Rotary vane

Abstract

To provide a rotary vane having light weight property and durability at high levels.SOLUTION: A rotary vane 10 includes a core material 11, a reinforcement layer 12, and a surface layer 13. The core material 11 is a part where a main part of the rotary vane 10 is formed. The core material 11 has a first main surface 111, a second main surface 112, a first side 113, and a second side 114. The reinforcement layer 12 is a layer covering the surface on the sides of the core material 11. The reinforcement layer 12 is composed of a fiber-reinforced composite material containing a resin 115 and a fiber 116. The fiber 116 is arranged to the second main surface 112 from the first main surface 111, on the sides of the core material 11.SELECTED DRAWING: Figure 2B

Description

Technical Field

[0001] The present invention relates to a rotary wing, and more particularly to a rotary wing provided in a flying device.

Background Art

[0002] Flying devices such as drones have rotary wings, and the flying device floats due to the lift generated by the rotation of the rotary wings. Further, by adjusting the rotational speed of the rotary wings, the position and attitude of the flying device during flight can be adjusted.

[0003] Inventions related to rotary wings are described in Patent Document 1 below and the like.

[0004] The rotor blade described in Patent Document 1 is composed of a structural core having a general aerodynamic airfoil shape and a covering material surrounding the structural core. The covering material is composed of a rigid thin outer skin having a desired aerodynamic airfoil shape and a layer made of a light flexible stress non-supporting compliant material. Further, the compliant material fills the space between the structural core and the outer skin. By doing so, the structural elements of the blade can be made by an optimal method with relatively high-precision tolerances without finishing work.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, there was room for improvement in the rotor blade according to the background art from the viewpoints of durability and the like.

[0007] Specifically, while the flying device is flying, the rotary wings continue to rotate at high speed. Then, air resistance is constantly applied to the side portion on the front side of the rotation direction of the rotary wings. Therefore, as the cumulative flight time of the flying device increases, there is a problem that scratches and damages occur on the side portion on the front side of the rotation direction of the rotary wings.

[0008] The present invention has been made in view of such problems, and an object of the present invention is to provide a rotary wing having high levels of lightness and durability.

Means for Solving the Problems

[0009] A rotary wing according to an embodiment of the present invention is a rotary wing that generates an aerodynamic effect by rotating, and includes a core material having a first main surface and a second main surface facing the first main surface, a reinforcing layer that covers the surface at the side of the core material, and a surface layer that covers the first main surface and the second main surface of the core material. The reinforcing layer is composed of a fiber-reinforced composite material containing resin and fiber, and the fiber is arranged from the first main surface to the second main surface at the side of the core material.

[0010] Further, in the rotary wing according to an embodiment of the present invention, the fiber-reinforced composite material is a unidirectional fiber-reinforced composite material in which the fibers are arranged along one direction.

[0011] Further, in the rotary wing according to an embodiment of the present invention, in the rotation direction, the distance from the side of the core material to the end of the fiber-reinforced composite material is 5 mm or more and 30 mm or less.

[0012] Further, in the rotary wing according to an embodiment of the present invention, the angle formed by the fiber included in the fiber-reinforced composite material and the side of the core material is 50 degrees or more and 130 degrees or less.

[0013] Further, in the rotary wing according to an embodiment of the present invention, a plurality of the fiber-reinforced composite materials are arranged along the side of the core material.

Effects of the Invention

[0014] The rotor blade according to an embodiment of the present invention is a rotor blade that generates an aerodynamic effect by rotating, and includes a core material having a first main surface and a second main surface facing the first main surface, a reinforcing layer covering the surface at the side of the core material, and a surface layer covering the first main surface and the second main surface of the core material. The reinforcing layer is composed of a fiber-reinforced composite material containing resin and fiber, and the fiber is arranged from the first main surface to the second main surface at the side of the core material. According to the rotor blade of the present invention, the side of the core material can be effectively protected by the fiber contained in the fiber-reinforced composite material because the fiber is arranged from the first main surface to the second main surface at the side of the core material.

[0015] Further, in the rotor blade according to an embodiment of the present invention, the fiber-reinforced composite material is a unidirectional fiber-reinforced composite material in which the fibers are arranged along one direction. According to the rotor blade of the present invention, since the fibers are arranged along one direction, the side of the core material can be protected by a large number of fibers.

