Core material structure, wind power blade and forming method

Abstract

The invention relates to a core material structure, a wind power blade and a forming method. The core material structure is applied to the wind power blade. The core material structure comprises a first core material layer, a second core material layer and a reinforcing layer, the reinforcing layer is connected to the side, in the first direction, of the first core material layer, and the second core material layer is connected to the side, away from the second core material layer, of the reinforcing layer in the first direction. Wherein the reinforcing layer, the first core material layer and the second core material layer are connected in a bonding mode, and the strength of the reinforcing layer is larger than that of the first core material layer and that of the second core material layer. According to the core material structure, the wind power blade and the forming method of the wind power blade, the thickness of the core material structure can be reduced to a certain extent while the strength performance of the core material structure is met, and the core material structure can achieve high strength with the light weight.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation equipment, and in particular to a core material structure, a wind turbine blade and a molding method. Background Art

[0002] Wind turbine blades are an important component of wind turbine generator sets. From the perspective of wind turbine blade design, considering the various demands placed on wind turbine blades by the working conditions and performance requirements of wind turbine generator sets, the entire design is relatively difficult.

[0003] As the size of wind turbine blades continues to increase and the external load increases, higher requirements are placed on the mechanical properties and anti-buckling instability of wind turbine blades. However, due to the inherent mechanical properties of the core material, the industry currently mainly increases the thickness of the core material to improve the anti-buckling ability of wind turbine blades. This often uneconomically increases the weight and cost of wind turbine blades, which is not conducive to the design principle and manufacturing process of lightweight and high-strength wind turbine blades. Summary of the invention

[0004] The core material structure, wind turbine blade and forming method provided in the embodiments of the present application can reduce the thickness of the core material structure to a certain extent while meeting the strength performance of the core material structure, so that the core material structure can achieve higher strength with lighter weight.

[0005] In a first aspect, an embodiment of the present application provides a core material structure for a wind turbine blade, the core material structure comprising:

[0006] a first core material layer;

[0007] a reinforcement layer, the reinforcement layer being connected to one side of the first core material layer along a first direction;

[0008] a second core material layer, the second core material layer being connected to a side of the reinforcement layer away from the first core material layer along the first direction;

[0009] The reinforcement layer, the first core material layer and the second core material layer are bonded and connected, and the strength of the reinforcement layer is greater than the strength of the first core material layer and the second core material layer.

[0010] In some embodiments, the reinforcement layer includes a plurality of first reinforcement portions that are spaced apart and a flexible connection portion connected between adjacent first reinforcement portions, wherein the flexible connection portion connects the plurality of first reinforcement portions into an integrated structure.

[0011] In some embodiments, a groove structure is provided on the flexible connection portion, and a projection of the groove structure in the first direction is staggered with a projection of the first reinforcement portion in the first direction.

[0012] In some embodiments, the groove structure includes a first groove extending along a second direction and a second groove extending along a third direction, and the first direction, the second direction and the third direction intersect each other;

[0013] The first groove and the second groove are connected to each other, the projection of the first groove in the first direction and the projection of the first reinforcement part in the first direction are staggered along the third direction, and the projection of the second groove in the first direction and the projection of the first reinforcement part in the first direction are staggered along the second direction.

[0014] In some embodiments, the first groove and the second groove are both formed by being recessed inwardly along a surface of the reinforcement layer facing the first core material layer;

[0015] Or, the first groove and the second groove are both formed by being recessed inwardly along a surface of the reinforcement layer facing the second core material layer;

[0016] Alternatively, the first groove is formed by a surface of the reinforcement layer that is concave inwardly facing the first core material layer, and the second groove is formed by a surface of the reinforcement layer that is concave inwardly facing the second core material layer.

[0017] In some embodiments, the reinforcement layer further includes a second reinforcement portion, the flexible connection portion forms a curved surface structure along the first direction toward one side of the first core material layer, and the second reinforcement portion is integrally filled and formed inside the first groove and the second groove;

[0018] Alternatively, the reinforcement layer further includes a second reinforcement portion, the flexible connection portion forms a curved surface structure along the first direction toward one side of the second core material layer, and the second reinforcement portion is integrally filled and formed inside the first groove and the second groove.

[0019] In some embodiments, the first core material layer is recessed inwardly toward the reinforcement layer to form a third groove, the third groove is connected to the first groove and the second groove, and the second reinforcement portion is integrally filled and formed in the first groove, the second groove and the third groove;

[0020] And / or, the second core material layer is recessed inwardly toward one side of the reinforcement layer to form a fourth groove, the fourth groove is interconnected with the first groove and the second groove, and the second reinforcement part is integrally filled and molded in the first groove, the second groove and the fourth groove.

[0021] In some embodiments, the first reinforcement portion is provided with a through hole along the first direction, and two ends of the through hole are respectively connected to the first core material layer and the second core material layer;

[0022] The reinforcement layer further includes a second reinforcement portion, and the second reinforcement portion is filled in the through hole.

[0023] In some embodiments, the first reinforcement portion is made of carbon fiber material or glass fiber material.

[0024] In a second aspect, an embodiment of the present application provides a wind turbine blade, comprising:

[0025] First surface layer;

[0026] The core material structure is connected to one side of the first surface layer along the first direction;

[0027] The second surface layer is connected to a side of the core structure away from the first surface layer along the first direction.

