JPH07217689A - Energy absorption member - Google Patents

Abstract

PURPOSE:To surely and smoothly advance successive destruction in a desired portion by embedding a separation assistant layer, hindering adhesion between layers, between reinforcing fiber layers in one end part in a longitudinal direction in an energy absorption member composed of FRP having plural reinforcing fiber layers. CONSTITUTION:FRP composing a cylindrical energy absorption member 1 has plural reinforcing fiber layers 2. Plural layers of separation assistant layers 3 hindering adhesion between layers are embedded between reinforced fiber layers 2 into one end part in the longitudinal direction of the energy absorption member 1. When shock energy P is applied to the energy absorption member 1 via a pressing member 4, interlayer separation is easily caused in the respective reinforcing fiber layers 2 to surely advance destruction from this portion. The respective reinforcing fiber layers 2 wherein the interlayer separation is caused are expanded internally and externally in an FRP plate thickness direction to apply a compression load and also a bending load to a layer beginning to expand. When the bending load exceeds a critical value, a reinforcing fiber in a layer is raptured to advance so-called successive destruction. Consequently, an energy absorption member having high energy absorption capacity can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an energy absorbing member made of fiber reinforced plastic (hereinafter referred to as FRP).

[0002]

2. Description of the Related Art For example, an energy absorbing member that absorbs impact energy is used around an aircraft seat, around an automobile seat, around a bumper, around a steering wheel, and in various structural members (Japanese Patent Laid-Open No. 60-109630). , JP-A-62-17438). This energy absorbing member has the ability to absorb impact energy well,
Generally, lightweight and high rigidity are required,
A composite material of a resin and a reinforcing fiber, so-called FRP, especially carbon fiber reinforced plastic (hereinafter sometimes referred to as CFRP) is suitable.

In such an energy absorbing member, the impact energy is absorbed by the destruction of the energy absorbing member itself, but in order to absorb the energy smoothly and effectively, it is desirable that the energy absorbing member successively breaks down. It is generally considered that the sequential fracture occurs in balance between delamination of the FRP forming the energy absorbing member and compression (bending) fracture. As a trigger for inducing the destruction accompanying the delamination, it is known that the tip end portion of the energy absorbing member has a tapered cross-sectional shape.

[0004]

However, in the energy absorbing member having the above-mentioned structure, the tip tapered shape as a trigger needs to be optimized according to the specifications of the FRP constituting the energy absorbing member. However, depending on the shape of the trigger, the target sequential destruction may not always be obtained.

An object of the present invention is to provide a structure of an energy absorbing member which can surely and smoothly cause a sequential destruction at a desired portion regardless of the shape of the energy absorbing member itself or its tip. And

[0006]

The energy absorbing member of the present invention for this purpose has an FR having a plurality of reinforcing fiber layers.
An energy-absorbing member made of P, characterized in that a peeling auxiliary layer that inhibits adhesion between the reinforcing fiber layers is embedded between the reinforcing fiber layers at one end in the longitudinal direction.

The peeling auxiliary layer may be a single layer, but it is preferable to provide a plurality of layers in order to cause smoother successive breakage. Further, the material of the peeling auxiliary layer is not particularly limited as long as it can inhibit the adhesion between the reinforcing fiber layers of the FRP constituting the energy absorbing member and cause the interlayer peeling between the reinforcing fiber layers relatively easily. , For example, polytetrafluoroethylene (PTF), which is a fluororesin
E, trade name Teflon), polyfluorinated alkoxyethylene resin (PFA), fluoroethylene propylene ether copolymer resin (FEP), silicone resin film, polyimide film, and other release-treated film Release films such as However, the peeling auxiliary layer is not limited to the release film, and can be selected from metal thin plates, metal nets, organic fiber woven fabrics, glass fiber woven fabrics, aramid fiber woven fabrics, and the like.

