JP2001099436A - Air conditioner flush with ceiling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner flush with ceiling, possessing high fan air efficiency with reduced air fan noise from a centrifugal fan in a heat exchanger. SOLUTION: A panel is mounted on a lower surface of a body buried in a ceiling surface, the panel including a suction hole at the center of the panel and blow-off outlets provided at four sides surrounding the suction hole. A centrifugal fan 7 is provided on an upper portion of said suction hole for blowing off to an outer periphery air sucked from the suction hole. A fin tube type heat exchanger 9 is provided around the centrifugal fan 7 to blow off air passing through the heat exchanger 9 from the blow-off outlet. There are further provided a plurality of wind guide plates 10 inclined oppositely to the rotation of the centrifugal fan 7 inside the heat exchanger 9 and substantially parallel top each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceiling-mounted air conditioner, and more particularly, to an arrangement for guiding air blown from a centrifugal fan to a heat exchanger.

[0002]

2. Description of the Related Art As shown in, for example, Japanese Patent Application Laid-Open No. 9-236276, a conventional ceiling-mounted air conditioner includes a centrifugal fan, a heat exchanger, In order to prevent interference noise when the separated vortex generated from the wing tip of the centrifugal fan flows between the fins of the heat exchanger, a rectifying member with It was a configuration arranged inside the heat exchanger.

[0003]

However, in the above configuration, since the plate-like member having the ventilation port covers the inside of the heat exchanger, there is a problem that ventilation resistance is increased and ventilation efficiency is reduced. Was. In view of the above problems, an object of the present invention is to provide a ceiling-embedded air conditioner that has a low blowing noise from a centrifugal fan in a heat exchanger and has a high blowing efficiency.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a panel in which a suction port is provided in the center on the lower surface of a main body embedded in a ceiling surface, and air outlets are provided on four sides around the suction port. A centrifugal fan that blows air sucked from the suction port to the outer periphery is provided above the suction port, and a fin tube type heat exchanger is provided around the centrifugal fan,
In the ceiling-mounted air conditioner, in which the air that has passed through the heat exchanger is blown out from the outlet, a plurality of substantially parallel plurality of inclined inside the heat exchanger in a direction opposite to a rotation direction of the centrifugal fan. It has a configuration in which a wind guide plate is provided.

The heat exchanger surrounds the centrifugal fan in a rectangular shape, and the air guide plate is provided substantially at the center of four sides of the heat exchanger.

Further, the air guide plate is formed in a curved shape bulging inward.

In addition, the upper and lower ends of the plurality of air guide plates are connected by a connection plate.

Further, a C-shaped engaging claw for holding the heat transfer tube of the heat exchanger projects from one end of the air guide plate.

[0009] Further, a concave portion is formed on both upper and lower sides of the locking claw.

[0010] Further, a plurality of the locking claws are formed on the plurality of wind guide plates.

[0011] Further, at least one of the plurality of wind guide plates may be positioned at an upper and lower diagonal position between two different wind guide plates.
It is configured to be formed one by one.

Further, the air guide plate, the connecting plate, and the locking claws are integrally formed of synthetic resin.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the embodiments of the present invention shown in FIGS. First, as shown in the overall configuration diagram of the ceiling-embedded air conditioner of FIG. 1, 1 is a main body embedded in the ceiling surface, 2 is a lower surface of the main body 1, and a suction port 3 for taking indoor air into the center. A panel provided with air outlets 5 provided with wind direction plates 4 on four sides; a suction grill 6 provided with a filter 6a on the inner side covering the inlet 3;
Reference numeral 7 denotes a centrifugal fan provided above the suction port 3 and driven by a drive motor 8. Reference numeral 9 denotes a heat exchanger provided so as to surround the centrifugal fan 7 in a rectangular shape. Reference numeral 10 denotes four sides of the heat exchanger 9. This is a baffle plate made of a synthetic resin such as ABS (acrylonitrile butadiene styrene) provided substantially at the center inside.

FIG. 2 is a perspective view of a main part (some parts are not shown).
As shown in FIG. 3 and a cross-sectional view of the main part of FIG. 3, 11 protrudes integrally from the end face of the air guide plate 10 and is formed in a C-shape so as to grip the heat transfer tube 12 of the heat exchanger 9. With locking claws,
A curved concave portion 1 is provided on both upper and lower sides of the locking claw 11 so that the locking claw 11 is fitted and held between the heat transfer tubes 12.
3 are formed. Reference numeral 14 denotes a connecting plate which connects the upper and lower ends of three substantially parallel air guide plates 10 provided substantially in the center of each side of the rectangular heat exchanger 9 and which are integrally formed with each other. Stop pawls 11 are connected to the three air guide plates 1
At least one is formed at the upper and lower oblique positions of the air guide plate 10 at both ends of the zero.

