JPS6270695A - Electric motor fan - Google Patents

Abstract

PURPOSE:To acquire a quiet motor fan, by forming recessions on a support rubber opposite to holes furnished near the periphery of an impeller, and furnishing projections to gear with the holes and the recessions on the support rubber or at the casing. CONSTITUTION:Plural holes 20 are furnished at a casing 17 at the front near the periphery of an impeller 11, and projections 21 formed unitary to a support rubber 18 are geared with these holes 20. Furthermore, recessions 22 are formed at the support rubber 18 opposite to the holes 20. Therefore, a high frequency sound passes the holes 20 through the recessions 22 while decreasing the high frequency sound including NZ sound, and a quiet motor fan is acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric blower used in a vacuum cleaner or the like.

2. Prior Art Conventionally, this type of electric blower was developed, for example, by the Japanese Patent Publication Publication No. 52-49
The configuration was as shown in Publication No. 168.

That is, as shown in FIG. 5, an impeller 2 and an air guide 3 are provided in a casing 1, and by rotating the impeller 2 at high speed with a motor 4, air volume and vacuum pressure are obtained.

Problems that the Necessary M tries to solve
When the airflow discharged from the airflow flows into the air guide 3, noise that is thought to be caused by collision at the air guide entrance has been a problem. This occurs as a product of the number of blades of the impeller 2, 2, and the rotational speed N (rpm) of the impeller 2, and is commonly called NZ sound.

The present invention solves these problems and provides an electric blower that is excellent in terms of noise reduction.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to provide holes in the casing near the outer periphery of the impeller, and to provide the support rubber covered on the outer periphery of the casing with the above-mentioned holes. Four parts are formed facing the hole, and a convex part that engages with the hole or the four parts is provided protruding from the casing or support rubber.

Action This technical means works as follows. That is, high-frequency sounds including NZ sounds generated by high-speed rotation of the impeller enter the recesses of the support rubber through holes in the casing, and are muffled by the principle of an expansion type muffler.

In addition, by forming a protrusion that engages with the recess or hole from one side, the support rubber's covering power with respect to the casing is increased, and it does not peel off when the device is assembled. It is also useful for alignment.

EXAMPLE Hereinafter, an example will be described according to the drawings. In FIGS. 1 to 3, a centrifugal impeller 11 having a plurality of blades is attached to a shaft 13 of a motor 12.
Further, an air guide 14 is disposed on the blowing side of the impeller 11. These 1 Numbera 11 and Air Guide 1
4, it has an intake port 16 on the top wall, and the lower part of the peripheral wall of the motor frame 16 is surrounded by a casing 17 that is airtightly attached.

Here, the air flow sent out from the impeller 11 is guided approximately to the center of the motor by an air guide 14 as shown by the arrow, and after cooling the motor 12, is discharged to the outside from a predetermined exhaust port 12'. It is.

Reference numeral 18 denotes support rubber for supporting the electric blower on a device 19 such as a vacuum cleaner, and is made of foamed rubber or the like. A plurality of holes 2o are provided on the front surface of the casing 17 near the outer periphery of the impeller 11, and a convex portion 21 integrally formed from the support rubber 18 is engaged with the hole 2o. A recess 22 is formed in the support rubber 18 to face the support rubber 18 .

Next, the functions of the hole 20, the recess 22, and the protrusion 21 will be explained.

First, the air flow sent out from the outer periphery of the impeller 11 is guided to the approximate center of the motor 12 by the air guide 14, cools the inside thereof, and is discharged from the exhaust port 12.

As mentioned above, a particularly problematic type of noise from electric blowers is called NZ sound. 5.3 KH in NZ Onmoto review
It occurs near z and is a very harsh sound to the auditory sense.

In the above embodiment, the high frequency sound generated by the rotation of the impeller 11 passes through the hole 2° of the casing 17 and enters the recess 22 of the support rubber 18 made of foamed rubber, where it is suppressed by the action of the expansion type muffler. High frequency sounds including NZ sound are reduced. Note that the support rubber 18 has the same effect even if it is not foam rubber. By the way, the outer diameter is 10
Casing 1 located on the outer periphery front of two impellers 11
By providing 20 64III+2 (8 x 8 MM) holes 20 in 7 and providing a 7M deep recess 22 in the 12 mm thick support rubber 18 made of foamed rubber, the noise level was reduced by about 3 dB.

In addition, a support rubber 1 is attached to the end surface of the hole 20 of the casing 17.
When the electric blower is installed in a device 19 such as a vacuum cleaner, the support rubber 18 is engaged with the convex portion 21 of the device 19.
When attached to the casing 17, it will rub against the surface and turn over, and it will not come off from the casing 17. The convex portion 21 also serves to ensure alignment between the hole 2Q and the concave portion 22.

Furthermore, as shown in the fourth column, a similar effect can be obtained by forming a cut-and-raised convex portion 21' from the casing 17 and engaging it with the concave portion 22 of the support rubber 18.

Effects of the Invention As described above, according to the present invention, it is possible to reduce the high-frequency sound that is a particular problem in electric blowers and promote quietness, and also to attach support rubber to the casing and to use the electric blower with vacuum cleaners, etc. This significantly improves the ease of assembly when setting it into equipment.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of the main parts of an electric blower showing an embodiment of the present invention, Fig. 2 is an overall sectional view thereof, Fig. 3 is an exploded perspective view, and Fig. 4 is a main part showing another embodiment. Enlarged sectional view, No. S
The figure is an exploded perspective view showing a conventional electric blower. 11... Impeller, 17... Casing, 18... Support rubber, 19...
Equipment, 20... Hole, 21.21'...
Convex portion, 22... Concave portion. Name of agent: Patent attorney Toshio Nakao and 1 other person//
---Inyara? ? ---Concave 3rd Figure 11-1-In to Ou2/'-11 Convex 2? -Recessed part Fig. 5

Claims (1)

[Claims] A centrifugal impeller driven by a motor, an air guide having a passage that guides the air flow sent out from the impeller from the outer periphery of the impeller to the motor, a casing containing these impellers and the air guide, and the above-mentioned casing for attachment to equipment. a support rubber covering the outer periphery of the impeller, a hole in the casing near the impeller outer periphery, a recess formed in the support rubber opposite to the hole, and a convex portion that engages with the hole or recess. An electric blower that protrudes from the support rubber or casing.