The matrix resin that constitutes the FRP energy absorbing member of the present invention is not particularly limited, and epoxy resin, unsaturated polyester resin, polyvinyl ester resin, phenol resin, guanamine resin, or bismaleimide triazine resin. Examples thereof include polyimide resins, furan resins, polyurethane resins, polydiallyl phthalate resins, and thermosetting resins such as amino resins such as melanin resins and urea resins. Also, polyamides such as nylon 6, nylon 66, nylon 11, nylon 610, nylon 612, or copolyamides of these polyamides, polyesters such as polyethylene terephthalate and polybutylene terephthalate, or copolyesters of these polyesters,
Furthermore, polycarbonate, polyamide imide, polyphenylene sulfide, polyphenylene oxide, polysulfone, polyether sulfone, polyether ether ketone, polyether imide, polyolefin, etc.,
Furthermore, thermoplastic elastomers represented by polyester elastomers and polyamide elastomers can be used. Furthermore, as the resin satisfying the above range, acrylic rubber, acrylonitrile butadiene rubber,
Rubber such as urethane rubber, silicone rubber, styrene-butadiene rubber, and fluorine-based rubber can also be used. Further, a complicated blended resin selected from the above-mentioned thermosetting resin, thermoplastic resin and rubber can be used.

The reinforcing fiber is not limited to carbon fiber, but glass fiber, aromatic polyamide fiber, alumina fiber, silicon carbide fiber, boron fiber, or the like can be used, and they can be used in combination. Is.

[0010]

In such an energy absorbing member, since the peeling auxiliary layer is embedded between the reinforcing fiber layers of the FRP at the end portion (tip portion) of the energy absorbing member, the reinforcing fiber layers on both sides of the peeling auxiliary layer are peeled off. Delamination becomes easier with the auxiliary layer as a boundary.
When a plurality of peeling auxiliary layers are provided, interlayer peeling easily occurs in each peeling auxiliary layer portion.

As described above, the delamination at the end of the energy absorbing member means that the part surely functions as a trigger when the impact energy is absorbed. When delamination occurs smoothly, flexural fracture also occurs in the reinforced fiber layers on both sides of the exfoliation aid layer, and the delamination and flexural (compression) fracture are well balanced, and the sequential fracture progresses in a desired form. Go. Through this sequential destruction, the impact energy is efficiently and effectively absorbed, and the target impact energy absorption capability of the energy absorbing member is exerted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the energy absorbing member of the present invention will be described below with reference to the drawings. 1 to 3 show an energy absorbing member according to an embodiment of the present invention. In the figure, 1 indicates an energy absorbing member made of a cylindrical FRP, and the FRP forming the energy absorbing member 1 has a plurality of reinforcing fiber layers 2. Carbon fibers are preferable as the reinforcing fibers, but other reinforcing fibers as described above may be used. In addition, the reinforcing fiber layer 2
As the matrix resin impregnated in the above, various resins as described above can be used and are not particularly limited.

The reinforcing fiber layer 2 may be a so-called unidirectional layer in which reinforcing fibers are aligned in one direction, a layer in which reinforcing fibers are arranged in a crossed manner, or a layer made of a woven fabric of reinforcing fibers. 2 is laminated in multiple layers within the thickness of the FRP.

At least one end portion in the longitudinal direction of the energy absorbing member 1 (in this embodiment, it is one end portion, but it may be both end portions), between the reinforcing fiber layers 2, a peeling assisting layer 3 which inhibits adhesion between layers. Is buried. As shown in FIG. 2, the peeling auxiliary layer 3 is embedded in a plurality of layers. The plurality of peeling auxiliary layers 3 may be embedded in each of the adjacent reinforcing fiber layers, or may be embedded in each of the plurality of reinforcing fiber layers.

The peeling assisting layer 3 extends in the circumferential direction of the cylindrical energy absorbing member 1 over substantially the entire length thereof, and the tip of the energy absorbing member 1 extends in the direction along the cylinder axis direction of the energy absorbing member 1. It extends from the surface 1a into the plate thickness of the energy absorbing member 1 by an appropriate length. This length may be a length that causes the layers on both sides of the peeling auxiliary layer 3 to cause predetermined delamination at the time of absorbing energy, and through repeated experiments, the configuration of the FRP, the shape of the energy absorbing member, and the absorption It may be determined according to the magnitude of impact energy to be applied.

The material of the peeling auxiliary layer 3 is, as described above,
An FEP film, a polyimide film, and a film subjected to a release treatment (for example, applying a release agent) are preferable. However, as described above, in addition to the release film, various sheet materials selected from metal thin plates, metal nets, organic fiber woven materials, glass fiber woven materials, aramid fiber woven materials, etc. You may use.

