JPH09105554A - Sound absorption apparatus for fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an air suction efficiency and a sound absorption effect even in a limited air suction space. SOLUTION: There are a flat plate-shaped support member 51 oppositely disposed at a predetermined interval on an air suction side end surface of a fan 17, and a sound absorption member 21 provided on the support member 51 which is disposed to oppose the fan 17 and which has a cross section of a crest shape protruding toward substantially the center of the air suction side end surface of the fan 17. The sound absorption member 21 is constructed as a hollow structure so as to form a closed sound absorbing space 21b between it and the side surface of the support member 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing device for a fan, and more particularly to a sound absorbing device for a fan in which a sound absorbing member is arranged to face an intake side end surface of a water heater fan or an intake port of a fan casing.

[0002]

2. Description of the Related Art As a conventional sound absorbing device for a fan of this type, there is a technique shown in FIG. FIG. 5 is a sectional view showing a conventional sound absorbing device for a water heater fan.

First, referring to FIG. 5, the water heater fan will be described.
1, a fan casing 15 attached to a predetermined position,
A fan motor 16 fixed to one side surface of the fan casing 15 and a fan 17 drivingly connected to a drive shaft (not shown) of the fan motor 16. On the other side of the fan casing 15, for example, an intake port 15a having a shape substantially corresponding to the end surface of the fan 17 and having a predetermined dimension d1 is provided.

On the other hand, the intake port 15 of the fan casing 15
An air supply plate 18 is superposed on the outside of a and is attached to the air supply plate 1.
8 is a dimension d2 smaller than the dimension d1 of the intake port 15a.
18a is formed. Then, conventionally, the dimension d2 of the opening 18a of the air supply plate 18 is adjusted to close a part of the intake port 15a by the peripheral edge of the opening 18a of the air supply plate 18,
The amount of intake air to the fan 17 is changed and adjusted by increasing or decreasing the opening area of the intake port 15a.
As a result, even if the same fan 17 is used, it is possible to adjust the amount of intake air and change the amount of air blown to the water heater 11, and as a result, one type of fan 17 has a different required amount of air blow. Various types of water heaters 11 can be dealt with.

The conventional sound absorbing device for a water heater fan is arranged so as to face the intake port 15a of the fan casing 15 of the water heater fan configured as described above. That is, the conventional sound absorbing device for a water heater fan has a fan casing 15
Plate-shaped support member 51 made of a metal plate or the like arranged so as to face the intake port 15a at a predetermined interval, and a plate-shaped sound absorbing sheet attached to a side surface of the support member 51 on the intake port 15a side. It consists of 52. The sound absorbing sheet 52 is
It is made of a sound absorbing material such as urethane foam, and is configured to reduce noise such as motor noise and wind noise of the fan 17 due to the rotational driving of the fan 17.

[0006]

The conventional sound absorbing device for the water heater fan is constructed as described above, and the support member 51 and the sound absorbing sheet 52 are arranged so as to face the intake port 15a of the water heater fan. Although the sound absorbing sheet 52 has a certain sound absorbing effect, the space between the support member 51 and the fan casing 15, that is, the air passage S is limited to a certain space, and the inflow efficiency of air into the intake port 15a is reduced. there is a possibility. Therefore, when the amount of air blown to the water heater 11 is increased, it is necessary to increase the rotation of the fan 17 to secure a constant intake air amount, and noise may increase as the fan rotation speed increases.

On the other hand, the conventional water heater fan is the fan 1
In order to adjust the amount of intake air to 7, the air intake plate 1 is attached to the intake port 15a.
8 is attached, however, the number of parts is increased, and the assembling work is required, so that the total cost is increased.

[0008] Therefore, an object of the present invention is to provide a sound absorbing structure for a fan, which has a good intake efficiency even in a limited intake space and has an improved sound absorbing effect.

Another object of the present invention is to provide a sound absorbing device for a fan capable of increasing or decreasing the area of the intake port to a desired value.

[0010]

According to a first aspect of the present invention, there is provided a sound absorbing device for a fan, wherein a flat plate-like supporting member is arranged opposite to an end surface of an intake side of the fan at a predetermined interval, and the sound absorbing member is opposed to the fan on the supporting member. The sound absorbing member has a mountain-shaped cross-section protruding toward the approximate center of the end surface on the intake side of the fan.

A sound absorbing device for a fan according to a second aspect of the present invention is the sound absorbing device according to the first aspect.
In the above, the sound absorbing member has a hollow structure so as to form a closed sound absorbing space between the sound absorbing member and the side surface of the support member on the fan side.

According to a third aspect of the present invention, there is provided a fan sound absorbing device, comprising: a fan; and a fan casing for housing the fan and having a fan casing having an intake port of a predetermined area at a position facing the one axial end surface of the fan. In the sound absorbing device, a flat plate-like support member is arranged to face an intake port of the fan casing at a predetermined interval, and the sound absorbing member is arranged on the support member so as to face the intake port. The intake port has a chevron shape that protrudes toward the approximate center, and the top portion thereof is a flat opening adjustment surface that is flush with the inside of the intake port.

[0013]

Embodiments of the present invention will be described below.

FIG. 1 is a sectional view showing a sound absorbing device for a fan according to a first embodiment of the present invention.

In the drawings, the same reference numerals and symbols as those of the conventional example indicate the same or corresponding parts as those of the conventional example, and thus, duplicated description will be omitted.

Referring to FIG. 1, in the fan sound absorbing device of the present embodiment, the sound absorbing member 21 is arranged on the supporting member 51 so as to face the intake port 15a of the fan casing 15, and the sound absorbing member 21 has a cross section. It has a chevron shape that projects toward the approximate center of the intake port 15a. More specifically, the sound absorbing member 21 has a top portion 21a having a curved shape with a predetermined radius, and its apex is arranged near the plane of the intake port 15a (shown by a chain line in the figure). In the present embodiment, the air intake plate 15 is not provided with the conventional air supply plate 18, but if necessary, such as the type of the water heater 11, the air supply plate 1 is not provided.
8 may be provided. Furthermore, the inside of the sound absorbing member 21 is
It has a hollow structure so as to form a closed sound absorbing space 21b between the supporting member 51 and the side surface on the fan side 17. The sound absorbing space 21b has a mountain-shaped cross section corresponding to the outer surface shape of the sound absorbing member 21. That is, the sound absorbing member 21
Has a substantially V-shaped cross section, and forms the sound absorbing space 21b between its inner surface and one side surface of the support member 51, and the sound absorbing space 21b absorbs noise particularly in a low frequency region. . The sound absorbing member 21 has its outer peripheral end face closely contacted with the side face of the support member 51 on the fan 17 side, and is joined with an adhesive or the like. Here, the outer shape of the sound absorbing member 21 is preferably a conical shape from the viewpoint of facilitating its manufacture and improving the air rectifying effect, but may be another shape such as a pyramid shape.

Here, as the kind of material of the sound absorbing member 21, slab urethane (urethane foam), polyethylene foam, a resin porous molded product made of ABS beads or PP beads, or crushed rubber is used as a binder. There are hardened rubber porous products. Sound absorbing member 21 of the present embodiment
After molding these materials into a flat foam, press-mold a part of the flat foam into the V-shaped cross section shown in FIG. 1, and cut the V-shaped cross section from the bottom side. Is formed by. Further, the bottom surface 21c of the sound absorbing member 21 is arranged in a straight line so as to be in close contact with the side surface of the support member 51 on the fan 17 side, and the outer peripheral edge portion thereof is, as shown in FIG.
An inclined surface 21d is formed so as to smoothly and continuously incline from one side surface of the support member 51. The sound absorbing member 21 may be foam-molded from the beginning to have a V-shaped cross section as shown in FIG.

Next, the operation of the sound absorbing device for the fan of the present embodiment having the above-described structure will be described.

When the water heater fan 11 is in operation, the fan 17 is rotationally driven by the fan motor 16, air is taken in through the intake port 15a of the fan casing 15, and the fan 17 blows air to the water heater 11. At this time, noise such as motor noise and wind noise of the fan 17 is generated due to the rotation of the fan 17, and this noise is absorbed by the sound absorbing member 21 made of a sound absorbing material such as urethane foam. In particular, since the sound absorbing member 21 of this embodiment has a V-shaped cross section, the sound absorbing sheet 5 having a flat plate shape in cross section and volume is used.
It becomes larger than 2 and the sound absorbing effect is improved. Further, since the sound absorbing space 21b provided inside the sound absorbing member 21 absorbs and attenuates the noise particularly in the low frequency region, it is possible to eliminate the low frequency noise which cannot be removed conventionally.

Further, as the fan 17 rotates, air is introduced through the air passage S into the intake port 15a of the fan casing 15.
Inflow. At this time, in the case of the flat sound absorbing sheet 52 as in the conventional case, the direction of the air flowing into the intake port 15a is changed from the vertical direction to the horizontal direction in FIG. As a result, the inflow efficiency decreases. However, in the present embodiment, the air flowing into the air intake port 15a is discharged from the air intake port 15a along the inclined surface 21d of the sound absorbing member 21.
The direction is changed so that it easily flows into the intake port 15a.
Smoothly flows into. As a result, the air flowing into the intake port 15a becomes a laminar flow, and the intake efficiency is improved.

As described above, in the fan sound absorbing device of the above-described embodiment, the flat plate-like support member 51, which is arranged to face the intake side end surface of the fan 17 at a predetermined interval, and the support member 5 are provided.
1 is provided so as to face the fan 17, and has a sound absorbing member 21 having a cross section protruding toward the substantial center of the intake side end surface of the fan 17, and the sound absorbing member 21 is supported by the support member. It has a hollow structure so as to form a closed sound absorbing space 21b between the member 51 and the side surface on the fan 17 side.

Therefore, in the above embodiment, the sound absorbing member 2
The inclined surface 21d of No. 1 rectifies the air flowing from the air passage S to the fan 17 through the intake port 15a to form a laminar flow, thereby smoothly supplying the air to the fan 17. As a result, the water heater 1
Since it is possible to increase the amount of air supplied to the fan 17 in the required amount of air blown to the fan 1, the number of rotations of the fan 17 can be reduced in the amount of air blown, and the motor noise and the wind noise of the fan 17 are correspondingly reduced. Can be reduced, and noise accompanying the rotation of the fan 17 can be reduced.

That is, in addition to the sound absorbing effect of the material of the sound absorbing member 21 and the rectifying effect of the shape of the sound absorbing member 21, the air flow to the fan 17 becomes a laminar flow, the intake resistance is reduced, and the fan rotation speed is reduced. As a result, the noise accompanying the rotation of the fan 17 can be reduced. Then, the inside of the sound absorbing member 21 has a hollow structure, and the sound absorbing space 2
By adopting 1b, it is possible to reduce the weight of the sound absorbing member 21, and the sound absorbing space 21b makes it possible to absorb sound in a low frequency region, which was difficult in the past. Further, since the sound absorbing member 21 has a V-shaped cross section, the volume of the sound absorbing member 21 as a whole can be increased and the sound absorbing effect can be enhanced, as compared with the conventional flat sound absorbing sheet 52.

Next, another embodiment according to the present invention will be described below. In each embodiment, only the differences from the first embodiment will be described, and the same components as those in the first embodiment will be designated by the same reference numerals in the drawings and the description thereof will be omitted.

FIG. 2 is a sectional view showing a sound absorbing device for a fan according to a second embodiment of the present invention.

In the sound absorbing device for a fan of this embodiment, the sound absorbing member 31 has a rectifying portion 32 having a V-shaped or conical cross section similar to that of the sound absorbing member 21 of the first embodiment, and the rectifying portion 3.
2 is different from the first embodiment in that the sticking portion 33 is provided so as to extend to the outer circumference of the bottom portion of No. 2, and other configurations are the same as those in the first embodiment. That is, the rectifying portion 32 is disposed so as to face the intake port 15a of the fan casing 15, and has a cross section that is a mountain shape protruding toward the substantial center of the intake port 15a. The top portion 32a of the rectifying portion 32 has a curved shape with a predetermined radius, and its apex is arranged near the plane of the intake port 15a. Further, the inside of the rectifying portion 32 has a hollow structure so as to form a sound absorbing space 32b having a hermetic cross-section mountain shape or a conical shape with the side surface of the support member 51 on the fan side 17.

