A method of forming a hollow reinforced permeable structure composite propeller duct

Abstract

The present application belongs to the technical field of manufacturing composite propeller duct for ships, in particular discloses a forming method of hollow stiffened water-permeable structure composite propeller duct. The forming method prepares the stator by integral forming process, optimizes the forming process, increases the continuity and connection strength of the cloth layer; the upper and lower parts of the skin are formed by OOA process respectively, solving the problem of unstable forming quality of the outer skin in the traditional process; except the flat plate of the rib plate, the rest parts are formed with net size, reducing the processing procedures and processing cost; and the pressure curing is realized by OOA process, increasing the compactness of the fibers inside the composite outer skin, reducing the porosity of the outer skin, solving the phenomena of surface pits, paint bulging and the like after pressure test, and improving the product use pressure. The forming method solves the technical barriers of low production efficiency, high cost and unstable quality existing in the existing forming method, and has the advantages of low cost and high quality.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing technology of composite material propulsion ducts for ships. Specifically, it relates to a molding method for composite material propulsion ducts based on a hollow reinforced permeable structure that combines low cost and high quality. Background Technology

[0002] Composite material propulsion ducts for ships are mainly of solid and sandwich structures. Due to the need for propulsion ducts to meet weight and performance requirements, sandwich structures are widely used because of their lightweight and high strength. However, the complex marine environment can lead to deformation of the sandwich layer or peeling of the outer layers in long-term marine conditions. This affects the strength and stiffness of the structure, making its service life a weak point, and can even cause significant economic losses to the vessel during operation due to damage to the propulsion duct.

[0003] The China Shipbuilding Scientific Research Center has developed a hollow, reinforced, and permeable structure technology for deep-sea propulsion composite material ducts, overcoming the previous challenges of heavy solid composite material propulsion ducts and short service life of sandwich composite material ducts. This hollow, reinforced, and permeable composite material propulsion duct design reduces weight and increases service life while maintaining product performance and rigidity.

[0004] As disclosed in Chinese patent application CN 111169615A, the current traditional method for manufacturing hollow reinforced permeable propeller ducts involves: forming the stator hub and blades, connecting and fixing them to form the stator; forming the stiffeners, connecting them to the inner skin and stator; and finally forming the outer skin. Since the inner and outer skins are supported only by a few stiffeners, the entire component collapses when the outer skin is formed on the surface created by the stiffeners, even with relatively small pressure. Therefore, the outer skin is often formed under pressureless conditions. However, this process suffers from the drawback of uncontrollable outer skin quality; long-term operation in a marine environment easily leads to defects such as pitting and paint blistering on the surface. Furthermore, this method presents technical challenges in mass production, including cumbersome production processes, long production cycles, extended mold-holding time, and high production costs.

[0005] Therefore, there is an urgent need to develop a low-cost, high-quality molding method for hollow reinforced permeable propeller ducts to further advance the development of composite material propeller ducts for ships. Summary of the Invention

[0006] In order to address the technical shortcomings of existing hollow reinforced permeable structure propeller duct molding technology, this invention aims to develop a low-cost, high-quality hollow reinforced permeable structure propeller duct molding method to overcome the technical barriers of low production efficiency, high cost, and unstable quality in hollow reinforced permeable structure propeller ducts.

[0007] The present invention specifically adopts the following technical solution: A method for forming a hollow reinforced permeable structure thruster duct includes: S1. Stator forming steps: The stator hub is formed using the fixed shaft in the stator forming mold, and the stator blades are formed using the slider in the stator forming mold to obtain the stator.

[0008] It should be noted that the aforementioned stator forming mold includes a chassis, a fixed shaft mounted on the chassis, and several detachable sliders located on the chassis and arranged around the fixed shaft. Each pair of adjacent sliders clamps a stator blade from a pre-formed stator, and the stator hub in the pre-formed stator is laid out based on the fixed shaft. The centripetal movement of the sliders is ensured by the engagement of inclined surfaces, thus ultimately all the sliders work together to form the stator blades in the entire pre-formed stator.

