Composite core material for wind driven generator blade and production process of composite core material

Abstract

The invention discloses a composite core material for a wind driven generator blade and a production process of the composite core material. An upper cork wood layer, an upper foam layer, a middle cork wood layer, a lower foam layer and a lower cork wood layer are sequentially arranged from top to bottom to form a core material body; the upper balsa wood layer and the lower balsa wood layer are each provided with a plurality of strip-shaped holes, and the strip-shaped holes in the upper balsa wood layer and the strip-shaped holes in the lower balsa wood layer are formed in a staggered mode. A through hole communicated with the strip-shaped hole is formed in the core material body; positioning grooves are formed in the positions, corresponding to the strip-shaped holes in the upper balsa wood layer, of the inner side of the lower balsa wood layer; positioning grooves are formed in the positions, corresponding to the strip-shaped holes in the lower balsa wood layer, of the inner side of the upper balsa wood layer; a supporting plate is inserted into the through hole; one end of the supporting plate is located in the strip-shaped hole of the upper balsa wood layer or the lower balsa wood layer, and the other end of the supporting plate is located in the positioning groove of the upper balsa wood layer or the lower balsa wood layer. According to the invention, the specific strength and specific modulus of the core material are improved, and meanwhile, the use amount of cork wood is reduced, so that the core material has better toughness and impact resistance.

Description

Technical Field

[0001] The invention relates to the technical field of wind turbine blade core material preparation, and in particular to a composite material core material for wind turbine blades and a production process thereof. Background Art

[0002] With the development of wind power technology, the capacity of a single unit has increased, the blades have become longer and longer, and the influence of the web on the performance of the blades has become more and more obvious. The main structural form of large wind turbine blades is composed of upper and lower wing surfaces and webs made of composite materials. The webs are mainly composed of plies and sandwich materials. The performance and quality of the sandwich materials play an extremely important role in whether the wind energy system can operate well and continuously.

[0003] The sandwich materials used in large quantities on blades mainly include balsa wood and rigid closed-cell foam. Among them, balsa wood has a relatively high specific strength and specific modulus, but due to various factors, the supply and price of balsa wood raw materials are unstable. Therefore, rigid closed-cell foam is currently used to make core materials. Rigid foam is usually formed by foaming PET or PVC, and its material strength and modulus are far behind balsa wood. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a composite core material for wind turbine blades, improve the specific strength and specific modulus of the core material, and reduce the amount of balsa wood, so that the core material has better toughness and impact resistance.

[0005] In order to solve the above technical problems, the present invention adopts the following technical scheme: a composite material core material for wind turbine blades, comprising an upper balsa wood layer, a middle balsa wood layer, a lower balsa wood layer, an upper foam layer and a lower foam layer; the upper balsa wood layer, the upper foam layer, the middle balsa wood layer, the lower foam layer and the lower balsa wood layer are arranged in sequence from top to bottom to form a core material body; the upper balsa wood layer and the lower balsa wood layer are both provided with a plurality of strip holes, and the strip holes on the upper balsa wood layer and the lower balsa wood layer are staggered; a through hole connected with the strip hole is provided in the core material body; a positioning groove is provided on the inner side of the lower balsa wood layer at a position corresponding to the strip hole of the upper balsa wood layer; a positioning groove is provided on the inner side of the upper balsa wood layer at a position corresponding to the strip hole of the lower balsa wood layer; a support plate is inserted into the through hole; one end of the support plate is located in the strip hole of the upper balsa wood layer or the lower balsa wood layer, and the other end is located in the positioning groove of the upper balsa wood layer or the lower balsa wood layer.

[0006] Furthermore, balsa wood cover plates are arranged on the outer sides of the upper balsa wood layer and the lower balsa wood layer.

[0007] Furthermore, the strip-shaped holes have a length of 1-1.5 cm and a width of 0.3-0.5 mm.

