JP2003090376A - Impact energy absorbing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact energy absorbing member capable of sufficiently absorbing impact energy from a moving body at the time of collision, for example, improving collision safety of an automobile, etc., and light and compact. SOLUTION: This endless belt type impact energy absorbing member made of fiber reinforcing resin constituted by impregnating matrix resin in a reinforcing fiber bundle constitutes its characteristic feature that ductility of the matrix resin is not less than 100% and not more than 500%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, a passenger car,
Automobiles such as trucks, aircraft such as airplanes and airliners,
The present invention relates to an impact energy absorbing member made of fiber reinforced resin (FRP), which is used for preventing damage when a transportation device such as a fishing boat or a ferry boat, a train, a vehicle such as a monorail, or the like collides.

[0002]

2. Description of the Related Art Transportation equipment such as vehicles and automobiles that may collide while moving is equipped with an impact energy absorption mechanism in order to protect human life at the time of collision. A hollow metal frame, a polymer foam material, or the like is used as the impact energy absorbing member.

The mechanism of energy absorption by the impact energy absorbing member is that metal or polymer foam material undergoes compressive deformation or bending deformation under impact force, and the impact energy is absorbed by subsequent plastic deformation or destruction.

For example, Japanese Patent Laid-Open No. 9-2178 discloses that
A shock absorbing structure for an automobile interior member has been proposed which absorbs a shock when a rib is pressed and bent and deformed, and characteristics such as bending elastic modulus and Izod strength are mentioned.

Further, Japanese Patent Laid-Open No. 9-95197 discloses that
The rib part is plastically deformed, and the load increases accordingly,
An energy absorbing structure on the side of the vehicle body that can efficiently absorb energy has been proposed, and a hollow shape is described.

Further, Japanese Patent Laid-Open No. 5-32147 proposes an impact energy absorbing member using a fiber reinforced composite material for a bumper, the mechanism of which is as follows.
At the time of compressive deformation, peeling and destruction occur, and the absorbed energy increases.

[0007]

However, as described above, since the conventional impact energy absorbing member utilizes plastic deformation and compressive fracture, it is necessary to absorb a larger impact energy such as a high-speed collision. However, the shape of the members must be large and thick, the indoor space of the transportation equipment is narrowed, the habitability is sacrificed, and the weight increases and the fuel consumption decreases, which is unfavorable to the economy and the environment. was there.

In view of these problems, WO-01 / 44
Japanese Patent No. 679A1 proposes an energy absorbing member in the form of an endless belt, which is suitable for the needs of the era in which weight reduction is sought, in which the FRP is tensilely broken to absorb impact energy.

However, in order to cause the FRP to be tensilely broken,
Since it is necessary to make the shape of the member thin, and if the shape of the member is thick, the rigidity of the entire member increases, and the deformation of the entire member causes the entire member to be broken by bending or compression. ) And the length (L) ratio (t / L) is 1/100
There was a limit of zero.

By the way, in recent years, fiber reinforced rubber materials reinforced by reinforcing fibers have been widely used for industrial materials such as tires, belts and hoses. These fiber-reinforced rubber materials are obtained by twisting the reinforcing fibers in a predetermined manner, surface-treating them with an adhesive or the like, sandwiching the cord-shaped material with sheet-shaped rubber, and then heating and pressing to crosslink the rubber. Manufactured. As the resin used for these fiber reinforced rubber materials, a resin with a high degree of elongation is used to withstand the bending fatigue peculiar to rubber materials, so even if it becomes thick, the rigidity does not increase too much, and if it receives an impact load. It deforms flexibly when hit and does not break by bending or compression. The idea of converting the fiber-reinforced rubber material to the impact energy absorbing member by utilizing such a high elongation characteristic has not existed until now.

As described above, an object of the present invention is to provide an impact energy absorbing member made of a fiber reinforced resin, which allows the FRP to be tensilely broken at the time of a collision even if the member has a thick shape and can sufficiently absorb the impact energy. It is in.

