JP2838955B2 - 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 in which a motor for rotating an axial fan is supported by a stay on the air suction side of the axial fan.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a blower in which a motor is supported by a stay on the air suction side of an axial fan.
The blower 100 has a front edge 101 extending in the radial direction.
Axial fan 103 having a plurality of blades 102, motor 104 for driving axial fan 103, and motor 1
The stay 104 is composed of twelve stays 105 extending in the radial direction for supporting the fan 04 on the air suction side of the axial fan 103. When the motor 104 operates, the blower 100
3 sucks air from the stay 105 side. At this time, the air flow passing through the stay 105 causes air turbulence downstream of the stay 105. This turbulent rotating wing 10
When the number reaches 2, interference noise due to air turbulence caused by the stay 105 is generated.

[0003]

However, in the blower 100 shown in FIG. 8, since the relative angle between the leading edge 101 of the wing 102 and the stay 105 is substantially the same, the interference sound causes the total length of the leading edge 101 of the wing 102 to be reduced. At the same time. For this reason, as shown in FIG. 9, the peak of the interference noise (see B1 in the figure) having the fundamental frequency as the product of the number of blades 102 and the rotation speed of the axial flow fan 103 is significantly increased in the fan noise B.

Therefore, as shown in FIG.
5 is inclined with respect to the radiation centered on the axial fan 103, the interference between the stay 105 and the blade 102 is shifted in time, and the peak of the interference sound is reduced as shown by C1 in FIG. A reduced blower 100 has been proposed. However, since the blower 100 also sucks air from around the axial fan 103, the air sucked by the axial fan 103 is centered around the axial fan 103 near the outer peripheral tip of the axial fan 103. Approach along with the radiation. For this reason, if the stay 105 is provided to be inclined with respect to the radiation, the stay 105 is inclined with respect to the air flow direction near the outer peripheral tip of the axial fan 103, and FIG.
As shown in FIG. 1, a very large air turbulence is generated on the inner peripheral side of the stay 105. As a result, the blower 1 shown in FIG.
00 indicates that while the peak of the interference sound can be reduced,
Since turbulent noise is generated on the outer peripheral side of the fan 05, the fan noise C is increased more than the fan noise B of the blower 100 of FIG. 8, as shown in FIG.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a blower that can reduce the peak of interference noise without increasing fan noise.

[0006]

The blower according to the present invention employs the following technical means. The blower includes an axial fan having blades that are driven to rotate to generate an air flow, a motor that drives the axial fan to rotate, and a stay that supports the motor on the air suction side of the axial fan. Have. And the stay is provided with an outer peripheral suction portion near an outer peripheral tip portion of the axial flow fan along a radiation centered on the axial fan, and an inner peripheral suction portion of an inner periphery of the outer peripheral suction portion. , Are provided at an angle to the radiation.

[0007] The leading edge of the wing is always at a predetermined angle or more (for example, 30 degrees) with respect to the outer and inner suction portions of the stay.
(Or more), it is possible to suppress the interference peak between the inner peripheral suction portion and the stay and also suppress the generation of the interference sound peak between the outer peripheral suction portion and the stay.

[0008]

When the motor drives the axial fan to rotate,
The axial fan draws air from the stay side and blows it out to a side different from the motor. At this time, since the axial fan also sucks air from the outer peripheral side of the axial fan, near the outer peripheral tip of the axial fan, the sucked air flows axially along the radiation centered on the axial fan. Guided by a fan. The outer peripheral suction portion of the stay, which is near the outer peripheral tip of the axial fan, is provided along the radiation. Therefore, the air flowing from the outer periphery to the inner periphery flows along both side surfaces of the outer peripheral suction portion of the stay. That is, the turbulence of the air near the outer periphery of the fan of the stay can be reduced as compared with the conventional technology in which the stay is inclined with respect to the radiation. Further, at the inner peripheral suction portion on the inner periphery of the outer peripheral suction portion of the stay, the air sucked by the axial fan flows substantially parallel to the axial direction. Therefore, even if the outer peripheral suction portion of the stay is provided to be inclined with respect to the radiation, the air flowing in the axial direction at the inner peripheral suction portion of the stay flows along both side surfaces of the inner peripheral suction portion. Since the inner peripheral suction portion is provided to be inclined with respect to the radiation, the intersection with the leading edge of the wing is temporally shifted. Therefore, the peak of interference between the inner peripheral suction portion of the stay and the blade can be suppressed.

[0009]

According to the blower of the present invention, the inner peripheral suction portion of the stay intersects with the leading edge of the blade with a time lag, so that the peak of the interference sound can be suppressed, and the outer peripheral suction portion of the stay can be prevented. In addition, the turbulence of the air flow downstream of the outer peripheral suction portion is suppressed, and the fan noise can be reduced. That is, the blower of the present invention can suppress the peak of the interference sound and the fan noise.

