JPH04316845A - Method for molding composite material blade shape - Google Patents

Abstract

PURPOSE:To prepare a thin blade thickness product or a product having a complicated curved surface shape air stream surface of a inferiority of the blade-shaped air stream surface of a blade-shaped product or the bonding inferiority of a honeycomb material and a prepreg. CONSTITUTION:Prepregs 6 are stacked on a molding jig 8 for respective blade- shaped single surfaces 4, 5 and a honeycomb material 7 is further superposed thereon and pressed under heating to be bonded and cured and the upper part is cut in a planar state to form one and other blade-shaped single surfaces 4, 5 to a blade-shaped product. By this method, the shape inferiority of a blade- shaped air stream surface and the generation of the bonding inferiority of the honeycomb material 7 and the prepregs 6 are prevented and, by obtaining the blade-shaped product by bonding the single cut surfaces of one and other blade- shaped single surfaces 4, 5 by an adhesive material 3, a product having a thin blade thickness or a complicated curved surface shape can be prepared.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming composite airfoils such as air flow rectifying vanes in wind fuselages, aircraft rotor blades, small blades for high-lift devices, and rudder blades.

0002

2. Description of the Related Art FIG. 5 shows an outline of a conventional airfoil product. As shown in Fig. 5, this airfoil product has an airfoil surface made of a composite material (fiber-reinforced thermosetting resin) outer skin 01, and the inside has a thin metal plate or core material as shown in the broken part. It contained a honeycomb core 02 made of plastic-impregnated paper. The outer skin 01 and the honeycomb core 02 were fixed with adhesive, ensuring product rigidity and an aerodynamic shape.

FIG. 4 shows the conventional airfoil forming method for the above-mentioned airfoil product.
This will be explained using (a), (b), and (c). First, (a)
As shown in the figure, honeycomb material 07 is cut using honeycomb cutting jig 012.
The honeycomb material 07 is cut as shown by the chain line using a honeycomb material cutting machine or the like so that the upper surface has an airfoil shape on one side. Next, after releasing the honeycomb material 07 from the honeycomb cutting jig 012, as shown in (b), the honeycomb material 07 is inverted, fixed to a honeycomb cutting jig 014 having an airfoil-like airflow surface shape on one side, and processed in the same manner as above. Honeycomb core 02 with an airfoil shape by cutting the upper surface
Manufacture.

Next, as shown in (c), an adhesive is laminated on a composite skin with an airfoil-like airflow surface shape that has been molded and hardened in advance, or prepreg (a sheet-like composite material in a semi-hardened state).
06 is laminated to cover the outer surface of the honeycomb core 02, the honeycomb core 02 and prepreg etc. 06 are placed on the upper surface of the forming jig 08 which has an airfoil shape on one side of the airflow surface, and one side of the remaining honeycomb core 02 and prepreg etc. 06 is stacked. Cowl plate (upper mold for molding) with airflow surface shaped like an airfoil on one side
Assemble 013. Furthermore, the honeycomb core 02, the prepreg 06, etc., and the cowl plate 013 are covered with a bag material (heat-resistant flexible film) 09 to maintain the pressurized state by applying pressure, and then vacuum is applied. Honeycomb core 02 and prepreg etc. 06 by pressure
Pressurize.

That is, the bag material 09 is adhesively sealed to the molding jig 08 with a sealant (heat-resistant, soft and viscous clay-like substance) 010, and the air inside the molding jig 08, the bag material 09, and the sealant 010 is sealed. By degassing the honeycomb core 02 and the prepreg etc. 06 are pressurized via the cowl plate 013 and brought into close contact with each other. In this case, the forming jig 08 must be airtight and not deformed under pressure, while the cowl plate 013 is used to pressurize the honeycomb core 02 and prepreg etc. 06 as described above. It needs to have some flexibility.

Honeycomb core 02 assembled in this way
, prepreg, etc. 06, forming jig 08, bag material 09, sealant 010, and cowl plate 013 are inserted into heat treatment equipment such as an autoclave or furnace, and heated for a certain period of time while maintaining a pressurized state to form honeycomb core 02, prepreg, etc. 06 is adhesively fixed and cured.

[0007] After this, the honeycomb core 02 is heated to the specified temperature.
The prepreg etc. 06, the molding jig 08, the bag material 09, the sealant 010, and the cowl plate 013 are cooled to form the bag material 09, the sealant 010, and the cowl plate 013.
was removed, and the honeycomb core material 02 and prepreg etc. 06 were released from the molding jig 08 to obtain an airfoil product shown in FIG.

