Air conditioner indoor unit

Abstract

To provide an indoor unit for an air conditioner, capable of reducing aerodynamic noise.SOLUTION: An indoor unit 10 for an air conditioner 1 includes a Sirocco fan 52 for delivering sucked air in the radial direction, and a casing storing the Sirocco fan 52. In the casing, there are provided a rectangular air outlet 58 for air delivered by the Sirocco fan 52 to be blown therefrom, and a tongue part 62 forming the lower edge of the air outlet 58. On an upper face 81 of the tongue part 62, a plurality of flat surfaces are provided including steps gradually lower as extending from the Sirocco fan 52 to the air outlet 58. On at least one flat surface at its edge located on the side of the air outlet 58, an irregular shape is provided in a planar view.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an indoor unit of an air conditioner. [Background technology]

[0002] Patent Document 1 discloses an indoor unit of a duct-type air conditioner. This air conditioner indoor unit allows the duct connection flange connected to the air outlet of the air conditioner body to be freely moved, allowing the opening dimensions of the air outlet to be freely changed. As a result, this air conditioner indoor unit can ensure a constant air speed by freely changing the opening area of ​​the air outlet, providing comfortable air conditioning. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-249287 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides an air conditioner indoor unit that can reduce aerodynamic noise. [Means for solving the problem]

[0005] The indoor unit of an air conditioner according to the present disclosure includes a sirocco fan that sends out intake air in a radial direction, and a casing that houses the sirocco fan. The casing includes an air outlet through which the air sent out by the sirocco fan is blown out, and a tongue portion that forms a lower edge of the air outlet. , are integral with the casing The tongue portion has an upper surface provided with a plurality of flat surfaces with steps that become lower from the sirocco fan toward the air outlet, and at least one of the flat surfaces has an edge located on the air outlet side that has an uneven shape in a plan view. An indoor unit of an air conditioner characterized in that, among the plurality of flat surfaces, when the dimension of the difference in height between a high-stage surface, which is the plane on which the uneven shape is provided, and a low-stage surface, which is the plane adjacent to the high-stage surface on the side of the air outlet, is H, and the width dimension of the low-stage surface along the direction from the air outlet toward the sirocco fan is L1, each of the flat surfaces satisfies the following relationship. 0 <H / L1≦1.5 [Effects of the Invention]

[0006] According to the present disclosure, aerodynamic noise can be reduced. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view taken along the rotation axis of a sirocco fan of an indoor unit included in an air conditioner according to a first embodiment of the present disclosure. [Figure 2] Vertical cross section of indoor unit [Figure 3] Perspective view of the blower [Figure 4] A perspective view of the tongue from the front [Figure 5] Perspective view of the tongue [Figure 6] FIG. 10 is a diagram schematically illustrating an airflow at an air outlet when a blower is driven. [Figure 7] FIG. 10 is a diagram schematically illustrating an airflow at an air outlet when a blower is driven. [Figure 8] A scatter diagram showing the relationship between the ratio of the height difference between the high and low stage surfaces to the width of the low stage surface, and the air volume of the fan. [Figure 9] Scatter diagram showing the relationship between the ratio of the width dimension of the recess along the direction in which the tongue extends to the width dimension of the recess along the direction from the outlet toward the sirocco fan, and the air volume of the blower. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) At the time the inventors arrived at the idea for this disclosure, there was technology available for indoor units of duct-type air conditioners that provide comfortable air conditioning. In this indoor unit of an air conditioner, the duct connection flange connected to the air outlet of the air conditioner body can be freely moved, allowing the opening dimensions of the air outlet to be freely changed. This allows the indoor unit of this air conditioner to ensure a constant air speed by freely changing the opening area of ​​the air outlet. The indoor unit of this air conditioner uses a blower equipped with a sirocco fan. A known type of such blower has a casing that houses the sirocco fan and blows out air sent by the sirocco fan from an outlet provided in the casing.

