JPH03222731A - Method for forming honeycomb core composite material - Google Patents

Abstract

PURPOSE:To form the above honeycomb core composite material having a highly accuracy by a method wherein honeycomb core is fixed to a jig plate by fitting a fixture, which is fixable to the cells of honey comb core, to the outer peripheral part of the honeycomb core and filler is filled in a gap made between the end of honeycomb core composite material and the fixture and, under the above-mentioned condition, the honeycomb core composite material is heated under pressure. CONSTITUTION:A fixture is fixed to the outer peripheries of honeycomb core 3 and of composite material laminated sheet 4. The honeycomb core 3 is fixed to jig 1 by fitting the projections 6a of the fixture to the outer peripheral cells 3a of the honeycomb core 3 and by means of a mechanical fixing tool 8 through a fitting hole 7. Filler 5 is filled in a gap 9 made between the end of honeycomb core composite material 2 and the fixture. By covering the honeycomb are composite material 2 and the fixture by vacuum bag 10 and arranging sealing material 11 at the outer peripheral edge of the bag and evacuating the interior of the vacuum bag 10 from a mouthpiece 12, the interior of the vacuum bag 10 is fixed under pressure by means of external pressure. After that, by heating the honeycomb core composite material 2 together with the jig 1 is heated for several hours, the composite material laminated sheet 4 is hardened and formed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for forming a honeycomb core composite material, and in particular, a honeycomb core having a tapered outer periphery and a method for coating one of the upper and lower surfaces of the honeycomb core. The present invention relates to a method for forming a honeycomb core composite material, in which a honeycomb structure consisting of a composite material laminate is covered with a vacuum bag, and then the composite material laminate is cured by heating under pressure.

[Conventional technology]

Honeycomb core composite material, which is made by covering a honeycomb core with a composite laminate, has various excellent properties such as high rigidity, light weight, and high fatigue strength, so it is used in aircraft, floating railway vehicles, automobiles, etc. or its use is being considered.

The method for forming this type of honeycomb core composite is as follows:
The outer periphery of the honeycomb core covered with a composite laminate is filled with resin and cured, and this resin is fixed to a jig using a mechanical fixture.Then, the honeycomb composite is covered with a plastic vacuum bag and the resin is cured. The honeycomb composite is fixed by vacuuming the inside, and then heated under pressure for several hours to form the composite material. Alternatively, composite prepregs are layered on both sides of the honeycomb core, and the composite prepregs are bonded to each other at the outer periphery of the composite material. A method in which an overlapping portion is provided, and this surplus portion is clamped and fixed between a needle-like protrusion on a jig and an elastic presser frame that presses down from above, and then pressurized and heated for several hours to form the product. There is
(See Publication No. 2621).

[Problem to be solved by the invention]

However, in the conventional molding method described above in which the honeycomb core is filled with resin and fixed to a jig using a mechanical fixture, the honeycomb core is damaged due to the pressure difference that occurs between the inside of the vacuum bag and the inside of the cells of the honeycomb core. Although it is possible to prevent sliding and deformation of the honeycomb core, it requires a step of filling the outer periphery of the honeycomb core with resin and curing it, which makes the series of operations complicated.

In addition, in a molding method in which the excess thickness of the composite material prepregs on the outer periphery of the composite material are held and fixed between the needle-like protrusions on the jig and the elastic presser frame, the composite material is only formed on one side of the honeycomb core. There is a problem in that it is difficult to apply when coating laminates.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for forming a honeycomb core composite material that can prevent the honeycomb core from sliding and deforming when the composite material is pressurized.

[Means to solve the problem]

In order to achieve this object, the present invention covers a honeycomb composite material consisting of a honeycomb core with a tapered outer periphery and a composite laminate plate covering at least one of the upper and lower surfaces of the honeycomb core with a vacuum bag. In a method for forming a honeycomb core composite material in which the inside of the vacuum bag is evacuated and then heated under pressure to harden and mold the composite laminate, removable protrusions that can be fitted with the cells of the honeycomb core are arranged in parallel. The fixed fixing device is fitted onto the outer periphery of the honeycomb core, and this fixing device is fixed to the jig plate by a mechanical fixing device. The method is characterized in that the voids are filled with a filler and then the pressure and heating described above is performed.

