JP5709628B2 - Windmill wing - Google Patents

Description

  The present invention relates to a wind turbine blade.

In recent years, wind power generators have become larger in order to improve power generation efficiency and increase power generation. As the wind turbine generator becomes larger, the wind turbine blades also become larger. For example, the blade length is 40 meters or more and the maximum blade width is more than 4 meters. In search of further increase in power generation, the blade length and blade width tend to be larger.
When the wind turbine blades are increased in size in this way, various problems in production and transportation arise. That is, in order to reduce the weight of the wind turbine blade, for example, it is manufactured from plastic reinforced with fibers, but when the sheet to be manufactured is enlarged, fiber wrinkles, resin non-impregnated defects, poor adhesion, etc. during manufacture There is a risk that the production defects will be increased and the product quality will be reduced. In addition, the manufacturing time becomes longer.

Transportation from a manufacturing plant to a construction site is difficult because of restrictions on vehicles, roads, etc., especially in land transportation. Even if transportation is possible, the transportation cost increases due to, for example, the handling of an extra large heavy machine.
In the case of a wind turbine blade having an integral structure, even if a part is damaged during operation, the whole is replaced.
In order to solve this problem, for example, as disclosed in Patent Document 1, a wind turbine blade that is divided in the longitudinal direction has been proposed. This is because a single windmill blade is formed by firmly connecting the divided beams of the windmill blade.
In addition, as shown in Patent Document 2, it has been proposed that a wide portion on the blade root side is further divided into a leading edge side member and a trailing edge side member in the width direction. In this state, the divided front edge side member and rear edge side member are fixed in a state where a seam cannot be formed.

JP 2010-59884 A Special table 2009-536704 gazette

The wind turbine blade in operation is greatly bent so that the tip is directed downstream of the wind direction due to the wind pressure, and when receiving the wind and rotating, it receives a tensile load due to centrifugal force. Large expansion and contraction, that is, bending deformation.
By the way, in the thing shown by patent document 2, since the load toward a longitudinal direction acts on the trailing edge side member by the deformation | transformation of the longitudinal direction of the leading edge side member integrally attached to the blade top side, the divided trailing edge side The member must be strong enough to withstand it. For this reason, since it is necessary to make a trailing edge side member into a firm structure, a structure will become complicated and a weight will also increase. Further, since the trailing edge side member is also deformed, there is a risk of adversely affecting aerodynamic performance and aerodynamic noise.

  In view of the above circumstances, the present invention provides a wind turbine blade that can suppress manufacturing and transportation restrictions, and can reduce weight and suppress deterioration of performance and noise.

The present invention employs the following means in order to solve the above problems.
One aspect of the present invention is a wind turbine blade comprising an outer skin that forms a long hollow space having an airfoil in cross section, and a girder that is longitudinally reinforced to reinforce the outer skin from the inside. The blade root side portion of the outer skin is divided into an outer skin body including a front edge in the width direction and a divided outer skin including a rear edge, and the front edge side end portion of the divided outer skin is movable in the longitudinal direction with respect to the outer skin body. before Kigaihi attached to edge end portion after the body is reinforced at the position where the rear edge end portion of the outer skin body close to該桁by該桁with projecting the rear edge side than the digit it is a wind turbine blades while creating.

According to the wind turbine blade according to this aspect, since it is manufactured by the unit of the outer skin main body and the divided outer skin divided in the width direction, it can be manufactured easily, inexpensively and with high quality as compared with those manufactured integrally. Can do.
Moreover, since it is conveyed by the manufactured unit, the constraints in the width direction are relaxed. As a result, securing a transport vehicle, selecting a road, and the like are facilitated and efficient transport can be performed, so that the transport work time and cost can be reduced.

  The split outer skin is attached to the outer skin main body or the girder so that it can move in the longitudinal direction with respect to the outer skin main body. For example, it is attached so as not to move relatively in the width direction. Therefore, even if the outer shell main body and the girder are deformed so as to expand and contract in the longitudinal direction during operation, the split outer shell moves relative to the longitudinal direction, so that it is possible to prevent the longitudinal load from acting on the split outer shell. Can do. Thereby, since the structure of a division | segmentation outer skin can be simplified and it can reduce in weight, a windmill blade can be reduced in weight.

