A forming process for a fan blade

Abstract

The application relates to the technical field of fan blades, in particular to a forming process of a fan blade, which specifically comprises the following steps: cleaning a mold; coating a release agent on the inner cavity surfaces of a lower mold and an upper mold, and respectively spraying a gel coat; respectively laying fiber cloth on the inner cavity surfaces of the upper mold and the lower mold; placing an inflatable soft film and wrapping the inflatable soft film with a flow guide net; loading a supporting cylinder into the inflatable soft film opening, inflating the inflatable soft film, placing a supporting column on the vacuum air bag wrapped with the flow guide net after forming, and finally laying a layer of fiber cloth, combining the upper mold and the lower mold to seal the inner cavity of the mold; installing an exhaust pipe, exhausting the exhaust pipe, and vacuumizing; taking out the supporting cylinder, injecting resin through a resin injection pipe, solidifying and forming, taking out the blade, taking out the inflatable soft film in the blade, and obtaining the fan blade. The fan blade is integrally formed, the overall strength of the blade is improved, no garbage is generated, the manufacturing process is simplified, and equipment investment is reduced.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade technology, and in particular to a forming process for wind turbine blades. Background Technology

[0002] Wind turbine blades are key moving components of wind power generation systems, directly affecting the performance of the entire system. They must also possess weather resistance for long-term use in outdoor natural environments and be reasonably priced. Therefore, the design and manufacturing quality of the blades are extremely important, considered a key technology and representative of the overall technological level of wind power generation systems. Wind turbine blades are composite materials, which are made by combining various fiber reinforcements within a matrix material. Currently, the most well-known composite materials involve combining reinforcing materials and resins, followed by a curing and molding process to create composite material products. The main molding processes for composite material products of wind turbine blades include: hand lay-up molding, injection molding, and prepreg molding.

[0003] Hand lay-up molding, also known as contact molding, is a molding process primarily performed manually, using epoxy resin or unsaturated polyester resin as the matrix material and bonding it to reinforcing materials. It is suitable for a wide variety of products in small batches. However, its disadvantages include difficulty in controlling resin content, low production efficiency, high labor intensity, environmental pollution, poor product repeatability, and difficulty in controlling product quality, making it unsuitable for mass production. Prepreg molding involves laying prepreg in a mold and then curing it to obtain composite material products. The advantages of prepreg molding are its simplicity compared to hand lay-up and casting processes, reduced environmental pollution, lower labor intensity, and simpler process control. The disadvantages are the higher price of prepreg, resulting in higher overall blade costs compared to hand lay-up and casting processes. Casting molding involves manually laying reinforcing materials in a mold, sealing the reinforcing materials within the mold, and then bonding the resin and reinforcing materials together using pressure injection or vacuum injection methods. Finally, it is cured at room temperature or with heat to obtain composite material products. Its advantages are that the product strength is higher than that of the hand lay-up process, while its disadvantages are that it requires multiple vacuum bags, the process is complicated, it is prone to manufacturing defects, and it generates more waste. Summary of the Invention

[0004] The purpose of this invention is to provide a forming process for wind turbine blades to solve the problems existing in the prior art of manufacturing wind turbine blades.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a forming process for wind turbine blades, comprising the following steps:

[0007] 1) Clean the mold;

[0008] 2) Apply release agent to the inner surfaces of the lower mold and upper mold, and then spray gel coat on them respectively;

[0009] 3) Lay fiber cloth on the inner surfaces of the upper and lower molds respectively;

[0010] 4) Place the inflatable membrane and wrap it with a guide net;

[0011] The inflatable soft film has a sealed end placed at the tip of the blade and an open end placed at the root of the blade; the open end of the inflatable soft film is provided with an injection tube that communicates with the inside and outside of the mold.

