JPH1016097A - Bisectional type honeycomb core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity and strength while a curved surface is easily made, and a joined position is prevented from being peeled off. SOLUTION: The bisectional type honeycomb core 8 is composed of a plane aggregate of many hollow columnar cells 10 wherein a plurality of corrugated plates 4 in which wavy irregularities are continuously formed by bending, and a plurality of bisectional sheets 9 are successively alternately laminated to be bonded, and sections are formed by using such the corrugated plates 4 and the bisectional sheets 9, and a cell end face is formed in a curved face so as to be equipped with a specific curvature. Then, the bisectional sheet 9 forming the cell wall and the cell 10 is made of a flat board which is curved 11 or bent 12, and a degree of freedom in deformation is given. It is made of, for example, plastics, and heated and pressurized in forming the curved face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a bisect type honeycomb core. That is, the present invention relates to a bisect-type honeycomb core in which a corrugated plate and a flat bisect sheet are laminated and joined, and are subsequently formed into a curved surface so as to have a predetermined curvature.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory plan view of a conventional example of this type before a curved surface is formed. FIG. 3 (1) shows a bisect type honeycomb core, and FIG. 3 (2) shows a general honeycomb core. Is shown. As shown in FIG.
It consists of a planar assembly of a large number of hollow columnar cells 3 defined by cell walls. As shown in FIG. 3 (2), a honeycomb core 1 in which, for example, only a corrugated plate 4 is laminated and joined as cell walls, and the cross-sectional shape of the cell 3 is a regular hexagon, is typical and typical. However, as shown in FIG. 3A, a corrugated plate 4 and a flat bisect sheet 5 are used as cell walls, and these are sequentially laminated and joined alternately. A bisect type honeycomb core 2 having a trapezoidal shape is also used. This bisect type honeycomb core 2 is a general honeycomb core 1
Compared with the above, the reinforcement by the bisect sheet 5 interposed between the corrugated plates 4 has an advantage that the compression strength in the cell axis direction and other rigidity and strength are excellent. And such a bisect type honeycomb core 2
Conventionally, a plurality of corrugated sheets 4 in which corrugations are continuously bent are formed, and a flat-plate bisect sheet having a completely cross-sectional shape that is completely flat without any bending or bending. 5 were laminated and joined.

[0003] Incidentally, the honeycomb cores 1 and 2 are
In some cases, the cell end surface is formed into a curved surface so as to have a predetermined curvature, and is used as a whole curved to a secondary curved surface or the like. For example, when used as a storage body for an aircraft engine, it is entirely curved. First, the general honeycomb core 1 shown in FIG. 3 (2), that is, the honeycomb core 1 whose cell 3 has a regular hexagonal cross section, has a flat plate shape. The curved surface is formed relatively smoothly into a curved shape. That is, the regular hexagonal cell 3 on the cell end face side on the inner side / contraction side of the curve easily contracts and deforms into a vertically long hexagonal shape (to be under-expanded) by the curved surface forming, and the outer side of the curve. The regular hexagonal cell 3 on the cell end surface side on the extension side is easily expanded and deformed into a horizontally long hexagonal shape (to be over-extended) by curved surface forming. As described above, the general honeycomb core 1 has a small stress caused by a relatively small pressing force and has a smooth curved surface.

[0004]

On the other hand, the bisect type honeycomb core 2 shown in FIG.
However, the following problems have been pointed out when forming a curved surface. FIG. 4A is a schematic perspective view before the curved surface is formed, FIG. 4B is a schematic perspective view during the curved surface forming, FIG. 3C is a schematic perspective view after the curved surface forming, and FIG. Is a schematic perspective view showing peeling due to curved surface forming, FIG. 5 (5) is a plan view of an inner main part before the curved surface forming, and FIG. 6 (6) is a bottom view of an outer main part before the curved surface forming. FIG. 7 (7) is a plan view of the main part showing the inside and the contraction side after the curved surface is formed, and FIG. 8 (8) is a bottom plan view of the main part showing the outside and the extension side after the curved surface is formed. .

The bisect type honeycomb core 2 is formed by sequentially laminating and joining corrugated plates 4 and flat bisect sheets 5 alternately, and the cells 3 have a trapezoidal shape.
From the flat plate shape shown in the figure, as shown in FIG. 4 (2), it is supplied and pressed between a pair of upper and lower concave and convex jigs 6 to thereby pressurize, as shown in FIG. 4 (3). It has been pointed out that when the curved surface is formed into a curved shape, it is difficult to form the curved surface smoothly, and as shown in FIG. Was. That is, the conventional bisect type honeycomb core 2 is
Since the bisect sheet 5 having a completely flat and linear cross section as a whole is interposed and reinforced, the sheet has excellent compressive strength and other rigidity and strength in the cell axial direction, but is not suitable for curved surface forming. Since seat 5 has no flexibility,
Correspondingly, a large pressing force is required and the generated stress is large. In particular, due to the concentration of stress on the portions joined in a strip shape by the adhesive 7, the corrugated plate 4 and the bisect sheet 5
Peeling S was likely to occur between them.

In other words, the cells 3 on the cell end face side on the inner side and on the contraction side of the curve shown in FIG. 4 (5) are formed by curved surface forming, except for the joints as shown in FIG. 4 (7). The corrugated sheet 4 forming the cell wall is about to shrink and deform, while FIG.
The cell 3 on the cell end face side on the outside / extension side of the curvature shown in FIG. 6 (6) is formed by a curved surface forming a cell wall other than the joint portion as shown in FIG. 4 (8). 4 tries to expand and deform. However, in the conventional bisect type honeycomb core 2 of this type, since the completely flat bisect sheet 5 is interposed, the bisect sheet 5 becomes an obstacle to such shrinkage deformation and expansion deformation. ,
Unlike the above-mentioned general honeycomb core 1, the curved surface is not formed smoothly. Therefore, a large pressing force is applied to form the curved surface forcibly, the stress is large, and peeling S is likely to occur at the joint portion by the adhesive 7.

[0007] When the base material of the corrugated sheet 4 and the bisect sheet 5 of such a bisect type honeycomb core 2 is made of fiber reinforced plastic (FRP), prior to forming the curved surface, FIG. (1) After heating at, for example, about 240 ° C. in the state shown in the drawing to make the corrugated plate 4 or the bisect sheet 5 as a cell wall flexible and prepreg,
By applying pressure as shown in FIG. 4 (2), a curved surface is formed. When the corrugated sheet 4 and the bisect sheet 5 are made of fiber-reinforced plastic, the bonding between the corrugated sheet 4 and the bisect sheet 5 is affected by the heating at the time of forming the curved surface. It has been pointed out that since the bonding strength of the agent 7 is reduced, the occurrence of the above-mentioned peeling S is promoted also from this surface, and it is particularly difficult to form a curved surface.

As described above, in the conventional bisect-type honeycomb core 2, the cell end face is hardly formed into a curved surface so as to have a predetermined curvature, and when it is forcibly bent to a secondary curved surface or the like, the peeling S is easily generated. . In some cases, the peeling S does not occur during or immediately after the formation of the curved surface, but may occur at the time of subsequent use. Therefore, there is a problem that the characteristics of the honeycomb core 2 and particularly the rigidity and strength, which are the characteristics of the bisect type, are impaired, such as a significant decrease in bending strength during use, due to such peeling S. It was pointed out.

The present invention has been made in view of such circumstances, and has been made to solve the above-mentioned problems of the prior art. By this, firstly, the curved surface forming is facilitated, the peeling of the joint portion is prevented, and secondly, the rigidity and strength are improved, and thirdly, this is easily and easily realized. The purpose of the present invention is to propose a honeycomb core.

[0010]

The technical means of the present invention for solving such a problem is as follows. First, claim 1 is as follows. That is, this claim 1
The bi-sect type honeycomb core is composed of a plurality of corrugated plates, each of which is formed by continuously bending corrugations, and a plurality of bi-sect sheets, which are sequentially stacked and joined alternately.
The corrugated plate and the bisect sheet are formed as a planar aggregate of a large number of hollow column-shaped cells which are defined as cell walls, and the cell end faces are formed into a curved surface so as to have a predetermined curvature. Each of the cell walls and the bisect sheet forming the cell are formed of a flat plate having a curved or bent portion, and are provided with a degree of freedom of deformation. Next, claim 2 is as follows. That is, the bisect-type honeycomb core according to claim 2 is the same as the bisect-type honeycomb core according to claim 1, wherein the corrugated sheet and the bisect sheet are made of fiber-reinforced plastic, and are heated and Curved surface is formed by pressing between the jigs.

