JP7286339B2 - Rotor blade, blower provided with the same, and rotor blade manufacturing method - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a rotor blade, a blower having the rotor blade, and a method for manufacturing the rotor blade.

For example, thermal power plants include an axial fan (Forced Draft Fan (FDF)) that blows air for fuel combustion, a primary fan that blows fine powder carrier gas for a solid fuel crusher, and the like. For the purpose of reducing the weight of the rotor blades applied to these axial fans, attention has been focused on techniques for manufacturing hollow rotor blades. For example, Patent Literature 1 reports a technique for producing a rotor blade having a hollow structure using a three-dimensional layered modeling machine (3D printer). Further, Patent Document 2 reports an impeller composed of segments having a cross section such as a square.

JP 2015-117626 A JP 2005-290987 A

Thus, there is a demand for a rotor blade that is lightweight and has the necessary strength without impairing the blowing efficiency of the blower. In addition, since the rotor blade is one of the replacement parts, reducing manufacturing costs and lead time (manufacturing time) is also an issue.

The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a rotor blade that is lightweight, has sufficient strength, and can be easily manufactured, and a method for manufacturing the rotor blade. .

In order to solve the above problems, the present disclosure employs the following means.
The rotor blade of the present disclosure includes a rotor blade body having a space formed therein, and a cube provided continuously in the space of the rotor blade body and having a hollow portion formed in at least a part of the interior. and a plurality of shaped stiffening members.

In the moving blade of the present disclosure, a plurality of cubic reinforcing members (for example, adjacent cubic surfaces are provided in a continuous arrangement so as to share each other). Since each reinforcing member has a cubic shape, the rotor blade of the present disclosure can obtain uniform strength distribution in multiple directions (longitudinal axis direction of the rotor blade body and direction intersecting with the longitudinal axis direction), and sufficiently strength. Also, since each reinforcing member has a hollow inside, the blade of the present disclosure is lightweight. Therefore, it is possible to simplify each reinforcing member necessary for securing the strength of the moving blade main body and the supporting structure of the blade root portion. Further, by forming each reinforcing member into a cubic shape, it is possible to manufacture the rotor blade by a three-dimensional layered modeling machine (3D printer). As a result, there is no need to use a plurality of molds to manufacture a moving blade having a complicated shape, so the cost and lead time (manufacturing time) required for manufacturing the moving blade can be reduced, and the manufacturing can be facilitated.

In the moving blade, each side of the cubic shape of the plurality of reinforcing members is provided so as to be inclined at a predetermined angle when viewed from any direction with respect to a plane perpendicular to the longitudinal axis of the moving blade body. .

Each side of the cubic shape of each reinforcing member is provided so as to be inclined at a predetermined angle with respect to a plane perpendicular to the longitudinal axis of the rotor blade body (for example, the bottom surface of the rotor blade body in this embodiment) when viewed from any direction. A molded blade and blade body are easier to manufacture with a 3D printer. Therefore, it is possible to further reduce the cost and lead time required for rotor blade manufacturing.

In the rotor blade, it is preferable that the predetermined angle is 45°±1° with respect to each side of the cubic shape of the plurality of reinforcing members.

Each side of the cubic shape of each reinforcing member intersects a plane perpendicular to the longitudinal axis of the rotor blade body (for example, the bottom surface of the rotor blade body in this embodiment). If the predetermined angle of inclination with respect to the surface is set to 45°±1°, it becomes easier to manufacture the moving blade using a 3D printer. In addition, by setting the predetermined angle of inclination to 45°±1°, each reinforcing member is axially symmetrical with respect to the longitudinal axis of the rotor blade body in the manufactured rotor blade, so that the strength distribution is uniform. In addition to improving the strength, the structure is balanced with respect to the longitudinal axis in terms of strength, suppressing the occurrence of unbalanced load and suppressing the occurrence of damage.

In the rotor blade, it is preferable that the volume of the solid portions of the plurality of reinforcing members other than the hollow portions accounts for 11.5% or more of the volume of the spaces.

