JP2020125732A - Manufacturing method for impeller and impeller - Google Patents

Abstract

To restrain deformation of end parts of an impeller when the impeller is formed by a lamination molding method.SOLUTION: A manufacturing method comprises: a structure formation step S1 of forming a structure comprising an impeller and a reinforcing member, by a lamination molding method; and a removal step S4 of removing the reinforcing member from the structure. In the structure formation step S1, the impeller comprises at least a pair of end parts arranged vertically, and the structure is formed so that one end of the reinforcing member is connected to at least a portion of an upper end part out of the pair of end parts.SELECTED DRAWING: Figure 7

Description

The present invention relates to an impeller manufacturing method and an impeller.

Conventionally, various impellers are used according to the pump. There are closed impeller, open impeller, non-clog type impeller and so on. The closed impeller is an impeller having a side plate in a centrifugal pump and a mixed flow pump. The open impeller is a centrifugal pump and a mixed flow pump and has no side plate. Of these, the one with the main plate extending to the outer circumference of the blade is called a semi-open type impeller, and the one with the main plate as short as possible is the full-open type impeller.

Further, different types of impellers are used depending on the suction type. In the case of a single suction pump, a single suction impeller is used, and in the case of a double suction pump, a double suction impeller is used. The impeller for both suction sucks fluid from both the left and right sides of the impeller evenly and accelerates. For example, a double suction impeller is used in a horizontal shaft double suction centrifugal pump.

As a technique applied to the 3D printer, a technique called a layered manufacturing method using a laser or the like is known. In this technique, for example, a metal powder is sintered or melted on a substantially two-dimensional plane by a laser or the like, and the metal powder is piled up to obtain a three-dimensional shape. Patent Document 1 describes a method of forming an impeller applied to a turbine wheel by an additive manufacturing method.

JP, 2016-037901, A

However, when forming an impeller used for a pump (especially a pump whose liquid carrier is a liquid) by the additive manufacturing method, if there is no supporting member below the end of the impeller, gravity will occur during the additive manufacturing. There is a problem that the end of the impeller falls and the end of the impeller (for example, the part that becomes the inlet or outlet of the flow path) is easily deformed.

The present invention has been made in view of the above problems, and a method for manufacturing an impeller and an impeller that can suppress the deformation of the end portion of the impeller when the impeller is formed by the additive manufacturing method. The purpose is to provide.

A method for manufacturing an impeller according to a first aspect of the present invention includes a structure forming step of forming a structure having an impeller and a reinforcing member by an additive manufacturing method, and removing the reinforcing member from the structure. In the structure forming step, the impeller has at least a pair of upper and lower end portions, and one end of the reinforcing member is an upper portion of the pair of end portions. The structure is formed so as to be connected to at least a part of an end of the structure.

According to this configuration, the reinforcing member supports at least a part of the upper end portion of at least a pair of upper and lower end portions, so that the deformation of the upper end portion can be suppressed. Therefore, when the impeller is formed by the additive manufacturing method, the deformation of the end portion of the impeller can be suppressed.

A method for manufacturing an impeller according to a second aspect of the present invention is the method for manufacturing an impeller according to the first aspect, wherein in the structure forming step, at least the reinforcing member of the reinforcing member is used. One end is formed to have substantially the same metal density as the end of the impeller to be connected.

According to this structure, one end of the reinforcing member has substantially the same density as the end of the impeller to be connected, and the reinforcing member can be maintained with the same strength as the end of the impeller. Can be suppressed. Further, since the reinforcing members have substantially the same density, the end portion of the impeller has the same heat dissipation property as the other portions of the impeller, so that the end portion of the impeller has the same speed as the other portions of the impeller. Since it is cooled by, deformation is suppressed.

A method for manufacturing an impeller according to a third aspect of the present invention is the method for manufacturing an impeller according to the first or second aspect, wherein in the structure forming step, the reinforcing members are connected to each other. It is formed at a density lower than the end of the impeller and at an angle inclined from the end of the impeller.

According to this configuration, the amount of material of the reinforcing member can be reduced, so that the manufacturing cost of the impeller can be suppressed. At the same time, since the reinforcing member is formed at an angle inclined from the end of the impeller, deformation of the reinforcing member is suppressed.

A method for manufacturing an impeller according to a fourth aspect of the present invention is the method for manufacturing an impeller according to any one of the first to third aspects, wherein in the structure forming step, at least a part of the structure is provided. Are supported and formed by a member having a metal density lower than that of the structure.

A method for manufacturing an impeller according to a fifth aspect of the present invention is the method for manufacturing an impeller according to any one of the first to fourth aspects, wherein the reinforcing member extends from the one end of the reinforcing member. The distance that the reinforcing member extends is equal to or less than the limit distance that is determined according to the material of the reinforcing member.

According to this configuration, by setting the distance that the reinforcing member extends to be equal to or less than the limit distance that is determined according to the material of the reinforcing member, it is possible to suppress the possibility that the reinforcing member collapses on the way.

A method for manufacturing an impeller according to a sixth aspect of the present invention is the method for manufacturing an impeller according to any one of the first to fifth aspects, in which the impeller is extended substantially horizontally from the one end of the reinforcing member. And a second member that extends in the vertical direction from the other end of the reinforcing member to support the first member, and the second member and the lower part of the pair of end portions. Has a horizontal distance to the end of.

According to this configuration, the lower end of the pair of end portions can be supported, so that the deformation of the lower end of the pair of end portions can be suppressed.

A method for manufacturing an impeller according to a seventh aspect of the present invention is the method for manufacturing an impeller according to any one of the first to sixth aspects, wherein at least one of a pair of end portions located at a lower end is located. It has a second reinforcing member extending from a part, the second reinforcing member has a first member extending from the one end of the reinforcing member, and the distance by which the first member extends is It is less than or equal to the limit distance determined according to the material of the first member.

According to this configuration, the lower end of the pair of end portions can be supported, so that the deformation of the lower end of the pair of end portions can be suppressed.

An impeller manufacturing method according to an eighth aspect of the present invention is the impeller manufacturing method according to any one of the first to seventh aspects, wherein the impeller includes a main plate, a side plate, and the main plate. A main wing provided between the side plate and the side plate for giving energy to the pumping liquid, and the pair of end portions is an end portion on the discharge side of the main plate or the side plate.

According to this configuration, the upper end of the discharge side end of the main plate or the side plate can be supported, so that the deformation of the discharge side end of the main plate or the side plate can be suppressed.

