Method for controlling wrinkles of rear edge bonding angle

Abstract

The invention discloses a method for controlling wrinkles of a rear edge bonding angle, which comprises the following steps of: wiping the surface of a rear edge bonding angle mold, paving a thermoplastic material, sealing, heating and melting to complete the molding of a pre-molded part, setting a gradient heating curve according to the physical characteristics of the thermoplastic material, and heating according to the gradient heating curve. After the thermoplastic material is melted, cooled and solidified, pre-shaping is completed, the pre-shaped part is demoulded, and the pre-shaped part is laid, poured and solidified on a leeside mould. The method has the beneficial effects that the popularization cost is low, the preset dusting fabric is heated, melted, cooled and solidified through the electric blanket, no air leakage control requirement exists in the solidification process, materials, equipment and labor cost are saved, operation is convenient, the method is suitable for both new and old staff, the control effect is good, trailing edge wrinkles are eliminated while the skin structure is not changed, and the blade quality is effectively improved; maintenance is reduced, and the influence of a combined section on the whole structure can be eliminated.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade manufacturing technology, and in particular to a method for controlling trailing edge bonding angle wrinkles. Background Technology

[0002] Wind power generation is one of the main new energy power generation methods. The main structure responsible for wind-facing forces is the wind turbine blade. The trailing edge bonding angle of the wind turbine blade is located in the critical aerodynamic area on the windward side of the blade. Its process quality has a global impact on the blade performance. Under the current process, there are many layers of flanged fabric at the trailing edge mold seam. The excess flange cannot be removed before vacuum sealing, resulting in improper installation of the tooling plate. Deviations in the shape and size of the bonding angle affect the mold gap. The multiple layers of fabric at the trailing edge bonding angle are laid without support, making it easy to slip. It is difficult to adhere properly during vacuum sealing, resulting in defects. The bonding angle forming tooling has poor conformity, which easily produces quality problems such as resin richness and wrinkles. These problems seriously affect the aerodynamic performance and structural strength of the blade. In the marine environment with salt spray corrosion and high-frequency load superposition, such defects may cause catastrophic failure and threaten the safe operation of the wind farm.

[0003] The patent CN108044957B discloses a process for prefabricating and integrally casting bonding corners, including steps such as bonding corner mold making, bonding corner prefabrication, skin forming, and integral casting. In the blade forming process, by adopting the technology of prefabricating bonding corners and integrally casting skin forming, the defects of the bonding corners are easy to control and identify due to the prefabrication of the bonding corner prefabricated parts in advance, and the defects can be repaired in a timely and effective manner. Moreover, there is no need to re-soak the bonding corner fabric layer with glue during the casting process, which effectively shortens the casting time. However, when using the above prefabrication technology for the production of large wind turbine blades, there are also shortcomings and risks, such as reduced blade forming efficiency, increased production costs, and, if the interface treatment is not done properly, it can also affect the blade strength to a certain extent. It cannot completely solve problems such as fabric slippage, wrinkles, inclusions, and steps. Summary of the Invention

[0004] The purpose of this invention is to provide a method for controlling wrinkles at the trailing edge bonding angle.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] A method for controlling trailing edge bonding corner wrinkles includes the following steps:

[0007] S1. Wipe the surface of the mold for bonding the rear edge corner, lay thermoplastic material, and then seal it.

[0008] S2. The pre-formed part is formed by heating and melting, specifically as follows:

[0009] S21. Set a gradient heating curve according to the physical properties of the thermoplastic material, including the heating period, melting period and cooling period;

[0010] S22. Heating according to the gradient heating curve, the thermoplastic coating melts and cools and solidifies to complete the predetermined shape;

[0011] S23. Demold the pre-formed part;

[0012] S3. Lay out and pour in the predetermined part for curing on the leeward mold.

[0013] Preferably, step S1 specifically includes:

[0014] S11. Prenatal preparation;

[0015] S12. In accordance with the standard operating procedure, the thermoplastic material pieces of specified length, width and specifications are laid sequentially on the surface of the rear edge bonding corner mold, and the layers are fixed together. After all the layers are laid, a vacuum sealing film layer is applied to the outside of the thermoplastic material.

[0016] Preferably, the pre-production preparation in step S11 includes preparing a release agent, an electric blanket, a soldering iron, vacuum tube tape, a vacuum membrane and auxiliary materials in advance. The release agent is soaked in a grease-free cloth and wiped in a Z-shape all around the surface of the mold at the rear edge bonding corner, and then waited for the release agent to dry completely.

[0017] Preferably, step S3 specifically includes:

[0018] S31. The pre-formed part is laid by laying the main forming fabric layer on the leeward mold. After all the pre-formed parts are laid, the pre-formed parts are laid in the specified axial position and fixed. Then the auxiliary materials are laid and vacuum pressure is maintained through the first pressure-sealing layer and the second pressure-sealing layer.

