JPH06272693A - Manufacture of impeller for vortex flow blower - Google Patents

Abstract

PURPOSE:To provide a method for the manufacture of an impeller for a vortex flow blower, having the capability of easily coping even with the complicated form of a vortex flow blower impeller, allowing the application of the advanced three-dimensional form to an impeller blade, and ensuring the sufficiently high performance of the blower. CONSTITUTION:Regarding a vortex flow blower impeller 1 having a blade casing 6 with an annular groove about a rotary shaft as a center, and a plurality of blades inclined along a peripheral direction in the groove in such a way as divisionally forming an annular groove in that direction across the groove of the casing 6, an impeller 1'' is integrally cast and molded, except a section 8c covered with a blade 8, viewed from the open side of the groove of the casing 6. Thereafter, the section 8c covered with the blade 8 is cut out at a different process. In this case, electric discharge machining is preferably used at the different process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller of a vortex blower and a method of manufacturing the same, and more particularly to a method of manufacturing an impeller suitable for use in an vortex blower having a three-dimensional blade.

[0002]

2. Description of the Related Art A swirl blower has been widely used as a blower with a relatively small capacity, but in recent years, there has been an increasing demand for a smaller and lighter swirl blower, higher discharge pressure, and lower noise. Accordingly, various proposals regarding the shape and structure of the impeller have been found. One of the proposals is the three-dimensional shaping of the impeller blades.

With the commercialization of the vortex flow blower equipped with such a three-dimensional blade, its manufacturing method has become a major issue. That is, such an eddy-current blower impeller 1 is usually manufactured mainly by integral molding by casting, such as die casting. At this time, the eddy-current blower impeller having a conventional two-dimensional blade is Since it has a relatively simple shape, it can be cast without any particular problems, but when the impeller blade is formed into a three-dimensional shape, the blade itself becomes curved, which complicates the shape of the mold and makes manufacturing difficult. Because it will become.

Then, as a solution to such a problem,
For example, in Japanese Patent Laid-Open No. 51-57011, when manufacturing such an impeller by casting, the impeller is divided into two parts in the rotating direction, and after the casting, the impeller is joined to complete the impeller. It discloses a method that can eliminate the need for a core.

Further, in Japanese Patent Laid-Open No. 2-922, there is disclosed an impeller having a three-dimensionally shaped blade formed by separately molding the blade casing and the blade and plastically fastening the blade casing and the blade in a separate process. Proposing a manufacturing method.

[0006]

The above-mentioned prior art does not give sufficient consideration to the high-level three-dimensional shape of the impeller blade, and is applicable to the impeller having a more complicated shape. There was a problem that it was difficult.
That is, die casting or die casting is generally used for manufacturing an impeller having such a complicated shape. At this time, if the blade has a three-dimensional shape, the product cannot be separated from the casting die. It will be impossible to deal with it.

The method of plastically fastening the other blade casing and the blade separately to each other can produce a highly three-dimensional shape, but on the other hand, since a plurality of blades are assembled in the blade casing and plastically fastened, the number of blades is extremely large. It is unavoidable that the number of steps is increased and a slight gap is generated in the joint surface between the blade casing and the blade, resulting in a pressure loss.

The object of the present invention is to easily cope with an impeller of a vortex flow blower having a complicated shape, to make the impeller blade more three-dimensional, and to sufficiently improve the performance of the vortex flow blower. Another object of the present invention is to provide a method for manufacturing an impeller of such an eddy current blower.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is characterized by a blade casing having an annular groove centered on a rotation axis, and this blade casing. In the annular groove of, while partitioning the annular groove in the circumferential direction across the annular groove, in the impeller of the vortex blower equipped with a plurality of blades inclined with respect to the circumferential direction, The impeller is integrally formed by casting while leaving a portion covered by the blade as viewed from the opening side of the groove of the blade casing, and then the portion covered by the blade is cut in another step.

In the separate process, various machining methods can be used, but it is desirable to use electric discharge machining.

According to a preferred embodiment of the present invention, when the electric discharge machining electrode is used to machine a portion covered by the electric discharge machining electrode, the electric discharge machining electrode and the blade machined by the electric discharge machining electrode are processed. The gap between the adjacent EDM electrode and the blade located at the rear of the EDM electrode is in the range of at least 0.1-1.0 mm, and the gap between the EDM electrode and the inner peripheral surface of the groove of the blade casing. It is desirable to carry out the electric discharge machining under the condition that is within the range of 0.02 to 0.3 [mm].