[0009] Specifically, S1 includes the following steps: S11. Place the sandblasted stator hub metal insert on the fixed shaft, cover it with epoxy carbon fiber prepreg, and vacuum pre-compact it. S12. Lay epoxy carbon fiber prepreg layer by layer on the inner surface of the slider and vacuum pre-compact it. S13. By sliding the slider through the inclined surface of the mold, the mold closing is completed; S14. After the mold is closed, the intermediate body is prepreg cured on a press, cooled, demolded, and the connecting holes are machined to obtain the stator.

[0010] Optionally, in step S12, a symmetrical layup design is preferably adopted, in which epoxy carbon fiber prepreg is laid layer by layer on the inner surface of the slider.

[0011] Optionally, in step S12, the layup direction along the axial direction of the preformed stator blade is mainly in the 0° / 90° / 45° / -45° direction.

[0012] Optionally, in step S12, a 45° layup is designed on the surface of the pre-formed stator blade to improve the shear resistance of the blade.

[0013] Optionally, in step S14, the curing process is as follows: after heating at 70℃~90℃ for 30 min~80 min, heat at 120℃~140℃ for 120 min~300 min to complete the curing.

[0014] Generally, in step S14, after curing is complete, the temperature is lowered to no more than 40°C before the mold can be removed for demolding.

[0015] S2. Upper skin forming step: The stator is placed in the upper skin forming mold, covered with epoxy carbon fiber prepreg, and then cured by OOA process to obtain the upper skin.

[0016] It should be noted that the above-mentioned upper skin forming mold includes a base, and a first female mold, a second female mold, and a third female mold disposed above the base. The first female mold is located on the base, and the second and third female molds are nested in concentric rings, located at the inner and outer edges of the first female mold, respectively; the first, second, and third female molds together form the first mold cavity.

[0017] Specifically, S2 includes the following steps: S21. Place the stator on the base of the upper skin forming mold, and then place and assemble the first female mold, the second female mold, and the third female mold in sequence, and preheat it. S22. Epoxy carbon fiber prepreg is laid in the first mold cavity formed by the first female mold, the second female mold and the third female mold, and cured by OOA process after laying. S23. Sequentially remove the third negative mold, the second negative mold, and the first negative mold to obtain the upper skin.

[0018] Optionally, in step S21, the preheating temperature is generally controlled at 55℃~65℃.

[0019] Preferably, in step S22, when laying the epoxy carbon fiber prepreg, the thickness of a single layer of fabric is controlled to be 0.2 mm, and cold pressing is performed every 1 mm of fabric laid until the laying is completed.

[0020] Optionally, in step S22, the curing process of the OOA process is as follows: after heating at 70℃~90℃ for 30 min~80 min, it is then heated at 120℃~140℃ for 120 min~300 min to complete the curing.

[0021] S3, Rib Structure Forming Steps: S31. Using epoxy carbon fiber fabric prepreg, a ribbed plate is prepared, and then the ring rib, the first longitudinal rib and the second longitudinal rib are prepared through processing technology. S32. Utilize mortise and tenon joints for fitting and bonding to obtain a ribbed structure.

[0022] Optionally, in step S31, a hot autoclave process can be used to prepare the stiffening plate.

[0023] S4. Adhere the ring reinforcement, the first longitudinal reinforcement, the second longitudinal reinforcement and the upper skin to obtain the splicing intermediate body.

[0024] S5. Lower skin forming step: Lay epoxy carbon fiber fabric prepreg in the lower skin forming mold, and then perform OOA process to cure to obtain the lower skin.

[0025] It should be noted that the aforementioned lower skin forming mold includes a fourth female mold, a fifth female mold, and a sixth female mold. The fourth female mold has a groove, and the fifth and sixth female molds are nested concentric rings, located at the inner and outer edges of the fourth female mold, respectively; the fourth, fifth, and sixth female molds together form a second mold cavity.