This bisect type honeycomb core is
A corrugated sheet and a bisect sheet are successively laminated and joined alternately. The corrugated sheet is composed of a planar assembly of a large number of cells. The bisect sheet interposed between the corrugated sheets is formed by bending or bending. Degree of freedom of deformation is provided, and it is easily bent and bent. Therefore, when the entire surface is curved into a secondary curved surface or the like, the contraction deformation on the inside / contraction side and the expansion deformation on the outside / extension side can be easily and reliably realized. Accordingly, the stress generated by the relatively small pressing force is small, and the cell end surface is smoothly formed into a curved surface so as to have a predetermined curvature, thereby preventing peeling between the joined corrugated plate and the bisect sheet.

Therefore, when the corrugated sheet and the bisect sheet are made of fiber reinforced plastic, the bonding strength due to the adhesive or the like is slightly reduced due to the influence of the heating for the flexibility and the prepreg at the time of forming the curved surface. Even if such a situation occurs, the applied pressure at the time of forming the curved surface is relatively small and the stress is small, so that peeling from the joint portion is prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments of the present invention shown in FIGS. FIG. 1 is an explanatory plan view, and FIG. 1 (1) is a main part of the first example,
(2) FIG. 2 is a main part of the second example, (3) is a main part of the third example,
(4) FIG. 4 is a main part of the fourth example, (5) FIG. 5 is a main part of the fifth example,
FIG. 6 shows a corrugated sheet common to each example, and FIG. 7 shows a bisect sheet of the first example. 2A is an explanatory plan view before forming a curved surface in the W direction, FIG. 2B is an explanatory front view before forming the curved surface in the W direction, and FIG. FIG. 4D is a front view showing the diameter and expansion / contraction after the curved surface is formed in the W direction. FIG. 2 (5) is a plan view before forming a curved surface in the L direction, FIG. 2 (6) is a front view before forming a curved surface in the L direction, and FIG. 7 (7) is a curved surface forming in the L direction. It is a front explanatory view of the back. FIG. 2 (8) is an explanatory plan view of an essential part showing the inside / retraction side after the curved surface of the first example described above, and FIG. 9 (9) is the outside / extended side after the curved surface of the first example. FIG.

First, the bisect type honeycomb core 8 will be generally described. This honeycomb core 8
Is a method in which a plurality of corrugated sheets 4 in which corrugations are continuously bent and a plurality of bisect sheets 9 are sequentially laminated and joined alternately, so that the corrugated sheets 4 and the bisect sheets 9 are formed. And a bisect type formed of a planar assembly of hollow columnar cells 10 defined as cell walls (see also FIG. 3 (1) for the overall shape). Thereafter, the cell end surface is formed into a curved surface so as to have a predetermined curvature.

Such a bisect type honeycomb core 8 will be described in more detail. Examples of the base material of the corrugated sheet 4 and the bisect sheet 9 include aluminum foil and other metal foils, fiber reinforced plastic (FRP) sheets, various plastic sheets, mixed sheets of various fibers, composite sheets containing pulp, and the like. Sheets of various materials are used. Fiber reinforced plastic (FRP) sheets include glass fiber, Kevlar fiber, carbon fiber, ceramic fiber, metal fiber, resin fiber, other fibers, epoxy resin, polyimide resin, and other thermosetting resins. Thermoplastic resin is selected as appropriate to adhere, impregnate,
A typical example is a combination by mixing or the like. Then, the corrugated sheet 4 is formed by supplying such a flat base material to a corrugating apparatus formed of gears, racks and the like, for example, by heating and pressurizing. It is bent at a predetermined pitch and height continuously and repeatedly in a parallel and longitudinal direction (see FIG. 1 (6) and the like). In the corrugated plate 4, the cross-sectional shape of the corrugated unevenness may be a trapezoidal shape, a substantially triangular shape, a substantially quadrangular shape, or other various shapes.

[0016] The corrugated sheet 4 is coated with a bonding material, for example, an adhesive 7 in the form of a stripe on the bottom lower surface and the top upper surface of the corrugated irregularities and dried. Cut into pieces. Then, by laminating between a plurality of corrugated sheets 4 with a bisect sheet 9 interposed therebetween,
By applying heat and pressure, the applied adhesive 7 is melted and hardened, and the corrugated plate 4 and the bisect sheet 9 are joined in a line shape by heating and pressing. . By following these steps, a bisect-type honeycomb core 8 is manufactured. The bisect sheet 9 is used one by one in the illustrated example, but a plurality of sheets, such as two sheets, may be used instead.