Further, since the divided outer skin does not move relative to the outer skin main body in the width direction, it is possible to suppress deterioration of performance and noise.
When a part of the outer surface of the wind turbine blade is damaged, it is only necessary to replace the outer skin main body or the divided outer skin where the damaged portion exists, so that the restoration is easier and cheaper than when the whole is replaced. it can.
In addition, when connecting the divided skin using a coupling member such as a bolt, the head of the coupling member should not protrude from the outer surface of the outer skin body or the divided skin, in other words, in a state where the divided skin is coupled by the coupling member. It is preferable to make the outer surface smooth. If it does in this way, degradation of performance and noise can be controlled further.

In the above aspect, the divided skin may overlap with the skin body facing in the width direction.
If it does in this way, a division | segmentation outer skin can be couple | bonded so that a level | step difference may not come out in a coupling | bond part with an outer skin main body, and degradation of performance and noise can be suppressed.

In the aspect described above, the split skin may be provided with split skin girders that are vertically run in the longitudinal direction and reinforce the split skin from the inside.
In this way, the strength can be maintained even if the divided skin is thinned. Thereby, since the deformation | transformation of a division | segmentation outer skin can be suppressed, deterioration of a performance and noise can be suppressed.

In the above aspect, at least the main body skin and the beam may be divided in the longitudinal direction.
In this way, since the manufacturing unit can be made smaller, it is possible to manufacture easily, inexpensively and with high quality as compared with a unit manufactured integrally.
Moreover, since it is conveyed by the manufactured unit, the constraints in the longitudinal direction are relaxed. As a result, securing a transport vehicle, selecting a road, and the like are facilitated and efficient transport can be performed, so that the transport work time and cost can be reduced.
Further, if the manufactured unit is small, the weight of each unit becomes lighter, so that handling at the time of repair including replacement becomes easier.

In the above aspect, the divided skin may be constituted by a partially divided skin divided in the longitudinal direction, and the partially divided skins may be movably attached to each other.
If it does in this way, since joining of a partial division outer skin is not fixed, it can prevent that an excessive load is applied to a specific joined part.

In the above aspect, the divided skin may be constituted by partially divided skins divided in the longitudinal direction, and the partially divided skins may be attached so as to be fixed by a coupling means.
If it does in this way, since there is no sliding part between partial division | segmentation outer skins, durability and reliability of a joint surface can be improved.

In the above aspect, a drain hole that connects the space and the external space may be formed at a rear edge side end portion of the divided skin.
When water enters the wind turbine blade structure due to rain or the like, the water can be discharged to the outside through the drain hole.
Thus, since the drain hole is provided in the division | segmentation outer skin, the process of a drain hole is easy. Moreover, even if a defect occurs in the drain hole, it is only necessary to replace the divided outer cover, so that the replacement is easy.

In the embodiment, the divided outer skins, attached by a coupling member having conductivity, may be linked by a ground wire and a main body ground installed in at least a portion the space of the coupling member.
When a lightning strike occurs in the coupling member and the vicinity thereof, a lightning current can be passed to the main body ground via the coupling member and the ground wire, so that it is possible to prevent damage to the divided outer skin and the like due to the lightning stroke.

According to the present invention, since it is manufactured in units of the outer skin main body and the divided outer skin divided in the width direction, it can be manufactured easily, inexpensively and with high quality as compared with those manufactured integrally.
Moreover, since it is conveyed by the manufactured unit, shortening of conveyance work time and cost can be achieved.
The split outer skin is attached to the outer skin main body or girders so that it can move in the longitudinal direction with respect to the outer skin main body, so that the structure of the split outer skin can be simplified and the weight can be reduced, and the wind turbine blades can be reduced in weight. Can be Further, since the divided outer skin does not move relative to the outer skin main body in the width direction, it is possible to suppress deterioration of performance and noise.
When a part of the outer surface of the wind turbine blade is damaged, it is only necessary to replace the outer skin main body or the divided outer skin where the damaged portion exists, so that the restoration is easier and cheaper than when the whole is replaced. it can.