[0028] In a third aspect, an embodiment of the present application provides a molding method for producing the core material structure, the molding method comprising:

[0029] Provide forming molds;

[0030] Laying down a first core material layer, a reinforcement layer and a second core material layer in sequence along a first direction inside the molding die;

[0031] The adhesive is poured into the molding die and cured to obtain the core material structure.

[0032] In some embodiments, the step of sequentially stacking the first core material layer, the reinforcement layer, and the second core material layer on the forming mold along the first direction includes:

[0033] forming a first groove on the reinforcing layer, wherein the first groove extends along a second direction;

[0034] A second groove is formed on the reinforcing layer, the second groove extends along a third direction, the second groove is connected to the first groove, and the first direction, the second direction and the third direction intersect each other;

[0035] A through hole is formed on the reinforcement layer, and the through hole penetrates the reinforcement layer along the first direction. The through hole and the first groove and the second groove are all staggered on the reinforcement layer.

[0036] The core material structure provided in the embodiment of the present application is mainly used in wind turbine blades. The core material structure includes a first core material layer, a second core material layer, and a reinforcement layer connected between the first core material layer and the second core material layer, and the strength of the reinforcement layer is greater than the strength of the first core material layer and the second core material layer. Through the above-mentioned method, while improving the overall structural performance of the core material structure, the thickness of the first core material layer and the second core material layer in the first direction can be reduced to a certain extent, the material consumption of the first core material layer and the second core material layer can be reduced, the production cost of the core material structure can be reduced, and the size of the core material structure as a whole in the first direction can be reduced. At the same time, the core material structure includes a three-layer structure with a clear structure, and the manufacturing route of the core material structure is relatively clear. While ensuring the structural performance of the core material structure, it also improves the production efficiency of the core material structure. Furthermore, the first core material layer, the reinforcement layer and the second core material layer in the core material structure are bonded with an adhesive, so that the reinforcement layer and the first core material layer, as well as the reinforcement layer and the second core material layer, can be contacted and connected everywhere in the first direction. When the wind turbine blade is subjected to a certain degree of shear force, the shear force can be evenly dispersed to various positions between the reinforcement layer and the first core material layer, thereby ensuring the shear resistance of the core material structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0038] Figure 1 A schematic diagram of the structure of a wind turbine blade provided in some embodiments of the present application;

[0039] Figure 2 for Figure 1 A partial enlarged view of part A;

[0040] Figure 3 A schematic diagram of a top view of a reinforcement layer in a core material structure provided in some embodiments of the present application;

[0041] Figure 4 A schematic diagram of a first cross-sectional structure of a reinforcement layer in a core material structure provided in some embodiments of the present application;

[0042] Figure 5 A schematic diagram of a first cross-sectional structure of a reinforcement layer in a core material structure provided in some embodiments of the present application;

[0043] Figure 6 A first schematic diagram of a molding method provided in some embodiments of the present application;

[0044] Figure 7 A second flow chart of a molding method provided in some embodiments of the present application.

[0045] Marking Description:

[0046] 100. Core material structure;

[0047] 10. first core material layer; 11. third groove;

[0048] 20. reinforcement layer; 21. first reinforcement portion; 211. through hole; 22. flexible connection portion; 221. groove structure; 222. first groove; 223. second groove; 23. second reinforcement portion;

[0049] 30. second core material layer; 31. fourth groove;

[0050] 200. Wind turbine blades;

[0051] 201, first surface layer; 202, second surface layer;

[0052] X, first direction; Y, second direction; Z, third direction.

[0053] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0054] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0055] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0056] The wind turbine blade 200 is an important component of the wind turbine generator set. From the design perspective of the wind turbine blade 200, considering the various requirements for the wind turbine blade 200 imposed by the working conditions and performance requirements of the wind turbine generator set, the entire design is relatively difficult.

[0057] As the size of wind turbine blades 200 continues to increase and the external load increases, higher requirements are placed on the mechanical properties and anti-buckling instability of wind turbine blades 200. However, due to the inherent mechanical properties of the core material, the industry currently mainly increases the thickness of the core material to improve the anti-buckling ability of wind turbine blades 200.

[0058] However, due to the requirements of the wind turbine blade 200 manufacturing process on the maximum thickness of the core material and the interlayer performance limitations of the core material, after the core material thickness reaches a certain level, the stress level can only be controlled and the anti-buckling performance of the core material can be improved by increasing the surface thickness, which often uneconomically increases the weight and cost of the wind turbine blade 200 and is not conducive to the lightweight and high-strength design principle and manufacturing molding process of the wind turbine blade 200.

[0059] In view of this, first of all, please refer to Figure 1 to Figure 2 , the embodiment of the present application provides a core material structure 100, which is applied to a wind turbine blade 200. The core material structure 100 includes a first core material layer 10, a second core material layer 30 and a reinforcement layer 20, wherein the reinforcement layer 20 is connected to one side of the first core material layer 10 along a first direction X, and the second core material layer 30 is connected to one side of the reinforcement layer 20 away from the second core material layer 30 along the first direction X. The reinforcement layer 20, the first core material layer 10 and the second core material layer 30 are bonded and connected, and the strength of the reinforcement layer 20 is greater than the strength of the first core material layer 10 and the second core material layer 30.