As shown in the sectional view of the main part of FIG. 4, reference numeral 15 denotes a plurality of rotors of the centrifugal fan 7, which rotate counterclockwise in FIG. It is inclined in the direction opposite to the rotation direction of the centrifugal fan 7 and is formed into a curved surface bulging inward.

Next, the operation and effect of the above configuration will be described with reference to FIG. 1 to FIG. 4 and FIG. 5 to FIG. Near the center of the inside of each side of the rectangular heat exchanger 9 is a portion where the outer peripheral tip of the rotary blade 15 of the centrifugal fan 7 is close to the heat exchanger 9. Due to the effects of the downsizing of the harmony machine and the high performance of the centrifugal fan, the wind speed is increasing as the vehicle is getting closer. The blow-out wind a of the centrifugal fan 7 is a tangential flow in the rotation direction. Blowing wind a between the provided fins 16
Changes rapidly in order for the wind speed to pass, and the wind speed V
Is large, the Reynolds number at the passing portion (Re = VL /
Since ν) increases, turbulence increases, which causes an increase in blowing noise and a reduction in blowing efficiency.

In response to such a phenomenon, the blowing wind a
Since the blowing air a flows into a narrow space of the baffle plate 10 before the fin 16 suddenly changes its direction by providing the baffle plate 10 inclined in a direction opposite to As L becomes smaller, the Reynolds number (R
e = VL / ν) is reduced, the turbulence is reduced, the blowing noise is reduced, and the blowing efficiency can be increased. Note that ν
Represents the kinematic viscosity coefficient of the blown air, and ν = μ / ρ, which is obtained from the viscosity coefficient μ of the blown air and the density ρ.

Further, by forming the air guide plate 10 into a curved surface bulging inward, the direction of the blow-out air a is gradually changed in the direction of the fins 16, so that a sudden change in direction is eliminated. Thus, the turbulent flow generated when the blown wind a collides with the fins 16 can be eliminated, and further, the blowing noise can be reduced and the blowing efficiency can be increased. Since the heat exchanger 9 has a rectangular shape, the approximate center of the inside of each of the four sides is close to the centrifugal fan 7, so that the air guide plate 10 needs to be provided at the approximate center of all the sides.

Various characteristic graphs obtained by measuring the effect of the present invention are shown in FIGS. FIG. 5 is a characteristic graph showing the relationship between the sound pressure level and the frequency based on the result of the 1/3 octave analysis at the same blowing air volume.
The characteristic when there is 0, and the characteristic b2 when there is no baffle plate 10. Compared to the case without the air guide plate 10, the high-frequency component that is more easily recognized as noise on the auditory sense
It can be seen that the sound pressure between 630Hz and 10kHz has decreased.

FIG. 6 is a characteristic graph of the noise level (A characteristic) when the air volume is changed.
And c2 is the characteristic without the baffle plate 10. It can be seen that in the case of the same air volume, the noise level is lower by about 0.5 dB to 1 dB than in the case where the air guide plate 10 is not present at any air volume.

FIG. 7 is a characteristic graph of the air flow when the number of revolutions of the centrifugal fan 7 is changed, where d1 is the characteristic when the air guide plate 10 is provided, and d2 is the characteristic when the air guide plate 10 is not provided. It is a characteristic. In the case of the same rotation speed, it can be seen that the air volume is increased by about 50 ° / h as compared with the case without the air guide plate 10 at any rotation speed.
As described above, it is clearly understood that the presence of the air guide plate 10 reduces the blowing noise and increases the blowing efficiency.

The upper and lower ends of the three air guide plates 10 are connected by the connection plates 14, and the locking claws 11 are connected to the upper and lower outer air guide plates of the three air guide plates 10. The two locking claws 11 are formed one by one at an oblique position.
Thus, the heat transfer tube 12 of the heat exchanger 9 can be gripped and attached, and since the two locking claws 11 are only two at oblique positions, even if the pitch of the two locking claws 11 is slightly shifted, The air guide plate 10 can be attached by only slightly tilting, and there is no need to make the dimensional accuracy too strict. By providing a large number of the locking claws 11 such as four at the top, bottom, left and right, it is possible to securely fix without vibrate due to vibration.