[0012]

According to the above, the impeller is formed by die casting or die casting to a shape close to the final shape that can be produced by opening and closing the mold, and the extra portion is processed in a separate process. Can be integrally manufactured. Therefore, it is possible to easily manufacture a high-precision impeller without lowering the strength, and it is possible to easily obtain a high-performance swirl blower by forming the blade into a three-dimensional shape.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An impeller of a vortex blower according to the present invention and a method for manufacturing the same will be described below in detail with reference to the illustrated embodiments.

FIG. 2 shows an embodiment of a vortex flow blower according to the present invention, in which 1 is an impeller, 2 is a casing forming a booster passage 3,
An electric motor 4 drives the impeller 1.

The booster path 3 is formed in an arc shape around the rotation center of the impeller 1, that is, the rotation axis center line 5 of the electric motor 4, opens parallel to the rotation axis center line 5, and is shown in the drawing. Is formed as a semi-circular groove. Reference numeral 6 is a blade casing, 7 is an annular groove, and 8 is a blade. The blade casing 6 and the blade 8 are integrally formed.

The annular groove 7 formed in the blade casing 6 is formed as an annular groove having a concentric circle centered on the rotation axis center line 5, and as shown in FIG.
A plurality of blades 8 are mounted therein in a direction transverse to it and circumferentially. The arrow F indicates the rotation direction of the impeller 1.

In this case, as shown in FIG. 4, these blades 8 are mounted so as to be directed from the rotation axis center line 5 in the radial direction, and as shown in FIG. There are various forms, such as a case where the blade 8 is attached so as to form a curved line as shown in FIG.

Further, the cross-sectional shape of the blade cut along a concentric circle centered on the rotation axis center line 5 is curved as shown in FIG. 7 (a) and straight as shown in FIG. 7 (b). There is a case where the part is parallel to the rotation axis center line 5 and a part where the inclined part b is combined as shown in FIG. 7C.

Further, the impeller 1 may be a single-sided blade as shown in FIG. 2 or a double-sided blade as shown in FIGS. 8 (a), 8 (b) and 8 (c).

Next, an embodiment of a method for manufacturing an impeller having a three-dimensional blade will be described. According to this, first, as shown in FIG. 1A, the impeller 1 is integrally formed by casting while leaving a portion 8c covered by the blade 8 as viewed from the opening side of the groove 7 of the blade casing 6. . In this case, since the portion 8c covered by the blade 8 remains, the upper mold A and the lower mold B can be easily opened. As the casting, general die casting or low pressure casting can be used. At this time, the front edge surface 8d viewed from the rotation direction F of the blade 8 requiring additional processing
Is preferably parallel to the mold opening direction c of the movable upper mold A or is provided with a slight draft taper θ, and the trailing edge surface 8b of the blade 8 is preferably formed to have a final shape. With such a shape, it becomes possible to easily manufacture by general die casting or low pressure casting as described above. By the way, in the case of the embodiment, the material is aluminum. Next, the impeller 1'formed in this way is shown in FIG.
As shown in (b), (c), (d) and (e), an electric discharge machining electrode 9 having the same surface as the front edge surface 8a of the blade 8 which is finally required is shown in FIG. 1 (c). Blade 8 as shown
A blade having a blade 8 having an arbitrary shape, if inserted between them and if electric discharge machining is performed while relatively rotating in the circumferential direction concentric with the rotation axis center line 5 as shown in FIG. 1 (d). Car 1
Can be manufactured. As a machining method at this time, each blade 8 may be sequentially machined by one electric discharge machining electrode 9, or may be simultaneously machined by a plurality of electrodes having the same number as the number of blades 8. In order to prevent damage to the trailing edge surface 8b of the blade formed by die-casting or the like, whether the electric discharge machining electrode 9 is sequentially machined or a plurality of electrodes are simultaneously machined, as shown in FIG. It is desirable to set the gap L between the machining electrode 9 and the trailing edge surface 8b of the blade 8 in the range of 0.3 to 1.0 [mm], in order to make the surface formed by casting and the surface processed by electric discharge machining the same. Is an electric discharge machining electrode 9 and a blade casing 6
The gap N between the groove 7 and the peripheral wall is preferably in the range of 0.02 to 0.3 [mm].

