JPH11216789A - Frp structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and inexpensively manufacture a fiber-reinforced plastic structure by cutting out a recess engaged with a part extended parallel to a fiber-reinforced plastic plate of a reinforcing member at least at one surface of an end of a core material, and integrally forming the plastic plate and the member, the core material with resin. SOLUTION: A core material 22 is disposed in a mold 21. And, reinforcing fiber base materials 23 are disposed on at least both surfaces. And, cutout recesses 26 are formed on bot sides of the material 22, and a reinforcing fiber base material 27 for forming a reinforcing member for a U-shaped sectional rib is disposed in the recess 26. An upper surface side of the material 23 is evacuated therein in a vacuum state by sucking by a vacuum pump 30. Then, a valve 31 is opened, and a liquid-like resin 32 is cast in a mold 21 held in vacuum. The cast resin is gradually impregnated in a thickness direction of the material 23. At this time, the rib and a cap are integrally molded simultaneously, Thus, a fiber-reinforced plastic(FRP) structure can be easily and inexpensively manufactured by a one-shot molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FRP structure and a method of manufacturing the same, and more particularly, to an optimum design technique of a core material and its peripheral portion of a lightweight and high-strength FRP structure using a core material, and the FRP. The present invention relates to a method for efficiently and inexpensively manufacturing a structure.

[0002]

2. Description of the Related Art As a lightweight and high-strength material, FRP (fiber reinforced plastic) has attracted attention in various industrial fields.
Attention has been paid to its excellent mechanical properties and the like.

When this FRP is formed into a relatively large member, a combined structure of an FRP skin material and a lightweight core material, particularly a sandwich structure in which FRP skin plates are arranged on both surfaces of the core material is adopted. There is. With such a configuration, an FRP structure that is large, lightweight, and has the necessary strength and rigidity can be obtained. It is also known that it is effective to arrange a reinforcing member such as a rib or a cap member at an appropriate position for further reinforcement.

[0004]

However, a relatively large FRP structure is often formed by a hand lay-up method or the like, and is not easy to manufacture.
There was a problem that the cost was relatively high.

[0005] The present inventors have now established a molding technique capable of easily and inexpensively producing a relatively large FRP structure.

An object of the present invention is to provide a lightweight, high-strength, high-rigidity FRP structure which can be easily and inexpensively manufactured with respect to the prior art, and a method of manufacturing the same. And to provide an optimum structure for the periphery thereof.

[0007]

In order to solve the above-mentioned problems, an FRP structure according to the present invention comprises a core material, an FRP plate disposed on at least one surface of the core material, and at least one end of the core material. A FRP structure comprising a FRP reinforcing member having a portion extending substantially parallel to the FRP plate and a portion extending perpendicularly to the FRP plate, wherein at least one surface of one end of the core material includes: FRP of the reinforcing member
A concave portion into which a portion extending substantially parallel to the plate is fitted is cut out, and the FRP plate, the FRP reinforcing member, and the core material are integrated with a resin. Consisting of

In the above-mentioned FRP structure, a structure in which the FRP plate is disposed only on one side of the core material can be adopted. However, it is preferable that the FRP plate has a sandwich structure in which the FRP plate is disposed on both surfaces of the core material, It is desirable that the member has a structure extending between the two FRP plates. Due to such a sandwich structure, FR
The strength, rigidity and surface durability of the FRP plate can be ensured by the FRP plates arranged on both sides while ensuring the lightness of the entire P structure.
Rigidity can be secured.

Further, the method of manufacturing an FRP structure according to the present invention is characterized in that a core material having a cutout recess on at least one surface of one end thereof in a mold, and a surface direction of the core material on at least one surface of the core material. Forming a reinforcing member having a reinforcing fiber substrate extending substantially parallel to the reinforcing fiber substrate and a portion extending perpendicularly to the reinforcing fiber substrate, wherein the parallel extending portion is located in the notch recess. And a medium for diffusing the resin in the surface direction above or below these, or forming a resin diffusion path in the core material for diffusing the resin in the surface direction. After covering the whole with the bag film, the inside covered with the bag film is evacuated, resin is injected and diffused at least on the surface of the reinforcing fiber substrate, and the resin is impregnated into the reinforcing fiber substrate. One shot It comprises a method which is characterized in that. In this method, the injected resin is continuously diffused on the surface of the reinforcing fiber base, and the resin is sequentially impregnated in the thickness direction of the reinforcing fiber base. Of course, there may be a portion where the diffusion of the resin in the surface direction along the surface of the reinforcing fiber base and the impregnation in the thickness direction of the reinforcing fiber base are performed substantially simultaneously.