[0009] In the above-described blower, the air blown out by the sirocco fan may collide with the lower edge of the outlet, generating a vortex. The inventors discovered a problem in the blower and an air conditioner equipped with the blower, in which the air is blown out from the outlet in a state in which a vortex is generated, generating so-called aerodynamic noise. In order to solve this problem, the present inventors have come up with the subject matter of the present disclosure. Therefore, the present disclosure provides an air conditioner and a blower that can reduce aerodynamic noise.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to Figures 1 to 4. In each figure, the symbol FR indicates the front of the indoor unit in a flat-hanging state, the symbol UP indicates the top of the indoor unit, and the symbol LH indicates the left of the indoor unit. In the following description, each direction is along the direction of each of these indoor units. [1-1.Configuration] [1-1-1. Air conditioner configuration] Fig. 1 is a cross-sectional view taken along the rotation axis 78 of the sirocco fan 52 of the indoor unit 10 provided in the air conditioner 1. Fig. 1 is a plan view of a cross section passing through the rotation axis 78 of the sirocco fan 52 and along the front-rear and left-right directions of the indoor unit 10.

[0012] As shown in Fig. 1, the air conditioner 1 of this embodiment includes an indoor unit 10. The air conditioner 1 includes a refrigeration cycle for the air conditioner 1 formed by a heat exchanger 69 housed in the indoor unit 10, a pressure reducing device such as a compressor and an electronic expansion valve housed in the outdoor unit, an outdoor heat exchanger, etc. The air conditioner 1 conditions a specified space to be conditioned by circulating a refrigerant through this refrigeration cycle.

[0013] The indoor unit 10 is an indoor unit of a duct-type air conditioner 1 that is installed in a ceiling space, inside a wall, or under the floor. The indoor unit 10 is installed so that its installation direction can be changed so that the air blowing direction can be changed depending on the installation location. For example, when blowing air horizontally, the indoor unit 10 is installed in a so-called flat-hanging state, with the outlet 18 that blows out conditioned air positioned to the side. When blowing air upward, the indoor unit 10 is installed in a so-called vertical-hanging state, with the air outlet positioned above. In the following description, the up-down direction refers to the up-down direction when the indoor unit 10 is installed in a flat-hanging state.

[0014] Fig. 2 is a vertical cross-sectional view of the indoor unit 10. Fig. 2 is a cross-section view of the indoor unit 10 taken along the front-to-back and up-to-down directions of the indoor unit 10, passing through a position avoiding the multiple fans 35, as viewed from the left of the indoor unit 10. 1 and 2, the indoor unit 10 has a housing 19 made up of a front panel 11, a back panel 12, a pair of side panels, a right panel 13 and a left panel 14, a bottom panel 15, and a top panel 16. An outlet port 18, which is an opening, is provided in the front panel 11 across the entire left-right direction. In addition, an inlet port 59, which is an opening, is provided in the back panel 12.

[0015] The internal space of the housing 19 is divided into an air blowing chamber 22 and a heat exchange chamber 23 by a partition plate 21 . The partition plate 21 is a flat plate member having a predetermined length, and both ends of the partition plate 21 in the longitudinal direction are connected to the approximate centers of the right side plate 13 and the left side plate 14, respectively.

[0016] In the blower chamber 22, a plurality of fans 35 and an electric motor 54 are arranged side by side along the left-right direction of the indoor unit 10. Each blower 35 includes a sirocco fan 52 and a scroll casing 56. The sirocco fan 52 is a centrifugal fan that blows out air. These sirocco fans 52 are supported by a rotary shaft 78 that extends in the left-right direction of the indoor unit 10. That is, the sirocco fans 52 included in each blower 35 are connected to each other via the rotary shaft 78. The scroll casing 56 is a casing that houses the sirocco fan 52. The scroll casing 56 is provided with an opening 57 that takes in air as the sirocco fan 52 rotates, and a duct-like blower section 65 that guides the air that has been taken in and then blown out by the sirocco fan 52 in a predetermined direction.

[0017] The electric motor 54 is connected to a rotary shaft 78 of the sirocco fan 52 and drives the sirocco fan 52 to rotate via the rotary shaft 78 . As shown in Fig. 1, in this embodiment, three fans 35 are arranged in the blower chamber 22. Note that the configuration in Fig. 1 is just an example, and any number of motors 54 and fans 35 may be provided in the indoor unit 10.

[0018] The partition plate 21 is provided with a plurality of communication openings 25 that communicate with the air blowing chamber 22 and the heat exchange chamber 23, and a blowing section 65 of the blower 35 is joined to each of these communication openings 25. In addition, an opening 57 of the blower 35 opens into the air blowing chamber 22.