[0012]

In order to solve the above problems, an impact energy absorbing member according to the present invention is an endless belt-like impact energy absorbing member made of fiber reinforced resin obtained by impregnating a reinforcing fiber bundle with a matrix resin. And
The matrix resin is a resin having an elongation of 100% or more and 500% or less.

The impact beam for transportation equipment of the present invention uses the above-mentioned impact energy absorbing member for absorbing impact energy.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an automobile door using the endless belt-shaped impact energy absorbing member 1 of the present invention as an impact beam, as seen from the inside. Although an actual automobile door is covered with an outer plate or the like, in order to make the embodiment of the present invention easy to see, FIG. 1 is illustrated with the outer plate of the automobile door removed. FIG. 2 is a perspective view showing an embodiment of the FRP impact energy absorbing member 1 according to the present invention. This figure is a view showing an endless belt-shaped body having a total length L (mm), a thickness t (mm), and a width B (mm), and the impact load (external force) is almost perpendicular to the thickness direction, that is, the longitudinal direction. Acts in the direction. As will be described later, the thickness does not necessarily have to be uniform, but when it is not uniform, an average value thereof is used to represent them.

The FRP (fiber reinforced resin) in the present invention means a fiber reinforced resin containing a matrix resin in a reinforcing fiber bundle.

The reinforcing fibers used in the present invention include inorganic fibers such as carbon fibers, glass fibers, alumina fibers, silicon nitride fibers and aramid fibers, polyamide synthetic fibers such as nylon, aramid fibers, PBO fibers, polyolefin fibers, Fibers such as polyester fibers and organic fibers such as polyphenylsulfone fibers may be used alone or in admixture of two or more.

The form of the reinforcing fiber may be a yarn bundle, a woven fabric or a braid.

Carbon fiber is particularly useful because it has high strength, high elastic modulus, and excellent corrosion resistance. This is because a reinforcing fiber having a higher elastic modulus can bear a load with a smaller amount of deformation. PAN (polyacrylonitrile)
It can be either pitch type or pitch type, but especially PAN
Carbon-based fibers are preferred because they have high strength and elongation.

The reinforcing fiber bundle used in the present invention preferably has higher strength and elongation. As will be described later, the greater the strength and the greater the amount of energy absorbed per unit volume, the smaller the size (volume) of the member, which is more preferable in terms of weight reduction and cost.

In the present invention, the reinforcing fiber bundle has a tensile elastic modulus of 180 GPa or more, preferably 230 Gpa.
It is preferable that it is Pa or more. This is because the higher the elastic modulus, the higher the stress due to the small deformation, and the larger the energy absorption amount with the small deformation.

Next, the matrix resin used in the present invention will be described. The matrix resin used in the present invention connects between the adjacent reinforcing fiber strands, plays a role of protecting the strands and transmitting a force between the strands, and its elongation is used in FRP for sports. 100%, an order of magnitude larger than structural epoxy resins
It is necessary to be above. As the elongation increases, the member can be flexibly deformed even when the thickness of the member increases, and thus the entire member is subjected to tensile failure, that is,
FRP can be tensilely broken to increase energy absorption. This is because the fracture mode transitions to bending fracture as the elongation decreases, and when the elongation is less than 100%, the energy absorption amount is not much different from that of the metal material.

Further, if the elongation of the matrix resin of the present invention is 200% or more, not only the flexibility of the member is increased, but also the scattering of reinforcing fibers and the like can be suppressed when the member is broken. it can. That is, since the member of the present invention undergoes tensile fracture, extremely large energy is released along with the fracture as compared with bending fracture, and at the same time, some fibers are not fractured like bending fracture, but almost all of the member is fractured. Since the fibers of No. 1 are broken, the reinforcing fibers are scattered, but if the elongation of the matrix resin is high at 200% or more, the resin part encloses the broken fibers, so that the fibers are scattered. Can be suppressed. In automobiles, it is indispensable to separate the members when disposing of a waste vehicle after a collision accident, and there is an advantage that the energy absorbing members can be collected and recycled without scattering.

The upper limit of the elongation is preferably as high as possible in consideration of easiness of deformation and energy absorption by it, but if it is too high, the shape retention of the member and the formability are deteriorated. It is necessary to be.