[0060] The core material structure 100 provided in the embodiment of the present application is applied to the structure on the wind turbine blade 200. The core material structure 100 can be applied to the outer shell part of the wind turbine blade 200 to improve the strength of the outer shell; or, the core material structure 100 can also be applied to the web part of the wind turbine blade 200 to improve the strength of the web; or, the core material structure can also be applied to the main beam part of the wind turbine blade 200 to improve the strength of the main beam.

[0061] Specifically, the core material structure 100 includes a first core material layer 10, a second core material layer 30, and a reinforcement layer 20 connected between the first core material layer 10 and the second core material layer 30, and the strength of the reinforcement layer 20 is greater than the strength of the first core material layer 10 and the second core material layer 30. By adding a reinforcement layer 20 with greater strength between the core material layers, the overall strength of the core material structure 100 can be improved while reducing the size of the core material structure 100 as a whole in the first direction X, so that the core material structure 100 can be produced with a relatively easy-to-process thickness during the processing and manufacturing process, ensuring the success rate and reliability of the core material structure 100 during the processing and manufacturing process. At the same time, after the reinforcement layer 20 is provided, the thickness of the first core material layer 10 and the second core material layer 30 in the first direction X can be reduced to a certain extent while satisfying the strength performance of the core material structure 100, so that the core material structure 100 can achieve higher strength with lighter weight.

[0062] In the embodiment of the present application, the reinforcing layer 20 is connected to one side of the first core material layer 10 along the first direction X, and the second core material layer 30 is connected to the side of the reinforcing layer 20 away from the first core material layer 10 along the first direction X. When the core material structure 100 is applied to the outer shell of the wind turbine blade 200, the core material structure 100 is mainly located at the bending position of the wind turbine blade 200, so that the first direction X is arranged to intersect with the wind direction. That is to say, when the wind acts on the core material structure 100, the wind acts obliquely on the core material structure 100 to make full use of the reinforcing layer 20. When the wind forms a certain degree of squeezing force and shearing force on the core material structure 100, the reinforcing effect of the reinforcing layer 20 can improve the compression resistance and buckling resistance of the core material structure 100, thereby ensuring the structural stability of the core material structure 100 and the wind turbine blade 200.

[0063] Regarding the size relationship of the projection areas of the first core material layer 10, the second core material layer 30 and the reinforcement layer 20 in the first direction X, in one achievable embodiment, the projection area of ​​the reinforcement layer 20 in the first direction X is smaller than the projection areas of the first core material layer 10 and the second core material layer 30 in the first direction X, and the first core material layer 10 and the second core material layer 30 are wrapped around the peripheral side of the reinforcement layer 20. In another achievable embodiment, the projection areas of the first core material layer 10, the reinforcement layer 20 and the second reinforcement layer 20 in the first direction X increase or decrease in sequence, and the first core material layer 10, the reinforcement layer 20 and the second reinforcement layer 20 have a gentle transition area.

[0064] Furthermore, the reinforcing layer 20 and the first core material layer 10 are bonded and connected by an adhesive. By bonding, an adhesive layer can be formed on the surfaces of the reinforcing layer 20 and the first core material layer 10 facing each other, and the adhesive layer is in contact and connected with the reinforcing layer 20 everywhere in the first direction X. At the same time, the adhesive layer is in contact and connected with the first core material layer 10 everywhere in the first direction X. In other words, the reinforcing layer 20 and the first core material layer 10 are in contact and connected everywhere in the first direction X by bonding. By the above arrangement, when the wind turbine blade 200 is subjected to a certain degree of shear force, the shear force can be evenly dispersed to various positions between the reinforcing layer 20 and the first core material layer 10, thereby ensuring the shear strength of the core material structure 100. At the same time, the reinforcing layer 20 and the second core material layer 30 are also bonded and connected by an adhesive, and the effect is similar to that of the bonding between the reinforcing layer 20 and the first core material layer 10, which will not be repeated here.

[0065] In the actual production process in this field, the first core material layer 10 and the second core material layer 30 are usually balsa wood core material or foam core material, and the material of the reinforcement layer 20 is different from that of the first core material layer 10 and the second core material layer 30, and the reinforcement layer 20 includes glass fiber material or carbon fiber material. As for the setting of the adhesive, it is preferred to set the adhesive to an epoxy resin. On the one hand, the epoxy resin has good mechanical properties, including adhesion, wear resistance, corrosion resistance and insulation. These properties enable the resin material to effectively bond the core material structure 100 and the various parts of the wind turbine blade 200 together to form an integral structure, thereby improving the overall strength of the wind turbine blade 200 and the core material structure 100. On the other hand, as a part of the composite material, the resin material, combined with the reinforcing material (such as glass fiber material or carbon fiber material), can provide higher strength and rigidity while keeping the core material structure 100 and the wind turbine blade 200 lightweight.

[0066] In some optional embodiments, the adhesive may also be a resin of a thermosetting or thermoplastic system such as polyurethane or acrylic, or a resin of a light-curing system. As for the arrangement of the reinforcing layer 20, based on whether it is a glass fiber material or a carbon fiber material, the reinforcing layer 20 may be a plywood structure with a relatively smooth surface, or a fabric structure with a relatively rough surface.