[0019] When the blower 35 operates, the blower 35 draws air from the blowing chamber 22 through the intake port 59, causing outside air to flow into the blowing chamber 22. The outside air is sent by the blower 35 to the heat exchange chamber 23 through the communication opening 25 formed in the partition plate 21. That is, in the indoor unit 10, the air blowing chamber 22 is a space on the primary side of the air blower 35, and the heat exchange chamber 23 is a space on the secondary side.

[0020] A heat exchanger 69 is disposed in the heat exchange chamber 23. The heat exchanger 69 is a user-side heat exchanger that functions as an evaporator that evaporates the refrigerant supplied from the outdoor unit, or as a condenser that condenses the refrigerant.

[0021] The heat exchanger 69 of this embodiment is a so-called fin-and-tube type heat exchanger, and the heat exchanger 69 is formed in the shape of a long plate overall, with multiple metal fins joined to copper refrigerant pipes. Refrigerant sent from the outdoor unit flows into one end of this refrigerant pipe, flows through the entire heat exchanger 69 via the refrigerant pipe, and then flows out again to the outdoor unit from the other end of the refrigerant pipe.

[0022] 1, the heat exchanger 69 is disposed so that its longitudinal direction is along the left-right direction of the heat exchange chamber 23. The heat exchanger 69 disposed in this manner has one flat surface facing the partition plate 21 and each blower 65, and the other flat surface facing the discharge port 18. As a result, the refrigerant pipes of the heat exchanger 69 extend along the longitudinal direction of the partition plate 21, and the fins are arranged so that the plate thickness direction of each fin is along the longitudinal direction of the partition plate 21.

[0023] The air sent to the air blowing chamber 22 by the blower 35 exchanges heat with the refrigerant flowing through the refrigerant pipe as it passes through the heat exchanger 69, mainly through the gaps between the fins, and is then blown out from the outlet 18 formed in the front panel 11. The indoor unit 10 may be equipped with a plurality of heat exchangers. These heat exchangers may be arranged arbitrarily in the heat exchange chamber 23.

[0024] [1-1-2. Blower configuration] FIG. 3 is a perspective view of the blower 35. Next, the configuration of the blower 35 will be described in detail. As shown in FIG. 3, blower 35 includes sirocco fan 52 that exhausts air in a radial direction, and scroll casing 56 that houses sirocco fan 52. Sirocco fan 52 is an impeller formed in a drum or cylindrical shape, including a disk-shaped main plate 71 and a large number of blades standing upright on the periphery of main plate 71. A rotary shaft 78 is inserted through approximately the center of main plate 71.

[0025] The scroll casing 56 is provided with a casing body 60 that houses the sirocco fan 52, and a blower 65 that protrudes from the casing body 60 in one direction. Casing body 60 includes a pair of side plates 72 located in the direction of the rotation axis of sirocco fan 52. As described above, each side plate 72 is provided with openings 57 that open in the direction of the rotation axis of sirocco fan 52. Blower 35 draws air through openings 57 as sirocco fan 52 rotates.

[0026] The air blower 65 is formed in a duct shape and includes an upper surface portion 61 that forms the upper surface of the air blower 65, a tongue portion 62 that forms the lower surface, and a pair of side surface portions 63 that form the left and right side surfaces of the air blower 65. Each side surface portion 63 is a flat plate portion that is continuous with each side plate 72.

[0027] An air outlet 58 is provided at the end of the blower 65 opposite the casing body 60. The air outlet 58 is a rectangular opening formed by the ends of the top surface 61, the tongue 62, and the pair of side surfaces 63 that are located on the front side of the indoor unit 10. Blower 65 and outlet 58 are provided opposite the side peripheral surface of sirocco fan 52. In other words, blower 65 and outlet 58 are arranged in the centrifugal direction of sirocco fan 52. The air sent out by sirocco fan 52 is blown out from the inside of scroll casing 56 to the outside through outlet 58.