The ratio of the volume of the solid portion other than the hollow portion of each reinforcing member to the volume of the space of the rotor blade body (ratio of the space of the rotor blade body occupied by the components constituting each reinforcing member: packing density) is 11. If it is 0.5% or more, the strength and durability of the moving blade can be sufficiently secured. Specifically, in order to ensure sufficient strength required when the peripheral speed of the blade tip of the moving blade is 120 to 130 m/s, it is preferable to set the packing density to 11.5% or more as described above. preferable.

The blower of the present disclosure includes the rotor blades described above.

Since the blower of the present disclosure includes the above-described moving blades, the reinforcing member structure of the moving blade main body and the supporting structure of the blade root are simplified by weight reduction, and the cost and lead time required for manufacturing moving blades are reduced. can be reduced. Therefore, it becomes a blower with high economic efficiency.

In the rotor blade manufacturing method of the present disclosure, a plurality of cubic reinforcing members each having a hollow portion formed in at least a part thereof are provided in the space portion of a rotor blade body having a space portion formed therein. Each side of the cubic shape of the reinforcing member is continuously arranged so as to be inclined at a predetermined angle when viewed from any direction with respect to a plane perpendicular to the longitudinal axis of the rotor blade body.

In the rotor blade manufacturing method of the present disclosure, a plurality of cubic reinforcement members (for example, adjacent are arranged continuously so as to share the cubic-shaped faces of each other). Since each reinforcing member has a cubic shape, the rotor blade has sufficient strength by obtaining uniform strength distribution in multiple directions (the longitudinal axis direction of the rotor blade body and the direction crossing the longitudinal axis direction). can be manufactured. In addition, since each reinforcing member has a hollow portion formed therein, a lightweight moving blade can be manufactured. Therefore, each reinforcing member necessary for securing the strength of the rotor blade main body and the supporting structure of the blade root can be simplified, thereby facilitating manufacturing. Further, by forming each reinforcing member into a cubic shape, it becomes possible to manufacture the rotor blade by a 3D printer. As a result, there is no need to use a plurality of molds in manufacturing a rotor blade of a complicated shape, so the cost and lead time (manufacturing time) required for manufacturing the rotor blade can be reduced, and the manufacturing is facilitated.

According to the rotor blade and the method for manufacturing the rotor blade of the present disclosure, a rotor blade that is lightweight, has sufficient strength, and can be easily manufactured is obtained.

1 is a vertical cross-sectional view of a blower according to an embodiment of the present disclosure; FIG. 1 is a front view of a rotor blade according to an embodiment of the present disclosure; FIG. 1 is a side view of a part of a rotor blade in cross section according to an embodiment of the present disclosure; FIG. 1 is a front view showing the inside of a rotor blade body according to an embodiment of the present disclosure; FIG. 3B is a cross-sectional view of the rotor blade body of FIG. 3A along the AA side; FIG. FIG. 3B is a side cross-sectional view of the rotor blade body of FIG. 3A along the BB side; FIG. 3B is a side cross-sectional view of the rotor blade body of FIG. 3A along the CC side; FIG. 5 is an image diagram showing a state in which one reinforcing member is arranged on the bottom surface of the rotor blade body; FIG. 5 is an image diagram showing a state in which a plurality of reinforcing members are continuously arranged in two directions perpendicular to each other on the bottom surface of the rotor blade body; FIG. 5 is an image diagram showing a state in which a plurality of reinforcing members are continuously arranged in three mutually orthogonal directions on the bottom surface of the rotor blade body; 5 is a graph showing the relationship between the packing density of the reinforcing member and the length of one side of the reinforcing member.

Preferred embodiments according to the present disclosure will be described below with reference to the accompanying drawings. In the present embodiment, "upward" means the vertically upward direction, and "downward" means the vertically downward direction.