FIG. 1 shows a method of manufacturing the impeller 1 of the single-sided blade of the vortex flow blower shown in FIG. 2. If one surface is inverted after electric discharge machining and the unmachined surface is electric-discharge machined again, FIG. Needless to say, it is possible to manufacture the impeller provided with the three-dimensional blade having the double-sided blade shown in FIG.

Further, FIGS. 4, 5 and 6 show the blade 8
Although the number of blades is 15 in this example, the number of blades is the diameter with which the blade 8 is circumscribed, and the portion that does not come off the casting mold as shown in FIG. The depth H1 of the blade and the value of the distance H2 between the leading edge surface 8a and the trailing edge surface 8b of the adjacent blades can be set, and the number is not limited.

As described above, according to the embodiment, in the manufacture of the impeller 1 of the vortex flow blower having the blade casing 6 and the plurality of blades 8, the impeller having the two-dimensional shaped blades formed by die casting, Since an impeller having a three-dimensional blade can be obtained by electric discharge machining, excellent effects as described below can be easily obtained.

That is, the impeller 1 having the three-dimensionally shaped blade 8 is generally formed by low pressure casting using a core, but in this case, there is a problem such as hot water flow. Is difficult to reduce, and as a result, it is also difficult to reduce the second moment of inertia of the impeller, and the drive motor cannot be downsized. However, according to the example, since the impeller formed by die casting or low pressure casting can be subjected to non-contact electric discharge machining without applying an external force, it is possible to reduce the necessary wall thickness and the electric motor required for driving. Can be sufficiently miniaturized.

In order to perform electric discharge machining on an impeller formed by die casting or low pressure casting, it is possible to obtain impellers having further different characteristics simply by changing the shape of the discharge electrode, and it is possible to produce a wide variety of products at low cost. It can be used with the swirl blower.

[0026]

As is apparent from the above description, according to the present invention, an impeller of a vortex flow blower having a complicated shape can be easily dealt with, and the blade of the impeller can be further formed into a three-dimensional shape. It is possible to obtain a method for manufacturing an impeller of an eddy-flow blower, which can sufficiently improve the performance of the eddy-flow blower.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of a vortex flow blower according to an embodiment of the present invention.

FIG. 3 is a perspective view of an impeller according to an embodiment of the present invention.

FIG. 4 is a plan view showing another example of the impeller.

FIG. 5 is a plan view showing still another example of the impeller.

FIG. 6 is a plan view showing still another example of the impeller.

FIG. 7 is a cross-sectional view showing an example of a central circumferential section of the impeller.

FIG. 8 is a cross-sectional view showing another example of the impeller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Impeller, 2 ... Casing, 3 ... Booster path, 4 ... Electric motor, 5 ... Rotation center line, 6 ... Blade casing, 7 ... Annular groove, 8 ... Blade, 9 ... EDM electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Noda 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Ltd. Narashino Factory

Claims (3)

[Claims] 1. A blade casing having an annular groove centered on a rotation axis, and a circular groove defined in the annular groove of the blade casing across the annular groove in the circumferential direction. In an impeller of an eddy-current blower equipped with a plurality of blades inclined with respect to the circumferential direction, the impeller is cast by casting while leaving a portion covered by the blades as viewed from the opening side of the groove of the blade casing. A method for manufacturing an impeller of a vortex blower, which is integrally molded, and then a portion covered by the blade is cut in a separate step. 2. The method for manufacturing an impeller of a swirl blower according to claim 1, wherein the separate step is electric discharge machining. 3. A gap between an electric discharge machining electrode and a blade adjacent to the blade machined by the electric discharge machining electrode and located at a rear portion of the electric discharge machining electrode in machining a portion covered by the electric discharge machining electrode. Is at least 0.1-1.0 [mm], and the gap between the electric discharge machining electrode and the inner peripheral surface of the groove of the blade casing is 0.
The method for manufacturing an impeller of an eddy current blower according to claim 2, wherein the electric discharge machining is performed under a condition of a range of 02 to 0.3 [mm].