CN114893438B

CN114893438B - Composite blade and processing method

Info

Publication number: CN114893438B
Application number: CN202210505541.4A
Authority: CN
Inventors: 康振亚; 郑会龙; 杨肖芳; 于浩; 李方; 陈晓奎; 张谭
Original assignee: Institute of Engineering Thermophysics of CAS
Current assignee: Institute of Engineering Thermophysics of CAS
Priority date: 2022-05-10
Filing date: 2022-05-10
Publication date: 2023-09-19
Anticipated expiration: 2042-05-10
Also published as: CN114893438A

Abstract

The application provides a composite blade and a processing method thereof, comprising the following steps: a metal skeleton comprising lightening holes; the hollow curing unit is arranged in the lightening hole in an embedded manner; the flexible braiding body wraps the outer layers of the metal framework and the hollow curing unit. The impact resistance of the aero-engine blade is effectively improved, the weight of the composite material blade is reduced through the hollow structure, and the light weight level of the composite material blade is effectively improved.

Description

Composite blade and processing method

Technical Field

The application relates to the field of aero-engine blades, in particular to a forming method for an aero-engine blade.

Background

The aero-engine is required to be continuously improved in light weight level for pursuing high thrust-weight ratio, and the composite material has the characteristics of high specific strength, high specific rigidity, good fatigue resistance and the like, and can effectively meet the characteristics of the aero-engine such as light weight, fatigue resistance and the like, so that the consumption and the occupation ratio of the composite material on the aero-engine are continuously improved. The aero-engine blades are large in number and mass, and the light weight of the aero-engine blades can effectively meet the actual use requirements of future engines. The existing metal material blade has high weight, and has stronger shock resistance, but the weight can be greatly reduced by introducing a composite material; the existing composite material blade adopts a layering hot pressing method or a three-dimensional weaving and RTM integrated curing forming method, the final composite material blade structure is a solid structure, the extreme weight reduction of the blade cannot be realized, and the impact resistance of the composite material blade which simply adopts the composite material is poor. Therefore, there is a need for a structure that combines the impact resistance of metal blades with the weight reduction advantages of composite blades.

Chinese patent CN202110637171, publication No. CN113547772a, publication date 2021, 10-26, discloses a method for manufacturing a fan blade with mixed structure, which adopts a metal front edge to insert into a blade composite material part and uses a suture to join the metal front edge part and the composite material part, but the blade composite material part in the manufacturing process is a solid structure, and the fan blade with mixed structure does not achieve the aim of reducing weight to the greatest extent. Chinese patent CN201711341200, publication No. CN108087318a, publication date 2018, month 05, and 29, discloses a composite blade with hybrid structure, comprising a titanium alloy matrix shaped like a Chinese character 'tian', and an outer surface covered with a thermoplastic skin to form a blade profile. Effects that may exist with such a manufacturing process include: the blade composite material part is of a solid structure, and the T-shaped lightening holes are filled with resin matrix composite materials, so that the hybrid structure fan blade does not achieve the aim of lightening the weight to the greatest extent.

However, the existing composite blade has insufficient impact resistance, the problem of impact delamination is easy to occur, the light weight degree of the composite blade needs to be further improved, and the pure solid composite blade cannot meet the requirement of extremely light weight.

Disclosure of Invention

In view of this, the embodiments of the present disclosure provide a composite blade and a processing method thereof, so as to achieve the purpose of improving the impact resistance and the light weight of the composite blade.

The embodiment of the specification provides the following technical scheme:

a composite blade comprising:

a metal skeleton comprising lightening holes;

the hollow curing unit can be embedded into the lightening hole;

the flexible braiding body wraps the outer layers of the metal framework and the hollow curing unit.

Further, the hollow curing unit includes: the hollow curing unit comprises a hollow curing unit first splicing block, a hollow curing unit second splicing block and a hollow curing unit splicing assembly, wherein the hollow curing unit first splicing block and the hollow curing unit second splicing block are spliced into a hollow curing unit through the hollow curing unit splicing assembly.