[0008]

[Problems to be Solved by the Invention] Conventional airfoil forming methods have the following problems. (1) It is difficult to cut the honeycomb material into an airfoil shape, which makes it particularly difficult to mold and manufacture thin airfoil products and small airfoil products. In this case, the rigidity of the product itself is reduced, which limits the range of use of the product. This is because honeycomb material has high rigidity in the honeycomb cell direction,
This is because other than that, the rigidity is low, so it is easily deformed during cutting, making it difficult to perform highly accurate cutting into an airfoil shape, and the rigidity further decreases as the thickness and size become smaller. (2) Due to (1) above, a shape mismatch occurs between the honeycomb core and the forming jig, resulting in poor adhesion between the composite skin and the honeycomb core and a shape defect in the airflow surface of the airfoil. In other words, if the shape of the honeycomb core is defective, the cowl plate is flexible and will deform under pressure, and the composite outer skin will be adhesively molded to fit the honeycomb core shape, and the airfoil airflow surface will be fixed. The shape becomes defective. Further, if the honeycomb core has a defective shape with local unevenness, the cowl plate cannot follow the shape of the honeycomb core, resulting in poor adhesion between the honeycomb core and the composite outer skin. These affect the aerodynamic performance of the airfoil product and can lead to damage to the product itself.

The present invention aims to provide an airfoil forming method that solves the above problems.

0010

[Means for Solving the Problems] The method for forming a composite airfoil of the present invention involves laminating prepregs on each curved surface portion of a forming jig having curved surface portions having the shapes of one and the other surfaces of an airfoil product. After layering the honeycomb material on top of the honeycomb material, the prepreg and honeycomb material are bonded and cured by heating under pressure, and the upper part of each is cut flat to obtain one side of one airfoil and the other side, and then the upper surface of one side of the same airfoil is The method is characterized in that an adhesive is applied to the airfoil, one side of one airfoil is inverted and stacked on one side of the other airfoil, and then the one side and the other side of the airfoil are heated under pressure to obtain an airfoil product. There is.

[0011]

[Operation] In the above, one side of the airfoil product and the other side of the airfoil are formed by laminating prepreg on the curved surface of the forming jig, and then layering the honeycomb material on top of the prepreg, and then applying heat and pressure to the prepreg. Because the honeycomb material is adhesively hardened and the upper part is cut into a flat surface, the conventional high-precision airfoil-shaped curved surface cutting process for honeycomb materials is no longer necessary, and the prepreg serves as a reinforcing material when cutting the honeycomb material into a flat surface. The honeycomb material is not deformed, and no defects in the shape of the airflow surface of the airfoil or poor adhesion between the honeycomb material and the prepreg due to defects in the shape of the honeycomb material occur.

[0012] In addition, the plane-cut surfaces of one side and the other side of the airfoil are bonded with an adhesive, and the adhesive acts as a wing spar, increasing the rigidity of the product. It is also possible to manufacture thick sheets.

Furthermore, even if the surface of the airfoil product has a complicated curved shape, it can be easily molded and manufactured since there is no need for cutting the curved surface.

[0014] As a result of the above, there is no occurrence of defects in the shape of the airflow surface of the airfoil product or poor adhesion between the honeycomb material and the prepreg.
A molding method that allows the production of products with thin blades and products with complex curved shapes will be realized.

[0015]

[Embodiment] An embodiment of the present invention will be explained with reference to FIG. In FIG. 1, prepreg or the like 6 is formed on the curved surface of the upper surface of the forming jig 8 for one side 4 and 5 of the airfoil product, respectively.
After layering the prepreg etc. 6 and the honeycomb material 7 on top of the honeycomb material 7, the prepreg etc. 6 and the honeycomb material 7 are covered with a bag material 9 and pressurized with vacuum pressure, which is heated for a certain period of time to bond and harden, and then cooled. After removing the bag material 9, the upper part of each is cut into planes to obtain airfoil single sides 4 and 5. This airfoil single side 4
, 5, after applying the adhesive 3 to the upper surface, one airfoil surface 4 or 5 is inverted and placed on the upper surface of the other airfoil surface 4 or 5. This superimposed one side and the other airfoil side 4
, 5 are covered with a bag material 9 and vacuum pressure is applied, and the material is heated for a certain period of time to bond and harden, thereby obtaining a wing-shaped product.

In the above, each of the forming jigs 8 for the airfoil single sides 4 and 5 shown in FIGS. 1(a) and 1(b) is provided with a curved surface portion that corresponds to the shape of one side of the airflow surface of the airfoil product. On this curved surface part, an adhesive is laminated to a composite skin having an airflow surface shape on one side of an airfoil, which has been molded and hardened in advance, or a prepreg 6 is laminated, and a honeycomb material 7 is stacked on top of the prepreg or the like 6. In this case, the honeycomb material 7 needs to have dimensions slightly larger than the thickness, width, and length of the airfoil single side 4 or 5 to be molded.

Since the honeycomb material 7 has low rigidity in directions other than the cell direction of the honeycomb, it easily bends along the curved surface of the forming jig 8 and comes into close contact with the prepreg etc. 6. In order to maintain the pressurized state, prepreg etc. 6 and 7 are used with bag material (heat-resistant flexible film) 9.
After coating, prepreg etc. 6 and honeycomb material 7 are applied under vacuum pressure.
Pressurize.

