JP2009074421A - Blade material for axial flow type windmill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide blade material for an axial flow type windmill capable of not only greatly reducing lamination time by change of a lamination method but also retaining strength by an overlap structure, whereas a shape of a root part is complicated and it takes time for lamination of FRP in blade material for an axial flow type windmill using FRP. <P>SOLUTION: The blade material for the axial flow type windmill comprises a core material made of foam body inside and fiber reinforced plastic laminating at lest two layers around the core material. The root part of the blade material for the axial flow type windmill formed by lamination of FRP has a structure in which fiber of FRP forming its vertical surface and fiber of FRP forming its horizontal surface do not continue, are laminated in two or more layers beforehand, and are mutually joined at an overlap part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blade member for an axial flow type windmill made of fiber reinforced plastic (hereinafter sometimes abbreviated as FRP) suitable for a blade for wind power generation or the like.

  The wing has a shape having a thickness distribution in its cross section, thereby expressing the function of controlling the flow of fluid. In general, horizontal wings and vertical wings typified by rear spoilers for aircraft and automobiles are used for propeller blades of aircraft, helicopters and ships, turbine blades of blowers, blades of stirrers, blades for wind power generation, and the like. As in these examples, the wing member is often used while being fixed to a moving body or rotating itself so as to control the flow of fluid. Therefore, weight reduction of the whole apparatus including a wing member and reduction of the inertia force of a windmill movable part are calculated | required, and the weight reduction request | requirement to the wing member which can achieve these simultaneously is strong.

  Conventionally, metal materials such as aluminum and titanium have been used as wing members, but FRP that is lighter in weight, higher in strength, and higher in rigidity than metal is used due to the demand for weight reduction and high rigidity. became. Furthermore, in recent years, in order to achieve further weight reduction while ensuring high strength and high rigidity, a sandwich structure in which a low density resin or honeycomb structure is filled as a core material surrounded by the FRP skin material and the skin material. Proposed. Further, since the wing member receives pressure from the fluid, it is indispensable to have sufficient strength and rigidity that can withstand destruction and deformation.

  Among them, especially in an axial flow type windmill, the peripheral speed during rotation increases as it goes to the tip of the blade, so that the influence of the inertia force due to the weight of the blade and the pressure from the fluid that the blade receives is reduced. There is a higher demand for weight reduction at the blade tip than at the blade root.

  Therefore, the blade shape of an axial-flow wind turbine generally has a wide root portion and a narrow tip, and the thickness is generally a structure where the root portion is thicker than the tip.

  In order to satisfy this requirement, many proposals and inventions have been made for axial flow type wind turbine blades, but most of them are related to the tip of the blade member and the cross-sectional structure, and most proposals related to the blade root part. The fact is that nothing has been done.

  Among these few proposals relating to the blade root part, for example, Patent Document 1 proposes a manufacturing method in which members constituting each surface are bonded while being a hollow molded body. Although this manufacturing method can be diverted to the blade root part, since it is a hollow molded body, a problem remains in strength.

Similarly to Patent Document 1, Patent Document 2 that can be diverted to the blade root part has been proposed. This molded body is composed of a core material having a corner portion and a reinforcing fiber fabric, and takes a form divided into at least three when the reinforcing fiber fabric is bonded to the corner portion of the core material. However, when the blade root portion is configured in a three-divided form, it takes time and effort to create each of the three-divided members, and in practice, the working time is also limited. In addition, when the intersecting line of the two surfaces constituting the right-angled portion is not a straight line but a complicated curve, the shape of the joining portion of each member becomes complicated, making it difficult to manufacture. Furthermore, skill of the operator and extra work time are required, and diversion to the blade root is extremely difficult.
JP 2006-44262 A JP 2005-178335 A

  In view of the drawbacks of the prior art, the present invention is a lightweight and high-profile member (referred to as “axial-type wind turbine blade member”) that has a complicated shape and forms a blade used in an axial-flow wind turbine. An object of the present invention is to provide an axial-flow type wind turbine blade member capable of significantly improving production efficiency while maintaining strength and high rigidity.