Further, the hollow curing unit further includes: the outer layer of the curing unit reinforcing rib is coated with the thermoplastic filler, and the thermoplastic filler and the curing unit reinforcing rib jointly form a weight-reducing cavity.

Further, the outer surface of the thermoplastic filler is provided with a plurality of curing unit projections.

Further, the hollow curing units and the lightening holes may be provided in a plurality of groups arranged at intervals.

Further, the metal framework is further provided with a plurality of threading holes, and the flexible braiding bodies and the metal framework are fixed by the fiber tows through the threading holes.

Further, the composite material blade further comprises a front edge wrapping edge, wherein the front edge wrapping edge is arranged at the front edge of the metal framework, and the flexible woven body and the metal framework are wrapped and fixed through the front edge wrapping edge.

Further, the processing method of the composite blade comprises the following steps:

step one, processing a metal framework and a hollow curing unit;

step two, fixedly mounting the hollow curing unit on a metal framework;

step three, wrapping the flexible braid outside the metal skeleton;

and fourthly, integrally curing and forming the metal framework, the hollow curing unit and the flexible braiding body by using a thermoplastic filling body.

Further, in the first step, the processing method of the hollow curing unit specifically comprises the following steps:

fixing a curing unit bulge on a metal mold in advance;

integrally curing and forming the curing unit reinforcing ribs and the curing unit protrusions by using thermoplastic filler;

and splicing the first splicing block of the hollow curing unit and the second splicing block of the hollow curing unit together through the splicing component of the hollow curing unit.

Further, wrapping the flexible braid around the metal skeleton comprises the steps of:

sleeving the flexible braiding body on a metal framework;

passing fiber tows through threading holes of the flexible braiding bodies and the metal frameworks to fix the metal frameworks and the flexible braiding bodies;

the front edge part of the blade uses a front edge wrapping to encapsulate and fix the metal framework and the flexible braid.

Compared with the prior art, the beneficial effects that above-mentioned at least one technical scheme that this description embodiment adopted can reach include at least:

the impact resistance of the aero-engine blade is effectively improved, the hollow of the composite material blade is realized, and the lightweight level of the blade is effectively improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an overall schematic of a composite blade according to an embodiment of the present application;

FIG. 2 is a flow chart of a method of processing a composite blade according to an embodiment of the present application;

FIG. 3 is a schematic view of a metal skeleton structure according to an embodiment of the present application;

FIG. 4 is a schematic view of a hollow curing unit according to an embodiment of the present application;

FIG. 5 is a side view of a hollow curing unit structure according to an embodiment of the present application;

FIG. 6 is a side view of a metal skeletal structure of an embodiment of the present application;

FIG. 7 is a cross-sectional view of the portion of FIG. 6A-A in accordance with an embodiment of the present application;

FIG. 8 is a schematic partial cross-sectional view of a composite blade according to an embodiment of the present application;

FIG. 9 is a schematic view of a first splice block of a hollow curing unit according to an embodiment of the present application;

FIG. 10 is a cross-sectional view of portions B-B of FIG. 9 in accordance with an embodiment of the present application;

FIG. 11 is a schematic diagram of a hollow curing unit prior to splicing in accordance with an embodiment of the present application;

FIG. 12 is a side view of a spliced hollow curing unit according to an embodiment of the present application;

fig. 13 is a schematic view of a spliced hollow curing unit according to an embodiment of the present application.

Reference numerals illustrate: 1. a metal skeleton; 2. a flexible braid; 3. a hollow curing unit; 301. solidifying the unit reinforcing ribs; 302. curing unit bulges; 303. a thermoplastic filler; 304. a first splice block of hollow curing units; 305. a second splice block of hollow curing units; 306. a hollow curing unit splicing assembly; 4. a tenon root; 5. a threading hole; 6. a lightening hole; 7. the leading edge is hemmed.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Other advantages and effects of the present application will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present application with reference to specific examples. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. The application may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present application. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, apparatus may be implemented and/or methods practiced using any number and aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should also be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present application by way of illustration, and only the components related to the present application are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided in order to provide a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

The following describes the technical scheme provided by each embodiment of the present application with reference to the accompanying drawings.

