JP7602798B2 - Manufacturing method of integrally molded product, integrally molded product, and electric aircraft component - Google Patents

Description

The present invention relates to a manufacturing method for an integrally molded product in which flexible structural material, flexible electrical wiring, and resin are integrally molded, for example for use in the housing of a small unmanned aerial vehicle, an integrally molded product, and an electric aircraft component.

As in Patent Document 1 (JP Patent Publication 2021-120246 A), a small unmanned aerial vehicle (also called a "drone") is known in which multiple arms extend outward from a housing equipped with multiple electronic components, and a motor is placed at the outer end of each arm to control the rotation of a propeller connected to the rotating shaft of each motor. For such small unmanned aerial vehicles, there is a need for lighter components, higher rigidity, smaller size, and mass production. In addition, because the housing and electrical wiring are independent components, the electrical wiring moves relative to the housing, causing noise when electricity is applied. Of course, similar issues have arisen not only in small unmanned aerial vehicles, but also in equipment components in fields such as construction machinery, railway vehicles, and artificial satellites.

On the other hand, in order to realize lighter weight, higher rigidity, and mass production of components, components using FRP (Fiber Reinforced Plastic) have been conventionally applied to various industrial fields. For example, as shown in Patent Document 2 (JP Patent Publication 61-19440), a method is known for molding aircraft fuselages in which reinforcing fibers such as a mixture of carbon fiber, glass fiber, aramid fiber, etc. are layered on a semi-cylindrical male mold, the reinforcing fibers are impregnated with resin, and the resin is heated and pressurized to form the mold.

JP 2021-120246 A Japanese Unexamined Patent Publication No. 61-19440

In a device such as the drone shown in Patent Document 1, for example, if the housing, arm, and electronic components are integrally molded, it is possible to simultaneously achieve weight reduction, high rigidity, miniaturization, mass production, and reduced noise when electricity is applied. To achieve weight reduction and high rigidity, as shown in Patent Document 2, a method of integral molding in which resin is impregnated into a structural material such as reinforced fiber, such as the FRP molding method, is desirable. However, a manufacturing method for an integrally molded product of a flexible structural material such as FRP, flexible electrical wiring, and resin, the integrally molded product, and components for electric aircraft were not known.

The present invention was made in consideration of the above circumstances, and aims to provide a manufacturing method for an integrally molded product of flexible structural material, flexible electrical wiring, and resin, an integrally molded product, and a component for an electric airplane.

The manufacturing method of the present invention is a manufacturing method of an integrally molded product of a structural material made of carbon fiber, glass fiber, or resin fiber, flexible electrical wiring, and resin, and has the following requirements: a first sewing step of sewing the structural material to a first base material, a second sewing step of sewing the electrical wiring to a second base material, a resin impregnation step of impregnating the first base material and the second base material with the resin, and a integral molding step of hardening the resin to integrally mold the structural material, the electrical wiring, and the resin.

Furthermore, the one-piece molded product of the present invention is an one-piece molded product of a structural material made of carbon fiber, glass fiber, or resin fiber , flexible electrical wiring, and resin, and the one-piece molded product is manufactured by sewing the structural material to a first base material, sewing the electrical wiring to a second base material, impregnating the first base material and the second base material with the resin, and then hardening the resin to integrally mold the structural material, the electrical wiring, and the resin.

Furthermore, the electric airplane component of the present invention is an integrally molded product of a structural material made of carbon fiber, glass fiber, or resin fiber, flexible electrical wiring, and resin, and the integrally molded product is manufactured by sewing the structural material to a first base material, sewing the electrical wiring to a second base material, impregnating the first base material and the second base material with the resin, and then hardening the resin to integrally mold the structural material, the electrical wiring, and the resin.