A method for manufacturing an impeller according to a ninth aspect of the present invention is the method for manufacturing an impeller according to any one of the first to seventh aspects, wherein the impeller includes a main plate, a side plate, and the main plate. A plurality of main wings provided between the side plate and the side plate, and the pair of end parts is an end part on the suction side of the side plate.

According to this configuration, since the suction-side end of the side plate can be supported, it is possible to suppress deformation of the suction-side end of the side plate.

A method for manufacturing an impeller according to a tenth aspect of the present invention is the method for manufacturing an impeller according to any one of the first to seventh aspects, wherein the impeller has a plurality of main blades that impart energy to pumping liquid. And the pair of end portions are end portions of adjacent main wings of the plurality of main wings.

According to this configuration, the ends of the adjacent main wings of the plurality of main wings can be supported, so that the deformation of the ends of the adjacent main wings of the plurality of main wings can be suppressed.

An impeller according to an eleventh aspect of the present invention is an impeller provided with a main plate, a side plate, and a main blade that is provided between the main plate and the side plate to give energy to pumping liquid, the main plate A flow path formed by the side plate and the main blade is formed by additive manufacturing, and at least one outer peripheral surface of the main plate and the side plate is formed by cutting.

According to this configuration, since the flow path is formed by additive manufacturing, the processing accuracy of the flow path is improved, and since the outer peripheral surface of at least one of the main plate and the side plate is cut, the processing accuracy of the end portion is improved. Is improved.

An impeller according to a twelfth aspect of the present invention is the impeller according to the eleventh aspect, wherein the flow passage surface and the outer peripheral surface have different surface roughnesses.

An impeller according to a thirteenth aspect of the present invention is the impeller according to the twelfth aspect, wherein the flow passage surface has a rougher surface than the outer peripheral surface.

A manufacturing method for an impeller according to a fourteenth aspect of the present invention is a structure forming step of forming a structure having an impeller and a reinforcing member by a layered manufacturing method, and removing the reinforcing member from the structure. In the structure forming step, the impeller is arranged such that a circular opening at an end of the impeller is perpendicular to a stacking surface, and one end of the reinforcing member is provided. However, the structure is formed so as to be connected to at least a part of an end of the circular end above the midpoint.

A method for manufacturing an impeller according to a fifteenth aspect of the present invention is the method for manufacturing an impeller according to the fourteenth aspect, wherein the circular opening at the end of the impeller is a suction port.

A method for manufacturing an impeller according to a sixteenth aspect of the present invention is the method for manufacturing an impeller according to the fourteenth or fifteenth aspects, wherein the circular opening at the end of the impeller is an opening of the impeller hub. ..

According to one aspect of the present invention, since the reinforcing member laminated from the base plate supports at least a part of the end portion of the main plate and the side plate to be laminated and manufactured later, one of the main plate and the side plate to be laminated and molded later. It is possible to suppress the deformation of the end portion of the. Therefore, when the impeller is formed by the additive manufacturing method, the deformation of the end portion of the impeller can be suppressed.

It is sectional drawing which shows the structure of the pump which concerns on 1st Embodiment. It is a front view of the pump casing of the pump shown in FIG. It is sectional drawing of the impeller shown in FIG. FIG. 4 is a partially cutaway front view of the impeller shown in FIG. 3 when viewed from the suction port side. It is sectional drawing of an example of the structure formed in the middle of the manufacturing process of the impeller which concerns on 1st Embodiment. It is a front view of a part cut when the structure formed in the manufacturing process of the impeller concerning a 1st embodiment is seen from the suction opening side. It is a flow chart which shows an example of the flow of the manufacturing method of the impeller concerning a 1st embodiment. It is sectional drawing of an example of the structure which concerns on the 1st modification of 1st Embodiment. It is sectional drawing of an example of the structure which concerns on the 2nd modification of 1st Embodiment. It is sectional drawing of an example of the structure which concerns on 2nd Embodiment. It is sectional drawing of an example of the structure which concerns on 3rd Embodiment. It is sectional drawing of an example of the structure which concerns on 4th Embodiment. It is a perspective view of an example of the structure concerning a 5th embodiment. It is sectional drawing of an example of the structure which concerns on 5th Embodiment.

Hereinafter, each embodiment will be described with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters and repeated description of substantially the same configuration may be omitted. This is for avoiding unnecessary redundancy in the following description and for facilitating understanding by those skilled in the art.

In the present embodiment, a structure serving as a prototype of the impeller according to the present embodiment is formed on the base plate by an additive manufacturing method using metal powder. Here, in the additive manufacturing method, the metal powder arranged according to the desired shape of the impeller is sintered by thermal energy such as laser or electron beam. By sequentially repeating the steps of arranging and sintering the metal powder, the sintered metal powder is laminated to form a structure that is a prototype of the impeller having a desired shape.

FIG. 1 is a cross-sectional view showing the structure of the pump according to the first embodiment. FIG. 2 is a front view of the pump casing of the pump shown in FIG. As shown in FIGS. 1 and 2, the pump includes a pump casing 1 having a suction port 1a and a discharge port 1b, and a casing cover 2. The impeller 3 is arranged inside the pump casing 1 so that its suction port 9 (see FIG. 3) faces the suction port 1a of the pump casing 1, and the fluid that has entered the pump casing 1 through the suction port 1a is The pressure is increased through the impeller 3 and is discharged to the outside from the discharge port 1b of the pump casing 1. The impeller 3 is fixed to an end portion of a pump shaft 6, which is a main shaft supported by bearings 5a and 5b incorporated in a bearing body 4, on the pump casing 1 side. A drive machine (not shown) is connected to the other end of the pump shaft 6, and the impeller 3 is rotationally driven via the pump shaft 6. FIG. 2 shows a view of the pump casing 1 as seen from the bearing body 4 side.

FIG. 3 is a cross-sectional view of the impeller shown in FIG. FIG. 4 is a partially cut front view of the impeller shown in FIG. 3 as viewed from the suction port side. As shown in FIGS. 3 and 4, the impeller 3 includes an impeller hub 10, a main plate 11, a side plate 12, and a plurality of main blades 13 arranged between the main plate 11 and the side plate 12. The impeller hub 10 is a rotating body that has an opening 8 through which the pump shaft 6 penetrates, is fixed to the pump shaft 6, and mounts the main wing 13. The main plate 11 is a side wall of the side walls forming the impeller 3 and connected to the impeller hub 10. The side plate 12 is a side wall of the side walls forming the impeller 3 that is supported by the main wing 13. The main wing 13 is a blade that gives energy to the pumped liquid, and is attached to the impeller hub 10. In this example, the main wing 13 is formed in a plate shape having a thickness t1, and is disposed between the front surface 13a of one main wing 13 on the rotation direction side and the back surface 13b of the other main wing 13 on the anti-rotation direction side that are adjacent to each other. The flow paths 20 are formed in sections. Further, FIG. 3 shows the outlet width B2 of the flow path 20 formed between the main plate 11 and the side plate 12.