Referring to fig. 1, the inner layer of the composite material blade before curing the thermoplastic filler is composed of a metal framework 1, and a plurality of lightening holes 6 are arranged on the metal framework 1, wherein the lightening holes 6 can be arranged in a row or a fork row. The structure of the lightening holes 6 depends on the composite blade structure and the load bearing requirements. According to the shape of the metal framework 1 designed according to various requirements of the blade, one hollow curing unit 3 can be inserted into and fixed to a corresponding lightening hole 6, the space shape of the hollow curing unit 3 is matched with that of the metal framework 1, the hollow curing unit 3 is clamped in the lightening hole 6 through shape matching, two side surfaces of the hollow curing unit 3 can be space planes or curved surfaces and the like, and two side surfaces of the metal framework 1 and two side surfaces of the hollow curing unit 3 can be spliced to form two smoothly-transitional space curved surfaces. The bottom of the metal framework 1 is provided with an integrally formed tenon root 4, and the tenon root 4 is used for integrally installing and fixing the blade. After the hollow curing unit 3 is mounted to the lightening hole 6 of the metal framework 1, the whole outer part is sleeved with the flexible braided body 2, so that the connection between the flexible braided body 2 before the thermoplastic filler is uncured and the metal framework 1 is more compact and tight, and the impact resistance of the composite material blade after the thermoplastic filler is cured is enhanced.

Referring to fig. 3, the leading edge of the metal skeleton 1 (i.e., the direction in which the gas flows in when the blade is in operation) is provided with a leading edge bead 7, and the leading edge bead 7 and the metal skeleton 1 body may be integrally designed and manufactured. The front edge wrapping 7 wraps and fixes the edges of the metal framework 1 and the flexible braiding body 2, so that the rigidity of the space structure of the metal framework 1 is improved, and the capability of the composite material blade for resisting the frontal impact of an obstacle is also improved. The metal skeleton 1 is provided with the plurality of threading holes 5, the threading holes 5 can be used for penetrating fiber tows made of the same material as the flexible braiding body 2, the fiber tows are wound, bound and tensioned by the threading holes 5, the metal skeleton 1 and the flexible braiding body 2 are tightly fixed together, the overall structure of the thermoplastic filling body before solidification is more compact and tight, and the impact resistance of the composite material blade after solidification of the thermoplastic filling body is stronger.

In other embodiments, the leading edge 7 may also be manufactured separately from the metal skeleton 1, and the leading edge 7 may be adhesively secured to the thermoplastic filler cured composite blade.

Referring to fig. 4 and 5, the hollow curing unit 3 of the present embodiment has an externally closed cavity structure, and the cavity can reduce the weight of the entire blade. The cavity is filled with gas, and the thermoplastic filler 303 is wrapped outside the cavity shell. The inside of the cavity can be provided with a curing unit reinforcing rib 301 to strengthen the strength of the cavity structure, the shell of the hollow curing unit 3 and the curing unit reinforcing rib 301 are soaked and cured by using a thermoplastic filler, so that the thermoplastic filler 303 is wrapped outside, and the inner cavity is filled with gas. The curing unit reinforcing ribs 301 can be provided with a plurality of curing unit bulges 302 in the direction of the surface, the curing unit bulges 302 and the curing unit reinforcing ribs 301 are integrally formed, the structure of the curing unit bulges 302 is similar to a Z-pin structure and is used for enhancing acting force between the hollow curing unit 3 and the carbon fiber structure of the flexible braiding body 2, so that the interlayer strength of the composite material blade after the thermoplastic filler is cured is improved, and the integral shock resistance of the blade is improved.

After the hollow curing unit 3 is embedded into the metal framework 1, the outer surfaces of the hollow curing unit 3 and the metal framework 1 are flush, namely the hollow curing unit 3 and the metal framework 1 have the same thickness and the same integral streamline, so that a smooth transition space curved surface is realized. The hollow solidifying unit 3 completes the topological optimization design according to the stress condition, the operation condition and the pneumatic structure of the blade, so as to form an optimal and maximum-size structure, and the internal cavity of the hollow solidifying unit is filled with gas, namely the composite blade is finally a hollow component, and the weight is lighter. The material of the curing unit protrusion 302 and the curing unit rib 301 is titanium alloy. The thermoplastic filler 303 in this embodiment is an epoxy resin.