[0028] [1-1-3. Tongue structure] The tongue portion 62 is disposed in the blower section 65 so as to face the plane of the upper surface portion 61, and forms the lower edge of the air outlet 58. The tongue portion 62 extends from one side surface portion 63 to the other side surface portion 63. The tongue portion 62 has a predetermined width dimension along both the up-down direction and the front-to-rear direction of the indoor unit 10. The upper surface 81 of the tongue portion 62 is formed into a rectangle in a plan view.

[0029] Fig. 4 is a perspective view of the tongue portion 62 as viewed from the front. Fig. 5 is a perspective view of the tongue portion 62. In Fig. 5, part of the tongue portion 62 in the left-right direction of the indoor unit 10 is omitted. As shown in Figures 4 and 5, the upper surface 81 is provided with a plurality of flat surfaces 83 that become lower in a so-called stepped manner from the sirocco fan 52 toward the air outlet 58. In this embodiment, two flat surfaces 83 are provided. By providing these two flat surfaces 83, a step portion 80 is provided on the upper surface 81. The step portion 80 extends along the vertical direction of the indoor unit 10, and the two flat surfaces 83 are parallel to the upper surface portion 61. Hereinafter, of the two planes 83, the plane 83 located on the upper surface 81 on the side of the sirocco fan 52 will be referred to as the high-stage plane 82, and the plane 83 located on the side of the outlet 58, in other words, adjacent to the high-stage plane 82 on the side of the outlet 58, will be referred to as the low-stage plane 84.

[0030] The high stage surface 82 and the low stage surface 84 are adjacent to each other, and the height dimension at which the high stage surface 82 is located is formed relatively higher than the height dimension at which the low stage surface 84 is located in the vertical direction of the indoor unit 10. The flat surface 83 and the upper surface 85 are both flat surfaces that are approximately parallel to the upper surface portion 61.

[0031] In this embodiment, an R-shape is provided on edge 97 located on the air outlet 58 side of lower stage surface 84. As a result, when air sent to sirocco fan 52 is blown out from air outlet 58, it is blown out while gently deflecting downward along the R-shape. This makes it possible to reduce air vortices generated by the air pressure gradient between the inside and outside of scroll casing 56.

[0032] The height difference between the high stage surface 82 and the low stage surface 84 is longer than the width of the low stage surface 84 in the direction from the air outlet 58 toward the sirocco fan 52, and is formed to be 1.5 times or less the width of the high stage surface 82. As a result, the air sent out from sirocco fan 52 flows along high-stage surface 82, then steps down and flows along low-stage surface 84. Therefore, in the space surrounded by step portion 80 and low-stage surface 84, the air gradually merges with the air outside scroll casing 56, where the pressure gradient is large, thereby reducing vortices.

[0033] Hereinafter, the height difference between the high stage surface 82 and the low stage surface 84 will be referred to as height dimension H, and the width dimension of the low stage surface 84 along the direction from the air outlet 58 toward the sirocco fan 52 will be referred to as width dimension L1 (FIG. 6). For ease of explanation, the space surrounded by the step portion 80 and the low stage surface 84 and facing the air outlet 58 will be referred to as space S.

[0034] The high step surface 82 is provided with a plurality of recesses 89 recessed from an edge 87 located on the air outlet 58 side toward the sirocco fan 52 in plan view. The plurality of recesses 89 are provided over the entire longitudinal direction of the tongue portion 62, and are also provided over the entire height direction of the step portion 80. Each recess 89 is formed in a substantially V-shape on the plane 83, with the width dimension narrowing from the edge 87 toward the sirocco fan 52. By providing the plurality of recesses 89, an uneven shape is formed on the edge 87 in plan view of the upper surface 81.

[0035] At the edge 87, the width dimension of each recess 89 extending from the edge 87 toward the sirocco fan 52 is longer than the width dimension of each recess 89 along the longitudinal direction of the tongue 62, and is formed to be four times or less the width dimension of each recess 89 along the longitudinal direction of the tongue 62. This allows recess 89 to have a width dimension that can divide the air sent out from sirocco fan 52. This prevents the air from joining together at tongue portion 62, making it possible to make vortices generated in the air finer.

[0036] Hereinafter, the width dimension of the recess 89 along the direction in which the tongue portion 62 extends is referred to as width dimension W, and the length dimension of the recess 89 along the direction from the air outlet 58 toward the sirocco fan 52 is referred to as length dimension L2 (FIG. 6).