FIG. 5: is sectional drawing of an example of the structure formed in the middle of the manufacturing process of the impeller which concerns on 1st Embodiment. FIG. 6 is a partially cut front view of the structure formed during the manufacturing process of the impeller according to the first embodiment, as seen from the suction port 9 side of the impeller 3. As shown in FIGS. 5 and 6, the structure 14 serving as a prototype of the impeller 3 includes an impeller hub 10, a main plate 11, a side plate 12, and a plurality of main wings provided between the main plate 11 and the side plate 12. An impeller 3 including a support member 22, a support member 22 that supports the side plate 12, a support member 23 that supports the impeller hub 10, and a reinforcing member 30. The structure 14 is formed on the base plate 21 by an additive manufacturing method using metal powder.

As shown in FIGS. 5 and 6, one end portion 30 a of the reinforcing member 30 is connected to the outer peripheral surface 11 c of the main plate 11. The second member 32 of the reinforcing member 30 is separated from the outer peripheral surface 11c of the main plate 11, and the other end 30b of the reinforcing member 30 is connected to the base plate 21.

More specifically, the reinforcing member 30 includes a first member 31 extending from one end 30a of the reinforcing member 30 toward the outer peripheral surface 11c of the main plate 11 and a vertical direction from the other end 30b of the reinforcing member 30. A second member 32 that extends to support the first member 31. The horizontal distance D between the second member 32 and the side plate 12 is set to be equal to or less than the limit distance determined according to the material to be molded. According to this configuration, by setting the horizontal distance D between the second member 32 and the main plate 11 to be equal to or less than the limit distance, it is possible to prevent the reinforcing member 30 from collapsing halfway. In the present embodiment, since the main plate 11 is arranged substantially horizontally and is laminated and manufactured, the first member 31 extends substantially horizontally from the one end portion 30 a of the reinforcing member 30. In one embodiment, the main plate 11 may be arranged to be inclined from the horizontal for additive manufacturing, and/or the first member 31 may be disposed at a predetermined angle from the one end 30a of the reinforcing member 30 with respect to the horizontal. You may stretch. Then, the horizontal distance D can be increased. In addition, in the layered manufacturing, it is possible to suppress the deformation of the formed structure 14 by minimizing the area of the horizontal planes that are sequentially layered. By forming the first member 31 at an angle inclined from the horizontal, the deformation of the reinforcing member 30 can be suppressed.

In the structure forming step according to the present embodiment, it is preferable that at least one end portion 30a of the reinforcing member 30 is formed to have substantially the same metal density as that of the impeller 3. Thereby, the one end portion 30a of the reinforcing member 30 connected to the outer peripheral surface 11c of the main plate 11 has substantially the same metal density as that of the main plate 11, and the reinforcing member 30 can be maintained with the same strength as the end portion of the main plate 11, so that the main plate 11 can be maintained. It is possible to suppress the deformation of the outer peripheral surface of the. In addition, in the layered modeling, if the heat at the time of modeling cannot be radiated well, the result is deformation. Here, if the outer peripheral surface 11c does not have the reinforcing member 30, the outer peripheral surface 11c is in contact with air and is less likely to radiate heat. Further, when the reinforcing member 30 having a metal density lower than that of the outer peripheral surface 11c comes into contact, the outer peripheral surface 11c may be partially deformed because it is less likely to radiate heat than the other parts of the impeller 3. However, if the reinforcing member 30 having substantially the same metal density as that of the outer peripheral surface 11c comes into contact with the outer peripheral surface 11c, the outer peripheral surface 11c has the same heat dissipation as the other parts of the impeller, and therefore the outer peripheral surface 11c does not correspond to other parts of the impeller. It is cooled at the same speed as the part and deformation is suppressed. In the present embodiment, all the first members 31 are formed with the same metal density as the impeller 3. In one embodiment, at least a part of the outer peripheral side of the first member 31 may be formed with a metal density lower than that of the impeller 3 (for example, a mesh structure or a sponge-like shaped object).

In the structure forming step according to the present embodiment, at least the other end 30b of the reinforcing member 30 of the reinforcing member 30 is formed with a metal density lower than that of the impeller 3 (for example, a mesh structure or a sponge-like shaped object). May be. Thereby, the amount of metal of the reinforcing member 30 can be reduced, so that the manufacturing cost of the impeller can be suppressed. In this embodiment, all the second members 32 are formed with a metal density lower than that of the impeller 3 (for example, a mesh structure or a sponge-like shaped object). In one embodiment, at least a part of the second member 32 may be formed with the same metal density as the impeller 3.

In the structure forming step according to this embodiment, the support member 22 may be formed to have a lower metal density (for example, a mesh structure or a sponge-like shaped object) than the impeller 3. As a result, the amount of metal of the support member 22 can be reduced, so that the manufacturing cost of the impeller 3 can be suppressed. In the present embodiment, the support member 22 is formed to support the impeller hub 10 and the side plate 12 as a whole. In one embodiment, the support member 22 may be formed to support at least a part of the side plate 12 as long as the side plate 12 can be stably formed due to the small diameter of the impeller 3 or the like. Furthermore, the support member 22 may be omitted.

The manufacturing method of the impeller according to the first embodiment will be described with reference to FIG. 7. FIG. 7 is a flowchart showing an example of the flow of the method for manufacturing the impeller according to the first embodiment.

(Step S1) First, the structure 14 serving as the prototype of the impeller 3 according to the present embodiment is formed on the base plate 21 by a layered manufacturing method using metal powder (for example, titanium or stainless steel).

(Step S2) Next, the structure 14 is peeled off from the base plate 21. For example, when the metal forming the structure 14 is titanium, the structure 14 may be peeled from the base plate 21 with pliers. On the other hand, for example, when the metal forming the structure 14 is stainless steel, the structure 14 may be peeled from the base plate 21 by machining.

