JP2001300812A - Impeller processing method - Google Patents

Abstract

(57) [Problem] To easily form a thin blade portion of an impeller without lowering the processing accuracy. SOLUTION: A rough processing for forming a thick part before finishing the blade part 5 into a thin shape is performed to a depth of about 1/3 and all the blade parts, and subsequently, the entire rough processing part is formed. On the other hand, finish processing is performed to reduce the thickness of about 1/3 of the upper part of the blade. Similarly, roughing and finishing are performed for each remaining about 1/3, and finally the hub surface is finished to form a thin blade portion. [Effect] Each blade is gradually finished in a thin shape, and when one blade is processed into a thin shape at once, the falling of the blade can be prevented. Work for pressing down the wing surface is not required, and the processing accuracy of the shoulder portion when the blade portion is thinned can be easily increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing an impeller.

[0002]

2. Description of the Related Art For example, an impeller used for a centrifugal compressor applied to a supercharger of an engine disclosed in Japanese Patent Application Laid-Open No. 4-365997 has been proposed to improve efficiency and reduce weight. It is conceivable to make the impeller blades as thin as possible. In order to form such a thin blade portion, an aluminum alloy, a titanium alloy, or the like has been cut and processed by, for example, milling.

[0003]

However, in the thinning of the blade portion by the conventional milling process, first, each recessed portion between each adjacent blade portion is formed over the entire circumference in a rough processing state. Then, each blade portion was thinned one by one. At that time, the blade surface of the blade portion will be milled and finished while reducing the thickness of the blade portion, and when the blade surface is finished, the thin blade portion easily falls down, and when the blade portion comes to fall during the finishing process However, there is a problem that the processing accuracy of the shoulder portion of the blade portion is reduced.

[0004] In order to prevent the above-mentioned falling, the surface opposite to the processing surface of the blade portion to be finished is pressed by a pressing member or the like. Therefore, there is a problem that the finishing process is complicated because the finishing process is performed while pressing the blade portions one by one with the pressing member.

[0005]

SUMMARY OF THE INVENTION In order to solve such a problem, it is possible to easily perform the processing without lowering the processing accuracy when forming the impeller blade portion to be thin.
According to the present invention, there is provided a method for processing an impeller in which a plurality of blades (5) of the impeller (1) are cut out and formed by machining, wherein the blades (5) are thicker than their final thin-walled shape. A step of performing rough processing for forming a thick-walled shape, and a step of performing finishing processing for converting the thick-walled blade portions (6a, 6b, and 6c) to the final thin-walled shape. The finishing is performed alternately in the depth direction a plurality of times, and after performing the roughing and the finishing at the same depth on all the blade portions (5) of the impeller (1), the following process is performed. The rough processing and the finishing processing for the depth are performed.

[0006] According to this, when the blade portion is cut out, when all the blade portions are roughed to a certain depth, the finishing process is performed, and the finishing process is performed a plurality of times in the depth direction. Therefore, each blade is gradually finished in a thin shape, and it is possible to prevent the blade from falling down when one blade is processed into a thin shape at a stretch.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to specific examples shown in the accompanying drawings.

FIG. 1 is an overall perspective view showing a main part of an impeller for a jet engine to which the present invention is applied. As shown in the figure, the impeller 1 has a bore portion 3 which is a portion near the rotor shaft 2 fixed in a fitted state on the rotor shaft 2.
And a disk portion 4 coaxially extending radially outward from the bore portion 3, and a radially outward direction on a J-shaped curved surface continuously formed by the bore portion 3 and the disk portion 4. It has a protruding blade portion 5 and is formed by cutting out, for example, a titanium alloy. Although only a part is shown by a solid line in the figure, a plurality of blade portions 5 are arranged at an equal angular pitch over the entire circumference of the rotor shaft 2 in the circumferential direction.

Next, the impeller 1 will be described with reference to FIGS.
The processing procedure of is described below. First, for a member whose outer peripheral surface is a surface passing through the protruding end of the blade portion 5, rough processing for forming the blade portion 5 into a thick shape before finishing the thin shape is performed in the depth direction (in the radial direction). Direction), for example, about 1/3 of the depth and for all the blades 5.