[0016] Further, in the rotor blade according to an embodiment of the present invention, in the rotational direction, the distance from the side of the core material to the end of the fiber-reinforced composite material is 5 mm or more and 30 mm or less. According to the rotor blade of the present invention, by setting the distance from the side of the core material to the end of the fiber-reinforced composite material to 5 mm or more, the side of the core material can be effectively protected by the fiber-reinforced composite material. Also, by setting the distance to 30 mm or less, the weight of the fiber-reinforced composite material can be limited and the rotor blade can be made lighter.

[0017] Further, in the rotor blade according to an embodiment of the present invention, the angle formed by the fiber contained in the fiber-reinforced composite material and the side of the core material is 50 degrees or more and 130 degrees or less. According to the rotor blade of the present invention, since the angle formed by the fiber contained in the fiber-reinforced composite material and the side of the core material is 50 degrees or more and 130 degrees or less, while ensuring the flexibility of the fiber, the side of the core material can be sufficiently protected by the fiber.

[0018] Further, in the rotor blade according to an embodiment of the present invention, a plurality of the fiber reinforced composite materials are arranged along the side edges of the core material. According to the rotor blade of the present invention, by arranging a plurality of fiber reinforced composite materials along the side edges of the core material, the curved side edges of the core material can be protected without gaps by the fiber reinforced composite materials.

Brief Description of the Drawings

[0019]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same members are basically denoted by the same reference numerals, and repeated descriptions are omitted. Further, in the following description, the outside in the rotational direction may be simply referred to as the outside, and the inside in the rotational direction may be simply referred to as the inside. Furthermore, in the following description, the right side may correspond to the inside in the rotational direction, and the left side may correspond to the outside in the rotational direction. Also, in the following description, the front side in the rotational direction may be simply referred to as the front side, and the rear side in the rotational direction may be simply referred to as the rear side.

[0021] FIG. 1A is a perspective view showing a flying device 20 having a rotor 10. FIG. 1B is a top view showing the rotor 10.

[0022] The flying device 20 is a device that can autonomously float in the air and is also referred to as a drone. The flying device 20 mainly includes a main body 21, an arm portion 22, a motor 24, and a rotor 10. The flying device 20 may be an electric drone in which all the rotors 10 are rotated by motors, or may be a hybrid drone in which an engine is housed in the main body 21 and the rotors 10 are rotated by the energy generated from the engine. As the hybrid drone, a series type and a parallel type can be adopted. In the series type, the engine drives a generator, the electric energy generated from the generator drives the motor, and the motor rotates all the rotors 10. In the parallel type, some of the rotors 10 are rotated by being drivingly connected to the engine, and the other rotors 10 are rotated by the motor.

[0023] The arm portion 22 is a substantially rod-shaped member extending from the main body 21 toward the periphery. Here, the flying device 20 includes four arm portions 22.

[0024] The motor 24 is attached to the outer end of the arm portion 22. The motor 24 has a function of rotating the rotor 10.

[0025] The mounting portion 23 is disposed at the outer end of the arm portion 22. The mounting portion 23 is non-rotatably connected to the rotor of the motor 24 and rotates together with the rotor. The rotary wing 10 is attached to the mounting portion 23.

[0026] Referring to FIG. 1B, the rotary wing 10 is a member that generates an aerodynamic effect by rotating. In the present embodiment, the rotary wing 10 generates lift to float the flying device 20 in the air by rotating. Further, in the present embodiment, by adjusting the rotational speed of the rotary wing 10, the position and attitude of the flying device 20 in the air can be precisely controlled. Here, two rotary wings 10 are symmetrically attached to the mounting portion 23. Further, the rotary wing 10 is attached to the mounting portion 23 by a fastening member such as a bolt passing through the mounting portion 25.

[0027] FIG. 2A is a top view showing the rotary wing 10. FIG. 2B is a cross-sectional view showing the rotary wing 10 and shows the cross-section along the cutting plane line A-A in FIG. 2A.

[0028] Referring to FIG. 2A, when the rotary wing 10 is viewed from above, the rotary wing 10 has a substantially rectangular shape with a longitudinal direction along the left-right direction. The rotary wing 10 has a first reinforcing layer 121 on the front side edge and a second reinforcing layer 122 on the rear side edge.

[0029] The connection hole 14 is a hole penetrating the right end which is the inner end of the rotary wing 10 and is used for fastening to the above-described mounting portion 23.

[0030] Referring to FIG. 2B, the rotary wing 10 includes a core material 11, a reinforcing layer 12, and a surface layer 13.

[0031] The core material 11 is a part forming the main body of the rotary wing 10. The specific configuration of the core material 11 will be described later with reference to FIGS. 3A and the like.

