JP3918111B2 - Air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner in which noise generated due to a relationship between a centrifugal fan and a heat exchanger is suppressed.
[0002]
[Prior art]
10 and 11 are a transverse sectional view and a longitudinal sectional view showing a conventional air conditioner described in Japanese Patent Application Laid-Open No. 2000-121089 as an example of a so-called ceiling-embedded air conditioner. In these drawings, 1 is a box-shaped unit body constituting a casing of an air conditioner, and 2 is a centrifugal fan. The centrifugal fan 2 is disposed in the unit main body 1 so as to be rotatable by a motor 3. Reference numeral 4 denotes a heat exchanger disposed in the unit main body 1 so as to surround the outer periphery of the centrifugal fan 2.
[0003]
Reference numeral 5 denotes a pair of rectifying plates, and these rectifying plates 5 are respectively located at positions where the centrifugal fan 2 and the heat exchanger 4 are closest to each other, that is, a center line of the centrifugal fan 2 and a straight portion of the heat exchanger 4. Is disposed at a position on the downstream side in the air blowing direction from a position (indicated by reference numeral A in FIG. 10) at which the angle is orthogonal. Each rectifying plate 5 is attached to the inner surface of the heat exchanger 4 so as to extend straight from the top plate 1a side of the unit body 1 to the lower side of the unit body 1 (the panel 7 side described later). That is, each rectifying plate 5 is provided such that its plate surface is parallel to the rotational axis direction (vertical direction) of the centrifugal fan 2.
[0004]
A drain pan 6 is disposed below the heat exchanger 4. Further, a panel 7 is arranged at the lower part of the unit body 1 so as to cover all the constituent elements indicated by the reference numerals 2 to 6 accommodated in the unit body 1 from below. The panel 7 is formed with a suction port 8 for sucking indoor air at the center thereof, and in the vicinity of the outer peripheral edge of the panel 7 is a blowout port for blowing out the air heat-exchanged inside the unit body 1 into the room. 9 is formed.
[0005]
Next, the operation will be described. When electric power is supplied to the motor 3, the centrifugal fan 2 attached to the motor 3 is driven to rotate, and indoor air is sucked into the unit body 1 from the suction port 8. The sucked air is blown out from the centrifugal fan 2 toward the heat exchanger 4, passes through gaps between a large number of fins of the heat exchanger 4, and then blown out into the room from the air outlet 9.
[0006]
Note that when the centrifugal fan 2 blows out air, the blowing direction is an oblique direction inclined to the front side in the rotational direction of the fan as compared with the diameter direction of the centrifugal fan 2 as shown by an arrow in FIG. On the other hand, in the vicinity of the position A where the centrifugal fan 2 and the heat exchanger 4 are closest, the fin direction of the heat exchanger 4 is substantially parallel to the diameter direction of the centrifugal fan 2. Therefore, in this vicinity, an air flow having a high flow velocity passes obliquely with respect to the fins of the heat exchanger 4 (impacts against the fins from an oblique direction), and wind noise (hulu-hurle / fluid noise) is likely to be generated. Therefore, in this prior art, by arranging the rectifying plate 5 as described above, the air flow is guided to the heat exchanger 4 and the flow velocity of the air flow when colliding with the fins by the rectifying plate 5 is reduced. Therefore, wind noise is reduced.
[0007]
[Problems to be solved by the invention]
However, the conventional air conditioner has the following problems.
That is, from the viewpoint of the effect of reducing wind noise (humur sound / fluid sound), it is desirable to arrange the rectifying plate 5 close to the position A where the centrifugal fan 2 and the heat exchanger 4 approach each other. However, when the current plate 5 is moved closer to the position A, wind noise can be reduced, but the distance between the blades of the centrifugal fan 2 and the current plate 5 is reduced. And since the blade | wing of the centrifugal fan 2 and the baffle plate 5 used as an obstacle approach, a sudden pressure change (rise / fall) arises in the vicinities of the baffle plate 5 with the passage of the blade, and is generated by the influence. The so-called NZ sound (interference sound / rotation sound between the air pushed out by the blades of the centrifugal fan 2 and the rectifying plate 5) increases.
