A paddle

Abstract

The utility model belongs to the field of thermoplastic composite material, specifically discloses a paddle. The utility model's paddle uses short fiber reinforced resin as the outer skin, and the core material formed by the cooperation of the inside continuous fiber reinforced unidirectional tape forms the multi-scale fiber reinforced interface at the interface of the outer skin and the core material, improves the high and low temperature impact resistance of the paddle, reduces the risk of low temperature brittle fracture, enhances the interface bonding force of the paddle core material and the outer skin, reduces the influence of interlayer shrinkage stress, reduces the risk such as interface delamination, bulging and paddle deformation, and improves the mounting of the paddle.

Description

Technical Field

[0001] This utility model belongs to the field of thermoplastic composite materials, and specifically relates to a blade. Background Technology

[0002] Composite materials, due to their advantages such as lightweight, high strength, and corrosion resistance, are gradually replacing traditional metal materials. With the increasing demands for lightweight design, longer flight range, and higher load-bearing capacity in the drone industry, the application of composite material propeller blades is becoming increasingly widespread. Currently, thermoset composite materials are widely used in drone propeller blades; however, thermoset composite blades have poor weather resistance and toughness, low production efficiency, and are not recyclable, failing to meet the safety and environmental protection requirements of drones and limiting their future development. Thermoplastic composite materials possess high impact resistance and damage tolerance, high toughness, and good environmental resistance. In particular, their recyclability and reusability meet the requirements of environmental protection and high performance. Therefore, future drone propeller blades will increasingly utilize thermoplastic composite materials. However, the current manufacturing technology for irregularly shaped thermoplastic composite parts is complex, resulting in poor dimensional accuracy, poor impact performance, interlaminar shrinkage between different components, and easy deformation in drone propeller products, leading to uncontrollable torsion angles achievable by drone propeller blades. Summary of the Invention

[0003] In view of the problems of poor dimensional accuracy and impact performance of thermoplastic composite drone propellers, interlayer shrinkage between different components, easy deformation, and uncontrollable torsion angle in the existing technology, this utility model will provide a propeller.

[0004] To achieve the above objectives, the following technical solutions are specifically included:

[0005] A blade includes a through-hole, an outer skin, and an inner core material. The through-hole penetrates both the outer skin and the core material. The core material is composed of multiple layers of continuous fiber-reinforced unidirectional tape layups. The length direction of the blade is the 0° layup direction. The continuous fiber-reinforced unidirectional tapes in the core material include 0° continuous fiber-reinforced unidirectional tapes, ±45° continuous fiber-reinforced unidirectional tapes, and 90° continuous fiber-reinforced unidirectional tapes. Furthermore, the core material satisfies the following relationship: d0 > d 45 >d 90 Where d0 is the total thickness of the 0° continuous fiber-reinforced unidirectional tape in the core material, d 45 d is the total thickness of the ±45° continuous fiber-reinforced unidirectional tape in the core material. 90 The total thickness of the 90° continuous fiber-reinforced unidirectional tape in the core material is given.

[0006] The blade of this invention has a ply direction where the length direction of the blade is the 0° ply direction, the angle formed with the length direction is ±45°, and the angle formed with the length direction is ±90°, which is the 90° ply direction. The inventors discovered that d0 > d 45 >d 90 When the core material is sufficiently reinforced, it can further improve the blade's resistance to high and low temperature impacts, reduce the risk of low-temperature brittle fracture, enhance the interfacial bonding between the blade core material and the outer skin, reduce the impact of interlayer shrinkage stress, and decrease the risks of interfacial delamination, bulging, and blade deformation, thereby improving the blade's load-bearing capacity. Preferably, d0 = 0.75-10 mm, d 45 =0.48-2.5mm, d 90 =0.24-1.8mm.

[0007] Preferably, the core material satisfies the following relationship: d0 ≥ 3 × d 90 d 45 ≥2×d 90 .

[0008] More preferably, the core material satisfies the following relationship: d0:d 45 :d 90 =(6-10):(4-6):1.

[0009] The inventors discovered that, when the above-mentioned relationship is satisfied in the core material, a suitable distribution of the number of 0° continuous fiber reinforced unidirectional strips, ±45° continuous fiber reinforced unidirectional strips, and 90° continuous fiber reinforced unidirectional strips can further improve the strength of the blade, further improve the blade's resistance to high and low temperature impacts, reduce the risk of low temperature brittle fracture, enhance the interfacial bonding force between the blade core material and the outer skin, reduce the influence of interlayer shrinkage stress, reduce the risk of interfacial delamination, bulging, blade deformation, etc., and improve the blade's load-bearing capacity.

[0010] ±45° means that two layers are set in the two directions of -45° and +45° respectively, and ±90° means that two layers are set in the two directions of -90° and +90° respectively.

[0011] Preferably, the outer skin is a short fiber reinforced resin.

[0012] Preferably, the core material and the outer skin are bonded by injection molding on the outer surface of the core material.

[0013] The blade of this invention uses short-fiber reinforced resin as its outer skin, where the short fibers enhance strength, toughen, and reduce shrinkage. Combined with an internal core material composed of continuous fiber-reinforced unidirectional tapes, the short-fiber reinforced resin and continuous fiber-reinforced unidirectional tapes not only reinforce the core material and outer surface respectively, but also form a multi-scale fiber-reinforced interface at the interface between the outer skin and the core material. This improves the blade's resistance to high and low temperature impacts, reduces the risk of low-temperature brittleness, enhances the interfacial bonding between the blade core material and the outer skin, reduces the impact of interlayer shrinkage stress, and minimizes the risks of interface delamination, bulging, and blade deformation, thereby improving the blade's load-bearing capacity. Furthermore, the blade's core material and outer skin are integrally injection molded, which further enhances the interfacial bonding between the core material and the outer skin, reduces the impact of interlayer shrinkage stress, and minimizes the risks of interface delamination, bulging, and blade deformation. The molding process can be controlled by a mold, resulting in precise dimensions, a smooth, contoured blade surface, lower cost, higher production efficiency, and the ability to mass-produce.

[0014] Preferably, in the thickness direction of the core material, from top to bottom, it includes an upper blade surface ply, an upper gasket ply, a center ply, a lower gasket ply, and a lower blade surface ply. Through-holes penetrate the upper blade surface ply, upper gasket ply, center ply, lower gasket ply, and lower blade surface ply. The central axis of the center ply, passing through the center of the through-hole and parallel to the blade length direction, is used as the central axis. The upper and lower blade surface plys are arranged symmetrically along the central axis, as are the upper and lower gasket plys. The area of ​​the upper gasket ply is 50-90% smaller than that of the upper blade surface ply, the area of ​​the center ply is 50-90% smaller than that of the upper gasket ply, and the area of ​​the lower gasket ply is 50-90% smaller than that of the lower blade surface ply.

[0015] Preferably, the upper leaf surface layup includes at least a first upper layup, an intermediate upper layup, and a second upper layup in sequence; the area of ​​the intermediate upper layup is reduced by 50-90% relative to the area of ​​the first upper layup, and the area of ​​the second upper layup is reduced by 50-90% relative to the area of ​​the intermediate upper layup; the first upper layup and the second upper layup are composed of two or more layers of 0° continuous fiber-reinforced unidirectional tapes.

[0016] Preferably, the lower leaf surface ply, upper pad ply, center ply, lower pad ply, and lower leaf surface ply are each composed of two or more layers of continuous fiber-reinforced unidirectional tape ply.

[0017] Preferably, the intermediate upper layer is composed of more than 2 layers of continuous fiber-reinforced unidirectional tape, and more preferably 3-6 layers.

[0018] Preferably, the lower leaf layup includes at least a first underlay, an intermediate underlay, and a second underlay in sequence; the area of ​​the intermediate underlay is reduced by 50-90% relative to the area of ​​the first underlay, and the area of ​​the second underlay is reduced by 50-90% relative to the area of ​​the intermediate underlay; the first underlay and the second underlay are composed of two or more layers of 0° continuous fiber-reinforced unidirectional tapes.

[0019] The first underlay and the first toplay are located on the outer layer of the core material, while the second toplay and the second underlay are located near the center of the core material. All of them are 0° continuous fiber reinforced unidirectional tape layup, which can significantly increase the high and low temperature impact resistance of the core material and improve the control accuracy of the blade's torsion angle, achieving a torsion angle range of <±0.65°.

[0020] Preferably, the intermediate underlay layer is composed of more than 2 layers of continuous fiber-reinforced unidirectional tape, and more preferably 3-6 layers.

[0021] More preferably, in the intermediate underlay, the layup methods between the continuous fiber-reinforced unidirectional tapes in each layer are different.