It is a side view which shows the whole schematic structure of the wind power generator concerning 1st embodiment of this invention. It is a perspective view which shows the windmill blade concerning 1st embodiment of this invention. It is XX sectional drawing of FIG. It is a fragmentary sectional view which expands and shows the Y section of FIG. FIG. 5 is a partial plan view of FIG. 4. It is explanatory drawing which shows the fastening state of FIG. It is a fragmentary top view which shows the fastening part of FIG. It is a fragmentary sectional view which shows another aspect of the coupling | bond part concerning 1st embodiment of this invention. It is a fragmentary sectional view which shows another aspect of the coupling | bond part concerning 1st embodiment of this invention. It is a fragmentary sectional view which shows another aspect of the coupling | bond part concerning 1st embodiment of this invention. It is a perspective view which shows the windmill blade concerning 2nd embodiment of this invention. It is a side view which shows the division | segmentation outer skin concerning 3rd embodiment of this invention. It is ZZ sectional drawing of FIG. It is sectional drawing which shows the windmill blade concerning 4th embodiment of this invention. It is a figure which shows the principal part of the windmill blade concerning other embodiment of this invention, Comprising: (a) is sectional drawing, (b) is an AA arrow directional view.

Embodiments of the present invention will be described below with reference to the drawings.
[First embodiment]
The wind power generator 1 concerning 1st embodiment of this invention is demonstrated based on FIGS.
FIG. 1 is a side view showing an overall schematic configuration of the wind turbine generator 1.
As shown in FIG. 1, the wind power generator 1 includes a support column 5 standing on the foundation 3, a nacelle 7 installed at the upper end of the support column 5, and a nacelle 7 that can rotate around a substantially horizontal axis. And a plurality of, for example, three wind turbine blades 11 attached radially around the rotation axis of the rotor head 9.

The wind force that hits the wind turbine blades 11 from the direction of the rotation axis of the rotor head 9 is converted into power that rotates the rotor head 9 about the rotation axis.
Inside the nacelle 7, although not shown in the drawings, a generator connected to the rotor head 9 via a coaxial gearbox is installed. That is, by rotating the rotor head 9 with a speed increaser and driving the power generator, an electrical output can be obtained from the power generator.

FIG. 2 is a perspective view showing the wind turbine blade 11. 3 is a cross-sectional view taken along the line XX of FIG. FIG. 4 is an enlarged partial cross-sectional view showing a Y portion in FIG. FIG. 5 is a partial plan view of FIG.
The wind turbine blade 11 includes a skin 13 that defines a long hollow blade shape, and a plurality of, for example, two main girders (girder) that are longitudinally passed in the longitudinal direction L inside the skin and reinforce the strength of the skin 13. 15).
The main girders 15 and 15 are attached so that their cross-sectional shapes are U-shaped and their open portions face each other.
The main girders 15 and 15 are made of, for example, glass fiber reinforced plastic. In addition, as these materials, it is good also as a carbon fiber reinforced plastic, for example, and you may use another raw material.

The outer skin 13 includes an outer skin body 19 including a front edge 17 and a divided outer skin 23 including a rear edge 21. The divided skin 23 is installed on the blade root side portion of the skin 13. Therefore, the blade root side portion of the outer skin 13 is divided into two in the width direction B into an outer skin body 19 including the front edge 17 and a divided outer skin 23 including the rear edge 21.
The outer skin body 19 and the divided outer skin 23 are made of, for example, fiber reinforced plastic (FRP) reinforced with fibers such as glass fiber reinforced plastic or carbon fiber reinforced plastic.