[0008]
On the other hand, when the rectifying plate 5 is moved away from the position A where the centrifugal fan 2 and the heat exchanger 4 approach each other to the downstream side in the air blowing direction of the centrifugal fan 2, NZ noise can be reduced. In the vicinity of the position A, wind noise generated when an air flow having a high flow velocity blows on the fins from an oblique direction increases.
[0009]
Because of the above, conventionally, only one of the noise of wind noise (Hulhur sound / fluid sound) and NZ sound (rotating sound) can be selectively suppressed, and both of these noises can be suppressed. There was a problem that it was very difficult.
[0010]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an air conditioner capable of suppressing both wind noise and NZ noise.
[0011]
[Means for Solving the Problems]
To achieve the above object, the present invention includes a box-shaped unit body, a centrifugal fan provided in said unit body rotation axis direction substantially perpendicular direction, said unit main body so as to surround the outer periphery of the centrifugal fan In an air conditioner provided with a heat exchanger provided inside, and a rectifying plate protruding from the inner surface of the heat exchanger and rectifying the flow of wind from the centrifugal fan,
The rectifying plate, the intermediate portion of the either one end of the vertical direction are disposed so than the other end portion positioned in the air blowing direction downstream side of the centrifugal fan, and at least the vertical direction Is configured in an inclined portion inclined from a direction perpendicular to the rotational axis direction of the centrifugal fan,
The rectifying plate has an upper end portion and a lower end portion formed substantially parallel to the rotation axis direction of the centrifugal fan, and is attached to the heat exchanger via an attachment portion formed integrally with the upper end portion and the lower end portion. It is attached .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 of the Invention
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In this embodiment, the present invention is applied to a ceiling-embedded air conditioner. In FIGS. 1 and 2, reference numeral 1 denotes a box-shaped unit main body, and 2 denotes a centrifugal fan accommodated in the unit main body 1. is there. Reference numeral 3 denotes a motor that rotationally drives the centrifugal fan 2, and the rotational axis directions of the motor 3 and the centrifugal fan 2 are substantially vertical (vertical direction). Reference numeral 10 denotes a blade of a centrifugal fan.
[0015]
Reference numeral 4 denotes a heat exchanger formed in a substantially U shape in plan view from a pair of opposing linear portions 4a and a curved portion 4b connecting the linear portions 4a. The heat exchanger 4 is disposed inside the unit main body 1 so as to surround the outer periphery of the centrifugal fan 2 at a position where the distance between the inner surface of each linear portion 4a and the outer peripheral surface of the centrifugal fan 2 is equal to each other. .
[0016]
Reference numeral 51 denotes a pair of rectifying plates having a bent shape as shown in FIG. 3, and these rectifying plates 51 are located at a position where the centrifugal fan 2 and the heat exchanger 4 are closest to each other, that is, a center line of the centrifugal fan 2. The heat exchanger 4 is provided at a position on the downstream side in the air blowing direction of the centrifugal fan 2 with respect to the position where the straight portion 4a of the heat exchanger 4 is orthogonal (indicated by symbol A in FIG. 1). These positions are portions where the flow velocity of the wind blown from the centrifugal fan 2 is fast.
[0017]
As shown in FIG. 3, an intermediate portion in the vertical direction (longitudinal direction) of each rectifying plate 51 is an inclined portion 5 a whose plate surface is inclined with respect to the rotation axis direction (substantially vertical direction) of the centrifugal fan 2. . Further, the upper end portion 5b continuous above the inclined portion 5a and the lower end portion 5c continuous below the inclined portion 5a are formed so that their plate surfaces are substantially parallel to the rotational axis direction of the centrifugal fan 2, respectively. Has been. Moreover, the upper end part 5b and the lower end part 5c are integrally formed with an attachment part 5d to the heat exchanger 4, respectively. Each attachment portion 5d is formed with a recess 5e that fits into the pipe of the heat exchanger 4 and is cut out.
