JP2560793B2 - Blower - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a blower used for a cooling system of a vehicle engine, an outdoor unit of a home air conditioner, and the like.

[Prior Art] In recent years, for example, the engine room of an automobile has become extremely crowded due to the horizontal installation of the engine due to the FF (front engine / front drive) system and the mounting of auxiliary equipment due to the upsizing of the automobile. ing. Therefore, the blower of the engine cooling system under such a condition is forced to be used under a high pressure loss, and noise particularly during idling which is the maximum high pressure loss becomes a problem.

Therefore, recently, it has been considered to reduce the noise by devising the structure of the axial fan that forms the main part of the blower.

For example, in the low speed axial flow fan disclosed in Japanese Utility Model Laid-Open No. 62-185889, the suction side surface of each blade has a rough surface state of unevenness with a gradually increasing density from the leading edge side to the trailing edge side. The fan noise is reduced (first conventional example).

Further, as shown in FIG. 6, the blade 11a is provided so as to be inclined so as to be advanced by a predetermined angle (advance angle) θ1 in the rotation direction X, and is also inclined by a predetermined angle (forward tilt angle) θ2 in the direction of the rotation axis L. Advance to lean forward to reduce noise
A forward tilt type axial fan 11 has also been proposed (second conventional example). Here, the effect of noise reduction is improved by configuring the shape of the blade 11a by combining both forward and forward leaning, and the noise reducing effect is achieved by configuring only one shape of forward and forward leaning. Is already known to decrease.

[Problem to be Solved by the Invention] However, in the low-speed axial flow fan of the first conventional example, the suction side surface of each blade has a rough surface state of unevenness with a gradually increasing density from the leading edge side to the trailing edge side. Had to be configured, and surface processing for that was not easy.

Further, the second conventional example has a problem in terms of its mounting space. For example, as shown in FIG. 8, when a blower is attached to a radiator 12 of an automobile, in order to improve the cooling effect by sucking air from a wide range of the radiator 12, the entire rear surface of the radiator 12 is covered. A shroud 13 is provided, and the tubular air-conducting portion 13a provided on the rear side of the shroud 13 is provided with the forward / forward tilt type axial fan 11.

Therefore, the width a of the axial fan 11 in the direction of the rotation axis L is increased due to the forward tilted shape of each blade 11a of the axial fan 11, and accordingly the front-back width b of the air conducting portion 13a is necessarily increased. Therefore, the physique W in the front-rear direction of the entire blower becomes large. Therefore, there is a problem that it is difficult to install the blower in the engine room with a limited space.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a blower that can be mounted in a small space to realize noise reduction without requiring special processing on each blade surface. is there.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, an axial fan that is rotated by a drive source is provided, and a predetermined amount of space is secured behind the axial fan. It is composed of a tubular air-conducting part that encloses the axial fan, and an open part that is open to the front of the axial fan continuously with the air-conducting part in order to guide a wide range of air in front of the coaxial fan to the air-conducting part. In a blower equipped with a shroud, an open part of the shroud is formed in a slanted shape so as to converge to an air-conducting part, and each blade of the axial fan is provided so as to be inclined so as to advance in its rotation direction, while an axial flow is provided. The front edge of each blade is substantially perpendicular to the rotation axis of the fan in the axial direction, and the front end side of the axial fan in the rotation axis direction is defined from the boundary between the air conducting portion and the open portion. It is arranged by advancing a predetermined amount toward the open part.

[Operation] That is, each blade is not provided with a forward tilt angle in the rotational axis direction of the axial fan, and the front end side of the axial fan in the rotational axis direction is advanced by a predetermined amount from the air conducting portion of the shroud to the open portion. Since they are arranged, it is possible to reduce the front-rear width of the air-conducting portion while ensuring a predetermined amount of space behind the axial fan, and to reduce the overall size of the blower in the front-rear direction.

Further, the front end side of the axial flow fan in the rotation axis direction is arranged so as to be advanced from the air conducting portion to the opening portion by a predetermined amount, and the opening portion of the shroud is formed in an oblique shape so as to converge to the air conducting portion. By doing so, the center of pressure of the aerodynamic force exerted on each blade of the axial fan can be moved to the front of the axial fan, whereby the air flow passing through each blade is directed in the centripetal direction. That is, due to the interference with the oblique opening, the air flow passing through the axial fan is directed in the centripetal direction.

Further, the fact that each blade of the axial fan is inclined so as to be advanced in the rotation direction thereof and the air flow directed in the centripetal direction are combined with each other to reduce noise generation in the blower.