[0012] 5) Insert the support cylinder into the opening of the inflatable soft membrane, inflate the soft membrane, and after it is formed, place the support column on the vacuum bag wrapped by the guide net. One end of the support column is connected to the support cylinder, and the other end is connected to the end plate at the blade tip.

[0013] 6) Finally, lay another layer of fiber cloth, close the upper and lower molds to seal the internal cavity of the mold;

[0014] 7) Install the exhaust pipe, exhaust air, and create a vacuum.

[0015] 8) Remove the support cylinder, inject resin through the injection tube, cure and shape it, remove the blade, and remove the inflatable soft film inside the blade to obtain the fan blade.

[0016] Optionally, after step 7) creates a vacuum and forms a negative pressure, positive pressure is then injected into the inflatable membrane, and the positive and negative pressures are repeated 2 to 3 times.

[0017] Optionally, the mold consists of an upper mold and a lower mold, and is flipped and closed by a four-bar linkage and a power rod. The upper mold and the lower mold are respectively provided with a sealing groove, a sealing strip, an air guide groove, a hole, and a positioning pin.

[0018] Optionally, in step 3), the fiber cloth laid in the lower mold is 70-130 cm wider than that in the upper mold.

[0019] Optionally, the edge of the guide net is 15-25 mm narrower than the edge of the lower mold cavity.

[0020] Optionally, the dispensing tube is in a closed state before dispensing the adhesive.

[0021] Optionally, the support column is made of foam material, and the upper and lower surfaces of the support column are respectively provided with guide grooves, and the surface of the support column is wrapped with fiber cloth.

[0022] Optionally, the end plate is made of foam material, and the surface of the end plate is wrapped with fiber cloth.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention designs a double-legged inflatable membrane that creates two cavities inside the blade, reducing the number of traditional vacuum bags and lowering production costs. It also includes an inflation port to apply positive pressure during inflation. This eliminates the need for other core materials, preventing waste and reducing environmental pollution. Furthermore, it simplifies the manufacturing process, improves labor efficiency, enhances the working environment, facilitates worker operation, reduces labor intensity, minimizes equipment investment, and reduces manufacturing defects in wind turbine blades. This invention is suitable for mass production of wind turbine blades.

[0025] The wind turbine blades of this invention are integrally formed, and a support column with a flow guide groove is added in the middle of the blade. This not only enhances the strength of the blade but also serves as a flow guide, eliminating the need for laying flow guide pipes. An end plate is added to the blade tip, which further enhances the overall strength of the blade and extends its service life. This invention can be applied to the production of wind turbine blades or air-cooled and water-cooled wind turbine blades.

[0026] This invention employs a positive pressure assisted vacuum infusion process. After vacuuming, a certain positive pressure is applied to the inflatable soft film, so that the core material that may shift during the mold closing process can be flattened and stretched. The negative pressure plays the role of infusion, ensuring the flow rate and leveling of the liquid inside. The combination of positive and negative pressure can effectively improve the injection speed, shorten the production cycle, and produce higher quality fan blades. Attached Figure Description

[0027] Figure 1 This is a schematic diagram showing the position of the inflatable soft film of the present invention laid in the lower mold;

[0028] Figure 2 This is a schematic diagram of the structure of the inflatable membrane of the present invention.

[0029] In the diagram: 1. Lower mold; 2. Lower mold cavity; 3. Inflatable soft film; 31. Inflatable soft film inflation end; 32. Inflatable soft film sealing end; 33. Injection tube; 4. Support column; 5. End plate; 6. Blade tip; 7. Blade root. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] In one specific embodiment of the present invention, a forming process for wind turbine blades is provided, comprising the following steps:

[0032] 1) Cleaning the mold; the mold consists of an upper mold and a lower mold, which are flipped and closed by a four-bar linkage and a power rod; the upper mold and the lower mold are respectively provided with a sealing groove, a sealing strip, an air guide groove, a hole, and a positioning pin.

