JPH01218826A - Molding method for curved surface honeycomb core - Google Patents

Abstract

PURPOSE:To mold a curved surface honeycomb core of superior accuracy including large compression strength, uniformity and the like easily and at low cost by disposing respective bases formed with recessed and projected sections arranged alternately and continuously along the longitudinal direction crossing square the direction along the curved surface of a curved surface mold/and also disposing one end section of the recessed or projected lower end in contact with the mold surface of the curved surface mold. CONSTITUTION:A base 2 is placed on a curved surface mold 8 mounted on a work bench in a manner that the longitudinal direction of the base 2 is along the direction crossing square the direction along the curved surface of a mold surface 8a of the curved surface mold 8 and that the width direction of the base 2 is along the vertical line, and the base 2 as a reference is disposed in a position in a manner that the lower ends of respective top wall sections 7a of respective recessed sections 7 of the base 2 are in contact with the mold surface 8a. Then, the base 2 to be disposed adjacent to said base 2 is disposed with the lower ends of respective top wall sections 7a disposed in contact with the mold surface 8a and with respective bottom wall sections 6a of respective recessed sections 6 of said base 2 disposed correspondingly in contact with respective top wall sections of the base 2 disposed previously through a bonding agent 9. The bonding agent 9 is cured in said state.

Description

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

"Prior art", "Problem to be solved by the invention" Using a base material in which concave parts and convex parts of a predetermined shape are formed alternately and consecutively in the thickness direction of a strip-shaped material having a predetermined width,
A flat reference surface is provided in a positional relationship in which a concave portion in one of the adjacent base materials and a convex portion in the other base material are brought into corresponding contact with each other via a bonding material such as an adhesive or a brazing material. A so-called corrugate is formed by layering each base material on a jig, etc., and joining the abutting parts of the concave and convex parts with a bonding material while maintaining the arrangement state to form a honeycomb core. Honeycomb cores formed by forming means are easy to form and have the characteristics of being able to obtain honeycomb cores with high strength such as compressive strength, so generally the cells of the formed honeycomb core are Those consisting of a planar aggregate of hollow columns having a substantially regular hexagonal shape are often used.

However, when forming a curved honeycomb core using such a honeycomb core, for example, if the honeycomb core is curved along the curved surface mold in the stacking direction (or the direction perpendicular to the stacking direction, that is, the longitudinal direction of the base material), the honeycomb core On the contrary, the longitudinal direction (or stacking direction) of the base material constituting the core is warped upward and distorted into a saddle shape, and does not fit into the curved shape. Since curved honeycomb cores are formed by fitting them into curved molds, for example, when molding a curved honeycomb core with a small radius of curvature, the walls of the base material that make up the cell walls may break. In addition, problems such as peeling of joints may occur, and the radius of curvature of the curved honeycomb core to be temporarily formed is large, resulting in problems such as cell walls breaking and peeling of joints. Even if this does not occur, permanent distortion occurs in the cell wall of the portion that is forced to fit into a curved shape due to torsional deformation, etc. Moreover, the occurrence of this distortion is uneven, so the strength etc. It was not possible to mold a curved honeycomb core with uniform precision.

Therefore, as a honeycomb core that can be easily processed into a curved surface shape, for example, as shown in FIG. Convex portions are continuously formed, and the base material B on which these complex-shaped concave portions C2 and convex portions are formed is sequentially inserted into each concave portion C in one base material B of adjacent base materials B and the other base material B. The convex portions of the material B are arranged in a positional relationship in which they are in corresponding contact with each other, and the abutting portions of the concave portions C and the convex portions are joined via a bonding material E such as an adhesive, and a predetermined number of sheets are assembled. A so-called flexible honeycomb core A is provided which is formed by overlaying a base material B.

Since the flexible honeycomb core A is highly flexible,
Although it is easy to mold a honeycomb core with a highly accurate curved surface, it is difficult to mold a base material B that has concave portions C1 and convex portions of a complex shape with high precision in a predetermined pattern. Since the core A is not easy to mold, it has the disadvantage that it is extremely expensive compared to, for example, a normal honeycomb core formed by a corrugate molding method and consisting of a planar aggregate of hollow columnar cells with substantially regular hexagonal cells. However, if the base materials have the same material, dimensions, etc., and densities are the same, ・Compared to a honeycomb core where the planar shape of the normal cells is approximately regular hexagon, for example, the strength such as compressive strength will be lower. is small, so
In order to form a flexible honeycomb core A that has the same strength as a honeycomb core whose cells have a substantially regular hexagonal planar shape,
Increase the thickness of the base material or use a wider base material,
Alternatively, since it is necessary to increase the density, there is a problem in that the weight increases. Therefore, it may not be suitable as a structural material for use in, for example, aerospace equipment where further weight reduction is desired.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide curved surfaces with excellent precision, such as having high strength such as compressive strength and uniformity in all parts. The present invention proposes a method for molding a curved honeycomb core that allows the honeycomb core to be molded easily and at low cost.