In order to achieve the above object, the present invention employs the following means. That is,
(1) A wing member for an axial-flow type wind turbine which is made of a core material made of a foam inside and a fiber reinforced plastic laminated at least two layers around the core material, and satisfies at least the following elements at the same time.
A. The laminated fiber reinforced plastic almost completely surrounds the surface of the root portion of the axial flow type wind turbine blade member.
B. The fiber portion of the fiber reinforced plastic constituting the vertical surface of the root portion of the axial flow type wind turbine blade member is discontinuous with the fiber portion of the fiber reinforced plastic constituting the horizontal surface of the root portion of the axial flow type wind turbine blade member. .
C. The fiber reinforced plastic that forms the vertical surface of the root part of the axial flow type wind turbine blade member has an overlap, and the fiber reinforced plastic that forms the horizontal plane of the root part of the axial flow type wind turbine blade member is joined at the overlap part. Or a fiber reinforced plastic that forms a horizontal surface of the root portion of the wing member for an axial flow type wind turbine has an overlap, and a fiber reinforced plastic that forms a vertical surface of the root portion of the wing member for an axial flow type wind turbine And joined at the overlap part.

  (2) The axial-flow wind turbine according to (1), wherein the fiber constituting the fiber-reinforced plastic is at least one selected from the group consisting of carbon fiber, glass fiber, polyimide fiber, polyamide fiber, and boron fiber. Wing member.

  (3) The axial flow type wind turbine blade member according to (1) and (2), wherein the matrix resin of the fiber reinforced plastic is a thermosetting resin or a thermoplastic resin.

  (4) The wing member for an axial flow type wind turbine according to (1) to (3), wherein the wing member for an axial flow type wind turbine has a curved portion at a line of intersection between a vertical plane of a root portion of the axial flow type wind turbine blade member and a horizontal plane.

  According to the present invention, in the axial flow type wind turbine blade member having a complicated shape, the fiber portion of the fiber reinforced plastic constituting the vertical surface of the root portion of the axial flow type wind turbine blade member is replaced with the axial flow type wind turbine blade. Axial flow that can significantly improve production efficiency while maintaining light weight, strength, and rigidity by making the fiber part of the fiber reinforced plastic constituting the horizontal plane at the base of the member discontinuous and joining them at the overlap part. A wind turbine blade member is obtained.

  The present invention relates to a blade member (a blade member for an axial flow type wind turbine) used in an axial flow type wind turbine, and has a structure in which a core material is provided inside and the outside is covered with FRP. Such an axial flow type wind turbine blade member is attached to a rotating shaft of an axial flow type wind turbine via a hub.

  The blade member for an axial flow type wind turbine according to the present invention has a root portion located on the side close to the contact portion with the hub and a tip portion located on the far side, and has an attachment portion on the portion that directly contacts the hub. In particular, it is important that the root portion that characterizes the configuration of the present invention has the FRP substantially completely surrounding the core material. This is because if there is a portion where the core material is not covered with the FRP portion, stress concentration on the FRP portion, hydrolysis of the core material due to moisture intrusion, or the like may occur. As used herein, “substantially completely surrounding” means that the core material is not visible to the naked eye, or when the FRP is perforated in the post-molding process, It means that it has been processed to maintain waterproofness so that it will not be submerged.

  It is preferable that at least one of carbon fiber, glass fiber, polyimide fiber, polyamide fiber, and boron fiber is included as a fiber used for FRP surrounding the core material. These fibers have high strength and can exhibit sufficient strength when used in an axial flow type wind turbine blade. Among these, carbon fibers having the highest strength are preferable for fiber materials used as FRP fibers having high general purpose.

  Moreover, the fiber used for FRP does not necessarily need to be a single fiber raw material, and may mix and use 2 or more types of fibers. In this case, natural fibers such as cotton and silk, organic fibers including thermoplastic fibers such as polyester and polyamide, and inorganic fibers such as metals are not particularly limited. Further, the fiber form is preferably a long fiber excellent in tensile strength, but a short fiber yarn such as spun yarn may be used, or a mixed use in knitting or knitting with a long fiber may be used. The fiber form in the FRP is most preferably a woven fabric which is thin and excellent in the balance of the background and is difficult to unravel the fibers by restraint between the fibers, but the prepreg (hereinafter referred to as UD) in which the fibers are aligned in the longitudinal direction and impregnated with a thermosetting resin. (Abbreviated as prepreg) may be laminated by changing the direction of the fibers, or may be a knitted fabric. Moreover, the woven structure of the woven fabric is not particularly limited, but a plain weave which is easy to balance front / back and background is preferable. Similarly, it is preferable to use the same yarn for warp and weft to balance the warp, but there is no particular limitation.

  The FRP matrix resin used in the present invention may be either a thermosetting resin or a thermoplastic resin, but a thermosetting resin that is generally widely used in combination with long fibers is preferred. Specifically, a resin that is cured by heat or external energy such as light or electron beam with a thermosetting resin such as epoxy, unsaturated polyester, vinyl ester, phenol, or polyimide, and at least partially forms a cured product. If it is good.