[0033] 2) Apply release agent to the inner surfaces of the lower mold and upper mold, and spray gel coat on the demolding machine, ensuring that the edges, gaps, leaf roots, and corners are all properly coated.

[0034] 3) Lay fiber cloth on the inner surfaces of the upper and lower molds respectively. The thickness of the fiber cloth can be adjusted according to the actual situation. The lower mold cloth is 70-130cm wider than the upper mold, preferably 100cm. Before closing the mold, the excess part of the lower mold can be folded and wrapped to strengthen the edge strength.

[0035] 4) Placement Figure 2 An inflatable soft film 3 of the shape shown is wrapped with a flow guide net. The edge of the flow guide net is 20mm narrower than the edge of the mold cavity to prevent the resin from flowing to the edge of the cavity too quickly. The material of the inflatable soft film is silicone rubber or fluororubber.

[0036] like Figure 1 As shown, the inflatable soft film sealing end 32 is placed at the blade tip 6, and the open end 31 is placed at the blade root 7; the function of the inflatable soft film 3 is to provide support, so that two cavities are formed inside the blade; the open end 31 of the inflatable soft film is provided with a glue injection tube 33 that communicates with the inside and outside of the mold, and the glue injection tube 33 is always in a closed state before glue injection.

[0037] This invention designs the inflatable membrane as follows: Figure 2 The double-legged type shown has an inflatable membrane that can be inflated, eliminating the need for other fillers to form cavities and avoiding waste. Two cavities can be formed using one air bag, and the inflatable membrane comes with its own injection tube, eliminating the need for laying the injection tube. After the membrane is formed, the air only needs to be removed, saving labor costs.

[0038] 5) Insert a support cylinder (not shown in the figure) into the opening end 31 of the inflatable membrane, inflate the inflatable membrane 3 to form its shape, and trim the guide net according to the shape of the inflatable membrane, such as... Figure 1 As shown, a support column 4 is placed on the inflatable soft membrane wrapped by the guide net. One end of the support column 4 is snapped into the support cylinder, and the other end is snapped into the end plate 5 at the blade tip 6.

[0039] The support column 4 is made of foam material, and the upper and lower surfaces of the support column 4 are respectively provided with flow guide grooves. The surface of the support column 4 is wrapped with fiber cloth. The purpose of adding the support cylinder is to fix the support column. The addition of the support column can improve the strength of the blade. At the same time, since the surface of the support column has flow guide grooves, the support column can also play a role in guiding the flow, eliminating the need for laying traditional flow guide pipes. The end plate is made of foam material and the surface is wrapped with fiber cloth. The addition of the end plate can enhance the strength of the blade tip and also play a role in fixing the support column.

[0040] 6) Finally, lay another layer of fiber cloth on the guide net. Fold the edge of the fiber cloth, which is wider than the upper mold, to wrap the top layer to strengthen the edge of the blades, fix the fiber cloth, and prevent displacement when the film is closed.

[0041] The upper and lower molds are closed. Before closing the molds, two supporting iron plates are inserted at the root of the blade to prevent collapse. After closing the molds, the plates are removed and the molds are locked. The root of the blade is locked with a sealing ring and the sealing ring is fixed with screws to seal the internal cavity of the mold.

[0042] 7) Install the vent pipe, vent the air, evacuate to -0.098 MPa, inflate the soft film, apply positive pressure to the mold cavity, repeat the evacuation and positive pressure application 3 times to make the inside of the mold cavity flat and smooth, ensuring the flow rate and leveling of the resin in the later stage.

[0043] 8) Remove the support cylinder and inject 9kg of resin through the injection tube. After the resin is introduced, it will be cured and molded. Open the upper and lower molds, remove the blades, and remove the inflatable soft membrane inside the blades. The original position of the inflatable soft membrane in the blades forms a cavity in the blades, resulting in a fan blade with a sealed tip and an open root. There are two cavities in the blades that are separated by the support column.