[0018]
Each rectifying plate 51 pushes the upper and lower attachment portions 5d into the vertical gaps formed between the fins (not shown) of the straight portion 4a with respect to the heat exchanger 4, and the heat exchanger 4 is inserted into the respective recesses 5e. By fitting a pipe (not shown) extending in the horizontal direction, the heat exchanger 4 is attached so as to protrude from the inner surface. And in this attachment state, the upper end part 5b of the baffle plate 51 is located in the ventilation direction downstream of the centrifugal fan 2 rather than the lower end part 5c. That is, when viewed in the blowing direction of the centrifugal fan 2, the lower end 5c is located downstream of the position A, and the upper end 5b is located downstream of the lower end 5c. The lower end 5c and the upper end 5b Is connected by an inclined portion 5a. Further, when viewed in the vertical direction, each rectifying plate 51 extends from the top plate 1 a of the unit body 1 to a height position corresponding to the lower end of the air discharge port of the centrifugal fan 2.
[0019]
A drain pan 6 is disposed below the heat exchanger 4. Further, a panel 7 is arranged at the lower part of the unit body 1 so as to cover all the constituent elements indicated by the reference numerals 2 to 6 accommodated in the unit body 1 from below. The panel 7 is formed with a suction port 8 for sucking indoor air at the center thereof, and in the vicinity of the outer peripheral edge of the panel 7 is a blowout port for blowing out the air heat-exchanged inside the unit body 1 into the room. 9 is formed.
[0020]
Next, the operation will be described. When electric power is supplied to the motor 3, the centrifugal fan 2 attached to the motor 3 is rotationally driven around the vertical axis, and indoor air is sucked into the unit body 1 from the suction port 8. The centrifugal fan 2 sucks air in the direction of the rotation axis from the suction port 8 and discharges the sucked air substantially in the radial direction. Therefore, the air sucked into the unit main body 1 from the suction port 8 is blown out from the centrifugal fan 2 toward the heat exchanger 4 and passes through the gaps between the numerous fins of the heat exchanger 4. It blows out from 9 toward the room. The heat exchanger 4 is connected to a refrigerant compressor, an outdoor heat exchanger, etc., which are not shown, by a refrigerant pipe to form a refrigerant circuit, and a gap between the refrigerant flowing in the pipe of the heat exchanger 4 and the fins. The air is cooled or heated by exchanging heat with air passing through.
[0021]
Here, normally, when the air sucked by the centrifugal fan 2 is blown out toward the heat exchanger 4, an air flow (wind) having a high flow velocity collides with the fins of the heat exchanger 4 from an oblique direction, and wind noise is generated. (Hulhur sound / fluid sound) occurs. However, in the air conditioner of this embodiment, wind noise is suppressed by the rectifying plate 51 attached to the heat exchanger 4 acting as follows. That is, as described above, the flow velocity of the wind blown from the centrifugal fan 2 on the downstream side in the blowing direction from the position A where the center line of the centrifugal fan 2 and the pair of linear portions 4a of the heat exchanger 4 are orthogonal to each other is as described above. It is arrange | positioned so that the upper end part 5b by the side of the top plate 1a of the unit main body 1 may be located in the ventilation direction further downstream rather than the lower end part 5c by the side of the panel 7. Therefore, on the upstream side of the rectifying plate 51, the flow velocity of the wind blown from the centrifugal fan 2 is reduced, and wind noise can be suppressed. In addition, the flow of the wind hits the rectifying plate 51 on the downstream side of the rectifying plate 51, the flow velocity is reduced and the direction of the flow is changed, and the flow is guided to the heat exchanger 4, so that the wind noise is generated. Can be suppressed.
[0022]
Further, although the lower end portion 5c of the rectifying plate 51 is arranged relatively close to the position A, the inclined portion 5a following the lower end portion 5c is inclined so as to gradually move away from the position A. Since the upper end portion 5b is disposed at the most downstream position, the portion of the centrifugal fan 2 that is close to the blades 10 is small when viewed as the entire rectifying plate 51, and the change in the wind direction is caused by the inclined portion 5a. As a result, a rapid pressure change (up / down) accompanying the passage of the blade 10 is unlikely to occur. Therefore, so-called NZ sound (interference sound / rotation sound between the air pushed out by the blades of the centrifugal fan 2 and the rectifying plate 51) generated due to the pressure change can be suppressed.
[0023]
In this embodiment, by setting the rectifying plate 51 as described above, both the wind noise and the NZ noise can be suppressed to the extent shown in FIGS.