[Embodiment] An embodiment in which the present invention is embodied in a radiator cooling fan of an automobile will be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, a shroud 2 is provided on the rear side of the radiator 1 so as to cover the whole. The shroud 2 is provided with a tubular air-conducting portion 2a, and an opening portion 2b which is opened to introduce a wide range of front air, that is, air from the entire rear side of the radiator 1 is provided in the front portion of the shroud 2a. It is formed continuously. Further, the open portion 2b of the shroud 2 is formed in a slanted shape so as to converge to the air conducting portion 2a, and the inside thereof is a slope 2c.

The axial fan 4 rotated by the motor 3 as a drive source is arranged so as to be included in the air conducting portion 2a. The axial fan 4 includes a boss portion 4a, and a plurality of blades 4b (a total of four blades in this embodiment) are provided on the outer periphery of the boss portion 4a. Each blade 4b is inclined at a predetermined advance angle θ1 so as to advance in the rotation direction X thereof.

FIG. 4 is a graph showing the relationship between the magnitude of the advance angle θ1 and the noise generated from the axial fan. As is clear from this figure, the noise of the axial fan decreases as the advancing angle θ1 increases. Although the advancing angle θ1 can be geometrically set to an angle of 360 degrees or more, in the axial fan 4 of this embodiment, the advancing is made in consideration of the noise reduction effect and the mechanical strength of each blade 4b. The angle θ1 is set to 45 degrees.

Further, as shown in FIG. 3, the axial fan 4 has a front end side 4c in the direction of the rotation axis L from the front side position P, which is a boundary between the open portion 2b of the air conducting portion 2a, to the open portion 2b by a predetermined amount ( Hereinafter, it is arranged by advancing by α). This advance amount α is the forward inclination angle θ2 of each blade in the axial fan.
(See FIG. 7), that is, it is known that it is related to the magnitude of the inclination angle of the axial fan toward the front in the rotation axis direction.
In this embodiment, as shown in FIG. 3, the front edge of each blade 4b in the rotational axis direction of the axial fan 4 is substantially perpendicular to the rotational axis L of the axial fan 4, and each blade is
No forward tilt angle θ2 is provided on 4b.

FIG. 5 is a graph showing the relationship between the magnitude of the forward tilt angle θ2 and the noise generation of the axial fan. As is clear from this figure, the noise is minimized when the forward tilt angle θ2 is 22.5 degrees. Further, in this embodiment, the advance amount α is set based on the following equation in order to obtain the effect corresponding to the noise reduction of the forward tilt angle θ2 of 22.5 degrees.

α = (D0−D1) ÷ 2 × sin (θ2) where D0 is the outer diameter of the axial fan 4, and D1 is the boss.
It is the outer diameter of 4a (see FIG. 1).

In this embodiment, the advance amount α is set to 40 mm by the above formula. That is, as shown in FIG. 3, the air conducting portion 2a
The front end side 4c of the boss portion 4a of the axial fan 4 is arranged by advancing by 40 mm toward the open portion 2b side with reference to the front side position P.

Generally, the size of the arc at the boundary between the air-conducting part and the open part of the shroud is related to the size of the shroud in the front-rear direction, and it is said that the larger the size, the larger the arc. There is. However, in the shroud 2 of this embodiment, the front-back width c of the shroud 2 and the size of the arc R of the boundary between the air conducting portion 2a and the open portion 2b are shown in FIG. 1 regardless of the above relationship. Can be set relatively roughly. That is, the size of the arc R is irrespective of the front-back width c of the shroud 2,
It may be set so that the front side position P of the air conducting portion 2a becomes clear and does not form a pin angle.

Incidentally, as shown in FIG. 3, the clearance S between the axial fan 4 and the shroud 2 in this embodiment is set to 3 mm as in the conventional blower.

Next, the operation of the blower configured as above will be described.

In this blower, the blade 11 in the second conventional example is used.
Unlike the axial fan 11 in which the forward inclination angle θ2 is provided in a, since the forward inclination angle θ2 is not provided in the angular blade 4b of the axial fan 4, the axial width of the axial fan 4 does not increase in the front-rear direction. Further, in the positional relationship between the shroud 2 and the axial fan 4, the front end side 4c of the boss portion 4a of the axial fan 4 is connected to the air conducting portion.
It is arranged by advancing by a predetermined advance amount α from the front position P of 2a to the opening 2b. Therefore, the front-rear width b of the air-conducting portion 2a can be reduced while the dimension of the open portion 2b in the front-rear direction is substantially the same as that of the conventional one and the rear space of the axial fan 4 is sufficiently secured. The front-rear width c of the shroud 2 can be reduced to reduce the front-rear physique W of the blower as a whole.