[0044] As can be seen from the above embodiments, this invention relates to an improvement on the integrated molding process of wind turbine blades, specifically an improvement on the vacuum infusion process. This invention designs a double-legged inflatable membrane, which allows two cavities to be formed inside the blade with a single inflatable membrane. This reduces the number of traditional vacuum bags, lowers production costs, and provides an inflation port to apply positive pressure through inflation. It eliminates the need for other core materials, generates no waste, reduces environmental pollution, simplifies the manufacturing process, improves labor efficiency, improves the working environment, facilitates worker operation, reduces labor intensity, reduces equipment investment, and reduces manufacturing defects in wind turbine blades. It is suitable for mass production of wind turbine blades.

[0045] The wind turbine blades of this invention are integrally formed, and a support column with a flow guide groove is added in the middle of the blade. This not only enhances the strength of the blade but also serves as a flow guide, eliminating the need for laying flow guide pipes. An end plate is added to the blade tip, which further enhances the overall strength of the blade and extends its service life. This invention can be applied to the production of wind turbine blades or air-cooled and water-cooled wind turbine blades.

[0046] This invention employs a positive pressure assisted vacuum infusion process. After vacuuming, a certain positive pressure is applied to the inflatable soft film, so that the core material that may shift during the mold closing process can be flattened and stretched. The negative pressure plays the role of infusion, ensuring the flow rate and leveling of the liquid inside. The combination of positive and negative pressure can effectively improve the injection speed, shorten the production cycle, and produce higher quality fan blades.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A forming process for wind turbine blades, characterized in that, Includes the following steps: 1) Clean the mold; 2) Apply release agent to the inner surfaces of the lower mold and upper mold, and then spray gel coat on them respectively; 3) Lay fiber cloth on the inner surfaces of the upper and lower molds respectively, with the fiber cloth on the lower mold being 70-130cm wider than that on the upper mold; 4) Place the inflatable membrane and wrap it with a guide net; the sealed end of the inflatable membrane is placed at the blade tip, and the open end is placed at the blade root; the open end of the inflatable membrane is provided with a glue injection tube that communicates with the inside and outside of the mold; wherein, the inflatable membrane is double-legged and serves as a support; the inflatable membrane can be inflated, and using one inflatable membrane can create two cavities inside the blade; 5) Insert the support cylinder into the opening of the inflatable soft membrane, inflate the soft membrane, and after it is formed, place the support column on the vacuum bag wrapped by the guide net. One end of the support column is connected to the support cylinder, and the other end is connected to the end plate at the blade tip. 6) Finally, lay another layer of fiber cloth, close the upper and lower molds to seal the internal cavity of the mold; 7) Install the exhaust pipe, exhaust the air, draw a vacuum to form a negative pressure, and then fill the inflatable membrane with positive pressure. Repeat the positive and negative pressure cycles 2 to 3 times. 8) Remove the support cylinder, inject resin through the injection tube, cure and mold, remove the blades, remove the inflatable soft film inside the blades, and obtain the fan blades; The support column is made of foam material, and the upper and lower surfaces of the support column are respectively provided with flow channels. The surface of the support column is wrapped with fiber cloth.

2. The forming process of a wind turbine blade according to claim 1, characterized in that, The mold consists of an upper mold and a lower mold, which are flipped and closed by a four-bar linkage and a power rod. The upper mold and the lower mold are respectively provided with a sealing groove, a sealing strip, an air guide groove, a hole, and a positioning pin.

3. The forming process for a wind turbine blade according to claim 1, characterized in that, The edge of the guide net is 15-25mm narrower than the edge of the lower mold cavity.

4. The forming process of a wind turbine blade according to claim 1, characterized in that, The dispensing tube is in a closed state before dispensing the adhesive.

5. The forming process of a wind turbine blade according to claim 1, characterized in that, The end plate is made of foam material, and the surface of the end plate is wrapped with fiber cloth.

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