[0026] Specifically, S5 includes the following steps: S51. Place and assemble the fourth, fifth, and sixth female molds in sequence, and preheat them; S52. Epoxy carbon fiber prepreg is laid in the second mold cavity formed by the fourth, fifth and sixth female molds, and cured by OOA process after laying. S53. Sequentially remove the sixth, fifth, and fourth negative molds to obtain the lower skin.

[0027] Optionally, in step S51, the preheating temperature is generally controlled at 55℃~65℃.

[0028] Preferably, in step S52, when laying the epoxy carbon fiber prepreg, the thickness of a single layer of fabric is controlled to be 0.2 mm, and cold pressing is performed every 1 mm of fabric laid until the laying is completed.

[0029] Optionally, in step S52, the curing process of the OOA process is as follows: after heating at 70℃~90℃ for 30 min~80 min, heat at 120℃~140℃ for 120 min~300 min to complete the curing.

[0030] S6. Adhesive bonding of the lower skin and splicing intermediate body.

[0031] S7. Forming of auxiliary structures: S71. Drill water-permeable holes on the upper and lower skins; S72. Simply spray an anti-corrosion and anti-fouling coating onto the surface.

[0032] The molding method for the hollow reinforced permeable composite material propeller duct provided by this invention breaks with traditional parting concepts and molding methods. Specifically, firstly, the stator is prepared by an integral molding process, optimizing the molding process and increasing the continuity and connection strength of the fabric layers; secondly, the outer skin is molded using the OOA process, solving the problem of unstable outer skin molding quality in traditional processes; thirdly, except for the stiffening plates and flat plates, all other components are molded to net dimensions, reducing processing steps and costs; fourthly, the OOA process achieves pressure curing, increasing the density of the internal fibers of the composite material outer skin, reducing the porosity of the outer skin, solving the problems of surface pitting and paint blistering after pressure testing, and improving the product's operating pressure.

[0033] The molding method provided by this invention starts with product segmentation, optimizes the molding process, and reduces processing steps, significantly reducing manufacturing costs. Compared with traditional manufacturing processes (where blades, inner skin, and stiffeners are all molded using compression molding, ensuring surface finish; stator hubs are molded using OOA (Out-of-Area) processes, ensuring surface finish; blades and stator hubs are bonded together on bonding fixtures; stiffeners, inner skin, and blades are assembled and bonded on a mold; and the outer skin can only be molded after the stiffeners, inner skin, and blades are assembled, followed by further processing), this method greatly simplifies the molding process and significantly improves efficiency, showing broad application prospects in the field of composite material propulsion ducts. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the stator forming mold in the forming method according to the present invention; Figure 2 This is a perspective view of the slider in the stator forming mold according to the forming method of the present invention; Figure 3 yes Figure 2 Right view of the middle slider; Figure 4 yes Figure 2 Top view of the middle slider; Figure 5 This is a perspective view of the stator obtained by the molding method according to the present invention; Figure 6 yes Figure 5 Left view of the middle stator; Figure 7 This is a schematic diagram of the upper skin forming mold in the forming method according to the present invention; Figure 8 This is a schematic diagram of the upper skin forming structure in the forming method according to the present invention; Figure 9 yes Figure 8 A cross-sectional view of the upper skin forming process; Figure 10 This is a schematic diagram of the assembled structure of the rib structure obtained by the molding method according to the present invention; Figure 11 This is a schematic diagram of the structure after the rib structure and the upper skin are bonded together in the molding method according to the present invention. Figure 12 yes Figure 11 Cross-sectional view of the rib structure and the upper skin after bonding; Figure 13 This is a schematic diagram of the structure of the lower skin forming mold in the forming method according to the present invention; Figure 14 This is a schematic diagram of the lower skin molding structure in the molding method according to the present invention; Figure 15 yes Figure 14 A cross-sectional view of the lower skin forming process; Figure 16 This is a schematic diagram of the hollow reinforced permeable composite material propeller duct obtained by the molding method of the present invention; Figure 17 yes Figure 16 A cross-sectional view of the hollow reinforced permeable composite material propulsion duct. Detailed Implementation

[0035] The present invention will be described in detail below through examples. Unless otherwise specified, the methods used in the following examples are conventional; the reagents and materials used are commercially available unless otherwise specified.