[0067] In summary, the core material structure 100 provided in the embodiment of the present application is mainly used in a wind turbine blade 200. The core material structure 100 includes a first core material layer 10 and a second core material layer 30 and a reinforcement layer 20 connected between the first core material layer 10 and the second core material layer 30, and the strength of the reinforcement layer 20 is greater than the strength of the first core material layer 10 and the second core material layer 30. Through the above-mentioned method, while improving the overall structural performance of the core material structure 100, the thickness of the first core material layer 10 and the second core material layer 30 in the first direction X can be reduced to a certain extent, the material consumption of the first core material layer 10 and the second core material layer 30 can be reduced, the production cost of the core material structure 100 can be reduced, and the size of the core material structure 100 as a whole in the first direction X can be reduced. At the same time, the core material structure 100 includes a three-layer structure with a clear structure, and the manufacturing route of the core material structure 100 is relatively clear. While ensuring the structural performance of the core material structure 100, the production efficiency of the core material structure 100 is also improved. Furthermore, the first core material layer 10, the reinforcement layer 20, and the second core material layer 30 in the core material structure 100 are bonded with an adhesive, so that the reinforcement layer 20 and the first core material layer 10 as well as the reinforcement layer 20 and the second core material layer 30 can be in contact and connected at the first direction X. When the wind turbine blade 200 is subjected to a certain degree of shear force, the shear force can be evenly dispersed to various positions between the reinforcement layer 20 and the first core material layer 10, thereby ensuring the shear resistance of the core material structure 100.

[0068] In some embodiments, see Figures 3 to 5 The reinforcement layer 20 includes a plurality of first reinforcement portions 21 disposed at intervals and a flexible connection portion 22 connected between adjacent first reinforcement portions 21 , and the flexible connection portion 22 connects the plurality of first reinforcement portions 21 into an integrated structure.

[0069] The first reinforcement part 21 is the main structure of the reinforcement layer 20, and is used to improve the strength of the core material structure 100. In the actual production process of the wind turbine blade 200, the wind turbine blade 200 has a curved structure of multiple parts. In order to make the core material structure 100 adapt to the curved structure of the wind turbine blade 200, the first reinforcement part 21 is provided in plurality, and the plurality of first reinforcement parts 21 are arranged at intervals. A single first reinforcement part 21 can correspond to a local area of ​​the curved structure in the wind turbine blade 200, so that the corresponding curved structure of the reinforcement layer 20 can correspond to the wind turbine blade 200.

[0070] When multiple first reinforcement parts 21 are arranged at intervals, in order to ensure that technicians can conveniently move the multiple first reinforcement parts 21 synchronously, a flexible connection part 22 is arranged between adjacent first reinforcement parts 21. While the flexible connection part 22 connects the adjacent first reinforcement parts 21 into an integral structure, it can also utilize its own flexibility to undergo a certain degree of deformation, thereby adjusting the spacing size between adjacent first reinforcement parts 21.

[0071] Regarding the deformation degree of the flexible connection part 22, the flexible connection part 22 includes a first part and a second part connected to each other along the first direction X. In some achievable embodiments, the first part and the second part are simultaneously stretched and deformed to increase the interval between adjacent first reinforcement parts 21; or, the first part and the second part are simultaneously compressed and deformed to reduce the interval between adjacent first reinforcement parts 21. In some achievable embodiments, the first part is stretched and deformed, and the second part is compressed and deformed, or the first part is compressed and deformed, and the second part is stretched and deformed, so that the flexible connection part 22 presents a curved structure with a special curvature.

[0072] In some embodiments, a groove structure 221 is disposed on the flexible connection portion 22 , and a projection of the groove structure 221 in the first direction X is staggered with a projection of the first reinforcement portion 21 in the first direction X.

[0073] The groove structure 221 is arranged on one side of the flexible connection part 22 to form an opening structure. In the part of the opening structure, a gap is still formed between adjacent first reinforcement parts 21. When the flexible connection part 22 is deformed to a certain extent, the first reinforcement parts 21 at the opening structure can relatively flexibly adjust the spacing size. The arrangement of the groove structure 221 reduces the binding effect of the flexible connection part 22 on adjacent first reinforcement parts 21, allowing relatively flexible adjustment between adjacent first connection parts, thereby improving the flexibility of the reinforcement layer 20 in the process of forming a curved structure.

[0074] In some embodiments, the groove structure 221 includes a first groove 222 extending along the second direction Y and a second groove 223 extending along the third direction Z, and the first direction X, the second direction Y and the third direction Z intersect each other. The first groove 222 and the second groove 223 are connected to each other, and the projection of the first groove 222 in the first direction X and the projection of the first reinforcing portion 21 in the first direction X are staggered along the third direction Z, and the projection of the second groove 223 in the first direction X and the projection of the first reinforcing portion 21 in the first direction X are staggered along the second direction Y.

[0075] The arrangement of the first groove 222 and the second groove 223 enables the multiple first reinforcement parts 21 to form a grid structure, and the flexible connection part 22 connects the multiple first reinforcement parts 21 into an integrated structure to ensure the integrity of the reinforcement layer 20 during the deformation process of forming a curved structure.

[0076] The combination of the first groove 222 and the second groove 223 can further improve the flexibility of the reinforcing layer 20 during deformation. The first reinforcing parts 21 located on both sides of the first groove 222 can relatively flexibly adjust the spacing size in the third direction Z, and the first reinforcing parts 21 located on both sides of the second groove 223 can relatively flexibly adjust the spacing size in the second direction Y. Further, based on the interconnected setting between the first groove 222 and the second groove 223, the first reinforcing part 21 can also undergo a certain torsional tilt deformation around the first direction X, so as to further improve the adaptability of the reinforcing layer 20 to the curved structure on the wind turbine blade 200.

