JP2012072926A - Indoor unit for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce air blowing noise, in an indoor unit for an air conditioner, including an electrical component box provided below a bell mouth.SOLUTION: This indoor unit for the air conditioner includes: a centrifugal blower 7; the electrical component box 14 provided on the suction side of the centrifugal blower; and the bell mouth 10 provided between the centrifugal blower and the electrical component box. The bell mouth is provided with: a flat plate 17 formed with an opening 31 having a smaller diameter than the suction opening 28 of the centrifugal blower and also placing the electrical component box thereon; a projecting member 15 projecting from the opening of the flat plate to the side of the centrifugal blower; and a guide member 16 located on the periphery of the projecting member and projecting from the flat plate to a side opposite to the centrifugal blower. The guide member sets a height from the flat plate so that a direction of air passed through the opening from the peripheral side of the bell mouth and sucked in the centrifugal blower is gradually changed.

Description

  The present invention relates to an indoor unit of an air conditioner.

  There are many types of indoor units for air conditioners, in which a casing is embedded in a ceiling, and air is sucked and blown out through a decorative panel installed on the ceiling surface. In the housing, the suction side of the centrifugal blower has a low pressure, and the discharge side has a high pressure. For this reason, the air sucked into the centrifugal blower and the air blown out from the centrifugal blower are partitioned by a bell mouth. Moreover, the bell mouth is provided in order to flow air smoothly to a centrifugal blower. Furthermore, the parts requiring maintenance such as electrical parts can be easily taken out by placing them on the low pressure side below the bell mouth.

  In order to dispose the electrical parts below the bell mouth, the flat portion of the bell mouth may be offset upward. However, since the shape of the bell mouth is complicated, the mold structure of the bell mouth is also complicated.

  The bell mouth of patent document 1 provides the thick part in the protrusion part which protrudes to the air inlet side, and forms the impeller side of the bell mouth on the same plane. As a result, the bell mouth and the mold do not have a complicated structure. It is described that sinks are likely to occur in the thick part where the resin is thickened, but that the thick part can be formed with high accuracy with a simple mold structure by providing a slit for preventing the sink.

JP 2001-124360 A

  However, the bell mouth of Patent Document 1 has a limit in increasing the thickness because the protruding portion, which is an air guide portion, is filled with resin. For this reason, since the curvature of the inlet side of a bellmouth cannot be made small and peeling of the flowing air cannot be reduced, there is a problem that a blowing sound is generated.

  An object of the present invention is to reduce blowing noise.

  In order to achieve the above object, the present invention includes a centrifugal fan, an electric box provided on the suction side of the centrifugal fan, and a bell mouth provided between the centrifugal fan and the electric box. In the indoor unit of the air conditioner, the bell mouth is provided with an opening having a diameter smaller than the suction port of the centrifugal blower and a flat plate on which the electrical component box is placed, and the centrifugal blower from the opening. A projecting member projecting to the side, and a guide member projecting from the flat plate to the opposite side of the centrifugal blower on the outer periphery of the projecting member, the guide member opening from the outer periphery side of the bell mouth The height from the flat plate is set so that the air sucked into the centrifugal blower through the section gradually changes its direction.

  According to the present invention, the blowing sound can be reduced.

(Example 1) which is sectional drawing of the indoor unit of an air conditioner. It is the perspective view which looked at the bell mouth from the anti-centrifugal blower side (Example 1). (Example 1) which is the perspective view which attached the electrical component box to the bellmouth. (Example 1) which was the perspective view which looked at the bellmouth from the centrifugal-blower side. (Example 1) which is AA cross-section arrow view of a bellmouth. It is sectional drawing which shows the flow of the air in a bell mouth (comparative example). (Example 1) which is sectional drawing which shows the flow of the air in a bell mouth. It is the perspective view which looked at the bellmouth from the anti-centrifugal blower side (Example 2). (Example 2) which is a BB cross-sectional arrow view of a bellmouth. (Example 2) which is sectional drawing which shows the flow of the air in a bellmouth. It is the perspective view which looked at the bell mouth from the anti-centrifugal blower side (Example 3). It is the perspective view which looked at the bell mouth from the anti-centrifugal blower side (Example 3). (Example 4) which is the perspective view which looked at the bellmouth from the anti-centrifugal blower side.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of an indoor unit of an air conditioner in the first embodiment. The indoor unit connects the decorative panel 1 and the housing 2. The decorative panel 1 includes a suction grill 3 at the center, and a blow-out port 5 around the suction grill 3. The air outlet 5 includes a wind direction plate 4. The motor 6 is installed in the housing, and the motor 6 is driven to rotate the centrifugal blower 7. As indicated by an arrow 8, room air is sucked into the centrifugal blower 7 from the suction port 28 through the suction grill 3, the filter 9 installed in the suction grill 3, and the bell mouth 10 installed in the housing. The bell mouth 10 guides room air to the centrifugal blower 7. As indicated by the arrow 13, the indoor air is heat-exchanged by the heat exchanger 11, and then blown out into the room through the outlet 5.

