JP3512870B2 - Centrifugal blower - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal blower having an improved nose portion of a casing. 2. Description of the Related Art Conventionally, this type of centrifugal blower is provided with a centrifugal impeller 1 and a casing 2 surrounding the centrifugal impeller 1, as shown in FIG. On the other hand, the casing 2 has a nose portion 4 close to the centrifugal impeller 1 and a gap from the nose portion 4 to the centrifugal impeller 2 gradually. Is formed in a spiral shape extending to the discharge port 5. In this configuration, when the centrifugal impeller 1 is driven to rotate by the motor 6 (see FIG. 20), the centrifugal impeller 2 sucks air from the axial direction, as shown by arrows in FIG. The air is discharged in the circumferential direction, and the discharged air is collected by the casing 2 and guided to the discharge port 5. [0004] In the case of the prior art, the nose portion 4 of the casing 2 is entirely formed in the axial direction of the centrifugal impeller 2 when viewed from the discharge port 5 as shown in FIG. It was parallel. According to this configuration, as shown in FIGS. 19 to 21, in the vicinity of the nose portion 4, the gap between the bell mouth 7, which is the suction port, and the centrifugal impeller 2, and the upper wall of the outer box 8 on the side facing the gap. The amount of wind (see arrows A and B) circulating in the casing 2 through the gaps with the centrifugal impeller 2 is large, and due to these circulating flows, a decrease in the air flow and an increase in static pressure due to an increase in pressure loss are caused. This has caused problems such as reduction and increase in noise. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to mainly increase the air volume and static pressure and reduce noise.
An object of the present invention is to provide a centrifugal blower capable of improving the productivity . In order to achieve the above object, a centrifugal blower according to the present invention comprises a centrifugal impeller which, when rotated, draws air in the axial direction and discharges it in the circumferential direction. A casing having a nose portion close to the centrifugal impeller and collecting air discharged from the centrifugal impeller and guiding the air to an outlet. co when the side portions, Ru is extended to the vicinity peripheral end or the peripheral end of the centrifugal impeller as viewed from the discharge port
Of the extension of the nose, the centrifugal impeller suction
At the opposite side of the casing to the self-hinge part
Formed more continuously and bent from its self-hinge part
It is characterized by being made to assemble . According to the above means, the extension of the nose portion allows
In both the centrifugal impeller suction-side portion and the suction-facing side portion, the resistance to the wind passing through increases, and the amount of the wind circulating through both portions can be reduced. Also, of the extension of the nose,
It is bent from the self-hinge part on the side of the root wheel suction opposing side
It is possible to improve manufacturability because it can be assembled
You. The basic structure of the present invention will be described below with reference to FIGS. First, FIG. 1 shows an outer box 11, which is a rectangular box having an open lower surface as shown in FIG. 2, having a discharge port 12 on one side, and a motor at the center of the upper wall. A bulging portion 13 for attachment is formed. A motor 14 is mounted inside the bulging portion 13,
A centrifugal impeller 16 is attached to the rotating shaft 15 of the. The centrifugal impeller 16 is composed of a large number of curved blade pieces 17 arranged in a cylindrical shape on a circular substrate 18, each end of which is surrounded by an end ring 19. Is surrounded by a casing 20. The casing 20 has a bell mouth 21 serving as a suction port on the lower surface, and has a nose portion 22 shown in FIG. 3 inside. The nose portion 22 gradually forms a gap with the centrifugal impeller 16. It is formed in a spiral shape extending to the discharge port 12. And the nose part 22 is the centrifugal impeller 16
The suction-side (bellmouth 21 side) portion 22a and the suction-facing side (upper wall side of the outer case 11) portion 22b are viewed from the discharge port 12 as shown in FIG.
As shown in FIG. 4, the extended portions 22 a and 22 b are part of the peripheral side surface of the centrifugal impeller 16 (the portion of the blade piece 17 on the substrate 18 side and the end ring 19 side).
And radially opposed to each other. In this case, the extension portions 22a and 22b of the nose portion 22 are connected to the centrifugal impeller 1.
6 may be extended to the vicinity of the peripheral end 16a slightly inside or slightly outside the peripheral end, instead of the peripheral end 16a. The outer box 11 also includes a motor 14
An electric box 23 containing a capacitor for use in the electric equipment is attached.
Connection tube 2 for connecting a duct 24 having a circular cross section shown in FIG.
