JPS61104199A - Motor-driven blower - Google Patents

Abstract

PURPOSE:To enhance the blowing efficiency by binding the contacting part between the air guide of a motor-driven blower and the casing by melting. CONSTITUTION:Volute chambers 25a formed by a casing 21 on which a suction port 22 is provided in its center and an air guide 25 are disposed so as to have enlarged passages around the outer circumference of an impeller 24. When the casing 21 is pressed in the air guide 25, the melting of contacting part D is carried out by supersonic method so that the upper end part of air guide 25 is melted to be bound on the surface of casing 21. Thus, the leakage of air flow between volute chambers 25a can be perfectly prevented, and the blowing efficiency can be enhanced.

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 Conventional Structure and Problems Conventionally, an electric blower for use in a vacuum cleaner has been used, in which a centrifugal impeller is directly connected to a high-speed rotating commutator motor.

The conventional electric blower as described above will be explained below with reference to the drawings.

FIG. 1 shows a conventional electric blower that separates water.

Reference numeral 1 denotes a casing, which has an intake port 2 opened in the center, and the side opposite to this 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 6& formed by a casing 1 and an air guide 5 is disposed around the outer periphery of the impeller 4, and an exhaust passage 5bf is provided on the opposite side.

A motor 6 drives the impeller 4.

Briefly explaining the operation, the airflow flowing in from the intake port 2 is given 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, which is then applied to the blower. Increase efficiency.

The exhaust flow then passes through the exhaust passage 6b and is exhausted while cooling the inside of the motor 6. In short, it is easy to understand that the importance of blower efficiency is to reduce losses as much as possible, and various efforts have been made. However, although the casing 1, impeller 4, air guide 5, etc. have been improved individually, problems may occur when these are assembled into a fan unit. The problem this time is when the casing 1 is press-fitted into the air guide 6, but if you look at the contact area between the two in cross section as shown in FIG. 2, it can be seen that there are 5 gaps d. This is because it is unnatural for the air guide to be in perfect contact with the air guide 5, which is mass-produced by resin molding.
It is difficult to obtain the dimensions shown in the drawing with the casing 1 mass-produced by sheet metal press.

In other words, if the dimensions were only determined by conventional press-fitting, a considerable amount of gaps would inevitably occur, resulting in losses such as leakage, and the improved performance of the air guide 5 could not be fully utilized.

OBJECTS OF THE INVENTION The present invention focuses on the above-mentioned conventional problems and provides an electric blower that can exhibit the original performance of an air guide and a casing.

Structure of the Invention To achieve this object, the electric blower of the present invention is composed of 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. The contact portion between the air guide and the casing is melted and brought into close contact with the air guide, thereby eliminating the gap between the air guide and the casing to improve air blowing efficiency.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention is shown in FIGS. 3, 4, 6, and 6.

In Figure 3, 21 is a casing, with an intake port 2 in the center.
2 is open. The opposite side of the intake port 220 is attached to the motor frame 23 so as to prevent air leakage. 2
Reference numeral 4 denotes a centrifugal impeller having a plurality of blades, and a volute chamber 252L formed by a casing 21 and an air guide 25 is arranged around the outer periphery of the impeller 24 so as to have a passage expanding in the outer circumferential direction. It continues to passage 25b. Then, the casing 21 is attached to the air guide 25.
.

When press-fitting, ultrasonic waves were used from the outside on the contact area. 2
6 is a driving motor.

The operation and effects of the above ultrasonic waves will be explained below. Generally, the casing 21 is only press-fitted into the motor frame 23.
The air guide 25 was in contact with the casing 21 by being press-fitted. However, due to the inability to achieve perfect dimensional accuracy during mass production of the air guide 26 and casing 21, and variations in pressure and position during the press-fitting process, a considerable gap occurs between them, and as shown in Figure 5. As shown, airflow leakage C between the adjacent volute chamber 25 &
occurs. This leakage causes loss, and further leakage airflow C
turbulence and vortices in the flow occur within the volume chamber 5a,
This significantly reduces efficiency because it prevents the original dynamic pressure from being converted to static pressure. Therefore, using ultrasonic waves near the contact area,
As shown in Fig. 4, when ultrasonic waves are applied from a person to B, the upper end of the air guide 26, that is, the contact portion D (broken line in Fig. 4) melts and comes into close contact with the surface of the casing 21. By closing the gaps that had no choice but to arise,
Airflow leakage between the volute chambers 25a can be completely prevented. FIG. 6 shows a Q-H curve showing this effect, and it can be seen that the blower that is brought into close contact with ultrasonic waves to eliminate leakage has less pressure loss, and is especially effective at low flow rates where pressure increases. In this way, it is possible to make the capacity of the blower high and stable, which has a very large effect. Furthermore, the chattering caused by the gap that existed up until now has been eliminated, and the tight contact with the casing 21 has increased rigidity and is effective in reducing noise.

Effects of the Invention As described above, the present invention is achieved by bonding the joint between the casing and the air guide by melting.

By stably obtaining a highly efficient blower, the effect is significant.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a conventional electric blower, FIG. 2 is a partially enlarged cross-sectional view, and FIGS. 3, 4, 5, and 6 are views of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing a part of an electric blower according to an embodiment. FIG. 3 is a partially enlarged sectional view, a plan view of the air guide, and a characteristic diagram showing a comparison with a conventional product. 21...Casing, 23...Motor frame. 24... Impeller, 25... Air guide, D... Contact part. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure 2

Claims (1)

[Claims] Consisting of 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, and the contact area between the air guide and the casing is tightly bonded by melting. An electric blower featuring: