JPH05126092A - Impeller with welded construction - Google Patents

Abstract

PURPOSE:To provide proper welded joints without full penetration or notches and to allow an impeller with welded construction to be easily and reliably welded by welding split impeller members having a blade root shape with a proper curvature while butting them at the middle part of a blade thickness. CONSTITUTION:A split impeller member 10 is formed to have a shape of an impeller split at a plurarity of positions along the peripheral direction as well as at the middle of the board thickness of a blade 3. Each split impeller member 10 composed of a main shroud 1, a front horizontal board 2, and a blade 3 is integrally formed by machining or casting. In addition, each split impeller member 10 integrally formed has a curved surface with a proper curvature formed at a blade root part in advance. Moreover, split impeller members 10 are arranged in the peripheral direction and adjacent members 10 are welded with weld metal 4 by deep penetration welding while butting blades 3 with each other. This constitution provides proper welded joints without full penetration or notches.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welded structure impeller applied to a refrigerator or the like.

[0002]

2. Description of the Related Art FIG. 2 shows a welded structure impeller having a structure in which a plurality of blades 3 are provided between a main plate 1 and a front transverse plate 2. The blades 3 are formed in a radial shape while curving from the inlet portion (center of rotation) toward the outlet portion (outer peripheral portion), and perform air supply and exhaust by rotating the impeller.

3 to 6 show a conventional welding structure of a welded structure impeller, and show a portion corresponding to the AA 'cross section of FIG. Of these, FIGS. 3 and 4 show examples of welded structures when the port width P is narrow, and FIGS. 5 and 6 show examples when the port width P is wide.

When the port width P is narrow as shown in FIGS. 3 and 4, welding is performed from the outer surface side to manufacture a welding impeller. 4 is a weld metal. With this welded structure, it was difficult to ensure complete penetration, and the notch generated in the blade root part 5 could not be avoided.

When the port width P is wide, as shown in FIG. 5, the blade 3 and the front horizontal plate 2 are welded from the inside, or as shown in FIG. 6, the blade 3 and the front horizontal plate 2 are welded from the inside. In addition, the blade 3 was welded to the main plate 1 to produce a welded impeller.
4 is a weld metal.

[0006]

By the way, FIG. 3 and FIG.
In the case of a welded structure impeller having a narrow port width P, as shown in FIG. 2, welding is performed from the outer surface side, but during this welding, the penetration into the blade root portion 5 on the inner surface side has an appropriate curvature, Currently, there is no technique for controlling notch formation, and it is difficult to cover this. For this reason, there was no choice but to sacrifice a slight lack of penetration or deterioration of the curvature of the blade root portion 5 on the inner surface side.

Further, as shown in FIGS. 5 and 6, in the case of a welded structure impeller having a wide port width P, the main plate 1 and the blades 3, or the front transverse plate 2 and the blades 3 are welded. 1. In the space limited by the front horizontal plate 2 and the blades 3, and because the weld joint line is a curve, the welding requires skill and many man-hours.

The present invention has been made in view of the above prior art, and an object thereof is to provide a welded structure impeller in which welding work is simple and reliable welding is performed.

[0009]

As described above, the main factors affecting the performance of the welded structure impeller are the complete penetration and the proper curvature of the blade root. Since it is easy to ensure complete penetration when the I-type butt joint is constructed by the deep penetration welding method (electron beam welding, laser welding, plasma welding, etc.), the I-type joint shape was adopted. On the other hand, since it is extremely difficult to secure the proper curvature of the root portion of the blade with weld metal, we decided to secure it at the material stage by machining, casting, forging, or the like. The most important consideration here is the position of the weld joint. A welded joint is provided in the blade thickness center part in the direction perpendicular to the blade thickness in order to obtain a welded structure that achieves complete penetration as described above and does not impair the proper curvature secured by machining, etc. With the structure.

[0010]

With the welding structure as described above, complete penetration welding can be performed by deep penetration welding from both sides or one side, and welding assembly can be performed without impairing the proper curvature provided at the blade root. Will be possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the present invention, showing a portion corresponding to the AA 'cross section of FIG.
The divided impeller member 10 has a shape obtained by dividing the impeller shown in FIG. 2 at a plurality of locations along the circumferential direction and at the plate thickness center portion of the blade 3. Then, an individual divided impeller member 1 composed of a main plate 1, a front lateral plate 2, and a blade 3 divided at a plurality of locations along the circumferential direction
0 is integrally formed by machining, casting or forging. In each of the integrally formed divided impeller members 10 made of this material, a curved surface having an appropriate curvature is previously formed on the blade root portion 5.

A plurality of divided impeller members 10 are arranged in the circumferential direction. Adjacent members 10 are divided into blades 3 by deep penetration welding (electron beam welding, laser welding, plasma welding, etc.). ) Are welded together. Reference numeral 4 denotes a weld metal, and before welding, the I-shaped groove portion is formed between the blades 3 and 3 facing each other.

FIG. 1 shows a case of welding on both sides, but a welding impeller having a small port width can perform welding on one side. Although not shown, the blade 3 is
In order to prevent the outer surface of the product from being oxidized, the part may be gas-shielded or may be cooled with a copper metal or the like.

[0014]

According to the present invention, the divided impeller members having a blade root portion shape with an appropriate curvature are butt-welded at the blade thickness central portion, so that proper welding without complete penetration and notch is achieved. A joint can be secured. In the case of the welded structure of the present invention, the welding is performed only from the outside, but by applying the deep penetration welding method (electron beam welding, laser welding, plasma welding, etc.), the present impeller is applied regardless of the port width. it can. In this way, the notch of the front blade side wing root portion is not formed unlike the conventional structure having a narrow port width shown in FIGS. 3 and 4.

Although the butt joints may be provided on all the blades, welding distortion can be further reduced by adopting the method of assembling the winged blocks capable of forming joints for every several blades.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a welded structure in an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a welded structure impeller.

FIG. 3 is a cross-sectional view showing a welding structure in the conventional technique.

FIG. 4 is a cross-sectional view showing a welding structure according to a conventional technique.

FIG. 5 is a cross-sectional view showing a welded structure in the related art.

FIG. 6 is a cross-sectional view showing a welding structure in the conventional technique.

[Explanation of symbols]

 1 Main Plate 2 Front Horizontal Plate 3 Blade 4 Weld Metal 5 Blade Root 10 Split Impeller Member P Port Width

Claims (1)

[Claims] 1. An impeller having a plurality of blades that are curved and radially provided between a disc-shaped main plate and a front transverse plate, wherein the impeller is provided at a plurality of locations along a circumferential direction. It has a shape that is divided at the center of the plate thickness, and the main plate, the front horizontal plate, and the blade that are divided at multiple points along the circumferential direction are integrally formed, and a curved surface with an appropriate curvature is attached to the blade root. A welded structure impeller, comprising a plurality of divided impeller members arranged in a circumferential direction, wherein adjacent divided impeller members are butt-welded together by divided blades.