JP2015121202A - Composite material blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite material blade that can resist a strong centrifugal force.SOLUTION: A composite material blade is the composite material blade attached to an outer surface of a rotational body in a state of extending radially, including: a blade root section attached to the outer surface of the rotational body; an airfoil section extending from the blade root section; and a reinforcement fiber bundle containing reinforcement fiber and extending between the blade root section and the airfoil section in the composite blade. The reinforcement fiber includes a first bent portion bent with an angle of 90 degrees or an acute angle in the blade root section.

Description

  The present disclosure relates to a composite blade, for example, a composite blade used in an axial fan such as a thermal power plant blower or an aero engine.

  A tensile stress acts on the composite blade that is radially attached to the outer surface of the rotating body by centrifugal force when the rotating body rotates. When the magnitude of the tensile stress increases, particularly, the stress concentrates on the root side that fixes the composite material blade to the rotating body, and the composite material blade may be damaged.

  Therefore, as described in Patent Document 1, a composite blade (fiber reinforced composite) in which reinforcing fibers are provided from a blade root portion (dovetail portion) where the composite blade is attached to a rotating body to a blade portion of the composite blade. Blades) have been proposed.

  The reinforcing fibers provided in the wing portion of the composite blade extend along the extending direction of the wing portion. The reinforcing fiber in the blade root portion extends in a fan shape so as to incline outward as it extends to the side opposite to the blade portion.

JP 06-137103 A

  In this conventional composite blade, local peeling stress (shearing force) caused by centrifugal force acting in the blade root part acts on the reinforcing fiber in the blade root part, and the blade root part may be locally damaged. . In particular, in order to increase the size of the composite blade and increase the peripheral speed, it is desired to develop a new structure of the composite blade that can withstand a greater centrifugal force.

  In view of the above circumstances, at least some embodiments of the present invention aim to provide a composite blade that can withstand large centrifugal forces.

Composite blades according to some embodiments of the present invention include:
A composite blade attached radially to the outer surface of the rotating body,
A blade root attached to the outer surface of the rotating body;
An airfoil extending from the blade root;
A reinforcing fiber bundle including reinforcing fibers extending between the blade root portion and the airfoil portion in the composite blade,
The reinforcing fiber has a first bent portion that bends at 90 degrees or an acute angle in the blade root portion.

  According to the composite material blade, when a centrifugal force acts on the composite material blade during rotation of the rotating body, a pulling force toward the top side of the composite material blade acts on the airfoil portion and the blade root portion. The pulling force acting on the airfoil is supported by the reinforcing fiber bundle in the airfoil. On the other hand, when a tensile force acts on the blade root portion, the reinforcing fiber bundle on the airfoil portion side with respect to the first bent portion is pulled toward the top side of the composite blade by this tensile force, but the reinforcing fiber extending from the first bent portion. The bundle acts as a hook in the blade root and supports the pulling force acting on the blade root. At this time, in the blade root portion, a force in a direction in which the reinforcing fiber bundle is separated from the bottom surface of the blade root portion is exerted in the blade root portion, and a force for this force is generated in the blade root portion. For this reason, there is no possibility of generating a shearing force in the blade root portion, and the possibility of local damage in the blade root portion can be prevented.

In some embodiments,
The reinforcing fiber bundle is
A main portion constituted by a first portion of the reinforcing fiber extending along the extending direction of the airfoil portion from the inside of the airfoil portion to the inside of the blade root portion;
And a latching portion constituted by a second portion of the reinforcing fiber continuous with the first portion via the first bent portion.

  In this case, when a pulling force is applied to the blade root portion, the pulling force acts on the blade root portion so that the hook portion on the airfoil portion side of the first bent portion is caught in the blade root portion. Support. Therefore, a composite blade capable of withstanding a greater centrifugal force can be realized.

In one embodiment,
The second portion is configured to extend in a direction away from the bottom surface of the blade root portion with the first bent portion as a starting point so as to form an angle of 90 degrees or an acute angle with the first portion. .

  In this case, since the second portion extends from the first bent portion in a direction away from the bottom surface of the blade root portion, a region of the blade root portion where the latching portion is hooked (opposite the bottom surface of the blade root portion across the latching portion). Wide area). Therefore, a composite blade capable of withstanding a greater centrifugal force can be realized.