That is, the bag material 9 is adhesively sealed to the molding jig 8 with a sealant (heat-resistant, soft and viscous clay-like substance) 10, and the molding jig 8, the bag material 9, and the sealant 1 are sealed together.
By degassing the air inside the sealed interior, the prepreg etc. 6 and the honeycomb material 7 are pressurized and completely adhered to each other. In this case, the forming jig 8 must be made airtight and not deformed under pressure. Here, as mentioned above, since the honeycomb material 7 has low rigidity in directions other than the honeycomb cell direction, the honeycomb protection material 11 is assembled to the end of the honeycomb material 7 before applying the bag material 9, and the honeycomb material 7 is Prevents the edges from collapsing.

Prepreg etc. assembled in this way 6,
Honeycomb material 7, forming jig 8, bag material 9, sealant 1
0 and the honeycomb protective material 11 are inserted into heat treatment equipment such as an autoclave or a furnace, and heated for a certain period of time while maintaining the pressurized state to bond and harden the prepreg etc. 6 and the honeycomb material 7.

After that, prepreg etc. 6, honeycomb material 7, forming jig 8, bag material 9, sealant 10 are heated to the specified temperature.
After cooling the honeycomb protection material 11, the bag material 9,
The sealant 10 and the honeycomb protection material 11 are removed, and the honeycomb material 7 is subjected to plane cutting as shown by chain lines in the figure using a honeycomb material cutting machine or the like to form airfoil single sides 4 and 5.

Next, as shown in FIG. 1(c), one of the molded airfoil surfaces 4 and 5 (in the figure, the airfoil surface 5) is kept aligned with the forming jig 8, and the honeycomb is formed. Adhesive material (sheet hardened resin) 3 is applied to the entire surface of the honeycomb core 2 obtained by plane cutting the material 7, and the other airfoil side 4 or 5 (in the figure, the airfoil side 4) is inverted. Align and secure so that it does not shift.

Thereafter, in order to pressurize and bring the airfoil surfaces 4 and 5 into close contact, the airfoil surfaces 4 and 5 are molded using bag material 9 and sealant 10 in the same manner as in the molding process for the airfoil surfaces 4 and 5 described above. After the coating, the air in the molding jig 8, bag material 9, and sealant 10 is evacuated.

[0023] The airfoil single side 4, 5 assembled in this way,
By pressurizing and heating the molding jig 8, bag material 9, and sealant 10 in the same manner as in the process of forming the airfoil single sides 4 and 5 described above, the airfoil single sides 4 and 5 are bonded and fixed.

Thereafter, this is cooled, the bag material 9 and the sealant 10 are removed, and the airfoil single side 4, 5 is released from the molding jig 8, thereby obtaining the airfoil product shown in FIG. 2.

[0025] As described above, the prepreg, etc. and the honeycomb material are molded according to the shape of the forming jig, so there is no shape mismatch between the prepreg, etc. and the honeycomb material and the forming jig, and there is no mismatch between the prepreg, etc. and the honeycomb material. There is no problem of poor adhesion or poor shape of the airflow surface of the airfoil, and it is possible to mold the airfoil into various shapes as shown in FIG. 3.

[0026]

[Effects of the Invention] In the method for forming a composite airfoil of the present invention, prepreg is laminated on a forming jig for one side of each airfoil, a honeycomb material is further layered on top of the prepreg, and the adhesive is cured by heating under pressure. After that, by plane-cutting the upper part to form one side of the airfoil and the other side of the airfoil, it is possible to prevent defects in the shape of the airflow surface of the airfoil and poor adhesion between the honeycomb material and the prepreg, and By bonding the planar cut surfaces of one side of the airfoil and the other airfoil with an adhesive to obtain an airfoil product, a molding method that can produce products with a thin blade thickness and complex curved shapes is realized.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a method for forming a composite airfoil product according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a schematic structure of a composite airfoil product according to the above embodiment.

FIG. 3 is a cross-sectional view of a typical composite airfoil product according to the above embodiment.

FIG. 4 is an explanatory diagram of the conventional molding method.

FIG. 5 is an explanatory diagram of a schematic structure of a composite airfoil product produced by a conventional molding method.

[Explanation of symbols]

1 Composite outer skin 2 Honeycomb core 3. Adhesive material 4,5　Airfoil single side 6 Prepreg 7 Honeycomb material 8 Molding jig 9 Bag material 10 Sealant 11 Honeycomb protection material

Claims (1)

[Claims] [Claim 1] Prepreg is laminated on each of the curved surface portions of a forming jig having the shape of one and the other surface of the airfoil product, and a honeycomb material is layered on top of the curved surface portions, and then the prepreg is heated under pressure. After the prepreg and honeycomb material are bonded and hardened, and the upper part of each is cut flat to obtain one side and the other side of the airfoil, adhesive is applied to the top surface of one side of the same airfoil, and one side of the airfoil is turned over. 1. A method for forming a composite airfoil, which comprises stacking one side of the airfoil on one side of the other airfoil, and then pressing and heating the one side and the other side of the airfoil as one body to obtain an airfoil product.