[0036] To address the shortcomings of existing hollow reinforced permeable propeller duct molding methods, such as uncontrollable outer skin quality, susceptibility to pitting and paint blistering, as well as cumbersome production processes, long production cycles, extended mold-holding time, and high production costs, this invention provides a novel, low-cost, high-quality molding method. This method involves fabricating the stator using an integral molding process, molding the skin using an OOA (Out-of-Area) process, and combining this with bonding and other processes to achieve the molding of the propeller duct, significantly simplifying the molding process.

[0037] The following will combine Figures 1-17 The molding process involves a detailed description of the molds, intermediate products, and final products at each stage.

[0038] The first step is stator forming.

[0039] Stator forming is achieved through an integrated forming process based on stator forming molds.

[0040] like Figure 1 As shown, the stator forming mold 1A includes a base 11A, a fixed shaft 12A located at the center of the base 11A, and a plurality of detachable sliders 13A located on the base 11A and arranged around the fixed shaft 12A.

[0041] The structural schematic diagram of slider 13A is shown below. Figures 2-4 As shown.

[0042] As can be seen, each pair of adjacent sliders 13A together form a blade in the pre-formed stator through clamping action. The stator hub in the pre-formed stator is laid on the fixed shaft 12A, and the centripetal movement of the sliders 13A is ensured by the cooperation of the inclined planes. Thus, all the sliders 13A together complete the forming of several stator blades in the pre-formed stator.

[0043] Specifically, the following process is adopted: the stator hub is formed by using the fixed shaft 12A in the stator forming mold 1A, and the stator blades are formed by using the slider 13A in the stator forming mold 1A, thus obtaining the stator.

[0044] The following detailed steps shall be followed: 1) Place the sandblasted stator hub metal insert on the fixed shaft 12A (the fixed shaft 12A is already placed on the chassis 11A), cover it with epoxy carbon fiber prepreg, and vacuum pre-compact it; 2) Lay epoxy carbon fiber prepreg layer by layer on the inner surface of the slider 13A, and vacuum pre-compact it; 3) Slide the slider 13A through the mold inclined surface fit relationship to complete the mold closing; 4) Cur the prepreg on the molded intermediate body on the press, cool it down, demold it, and process the connecting holes to obtain the stator 1.

[0045] Furthermore, when laying epoxy carbon fiber prepreg on the inner surface of slider 13A layer by layer, a symmetrical layup design is preferred to maintain balance; and the layup direction along the axial direction of the preformed stator blade is mainly laid in the 0° / 90° / 45° / -45° direction.

[0046] Furthermore, in order to improve the shear resistance of the preformed stator blades, a 45° layup is designed on the surface of the preformed stator blades.

[0047] Generally, the prepreg is cured using a curing process of heating at 70℃~90℃ for 30 min~80 min, followed by heating at 120℃~140℃ for 120 min~300 min; demolding is then carried out once the temperature drops to no more than 40℃.

[0048] For example, a curing process could be "heating at 80℃ for 30 minutes to heating at 120℃ for 2 hours".

[0049] The structural schematic diagram of the stator 1 obtained by the above process is shown below. Figures 5-6 As shown, the stator 1 includes a stator hub 11 located at the center and several stator blades 12 evenly distributed around the stator hub 11.

[0050] In the above molding method, the present invention uses an integral molding process to prepare the stator 1, which optimizes the molding process and increases the continuity and connection strength of the fabric layers when preparing the skin in the subsequent process.

[0051] Then comes the shaping of the upper skin.

[0052] The upper skin is formed based on the upper skin forming mold.