This bisect type honeycomb core 8
As described above, the corrugated sheet 4 and the bisect sheet 9 are sequentially laminated and joined alternately as described above, and the corrugated sheet 4 and the bisect sheet 9 are used as cell walls, and a large number of hollow columnar sections are formed in independent spaces. It consists of a planar assembly of cells 10. The cross-sectional shape of each cell 10 is basically and entirely based on the shape of the corrugated sheet 4 described above, and slightly deformed by the bending 11 and the bending 12 of the bisect sheet 9. Note that the basic and overall shape of the corrugated plate 4 is typically a trapezoidal shape as shown in the figure, but a triangular shape, a substantially square shape, or other various shapes are also possible. The honeycomb core 8 is excellent in weight ratio strength, is lightweight, has high rigidity and strength, is excellent in rectification effect, surface accuracy, heat insulation, sound insulation, and has a unit volume similar to a general honeycomb core. It has such properties as a large surface area per contact. In view of the fact that the bisect sheet 9 is of the bisect type with the interposition, the rigidity and
It has the property of being excellent in strength.

Furthermore, the honeycomb core 8 of this bisect type is subsequently formed into a curved surface so that the cell end surface thereof has a predetermined curvature, and is curved as a whole to a secondary curved surface or the like. Used as a material. That is, the bisect-type honeycomb core 8 manufactured as described above is used as a pair of upper and lower jigs 6 (see FIG.
(See FIG. 2 (b)), and a pressure is applied from above and below to form a curved surface and bend into a secondary curved surface as a whole. FIG. 2 (1), FIG. 2 (2),
FIGS. 3 (3) and 4 (4) show a case where a curved surface is formed along the lamination direction W direction, and FIG. 2 (5) and FIG. 2 (6).
FIGS. 7A and 7B show L orthogonal to the W plane on the same plane.
The case where a curved surface is formed along the direction is shown.

It should be noted that, for such a bisect type honeycomb core 8, the corrugated sheet 4 and the bisect sheet 9 are provided.
When a fiber-reinforced plastic sheet or the like is used as the base material of the above, the curved surface is formed as follows. That is, prior to the curved surface forming, first, heating is performed at, for example, about 240 ° C., so that the corrugated plate 4 or the bisect sheet 9 serving as the cell wall is made flexible and prepreg, and then the surface is formed by applying pressure, so-called heat forming. The law is implemented. The above is the bi-sect type honeycomb core 8
Is a general description of.

Hereinafter, the present invention will be described. In the bisect type honeycomb core 8 of the present invention, a curved plate 11 and a bent plate 12 are formed on a flat plate as a bisect sheet 9 that forms each cell wall and cell 10 together with the corrugated plate 4.
The one to which the degree of freedom of deformation is given is used.
That is, this bisect sheet 9 is different from the above-mentioned conventional bisect sheet 5 which is made entirely of a flat plate having a completely flat and linear cross section.
A bend 11 and a bend 12 are formed.

The curvature 1 of such a bisect sheet 9
1 and the bend 12 will be described in more detail. First, according to the above-described case of forming the corrugated sheet 4, the bending 11 and the bending 12 supply the flat base material of the bisect sheet 9 to a corrugating apparatus including a gear, a rack, and the like. It is formed by heating and pressing, so that the bends 11 and the folds 12 are formed at predetermined pitches and heights that are linear and parallel in the short direction and repeated in the long direction (for example, FIG. 1).
(See FIG. 7 (7)). And this 11 and bent 1
The pitch of 2 is one unit of curvature 11 per cell 10.
And fold 12 are set to exist, and
The height of the bends 11 and the folds 12 is set smaller than the height of the corrugated sheet 4.

For example, FIG. 1 (1), FIG. 1 (7), FIG. 2 (1), FIG. 2 (5), FIG. 2 (8), FIG. (9) In the example shown in the figures and the like, the bisect sheet 9 in which one curved section 11 having a substantially round cross section is formed so as to entirely exist for each cell 10 is shown. In addition, in the example shown in FIG. 1C, two curves 11 having a substantially round cross-section, which are inverted up and down or the like, for each cell 10, that is, a curve 1 forming one cycle.
1 shows a bisect sheet 9 formed so as to exist. Further, in the example shown in FIG.
A bisect sheet 9 formed so as to have one bent portion 12 having a triangular cross section is provided for each cell 10, and in the example shown in FIG. , 1
A bisect sheet 9 formed so as to have a plurality of bent portions 12 each having a trapezoidal cross section is shown. In the example shown in FIG. 1 (5) in FIG. The bisect sheet 9 formed so that the fold 12 exists is shown.