The sticking portion 33 has a flat plate shape extending in the radial direction from the bottom of the conical straightening portion 32, and is in close contact with the side surface of the support member 51 on the fan 17 side, and is joined by an adhesive or the like. Further, the sticking portion 33 has a predetermined distance, for example, the rectifying portion 3 from the outer periphery of the bottom portion of the rectifying portion 32 to the periphery of the intake port 15a so as not to affect the rectifying effect of the rectifying portion 32.
It is preferable to extend over a distance substantially equal to the diameter of the bottom portion of No. 2. In addition, the material of the sound absorbing member 31 and the outer shape of the rectifying unit 32 can be selected from various materials as in the first embodiment.

In the fan sound absorbing device of the present embodiment, the rectifying portion 32 of the sound absorbing member 31 functions similarly to the sound absorbing member 21 of the first embodiment due to the inclined surface 32c and the like, and the same effect is obtained. In addition to this, the sticking portion 33 more firmly joins the sound absorbing member 31 to the supporting member 51, prevents the peeling and the like, and increases the entire cross-sectional area or volume to improve the sound absorbing effect. Since the sticking portion 33 extends from the outer periphery of the bottom portion of the rectifying portion 32 over the peripheral edge of the intake port 15a by a predetermined distance, the rectifying effect of the rectifying portion 32 is not reduced.
Further, in the present embodiment, for example, since it can be manufactured by press-molding the rectifying portion 32 portion such as a flat-plate urethane foam, the cutting step as in the first embodiment is unnecessary, and its manufacturing becomes easy, Also, the material yield is improved.

FIG. 3 is a sectional view showing a sound absorbing device for a fan according to a third embodiment of the present invention.

The sound absorbing device for a fan according to this embodiment has a sound absorbing member 4 having the same overall shape as that of the sound absorbing member 21 according to the first embodiment.
1 has a flat opening adjustment surface 41 that is flush with the intake port 15a of the fan casing 15 at the top thereof.
Different from the first embodiment in that a is provided, the other points are the same as in the first embodiment. That is, in the present embodiment, the sound absorbing member 41 is arranged so as to face the intake port 15a of the fan casing 15 with respect to the support member 51, and the cross section of the sound absorbing member 41 is directed toward the approximate center of the intake port 15a. It has a protruding mountain shape. Specifically, the sound absorbing member 41
Has a flat circular opening adjustment surface 41a having a predetermined diameter at its top.
On the plane of the intake port 15a (indicated by a chain line in the figure)
Has been placed. In this embodiment, the intake port 15a is not provided with the conventional air supply plate 18. Instead, the opening adjustment surface 41a having the predetermined dimension d3 increases or decreases the opening area of the intake port 15a having the dimension d1 to adjust the amount of air flowing into the fan 17 from the intake port 15a.

The inside of the sound absorbing member 41 has a support member 51.
The sound absorbing space 41b is hermetically sealed between the fan side 17 and the side surface thereof.
Is formed to have a hollow structure. The sound absorbing space 41b has a mountain-shaped cross section corresponding to the outer surface shape of the sound absorbing member 41. That is, the sound absorbing member 41 has a mountain-shaped or conical shape with a flat top, and the inner surface thereof and the support member 5 are
The sound absorbing space 41b is formed between the sound absorbing space 41b and one side surface of the first sound absorbing space 41b, and the sound absorbing space 41b absorbs noise particularly in a low frequency region. The sound absorbing member 41 is joined with an adhesive or the like so that the outer peripheral end surface 41c of the bottom portion is in close contact with the side surface of the support member 51 on the fan 17 side. The material and outer shape of the sound absorbing member 41 can be selected from various materials as in the first embodiment.

In the fan sound absorbing device of the present embodiment, the sound absorbing member 41 functions similarly to the sound absorbing member 21 of the first embodiment due to the inclined surface 41d and the like, and exhibits the same effect.
In addition to this, by the opening adjustment surface 41a of the sound absorbing member 41,
Since the intake amount can be changed to a desired value by adjusting the opening amount of the intake port 15a, the conventional air supply plate 18 can be eliminated,
The number of parts can be reduced, the assembling work is unnecessary, and the manufacturing cost can be reduced. That is, the opening area of the intake port 15a of the fan casing 15 can be changed by appropriately changing the shape and the area of the opening adjusting surface 41a of the sound absorbing member 41, especially on the top portion, and the air supply that has been conventionally required. The plate 18 can be eliminated.