In one embodiment,
A pair of the reinforcing fiber bundles are provided inside the blade,
The first portions constituting the main portion of the pair of reinforcing fiber bundles extend along the extending direction in parallel with each other,
The second portions constituting the hook portions of the pair of reinforcing fiber bundles are configured to extend in opposite directions.

  In this case, since the second portions of the pair of reinforcing fiber bundles are arranged in opposite directions to each other, the region of the blade root portion where the latching portion is caught (on the opposite side of the bottom surface of the blade root portion across the latching portion) Area) can be secured more widely. Therefore, a composite blade capable of withstanding a larger centrifugal force can be realized.

In one embodiment,
It is comprised so that the insert provided in the opposite side to the said bottom face of the said blade root part may be further provided on the inside of the said blade root part on both sides of the said latching | locking part.

  In this case, when a centrifugal force acts on the composite material blade, the latching portion is caught by the insert. Therefore, a composite blade capable of withstanding a large centrifugal force can be realized. In addition, since the insert only needs to be able to hook the hook portion, the width of the insert can be reduced and the width of the blade root portion can also be reduced.

In one embodiment,
Further comprising an insert provided on the opposite side of the bottom surface of the blade root portion with the latching portion sandwiched inside the blade root portion,
The main part of the bundle of reinforcing fibers extends inside the blade root part toward the bottom surface through both sides of the insert,
The hooking portion of the reinforcing fiber bundle is configured to extend between the insert and the bottom surface.

  In this case, since the pair of latching portions extend between the insert and the bottom surface from both sides of the insert, when the centrifugal force acts on the blade, each of the pair of latching portions is hooked on the insert. Therefore, a composite blade capable of withstanding a large centrifugal force can be realized. In addition, since the insert only needs to be able to hook the hook portion, the width of the insert can be reduced and the width of the blade root portion can also be reduced.

In one embodiment,
The reinforcing fiber is
A second bent portion provided at the other end of the second portion in the blade root;
A third portion continuing to the second portion via the second bent portion;
The reinforcing fiber bundle is
A first main part constituted by the first part of the reinforcing fiber passing through one side of the insert;
A common latching portion constituted by the second portion of the reinforcing fiber extending between the insert and the bottom surface;
And a second main part constituted by the third part of the reinforcing fiber passing through the other side of the insert.

  In this case, since the reinforcing fiber bundle is connected to the first main portion and the second main portion via the common hooking portion, when the centrifugal force acts on the blade, the entire common hooking portion is hooked on the insert. Therefore, a composite blade capable of withstanding a greater centrifugal force can be realized. In addition, since the insert only needs to be able to hook the hook portion, the width of the insert can be reduced and the width of the blade root portion can also be reduced.

  According to at least some embodiments of the present invention, a composite blade capable of withstanding large centrifugal forces can be provided.

It is an internal structure figure which shows the structural example of a composite material blade. It is a partial expanded sectional view of the blade root part which illustrated the force generated in the reinforcing fiber bundle in the blade root part concerning one embodiment. It is a partial expanded sectional view of the blade root part in which two inserts were provided in the blade root part concerning one Embodiment. It is a partial expanded sectional view of the blade root part in which a latching part is latched from the both sides of the insert concerning one Embodiment. It is a partial expanded sectional view of the blade root part in which one insert was provided in the blade root part concerning one Embodiment. It is a partial expanded sectional view of the blade root part in which the small insert concerning one Embodiment was provided.

  Hereinafter, embodiments of the composite blade of the present invention will be described with reference to the accompanying drawings. However, the materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. In the present embodiment, a composite blade used for a fan blade of a gas turbine engine will be described.

  As shown in FIG. 1 (internal structure diagram), the composite blade 1 includes a blade root portion 5 attached to the outer periphery of a disk-shaped disk 90, an airfoil portion 10 extending from the blade root portion 5, and the composite blade 1. A reinforcing fiber bundle 20 including reinforcing fibers 21 extending between the blade root portion 5 and the airfoil portion 10 is formed inside. The reinforcing fiber 21 has a first bent portion 21 b that bends with an acute angle in the blade root portion 5. A plurality of attachment portions 91 are provided on the outer periphery of the disk 90 with a predetermined interval in the circumferential direction. The mounting portion 91 extends along the axis S direction of the disk 90 (hereinafter referred to as the width direction), and the blade root portion 5 of the composite blade 1 is inserted along the width direction of the disk 90 so as to be combined. The material blade 1 is attached to the disk 90 in a state of extending radially.