That is, FIG. 8 shows the noise value in the low frequency band mainly including the NZ sound, and FIG. 9 shows the noise value in the high frequency band mainly including the wind noise. In both figures, the solid line represents the noise value in the present invention (this embodiment), and the fine broken line represents the noise value of the conventional product (when the same rectifying plate as that of the prior art shown in FIGS. 10 and 11 is provided). The rough broken lines indicate the noise values when no current plate is provided.
[0024]
First, the NZ sound will be described. As shown by an arrow a in FIG. 8, the NZ sound (generated with an abrupt pressure change due to an obstacle near the centrifugal fan 2) is conspicuous in the conventional product. On the other hand, in the present invention, only the same level of noise is generated as when there is no current plate. This is because when the current plate is placed straight (vertically) from the upper end to the lower end as in the conventional product, it becomes a state where the wind flow is blocked at a stretch in a large area, and a sudden pressure change On the other hand, if the rectifying plate 51 is disposed obliquely as in this embodiment, an action that gradually increases the area for blocking the ridge occurs, and the pressure in the vicinity of the rectifying plate 51 is generated. This is an effect that is obtained because the change in is moderate.
[0025]
On the other hand, with regard to wind noise, as shown in FIG. 9 surrounded by an ellipse b, the conventional product is slightly more wind noise (Hururu sound: obstacle is near the position A) than the present invention. It is superior in the effect of suppressing. This is a trivial result because the wind noise can be suppressed as the current plate is moved closer to the position A. However, it can be said that both the present invention and the conventional product can sufficiently suppress the wind noise compared to the case where the current plate is not provided.
When viewed as the total noise of the wind noise and the NZ sound, the difference in the magnitude of the wind noise between the present invention and the conventional product is so small that it can be ignored compared to the NZ sound of the conventional product. I understand that. That is, in the present invention, the generation of NZ noise can be greatly reduced, and the wind noise can be suppressed to the same level as that of the conventional product. Therefore, when viewed comprehensively, it can be said that the present invention has a greater effect of suppressing noise than the conventional product.
[0026]
Embodiment 2 of the Invention
In the first embodiment, the rectifying plate 51 has a bent shape as shown in FIG. 3, but from the standpoint of the effect of suppressing noise, the rectifying plate 51 is replaced with the rectifying plate 51 shown in FIG. As described above, it is more effective to provide the rectifying plate 52 having an inclined shape as a whole. That is, it can be said that the entire rectifying plate 52 is configured as an inclined portion that is inclined with respect to the rotation axis direction of the centrifugal fan 2, and the change in the air flow (wind direction) can be made smoother. It is.
However, in this baffle plate 52, the attachment part 5d integrally formed at the upper and lower ends thereof is also inclined, so that attachment to the heat exchanger 4 is difficult. That is, the fins of the heat exchanger 4 generally extend in the vertical direction (direction parallel to the rotation axis direction of the centrifugal fan 2), and the gap between the fins is as narrow as about 1 mm, so that the gap is inclined. When the attachment portion 5d is pushed in, there may be a situation in which a part of the fin has to be cut out. On the other hand, in the rectifying plate 51 of FIG. 3, the upper and lower attachment portions 5d are parallel to the direction of the rotation axis of the centrifugal fan 2, and therefore can be easily pushed into the gap between the fins.
[0027]
Embodiment 3 of the Invention
Further, instead of the rectifying plate 51 of FIG. 3, it is conceivable to provide a rectifying plate 53 having a curved shape as shown in FIG. The rectifying plate 53 is formed in an inclined portion 5a whose intermediate portion in the vertical direction is inclined with respect to the rotational axis direction of the centrifugal fan 2, and substantially parallel to the rotational axis direction of the centrifugal fan 2 above and below the inclined portion 5a. The upper end portion 5b and the lower end portion 5c are connected to each other, and the inclined portion 5a, the upper end portion 5b, and the lower end portion 5c are each formed into a smooth curved surface. In this rectifying plate 53, the attachment portion 5d can be easily pushed into the gap between the fins and attached to the heat exchanger 4, and since the overall shape is smooth, the air flow can be changed smoothly. Also, it has excellent noise suppression effect.
