JP2856973B2 - Centrifugal blower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower used for a ventilation fan for a duct, an air conditioning ventilation fan, and the like.

[0002]

2. Description of the Related Art A conventional centrifugal blower used as a blower for a duct ventilation fan, an air-conditioning ventilation fan, or the like has a depression 5 formed in a substrate 4 of a centrifugal blade 3 as shown in FIG. The concave portion 5 is configured to function as a guide plate in order to make the flow of the intake air discharged by the rotational centrifugal force efficient. Therefore, the recess 5 and the casing 1
A large space A having a shape corresponding to the concave portion 5 is formed between the inner wall 2 and the flat back wall 2.

[0003]

In the centrifugal blower of the above construction, part of the air flowing from the intake opening 6 of the casing 1 during the blowing operation flows into the space A as shown by the arrow B, and is completely closed. There has been a problem that the pressure is reduced, the air volume at the time of static pressure is reduced, and noise is increased.

The present invention has been made in order to solve the above-mentioned conventional problems.
A centrifugal blower that can increase the fully closed static pressure by forming a depression in the substrate of the centrifugal blade and forming a bulge projecting into the depression on the back wall of the casing. To offer.

[0005]

According to the present invention, there is provided a centrifugal blower having a casing having an intake opening on one side and a discharge port on the other side, and a centrifugal fan arranged in the casing and driven to rotate by a motor. And a recess protruding toward the motor is formed substantially at the center of the substrate located on the side opposite to the motor of the centrifugal blade, and a recess is formed in the inner wall of the casing facing the recess. A bulging portion that protrudes from the base member. In this case, the bulging portion of the casing may be formed in a shape similar to the shape of the concave portion of the centrifugal blade.

[0006]

When the centrifugal blade is driven to rotate, air is sucked by the centrifugal blade and discharged from a discharge port (not shown) of the casing. In this case, the inflow of air to the back side of the substrate of the centrifugal blade is prevented as much as possible.

[0007]

1 and 2 show an embodiment of the present invention.
This will be described with reference to FIG.

Reference numeral 11 denotes a main body of, for example, a duct ventilation fan having an exhaust port (not shown) on one side.
The casing 12 has an intake opening 14 formed on one side surface on the side opposite to the back wall 13. In the casing 12, centrifugal blades 16 rotationally driven by a motor 15 are disposed such that the substrate 17 is located on the back wall 13 side of the casing 12, that is, on the side opposite to the motor 15, A depression 19 is formed at the center so as to protrude toward the blade piece 18, that is, toward the motor 15.

A bulging portion 20 is formed integrally with the inner wall 13 of the casing 12 facing the dent portion 19 so as to protrude into the dent portion 19. It is formed in a similar shape corresponding to the shape, and the depression 1
9 has a slight gap.

Reference numeral 21 denotes the intake opening 1 of the casing 12.
4 is a motor mounting plate which is attached to the main body 11 so as to close the main body 11 and holds a motor base 22 holding the motor 15, and a bell mouth 23 which is opposed to the centrifugal blade 16.
Is formed. Next, the operation of the above configuration will be described.

When the centrifugal impeller 16 is driven to rotate by the motor 15, air is sucked into the casing 12 through the bell mouth 23, and the air is discharged by the centrifugal impeller 16 by the centrifugal action of the casing 12 and then the exhaust port of the main body 11. (Both not shown). In this case, the air sucked into the casing 12 is prevented from flowing into the back side of the centrifugal blade 16 by the bulging portion 20 of the casing 11 as much as possible.

[0012] Figure 2 is the invention and the air volume of the total閉静pressure and static pressure time in a conventional centrifugal type blower "full open air volume 500 meters ³ /
In the centrifugal blower of the present invention, the measured air volume at the fully closed static pressure and the static pressure are both increased compared to the conventional centrifugal blower. .

The present invention is particularly effective for equipment such as the duct ventilation fan of the above-described embodiment, which is used for duct (pipe) piping. It can be widely applied to devices having the same.

In addition, the present invention is not limited to the embodiment described above and shown in the drawings. The bulging portion does not necessarily need to be formed integrally with the casing. A configuration in which a bulging portion made of a member is provided, or a configuration in which the whole or a part of the inner wall of the casing is shared by the main body 11 and a bulging portion that is integral with or separate from the main body 11 may be provided. For example, the present invention can be appropriately changed and implemented without departing from the gist.

[0015]

As is apparent from the above description, according to the present invention, a dent protruding toward the motor is formed substantially at the center of the substrate located on the side opposite to the motor from the centrifugal blade, and the dent is opposed to the dent. By forming a bulging portion projecting into the recessed portion on the back wall of the casing, it is possible to prevent air sucked into the casing from flowing into the back side of the centrifugal blade as much as possible, and to increase the total closing static pressure. Therefore, it is possible to increase the air volume at the time of static pressure and to reduce noise.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a view showing measured values of a fully closed static pressure and a flow rate at a static pressure in the centrifugal blower of the present invention and a conventional centrifugal blower

FIG. 3 is an equivalent view of FIG. 1 showing a conventional centrifugal blower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Casing 13 Back wall 16 Centrifugal blade 17 Substrate 19 Narrow part 20 Swelling part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F04D 29/18-29/38

Claims (2)

(57) [Claims] 1. A centrifugal vane having an intake opening on one side surface and a discharge port on the other side surface, and a centrifugal blade disposed in the casing and driven to rotate by a motor. A recessed portion protruding toward the motor was formed at a substantially central portion of the substrate located on the side opposite to the motor of the blade, and a bulging portion projecting into the recessed portion was formed on a rear wall of the casing facing the recessed portion. A centrifugal blower characterized in that: 2. The centrifugal blower according to claim 1, wherein the bulging portion of the casing is formed in a shape similar to the shape of the concave portion of the centrifugal blade.