By this one-shot molding, a relatively large-sized FRP structure with a built-in reinforcing member can be easily, efficiently, and inexpensively manufactured while securing the characteristics of light weight, high strength, and high rigidity.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

An FRP structure according to the present invention comprises: a core material;
An FRP plate disposed on at least one side of the core material, and a portion disposed on at least one end of the core material and extending substantially parallel to and perpendicular to the FRP plate (that is, L-shaped or And a reinforcing member made of FRP (having a cross section such as a letter shape, a T shape, and an I shape). The FRP plate and the reinforcing member are a composite material containing a reinforcing fiber and a matrix resin. As the reinforcing fibers of these FRP materials, it is preferable to use carbon fiber fabrics, mats, and strands, or glass fiber fabrics, mats, and rovings alone or in combination. Particularly, in order to maximize the effect of weight reduction, it is preferable to use carbon fiber. And the carbon fiber also has a number of filaments of one carbon fiber yarn of less than the ordinary 10,000 filaments,
000 to 300,000, more preferably 5
The use of tow-like carbon fiber filament yarns in the range of 0000 to 150,000 yarns has better resin impregnation,
It is preferable because it is more excellent in handleability as a reinforcing fiber base material and further in economic efficiency of the reinforcing fiber base material. Also F
Placing a carbon fiber woven fabric on the surface of the RP structure enhances the design of the surface, which is more preferable. In addition, a reinforcing fiber base is formed by laminating a plurality of layers of reinforcing fibers as necessary or in accordance with required mechanical properties or the like, and the reinforcing fiber base is impregnated with a resin. On the reinforcing fiber layer to be laminated, a fiber layer or a fabric layer aligned in one direction can be appropriately laminated, and the fiber orientation direction can be appropriately selected according to the direction of required strength.

As the FRP resin, thermosetting resins such as epoxy, unsaturated polyester, phenol, and vinyl ester are preferable in view of moldability and cost. However,
A thermoplastic resin such as nylon or ABS resin, or a mixed resin of a thermosetting resin and a thermoplastic resin can also be used.

As the core material, a foam or wood can be used, and a foam is preferable from the viewpoint of weight reduction. As the material of the foam, polyurethane, polystyrene, polyethylene, polypropylene, PVC, silicon, or the like is used, and its specific gravity is preferably selected from 0.02 to 0.2.
If the specific gravity is less than 0.02, sufficient strength may not be obtained. On the other hand, when the specific gravity exceeds 0.2, the strength is increased, but the weight is increased, which is contrary to the purpose of reducing the weight. Also, a honeycomb material can be used as the core material. Examples of the material of the honeycomb material include an aluminum honeycomb and an aramid honeycomb, and the material and dimensions thereof can be selected according to the required strength and the like.

FIG. 1 shows a typical structural example of an FRP structure according to the present invention. The FRP structure 1 includes a core material 2, FRP plates 3 a and 3 b disposed on at least one surface (both surfaces in the present embodiment) of the core material 2, and at least one end portion (both ends in the present embodiment) of each core material 2. ), And FRP reinforcing members 4a and 4b having a U-shaped cross section. F
The reinforcing member 4a disposed at the center of the RP structure 1 functions as a reinforcing rib, and the reinforcing member 4b disposed at an end.
Functions as a cap member. These reinforcing members 4
The cross-sectional shapes of a and 4b may be L-shape, T-shape, I-shape, etc. other than the U-shape. Any shape having a portion extending substantially parallel to the FRP plate 3a or 3b and a portion extending perpendicularly may be used. A portion extending substantially parallel to the FRP plate, that is, a flange portion having a U-shaped cross section in the example of FIG. 1 is fitted to a cutout concave portion 2 a formed on at least one surface of an end portion of the core material 2. I have. It is preferable that the depth of the cutout recess 2a is substantially equal to the thickness of the reinforcing member portion fitted therein, so that the flatness of the FRP plate disposed thereon is ensured.