The outer skin main body 19 is formed by combining two halves of a back skin and a ventral skin. The position corresponding to the divided outer skin 23 of the outer skin main body 19 forms an open portion with the rear edge 21 side end projecting toward the rear edge 21 rather than the main girder 15 on the rear edge 21 side. That is, the outer skin body 19 is reinforced by the main girders 15 and 15.
A main body coupling portion 25 in which a part on the inner surface side protrudes in a rectangular cross section is provided at a rear edge 21 side end portion of the outer skin body 19 at a position corresponding to the divided skin 23.

The divided skin 23 has a structure in which two halves of a back skin and a ventral skin are joined by a rear edge 21 and the front edge 17 side is open. The split skin 23 is provided with a split skin girder 27 extending in the longitudinal direction L at an intermediate position in the width direction B in order to reinforce the structure from the inside.
When the split outer girder 27 is provided, the shape of the split outer shell 23 can be maintained even if the dorsal and ventral outer shells forming the outer shape of the split outer shell 23 are thinned, and they are deformed even when a load is applied. Can be suppressed.
Note that the divided hull girder 27 may be omitted when the divided hull 23 is configured to have a required strength.

A split coupling portion 29 in which a part on the outer surface side protrudes in a rectangular cross section is provided at the end portion on the front edge 17 side of the split skin 23.
The main body coupling portion 25 and the split coupling portion 29 are overlapped as shown in FIG. The division | segmentation outer skin 23 is made to overlap with the outer skin main body 19 which opposes the width direction B mutually.

The height from the outer surface of the outer skin main body 19 to the main body coupling portion 25 and the thickness of the split coupling portion 29 are the coupling portion 31, and the outer surface of the split coupling portion 29 is flush with the outer surface of the outer skin body 19. It is made the size.
In this way, by adjusting the depth of the main body coupling portion 25 and the thickness of the division coupling portion 29, the outer surface of the divided outer skin 23 and the outer surface of the outer skin main body 19 are coupled so as not to have a step. be able to.

A plurality of long holes 33 that are long in the longitudinal direction L are provided in the split coupling portion 29 at intervals in the longitudinal direction L. The distance between the adjacent long holes 33 is set to be twice or more the distance K1 from the front edge 17 side end of the split coupling portion 29 to the long hole 33. A peripheral portion of the long hole 33 is an inclined surface 35.
A cylindrical hole 37 is formed in the main body coupling portion 25 at a position corresponding to the long hole 33 so as to penetrate in the thickness direction.

The main body coupling portion 25 and the split coupling portion 29 are configured to be coupled by a coupling member 39.
The coupling member 39 includes a bolt 41 and a nut 43 that is screwed into the bolt 41. The bolt 41 is provided with a shaft portion 45 and a head portion 47 which are male threaded.
The diameter of the shaft portion 45 is substantially equal to the length B in the width direction of the long hole 33 and the diameter of the hole 37. The upper surface of the head 47 is flat, and the lower surface is inclined so as to engage with the inclined surface 35.

As shown in FIG. 6, the outer skin main body 19 and the divided outer skin 23 are arranged such that the main body coupling portion 25 and the divided coupling portion 29 are in a relationship such that the long hole 33 and the hole 37 coincide with each other. 4 and is connected as shown in FIG. 4 by screwing a nut 43 into the bolt 41.
At this time, since the length K in the longitudinal direction L of the long hole 33 is made larger than the diameter of the shaft portion 45 of the bolt 41, the divided skin 29 can move in the longitudinal direction L with respect to the skin body 19. it can.

In the present embodiment, the main body coupling portion 25 and the split coupling portion 29 protrude in a rectangular cross section and are stacked one above the other. However, the present invention is not limited to this.
For example, as shown in FIG. 8, the main body coupling portion 25 may be provided on the outer side and the inner side of the outer skin main body 19 so as to sandwich the split coupling portion 29 provided at an intermediate position in the thickness direction.
Further, as shown in FIG. 9, the opposing surfaces of the main body coupling portion 25 and the split coupling portion 29 may be inclined surfaces and may be engaged in a wedge shape.