The present invention is configured as described above. Then, it becomes as follows. The bisect type honeycomb core 8 has a large number of cells 10 in which the corrugated sheet 4 and the bisect sheet 9 are alternately laminated and joined as cell walls.
Consists of a planar assembly of As the bisect sheet 9, a sheet having a characteristic in which a curved surface 11 or a bent surface 12 is formed on a flat plate to impart a degree of freedom to deformation and easily bent or bent easily is used.

Therefore, this bisect type honeycomb core 8 is, for example, shown in FIGS. 2A and 2B and FIG.
From the state of forming a flat plate as a whole as shown in FIGS. 5 and 6, the cell end face is provided with a predetermined curvature in the W direction as shown in FIGS. 3 and 4. As shown in FIG. 7 (7), a curved surface is formed so that the cell end surface has a predetermined curvature in the L direction.
The following is the case where the next curved surface is curved (right and left upwards and the center is downwards in the drawing). First, the cell 1 on the cell end face side on the inside / shrink side (upper side in the illustrated example) of the curve
0, the bisect sheet 9 bends and bends so as to close each other, thereby easily and reliably.
It is shrunk and deformed so as to be pushed in (see FIG. 2 (8)). On the other hand, the cell 10 on the cell end face side on the outside / extension side (lower side in the illustrated example) of the curve is the bisect sheet 9
Are easily and reliably expanded and deformed by bending and bending so as to spread, respectively ((9) in FIG. 2).
See figure).

As shown in FIG. 2 (4), the honeycomb core 8 of this bisect type has a curvature R ₁ of the cell end surface on the inner side and the contracted side when forming the curved surface, based on the thickness T. If, although the curvature R ₂ of the cell edge surface of the outer-extension-side are different, it is by bisected sheet 9 Luwan song 11 and bent 12 is deformed by the above, is solved without problems. The bisect-type honeycomb core 8 has the following first, second, and third configurations.

First, as described above, in the bisect type honeycomb core 8, the bisect sheet 9 is provided with a degree of freedom of deformation by the curvature 11 or the bend 12, and a relatively small pressing force is applied. The resulting stress is small and the curved surface is formed smoothly. Therefore, a large stress concentration or the like does not occur at the portions joined in the form of stripes with the adhesive 7 or the like, and as a result, the peeling S (between the bonded corrugated sheet 4 and the bisect sheet 9) occurs. (See (4) in FIG. 4)
Is also prevented from occurring.

Thus, even when the corrugated sheet 4 and the bisect sheet 9 are made of fiber-reinforced plastic, the curved surface can be smoothly formed without being affected by the heating performed at the time of forming the curved surface. In other words, even if the bonding strength due to the adhesive 7 or the like is slightly reduced due to the influence of heating for flexibility and prepreg, the pressing force for forming the curved surface is relatively small and the stress is small. Peeling S from the joint by the adhesive 7 or the like is prevented.

Secondly, the bisect-type honeycomb core 8 is formed into a curved surface smoothly as in the above-described first embodiment, and the corrugated sheet 4 and the bisect sheet which are joined in the form of a stripe with an adhesive 7 or the like. 9 is prevented, the rigidity and
Strength is maintained. Further, since the bend 11 and the bend 12 are formed in the bisect sheet 9, the cell wall is reinforced by that amount, and the rigidity and strength are further improved from this surface.

Third, the bisect-type honeycomb core 8 has a simple structure in which a bend sheet 11 and a bent sheet 12 are formed on a bisect sheet 9 constituting the cell wall. That is, a particularly complicated configuration is not necessarily adopted in order to realize the first and second points.

[0030]

As described above, the bisect-type honeycomb core according to the present invention has the following effects by forming a bend or a bend in the bisect sheet to impart a degree of freedom of deformation. Demonstrate.

First, the formation of a curved surface is facilitated, and peeling of a joint portion is also prevented. That is, in the bisect type honeycomb core, since the bisect sheet is provided with a degree of freedom of deformation by bending and bending, a relatively small pressing force causes a small stress to be generated and a smooth curved surface is formed. That is, unlike the conventional example of this type described above, a large pressing force is not required for forming a curved surface, and the generated stress does not increase. Peeling between sheets is prevented.

In particular, even if the corrugated sheet or the bisect sheet is made of fiber reinforced plastic (FRP), and the heating performed in forming the curved surface may slightly decrease the bonding strength due to the adhesive or the like, Thus, since the curved surface is formed smoothly, the pressing force at the time of forming the curved surface is relatively small, and the stress is small, peeling does not occur. In addition,
Such prevention of peeling can be realized not only during or immediately after the formation of the curved surface, but also during the subsequent use.