The cutout recess of the core material 2 is, for example, as shown in FIG.
It is formed as shown in FIG. In FIG. 2, (a)
Is a core material 11 made of, for example, a foam, and is formed, for example, in a rectangular shape. At least one end of the material 11 is cut out in a concave portion as shown in FIGS. In the example shown in FIG. 2B, the core member 13 is provided with cutout recesses 12a and 12b on both sides so that a reinforcing member having a U-shaped cross section as shown in FIG. In the example shown in (c), the core member 15 has the cutout recess 14 provided on only one side.

The above-described FRP structure can be formed by a one-shot molding method using a vacuum bag method. This one-shot molding is performed, for example, as shown in FIG. FIG. 3 illustrates molding of an FRP structure having a sandwich structure.

In the method shown in FIG.
A core material 22 made of a foam or the like is disposed, and a reinforcing fiber base material 23 is disposed on at least both surfaces thereof. The core member 22 has a plurality of divided structures in the present embodiment, and the plurality of core members 22 are arranged vertically and horizontally as viewed in plan.
The ends of the rows of the arranged core materials 22 may be arranged so that the reinforcing fiber base material 23 wraps the core material 22 or, as shown in FIG. 3, a U-shaped cap-shaped reinforcing fiber base. Material 28 may be arranged.

Each core member 22 is configured as shown in FIG. 4, for example, and has a large groove 24 serving as a path for the resin and a large number of small grooves 25 branched from the large groove 24. The resin is applied to the reinforcing fiber base material 2 through the large grooves 24 and the small grooves 25.
3 is diffused in the surface direction, and the diffused resin is impregnated into the base material 23 in the thickness direction of the reinforcing fiber base material 23. In this embodiment, the core member 22 itself is provided with a diffusion path for diffusing the resin in the direction of the substrate surface by the groove portion. However, separately from this structure or together with this structure, a separate member is formed. Alternatively, a sheet-like medium that diffuses the resin in the surface direction of the reinforcing fiber base may be provided. This medium can be arranged on the upper surface side of the reinforcing fiber base material 23 or on both upper and lower surfaces. Although the structure of the medium is not particularly limited, the medium can be composed of a sheet-like member having a groove structure similar to that shown in FIG. 4, a sheet-like member having vertical and horizontal grooves, or a net-like member.

In the embodiment shown in FIG. 4, cutout recesses 26 are formed on both sides (or four sides) of the core material 22, and the cutout recesses 26 have a U-shaped cross section as shown in FIG. The reinforcing fiber base material 27 for forming the rib-shaped reinforcing member is disposed. At the center of the panel, the U-shaped reinforcing fiber bases 27 forming the ribs abut against each other, and at the end of the arranged core material 22, a U-shaped cap reinforcing fiber base 28 is disposed. These are covered with a reinforcing fiber base material 23 disposed on both sides together with the core material 22. However, when the end portions of the arranged core members 22 are to be covered with the reinforcing fiber base material 23, the U-shaped cap-shaped reinforcing fiber base material 28 at the end portions is used.
Need not necessarily be provided.

The upper surface of the mold of the reinforcing fiber base 23 is covered with a bag film 29, and the inside is evacuated by suction by a vacuum pump 30. Next, the valve 31
Is opened, and the liquid resin 32 is injected into the mold 21 maintained in the vacuum state. The injection is performed through an edge breather 33 made of a porous material or the like, and the suction to the pump 30 is also performed through a similar edge breather 34. The resin injection position, the vacuum suction position, and the installation positions of the edge breathers 33 and 34 can be appropriately changed. For example, the resin may be injected from the center of the FRP structure.
In the present embodiment, the upper surface of the reinforcing fiber base 23 is directly covered with the bag film 29. However, if necessary, a release material (not shown) that is peeled off after molding is interposed therebetween. Is also good. In the above embodiment, the bag film 29 itself has the function of a release material. The release material provided as necessary is preferably a release material (for example, a nylon taffeta woven sheet or the like) that can pass through the resin but can be peeled off after being cured and removed from the FRP structure. Furthermore, the bag film 29 and the reinforcing fiber base material 2
A rigid plate such as an iron plate may be arranged between the third mold and the upper surface side.