By going through the above steps in the manufacturing method of the integrally molded product according to the present invention, it is possible to reduce the weight and increase the rigidity of the integrally molded product. In addition, the number of steps required to manufacture the integrally molded product of the structural material, electrical wiring, and resin can be reduced, making it possible to mass-produce the integrally molded product. Furthermore, by embedding the electrical wiring in the resin, it is possible to reduce the size of the integrally molded product. Furthermore, by embedding the electrical wiring in the resin, it is possible to reduce noise when electricity is applied.

In addition, the above-mentioned configuration of the integrally molded product according to the present invention makes it possible to reduce the weight and increase the rigidity of the integrally molded product. Furthermore, the number of steps required to manufacture the integrally molded product of the structural material, electrical wiring, and resin can be reduced, making it possible to mass-produce the integrally molded product. By embedding the electrical wiring in the resin, the integrally molded product can be made smaller. Furthermore, by embedding the electrical wiring in the resin, it is possible to reduce noise when electricity is applied.

In addition, in the electric airplane component according to the present invention, the above configuration allows the integrally molded product to be lightweight and highly rigid. Furthermore, the man-hours required for manufacturing the integrally molded product of the structural material, electrical wiring, and resin can be reduced, enabling mass production of the integrally molded product to be realized. By embedding the electrical wiring in the resin, the integrally molded product can be made smaller. Furthermore, by embedding the electrical wiring in the resin, noise generated when electricity is applied can be reduced.

FIG. 2 is a plan view of a first base material having a flexible structural material sewn thereto in the present invention. FIG. 2 is a plan view of a second base material to which flexible electrical wiring is sewn in accordance with the present invention. 4A to 4C are explanatory diagrams of a manufacturing method of an integrally molded product according to the first embodiment of the present invention. 4A to 4C are explanatory diagrams of a manufacturing method of an integrally molded product according to the first embodiment of the present invention. FIG. 2A is a perspective view of an upper portion of an integrally molded product of the present invention, and FIG. 2B is a perspective view of a lower portion of the integrally molded product of the present invention. 10A to 10C are explanatory diagrams of a manufacturing method of an integrally molded product according to a second embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a first substrate to which a flexible structural material is sewn in the present invention. FIG. 2 is a plan view of a second substrate to which a flexible electrical wiring is sewn in the present invention. FIG. 3 is an explanatory diagram of a method for manufacturing an integrally molded product in the first embodiment of the present invention. FIG. 4 is an explanatory diagram of a method for manufacturing an integrally molded product in the first embodiment of the present invention. FIG. 5(a) is an upper perspective view of an integrally molded product in the present invention, and FIG. 5(b) is a lower perspective view of an integrally molded product in the present invention. FIG. 6 is an explanatory diagram of a method for manufacturing an integrally molded product in the second embodiment of the present invention. In addition, in all the drawings for explaining each embodiment, the same reference numerals are used for members having the same functions, and repeated explanations thereof may be omitted. In addition, in Figures 1, 2, 3, 4, and 6, the structural material 10 and electrical wiring 12 are shown simplified for the purpose of explanation, but in reality, as shown in Figure 5, it may be an integrally molded product (electric aircraft component) 100 (120) having a complex-shaped structural material 10 and electrical wiring 12. Note that the connector 15 is omitted from Figures 4 to 6.