(Step S3) Next, the support member 22 is removed from the structure 14. For example, when the metal forming the structure 14 is titanium, the support member 22 may be removed from the structure 14 with pliers. On the other hand, for example, when the metal forming the structure 14 is stainless steel, the support member 22 may be removed from the structure 14 by machining (for example, cutting).

(Step S4) Next, the reinforcing member 30 is removed from the structure 14 by machining or the like (cutting as an example here). Here, in the present embodiment, after the second member 32 is removed from the structure 14, the first member 31 is removed from the structure 14. Specifically, a member having a lower metal density than the impeller 3 (the second member 32 in the present embodiment) is cut from the structure 14 with pliers or a cutter, and then the impeller 3 has the same metal density. The portion (the first member 31 in this embodiment) is cut by a lathe. The cutting with the lathe can double as the polishing work in step S5, so that the working process can be simplified. Further, in a lathe, if the hardness of the work piece changes during processing, the processing machine may be damaged (particularly, the tool blade), so at least one end portion 30 a of the reinforcing member 30 has an outer peripheral surface of the main plate 11. It is preferable that they are connected over one round and have the same metal density as that of the main plate 11.

(Step S5) Next, the structure 14 is polished. The outer surfaces 11a, 12a of the main plate 11 and the side plate 12 are polished by a lathe or the like by cutting, and the flow path 20 formed by the main plate 11, the side plate 12 and the main wing 13 is a fluid such as slime. Polished. Note that step S5 may be omitted.

Here, in the impeller 3 manufactured in step S5, a stacking step remains on the surface of the surface formed by additive manufacturing that is inclined with respect to the stacking surface, and the surface parallel to the stacking surface is a laser or electron beam. A coating mark due to etc. remains. On the other hand, tool marks (for example, scratches in the streak direction) remain on the surface of the cutting work. As described above, the impeller 3 includes the flow path surfaces (flow path surfaces 11b and 12b, and the front surface 13a and the back surface 13b of the main wing 13) formed by additive manufacturing, and the machined surfaces (outer peripheral surfaces 11c and 12c and the outer surface). The surface roughness is different from the surface 11a, 12a). The surface roughness of the flow path surface 11b of the main plate 11 is rougher than that of the outer peripheral surface 11c. As an example, the surface roughness of the flow path surface 11b (upper surface of the flow path surface) of the main plate 11 is Sa (arithmetic mean height) of 20 μm to 100 μm, whereas the outer peripheral surface 11c (the surface subjected to lathe processing). The surface roughness Sa) is 5 μm or less.
In particular, in the manufacturing of a closed impeller, if the additive manufacturing is more complicated than casting or welding, a complicated flow path can be formed, and further, the main plate 11 and/or the side plate 12 that is easily deformed by additive manufacturing is a lathe or the like. The impeller 3 having a desired shape can be manufactured by cutting from the blade.

The order of step S3 and step S4 may be reversed.

Thus, the impeller 3 has the outer peripheral surfaces 11c and 12c that are at least a pair of end portions arranged vertically, and the one end portion 30a of the reinforcing member 30 has the upper end portion (of the pair of end portions) ( The structure 14 is formed so as to be connected to at least a part of the outer peripheral surface 11c). In addition, the surface roughness of the flow path 20 formed by the main plate 11, the side plate 12, and the main wing 13 formed by additive manufacturing, and the one end portion 11c that is the outer peripheral end of the main plate 11 formed by cutting. But different.

In the present embodiment, as an example, as shown in FIG. 6, the reinforcing member 30 is connected over the entire circumference of the outer peripheral surface 11c of the main plate 11, but the embodiment is not limited to this, and the outer periphery of the main plate 11 is not limited to this. For each half circumference of the surface 11c, the reinforcing members 30 corresponding to a half circumference may be connected, or a plurality of reinforcing members 30 corresponding to an arc may be connected at intervals in the outer circumferential direction. Further, the reinforcing member 30 is not limited to the outer peripheral surface of the main plate 11, and may be connected to the outer peripheral side end portion (front surface end portion or back surface end portion) of the main plate 11. Thus, the reinforcing member 30 may be connected to at least a part of the end portion (for example, the outer peripheral surface) of the main plate 11. In particular, since the main wing 13 can support the main plate 11 at the time of additive manufacturing similarly to the reinforcing member 30, the reinforcing member 30 may be arranged at a predetermined interval from the portion of the outer peripheral surface 11c that is in contact with the main wing 13. Further, in the present embodiment, the first member 31 extends over the entire circumference of the outer peripheral surface 11 c of the side plate 11, and the plurality of second members 32 extend over the entire circumference of the first member 31. .. In one embodiment, the first member 31 may extend over the entire circumference of the outer peripheral surface 11 c of the side plate 11, and the second member 32 may be provided on at least a part of the outer peripheral side of the first member 31.

<First Modification of First Embodiment>
Then, the 1st modification of 1st Embodiment is demonstrated. FIG. 8 is a cross-sectional view of an example of the structure according to the first modification of the first embodiment. The structure of the first embodiment has been described as the side plate 12 stacked on the main plate 11 and the reinforcing member 30 connected to the side plate 12, but the first modification of the first embodiment. The structure according to (1) is different in that the side plate 12 is laminated and formed on the main plate 11, and the reinforcing member 40 is connected to the side plate 12 instead of the main plate 11. This is because the main plate 11 comes to be supported by the supporting member 23, while the outer peripheral surface 12c side of the side plate 12 is no longer supported by the supporting member, so that the reinforcing member 40 supports it.

As shown in FIG. 8, one end 40 a of the reinforcing member 40 is connected to the outer peripheral surface 12 c of the side plate 12. The second member 42 of the reinforcing member 40 is separated from the outer peripheral surface of the main plate 11. The other end 40b of the reinforcing member 40 is connected to the base plate 21.

The reinforcing member 40 includes a first member 41 extending substantially horizontally from one end 40a of the reinforcing member 40 and a second member 41 extending vertically from the other end 40b of the reinforcing member 40 to support the first member 41. And the member 42 of. The horizontal distance D between the second member 42 and the main plate 11 is less than or equal to the limit distance determined according to the material to be laminated. According to this configuration, the horizontal distance D between the second member 42 and the main plate 11 is provided. This is because when the second member 42 and the main plate 11 that have been brought into contact with each other are laminated and molded, and the second member 42 enters the flow path 20 as a foreign matter due to defective formation or the like, the second member 42 in the flow path is damaged. This is because the member 42 has to be removed from the flow path 20 in a later step. In particular, in the case where the carrier fluid is a pump in which the carrier fluid is a liquid as compared with an impeller of a turbine in which the carrier fluid is a gas or the like, the pressure loss due to the foreign matter in the flow passage 20 becomes remarkable. However, it is difficult to remove foreign matter from the flow path 20 formed by the main plate 11, the side plate 12, and the main wing 13. Therefore, especially when the carrier fluid is a liquid pump, it is effective to provide the horizontal distance D to prevent foreign matter from entering the flow path 20. Further, by stretching the first member 41 within the limit distance, it is possible to prevent the reinforcing member 40 from collapsing halfway.