The injected resin is, as described above, the core material 2
While being rapidly diffused in the surface direction of the reinforcing fiber base material 23 along the second large groove 24 and the small groove 25, it is gradually impregnated in the thickness direction of the reinforcing fiber base material 23. At the same time, the resin is also impregnated into the U-shaped reinforcing fiber base materials 27 and 28 forming the ribs and the cap, and the ribs and the cap are integrally formed.
The impregnated resin is cured at room temperature and possibly by heating to complete the FRP structure. After curing, the bag film 29 is removed, and the cured FRP structure is removed from the mold 21. Thus, the FRP structure is formed by one shot. In the above-described molding, the grooves provided in the core material serve as paths for the resin during molding. The relationship between the groove and the cutout recess provided in the core material described above can take various forms.

For example, as shown in FIG. 5 (a), if a plurality of grooves 42 are arranged in the core material 41 and the grooves 42 are formed so as to communicate with the cutout recesses 43 provided at the ends. At the time of molding, the resin can be smoothly guided to the notch concave portion 43, and the resin can be easily diffused into the reinforcing member forming base material arranged at this portion. Also, as shown in FIG.
The core material 51 in which the groove 52 extends to the bottom of the notch recess 53
In this case, the resin can be more favorably diffused, and the extended portion is formed into only the resin or a resin-rich portion, so that the extended portion also serves as a void escape area.
It can also contribute to a reduction in the void ratio of the RP molded part.

The core material 4 shown in FIGS.
The structures in which the FRP reinforcing members 61 and 62 or the reinforcing fiber base material for forming the reinforcing members are disposed on the components 1 and 51 are as shown in FIGS. 6A and 6B, respectively.

Further, as shown in FIG. 5C, a groove 72 extending in a direction parallel to the extending direction of the cutout concave portion 73 can be formed in the core material 71.
A groove 74 parallel to the groove 72 may be formed on the surface of one other portion. The groove 72 mainly contributes to the diffusion of the resin to the reinforcing member portion, and the groove 74 contributes to the resin diffusion to the reinforcing fiber base material for forming the FRP plate.

As shown in FIG. 7, the grooves formed in the core material described above have their pitch p, depth h, and width w determined by the molding conditions (temperature, pressure, etc.) and the viscosity of the resin used. It can be set appropriately as needed. For example, (a) 200 ≧ w × h ≧ 1 (mm ² ), (b) 300 ≧
p ≧ 5 (mm) More preferably, (a) 100 ≧ w × h ≧ 5 (mm ² ), (b) 100 ≧
p ≧ 20 (mm) is set. If w × h is too small, the molding speed becomes slow. Conversely, if it is too large, the amount of resin increases and the weight of the molded body increases. If p is too narrow, the amount of resin increases and the weight of the molded body increases. Conversely, if it is too wide, the molding speed is slow, impregnation is poor, and stable molding becomes difficult.

As described above, the optimum core material having the cutout concave portion and the groove is designed, thereby facilitating one-shot molding of the entire FRP structure including the reinforcing member.

[0028]

As described above, according to the FRP structure of the present invention and the method of manufacturing the same, particularly by optimizing the structure of the core material, a light-weight, high-strength, high-rigidity relatively large FRP structure is obtained. Can be easily and inexpensively manufactured by one-shot molding.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an FRP structure according to one embodiment of the present invention.

FIG. 2 is a partial perspective view showing an example of forming a cutout concave portion of a core material according to the present invention.

FIG. 3 is a schematic configuration diagram showing an example of a one-shot molding method according to the present invention.

FIG. 4 is an enlarged perspective view of a core material used in the method of FIG.

FIG. 5 is a partial perspective view showing an example of forming a groove in a core material.

6 is an end sectional view of a core material corresponding to FIGS. 5A and 5B. FIG.

