AIR BLOWING STRUCTURE AND INDOOR UNIT OF AIR CONDITIONER

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application is a continuation of, and claims the benefit of priority from International Application No. PCT/JP2024/023661, filed on Jun. 28, 2024, which claims the benefit of priority from Japanese Patent Application No. 2023-108412, filed on Jun. 30, 2023, the entire contents of each of which are incorporated herein by reference.

TECHNICAL FIELD

[0002]The present disclosure relates to an air blowing structure and an indoor unit of an air conditioner.

BACKGROUND ART

[0003]As a technique relating to cross flow fans, the technology described in JPS61-114000U is known. In JPS61-114000U, the entire fan casing is formed of a porous material.

SUMMARY

[0004]An air blowing structure in one general aspect includes a cross flow fan and a housing in which the cross flow fan is disposed. The housing includes a case portion that includes an air inlet through which air is drawn in, and a first member. The first member includes a tongue portion that defines a suction region in which air is drawn into the cross flow fan and a discharge region in which air is discharged from the cross flow fan, and an outlet portion located closer to an air outlet than the tongue portion is. The tongue portion is made of a non-porous material. A part of the outlet portion is made of a porous material. The porous material is provided so as to extend from an upper surface to a lower surface of the outlet portion.

BRIEF DESCRIPTION OF DRAWINGS

[0005]FIG. 1 A perspective view of an indoor unit of an air conditioner according to an embodiment.

[0006]FIG. 2 A cross-sectional view of the indoor unit of FIG. 1 as viewed from the longitudinal direction.

[0007]FIG. 3 An enlarged view of a part of the cross-sectional view of FIG. 2.

[0008]FIG. 4 An example of a graph showing the magnitude of the airflow noise in relation to the airflow rate in a case in which a porous material is provided in the outlet portion and also in the tongue portion, and in a case in which a porous material is provided in the outlet portion but not in the tongue portion.

[0009]FIG. 5 An example of a graph showing the magnitude of the airflow noise in relation to the airflow rate in a case in which a porous material is provided in the outlet portion, and in a case in which no porous material is provided in the outlet portion.

[0010]FIG. 6 An enlarged view of a porous material of a first modification.

[0011]FIG. 7 An enlarged view of a porous material of a second modification.

DESCRIPTION OF EMBODIMENTS

Embodiment

[0012]An air blowing structure 21 and an indoor unit 11 of an air conditioner according to the present embodiment will be described with reference to FIGS. 1 to 5.

Indoor Unit and Air Blowing Structure of Air Conditioner

[0013]The indoor unit 11 of the air conditioner shown in FIGS. 1 to 3 is configured to cool or heat an indoor space. The indoor unit 11 is a wall-mounted type that is attached to a wall WL in a room. The indoor unit 11 is connected to an outdoor unit of an air conditioner through refrigerant piping.

[0014]The indoor unit 11 includes an air blowing structure 21 and a heat exchanger 12. The air blowing structure 21 includes a cross flow fan 22 and a housing 30, in which the cross flow fan 22 is disposed.

[0015]The housing 30 is formed in a box shape extending in a longitudinal direction X of the indoor unit 11. The housing 30 includes a case portion 31. The case portion 31 includes a top surface portion 32, a first front surface portion 33, a second front surface portion 34, a rear surface portion 35, a bottom surface portion 36, a first side surface portion 37, and a second side surface portion 38. The top surface portion 32, the first front surface portion 33, the second front surface portion 34, the rear surface portion 35, and the bottom surface portion 36 extend in the longitudinal direction X.

[0016]The first side surface portion 37 is connected to one end in the longitudinal direction X of each of the top surface portion 32, the first front surface portion 33, the second front surface portion 34, the rear surface portion 35, and the bottom surface portion 36. The second side surface portion 38 is connected to the other end of each of the top surface portion 32, the first front surface portion 33, the second front surface portion 34, the rear surface portion 35, and the bottom surface portion 36 in the longitudinal direction X.

[0017]The case portion 31 includes an internal space IS defined by the top surface portion 32, the first front surface portion 33, the second front surface portion 34, the rear surface portion 35, the bottom surface portion 36, the first side surface portion 37, and the second side surface portion 38. The indoor unit 11 is installed on the wall WL, for example, by attaching the rear surface portion 35 to an attachment plate provided on the wall WL with screws or the like.