As a configuration for attaching the air guide plate 10, a method in which one end is fixed by the locking claw 11 and the connecting plate 14 at the other end is screwed to the main body 1 is also conceivable. When performing a drop test with a simple configuration,
This is not an appropriate method because a large force acts on the main body 1 to move the heavy heat exchanger 9 with respect to the main body 1 due to the impact, and the locking claw 11 or the screwed portion is damaged. The method of fixing to the heat exchanger 9 only by the locking claw 11 as in the present invention is appropriate.

By forming the curved concave portions 13 on both upper and lower sides of the locking claw 11, not only the holding claws 11 can grip the heat transfer tube 12, but also the heat transfer tubes 1 can be formed.
2 can be fitted with the locking claw 11,
The position of the air guide plate 10 can be changed by a half pitch of the interval between the heat transfer tubes 12 in the vertical direction, and can be attached to a more appropriate position.

By integrally forming the air guide plate 10, the locking claw 11, and the connecting plate 14 with a synthetic resin such as ABS (acrylonitrile butadiene styrene),
Since the dimensional accuracy of each part can be managed on a component basis, dimensional accuracy can be easily obtained, and the configuration can be made at low cost.

[0026]

As described above, according to the present invention,
Low ventilation noise from centrifugal fan in heat exchanger,
And it will be a ceiling-mounted air conditioner with high ventilation efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of a ceiling-mounted air conditioner according to the present invention.

FIG. 2 is a perspective view of a main part showing one embodiment of the ceiling-mounted air conditioner according to the present invention.

FIG. 3 is a cross-sectional view of an essential part showing an embodiment of a ceiling-embedded type air conditioner according to the present invention, wherein (A) shows a case where locking claws are fitted between heat transfer tubes, and (B) shows locking. This is a case where the heat transfer tube is gripped by claws.

FIG. 4 is a cross-sectional view of a principal part showing an embodiment of an embedded ceiling air conditioner according to the present invention.

FIG. 5 is a characteristic graph showing a relationship between a sound pressure level and a frequency based on a result of a 1/3 octave analysis at the same blowing air volume in a case where a baffle plate of the present invention is provided and a case where a baffle plate is not provided.

FIG. 6 is a characteristic graph of a noise level (A characteristic) when the air volume is changed, comparing the case with and without the air guide plate of the present invention.

FIG. 7 is a characteristic graph of the air volume when the number of rotations is changed, comparing the case with and without the air guide plate of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Panel 3 Suction port 5 Air outlet 7 Centrifugal fan 9 Heat exchanger 10 Baffle plate 11 Locking claw 12 Heat transfer tube 13 Concave part 14 Connection plate

Claims (9)

[Claims] 1. A panel provided with a suction port at the center and a vent on four sides around the suction port is attached to the lower surface of the main body embedded in the ceiling surface, and a suction port is provided above the suction port from the suction port. Centrifugal fan that blows the blown air to the outer periphery, a fin tube-type heat exchanger is provided around the centrifugal fan, and the air that has passed through the heat exchanger is blown out from the blow-out port. The ceiling-mounted air conditioner according to any one of claims 1 to 3, further comprising a plurality of substantially parallel air guide plates inclined in a direction opposite to a rotation direction of the centrifugal fan inside the heat exchanger. 2. The heat exchanger according to claim 1, wherein the heat exchanger surrounds the centrifugal fan in a rectangular shape, and the air guide plate is provided substantially at the center inside four sides of the heat exchanger. The ceiling-mounted air conditioner described. 3. The ceiling-mounted air conditioner according to claim 1, wherein the air guide plate is formed in a curved shape protruding inward. 4. The embedded ceiling air conditioner according to claim 1, wherein upper and lower ends of the plurality of air guide plates are connected by a connection plate. 5. The ceiling-mounted air conditioner according to claim 4, wherein a C-shaped engaging claw for gripping a heat transfer tube of the heat exchanger projects from one end of the air guide plate. . 6. The ceiling-embedded air conditioner according to claim 5, wherein concave portions are formed on both upper and lower sides of the locking claw. 7. The air conditioner according to claim 5, wherein a plurality of the locking claws are formed on the plurality of air guide plates. 8. The ceiling pad according to claim 7, wherein at least one locking claw is formed at an upper and lower diagonal position of two different air guide plates among the plurality of air guide plates. Built-in air conditioner. 9. The ceiling-mounted air conditioner according to claim 5, wherein the air guide plate, the connecting plate, and the locking claw are integrally formed of synthetic resin.