JP3107478B2 - Method for manufacturing flexible honeycomb core and flexible honeycomb core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flexible honeycomb core and a method for manufacturing the same. In other words, it can be bent into a cubic curved surface or other complicated curved surface, and is used for the core material of various equipment and structural materials, including the outer wall of the rocket tip,
The present invention relates to a flexible honeycomb core and a method for manufacturing the same.

[0002]

2. Description of the Related Art Honeycomb cores are formed of planar aggregates of hollow columnar cells and have various characteristics such as excellent strength by weight, and are widely used for various applications. None, each cell typically has a prismatic shape such as a regular hexagon. By the way, when such a honeycomb core is bent into a curved surface, warpage, distortion, breakage, peeling, and the like are likely to occur. It was extremely difficult to do so. So conventionally,
As a honeycomb core for forming such a curved surface, a fixed-shaped flexible honeycomb core 1 shown in FIG. 5 (2) has been developed and used. That is, the fixed-shaped flexible honeycomb core 1 is formed of a planar assembly of hollow columnar cells 2, and all the cell walls 3 are bent in the middle, and the respective cell walls 3 are bonded at the contact portions. Thus, each cell 2
However, it had a rounded substantially convex shape, and was composed of a central portion 4 close to a rectangle and a protruding portion 5 close to a triangle. The fixed-shaped flexible honeycomb core 1 has such a special cell 2
Since it is made of a shape, it can be easily and accurately formed into a cubic curved surface or any other complicated curved surface without warping, distortion, breakage, peeling, etc., and can be freely deformed into various curved surfaces. .

[0003]

The following problems have been pointed out in such a conventional example. That is, although the conventional fixed-shaped flexible honeycomb core 1 can be freely deformed into various curved surfaces, there is a problem that the strength difference is large between the bonding direction, that is, the ribbon direction L, and the direction orthogonal thereto, that is, the stretching direction W. there were. That is, the shear strength, the shear modulus, and the like are significantly different between the orthogonal ribbon direction L and the stretching direction W, and are strong in the ribbon direction L and weak in the stretching direction W. In such a case, there is a problem that the directionality in terms of strength appears in the panel, and it is necessary to always consider the directionality in designing the panel.

The present invention has been made in view of such circumstances, and has been made in order to solve the above-mentioned problems of the conventional example. A fixed-shaped flexible honeycomb core is further reduced from 128% to 17%.
By over-stretching to about 3%, first, the difference in strength between the ribbon direction, which is the bonding direction, and the stretching direction is small,
Secondly, it is another object of the present invention to propose a flexible honeycomb core and a method for manufacturing the same, which can obtain various strengths freely while reducing the density and reducing the weight.

[0005]

The technical means of the present invention for achieving this object is as follows. First, claim 1
Is as follows. In other words, in this method for manufacturing a flexible honeycomb core, first, the flexible honeycomb core is formed of a planar assembly of hollow columnar cells, all the cell walls are bent in the middle and the respective cell walls are bonded, and each cell is rounded. A fixed-shaped flexible honeycomb core having a substantially convex shape is prepared. Then, a tensile force is applied to the fixed-shaped flexible honeycomb core in a direction orthogonal to the bonding direction of the cell wall, and the core is over-extended from about 128% to about 173%. As a result, all the cell walls are bent at an obtuse angle on the way, and each cell wall also forms an obtuse angle.Each cell has a rounded and deformed substantially convex special shape, and a central shape close to a hexagon. Thus, a flexible honeycomb core including the portion and the protruding portion is obtained.

Next, claim 2 is as follows. That is, this flexible honeycomb core is formed of a planar aggregate of hollow columnar cells, and all the cell walls are bent in the middle and the respective cell walls are adhered to each other, and each cell has a rounded substantially convex shape. The fixed-shaped flexible honeycomb core having a shape is formed by applying a tensile force in a direction perpendicular to the bonding direction of the cell wall, and is further expanded from about 128% to about 173%. Each cell wall is bent at an obtuse angle on the way and forms an obtuse angle between the cell walls. Each cell has a rounded and deformed substantially convex special shape, and a central portion close to a hexagon. And a protrusion.