FIG. 7 is a sectional view of a groove of a core material.

[Explanation of symbols]

1 FRP structure 2, 13, 15, 22, 41, 51, 71 Core material 3a, 3b FRP plate 4a, 4b, 61, 62 Reinforcement member 11 Core material 12a, 12b, 14, 26, 43, 53, 73 Notch concave portion 21 Type 23 Reinforcement fiber base material 24, 25, 42, 52, 72, 74 Groove 27, 28 U-shaped reinforcement fiber base material 29 Bag film 30 Vacuum pump 31 Valve 32 Resin 33, 34 Edge breather

Claims (18)

[Claims] 1. A core material, an FRP plate disposed on at least one side of the core material, and a portion disposed on at least one end of the core material and extending perpendicular to a portion extending substantially parallel to the FRP plate. A reinforcing member made of FRP having: a portion extending substantially parallel to an FRP plate of the reinforcing member is fitted to at least one surface of one end of the core material. An FRP structure, wherein a concave portion is cut out, and the FRP plate, the FRP reinforcing member, and the core material are integrated with a resin. 2. A sandwich structure in which the FRP plates are arranged on both surfaces of the core material, and the reinforcing member is made of a pair of FRs.
The FRP structure of claim 1, wherein the FRP structure extends between the P plates. 3. The FRP structure according to claim 1, wherein the cutout recesses are provided on both surfaces of the core material. 4. The FRP structure according to claim 1, wherein the core material has a groove that serves as a path for the resin during molding. 5. The FRP structure according to claim 4, wherein the groove is formed in a large groove and a small groove branched from the large groove. 6. The FRP structure according to claim 4, wherein the groove communicates with the notch recess. 7. The FRP structure according to claim 6, wherein a groove communicating with the notch recess extends to a bottom surface of the notch recess. 8. The FRP structure according to claim 4, wherein a groove is provided on a bottom surface of the notch recess and a surface of the other core material. 9. The FRP structure according to claim 4, wherein a plurality of the grooves are arranged in parallel. 10. When the depth of the groove is h, the width of the groove is w, and the pitch of the grooves is p, (a) 200 ≧ w × h ≧ 1 (mm ² ), (b) 300 ≧
The FRP structure according to claim 9, wherein a relationship of p≥5 (mm) is satisfied. 11. The FRP structure according to claim 1, wherein the depth of the notch recess is substantially equal to the thickness of a reinforcing member portion fitted into the notch recess. 12. The FRP structure according to claim 1, wherein the core material is made of a foam. 13. The reinforcing fiber of the FRP structure, wherein the number of filaments per yarn is 10,000 to 300,0.
The FRP structure according to any one of claims 1 to 12, wherein carbon fibers in a range of 00 fibers are used. 14. A core material having a cutout recess provided on at least one surface of one end portion in a mold, a reinforcing fiber base material extending on at least one surface of the core material in a surface direction of the core material, and a reinforcing fiber base. A portion extending substantially parallel to the material and a portion extending perpendicularly to the material, and the parallel extending portion arranges the reinforcing member forming base material located in the cutout recess, and Or, arrange a medium for vertically diffusing the resin in the surface direction or form a resin diffusion path for diffusing the resin in the surface direction in the core material,
After the whole is covered with the bag film, the inside covered with the bag film is evacuated, a resin is injected and diffused at least on the surface of the reinforcing fiber base material, and the resin is impregnated into the reinforcing fiber base material. A method for producing an FRP structure, comprising forming by extrusion. 15. The method for producing an FRP structure according to claim 14, wherein said base material for forming a reinforcing member is also made of a reinforcing fiber base material. 16. The method for producing an FRP structure according to claim 14, wherein said base material for forming a reinforcing member comprises a preformed FRP base material. 17. The FR according to claim 14, wherein a reinforcing fiber base is disposed on both surfaces of the core material, and a reinforcing member forming base is disposed between both FRP plates.
A method for manufacturing a P structure. 18. A resin diffusion path of the core material is communicated with the notch recess, and the injected resin is guided into the notch recess to integrally form the reinforcing member forming base material.
A method for producing an FRP structure according to any one of claims 14 to 17.