[0077] Regarding the setting of the groove depth and groove width of the first groove 222 and the second groove 223, in some optional embodiments, considering the emphasis on the strength of the reinforcing layer 20, the groove depth and groove width of the first groove 222 and the second groove 223 are set to a relatively small form. For example, the groove depth of the first groove 222 and the second groove is less than half of the extension dimension of the flexible connecting portion 22 in the first direction X. The groove depth of the first groove 222 and the second groove can be set to between 1 mm and 2 mm. The groove depth of the first groove 222 and the second groove can be set to The projection of the first reinforcing portion 21 in the first direction X can be set to a rectangular structure, the extension dimension of the first reinforcing portion 21 in the second direction Y is the groove spacing dimension of the adjacent second grooves 223 in the second direction Y, and the groove spacing dimension of the adjacent second grooves 223 in the second direction Y can be set to between 28mm-32mm, and the extension dimension of the first reinforcing portion 21 in the third direction Z is the groove spacing dimension of the adjacent first grooves 222 in the third direction Z, and the groove spacing dimension of the adjacent first grooves 222 in the third direction Z can also be set to between 28mm-32mm. In other optional embodiments, considering the emphasis on the bending flexibility of the reinforcing layer 20, the groove depth dimension and the groove width dimension of the first groove 222 and the second groove 223 are set to a relatively large form, the groove spacing between adjacent first grooves 222 is set to a relatively small form, and the groove spacing between adjacent second grooves 223 is also set to a relatively small form.

[0078] In some embodiments, first grooves 222 extending along the second direction Y may be formed on the flexible connection part 22, and adjacent first grooves 222 may be arranged in parallel, or second grooves 223 extending along the third direction Z may be formed on the flexible connection part 22, and adjacent second grooves 223 may be arranged in parallel. When both the first groove 222 and the second groove 223 are formed on the flexible connection part 22, the intersection angle between the first groove 222 and the second groove 223 is between 30 degrees and 90 degrees.

[0079] In some embodiments, the first groove 222 and the second groove 223 are both formed by being recessed inwardly along one side surface of the reinforcing layer 20 toward the first core material layer 10. Alternatively, the first groove 222 and the second groove 223 are both formed by being recessed inwardly along one side surface of the reinforcing layer 20 toward the second core material layer 30. Alternatively, the first groove 222 is formed by the one side surface of the reinforcing layer 20 being recessed inwardly toward the first core material layer 10, and the second groove 223 is formed by the one side surface of the reinforcing layer 20 being recessed inwardly toward the second core material layer 30.

[0080] Corresponding to the different changes in the concave and convex surfaces of the curved structure in the wind turbine blade 200 at different positions, the groove structure 221 can be formed by the inward depression of one side surface of the reinforcement layer 20 facing the first core material layer 10, or by the inward depression of one side surface of the reinforcement layer 20 facing the second core material layer 30. Alternatively, the first groove 222 and the second groove 223 are respectively located on different surfaces of the reinforcement layer 20. On different surfaces of the reinforcement layer 20, only the first groove 222 or only the second groove 223 can be set, or both the first groove 222 and the second groove 223 can be set.

[0081] In some embodiments, the reinforcing layer 20 further includes a second reinforcing portion 23, the flexible connecting portion 22 forms a curved surface structure along the first direction X toward the side of the first core material layer 10, and the second reinforcing portion 23 is integrally filled and molded inside the first groove 222 and the second groove 223. Alternatively, the reinforcing layer 20 further includes a second reinforcing portion 23, the flexible connecting portion 22 forms a curved surface structure along the first direction X toward the side of the second core material layer 30, and the second reinforcing portion 23 is integrally filled and molded inside the first groove 222 and the second groove 223.

[0082] During the process of the flexible connection part 22 deforming to form a curved surface structure, the interval between adjacent first reinforcement parts 21 is adjusted, and the entire reinforcement layer 20 forms a curved structure. During the above process, the groove widths at different positions between the first groove 222 and the second groove 223 change to a certain extent. Before the flexible connection part 22 forms a specific curved surface structure, the second reinforcement part 23 is filled in the first groove 222 and the second groove 223 to fix the groove widths of the first groove 222 and the second groove 223, and at the same time fix the relative positions between adjacent first reinforcement parts 21.

[0083] In some optional embodiments, the second reinforcement part 23 can be set to epoxy resin, which can not only play the role of bonding the first reinforcement parts 21, but also form a composite material with the first reinforcement part 21 inside the groove structure 221, which can further improve the strength of the reinforcement layer 20. At the same time, the second reinforcement parts 23 located at different positions inside the groove structure 221 are integrally filled and integrally formed, which can make the second reinforcement parts 23 located at different positions inside the groove structure 221 stable and reliable in strength, and at the same time, can also improve the reliability of the relative position between the second reinforcement part 23 and the first reinforcement part 21.

[0084] In some embodiments, the first core material layer 10 is recessed inwardly toward one side of the reinforcement layer 20 to form a third groove 11, the third groove 11 is interconnected with the first groove 222 and the second groove 223, and the second reinforcement portion 23 is integrally filled and molded in the first groove 222, the second groove 223 and the third groove 11. And / or, the second core material layer 30 is recessed inwardly toward one side of the reinforcement layer 20 to form a fourth groove 31, the fourth groove 31 is interconnected with the first groove 222 and the second groove 223, and the second reinforcement portion 23 is integrally filled and molded in the first groove 222, the second groove 223 and the fourth groove 31.

