A process for forming the outer shell of an electric-driven aircraft

Abstract

The present invention discloses a process for forming an electric-drive aircraft shell outside a tank, comprising: preparing a fiber preform: dividing the fiber preform into several components, cutting the reinforcement fabric according to the structure of the components to obtain the reinforcement fabric components; splicing the inner molds: assembling the inner molds of the electric-drive aircraft shell together, placing a pre-catalytic resin film on the outer side of the inner molds, then assembling the reinforcement fabric components on the outer side of the pre-catalytic resin film, and sewing the seams of adjacent reinforcement fabric components with conductive wire to obtain the fiber preform; splicing the outer mold: assembling the outer mold of the electric-drive aircraft shell outside the fiber preform; and vacuuming. Through the above-mentioned methods, the electric-drive aircraft shell outside-tank forming process described in the present invention realizes the outside-tank forming of large electric-drive aircraft shells, can reduce porosity and bubble problems, and improve fiber content and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of external tank molding of large shells, and in particular to an external tank molding process for an electric-drive aircraft shell. Background Art

[0002] For small electric-drive aircraft, the performance improvement that can be provided by the composite material of the shell is limited, but for large electric-drive aircraft, the composite material and lightweighting of the shell are of great significance to improving speed, endurance, ammunition load and maneuverability.

[0003] Compared to metal components, composite shells can reduce weight by over 70%. For large electric aircraft, component reduction and consolidation should be considered as much as possible. Aircraft component consolidation is generally easy to achieve using composite material processing technology, minimizing the number of components and reducing the aircraft's failure rate.

[0004] In order to minimize the number of shell components, it is necessary to integrate and form them in one piece, which results in a single shell being too large. In the production of composite shells, the size of conventional autoclave processes is limited, making it impossible to produce large electric aircraft shells in a tank, and only external molding is possible. Compared to in-tank molding, external molding does not use large, size-restricted pressure equipment and has a wide range of applications. However, large-sized shells are more prone to bubble problems during production, have high porosity, low fiber content, and require higher resin fluidity, which requires improvement. Summary of the Invention

[0005] The main technical problem solved by the present invention is to provide an electric-drive aircraft shell outside the tank molding process, which can be used to carry out the outside tank molding of large electric-drive aircraft shells, reduce bubble problems and porosity, and improve fiber content, construction efficiency and mechanical properties.

[0006] In order to solve the above technical problems, the present invention adopts a technical solution: providing an electric drive aircraft shell tank outer molding process, comprising the following steps:

[0007] Fabrication of fiber preforms: The electric aircraft shell is modeled in three dimensions using software. The fiber preform is then divided into several components. Reinforced fabrics of a certain thickness are produced using reinforced fiber materials. The reinforced fabrics are then cut according to the structure of the components to obtain the reinforced fabric components.

[0008] Inner mold assembly: Assemble the inner molds of the electric aircraft shell together, place the pre-catalyzed resin film on the outer side of the inner mold, then assemble the reinforced fabric components on the outer side of the pre-catalyzed resin film, and use conductive thread to sew the seams of adjacent reinforced fabric components to obtain a fiber preform;

[0009] Splicing of outer mold: Assemble the outer mold of the electric drive aircraft shell on the outside of the fiber preform, and prefabricate air holes on the outer mold;

[0010] Vacuuming: Lay a layer of breathable material on the outside of the outer mold, then seal the breathable material with a vacuum bag, and evacuate the vacuum bag to make the pre-catalytic resin film heat up and melt, and penetrate into the fiber preform under vacuum state. After curing, the electric drive aircraft shell is obtained.

[0011] In a preferred embodiment of the present invention, the reinforced fabric is sandwich fabric.

[0012] In a preferred embodiment of the present invention, a vibration generator is installed on the outer mold to vibrate during the vacuuming process.

[0013] In a preferred embodiment of the present invention, an electric heating plate is provided in the inner mold, and is energized and heated during the vacuuming process.

[0014] In a preferred embodiment of the present invention, the conductive wire is externally connected to a power supply module, and is powered and heated during the vacuuming process.

[0015] In a preferred embodiment of the present invention, the conductive wire is a conductive carbon fiber wire.

[0016] In a preferred embodiment of the present invention, the reinforcing fiber material is one of carbon fiber, aramid fiber or PBO fiber.

[0017] In a preferred embodiment of the present invention, the breathable material is made of polytetrafluoroethylene cloth or adhesive felt.

[0018] The beneficial effects of the present invention are as follows: the present invention points out an electric-drive aircraft shell outside tank molding process, which utilizes component blocks for assembly, has high laying efficiency, and utilizes conductive threads to sew the seams of adjacent reinforced fabric component blocks, which can not only improve structural stability, but also heat during the vacuuming process, thereby improving the fluidity of the resin at the seam position, which is beneficial to reducing porosity and bubble problems, improving fiber content and mechanical properties, and realizing the outside tank molding of large electric-drive aircraft shells with high construction efficiency. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The embodiments of the present invention include:

[0021] A process for forming an outer shell of an electric-driven aircraft, comprising the following steps:

[0022] Fabrication of fiber preforms: Software is used to create three-dimensional fiber preforms for the electric aircraft shell. The fiber preforms are then divided into several blocks and numbered. Large blocks can be used in the flat parts of the electric aircraft shell to reduce seams, while multiple small blocks can be used for splicing in the curved parts of the shell.