5 and a casing 20
Is provided via a mounting spring 27 to cover an open portion on the lower surface of the outer box 11. Now, in the case of the above-described configuration,
When the centrifugal impeller 16 is rotated by the motor 14, the centrifugal impeller 16 inhales air from the axial direction through the decorative frame 28 and the bell mouth 21 of the casing 20 and discharges the air in the circumferential direction. The casing 2
0 are collected and guided to the discharge port 12, and the connection pipe 25 is connected to the duct 2.
Discharge outdoors through 4. However, among them, the nose portion 22 of the casing 20 has a suction-side portion 22a of the centrifugal impeller 16.
And suction face side portion 22b, since is extended to the vicinity circumferential end 16a or the peripheral end 16a of the centrifugal impeller 16 when viewed from the discharge port 12, as shown in FIG. 4, in that both, The resistance of the wind that tries to pass through the gap between the bell mouth 21 and the centrifugal impeller 16 and the gap between the upper wall of the outer box 11 and the centrifugal impeller 16 on the opposite side increases,
The amount of wind circulating through both portions can be reduced, and thus the air volume and static pressure can be increased, and noise can be reduced. FIG. 5 shows a first embodiment of the present invention, in which the gap between the distal ends of the extended portions 22a and 22b of the nose portion 22 and the centrifugal impeller 16 is denoted by G1, and the base portion side is defined as G1. When the gap with the centrifugal impeller 16 is G2, G1 <G2
In other words, the end portions of the extension portions 22a and 22b of the nose portion 22 are closer to the centrifugal impeller 16 than the base portion side.
Since the wind resistance of the portions a and 22b can be further increased and the amount of wind circulating through both portions can be further reduced, the air volume and static pressure can be further increased, and the noise can be further reduced. FIGS. 6 and 7 show a second embodiment of the present invention, in which the circumferential length L1 of the extension portions 22a and 22b of the nose portion 22 is substantially equal to the axial length L2 of the centrifugal impeller 16.ゞ In this case, as shown in FIG. 8, the axial length L2 of the centrifugal impeller 16 is kept constant, as shown in FIG.
On the other hand, when an experiment was performed by sequentially increasing the circumferential lengths L1 (L1 / L2) of the extension portions 22a and 22b of the nose portion 22 from "0", the length L1 was set to the axial length of the centrifugal impeller 16. The result that the air volume and the static pressure were the largest and the noise could be minimized when the value was set to be almost equal to L2 was obtained. The extension portions 22a of the nose portion 22,
As shown in FIG. 9, the circumferential length L1 of 22b is set to be substantially equal to the axial length L2 of the centrifugal impeller 16, as shown in FIG.
An experiment was conducted by sequentially reducing the bending depth of the extension portions 22a and 22b of the nose portion 22. As a result, the air volume decreased and the noise increased, and especially the extension portions 22a and 22 of the nose portion 22 were increased.
When the bending depth by 2b is set to “0”, that is, when the nose portion 22 is extended entirely while being parallel to the axial direction of the centrifugal impeller 16, the air volume is drastically reduced, and the noise is drastically increased. FIGS. 10 to 13 show a third reference example of the present invention, in which the cross-sectional shape of the extension portions 22a and 22b of the nose portion 22 on the side of the casing 20 air passage (right side in the drawing) is arc-shaped. By doing this,
Since the flow of the wind from the air passage of the casing 20 to the duct 24 having a circular cross section can be smoothly performed, the air volume and the static pressure can be further increased, and the noise can be reduced. Furthermore, in this case, the extension 2 of the nose 22
The air passages of the casing 20 in the portions 2a and 22b are also formed so as to gradually become circular in cross section toward the discharge port 12, whereby the flow of wind from the air passages of the casing 20 into the duct 24 having a circular cross section is formed. Therefore, the air volume and the static pressure can be further increased, and the noise can be further reduced. FIG. 14 shows a fourth embodiment of the present invention. Of the extensions 22 a and 22 b of the nose portion 22, the portion 22 b of the centrifugal impeller 16 on the suction opposing side is separate from the casing 20. It is formed and attached to the casing 20 with the screw 29. By doing so, it is possible to easily manufacture the casing 20 without the difficult integral molding with the casing 20, thereby improving the manufacturability. Can be. FIGS. 15 and 16 show an embodiment of the present invention. Of the extended portions 22a and 22b of the nose portion 22, the portion 22b of the centrifugal impeller 16 on the suction opposing side is self-hinged to the casing 20. A part 30 is formed integrally by being connected by a part 30 and bent from the self-hinge part 30 to lock the claw part 31 in the hole 32, thereby assembling the apparatus.
