JPH05296195A - Axial fan - Google Patents

Abstract

PURPOSE:To improve the flow characteristic of an axial fan by a simple means by providing the outer peripheral part of each blade piece with a suction sub- blade protruding acutely in the rotating direction. CONSTITUTION:An axial fan is formed of a hub 1 to be the rotational center, and plural blade pieces 2, 2... provided radially at the periphery of the hub 1. A suction sub-blade 3 protruding acutely in the rotating direction M is formed at the outer peripheral part 2d of each blade piece 2 by cutting a part of the outer peripheral edge part of the blade piece 2. With the rotatory-driving of the axial fan, air flows in from the front edge 2a of the blade piece 2 and is blown off from the rear edge 2c of the blade piece 2 after being pressure- boosted by the blade face of the suction sub-blade 3. Air suction performed by the suction sub-blade 3 thereby becomes further smooth and effective, and the flow characteristic of the axial fan can be further improved in large degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial fan,
More specifically, it relates to the structure of blades in an axial fan.

[0002]

2. Description of the Related Art Generally, an axial fan, as shown in FIG. 5, has a hub 1 as a center of rotation and a plurality of (for example, four) blades 2, which are radially provided on the outer periphery of the hub 1. It consists of 2 ...

Conventionally, in the case of the axial fan having the above-mentioned structure, the air is introduced from the front edge 2a of the blade 2 by the rotational driving, the pressure is increased on the blade surface 1b, and then the air is supplied from the rear edge 2c of the blade 2. It is designed based on the principle of being blown out. That is, no consideration was given to the entry and exit of air in the outer peripheral portion 2d of the blade 2.

By the way, when the suction flow velocity vector Fb was measured with the meridional surface shape of the axial fan, it was found that a large amount of air was also flowing in from the outer peripheral portion 2d of the blade 2, as shown in FIG. ..

Conventionally, the inflow of air from the outer peripheral portion 2d of the blade 2 was not taken into consideration at the time of design, because the diameter of the axial fan was larger than the axial length.
This is because even if the design is based on the inflow of air from the front edge 2a of the above, it is possible to obtain one that can be sufficiently used.

Incidentally, the one in which the front edge of the wing piece is provided with a notch so as to generate a vertical vortex on the wing surface, is the actual open sho 54-5.
Although disclosed in Japanese Patent No. 5405, in the case of the known example as well, no consideration is given to the above-described air inflow from the blade outer peripheral portion.

[0007]

However, in recent years, there has been an increasing demand for miniaturization of air conditioners (in particular, outdoor units for air conditioners), and they are often used as blowers for outdoor units for air conditioners. The downsizing of existing axial fans has become an important issue. In order to solve such a problem, it has been required to effectively utilize the air inflow from the outer peripheral portion of the blade, which has not been taken into consideration when designing the axial fan.

The present invention has been made in view of the above points, and it is an object of the present invention to positively promote air suction from the outer peripheral portion of the blade.

[0009]

In the invention of claim 1, as means for solving the above-mentioned problems, as shown in the drawings, a hub 1 as a center of rotation and a hub 1 radially provided on the outer periphery of the hub 1 are provided. In the axial flow fan composed of a plurality of blade pieces 2, 2, ..., Suction auxiliary blades 3 projecting at an acute angle in the rotational direction are provided on the outer peripheral portion 2d of each blade piece 2.

According to a second aspect of the present invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the axial fan according to the first aspect, the suction auxiliary blade 3 is provided outside the blade piece 2. It is formed by cutting off a part of the peripheral portion.

According to a third aspect of the present invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the axial fan according to the first aspect, the suction auxiliary blades 3 are provided on the outer periphery of the blade pieces 2. It is arranged to project to the portion 2d.

According to the invention of claim 4, as means for solving the above-mentioned problems, as shown in the drawings, said claim 1,
In the axial flow fan described in 2 or 3, the suction auxiliary blade 3 is bent to the suction surface side with respect to the blade piece 2 by a predetermined angle.

[0013]

According to the first, second or third aspect of the invention, the following actions are obtained by the above means.

That is, by the rotational driving of the axial fan, the air flows in from the front edge 2a of the blade piece 2 and the air flows smoothly from the front edge of the suction auxiliary blade 3 (that is, the outer peripheral portion 2d of the blade piece 2). To the trailing edge 2c of the blade 2 after the pressure is increased by the blade surface 1b.
Will be blown out from.

According to the invention of claim 4, the following actions can be obtained by the above means.

That is, the suction of air by the suction auxiliary blades 3 becomes smoother and more effective.

[0017]

According to the first, second or third aspect of the present invention, a shaft comprising a hub 1 as a center of rotation and a plurality of blades 2, 2, ... Radially provided on the outer periphery of the hub 1. In the flow fan, suction auxiliary vanes 3 each projecting at an acute angle in the rotation direction are provided on the outer peripheral portion 2d of each of the blades 2 so that the rotation of the axial fan causes the leading edge 2a of the blade 2 to move. As the air flows in, the air smoothly flows in from the front edge of the suction auxiliary blade 3 (that is, the outer peripheral portion 2d of the blade piece 2),
Since the pressure is increased on the blade surface 1b and then the air is blown off from the trailing edge 2c of the blade piece 2, there is an excellent effect that the flow rate characteristic of the axial fan can be greatly improved by an extremely simple means. ..

