JPH065080B2 - 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 The configuration of a conventional electric blower of this type will be described with reference to FIG.

A centrifugal impeller 3 is fixed to a motor shaft 2 of a drive motor 1, and an air guide 6 integrally formed with a diffuser 4 and a subsequent return passage 5 is provided around the impeller 3, and further the impeller 3 and the air guide are provided. 6 and 6 are covered with a casing 7, and the impeller 3 is rotated at a high speed to
It was like getting a 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.

In other words, 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 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 fuser 4, the compression wave is reinforced and can be heard as a large sound to the outside.

The present invention solves such a problem and reduces the sound level.

Means for Solving Problems The technical means of the present invention for solving the above problems are as follows. That is, a small hole and a closed space subsequent to the small hole are provided in the air guide at a position facing the air flow.

Action The action of this technical means is as follows.

That is, the air flow with a high sound level including the compression wave generated by the impeller flows to the place having the small holes provided in the air guide. The energy of sound including compression waves is reduced by being reflected in the closed space following the small hole, and as a result, an electric blower with a low noise level can be obtained.

Example Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 8 denotes a casing, and an air intake port 9 is opened in the center of the casing, and the opposite side of the air intake port 9 is attached to a 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 (not shown), a spacer 14 and a washer 15. On the outer periphery of the impeller 12, a diffuser 16 including a plurality of enlarged passages and the diffuser 16 are provided.
An air guide 18 integrally formed with a return passage 17 communicating with each of the enlarged passages is installed. 19 is a motor.

A closed space 21 is provided so that the recess formed in the wall of the diffuser 16 is closed by a part of the casing 8, and a small hole 20 communicating with the closed space 21 is formed in the wall of the diffuser 16. I am doing it.

Next, the operation of this embodiment will be described. Impeller 1
The air flow inside 2 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 rotational direction of the flade 11. This becomes a compressional wave at the time of entering the diffuser 16, overlaps with the sound generated by other causes, and becomes an air flow with a large sound level, and reaches the small hole 20.
In the closed space 21 following the small hole 20, the energy of sound such as compressional waves is reduced by reflection and the like, and the level of the sound is reduced by eliminating the difference in compressional density.

EFFECTS OF THE INVENTION As described above, according to the present invention, a small hole and a closed space that follows the small hole are provided in a location of the air guide facing the air flow. Can reduce the energy of the sound
As a result, the effect that an electric blower with a low noise level can be obtained is obtained.

[Brief description of drawings]

1a is a top view of an air guide in an embodiment of the present invention, FIG. 1b is an enlarged top view of part A of FIG. 1, FIG. 2 is a partially cutaway side view showing the overall structure, FIG. [Fig. 6] is a partially cutaway side view of a conventional example. 8 ... Casing, 12 ... Impeller, 18 ... Air guide, 19 ... Motor, 20 ... Small hole, 21 ... Closed space.

Claims (1)

[Claims] 1. A centrifugal type impeller, an air guide for guiding an air flow, a casing for covering the impeller / air guide, and a motor for driving the impeller, the air guide in a location facing the air flow. An electric blower with a small hole and a closed space that follows it.