[0053] like Figure 7As shown, the upper skin forming mold 2A includes a base 21A, and a first female mold 22A, a second female mold 23A, and a third female mold 24A disposed above the base 21A. The first female mold 22A is located on the base 21A, while the second female mold 23A and the third female mold 24A are nested in concentric rings, located at the inner and outer edges of the first female mold 22A, respectively. Thus, the first female mold 22A, the second female mold 23A, and the third female mold 24A enclose a ring groove, hereinafter referred to as the first mold cavity 25A, for forming the upper skin.

[0054] Specifically, the following process is adopted: the stator 1 is placed in the upper skin forming mold 2A, and after being covered with epoxy carbon fiber fabric prepreg, the upper skin is obtained by OOA process curing.

[0055] Follow the detailed steps below: 1) Place the stator 1 on the base 21A, then sequentially place and assemble the first female mold 22A, the second female mold 23A, and the third female mold 24A, followed by preheating; 2) Lay epoxy carbon fiber prepreg in the first mold cavity 25A, such as... Figure 8 and Figure 9 As shown, after the covering is completed, it is cured by the OOA process; 3) The third female mold 24A, the second female mold 23A and the first female mold 22A are removed in sequence, and the upper skin 2 is formed on the stator 1.

[0056] Preferably, after the first female mold 22A, the second female mold 23A and the third female mold 24A are placed and assembled, preheating is generally carried out at a temperature of 55℃~65℃.

[0057] Preferably, during the process of laying the epoxy carbon fiber fabric prepreg into the first mold cavity 25A, the thickness of each fabric layer is controlled to be 0.2 mm, and cold pressing is performed every 1 mm of fabric laid until the laying is completed. Cold pressing ensures that the product is uniformly compressed during the pre-compaction process, maximizing the removal of gas and reducing interlayer slippage that may occur during the curing stage due to the decrease in resin viscosity. This results in a product with low porosity, uniform thickness, few and small wrinkles, and high appearance quality.

[0058] Generally, after the coating is laid, it is heated at 70℃~90℃ for 30 min~80 min, and then heated at 120℃~140℃ for 120 min~300 min to complete the curing process and achieve curing through OOA.

[0059] The third step is the formation of the rib structure.

[0060] Specifically, the following process is adopted: 1) Using epoxy carbon fiber prepreg, a ribbed plate is prepared, and then processed to prepare ring ribs 31, first longitudinal ribs 32, and second longitudinal ribs 33; 2) Using mortise and tenon joints for fitting and bonding, the rib structure 3 is obtained, such as... Figure 10 As shown.

[0061] That is, the two ring ribs 31 are spaced a certain distance apart and arranged in parallel. The groove of the first longitudinal rib 32 is inserted into the slot of the two ring ribs 31 from the inside of the ring rib 31 with the help of a tenon and mortise structure. At the same time, the groove of the second longitudinal rib 33 is inserted into the slot of the two ring ribs 31 from the outside of the ring rib 31 with the help of a tenon and mortise structure. The first longitudinal rib 32 and the second longitudinal rib 33 are distributed alternately, thereby fixing the two ring ribs 31 to form the rib structure 3.

[0062] The fourth step is to glue the reinforcing rib structure to the upper skin to obtain the spliced ​​intermediate body.

[0063] Specifically, adhesives are used to bond the ring ribs, first longitudinal ribs, and second longitudinal ribs in the rib structure 3 to the upper skin 2 connected to the stator 1, such as... Figure 11 and Figure 12 As shown.

[0064] The fifth step is the shaping of the lower skin.

[0065] The lower skin is formed based on the lower skin forming mold.

[0066] like Figure 13 As shown, the lower skin forming mold 3A has a structure similar to the upper skin forming mold, except that it lacks a base. The lower skin forming mold 3A includes a fourth female mold 31A, a fifth female mold 32A, and a sixth female mold 33A. The fourth female mold 31A has a groove, and the fifth female mold 32A and the sixth female mold 33A are nested concentric rings, located at the inner and outer edges of the fourth female mold 31A, respectively. Thus, the fourth female mold 31A, the fifth female mold 32A, and the sixth female mold 33A enclose a ring groove, hereinafter referred to as the second mold cavity 34A, for forming the lower skin.

