JPH0656155B2 - 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 has a structure as shown in FIG. That is, the motor shaft 2 of the drive motor 1
A centrifugal impeller 3 is fixedly attached to the impeller 3, and an air guide 6 integrally formed with a diffuser 4 located around the impeller 3 and a return passage 5 following the diffuser 4 is provided adjacent to the impeller 3. The guide 6 and the casing 7 were covered. 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 However, the above-described conventional configuration has a problem that noise is large when operating the electric blower. That is,
The air flow 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 blades and a sparse flow on the rear side of the blades in the rotational direction. By colliding with the tip of the diffuser wall at the entrance of the diffuser 4, the compression wave is emphasized and can be heard as a large sound to the outside.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an electric blower capable of reducing the noise by reducing the difference between sparse and dense dense waves in the discharge flow from an impeller. .

Means for Solving the Problems In order to solve the above problems, an electric blower according to the present invention includes a centrifugal impeller, an air guide integrally formed with a diffuser and a return passage, and an impeller and an air guide. A casing for covering and a motor for driving the impeller are provided, each blade of the impeller has a thickness that gradually increases from the central portion to the outer peripheral portion, and the outer peripheral side from the intermediate portion branches into two branch portions, Of the two branch portions, the branch portion on the front side in the rotation direction is made to communicate with the small space portion having an open outer peripheral end formed between the two branch portions and the large space portion formed between the adjacent blades. It has a structure in which a slit is formed.

Action According to the above configuration, the flow that is sparsely and densely distributed between the blades inside the impeller is compensated for the part of the flow that is sparse due to the blades that are thicker toward the outer peripheral side, The air flow flows into the small space between the bifurcated parts that split into two parts through the slit. As a result, the flow has a reduced difference in density as a whole, the collision of compression waves at the tip of the diffuser wall is weakened, and an electric blower with a low noise level can be obtained.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, reference numeral 11 is a casing, and an intake port 12 is formed in the center thereof, and the opposite side of the intake port 12 is attached to a motor frame 13 so as not to leak air. Centrifugal impeller 15 with multiple blades 14
Are attached to the motor shaft 16 by nuts 17.
An air guide 20 in which a diffuser 18 composed of a plurality of enlarged passages and a return passage 19 are integrated is installed on the outer periphery and below the impeller 15. Reference numeral 21 is a driving motor.

As shown in FIG. 1, each of the blades 14 is composed of one blade on the center side of the impeller, but is divided into two branch portions 14a and 14b from the middle to reach the outer periphery, which is different from the center side. In addition, the thickness gradually increases on the outer peripheral side, and a small space portion 22 having an open outer peripheral end is formed between the two branch portions 14a and 14b. In addition, two branch parts 14a, 14b
Among these, a slit 23 is formed in the branch portion 14a on the front side in the rotation direction. Through this slit 23, the small space 22
And the large space 24 between the adjacent blades 14 communicate with each other.

Next, the operation will be described. The airflow inside the impeller 15 tends to be a dense flow on the front side in the rotating direction of the blade 14 and a sparse flow on the rear side as it goes from the center to the outer periphery, but in the impeller 15 of the present embodiment, the blade
Since the thickness of 14 becomes thicker toward the outer circumference, the portion of the sparse flow is occupied by the blade 14. Further, since the slit 23 is provided in the dense flow portion, the air flow therethrough passes through the small space portion 22 and the blade 14
Flows toward the outer circumference of. As a result, a uniform flow is generated inside the impeller 15, and a flow having a small density difference flows into the diffuser 18. Therefore, an electric blower with a low noise level can be obtained.

EFFECTS OF THE INVENTION As described above, according to the present invention, the airflow inside the impeller becomes uniform, and the airflow with a small difference in density flows into the diffuser, so that the noise level can be reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of an impeller of an electric blower according to an embodiment of the present invention, FIG. 2 is a partially cutaway front view of the same electric blower, and FIG. 3 is a partially cutaway front view of a conventional electric blower. Is. 11 …… Casing, 14 …… Blade, 14a, 14b …… Branch, 15 …… Impeller, 18 …… Diffuser, 19 …… Return passage, 20 …… Air guide, 21 …… Motor, 22 …… Small space Department, 23 …… Slit, 24 …… Large space

Claims (1)

[Claims] 1. A centrifugal impeller, an air guide integrally formed with a diffuser and a return passage, a casing for covering the impeller and the air guide, and a motor for driving the impeller, each of the impellers being provided. The blade gradually becomes thicker from the center to the outer periphery,
In addition, the outer peripheral side of the intermediate portion is branched into two branch portions, and the branch portion on the front side in the rotation direction of the two branch portions has the above-mentioned 2
An electric blower having a slit for communicating a small space portion formed between the branch portions of the sheet and having an open outer peripheral end with a large space portion formed between adjacent blades.