JPH0110449Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a wind turbine blade, specifically a wind turbine blade made of pultruded FRP (fiber reinforced plastic),
This relates to the connection structure with the metal spar (wing stem).

When a pultruded FRP wind turbine blade is used in a wind turbine device, the FRP blade is attached to the wind turbine shaft hub via a metal spar, but conventional FRP blades and metal spar are connected by mechanical joining means. has been done.

Since the pultruded FRP blade has the same cross-sectional shape at the blade tip and the blade root, the section modulus of the blade root is smaller than that of a tapered blade, and the force applied to the joint is larger.

Pultrusion molding with such shape characteristics
Figure 1 shows an example of FRP blades joined using conventional means.

The means shown in this figure has a structure in which an FRP spar a of an FRP wing is sandwiched between the tip of a metal spar b and a metal wedge c, and fixed with a bolt d.

In such a structure, FRP is used for tapered blades.
Because the spar part has a large shape and rigidity, stress concentration is avoided at the joint between the metal wedge and the FRP spar, making it a practical joining method.

However, when the above structure is applied to a pultruded FRP wing, the spar e in the pultruded FRP wing has an irregular shape as shown in Figure 2, making it difficult to process the metal wedge that fits into the spar e. At the same time, it is difficult to obtain adhesion between the joint surfaces, and the attachment cross-section of the metal wedge and FPR spar is smaller than that of a tapered blade, so the structure using the metal wedges described above has a large stress concentration at the joint. It is impossible to obtain sufficient strength.

Further, as another conventional example, there is a means shown in FIG. In the conventional example shown in this figure, a metal tube g having the same cross-section as the metal spar h is inserted into the FRP spar f, and the metal tube g and the metal spar h are mechanically connected using bolts i, etc. It is becoming more and more connected.

In such a structure, the inserted metal cylinder g
Since the metal spar h is further inserted into the structure, the cross-sectional shape of the metal spar h becomes smaller, and it becomes difficult to align the metal cylinder g with the inner wall shape of the FRP spar f. The joint strength between the metal cylinder g and the FRP spar f is low, especially in the direction of centrifugal force.
Cannot be applied to manufactured wings.

As mentioned above, when pultruded FRP wind turbine blades with the same cross-sectional shape in the longitudinal direction are attached to a wind turbine rotor blade using conventional mechanical joining means, the joining strength is insufficient, the joint structure becomes complicated, etc. becomes a problem.

The present invention was developed in consideration of the above-mentioned issues, and it is possible to accurately and easily join an FRP wind turbine blade and a metal spar, and to create a wind turbine blade that has a joint strength that can withstand sufficient load stress for wind turbine operation. This is what we are trying to provide.

Embodiments of the present invention will be described below based on FIG. 4 and subsequent figures.

In the figure, 1 is an FRP blade formed by pultrusion. This blade 1 is provided with an irregularly shaped spar 2 in the longitudinal direction, and the spar 2 and the wall forming the blade 1 form a substantially square cylinder. A shape space 3 is constructed. Reference numeral 4 denotes a metal spar that fits into the cylindrical space 3 of the blade 1. The fitting portion of the metal spar 4 into the cylindrical space 3 has a cross-sectional shape that is substantially similar to the sectional shape of the cylindrical space 3, or has an arbitrary shape, and is small. Two ribs 5 and 6 are provided at separate positions to be press-fitted into the cylindrical space 3 having the same cross-sectional shape as the cylindrical space 3. Small holes 7 and 8 communicating with the cylindrical space 3 are provided on the front and back sides of the blade 1.

In order to connect the blade 1 and the metal spar 4, the tip of the metal spar 4 is moved until the rib 6 on the base side of the two ribs 5 and 6 in this part is located at the end of the blade 1. Press in spar 4. Then, adhesive 9 is press-fitted into the space closed by both ribs 5 and 6 through one of the small holes 7 provided on both sides of the wing 1 using an adhesive injector 10 at a predetermined pressure, for example, 10 to 30 kg/cm ² . . At this time, the air in the space escapes through the other small holes 8.
As the adhesive, a room temperature curing type (two-component mixture type) epoxy type, modified acrylate type, urethane type, etc. is used.

Since the present invention is as described above, the metal spar 4 is formed by press-fitting the two ribs 5 and 6 into the cylindrical space 3 of the FRP blade 1 and applying the adhesive 9 between the two ribs. The wind turbine blade according to the present invention, which is firmly fixed, can exhibit the following effects unique to the present invention. In other words, (1) the blade 1 and the metal spar 4 can be easily attached with high precision, (2) a large bonding area can be secured, which avoids stress concentration at the joint, and (3) the joint (4) A highly elastic adhesive layer is formed between the bonding layers of FRP and metal, which have different rigidities, and
Stress transmission becomes smooth, impact resistance and thermal expansion strain absorption effects can be expected, and (5) the cross-sectional shape of the metal spar 4 can be set to an effective size.

[Brief explanation of drawings]

Figures 1 to 3 show conventional examples.
The figure is a cross-sectional perspective view showing an example of joining an FRP blade and a metal spar with a wedge, Figure 2 is a perspective view of a pultruded FRP wind turbine blade, and Figure 3 is an example of inserting a metal tube. FIG. Figure 4 and below show the main parts of the embodiment of the present invention.
FIG. 4 is a perspective view, FIG. 5 is a sectional view taken along the line - in FIG. 4, and FIG. 6 is a sectional view showing a state in which the adhesive is injected. 1 is a wing, 2 is a spar, 3 is a cylindrical space, 4 is a metal spar, 5 and 6 are ribs, and 9 is an adhesive.

Claims (1)

[Scope of utility model registration request] In the cylindrical space 3 of the pultruded FRP wing 1 having a cylindrical space 3 formed by an irregularly shaped spar 2, ribs 5 are press-fitted into the cylindrical space 3 at at least two locations in the longitudinal direction of the fitting portion. 6, and the cross-sectional area between the two ribs 5, 6 is smaller than the cross-sectional area of the cylindrical space 3, and the metal spar 4 is press-fitted. A wind turbine blade characterized in that the surface and the inner surface of the cylindrical space 3 of the irregularly shaped spar 2 are adhered with an adhesive.