JPS6287698A - Motor-driven blower - Google Patents

Abstract

PURPOSE:To reduce a noise, by providing an annular projection having communication holes in a return passage of an air guide, and defining spaces between the projection and a motor frame with the communication holes serving as an inlet. CONSTITUTION:A return passage 28 of an air guide 25 forming a diffuser 26 is integrally formed with an annular projection 31 having communication holes 32. There are defined spaces A as a silencer inside the projection 31 in cooperation with the air guide 25 and a motor frame 23. Thus, the spaces A serve as a silencer having an inlet formed by the communication holes 32 to thereby reduce a noise in air flow.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric blower for use in a vacuum cleaner.

2. Description of the Related Art Conventionally, this type of electric blower has been developed, for example, in Japanese Patent Publication No. 52-491.
This is shown in Publication No. 68. That is, as shown in FIG. 5, an impeller 2° air guide 3 is provided in a casing 1, and a motor 4 rotates the impeller 2 at high speed to obtain air volume and vacuum pressure.

Problems to be Solved by the Invention In a structure in which the air guide 3 is provided on the outer periphery of the impeller 2 like the electric blower described above, when the airflow discharged from the impeller 2 flows into the air guide 3, there is a problem at the air guide inlet. Noise thought to be caused by collisions was a problem. In addition, the present invention solves the problem of airflow noise caused by flowing airflow, and reduces noise without reducing the performance of the blower. The present invention provides an electric blower.

Means for Solving the Problems The technical means of the electric blower of the present invention to solve the above problems is to provide an annular protrusion in the return path of the air guide, and to dispose the air guide on the inner circumferential side of the protrusion. The entire space is formed jointly with the motor frame, and a communicating hole is provided in the protrusion to communicate the space and the return passage.

Operation This technical means operates as follows. By forming a space on the inner circumference of the annular protrusion with gold film in the return passage of the hair air guide, the space forms a muffler with the communication hole as an inlet, and the airflow is directed into the return passage. When the flow of water flows into the motor, it can be greatly muffled.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4. In the figure, 21 is a casing, and an intake port 22 is open in the center. Further, the opposite side of the intake port 22 is attached to the motor frame 23 so as to prevent air leakage. Reference numeral 24 denotes a centrifugal impeller having a plurality of blades, and a diffuser 26 formed by a casing 21 and an air guide 25 is disposed around the outer periphery of the impeller 24 so as to have a passage that expands toward the outer periphery.

A return passage 28 is formed on the back surface of the loose air guide 25, which smoothly and independently communicates with the end of the diffuser 26 and guides the airflow to the intake hole 2T. Reference numeral 29 denotes a commutator motor for driving, and the airflow flowing into the motor intake hole 273 cools the inside of the motor and is discharged from the air hole 30. A ring-shaped protrusion 31 is integrally provided, and a communication hole 32 is provided in the protrusion 31. On the inner peripheral side of the protrusion 31, a space A is formed as a muffler in cooperation with the air guide 26 and the motor frame 23. In the case of this example,
Four of the guide walls 33 of the return passage 28 extend to the inner periphery, resulting in a four-sided bottom. The shape of the space Japanese person is not limited to that of the embodiment, but may be of various shapes. The same applies to the protrusion 31. Note that the intake hole 2 is provided in the motor frame 23 on the outside (outer circumferential side) of the annular protrusion 31 .

As can be seen in FIG. 1, in this embodiment, when the air guide 25 is installed, a space surrounded by the motor frame 23, the return passage 28 of the air guide, and the projection 31 is automatically formed. . Projection 3 serves as the entrance for Japanese people in that space.
1 is provided with the communication hole 32. In the embodiment, the communication hole 32 provided in the protrusion 31 is elongated and cut to approximately half the height of the protrusion 31, but there are no restrictions on the number, size, or shape. All experiments were conducted with the holes arranged at equal pitches on the circumference of the protrusion 31.
The same silencing effect as in the case of the communication hole 32 was obtained.

Next, the operation of the configuration of this embodiment will be explained. Generally, fan noise is transmitted to the outside through the equipment in which the fan is installed, causing many problems.

Measures have been taken to counter this, such as adding soundproofing materials, but this is becoming difficult as devices tend to become smaller. Therefore, in the embodiment of the present invention, the fan itself is used to reduce the chanting noise. Airflow diffuser 26
When the air flows into the return passage 28 and further into the intake hole 27, it acts as a muffler with the above-mentioned space Japanese person having the 32-minute inlet of the communication hole, completely reducing one sound in the airflow. Is there a fan in the load? A great effect can be obtained by optimizing the shape of the spacecraft so that the NZ sound (generated by the temporary QZ of the impeller 24 blade and the bond of rotation speed N; - sound) that becomes Q can be silenced. . In the example, a reduction of about e dB was achieved.

Effects of the Invention The electric blower of the present invention has an annular protrusion in the return passage of the air guide, and forms a space between the motor frame and the communicating hole provided in the protrusion.
The NZ sound generated by the impeller and the noise in the airflow can be greatly reduced by the function of the space as a muffler.

In addition, its structure is simply to provide a protrusion on the air guide, so it can be easily formed integrally with the air guide.
Moreover, just by installing the air guide in a predetermined position, a space can be automatically formed as a silencer, and it is easy to assemble and does not differ in appearance from a conventional electric blower. be.

[Brief explanation of drawings]

Figure 1 shows an embodiment of the integrated invention, with a partially missing 1111 side of an electric blower.Figure 2 is a roadside plan view of the air guide. 4 is a side plan view taken along the line B--B in FIG. 2, and FIG. 5 is an exploded perspective view of a conventional electric blower. 23... Motor frame, 24... Inhaler, 25... Air guide, 27...
・Intake hole, 28...Return passage, 29...
・Motor, 31...Protrusion, 32...
Communication holes, people...space. Name of agent: Patent attorney Toshio Nakao and one other person. 3--Shoes b-A z4-m-in 31 Figure 25-1 Air field
Do26--Diffuser? 9---Moog 31' 31 origin

Claims (1)

[Claims] attached to the motor and the motor frame of this motor,
The air guide has an air guide and a casing containing an impeller, and the air guide has an annular protrusion in its return passage, and a space is formed on the inner circumferential side of the protrusion in cooperation with the air guide and the motor frame. An electric blower in which the protrusion is provided with a communication hole that communicates the space with the return passage.