[0007]

The present invention comprises the above-mentioned means, and operates as follows. This flexible honeycomb core is obtained by further extending a fixed-shaped flexible honeycomb core in which each cell has a rounded and substantially convex shape from about 128% to about 173%, and each cell is rounded and deformed. It has a special shape of a substantially convex shape, and has a hexagonal central portion and a protruding portion, and can be freely deformed into various curved surfaces. First, in this flexible honeycomb core, since each cell has a predetermined special shape, a difference in strength between the ribbon direction, which is the bonding direction, and the stretching direction is small, such as a difference in shear strength and shear modulus is small. Second, since the fixed-shaped flexible honeycomb core is over-expanded, the density is reduced and the weight is reduced accordingly. Third, by selecting the type and thickness of the base material sheet,
Various strengths can be obtained easily and freely.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. 1, 2 and 3 show an embodiment of a flexible honeycomb core according to the present invention. FIG. 1 is a plan view, FIG. 2 is a plan view of a main part in an over-expanded state, and FIG. 3 is a perspective view. is there. 4 and 5 are front explanatory views showing an example of the manufacturing process of the fixed-shaped flexible honeycomb core. FIG. 4 (1) shows a base material sheet, FIG. 4 (2) shows a corrugated sheet, and FIG. 5) shows a corrugated sheet to which an adhesive is applied, (4) shows a stacked corrugated sheet, FIG. 5 (1) shows each corrugated sheet heated and pressed, and (2) FIG. Indicates a fixed-shaped flexible honeycomb core manufactured by stretching.

In the method for manufacturing the flexible honeycomb core 6 according to the present invention, first, the flexible honeycomb core 6 is formed of a planar assembly of hollow columnar cells 2, and all the cell walls 3 are bent in the middle, and the space between the cell walls 3 is bonded. Then, a fixed-shaped flexible honeycomb core 1 in which each cell 2 has a rounded and substantially convex shape is prepared.

First, an example of a manufacturing process of the fixed-shaped flexible honeycomb core 1 will be described in detail. FIG. 4 (1)
As the base material sheet 7 shown in the figure, aluminum and other metal foils, various plastic sheets, fiber reinforced plastic sheets (FRP sheets), composite material sheets of organic and inorganic materials including pulp, other various fibers and cloths And the like. Then, as shown in FIG. 4 (2), by corrugating the base material sheet 7 prepared in this way, for example, the irregularities of a triangular waveform are continuously formed at a predetermined pitch and height. The corrugated plate 8 is formed by corrugating. Then, (3) in FIG.
As shown in the drawing, the corrugated sheet 8 formed in this manner is cut every predetermined length after the adhesive 9 is applied to the top every other line. Then, as shown in FIG. 4 (4), the positional relationship in which such a plurality of corrugated sheets 8 are shifted by one wave between the upper and lower sides each time one layer is stacked, that is, the adhesive applied every other line The agent 9 is densely stacked in a multilayer block shape while the tops and the valleys are aligned with each other in a positional relationship in which the agent 9 is shifted left and right between the top and bottom.

Thereafter, as shown in FIG. 5A, the corrugated sheets 8 stacked in this way are connected to the upper and lower plates 1.
0, the plate 10 is heated and pressurized by moving up and down in a furnace or the like, so that the adhesive 9 is melt-hardened,
The stacked corrugated sheets 8 are bonded together. Then, by applying a tensile force to the corrugated sheet 8 thus stacked and partially adhered with the stacking direction being the extension direction W, the non-adhered portion of each corrugated sheet 8 is extended and deformed. Separate and separate. In this way, by performing the expansion with the ribbon direction L as the bonding direction and the stacking direction orthogonal to the ribbon direction L as the expansion direction W, the fixed-shaped flexible honeycomb core 1 shown in FIG. 5B is manufactured. You. The fixed-shaped flexible honeycomb core 1 is composed of a planar assembly of hollow columnar cells 2, and each cell wall 3 formed by each corrugated plate 8.
However, while being bent while keeping the ares all along the way,
Each cell wall 3 is adhered by an adhesive 9, and each cell 2 has a rounded, substantially convex shape, and is composed of a central portion 4 that is nearly rectangular and a protrusion 5 that is nearly triangular.

The fixed-shaped flexible honeycomb core 1
Can be manufactured without such a manufacturing process,
For example, a special corrugated sheet in which a large wave portion and a small wave portion of a predetermined shape are successively bent continuously (that is, a corrugated plate corresponding to the shape of the cell wall 3 of the fixed-shaped flexible honeycomb core 1) is used as the base material sheet 7. It can also be manufactured by forming into a single piece, stacking and gluing it. Furthermore, it is also possible to manufacture the fixed-shaped flexible honeycomb core 1 by a method in which the adhesive 9 is applied to the base material sheet 7 in a striped form, a plurality of sheets are stacked, bonded, and then spread.