  Condensed water is generated in the heat exchanger 11 during cooling. A drain pan 12 for receiving condensed water is installed at the lower part of the heat exchanger 11. The suction grill 3 can be detached from the decorative panel 1 together with the filter 9, and the filter 9 can be easily cleaned. An electrical component box 14 is installed on the lower surface of the bell mouth 10. The electrical component box 14 houses a control board (not shown) for controlling the operation of the indoor unit. By opening the suction grill 3, the electrical component box 14 can be easily maintained.

  FIG. 2 is a perspective view of the bell mouth 10 in the first embodiment as viewed from the anti-centrifugal blower side. The bell mouth 10 is provided with a circular opening 31 at the center of the flat plate 17. The opening 31 is provided with a cylindrical convex member 15 so as to surround the opening 31. The convex member 15 is provided so as to protrude to the centrifugal blower side. The convex member 15 has a smaller diameter than the suction port 28 of the centrifugal blower 7. On the anti-centrifugal blower side of the bell mouth 10, a guide member 16 having a diameter larger than that of the convex member 15 is provided around the convex member 15. Along with the rotation of the centrifugal blower 7, the flow becomes axisymmetric about the rotation axis. The guide member 16 has a shape in which a part of the circumference of the guide member 16 is cut out from the end on the anti-centrifugal blower side to the connecting portion with the flat plate 17 so as to have a C shape when viewed from the rotation axis direction of the motor 6. ing. By bending the outer edge of the bell mouth 10 on the side of the anti-centrifugal blower, the strength of the bell mouth is increased.

  FIG. 3 is a perspective view in which an electrical component box is attached to the bell mouth 10 in the first embodiment. The electrical component box 14 is provided on the suction side of the centrifugal blower 7. Since the air blown out from the centrifugal blower 7 is higher in pressure than the air sucked from the suction port 28, a bell mouth 10 is provided between the centrifugal blower 7 and the electrical component box 14 so that the low pressure side space and the high pressure side Partitions the space. Maintenance is also facilitated by providing the electrical component box 14 on the anti-centrifugal blower side of the bell mouth 10. When the bell mouth 10 is made smaller to make the indoor unit smaller, the electric component box 14 and the guide member 16 collide with each other, and they overlap. However, the electrical component box 14 can be installed up to the inside of the guide member 16 by deleting the overlapping guide member 16 and forming the notched shape as described above. For this reason, the indoor unit can be reduced in thickness and size. In this case, the side wall of the electrical component box 14 serves as the guide member 16.

  FIG. 4 is a perspective view of the bell mouth 10 in the first embodiment as viewed from the centrifugal fan side. On the centrifugal blower side of the bell mouth 10, the outer periphery of the convex member 15 is formed by a substantially flat plate 17, and there is no step on the back side (centrifugal blower side) of the bell mouth 10 when placing the electrical component box. . Therefore, the flow of air blown out from the centrifugal blower 7 is less likely to collide, and the blowing sound can be reduced. Even if there is a step such as screwing or the flat plate is slightly curved, it may be flat enough to reduce air collisions.

  FIG. 5 is a cross-sectional view of the bell mouth 10 taken along the line AA in the first embodiment, and shows a view in which the guide member is cut along a plane passing through the rotating shaft of the centrifugal blower. When the vertical direction in the figure is the height direction of the indoor unit, the height position of the flat plate 17 on the centrifugal blower side is constant. The convex member 15 and the guide member 16 protrude from the flat plate 17. The guide member 16 is formed such that a thin plate is bent on an arc along the circumference of the opening 31 and is erected on the flat plate 17. The height X of the guide member 16 (the length from the end of the guide member 16 on the anti-centrifugal transmitter side to the connecting portion with the flat plate 17) is from the connecting portion between the guide member 16 and the flat plate 17 to the opening 31. It is desirable that the length Y is substantially the same. The end of the convex member 15 on the centrifugal blower side reduces the thickness of the plate. The plate thickness of the inner peripheral surface of the convex member 15 is gradually reduced toward the centrifugal blower side. The end of the guide member 16 on the anti-centrifugal transmitter side, the opening 31, and the inner peripheral surface of the convex member 15 are arcs centered on the connecting portion between the guide member 16 and the flat plate 17 as indicated by a broken line. Arrange as you draw. Thereby, the air which passed the bell mouth 10 flows along the shape of the inlet_port | entrance of the centrifugal blower 7, it becomes easy to be sucked into the centrifugal blower 7, and a blowing sound can be reduced.

