JPH0238036A - Honeycomb core - Google Patents

Abstract

PURPOSE:To make equal the shearing strength of a cell between in an extending direction and in a ribbon direction, with uniforming the shape of each cell, by arranging linearly cells of a generally parallelogram in a plane with every side of an equal length, constituting a cell wall of one of a pair of said cells by one base material and a cell wall of the other of the pair by two base materials, in a predetermined positional relation between said base materials. CONSTITUTION:A shorter side 5 having the equal length to one side of a cell 3 is bent 90 deg. to a longer side 6 having twice the length of the side of the cell 3 in each of cell walls 2, 2a. A predetermined number of base materials 4 are positioned in a predetermined length with their shorter sides 5 and longer sides 6 being continuously connected in a manner that the shorter side 5 of the one base material 4 is perpendicular to the center in an elongated direction of the longer side 6 of the adjacent base material 4, and the longer sides 6 of the adjacent two materials 4 are shifted 1/2 each other in the elongated direction. The longer sides 6 are bonded through an adhesive layer 7 at respective connecting portions. The base material 4 is constructed in the above manner.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a honeycomb core.

More specifically, the present invention relates to a honeycomb core in which shear strength in one direction, for example, the so-called expansion direction, and the shear strength in a direction perpendicular to the expansion direction are approximately equal.

"Prior Art" and "Problem to be Solved by the Invention" Honeycomb cores have a high weight-to-strength ratio and are easy to mold, so generally, as shown in FIG. A hollow columnar cell B with a thousand-sided approximately regular hexagonal shape is formed.
A honeycomb core A consisting of a planar aggregate of is widely used.

However, in the honeycomb core A, between the so-called stretching direction W in the honeycomb core A and the direction perpendicular to this stretching direction, the so-called ribbon direction, within a unit area, along the stretching direction W, for example, The number of cell walls C existing in the cut plane when cut along the X-X line and the cells existing in the cut plane when cut along the ribbon direction, for example, along the Y-Y line. With the number of walls C, the extension direction W
Since there are about 1.5 times as many cell walls in the cut plane along the ribbon, the shear strength in the ribbon direction is significantly larger than the shear strength in the stretching direction W, mainly due to this.

Therefore, for example, in a sandwich panel using the honeycomb core A as a core material, the shear strength is significantly different in the longitudinal direction and the width direction, so such a sandwich panel may not be used as a structural material depending on the equipment. There have been many cases where it has not been possible to use it.

Furthermore, even if such a sandwich panel can be used as a structural material, depending on the way the load is applied, for example, large distortions may easily occur in the direction of low shear strength. Since the use direction of the honeycomb core A constituting the core material, such as the stretching direction W and the ribbon direction, is limited, it is not easy to form the sandwich panel, and the yield rate of the honeycomb core A is low, making the sandwich panel expensive. There were drawbacks such as.

Therefore, the drawbacks of the honeycomb core A are solved, and the shear strength in the stretching direction W and the ribbon direction are approximately equal, and as shown in FIG. A honeycomb core, a so-called overexpanded core D, is made of a planar assembly of rectangular cells E in which the cell walls F and F1 forming each cell E formed by expansion form a bending angle of approximately 90'.
It has been known.

In this overexpanded core D, the number of cell walls F1 existing in the cut plane when cut along the expansion tension direction W at a predetermined position within a unit area, and the number of cell walls F1 present in the cut plane when cut along the expansion tension direction W, Since the number of cell walls F existing in the cut plane is approximately equal, the shear strength in the stretching direction W and the ribbon direction are approximately equal, but the overexpanded core D
further expands the honeycomb core A in the expansion direction W,
That is, for example, the planar shape of each cell E is changed by applying an expansion tension to the extent that the cell walls F2, F, which are bonded to each other via a linear adhesive layer (not shown), do not peel off.
To form the over-expanded core D, which is formed by expanding as much as possible into a rectangular shape in which the cell walls F and F have a bending angle of approximately 90°, select the adhesive and over-expand. It is troublesome to calculate the expansion tension and the means to uniformly over-extend it.
In particular, it has been pointed out that it is extremely difficult to mold an overexpanded core D in which each cell E has a uniform shape.