Here, the elongation of the matrix resin is J
The value measured at room temperature by the method of IS K6251.

The matrix resin used in the present invention has an elongation of 1 since its purpose is to facilitate the deformation of the entire member.
The composition and structure thereof are not particularly limited as long as they are 00% or more and 500% or less, but isoprene rubber, chloroprene rubber (CR), butadiene rubber, acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EP
M, EPDM), styrene-butadiene rubber (SB
It is preferable to use at least one rubber component selected from the group consisting of R), silicone rubber, sulfide rubber, and fluororubber.

Among them, liquid polyisoprene, liquid chloroprene (CR), liquid butadiene, liquid acrylonitrile-butadiene (NBR) copolymer, liquid ethylene-propylene (EPM, EPDM) copolymer, styrene-
Liquid rubbers such as butadiene (SBR) copolymers, liquid silicones, liquid sulfides, and liquid fluorine are preferable because the fibers are more easily impregnated with the resin than the solid rubbers. Above all,
A liquid rubber containing NBR as a main component is preferable because it has excellent adhesiveness to carbon fibers and can more effectively suppress scattering of the fibers.

Further, the rubber component contained in the matrix resin is contained in an amount of 50% by weight or more, preferably 90% by weight or more, based on the total weight of the resin. When it is less than 50% by weight, the elongation of the matrix resin is lowered, and when it is shocked, it is likely to be broken by bending. Further, ceramic powder or the like may be added for the purpose of improving heat resistance.

The matrix resin used in the present invention is
It is preferable to include at least one thermosetting resin component selected from the group consisting of epoxy, vinyl ester, unsaturated polyester, phenol, and benzoxazine. By including these thermosetting resin components, the crosslinkability of the rubber component can be assisted and the shape of the impact energy absorbing member of the present invention can be stabilized. Of these, epoxy resins are particularly preferable because they are excellent in cost and handleability.
Further, the thermosetting resin component contained in the matrix resin is preferably in the range of 2 to 20% by weight based on the total weight of the resin. If it is less than 2% by weight, the above-mentioned effect of assisting the crosslinking property is too weak, and if it exceeds 20% by weight,
On the contrary, the crosslinkability becomes too strong, and the elongation of the matrix resin becomes 100% or less, and the effect of the present invention of absorbing impact energy is lost. More preferably, it is in the range of 3 to 17% by weight.

The matrix resin used in the present invention is
It is preferable to include at least one thermoplastic resin selected from the group consisting of polyethylene glycol, acrylic, polyethylene, polypropylene, polyamide, ABS, potybutylene terephthalate, polyacetal, and polycarbonate. By including these thermoplastic resin components, the viscosity of the matrix resin can be appropriately adjusted, the impregnability with carbon fibers can be increased, and the handleability can be improved. Among them, polyethylene glycol is particularly preferable because of its excellent cost and handleability. Further, the thermoplastic resin component contained in the matrix resin is preferably in the range of 2 to 20% by weight based on the total weight of the resin. This is because if it is less than 2% by weight, the effect of adjusting the viscosity is too weak, and if it exceeds 20% by weight, the viscosity becomes too high and the handleability is impaired.
More preferably, it is in the range of 3 to 17% by weight.

The volume ratio of resin to reinforcing fiber is 2:
The range of 8 to 4: 6 is preferable for ensuring the flexibility and lightness of the member. Further, in order to secure the appearance as a member, the range of 3: 7 to 4: 6 is preferable.

Next, in the impact energy absorbing member of the present invention, the ratio (t / L) of the thickness t (mm) and the total length L (mm) is preferably within the range of 1/1000 to 1/80, The impact energy absorbing member is arranged so that the direction in which the impact force acts and the thickness direction substantially coincide with each other. This t
Since the / L ratio is thicker than that of the belt-shaped member of WO-01 / 44679A1, the volume of the member can be increased, and high-speed collision, collision with a large vehicle, etc.
It becomes easy to absorb a larger impact energy. However, what is destroyed by tension is a shape with a t / L ratio up to about 1/80, and a thicker shape than this (t / L is 1/80
Bending fracture occurs and the amount of impact energy absorption decreases.

