COMPOSITE MATERIAL, METHOD FOR MANUFACTURING COMPOSITE MATERIAL, AND METHOD FOR CURING COMPOSITE MATERIAL

Abstract

The present invention addresses the problem of providing a composite material that can prevent a strength reduction when fibers of a skin material are bent during curing of the composite material. In a composite material, a filler is arranged between a honeycomb core and a first skin material and/or between the honeycomb core and a second skin material so as to overlap the tip of an end of the honeycomb core. In a horizontal view, the filler arranged between the honeycomb core and the second skin material protrudes outside the composite material by a length equal to or less than a length of a portion thereof overlapping the tip of the end of the honeycomb core.

Claims

1. A composite material comprising: a honeycomb core; a first skin material disposed on one surface of the honeycomb core to be bonded to the honeycomb core; a second skin material disposed on an opposite surface of the honeycomb core from the one surface to be bonded to the honeycomb core; a lightning protection mesh disposed on an opposite surface of the second skin material from a surface of the second skin material, the surface being bonded to the honeycomb core; and a resin material disposed on an opposite surface of the lightning protection mesh from a second skin material side, wherein a filler is disposed between the honeycomb core and the first skin material, between the honeycomb core and the second skin material, or in both locations so as to overlap a tip of an end portion of the honeycomb core.

2. The composite material according to claim 1, wherein in a horizontal view, the filler disposed between the honeycomb core and the second skin material protrudes outside the composite material by a length equal to or less than a length of a portion of the filler, the portion overlapping the tip of the end portion of the honeycomb core.

3. The composite material according to claim 1, wherein a first film adhesive bonding the first skin material to the honeycomb core is disposed between the first skin material and the honeycomb core, and a second film adhesive bonding the second skin material to the honeycomb core is disposed between the second skin material and the honeycomb core.

4. The composite material according to claim 1, wherein the end portion of the honeycomb core is chamfered so as to be inclined toward the second skin material side.

5. A method for producing a composite material, the method comprising: a preparation step of preparing a composite material including a honeycomb core, a first skin material disposed on one surface of the honeycomb core to be bonded to the honeycomb core, a second skin material disposed on an opposite surface of the honeycomb core from the one surface to be bonded to the honeycomb core, a lightning protection mesh disposed on an opposite surface of the second skin material from a surface of the second skin material, the surface being bonded to the honeycomb core, and a resin material disposed on an opposite surface of the lightning protection mesh from a second skin material side; and an alignment step of disposing a filler between the honeycomb core and the first skin material, between the honeycomb core and the second skin material, or in both locations so as for the filler to overlap a tip of an end portion of the honeycomb core.

6. The method for producing a composite material according to claim 5, wherein in the alignment step, in a horizontal view, the filler is disposed between the honeycomb core and the second skin material so as to protrude outside the composite material by a length equal to or less than a length of a portion of the filler, the portion overlapping the tip of the end portion of the honeycomb core.

7. The method for producing a composite material according to claim 5, wherein in the preparation step, the composite material in which a first film adhesive bonding the first skin material to the honeycomb core is disposed between the first skin material and the honeycomb core and a second film adhesive bonding the second skin material to the honeycomb core is disposed between the second skin material and the honeycomb core is prepared.

8. The method for producing a composite material according to claim 5, wherein in the preparation step, the composite material in which the end portion of the honeycomb core is chamfered so as to be inclined toward the second skin material side is prepared.

9. A method for curing a composite material, the method comprising: collectively curing the composite material according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is a longitudinal cross-sectional view illustrating the state of the vicinity of a tip of an end portion of a honeycomb core when a composite material according to a first embodiment of the invention is cured.

[0034] FIG. 2 is a longitudinal cross-sectional view illustrating the state of the vicinity of a tip of an end portion of a honeycomb core when a composite material according to a second embodiment of the invention is cured.

[0035] FIG. 3 is a longitudinal cross-sectional view illustrating the state of the vicinity of a tip of an end portion of a honeycomb core when a composite material according to a third embodiment of the invention is cured.

[0036] FIG. 4 is a perspective view for describing a configuration of the composite material according to the first embodiment of the invention.

[0037] FIGS. 5(a), 5(b) and 5(c) are schematic views for describing one example of a method for producing a composite honeycomb sandwich panel in the related art, in which step of FIG. 5(a) illustrates a state where prepregs for forming skin materials are prepared, step of FIG. 5(b) is a view illustrating a state where the laminated prepregs are cured, and step of FIG. 5(c) is a view illustrating a state where a composite material is cured.

[0038] FIGS. 6(a) and 6(b) are schematic views for describing another example of a method for producing a composite honeycomb sandwich panel in the related art, in which the step of FIG. 6(a) is a view illustrating a state where a composite material is prepared and the step of FIG. 6(b) is a view illustrating a state where the composite material in the step of FIG. 6(a) is cured.

