JP2002221144A - Wind mill for small size wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a windmill for a small-sized wind power generator capable of preventing a secondary disaster from fragments of a blade flew all around when the blade of the windmill is destroyed during rotating, with low rotation noise and superior in mobility to respond to the change of a wind speed or direction. SOLUTION: In the windmill 11 for the small-sized wind power generator 10 provided with a plurality of blades 13 converting wind power into rotation, each blade 13 includes a blade body 15 receiving the wind power and generating a rotational force and a blade attachment member 16 fixed on the blade body 15 and attaching the blade body 15 on a rotating shaft 14 of the windmill 11. The blade body 15 is made of a porous flexible material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind turbine for a small wind power generator which is excellent in responsiveness to fluctuations in wind speed and direction, safe and quiet, and excellent in over-rotation prevention.

[0002]

2. Description of the Related Art Conventionally, wind turbines for small wind power generators have blades made of hard materials such as wood and fiber-reinforced plastic.

[0003]

However, the blades used in conventional wind turbines for small wind power generators are made of a hard material, so that when the blades of a rotating wind turbine are destroyed. However, there was a high possibility that secondary destruction would occur when the shards of the blade scattered around and collided. Also, when the rotation speed of the wind turbine blades is increased, the wind noise is increased and a noise problem occurs. Furthermore, since the weight of the windmill blades is heavy, there is also a problem that the response time from the start of the wind to the start of rotation of the windmill blades is long, resulting in poor mobility. The present invention has been made in view of such circumstances, and even if destruction of the blade occurs during rotation of the windmill and fragments of the blade scatter around, the occurrence of secondary damage is suppressed and noise during rotation is small, and furthermore, An object of the present invention is to provide a wind turbine for a small wind power generator having excellent mobility in response to fluctuations in wind speed and direction.

[0004]

According to the present invention, there is provided a wind turbine for a small wind turbine having a plurality of blades for converting wind power into rotational force. The blade has a blade body that generates a rotational force in response to wind, and a blade mounting member fixed to the blade body and mounting the blade body to a rotation shaft of the windmill, and the blade body is made of a porous flexible material. Is formed.

[0005] The porous flexible material has mechanical properties such as being light, easily deformable, and easily absorbing vibration.
Therefore, by using the porous flexible material, the weight of the blade portion of the wind turbine can be reduced, and the mobility of the wind turbine that responds sensitively to fluctuations in wind speed, wind direction, and the like can be improved. Further, even if the rotating blade is broken and the fragments of the blade scatter around, the weight of the fragments is light and soft, so that secondary damage is reduced even if the fragments of the scattered blade collide. Further, wind noise of a windmill is generated when air vortices called Karman vortices are regularly generated on the trailing edge side of the blades, and the blades vibrate due to pressure fluctuations caused by the vortices. Since the blade according to the present invention is formed of a porous flexible material, even if the blade vibrates due to pressure fluctuation when a vortex is generated, the energy of this vibration is immediately absorbed by the blade body and attenuated. It is considered that the vibration of the blades does not continue and continuous wind noise is unlikely to occur. As a porous flexible material having such properties, for example, there is a foamed polypropylene resin.
15 times, apparent density 0.08-0.2g / cm ³ , S
25 hardness by RIS0101 spring hardness tester
~ 70 degrees.

In the wind turbine for a small wind power generator according to the present invention, it is preferable that the porous flexible material is a chlorine-free porous synthetic resin. Since a chlorine-free porous synthetic resin is used, a blade having a complicated shape can be easily formed by injecting the porous synthetic resin into a mold. In addition, since it is a non-chlorine resin, even if incineration of used blades is performed, environmental pollution due to generation of dioxin does not occur, and disposal of the discarded blades becomes easy.