〔Blower〕
An axial fan (blower) 1 according to an embodiment of the present disclosure will be described below with reference to FIG. FIG. 1 shows a case in which the rotating shaft direction of the rotor blades 7 or the flow direction of the flow path 10 is the horizontal direction in the figure, but the flow path direction does not necessarily have to be the horizontal direction. may be

The axial flow fan 1 includes a main shaft 2, an impeller 3 installed and fixed to the main shaft 2, an electric motor 4, an inner cylinder 5, an outer cylinder 6, and the like. A plurality of moving blades 7 are installed on the impeller 3 in the circumferential direction of the impeller 3 . The power generated by the electric motor 4 is transmitted to the main shaft 2 and the impeller 3 to rotate around the rotation axis (one-dot chain line in FIG. 1). Between the inner cylinder 5 and the outer cylinder 6, a channel 10 is formed through which fluid such as air or gas can flow. The rotor blades 7 provided on the impeller 3 are positioned on the extension of the flow path 10 formed between the inner cylinder 5 and the outer cylinder 6, and when the rotor blades 7 provided on the impeller 3 rotate, , the fluid flows through the channel 10 formed between the inner cylinder 5 and the outer cylinder 6 .
Here, the impeller 3 is a rotor blade mounting annular portion to which the rotor blades 7 are attached and supported, and impeller is the name used in this embodiment. determined as appropriate by

In the following, an axial fan 1 is taken as an example of a blower, and a case where the present disclosure is applied to the axial fan 1 will be described, but the present disclosure is not limited to this example. The present disclosure can be applied to, for example, an axial flow fan (FDF) for blowing combustion air in a thermal power plant, as well as a primary fan for blowing fine powder carrier gas in a solid fuel crusher. In addition, the axial fan of this embodiment is suitable for blowing a non-corrosive gas at room temperature.

A side plate 8 is installed on the impeller 3 in a plane perpendicular to the rotating shaft direction of the impeller 3 . The side plate 8 is installed at the axial end of the impeller 3, as shown in FIG. The side plates 8 may be installed on the side surfaces of both ends of the impeller 3, or may be installed only on the side surface of one of the ends. In addition, an annular groove 9 is formed on the surface of the side plate 8 along the circumferential direction of the side plate 8 , thereby suppressing gas flow between the side plate 8 and the flow path 10 .

[Rotor blade]
Next, the rotor blade according to this embodiment will be described with reference to FIGS. 2A and 2B. The rotor blade according to this embodiment is applied to, for example, the axial fan 1 shown in FIG.

As shown in FIG. 2A, the rotor blade 7 is provided on the rotor blade body 11 and the bottom surface 12 side of the rotor blade body 11 (one end side of the rotor blade body 11 in the Y-axis direction), and is embedded in the rotor 3 side. and a blade root portion 13 supported by the blade. A space is formed inside the rotor blade body 11 as will be described later. In this embodiment, the side opposite to the bottom surface 12 of the rotor blade main body 11 (the other end side of the rotor blade main body 11 in the Y-axis direction) is opened to form an open portion 14 . The open part 14 communicates with a part of the space described later. It should be noted that providing the open portion 14 in the moving blade main body 11 is not necessarily a necessary structure.

As shown in FIG. 2B , a space 15 is formed inside the rotor blade body 11 from one end side to the other end side in the direction of the longitudinal axis AX of the rotor blade body 11 . In the space 15 of the rotor blade body 11, a plurality of cubic reinforcement members 21 each having a hollow portion 22 formed in at least a part thereof are continuously arranged from one end side to the other end side in the direction of the longitudinal axis AX. there is In FIG. 2B, the space 15 inside the moving blade body 11 is illustrated by simplifying the reinforcing member 21 . The rotor blade main body 11 and the reinforcing member 21 are made of, for example, the same material. Examples of materials for forming them include plastics and metals. Specifically, polycarbonate materials, nylon-based materials, and materials reinforced by mixing these with carbon fiber can be used. A specific method of continuously arranging the reinforcing member 21 with respect to the space 15 of the moving blade main body 11 will be described later.

Next, referring to FIGS. 3A to 3D, the internal shape of the rotor blade body according to this embodiment will be specifically described. FIG. 3A is a front view showing the inside of the rotor blade body 11 according to this embodiment. Note that illustration of the blade root portion 13 is omitted in FIGS. 3A to 3D.