As shown in fig. 6 and 7, fig. 6 is a side view of the composite blade of the present embodiment before being cured. Fig. 7 is a cross-sectional view of section A-A of fig. 6. From the sectional view, it can be seen that the metal skeleton 1 is embedded with a hollow curing unit 3, and the tenon 4 at the lower side of the metal skeleton 1 can be conical or iris-shaped so as to be installed into the engine hub. The metal framework 1 and the hollow curing unit 3 are integrated by the flexible braiding body 2 to form a unified composite material blade integral structure.

FIG. 8 is a leading edge wrapping portion of a composite blade of the present embodiment, wherein the leading edge of the metal skeleton 1 comprises a wrapping structure: leading edge wrapping 7. The leading edge trim 7 enables the flexible braid 2 to be inlaid into the metal skeleton 1. The hollow curing unit 3 is embedded in the lightening holes 6 of the metal framework 1 before the thermoplastic filler of the composite blade is cured. In the process of implementing the infiltration and solidification of the thermoplastic filler, the surface of the hollow solidification unit 3 is melted after the infiltration and solidification of the thermoplastic filler, the hollow solidification unit 3 and the thermoplastic filler are integrated and formed again, and the hollow solidification unit 3, the metal framework 1 and the flexible braiding body 2 are solidified into a whole after the solidification layer of the thermoplastic filler is cooled, so that the composite blade with the solidification layer of the thermoplastic filler is finally formed.

As shown in fig. 9 and 10, each of the hollow curing unit first splice block 304 and the hollow curing unit second splice block 305 is made by curing the thermoplastic filler 303 using a metal mold. The first and second hollow curing unit tiles 304, 305 are identical in body portion, with only the hollow curing unit tile assembly 306 being shaped differently. In the manufacturing process, the structure of the curing unit protrusion 302 is fixed in advance on a metal mold, and the thermoplastic filler 303 is filled into the metal mold, so that the curing unit protrusion 302 and the thermoplastic filler 303 are cured and formed together. The surface shape of the hollow curing unit 3 is ensured by a metal mold, so that the surface of the hollow curing unit 3 can realize smooth transition after being embedded into the metal framework 1.

As shown in fig. 11, 12 and 13, the hollow curing unit splice assembly 306 includes a recess and a protrusion that are cooperatively mated with each other. Wherein the recesses and protrusions are used to achieve spatial positioning of the hollow curing unit first tile 304 and the hollow curing unit second tile 305. After the first and second hollow curing unit tiles 304, 305 are positioned by the hollow curing unit tile assembly 306, they are then secured together by an adhesive or other joining process to form the final hollow curing unit 3.

Referring to fig. 2, an embodiment of the present application provides a method for manufacturing a composite blade, including the steps of:

s201, processing the metal framework 1 and the hollow curing unit 3.

The step is mainly to process the metal framework 1 of the blade according to the shape and technological requirements of the blade. Specifically, the steps of processing the metal skeleton 1 include:

s2011, machining and manufacturing the metal framework 1.

Specifically, the tenon 4 and the front edge wrapping 7 are integrally formed on the metal framework 1, and the lightening holes 6 and the threading holes 5 are machined. The processing method comprises the following steps of, but is not limited to: 3D printing a metal blank, then finishing the final metal skeleton shape through machining, directly machining a forging piece to the final blade shape, and using an electric spark forming technology of a graphite electrode;

s2012, surface treatment of the metal skeleton 1. Surface treatments generally include, but are not limited to, texturing, sand blasting, and methods of machining precision microstructures.

The hollow curing unit 3 may be manufactured by various methods, and in this embodiment, the hollow curing unit 3 may be formed by splicing upper and lower splice blocks. The two splice blocks are manufactured by adopting a metal mold to cure the thermoplastic filler 303, in the manufacturing process, the structure of the curing unit bulge 302 is fixed on the metal mold in advance, the thermoplastic filler 303 is filled into the metal mold, and the curing unit reinforcing ribs 301, the curing unit bulge 302 and the thermoplastic filler 303 are cured and formed together. The two splicing blocks comprise a plurality of grooves and protrusions for splicing, the grooves and the protrusions for splicing are in splicing fit, and after the two hollow splicing blocks are positioned, the two hollow splicing blocks are fixed together through bonding or other connecting processes to form a final hollow curing unit 3 structure.