[0028]
In addition, it cannot be overemphasized that embodiment of this invention is not limited by the above description, For example, although the above demonstrated the case where this invention was applied to the air conditioner provided with the heat exchanger 4 of planar view U shape. Even if the present invention is applied to an air conditioner including a heat exchanger 4 having a shape other than a U-shape as shown in FIGS. 6 (a) and 6 (b), it is almost the same as the above embodiments. Similar effects can be obtained.
In the above description, the present invention is applied to a ceiling-embedded air conditioner. However, the present invention can be applied to various types of air conditioners such as a ceiling suspended type.
[0029]
Further, the shape of the side surface of the current plate can be arbitrarily changed. In addition to the current plate having a constant width from the upper end to the lower end as shown in FIG. 7A, for example, as shown in FIG. Various shapes of rectifying plates such as a trapezoidal rectifying plate and a rectifying plate having a non-constant width as shown in FIG. 7C can be adopted. Further, these rectifying plates can be used by being bent as shown in FIGS. 3 and 5 in addition to making the whole slanted as shown in FIG. Furthermore, the bending shape when the current plate is bent is arbitrary, and for example, it is conceivable that the shape viewed from the front (center side of the centrifugal fan 2) is stepped.
[0030]
Moreover, although the upper end part 5b of the baffle plate was distribute | arranged downstream rather than the lower end part 5c with respect to the ventilation direction of the centrifugal fan 2 above, the lower end part 5c has the lower end part 5c from the upper end part 5b on the contrary. Even if it is disposed so as to be located downstream in the blowing direction, the same effect as described above can be obtained.
[0031]
【The invention's effect】
As described above, according to the present invention, a low-noise air conditioner that suppresses both wind noise and NZ sound can be obtained.
[0032]
In addition, since at least the middle part of the rectifying plate in the vertical direction is an inclined portion, the change in the air flow direction in the vicinity of the rectifying plate becomes smooth, and further noise reduction can be achieved.
[0033]
In addition, the current plate is attached to the heat exchanger through an attachment part formed integrally with the upper end and the lower end substantially parallel to the centrifugal fan rotation axis direction, so that the current plate can be easily attached to the heat exchanger. It becomes.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an air conditioner according to Embodiment 1 of the present invention.
FIG. 2 is a longitudinal sectional view of the air conditioner according to Embodiment 1 of the present invention.
3A and 3B are diagrams showing a current plate according to Embodiment 1 of the present invention, in which FIG. 3A is a side view and FIG. 3B is a front view.
4A and 4B are diagrams showing a current plate according to Embodiment 2 of the present invention, in which FIG. 4A is a side view and FIG. 4B is a front view.
5A and 5B are diagrams showing a current plate according to Embodiment 3 of the present invention, in which FIG. 5A is a side view and FIG. 5B is a front view.
FIG. 6 is an explanatory plan view showing another embodiment of the heat exchanger used in the air conditioner according to the present invention.
FIG. 7 is a side view showing another form of the current plate.
FIG. 8 is a graph showing measured values of noise in a low frequency band mainly including NZ sounds.
FIG. 9 is a graph showing measured values of noise in a high frequency band mainly including wind noise.
FIG. 10 is a cross-sectional view of a conventional air conditioner.
FIG. 11 is a longitudinal sectional view of a conventional air conditioner.
[Explanation of symbols]
1 unit body, 2 centrifugal fan, 4 heat exchanger, 51, 52, 53 current plate, 5a inclined portion, 5b upper end portion, 5c lower end portion, 5d attachment portion.

Claims (1)

A box-shaped unit main body, a centrifugal fan provided in the unit main body with the rotation axis direction being substantially vertical, a heat exchanger provided in the unit main body so as to surround the outer periphery of the centrifugal fan, In an air conditioner provided with a rectifying plate protruding from the inner surface of the heat exchanger and rectifying the flow of wind from the centrifugal fan,
The rectifying plate is disposed so that one of the ends in the vertical direction is located downstream of the other end in the air blowing direction of the centrifugal fan, and at least an intermediate portion in the vertical direction Is configured in an inclined portion inclined from a direction perpendicular to the rotational axis direction of the centrifugal fan ,
The rectifying plate has an upper end portion and a lower end portion formed substantially parallel to the rotation axis direction of the centrifugal fan, and is attached to the heat exchanger via an attachment portion formed integrally with the upper end portion and the lower end portion. An air conditioner characterized by being attached .

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