[0022] More preferably, the layup pattern of the upper leaf surface layer is: 0° / 0°, 0° / ±45°, 0° / 0° / ±45°, 90° / ±45°, 0° / 0°, 0° / 90°, 0° / 0°; and the layup pattern of the lower leaf surface layer is: 0° / 0°, 0° / ±45°, 0° / 0° / ±45°, 90° / ±45°, 0° / 0°, 0° / 90°, 0° / 0°.

[0023] Preferably, the upper gasket layer and the lower gasket layer are composed of two or more layers of continuous fiber-reinforced unidirectional tape, and the layup methods between the layers of continuous fiber-reinforced unidirectional tape are different.

[0024] Preferably, the central layup is composed of multiple layers of continuous fiber-reinforced unidirectional tapes, including 0° continuous fiber-reinforced unidirectional tapes and 90° continuous fiber-reinforced unidirectional tapes.

[0025] The center layup is located at the blade root and uses 0° and 90° continuous fiber-reinforced unidirectional tape layup, which can realize multi-axial reinforcement design, further improve the strength of the core material and the load stability of the blade, and increase the load-bearing capacity of the blade root.

[0026] Preferably, the through hole is cylindrical and has a diameter of 5-50 mm.

[0027] Preferably, an annular tube is embedded in the through hole, and an annular gasket is wound around the annular tube. The annular gasket is composed of a 0° continuous fiber-reinforced unidirectional tape and a 90° continuous fiber-reinforced unidirectional tape, and the thickness ratio of the 0° continuous fiber-reinforced unidirectional tape to the 90° continuous fiber-reinforced unidirectional tape in the annular gasket is (1~5):1.

[0028] Preferably, the thickness of a single layer of continuous fiber reinforced unidirectional tape is 0.12-0.25 mm, and the fiber mass percentage of the continuous fiber reinforced unidirectional tape is 40-80%.

[0029] Preferably, the continuous fiber reinforced unidirectional tape is obtained by hot pressing of continuous fiber reinforced unidirectional prepreg tape.

[0030] More preferably, the continuous fiber reinforced unidirectional prepreg tape is made by melt impregnation of continuous glass fiber or continuous carbon fiber with thermoplastic resin; the thermoplastic resin comprises the following components in parts by weight: 70-95 parts PA, 0.3-0.8 parts antioxidant, 1-10 parts compatibilizer, and 5-20 parts toughening agent.

[0031] More preferably, the PA includes at least one of PA6, PA610, and PA612.

[0032] Preferably, the carbon fiber is T300 or T700 carbon fiber, and the yarn bundle is 6K-24K.

[0033] Preferably, the short fiber reinforced resin comprises the following components in parts by weight: 40-95 parts thermoplastic resin, 10-50 parts short fiber, 5-15 parts toughening agent, 0-5 parts compatibilizer, 0.1-0.8 parts antioxidant, and 0.2-0.8 parts lubricant.

[0034] More preferably, in the short fiber reinforced resin, the length of the short fibers is 1-30 mm.

[0035] More preferably, the thermoplastic resin has a heat distortion temperature (HDT) > 90°C and a melt index of 60-120 g / 10 min.

[0036] Preferably, the short fiber is at least one of glass fiber and carbon fiber.

[0037] Preferably, the toughening agent includes at least one of ethylene octene block copolymer and styrene-ethylene / butene-styrene block copolymer (such as SEBS-g-MAH).

[0038] Preferably, the lubricant includes at least one of amide lubricants and epoxy lubricants.

[0039] Preferably, the antioxidant includes at least one of hindered phenolic antioxidants, thioester antioxidants, and phosphite antioxidants.

[0040] There are no special restrictions on the compatibilizers and thermoplastic resins used in short fiber reinforced resins; the purpose can be achieved by using compatibilizers and thermoplastic resins conventional in the field.

[0041] Preferably, the blade's overall shape maintains a dynamic shape conducive to flight, such as a streamlined structure, and the outer contour of the core material remains consistent with the blade's shape.