[0085] The third groove 11 is provided on the first core material layer 10, and the third groove 11 is interconnected with the first groove 222 and the second groove 223, and the second reinforcement part 23 is integrally formed in the first groove 222, the second groove 223 and the third groove 11. The second reinforcement part 23 can also improve the connection strength between the first core material layer 10 and the reinforcement layer 20. For the same reason, the fourth groove 31 is provided on the second core material layer 30, and the second reinforcement part 23 is integrally formed in the first groove 222, the second groove 223 and the fourth groove 31, which can also improve the connection strength between the second core material layer 30 and the reinforcement layer 20.

[0086] The third groove 11 is provided to divide the first core material layer 10 to a certain extent, so that the large-sized flat core material of the first core material layer 10 is formed into a small-sized core material of a specific size. Furthermore, the third groove 11 may also include a first sub-groove extending along the second direction Y and a second sub-groove extending along the third direction Z, and the first sub-groove and the second sub-groove are interconnected. The first sub-groove and the second sub-groove cut the first core material layer 10 into small pieces of core material of a specific size. When the first core material layer 10 is set as a balsa wood core material, the length axial dimension of the small piece of core material is between 48mm-52mm, and the width chord dimension of the small piece of core material is between 23mm-27mm. When the first core material layer 10 is set as a foam core material, the length axial dimension of the small piece of core material is between 28mm-32mm, and the width chord dimension of the small piece of core material is between 28mm-32mm. Cutting the large-sized core material into small pieces, where the size of the small pieces is smaller than the curvature change of the curved structure of the wind turbine blade 200, can improve the deformation capacity of the first core material layer 10. The principle and effect are similar to setting the groove structure 221 on the reinforcement layer 20, which will not be repeated here.

[0087] The arrangement principle and effect of the fourth groove 31 are similar to those of the third groove 11, and will not be repeated here. Similarly, the arrangement principle and effect of the second core material layer 30 are similar to those of the first core material layer 10, and will not be repeated here.

[0088] In some embodiments, the first reinforcement part 21 is provided with a through hole 211 along the first direction X, and two ends of the through hole 211 are respectively connected to the first core material layer 10 and the second core material layer 30 . The second reinforcement part 23 is filled in the through hole 211 .

[0089] The through hole 211 penetrates the first reinforcement part 21 along the first direction X, and the two ends of the through hole 211 are respectively connected to the first core material layer 10 and the second core material layer 30. When the second reinforcement part 23 is filled in the through hole 211, the two ends of the second reinforcement part 23 are in contact with the first core material layer 10 and the second core material layer 30. The second reinforcement part 23 extends inside the first reinforcement part along the first direction X, and can improve the shear strength of the reinforcement layer 20 when the first reinforcement part 21 is subjected to shear force. At the same time, setting the second reinforcement part 23 to epoxy resin can also improve the connection strength between the reinforcement layer 20, the first core material layer 10 and the second core material layer 30.

[0090] In some embodiments, the first reinforcement portion 21 is made of carbon fiber material or glass fiber material.

[0091] In the reinforcement layer 20, the first reinforcement part 21 is used as the main structure. The material of the first reinforcement part 21 is set to carbon fiber material or glass fiber material. Carbon fiber material or glass fiber material as a reinforcing material can effectively ensure that the reinforcement layer 20 improves the structural performance of the core material structure 100. The flexible connection part 22 is used as a connection structure connecting the first reinforcement part 21. It can be set to the same material as the first reinforcement part 21, or it can be set to a different material from the first reinforcement part 21, as long as its deformation ability is guaranteed. The second reinforcement part 23 is filled in the groove structure 221, and the second reinforcement layer 20 is preferably made of epoxy resin material.

[0092] Second, see Figure 1 to Figure 2 The embodiment of the present application provides a wind turbine blade 200, comprising a first surface layer 201, the core material structure 100 and a second surface layer 202, wherein the core material structure 100 is connected to one side of the first surface layer 201 along the first direction X, and the second surface layer 202 is connected to one side of the core material structure 100 away from the first surface layer 201 along the first direction X. The wind turbine blade 200 comprises all the technical features of the core material structure 100, and has all the beneficial effects of the core material structure 100, which will not be described in detail.

[0093] When the core material structure 100 is applied to the outer shell structure of the wind turbine blade 200, a curved structure is formed between the core material structure 100 and the first surface layer 201 and the second surface layer 202, and the structure is fixed by bonding. When the core material structure 100 is applied to the web structure of the wind turbine blade 200, a planar structure is formed between the core material structure 100 and the first surface layer 201 and the second surface layer 202, and the structure can be connected and fixed by other means, such as fixing with bolts and nuts. When fixing with bolts, the bolts can be formed together with the core material structure 100 as prefabricated structural parts during the production process of the core material structure 100.

[0094] Third, see Figure 6 to Figure 7 The present application embodiment provides a molding method for producing the core material structure 100. The molding method includes:

[0095] S1. Provide a molding mold;

[0096] S2, stacking the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 in sequence along the first direction X inside the forming mold;

[0097] S3, pouring the adhesive into the molding mold and curing it to obtain the core material structure 100.