(Integrated moldings and electric aircraft components)
5(a) and 5(b), the integrally molded product (electric aircraft component) 100 (120) in this embodiment is an integrally molded product (electric aircraft component) 100 (120) in which a flexible structural material 10, flexible electrical wiring 12, electronic components 14, a thickness adjustment member 16, and a resin 20 are integrally molded. As described in detail in each embodiment, the integrally molded product (electric aircraft component) 100 (120) is an integrally molded product (electric aircraft component) 100 (120) in which a first substrate 11 (first preform 70) to which the flexible structural material 10 is sewn and a second substrate 13 (second preform 80) to which the flexible electrical wiring 12 is sewn are stacked, then impregnated with the resin 20, and then the resin 20 is hardened to form an integral molded product. More specifically, in FIG. 5B, the integrally molded product (electric aircraft component) 100 (120) is a housing of resin 20 having a recess in the downward direction of the paper, and the structural material 10, electrical wiring 12, electronic components 14, and thickness adjustment member 16 are embedded inside the resin 20. The end of the electrical wiring 12 is exposed from the resin 20. The resin 20 is cured by the autoclave process or VaRTM process described later. In FIG. 4 and FIG. 6, the integrally molded product (electric aircraft component) 100 (120) is configured such that the structural material 10, electrical wiring 12, electronic components 14, and thickness adjustment member 16 are embedded in the resin 20 that is generally bowl-shaped, but it may be flat, curved, or have a recess as shown in FIG. Although there is one electronic component 14 and one thickness adjusting member 16 in FIGS. 5( a ) and 5 ( b ), there may be two or more electronic components 14 and two or more thickness adjusting members 16 .

The above configuration allows the integrally molded product to be lightweight and highly rigid. In addition, the labor required to manufacture the integrally molded product of the structural material, electrical wiring, and resin can be reduced, allowing for mass production of the integrally molded product. Since the integrally molded product (electric aircraft component) 100 (120) is integrally molded with not only the structural material 10 but also the electrical wiring 12, the device using the integrally molded product (electric aircraft component) 100 (120) can be made smaller. In addition, since the electrical wiring 12 is embedded in the resin, the electrical wiring 12 is stationary relative to the resin (the housing in the above example) 20, and noise during current flow can be reduced.

The integrally molded product (electric aircraft component) 100 (120) in this embodiment may be an integrally molded product (electric aircraft component) 100 (120) in which a flexible structural material 10, flexible electrical wiring 12, electronic components 14, and resin 20 are integrally molded. By not having a thickness adjustment member 16, the number of parts can be reduced. Of course, the integrally molded product (electric aircraft component) 100 (120) may be an integrally molded product (electric aircraft component) 100 (120) in which a flexible structural material 10, flexible electrical wiring 12, and resin 20 are integrally molded.

(Manufacturing method of integrally molded products)
First Embodiment
Next, a manufacturing method of the integrally molded product 100 in the first embodiment will be described. As shown in Fig. 1 and Fig. 2, the manufacturing method includes a first sewing step of sewing a flexible structural material 10 to a first base material 11, a second sewing step of sewing a flexible electrical wiring 12 to a second base material 13, a resin impregnation step of impregnating the first base material 11 (i.e., the first preform 70) or the second base material 13 (i.e., the second preform 80) with a resin 20, and an integral molding step (autoclave step) of hardening the resin 20 to integrally mold the structural material 10, the electrical wiring 12, and the resin 20.

(First sewing process)
In the first sewing step in this embodiment, data of a carbon fiber (hereinafter, sometimes simply referred to as "CF") path (CF path) 10 is prepared as a flexible structural material 10 to be sewn to a first base material 11 described later. The CF path 10 may have any shape as long as it functions as a reinforcing fiber of the integrally molded product 100 and can be accommodated in a lower mold 30 and an upper mold 40 described later and arranged on a virtual plane or a virtual curved surface. As an example, as shown in Fig. 5(a) and Fig. 5(b), a path shape designed by topology optimization design and that can be produced in one stroke (i.e., a single CF path 10) is preferable. This is because the number of steps in sewing can be reduced.

In topology optimization design, a weight reduction level is determined, which indicates the degree of weight reduction relative to the weight (model weight) of the integrally molded product 100 before optimization, and the shape after weight reduction is calculated by numerical calculation using one of the following methods: homogenization method, level set method, or density method. Next, data for the CF path 10 corresponding to the shape obtained by one of these methods is created.

In addition to topology optimization design, data for the CF path 10 may be created using dimension optimization design or shape optimization design.

