JPH06280792A - Blowing device - Google Patents

Abstract

PURPOSE:To prevent the generation o a local pack on the frequency of interference noise between a stay and a blade and to suppress the generation of fan noise. CONSTITUTION:Angles between adjoining blades 3 are all set to different values from each other and the blades are arranged at an unequal pitch such that the angle between the adjoining blades 3 is set to a value which is prevented from being the multiple of an angle between other adjoining blades 3 and an angle between adjoining stays 6. Further, angles between the adjoining stays 6 are all set to different values from each other and the stays are arranged at an unequal pitch such that the angle between the adjoining stays 6 is prevented from being the multiple of an angle between other adjoining stays 6 and an angle between the adjoining blades 3. This constitution prevents the simultaneous starting of two or more crosses between the blade 3 and the stay 6 during one full rotation of an axial flow fan. Thereby, the generation of a local peak on the frequency of interference noise is prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower device in which a motor is supported by a plurality of stays arranged to face an axial fan.

[0002]

2. Description of the Related Art An example of an air blower in which a motor is supported by a plurality of stays arranged to face an axial fan is shown in FIG.
Shown in. The blower 100 includes an axial fan 102 having five blades 101, and the axial fan 10
The motor 104 is supported by twelve stays 103 on the air suction side of 2, and five blades 101 are provided at equal intervals and twelve stays 103 are also provided at equal intervals.

[0003]

When the motor 104 of the blower device 100 is activated, the axial fan 102 stays in the stay 10.
Air is sucked from the 3 side. At this time, the air flow passing between the stays 103 causes turbulence of air downstream of the stays 103. When this turbulence reaches the rotating blade 101, a periodic interference sound is generated. As shown in FIG. 5, the interference sound between the stays 103 and the blades 101 has an equal pitch of five blades 101 and a rotational speed of the axial fan 102 of 200.
At 0 rpm, the fundamental frequency is about 167 Hz (= 5
・ 2000/60), and peak A appears in multiples thereof. For the purpose of reducing the peak A, as shown in FIG. 6, the mounting angles of the five blades 101 of the axial fan 102 are set to different angles. Then, as shown in FIG. 7, the interference sound is 12 rpm of the stays 103 provided at equal intervals and the rotation speed of the axial fan 102 is 2000 rpm.
Basic frequency 400Hz (= 12.2000)
The peak B appeared in a multiple of / 60) and the peak could not be eliminated.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a blower device capable of eliminating a local peak on the frequency of an interference sound and suppressing generation of fan noise. It is in.

[0005]

The blower of the present invention employs the following technical means. The blower includes an axial fan having a plurality of blades that are rotationally driven to generate an air flow, a motor that rotationally drives the axial fan, and a plurality of fans that are arranged to face the axial fan and support the motor. And a stay. And, the blower device, among the plurality of blades,
The angle of each adjacent blade is set to be different from the angle of the other adjacent blades, and the angle of each adjacent blade is set so as not to be a multiple of the angle of the other adjacent blades. Further, the blower is provided such that, among the plurality of stays, an angle of each adjacent stay is different from an angle of another adjacent stay, and an angle of each adjacent stay is adjacent to another. It is provided so as not to be a multiple of the stay angle. Furthermore, the blower
The angle of each adjacent wing and the angle of each adjacent stay are provided at different angles, and one of the angle of each adjacent wing and the angle of each adjacent stay is the other. It is provided so as not to be a multiple of the angle.

[0006]

In the air blower having the above structure, when the motor operates and the axial fan rotates, the blades and the stays do not start a plurality of intersections at the same time. Therefore, a local peak does not occur on the frequency of the interference sound between the blade and the stay regardless of the rotation speed of the axial fan.

[0007]

According to the blower of the present invention, since a local peak does not occur on the frequency of the interference sound due to the blade and the stay, the fan noise can be suppressed as compared with the conventional case.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an air blower of the present invention will be explained based on an embodiment shown in the drawings. [Configuration of Embodiment] FIGS. 1 to 3 show an embodiment of the present invention. FIG. 1 is a front view of a blower, and FIG. 2 is a side view of the blower. The blower device 1 of the present embodiment is a push-type blower device for forcibly sending air from a traveling direction side of a vehicle to a heat exchanger 2 such as a refrigerant condenser and a radiator, and an axial fan 4 having a plurality of blades 3. An electric motor 5 that rotates to drive the axial fan 4 when energized, a plurality of stays 6 that support the electric motor 5 on the air intake side of the axial fan 4, and a shroud portion 7 that covers the axial fan 4. And a fan shroud 8 that is integrally provided.