The wind turbine blade 11 configured as described above is manufactured easily, inexpensively, and with high quality as compared with the one manufactured integrally because the outer shell body 19 and the divided outer shell 23 are independently manufactured. Can do.
That is, the mold for manufacturing the outer skin main body 19 and the divided outer skin 23 can be made compact. For this reason, since quality control can fully be performed, the quality of a product improves. Furthermore, since the amount of waste due to a manufacturing error is reduced, the product yield is improved. Moreover, the place which manufacture requires can be made small.

The manufactured outer skin body 19 and the divided outer skin 23 are transported to the installation location of the wind turbine generator 1.
At this time, the outer skin main body 19 or the divided outer skin 23 is smaller in length in the width direction B and smaller in weight than the integrated wind turbine blade 11, so that it is easy to secure a transport vehicle, select a road, and the like. . Thereby, since efficient conveyance can be performed, the conveyance work time can be shortened and the cost can be reduced.
The outer skin main body 19 and the divided outer skin 23 transported to the installation place are connected by a coupling member 39 to form a wind turbine blade 11 and attached to the rotor head 9.

When the main body outer skin 19 and the main girders 15 and 15 are long in the longitudinal direction L, the main body outer skin 19 and the main girders 15 and 15 may be divided in the longitudinal direction L.
In this way, since the manufacturing unit can be made smaller, it is possible to manufacture easily, inexpensively and with high quality as compared with a unit manufactured integrally.
Moreover, since it is conveyed by the manufactured unit, the constraints in the longitudinal direction are relaxed. As a result, securing a transport vehicle, selecting a road, and the like are facilitated and efficient transport can be performed, so that the transport work time and cost can be further reduced.

  When the wind turbine generator 1 manufactured in this way is operated, the wind turbine blade 11 receives wind pressure and bends greatly so that the tip is directed to the downstream side of the wind direction as shown by a two-dot chain line in FIG. Moreover, when receiving wind and rotating, it receives a tensile load due to centrifugal force. As a result, the wind turbine blade 11 greatly expands and contracts in the longitudinal direction L, that is, bends and deforms. Accordingly, the outer skin body 19 and the main girders 15 and 15 are deformed so as to expand and contract in the longitudinal direction L.

Thus, even if the outer skin body 19 and the main girders 15 and 15 are deformed so as to expand and contract in the longitudinal direction L, the coupling member 39 moves in the longitudinal direction L along the long hole 33 of the divided skin 23, in other words, Since the outer skin body 19 and the divided skin 23 are relatively moved in the longitudinal direction L, it is possible to prevent the load in the longitudinal direction L from acting on the divided skin 23.
Thereby, since the structure of the division | segmentation outer skin 23 can be simplified and it can reduce in weight, the windmill blade 11 can be reduced in weight.

The length K in the axial direction L of the plurality of long holes 33 is calculated by analyzing the maximum strain in the longitudinal direction L of the outer skin main body 19 at the position of each long hole 33. It may be a size that can cover. In this way, the length K of each elongated hole 33 is not unnecessarily increased, so that the strength of the divided outer shell 23 can be increased or the weight can be further reduced.
Further, by analysis, the maximum strain in the longitudinal direction L of the outer skin main body 19 at the position of each long hole 33 is calculated, and the largest of the calculated maximum strains is set as the length K of the long hole 33. May be.
If it does in this way, since all the length of the long hole 33 can be made into the same thing, it can construct easily.

Further, since the shaft portion 45 of the bolt 41 has a diameter substantially equal to the length B in the width direction of the long hole 33, the bolt 41 does not move in the width direction B of the long hole 33. That is, since the split outer skin 23 does not move relative to the outer skin body 19 in the width direction B, it is possible to suppress degradation of the aerodynamic performance and noise of the wind turbine blade 11.
When a part of the outer surface of the wind turbine blade 11 is damaged, it is only necessary to replace the outer shell body 19 or the divided outer shell 23 in which the damaged portion is present, so that the recovery is easier than when the entire wind turbine blade 11 is replaced. Can be done inexpensively.