[0042] Compared to existing technologies, this invention offers the following advantages: The blade of this invention uses short-fiber reinforced resin as its outer skin, where the short fibers enhance strength, toughen, and reduce shrinkage. Combined with a core material composed of internal continuous fiber-reinforced unidirectional tapes, the short-fiber reinforced resin and continuous fiber-reinforced unidirectional tapes not only reinforce the core material and outer surface respectively, but also form a multi-scale fiber-reinforced interface at the interface between the outer skin and the core material. This improves the blade's resistance to high and low temperature impacts, reduces the risk of low-temperature brittleness, enhances the interfacial bonding between the blade core material and the outer skin, reduces the impact of interlayer shrinkage stress, and minimizes the risks of interface delamination, bulging, and blade deformation, thereby improving the blade's load-bearing capacity. Furthermore, the core material and outer skin of the blade are integrally injection molded, which further enhances the interfacial bonding between the core material and the outer skin, reduces the impact of interlayer shrinkage stress, and minimizes the risks of interface delamination, bulging, and blade deformation. The molding process can be controlled by a mold, resulting in precise dimensions, a smooth contoured blade surface, lower costs, higher production efficiency, and the ability to mass-produce. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the blade structure;

[0044] Figure 2 This is a schematic diagram of the core material's layup.

[0045] Figure 3 A schematic diagram of the paddle and annular tube component;

[0046] 1-Outer skin, 2-Core material, 3-First top layer, 4-Intermediate top layer, 41-First intermediate top layer, 42-Second intermediate top layer, 43-Third intermediate top layer, 44-Fourth intermediate top layer, 45-Fifth intermediate top layer, 5-Second top layer, 6-Upper gasket layer, 7-Center layer, 8-Annular tube (metal), 9-Lower gasket layer, 10-Second lower layer, 11-Intermediate lower layer, 111-First intermediate lower layer, 112-Second intermediate lower layer, 113-Third intermediate lower layer, 114-Fourth intermediate lower layer, 115-Fifth intermediate lower layer, 12-First lower layer, 13-Annular gasket. Detailed Implementation

[0047] To better illustrate the purpose, technical solution, and advantages of this utility model, specific embodiments will be used to further explain it below. Unless otherwise specified, the test methods used in the embodiments and / or comparative examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.

[0048] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. In a ply structure, 0° is parallel to the length direction, and 90° is parallel to the width direction.

[0049] Example 1

[0050] The blades in this embodiment are shown in the attached figure. Figure 1 As shown, the blade includes an outer skin 1 and an inner core material 2. The outer skin 1 is made of short fiber reinforced resin, and the core material 2 is composed of multiple layers of continuous fiber reinforced unidirectional tape layup. The core material 2 and the outer skin 1 are bonded together by injection molding short fiber reinforced resin onto the outer surface of the core material 2. The blade also includes a through hole that penetrates the outer skin 1 and the core material 2, and an annular cylindrical tube 8 is embedded in the through hole. The blade has a streamlined shape, and the outer skin 1 and its interior have a consistent outline. The through hole is cylindrical, with a diameter of 15-22 mm, and is located at the blade root.

[0051] The continuous fiber reinforced unidirectional tape includes 0° continuous fiber reinforced unidirectional tape, ±45° continuous fiber reinforced unidirectional tape, and 90° continuous fiber reinforced unidirectional tape. The thickness of a single layer of continuous fiber reinforced unidirectional tape in each angle direction is 0.12-0.25 mm, and the fiber mass percentage of the single layer of continuous fiber reinforced unidirectional tape in each angle is 40-80%. The continuous fiber reinforced unidirectional prepreg tape is made by melt impregnation of continuous glass fiber or continuous carbon fiber with thermoplastic resin. The thermoplastic resin includes the following components in parts by weight: 80 parts PA, 0.5 parts antioxidant, 5 parts compatibilizer, and 15 parts toughening agent; the carbon fiber is T300 or T700 carbon fiber, the yarn bundle is 6K-24K, and the PA is PA6.

[0052] The short fiber reinforced resin comprises the following components in parts by weight: 60 parts of thermoplastic resin (HDT > 90℃, 60-120g / 10min), 20 parts of carbon fiber, 7 parts of SEBS-g-MAH, 1 part of compatibilizer, 0.5 parts of hindered phenolic antioxidant, and 0.5 parts of amide lubricant, wherein the length of the short fiber is 1-30mm.

[0053] The core material 2 is divided into upper and lower sections along its thickness axis, and includes, in sequence, an upper blade surface ply, an upper gasket ply 6, a central ply 7, a lower gasket ply 9, and a lower blade surface ply. Through holes penetrate the upper blade surface ply, upper gasket ply 6, central ply 7, lower gasket ply 9, and lower blade surface ply. The central axis is the central axis of the central ply 7, which passes through the center of the through hole and is parallel to the blade length direction. The upper and lower blade surface plys are arranged symmetrically along the central axis, as are the upper gasket ply 6 and lower gasket ply 9. The areas of the upper blade surface ply, upper gasket ply 6, and central ply 7 are reduced by 50-90% in sequence, as are the areas of the lower blade surface ply and lower gasket ply 9.