Therefore, in order to solve the above-mentioned drawbacks of the over-expanded core D, in part, the strip-shaped base material sheets constituting the cell walls are coated at predetermined intervals in the longitudinal direction of the base material sheets. Along the width direction and 1/2 of the length in the width direction
Forming a slit-shaped gap having a length of A honeycomb core formed by a planar assembly of approximately square cells, or, for example, a honeycomb core formed by bonding hollow prismatic substrates with approximately square cross sections side-to-side with each other. are also provided. However, in these honeycomb cores, for example, the shear strength in the left-right direction and the front-back direction of the honeycomb core, which corresponds to the expansion direction W of the overexpanded core D and the ribbon direction, is equal, and the shape of each cell is Although it is possible to mold a uniform honeycomb core, it is difficult to mold any honeycomb core with a small cell size, and in the case of the former in particular, it is extremely troublesome and difficult to fix each assembly part by adhesive etc. In addition, in the latter case, it is difficult to form a hollow prismatic base material with a thin wall thickness and a substantially square cross section with high precision, and the joining part by adhesive etc. It has been pointed out that there are many problems compared to the above, so the joining work is troublesome, and the molded honeycomb core has a high density, making it heavy.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to increase the shear strength in the so-called stretching direction of a normal honeycomb core and in the direction perpendicular to this stretching direction, the so-called ribbon direction. It is also possible to mold a honeycomb core with approximately equal cell size, small cell size, and uniform shape of each cell.
The object of the present invention is to propose a honeycomb core that can be formed by a conventional honeycomb core and a time-opening means, such as a honeycomb core made of a planar assembly of cells having a substantially regular hexagonal shape on a thousand faces.

"Means for Solving the Problems" The present invention has been made to achieve the above object, and the technical solutions thereof are as follows.

This honeycomb core consists of a planar assembly of hollow columnar cells having a predetermined planar shape formed by cell walls made of a base material, and the cell walls forming the cells have a predetermined length. A predetermined shape in which a short side having a length and a long side having a length twice that of the short side are bent at a predetermined angle to each other and are alternately and continuously positioned. A large number of base materials each having a long length are located approximately at the center of each long side of one adjacent base material in the longitudinal direction of the base material,
In order that each short side of the other base material is located parallel to each short side of the one base material, the long sides of both base materials are aligned with each other with a positional relationship shifted by 1/2. The corresponding abutting portions on each long side are joined, and there is an interval equal to 1/2 the length of the long side of the base material, that is, equal to the length of the short side. One cell wall made of a single base material formed by short sides located parallel to each other in a straight line, and a predetermined bending angle between the one cell wall and the base material is equal to located intersectingly at an angle, and
The other is made up of two base materials formed by corresponding abutting portions of the joined long sides located parallel to each other in a straight line with an interval equal to the length of the short side. are formed by a pair of said one cell walls and a pair of said other cell walls, which are located at a predetermined angle in an intersecting manner and both have a length equal to the length of said short side part. The cells each having a substantially parallelogram shape are arranged in series.

"Function" Since the present invention is comprised of the above means, it functions as follows. That is, the honeycomb core according to the present invention has a configuration in which each cell is arranged in series, and each cell is formed into a substantially parallelogram in plan with cell walls having the same length, that is, the length of each side is the same. Therefore, it is perpendicular to one of the diagonals of the cells, and the diagonals of each cell are located in a straight line. In addition, the cell walls forming the cell are such that one of the cell walls of the pair facing each other along one direction is each made of one base material, and one of the cell walls facing each other along the other direction is constructed of two sheets of base material. The other cell wall is each composed of two base materials, and the base materials having a predetermined shape and a predetermined length are arranged in a predetermined positional relationship. Therefore, at a predetermined position within a unit area of the honeycomb core, the direction corresponding to the so-called expansion direction of the normal honeycomb core and the direction perpendicular to this expansion tension direction, the so-called ribbon direction, that is, one diagonal of the cell. The number of cell walls (number of base materials) existing within the cut plane when cut along the direction along the diagonal line, and the number of cells existing within the cut plane when cut along the other diagonal line. Since the number (number of base materials) is approximately equal, the shear strength in the direction along one diagonal of each cell in this honeycomb core and the direction along the other diagonal are approximately equal.