[0008] The present invention also discloses a production process of a composite material core material for a wind turbine blade, which is characterized by comprising the following steps: 1) Preparation of the core material body: the upper balsa wood layer, the upper foam layer, the middle balsa wood layer, the lower foam layer and the lower balsa wood layer are compounded in sequence from top to bottom to form the core material body; 2) Punching: punching holes on one side of the core material body to form hole A, and punching holes on the other side of the composite core material body to form hole B; hole A penetrates the upper balsa wood layer, the upper foam layer, the middle balsa wood layer and the lower foam layer to form a positioning groove on the lower balsa wood layer; hole B penetrates the lower balsa wood layer, the lower foam layer, the middle balsa wood layer and the upper foam layer to form a positioning groove on the upper balsa wood layer; 3) Inserting the support plates: Fix several support plates on the fixture, and the core material body is transported by the conveying mechanism. When the strip hole is located directly below the corresponding support plate, the lifting structure drives the fixture to move downward, and the support plate is placed in the strip hole. The cutting mechanism cuts the support plate; 4) Glue filling: The core material body is continuously conveyed by the conveying mechanism to the bottom of the glue filling mechanism, and glue is filled in the strip holes, and then dried to fix the support plate and the core material body; 5): The flipping mechanism turns over and repeats steps 3) and 4); 6) Sanding and gluing: Send the core material body to the sanding machine, sand both sides of the core material body, apply a layer of glue on the surface of the core material body, and dry the glued core material; 7) A layer of mesh glass fiber cloth is compounded on the back of the core material body; the mesh glass fiber cloth covers the entire surface of the core material; 8) Punching: Punch holes on the core material body, and avoid the position of the support plate inside the core material body; 9) Knife cutting: Cutting is done vertically and horizontally at the position avoiding the holes to cut the plate into several pieces; 10) Chamfering: Processing is performed on one side of the core material to form a slope structure.

[0009] Furthermore, in the step 2), holes are punched on both sides of the composite core material body, with transverse holes punched downward from the upper balsa wood layer and longitudinal holes punched from the lower balsa wood layer.

[0010] Furthermore, after step 5), balsa wood cover plates are fixed on both sides of the core material body.

[0011] The beneficial effects of the present invention are as follows: the new composite material of the present invention adopts a sandwich structure combining balsa wood and foam layers, a plurality of support plates are arranged vertically and horizontally in the balsa wood layer and the foam layer to improve the specific strength and specific modulus of the core material, and the arrangement of the foam layer reduces the amount of balsa wood used, thereby improving the compressive strength, toughness and impact resistance.

[0012] The longitudinal and transverse cutting on the surface of the core material during the preparation of the present invention increases the flow channel of the resin in the subsequent resin filling process, thereby effectively improving the resin filling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0014] Figure 1 It is a schematic diagram of the structure of the present invention.

[0015] Figure 2 This is a top view of the middle balsa wood layer.

[0016] Figure 3 This is a schematic diagram of Example 2. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below through specific implementation methods. Example

[0018] refer to Figure 1 and Figure 2 , is a composite core material for a wind turbine blade of this embodiment, comprising an upper balsa wood layer 1, a middle balsa wood layer 2, a lower balsa wood layer 3, an upper foam layer 4 and a lower foam layer 5.

[0019] In this embodiment, an upper balsa wood layer 1, an upper foam layer 4, a middle balsa wood layer 2, a lower foam layer 5 and a lower balsa wood layer 3 are sequentially arranged from top to bottom to form a core material body.

[0020] A plurality of strip-shaped holes 11 are arranged on both the upper balsa wood layer 1 and the lower balsa wood layer 3 , and the strip-shaped holes 11 on the upper balsa wood layer 1 and the lower balsa wood layer 3 are staggered.

[0021] The core material body is provided with a through hole connected with the strip hole 11; a positioning groove is provided on the inner side of the lower balsa wood layer 3 at a position corresponding to the strip hole of the upper balsa wood layer 1; a positioning groove is provided on the inner side of the upper balsa wood layer 3 at a position corresponding to the strip hole of the lower balsa wood layer 1; a support plate 6 is inserted into the through hole; one end of the support plate 6 is located in the strip hole 11 of the upper balsa wood layer 1 or the lower balsa wood layer 3, and the other end is located in the positioning groove of the upper balsa wood layer 1 or the lower balsa wood layer 3. The length of the strip hole is 1-1.5 cm, and the width is 0.3-0.5 mm.