[0019] S32. After the vacuum pressure test is passed, the injection begins. After the main molding fabric layer is completely impregnated, the material is pre-cured by the mold heater. After the pre-curing is completed, the auxiliary material is removed.

[0020] Preferably, in step S22, heating is performed using a mold heater or an electric blanket.

[0021] Preferably, the pre-formed part is fixed to the leeward mold using a spray adhesive and a trailing edge bonding angle limiting fixture.

[0022] Preferably, the thermoplastic material is a powder-coated fabric layer.

[0023] Preferably, the gradient heating curve set according to the physical characteristics of the powder-coated fabric layer has three temperature gradients: 25℃-100℃ during the heating period, 100±2℃ during the melting period, and 100℃-40℃ during the cooling period.

[0024] Preferably, the temperature change rate during the heating period, the melting period, and the cooling period is all set to 0.5℃ / h.

[0025] Preferably, the powder-sprinkled fabric layup is formed by laying up several pieces of powder-sprinkled fabric layup.

[0026] Preferably, the fixing method between the layers of the powdered fabric lay-up pieces is either a single-point heating and melting fixing method or a single-point adhesive bonding fixing method.

[0027] Preferably, the heating tool for the single-point heating and melting fixing method is one of an iron, a heating wire, or a heating rod.

[0028] Preferably, in step S23, a vacuum suction cup demolding fixture is used to assist in demolding, which helps to maintain the shape of the pre-formed part, prevents edge deformation and the problem of the pre-formed part not conforming to the shape, and prohibits the use of rigid tools for demolding.

[0029] The beneficial effects of the method for controlling trailing edge bonding corner wrinkles described in this invention are as follows:

[0030] The promotion cost is low. The pre-made powder-sprinkled fabric is heated and melted by an electric blanket and then cooled and solidified. There are no requirements for air leakage control during the solidification process, avoiding the risk of air leakage during the prefabrication process. The laying process does not require extensive use of tooling, and at the same time, it can save on material, equipment and labor costs.

[0031] With a wide audience and easy operation, it can be directly covered with an electric heating blanket after being sprinkled with powder, cut into pieces and laid out. It melts, cools and solidifies, has a simple structure and is easy to operate, and is suitable for both new and old employees.

[0032] It has good control effect, eliminates trailing edge wrinkles without changing the skin structure, effectively improves blade quality, reduces maintenance, saves a lot of manpower and material resources, and shortens the manufacturing cycle;

[0033] Powdered fabric is essentially composed of glass fiber heated and melted with adhesive. The surface of the pre-formed part after powdered fabric is formed has micropores, which allows the resin to fully impregnate the part during the injection process. Compared with one-piece injection pre-forming, this eliminates the influence of the joint section on the overall structure. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the preform laying structure in the mold of the trailing edge bonding angle, which is described in the invention as a method for controlling the wrinkles of the trailing edge bonding angle;

[0035] Figure 2 This is a schematic diagram of the preform placement structure in the leeward mold of the method for controlling the wrinkles at the trailing edge bonding angle described in the invention.

[0036] The attached figures are labeled as follows:

[0037] 1. Rear edge bonding corner mold; 2. Leeward side mold; 3. Rear edge bonding corner limiting fixture; 4. Vacuum sealing film layer; 5. Thermoplastic material; 6. Electric blanket; 7. Pre-formed part; 8. Pressure holding sealing layer two; 9. Pressure holding sealing layer one; 10. Auxiliary materials; 11. Main forming fabric layer. Detailed Implementation

[0038] The present invention will now be described with reference to the accompanying drawings:

[0039] like Figure 1-2 As shown, a method for controlling trailing edge bonding corner wrinkles includes the following steps:

[0040] S1. Wipe the surface of the rear edge bonding corner mold 1, lay thermoplastic material 5, and then seal it. Specifically:

[0041] S11. Pre-production preparation: Prepare release agent, electric blanket 6, soldering iron, vacuum tube tape, vacuum film and auxiliary materials 10 in advance. Use a grease-free cloth soaked in release agent to wipe the surface of the rear edge bonding corner mold 1 in a Z-shape and wait for the release agent to dry completely.

[0042] S12. In accordance with the standard operating procedure, lay the thermoplastic material pieces of specified length, width and specifications onto the surface of the rear edge bonding corner mold 1 in sequence, fix the layers together, and after all the layers are laid, use sealing tape and vacuum film to seal the outside of the thermoplastic material 5 to form a vacuum sealing film layer 4 (the vacuum effect makes the thermoplastic material pieces tightly compressed before heating, and at the same time prevents displacement and deformation).