Next, in the method for manufacturing the flexible honeycomb core 6 of the present invention, the bonding direction of the cell wall 3 of the fixed-shaped flexible honeycomb core 1 shown in FIG. A tensile force is applied in the stretching direction W orthogonal to the ribbon direction L, and the ribbon is over-stretched again from about 128% to about 173%, whereby the predetermined flexible honeycomb core 6 shown in FIGS. can get. In this flexible honeycomb core 6, each cell wall 1 formed by over-extending the original cell wall 3 is provided.
All cells 1 are bent at an obtuse angle while maintaining a radius, and the respective cell walls 11 are also obtuse at an obtuse angle. It has a special shape of a letter, and has a central portion 13 close to a hexagon in which the original central portion 4 is over-extended, and a projecting portion 14 in which the original projecting portion 5 is over-extended.

The flexible honeycomb core 6 will be described in more detail. First, in the fixed-shaped flexible honeycomb core 1, when the cell size meter of 10 cells 2 in the expansion direction W is set to 78 mm and the expansion rate is set to 100%, the flexible honeycomb core 6 which is further expanded over this is 10 cells 12 in the extension direction W
Is as follows. That is, 100 mm at an expansion rate of 128%, 110 mm at an expansion rate of 141%,
115mm at 147% elongation, 12 at 159% elongation
5mm, 130% at 166% elongation, 173% elongation
135mm, etc. If the elongation is less than 128%, the effect of reducing the difference in strength cannot be obtained, so that the flexible honeycomb core 6 does not belong to the flexible honeycomb core 6, but still belongs to the range of the fixed-shaped flexible honeycomb core 1.
If the expansion ratio exceeds 173%, breakage and cutting of the cell wall 11 due to over-expansion will be observed, so that the expansion ratio of 173% is the limit of the flexible honeycomb core 6.

The over-expansion for obtaining such a flexible honeycomb core 6 is performed by inserting a pin into each cell 2 of the fixed-shaped flexible honeycomb core 1 or every cell 2 at a constant interval, as in the ordinary expansion process. Thereafter, the process is performed by applying a tensile force to the entire fixed-shaped flexible honeycomb core 1. In addition, the flexible honeycomb core 6 obtained by over-stretching in this manner is used as a base material sheet 7 as a fiber-reinforced plastic sheet (FRP sheet).
Is used, heat treatment is performed afterwards to hold the shape fixedly, and when a composite sheet containing pulp is used as the base material sheet 7, steam is used afterwards to hold the shape fixedly Treatment is performed, and when strength is particularly required, impregnation, adhesion, and coating treatment by immersion in a resin solution are performed. The flexible honeycomb core 6 thus obtained is also excellent in weight ratio strength, and has high rigidity and strength as well as light weight, as well as a general honeycomb core, and has a rectifying effect, heat insulation, and sound insulation. It has excellent properties and the like, and has a large surface area per unit volume. By the way, regardless of the over-stretching as in the present invention, the base material sheet 7 is formed into a special corrugated sheet (that is, a special corrugated sheet in which a large wave portion and a small wave portion of a predetermined shape are sequentially and continuously bent.
The same shape as the flexible honeycomb core 6 can also be manufactured by forming into a corrugated sheet corresponding to the shape of the cell wall 11 of the flexible honeycomb core 6 and stacking and bonding the same.

The present invention has been described above. Then, it becomes as follows. This flexible honeycomb core 6 has a substantially convex shape in which each cell 2 is rounded,
The fixed-shaped flexible honeycomb core 1 (see FIG. 5 (2)) comprising a central portion 4 close to a rectangle and a protrusion portion 5 close to a triangle is further extended from about 128% to about 173%. 1, 2 and 3), each cell has a rounded and deformed substantially convex special shape, and includes a central portion 13 and a protruding portion 14 which are nearly hexagonal. Since each cell 12 has such a predetermined special shape, the flexible honeycomb core 6 can be freely deformed into various curved surfaces, and easily and accurately without warping, distortion, breakage, peeling, and the like. In addition to being able to bend into a cubic curved surface and other complicated curved surfaces, the following first, second, and third shapes are obtained.

First, this flexible honeycomb core 6
Since each cell 12 has a predetermined special shape, the difference in shear strength, shear modulus, etc., between the ribbon direction L and the stretching direction W, which are the bonding directions, is small. The difference in intensity is small. Second, since the flexible honeycomb core 6 is formed by over-extending the fixed-shaped flexible honeycomb core 1, the density is reduced and the weight is reduced accordingly. Third, since the strength difference between the ribbon direction L and the stretching direction W of the flexible honeycomb core 6 is small, the flexible honeycomb core 6 can be easily and easily selected by selecting the type and the thickness of the base material sheet 7 which is the material of the cell wall 11. Various strengths can be obtained freely.