[0067] Specifically, the following process is adopted: epoxy carbon fiber fabric prepreg is laid in the lower skin forming mold 3A, and then cured by OOA process to obtain the lower skin.

[0068] Follow the detailed steps below: 1) Place and assemble the fourth female mold 31A, the fifth female mold 32A, and the sixth female mold 33A in sequence, and preheat them; 2) Lay epoxy carbon fiber prepreg in the second mold cavity 34A, such as... Figure 14 and Figure 15 As shown, after the paving is completed, it is cured by the OOA process; 3) The sixth female mold 33A, the fifth female mold 32A and the fourth female mold 31A are removed in sequence to obtain the lower skin 4.

[0069] The molding process of the lower skin 4 is basically the same as that of the upper skin 2.

[0070] Preferably, after the fourth female mold 31A, the fifth female mold 32A and the sixth female mold 33A are placed and assembled, preheating can generally be carried out at a temperature of 55℃~65℃.

[0071] Preferably, during the process of laying the epoxy carbon fiber fabric prepreg into the second mold cavity 34A, the thickness of each fabric layer is controlled to be 0.2 mm, and cold pressing is performed every 1 mm of fabric laid until the laying is completed. The purpose of cold pressing is to ensure that the product is uniformly compressed during the pre-compaction process, to maximize the removal of gas, and to reduce interlayer slippage that may occur during the curing stage due to the decrease in resin viscosity. This results in a product with low porosity, uniform thickness, few and small wrinkles, and high appearance quality.

[0072] Generally, after the coating is laid, it is heated at 70℃~90℃ for 30 min~80 min, and then heated at 120℃~140℃ for 120 min~300 min to achieve OOA curing.

[0073] In the above molding method, the present invention uses the OOA process to separately mold the upper skin 2 and the lower skin 4, and then splices them together to simultaneously form the inner and outer skins, solving the problem of unstable molding quality of the outer skin in traditional processes. At the same time, the OOA process for pressure curing can increase the density of the internal fibers of the composite material outer skin (formed by splicing the outer side of the upper skin 2 and the outer side of the lower skin 4), reduce the porosity of the outer skin, and solve the problems of pitting on the outer surface and blistering of the paint layer after pressure testing, thereby improving the product's operating pressure.

[0074] The sixth step is to glue and splice the intermediate body and the lower skin together.

[0075] Specifically, adhesive is used to bond the splicing intermediate body to the lower skin 4.

[0076] Finally, the auxiliary structures are formed.

[0077] Specifically, water-permeable holes are drilled along the engraving lines on the upper skin 2 and lower skin 4 using drilling tools such as electric drills, and an anti-corrosion and anti-fouling coating is sprayed onto the surface.

[0078] Generally, the product model value is inspected using equipment such as coordinate measuring machine and laser scanning, thus completing the preparation of hollow reinforced permeable composite material propulsion duct products.

[0079] The structure of the obtained hollow reinforced permeable composite material propulsion duct is as follows: Figure 16 and Figure 17 As shown, the stator 1 is connected to the upper skin 2, and the upper skin 2 and the lower skin 4 are joined together to cover the rib structure 3 inside.

[0080] The hollow reinforced permeable composite material propeller duct prepared by the molding method provided in the above embodiments can be used under full ocean depth pressure, and the appearance quality and shape value of the product did not change after pressure testing.