  For the core material, it is necessary to use a material having a smaller bulk density than the skin material in order to achieve weight reduction while maintaining rigidity. Preferably, a resin porous material having a structure in which the main component is made of a resin and a large number of voids inside the structure is preferable. The void may be a foamed foam material or a core made of a syntactic foamed plastic containing a large number of hollow glass beads and the like. As the material of the core material resin, a thermosetting resin or a thermoplastic resin can be used. For example, as the thermosetting resin, there are epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, etc., and as the thermoplastic resin, polyamide resin, polyacetal resin, polyphenylene sulfide resin, polyethylene terephthalate, polybutylene terephthalate, Polyester resin such as polycyclohexanedimethyl terephthalate, polyarylate resin, polycarbonate resin, polystyrene resin, HIPS resin, ABS resin, AES resin, AAS resin and other styrene resins, polymethyl methacrylate resin and other acrylic resins, vinyl chloride, polyethylene, Polyolefin resins such as polypropylene, polyurethane resins, imide resins such as polyetherimide and polymethacrylimide, and various elastomersThese may be used alone or in combination.

  As an example of a method for obtaining the FRP constituting the axial flow type wind turbine blade member according to the present invention, there is a method in which prepregs are stacked and molded with a mold. At that time, the tip portion of the axial flow type wind turbine blade member may be molded by adhering the prepreg from the upper and lower surfaces of the horizontal plane or surrounding the core material with a series of prepregs.

  At the root of the axial wind turbine blade member, the thickness of the blade increases and the shape becomes more complex than the tip.Therefore, the prepreg that covers the horizontal surface of the root is adhesive to the vertical surface of the root. For the purpose of maintaining strength, it is essential that an overlap is provided. In this case, it is desirable that the vertical surface of the root portion of the axial flow type wind turbine blade member is not folded back to the horizontal surface of the root portion of the axial flow type wind turbine blade member. In addition, the overlap provided in the prepreg on the horizontal surface of the root portion may be present in all layers stacked on the horizontal surface. Further, instead of providing an overlap on the prepreg that covers the horizontal surface of the root portion of the blade member for the axial flow type wind turbine according to the present invention, the blade for the axial flow type wind turbine is used for the purpose of maintaining adhesion and strength with the horizontal surface of the root portion. You may provide an overlap in the prepreg which covers the vertical surface of the base part of a member. In this case, it is desirable that the horizontal surface of the root portion of the axial flow type wind turbine blade member is not folded back to the vertical surface of the root portion of the axial flow type wind turbine blade member. In addition, the overlap provided in the prepreg on the vertical surface of the root portion may be present in all layers stacked on the vertical surface.

  Such an overlap may consist of a region that is slightly folded back to a horizontal plane or a vertical plane. The direction of the fibers in the FRP may be any direction as long as it is a woven fabric. However, when a UD prepreg is used, at least one layer is in a state along the longitudinal direction of the wind turbine blades and must be angled. It is preferable to laminate the layers or laminate a woven prepreg (hereinafter referred to as cross prepreg) because the strength balance as the laminate can be maintained.

  Furthermore, the axial flow type wind turbine blade member according to the present invention preferably has a curved portion at the intersection line between the vertical surface of the root portion and the horizontal plane. In other words, the wing for an axial wind turbine is rotated by receiving wind perpendicularly to the longitudinal direction of the wind turbine blade, but when the rotation speed is high, it is similar to the horizontal blade of an airplane for the purpose of reducing the air resistance of the wind turbine blade. However, this shape is slightly bent even in the horizontal plane when the cross section perpendicular to the longitudinal direction of the axial flow type wind turbine blade is viewed. Therefore, in the present invention, as shown in the horizontal plane (upper surface) 2 and the horizontal plane (lower surface) 3 in FIG. 3, a horizontal plane with a small degree of curvature is defined as a horizontal plane (lower surface) and a horizontal plane with a large degree of curvature is defined as a horizontal plane (upper surface). Yes. When the cross section is rectangular, there is no distinction between a horizontal plane (upper surface) and a horizontal plane (lower surface). Moreover, the edge part of the wing member for axial flow type windmills makes the rotation direction side the front edge part 6, and makes the other side the rotation direction the rear edge part 7. FIG.