With respect to the first intensity difference and the second density, the results of the characteristic test are as follows. That is, an aluminum foil having a thickness of 0.94 mm is used as the base material sheet 7 of the cell wall 11, and the entire thickness thereof is 15.
A 9 mm one was used. The fixed-shaped flexible honeycomb core 1 having a 100% expansion ratio (the cell size meter of 10 cells 2 in the expansion direction W is 78 mm) and the flexible honeycomb core 6 having a 150% expansion ratio of the present invention (the expansion direction W).
The density (g / cm ³ ), shear strength (kg / cm ² ),
The results of measuring the shear modulus (kg / cm ² ) and the like are as shown in Table 1 below.

[0019]

[Table 1]

As described above, the flexible honeycomb core 6 of the present invention having an expansion ratio of 150% can obtain data having a lower density than the fixed-shaped flexible honeycomb core 1 having an expansion ratio of 100%, and can obtain the data in the ribbon direction L. And the shear strength and the shear modulus in the stretching direction W were almost the same.

[0021]

As described above, the flexible honeycomb core according to the first and second aspects of the present invention and the method for manufacturing the same have the same configuration as the flexible honeycomb core of the present invention.
The following effect is exhibited by making the overstretch from about% to 173%.

First, a flexible honeycomb core having a small difference in strength between the bonding direction, ie, the ribbon direction and the stretching direction, can be obtained. That is, this flexible honeycomb core is
Of course, it can be freely deformed into various curved surfaces, and because the difference in strength in both orthogonal directions is small, for example, when commercializing a panel using this as a core material, there is a panel with no directionality in the strength surface In addition to this, it is not necessary to pay particular attention to the direction in designing the panel.

Second, the density is further reduced, the weight is reduced, and the material cost is reduced due to the over-expansion.
Third, by selecting the type and thickness of the base material sheet as the material, various strengths can be freely obtained. As described above, the effects exhibited by the present invention are remarkably large, for example, the problems existing in this type of conventional example are eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view of a flexible honeycomb core used for describing an embodiment of the present invention.

FIG. 2 is a plan view of a main portion in a state of being over-extended from a fixed-shaped flexible honeycomb core to a flexible honeycomb core of the present invention for explanation of the embodiment.

FIG. 3 is a perspective view of a flexible honeycomb core for explaining the embodiment.

FIG. 4 is a front view for explaining a manufacturing process of a fixed-shaped flexible honeycomb core; (1) FIG. 4 shows a base material sheet, (2) shows a corrugated sheet, and (3) shows an adhesive applied. (4) shows a stacked corrugated sheet.

5 is an explanatory front view for explaining a manufacturing process of the fixed-shaped flexible honeycomb core, wherein FIG. 5A shows each corrugated sheet to be heated and pressed, and FIG. 3 shows a shape flexible honeycomb core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed-shaped flexible honeycomb core 2 Cell 3 Cell wall 4 Central part 5 Projection part 6 Flexible honeycomb core 7 Base material sheet 8 Corrugated plate 9 Adhesive 10 Plate 11 Cell wall 12 Cell 13 Central part 14 Projection part L Ribbon direction W Extension direction

Claims (2)

(57) [Claims] First, a cell is formed of a planar assembly of hollow columnar cells, and all cell walls are bent in the middle and the respective cell walls are bonded to each other, so that each cell has a rounded substantially convex shape. Next, a tensile force is applied to the fixed-shaped flexible honeycomb core in a direction perpendicular to the bonding direction of the cell walls, and the fixed-shaped flexible honeycomb core is further extended from about 128% to about 173%. As a result, all the cell walls are bent at an obtuse angle on the way, and the respective cell walls also form an obtuse angle.Each cell has a rounded and deformed substantially convex special shape, and a central part close to a hexagon. And obtaining a flexible honeycomb core comprising: a protruding portion. 2. A planar assembly of hollow columnar cells, wherein all the cell walls are bent in the middle and the respective cell walls are adhered to each other, and each cell has a rounded and substantially convex shape. The fixed-shaped flexible honeycomb core is formed by applying a tensile force in a direction perpendicular to the bonding direction of the cell walls, and is further extended from about 128% to about 173%, and all the cell walls are bent at an obtuse angle in the middle. It is characterized by being bent and forming an obtuse angle between the cell walls, each cell having a rounded and deformed substantially convex special shape, and having a central portion close to a hexagon and a protruding portion. Flexible honeycomb core.