In the present embodiment, similarly to the reinforcing member 30, the one end portion 40a is formed with the same metal density as the impeller 3 and is connected over the entire circumference of the outer peripheral surface 12c of the side plate 12, so that the first member 41 is connected. Can be satisfactorily cut with a lathe.

Thus, the impeller 3 in the first modified example of the first embodiment has the outer peripheral surfaces 11c and 12c that are at least a pair of upper and lower end portions, and the one end portion 40a of the reinforcing member 40 is The structure 14 is formed so as to be connected to at least a part of the upper end (outer peripheral surface 12c) of the pair of ends. Further, as in the first embodiment, the flow path 20 formed by the side plate 12 formed by additive manufacturing and the one end portion 12c which is the end portion on the outer peripheral side of the side plate 12 formed by cutting work. The surface roughness is different.

In the first modification of the first embodiment, as an example, the reinforcing member 40 is connected over the entire circumference of the outer peripheral surface 12c of the side plate 12, but the invention is not limited to this. For each half of the outer peripheral surface 12c, the reinforcing members 40 corresponding to a half circumference may be connected, or a plurality of reinforcing members 40 corresponding to an arc may be connected at intervals in the outer circumferential direction. Further, the reinforcing member 30 is not limited to the outer peripheral surface of the side plate 12, and may be connected to the outer peripheral side end of the side plate 12 (front surface end or back surface end). As described above, the reinforcing member 40 may be connected to at least a part of the end portion (for example, the outer peripheral surface) of the side plate 12.

<Second Modification of First Embodiment>
Subsequently, a second modification of the first embodiment will be described. FIG. 9 is a cross-sectional view of an example of a structure according to a second modification of the first embodiment. In the structure according to the first modified example of the first embodiment, the number of the reinforcing member 40 is one, whereas in the structure according to the second modified example of the first embodiment, the second reinforcing member 40 is provided. The reinforcing member 43 is added, and the supporting member 24 is further longer in the horizontal direction than the supporting member 23 according to the first modification, and the first member of the reinforcing member 40 according to the first modification is added. The difference is that the first member 41c of the reinforcing member 40c is longer than the reference numeral 41 in the horizontal direction.

As shown in FIG. 9, the structure 14c has a second reinforcing member 43 that is connected to at least a part of the outer peripheral surface of the main plate 11 (here, the entire outer peripheral surface as an example). Similarly to the reinforcing member 40, the second reinforcing member 43 includes a first member 43c extending substantially horizontally from one end 43a of the second reinforcing member 43 and another end 43b of the first member 43c. And a second member 44 that extends in the vertical direction to support the first member 43c.
Similar to the reinforcing member 40, the reinforcing member 40c includes a first member 41c that extends substantially horizontally from one end 40a of the reinforcing member 40c and a first member 41c that extends vertically from the other end 40b of the reinforcing member 40c. The second member 42 that supports the first member 41c. The horizontal distance D between the second member 42 and the second reinforcing member 43 is less than or equal to the limit distance determined according to the material of the metal powder.
In the removing step in step S4 of FIG. 7, the second reinforcing member 43 is removed from the structure 14c in addition to the reinforcing member 40c. Therefore, similarly to the reinforcing member 30, the one end portion 40a of the reinforcing member 40c and the one end portion 43a of the second reinforcing member 43 may be formed with the same metal density as that of the impeller 3.
According to this configuration, both the outer peripheral surface 11c of the main plate 11 and the outer peripheral surface 12c of the side plate 12 can be supported, so that both the outer peripheral surfaces 11c and 12c of the impeller 3 are prevented from being deformed. You can

According to the above, the method for manufacturing the impeller according to the embodiment includes the main plate 11, the side plate 12, the plurality of main wings 13 provided between the main plate 11 and the side plate 12, and the reinforcing members 30, 40 or. A structure forming step of forming a structure 14, 14b or 14c having 40c by a layered manufacturing method using a metal powder on the base plate 21, and the reinforcing member 30, 40 from the structure 14, 14b or 14c. Or a removal step of removing 40c.
In this structure forming step, one end of the reinforcing member 30, 40 or 40c is connected to at least a part of the end of one of the main plate 11 and the side plate 12 to be layered later, and the reinforcing member 30, 40 or 40c is the main plate. The structure 14, 14b or 14c is formed such that the structure 11 is separated from the end of the side plate 12 on which the additive manufacturing is performed first and the other end of the reinforcing member 30, 40 or 40c is connected to the base plate 21. R.

According to this configuration, since the reinforcing member 30, 40 or 40c laminated from the base plate 21 supports at least a part of the end portion of the main plate 11 and the side plate 12 which is to be later laminated and manufactured, the main plate 11 and the side plate 12 are formed. It is possible to suppress the deformation of the end portion of the one to be layered and formed later. Therefore, when the impeller 3 is formed by the additive manufacturing method, it is possible to suppress the deformation of the end portion of the impeller 3 (the end portions on the outer peripheral surfaces 11c and 12c of the main plate 11 and/or the side plate 12).

In the structure forming step, the reinforcing member 30, 40 or 40c is connected to the base plate 21 of the reinforcing member 30, 40 or 40c at the other end 30b or 40b or in the middle of the reinforcing member 30, 40 or 40c. From the height to the one end 30a or the other end 30b of the reinforcing member 30, 40 or 40c may be formed at an angle inclined from the horizontal. According to this configuration, since the outer peripheral surface 11c of the main plate 11 or the outer peripheral surface 12c of the side plate 12 can be obliquely supported, the other end portion 30b of the reinforcing member 30, 40 or 40c and the main plate 11 or the side plate 12 can be supported. The horizontal distance between them can be increased. When formed at an inclined angle, the number of formation surfaces is smaller than that when formed horizontally. Therefore, the shape of the first members 31, 41, 41c of the reinforcing members 30, 40, 40c is stable even if they are formed with a low metal density (for example, a mesh structure). is there.