[0018]The case portion 31 includes an air inlet 39, through which air is drawn in. The air inlet 39 is provided in the top surface portion 32. The air inlet 39 extends in the longitudinal direction X along the top surface portion 32. The case portion 31 includes an air outlet 40, from which drawn-in air is discharged. The air outlet 40 is provided between the second front surface portion 34 and the bottom surface portion 36. The air outlet 40 extends in the longitudinal direction X along the second front surface portion 34 and the bottom surface portion 36.

[0019]The heat exchanger 12 performs heat exchange on air drawn in through the air inlet 39. The heat exchanger 12 includes multiple fins and multiple heat transfer tubes penetrating the fins. The heat exchanger 12 performs heat exchange between refrigerant flowing through the heat transfer tubes and the air passing through the heat exchanger 12. The heat exchanger 12 functions as an evaporator or a condenser depending on the operation state of the indoor unit 11. The heat exchanger 12 is disposed in the internal space IS of the case portion 31 so that at least a part of the heat exchanger 12 is positioned closer to the air inlet 39 than the cross flow fan 22 is.

[0020]The indoor unit 11 further includes an air filter 13. The air filter 13 is provided in the internal space IS of the case portion 31. The air filter 13 is detachably attached to the case portion 31. The air filter 13 is supported by air filter support portions 31a, which include a first air filter support portion 31b located near the rear surface portion 35 and a second air filter support portion 31c located near the second front surface portion 34. The second air filter support portion 31c is in contact with the first member 41. The air filter 13 is supported by the first air filter support portion 31b and the second air filter support portion 31c.

[0021]The air filter 13 captures dust contained in indoor air drawn in through the air inlet 39. When attached to the case portion 31, the air filter 13 is positioned between the top surface portion 32 of the case portion 31 and the heat exchanger 12. The air filter 13 prevents dust in indoor air from adhering to the surface of the heat exchanger 12.

[0022]The cross flow fan 22 is a substantially cylindrical impeller extending in the longitudinal direction X. The cross flow fan 22 is provided in the internal space IS of the case portion 31. The cross flow fan 22 has a blade tip circle 23 on the outer circumference of the cross flow fan 22.

[0023]When the cross flow fan 22 rotates, indoor air is drawn into the internal space IS of the case portion 31 through the air inlet 39. The drawn-in air sequentially passes through the air filter 13 and the heat exchanger 12. The air that has undergone heat exchange in the heat exchanger 12 is discharged into the room from the air outlet 40 by the cross flow fan 22.

[0024]The housing 30 includes a first member 41. The first member 41 extends from the second front surface portion 34 toward the cross flow fan 22. The first member 41 extends along the cross flow fan 22 in the longitudinal direction X. The first member 41 includes a tongue portion 44 that faces the cross flow fan 22 in the radial direction of the cross flow fan 22. A gap is provided between the tongue portion 44 of the first member 41 and the outer periphery of the cross flow fan 22. The heat exchanger 12 is disposed above the first member 41. The first member 41 is formed of, for example, a porous resin material and a non-porous resin material.

[0025]The housing 30 includes a second member 42. The second member 42 is provided rearward and obliquely downward of the cross flow fan 22. The second member 42 guides air discharged from the cross flow fan 22 to the air outlet 40. The second member 42 is, for example, a part of the housing 30. The second member 42 may be provided separately from the housing 30. The length of the second member 42 in the longitudinal direction X is substantially equal to the length of the air outlet 40 in the longitudinal direction X.

[0026]The indoor unit 11 further includes a flap 14. The flap 14 is provided at the lower edge of the second member 42 so as to be rotatable with respect to the second member 42. The flap 14 has the shape of a flat plate extending in the longitudinal direction X. The length of the flap 14 in the longitudinal direction X is substantially equal to the length of the air outlet 40 in the longitudinal direction X. For example, the flap 14 is rotated with respect to the second member 42 by a motor for driving the flap.

[0027]A region in which air is drawn into the cross flow fan 22 from the air inlet 39 is defined as a suction region SR. The suction region SR is, for example, a region between the heat exchanger 12 and the cross flow fan 22. A region in which air is discharged from the cross flow fan 22 is defined as a discharge region BR. The discharge region BR is, for example, a region between the second member 42 and the cross flow fan 22. The discharge region BR is, for example, a region between the flap 14 and the cross flow fan 22. The discharge region BR is, for example, a region between the flap 14 and the first member 41.

[0028]The first member 41 includes a tongue portion 44 and an outlet portion 43. The outlet portion 43 is located closer to the air outlet 40 than the tongue portion 44 is. The outlet portion 43 includes a section made of a porous material 51. A section of the first member 41 other than the tongue portion 44 is the outlet portion 43. The outlet portion 43 and the tongue portion 44 are integrally formed. Details of the tongue portion 44 and the porous material 51 will be described later.