In addition, when forming the honeycomb core according to the present invention, for example, when using a so-called stretch forming method that is easy to form, in the step of forming a bonding material layer using an adhesive or the like on a sheet-like base material, forming A linear bonding material layer with a predetermined width to be formed, that is, a bonding material layer whose width is equal to the length of one side of the cells of the honeycomb core to be formed, is formed to a length twice the predetermined width of the bonding material layer. formed every pitch equal to
A predetermined number of base materials on which these bonding material layers are formed are placed, for example, on one side of each bonding material layer of the base material located on the lower side, and on the other side of each bonding material layer of the base material stacked on this base material. A honeycomb core in an unexpanded state is formed by stacking the honeycomb core in a sequential manner so that the sides coincide with each other. A honeycomb core can be formed by expanding in a direction along each joint formed by two base materials joined via a honeycomb core.

Therefore, the width and pitch of the bonding material layers to be formed are set at a ratio of 1:3 as much as possible, and in the layering process, the positional relationship of the bonding material layers of each stacked base material is set so that the bonding material layers are overlapped as much as possible to match the above-mentioned positional relationship. The subsequent forming means are substantially the same as in the case of conventional honeycomb cores.

In addition, in the case of forming by so-called corrugate forming means, the wave-shaped base material prepared in advance is set to a predetermined length, that is, a length equal to the length of one side of the cell of the honeycomb core to be formed. A wavy shape in which a short side with a long side and a long side with a length twice that of the short side are bent at a predetermined angle to each other and are alternately and consecutively positioned. A predetermined number of these base materials are sequentially formed into
Each long side of both base materials is shifted by 1/2 so that each short side of the other base material is located approximately at the longitudinal center of the base material on each long side of one base material. They can be formed by arranging them in a positional relationship in which they abut correspondingly, and by joining the correspondingly abutting long sides.

Therefore, although the shape of the base material formed into a wave shape and the positional relationship in which the base materials are arranged are slightly different, it can be molded using a conventional honeycomb core and time-opening molding means.

Therefore, regardless of which molding method is used, it is possible to mold a honeycomb core with a small cell size, it is also possible to mold a honeycomb core with a uniform cell shape, and the molding is easy.

"Example" Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a plan view of essential parts showing an embodiment of a honeycomb core according to the present invention, and FIG. 2 is an explanatory diagram showing the arrangement of base materials constituting cell walls.

In the figure, 1 is a honeycomb core, and this honeycomb core 1 is composed of a planar assembly of hollow columnar cells 3 of square plane formed by cell walls 2 and 2a.

The cell walls 2 and 2a forming the cell 3 are as follows.

That is, each cell wall 2, 2a has a short side 5 having a length equal to the length of one side of the cell 3, and a long side 6 having a length twice the length of this short side 5. , a predetermined number of base materials 4 each having a predetermined length and having a shape in which the short sides 5 and the long sides 6 are alternately and continuously bent at 90 degrees, respectively. One base material 4 is placed at the center of the longitudinal direction of the base material 4 in each long side portion 6 of the adjacent one base material 4.
Each short side 5 on the other base material 4 with respect to each long side 6 of
The long sides 6 of both adjacent base materials 4 are shifted by 1/2 in the longitudinal direction so that the long sides 6 of the two adjacent base materials 4 are positioned vertically, that is, parallel to each short side 5 of the one base material 4. The corresponding contact portions on the long sides 6 are bonded, for example, through an adhesive layer 7 formed of an applied adhesive, and each base material 4 is assembled. .

Therefore, each base material 4 assembled in this way has a length of 1/2 of the length of the long side 6 of the base material 4, that is, the length of the base material 4
One cell wall 2 is made of a single base material 4 formed by short sides 5 extending parallel to each other in a straight line with an interval equal to the length of the short sides 5 of the cell wall 2; , located intersecting one of these cell walls 2 at an angle of 90°, and
Two long sides 6 are connected in a straight line with an interval equal to the length of the short sides 5 of the base material 4 and are bonded to each other via an adhesive layer 7 that is parallel to each other. The other cell wall 2a is formed of two base materials 4, and one of the pair is located to intersect with each other at right angles and both have a length equal to the length of the short side 5 of the base material 4. The cells 3 formed by the cell wall 2 and the other pair of cell walls 2a are square in plan, and the cells 3 are arranged in series.