As shown in FIG. 3A, the moving blade main body 11 has a bottom surface 12 and an outer peripheral surface 16, and an open portion 14 is formed in the upper portion which is the other end. Inside the rotor blade body 11, a space 15 is formed from one end side to the other end side in the direction of the longitudinal axis AX of the rotor blade body 11 and from the center of the rotor blade body 11 in the direction of the longitudinal axis AX to the outer peripheral surface 16. there is

The space 15 has a hollow portion at least partly inside from one end side to the other end side in the direction of the longitudinal axis AX of the rotor blade body 11 and from the center of the rotor blade body 11 in the direction of the longitudinal axis AX to the outer peripheral surface 16. A plurality of cubic reinforcing members 21 having 22 formed thereon are continuously arranged. Specifically, a plurality of reinforcing members 21 are continuously arranged so that the internal structure of the rotor blade body 11 has a lattice shape when viewed from the front. The solid lines indicating the sides of the cubic shape of the reinforcing member 21 in FIG. 3A indicate the sides around the surfaces forming the reinforcing member 21. and manufacturing conditions, it is, for example, 2 mm or more. In this embodiment, the thickness of each surface constituting each reinforcing member 21 is made equal.

Each side of the cubic shape of each reinforcing member 21 provided in the space 15 is inclined at a predetermined angle with respect to a plane perpendicular to the longitudinal axis AX of the moving blade main body 11 . The predetermined angle is selected in consideration of the material, manufacturing conditions, manufacturing error, etc., and is provided so as to incline at 45°±1°. In the present embodiment, among the reinforcing members 21 provided in the space 15, those provided at the lowest end (for example, the reinforcing members 21A, 21B, and 21C in FIG. 3A) have a cubic shape whose lowermost sides are It is connected to the bottom surface 12 of the main body 11 at a point, facilitating management of the reference position for design and manufacture. The connection point between the bottom side of the cubic shape of the reinforcing member 21 and the bottom surface 12 is not limited to the vertex portion of the reinforcing member 21 .

As shown in FIG. 3A, in this embodiment, each reinforcing member 21 has the same side length, the thickness of each side, and the angle of inclination of each side of the cubic shape, so that the strength distribution is uniform. are improving their sexuality. On the other hand, if anisotropic strength is required in a specific direction of the rotor blade body 11, it is not limited to this.

FIG. 3B is a cross-sectional view of the rotor blade body 11 of FIG. 3A along the AA side. Specifically, FIG. 3B is a side sectional view including a point where the reinforcing member 21A and the reinforcing member 21B in FIG. 3A are connected at a point when viewed from the front. 3B, each side of the cubic shape of each reinforcing member 21 is 45°±1° as a predetermined angle with respect to a plane orthogonal to the longitudinal axis AX of the rotor blade body 11 (hereinafter, 45° with the range omitted). °) are continuously arranged in a grid shape so as to be inclined. In FIG. 3B as well, the lowermost sides of the cubic shape of the reinforcement member 21 provided at the lowermost end are all connected to the bottom surface 12 of the rotor blade body 11 at points. In addition, in FIG. 3B, the white arrow indicates the front direction, and the same applies to FIGS. 3C and 3D.

FIG. 3C is a BB side sectional view of the rotor blade body 11 of FIG. 3A. Specifically, FIG. 3C is a side cross-sectional view including a point where the reinforcing member 21B is connected to the bottom surface 12 of the rotor blade body 11 in FIG. 3A. As shown in FIG. 3C, the reinforcing member 21B provided on the front side has a cubic shape in which approximately half of the front side is missing. In FIG. 3C as well, each side of the cubic shape of each reinforcing member 21 is continuously arranged in a lattice shape so as to be inclined at a predetermined angle of 45° with respect to a plane perpendicular to the longitudinal axis AX of the moving blade main body 11 . In FIG. 3C as well, the lowermost sides of the cubic shape of the reinforcing member 21 provided at the lowermost end are all connected to the bottom surface 12 of the rotor blade body 11 at points.