The surface shape of the hollow curing unit 3 is ensured by a metal mold, so that the space surface formed by the hollow curing unit 3 can realize smooth transition after the hollow curing unit 3 is embedded into the metal framework 1.

Specifically, the steps of processing and manufacturing the hollow curing unit 3 include:

s2013, fixing the curing unit protrusion 302 on the metal mold in advance.

S2014, integrally curing and forming the curing unit reinforcing ribs 301 and the curing unit protrusions 302 by using the thermoplastic filler 303.

Specifically, in the metal mold, the curing unit projections 302 and the curing unit reinforcing ribs 301 are infiltrated and cured with the thermoplastic filler 303 to form the hollow curing unit first joint block 304, and the internal cavity is filled with the gas or the thermoplastic filler. The hollow curing unit second splice block 305 is manufactured by the same method.

S2015, the first hollow curing unit splicing block 304 and the second hollow curing unit splicing block 305 are spliced by the hollow curing unit splicing component 306.

Specifically, after the first hollow curing unit splice block 304 and the second hollow curing unit splice block 305 are positioned by the hollow curing unit splice assembly 306, they are then fixed together by an adhesive or other joining process to form the final hollow curing unit 3.

S202, fixedly mounting the hollow curing unit 3 on the metal framework 1.

Specifically, because the turbine fan blade of the engine is of a curved surface structure, the lightening hole 6 of each metal framework 1 corresponds to one hollow curing unit 3, and the hollow curing units 3 are embedded and fixed at the lightening hole 6 of the metal framework 1 according to the requirement of complete surface fitting, and the hollow curing units 3 are flush with the surface of the metal framework 1.

S203, wrapping the flexible braid 2 outside the metal skeleton 1.

Specifically, the step of wrapping the metal skeleton 1 with the flexible braid 2 includes:

s2031, sleeving the flexible braiding body 2 on the metal framework 1.

Specifically, the metal skeleton 1 which has been embedded in the hollow curing unit 3 is sleeved in the sleeve of the manufactured flexible braid 2, forming a composite blade which is not cured by the thermoplastic filler.

S2032, fiber tows pass through the flexible braid 2 and the threading holes 5 of the metal skeleton 1 to fix the metal skeleton 1 and the flexible braid 2.

Specifically, the fiber tows pass through the threading holes 5 and two side surfaces of the flexible braiding body 2, fix the metal framework 1 and the flexible braiding body 2, and finally stitch the interface of the flexible braiding body 2 by using the fiber tows.

S2033, the leading edge portion of the blade is sealed and fixed by the leading edge wrapping 7, and the metal skeleton 1 and the flexible braid 2 are fixed.

In particular, the leading edge of the blade generally requires a higher strength, where the metal skeleton 1 and the flexible braid 2 are integrally encapsulated and fixed by a leading edge trim 7 integrally formed with the metal skeleton 1.

S204, the metal skeleton 1, the hollow curing unit 3 and the flexible braid 2 are integrally cured and molded by using the thermoplastic filler 303.

Specifically, the composite blade is finally infiltration cured and formed by the curing process of the thermoplastic filler 303, and during the injection process of the thermoplastic filler 303, the thermoplastic filler 303 on the outer layer of the hollow curing unit 3 is partially melted and fused with the newly entered thermoplastic filler 303 and cured. In the implementation process, the hollow curing unit 3, the metal framework 1 and the flexible braid 2 are subjected to permeation curing molding through the thermoplastic filler 303, and finally the composite material blade with the thermoplastic filler curing layer can be formed, and the processes for curing the thermoplastic filler comprise RTM curing and other processes. Finally, the composite material blade after the thermoplastic filler is solidified is subjected to surface treatment to meet the requirements of the precision and the surface roughness of the final composite material blade.

