JP2518367B2 - Low noise electric blower - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a low-noise electric blower, and more particularly to a low-noise countermeasure for a fan case having an impeller installed therein.

[Prior Art] FIG. 6 shows a noise reduction measure for a fan case of an electric blower for an electric vacuum cleaner disclosed in Japanese Utility Model Laid-Open No. Sho 61-255300, in which a ventilation hole (1) is provided in the fan case (1). A sound insulation case (5) having a sound absorbing material (4) attached to the inside is provided outside the 1a) in a superposed state. (6) is an impeller rotated in the fan case (1), (7) is a guide blade, (8) is a bracket, and (9) is a frame.

FIG. 7 shows a low noise countermeasure for the fan case of the once-through type blower disclosed in Japanese Utility Model Laid-Open No. 60-26240. In this case, the sound-insulating material (4) is attached at a predetermined inner position. The case (5) is fitted over the outer peripheral surface of the fan case (1) in a superposed state.

[Problems to be Solved by the Invention] Since the fan case of the conventional electric blower is configured as described above, the sound insulating case (5) and the sound absorbing material (4) are provided.
There is a problem that it is necessary to add separate parts such as.

The present invention has been made to solve the above problems, and an object thereof is to provide a fan case of an electric blower itself with desired strength and good sound absorbing action without impairing aerodynamic performance. To do.

[Means for Solving the Problems] A fan case according to the present invention is formed by a foam molding method of a synthetic resin or a sintering molding method of particles of resin, metal or ceramics, and is a porous sound absorbing body having open pores. The fan case (1) is composed of a two-layer member that is an integrated product of the layer (2) and the non-breathable solid solution layer (3) formed by melting the surface portion.

[Operation] In the case of the present invention, the sound absorbing layer forming the inner surface of the fan case has a good sound absorbing effect, and the solid solution layer forming the outer surface of the fan case prevents air leakage, and It has strength.

[Embodiment] FIG. 1 is a partially enlarged sectional view of a constituent material of a fan case of the present invention, in which (2) is the sound absorbing layer in contact with the forced air flow, and (3) is formed on the outer surface thereof. These non-breathable solid solution layers are integrally formed with the two-layer member.

Fig. 2 shows the case where the above two-layer member is formed by the synthetic resin foam molding method or the sintering molding method, and (10) is a molding die,
The inside after molding becomes a porous sound absorbing layer (2) having communicating pores, and the outer surface in contact with the molding die (10) is melted to become an impermeable solid solution layer (3). Therefore, after that, one surface of the solid solution layer (3) which becomes the inner side surface of the fan case is removed by peeling, etching, cutting or the like as shown in the figure to expose the sound absorbing layer (2) to the portion.

In the case of FIG. 3, the sound absorbing layer (2) is formed by the sintering forming method of the particles of metal or ceramics, and (10) is a molding die, which is porous as a whole after molding. It has a communicating hole. Therefore, only the required surface portion that is the outer side surface of the fan case is heated and melted thereafter, and an impermeable solid solution layer (3) having a predetermined thickness is formed in the portion as shown in the figure to similarly construct a two-layer member. To do.

As described above, according to the present invention, the well-known foam molding method (injection molding method by chemical or gas injection or the like) or the sintering molding method is used to form a porous sound absorbing layer (2) having communicating pores and a non-air-permeable material. A fan case is formed by the above-mentioned two-layer member which is integrally formed with the solid solution layer (3). In terms of strength of the fan case, the strength of the fan case is higher than that of a completely porous body by the presence of the solid solution layer (3), and this strength is increased by the thickness of the solid solution layer (3). Can be further strengthened by
The adjustment can be done easily.

FIG. 4 is a specific example of the present invention in which the above-mentioned two-layer member is applied to an electric blower for an electric vacuum cleaner. In the figure, (1) shows that the inner surface is the sound absorbing layer (2) and the outer surface is a solid solution. A fan case in this invention comprising layers (3),
(6) is an impeller rotated in this fan case, (7)
Is a guide vane, (8) is a bracket, and (9) is a frame.

FIG. 5 shows another example in which the above-mentioned two-layer member of the present invention is applied to a fan case of a once-through type blower.

As described above, in the fan case according to the present invention, the inner surface contacting the forced air flow is composed of the porous sound absorbing layer (2) having pores communicating therewith, and the outer surface is formed by melting the surface portion. Since it is composed of a non-breathable solid solution layer (3), a fan case can be obtained as a single product, and in the solid solution layer (3), the strength of the fan case is maintained and air leaks from the inside of the fan case. This improves the aerodynamic performance of the electric blower, and the sound absorbing layer (2) can obtain a good sound absorbing effect of noise due to the fluid in the fan case without impairing the aerodynamic performance.

[Advantages of the Invention] Since the fan case in the low-noise electric blower of the present invention is configured as described above, it is not necessary to attach a separate sound insulation case or sound absorbing material as in the conventional case, and the manufacturing is easy accordingly. Moreover, an inexpensive low-noise electric blower can be obtained, and further, the strength of the fan case can be freely set by controlling the thickness of the solid solution layer without sacrificing the sound absorbing effect.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a two-layer member used for a fan case in the low noise electric blower of the present invention, and FIGS. 2 and 3 are process diagrams schematically showing the constituent means of the above-mentioned two-layer member. FIG. 4 is a vertical cross-sectional view of a main part showing a specific example in which the two-layer member of the present invention is applied to an electric blower for an electric vacuum cleaner.
The figure is a horizontal sectional view of the main part of another embodiment which is also implemented in the fan case of the once-through type blower, and FIG. 6 and FIG.
It is a figure which shows the prior art example corresponded to FIG. 5 and FIG. In the figure, (1) is a fan case, (2) is a sound absorbing layer,
(3) is a solid solution layer, and (6) is an impeller. In the other figures, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohisa Imai 1728 Omaeda, Hanazono-cho, Oza-gun, Saitama 1 Mitsubishi Electric Home Appliances Co., Ltd. (72) Yoshihiro Noguchi 1728 Omaeda, Hanazono-cho, Saitama-gun 1 Mitsubishi Electric Home Equipment Co., Ltd. (72) Inventor Yutaka Takahashi 1728 Omaeda, Ozono-gun, Hanazono-cho, Saitama Prefecture 1 Mitsubishi Electric Home Equipment Co., Ltd. (56) Reference JP 62-237099 (JP, A) JP 56-146096 (JP, A) JP 59-45134 (JP, A)

Claims (3)

(57) [Claims] 1. A porous sound-absorbing layer having communicating pores, which is formed by a synthetic resin sinter molding method or a foam molding method, the inner surface in contact with the forced air flow, and the outer surface facing the outside. A low-noise electric blower characterized in that a fan case of an internal impeller is constituted by a planar two-layer member integrally formed with a solid solution layer that is made air-impermeable by melting the surface portion of the sound absorbing layer. . 2. A porous sound-absorbing layer having communicating pores, the inner surface of which is in contact with the forced air flow is formed by a sintering method of metal or ceramic particles, and the outer surface of which is facing the outside.
A low-noise electric blower characterized in that a fan case of an internal impeller is constituted by a planar two-layer member integrally formed with a solid solution layer that is made air-impermeable by melting the surface portion of the sound absorbing layer. . 3. The low noise electric blower according to claim 1, wherein the strength of the fan case is set by controlling the thickness of the solid solution layer to be generated.