[0043] S2. The pre-formed part 7 is formed by heating and melting, specifically as follows:

[0044] S21. Set a gradient heating curve, including a heating period, a melting period, and a cooling period. The gradient heating curve is set according to the physical properties of the thermoplastic material 5.

[0045] S22. Heating according to the gradient heating curve, the thermoplastic material 5 melts and cools and solidifies to complete the pre-formation. Heating can be carried out by a mold heater or by covering the vacuum membrane sealing layer 4 with an electric heating blanket 6.

[0046] S23. Demold the pre-formed part 7. In order to maintain the shape of the pre-formed part 7, a vacuum suction cup demolding tool can be used to assist in demolding, which can effectively prevent edge deformation and the problem of the pre-formed part not conforming to the shape. Rigid tools (such as levers, iron pry bars, etc.) are prohibited from being used for demolding.

[0047] S3. Lay out and pour in the pre-formed part 7 for curing on the leeward side of the mold 2, specifically as follows:

[0048] S31. Laying the pre-formed part 7: Lay the main forming fabric layer 11 on the leeward mold 2. After all the fabric layers are laid, lay the pre-formed part 7 in the specified axial position. The pre-formed part 7 is fixed with spray adhesive and the rear edge bonding angle limiting tool 3. Then, lay the auxiliary material 10 and vacuum pressurize it through the pressure sealing layer 2 8 and the pressure sealing layer 1 9.

[0049] S32. After the vacuum pressure test is passed, the injection begins. After the main molding fabric layer 11 is completely impregnated, it is pre-cured by the mold heater. After the pre-curing is completed, the auxiliary material 10 is removed to complete the process.

[0050] In the above description, trailing edge bonding angle refers to the internal angular structure with a specific geometric angle formed after the main shell of a large wind turbine blade is bonded with structural adhesive in the trailing edge area. Prefabricated trailing edge bonding angle refers to the process of laying a cloth layer on the trailing edge bonding angle mold in advance, pouring and curing it, and then demolding it to form a component with a specific shape and a certain rigidity.

[0051] The present invention will be further illustrated by the following examples:

[0052] Example

[0053] A method for controlling trailing edge bonding corner wrinkles includes the following steps:

[0054] S1. Wipe the surface of the rear edge bonding corner mold 1, lay a powdered fabric layer, and then seal it. Specifically:

[0055] S11. Pre-production preparation: Prepare release agent, electric blanket 6, soldering iron, vacuum tube tape, vacuum film and auxiliary materials 10 in advance. Use a grease-free cloth soaked in release agent to wipe the surface of the rear edge bonding corner mold 1 in a Z-shape and wait for the release agent to dry completely.

[0056] S12. In accordance with the standard operating procedure, lay the powder-sprinkled fabric layer pieces of specified length, width and specifications onto the surface of the back edge bonding corner mold in sequence, fix the layers together, and after all the layers are laid, use sealing tape and vacuum film to seal the outside of the powder-sprinkled fabric layer to form a vacuum sealing film layer 4.

[0057] S2. The pre-formed part 7 is formed by heating and melting, specifically as follows:

[0058] S21. Set a gradient heating curve based on the physical characteristics of the powder-coated fabric layup, with three temperature gradients: 25℃-100℃ during the heating period, 100±2℃ during the melting period, and 100℃-40℃ during the cooling period. The temperature change rate is set to 0.5℃ / h for each gradient.

[0059] S22. Heating according to the gradient heating curve, the powdered fabric layered cut piece melts and cools and solidifies to complete the pre-forming. Heating can be carried out by a mold heater or by covering the vacuum membrane sealing layer 4 with an electric heating blanket 6.

[0060] S23. Demold the pre-formed part 7;

[0061] S3, the laying and curing of the pre-designed component 7, specifically:

[0062] S31. Laying the pre-formed part 7: Laying the skin layer on the leeward mold 2. After all the layers are laid, the pre-formed part 7 is laid in the specified axial position. The pre-formed part is fixed with spray glue and the rear edge bonding angle limiting tool 3. The auxiliary material 10 is laid and vacuum pressure is maintained through the first pressure sealing layer 8 and the second pressure sealing layer 9.

[0063] S32. After the vacuum pressure test is passed, the injection begins. After the main molding fabric layer 11 is fully impregnated, it is pre-cured by the mold heater. After the pre-curing is completed, the skin fabric layer is removed to finish the process.

[0064] In this embodiment, in step S12, the fixing method between the layers of the powdered fabric lay-up piece is either a single-point heating and melting fixing method or an adhesive single-point bonding fixing method. The heating tool for the single-point heating and melting fixing method is either an iron, an electric heating wire, or an electric heating rod.

