JP2692058B2 - Electric blower - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric blower used for a vacuum cleaner. Configuration of Conventional Example and Its Problems Conventionally, as an electric blower used in a vacuum cleaner, a high-speed rotating commutator motor directly connected to a centrifugal impeller has been used. The conventional electric blower as described above will be described below with reference to the drawings. FIG. 1 shows a conventional electric blower. Reference numeral 1 denotes a casing, an intake port 2 is opened in the center, and the opposite side of the intake port 2 is attached to a motor frame 3 so as to prevent air leakage. Reference numeral 4 denotes a centrifugal impeller having a plurality of blades, a volute chamber 5a formed by the casing 1 and an air guide 5 is arranged on the outer circumference of the impeller 4, and an exhaust passage 5b is provided on the opposite side. A motor 6 drives the impeller 4. The operation will be briefly described. The airflow flowing from the intake port 2 is given a dynamic pressure in the impeller 4, and this dynamic pressure is efficiently converted into static pressure in the volute chamber 5a of the air guide 5 to generate a static pressure in the blower. Increase efficiency. And the exhaust flow is the exhaust passage
While passing through 5b, the inside of the motor 6 is cooled while passing through and exhausted. In short, it is easy to understand that it is important for the efficiency of the blower to reduce the loss as much as possible, and various measures have been taken. However, although the casing 1, the impeller 4, the air guide 5 and the like are individually improved, problems may occur when they are assembled as a fan unit. The problem this time is when the casing 1 is press-fitted into the air guide 5, but it can be seen that there is a gap d when the contact portion between the two is viewed in cross section as shown in FIG. This is more unnatural when they are in close contact, and it is difficult to obtain the dimensions in the drawing with the air guide 5 mass-produced by resin molding and the casing 1 mass-produced by sheet metal pressing. That is, there is a drawback in that a gap is inevitably formed only by the conventional press-fitting dimension, and a loss such as leakage occurs, and the performance improved by the air guide 5 cannot be fully utilized. SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional problems, and an object thereof is to provide an electric blower capable of exhibiting the original performance of an air guide and a casing. In order to achieve this object, an electric blower of the present invention includes a motor, a motor frame attached to the motor, and
The casing is attached to the outer periphery of the motor frame and includes a casing enclosing an impeller and an air guide, and a volute chamber formed of the casing and the air guide is disposed on the outer periphery of the impeller. The volute chamber is made of resin. Since the contact portion between the air guide and the casing is closely adhered by melting, the gap between the air guide and the casing can be eliminated, the leakage of the air flow between the volute chambers can be prevented, and the air blowing efficiency can be improved. Description of Embodiments One embodiment of the present invention will be described with reference to FIGS. 3, 4, 5, and 6. In FIG. 3, reference numeral 21 denotes a casing, and an intake port 22 is opened in the center. The opposite side of this intake port 22 is the motor frame 23
It is installed so that there is no air leakage. 24 is a centrifugal impeller having a plurality of blades, the volute chamber 25a formed by the casing 21 and the air guide 25 on the outer periphery of the impeller 24, is arranged so as to have a passage enlarged in the outer peripheral direction, It leads to passage 25b. Then, when the casing 21 was press-fitted into the air guide 25, ultrasonic waves were applied to the contact portion D from the outside. 26 is a drive motor. The operation and effects of the above ultrasonic waves will be described above.
Generally, the casing 21 is joined to the motor frame 23 only by press fitting, and the air guide 25 is pressed into the casing 21.
I was in contact with. However, due to the fact that the dimensional accuracy of the air guide 25 and the casing 21 in mass production cannot be obtained, and due to variations in pressure and position during the press-fitting process, there is a considerable gap between the two, and as shown in FIG. As shown, the air leak C occurs between the adjacent volute chamber 25a.
This leakage becomes a loss, and the turbulence and vortex of the flow due to the leakage airflow C are generated in the volute chamber 5a, which hinders the original conversion from dynamic pressure to static pressure, resulting in a significant decrease in efficiency.
Therefore, when ultrasonic waves are applied in the vicinity of the contact portion D and ultrasonic waves are applied from A to B as shown in FIG. 4, the upper end portion of the air guide 25, that is, the contact portion D (broken line portion in FIG. 4) is melted. It comes into close contact with the casing 21 surface. In this case, it is possible to close the gap that has been unavoidable until now, and it is possible to completely prevent the airflow from leaking between the volute chambers 25a. FIG. 6 shows a Q-H curve showing the effect, and it can be seen that the blower in which ultrasonic waves are used for close contact to eliminate leakage has a small pressure loss, and is particularly effective at a low flow rate where the pressure increases. In this way, it becomes possible to stabilize the capacity of the blower at a high level, and the effect is very large. Further, the chattering caused by the gap so far has been eliminated, and the close contact with the casing 21 has increased the rigidity and has also been effective for noise. Effects of the Invention As described above, according to the present invention, a blower having high efficiency can be stably obtained by bringing the joint portion of the casing and the air guide into close contact with each other by melting, and the effect thereof is great.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view in which a part of a conventional electric blower is cut away, and FIG. 2 is a partially enlarged sectional view thereof, FIG. 3, FIG. 4, FIG. 5 and FIG. The drawings are a side view with a part cut away, an enlarged sectional view, a plan view of an air guide, and a characteristic diagram showing a comparison with a conventional product of an electric blower showing an embodiment of the present invention. 21 ... Casing, 23 ... Motor frame, 24 ... Impeller, 25 ... Air guide, D ... Contact part.

Continuation of front page    (56) References JP-A-56-129798 (JP, A)                 JP-A-59-136600 (JP, A)                 JP-A-59-170496 (JP, A)

Claims (1)

(57) [Claims] A motor, a motor frame attached to the motor, and a casing attached to the outer periphery of the motor frame and containing an impeller and an air guide,
An electric blower characterized in that a volute chamber formed by a casing and an air guide is disposed on the outer periphery of the impeller, and a contact portion between the resin air guide and the casing in the volute chamber is in close contact by melting.