FIG. 3D is a CC side sectional view of the rotor blade body of FIG. 3A. Specifically, FIG. 3D is a side cross-sectional view of a portion in FIG. 3A where each side of the cubic shape of the reinforcing member 21C is not connected to other adjacent reinforcing members or the bottom surface 12 at points in a front view. As shown in FIG. 3D, the reinforcing member 21C provided on the front side has a cubic shape in which a part of the front side is missing. In FIG. 3D as well, each side of the cubic shape of each reinforcing member 21 is continuously arranged in a lattice shape so as to be inclined at a predetermined angle of 45° with respect to a plane perpendicular to the longitudinal axis AX of the rotor blade body 11 .

As shown in FIGS. 3A to 3D, inside the rotor blade body 11, each side of the cubic shape of each reinforcing member 21 intersects with the direction of the longitudinal axis AX of the rotor blade body 11 (front view). direction, side cross-sectional direction, etc.), the inclination angle with respect to a plane perpendicular to the longitudinal axis AX of the moving blade main body 11 is set to 45° as a predetermined angle. That is, in the moving blade 7, each reinforcing member 21 has a shape that is axially symmetrical with respect to the longitudinal axis AX direction of the moving blade main body 11, so that the strength is well-balanced.

Next, referring to FIGS. 4A to 4C, a specific method of continuously arranging the reinforcing members in this embodiment will be described in detail. The cubes shown in FIGS. 4A to 4C are images of individual cubes for explaining the structure of the reinforcing member 21 inside the rotor blade 7 . In the present embodiment, a manufacturing method in which a plurality of cubes are individually manufactured with the reinforcing member 21 and the cubes are arranged and connected to provide the reinforcing member 21 in the space 15 of the moving blade main body 11 is not used. When manufacturing the rotor blade 7, a three-dimensional layered molding machine (3D printer) is used to continuously arrange cubes in the space 15 of the rotor blade body 11, so that the surfaces of the adjacent cubes are shared. Reinforce as follows. With this structure, the internal structure of the rotor blade main body 11 is configured such that a plurality of reinforcing members 21 shown in FIGS. 4A to 4C are continuously arranged.

FIG. 4A is an image diagram showing a state in which one reinforcing member 21 is arranged on the bottom surface 12 of the rotor blade body 11. FIG. In this embodiment, the bottom surface 12 is a surface perpendicular to the longitudinal axis AX of the moving blade main body 11 . As shown in FIG. 4A , each side of the cubic shape of the reinforcing member 21 is provided such that each side of the cubic shape of the reinforcing member 21 is inclined at a predetermined angle of 45° with respect to the bottom surface 12 of the rotor blade body 11 on the XY axis plane. Although not shown, each side of the cubic shape of the reinforcing member 21 is provided so that the angle of inclination with respect to the bottom surface 12 of the rotor blade body 11 is 45° on the YZ-axis plane and the XZ-axis plane as well. The length of one side of each side of the cubic reinforcing member 21 (pitch of the reinforcing member 21) L is the thickness of the wall surface of the reinforcing member 21, considering the ease of manufacturing the rotor blade 7 with a 3D printer. For example, it may be 2 mm or more. Further, there is an upper limit to the length L of one side of the reinforcing member 21 in order to ensure the strength of the moving blade main body 11. In this embodiment, the upper limit is, for example, 50 mm as described later. For this reason, preferably L is in the range of 2 mm to 50 mm.

FIG. 4B is an image diagram showing a state in which six reinforcing members 21 are continuously arranged in two mutually orthogonal directions. Specifically, from the bottom surface 12 side, the reinforcing members 21 are arranged in the order of three, two, and one, so that adjacent cubic surfaces are shared (surfaces of the adjacent reinforcing members 21 are placed consecutively so that they overlap). 4B, each side of the cubic shape of each reinforcing member 21 is provided so that the angle of inclination with respect to the bottom surface 12 of the rotor blade body 11 is 45° in the XY-axis plane, the YZ-axis plane, and the XZ-axis plane. there is

FIG. 4C is an image diagram showing a state in which 18 reinforcing members 21 are continuously arranged in three mutually orthogonal directions. Specifically, two sets of six reinforcing members 21 stacked in the same manner as in FIG. 4B are prepared for the six reinforcing members 21 stacked as shown in FIG. piled up. 4C, each side of the cubic shape of each reinforcing member 21 is provided so that the angle of inclination with respect to the bottom surface 12 of the rotor blade body 11 is 45° in the XY-axis plane, the YZ-axis plane, and the XZ-axis plane. there is

Next, referring to FIG. 5, the ratio of the volume of the solid portion of each reinforcing member 21 other than the hollow portion 22 to the volume of the space portion 15 of the rotor blade body 11 A specific description will be given of a method for determining a suitable range of the ratio of the main body 11 to the space 15 (filling density).
The packing density of the reinforcing member 21 in the space 15 is determined by the thickness of the surface forming the reinforcing member 21 and the length L of one side of the reinforcing member 21 .