The head 47 of the bolt 41 does not protrude from the outer surface of the outer skin main body 19 or the divided outer skin 23, in other words, the outer surface is made smooth in a state where the divided outer skin 23 is coupled by the coupling member 39, And since the division | segmentation outer skin 23 is couple | bonded so that a level | step difference may not come out in the coupling | bond part with the outer skin main body 19, degradation of aerodynamic performance and noise can be suppressed further.
Since the divided skin 23 is reinforced from the inside by the divided skin girder 27, strength can be maintained even if the divided skin 23 is thinned, and deformation of the divided skin 23 can be suppressed, so that aerodynamic performance and noise are deteriorated. Can be suppressed.

In the present embodiment, the divided outer skin 23 is attached to the outer skin main body 19, but it may be attached to the main beam 15 as shown in FIG. 10.
The outer skin body 19 has a size up to the main girder 15 on the rear edge 21 side in the width direction B, and the end portion on the rear edge 21 side is a substantially vertical surface. The division | segmentation outer skin 23 is made into the magnitude | size to the location of the main girder 15 by the side of the rear edge 21 in the width direction B, The front edge 17 side edge part is made into the substantially perpendicular | vertical surface.
A long hole 33 shown in FIG. 5 is formed in the split outer shell 23, and a hole 37 shown in FIG. 7 is formed in the main girder 15. The split outer shell 23 is joined to the main girder 15 by a connecting member 39. Has been.
In this way, the divided outer skin 23 is attached to the main girder 15 which is stronger than the outer skin main body 19, so that the reliability of the coupling structure can be improved.

[Second Embodiment]
Next, the windmill blade 11 concerning 2nd embodiment of this invention is demonstrated using FIG.
In the present embodiment, since the configuration of the divided outer shell 23 is different from that of the first embodiment, this different part will be mainly described here, and the same part as that of the first embodiment described above will not be repeated. In addition, the same code | symbol is attached | subjected to the same member as 1st embodiment.
FIG. 11 is a perspective view showing the wind turbine blade 11 according to the present embodiment.

In the present embodiment, the divided skin 23 is composed of a plurality of, for example, three partially divided skins 49 divided in the longitudinal direction L. The partially divided outer skins 49 are coupled to each other by a coupling member 51. The coupling member 51 is coupled so as to suppress the partial division outer skins 49 from moving with respect to each other.
Thereby, the division | segmentation outer shell 23 operate | moves as integral.

The divided skins 23 are formed by manufacturing the three partially divided skins 49 and connecting them by the joining member 51 at the manufacturing factory or the installation location of the wind power generator 1.
As described above, the unit for manufacturing the split outer shell 23 is smaller than the partial split outer shell 49, so that it can be manufactured more easily, inexpensively and with high quality. In addition, the partial replaceability is further improved and the transportation becomes easier.

[Third embodiment]
Next, the windmill blade 11 concerning 3rd embodiment of this invention is demonstrated using FIG. 12 and FIG.
In the present embodiment, since the configuration of the divided outer shell 23 is different from that of the first embodiment, this different part will be mainly described here, and the same part as that of the first embodiment described above will not be repeated. In addition, the same code | symbol is attached | subjected to the same member as 1st embodiment.
FIG. 12 is a side view showing the divided skin 23 according to the present embodiment. FIG. 13 is a ZZ cross-sectional view of FIG.

In the present embodiment, a drain hole 55 that connects the internal space (space) 53 and the external space is formed at the end portion of the divided skin 23 on the rear edge 21 side.
The drain hole 55 is for discharging water to the outside when water enters the structure inside the wind turbine blade 11 due to rain or the like.

  Thus, since the drain hole 55 is provided in the division | segmentation outer skin 23, the process of the drain hole 55 is easy. Further, even when a defect occurs in the drain hole 55, it is only necessary to replace the split outer shell 23, so that the replacement is easy.

[Fourth embodiment]
Next, the windmill blade 11 concerning 4th embodiment of this invention is demonstrated using FIG.
In the present embodiment, the configuration of the wind turbine blade 11 is different from that of the first embodiment. Therefore, the different portions will be mainly described here, and the same portions as those of the first embodiment described above will not be repeated. In addition, the same code | symbol is attached | subjected to the same member as 1st embodiment.
FIG. 14 is a cross-sectional view showing the wind turbine blade 11 according to the present embodiment.