  The blade root portion 5 is formed in a box shape and is formed in a rectangular shape in a side view. The surface of the blade root portion 5 is inclined to the side away from the bottom surface 5a of the blade root portion 5 as it goes from the side surface on one side of the blade root portion 5 to the center side, and a pair of curved surfaces curved concavely toward the bottom surface 5a side of the blade root portion 5 5b is formed. These curved surfaces 5b are formed symmetrically with respect to the width direction of the disk 90, and the shape of the curved surface 5b is formed based on aerodynamic design. The airfoil portion 10 is connected to the tip portions of the pair of curved surfaces 5b. The airfoil portion 10 extends linearly in a direction away from the bottom surface 5a of the blade root portion 5 (outside in the radial direction of the disk 90). A reinforcing fiber bundle 20 extends in the airfoil portion 10 and the blade root portion 5. Details of the reinforcing fiber bundle 20 will be described later.

  The blade root portion 5 and the airfoil portion 10 are formed of a thermoplastic resin, such as polyethylene or polypropylene. The blade root portion 5 and the blade shape portion 10 are not limited to being formed of a thermoplastic resin, but may be a thermosetting resin (for example, a phenol resin, an unsaturated polyester resin, an epoxy resin, or the like). The airfoil portion 10 is formed such that the width decreases for a while as it extends from the proximal end side to the distal end side.

  In some embodiments, the reinforcing fiber bundle 20 is configured by bundling a large number of reinforcing fibers 21. The reinforcing fiber 21 is composed of carbon fiber, glass fiber, or the like. The reinforcing fiber bundle 20 extends between the blade root portion 5 and the airfoil portion 10. The reinforcing fiber bundle 20 includes a main portion 20a constituted by a first portion 21a of a reinforcing fiber 21 extending along the extending direction of the airfoil portion 10 from the inside of the airfoil portion 10 to the inside of the blade root portion 5; And a latching portion 20b constituted by the second portion 21c of the reinforcing fiber 21 having one end connected to the first portion 21a via the one bent portion 21b.

  The first portion 21 a of the reinforcing fiber 21 extends from the inner front end portion of the airfoil portion 10 to the vicinity of the bottom surface 5 a of the blade root portion 5 beyond the inner base end portion inside the airfoil portion 10. The second portion 21c of the reinforcing fiber 21 is connected via a first bent portion 21b that is bent with an acute bending angle θ (about 75 degrees in the drawing) in the blade root portion 5. The bending angle θ of the first bent portion 21b may be 90 degrees or an acute angle. The bending angle θ is preferably 90 degrees to 60 degrees, for example. By setting an acute angle, the resistance to the pulling force increases. Such an insertion form of the reinforcing fiber bundle can be applied to T-joining of the composite member.

  In some embodiments, a pair of reinforcing fiber bundles 20 are provided in the width direction of the composite blade 1 with respect to the central axis Q of the composite blade 1 inside the composite blade 1. The first portions 21a constituting the main portion 20a of the pair of reinforcing fiber bundles 20 extend along the extending direction of the airfoil portion 10 in parallel with each other, and constitute the latching portions 20b of the pair of reinforcing fiber bundles 20. The second portions 21c extend in opposite directions. The second portion 21 c extends from the center in the width direction in the blade root portion 5 to the vicinity of the inside of the outer end portion in the width direction in the blade root portion 5.

  As described above, according to the composite blade 1 according to some embodiments, when the disk 90 rotates, the centrifugal force F acts on the composite blade 1 as shown in FIG. 2 (partially enlarged sectional view). Then, a pulling force T directed toward the top side of the composite blade 1 acts on the airfoil portion 10 and the blade root portion 5. The pulling force T acting on the airfoil portion 10 is supported by the reinforcing fiber bundle 20 in the airfoil portion 10. On the other hand, when a tensile force T acts on the blade root portion 5, the reinforcing fiber bundle 20 closer to the airfoil portion 10 than the first bent portion 21 b is pulled toward the top direction side of the composite blade 1 by this tensile force T. The latching part 20b which comprises the 2nd part 21c extended from the 1 bending part 21b acts so that it may be hooked in the blade root part 5, and supports the tensile force T which acts on the blade root part 5. FIG. At this time, in the blade root portion 5, the reinforcing fiber bundle 20 exerts a force Fa in the direction away from the bottom surface 5 a of the blade root portion 5 in the blade root portion 5, while a force Fb for the force Fa is generated in the blade root portion 5. For this reason, there is no possibility that a shearing force is generated in the blade root portion 5, and the possibility of local damage in the blade root portion 5 can be prevented.