[0032] The reinforcing layer 12 is a layer that covers the surface at the side of the core material 11. The reinforcing layer 12 has a first reinforcing layer 121 and a second reinforcing layer 122. The first reinforcing layer 121 is a layer that covers the side at the front side in the rotational direction of the core material 11. The second reinforcing layer 122 is a layer that covers the side at the rear side in the rotational direction of the core material 11. Details of the reinforcing layer 12 will be described later with reference to FIGS. 3A, 4B, etc.

[0033] The surface layer 13 is a layer that covers the substantially flat surface of the core material 11. The surface layer 13 has a first surface layer 131 and a second surface layer 132. The first surface layer 131 is a layer that covers the upper surface (the first main surface 111 described later) of the core material 11. The second surface layer 132 is a layer that covers the lower surface (the second main surface 112 described later) of the core material 11. The first surface layer 131 and the second surface layer 132 are made of a fiber-reinforced composite material, which is the same material as the reinforcing layer 12.

[0034] The reinforcing layer 12 and the surface layer 13 are configured such that their ends overlap each other. In FIG. 2B, the overlapping portion of the reinforcing layer 12 and the surface layer 13 is shown in a stepped shape, but in the actual rotor blade 10, the surface of the reinforcing layer 12 and the surface of the surface layer 13 present a continuous and smooth surface. Also, the surface layer 13 and the reinforcing layer 12 have the same thickness in substantially the entire area including the overlapping portion therebetween. By doing so, it is possible to suppress the weakening of the boundary portion between the reinforcing layer 12 and the surface layer 13.

[0035] The front end in the rotational direction of the core material 11 is covered by the first reinforcing layer 121. Here, the front end in the rotational direction of the rotor blade 10 and the core material 11 is also referred to as the leading edge. On the upper surface of the core material 11, the upper rear end portion of the first reinforcing layer 121 overlaps with the front end portion of the first surface layer 131. Here, the first surface layer 131 is arranged above the first reinforcing layer 121, but the first surface layer 131 may be arranged below the first reinforcing layer 121. On the other hand, on the lower surface of the core material 11, the lower rear end portion of the first reinforcing layer 121 overlaps with the front end portion of the second surface layer 132. Here, the second surface layer 132 is arranged below the first reinforcing layer 121, but the second surface layer 132 may be arranged above the first reinforcing layer 121.

[0036] On one hand, the rear end of the core material 11 in the rotation direction is covered by the second reinforcing layer 122. On the upper surface of the core material 11, the front upper end of the second reinforcing layer 122 overlaps with the rear end of the first surface layer 131. Here, the first surface layer 131 is arranged above the second reinforcing layer 122, but the first surface layer 131 may also be arranged below the second reinforcing layer 122. On the other hand, on the lower surface of the core material 11, the front lower end of the second reinforcing layer 122 overlaps with the rear end of the second surface layer 132. Here, the second surface layer 132 is arranged below the second reinforcing layer 122, but the second surface layer 132 may also be arranged above the second reinforcing layer 122.

[0037] FIG. 3A is an exploded cross-sectional view showing the rotating blade 10. FIG. 3B is a top view showing the core material 11.

[0038] Referring to FIGS. 3A and 3B, the core material 11 is a part that constitutes the main body of the rotating blade 10. The shape and size of the core material 11 are substantially the same as those of the rotating blade 10. In fact, depending on the thickness of the surface layer 13 and the reinforcing layer 12, the core material 11 is, for example, about several millimeters smaller than the rotating blade 10. As the material of the core material 11, a material that ensures a predetermined mechanical strength and is excellent in lightness is adopted. Specifically, as the material of the core material 11, for example, a lightweight foam material can be adopted, and as an example, a polylactic acid foam material can be adopted. In addition, a connection hole portion 117 is provided at the inner end portion of the core material 11. The connection hole portion 117 is, for example, a cylindrical metal member embedded in the main body of the core material 11.

[0039] As shown in FIG. 3A, the core material 11 has a first main surface 111, a second main surface 112, a first side 113, and a second side 114.

[0040] The first main surface 111 is a surface that constitutes the upper surface of the core material 11, and is a surface in which the middle portion in the front-rear direction bulges upward. The second main surface 112 is a surface that constitutes the lower surface of the core material 11 and presents a substantially flat surface.

[0041] Referring to FIG. 3B, the first side 113 is a side disposed on the front side of the core material 11 and is also referred to as a leading edge. The second side 114 is a side disposed on the rear side of the core material 11.

