. 14. The impact energy absorbing material according to claim 1, wherein the body is around a sliding roof.