[0029]A drain pan surface 41a for receiving condensate from the heat exchanger 12 is provided on an upper surface 43a of the outlet portion 43. The drain pan surface 41a includes a surface of the upper surface 43a of the outlet portion 43 closer to the cross flow fan 22 than the second air filter support portion 31c is and a third surface 44e of the tongue portion 44. In the longitudinal direction X, the length of the drain pan surface 41a is substantially equal to the length of the heat exchanger 12.

[0030]The tongue portion 44 separates the suction region SR and the discharge region BR from each other. The tongue portion 44 divides the space around the cross flow fan 22 into the suction region SR and the discharge region BR. The tongue portion 44 extends in the longitudinal direction X along the cross flow fan 22. The tongue portion 44 faces the cross flow fan 22 in the radial direction of the cross flow fan 22. A gap is provided between the tongue portion 44 and the outer periphery of the cross flow fan 22.

[0031]The tongue portion 44 is a portion at which airflow along the blade tip circle 23 of the cross flow fan 22 is divided into a flow directed toward the suction region SR through the gap between the cross flow fan 22 and the tongue portion 44, and a flow directed toward the air outlet 40. The tongue portion 44 includes a tongue surface portion 44x disposed on the surface of the tongue portion 44. The tongue surface portion 44x includes an inner end 44a facing the flap 14. The tongue surface portion 44x includes an outer end 44b adjacent the porous material 51. The tongue surface portion 44x includes a first surface 44c, a second surface 44d, and a third surface 44e. The tongue portion 44 is formed of a non-porous material. The non-porous material has a density higher than that of the porous material 51.

[0032]The first surface 44c is curved so as to protrude from the inner end 44a toward the discharge region BR, which is adjacent to the cross flow fan 22. The second surface 44d is connected to the first surface 44c. The second surface 44d is curved along the outer peripheral shape of the cross flow fan 22. The second surface 44d faces the cross flow fan 22 with a gap therebetween. The third surface 44e is connected to the second surface 44d. The third surface 44e is provided between an upper end of the second surface 44d and the outer end 44b. The third surface 44e is a flat surface.

[0033]The discharge region BR is formed by a first wall surface 45 on a side including the first member 41 and a second wall surface 46 on the opposite side of the discharge region BR from the first wall surface 45. The first wall surface 45 is formed on the lower surface of the first member 41. The second wall surface 46 is formed by the second member 42 and the flap 14. The first wall surface 45 and the second wall surface 46 are arranged such that the cross-sectional area of the discharge region BR increases toward the downstream end. Since the cross-sectional area of the discharge region BR increases toward the air outlet 40, the discharge region BR functions as a diffuser.

Porous Material

[0034]The porous material 51 has a structure that allows air to pass therethrough. The material of the porous material 51 is not particularly limited. The material of the porous material 51 is, for example, resin, ceramics, metal, or the like. The resin is, for example, foam plastic. The ceramics or metal is, for example, a porous sintered body. The metal may be a net-shaped body, which is also referred to as a mesh.

[0035]The porous material 51 is disposed in the outlet portion 43 at a position downstream of the tongue portion 44 in the direction of airflow generated by the cross flow fan 22. The porous material 51 is provided so as to extend from the upper surface 43a to the lower surface 43b of the outlet portion 43. In one example, the porous material 51 is provided so as to extend from a section of the drain pan surface 41a that does not face the heat exchanger 12 to the lower surface 43b of the outlet portion 43.

[0036]The porous material 51 is disposed in a section of the outlet portion 43 adjacent to the tongue portion 44. The porous material 51 is provided in a section of the outlet portion 43 other than a section having the lowest height in the vertical direction. The porous material 51 is attached to the outlet portion 43 by insert molding, adhesive bonding, ultrasonic welding, screw fastening, or the like. The porous material 51 may be provided discontinuously or continuously along the outlet portion 43 in the longitudinal direction X.

[0037]A section of the outlet portion 43 made of the porous material 51 includes a first end 52 closer to the air outlet 40. The first end 52 is the downstream end in the direction of airflow generated by the cross flow fan 22. The first end 52 is closer to the tongue portion 44 than the air outlet 40 is.

[0038]The section of the outlet portion 43 made of the porous material 51 includes a second end 53 closer to the tongue portion 44. The second end 53 is the upstream end in the direction of airflow generated by the cross flow fan 22. The second end 53 is in contact with the tongue portion 44.