[0037] By providing these recesses 89, a protrusion 86 is provided on edge 87, with a tip 91 protruding from the sirocco fan 52 side toward lower stage surface 84 and air outlet 58. This protrusion 86 is formed in a substantially V-shape with a width that narrows as it goes from sirocco fan 52 toward air outlet 58. Tip 91 of protrusion 86 and protruding portion sides 95, which are a pair of sides located on either side of tip 91, form part of edge 87.

[0038] The protruding portion sides 95 are part of the edge portion 87 and are one side of the plane 83. These protruding portion sides 95 form the upper end sides located on both sides of the tip 91 and correspond to the sides located on both sides of the recessed portion 89. Because the convex portion 86 is formed in a substantially V-shape, these protruding portion sides 95 are oblique sides of the tongue portion 62 in a plan view.

[0039] [1-2. Operation] [1-2-1. Air conditioner operation] The operation of the air conditioner 1 configured as above will now be described. In the air conditioner 1, when the blower 35 is operating, air drawn in through the intake port 59 flows into the scroll casing 56 from the opening 57 along the direction of the rotation axis. The blower 35 blows the air that has flowed in from the blowing section 65 to the heat exchanger 69. The blown air undergoes heat exchange in the heat exchanger 69 to become conditioned air, which is then discharged from the discharge port 18 into the space to be conditioned.

[0040] Fig. 6 is a diagram schematically showing airflow A at the air outlet 58 when the blower 35 is driven. Fig. 6 schematically shows a portion of a vertical cross section of the blower section 65 along the front-to-rear direction of the indoor unit 10. For ease of explanation, Fig. 6 shows airflow A, which is the flow of air sent out by the blower 35, by a dashed line. Also, in Fig. 6, space S is shown by a two-dot chain line. The air blown out by blower 35 is sent out by sirocco fan 52 in the radial direction of sirocco fan 52, passes through blower section 65 and heads toward air outlet 58. At this time, part of the air is blown obliquely downward from the upper surface section 61 toward upper surface 81, as shown in FIG.

[0041] In conventional air conditioners, upper surface 81 is a flat surface, and airflow A, which is the flow of air blown down, collides with upper surface 81, is deflected, and flows approximately parallel to upper surface 81 toward air outlet 58. At this time, in conventional air conditioners, multiple vortices are generated in airflow A, and these vortices grow as they flow along upper surface 81. Furthermore, when the edge 97 located on the air outlet 58 side of the upper surface 81 is linear, a plurality of vortices may be connected along the longitudinal direction of the upper surface 81, thereby increasing the vortex size.

[0042] Here, in the driven blower 35, the speed of airflow A inside the scroll casing 56, particularly inside the blower section 65, is faster than the speed outside the scroll casing 56, such as in the heat exchange chamber 23. For this reason, in the air conditioner 1, a pressure gradient occurs in which the pressure inside the blower section 65 is higher than the pressure outside the scroll casing 56. As a result, in conventional air conditioners, when air is blown out from the high-pressure inside the blower section 65 to the outside of the scroll casing 56 through the air outlet 58, this pressure gradient can further increase the vortex generated in the airflow A. In this way, the vortex generated and increased as the blower 35 is driven may come into contact with the heat exchanger 69, for example, thereby increasing so-called aerodynamic noise.

[0043] In this embodiment, as shown in Fig. 6, upper surface 81 is provided with high-stage surface 82 and low-stage surface 84. By providing these high-stage surface 82 and low-stage surface 84, part of airflow A flows downward between high-stage surface 82 and low-stage surface 84. This allows airflow A to be blown out from outlet 58 without colliding with upper surface 81, i.e., without being deflected. This prevents vortexes from being generated when airflow A collides with upper surface 81 in blower 35.

[0044] Furthermore, a space S is provided on the upper surface 81. The pressure in this space S is intermediate between the relatively high pressure inside the blower section 65 and the relatively low pressure outside the scroll casing 56. Therefore, part of the airflow A descends through each step 80 and flows through this space S, thereby gradually merging with air having the pressure outside the scroll casing 56. That is, in the blower 35, the space S reduces the pressure gradient between the inside of the blower section 65 and the outside of the scroll casing 56. This suppresses the generation of vortices in airflow A in blower 35. In addition, even when airflow A collides with upper surface 81 in blower 35, the airflow descends between high-stage surface 82 and low-stage surface 84 and flows through space S, thereby suppressing the growth of the vortex.