Second, rigidity and strength are also improved. First, the bisect-type honeycomb core is smoothly formed into a curved surface as described above in the first aspect, and peeling between the corrugated sheet and the bisect sheet is prevented, so that its rigidity and strength are maintained. In other words, it is possible to avoid the deterioration of the rigidity and strength, which are the characteristics of the honeycomb core and particularly the bisect type, such as the drastic reduction in the bending strength upon use due to peeling, as in the above-described conventional example of this type. Is done. And furthermore
This bisect type honeycomb core has a bend or a fold formed in the bisect sheet, and accordingly, compared to the conventional example using the completely flat bisect sheet described above, The cell wall is reinforced, the core density is high, and the rigidity and strength are excellent. Therefore, the rigidity and strength of the bisect type honeycomb core are greatly improved.

Third, and this is easily and easily realized. In other words, this bisect type honeycomb core has a simple configuration in which the bisect sheet is formed with a bend or a bend, and the first and second honeycomb cores described above.
Is easily realized. As described above, the effects exhibited by the present invention, such as the problem existing in this kind of conventional example is solved,
Some are significant and significant.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view for explaining an embodiment of a bisect type honeycomb core according to the present invention, wherein FIG. 1A is a main part of the first example, and FIG. (3) is a main part of the third example, (4) is a main part of the fourth example, (5) is a main part of the fifth example, and (6) is each example. A common corrugated sheet, FIG. 7 shows a first example of a bisect sheet.

FIGS. 2A and 2B are explanatory views of an embodiment of the present invention, in which FIG. 1A is a plan explanatory view before forming a curved surface in a W direction, FIG. FIG. 3 (3) is a front view after the curved surface is formed in the W direction, and FIG. 4 (4) is a front view showing the diameter and expansion / contraction after the curved surface is formed in the W direction. (5)
The figure is a plane explanatory view before forming a curved surface in the L direction, and FIG.
FIG. 7 is an explanatory front view before forming a curved surface in the L direction, and FIG.
It is a front explanatory view after forming a curved surface in the direction. (8) FIG. 8 is a plan view of a main part showing the inside and the contraction side after the curved surface of the first example described above, and FIG. 9 (9) shows the outside and the extended side after the curved surface of the first example. It is a bottom view explanatory drawing of a principal part.

FIG. 3 is an explanatory plan view of a conventional example before a curved surface is formed;
(1) The figure shows a bisect type honeycomb core,
(2) The figure shows a general honeycomb core.

FIG. 4 is provided for explanation of a conventional bisect type honeycomb core, and FIG. 4A is a schematic perspective view before forming a curved surface;
(2) is a schematic perspective view during curved surface forming, (3) is a schematic perspective view after curved surface forming, (4) is a schematic perspective view showing peeling by curved surface forming, and (5) is a diagram. FIG. 6 is a plan view of an essential part showing the inside before the curved surface is formed, FIG. 6B is a bottom view of the essential part showing the outside before the curved surface is formed, and FIG. (8) is a bottom view of a main part showing the outer side and the extension side after the curved surface is formed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Honeycomb core (conventional example) 2 Honeycomb core (conventional example) 3 Cell (conventional example) 4 Corrugated plate 5 Bisect sheet (conventional example) 6 Jig 7 Adhesive 8 Honeycomb core (book) 9) Bisect sheet (of the present invention) 10 Cell (of the present invention) 11 Curve 12 Bending L direction R ₁ curvature R ₂ curvature S Peeling T Thickness W direction

Claims (2)

[Claims] 1. A plurality of corrugated sheets in which corrugations are continuously bent and a plurality of bisect sheets are sequentially laminated and joined alternately, so that the corrugated sheets and the bisect sheets are formed. A bi-sect type honeycomb core comprising a planar aggregate of a large number of hollow columnar cells partitioned and formed as cell walls, wherein the cell end faces are curved to have a predetermined curvature. A bisect type honeycomb core, wherein the bisect sheets forming the cells are each formed by bending and bending a flat plate, thereby imparting a degree of deformation freedom. 2. The bisect-type honeycomb core according to claim 1, wherein the corrugated sheet and the bisect sheet are made of fiber reinforced plastic, and are heated and pressurized between upper and lower jigs. A bisect-type honeycomb core characterized by being formed into a curved surface by being formed.