In the present embodiment, instead of CF, resin fibers such as glass fiber, aramid fiber (Kevlar (registered trademark) fiber), polyethylene fiber (Dyneema (registered trademark) fiber), Zylon (registered trademark) fiber, and boron fiber can be preferably used as the flexible structural material 10. As another example, a metal wire such as tungsten can be preferably used.

Next, the first substrate 11 is prepared. The first substrate 11 in this embodiment is a glass cloth substrate 11, but other substrates such as carbon fiber substrates, nylon fiber substrates, polyester fiber substrates, and cotton fiber substrates can be used. Any substrate can be used as long as the structural material 10 can be sewn to the substrate and the resin 20 can be impregnated therein. Since the integrally molded product 100 in this embodiment is an integrally molded product 100 including a curved shape, the first substrate 11 is preferably a plain weave material having a thickness of about several tens of μm to several hundreds of μm, for example. In addition, in order to impregnate the resin 20 in the resin impregnation process described later, the first substrate 11 has a fiber density that allows the resin to pass through. As long as the resin 20 can pass through, a film-like substrate can be used. In addition, the film-like first substrate 11 can be preferably one that melts in the resin 20 in the integral molding process. In this way, the first substrate 11 can be used instead of the resin 20.

Next, the CF pass (in this embodiment, CF tow (carbon fiber bundle)) 10 is sewn to the first substrate 11 by TFP (Tailored Fiber Placement). TFP is generally a fiber preform technology that applies textile technology. For TFP, an industrial embroidery machine (not shown) dedicated to reinforcing fibers is used. Based on the data of the above-mentioned CF pass 10, the CF tow 10 is printed (i.e., placed on the first substrate 11) on the first substrate 11 and sewn by the embroidery machine. This makes it possible to produce the first preform 70 in which the structural material 10 is sewn to the first substrate 11 by the thread 17. When sewing the CF tow 10 to the first substrate 11, the fiber orientation angle is continuously changed by a moving stage and a rotating head (neither of which are shown). The width of the CF tow 10 is, for example, about several mm to a dozen mm, and the thickness is, for example, about several μm to several mm.

The sewing method may be any method capable of sewing the CF tow 10 to the first base material 11. In this embodiment, a zigzag stitch is applied without penetrating the CF tow 10 itself. In other words, the CF tow 10 is attached to the first base material 11 by the thread 17. The stitch pitch is, for example, about 1 mm to 5 mm.

The CF tow 10 may be either a PAN-based or pitch-based CF tow 10. PAN-based CF tows can be preferably used for the CF tow 10 of this embodiment. The CF tow 10 may be any of large tow, regular tow, and small tow. Regular tow can be preferably used for the CF tow 10 of this embodiment.

In addition, other than tow, filaments, stable yarns, cloth, grades, chopped yarns, felts, mats, papers, prepregs, and compounds can be suitably used as the CF tow 10, provided that they are not in powder form.

(Second sewing process)
Next, in the second sewing step in this embodiment, a flexible electric wiring (hereinafter, sometimes simply referred to as "electric wiring") 12 to be sewn to the second base material 13 described later is prepared. The electric wiring 12 in this embodiment is an insulating coated electric wire such as a silicon cable having a copper wire inside or a stretchable conductive ribbon. As described above, the integrally molded product 100 in this embodiment is an integrally molded product 100 including a curved shape. In this embodiment, a silicon cable 12 is used. Note that the electric wiring 12 may be a bare electric wire since it can maintain insulation by being embedded in the resin 20.

The cross-sectional diameter of the electrical wiring (silicon cable) 12 may be varied depending on the electrical characteristics required for the device using the integrally molded product 100, but in this embodiment, as an example, it is approximately a few mm.