The honeycomb core 1 is constructed as described above.

Therefore, in the honeycomb core 1 in the above-described embodiment, each cell 3 formed into a square plane is arranged in series, so that one diagonal line (not shown) of the cell 3 Other diagonal (not shown)
are orthogonal to each other, and one diagonal line and the other diagonal line of each cell 3 are located in a straight line. Further, in the cell walls 2° 2a forming the cells 3, one of the cell walls 2 of the pair is constituted by − pieces of the base material 4, and the other cell wall 2a is
Since each is composed of two base materials 4, the third
As shown in the figure, within the unit area of the honeycomb core 1 (the solid line part in the figure), there are two directions corresponding to the so-called expansion direction of a normal honeycomb core and a direction perpendicular to this expansion direction, the so-called ribbon direction. One diagonal line of cell 3 (vertical diagonal line in the diagram)
For example, the number of cell walls 2, 2a existing in the cut plane when cut along the direction along the I-1 line, that is, the number of cell walls 2, 2a of the base material 4 constituting the cell walls 2, 2a. number and
The number of cell walls 2, 2a present in the cut plane when cutting along the other diagonal (the diagonal in the left-right direction in the figure), for example, along the line ■-■, that is, the number of cells Since the number of base materials 4 constituting the walls 2 and 2a is the same at nine, each cell 3 in the honeycomb core 1
The shear strength in the direction along one diagonal of is the same as that in the direction along the other diagonal.

Next, a method for forming the honeycomb core 1 will be explained.

First, a method of forming by so-called stretch forming means will be explained with reference to FIGS. 1 and 2.

In the case of the stretch forming method, as shown in FIG. 4, first, a honeycomb core 1 is formed on one surface of a sheet-like base material 4 along its longitudinal direction or width direction.
Length of one side of cell 3 (cell wall 2.2 forming cell 3)
For example, the adhesive layer 7 in the form of a stripe is applied with a width Wa equal to the length Wa of the adhesive layer 7 at a pitch P equal to twice the width Wa of the adhesive layer 7. formed by

Next, a predetermined number of base materials 4 on which these adhesive layers 7 are formed
For example, as shown in FIG. (III!I7b) By sequentially stacking a predetermined number of stacked base materials 4 in the same positional relationship, the unexpanded honeycomb core 1
1, and after cutting this unexpanded honeycomb core 11 into predetermined lengths along the direction perpendicular to the adhesive layer 7, the adhesive layer 7 is slightly inclined and arranged in a straight line.
The base material 4 (corresponding to the cell wall 2), which is formed by two base materials bonded together through a single sheet, is bent by 90 degrees along the side edges of both bonded parts. , a honeycomb core 1 shown in FIG. 1 is obtained.

Therefore, the width of the adhesive layer 7 to be formed and its pitch P are set to be 1:3 as much as possible, and in the layering step,
The positional relationship of the adhesive layers 7 of the base materials 4 to be stacked is as much as possible in the above-mentioned positional relationship, so that the subsequent forming means is substantially the same as in the case of a conventional honeycomb core.

Next, a method of forming by so-called corrugate forming means will be explained with reference to FIGS. 1 and 2.

In the case of using corrugate forming means, first, a band-shaped base sheet having a predetermined length is set to a length equal to the length of one side of the cells 3 of the honeycomb core 1 to be formed by an appropriate processing means. The short side 5 and the long side 6, which is twice the length of the short side 5, are bent at 90 degrees to each other and are formed in a wave shape so that they are alternately and consecutively positioned. Then, a predetermined number of base materials 4 formed in a wave shape are
Each long side 6 of the side base material 4 is sequentially placed so that each short side 5 of the other base material 4 is located at the longitudinal center of the base material 4 of each long side 6 of one base material 4. are arranged in a positional relationship that is shifted by 1/2 and corresponds to each other, and each long side portion 6 that corresponds to each other is bonded, for example, via an adhesive layer 7 formed on one of the base materials 4. By doing so, the honeycomb core 1 shown in FIG. 1 can be formed.