According to the second or third aspect of the invention, in the axial flow fan according to the first aspect, the suction auxiliary blade 3 is formed by cutting off a part of the outer peripheral edge portion of the blade piece 2 or the blade piece 2. Since it is provided so as to project from the outer peripheral portion 2d, there is an excellent effect that the suction auxiliary blade 3 can be formed extremely easily.

According to the invention of claim 4, in the axial flow fan of claim 1, 2 or 3, the suction auxiliary blades 3 are
Since the blades 2 are bent to the suction surface side by a predetermined angle, the air suction by the suction auxiliary vanes 3 becomes smoother and more effective, and the flow characteristics of the axial fan can be further improved. It has an excellent effect that it can be done.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG. 1 shows an axial flow fan according to Embodiment 1 of the present invention. The present embodiment corresponds to the inventions of claims 1 and 2.

The axial fan of this embodiment has a hub 1 which is the center of rotation, as described in the section of the prior art.
And a plurality of (for example, four) wing pieces 2, 2, ... Radially provided on the outer periphery of the hub 1.
Reference numeral 2a is a leading edge, 2b is a blade surface, 2c is a trailing edge, and 2d is an outer peripheral portion.

In this embodiment, however, the suction assisting blades 3 projecting at an acute angle in the rotational direction M are formed on the outer peripheral portion 2d of each blade 2 at a part of the outer peripheral edge portion of the blade 2. Are formed by excising each.

The axial fan constructed as described above has the following effects.

By the rotational drive of the axial fan, air flows in from the leading edge 2a of the blade piece 2 and smoothly flows from the leading edge of the suction auxiliary blade 3 (ie, the outer peripheral portion 2d of the blade piece 2). However, after the pressure is increased on the blade surface 1b, it is blown out from the trailing edge 2c of the blade piece 2, and the flow rate characteristic of the axial fan can be greatly improved by a very simple means.

In the case of this embodiment, the suction auxiliary blade 3 can be formed by a very simple means of cutting off a part of the outer peripheral edge portion of the blade piece 2 (that is, a chain line portion).

Embodiment 2 FIG. 2 shows an axial flow fan according to Embodiment 2 of the present invention. The present embodiment corresponds to the inventions of claims 1, 2 and 4.

In the case of this embodiment, the suction auxiliary blade 3 in Embodiment 1 is bent toward the suction surface side with respect to the blade surface 2b.
By doing so, the suction of the air by the suction auxiliary blades 3 becomes smoother and more effective, and the flow rate characteristic of the axial fan can be further improved. Other configurations, functions, and effects are similar to those of the first embodiment, and therefore description thereof will be omitted.

Embodiment 3 FIG. 3 shows an axial flow fan according to Embodiment 3 of the present invention. The present embodiment corresponds to the inventions of claims 1 and 3.

In the case of this embodiment, the suction assisting blade 3 is integrally provided on the outer peripheral portion 2d of the blade piece 2 so as to project therefrom. Other configurations, functions, and effects are similar to those of the first embodiment, and therefore description thereof will be omitted.

Embodiment 4 FIG. 4 shows an axial flow fan according to Embodiment 4 of the present invention. The present embodiment corresponds to the inventions of claims 1, 3 and 4.

In the case of this embodiment, the suction auxiliary blade 3 in the third embodiment is bent toward the suction surface side with respect to the blade surface 2b.
Other configurations, functions and effects are the same as those of the second embodiment, and therefore description thereof will be omitted.

The invention of the present application is not limited to the configuration of each of the above-described embodiments, and it goes without saying that the design can be changed as appropriate without departing from the spirit of the invention.

[Brief description of drawings]

FIG. 1 is a front view of an axial fan according to a first embodiment of the present invention.

FIG. 2 is a front view of an axial flow fan according to a second embodiment of the present invention.

FIG. 3 is a front view of an axial flow fan according to a third embodiment of the present invention.

FIG. 4 is a front view of an axial flow fan according to a fourth embodiment of the present invention.

FIG. 5 is a front view of a conventional axial fan.

FIG. 6 is a diagram showing a suction flow velocity vector in a meridional surface shape of a conventional axial fan.

[Explanation of symbols]

Reference numeral 1 is a hub, 2 is a blade piece, 2a is a leading edge, 2b is a blade surface, 2c is a trailing edge, 2d is an outer peripheral portion, and 3 is a suction auxiliary blade.

Claims (4)

[Claims] 1. A hub (1) as a center of rotation, and the hub (1)
A plurality of winglets (2), (2) ...
And an intake auxiliary vane (3) projecting at an acute angle in the direction of rotation is provided on the outer peripheral portion (2d) of each blade (2). Axial fan. 2. The axial fan according to claim 1, wherein the suction auxiliary blade (3) is formed by cutting off a part of an outer peripheral edge portion of the blade piece (2). 3. The suction auxiliary wing (3) is provided on the outer peripheral portion (2d) of the wing piece (2) so as to project therefrom.
Axial fan described. 4. The axial fan according to claim 1, 2 or 3, wherein the suction auxiliary blade (3) is bent at a predetermined angle to the suction surface side with respect to the blade piece (2).