[0039] FIG. 7 is a longitudinal cross-sectional view illustrating the state of the vicinity of a tip of an end portion of a honeycomb core when the composite material in FIG. 6(b) is cured.

DESCRIPTION OF EMBODIMENTS

[0040] Hereinafter, embodiments of a composite material and a method for producing a composite material according to the invention will be described with reference to the drawings.

Composite Material

First Embodiment

[0041] Hereinafter, a composite material according to a first embodiment of the invention will be described with reference to FIGS. 1 and 4.

[0042] FIG. 4 is a perspective view for describing a configuration of the composite material according to the present embodiment.

[0043] As illustrated in FIG. 4, a composite material 1 according to the present embodiment includes a honeycomb core 2, a first film adhesive 3, a first skin material 4, a second film adhesive 5, a second skin material 6, a lightning protection mesh 7, and a resin material 8. Specifically, the first film adhesive 3 is disposed on one surface (upper surface) of the honeycomb core 2, and the first skin material 4 is bonded to the honeycomb core 2 via the first film adhesive 3. Meanwhile, the second film adhesive 5 is disposed on an opposite surface (lower surface) of the honeycomb core 2 from the one surface, and the second skin material 6 is bonded to the honeycomb core 2 via the second film adhesive 5. Then, the lightning protection mesh 7 is disposed on an opposite surface of the second skin material 6 from a surface of the second skin material 6, the surface being bonded to the honeycomb core 2, and the resin material 8 is disposed on an opposite surface of the lightning protection mesh 7 from a second skin material 6 side. Examples of the resin material 8 include a film adhesive and a surface conditioner.

[0044] An end portion of the honeycomb core 2 is, as will be described later, chamfered so as to be inclined toward the second skin material 6 side. The first skin material 4 and the second skin material 6 are, for example, a plurality of laminated uncured prepregs.

[0045] Next, the configuration of the vicinity of a tip of the end portion of the honeycomb core 2 in the composite material 1 according to the present embodiment will be specifically described with reference to FIG. 1. FIG. 1 is a longitudinal cross-sectional view illustrating the state of the vicinity of the tip of the end portion of the honeycomb core 2 when the composite material 1 according to the present embodiment is cured. As illustrated in FIG. 1, the end portion of the honeycomb core 2 is chamfered so as to be inclined, for example, at 30 toward the second skin material 6 side. Then, a filler 9 is disposed between the second film adhesive 5 and the second skin material 6 so as to overlap the tip of the chamfered end portion of the honeycomb core 2. Specifically, in a horizontal view, the filler 9 disposed between the second film adhesive 5 and the second skin material 6 protrudes outside the composite material 1 (particularly, the tip of the end portion of the honeycomb core 2) by a length equal to or less than the length of a portion of the filler 9, the portion overlapping the tip of the end portion of the honeycomb core 2.

[0046] The material of the filler 9 is not particularly limited, and composite materials (for example, carbon fiber reinforced plastics (CFRP), glass fiber reinforced plastics (GFRP), and the like), film adhesives, resin materials, and the like can be provided as examples of the material. The curing state of the filler 9 may be a cured state or an uncured state. The number of laminated layers (ply number) of the filler 9 is determined according to the height of an adhesive accumulation that is expected to occur, and when the thickness of the filler 9 is 0.3 mm/ply or less, approximately one to three plies are desirable. When a plurality of the fillers 9 are applied in a laminated manner, the lengths of the plies may be the same or different.

[0047] According to the present embodiment with the above-described configuration, the following effects are obtained.

[0048] In the composite material 1 of the present embodiment, the filler 9 is disposed between the honeycomb core 2 and the second skin material 6 so as to overlap the tip of the end portion of the honeycomb core 2. As in the present embodiment, when the filler 9 is disposed between the honeycomb core 2 and the second skin material 6 (in a portion below the end portion of the honeycomb core 2), the rigidity of the filler 9 provides the effect of suppressing the adhesive accumulation; and thereby, the skin material (second skin material 6) can be suppressed from being bent. When the filler 9 is disposed in the composite material 1 in such a manner, during curing of the composite material 1, fibers of the second skin material 6 can be suppressed from being bent to cause a reduction in strength. Therefore, the composite material 1 of the present embodiment can be suitably used in the aircraft structure.

[0049] In the present embodiment, in a horizontal view, the filler 9 protrudes outside the composite material 1 by a length equal to or less than the length of the portion of the filler 9, the portion overlapping the tip of the end portion of the honeycomb core 2. When the filler 9 is disposed in such a manner, the second skin material 6 can be sufficiently suppressed from being bent. Since the size of the filler 9 can be set to an appropriate size, excessive overlapping can be suppressed from occurring in the composite material 1.