[0045] Fig. 7 is a diagram schematically showing airflow A at air outlet 58 when blower 35 is driven. Fig. 7 is a schematic plan view of tongue portion 62. For ease of explanation, Fig. 7 shows airflow A, which is the flow of air sent out by blower 35, by a dashed dotted line. 7, airflow A flowing along upper surface 81 is divided by protruding portion side 95 as it descends between high-stage surface 82 and low-stage surface 84. Accordingly, vortices generated by airflow A colliding with upper surface 81 are similarly divided by protruding portion side 95, and are reduced and made finer. As a result, blower 35 suppresses the growth of these vortices.

[0046] Furthermore, in the present embodiment, recess 89 is formed in a substantially V-shape, and therefore the width dimension along the longitudinal direction of tongue 62 increases from the sirocco fan 52 side toward low-stage surface 84 and air outlet 58 side. This recess 89 is continuous with space S, and therefore airflow A divided by protruding portion side 95 flows into space S in stages, descending between high-stage surface 82 and low-stage surface 84 as the width dimension of recess 89 increases. This suppresses the increase in vortices due to the pressure gradient between the inside of blower section 65 and the outside of scroll casing 56 in blower 35.

[0047] Additionally, in the blower 35, the high-stage surface 82, the low-stage surface 84, and the recesses 89 guide the airflow A further downward, thereby increasing the air volume below the air outlet 58 and improving the air volume distribution in the vertical direction of the air outlet 58. In the indoor unit 10, deviations in the air flow speed in the vertical direction of the heat exchanger 69 are suppressed, making it possible to improve the heat exchange efficiency.

[0048] [1-2-2. Air conditioner experiment] Next, an experiment conducted by the inventors to analyze the relationship between the structure of tongue portion 62 of blower 35 in this embodiment and the air volume will be described. 8 is a diagram showing the relationship between the ratio of the height dimension H of the height difference between the high-stage surface 82 and the low-stage surface 84 to the width dimension L1 of the low-stage surface 84, and the air volume of the fan 35. In FIG. 8, the horizontal axis X1 represents the ratio H / L1, and the vertical axis Y represents the air volume of the fan 35. The inventors changed the ratio between the height dimension H and the width dimension L1 and measured the air volume for each ratio at a predetermined rotation speed of the fan 35.

[0049] The results obtained by the above-mentioned measurements are shown in the plots in Figure 8. In Figure 8, curve e2 is an approximation curve for each plot, and dashed line e1 is the air volume of a conventional fan. From the results shown in Figure 8, the inventors have discovered that when the ratio of height dimension H to width dimension L1 satisfies the following formula (1), fan 35 can deliver a larger air volume than a conventional fan at the same rotation speed. 0 <H / L1≦1.5 (1)

[0050] By satisfying the above formula (1), a portion of the airflow A sent out to the blower 35 does not pass over the low-stage surface 84 and is not blown out from the outlet 58, but rather passes down through the high-stage surface 82 and the low-stage surface 84 and is then blown out from the outlet 58. The airflow A then flows through the space S, which reduces the pressure gradient between the inside of the blower section 65 and the outside of the scroll casing 56, thereby suppressing the increase in the vortex of the airflow A. Based on the above measurements, the inventors have found that it is desirable for the height dimension H to be 5 mm and the width dimension L1 to be 6.5 mm on average.

[0051] 9 is a diagram showing the relationship between the ratio of the width dimension W of recess 89 along the direction in which tongue portion 62 extends to the length dimension L2 of recess 89 along the direction from air outlet 58 toward sirocco fan 52, and the air volume of blower 35. In FIG. The inventors changed the ratio between the width dimension W of the recess 89 along the direction in which the tongue portion 62 extends and the length dimension L2 of the recess 89 along the direction from the outlet 58 toward the sirocco fan 52, and measured the air volume for each ratio at a predetermined rotation speed of the blower 35.