Since integral molding with the casing 20 can be desired and can be easily manufactured, manufacturability can be improved. In addition, the present invention is not limited to the embodiment described above and shown in the drawings, but can be implemented with appropriate modifications without departing from the scope of the invention. The centrifugal blower of the present invention is as described above, and has the following effects. Mainly , a centrifugal impeller that inhales air in the axial direction by being rotated and discharges in the circumferential direction, and has a nose portion close to the centrifugal impeller to collect and discharge air discharged by the centrifugal impeller. And a casing that guides the centrifugal impeller suction side portion and the suction-facing side portion of the nose portion to the peripheral end of the centrifugal impeller or the vicinity of the peripheral end when viewed from the discharge port. Thereby, in both the centrifugal impeller suction-side portion and the suction-facing side portion of the nose portion, the resistance against the wind trying to pass through can be increased, and the amount of wind circulating through both portions can be reduced, Air volume and static pressure can be increased, and noise can be reduced. [0023] In addition, among the extension of the nose portion, its centrifugal impeller suction face side portion formed integrally been chosen by the self-hinge to the casing, and to assemble by bending from the self hinge portion Thereby, integral molding with the casing can be performed as desired, and it can be easily manufactured, and the manufacturability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a basic configuration of the present invention as viewed from a discharge port side. FIG. 2 is an exploded perspective view. FIG. 3 is a bottom view. FIG. FIG. 5 is a cross-sectional bottom view showing a first embodiment of the present invention. FIG. 6 is a diagram corresponding to FIG. 3 showing a second embodiment of the present invention. FIG. FIG. 8 is a characteristic diagram, FIG. 9 is a characteristic diagram, FIG. 9 is a characteristic diagram, FIG. 10 is a diagram corresponding to FIG. 3, showing a third reference example of the present invention. a casing of a fourth reference example of a longitudinal section view taken along the O line 14 of the present invention - O of the vertical sectional view taken along the d line [13] Figure 10 - d longitudinal section view [12] Figure 10 perspective view of the assembled state of the exploded perspective view [16] casing and nose portion on one side of the casing and a nose portion on one side of an embodiment of an exploded perspective view of a nose portion on one side [15] the present invention FIG. 7 shows a conventional example. FIG. 18 shows a view corresponding to FIG. 1. FIG. 19 shows a plan view on one side. FIG. 20 shows a view corresponding to FIG. 4. FIG. 21 shows a bottom view on one side. Outlet, 14 is a motor, 16 is a centrifugal impeller, 16
a is the peripheral end of the centrifugal impeller, 20 is the casing, 22 is the nose, 22a and 22b are the extensions of the nose, 24 is the duct, 30 is the self-hinge, L1 is the circumferential direction of the extension of the nose. The length L2 indicates the axial length of the centrifugal impeller.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Satoru Nomura 991 Anada-cho, Seto-shi, Aichi Toshiba Aichi Plant (56) References JP-A-1-100399 (JP, A) Shokai Sho59- 54797 (JP, U) Actually open 1979-89510 (JP, U) Actually open 1979-83013 (JP, U) Actually open 1979-85605 (JP, U) Actually open, 1979-5311 (JP, U) JP-A-1-108399 (JP, U) JP-T 8-503284 (JP, A) West German Patent 4331606 (DE, B) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04D 29 / 44 F04D 17/04

Claims (1)

(1) A centrifugal impeller that inhales air in the axial direction by being rotated and discharges the air in a circumferential direction, and a centrifugal impeller having a nose portion close to the centrifugal impeller. A casing that collects air discharged by the impeller and guides the air to a discharge port, wherein the suction-side portion and the suction-facing portion of the nose portion of the centrifugal impeller are viewed from the discharge port, and the peripheral end of the centrifugal impeller. part or peripheral end Rutotomoni is extended to the vicinity, the extension of the nose portion
Of the centrifugal impeller suction-facing side portion
Formed integrally with the casing by a self-hinge part
And bend it from its self-hinge to assemble it.
Centrifugal blower, characterized in that the.