In the wind turbine for a small wind power generator according to the present invention, the blade mounting member is provided in the blade main body to support the blade main body, and the blade mounting member is provided at one end of the support portion. It is preferable to have a fixing portion for fixing the blade main body to the rotation shaft. When the wings begin to rotate,
A centrifugal force is generated in the blade body with the rotation. Due to this centrifugal force, a tensile stress is generated in the blade main body, and even if the blade main body formed of the porous flexible material is supported only from the inside by the support portion, the predetermined shape is maintained during rotation. Becomes possible. In addition, since the blade body is supported only from the inside by the support portion, when the wind speed is increased, the rotation speed of the windmill is increased, and the resistance of the blade body to wind is improved, the blade body is easily deformed. As a result, the angle of opposition of the blade body to the flow of the wind increases, and the effective area of the blade body that receives the wind increases (the blade stands up in the direction of the wind). When each blade stands in the direction of the wind, the rotation resistance of the windmill increases, and the rotation speed of the windmill decreases. Therefore, the wind turbine can change the shape of the blade main body in accordance with the number of rotations, and can perform self-control so that excessive rotation does not occur.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1A is a side view showing a conceptual structure of a small wind generator to which a wind turbine for a small wind generator according to an embodiment of the present invention is applied, and FIG. 2A is a partial cross-sectional view showing a conceptual structure, FIG. 2A is a side cross-sectional view of each part of a blade of a wind turbine for a small wind turbine according to an embodiment of the present invention, and FIG. FIG. 3C is a plan view, and FIG. 3C is a front view of the blade of the wind turbine. Figure 1
As shown in (a) and (b), a small wind turbine 10 to which a wind turbine 11 for a small wind generator according to an embodiment of the present invention is applied includes a wind turbine 11 that converts wind power into rotational force, An AC power generation unit 12 that converts the rotational energy of the windmill 11 into electric energy is provided. Hereinafter, these will be described in detail.

The windmill 11 converts wind power into rotational force, for example, three blades 13, and a flywheel 19 to which each blade 13 is attached and converts the rotational force generated by each blade 13 into rotational energy and accumulates it. , A rotary shaft 14 of the windmill 11 provided on the flywheel 19. Further, the blade 13 is a blade main body 15 that generates a rotational force by receiving wind.
And a blade mounting member 16 for mounting the blade body 15 to a flywheel 19 provided with the rotation shaft 14 of the windmill 11.
And Further, the blade mounting member 16 includes a support portion 17 (see FIG. 2) which is provided in each blade main body 15 and supports the blade main body 15 from the inside, and a fixing portion 18 provided on one end side of the support portion 17. Have. In this way, the blade body 15 is fixed to the flywheel 19 by the fixing portion 18.
Fixed to With the above configuration, the flywheel 19
The blade main body 15 is attached to the rotating shaft 14 via the. The rotating shaft 14 is provided so as to penetrate the flywheel 19, and at the tip of the rotating shaft 14, for example, a male screw portion 20 is provided.
Is formed, and a protective cover 21 made of, for example, a synthetic resin and having a female screw portion to be screwed into the male screw portion 20 is attached.

As shown in FIGS. 2A to 2C, the blade body 15 has a wing-shaped cross section.
Are, for example, 500-700 mm in length and 110 in width.
mm to 150 mm and a maximum thickness of 15 to 20 mm. Further, as shown in FIG. 2A, the rising angle of the base end of the blade main body 15 with respect to the flow of the wind is large, gradually decreasing toward the tip end, and the rising angle with respect to the flow of the wind at the tip is minimized. ing. Therefore, the blade body 1
5 is decomposed into a plurality of parts, each part is formed of a non-chlorine-based porous synthetic resin, for example, a foamed polypropylene resin, which is an example of a porous flexible material, and these parts are combined to manufacture the blade body 15. Do. For example, the blade body 15
The outer shape on one side and the outer shape on the other side are transferred to the inside of each blade body 15 side, and the outer shape on one side and the other side on the inner side of the support portion 17 installed are respectively The molds on the side of each support portion 17 transferred to the outside are produced, and the corresponding molds are combined with each other to form each mold.
Next, each part is obtained by injecting and solidifying a foamed polypropylene resin into each molding die and demolding each mold. The blade body 15 is formed by laminating the components on one side and the other side of the obtained blade body 15. In addition, each outer mold and each inner mold for molding are manufactured by cutting out from a mold material using a three-dimensional processing machine such as a machining center to which three-dimensional coordinate values representing the outer shapes of the blade body 15 and the support part 17 are input. can do.