[0098] Among them, in S1, providing a molding mold, the surface of the molding mold is cleaned, and the molding mold may include a flat part and a curved part. After cleaning the surface of the molding mold, a release agent is applied to the surface of the molding mold, and auxiliary materials such as a release cloth are laid on the mold surface in sequence. In S2, the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are stacked and laid in sequence along the first direction X inside the molding mold. The first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are laid in sequence along the boundary positioning line of the core material structure 100. If necessary, the reinforcement layer 20 and the second core material layer 30 can be laid repeatedly for multiple times. The thickness of the core material structure 100 can be 5mm to 80mm. The reinforcement layer 20 can be a single layer or a multi-layer, and can be a uniaxial fiber material or a biaxial fiber material. Carbon fiber or glass fiber can be selected according to the structural design. The elastic modulus between the layers in the core material structure 100 can also be selected from low to high, or combined and laid according to the structural design. After the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are stacked in sequence along the first direction X inside the molding mold in S2, the adhesive is poured into the molding mold in S3, and before the adhesive is cured to obtain the core material structure 100, auxiliary materials such as release cloth are laid on the surface of the upper core material layer.

[0099] In some optional embodiments, when the core material structure 100 is applied to the shell structure of the wind turbine blade 200, the core material structure 100 is bonded to the first surface layer 201 and the second surface layer 202, and the first surface layer 201 and the second surface layer 202 and the core material structure 100 can be integrally formed. At S2, before the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are sequentially stacked and laid in the first direction X inside the forming mold, the first surface layer 201 is laid inside the forming mold. At S2, after the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are sequentially stacked and laid in the first direction X inside the forming mold, the second surface layer 202 is laid inside the forming mold.

[0100] In some optional embodiments, in S3, the adhesive is poured into the molding mold, and the core material structure 100 is obtained by curing. The adhesive is set as a resin, and the resin is injected into the molding mold using a vacuum infusion technology. Before S3, the adhesive is poured into the molding mold, and the core material structure 100 is obtained by curing, an infusion system and a vacuum system are established: on the inner surface of the molding mold, a perforated isolation film, a guide net, a glue injection channel and a glue injection port are laid at designated positions, and the glue injection port is connected to an external resin feed pipe. The exhaust material is laid along the flanges at the front and rear edges of the molding mold, and the corresponding exhaust material overlaps the demoulding cloth layer by a certain size, and an external vacuum exhaust device is connected. An absolute pressure gauge is inserted into the vacuum system, and a vacuum film is sealed. Optionally, two layers of vacuum film are wrapped. Subsequently, the vacuum exhaust device is turned on, and the vacuum value inside the molding mold is evacuated to a certain range, and the vacuum pressure drop within a certain period of time is tested. The absolute pressure gauge is required to increase the value of 15min less than 2kPa, and a pressure gauge is used to monitor the pressure during the entire infusion process. A digital vacuum gauge can also be used to maintain the pressure. The vacuum pressure should be ≤-98kpa and then stabilized before pressure maintenance begins. The pressure maintenance requirements remain unchanged.

[0101] In S3, the adhesive is poured into the molding mold, and the core material structure 100 is obtained by curing. The injection port is opened in sequence, and the valve can be closed after the demoulding cloth layer is completely soaked. The residual glue in the injection tube is handled and the site is cleaned. Before pouring, turn on the molding mold heater, set the curing system, preheat for a certain time, and insulate special areas. After the pouring is completed, turn on the molding mold heater according to the curing system, and cool the mold surface in a water bath during the resin exotherm. After the exotherm peak, cover the entire mold with a quilt for insulation; the insulation requirement is that the shell reaches the specified temperature and is kept warm for a specified time. After the blade root area and the bonding angle are fully cured, it is confirmed that the curing is complete.

[0102] In some embodiments, in S2, sequentially stacking and laying the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 along the first direction X inside the forming mold includes:

[0103] S21, forming a first groove 222 on the reinforcing layer 20, wherein the first groove 222 extends along the second direction Y;

[0104] S22, forming a second groove 223 on the reinforcing layer 20, the second groove 223 extending along the third direction Z, the second groove 223 and the first groove 222 are connected to each other, and the first direction X, the second direction Y and the third direction Z intersect each other;

[0105] S23 , forming a through hole 211 on the reinforcing layer 20 , wherein the through hole 211 penetrates the reinforcing layer 20 along the first direction X, wherein the through hole 211 and the first groove 222 are staggered on the reinforcing layer 20 , and wherein the through hole 211 and the second groove 223 are staggered on the reinforcing layer 20 .

[0106] In S21, forming the first groove 222 on the reinforcing layer 20 and S22, forming the second groove 223 on the reinforcing layer 20, a knife or other tool may be used to shape the first groove 222 and the second groove 223. The first groove 222 and the second groove 223 are formed on one side or both sides of the reinforcing layer 20.

[0107] In some embodiments, in S3, an adhesive is poured into the molding die and cured to obtain the core material structure 100, and the adhesive is filled in the through hole 211, the first groove 222, and the second groove 223. The adhesive is set as an epoxy resin, and the resin can also improve the strength of the reinforcement layer 20 after filling the through hole 211, the first groove 222, and the second groove 223.