[0050] Incidentally, in the first embodiment described above, the case where in a horizontal view, the filler 9 protrudes outside the composite material 1 by a length equal to or less than the length of the portion of the filler 9, the portion overlapping the tip of the end portion of the honeycomb core 2, has been described as an example; however, the invention is not limited thereto. Specifically, as long as the filler 9 overlaps the vicinity of the tip of the end portion of the honeycomb core 2, in which the adhesive accumulation occurs, the length of the filler 9 is not particularly limited.

Second Embodiment

[0051] Next, a second embodiment of the invention will be described with reference to FIG. 2.

[0052] The basic configuration of the present embodiment is basically the same as that of the first embodiment; however, the present embodiment differs from the first embodiment in that instead of the filler 9, a filler 9 is disposed between the first film adhesive 3 and the first skin material 4. Therefore, in the present embodiment, the different part will be described and the description of other duplicate parts will be omitted.

[0053] Incidentally, the same reference signs are assigned to the same components as those of the first embodiment and duplicate descriptions will be omitted.

[0054] FIG. 2 is a longitudinal cross-sectional view illustrating the state of the vicinity of the tip of the end portion of the honeycomb core 2 when a composite material 21 according to the present embodiment is cured. In the composite material 21 according to the present embodiment, the filler 9 is disposed between the first film adhesive 3 and the first skin material 4 so as to overlap the tip of the chamfered end portion of the honeycomb core 2. Incidentally, the filler 9 may be the same as the filler 9 in the first embodiment described above.

[0055] According to the present embodiment with the above-described configuration, the following effects are obtained.

[0056] In the composite material 21 of the present embodiment, the filler 9 is disposed between the honeycomb core 2 and the first skin material 4 so as to overlap the tip of the end portion of the honeycomb core 2. As in the present embodiment, when the filler 9 is disposed between the honeycomb core 2 and the first skin material 4 (in a portion above the end portion of the honeycomb core 2), the pressure of an autoclave is easily transmitted via the filler 9 to a portion where adhesive accumulation occurs. As a result, the adhesive accumulation can be suppressed from occurring. When the filler 9 is disposed in the composite material 21 in such a manner, during curing of the composite material 21, the fibers of the second skin material 6 can be suppressed from being bent to cause a reduction in strength. Therefore, the composite material 21 of the present embodiment can be suitably used in the aircraft structure.

Third Embodiment

[0057] Next, a third embodiment of the invention will be described with reference to FIG. 3.

[0058] The basic configuration of the present embodiment is basically the same as that of the first embodiment; however, the present embodiment differs from the first embodiment in that in addition to the filler 9, the filler 9 of the second embodiment is also disposed. Therefore, in the present embodiment, the different part will be described and the description of other duplicate parts will be omitted.

[0059] Incidentally, the same reference signs are assigned to the same components as those of the second embodiment and duplicate descriptions will be omitted.

[0060] FIG. 3 is a longitudinal cross-sectional view illustrating the state of the vicinity of the tip of the end portion of the honeycomb core 2 when a composite material 31 according to the present embodiment is cured. In the composite material 31 according to the present embodiment, the filler 9 and 9 are disposed between the first film adhesive 3 and the first skin material 4 and between the second film adhesive 5 and the second skin material 6, respectively.

[0061] According to the present embodiment with the above-described configuration, the following effects are obtained.

[0062] In the composite material 31 of the present embodiment, the filler 9 and 9 are disposed both between the honeycomb core 2 and the first skin material 4 and between the honeycomb core 2 and the second skin material 6 so as to overlap the tip of the end portion of the honeycomb core 2. As in the present embodiment, when the filler 9 is disposed between the honeycomb core 2 and the first skin material 4 (in a portion above the end portion of the honeycomb core 2), the pressure of the autoclave is easily transmitted via the filler 9 to a portion where adhesive accumulation occurs. As a result, the adhesive accumulation can be suppressed from occurring. When the filler 9 is disposed between the honeycomb core 2 and the second skin material 6 (in a portion below the end portion of the honeycomb core 2), the rigidity of the filler 9 provides the effect of suppressing the adhesive accumulation; and thereby, the second skin material 6 can be suppressed from being bent. When the fillers 9 and 9 are disposed in the composite material 31 in such a manner, during curing of the composite material 31, the fibers of the second skin material 6 can be suppressed from being bent to cause a reduction in strength. Therefore, the composite material 31 of the present embodiment can be suitably used in the aircraft structure.