[0052] The results obtained by the above-mentioned measurements are shown in the plots in Figure 9. In Figure 9, curve e3 is an approximation curve for each plot, and dashed line e1 is the air volume of a conventional fan. From these results, the inventors have discovered that when the ratio of width dimension W to length dimension L2 satisfies the following formula (2), fan 35 can deliver a larger air volume than a conventional fan at the same rotation speed. 0 <L2 / W≦4 (2)

[0053] By satisfying the above formula (2), in the blower 35, as the air flows down from the high-stage surface 82 to the low-stage surface 84, the vortices generated in the airflow A are divided by the protruding portion edge 95, and the vortices are prevented from joining together and being blown out from the outlet 58. Based on the above measurements, the inventors have found that it is desirable for the width dimension W to be 24 mm and the length dimension L2 to be 6 mm.

[0054] In this way, by satisfying the above formulas (1) and (2), blower 35 produces less aerodynamic noise than a conventional blower when blowing out approximately the same amount of air. In other words, by satisfying the above formulas (1) and (2), blower 35 can blow out a larger amount of air with a lower input power while suppressing aerodynamic noise more than a conventional blower.

[0055] [1-3. Effects, etc.]

[0056] As described above, in the present embodiment, air conditioner 1 includes sirocco fan 52 that sends out intake air in the radial direction, and scroll casing 56 that houses sirocco fan 52. Scroll casing 56 is provided with rectangular outlet 58 through which the air sent out by sirocco fan 52 is blown out, and tongue 62 that forms the lower edge of outlet 58. An upper surface 81 of tongue 62 is provided with a plurality of flat surfaces 83 that have steps that become lower as they go from sirocco fan 52 toward outlet 58. Of the plurality of flat surfaces 83, at least one edge 87 of flat surface 83 located on the side of sirocco fan 52 is provided with an uneven shape in plan view.

[0057] As a result, in blower 35, the air that collides with tongue portion 62 flows down high-stage surface 82 and low-stage surface 84, and gradually merges with the air outside scroll casing 56, where the pressure gradient is large. Therefore, blower 35 can reduce air vortices that are generated and increased due to the pressure gradient. Additionally, in blower 35, the air that collides with tongue 62 flows down between high-stage surface 82 and low-stage surface 84 and is divided by protruding portion side 95 formed by recess 89. Therefore, in blower 35, vortices generated when air collides with tongue 62 are divided, reduced, and made finer, thereby reducing aerodynamic noise.

[0058] As in the present embodiment, in blower 35, at least one of flat surfaces 83 is provided with a V-shaped recess 89 in a plan view. As a result, airflow A divided by protruding portion side 95 flows stepwise into space S, descending between high-stage surface 82 and low-stage surface 84 as the width dimension of recess 89 increases. Therefore, in blower 35, an increase in vortexes due to a pressure gradient between the inside of blower section 65 and the outside of scroll casing 56 is suppressed.

[0059] As in this embodiment, when the height difference between the high stage surface 82 and the low stage surface 84 is defined as the height dimension H, and the width dimension of the low stage surface 84 along the direction from the air outlet 58 toward the sirocco fan 52 is defined as the width dimension L1, each may be made to satisfy the following relationship. 0 <H / L1≦1.5

[0060] As a result, part of the airflow A sent out to the blower 35 descends between the high-stage surface 82 and the low-stage surface 84 and flows through the space S, and the space S reduces the pressure gradient between the inside of the blower section 65 and the outside of the scroll casing 56. Therefore, in the blower 35, the increase in vortices of the airflow A is suppressed, and aerodynamic noise is reduced.

[0061] As in this embodiment, at least one of the planes 83 has a plurality of recesses 89 formed along the direction in which the lower edge of the air outlet 58 extends, and when the width dimension of the recesses 89 along the direction in which the lower edge of the air outlet 58 extends is defined as width dimension W and the length dimension of the recesses 89 along the direction from the air outlet 58 toward the sirocco fan 52 is defined as length dimension L2, each may be configured to satisfy the following relationship. 0 <L2 / W≦4

[0062] As a result, in blower 35, as blower 35 descends from each step 80, vortices generated in flow A are divided by protruding portion side 95, and the vortices are prevented from joining together and being blown out from outlet 58. As a result, in blower 35, aerodynamic noise is reduced.

[0063] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the first embodiment above to create new embodiments. Therefore, other embodiments will be exemplified below.