[0023] A reinforced fabric of a certain thickness is produced using a reinforcing fiber material. In this embodiment, the reinforcing fiber material is one of carbon fiber, aramid fiber, or PBO fiber, which has light weight and high strength. The reinforcing fabric is a sandwich fabric, which is obtained by three-dimensionally weaving the reinforcing fiber material.

[0024] According to the structure of the component blocks, the reinforced fabric is automatically cut by a laser cutting machine to obtain the reinforced fabric component blocks, and the blocks are numbered with a marker;

[0025] Inner mold assembly: Assemble the inner molds of the electric aircraft shell and place the pre-catalytic resin film on the outer side of the inner mold. In this embodiment, an electric heating plate is provided in the inner mold to facilitate power supply and heating during the subsequent vacuuming process, thereby improving the efficiency of heating and melting the pre-catalytic resin film.

[0026] The reinforced fabric blocks are then assembled on the outer side of the pre-catalyzed resin film, and the seams of adjacent reinforced fabric blocks are sewn using conductive thread to obtain a fiber preform. Since the reinforced fabric blocks are prefabricated, they can be assembled according to the numbering, which improves the efficiency of laying the fabric. In addition, the conductive thread is made of conductive carbon fiber thread, which can not only improve structural stability but also heat during the vacuuming process. Subsequently, the conductive thread is connected to an external power module and energized and heated during the vacuuming process, which improves the fluidity of the resin at the seam position and helps reduce porosity and bubble problems.

[0027] Assembly of the outer mold: The outer mold of the electric aircraft shell is assembled on the outside of the fiber preform, and air holes are prefabricated on the outer mold. In this embodiment, a vibration generator is installed on the outer mold to vibrate during the vacuuming process, further reducing porosity and air bubbles, improving resin flow, and further increasing fiber content.

[0028] Vacuuming: Lay a layer of breathable material on the outside of the outer mold. The breathable material can be made of either polytetrafluoroethylene cloth or adhesive felt. Then use a vacuum bag to seal the breathable material, evacuate the vacuum bag, turn on the vibration generator and the power module connected to the conductive wire, so that the pre-catalytic resin film heats up and melts, and penetrates into the fiber preform under vacuum. After curing, the electric drive aircraft shell is obtained, and the inner and outer molds are removed.

[0029] In summary, the electric-drive aircraft shell out-of-tank molding process pointed out in the present invention can be used for out-of-tank molding of large electric-drive aircraft shells, realizing the integration and one-time molding of the shells, improving the structural strength and production efficiency, reducing the dead weight, and being beneficial to improving the comprehensive performance of the electric-drive aircraft shells.

[0030] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A process for forming the outer shell of an electric-driven aircraft, characterized in that: The following steps are involved: Fabrication of fiber preforms: The electric aircraft shell is modeled in three dimensions using software. The fiber preform is then divided into several components. Reinforced fabrics of a certain thickness are produced using reinforced fiber materials. The reinforced fabrics are then cut according to the structure of the components to obtain the reinforced fabric components. Inner mold assembly: Assemble the inner molds of the electric aircraft shell together, place the pre-catalyzed resin film on the outer side of the inner mold, then assemble the reinforced fabric components on the outer side of the pre-catalyzed resin film, and use conductive thread to sew the seams of adjacent reinforced fabric components to obtain a fiber preform; Splicing of outer mold: Assemble the outer mold of the electric drive aircraft shell on the outside of the fiber preform, and prefabricate air holes on the outer mold; Vacuuming: Lay a layer of breathable material on the outside of the outer mold, then seal the breathable material with a vacuum bag. The vacuum bag is evacuated, causing the pre-catalytic resin film to heat up and melt, and then penetrate into the fiber preform under vacuum. After curing, the electric drive aircraft shell is obtained; The inner mold is provided with an electric heating plate, which is energized and heated during the vacuuming process. The conductive wire is externally connected to a power supply module, which is energized and heated during the vacuuming process.

2. The outer tank molding process of the electric-driven aircraft shell according to claim 1 is characterized in that: The reinforced fabric is a sandwich fabric.

3. The outer tank molding process of the electric-driven aircraft shell according to claim 1 is characterized in that: The outer mold is provided with a vibration generator for vibrating during the vacuuming process.

4. The outer tank molding process of the electric-driven aircraft shell according to claim 1 is characterized in that: The conductive wire is a conductive carbon fiber wire.

5. The outer tank molding process of the electric-driven aircraft shell according to claim 1 is characterized in that: The reinforcing fiber material is one of carbon fiber, aramid fiber or PBO fiber.

6. The outer tank molding process of the electric-driven aircraft shell according to claim 1 is characterized in that: The breathable material is made of polytetrafluoroethylene cloth or adhesive felt.