<Second Embodiment>
Next, the second embodiment will be described. FIG. 10 is a cross-sectional view of an example of the structure according to the second embodiment. As shown in FIG. 10, in the second embodiment, the stacking direction forming the structure 14d is rotated by 90 degrees with respect to the stacking method of the first embodiment.
As shown in FIG. 10, in addition to the main plate 11, the side plate 12, and the main wing 13, the structure 14d includes a reinforcing member 51 connected to the side plate 12, a reinforcing member 52 connected to the impeller hub 10, and an impeller hub 10. The reinforcing member 53 that is connected, the reinforcing member 54 that is connected to the side plate 12, and the support member 25 that supports the main plate 11, the side plate 12, and the main wing 13 are provided. In this embodiment, as shown in the sectional view A and the sectional view B of FIG. 10, the one ends 52a and 53a of the reinforcing member are connected over the entire circumference of the opening 8. That is, the one end 52a of the reinforcing member is connected to the end above the midpoint R of the opening 8, and the one end 53a of the reinforcing member is connected to the end below the midpoint R of the opening 8. Similarly, one end 51a of the reinforcing member is connected to an end above the midpoint R of the suction port 9, and one end 54a of the reinforcing member is connected to an end below the midpoint R of the opening 8. .. In one embodiment, the one end 52a of the reinforcing member is connected to at least a part of the end above the midpoint R of the opening 8, and the one end 53a of the reinforcing member is below the midpoint R of the opening 8. Is connected to at least a part of the end of the. Similarly, one end 51a of the reinforcing member is connected to at least a part of the upper end of the suction port 9 above the midpoint R, and the one end 54a of the reinforcing member is lower than the midpoint R of the opening 8. Connect to at least a portion of the section.

The manufacturing process of the impeller according to the second embodiment is different from the manufacturing process of the impeller according to the first embodiment in FIG. 7 in that the configuration of the structure 14d itself is different, and the step of FIG. The difference is that the reinforcing member 51 and the reinforcing member 52 are removed from the structure 14d in the removal step in S4, and the support member 25 is removed from the structure 14d in the removal step in step S3 of FIG. Further, a structure forming step (S1) of forming the structure 14d having the impeller 3 and the reinforcing members 51, 52, 53, 54 by the additive manufacturing method, and the reinforcing members 51, 52, 53, 54 from the structure 14d. And a removing step (S4) of removing. In the structure forming step S1, the impeller 3 is arranged such that the circular opening (suction port 9, opening 8) at the end of the impeller 3 is perpendicular to the stacking surface. Then, the one end 51a of the reinforcing member is connected to at least a part of the upper end of the suction port 9 above the midpoint R (that is, the axis), and the one end 53a of the reinforcing member is located at the midpoint R of the suction port 9 (that is, It is connected to at least a part of the end below the axis. Further, one end 52a of the reinforcing member is connected to at least a part of an end portion above the midpoint R of the opening portion 8, and one end portion 53a of the reinforcing member is an end portion below the midpoint R of the opening portion 8. To at least a part of. Thereby, similarly to the first embodiment, it is possible to prevent the deformation of the suction port 9 and/or the opening 8 which is the end of the impeller 3.

Further, the one ends 51a and 54a are formed with the same metal density as the impeller 3 and are connected over the entire circumference of the outer peripheral surface of the suction port 9, and the one ends 52a and 53a are formed with the same metal density as the impeller 3. Since the outer peripheral surface 10c of the impeller hub 10 is connected over the entire circumference, it can be satisfactorily cut by a lathe in the cutting process of S4, like the reinforcing member 30.

<Third Embodiment>
Subsequently, a third embodiment will be described. FIG. 11 is a cross-sectional view of an example of the structure according to the third embodiment. In the first and second embodiments, the impeller 3 for single suction is used, whereas in the third embodiment, the impeller 103 is for both suction. The configuration diagram of the double-suction pump according to the third embodiment is omitted.

As shown in FIG. 11, in addition to the impeller 103 including the impeller hub 61a, the main plate 61b, and the side plates 62a and 62c, the structure 14e according to the third embodiment has one end connected to the end of the side plate 62a. And a reinforcing member 64a having the other end connected to the base plate 21, and a reinforcing member 64b having one end connected to the end of the side plate 62a and the other end connected to the base plate 21.
Further, the structure 14e has a reinforcing member 65a having one end connected to the end of the impeller hub 61a and the other end connected to the base plate 21, and one end connected to the end of the impeller hub 61a and the other end connected to the base plate 21. And a reinforcing member 65b connected to. Further, the structure 14e includes a support member 26 that supports the impeller hub 61a and a support member 27 that supports the side plate 62c.

The reinforcing members 64a and 65a are vertically stacked from the other end connected to the base plate 21, and then are formed at an angle inclined from the horizontal from the midway height to one end of the reinforcing members 64a and 65a. .. Specifically, the reinforcing member 64a is configured to incline from the end of the side plate 62a at a predetermined angle θ1 with respect to the horizontal line, and the reinforcing member 65a extends from the end of the main plate 61b to the horizontal line. And is inclined at a predetermined angle θ2. Here, the angle θ1 and the angle θ2 may be the same or different. It is preferable that the reinforcing members 64a and 65a have a lower density than the end portion (here, the end portion of the side plate 62a or the end portion of the impeller hub 61a) of the impeller 103 to be connected. As a result, the amount of material of the reinforcing members 64a and 65a can be reduced, so that the manufacturing cost of the impeller 103 can be suppressed. In the present embodiment, the reinforcing members 64a, 65a, 64b, 65b are provided at axially symmetrical positions of the ends of the side plates 62a, 62c. In one embodiment, a plurality of reinforcing members 64a and 65a that are inclined at a predetermined angle may be provided at the ends of the side plates 62a and 62c. In one embodiment, the reinforcing members 64a and 65a may not be provided, and only the reinforcing members 64b and 65b may be provided over the entire circumference of the end portions of the side plates 62a and 62c. Further, in one embodiment, the reinforcing members 64b and 65b are not provided, and only the reinforcing members 64a and 65a that are inclined at a predetermined angle with respect to the horizontal line are provided over the entire circumference of the end portions of the side plates 62a and 62c. Good.

The manufacturing process of the impeller 130 according to the third embodiment is different from the manufacturing process of the impeller according to the first embodiment in FIG. 7 in that the structure 14e itself is different from the manufacturing process in FIG. In the removing step in step S3, the support members 26 and 27 are removed from the structure 14e, and in the removing step in step S4 in FIG. 7, the reinforcing members 64a, 64b, 65a, 65b are removed from the structure 14e. Is different.