[0042] Referring again to FIG. 3A, in the front-rear direction which is the rotational direction, the length that the first reinforcing layer 121 and the second reinforcing layer 122 cover the surface of the core material 11 is set to a range that can sufficiently protect the first side 113 of the core material 11 while suppressing an increase in the weight of the rotor blade 10.

[0043] Specifically, in the front-rear direction which is the rotational direction, the distance L10 from the first side 113 of the core material 11 to the rear end of the first reinforcing layer 121 covering the second main surface 112 is set to be 5 mm or more and 30 mm or less. By setting L10 to be 5 mm or more, the first side 113 of the core material 11 can be effectively protected by the first reinforcing layer 121. By setting L10 to be 30 mm or less, the weight of the first reinforcing layer 121 can be limited to reduce the weight of the rotor blade 10. Also, the distance of the portion of the first reinforcing layer 121 covering the first main surface 111 can be made the same as L10. Here, a more preferable range of the distance L10 is 10 mm or more and 25 mm or less, and a particularly preferable range is 15 mm or more and 20 mm or less. By doing so, the above-described effects become remarkable.

[0044] Furthermore, in the front-rear direction which is the rotational direction, the distance L11 from the second side 114 of the core material 11 to the front end of the second reinforcing layer 122 covering the second main surface 112 can be made equivalent to the above-described distance L10. Moreover, in the front-rear direction which is the rotational direction, the distance from the second side 114 of the core material 11 to the front end of the second reinforcing layer 122 covering the first main surface 111 can be made equivalent to the distance L11.

[0045] FIG. 4A is a top view and a cross-sectional view showing the core material 11 and the reinforcing layer 12. In FIG. 4A, a top view of the core material 11 and the reinforcing layer 12 is shown in the upper part, and a cross-sectional view in the B-B cross-section is shown in the lower part.

[0046] Referring to the upper part of FIG. 4A, the first side 113 of the core material 11 is reinforced by being covered with the first reinforcing layer 121. Also, the second side 114 of the core material 11 is reinforced by being covered with the second reinforcing layer 122. That is, all sides of the core material 11 are reinforced by the reinforcing layer 12. Here, the reinforcing layer 12 may be integrally continuous across all sides of the core material 11, or a plurality of fragmented reinforcing layers 12 may be arranged along the core material 11.

[0047] Referring to the lower part of FIG. 4A, in this embodiment, the reinforcing layer 12 is configured to be able to sufficiently protect the end of the core material 11.

[0048] Specifically, the first reinforcing layer 121 is composed of a fiber-reinforced composite material including a resin 115 and a fiber 116. As the resin 115, for example, a thermosetting resin such as an epoxy resin is adopted. As the fiber 116, for example, a carbon fiber is adopted, and as an example, a fiber composed of polyacrylonitrile fiber, coal tar pitch, etc. is adopted.

[0049] As the first reinforcing layer 121, a unidirectional fiber-reinforced composite material in which the fibers 116 are arranged along one direction can also be adopted. By doing so, the fibers 116 are arranged along one direction, and the side of the core material 11 can be protected by a large number of fibers 116. Also, as the first reinforcing layer 121, a bidirectional fiber-reinforced composite material in which the fibers 116 are arranged along two intersecting directions, etc. can be adopted.

[0050] As shown in the cross-sectional view, the first reinforcing layer 121 is arranged across the first main surface 111 to the second main surface 112 at the first side 113 of the core material 11. Specifically, the upper end portion of the first reinforcing layer 121 covers the front end portion of the first main surface 111, and the lower end portion of the first reinforcing layer 121 covers the front end portion of the second main surface 112. The middle portion of the first reinforcing layer 121 covers the front end of the core material 11, that is, the first side 113 which is the leading edge. In other words, the first reinforcing layer 121 is in close contact with the front end portion of the first main surface 111, the first side 113, and the front end portion of the second main surface 112.

[0051] Furthermore, the fibers 116 included in the first reinforcing layer 121 are arranged across the first side 113 of the core material 11 from the first main surface 111 to the second main surface 112. Specifically, the upper end portion of the fiber 116 is disposed on the upper surface side of the first main surface 111, and the lower end portion of the first reinforcing layer 121 is disposed on the lower surface side of the second main surface 112. Also, the middle portion of the first reinforcing layer 121 covers the first side 113. In this way, on the side of the core material 11, by continuously arranging the fibers 116 across from the first main surface 111 to the second main surface 112, the fibers 116 included in the fiber-reinforced composite material can effectively protect the side of the core material 11.