[0010]

Next, a blower according to the present invention will be described with reference to an embodiment shown in the drawings. 1 to 4 show an embodiment of the present invention. FIG. 1 is a front view of a blower, and FIG. 2 is a side sectional view of the blower. The blower 1 of the present embodiment includes a heat exchanger 2 such as a refrigerant condenser or a radiator from the traveling direction side of the vehicle.
A forced air blower for forcibly sending air to the fan, an axial fan 4 having five blades 3, an electric motor 5 for rotating the axial fan 4 when energized, and a periphery of the axial fan 4. A cylindrical shroud portion 6 to be covered, and the shroud portion 6 and a resin provided integrally with the
And 12 stays 7 supported on the air suction side.

Each stay 7 provided on the shroud portion 6
Are leg portions 7a extending from the shroud portion 6 on the air suction side and parallel to the axial direction of the axial fan 4;
And a radial rib 7b extending to the inner side of the electric motor 5 side. Each of the stays 7 has a substantially D-shaped cross section in which the inflow side of the air is curved over the entire length. The radial rib 7b is provided to be long in the axial direction of the axial fan 4, and the leg 7a is provided. Are long in the inner diameter direction. Further, each stay 7 is distinguished into an outer peripheral suction portion 7o near the outer peripheral front end portion of the axial fan 4 and an inner peripheral suction portion 7i on the inner periphery thereof. The outer peripheral suction portion 7o is a stay 7 portion that is arranged at a location where the air flow from the outer peripheral side toward the inner peripheral portion is relatively strong when the axial flow fan 4 sucks air, and also includes the leg portion 7a in the present embodiment. It is. Further, the inner peripheral suction portion 7i is a stay 7 portion arranged at a position where an air flow is generated in parallel with the axial direction of the axial fan 4 when the axial fan 4 sucks air. It should be noted that the outer peripheral suction portion 7o and the inner peripheral suction portion 7
The boundary d1 for distinguishing the fan from the i is the fan diameter d of the axial fan 4.
If it is set to 0, it is provided in the range of d1 ≧ d0 × 0.8.

The outer peripheral suction portion 7o of the stay 7 is provided with a radiation (hereinafter referred to as radiation, α
Reference). Further, the inner peripheral suction portion 7i of the stay 7 is provided to be inclined to the opposite side in the rotation direction with respect to the radiation. The inclination angle θ between the inner peripheral suction portion 7i and the radiation.
1 is provided such that the inner peripheral suction portion 7i and the front edge 3a of the wing 3 form a relative angle of 30 ° or more and about 60 ° even if the front edge 3a of the wing 3 is provided along the radiation. In this embodiment, the inclination angle θ1 is set at 30 °.

The axial fan 4 is composed of a boss 9 rotated by an electric motor 5 and five blades 3 radially provided on the boss 9.
The front edge 3a has an advanced shape that is advanced in the rotational direction. The leading edge 3a extends from the base of the wing with the boss 9 toward the outer periphery,
Angle of inclination in rotation direction (angle between radiation and leading edge 3a)
The outer peripheral suction portion 7o and the inner peripheral suction portion 7i
Is set so that the outer peripheral suction portion 7o and the front edge 3a of the blade 3 form a relative angle of 30 ° or more, and in the present embodiment, the tilt angle θ2 is set to 30 °. ing.

That is, the inner peripheral suction portion 7i and the leading edge 3a of the blade 3
Is always at least 30 °, and the relative angle between the outer peripheral suction portion 7o and the leading edge 3a of the blade 3 is always at least 30 °.

[Operation of Embodiment] Next, the operation of the above embodiment will be briefly described. When the electric motor 5 is energized, the axial fan 4 sucks air from between the stays 7 and blows the sucked air toward the heat exchanger 2. The airflow sucked by the axial fan 4 is, as shown by arrows in FIG.
In the outer peripheral suction portion 7o, an airflow from the outer periphery toward the inner periphery is generated, and in the inner peripheral suction portion 7i of the stay 7, an airflow substantially parallel to the axial direction of the axial fan 4 is generated. Since the airflow flowing from the outer circumference to the inner circumference flows substantially in the radial direction, the airflow flowing from the outer circumference to the inner circumference flows along the outer circumference suction portion 7o as shown in FIGS. For this reason, the outer peripheral suction portion 7
Occurrence of turbulence downstream of o can be kept low. The inner peripheral suction portion 7i is provided at an angle of 30 ° with respect to the radiation. However, in the inner peripheral suction portion 7i, since the air flows substantially parallel to the axial direction of the axial fan 4, the outer peripheral suction portion 7o is provided.
However, even if the air is inclined with respect to the radiation, the air flowing in the axial direction flows along both side surfaces of the inner peripheral suction portion 7i.
Therefore, the generation of the turbulent flow can be suppressed low even downstream of the inner peripheral suction portion 7i.