As described above, in the manufacturing process of the impeller 103 according to the present embodiment, the reinforcing member 64a or/and 64b has the end portions of the main plate 61b and the side plate 62a, which are a pair of upper and lower end portions. A structure 14e is formed, one end of which is connected to at least a part of the side plate 62a which is the upper end of the pair of ends. In the manufacture of the impeller 3, the main plate 61b, which is a pair of upper and lower ends, and the side plate 62c have an end portion, and one end of the reinforcing member 65a or/and 65b is the end portion of the pair. A structure 14e that is connected to at least a part of the main plate 61b that is the upper end of the portion is formed.

As described above, in the manufacturing process of the impeller according to the third embodiment, the main plate 61b, the side plates 62a and 62c, the main wing 63 provided between the main plate 61b and the side plates 62a and 62c, and the reinforcing member 64a, A structure forming step of forming a structure 14e having 64b, 65a, 65b on the base plate 21 by a layered manufacturing method using metal powder; and a reinforcing member 64a, 64b, 65a, 65b from the structure 14e. And a removing step of removing.
In this structure forming step, one end of the reinforcing members 64a, 64b, 65a, 65b is connected to at least a part of the end of the main plate 61b or at least a part of the end of the side plate 62a, and the reinforcing members 64a, 64b, The structure 14e is formed so that the other ends of the 65a and 65b are connected to the base plate 21.

According to this configuration, since the reinforcing members 64a, 64b, 65a, 65b stacked from the base plate 21 support at least a part of the end portion of the main plate 61b or at least a part of the end portion of the side plate 62a, the main plate 61b is not supported. The deformation of the end portion or the end portion of the side plate 62a can be suppressed. Therefore, when the impeller is formed by the additive manufacturing method, the deformation of the end portion of the impeller can be suppressed.

<Fourth Embodiment>
Subsequently, a fourth embodiment will be described. FIG. 12 is a cross-sectional view of an example of the structure according to the fourth embodiment. As shown in FIG. 12, in the fourth embodiment, the stacking direction forming the structure 14f is rotated by 90 degrees with respect to the stacking method of the third embodiment.

As shown in FIG. 12, in addition to the impeller 103 including the impeller hub 61a, the main plate 61b, the side plates 62a, 62b, 62c, 62d, and the main wing 63, the structure 14f includes a reinforcing member 66a connected to the side plate 62a, A reinforcing member 66c connected to the side plate 62c, a support member 26 that supports the main plate 61b, and a support member 27 that supports the side plates 62b and 62d are provided. In this embodiment, the reinforcing members 66a and 66c are provided so as to be connected only to the uppermost portions of the side plates 62a and 62c. In one embodiment, the reinforcing members 66a and 66c may be in contact with all of the ends of the side plates 62a and 62c located above the midpoint R1 of the suction port 9 (that is, the axis).

The manufacturing process of the impeller according to the fourth embodiment is different from the manufacturing process of the impeller according to the first embodiment in FIG. 7 in that the structure of the structure 14f itself is different, and the step of FIG. The difference is that the reinforcing members 66a and 66c are removed from the structure 14f in the removal step in S4, and the support members 26 and 27 are removed from the structure 14f in the removal step in Step S3 of FIG.

In this way, the structure forming step (S1) of forming the impeller 3 and the structure 14f having the reinforcing members 66a and 66c by the additive manufacturing method, and the removing step of removing the reinforcing members 66a and 66c from the structure 14d ( S4), and. In the structure forming step S1, the impeller 3 is arranged such that the circular opening (suction port 9) at the end of the impeller 3 is perpendicular to the stacking surface. Then, the one end 66a1 of the reinforcing member 66a is connected to at least a part of the end above the midpoint R1 (that is, the axis) of the suction port 9, and the one end 66c1 of the reinforcing member 66c is the midpoint R of the suction port 9. It is connected to at least a part of the upper end (that is, the axis). Thereby, similarly to the first embodiment, it is possible to prevent the deformation of the suction port 9 which is the end portion of the impeller 103.

<Fifth Embodiment>
Subsequently, a fifth embodiment will be described. FIG. 13 is a perspective view of an example of a structure according to the fifth embodiment. FIG. 14 is a cross-sectional view of an example of the structure according to the fifth embodiment. The impellers of the first, second, third and fourth embodiments are closed impellers, whereas the impeller of the fifth embodiment is an open type impeller.

As shown in FIGS. 13 and 14, the structure 14g is connected to an impeller hub 70, an impeller 203 including a plurality of main blades 71, 72, 73, 74 connected in order, and an outer peripheral surface of the main blade 72. Reinforcing member 83, the reinforcing member 83 connected to the outer peripheral surface of the main wing 73, the reinforcing member 84 connected to the outer peripheral surface of the main wing 72, and the reinforcing member 85 connected to the outer peripheral surface of the main wing 73. And a support member 28 that supports the main wing 74.

The manufacturing process of the impeller according to the fifth embodiment is different from the manufacturing process of the impeller according to the first embodiment in FIG. 7 in that the structure 14g itself is different in structure, and the step of FIG. The difference is that the reinforcing members 82 and 83 are removed from the structure 14g in the removing step in S4, and the support member 28 is removed from the structure 14g in the removing step in step S3 of FIG.

As described above, in the method for manufacturing the impeller according to the fifth embodiment, the structure 14g having the plurality of main wings 71 to 74 and the reinforcing members 82 and 83 is laminated on the base plate 21 using the metal powder. The method includes a structure forming step of forming by a method and a removing step of removing the reinforcing members 82 and 83 from the structure 14g. That is, in the manufacturing process of the impeller 203 according to this embodiment, the main blades 72, 73 that are a pair of upper and lower end portions are provided, and one end portion of the reinforcing member 82 is located above the pair of end portions. 14g that is connected to at least a part of the end of the main wing 72 that is the end of the structure. Further, it has a pair of main wings 73, 74 arranged vertically and one end of the reinforcing member 83 is at least one of the ends of the main wing 73 which is an upper end of the pair of ends. The structure 14g connected to the part is formed.
In this structure forming step, one end of the reinforcing member 83 is connected to at least a part of the end portion of the one of the plurality of main wings to be layered later (for example, the main wing 73), and the reinforcing member 83 is included in the plurality of main wings. The structure 14g is formed so that it is separated from the end of the one to be layered first (for example, the main wing 74) and the other end of the reinforcing member 83 is connected to the base plate 21.