FIG. 5 is a graph showing the relationship between the packing density of the reinforcing member 21 and the length L of one side of the reinforcing member 21. As shown in FIG. In FIG. 5 , the vertical axis indicates the packing density (%) of the reinforcing member 21 and the horizontal axis indicates the length L of one side of the reinforcing member 21 . In FIG. 5, the graph indicated by the solid line is the graph when the thickness of the surface forming the reinforcing member 21 is 2 mm. In FIG. 5, the graph indicated by the dashed-dotted line is the graph when the thickness of the surface constituting the reinforcing member 21 is made thicker than 2 mm. In FIG. 5, the graph indicated by the dashed line is the graph when the thickness of the surface forming the reinforcing member 21 is less than 2 mm.

As an example, a case will be described in which the necessary strength is ensured for the moving blade 7 and the moving blade main body 11 when the peripheral speed of the blade tip of the moving blade 7 is 120 to 130 m/s. In this case, as shown in the solid line graph in FIG. If the packing density of the member 21 is 11.5% or more and less than 100%), the strength of the rotor blade main body 11 can be sufficiently secured. That is, when the peripheral speed of the blade tip of the moving blade 7 is 120 to 130 m/s, the moving blade main body 11 is required to have a packing density of the reinforcing member 21 of 11.5% or more and less than 100%. It is a range in which sufficient strength can be secured (strength securing range). In addition, the strength securing range is appropriately determined based on the value of the peripheral speed of the blade tip of the rotor blade 7 . By setting L to be 2 mm or more, the thickness is equal to or greater than the thickness of the wall surface of the reinforcing member 21, thereby facilitating manufacturing control. Further, by effectively increasing L with respect to the strength required for the moving blade main body 11, it is possible to prevent an increase in cost and weight due to a decrease in the hollow portion 22. FIG. On the other hand, by setting L to 50 mm or less, the strength and durability of the rotor blade 7 and the rotor blade body 11 can be sufficiently ensured without impairing the blowing efficiency of the blower due to deformation of the rotor blade body 11 or the like.

As the thickness of the surface forming the reinforcing member 21 increases, the proportion of the solid portion other than the hollow portion 22 of each reinforcing member 21 increases (that is, the packing density increases). As the thickness of the surface forming the reinforcing member 21 becomes thinner, the proportion of the solid portion other than the hollow portion 22 of each reinforcing member 21 decreases (that is, the packing density decreases). Therefore, when the thickness of the surface constituting the reinforcing member 21 exceeds 2 mm, as shown in the dashed line graph in FIG. The lower limit becomes larger than the thickness of 2 mm. On the other hand, when the thickness of the surface constituting the reinforcing member 21 is less than 2 mm, the upper and lower limits of L for obtaining a filling density within the strength ensuring range are lower than when the thickness is 2 mm. becomes smaller. Taking these factors into consideration, L, which is the length of one side of the reinforcing member 21, is appropriately selected according to the size of the rotor blade 7 and the rotor blade main body 11 and the required strength.

[Manufacturing method of rotor blade]
Next, an example of the manufacturing method of the rotor blade of the present disclosure will be described.
In the rotor blade manufacturing method of the present disclosure, a plurality of cubic reinforcing members each having a hollow portion formed in at least a part thereof are continuously arranged in a space portion of a rotor blade body having a space portion formed therein. It has a step of providing.

In addition, although the case of manufacturing the rotor blade 7 shown in FIG. 2A will be described below as an example, the present invention is not limited to this.