The axial fan 4 is composed of a boss portion 9 which is rotationally driven by an electric motor 5 and five blades 3 which are radially provided from the boss portion 9. The angles of the adjacent blades 3 (for example, the angles formed by the perpendicular lines extending in the radial direction from the center of the root portion of each blade 3) are all set to different angles, and the angles of the adjacent blades 3 are different from each other. Are provided at unequal pitches so as not to be a multiple of the angle between the adjacent blades 3 and the angle between the adjacent stays 6 described later.

The fan shroud 8 has a substantially cylindrical shroud portion 7 that covers the periphery of the axial fan 4, and 12 stays 6 that support the motor on the air intake side of the shroud portion 7 that are integrally formed of resin. It is molded. Each stay 6 has a leg portion 6a extending from the shroud portion 7 on the air intake side and parallel to the axial direction of the axial fan 4, and a radial rib 6b extending from the leg portion 6a toward the electric motor 5 on the inner periphery.
It consists of and. The angles of the adjacent stays 6, that is, the angles formed by the adjacent radial ribs 6b are all different angles and different from the angle of the adjacent blades 3, and the adjacent stays 6 are adjacent to each other. Are provided at unequal pitches so that they do not become multiples of the angle of the other adjacent stays 6 and the angle of the adjacent blades 3.

[Operation of Embodiment] Next, the operation of the above embodiment will be briefly described. When the electric motor 5 is energized, the electric motor 5 rotationally drives the axial fan 4. When the axial fan 4 rotates, the five blades 3 of the axial fan 4 suck air from between the stays 6 into the shroud portion 7, and blow the sucked air toward the heat exchanger 2. At this time, the air flow passing between the stays 6 causes turbulence of air in the downstream of the stays 6. When this turbulence reaches the rotating blade 3, an interference sound is generated due to the turbulence of the air by the stay 6. However, the air blower 1 of this embodiment is
When the axial fan 4 makes one rotation, two or more blades 3 and each stay 6 do not start intersecting at the same time. Therefore, in FIG.
In the fan noise shown in (1), no peak occurs in the interference sound between the blade 3 and the stay 6. Note that FIG. 3 is noise data of the rotational speed of the axial fan 4 of 2000 rpm, and many small peaks in the figure are peaks of the interference sound generated by the blades 3 at the rotational speed of the axial fan 4.

[Effects of Embodiment] Blower 1 of this embodiment
As shown in FIG. 3, the interference noise between the blade 3 and the stay 6 does not have a local peak in frequency, so that the fan noise is smaller than in the conventional case.

[Modification] In the above embodiment, the motor and stay are provided on the air intake side of the axial fan, but they may be provided on the blowout side. In this case, it is possible to suppress the local increase of the interference sound due to the pressure fluctuation due to each blade that occurs immediately after the axial fan. Although an electric motor is shown as an example of the motor, a hydraulic motor may be used. Although the stay is provided on the shroud in the example, it may be provided on another member. A protective net may be combined with the stay supporting the motor.

[Brief description of drawings]

FIG. 1 is a front view of an air blower (embodiment).

FIG. 2 is a side view of an air blower (embodiment).

FIG. 3 is a graph of fan noise showing the relationship between noise level and frequency (Example).

FIG. 4 is a front view of a blower (prior art).

FIG. 5 is a graph of fan noise showing the relationship between noise level and frequency (prior art).

FIG. 6 is a front view of a blower (prior art).

FIG. 7 is a graph of fan noise showing the relationship between noise level and frequency (prior art).

[Explanation of symbols]

 1 Blower 3 Blade 4 Axial fan 5 Electric motor 6 Stay

Claims (1)

[Claims] 1. An axial fan having a plurality of blades that are rotationally driven to generate an air flow, a motor that rotationally drives the axial fan, and a motor that is disposed opposite to the axial fan to support the motor. In the blower device including a plurality of stays, the angle of each adjacent blade of the plurality of blades is different from the angle of the other adjacent blades, and the angle of each adjacent blade is Is provided so as not to be a multiple of the angle of another adjacent wing, and among the plurality of stays, the angle of each adjacent stay is provided at an angle different from the angle of another adjacent stay, and Is provided so that the angle of the adjacent stays of is not a multiple of the angle of the other adjacent stays. Furthermore, the angle of each adjacent wing and the angle of each adjacent stay are different. Together provided, among the angles of the respective next match wing angle and respective neighboring suit stays, one angle, blower, characterized in that provided as not a multiple of the other angle.