According to this configuration, since the reinforcing member laminated from the base plate supports at least a part of the end portion of the one of the plurality of main wings that is laminated and then modeled, the main member is laminated first of the plurality of main wings. It is possible to suppress the deformation of the end of the layered modeling after the modeling. Therefore, when the impeller is formed by the additive manufacturing method, the deformation of the end portion of the impeller can be suppressed.

In the above-mentioned impellers 103 and 203 manufactured in step S5, similarly to the impeller 3, a laminated step is left on the surface inclined by the laminated surface of the surface formed by additive manufacturing, and the laminated surface A mark left by a laser, an electron beam, or the like remains on the surface parallel to. On the other hand, tool marks (for example, scratches in the streak direction) remain on the surface of the cutting work. As described above, also in the impellers 103 and 203, the surface roughness of the surface formed by additive manufacturing is different from the surface machined, and the surface roughness of the surface formed by additive manufacturing is Rougher than the machined surface. As described above, the structures 14 to 14g are formed by additive manufacturing capable of manufacturing a complicated shape as compared with casting or welding, and a reinforcing member connected to an end portion that is easily deformed by additive manufacturing is latheed. An impeller having a desired shape can be manufactured by performing a cutting process later.

In addition, in each of the embodiments, the base plate 21 is stacked, but the base plate 21 may be omitted. In each embodiment, the material forming the impeller is not limited to metal, but may be synthetic resin, carbon, or a composite material. In that case, synthetic resin powder, carbon powder, or composite material. You may laminate-mold using the powder of. Further, in each of the embodiments, the powder is used for additive manufacturing, but the present invention is not limited to this, and wire additive may be applied for additive manufacturing.

As described above, the present invention is not limited to the above-described embodiments as they are, and constituent elements can be modified and embodied without departing from the scope of the invention in an implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, the constituent elements of different embodiments may be combined appropriately.

1 Pump casing 1a Suction port 1b Discharge port 11 Main plate 11a Outer surface 11b Flow path surface 11c Outer peripheral surface 12 Side plate 12a Outer surface 12b Flow path surface 12c Outer peripheral surface 13 Main wing 13a Surface 13b Back surface 14, 14b, 14c, 14d, 14e, 14f, 14g Structure 2 Casing cover 20 Flow path 21 Base plate 22-28 Support member 3 Impeller 30, 40, 40c, 51, 52, 64a, 64b, 65a, 65b, 66a, 66c, 82, 83, 84, 85 Reinforcement member 31, 41, 41c First member 32, 42 Second member 30a One end portion 30b Other end portion 4 Bearing body 43, 43b Second reinforcing member 5a Bearing 6 Pump shaft 61a, 61b Impeller hub 62a, 62b, 62c, 62d Side plates 63, 71, 72, 73, 74 Main wings

Claims (16)

A structure forming step of forming a structure having an impeller and a reinforcing member by a layered manufacturing method;
A removing step of removing the reinforcing member from the structure,
Have
In the structure forming step,
The impeller has at least a pair of end portions arranged vertically,
The method for manufacturing an impeller, wherein the structure is formed so that one end of the reinforcing member is connected to at least a part of an upper end portion of the pair of end portions. The impeller according to claim 1, wherein in the structure forming step, at least the one end of the reinforcing member of the reinforcing member is formed to have substantially the same density as an end portion of the impeller to be connected. Manufacturing method. The blade according to claim 1, wherein in the structure forming step, the reinforcing member is formed with a density lower than an end portion of the impeller to be connected and at an angle inclined from an end portion of the impeller. Car manufacturing method. The impeller manufacturing method according to claim 1, wherein in the structure forming step, at least a part of the structure is formed by being supported by a member having a metal density lower than that of the structure. The reinforcing member extends from the one end of the reinforcing member,
The manufacturing method of the impeller according to any one of claims 1 to 4, wherein a distance that the reinforcing member extends is equal to or less than a limit distance that is determined according to a material of the reinforcing member. The reinforcing member includes a first member that extends substantially horizontally from the one end of the reinforcing member, and a second member that vertically extends from the other end of the reinforcing member to support the first member. Has,
There is a horizontal distance between the second member and the lower end of the pair of ends.
The manufacturing method of the impeller according to any one of claims 1 to 5. The structure has a second reinforcing member extending from at least a part of the lower end of the pair of ends,
The second reinforcing member has a first member extending from the one end of the reinforcing member,
The method for manufacturing an impeller according to any one of claims 1 to 6, wherein a distance that the first member extends is equal to or less than a limit distance that is determined according to a material of the first member. The impeller is
A main plate, a side plate, and a main wing provided between the main plate and the side plate to give energy to the pumping liquid,
The pair of end portions are end portions on the discharge side of the main plate or the side plate,
A method for manufacturing an impeller according to any one of claims 1 to 7. The impeller is
A main plate, a side plate, and a plurality of main wings provided between the main plate and the side plate,
The pair of end portions are suction-side end portions of the side plates,
A method for manufacturing an impeller according to any one of claims 1 to 7. The impeller is
A plurality of main wings that give energy to the pumping liquid,
The pair of ends are ends of adjacent main wings of the plurality of main wings,
A method for manufacturing an impeller according to any one of claims 1 to 7. An impeller provided with a main plate, a side plate, and a main wing provided between the main plate and the side plate for giving energy to pumping liquid,
An impeller in which a flow path formed by the main plate, the side plate, and the main blade is formed by additive manufacturing, and at least one outer peripheral surface of the main plate and the side plate is formed by cutting. The impeller according to claim 11, wherein the flow passage surface and the outer peripheral surface have different surface roughnesses. The impeller according to claim 12, wherein the flow passage surface has a rougher surface than the outer peripheral surface. A structure forming step of forming a structure having an impeller and a reinforcing member by a layered manufacturing method;
A removing step of removing the reinforcing member from the structure,
Have
In the structure forming step,
The impeller is arranged so that the circular opening at the end of the impeller is perpendicular to the stacking plane,
The method for manufacturing an impeller, wherein the structure is formed so that one end of the reinforcing member is connected to at least a part of an end of the circular end above the midpoint. The method for manufacturing an impeller according to claim 14, wherein the circular opening at the end of the impeller is a suction port. The method of manufacturing an impeller according to claim 14 or 15, wherein the circular opening at the end of the impeller is an opening of an impeller hub.