JPH08159088A - Manufacture of impeller - Google Patents

Abstract

PURPOSE: To reduce a manufacturing cost, and obtain an impeller of high strength by forming fillet Rs on a blade between a hub and a shroud, and connecting a surface of the blade to the shroud by duffising soldering. CONSTITUTION: A hub 2 and a blade 4 are integrally formed of titanium alloy. A fillet R part 12 is formed on the blade 4 on the side of a shroud 3. Similarly, a fillet R part 13 is formed on the side of the hub 2. A connection surface 14 of the blade 4 is formed in a curved projection manner. A connection surface 15 of the shroud 3 is formed in a curved recession manner. Afterward, the connection surfaces 14 and 15 are connected to each other by diffusing soldering on one of them or both of them through heating at a specified temperature. It is thus possible to keep strength of the connection surfaces 14, 15, equivalent to that of a mother material, and easily obtain an impeller of high strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an impeller with a shroud.

[0002]

2. Description of the Related Art A conventional impeller with a shroud has, for example, a structure shown in a side sectional view of FIG. In FIG. 3, 1 is an impeller, 2 is a hub, 3 is a shroud, 4 is a wing portion, 5 is a central shaft hole, and 6 is an arrow indicating a fluid flow.

FIG. 4 is a view taken in the direction of arrow AA in FIG. 3, which is expanded to show a part thereof. Further, since the blade portion 4 is a fluid guide blade, several blades or ten or more blades are provided between the hub 2 and the shroud 3, and FIG. 5 is a perspective view showing one of them. The conventional manufacturing method of such an impeller 1 is as follows: first, an integrated shaving method; second, a method for integrally manufacturing by precision casting; and third, after integrally forming the hub 2 and the blade portion 4. There is a method of joining the shroud 3.

[0004]

However, although the first integral cutting method of the above-mentioned conventional methods for manufacturing the impeller 1 has sufficient strength, the manufacturing cost is too high. In the second precision casting method, the material is aluminum 6%, vanadium 4
% Titanium alloy is used, but there is a problem in that a titanium alloy with sufficient strength cannot be obtained. Furthermore, the method of joining the third shroud 3 also has the following problems.

That is, the method of joining the shroud 3 is as shown in FIG. 6, when the joining portions 7 and 8 of the shroud 3 and the blade portion 4 are joined by brazing, and as shown in FIG. In some cases, the joint portion 9 of the blade portion 4 and the blade portion 4 are diffusion-bonded. However, in the case of brazing in FIG. 6, the fillet radius (corner R) portion 10 has insufficient strength, and in the case of diffusion-bonding in FIG. There is a problem that the fillet radius cannot be formed, the corners 11 and 11 have insufficient strength, and the blade 4 is deformed because it cannot receive the pressure, resulting in a defective joint at the joint 9. there were.

The present invention is intended to solve the above problems. That is, it is an object of the present invention to provide an impeller manufacturing method that can obtain a high-strength impeller with low manufacturing cost.

[0007]

In order to achieve the above object, the present invention provides an impeller having a wing portion between a hub and a shroud, wherein a fillet radius is formed on the wing portion, and The method of joining the joining surface to the shroud by diffusion brazing was adopted.

[0008]

According to the present invention, in an impeller having a wing portion between a hub and a shroud, a fillet radius is formed on the wing portion, and a joining surface of the wing portion to the shroud is joined by diffusion brazing. Therefore, the process is simple, and there is a fit radius part where stress concentrates during use in the wing part, and moreover, the joint part between the wing part and the shroud is made by diffusion brazing, so that the joint part is The impeller has the same strength as that of the base material, and therefore, an impeller having a high strength structure can be obtained.

[0009]

1 is a partially cutaway enlarged plan view showing a state before joining a shroud 3 and a blade portion 4 of a first embodiment of the present invention. That is, the hub 2 and the blade portion 4 are integrally formed from a titanium alloy as in the conventional case, and the fillet round portions 12 and 12 are formed on the shroud 3 side of the blade portion 4.
Fillet radius parts 13 and 13 are also formed on the side.
The shroud 3 is also made of titanium alloy. And wing 4
The joining surface 14 of the shroud 3 is formed in a convex curve shape, and the joining surface 15 of the shroud 3 is formed in a concave curve shape.

After that, one or both of the joint surface 14 of the blade portion 4 and the joint surface 15 of the shroud 3 is coated with, for example, a titanium alloy brazing material or a copper plating or nickel plating which has the same effect as the brazing material, and is evacuated. Without applying pressure, for example, by heating at a temperature of 750 to 800 ° C. for about 4 hours,
The joining surfaces 14 and 15 are joined by diffusion brazing. By doing so, the blade portions 4 are provided with the fillet rounded portions 12 and 13 on which stress is concentrated during use, and the joint surface 14 of the blade portion 4 and the joint surface 15 of the shroud 3 are diffusion-brazed. Therefore, the joint surfaces 14 and 15 have the same strength as the base material, and a high-strength impeller can be easily obtained.

FIG. 2 is a plan view similar to FIG. 1, showing a second embodiment of the present invention. The second embodiment is different from the first embodiment described above in that the joint surface 14 of the wing portion 4 and the joint surface 15 of the shroud 3 are in a straight line shape (one plane shape). Since it is exactly the same, detailed description is omitted.

[0012]

As described above, according to the present invention,
In an impeller having wings between a hub and a shroud, a fillet radius is formed on the wings and the joining surface of the wings to the shroud is joined by diffusion brazing, so that the process is simple. In addition, because the blade has a fit-earl portion where stress can be concentrated during use and the blade and the shroud are joined by diffusion brazing, the joint is the mother part. It has the same strength as the material, and therefore has the effect of obtaining a high-strength impeller.

[Brief description of drawings]

FIG. 1 is a partially cutaway enlarged plan view showing a state before joining a shroud and a wing portion according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway enlarged plan view showing a state before joining the shroud and the blade portion according to the second embodiment of the present invention.

FIG. 3 is a side sectional view showing an example of a conventional impeller with a shroud.

FIG. 4 is a plan view showing a part of the development along the line AA of FIG.

5 is a perspective view showing a wing portion of FIG. 3. FIG.

FIG. 6 is an enlarged plan view showing one example of the conventional joining of the blade portion and the shroud.

FIG. 7 is an enlarged plan view showing another example of the conventional joining of the blade portion and the shroud.

[Explanation of symbols]

 1 Impeller 2 Hub 3 Shroud 4 Wing portion 12 Fillet radius portion 14 Wing portion joint surface 15 Shroud joint surface

Claims (4)

[Claims] 1. An impeller having a wing portion between a hub and a shroud, wherein a fillet radius is formed on the wing portion, and a joining surface of the wing portion to the shroud is joined by diffusion brazing. And a method for manufacturing an impeller. 2. The hub and the wing portion are integrally formed, and then,
The shroud is joined to the wing portion.
A method for manufacturing the impeller described. 3. The method of manufacturing an impeller according to claim 1, wherein at least one of the joint surface of the blade portion and the joint surface of the shroud is brazed, and then both joint surfaces are diffusion brazed. . 4. The method according to claim 1, wherein at least one of the joint surface of the blade portion and the joint surface of the shroud is plated with the same effect as brazing, and then both joint surfaces are diffusion brazed. Impeller manufacturing method.