  FIG. 6 shows the flow of wind in the bell mouth 10 when the centrifugal blower is operated. FIG. 6a shows a comparative example, and FIG. 6b shows this example. When the guide member 16 is not provided on the anti-centrifugal blower side, the suction air 18 having a lateral flow component sucked from the end of the suction grill 3 is suddenly sucked into the centrifugal blower 7 at the opening 31 of the bell mouth 10. Can be changed. That is, since the curvature at the opening 31 is large, the air cannot bend completely. For this reason, the flow is separated from the bell mouth 10, and noise and power of the centrifugal blower 7 are increased. In particular, the air sucked into the centrifugal blower 7 through the opening 31 from the outer peripheral side of the bell mouth 10 is reduced in curvature by setting the height from the flat plate 17 so as to gradually change the direction in the bell mouth 10. It is preferable. The bell mouth 10 of the present embodiment is provided with the guide member 16 so that the air that has to rapidly change the flow direction like the suction air 18 does not flow to the convex member 15. The air that has been able to pass through the guide member 16 can gradually change its direction with a small curvature like the suction air 19 from the end of the guide member 16 on the anti-centrifugal blower side to the convex member 15. Thereby, since the flow is not peeled off by the convex member 15 and is sucked into the centrifugal blower 7, the blowing sound can be reduced.

  According to the present embodiment, the surface connecting the end of the guide member 16 on the side opposite to the centrifugal fan and the opening 31 is formed in a pseudo manner as a guide for guiding the wind to the centrifugal fan 7. For this reason, the curvature of the flow of air passing through the bell mouth 10 is reduced, and the air can flow along the convex member 15. Therefore, since the flow is difficult to peel off by the convex member 15, the blowing sound of the intake air can be reduced. Since the outer periphery of the convex member 15 is flattened on the blown air side of the bell mouth 10, it does not easily collide with the bell mouth 10 even if the air blown from the centrifugal blower 7 turns. For this reason, the blowing sound of blowing air can also be reduced. Moreover, since ventilation resistance becomes small, the motive power of the centrifugal blower 7 can also be reduced. Furthermore, since only the convex member 15 and the guide member 16 are provided on the flat plate 17, the bell mouth 10 can be easily molded.

  FIG. 7 is a perspective view of the bell mouth 20 in the second embodiment as viewed from the anti-centrifugal blower side, and FIG. 8 is a sectional view taken along the line B-B of the bell mouth 20 in the second embodiment. The figure by which the guide member was cut | disconnected by the plane which passes along an axis | shaft is shown. This embodiment is different from the first embodiment in that the guide member on the anti-centrifugal blower side is doubled. The height of the guide member 21 having a large diameter in the suction direction is determined by connecting the end of the guide member 22 having a small diameter on the side of the anti-centrifugal blower and the opening 31 of the flat plate 17 and extending from the extension line 25 extending to the side of the anti-centrifugal blower. Also lower. In other words, the end on the anti-centrifugal blower side of the outermost guide member 21 is closer to the flat plate 17 than the extension line 25 so that the extension line 25 and the guide member 21 do not intersect. The plurality of guide members are arranged so that the line connecting the end portions on the anti-centrifugal blower side of the plurality of guide members in order from the outermost periphery to the opening 31 is convex upward with the end portion of the outermost guide member 21 as the apex. Provide. If the plurality of guide members are arranged so that the end portions on the anti-centrifugal blower side of the plurality of guide members draw an arc centering on the connection portion between the guide member 21 and the flat plate 17, the separation of air can be further reduced.

  FIG. 9 shows the flow of wind in the bell mouth 10 when the centrifugal blower is operated. The air flow from the outer periphery toward the center is bent at the end of each guide member as shown by the intake air 26 in FIG. By providing a plurality of guide members, the line connecting the end portions of the guide members on the anti-centrifugal blower side to the opening 31 can be brought close to the curve of a bell mouth having a large R shape and a small curvature. Thereby, the direction of the intake air 26 can be changed more smoothly than in the first embodiment, and the air can flow along the convex member 23. For this reason, lower noise and higher efficiency can be realized as compared with the first embodiment. In this embodiment, the guide member is doubled, but it may be increased to triple or quadruple. If the number of guide members is increased, the curve can be made closer to the curve of a bell mouth with a larger curvature and a smaller curvature.