Next, the second substrate 13 is prepared. The second substrate 13 is a glass cloth substrate 13 like the first substrate 11, but other substrates such as carbon fiber substrates, nylon fiber substrates, polyester fiber substrates, and cotton fiber substrates can also be used. Any substrate can be used as long as the electrical wiring 12 can be sewn to it and the resin 20 can be impregnated therein. As an example, the second substrate 13 is preferably a plain weave material having a thickness of about several tens of μm to several hundreds of μm. In addition, in order to impregnate the resin 20 in the resin impregnation process described below, the second substrate 13 also has a fiber density that allows the resin 20 to pass through. In addition, the second substrate 13 may be in the form of a film as long as the resin 20 can pass through it. In addition, the film-like second substrate 13 can be preferably one that melts in the resin 20 in the integral molding process. In this way, the second substrate 13 can be used instead of the resin 20.

Next, the electrical wiring 12 is sewn to the second substrate 13. This sewing may be performed using a general-purpose industrial embroidery machine or by hand sewing. In this embodiment, a zigzag stitch is performed without penetrating the silicon cable 12 itself. This allows the electrical wiring 12 to be attached to the second substrate 13 by the thread 18, and a second preform 80 can be produced in which the electrical wiring 12 is sewn to the second substrate 13.

In this embodiment, the electrical wiring 12 is configured as shown in FIG. 5, with the electronic component 14 disposed in the center of the integrally molded product 100, and the electrical wiring 12 extending from the electronic component 14 toward the periphery of the integrally molded product. A connector 15 may be connected to the end of the electrical wiring 12 opposite the electronic component 14. It is preferable that the connector 15 and the electrical wiring 12 in the vicinity of the connector 15 are not sewn to the second substrate 13. This is to prevent the connector 15 and the tip of the electrical wiring 12 from being embedded in the resin 20 in the integral molding process described below.

(Electronic component mounting process)
Next, an electronic component mounting step is performed in which the electronic component 14 is mounted on the second substrate 13. In this embodiment, the electronic component 14 is mounted or attached to the center of the second substrate 13. The electronic component 14 in this embodiment is a speed controller 14.

The electronic component mounting process preferably includes a process of providing (adhering) a thickness adjustment member 16 between the electronic component 14 and the second substrate 13. This is because the resin penetrates up to the back surface of the electronic component 14 (the gap between the electronic component 14 and the second substrate 13). The thickness adjustment member 16 has a thickness of about several mm, for example. The material of the thickness adjustment member 16 is, for example, processed resin, FRP, or metal such as aluminum. Note that the thickness adjustment member 16 may be formed by laying reinforcing fibers in multiple layers under the electronic component 14 and impregnating them with resin 20.

In addition, it is preferable that the thickness adjustment member 16 is larger than the external shape of the electronic component 14 in a plan view. In other words, it is preferable that the end of the electrical wiring 12 on the electronic component 14 side is placed on the thickness adjustment member 16. This makes it possible to prevent the end of the electrical wiring 12 on the electronic component 14 side from being broken in the resin impregnation process and integral molding process described below.

In this embodiment, a speed controller 14 is used as the electronic component 14, but other electronic components 14 may be mounted. Also, although there is one electronic component 14 in this embodiment, two or more electronic components may be mounted.

(Resin impregnation process)
Next, the resin impregnation process will be described. As shown in Figs. 3 and 4, a molding die (lower die) 30 having a shape of an integrally molded product 100 is prepared. Next, a first preform 70 and a second preform 80 on which an electronic component 14 and a thickness adjusting member 16 are mounted or attached are laminated in order on the lower die 30. Next, resin 20 is laminated on the second preform 80 so that the connector 15 and the end of the electrical wiring 12 are not embedded, and the first preform 70 and the second preform 80 are impregnated with the resin 20. Next, a molding die (upper die) 40 is placed on the second preform 80. This allows a pre-molded product 90 before the integral molding process to be obtained.

Alternatively, resin 20 may be laminated on the surface of the first preform 70, and then the first preform 70 and the second preform 80 may be impregnated with resin 20.

The resin 20 may be a liquid resin 20 that can be applied, or may be a resin sheet 20. In this embodiment, the resin 20 is applied by a hand layup method, so a liquid resin 20 is used.