In use, the energy absorbing member of the present invention is mechanically and / or mechanically located at the location where it is desired to absorb impact energy, such as the inside of a door or bumper, the inner or outer surface of a side plate, the rear of an engine, or the periphery of a passenger cabin. Alternatively, they may be fixed by joining them with adhesive.

The impact energy absorbing member of the present invention includes automobiles generically referred to as automobiles, trucks, trailers, passenger cars, sports cars, racing cars, three-wheeled vehicles, aircrafts, motorcycles, trains, cargoes, ships, etc. Suitable for a wide range of applications such as general transportation equipment.

Among these, one of the preferable uses is an automobile door.

By referring to the impact beam, the impact energy absorbing member made of the endless belt type FRP of the present invention is attached to the place where the metallic iron pipe is attached inside the door to absorb the impact energy due to the side collision. This makes it possible to protect personnel and reduce the weight of the door. More specifically, the closed loop-shaped carbon fiber reinforced rubber material has a thickness of 3 mm and a length of 1000.
A belt material (FIG. 2) having a width of about 30 mm and a width of about 30 mm is fixed to the door frame. At this time, it is preferable that the frame has higher strength than the conventional one. Pretensioning may be applied and fixed to reduce the amount of colliding objects entering the room.

Further, not only the door, but also a bulkhead for separating the engine room from the cabin, a member for protecting the fuel container, and the like are preferable.

Next, a method of manufacturing the belt-shaped impact energy absorbing member of the present invention will be described. In order to manufacture the impact energy absorbing member of the present invention, any technique such as a filament winding method, a pull winding method, a hand-up method, a resin transmolding method or the like can be used. Among them, the filament winding method is a preferable molding method. FIG. 4 shows the manufacturing method of the present invention by the filament winding method. When manufacturing the impact energy absorbing member of the present invention, a reinforcing fiber or a reinforcing fiber 6 impregnated with a matrix resin is wound around a mandrel 3 having a cross section corresponding to a desired loop shape, and then the matrix resin is entirely or partially covered. The matrix resin is impregnated or additionally impregnated, and then the matrix resin is cured on the mandrel or after being removed from the mandrel to obtain the tubular member 4. Furthermore, the present tubular material 4 is sliced into required widths 5 and the impact energy absorbing member 1 of the present invention is cut.
Can be obtained. In the filament winding method, since the reinforcing fibers are continuous over the entire circumference of the loop, the tensile energy is extremely high and uniform, and the most preferable impact energy absorbing member can be obtained.

[0039]

EXAMPLES Examples 1 and 2 Carbon fibers (elastic modulus 235 GPa, strength 4900 MPa,
Elongation of 2.1%) Polyisoprene (Kuraray Co., Ltd .: LIR-30), sulfur, zinc oxide, stearic acid, mercaptobenzothiazole, styrene-based thermoplastic elastomer (Shell Chemical Co., Ltd .: Kraton) G16
50) respectively in weight ratios of 100, 15, 5, 1,
After the liquid rubber resin obtained by kneading at 1 and 5 was impregnated on the rotating roller, the mandrel (peripheral length 1700 mm) on the filament winder was operated at a speed of 10 cm / min and a width of 5 cm.
It was wound to 0 mm and a thickness of 1 mm (Example 1) and 2.2 mm (Example 2). Then 16 in the oven
After cross-linking at 0 ° C. for 60 minutes, the cross-section was removed from the mandrel to obtain a CFRP loop member (volume content of carbon fiber was 62%).

The elongation of the resin measured by the method of JIS K6251 at room temperature was 110%.