[0052] The same applies to the second reinforcing layer 122. Specifically, although not shown here, the aforementioned second reinforcing layer 122 and the fibers 116 included therein are also continuously arranged across from the first main surface 111 to the second main surface 112 on the second side 114 of the core material 11.

[0053] FIG. 4B is an enlarged top view partially showing the core material 11 and the reinforcing layer 12. FIG. 4B shows an enlarged view of the portion surrounded by the dotted circle in the plan view of FIG. 4A.

[0054] As described above, the first reinforcing layer 121 is a fiber-reinforced composite material made of the resin 115 impregnated with the fibers 116. Here, the angle θ formed between the fibers 116 included in the fiber-reinforced composite material and the side of the core material 11 is, for example, 50 degrees or more and 130 degrees or less. By the angle θ being 50 degrees or more and 130 degrees or less, while ensuring the flexibility of the fibers 116, the side of the core material 11 can be sufficiently protected by the fibers 116. Also, a more preferable range of the angle θ is 70 degrees or more and 110 degrees or less, and a particularly preferable range is 80 degrees or more and 100 degrees or less, and a specific example is 90 degrees. By setting the angle θ within such a range, the aforementioned effects become prominent.

[0055] Based on FIGS. 5A and 5B, while also referring to the above-described respective figures, the molding process included in the manufacturing method of the rotor blade 10 will be described.

[0056] FIG. 5A is a cross-sectional view showing an initial stage of a molding process included in a method for manufacturing the rotary wing 10. FIG. 5B is a cross-sectional view showing the situation after the molding process is completed.

[0057] Referring to FIG. 5A, a core material 11 with a reinforcing layer 12 and a surface layer 13 attached thereto is housed inside a mold 30. The mold 30 is composed of an upper mold 31 disposed on the upper side and a lower mold 32 disposed on the lower side. A cavity 33 is formed as a gap between the lower surface of the upper mold 31 and the upper surface of the lower mold 32. The cavity 33 is made to be the same as the outer shape of the rotary wing 10 to be manufactured. On the surface of the core material 11, the aforementioned reinforcing layer 12 and surface layer 13 are attached in a state where the containing resin is not cured. The core material 11 is housed in the cavity 33.

[0058] Referring to FIG. 5B, with the core material 11 housed in the cavity 33, the upper mold 31 and the lower mold 32 are brought into contact with each other. At the same time, the upper mold 31 and the lower mold 32 are heated. Thereby, the thermosetting resin constituting the reinforcing layer 12 and the surface layer 13 is cured.

[0059] Thereafter, the upper mold 31 and the lower mold 32 are released from the mold, and the core material 11 with the reinforcing layer 12 and the surface layer 13 cured is taken out from the cavity 33 to the outside. Thereby, the rotary wing 10 shown in FIG. 2A etc. can be manufactured.

[0060] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to this, and can be modified without departing from the gist of the present invention. Also, the above-described embodiments can be combined with each other.

Explanation of Signs

[0061] 10 Rotary wing 11 Core material 111 First main surface 112 Second main surface 113 First side 114 Second side 115 Resin 116 Fiber 117 Connecting hole portion 12 Reinforcement layer 121 First reinforcement layer 122 Second reinforcement layer 13 Surface layer 131 First surface layer 132 Second surface layer 14 Connection hole 20 Flying device 21 Body part 22 Arm part 23 Mounting part 24 Motor 25 Mounting part 30 Mold 31 Upper mold 32 Lower mold 33 Cavity

Claims

1. A rotor blade that generates an aerodynamic effect by rotating, a core material having a first main surface and a second main surface facing the first main surface, a reinforcing layer covering the surface at the side of the core material, and a surface layer covering the first main surface and the second main surface of the core material, wherein the reinforcing layer is composed of a fiber-reinforced composite material containing resin and fibers, and the fibers are arranged from the first main surface to the second main surface at the side of the core material. A rotor blade characterized by this.

2. The rotor blade according to claim 1, wherein the fiber-reinforced composite material is a unidirectional fiber-reinforced composite material in which the fibers are arranged along one direction.

3. In the rotational direction, the distance from the side of the core material to the end of the fiber-reinforced composite material is 5 mm or more and 30 mm or less. The rotor blade according to claim 1, characterized by this.

4. The angle formed by the fibers contained in the fiber-reinforced composite material and the side of the core material is 50 degrees or more and 130 degrees or less. The rotor blade according to claim 1, characterized by this.

5. The rotor blade according to claim 1, characterized in that a plurality of the fiber-reinforced composite materials are arranged along the side of the core material.

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