[0022] The new composite material of the present invention adopts a sandwich structure combining balsa wood and foam layers. A plurality of support plates are arranged vertically and horizontally in the balsa wood layer and the foam layer to improve the specific strength and specific modulus of the core material. The arrangement of the foam layer reduces the amount of balsa wood used and improves the compressive strength, toughness and impact resistance. Example

[0023] like Figure 3 As shown, a composite core material for a wind turbine blade of this embodiment includes an upper balsa wood layer 1, a middle balsa wood layer 2, a lower balsa wood layer 3, an upper foam layer 4, a lower foam layer 5 and a balsa wood cover plate 7.

[0024] The upper balsa wood cover board 7, the upper balsa wood layer 1, the upper foam layer 4, the middle balsa wood layer 2, the lower foam layer 5, the lower balsa wood layer 3 and the lower balsa wood cover board 7 are arranged in sequence from top to bottom to constitute the core material body.

[0025] A plurality of strip holes 11 are arranged on the upper balsa layer 1 and the lower balsa layer 3, and the strip holes 11 on the upper balsa layer 1 and the lower balsa layer 3 are arranged staggered; a through hole connected with the strip hole 11 is arranged in the core material body; a positioning groove is arranged on the inner side of the lower balsa layer 3 at a position corresponding to the strip hole of the upper balsa layer 1; a positioning groove is arranged on the inner side of the upper balsa layer 3 at a position corresponding to the strip hole of the lower balsa layer 1; a support plate 6 is inserted into the through hole; one end of the support plate 6 is located in the strip hole 11 of the upper balsa layer 1 or the lower balsa layer 3, and the other end is located in the positioning groove of the upper balsa layer 1 or the lower balsa layer 3. Balsa cover plates 7 are covered on both sides of the core material body.

[0026] This embodiment adds a balsa wood cover plate 7 on the basis of embodiment 1, which can be more effective. Example

[0027] A production process of a composite material core material for a wind turbine blade in this embodiment includes the following steps: 1) Preparation of the core material body: the upper balsa wood layer, the upper foam layer, the middle balsa wood layer, the lower foam layer and the lower balsa wood layer are compounded in sequence from top to bottom to form the core material body; 2) Punching: punching holes on one side of the core material body to form hole A, and punching holes on the other side of the composite core material body to form hole B; hole A penetrates the upper balsa wood layer, the upper foam layer, the middle balsa wood layer and the lower foam layer to form a positioning groove on the lower balsa wood layer; hole B penetrates the lower balsa wood layer, the lower foam layer, the middle balsa wood layer and the upper foam layer to form a positioning groove on the upper balsa wood layer; 3) Inserting the support plates: Fix several support plates on the fixture, and the core material body is transported by the conveying mechanism. When the strip hole is located directly below the corresponding support plate, the lifting structure drives the fixture to move downward, and the support plate is placed in the strip hole. The cutting mechanism cuts the support plate; 4) Glue filling: The core material body is continuously conveyed by the conveying mechanism to the bottom of the glue filling mechanism, and glue is filled in the strip holes, and then dried to fix the support plate and the core material body; 5): The flipping mechanism turns over and repeats steps 3) and 4); 6) Sanding and gluing: Send the core material body to the sanding machine, sand both sides of the core material body, apply a layer of glue on the surface of the core material body, and dry the glued core material; 7) A layer of mesh glass fiber cloth is compounded on the back of the core material body; the mesh glass fiber cloth covers the entire surface of the core material; 8) Punching: Punch holes on the core material body, and avoid the position of the support plate inside the core material body; 9) Knife cutting: Cutting is done vertically and horizontally at the position avoiding the holes to cut the plate into several pieces; 10) Chamfering: Processing is performed on one side of the core material to form a slope structure.