[0054] The upper leaf surface layup includes at least a first upper layup 3, an intermediate upper layup 4, and a second upper layup 5 in sequence; the area of ​​the first upper layup 3, the intermediate upper layup 4, and the second upper layup 5 is reduced by 50-90% in sequence; the first upper layup 3 and the second upper layup 5 are composed of two or more layers of 0° continuous fiber-reinforced unidirectional tapes.

[0055] The lower leaf surface layup includes at least a first underlay 12, an intermediate underlay 11, and a second underlay 10 in sequence; the area of ​​the first underlay 12, the intermediate underlay 11, and the second underlay 10 is reduced by 50-90% in sequence; the first underlay 12 and the second underlay 10 are composed of two or more layers of 0° continuous fiber-reinforced unidirectional tapes.

[0056] In this embodiment, the layup pattern of the upper leaf surface layer is as follows: 0° / 0° (first upper layer 3), 0° / ±45° (first intermediate upper layer 41), 0° / 0° / ±45° (second intermediate upper layer 42), 90° / ±45° (third intermediate upper layer 43), 0° / 0° (fourth intermediate upper layer 44), 0° / 90° (fifth intermediate upper layer 45), 0° / 0° (second upper layer 5); the layup pattern of the lower leaf surface layer is as follows: 0° / 0° (first lower layer 12), 0° / ±45° (first intermediate underlay 111), 0° / 0° / ±45° (second intermediate underlay 112), 90° / ±45° (third intermediate underlay 113), 0° / 0° (fourth intermediate underlay 114), 0° / 90° (fifth intermediate underlay 115), 0° / 0° (second underlay 10); the layup pattern of the upper pad layer 6 and the lower pad layer 9 is 90° / 0° / 0° / ±45°, and the layup pattern of the center layer 7 is 0° / 90° / 0°, as detailed in the appendix. Figure 2 As shown.

[0057] The central ply 7 is located at the blade root and extends along the blade length. An annular tube 8 is embedded in the through hole at the blade root. The annular tube 8 is surrounded by a continuous fiber-reinforced unidirectional strip, i.e., an annular gasket 13. The thickness ratio of the annular gasket 13 distributed along the circumferential and axial directions of the blade hole is (1~5):1. That is, the ply pattern on the annular gasket 13 is 0° / 90°, and the thickness ratio of the total 0° continuous fiber-reinforced unidirectional strip to the total 90° continuous fiber-reinforced unidirectional strip on the annular gasket 13 is (1~5):1. This can realize a multi-axial reinforcement design and improve the bearing capacity of the blade root.

[0058] The blade preparation method in this embodiment includes the following steps:

[0059] (1) Preparation of continuous fiber reinforced unidirectional tape: The continuous fiber is unwound, spread, melt-impregnated with thermoplastic resin, cooled and shaped, and then wound up to obtain a continuous fiber reinforced unidirectional prepreg tape;

[0060] (2) Preparation of core material 2: according to Figure 2 In the layered design, the annular tube 8 wound with annular gasket 13 and each layer are stacked in the mold in sequence, and the core material 2 is formed by direct hot pressing. The shape of the (irregular) core material 2 is designed according to different blade structures and performance. After the core material 2 is processed, the surface needs to be sandblasted with sand particles of 0.4-2.0mm (30-40 mesh). After sandblasting, the roughness Ra>2.

[0061] (3) Injection molding preparation of outer skin 1: Using core material 2 as an insert, short fiber reinforced resin is injected into the outer surface by injection molding. The short fiber reinforced resin and core material 2 are integrated to form a thermoplastic composite blade. The blade structure is as follows: Figure 1 As shown.