[For production]

According to the present invention, a fixing device in which removable protrusions that can fit into the cells of the honeycomb core are arranged in parallel is fitted onto the outer circumference of the honeycomb core, and the fixing device is attached to the jig plate by a mechanical fixing device. In addition to fixing the honeycomb core composite material to Even when heated, the internal honeycomb core can be prevented from sliding and deforming.

〔Example〕

An embodiment of the method for forming a honeycomb core composite material according to the present invention will be described below with reference to FIG.

In FIG. 1, a honeycomb composite material 2 is placed on a flat plate-shaped jig 1. The honeycomb composite material 2 includes a honeycomb core 3, a composite laminate 4 covering the lower surface of the honeycomb core 3, and a filler 5 filling the outer peripheral portion of the honeycomb core 3. This honeycomb core 3 includes a large number of cells 3a, and aramid fiber or the like is used as the material thereof. Further, the composite material laminate 4 on the lower surface is composed of a prepreg laminate in which a plurality of prepreg sheets are laminated.

On the other hand, a fixing device 6 is fixed to the outer periphery of the honeycomb core 3 and the composite material laminate 4. The fixing device 6 is composed of a flat plate bent at an angle substantially equal to the angle of the taper formed at the end of the honeycomb core 3 and forming an inverted C-shape. A plurality of protrusions 6as6a, . . . are arranged in a stepped manner on the contact surface of the fixing device 6 with the honeycomb core 3.

The protrusions 6a are formed into a cylindrical or hexagonal column shape large enough to fit into the cells of the honeycomb core, and their height is set to a level that does not affect the quality of the product relative to the cells 3a. . For this purpose, the protrusions 6a are fitted into the outer peripheral cells 3a of the honeycomb core 3, and the honeycomb core 3 is fixed with a mechanical fixing device 8 such as a bolt or a bottle through a mounting hole 7 drilled at the other end. It can be fixed to tool 1.

Further, a gap 9 is formed between the end of the honeycomb core composite material 2 and the fixing device 6, and a filler 5 is formed in this gap 9.
The cell 3a is filled with the cell 3a to prevent deformation of the cell 3a in this portion.

The honeycomb composite material 2 fixed to the jig 1 in this way and the fixing tool 6 are placed in a vacuum bag 10 made of nylon film.
At the same time, a sealing material 11 is arranged on the outer periphery, and then the inside of the vacuum bag 10 is evacuated through the base 12 and the inside of the vacuum bag 10 is fixed by applying external pressure. At this time, since the honeycomb core 3 has a tapered portion formed on its outer circumferential portion, this tapered surface receives an external force from the side.

However, since the honeycomb composite material 2 is firmly fixed to the jig 1 by a fixing device 6 and a fixing device 8 such as a bolt, even if the above-mentioned external force is applied, the honeycomb composite material 2 may slide or the cells may be crushed. There's nothing to do.

Thereafter, the honeycomb composite material 2 is heated together with the jig 1 for several hours to harden and mold the composite material laminate 4.

In addition, it is necessary to use a material for the fixing device 6 that has a heat resistance higher than the curing temperature of the composite material laminate 4, and a material that does not lose its shape and dimensions even after repeated use. It is preferable to do so.

FIG. 2 shows another embodiment of the fixing device used in the molding method according to the present invention. In this embodiment, the protrusions 6a are plate-shaped and integrally formed in a plurality or rows. A plate-shaped protrusion 6a is removably fixed to a holding plate 6b by a screw 13, thereby forming a fixing device 6.