  It is preferable that two or more layers are laminated by cutting the prepreg in advance so as to cover the entire surface of the vertical surface at the vertical surface of the root portion of the axial flow type wind turbine blade. In this case, what is necessary is just to comprise so that it may have an overlap with a horizontal surface as mentioned above. That is, the FRP constituting the vertical plane has an overlap, and the FRP constituting the horizontal plane is joined with the overlap portion, or the FRP constituting the horizontal plane has an overlap, and the fiber reinforcement constituting the vertical plane What is necessary is just to comprise so that it may join with an overlap part with plastic.

  The FRP fibers to be laminated may be in any direction as long as they are woven. However, when using unidirectional fibers that are aligned, at least one layer is in a state along the width direction of the wind turbine blade, and the angle is always set. Laminate another layer attached or fabric FRP.

  In the present invention, the prepreg may be cut and laminated so that the horizontal and vertical surfaces of the blades are discontinuous in advance at the root of the blade for the axial flow type wind turbine. The prepreg is made discontinuous. In the work of stacking vertical surfaces, wrinkles occur at the folded part, and the work of cutting the vertical surfaces to remove wrinkles is complicated and prevents the work time from becoming longer. Because. In addition, the working time can be further shortened by previously laminating the horizontal plane portion and the vertical plane portion in advance.

  Furthermore, it is preferable to use a woven fabric for the prepreg of the outermost layer on all surfaces regardless of a horizontal plane or a vertical plane. This is because the direction of the fibers in the FRP is not biased in the outermost layer, and in the wind turbine that is assumed to be used outdoors, the FRP durability and the fiber shape of the FRP are maintained. A fabric in which the fiber is constrained is optimal because of its high fiber shape maintenance.

  The number of layers of the prepreg to be laminated is not particularly limited as long as it is 2 layers or more in both the horizontal plane and the vertical plane, but from the viewpoint of strength, cost, and weight, 5 layers or less are preferable, and 2 to 4 layers are more preferable. preferable.

  As a method for molding the axial flow type wind turbine blade according to the present invention, it is preferable to use press molding using a mold because injection molding is difficult. In particular, a prepreg is generally used, laminated before molding, and put into a mold and press-molded. In particular, since it has a core material, if a prepreg is laminated on the core material in advance, it can be produced by a single press molding.

  The present invention will be described more specifically with reference to the following examples. However, the following examples are not intended to limit the present invention in any way, and modifications within the scope of the present invention may be made without departing from the spirit of the present invention. It is a range. The characteristics used in this example are measured as follows.

[Tensile strength of the mounting part of the blade member for an axial flow type wind turbine]
The measurement was performed according to the following procedure.
(1) The axial flow type wind turbine blade is cut into a length of about 300 mm including the root portion in the longitudinal direction.
(2) Attach the root part to the hub, and attach the jig to each of the hub and the cut windmill blade side.
(3) The sample is left overnight in a test room in an environment with a temperature of 23 ± 2 ° C.
(4) A predetermined load cell is attached to the testing machine.
(5) The sample is fixed to the constant speed compression tester through the attached jig.
(6) Pull the sample at a speed of 1 mm / min, and record the displacement and load of the compression jig.
(7) The maximum load is the tensile strength.

Example 1
A urethane foam was used as the core material, and the core material was cut into an axial flow type wind turbine blade shape having a total length of about 900 mm.

  A carbon fiber reinforced epoxy resin was used as the FRP laminated on the core material. Moreover, as for the form of carbon fiber, all were long fiber filaments, and used two types, a plain weave and a sheet aligned in a single direction. These carbon fibers were impregnated with an epoxy resin to form a cross prepreg and a UD prepreg, respectively.

  In the present invention, first, the horizontal surface (upper surface) 2 and the horizontal surface (lower surface) 3 of the core material 4 of FIG. 2 were covered with the UD prepreg so that the carbon fibers were aligned in the longitudinal direction of the wind turbine blade. Subsequently, a sheet laminated in three layers using a cross prepreg in advance was pasted as the vertical surface 1. The overlap 5 was provided only on the outermost layer of the vertical surface 1.

  Next, after the cross prepreg is cut for the upper surface and the lower surface only in the portion forming the horizontal plane of the wind turbine blade, the core material is placed on the outer layers of the horizontal plane (upper surface) 3 and the horizontal plane (lower surface) 4 of the core material laminated with the UD prepreg. Was placed in a mold and press-molded at a temperature of 100 ° C. or higher with a press. After demolding, an axial flow type wind turbine blade was manufactured through trimming and repair work.