In the method for manufacturing the moving blade 7 of the present embodiment, a plurality of cubic reinforcing members 21 each having a hollow portion 22 formed in at least a part thereof are continuously arranged in the space 15 of the moving blade main body 11. . As a method of continuously arranging the reinforcing members 21, for example, as shown in FIGS. 4A to 4C, the reinforcing members 21 are continuously arranged so that the cubic surfaces adjacent to the bottom surface 12 of the rotor blade body 11 are shared. methods can be mentioned.

The rotor blade 7 can be manufactured using, for example, a three-dimensional layered manufacturing machine (3D printer). Specifically, a FDM (Fused Deposition Modeling) 3D printer is used to reinforce the space 15 of the rotor blade main body 11 into a structure in which cubes are continuously arranged when the rotor blade 7 is manufactured. , the internal structure of the rotor blade body 11 can be such that a plurality of reinforcing members 21 are arranged in succession.

With the configuration described above, according to this embodiment, the following effects are obtained.
In the moving blade 7 of the present embodiment, a plurality of cubic reinforcing members 21 each having a hollow portion 22 formed in at least a part thereof are provided in the space 15 formed inside the moving blade main body 11 (for example, are arranged continuously so as to share adjacent cubic faces. Since each reinforcing member 21 has a cubic shape, the rotor blade 7 of the present embodiment has a uniform strength distribution in multiple directions (the direction of the longitudinal axis AX of the rotor blade body 11 and the direction crossing the direction of the longitudinal axis AX). It is durable and has sufficient strength. Further, since each reinforcing member 21 has a hollow portion 22 formed therein, the rotor blade 7 of the present embodiment is lightweight. Therefore, each reinforcing member 21 necessary for securing the strength of the moving blade main body 11 and the supporting structure of the blade root portion 13 can be simplified. Further, by forming each reinforcing member 21 into a cubic shape, it is possible to manufacture the rotor blade by a 3D printer. As a result, there is no need to use a plurality of molds when manufacturing a moving blade having a complicated shape, so the cost and lead time required for manufacturing the moving blade can be reduced, and the manufacturing can be facilitated.

Each side of the cubic shape of each reinforcing member 21 has a predetermined angle with respect to a plane perpendicular to the longitudinal axis AX of the rotor blade body 11 (for example, the bottom surface 12 of the rotor blade body 11 in this embodiment) when viewed from any direction. If the rotor blade 7 and the rotor blade main body 11 are provided so as to incline with , it becomes easier to manufacture with a 3D printer. Therefore, it is possible to further reduce the cost and lead time required for rotor blade manufacturing.

When viewed from any direction in which each side of the cubic shape of each reinforcing member 21 intersects a plane orthogonal to the longitudinal axis AX of the rotor blade body 11 (for example, the bottom surface 12 of the rotor blade body 11 in this embodiment) If the rotor blade 7 and the rotor blade main body 11 are provided so that the inclination angle with respect to the plane perpendicular to the longitudinal axis AX is 45°±1° as a predetermined angle, the rotor blade 7 can be manufactured more easily by a 3D printer. becomes. Further, by setting the predetermined inclination angle to 45°±1°, in the manufactured moving blade 7, each reinforcing member 21 becomes axially symmetrical with respect to the longitudinal axis AX direction of the moving blade main body 11. In addition to improving the uniformity of the strength distribution, the structure is balanced in terms of strength, suppressing the occurrence of unbalanced load and suppressing the occurrence of damage.

The ratio of the volume of the solid portion of each reinforcing member 21 other than the hollow portion 22 to the volume of the space 15 of the rotor blade body 11 If the ratio (packing density) is 11.5% or more, the strength and durability of the rotor blade 7 can be sufficiently secured. Specifically, in order to ensure sufficient strength required when the peripheral speed of the blade tip of the rotor blade 7 is 120 to 130 m/s, the packing density is set to 11.5% or more as described above. is preferred.

Since the blower 1 of the present embodiment includes the rotor blades 7 described above, the structure of the reinforcing member for the rotor blade main body 11 and the support structure of the blade root portion 13 are simplified by weight reduction, and the manufacturing of the rotor blades is simplified. Cost and lead time can be reduced. Therefore, the air blower 1 is highly economical.

