JPS6133964B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing an impeller.

For example, a shroud 1 and a blade 2 as shown in FIG.
Conventionally, methods for manufacturing an impeller having a shroud and a blade have generally been made by casting the entire impeller, by cutting out the blade to form an impeller in which the shroud and the blade are integrated, or by forming an impeller in which the shroud and the blade are integrated. One of the methods adopted is to form the parts separately and then fix them to each other. Each of these methods has its own advantages and disadvantages; for example, casting can be used to manufacture the blade at low cost, but due to the shape of the blades, if a sand mold or the like is used, the productivity will be poor. Furthermore, although the manufacturing method by machining improves strength and precision, the cost becomes extremely high in the case of complex blade shapes. In this regard, the method of forming the shroud and blades separately and then fixing the blades to the shroud has the advantage of being flexible in terms of productivity and cost even when the blade shape is complex, but it is difficult to fix the blades in terms of accuracy. There is a problem with the accuracy of

The present invention has been made in view of the problems in the method of manufacturing an impeller, and in particular, it is an object of the present invention to further improve the method of manufacturing an impeller by forming a shroud and a blade separately and then fixing them to each other. The purpose is to

For this reason, the present invention utilizes extrusion molding technology to form a blade material that has all the blades in one piece, processes this blade material to form a desired blade shape, forms a blade assembly in which the blades are fixed to each other, and separately The method is characterized in that it includes a step of fixing the blade assembly as it is to the shroud to be formed, and then removing the blade connection portion as necessary.

That is, according to the present invention, each blade is not formed as a single item, but is formed as a combination of connected blades having a predetermined spacing and shape, which improves the accuracy of fixing to the shroud. Significant improvements can be achieved.

Here, the manufacturing method of the present invention is mainly intended to be applied to small impellers, and focuses on manufacturing from aluminum or aluminum alloy materials. However, it is of course possible to apply it to the manufacture of large impellers, and other materials such as synthetic resin and copper can also be used.

An example of manufacturing the impeller shown in FIG. 1 by the method of the present invention will be described below with reference to FIGS. 2 to 5.

As a feature of the invention, the vanes 2 are made using extrusion technology. Here, as shown in Figure 1,
The blades 2 have a completed shape that can be curved in the axial direction, radial direction, and rotational direction of the impeller 1.
Therefore, since it is not possible to extrude the completed shape as it is, the blades 2 are developed into a shape that can be extruded, that is, curved in the axial direction, and parallel to the axis, and each blade 2 is shaped as shown in FIG. A blade material 4 is extruded to form a cylindrical body 3 on which fins 2A corresponding to the fins 2A are formed.

The blade material 4 extruded in this way is then
As shown in the figure, the fins 2A are cut along the line 5 to a predetermined length, and the fins 2A are further processed into a blade shape to form a blade assembly 6 as shown in FIG. Here, according to the feature of the present invention, the processed blades 2 are each connected and held by a connecting portion 3A, which is a portion of the cylindrical body 3 that remains at least in part. This process is preferably a turning process in which the cut blade material 4 is cut while being rotated. However, other methods may optionally be used. Further, after processing the outer shape of the blade, a predetermined curvature in the axial direction is added, and the final shape is obtained by combining each blade except for the vicinity of the joint portion 3A.

On the other hand, the shroud 1 is formed as a single unit as shown in FIG. As the forming means, casting, cutting, forging, etc. can be selected as appropriate. Further, it is desirable to form a groove 1A along the slope forming the flow path surface of the shroud 1 into which the blade 2 to be fixed is fitted. However, such groove 1A
is not essential.

The blade assembly 6 and the shroud 1 formed as described above are assembled to each other as shown in FIG. 5 and fixed to each other by brazing. During this assembly and brazing, forming the groove 1A in the shroud 1 is advantageous in terms of ease of work, fixing strength, and positional accuracy. For example, it is also preferable to set the maximum diameter to the shroud and the outer diameter of the coupling portion 3A to be equal.

For the semi-finished product shown in FIG. 5 obtained by fixing the blade assembly 6 to the shroud 1 in this way, the joint part 3A and the peripheral edge of the shroud 1 corresponding to this thickness are turned, and finally the blade is By modifying the shape of 2, the production of the impeller shown in FIG. 1 is completed.

The above description relates to a preferred example, and many modifications may be made, such as making the fins 2A of the blade material 4 have a shape that extends outward, or applying it to the manufacture of an axial flow impeller other than a centrifugal impeller. is possible. In addition, if the shroud 1 and the blade assembly 6 are made of different materials, or if the shroud 1 and the blade assembly 6 are made of a synthetic resin material in which the difference in melting temperature of the materials becomes large depending on the individual structures even if they are made of the same material, the shroud 1 may be It is also possible to fix both at the same time by molding and enclosing the blade assembly 6 during the molding.

According to the manufacturing method of the present invention explained above, the following effects can be achieved.

(1) Since the blades 2 are formed using extrusion molding technology, high dimensional and surface accuracy can be obtained, and since all the blades are fixed to the shroud while being fixed to each other as a combined body, the assembly accuracy is also very high. Can be made high.

(2) The shape and orientation of the blades 2 can be easily and accurately modified in the combined state.

(3) Processing technology can be implemented using a combination of easy methods;
Significant increases in productivity and cost reductions are achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of an impeller manufactured by the method of the present invention. Figures 2 to 5 illustrate each step of the present invention for manufacturing the impeller shown in Figure 1. Figure 2 is a perspective view showing the state of extrusion molding of the blade material, and Figure 3 is a blade assembly. FIG. 4 is a perspective view of the shroud, and FIG. 5 is a perspective view of a semi-finished product combining the blade assembly and the shroud. 1...Shroud, 1A...Groove, 2...Blade,
2A...fin, 3...cylindrical body, 4...blade material, 6...blade combination body.

Claims (1)

[Claims] 1. A blade material in the form of a cylindrical body having fins corresponding to blades arranged in the radial direction is extruded, and the blade material is processed to form parts that will become each blade and these parts. A method for manufacturing an impeller, comprising the steps of: forming a blade assembly in which parts of the cylindrical bodies are connected and held together; and fixing the blade assembly to a separately formed shroud. 2. The impeller manufacturing method according to claim 1, further comprising the step of removing a portion of the cylindrical body and a peripheral portion of the shroud corresponding to the portion in the impeller assembly. 3. The impeller manufacturing method according to claim 1 or 2, further comprising the step of forming a fitting groove for assembling the blades in the shroud. 4. The impeller manufacturing method according to any one of claims 1 to 3, comprising the step of correcting the blade shape and orientation of the combined impeller.