[0108] In some embodiments, in S2, in the process of sequentially stacking the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 in the molding die along the first direction X, the reinforcement layer 20 and the first core material layer 10 are connected to form an integral structure through a preforming process; or, the reinforcement layer 20 and the second core material layer 30 are connected to form an integral structure through a preforming process. The preforming process may be a connection method such as bonding or local perforation fixed connection.

[0109] In some embodiments, in S2, the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are sequentially stacked and laid inside the molding die along the first direction X. When laying, the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 are laid alternately, and are not limited by a specific number of layers. The reinforcement layer 20 can be a whole or can be designed in blocks.

[0110] In some embodiments, in S3, the adhesive is poured into the molding mold and cured to obtain the core material structure 100. The adhesive is set as a resin, and the resin can be a film resin or a pre-coated resin. During the injection molding process, the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 can be integrally injection molded or separately injection molded. Alternatively, the first core material layer 10, the reinforcement layer 20 and the second core material layer 30 can also be formed into an integral structure by hand lay-up molding, or can be obtained by molding and other methods.

[0111] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A core material structure for a wind turbine blade, characterized in that: The core material structure comprises: a first core material layer; a reinforcement layer, the reinforcement layer being connected to one side of the first core material layer along a first direction; a second core material layer, the second core material layer being connected to a side of the reinforcement layer away from the first core material layer along the first direction; The reinforcement layer, the first core material layer and the second core material layer are bonded and connected, and the strength of the reinforcement layer is greater than the strength of the first core material layer and the second core material layer.

2. The core material structure according to claim 1, characterized in that: The reinforcement layer includes a plurality of first reinforcement parts arranged at intervals and a flexible connection part connected between adjacent first reinforcement parts, and the flexible connection part connects the plurality of first reinforcement parts into an integrated structure.

3. The core material structure according to claim 2, characterized in that: A groove structure is arranged on the flexible connection portion, and a projection of the groove structure in the first direction is staggered with a projection of the first reinforcement portion in the first direction.

4. The core material structure according to claim 3, characterized in that: The groove structure comprises a first groove extending along a second direction and a second groove extending along a third direction, wherein the first direction, the second direction and the third direction intersect each other; The first groove and the second groove are connected to each other, the projection of the first groove in the first direction and the projection of the first reinforcement part in the first direction are staggered along the third direction, and the projection of the second groove in the first direction and the projection of the first reinforcement part in the first direction are staggered along the second direction.

5. The core material structure according to claim 4, characterized in that: The first groove and the second groove are both formed by being recessed inwardly along a surface of the reinforcement layer facing the first core material layer; Or, the first groove and the second groove are both formed by being recessed inwardly along a surface of the reinforcement layer facing the second core material layer; Alternatively, the first groove is formed by a surface of the reinforcement layer that is concave inwardly facing the first core material layer, and the second groove is formed by a surface of the reinforcement layer that is concave inwardly facing the second core material layer.

6. The core material structure according to claim 4, characterized in that: The reinforcement layer further includes a second reinforcement portion, the flexible connection portion forms a curved surface structure along the first direction toward one side of the first core material layer, and the second reinforcement portion is integrally filled and formed inside the first groove and the second groove; Alternatively, the reinforcement layer further includes a second reinforcement portion, the flexible connection portion forms a curved surface structure along the first direction toward one side of the second core material layer, and the second reinforcement portion is integrally filled and formed inside the first groove and the second groove.

7. The core material structure according to claim 6, characterized in that: The first core material layer is indented inwardly toward the reinforcement layer to form a third groove, the third groove is connected to the first groove and the second groove, and the second reinforcement portion is integrally filled and formed in the first groove, the second groove and the third groove; And / or, the second core material layer is recessed inwardly toward one side of the reinforcement layer to form a fourth groove, the fourth groove is interconnected with the first groove and the second groove, and the second reinforcement part is integrally filled and molded in the first groove, the second groove and the fourth groove.

8. The core material structure according to claim 2, characterized in that: The first reinforcement portion is provided with a through hole along the first direction, and two ends of the through hole are respectively connected with the first core material layer and the second core material layer; The reinforcement layer further includes a second reinforcement portion, and the second reinforcement portion is filled in the through hole.

9. The core material structure according to claim 2, characterized in that: The first reinforcement part is made of carbon fiber material or glass fiber material.

10. A wind turbine blade, characterized in that: include: First surface layer; The core material structure according to any one of claims 1 to 9, connected to one side of the first surface layer along the first direction; The second surface layer is connected to a side of the core structure away from the first surface layer along the first direction.

11. A molding method, characterized in that: For producing the core material structure according to any one of claims 1 to 9, the molding method comprises: Provide forming molds; Laying down a first core material layer, a reinforcement layer and a second core material layer in sequence along a first direction inside the molding die; The adhesive is poured into the molding die and cured to obtain the core material structure.

12. The molding method according to claim 11, characterized in that: The step of sequentially stacking the first core material layer, the reinforcement layer and the second core material layer on the forming mold along the first direction includes: forming a first groove on the reinforcing layer, wherein the first groove extends along a second direction; A second groove is formed on the reinforcing layer, the second groove extends along a third direction, the second groove is connected to the first groove, and the first direction, the second direction and the third direction intersect each other; A through hole is formed on the reinforcement layer, and the through hole penetrates the reinforcement layer along the first direction. The through hole and the first groove and the second groove are all staggered on the reinforcement layer.

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