The support portion 17 provided inside the blade body 15 and supporting the blade body 15 from the inside, and the fixing portion 18 provided at one end of the support portion 17 have a thickness of, for example, 3 to 5 mm.
The aluminum alloy plate is processed to be integrally formed.
The support portion 17 provided inside the blade main body 15 is
Is gradually changed from the base end side to the front end side, so that the shape of the support portion 17 is produced in accordance with this change in shape. Further, the fixing portion 18 is provided with a plurality of bolt insertion holes 22 for fixing to the flywheel 19. Support part 1
Each of the components of the blade main body 15 formed of a foamed polypropylene resin is bonded to each other with, for example, an epoxy resin adhesive to form the blade main body 15 having the support portion 17 therein. The blade 13 provided with the fixing portion 18 of the blade mounting member 16 attached to the flywheel 19 on the side can be configured. Therefore, the blade 1
3 are arranged between a pair of holding plates 23 provided on the flywheel 19 and fixed with bolts, whereby the respective blades 13 are fixed.
Can be fixed to the flywheel 19. As a result, the rotational force generated by each blade 13 due to the wind force is
The energy is transmitted to the flywheel 19 and accumulated as rotational energy, so that the rotating shaft 14 of the windmill 11 can be rotated.

The alternating-current power generation unit 12 is a rotating shaft 1 of the windmill 11.
An AC generator 24 having an input shaft (not shown) to which the AC generator 4 is connected and an installation table 25 on which the AC generator 24 is installed. The installation table 25 on which the AC generator 24 is installed has an output cable (not shown) for taking out the power generated by the AC generator 24 through the bearing 26, for example, a length of 15 to 20 m. It is supported by support columns 27. The AC power generation unit 12 and the support column 2
The upper side of 7 is covered with a protective cover 28 made of, for example, a synthetic resin having a gap between the support pillar 27 and the support pillar 27. With such a configuration, the rotation of the windmill 11 is
The power is transmitted to the AC generator 24 via the power generator 4 to generate power, and the generated power is input to a power storage facility (not shown) via an output cable. Since the support column 27 and the mounting table 25 of the AC generator 24 are connected via the bearing 26, when the wind direction changes, the windmill 11 and the AC generator unit 12 follow the wind direction and are integrated. The direction can be freely changed, and each blade 13 of the windmill 11 always rotates more efficiently.

Next, the operation of the wind turbine 11 for a small wind power generator according to one embodiment of the present invention will be described in detail. When the wind blows on the installed small wind power generator 10, the blade 1
The wind turbine 11 starts rotating when the wind turbine 3 receives the wind, and the wind turbine 11 changes the direction of the wind turbine 11 so that an efficient rotational driving force is obtained from the blade 13 with respect to the wind direction. As the rotation speed of the blades 13 increases, the centrifugal force acting on the blade main body 15 also increases, and the centrifugal force improves the shape retention of the blade main body 15. The shape of the main body 15 can be maintained. When the windmill 11 has three blades 13 and the diameter of the windmill 11 is 1.5 m, for example, power generation starts at a wind speed of 3.5 m / sec or more.

As the rotation speed of the windmill 11 increases,
A Karman vortex is generated on the trailing edge side of the rotating blade body 15,
When this vortex separates from the blade main body 15, pressure fluctuation occurs, and the trailing edge side of the blade main body 15 vibrates. However, since the blade body 15 is formed of the foamed polypropylene resin, even if the trailing edge side of the blade body 15 vibrates, the energy of the vibration is immediately absorbed by the foamed polypropylene resin forming the blade body 15 and attenuated. Therefore, the vibration on the trailing edge side of the blade main body 15 does not continue, and no continuous wind noise is generated. For this reason, the noise from the rotating windmill 11 becomes very small.

