JPH0736154Y2 - Axial fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Purpose of the Invention [Industrial field of application] The present invention relates to an axial flow fan, and more particularly to a structure of a small axial flow fan used for internal cooling of electronic equipment. .

[Prior Art] FIG. 4 shows a structure of an axial fan that has been conventionally practiced. FIG. 4A is an external perspective view and FIG. 4B is a view A in FIG.
-(A) is a cross-sectional view of the main part taken along the line A ', and FIG.
The main-part cross-sectional views along the line B'are respectively shown.

In FIG. 4, a quadrangular mounting flange 4b is provided at the end on the air intake side of the cylindrical wind tunnel 4, and a quadrangular mounting flange 4c is provided at the end on the discharge port side. The motor 1 is supported by a plurality of supporting legs 7 provided in the fan 1, and the vanes 3 are fixed to the outer periphery of the fan boss 2 fixed to the rotor hub 1a of the motor 1 to form an impeller. They are arranged opposite to each other with a gap.

When mounting the illustrated axial fan on an electronic device, the mounting flange 4b or 4c is designed to be screwed through holes 8 provided at the four corners of the mounting flange 4b or 4c.
There is a feature that the same axial flow fan can be used for both intake and exhaust of air by selecting either of 4c.

The axial fan shown in the figure operates as a fan by energizing the motor 1 to rotate the impeller having the blades 3 fixed thereto, sucking air from the suction port 5 and discharging from the discharge port 6.

[Problems to be Solved by the Invention] In the axial flow fan according to the prior art shown in FIG. 4, the shape of the wind tunnel 4 on the discharge port side is a sectional view of a main part taken along the line AA ′ in FIG. A part of the tapered conical shape is formed in b), but the tapered conical shape is not formed in the main part sectional view (c) taken along the line BB '.

If the discharge port side of the wind tunnel has the shape as shown in the figure, there is a problem that the air resistance increases and the air volume decreases in the portion having the shape shown in FIG.

The present invention is to improve the shape near the outlet of the wind tunnel to obtain an axial fan that can increase the air volume without changing the mounting size and the electric capacity of the motor.

(2) Configuration of the device [Means for solving the problems] The axial fan according to the present invention has a shape in which the outer diameter of the wind tunnel is increased to reach the outside of the quadrangle connecting the outer circumferences of the mounting flanges. This is achieved by a structure in which a conical discharge port that is concentric with the center of rotation of the impeller is evenly provided over the entire circumference at the outlet end.

[Operation] As a result of increasing the outside diameter of the wind tunnel, the conical discharge port provided at the end of the air discharge port can be provided uniformly over the entire circumference, resulting in a reduction in air resistance at the discharge port. However, there is an effect that the air volume can be increased without changing the electric capacity of the blade and the motor.

[Embodiment] FIG. 1 is a view showing the structure of an axial fan according to the present invention.
(A) is an external perspective view, (b) is a sectional view of a main part taken along the line DD 'of (a), and (c) is a sectional view of the main part likewise taken along the line EE'. Shows.

In the illustrated axial flow fan, the outer diameter dimension B of the cylindrical wind tunnel 24 is formed larger than the quadrangle A connecting the outer peripheries of the mounting flanges 24b and 24c, and the blades 3 are provided on the inner peripheral portion of the wind tunnel 24 on the outlet side. Conical portion 24d concentric with the center of rotation of the fixed impeller
Is evenly distributed all around the wind tunnel.

The inner diameter of the wind tunnel 24 and the impeller and the motor 1 to which the blades 3 are fixed are the same as those of the axial fan of the prior art shown in FIG. 4, in other words, the inner diameter of the wind tunnel and the mounting flange. This is a structure in which the wall thickness of the cylindrical portion 24a is increased without changing the pitch dimensions of the outer periphery and the mounting holes 8.

In the illustrated axial fan according to the present invention, since the shape of the discharge port of the wind tunnel is formed into a conical 24d shape over the entire circumference, the discharge air is discharged as the diameter of the discharge port increases. Since the pressure is reduced and the air resistance is reduced, the air volume can be increased even if the same blade and motor are used.

FIG. 2 is an external perspective view of another embodiment of the present invention in which a mounting flange is provided only on the air discharge port side, and since there is no mounting flange on the suction port side, air turbulence near the suction port is small. , Also has the effect of reducing noise.

FIG. 3 is an external perspective view of still another embodiment. The mounting flange is provided only on the air outlet side, and the outer diameter B of the wind tunnel is
It is formed to be larger than a quadrangle A that connects the outer circumference of a mounting flange that is provided only near the discharge port side, and the outer diameter of the suction port side 34 is approximately the same as the quadrangle A that connects the outer circumference of the flange. Similar to the embodiment of the figure, it also has the effect of reducing noise.

[Advantage of the Invention] Since the axial fan according to the present invention has the above-described structure, it has a large air flow without changing the pitch of the mounting holes of the mounting flange and without changing the electric capacity of the motor. Since a fan can be obtained, there is an effect that mounting and replacement can be facilitated.

[Brief description of drawings]

FIG. 1 is a view showing the structure of an axial fan according to the present invention. It is an external perspective view (a), a sectional view of a main part taken along the line D-D '(b), and a line E-E'. Second cross-sectional view of the main part (c)
FIG. 3 is an external perspective view of another embodiment of the present invention, and FIG. 4 is an external perspective view (a) of an axial fan which has been conventionally used and a main view taken along the line AA ′. Sectional view (b) and B
It is a principal part sectional view (c) along the line -B '. Explanation of symbols 1 …… motor, 1a …… motor rotor hub, 2 …… fan boss, 3 …… blades, 4,24 …… cylindrical wind tunnel, 4b, 24b …… suction port side mounting flange, 4c, 24c ...... Discharge port side mounting flange, 4d, 24d …… Discharge port side conical part, 5 ……
Air suction port, 6 …… Air discharge port, 7 …… Support leg, 8 …… Mounting hole, 4a, 24a …… Cylindrical part of wind tunnel, 34 …… Suction port side of cylindrical wind tunnel.

Claims (3)

[Scope of utility model registration request] 1. A cylindrical wind tunnel and an impeller fixed to a shaft of a motor supported by support legs radially arranged inside the wind tunnel are arranged in the wind tunnel and attached to the outer periphery of the wind tunnel. In the axial fan provided with the flange, the outer diameter dimension (B) of the wind tunnel is formed larger than the quadrangular shape (A) that connects the outer periphery of the mounting flange, and the air outlet has a concentric shape with the rotation center of the impeller. An axial fan in which conical flow passages are uniformly provided all around the circumference, and mounting flanges are provided at both the air suction port and the discharge port. 2. The axial flow fan according to claim 1, wherein a mounting flange is provided only on the air discharge port side. 3. A mounting flange is provided only on the air outlet side, and an outer diameter dimension (B) of a wind tunnel at a position where the mounting flange is provided is formed larger than a quadrangle (A) connecting the outer periphery of the mounting flange. The axial flow fan according to claim 1, wherein the outer diameter of the wind tunnel on the suction port side is substantially the same as that of the quadrangle (A) connecting the outer circumferences of the mounting flanges.