In the energy absorbing member 1 thus constructed, when the impact energy P is applied, the energy is absorbed as follows. 2 and 3, reference numeral 4 denotes a pressing member that is brought into contact with the tip of the energy absorbing member 1, and impact energy P is applied to the energy absorbing member 1 via the pressing member 4.

Since a plurality of peeling auxiliary layers 3 are embedded in the tip portion of the energy absorbing member 1, delamination easily occurs between the reinforcing fiber layers on both sides of each peeling auxiliary layer 3. When impact energy P is applied in such a state, as shown in FIG.
As shown in FIG. 5, the reinforcing fiber layers of the tip portion FRP of the energy absorbing member 1 easily cause delamination, and the destruction surely proceeds from this portion. As shown in the figure, each reinforced fiber layer that has undergone delamination spreads in and out in the FRP plate thickness direction,
Bending load acts on the layer to be expanded together with compression. When this load exceeds the limit value, the reinforcing fibers in the layer break, and so-called sequential breakage progresses. Since the delamination is started smoothly, the sequential fracture also progresses smoothly.

The fact that the reinforcing fibers in each layer lead to breakage means that energy is consumed for the breakage, which means that the impact energy is absorbed more efficiently. Therefore, by causing such sequential fracture in which delamination and bending fracture are well balanced, impact energy is efficiently absorbed, and a large energy absorption capability is exhibited.

In the above-mentioned embodiment, the energy absorbing member 1 has a cylindrical shape, but the present invention is not limited to this, and various shapes can be adopted.

For example, FIGS. 4 to 7 show energy absorbing members having various other shapes. FIG. 4 shows the flange portion 1.
1 shows a cylindrical energy-absorbing member 12 provided with 1 and FIG. 5 shows an energy-absorbing member 22 having a T-shaped cross section provided with ribs 21, and FIG. 6 shows flange portions 31 at both ends. The energy absorbing member 32 having a U-shaped cross section is shown, 34 is a lid member that can be attached to the energy absorbing member 32, and FIG. There is.

Also in the energy absorbing members 12, 22, 32, 42 having various shapes as described above, the peeling assisting layer 13, similar to that described above, is provided at least at one end portion in the longitudinal direction thereof.
23, 33, 43 are buried. The operation and effect of embedding the peeling auxiliary layer are the same as those of the embodiment shown in FIGS.

[0023]

As described above, according to the energy absorbing member of the present invention, a peeling assisting layer that hinders the adhesion between the reinforcing fiber layers is embedded in the end portion of the FRP energy absorbing member, and impact energy is applied. At this time, since delamination was made to occur easily at this part, delamination and the bending fracture of the layer expanding on both sides of the delamination aid layer were well balanced to ensure the desired sequential fractures reliably and smoothly. An energy absorbing member that can be advanced and has high energy absorbing performance can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of an energy absorbing member according to an embodiment of the present invention.

FIG. 2 is an enlarged partial vertical sectional view of one end of the energy absorbing member of FIG.

3 is a vertical cross-sectional view showing a state of destruction of an end portion of the energy absorbing member of FIG.

FIG. 4 is a perspective view of an energy absorbing member according to a modified example of the present invention.

FIG. 5 is a perspective view of an energy absorbing member according to another modification of the present invention.

FIG. 6 is a perspective view of an energy absorbing member according to still another modification of the present invention.

FIG. 7 is a perspective view of an energy absorbing member according to still another modification of the present invention.

[Explanation of symbols]

 1, 12, 22, 32, 42 Energy absorbing member 2 Reinforcing fiber layer 3, 13, 23, 33, 43 Peeling aid layer

Claims (5)

[Claims] 1. An energy absorbing member made of FRP having a plurality of reinforcing fiber layers, wherein a peeling auxiliary layer for hindering adhesion between the reinforcing fiber layers is embedded between reinforcing fiber layers at one end in the longitudinal direction. Characteristic energy absorbing member. 2. A plurality of the peeling auxiliary layers are provided,
The energy absorbing member according to claim 1. 3. The release aid layer is composed of a release film.
The energy absorbing member according to claim 1 or 2. 4. The energy absorbing member according to claim 1, wherein the peeling auxiliary layer is one kind selected from a thin metal plate, a metal net, a woven fabric of organic fibers, a woven fabric of glass fibers, and a woven fabric of aramid fibers. 5. The energy absorbing member according to claim 1, wherein the reinforcing fiber layer is formed of carbon fiber.