In this embodiment, the lower die 30 is a molding die and the upper die 40 is a cowl plate (backing plate), but a method using only the lower die 30 may be adopted. Also, in this embodiment, the lower die 30 and the upper die 40 have a curved shape, but if the integrally molded product 100 is a flat plate, the contact surface between the lower die 30 and the upper die 40 may be a flat shape. As an example, the molding dies 30 and 40 have a base material made of a metal material such as prehardened steel.

The lower mold 30 has a structure in which a conductive metal spray coating 32 is layered on top of a metal material 31 by a transfer method. The conductive metal spray coating 32 is formed, for example, from a metal spray coating such as a nickel-chromium alloy, and is configured to generate surface heat when electricity is passed through it. An electrode 33 is provided on the conductive metal spray coating 32, and is configured to be connected to a power source by a conductor (not shown).

If the upper mold 40 is not used, the second preform 80 and the upper part of the resin 20 may be covered with a microwave shielding sheet (not shown). One example of the microwave shielding sheet is a metal film in which a metal foil such as aluminum foil is attached to a resin film. Note that since the lower parts of the first preform 70 and the resin 20 are covered by the lower mold 30, a microwave shielding sheet is not necessary.

To facilitate the release of the integrally molded product 100 from the molds 30, 40, a fluorine-based release sheet (not shown) may be placed between the first preform 70, the second preform 80, and the resin 20 and each of the molds 30, 40. Alternatively, instead of the release sheet, a release agent may be applied to the inside of each of the molds 30, 40.

In addition, when the lower mold 30 has a curved shape, the first substrate 11 and the second substrate 13 may be provided with predetermined cuts or removed portions (neither shown). This allows the structural material 10 and the electrical wiring 12 to be positioned at predetermined positions in the lower mold 30. In the example shown in FIG. 3, by providing cuts or removed portions between the multiple electrical wiring 12 extending outward from the electronic components 14, the structural material 10 and the electrical wiring 12 can be positioned along the curved shape of the lower mold 30.

The resin 20 used in the resin impregnation process in this embodiment is a thermosetting resin such as an epoxy resin, but it is also possible to suitably use thermosetting resins such as phenolic resin (PF), unsaturated polyester resin (UP), and acrylic resin (urethane acrylate, for example), and thermoplastic resins such as polyamide (PA), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyether ketone (PEK), and polyetherimide (PEI). When UP or an acrylic resin is used for the resin 20, the curing temperature can be freely changed depending on the type of radical initiator (more specifically, the organic peroxide curing initiator), so that the range of types of electronic components 14 that can be applied to this embodiment can be expanded.

(Bagging process)
Next, the bagging process will be described. The lower mold 30, the upper mold 40, and the pre-molded product 90 are all bagged with a flexible vacuum bag (nylon bag) 50 for vacuuming. Specifically, as shown in FIG. 4, air in the vacuum bag 50 is sucked from a suction port 51 by a vacuum pump (not shown). The bagging process sucks air in the vacuum bag 50, creating a vacuum (negative pressure) state in the vacuum bag 50, and the resin 20 inside is tightly attached to the lower mold 30 and the upper mold 40. As an example, the vacuum pressure is set to -80 kPa (relative pressure) or less. Note that the vacuuming in the bagging process may be performed before or after the vacuum bag 50 is placed in the autoclave container 60 described later.

The vacuum bag (nylon bag) 50 may be one integrally formed into a bag shape, or may be one formed by gluing the edges of two sheets together with an adhesive or sealant. The vacuum bag 50 is made of an electrical insulator and is made of a material (nylon is one example) that can withstand the temperature during integral molding.

(Integrated molding process (autoclave process))
Next, the integral molding process (autoclave process) will be described. In the autoclave process, the airtight vacuum bag 50 in which the molding dies 30 and 40 are sealed is heated and pressurized in an autoclave container 60, thereby hardening the resin 20.