[0039]The section of the outlet portion 43 made of the porous material 51 faces both the discharge region BR and the suction region SR. The section of the outlet portion 43 made of the porous material 51 has a first end face 54 facing the discharge region BR. The section of the outlet portion 43 made of the porous material 51 has a second end face 55 facing the suction region SR.

[0040]The dimension of the first end face 54 is defined as a first width L1. The first width L1 is the distance, on the first wall surface 45, between the downstream end and the upstream end of the porous material 51 in the direction of airflow generated by the cross flow fan 22. The dimension of the second end face 55 is defined as a second width L2. The second width L2 is the distance, on the section of the second end face 55 facing the suction region SR, between the downstream end and the upstream end in the direction of airflow generated by the cross flow fan 22.

[0041]FIG. 4 shows an example of a graph showing the magnitude of the airflow noise in relation to the airflow rate in Pattern 1 and Pattern 2. Pattern 1 represents a case in which the porous material 51 is provided in the outlet portion 43 and is also provided in the tongue portion 44. Pattern 2 represents a case in which the porous material 51 is provided in the outlet portion 43 but not in the tongue portion 44. The solid line in FIG. 4 represents a graph of the magnitude of the airflow noise in relation to the airflow rate in Pattern 1. The broken line in FIG. 4 represents a graph of the magnitude of the airflow noise in relation to the airflow rate in Pattern 2.

[0042]The magnitude of the airflow noise in relation to the airflow rate in Pattern 1 is greater than the magnitude of the airflow noise in relation to the airflow rate in Pattern 2. In other words, in Pattern 2, the airflow noise is more reduced than in Pattern 1.

Relationship Between Dimensions of First Wall Surface and Porous Material

[0043]The first wall surface 45 has a first dimension S1 extending from the air outlet 40 to the inner end 44a. Specifically, the first dimension S1 is the distance between a downstream end of the first wall surface 45 in the direction of airflow generated by the cross flow fan 22 and the inner end 44a. The first wall surface 45 has a second dimension S2 extending from the air outlet 40 to a position corresponding to 60% of the first dimension S1. Specifically, the first dimension S1 is the distance between the downstream end of the first wall surface 45 in the direction of airflow generated by the cross flow fan 22 and a position corresponding to 60% of the first dimension S1. The first wall surface 45 has a third dimension S3 from the air outlet 40 to the end of the porous material 51 closer to the air outlet 40. Specifically, the first dimension S1 is the distance between the downstream end of the first wall surface 45 in the direction of airflow generated by the cross flow fan 22 and the downstream end of the porous material 51 in the direction of airflow generated by the cross flow fan 22 on the first wall surface 45.

[0044]The second width L2 is shorter than the first width L1. The second width L2 may be longer than the first width L1 or may be equal to the first width L1. The second width L2 is greater than or equal to 30% of the first width L1. Preferably, the second width L2 is greater than or equal to 50% of the first width L1. Preferably, the second width L2 is greater than or equal to 80% of the first width L1.

[0045]The third dimension S3 is longer than the second dimension S2. The third dimension S3 is greater than or equal to 70% of the first dimension S1. Preferably, the third dimension S3 is greater than or equal to 80% of the first dimension S1. The first width L1 is greater than or equal to 10% of the first dimension S1.

[0046]FIG. 5 shows an example of a graph showing the magnitude of the airflow noise in relation to the airflow rate in Pattern 3 and Pattern 4. Pattern 3 represents a case in which the porous material 51 is provided in the outlet portion 43. Pattern 4 represents a case in which the porous material 51 is not provided in the outlet portion 43. In one example, the position at which the porous material 51 is provided in the outlet portion 43 satisfies Expressions (1) through (3).

$\begin{array}{cc}S3/S1=0\text{.85}& \left(\mathrm{Expression}1\right)\end{array}$$\begin{array}{cc}L1/S1=0.13& \left(\mathrm{Expression}2\right)\end{array}$$\begin{array}{cc}L2/L1=0.83& \left(\mathrm{Expression}3\right)\end{array}$

[0047]The solid line in FIG. 5 represents a graph of the magnitude of the airflow noise in relation to the airflow rate in Pattern 3. The broken line in FIG. 5 represents a graph of the magnitude of the airflow noise in relation to the airflow rate in Pattern 4. The magnitude of the airflow noise in relation to the airflow rate in Pattern 3 is lower than the magnitude of the airflow noise in relation to the airflow rate in Pattern 4. In other words, in Pattern 3, the airflow noise is more reduced than in Pattern 4.

Modifications

EXPLANATION OF REFERENCES