"Means for Solving the Problems" The present invention has been made to achieve the above-mentioned object, and its technical solution first involves forming concave portions and convex portions of a predetermined shape in the thickness direction of a strip material having a predetermined width. Prepare a predetermined number of base materials formed such that the parts are alternately and consecutively located, and then
Each of these base materials is sequentially positioned so that its longitudinal direction is perpendicular to the direction along the curved surface of the curved mold, and one end of the lower end of the concave or convex portion is in contact with the mold surface of the curved mold. In addition, adjacent base materials are arranged on the mold surface so that the recesses on one base material and the protrusions on the other base material are in a positional relationship such that they respectively abut correspondingly with each other via the bonding material. A curved honeycomb core is formed by arranging the concave portions and the convex portions through the bonding material while maintaining this arrayed state, and plying a predetermined number of base materials. be.

"Operation" According to the method for forming a curved honeycomb core of the present invention, each base material formed in such a way that concave portions and convex portions of a predetermined shape are successively positioned alternately in the thickness direction of the strip material is sequentially formed. The longitudinal direction of these base materials is along a direction perpendicular to the direction along the curved surface of the curved surface mold, and one end of the lower end of the concave portion or convex portion of each base material is placed in contact with the mold surface, The recesses on one of the adjacent base materials and the protrusions on the other base material are arranged on the mold surface in a positional relationship in which they correspond and abut each other via the bonding material, and while maintaining this arrangement state, the bonding material is applied. A curved honeycomb core is formed by joining the abutting parts of the concave part and the convex part through the base material and overlapping each base material, so for example, a curved honeycomb core with a small radius of curvature of the curved surface is desired. Even if the cell wall is damaged, there will be no problems such as breakage of the cell walls or peeling of the joints, and the high-precision curved honeycomb has a high strength such as compressive strength and is uniform in strength. Core is obtained.

In addition, there is no need for bending along a curved surface mold, and it can be formed using a normal flat honeycomb core formed by conventional corrugate forming means. It's easy.

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

Figure 1 is an explanatory diagram showing the process of forming the base material, Figure 2 is a plan view of the main parts of the base material, Figure 3 is an explanatory diagram showing the process of arranging the base material for molding a curved honeycomb core, 4 to 6 show the main parts of the molded curved honeycomb core, respectively. FIG. 4 is a plan view thereof, FIG. 5 is a cross-sectional view along line v-v in FIG. 4, and FIG. FIG. 6 is a perspective view of section vI in FIG. 4.

First, a method for molding the base material 2 constituting the curved honeycomb core 1 will be explained.

This base material 2 is divided into two approximately regular hexagonal shapes along opposing apex angles in the thickness direction of a strip material 5 having a predetermined width by a gear-type processing device W4 equipped with a set of gear-shaped molds 3. The bottom wall portions 6a have a symmetrical trapezoidal shape and are parallel to each other.
It is formed by alternately and continuously forming concave portions 6 and convex portions 7 having a top wall portion 7a and a top wall portion 7a.

Next, a predetermined number of base materials 2 thus molded are molded with a convex mold surface 8a formed so that one surface of the molded curved honeycomb core 1 has a desired concave curved surface. For example, as shown in FIG. 3, place the substrate 2 on a curved mold 8 placed on a workbench with the surface 8a as the upper surface so that the longitudinal direction of the base material 2 is along the curved surface of the mold surface 8a of the curved mold 8. The base material 2 is positioned so that the width direction of the base material 2 is along the vertical line, and the width direction of the base material 2 is along the vertical line.
The lower end tip of the top wall portion 7a of each convex portion 7 is the mold surface 8a.
First, the base material 2 to be used as a reference is placed in a positional relationship in contact with the base material 2, and then the base material 2 to be placed adjacent to this base material 2 is placed so that the lower end tip of each top wall portion 7a is shaped like the base material 2. While contacting the surface 8a, the bottom wall portion 6a of each recess 6 of this base material 2 and first,
The top wall portions 7a of the disposed base material 2 are arranged in a positional relationship such that they respectively abut correspondingly through the adhesive 9.