  Further, when the pulling force T acts on the blade root portion 5, the pulling force T acts so that the hook portion 20 b on the airfoil portion 10 side of the first bent portion 21 b is hooked in the blade root portion 5, and the blade root portion 5. It effectively supports the tensile force T acting on the. Furthermore, since the second portion 21c extends in a direction away from the bottom surface 5a of the blade root portion 5 with the first bent portion 21b as a starting point, a region W (with the latching portion 20b sandwiched between the hook portions 20b) of the blade root portion 5 is sandwiched. Thus, a wide area on the opposite side of the bottom surface 5a of the blade root portion 5 can be secured. Therefore, the composite blade 1 that can withstand a greater centrifugal force F can be realized.

  Further, since the second portions 21c of the pair of reinforcing fiber bundles 20 are arranged in opposite directions to each other, the region W of the blade root portion 5 where the hook portion 20b is hooked (the blade root portion across the hook portion 20b). 5 can be secured more widely. Therefore, the composite blade 1 that can withstand a greater centrifugal force F can be realized.

  Next, the individual contents of the exemplary embodiment shown in FIGS. 3 to 6 will be described. In the exemplary embodiment shown in FIG. 3, an insert 30 is provided inside the blade root portion 5 on the side opposite to the bottom surface 5 a of the blade root portion 5 with the latching portion 20 b interposed therebetween. This insert 30 is a rod-shaped member extending in a direction substantially orthogonal to the width direction of the composite blade 1. The insert 30 may be in a state of being in contact with the hooking portion 20b when inserted into the blade root portion 5, or may be in a non-contact state. The insert 30 is made of a metal material, and is formed of, for example, a Ti alloy. The cross-sectional shape of the insert 30 may be any shape (circular in the drawing) as long as the latching portion 20b can be latched. For example, in addition to a circle, the cross-sectional shape may be any of an ellipse, a triangle, a rectangle, and the like.

  Thus, by providing the insert 30 on the opposite side of the bottom surface 5a of the blade root portion 5 with the latching portion 20b inside the blade root portion 5, when the centrifugal force F acts on the composite blade 1, the latching portion 20b is caught in the insert 30. Therefore, the composite blade 1 that can withstand a large centrifugal force F can be realized.

  In the exemplary embodiment shown in FIG. 4, the main portion of the reinforcing fiber bundle 20 is provided with an insert 32 provided on the opposite side of the bottom surface 5 a of the blade root portion 5 with the latching portion 20 b sandwiched inside the blade root portion 5 ′. 20a passes through both sides of the insert 32 in the width direction and extends inside the blade root portion 5 'toward the bottom surface 5'a, and the hooking portion 20b of the reinforcing fiber bundle 20 includes the insert 32 and the bottom surface 5'a. Extending between. The latching portion 20 b extending between the insert 32 and the bottom surface 5 ′ a extends along the bottom surface 32 a of the insert 32 from both sides of the insert 32. A pair of latching | locking part 20b extended along the bottom face 32a from the both sides of the insert 32 exists in a non-connection state.

  In the composite material blade 1 having this configuration, the pair of latching portions 20b extend from both sides of the insert 32 between the insert 32 and the bottom surface 5′a of the blade root portion 5 ′. As a result, each of the pair of latching portions 20 b is hooked on the insert 32. Therefore, the composite blade 1 ′ that can withstand a large centrifugal force F can be realized. Moreover, since the insert 32 should just be able to latch the latching | locking part 20b, the width | variety of the insert 32 can be made small. Therefore, the width B of the blade root portion 5 'can also be reduced.

  In the exemplary embodiment shown in FIG. 5, the reinforcing fiber 21 includes, in the blade root portion 5 ′, a second bent portion 21 d provided at the other end portion in the width direction of the blade root portion 5 ′ of the second portion 21 c, and a second portion. The reinforcing fiber bundle 20 further includes a third portion 21e that is continuous with the second portion 21c via the bent portion 21d, and the reinforcing fiber bundle 20 includes a first portion 21a of the reinforcing fiber 21 that passes through one side of the insert 32. 1 main portion 20c, common latching portion 20d constituted by the second portion 21c of the reinforcing fiber 21 extending between the insert 32 and the bottom surface 5'a of the blade root portion 5 ', and the other side of the insert 32 And a second main portion 20e configured by the third portion 21e of the reinforcing fiber 21 that passes through. That is, in the exemplary embodiment shown in FIG. 5, the first main portion 20c and the second main portion 20e are connected via the common latching portion 20d.