In the method for manufacturing the rotor blade 7 of the present embodiment, a plurality of cubic shaped hollow portions 22 are formed in at least a part of the space portion 15 of the rotor blade body 11 in which the space portion 15 is formed. The reinforcing members 21 are continuously arranged (for example, so as to share adjacent cubic surfaces). Since each reinforcing member 21 has a cubic shape, uniformity in strength distribution is obtained in multiple directions (the direction of the longitudinal axis AX of the blade body 11 and the direction intersecting the direction of the longitudinal axis AX), resulting in sufficient strength. can be manufactured. In addition, since each reinforcing member 21 has a hollow portion 22 formed therein, a lightweight moving blade 7 can be manufactured. Therefore, each reinforcing member 21 necessary for securing the strength of the moving blade main body 11 and the supporting structure of the blade root portion 13 can be simplified, thereby facilitating manufacturing. Further, by forming each reinforcing member 21 into a cubic shape, it is possible to manufacture the rotor blade by a 3D printer. As a result, there is no need to use a plurality of molds for manufacturing a moving blade having a complicated shape, so the cost and lead time required for manufacturing the moving blade can be reduced, and the manufacturing is facilitated.

In the above-described embodiment, the case where the upper end of the rotor blade body 11 is opened and the open portion 14 is provided has been described as an example, but the present invention is not limited to this. For example, the upper end of the moving blade body 11 may be closed. By providing the opening 14 at the upper end of the moving blade main body 11, the manufacturing cost can be reduced. Therefore, it becomes easy to manufacture the moving blade 7 . In addition, the eigenvalue of the rotor blade 7 can be adjusted by accessing the inside of the rotor blade body 11 from the open portion 14 and depositing a material such as a filler. In addition, since a counterweight can be installed in the open portion 14 as necessary, it is also effective in balancing the rotation of the blower (axial fan) 1 .

In the above-described embodiment, the case where the reinforcing member 21 is provided so as to be inclined from any direction with respect to the plane perpendicular to the longitudinal axis AX of the rotor blade body has been described as an example, but the present invention is not limited to this. . For example, each reinforcing member 21 may be provided in the space 15 so that each reinforcing member 21 is parallel to the bottom surface 12 of the rotor blade body 11 (so as to be in surface contact with the bottom surface 12).

In addition, the rotor blades of the present disclosure described above need not be applied to all of the rotor blades provided in the blower. It is good also as a mode to carry out.

1 Axial fan (blower)
2 Main shaft 3 Impeller 4 Electric motor 5 Inner cylinder 6 Outer cylinder 7 Moving blade 8 Side plate 9 Groove 10 Channel 11 Moving blade main body 12 Bottom surface 13 Blade root 14 Open portion 15 Space 16 Outer peripheral surface 21, 21A, 21B, 21C Reinforcing member 22 Hollow part AX Longitudinal axis L Length of one side

Claims (5)

a rotor blade body having a space formed therein;
a plurality of cubic reinforcing members continuously arranged in the space of the rotor blade body and having a hollow portion formed in at least a part of the interior thereof;
with
Each side of the cubic shape of the plurality of reinforcing members is provided so as to be inclined at a predetermined angle with respect to a plane orthogonal to the longitudinal axis of the rotor blade body when viewed from any direction. 2. The moving blade according to claim 1 , wherein the predetermined angle is 45[deg.]±1[deg.] with respect to each side of the cubic shape of the plurality of reinforcing members. 3. The rotor blade according to claim 1 , wherein the ratio of the volume of the solid portions other than the hollow portions of the plurality of reinforcing members to the volume of the space is 11.5% or more. A fan comprising the moving blade according to any one of claims 1 to 3 . A plurality of cubic reinforcing members having a hollow portion formed in at least a part of the inside thereof are provided in the space portion of the moving blade body having a space formed therein, and each side of the cubic shape of the plurality of reinforcing members 3. A method of manufacturing a moving blade, comprising the step of continuously arranging the moving blade body so as to be inclined at a predetermined angle when viewed from any direction with respect to a plane perpendicular to the longitudinal axis of the moving blade body.

Images