JPH068635B2 - Electric blower - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric blower used in a vacuum cleaner or the like.

2. Description of the Related Art A conventional electric blower of this type is disclosed, for example, in Japanese Patent Application No. 59-41.
As shown in the specification and drawings of No. 3, the structure was as shown in FIG.

That is, the centrifugal impeller 3 is fixed to the motor shaft 2 of the drive motor 1, and the air guide 6 in which the diffuser 4 located around the impeller 3 and the subsequent return passage 5 are integrally formed is provided with the impeller 3. And the impeller 3 and the air guide 6 are covered with a casing 7. Then, the impeller 3 was rotated at a high speed to obtain the air volume and the vacuum pressure.

Problems to be Solved by the Invention In such a conventional configuration, there is a problem that noise is large when the electric blower is operated. This is due to the following reasons.

That is, the airflow discharged from between the blades of the impeller 3 flows into the diffuser 4 in a biased flow state such as a dense flow on the front side of the blade and a sparse flow on the rear side in the rotational direction, By colliding with the tip of the wall of the diffuser at the entrance of the diffuser 4, the sparse density is emphasized and a large sound is opened to the outside.

The present invention solves such a problem and reduces the noise by reducing the difference between the sparse density and the dense density in the discharge flow from the impeller.

Means for Solving Problems The technical means of the present invention for solving the above problems are as follows. That is, the outer peripheral end shape of the blade in the impeller is configured to be sharp in the outer peripheral direction of the impeller.

Action The action of this technical means is as follows.

That is, since the blades in the vicinity of the outer periphery are sharp, the flow biased in a sparse and dense manner between the blades inside the impeller causes a gap as the time when the air flow separates from the blades immediately after discharge from the impeller. , The density of mixed air flow will be reduced. As a result, the air flow whose degree of sparseness is weakened flows into the diffuser, so that the collision of sparse density at the tip of the diffuser wall is weakened, and as a result, an electric blower with a low noise level can be obtained.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 8 denotes a casing, which has an intake port 9 formed at the center thereof, and the other side of the intake port 9 is attached to the motor frame 10 so as not to leak air. There is. A centrifugal impeller 12 having a plurality of blades 11 is attached to a motor shaft 13 via a nut 14, a spacer 15 and a washer 16. Below the impeller 12, a diffuser 17 located on the outer circumference of the diffuser 17 to form a plurality of enlarged passages, and a return passage 1 communicating with each enlarged passage of the diffuser 17.
An air guide 19 that is integrally formed with 8 is installed.
20 is a motor.

The impeller 12 is composed of the shroud 22, the rear shroud 23, and a large number of blades 11, and is integrated with the front and rear shrouds 23 by crimping the crimp heads 24 provided on these blades 11. When viewed on a plane perpendicular to the rear shroud 23, the blade 11 has a shape that is sharpened toward the outer periphery near the outer periphery.

Next, the operation of this embodiment will be described.

The airflow inside the impeller 12 is a biased flow such as a dense flow on the front side and a sparse flow on the rear side with respect to the rotating direction of the blade 11. In the vicinity of the outer circumference of the impeller 12, the blade 11 is sharpened toward the outer circumference, so that a deviation occurs when the airflow leaves the blade 11. As a result, the airflow immediately after discharge from the impeller 12 becomes a mixed flow of a sparse flow and a dense flow, and the mixed flow of the sparse flow and the dense flow flows into the diffuser 17 at the same time. As a result, it is possible to obtain an electric blower with a low noise level in which the difference in sparseness and density is reduced and the generated sound is also reduced.

As described above, according to the present invention, since the blade in the impeller is sharpened toward the outer periphery in the vicinity of the outer periphery of the impeller, a deviation occurs in the time when the air flow separates from the blade, and as a result, the discharge flow contains mixed density. As a result, an electric blower with a low noise level can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an impeller in one embodiment of the present invention,
FIG. 2 is a partially cutaway side view of the entire structure in the same embodiment, and FIG. 3 is a partially cutaway side view of a conventional example. 8 ... Casing, 11 ... Blade, 12 ... Impeller, 17 ... Diffuser, 18 ... Return passage, 19
...... Air guide, 20 ...... motor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Kogei Kato, 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-55-107099 (JP, A)

Claims (1)

[Claims] 1. An outer circumference of a blade of the impeller, comprising a centrifugal impeller, an air guide in which a diffuser and a return passage are integrated, a casing covering the impeller and the air guide, and a motor for driving the impeller. An electric blower whose end is sharpened toward the outer circumference of the impeller.