In this embodiment, the division | segmentation outer skin 23 is attached to the main beam 15 with the coupling member 56, as FIG. 10 shows.
The coupling member 39 is made of a conductive material, for example, a metal. The coupling member 39 may be a conductive material and may be made of resin.
A main body ground wire (main body ground) 57 is attached to the main girder 15 on the front edge 17 side over substantially the entire length. Among the plurality of coupling members 39, at least a part of the joining members 39 and the main body ground wire 57 are connected by a ground wire 59.

In the wind turbine blade 11 according to the present embodiment configured as described above, when there is a lightning strike in the coupling member 39 and the vicinity thereof, a lightning strike current is caused to flow to the main body ground wire 57 via the coupling member 39 and the ground wire 59. Guide to the outside through the ground wire 57.
In this way, since the lightning current accompanying lightning strikes on the split outer shell 23 can be guided to the outside through the coupling member 39, the ground wire 59 and the main body ground wire 57, damage to the split outer shell 23 and the like due to the lightning strike can be prevented. .

In addition, this invention is not limited to each embodiment mentioned above, In the range which does not deviate from the summary, it can change suitably.
For example, as shown in FIG. 15, in the above-described second embodiment, it is more preferable that the partially divided outer skins 49 are attached so as to be movable with respect to each other.
If it does in this way, since joining of partial division skin 49 is not fixed, it can prevent that an excessive load is applied to a specific joined part.
Here, reference numeral 71 in FIG. 15 is a bolt, reference numeral 72 is a nut, reference numeral 73 is a through hole provided in one partial division outer skin 49, and reference numeral 74 is a through hole provided in the other partial division outer skin 49. .
The through holes 73 and 74 are round holes each having a circular shape in plan view, and the through hole 73 is formed so that the inner diameter thereof is larger than the inner diameter of the through hole 74.

11 Windmill blade 13 Outer skin 15 Main girder 17 Front edge 19 Outer skin main body 21 Rear edge 23 Divided outer skin 27 Divided outer girder 49 Partially divided outer skin 53 Internal space 55 Drain hole 57 Main body ground wire 59 Ground wire

Claims (8)

A windmill blade comprising an outer skin that forms a long hollow space having an airfoil in cross section, and a girder that is longitudinally reinforced to reinforce the outer skin from the inside,
The blade root side part of the outer skin is divided into an outer skin body including a front edge in the width direction and a divided outer skin including a rear edge,
Front edge end portion of the split skin is attached to the edge end portion after the previous Kigaihi body to be movable in the longitudinal direction with respect to the outer skin body,
A wind turbine blade in which the rear edge side end portion of the outer skin body projects toward the rear edge side with respect to the girder and is reinforced by the girder at a position close to the girder .   The wind turbine blade according to claim 1, wherein the divided outer skin overlaps the outer skin main body facing in the width direction.   3. The wind turbine blade according to claim 1, wherein the split outer shell is provided with a split outer girder which is vertically connected in a longitudinal direction and reinforces the split outer shell from the inside.   The wind turbine blade according to any one of claims 1 to 3, wherein at least the main body skin and the beam are divided in a longitudinal direction.   The wind turbine blade according to any one of claims 1 to 4, wherein the divided outer skin is configured by a partially divided outer skin that is divided in a longitudinal direction, and the partially divided outer skins are movably attached to each other.   The wind turbine blade according to any one of claims 1 to 4, wherein the divided outer skin is configured by partially divided outer skins that are divided in a longitudinal direction, and the partially divided outer skins are fixed by a coupling means.   The wind turbine blade according to any one of claims 1 to 6, wherein a drain hole for connecting the space and the external space is formed at a rear edge side end portion of the divided outer skin. The divided outer skins, attached by coupling a conductive member, one of claims 1, which is connected to the body grounding disposed on at least a portion and the space of the coupling member by a ground wire of claim 7 A wind turbine blade according to claim 1.

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