The autoclave vessel 60 is, for example, a pressure-resistant vessel made of chrome molybdenum steel. In the autoclave process, in order to pressurize the gas inside the autoclave vessel 60, the vessel is configured to be able to seal in gas (compressed air, nitrogen gas, etc.) using a pump (not shown). In addition, the autoclave vessel 60 is provided with an electric heater as a heat source and a blower fan for circulating hot air (neither of which are shown). This allows the gas in the sealed space to be heated and pressurized, thereby also heating and pressurizing the resin 20 in the vacuum bag 50, and allowing it to be thermally cured.

Specifically, the vacuum bag 50 containing the lower mold 30, the upper mold 40, and the pre-molded product 90 and evacuated is placed inside the autoclave container 60, and the autoclave container 60 is then sealed.

Next, electricity is passed through the conductor connected to the electrode 33 to heat the surface of the lower mold 30. The heat generation temperature of the conductive metal spray coating 32 according to this embodiment is, for example, about 100°C to 180°C, but can be changed depending on the material of the resin 20. At the same time as the above heating, air is forced into the autoclave container 60 to pressurize it to a predetermined pressure (for example, a pressure inside the container of 200 kPa to 600 kPa). In this embodiment, heating and pressurization are performed for about one hour at a heat generation temperature of 110°C and a predetermined pressure of 300 kPa. This melts and thermally hardens the resin 20, and an integrally molded product 100 can be obtained by integrally molding the pre-molded product 90.

The use of an electric heater and air blowing operation inside the autoclave container can be omitted depending on the integrally molded product 100.

Next, after the autoclave process is completed, the integrally molded product 100 is removed from the lower mold 30, and unnecessary portions of the outer periphery of the integrally molded product 100 are removed (trimmed) as necessary.

(Manufacturing method of integrally molded products)
Second Embodiment
Next, a method for manufacturing the integrally molded product 120 in the second embodiment will be described. In the resin impregnation process, bagging process, and integral molding process in this embodiment, the pre-molded product 110 not including the resin 20 and the upper mold 45 are sequentially placed on the lower mold 35. Then, the pre-molded product 110 is sealed in a vacuum bag 55, and the vacuum bag 55 is evacuated. Then, the resin 20 is sealed, and the pre-molded product 110 is impregnated with the resin 20. Then, integral molding is performed by utilizing the pressure difference with the atmospheric pressure. This process is a so-called VaRTM (Vacuum assisted Resin Transfer Molding) process. Here, the VaRTM process will be mainly described.

(Resin impregnation process, bagging process, integral molding process (VaRTM process))
After the first sewing step, the second sewing step, and the electronic component mounting step described in the first embodiment, the first preform 70 and the second preform 80 are placed in this order on the lower mold 35 as shown in Fig. 6. Then, the upper mold 45 is further placed on it. The difference from the first embodiment is that the resin 20 is not impregnated at this stage.

Next, a vacuum is drawn inside the vacuum bag 55, and then the resin 20 is sealed inside the vacuum bag 55. Specifically, air is sucked in from the suction port 56 by a vacuum pump (not shown) to create a vacuum (negative pressure) in the gap between the lower die 35 and the upper die 45 (i.e., the space in which the pre-molded product 110 containing no resin 20 exists). Next, the resin 20 is sealed in from the resin sealing port 57, and the pre-molded product 110 is impregnated with the resin 20.

In the resin impregnation process in this embodiment, it is preferable that a resin diffusion mesh sheet (pass media, not shown) is attached to the surfaces of the lower die 35 and the upper die 45 (the sides on which the first substrate 11 and the second substrate 13 are placed). This makes it easier for the resin 20 to diffuse into the lower die 35 and the upper die 45. It is also preferable that a release sheet (peel ply, not shown) is attached. This makes it possible to adjust the surface properties of the integrally molded product 120.