[0064] In the above embodiment 1, two flat surfaces 83 are provided on the upper surface 81, but this is not limited to this, and three or more flat surfaces 83 may be provided as long as the flat surface 83 located on the air outlet 58 side is relatively lower than the flat surface 83 located on the sirocco fan 52 side.

[0065] In the first embodiment, the recess 89 is not limited to a V-shape, but may have other shapes such as a rectangle, an arc, a curve, etc. In addition, the tip 91 may be rounded or chamfered.

[0066] Similarly, each of the protrusions 86 may have any shape as long as the above formulas (1) and (2) are satisfied and each of the protrusions 86 has a pair of protruding sides 95. Furthermore, each of the protrusions 86 may have different shapes and dimensions depending on the position of the protrusions 86 in the longitudinal direction of the tongue portion 62, as long as the above formulas (1) and (2) are satisfied.

[0067] In the first embodiment described above, the step portion 80 extends in the vertical direction of the indoor unit 10, and each flat surface 83 is parallel to the upper surface portion 61. However, this is not limiting, and as long as the flat surface 83 located on the air outlet 58 side is located relatively lower than the flat surface 83 located on the sirocco fan 52 side, each flat surface 83 may be inclined at a predetermined angle or have an R-shape.

[0068] For example, the plane 83 may be provided with an inclination or a radius. As a result, the air sent out to the sirocco fan 52 flows down along the plane 83, causing the air blown out from the air outlet 58 to be diffused downward. As a result, in the indoor unit 10, the flow rate of the air sent out to the lower part of the heat exchanger 69 increases, preventing deviations in the air flow rate in the vertical direction of the heat exchanger 69, and improving heat exchange efficiency.

[0069] Furthermore, for example, the flat surface 83 located on the air outlet 58 side may be formed at an angle that is inclined downward more than the flat surface 83 located on the sirocco fan 52 side. As a result, the air that has descended the flat surface 83 is gradually deflected downward and diffused as it heads toward the air outlet 58. Therefore, in the indoor unit 10, it is possible to suppress the air from being deflected at a steep angle due to collision with the upper surface 81, and reduce the pressure loss that accompanies this deflection.

[0070] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0071] The present disclosure is applicable to air conditioners equipped with indoor units equipped with sirocco fans. Specifically, the present disclosure is applicable to refrigeration cycle devices such as ceiling-mounted duct-type indoor units, ceiling-suspended indoor units, and floor-standing indoor units, as well as drying devices and air intake / exhaust ventilation devices. [Explanation of symbols]

[0072] 1. Air conditioner 10 Indoor unit 35 Blower 52 Sirocco fan 56 Scroll casing (casing) 58 Air outlet 62 Tongue 80 multi-layered section 81 Top surface 83 plane 82 High step surface (plane) 84 Low step surface (plane) 87 Edge 89 Recess A. Airflow H Height dimension L1, W width dimension L2 length dimension S space

Claims

1. A sirocco fan that sends out the intake air in a radial direction; a casing in which the sirocco fan is housed, The casing has an air outlet through which air sent by the sirocco fan is blown out; a tongue portion forming a lower edge of the air outlet; is integrally provided on the casing, The upper surface of the tongue portion is provided with a plurality of flat surfaces having steps that become lower as the sirocco fan moves toward the air outlet, An edge portion of at least one of the planes located on the side of the air outlet has an uneven shape in a plan view, Among the plurality of planes, The dimension of the height difference between the high stage surface, which is a plane on which the uneven shape is provided, and the low stage surface, which is a plane adjacent to the high stage surface on the side of the air outlet, is defined as H, When the width dimension of the lower stage surface along the direction from the air outlet toward the sirocco fan is L1, Each satisfies the following relationship: An indoor unit of an air conditioner characterized by: 0<H / L1≦1.5

2. The uneven shape is V-shaped.

2. The indoor unit of an air conditioner according to claim 1.

3. a width dimension of at least one recess provided by the uneven shape along the direction in which the tongue portion extends is defined as W; When the width dimension of the recess along the direction from the air outlet toward the sirocco fan is L2, Each satisfies the following relationship:

3. The indoor unit of an air conditioner according to claim 1 or 2. 0<L2 / W≦4

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