[0028] The production process of the present invention is simple, and the plate composite unit and the support plate installation unit are added on the basis of the original production line, and the original production line is less modified.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.

Claims

1. A composite material core material for a wind turbine blade, characterized in that: The core material comprises an upper balsa wood layer (1), a middle balsa wood layer (2), a lower balsa wood layer (3), an upper foam layer (4) and a lower foam layer (5); the upper balsa wood layer (1), the upper foam layer (4), the middle balsa wood layer (2), the lower foam layer (5) and the lower balsa wood layer (3) are arranged in sequence from top to bottom to form a core material body; the upper balsa wood layer (1) and the lower balsa wood layer (3) are both provided with a plurality of strip holes (11), and the strip holes (11) on the upper balsa wood layer (1) and the lower balsa wood layer (3) are arranged in a staggered manner; The core material body is provided with a through hole connected to the strip hole (11); a positioning groove is provided on the inner side of the lower balsa wood layer (3) at a position corresponding to the strip hole of the upper balsa wood layer (1); a positioning groove is provided on the inner side of the upper balsa wood layer (3) at a position corresponding to the strip hole of the lower balsa wood layer (1); a support plate (6) is inserted into the through hole; one end of the support plate (6) is located in the strip hole (11) of the upper balsa wood layer (1) or the lower balsa wood layer (3), and the other end is located in the positioning groove of the upper balsa wood layer (1) or the lower balsa wood layer (3).

2. The composite material core material for wind turbine blades according to claim 1, characterized in that: Balsa wood cover plates (7) are provided on the outer sides of the upper balsa wood layer (1) and the lower balsa wood layer (3).

3. The composite material core material for wind turbine blades according to claim 1, characterized in that: The strip-shaped holes have a length of 1-1.5 cm and a width of 0.3-0.5 mm.

4. The production process of a composite material core material for wind turbine blades according to claim 1, characterized in that: The steps include: 1) Preparation of the core material body: the upper balsa wood layer, the upper foam layer, the middle balsa wood layer, the lower foam layer and the lower balsa wood layer are compounded in sequence from top to bottom to form the core material body; 2) Punching: punching holes on one side of the core material body to form hole A, and punching holes on the other side of the composite core material body to form hole B; hole A penetrates the upper balsa wood layer, the upper foam layer, the middle balsa wood layer and the lower foam layer to form a positioning groove on the lower balsa wood layer; hole B penetrates the lower balsa wood layer, the lower foam layer, the middle balsa wood layer and the upper foam layer to form a positioning groove on the upper balsa wood layer; 3) Inserting the support plates: Fix several support plates on the fixture, and the core material body is transported by the conveying mechanism. When the strip hole is located directly below the corresponding support plate, the lifting structure drives the fixture to move downward, and the support plate is placed in the strip hole. The cutting mechanism cuts the support plate; 4) Glue filling: The core material body is continuously conveyed by the conveying mechanism to the bottom of the glue filling mechanism, and glue is filled in the strip holes, and then dried to fix the support plate and the core material body; 5): The flipping mechanism turns over and repeats steps 3) and 4); 6) Sanding and gluing: Send the core material body to the sanding machine, sand both sides of the core material body, apply a layer of glue on the surface of the core material body, and dry the glued core material; 7) A layer of mesh glass fiber cloth is compounded on the back of the core material body; the mesh glass fiber cloth covers the entire surface of the core material; 8) Punching: Punch holes on the core material body, and avoid the position of the support plate inside the core material body; 9) Knife cutting: Cutting is done vertically and horizontally at the position avoiding the holes to cut the plate into several pieces; 10) Chamfering: Processing is performed on one side of the core material to form a slope structure.

5. The production process of a composite material core material for wind turbine blades according to claim 4, characterized in that: In the step 2), holes are punched on both sides of the composite core material body, with transverse holes punched downward from the upper balsa wood layer and longitudinal holes punched from the lower balsa wood layer net.

6. The production process of a composite material core material for wind turbine blades according to claim 4, characterized in that: Step 5) Then fix the balsa wood cover on both sides of the core material body.

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