As a result, as shown in FIG. 2A, a thick upper portion 6a having a depth of about 1/3 is formed over the entire periphery of the impeller 1. Subsequently, the upper rough processing portion 6a thus formed is finished into a thin shape having a predetermined thickness to form the blade upper portion 5a as shown in FIG. 2B.

Next, as shown in FIG. 3 (a), a portion corresponding to a depth of about 1/3 of the intermediate portion of the blade portion 5 is roughly machined into a thick shape in the same manner as described above. A rough part 6b is formed. Subsequently, the intermediate rough part 6b is finished in the same manner as described above to form the blade upper intermediate part 5b as shown in FIG. 3B.

Then, as shown in FIG. 4 (a), a portion corresponding to the remaining depth of about 1/3, which is a lower portion of the blade portion 5, is roughly machined into a thick shape in the same manner as described above. The lower rough processing part 6c is formed. Subsequently, similarly to the above, the lower rough processing portion 6
Finish processing is performed on c to form the entire blade portion 5 as shown in FIG.

In the state shown in FIG. 4B, each blade 5
Since the curved surface corresponding to the bottom surface in the recessed cross-sectional shape between them is formed with multi-row grooves generated at the time of machining (milling) processing, the hub surface (curved surface) 7 is finally finished by finishing. Finish in condition 1.

[0014] Thus, the blades 5 are not finished at once, but the roughing and finishing are divided in the depth direction and are performed on all the blades 5. Become. Therefore, when one of the blade surfaces of the blade portion 5 is finished (thinned), the thinned portion is small, so that the thin portion can sufficiently withstand the pressing force of the milling cutter on the blade surface. It is possible,
Even if the opposite surface is not pressed by a pressing member or the like, it is possible to prevent the blade portion 5 from falling down during the thinning processing. In particular, when the upper part of the blade part 5 is subjected to the thinning finish processing, in the conventional case, the lower part thereof was thin, so that it was easy to fall down. It is difficult to fall down because it is only cut in the direction, and as a result, the processing accuracy of the shoulder portion of the blade portion 5 can be improved.

Although the illustrated example shows the impeller 1 composed of only the long blades 5, the impeller to which the present processing method can be applied is not limited to the illustrated example. The present invention is applicable to various types of impellers, and includes, for example, a short wing (a wing having a wing length from an intermediate portion in the extending direction of the long wing to an outlet portion) provided between adjacent long wings. It can also be applied to other types of impellers.

[0016]

As described above, according to the present invention, roughing and finishing are performed on all the blades of the impeller a plurality of times in the depth direction. Since it is finished in a thin shape and it is possible to prevent the blade portion from falling down when one blade portion is processed at once to a thin shape, it is not necessary to press the opposite wing surface with the holding member and In addition, the processing accuracy of the shoulder portion when the blade portion is thinned can be easily increased.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing a main part of a jet engine impeller to which the present invention is applied.

FIG. 2A is a perspective view showing a state in which approximately one third of an upper part of a blade is roughly processed, and FIG. 2B is a perspective view showing a state in which the finishing processing is performed.

FIG. 3A is a perspective view showing a state in which approximately 1/3 of an intermediate portion of a blade portion is roughly processed, and FIG. 3B is a perspective view showing a state in which the finishing processing is performed.

FIG. 4A is a perspective view showing a state in which approximately 1/3 of a lower part of a blade portion is roughly processed, and FIG. 4B is a perspective view showing a state in which the finishing processing is performed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impeller 5 Blade part 6a Upper rough processing part (thick blade part) 6b Middle rough processing part (thick blade part) 6c Lower rough processing part (thick blade part)

Claims (1)

[Claims] 1. A method of processing an impeller, wherein a plurality of blades of the impeller are formed by shaving and processing, wherein a rough processing is performed to make the blades thicker than a final thin shape. Performing a finishing process to make the thick-walled blade portion the final thin-walled shape, and performing the roughing process and the finishing process alternately in the depth direction a plurality of times. A method of processing an impeller, wherein the rough processing and the finishing processing of the same depth are performed on all the blade portions of the impeller, and then the rough processing and the finishing processing are performed on the next depth.