[0081] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for forming a hollow reinforced permeable structure propeller duct, characterized in that, include: S1. Stator forming step: Based on the stator forming mold, it is realized by an integrated forming process; the stator forming mold includes a chassis, a fixed shaft located at the center of the chassis, and several detachable sliders located on the chassis and arranged around the fixed shaft. S1 specifically includes step: S11. Place the sandblasted stator hub metal insert on the fixed shaft, cover it with epoxy carbon fiber prepreg, and vacuum pre-compact it. S12. Lay epoxy carbon fiber prepreg layer by layer on the inner surface of the slider and vacuum pre-compact it. S13. By sliding the slider through the inclined surface of the mold, the mold closing is completed; S14. The intermediate body after mold closing is prepreg cured on a press, cooled, demolded, and connected holes are machined to obtain the stator; S2, Upper Skin Forming Step: Implemented based on the upper skin forming mold; the upper skin forming mold includes a base, and a first female mold, a second female mold, and a third female mold disposed above the base; wherein, the first female mold is located on the base, and the second female mold and the third female mold are in a concentric ring state nested within each other, located at the inner edge and outer edge of the first female mold respectively, so that the first female mold, the second female mold, and the third female mold enclose a ring groove first mold cavity; S2 specifically includes the following steps: S21. Place the stator on the base of the upper skin forming mold, and place the first female mold, the second female mold and the third female mold in the upper skin forming mold, and then preheat it; S22. Epoxy carbon fiber prepreg is laid in the first mold cavity formed by the first female mold, the second female mold and the third female mold, and cured by OOA process after laying. S23. Sequentially remove the third female mold, the second female mold, and the first female mold to obtain the upper skin; S3. Rib structure forming steps: Using epoxy carbon fiber fabric prepreg, prepare rib plate flat sheets, and then process them to prepare ring ribs, first longitudinal ribs and second longitudinal ribs; use mortise and tenon structure to fit and assemble, and then bond them to obtain the rib structure; S4. The step of gluing the rib structure to the upper skin is used to obtain the splicing intermediate body; S5. Lower skin forming step: implemented based on the lower skin forming mold; the lower skin forming mold includes a fourth female mold, a fifth female mold, and a sixth female mold; wherein, the fourth female mold has a groove, and the fifth female mold and the sixth female mold are in a concentric ring state nested in each other, located at the inner edge and outer edge of the fourth female mold respectively, so that the fourth female mold, the fifth female mold, and the sixth female mold surround to form a ring groove second mold cavity; S5 specifically includes the following steps: S51. Place the fourth, fifth, and sixth female molds in the lower skin forming mold and preheat them; S52. Epoxy carbon fiber prepreg is laid in the second mold cavity formed by the fourth female mold, the fifth female mold and the sixth female mold, and cured by OOA process after laying. S53. Sequentially remove the sixth negative mold, the fifth negative mold, and the fourth negative mold to obtain the lower skin; S6. The step of gluing the lower skin to the splicing intermediate body; S7. Auxiliary structure forming steps: Drill water-permeable holes on the upper skin and the lower skin, and spray an anti-corrosion and anti-fouling coating on the surface to obtain the final product.

2. The molding method according to claim 1, characterized in that, In step S12, a symmetrical layup design is adopted, and epoxy carbon fiber prepreg is laid layer by layer on the inner surface of the slider. And / or, in step S12, the preformed stator blades are laid up in the axial direction at 0° / 90° / 45° / -45°.

3. The molding method according to claim 1, characterized in that, In step S14, the curing process is as follows: after heating at 70℃~90℃ for 30 min~80 min, heat at 120℃~140℃ for 120 min~300 min to complete the curing.

4. The molding method according to claim 1, characterized in that, In step S22, when laying the epoxy carbon fiber prepreg, the thickness of a single layer of fabric is controlled to be 0.2 mm, and cold pressing is performed every 1 mm of fabric laid until the laying is completed.

5. The molding method according to claim 1 or 4, characterized in that, In step S22, the curing process of the OOA process is as follows: after heating at 70℃~90℃ for 30 min~80 min, it is then heated at 120℃~140℃ for 120 min~300 min to complete the curing.

6. The molding method according to claim 1, characterized in that, In step S52, when laying the epoxy carbon fiber prepreg, the thickness of a single layer of fabric is controlled to be 0.2 mm, and cold pressing is performed every 1 mm of fabric laid until the laying is completed.

7. The molding method according to claim 1 or 6, characterized in that, In step S52, the curing process of the OOA process is as follows: after heating at 70℃~90℃ for 30 min~80 min, it is then heated at 120℃~140℃ for 120 min~300 min to complete the curing.

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