Therefore, although the shape of the base material 4 formed in a wavy shape and the positional relationship in which the base materials 4 are arranged are slightly different, the honeycomb core can be formed by approximately the same molding means as the honeycomb core molded by conventional so-called corrugate molding means. be able to.

Therefore, no matter which molding method is used, it is possible to mold the honeycomb core 1 with the small size of the cells 3, and it is also possible to mold the honeycomb core 1 with the uniform shape of the cells 3. Molding is easy.

In addition, in the above-mentioned example, although the shape of the cell 3 was explained about the honeycomb core 1 with a square plane, the shape of the cell 3 is not limited to a square, It may be a rhombic quadrilateral, In the case of a quadrilateral shape approximating a square, the shear strength in the direction along each diagonal of the cell 3 is approximately the same as in the case where the shape of the cell 3 is a square.

"Effects of the Invention" As detailed above, according to the honeycomb core according to the present invention, each cell formed by cell walls in a planar substantially parallelogram with equal length on each side is arranged in series. In addition, in the cells forming the cell, one of the cell walls of the pair is constituted by two base materials, and the other cell wall of the pair is constituted by two base materials. , these cell walls are made of a base material with a predetermined shape and a predetermined length, or are arranged in a predetermined positional relationship, so that the so-called expansion tension direction of a normal honeycomb core and this expansion tension It is easy to form a honeycomb core in which the shear strength in the direction perpendicular to the ribbon direction, that is, the shear strength in the direction along each diagonal of the cells corresponding to the so-called ribbon direction, is approximately equal, the cell size is small, and each cell has a uniform shape. The problems that conventional honeycomb cores of this type have have been eliminated, and the effects of the present invention are significantly large.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for comparing the shear strength in the direction along the square line of an example of the honeycomb core according to the present invention, and FIGS. 4 and 5 each show an example of the honeycomb core forming process. , Fig. 4 is a front view of the main parts showing the adhesive layer formed on the base material, and Fig. 5 is a predetermined number of base materials stacked and layered to form an unexpanded honeycomb core. It is an explanatory diagram showing a process. Figures 6 and 7 respectively show conventional examples, and Figure 6 compares the shear strength in the stretching direction and the ribbon direction of a honeycomb core consisting of a planar aggregate of cells of approximately regular hexagonal shapes. FIG. 7 is a plan view of the main parts of the overexpanded core. 1...Honeycomb core 2.2a...Cell wall 3...Cell 4...Base material 5...Short side portion 6...・Long side portion 7...Adhesive layer 11...Honeycomb core P in unexpanded state...
...Adhesive layer pitch Wa...Adhesive layer width

Claims (1)

[Claims] A honeycomb core consisting of a planar assembly of hollow columnar cells having a predetermined planar shape formed by cell walls made of a base material, each cell wall forming the cells of the honeycomb core having a predetermined planar shape. A predetermined shape in which a short side portion having a length and a long side portion having a length twice that of the short side portion are bent at a predetermined angle and are alternately and continuously positioned. A plurality of base materials each having a long length are arranged such that each of the long sides of one of the adjacent base materials is approximately centered in the longitudinal direction of the base material, and each short side of the other base material is located approximately at the center of the base material in the longitudinal direction of the base material. The long sides of both base materials correspond to each other in a positional relationship shifted by 1/2 in order to be positioned parallel to each short side of the substrate,
And, the corresponding abutting portions on the long sides are joined and formed in a straight line with an interval equal to 1/2 the length of the long side of the base material, that is, the length of the short side. In a continuous state, one cell wall made of a single base material constituted by short sides located parallel to each other, and the one cell wall intersects at an angle equal to a predetermined bending angle of the base material. two sheets, which are connected in a straight line with an interval equal to the length of the short side, and are formed by corresponding abutting portions of the joined long sides that are located parallel to each other; A pair of cell walls are formed of a base material of the cell walls, and a pair of cell walls are formed so as to intersect with each other at the predetermined angle, and both have a length equal to the length of the short side; A honeycomb core characterized in that each cell formed in a planar substantially parallelogram shape by the other cell wall is arranged in series.