FIG. 4 is a characteristic diagram showing the sound absorbing effect of the fan sound absorbing device of one embodiment of the present invention in comparison with the sound absorbing effect of the conventional fan sound absorbing device. In the drawing, a thin line indicates a case where only the supporting member 51 is provided for the fan, a dashed line indicates the supporting member 51 and the sound absorbing sheet 52 of the conventional example, and a thick line indicates the supporting member and the sound absorbing members 21, 31, 41 of the present invention. The case where is provided is shown respectively.

As shown in FIG. 4, the sound absorbing device for the fan of each embodiment of the present invention has a remarkable sound absorbing effect as compared with the sound absorbing device for the fan of the conventional example, and is particularly recognized as noise. The effect is remarkable in the frequency region over 3 KHz.

By the way, the sound absorbing device for the fan of the above-mentioned embodiment is composed of the supporting member 51 and the sound absorbing members 21, 31, 41, but when the present invention is carried out, the present invention is not limited to this. For example, in order to further improve the air rectifying effect, it is possible to attach a rectifying member such as a fin to the outer surface of the sound absorbing members 21, 31, 41. Further, a skin layer is provided on the outer surface of the sound absorbing members 21, 31, 41, that is, the surface of the foam to further reduce the air resistance of the surface,
The air flow may be made smoother to improve the rectification effect.

Furthermore, the present invention can be embodied in various fans that require sound absorption, and the type of the fan 17 is also a centrifugal fan,
It can be embodied in various types of turbo fans, such as axial fans. The sound absorbing members 21, 31, 41 are, for example,
When the fan is a ventilation fan, a support member may be provided inside the decorative panel forming the ventilation fan or exclusively.

[0037]

As described above, in the sound absorbing device for a fan according to the first aspect of the present invention, the cross section of the sound absorbing member has a chevron shape protruding toward the approximate center of the end surface on the intake side of the fan, so that even in a limited intake space. It is possible to improve the intake efficiency and improve the sound absorbing effect.

The sound absorbing device for a fan according to claim 2 is the sound absorbing device according to claim 1.
In the above, since the sound absorbing space is formed in the sound absorbing member, it is possible to absorb or attenuate the noise particularly in the low frequency region.

In the sound absorbing device for the fan according to the third aspect, since the cross section of the sound absorbing member has a mountain shape protruding toward the substantial center of the intake port, the intake efficiency is improved even in a limited intake space, and the sound absorbing effect is obtained. Can be improved. Further, since the top portion thereof is a flat opening adjustment surface that is flush with the surface of the intake port, the area of the intake port can be increased or decreased to a desired value without providing an air supply plate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a sound absorbing device for a fan according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a sound absorbing device for a fan according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a sound absorbing device for a fan according to a third embodiment of the present invention.

FIG. 4 is a characteristic diagram showing the sound absorbing effect of the fan sound absorbing device according to the embodiment of the present invention in comparison with the sound absorbing effect of the conventional fan sound absorbing device.

FIG. 5 is a cross-sectional view showing a conventional fan sound absorbing device.

[Explanation of symbols]

 15 fan casing 15a intake port 17 fan 21 sound absorbing member 21b sound absorbing space 31 sound absorbing member 32b sound absorbing space 41 sound absorbing member 41a opening adjustment surface 41b sound absorbing space 51 support member

Claims (3)

[Claims] 1. A flat plate-shaped support member that is arranged to face the intake side end surface of the fan at a predetermined interval, and a support member that is disposed on the support member so as to face the fan and has a cross section of the intake side end surface of the fan. A fan-shaped sound absorbing member protruding toward substantially the center of the fan sound absorbing device. 2. The sound absorbing member for a fan according to claim 1, wherein the sound absorbing member has a hollow structure so as to form a closed sound absorbing space between the sound absorbing member and a side surface of the support member on the fan side. apparatus. 3. A sound absorbing device for a fan, comprising: a fan; and a fan casing that accommodates the fan and has an air inlet having a predetermined area at a position facing one axial end surface of the fan, the air inlet of the fan casing. A flat plate-shaped support member that is disposed to face the air intake port at a predetermined interval, and has a chevron shape that is disposed on the support member so as to face the air intake port and has a cross section that projects toward the approximate center of the air intake port, A sound absorbing device for a fan, further comprising: a sound absorbing member having a flat opening adjusting surface whose top is flush with the surface of the intake port.