JPS63109300A - Motor-driven blower - Google Patents

Abstract

PURPOSE:To reduce the level of noise, by forming an air guide by a disk part facing to the under surface of an impeller and a plurality of guide parts each of which has an inclined face, and making the height of guide part equal to or lower than the under surface of the impeller. CONSTITUTION:An air guide 19 is made up of a guide part 30 having a disk part 27 facing to the under surface of an impeller 21, a cylindrical part 29 forming the outer circumference thereof, a flat part 31, and inclined-face parts 28. The guide part 30 is placed in the position equal to or lower than the under surface of the impeller 21, so that the impingement of air current from the impeller 21 to the guide part 30 can be eliminated. Thus, the flowing efficiency can be enhanced with low noise.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric blower for generating suction pressure used in a vacuum cleaner or the like.

2. Description of the Related Art A conventional electric blower of this type will be explained with reference to FIGS. 5 to 7. In FIG. 5, 1 is a motor, 22 a rotating shaft thereof, and 3 an impeller fixed to the rotating shaft 2. In FIG. Reference numeral 4 denotes an air guide that accommodates the impeller 3, and has a diffuser 5, which is an air passage that widens toward the periphery, and a return passage 6 on the back surface that follows the diffuser 5.

7 is a casing that covers the impeller 3 and the air guide 4;
It is press-fitted and fixed into the motor bracket 8. 9 is an intake port.

As shown in FIG. 6, the impeller 3 includes a conical front shroud 11 having an air suction port 10 in the center, a flat rear shroud 12, and a plurality of curved grades 13.
The grade 13 is arranged vertically between the front shroud 11 and the rear shroud 12 at a constant interval, and is fixed by caulking.

As shown in FIG. 7, the air guide 4 is made up of a diffuser 5 made up of a large number of passages 16 sandwiched between tongue walls 15, and a return passage 6 communicating with these, which are integrally molded. Problems to be Solved by the Invention However, with such a structure, the airflow that attempts to enter the air guide 4 after passing through the impeller 33 is caused by the tongue wall on the rotating surface of the impeller 3 immediately after being discharged. 15, causing a large amount of noise.

The present invention solves these problems, and by changing the shape of the air guide, the airflow discharged from the impeller does not collide with the tip of the tongs immediately after discharge, thereby obtaining an electric blower with a low noise level. This is what we are trying to do.

Means for solving the problems and technical means in the present invention for solving the above problems are as follows.

That is, the air guide has a disc part facing the lower surface of the impeller, and a plurality of guide parts connected to the outer periphery thereof and having sloped surfaces that guide the airflow to the back side of the air guide, and the guide part The height is equal to or lower than the lower surface of the impeller.

action The effect of this technical means is as follows.

In other words, the airflow immediately after being discharged from the impeller does not collide with the tongs, but instead flows into the motor along the inclined surface of the guide part, eliminating the cause of noise generation and reducing the noise level. It is possible to obtain a low-cost electric blower.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. In Figures 1 to 4, 17 is a casing that covers the impeller and air guide, and in the center is an intake port 18.
is provided, and the opposite side is airtightly attached to the outer periphery of the motor bracket 20 via the outer periphery wall of an air guide 19 that guides airflow toward the motor side. 21 is a centrifugal impeller having the same structure as the conventional one, and a nut 23.21 is attached to the motor shaft 22. A reference numeral 026 attached via a spacer 24 and a washer 25 is a motor for driving an impeller.

The air guide 19 described above includes a disc part 27 facing the lower surface of the impeller 21, a cylindrical part 29 on the outer periphery of the disc part 27, and a cylindrical part 27.
It has a guide part 30 that continues to the outer periphery of 9. The guide portion 3o consists of a flat portion 31 that is flush with the top of the cylindrical portion l-2 29, and an inclined surface 28 connected to the flat portion 31, and is provided in plural pieces on the outer periphery of the cylindrical portion 29. There is. This inclined surface 28 and flat part 3
1 is sandwiched between the cylindrical portion 29 and the casing 17 and acts to guide the airflow from the impeller 21 to the back side of the air guide 19, and the inclined surface 28 gradually slopes toward the motor 26. It has a shape. The positional relationship between these impellers 21 and the guide section 30 is such that the guide section 30 is at a position equal to or lower than the lower surface of the impeller 21.
is located, the airflow from the impeller 21 is directed to the guide part 3.
This eliminates collisions with 0.

Although the air guide 19 is provided with the cylindrical portion 29, this is not necessarily necessary and only the disk portion 27 may be provided. Furthermore, the guide portion 30 functions even if it has only the inclined surface 28.

Next, the operation of the configuration of this embodiment will be explained. The airflow discharged from the impeller 21 at high speed is
7 toward the air guide 19, the airflow is rectified by the flat portion 31 and the inclined surface 28, and is guided to the back side of the air guide 19 and smoothly from the return passage 27 to the motor 26. It flows inside. This impeller 21
Immediately after the air is discharged from the air, there is nothing that causes wind noise such as tongs, which suppresses the generation of noise, and the air flow is guided along the slope 28 and smoothly decelerated, resulting in high air blowing efficiency. Effects of the Invention As described above, in the electric blower of the present invention, the air guide is shaped without tongues, thereby providing an electric blower with low noise and high air blowing efficiency.

[Brief explanation of the drawing]

Fig. 1 is a cutaway sectional view of the main parts of an embodiment of the electric blower of the present invention, Fig. 2 is a sectional view of the air guide of the same embodiment, and Fig. 3
The figure is a plan view of the air guide of the same embodiment as seen from the impeller side, Figure 4 is a partial perspective view of the impeller and air guide in the same embodiment, and Figure 5 is a cutaway sectional view of main parts of a conventional electric blower. FIG. 6 is a sectional view of a conventional impeller, and FIG. 7 is a partial sectional view of a conventional electric blower as viewed from the suction port side. 17... Casing, 19... Air guide, 21... Impeller, 26... Motor, 27... Disc portion, 28... ... Slanted surface, 30 ... Guide part. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
figure? 8 Figure 4

Claims (1)

[Claims] The air guide includes a centrifugal impeller, an air guide that guides airflow from the impeller, a casing that covers the impeller and the air guide, and a motor for driving the impeller. , a plurality of guide parts with inclined surfaces that are connected to the outer periphery and guide the air flow to the back side of the air guide, and the guide part has a height that is equal to or higher than the lower surface of the impeller. Lowered electric blower.