As shown in FIG. 3, the present loop-shaped member was mounted on a pendulum impact tester through two pins with a total length of 800 mm and subjected to an impact test. The member was divided / scattered almost entirely and tensile fracture occurred. I was able to confirm that I did. The energy absorption value per unit weight at this time is 2 for 1.0 mm thickness.
1.2 J / g, thickness 2.2 mm was 17.5 J / g

[0042]

[Table 1]

Comparative Examples 1 and 2 Silica particles (20 μm in particle size) were added (5% by weight) to the resins of Examples 1 and 2 for the purpose of improving heat resistance, and the elongation of the resin was set to 40%. A member having the same resin composition as in Examples 1 and 2 and having a thickness of 1.0 mm and 2.2 m was prepared and subjected to an impact test. A member with a thickness of 1.0 mm partially bends and breaks, absorbing 5.0 J / g of energy, and having a thickness of 2.2.
Bending fracture of 3.0 mm member, energy absorption is 3.0 J /
It was g (Table 1). Examples 3 and 8 Carbon fiber (elastic modulus 235 GPa, strength 4900 MPa,
Elongation 2.1%), NBR rubber (bonded nitrile content 34% by weight), sulfur, zinc oxide, stearic acid, mercaptobenzothiazole, styrene thermoplastic elastomer (Shell Chemical Co., Ltd .: Kraton G165).
0) to the weight ratios 100, 14, 5, 1, 1,
After the liquid rubber resin obtained by kneading in No. 5 was impregnated on the rotating roller, the mandrel (peripheral length 1700 mm) on the filament winder was operated at a speed of 10 cm / min and a width of 50 m.
m, and the thickness was 2.2 mm (Example 3) and 5.0 mm (Example 8). Then 15 in the oven
After cross-linking at 0 ° C. for 30 minutes, it was removed from the mandrel to obtain a CFRP loop member (volume content of carbon fiber was 60%).

The elongation of the resin measured by the method of JIS K7113 at room temperature was 230%.
Then, when the above-mentioned loop-shaped member was subjected to an impact test in the same manner as in Example 1, it was confirmed that a member having a thickness of 2.2 mm was divided / scattered almost entirely, and tensile fracture occurred.
It was confirmed that the member of m was also partially bent and broken. There is no scattering of reinforcing fibers in both members, and the energy absorption value per unit weight is 20.2 J / for a thickness of 2.2 mm.
g, thickness 5.0 mm was 17.0 J / g (Table 1). Examples 4, 5, 6, 7 Carbon fiber (elastic modulus 235 GPa, strength 4900 MPa,
Elongation 2.1%), NBR rubber (bound nitrile content 28% by weight), sulfur, zinc oxide, stearic acid, mercaptobenzothiazole, styrene thermoplastic elastomer (Shell Chemical Co., Ltd .: Kraton G165).
0) to the weight ratios 100, 14, 5, 1, 1,
After the liquid rubber resin obtained by kneading in No. 5 was impregnated on the rotating roller, the mandrel (peripheral length 1700 mm) on the filament winder was operated at a speed of 10 cm / min and a width of 50 m.
m, thickness 2.2 mm (Example 4), thickness 3.0 mm (Example 5), thickness 5.0 mm (Example 6), thickness 8.0 m
It was wound until it became m (Example 7). Then, after cross-linking in an oven at 150 ° C. for 30 minutes, the cross-section was removed from the mandrel to obtain a CFRP loop member (having a carbon fiber volume content of 60%).

The elongation of the resin measured by the method of JIS K7113 at room temperature was 320%.