[0063] The composite material of the invention as described above can be collectively cured. Even if the composite material of the invention is collectively cured and molded (one-shot molding), during curing of the composite material, the fibers of the skin material can be sufficiently suppressed from being bent to cause a reduction in strength. Therefore, one-shot molding is performed, and thus in addition to reducing the operation cost of the autoclave, a curing operation with a bag for curing is performed once; and thereby, the molding cost can be reduced. There is no need to perform a rough trim operation and a jig cleaning operation after the skin material is cured, which are required in secondary adhesive molding, and thus the process is simple.

[0064] The composite material of the invention as described above is suitably applicable to products, such as a control surface structure for future commercial aircrafts, a panel for future helicopters and space shuttles, aircraft floor materials, floor materials and frame materials for new transportation and railway vehicles, which require a lightweight and high-rigidity composite honeycomb sandwich panel.

[0065] [Method for Producing Composite Material]

[0066] Next, one embodiment of a method for producing a composite material in the invention will be described.

[0067] The method for producing a composite material in the invention includes a preparation step and an alignment step. In the preparation step, the above-described composite material of the invention is prepared. In the alignment step, a filler is disposed between the honeycomb core and the first skin material, between the honeycomb core and the second skin material, or in both locations so as to overlap the tip of the end portion of the honeycomb core.

[0068] Incidentally, hereinafter, a case where the method for producing a composite material in the invention is applied to producing the composite material 1 illustrated in FIGS. 1 and 4 will be described as one example; however, the invention is not limited thereto.

[0069] (Preparation Step)

[0070] In the preparation step, the composite material 1 of the first embodiment described above is prepared. Here, as one example, the composite material 1 illustrated in FIG. 4 is prepared and the following step is performed.

[0071] (Alignment Step)

[0072] In the alignment step, as illustrated in FIG. 1, the filler 9 is disposed between the second film adhesive 5 and the second skin material 6 so as to overlap the tip of the chamfered end portion of the honeycomb core 2.

[0073] In the alignment step, specifically, as illustrated in FIG. 1, in a horizontal view, the filler 9 is disposed between the second film adhesive 5 and the second skin material 6 so as to protrude outside the composite material 1 by a length equal to or less than the length of a portion of the filler 9, the portion overlapping the tip of the end portion of the honeycomb core 2.

[0074] According to the present embodiment with the above-described configuration, the following effects are obtained.

[0075] In the method for producing the composite material 1 of the present embodiment, in the alignment step, the filler 9 is disposed between the honeycomb core 2 and the second skin material 6 so as to overlap the tip of the end portion of the honeycomb core 2. As in the present embodiment, when the filler 9 is disposed between the honeycomb core 2 and the second skin material 6 (in a portion below the end portion of the honeycomb core 2), the rigidity of the filler provides the effect of suppressing the adhesive accumulation; and thereby, the skin material (second skin material 6) can be suppressed from being bent. When the filler 9 is disposed in the composite material 1 in such a manner, during curing of the composite material 1, the fibers of the second skin material 6 can be suppressed from being bent to cause a reduction in strength. Therefore, the method for producing the composite material 1 of the present embodiment can be suitably used in the aircraft structure.

[0076] Incidentally, in one embodiment of the method for producing a composite material in the invention described above, the case where the filler 9 is provided between the second film adhesive 5 and the second skin material 6 has been described as an example; however, the invention is not limited thereto. As illustrated in FIG. 2, the filler 9 may be provided only between the first film adhesive 3 and the first skin material 4 or as illustrated in FIG. 3, the fillers 9 and 9 are disposed both between the first film adhesive 3 and the first skin material 4 and between the second film adhesive 5 and the second skin material 6, respectively. In addition, the invention is not limited to the modes.

[0077] In the composite material and one embodiment of the method for producing a composite material in the invention described above, the case where the first film adhesive 3 and the second film adhesive 5 are used has been described as one example; however, a mode where the two film adhesives are not used may be adopted. In such a case, since the film adhesives are not required, the cost can be lowered. In addition, also in the mode where the above two film adhesives are not used, molding can be performed by one-shot molding. In this case, the two skin materials (uncured prepregs) are directly bonded to the honeycomb core.

[0078] In the composite material and one embodiment of the method for producing a composite material in the invention described above, the case where the end portion of the honeycomb core 2 is chamfered has been described as one example; however, chamfering may not be performed. Also when the honeycomb core is not chamfered, above-described adhesive accumulation is expected to occur; however, when the filler is provided as described above, such adhesive accumulation can be prevented from occurring.

REFERENCE SIGNS LIST

[0079] 1, 21, 31: Composite material [0080] 2: Honeycomb core [0081] 3: First film adhesive [0082] 4: First skin material [0083] 5: Second film adhesive [0084] 6: Second skin material [0085] 7: Lightning protection mesh [0086] 8: Resin material [0087] 9, 9: Filler