Moreover, the dimensions of the protrusion 6a formed in a plate shape in this way are as follows:
As shown in FIGS. 3 and 4, it is possible to replace the honeycomb core 3 according to the shape of the honeycomb core 3 used for molding. At this time, the shape of the protrusion 6a is not limited to the cylindrical shape as shown in FIG. 5(a), but is inscribed in the core surface of the honeycomb core as shown in FIGS. 5(b) to 5(d). Various shapes can be set. These protrusions 6a may be fixed one by one to the presser plate 6b, or, as described above, a plurality of protrusions may be formed into a plate shape and attached to the presser plate 6b.
It may be screwed on.

Next, the shape of the pressing plate 6b will be explained.

FIG. 6 shows the holding plate 6b shown in FIG. 2 unfolded from above. This presser plate 6b is provided with screw holes 6c at predetermined intervals vertically and horizontally. The protrusion 6a can be fixed with a screw 13 through this screw hole 6c.

Further, FIG. 7 shows another embodiment of the above-mentioned holding plate 6b, in which mounting holes 6d are bored at intervals so as to match the mounting positions of the protrusions 6a. ing. This attachment hole 6d is different from the screw hole 6c described above and is configured as a circular hole having a diameter larger than the diameter of the screw 13 for attaching the protrusion 6a.

An embodiment of mounting the protrusion 6a using the holding plate 6b having the mounting hole 6d will be described with reference to FIG.

In FIG. 8, the large head of the screw 13 is covered with silicone rubber, and this large head can close the clearance of the mounting hole 6d and fix the protrusion 6a to the holding plate 6b. According to this fixing method, the protrusions 6a can be slightly moved on the surface of the holding plate 6b by the clearance of the attachment holes 6d, and the honeycomb core can be securely fixed.

Note that the fixing tool 6 may be manufactured by integrally forming the projection 6a and the pressing plate 6b.

As the mechanical fixing device 8 for fixing the fixing device 6 having the protrusion 6a to the jig 1, a fixing pin as shown in FIG. 1 is usually used, but a fixing pin as shown in FIG. It is also possible to use shapes.

This fixing pin 8 has the advantage that it can be easily attached to and detached from the jig 1. At this time, it is preferable to use a material for the fixing pin 8 that has a heat resistance higher than the curing temperature of the composite material laminate 4 and is highly flexible.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the honeycomb core is fixed to the jig using a fixing tool in which protrusions that can be fitted with the cells of the honeycomb core are arranged in parallel, and the honeycomb core composite is Since the filler is filled between the end of the housing and the fixing tool, and then the pressure and heating described above is performed, even if the honeycomb core is subjected to external force from the side when the inside of the vacuum bag is evacuated, the honeycomb core will remain intact. This method has the effect of being able to mold a honeycomb core composite material with high precision without causing sliding or deformation.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the method for forming a honeycomb core composite material according to the present invention, and FIGS. 2 to 4 and 8 are cross-sectional views showing fixing devices according to other embodiments. Figure 5 (a)
7(d) are perspective views showing one embodiment of the protrusion of the fixing device according to the present invention, FIGS. 6 and 7 are plan development views showing pressing plates according to other embodiments, and FIG. 9 is a plan view showing another embodiment. FIG. 3 is a cross-sectional view of a fixture according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Jig, 2... Honeycomb composite material, 3... Honeycomb core, 4... Composite material laminate, 5... Filler, 6
... Fixing tool, 8... Fixing tool, 10... Vacuum bag, 13... Screw.

Claims (1)

[Claims] A honeycomb composite material consisting of a honeycomb core with a tapered outer periphery and a composite laminate plate covering at least one of the upper and lower surfaces of the honeycomb core is covered with a vacuum bag, and the inside of the vacuum bag is evacuated before being processed. In a honeycomb core composite molding method in which the composite laminate is hardened and molded by pressure heating, a fixing tool that can be fitted with the cells of the honeycomb core and has removable protrusions arranged in parallel is attached to the outer periphery of the honeycomb core. The fixing device is fixed to the jig plate by a mechanical fixing device, and the gap formed between the end of the honeycomb core composite material and the fixing device is filled with a filler, and then the fixing device is fixed to the jig plate using a mechanical fixing device. A method for forming honeycomb core composite materials characterized by applying pressure and heating.