[0062] This invention relates to a continuous fiber-reinforced thermoplastic composite blade, characterized by lightweight, high rigidity, high-temperature resistance, dimensional stability, resistance to deformation, significant load-bearing capacity, high blade root strength, and shock absorption. It can enhance the loading capacity of drones and other equipment. Testing has shown that the blade withstands high and low temperature impacts within a range of -40 to 85°C, has a load capacity >40kg, and a torsion angle range <±0.65°. Furthermore, the short fiber reinforced resin outer skin improves the core material appearance, enhances blade dimensional accuracy, reduces torsion angle, and provides the blade with multifunctionality and aesthetic advantages. Compared to conventional thermoset composite blades or fiber-reinforced composite injection-molded blades, this invention offers higher processing efficiency, recyclability, safety, environmental friendliness, and lower cost, solving the problems of high-temperature deformation performance degradation and insufficient load-bearing capacity.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. A blade, characterized in that, The blade includes through-holes, an outer skin, and a core material inside. The through-holes penetrate the outer skin and the core material. The core material is composed of multiple layers of continuous fiber-reinforced unidirectional tape layups. The length direction of the blade is the 0° layup direction. The continuous fiber-reinforced unidirectional tapes in the core material include 0° continuous fiber-reinforced unidirectional tapes, ±45° continuous fiber-reinforced unidirectional tapes, and 90° continuous fiber-reinforced unidirectional tapes. Furthermore, the core material satisfies the following relationship: d0 > d 45 >d 90 Where d0 is the total thickness of the 0° continuous fiber-reinforced unidirectional tape in the core material, d 45 d is the total thickness of the ±45° continuous fiber-reinforced unidirectional tape in the core material. 90 The total thickness of the 90° continuous fiber-reinforced unidirectional tape in the core material is given.

2. The blade as described in claim 1, characterized in that, Includes at least one of the following: d0 = 0.75-10 mm; d 45 <0.48-2.5mm; d 90 =0.24-1.8mm。 3. The blade as described in claim 2, characterized in that, The core material satisfies the following relationship: d0 ≥ 3 × d 90 d 45 ≥2×d 90 .

4. The blade as described in claim 1, characterized in that, The core material satisfies the following relationship: d0:d 45 :d 90 =(6-10):(4-6):

1.

5. The blade as described in claim 1, characterized in that, In the thickness direction of the core material, from top to bottom, it includes an upper blade surface ply, an upper gasket ply, a center ply, a lower gasket ply, and a lower blade surface ply. Through holes penetrate the upper blade surface ply, the upper gasket ply, the center ply, the lower gasket ply, and the lower blade surface ply. The central axis of the center ply, which passes through the center of the through hole and is parallel to the blade length direction, is taken as the central axis. The upper and lower blade surface plys are arranged symmetrically along the central axis, as are the upper and lower gasket plys. The area of ​​the upper gasket ply is 50-90% smaller than that of the upper blade surface ply, the area of ​​the center ply is 50-90% smaller than that of the upper gasket ply, and the area of ​​the lower gasket ply is 50-90% smaller than that of the lower blade surface ply.

6. The blade as described in claim 5, characterized in that, The upper leaf surface layup comprises at least a first upper layup, an intermediate upper layup, and a second upper layup in sequence; the area of ​​the intermediate upper layup is reduced by 50-90% compared to the area of ​​the first upper layup, and the area of ​​the second upper layup is reduced by 50-90% compared to the area of ​​the intermediate upper layup; the first upper layup and the second upper layup are composed of two or more layers of 0° continuous fiber-reinforced unidirectional tape; the lower leaf surface layup comprises at least a first lower layup, an intermediate lower layup, and a second lower layup in sequence; the area of ​​the intermediate lower layup is reduced by 50-90% compared to the area of ​​the first lower layup, and the area of ​​the second lower layup is reduced by 50-90% compared to the area of ​​the intermediate lower layup; the first lower layup and the second lower layup are composed of two or more layers of 0° continuous fiber-reinforced unidirectional tape.

7. The blade as described in claim 6, characterized in that, The intermediate upper layer is composed of more than 2 layers of continuous fiber-reinforced unidirectional tape, and the intermediate lower layer is composed of more than 2 layers of continuous fiber-reinforced unidirectional tape.

8. The blade as described in claim 1, characterized in that, An annular tube is embedded in the through hole, and an annular gasket is wound around the annular tube. The annular gasket is composed of 0° continuous fiber reinforced unidirectional tape and 90° continuous fiber reinforced unidirectional tape. The thickness ratio of the 0° continuous fiber reinforced unidirectional tape to the 90° continuous fiber reinforced unidirectional tape in the annular gasket is (1~5):

1.

9. The blade as described in claim 1, characterized in that, The outer skin is made of short fiber reinforced resin.

10. The blade as claimed in claim 9, characterized in that, In the short fiber reinforced resin, the length of the short fibers is 1-30 mm.

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