  The width of the insert 32 is larger than the width of the reinforcing fiber bundle 20. For this reason, the first portion 21a and the third portion 21e of the reinforcing fiber 21 extend toward the bottom surface 5′a side of the blade root portion 5 ′ toward the side surface 32b of the insert 32, and the bottom surface 5′a side along the side surface 32b. It extends to.

  In the composite material blade 1 having this configuration, the reinforcing fiber bundle 20 is connected to the first main portion 20c and the second main portion 20e via the common hooking portion 20d, so that the centrifugal force F acts on the composite material blade 1. Then, the entire common latching portion 20 d is hooked on the insert 32. Therefore, the composite blade 1 that can withstand a greater centrifugal force F can be realized. Moreover, since the insert 32 should just be able to latch the common latching | locking part 20d, the width | variety of the insert 32 can be made small. Therefore, the width B of the blade root portion 5 'can also be reduced.

  In the exemplary embodiment shown in FIG. 6, a specific example in which the insert 33 having a smaller width than the insert 32 shown in FIG. 5 is used is shown. Since the insert 33 only needs to be able to hook the hook portion 20b, the insert 33 having a small width can be realized. Therefore, the width B of the blade root portion 5 'can be further reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the object of the present invention. For example, the various embodiments described above may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Composite blade 5, 5 'Blade root part 5a Bottom surface 5b Curved surface 10 Airfoil part 20 Reinforcement fiber bundle 20a Main part 20b Hanging part 20c 1st main part 20d Common hanging part 20e 2nd main part 21 Reinforcing fiber bundle 21a 1st 1 part 21b 1st bent part 21c 2nd part 21d 2nd bent part 21e 3rd part 30, 32, 33 Insert 90 Disc 91 Attachment part F Centrifugal force Fa, Fb force S Shaft core W area | region

Claims (7)

A composite blade attached radially to the outer surface of the rotating body,
A blade root attached to the outer surface of the rotating body;
An airfoil extending from the blade root;
A reinforcing fiber bundle including reinforcing fibers extending between the blade root portion and the airfoil portion in the composite blade,
The reinforcing fiber has a first bent portion that bends at 90 degrees or an acute angle in the blade root portion. The reinforcing fiber bundle is
A main portion constituted by a first portion of the reinforcing fiber extending along the extending direction of the airfoil portion from the inside of the airfoil portion to the inside of the blade root portion;
The composite part according to claim 1, further comprising: a latching part configured by a second part of the reinforcing fiber having one end connected to the first part via the first bent part. Wood blade. The second portion extends in a direction away from the bottom surface of the blade root portion with the first bent portion as a starting point so as to form the 90 degree or acute angle with the first portion. The composite blade according to claim 2. A pair of the reinforcing fiber bundles are provided inside the composite blade,
The first portions constituting the main portion of the pair of reinforcing fiber bundles extend along the extending direction in parallel with each other,
The composite blade according to claim 3, wherein the second portions constituting the hooking portions of the pair of reinforcing fiber bundles extend in opposite directions. 5. The composite blade according to claim 3, further comprising an insert provided on a side opposite to the bottom surface of the blade root portion across the hook portion inside the blade root portion. Further comprising an insert provided on the opposite side of the bottom surface of the blade root portion with the latching portion sandwiched inside the blade root portion,
The main part of the bundle of reinforcing fibers extends inside the blade root part toward the bottom surface through both sides of the insert,
The composite blade according to claim 2, wherein the hook portion of the reinforcing fiber bundle extends between the insert and the bottom surface. The reinforcing fiber is
A second bent portion provided at the other end of the second portion in the blade root;
A third portion continuing to the second portion via the second bent portion;
The reinforcing fiber bundle is
A first main part constituted by the first part of the reinforcing fiber passing through one side of the insert;
A common latching portion constituted by the second portion of the reinforcing fiber extending between the insert and the bottom surface;
The composite blade according to claim 6, further comprising: a second main portion configured by the third portion of the reinforcing fiber passing through the other side of the insert.

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