Then, the above-mentioned loop-shaped member was subjected to an impact test in the same manner as in Example 1, and the thickness was 2.2 mm and 3.0 m.
It was confirmed that the members of m and 5.0 mm were divided / scattered almost entirely and tensile fractured, and that the member of 8.0 mm thickness was also partially bent and fractured. There is no scattering of reinforcing fibers, and the energy absorption value per unit weight is shown in Table 1.
It was as follows. Examples 9 and 10 In Examples 4 and 6, the reinforcing fibers were carbon fibers (elastic modulus 2).
35 GPa, strength 3000 MPa, elongation 1.5%), thickness 2.2 mm obtained in the same manner as in Examples 4 and 6.
When an impact test was conducted on the loop member of Example 9 and the thickness of 5.0 mm (Example 10), the results shown in Table 1 were obtained. Comparative Examples 3, 4 and 5 Examples except that silica particles (particle size: 20 μm) were added (5% by weight) to the resin of Example 3 for the purpose of improving heat resistance and the elongation of the resin was 70%. The same resin composition as in No. 3 and a thickness of 1.0 mm (Comparative Example 3), 2.2 m (Comparative Example 4),
A member of 5.0 mm (Comparative Example 5) was prepared and subjected to an impact test. A member with a thickness of 1.0 mm partially bends and has energy absorption of 7.2 J / g, and a member with a thickness of 2.2 mm has bending fracture and energy absorption of 3.1 J / g, and a thickness of 5 J Bending fracture of as much as 0.0 mm and energy absorption of 2.9 J / g
Was (Table 1). Comparative Example 6 A member was manufactured and tested in the same manner as in Example 1 except that the resin was an epoxy resin having an elongation of 9%.
The energy absorption value per unit weight was 5.0 J / g (Table 1).

[0047]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a shock energy absorbing member which has not been hitherto excellent and which is easy to break in a tensile mode, has excellent impact energy absorbing characteristics while being lightweight, and thus has excellent impact resistance. A transportation device member can be obtained.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing an embodiment of an impact energy absorbing member of the present invention.

FIG. 3 is a perspective view of a pendulum impact test including a method of mounting an impact energy absorbing member in an example.

FIG. 4 is a schematic view showing one embodiment of the manufacturing method of the present invention.

[Explanation of symbols]

1 Impact energy absorbing member 2 pins (fixing jig) 3 Mandrel 4 tubular material 5 Round width of impact energy absorbing member 6 Reinforcing fibers or reinforcing fibers impregnated with matrix resin L total length t thickness B width

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3J059 AB11 BA41 GA01                 3J066 AA02 AA23 BA01 BB01 BB04                       BC03 BD05                 4F072 AB05 AB06 AB08 AB09 AB10                       AD02 AD04 AD05 AD23 AD37                       AD38 AD41 AD42 AD46 AH31                       AJ04 AL16 AL17

Claims (10)

[Claims] 1. An endless belt-like impact energy absorbing member made of fiber reinforced resin, which is obtained by impregnating a reinforcing fiber bundle with a matrix resin, wherein the matrix resin has an elongation of 1.
An impact energy absorbing member, which is a resin of 00% or more and 500% or less. 2. The ratio t / L between the thickness t (mm) and the total length L (mm) of the belt-shaped member is 1/1000 to 1/80.
The impact energy absorbing member according to claim 1, characterized in that 3. The matrix resin is at least selected from the group consisting of isoprene rubber, chloroprene rubber, butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber, styrene-butadiene rubber, silicone rubber, sulfide rubber, and fluororubber. The impact energy absorbing member according to claim 1 or 2, comprising a kind of rubber component. 4. The impact according to claim 3, wherein the content of the rubber component in the matrix resin is in the range of 50 to 100% by weight based on 100% by weight of the total matrix resin. Energy absorbing member. 5. The matrix resin contains at least one thermosetting resin component selected from the group consisting of epoxy, vinyl ester, unsaturated polyester, phenol, and benzoxazine.
The impact energy absorbing member according to any one of 1 to 4. 6. The impact energy absorption according to claim 5, wherein the content of the thermosetting resin component is in the range of 2 to 20% by weight with respect to 100% by weight of the total matrix resin. Element. 7. The matrix resin is polyethylene glycol, acrylic, polyethylene, polypropylene,
The impact energy absorbing member according to claim 3, comprising at least one thermoplastic resin selected from the group consisting of polyamide, ABS, potybutylene terephthalate, polyacetal, and polycarbonate. 8. The impact energy absorbing member according to claim 7, wherein the content of the thermoplastic resin component is in the range of 2 to 20% by weight with respect to 100% by weight of the total matrix resin. . 9. The impact energy absorbing member according to claim 1, wherein the reinforcing fiber bundle contains at least carbon fiber. 10. An impact beam for transportation equipment, which uses the impact energy absorbing member according to any one of claims 1 to 9.