On the other hand, the inner peripheral suction portion 7i is
Since it is provided at an angle of 30 ° toward the rotation rear side, the leading edge 3a of the blade 3 intersects the inner peripheral suction portion 7i at a relative angle of 30 ° or more. Therefore, the intersection between the inner peripheral suction portion 7i and the leading edge 3a of the blade 3 is temporally shifted, and the inner peripheral suction portion 7i is shifted.
The peak of the interference sound between the wing 3 and the wing 3 can be suppressed. Further, the leading edge 3a of the wing 3 intersecting with the outer peripheral suction portion 7o is provided at an angle of 30 ° or more in the rotational direction with respect to the radiation. , 3
Cross at a relative angle of 0 ° or more. For this reason, the outer peripheral suction portion 7
The intersection between o and the leading edge 3a of the wing 3 is temporally shifted, and the peak of the interference sound between the outer peripheral suction portion 7o and the wing 3 can be suppressed.

[Effects of the Embodiment] The characteristics of the fan noise of the blower 1 of the present embodiment are shown by the solid line A in FIGS.
As shown by the solid line A in FIG. 5, the peak of the interference sound is smaller by A1 than the peak B1 of the interference sound of the conventional blower in which the stays are arranged radially (the blower shown in FIG. 8 of the prior art). it can. In addition, as shown by a solid line A in FIG. 6, the fan noise (solid line C) of the conventional blower (the blower shown in FIG. 10 of the related art) in which the stay is inclined with respect to the radiation is compared. Fan noise can be reduced. That is, the blower 1 of the present embodiment can suppress the peak of the interference sound as compared with the related art, and can reduce the turbulent noise and the fan noise.

[Modification] In the above embodiment, an example is shown in which the leading edge of the wing is a forward wing advanced in the rotational direction, and the inner peripheral suction portion of the stay is inclined in the opposite direction to the rotational direction. As shown in FIG. 7, the leading edge 3 a of the wing 3 is a retreating wing that is retracted in the opposite direction to the rotation direction, and the inner peripheral suction portion 7 i of the stay 7 is inclined in the rotating direction, so that the leading edge 3 a of the wing 3 and the stay 7 may be set to a predetermined angle (for example, 30 °) or more. Although the example in which the inner peripheral suction portion is provided linearly has been described, it may be provided in a curved shape. Further, the outer peripheral suction portion may be substantially along the radiation direction, in particular, any portion where the flow of air from the outer peripheral side is strong along the radiation direction may be used.For example, the shroud portion side may be provided in a curved shape along the radiation. good. Although the inner peripheral suction portion is provided linearly, it may be curved or zigzag.
By providing the inner peripheral suction portion in a zigzag manner, it is possible to provide the inner peripheral suction portion so as to absorb not only the axial vibration generated by the motor but also the radial vibration. Although an electric motor has been described as an example of the motor, a hydraulic motor may be used. The stay supporting the motor may be combined with a protection net.

[Brief description of the drawings]

FIG. 1 is a front view of a blower (Example).

FIG. 2 is a sectional view of a blower (Example).

FIG. 3 is a sectional view taken along line II of FIG. 2 (Example).

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 2 (Example).

FIG. 5 is a characteristic diagram of fan noise showing the relationship between noise level and frequency.

FIG. 6 is a characteristic diagram of fan noise showing the relationship between noise level and frequency.

FIG. 7 is a front view of a blower (modification).

FIG. 8 is a front view of a blower (prior art).

FIG. 9 is a characteristic diagram of fan noise showing the relationship between noise level and frequency (prior art).

FIG. 10 is a front view of a blower (prior art).

FIG. 11 is an explanatory diagram of turbulent noise (prior art).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blower 3 Blade 3a Leading edge 4 Axial fan 5 Electric motor 7 Stay 7o Outer suction port 7i Inner suction port

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F04D 29/52 F04D 29/66 F01P 11/10

Claims (3)

(57) [Claims] An airflow is generated by being rotationally driven by a driving source.
Axial fan with wings A cylindrical shroud portion that covers the outer peripheral side of the axial fan
When, It is integrally formed with the duroud part and supports the drive source.
Support, Integrally formed with the shroud portion and the support portion,
The shroud portion and the
With a plurality of stays that connect with the support, The plurality of stays have an outer peripheral suction near the shroud portion.
Section along the radiation centered on the axis of the axial fan
And the inner peripheral suction portion near the support portion is
Characterized in that it is provided at an angle to radiation.
Wind equipment. 2. The inner peripheral suction portion of the stay receives the radiation.
The wings are installed at an angle opposite to the direction of travel of the wing.
The blower according to claim 1, characterized in that: 3. The leading edge of the wing is connected to the outer periphery of the stay.
Relative angle more than a predetermined angle with respect to the suction part and the inner circumference suction part
The contractor is provided so as to intersect
3. The blower according to claim 1 or 2.