In addition, regarding the application of the adhesive 9 to each base material 2 for arranging each base material 2 in a predetermined positional relationship via the adhesive 9, the top wall portion 7a of all the base materials 2 or the like is applied in advance. Bottom wall part 6
After applying the adhesive 9 to a, the base materials 2 may be arranged in sequence, or in the process of arranging, each top wall portion 7a of one of the adjacent base materials 2 or the other base material 2 may be arranged while being applied to each bottom wall portion 6a.

After sequentially arranging and setting a predetermined number of base materials 2 on the mold surface 8a in this way, each base material is cured, for example, by curing the adhesive 9 in a heating furnace while maintaining the set state. 2 is bonded between each top wall portion 7a and each bottom wall portion 6a via adhesive 9, and is overlapped by each joint portion 11 formed at these portions, and the mold surface 8
A curved honeycomb core 1 is obtained, which is a planar assembly of hollow columnar cells 10 having a substantially regular hexagonal shape and having a desired curved surface in contact with the curved surface of the mold surface 8a at the portion abutting on the mold surface 8a.

Note that W is the direction in which the base material 2 is stacked.

Therefore, for example, even if a curved honeycomb core 1 with a small radius of curvature is desired, problems such as breakage of each wall portion of the base material 2 constituting the cell walls and peeling of the joint portions 11 occur. High precision curved honeycomb core 1
can be molded.

In addition, in the above-mentioned embodiment, the method of forming the curved honeycomb core 1 in which the desired curved surface exhibits a predetermined concave curved surface has been described. However, if a curved honeycomb core that exhibits a predetermined convex curved surface is desired, Molding can be carried out using a curved mold with a concave mold surface, and by using a curved mold with a continuous convex mold surface and a concave mold surface, it is possible to form a curved honeycomb core with a complex curved surface. Molding is also possible.

Regarding the shapes of the concave portions 6 and convex portions 7 provided in the base material 2, in the above-mentioned embodiment, when the curved honeycomb core 1 is formed by laminating each base material 2, the planar shape of the cells 10 is In order to form a substantially regular hexagon, we have described a structure in which a substantially regular hexagon is divided into two parts along opposing apex angles to form symmetrical trapezoidal recesses 6 and protrusions 7. The shape is not limited to the examples. For example, when a curved honeycomb core is molded, the planar shape of the cells is a hexagonal shape that is vertically elongated in the stacking direction, or another polygonal shape.
Symmetrical concave portions and convex portions may be formed.

"Effects of the Invention" As detailed above, according to the method for molding a curved honeycomb core according to the present invention, even when molding a curved honeycomb core with a small radius of curvature, the cell walls are not deformed or broken, or the joints are Since problems such as peeling do not occur, a highly accurate curved honeycomb core with high compressive strength and uniform strength can be obtained.

In addition, there is no need for bending along a curved surface mold, and the molding can be performed easily by using a normal flat honeycomb core formed by a conventional corrugate molding method and a groove molding method. It is possible to form a curved honeycomb core at a low cost, and the problems that conventional methods of forming a curved honeycomb core of this type had have been eliminated, and the effects are significant.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention.
The figure is an explanatory diagram showing the process of forming the base material, Figure 2 is a plan view of the main part of the base material, Figure 3 is an explanatory diagram showing the process of arranging the base material for molding a curved honeycomb core, and Figure 4 is an explanatory diagram showing the process of forming the base material. Figures 6 to 6 show the main parts of the molded curved honeycomb core, respectively.
FIG. 4 is a plan view thereof, FIG. 5 is a cross-sectional view taken along the line v--v in FIG. 4, and FIG. 6 is a perspective view of the section ■ in FIG. 4. FIG. 7 is a plan view of the main parts of a conventional flexible honeycomb core. DESCRIPTION OF SYMBOLS 1...Curved honeycomb core, 2...Base material, 4...Gear type % formula% 8...Curved surface mold, 8a...Mold surface, 9...Adhesive, 1
0... Cell, 11... Junction, W... Overlapping direction.

Claims (1)

[Claims] A predetermined number of base materials each having a predetermined width are sequentially formed so that recesses and protrusions of a predetermined shape are located alternately and continuously in the thickness direction of the strip material, and the longitudinal direction thereof is formed into a curved surface in a curved surface mold. A recess in one of the adjacent base materials, along a direction perpendicular to the direction along the curve, and one end of the lower end of the recess or projection is located in contact with the mold surface of the curved surface mold. and the convex portions on the other base material are arranged on the mold surface in a positional relationship in which they correspond and abut each other via the bonding material, and while maintaining this arrangement state, the concave portions and the convex portions are bonded to each other via the bonding material. A method for forming a curved honeycomb core, characterized in that each of the base materials is layered by bonding them together.