  In FIG. 4, the cross section of the root portion of the axial flow type wind turbine blade member obtained by the present invention has an overlap 5 on the vertical surface 1, and a horizontal surface (upper surface) 2 and a horizontal surface (lower surface) 3. It is joined. At this time, the horizontal plane (upper surface) 2 uses the UD prepreg 8 for the innermost layer and the cross prepreg 9 for the outermost layer.

  As a result, the tensile strength of the mounting part of the axial flow type wind turbine blade member was 4 kN, and the working time could be reduced by about 43% per one while maintaining the same strength as the conventional product.

(Comparative Example 1)
As in the example, urethane foam was used for the core material 4, and the core material 4 was cut into an axial-flow wind turbine blade shape having a total length of about 900 mm. Also, the FRP used was the same as in the examples.

  In this comparative example, first, as in Example 1, the horizontal surface (upper surface) 2 and the horizontal surface (lower surface) 3 of the core material were covered with a UD prepreg. Subsequently, one layer of cross prepreg was attached to the vertical surface. There is no overlap.

  Next, the cross prepreg was cut so as to be laminated on the outer layer of the horizontal surface (upper surface) 2 and the horizontal surface (lower surface) 3 of the core material on which the UD prepreg was placed. First, the horizontal plane (upper surface) 2 was cut so that the end portion was aligned with the intersecting line of the horizontal plane (upper surface) and the vertical plane 1 so that the vertical plane 1 hardly formed an overlap. The horizontal surface (lower surface) 3 was placed on the outer layer of the UD prepreg placed on the core material, then turned back to the vertical surface 1 and cut so as to be aligned with the intersecting line. When the horizontal surface (lower surface) 3 is folded back to a vertical surface, the shape of the vertical surface is complicated and wrinkles are generated. Therefore, it was necessary to cut and remove the wrinkles. After the horizontal surface (lower surface) 3 was stacked, the horizontal surface (upper surface) 2 was stacked.

  After the operation, an axial flow type wind turbine blade was manufactured under the same conditions as in the example.

  As a result, the tensile strength of the attachment portion of the axial flow type wind turbine blade member was 4 kN or more.

  The axial flow type wind turbine blade of the present invention is preferably used mainly for a small axial flow type wind turbine.

1 is an overall view of an axial wind turbine blade according to the present invention. It is sectional drawing (AA cross section of FIG. 1) of the axial flow type windmill blade in this invention. It is sectional drawing (BB cross section of FIG. 1) of the axial flow type windmill blade in this invention. FIG. 2 is a cross-sectional view (A-A cross section in FIG. 1) of the root portion of the axial-flow wind turbine blade according to the present invention.

Explanation of symbols

1: Vertical plane 2: Horizontal plane (upper surface)
3: Horizontal surface (bottom surface)
4: Core material 5: Overlap 6: Front edge 7: Rear edge 8: UD prepreg 9: Cross prepreg

Claims (4)

An axial-flow type wind turbine blade member comprising a core material made of foam inside and a fiber-reinforced plastic laminated at least two layers around the core material, and satisfying at least the following elements simultaneously.
(1) The laminated fiber reinforced plastic almost completely surrounds the surface of the root portion of the blade member for the axial flow type wind turbine.
(2) The fiber portion of the fiber reinforced plastic that constitutes the vertical surface of the root portion of the axial flow type wind turbine blade member is different from the fiber portion of the fiber reinforced plastic that constitutes the horizontal surface of the root portion of the axial flow type wind turbine blade member. It is continuous.
(3) The fiber reinforced plastic constituting the vertical surface of the root portion of the axial flow type wind turbine blade member has an overlap, and the fiber reinforced plastic and the overlap constituting the horizontal surface of the root portion of the axial flow type wind turbine blade member The fiber reinforced plastic that is joined at the portion or that forms the horizontal surface of the root portion of the axial flow type wind turbine blade member has an overlap, and constitutes the vertical surface of the root portion of the axial flow type wind turbine blade member It is joined with fiber reinforced plastic at the overlap. The wing member for an axial flow type wind turbine according to claim 1, wherein the fiber constituting the fiber reinforced plastic is at least one selected from the group consisting of carbon fiber, glass fiber, polyimide fiber, polyamide fiber, and boron fiber. The blade member for an axial flow type wind turbine according to claim 1 or 2, wherein the fiber reinforced plastic matrix resin is a thermosetting resin or a thermoplastic resin. The wing member for an axial flow type wind turbine according to claim 1, wherein the wing member for an axial flow type wind turbine has a curved portion at an intersection line between a vertical surface of a root portion of the wing member for an axial flow type wind turbine and a horizontal plane.

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