As a result, even in a congested engine room, the blower can be installed in a relatively small space while maintaining the basic blow performance of the blower.

In addition, the front end side 4c of the boss portion 4a of the axial fan 4 is connected to the air conducting portion.
By arranging the shroud 2 so as to advance from the opening portion 2b to the opening portion 2b by an advance amount α, and by forming the opening portion 2b of the shroud 2 in an oblique shape so as to converge to the air conducting portion 2a, the axial fan It is possible to move the pressure center of the aerodynamic force related to each blade 4b of No. 4 to the front of the axial fan 4. As a result, the flow of air passing through each blade 4b is directed in the centripetal direction of the axial fan 4, as shown by the arrows in FIGS. That is, the flow of air guided to the open portion 2b is the slope 2c.
Directed toward the centripetal direction by interference with.

As a result, the air vortex generated at the end of each blade 4b, that is, the wing tip vortex can be reduced, and noise generation can be reduced.

Further, each blade 4b of the axial fan 4 is rotated in the rotation direction X
The effect of reducing the noise in the blower can be further improved by the fact that it is tilted so as to move forward and the air passing through the axial fan 4 is directed in the centripetal direction as described above.

In the blower of this example, noise reduction of about 3 dB could be realized as compared with an axial fan in which each blade does not have a forward / forward tilted shape. That is, with the blower of this embodiment, an effect comparable to the noise reduction of the blower provided with the forward / forward tilt type axial flow fan 11 in the second conventional example could be realized.

Therefore, in the blower of this embodiment, noise reduction can be effectively performed without performing any processing such as special unevenness on the surface of each blade 4b.

The present invention is not limited to the above-described embodiments, and a part of the configuration can be appropriately modified and carried out as follows without departing from the spirit of the invention.

(1) In the above embodiment, the advance amount α of the axial fan 4 is 40 mm.
However, the advance amount α may be appropriately increased or decreased within a range that does not impair the noise reduction effect.

(2) In the above embodiment, the advancing angle θ1 of each blade 4b of the axial fan 4 is set to 45 degrees, but the advancing angle θ1 may be appropriately increased or decreased within a range that does not impair the noise reduction effect.

(3) In the above-described embodiment, the fan is used for cooling the radiator of the automobile, but it may be embodied as the fan for the outdoor unit of the home air conditioner.

(4) In the above embodiment, the drive source for rotating the axial fan 4 and the motor 3 are provided, but an automobile engine may be used as the drive source.

[Effects of the Invention] As described in detail above, according to the present invention, it is not necessary to perform any special processing on the surface of each blade, and the dimension of the open portion in the front-rear direction is substantially the same as the conventional one. The front and rear width of the air-conducting part can be reduced while ensuring a certain amount of space behind the axial fan, and the front and rear width of the blower can be reduced by reducing the front and rear width of the shroud. It has the excellent effect of being able to achieve noise reduction.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a blower showing an embodiment of the present invention, and FIG. 2 is a front view of the blower, and FIG.
Similarly, the figure is a partially broken side view of the blower, and FIG. 4 is a graph showing the relationship between the advancing angle of the blade of the axial fan and noise generation.
FIG. 5 is a graph showing the relationship between the forward inclination angle of the blade of the axial fan and noise generation. FIG. 6 is a partially cutaway front view of the axial fan of the second conventional example, FIG. 7 is a partially cutaway side view of the axial fan of the same, and FIG. 8 is a blower part to which the axial fan of the second conventional example is applied. It is a fracture | rupture side view. In the figure, 2 is a shroud, 2a is an air conducting part, 2b is an open part,
3 is a motor as a drive source, 4 is an axial fan, 4b is a blade, 4c is a front end side, L is a rotation axis, X is a rotation direction, and θ1
Is the advance angle, and α is the advance amount.

Claims (1)

(57) [Claims] 1. A tubular air conducting portion including an axial fan that is rotated by a drive source, the tubular air conducting portion including the axial fan while ensuring a predetermined amount of space behind the axial fan, and the front of the coaxial fan. A blower provided with a shroud that is open to the front of the axial fan and that is continuous with the air-conducting part to guide a wide range of air to the air-conducting part. The blade is formed in a slanted shape so as to converge to the air-conducting portion, and each blade of the axial fan is provided so as to be inclined so as to advance in the rotation direction thereof, while in the axial direction with respect to the rotation axis of the axial fan. The front edge portion of each blade is made substantially vertical, and the front end side of the axial fan in the rotation axis direction is arranged by advancing by a predetermined amount from the boundary between the air conducting portion and the opening portion to the opening portion. To Characterized blower.