As the wind speed further increases, the rotation speed of the windmill 11 increases, but at the same time, the resistance acting on the blade body 15 also increases. Since the blade body 15 is formed of a foamed polypropylene resin, when the resistance force acting on the blade body 15 increases, the deformability due to this resistance exceeds the shape retention of the blade body 15 due to the centrifugal force of rotation, and The main body 15 stands in the direction of the wind. For this reason, the effective area of the blade main body 15 receiving the wind increases, the rotational resistance of the windmill 11 further increases, and the rotational speed of the windmill 11 decreases. Therefore, even if the wind speed fluctuates greatly, the wind turbine 11 does not become overspeed, but can always rotate around the rated speed around the rated wind speed. For example, when the windmill 11 has three blades 13 and the diameter of the windmill 11 is 1.5 m, the rated wind speed is 9 m / sec and the rated output is 200 W.

The embodiments of the present invention have been described above.
The present invention is not limited to this embodiment,
For example, although a foamed polypropylene resin is used as the non-chlorine-based porous synthetic resin, a foamed ethylene resin or a sponge-like synthetic rubber may be used. Further, although the number of blades is three, two or four or more blades may be used.

[0017]

According to the first to third aspects of the present invention, in the wind turbine for a small wind power generator, each blade receives a wind to generate a rotational force, and the blade main body is fixed to the blade main body and is connected to the rotating shaft of the wind turbine. The present invention provides a safe and quiet wind turbine that has excellent responsiveness to fluctuations in wind speed and direction because the blade body is formed of a porous flexible material. Becomes possible.

In particular, in the wind turbine for a small wind power generator according to the second aspect, since the porous flexible material is a chlorine-free porous synthetic resin, the blade body can be manufactured at low cost, Waste can be treated at low cost.

According to a third aspect of the present invention, in the wind turbine for a small wind power generator, the blade mounting member includes a support portion provided in the blade body for supporting the blade body, and a blade body provided at one end of the support portion. With a fixed part fixed to the rotating shaft, the blade body gradually deforms during rotation to prevent over-rotation of the wind turbine, maintaining rated operation and preventing destruction of the wind turbine Becomes

[Brief description of the drawings]

FIGS. 1A and 1B are side views showing a conceptual structure of a small wind turbine to which a wind turbine for a small wind generator according to an embodiment of the present invention is applied, and FIG. It is a partial front view showing a conceptual structure.

FIGS. 2 (a), (b), and (c) are side sectional views of respective portions of a blade of a wind turbine for a small wind turbine according to an embodiment of the present invention, and plan views of the blade of the wind turbine. It is a front view of the blade of the windmill.

[Explanation of symbols]

10: small wind power generator, 11: windmill, 12: AC power generation unit, 13: blade, 14: rotating shaft, 15: blade body, 1
6: blade mounting member, 17: support portion, 18: fixing portion, 1
9: Flywheel, 20: Male thread, 21: Protective cover, 22: Bolt insertion hole, 23: Holding plate, 24: Alternating current generator, 25: Installation stand, 26: Bearing, 27: Support column, 28: Protection cover

Claims (3)

[Claims] 1. A wind turbine for a small wind turbine having a plurality of blades for converting wind power into rotational force, wherein each of the blades receives a wind to generate a rotational force, and is fixed to the blade body. A blade mounting member for mounting the blade main body to a rotating shaft of the wind turbine, wherein the blade main body is formed of a porous flexible material. 2. The wind turbine for a small wind power generator according to claim 1, wherein the porous flexible material is a chlorine-free porous synthetic resin. 3. The wind turbine for a small wind power generator according to claim 1, wherein the blade mounting member is provided in the blade main body to support the blade main body, and one end of the support portion. A wind turbine for a small wind power generator, comprising: a fixing portion provided on a side of the blade to fix the blade main body to the rotating shaft.