In this embodiment, the thermoplastic fillers used for curing are all epoxy resins. The fiber tows and the flexible braiding body 2 are both carbon fibers.

The composite material of the embodiment is suitable for the composite material blade of the turbofan engine, and can be applied to other structures such as aircraft wings and large composite material parts. The fiber tows and the flexible braid 2 may be a combination of carbon fibers, carbon fiber-glass fibers, carbon fiber-optical fibers, and the like.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment focuses on differences from other embodiments. In particular, for the method embodiments described later, since they correspond to the system, the description is relatively simple, and reference should be made to the description of some of the system embodiments.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present application should be included in the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A composite blade, comprising:

a metal skeleton (1), the metal skeleton (1) comprising lightening holes (6);

the hollow curing unit (3), the hollow curing unit (3) can be embedded in the lightening hole (6);

the flexible braiding body (2), the flexible braiding body (2) wraps the metal skeleton (1) and the outer layer of the hollow solidifying unit (3);

the hollow curing unit (3) comprises: the thermoplastic filling body (303) and the curing unit reinforcing rib (301), the curing unit reinforcing rib (301) is of a hollowed-out structure, the thermoplastic filling body (303) is arranged on the outer layer of the curing unit reinforcing rib (301) in a coating mode, the thermoplastic filling body (303) and the curing unit reinforcing rib (301) form a weight-reducing cavity together, and the thermoplastic filling body (303) is used for integrally curing and forming the metal framework (1), the hollow curing unit (3) and the flexible braiding body (2).

2. Composite blade according to claim 1, wherein the hollow curing unit (3) comprises: the hollow curing unit comprises a first hollow curing unit splicing block (304), a second hollow curing unit splicing block (305) and a hollow curing unit splicing assembly (306), wherein the first hollow curing unit splicing block (304) and the second hollow curing unit splicing block (305) are spliced into a hollow curing unit (3) through the hollow curing unit splicing assembly (306).

3. A composite blade according to claim 1, wherein the outer surface of the thermoplastic filler body (303) is provided with a plurality of curing unit projections (302).

4. A composite blade according to claim 1, wherein the hollow curing units (3) and the lightening holes (6) are arranged in groups at intervals.

5. The composite blade according to claim 1, wherein the metal skeleton (1) is further provided with a plurality of threading holes (5), and the fiber tows fix the flexible braid (2) and the metal skeleton (1) through the threading holes (5).

6. The composite blade according to claim 1, further comprising a leading edge bead (7), the leading edge bead (7) being arranged at the leading edge of the metal skeleton (1), the flexible braid (2) and the metal skeleton (1) being secured by the leading edge bead (7).

7. A method of manufacturing a composite blade, for use in manufacturing a composite blade according to any one of claims 1 to 6, comprising the steps of:

step one, processing a metal framework (1) and a hollow curing unit (3);

step two, fixedly mounting the hollow curing unit (3) on the metal framework (1);

step three, wrapping the flexible braiding bodies (2) outside the metal framework (1);

and fourthly, integrally curing and forming the metal framework (1), the hollow curing unit (3) and the flexible braiding body (2) by using a thermoplastic filling body (303).

8. The method for manufacturing a composite blade according to claim 7, wherein in the first step, the method for manufacturing the hollow curing unit (3) specifically comprises:

pre-fixing a curing unit protrusion (302) on a metal mold;

integrally curing and forming the curing unit reinforcing ribs (301) and the curing unit protrusions (302) by using a thermoplastic filler (303);

the first splice block (304) of the hollow curing unit and the second splice block (305) of the hollow curing unit are spliced together by a splice assembly (306) of the hollow curing unit.

9. The method of manufacturing a composite blade according to claim 7, wherein wrapping the flexible braid (2) around the metal skeleton (1) comprises the steps of:

sleeving the flexible braiding bodies (2) on the metal framework (1);

the fiber tows pass through the threading holes (5) of the flexible braiding body (2) and the metal framework (1) to fix the metal framework (1) and the flexible braiding body (2);

the front edge part of the blade uses a front edge wrapping (7) to fix the metal framework (1) and the flexible braiding body (2) in a sealing way.