Since the vacuum bag 55 is at negative pressure, a pressure difference with the atmospheric pressure occurs, and this pressure difference allows the resin 20 to harden and obtain the integrally molded product 120. Note that the vacuum pressure inside the vacuum bag 55 in this embodiment is, for example, -95 kPa (relative pressure) or less. By adopting the VaRTM process, it is possible to reduce costs without requiring large-scale equipment such as the autoclave process in the first embodiment.

Next, after the VaRTM process is completed, the integrally molded product 120 is removed from the lower mold 35, and unnecessary portions of the outer periphery of the integrally molded product 120 are removed (trimmed) as necessary.

The above describes each embodiment of the present invention. According to the manufacturing method of the integrally molded product, the integrally molded product, and the electric airplane component of the present invention, the integrally molded product 100 (120) can be made lighter and more rigid. In addition, the man-hours required for manufacturing the integrally molded product of the structural material 10, the electrical wiring 12, and the resin 20 can be reduced, and mass production of the integrally molded product 100 (120) can be realized. Furthermore, by embedding the electrical wiring 12 in the resin 20, the integrally molded product 100 (120) can be made smaller. Furthermore, by embedding the electrical wiring 12 in the resin 20, noise during current flow can be reduced.

The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention. As an example, in the manufacturing method of the integrally molded product of the first and second embodiments, the electronic component mounting process can be omitted. It goes without saying that the above technical ideas can be applied not only to components for electric aircraft (drones), but also to components for equipment in other fields.

REFERENCE SIGNS LIST 10 Structural material 11 First substrate 12 Electric wiring 13 Second substrate 14 Electronic component 16 Thickness adjusting member 17, 18 Thread 20 Resin 30, 35 Lower mold 40, 45 Upper mold 100 Integral molded product (electric airplane component)
120 Integral molding (electric aircraft parts)

Claims (7)

A method for manufacturing an integrally molded product of a structural material made of carbon fiber, glass fiber, or resin fiber, flexible electrical wiring, and resin, comprising the steps of:
a first sewing step of sewing the structural material to a first base material;
a second sewing step of sewing the electrical wiring to a second base material;
Next, a resin impregnation step of impregnating the first base material and the second base material with the resin;
A method for manufacturing an integrally molded product, comprising the steps of: subsequently, hardening the resin to integrally mold the structural material, the electrical wiring, and the resin. 2. The method for manufacturing an integrally molded product according to claim 1, wherein the integral molding step is an autoclave step in which the resin is hardened by applying heat and pressure in a vacuum state to integrally mold the structural material, the electrical wiring, and the resin. The resin impregnation step includes sealing the first base material and the second base material in a vacuum bag,
Next, a vacuum is drawn inside the vacuum bag,
Next, the resin is sealed in the vacuum bag,
Next, a resin impregnation step is performed in which the first base material and the second base material are impregnated with the resin,
2. The method for manufacturing an integrally molded product according to claim 1, wherein the integral molding step is a step of hardening the resin by a pressure difference with respect to atmospheric pressure to integrally mold the structural material, the electrical wiring, and the resin. 4. The method for manufacturing an integrally molded product according to claim 1, further comprising an electronic component mounting process, which is a process preceding the resin impregnation process, for placing an electronic component on the second substrate and electrically connecting the electrical wiring to the electronic component. 5. The method for manufacturing an integrally molded product according to claim 4, wherein the electronic component mounting step includes a step of providing a thickness adjusting member between the electronic component and the second base material. An integrally molded product of a structural material made of carbon fiber, glass fiber, or resin fiber, flexible electrical wiring, and resin,
The integrally molded product is
The structural material is sewn to a first substrate;
The electrical wiring is sewn to a second substrate,
Next, the first substrate and the second substrate are impregnated with the resin,
Next, the resin is hardened to integrally mold the structural material, the electrical wiring, and the resin, thereby producing an integrally molded product. A component for an electric aircraft, comprising the integrally molded product according to claim 6.

Images