  FIG.10 and FIG.11 shows the perspective view seen from the anti-centrifugal blower side of the bellmouth 27 in 3rd Example. The bell mouth 27 in FIG. 10 fills the outer peripheral space of the guide member 29. The bell mouth 27 in FIG. 11 is provided with a guide member 30 having a smaller diameter. Providing the convex member 32 is the same as in the above embodiment.

  By filling the outer peripheral space of the guide member 29 as in this embodiment, the intake air that has passed through the intake grille 3 does not enter the outer periphery of the guide member. For this reason, it can prevent that the flow of the outer peripheral side of the guide member 29 is disturb | confused, and can further reduce the ventilation sound and the motive power of the centrifugal blower 7 rather than the said Example.

  FIG. 12: shows the perspective view which looked at the bell mouth 33 in the 4th Example from the anti-centrifugal blower side. In this embodiment, a rib 36 is provided between the guide member 34 having a small diameter and the guide member 35 having a larger diameter. Moreover, if the rib 36 is provided along the direction in which air is sucked into the centrifugal blower 7 as shown in the figure, it is difficult to inhibit the flow of the sucked air. Furthermore, if the rib 36 is made lower than or equal to the lower guide member (the guide member 34 in this embodiment) among the guide members adjacent to the rib 36, the flow of the intake air is hardly hindered. . According to the present embodiment, the rib mouth 33 can be lightened while maintaining sufficient strength because the ribs 36 are provided even if the plate thickness of the guide member is reduced.

  In the above embodiments, the bell mouth can be made of resin and integrally molded, thereby reducing the manufacturing cost.

DESCRIPTION OF SYMBOLS 1 Decorative panel 2 Case 3 Suction grill 4 Wind direction plate 5 Outlet 6 Motor 7 Centrifugal blower 8 Suction air 9 Filter 10, 20, 27 Bell mouth 11 Heat exchanger 12 Drain pan 13 Blowing air 14 Electrical box 15, 23, 32 Convex member 16, 21, 22, 29, 30, 34, 35 Guide member 17 Flat plate 18, 19, 26 Suction air 25 Extension line 28 Suction port 31 Opening 36 Rib

Claims (11)

In an indoor unit of an air conditioner comprising a centrifugal blower, an electrical component box provided on the suction side of the centrifugal blower, and a bell mouth provided between the centrifugal blower and the electrical component box,
The bell mouth is provided with an opening having a smaller diameter than the suction port of the centrifugal blower and a flat plate on which the electrical component box is placed, and a convex member protruding from the opening toward the centrifugal blower, A guide member that is an outer periphery of the convex member and protrudes from the flat plate to the opposite side of the centrifugal blower,
The air conditioner is characterized in that the guide member sets a height from the flat plate so that the air sucked into the centrifugal blower from the outer peripheral side of the bell mouth gradually changes its direction. Indoor unit of the machine.   The length from the end of the guide member opposite to the centrifugal blower to the connecting portion with the flat plate is the length from the connecting portion with the flat plate to the opening. Air conditioner indoor unit.   3. The bell mouth according to claim 1, wherein the bell mouth includes a plurality of the guide members, and the guide member having a smaller diameter among the plurality of guide members has a lower height in the suction direction. Air conditioner indoor unit.   3. The air according to claim 1, wherein the guide member has a shape in which a part of a circumference of the guide member is cut out from an end portion on the opposite side to the centrifugal blower to a connection portion with the flat plate. The indoor unit of the harmony machine.   The indoor unit of an air conditioner according to claim 1 or 2, wherein the convex member gradually decreases the thickness of the inner peripheral surface toward the centrifugal blower side.   The indoor unit of an air conditioner according to claim 1 or 2, wherein a space on an outer peripheral side of the guide member is filled.   4. The centrifugal blower of another guide member having a smaller diameter than a guide member which is an outermost periphery among the plurality of guide members when the bell mouth is cut along a plane passing through a rotation axis of the centrifugal blower. The end of the guide member on the outermost side opposite to the centrifugal blower is closer to the flat plate than the extended line that extends the line connecting the end on the opposite side and the opening to the outer peripheral side. An air conditioner indoor unit characterized by that.   The indoor unit of an air conditioner according to claim 3, wherein a space on the outer peripheral side of the outermost guide member among the plurality of guide members is filled.   The indoor unit of an air conditioner according to claim 3, wherein a rib is provided between one guide member of the plurality of guide members and an adjacent guide member having a smaller diameter than the guide member.   The indoor unit of an air conditioner according to claim 9, wherein one end of the rib is connected to the one guide member, and the other end of the rib is connected to the adjacent guide member.   The indoor unit of an air conditioner according to claim 9 or 10, wherein the rib is provided along a direction in which air is sucked into the centrifugal blower.

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