[0065] In this embodiment, the thermoplastic material 5 is a powder-sprinkled fabric layer. The powder-sprinkled fabric is a specific type of fiber-reinforced material. Its characteristic is that a layer of low-melting-point thermoplastic powder is attached to the surface of the fabric. It has a low cost and can be melted and cooled by heating with an electric blanket. By applying specific heat, pressure and time, the hot-melt powder on the surface of the powder-sprinkled fabric is activated, causing it to melt and re-solidify. This temporarily solidifies the multiple loosely laid fabrics into a whole with a certain rigidity. There are no air leakage control requirements in the curing process, avoiding the risk of air leakage in the prefabrication process. The laying process does not require extensive use of tooling, and it can save material, equipment and labor costs. Using the powder-sprinkled fabric as raw material, a gradient heating curve is set according to the physical characteristics of the powder-sprinkled fabric layer to achieve the melting and cooling molding of the pre-shaped part.

[0066] In addition to the powdered fabric material used in this embodiment, other thermoplastic materials can also be used for thermoplastic material molding.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method of controlling trailing edge adhesive angle creases, characterized by, It comprises the following steps: S1, wipe the surface of the trailing edge bonding angle mold and lay the thermoplastic material back seal; S2, complete the molding of the predetermined shape by heating and melting, specifically: S21, set a gradient heating curve according to the physical properties of the thermoplastic material, including the warming-up period, the melting period and the cooling period; S22, heat according to the gradient heating curve, and complete the predetermined shape after the thermoplastic material is melted and cooled and solidified; S23, demold the predetermined shape; S3, lay and pour the predetermined shape on the leeward side mold.

2. The method of controlling trailing edge adhesive angle creases according to claim 1, wherein, Step S1 specifically includes: S11, prenatal preparation; S12, according to the requirements of standard operating procedures, lay the thermoplastic material pieces of specified length and width and specifications in order on the surface of the trailing edge bonding angle mold, fix between layers, and after all laying is completed, set a vacuum sealing film layer outside the thermoplastic material.

3. A method of controlling trailing edge adhesive angle creases according to claim 2, characterised in that: The prenatal preparation in step S11 includes preparing demolding agent, electric blanket, electric iron, vacuum tube adhesive tape, vacuum film and auxiliary materials in advance, using a non-fat cloth to soak the demolding agent and wipe the surface of the trailing edge bonding angle mold in Z shape, and waiting for the demolding agent to dry.

4. The method of controlling trailing edge adhesive angle creases according to claim 1, wherein, Step S3 specifically includes: S31, lay the predetermined shape, lay the main molding cloth layer on the leeward side mold, after all laying is completed, lay the predetermined shape at the specified axial position and fix it, then lay the auxiliary materials and vacuum seal layer one and layer two to seal the layer; S32, after the vacuum pressure test is qualified, start pouring until the main molding cloth layer is fully soaked, then pre-solidify by the mold heater, and after pre-solidification is completed, tear off the auxiliary materials.

5. The method of controlling trailing edge adhesive angle creases according to claim 1, wherein: In step S22, heating is performed by the mold heater or the electric blanket.

6. The method of controlling trailing edge adhesive angle creases according to claim 4, wherein: The predetermined shape is fixed on the leeward side mold using glue spraying and trailing edge bonding angle limiting tooling.

7. The method of controlling trailing edge adhesive angle creases according to claim 1, wherein: The thermoplastic material uses powder-spreading fabric layers.

8. A method of controlling trailing edge adhesive angle creases according to claim 7, characterised in that: The gradient heating curve set according to the physical properties of the powder-spreading fabric layers has three temperature gradients, which are 25℃-100℃ for the warming-up period, 100±2℃ for the melting period, and 100℃-40℃ for the cooling period.

9. A method of controlling trailing edge adhesive angle creases according to claim 8, characterised in that: The temperature change rate of the warming-up period, the melting period and the cooling period is all set to 0.5℃ / h.

10. The method of controlling trailing edge adhesive angle creases according to claim 7, wherein: The powder-spreading fabric layers are laid by a plurality of powder-spreading fabric layer pieces.

11. A method of controlling trailing edge adhesive angle creases according to claim 10, characterized in that: The fixing method between layers of the powder-spreading fabric layer pieces is one of single-point heating and melting fixing method or single-point adhesive fixing method.

12. A method of controlling trailing edge adhesive angle creases according to claim 11, characterized in that: The heating tool of the single-point heating and melting fixing method is one of iron, electric heating wire and electric heating rod.

13. The method of controlling trailing edge adhesive angle creases according to claim 1, wherein: In step S23, vacuum chuck demolding tooling is used to assist demolding, which is convenient for maintaining the shape of the predetermined shape, preventing edge deformation and the problem of not following the shape of the predetermined shape, and rigid tooling is prohibited.

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