Indoor unit and air conditioner

Abstract

This indoor unit for an air conditioner, which has a refrigerant circuit through which a refrigerant circulates, comprises a refrigerant sensor unit, wherein: the refrigerant sensor unit has a sensor body and a housing provided with an accommodation space for accommodating the sensor body and a refrigerant inlet; the sensor body has a substrate, a sensor element mounted on a mounting surface of the substrate, and a cylindrical element case that is fixed to the mounting surface, surrounds the sensor element, and extends in a direction orthogonal from the mounting surface; an end of the element case on the side opposite to the mounting surface is provided with a case opening that guides the refrigerant to the inside of the element case; the housing has a housing body, and a lid body that is assembled on the housing body from an assembly direction and surrounds the accommodation space together with the housing body; and the refrigerant inlet extends in the horizontal direction or downward direction from the accommodation space and faces an external space.

Description

Indoor units and air conditioners

[0001] The present disclosure relates to an indoor unit and an air conditioner.

[0002] Conventionally, air conditioners using flammable refrigerants have been known that include a refrigerant sensor attached to the indoor unit. The refrigerant sensor detects refrigerant leakage from the heat exchanger. Patent Document 1 discloses a refrigerant gas detection sensor that includes a substrate, a detection element mounted on the substrate, a cylindrical case member surrounding the detection element, and a housing that accommodates these components. The refrigerant gas detection sensor of Patent Document 1 has an opening at the bottom end of the case member. Therefore, the detection element detects refrigerant gas only when a sufficient amount of refrigerant gas has accumulated below the refrigerant gas detection sensor within the housing. This prevents erroneous detection of a small amount of insecticide as refrigerant gas.

[0003] JP 2016-90108 A

[0004] In conventional refrigerant gas detection sensors, the cylindrical case surrounding the detection element must be positioned vertically, which places restrictions on the orientation of the circuit board on which the detection element is mounted. More specifically, in conventional structures, the circuit board must be positioned perpendicular to the vertical direction, which increases the projected area of ​​the refrigerant gas detection sensor and hinders the miniaturization of indoor units.

[0005] In view of the above circumstances, one of the objects of the present disclosure is to provide an indoor unit and an air conditioner that have a refrigerant sensor unit that allows greater freedom in the placement of each component.

[0006] One aspect of the indoor unit according to the present disclosure is an indoor unit for an air conditioner having a refrigerant circuit through which a refrigerant circulates, and is equipped with a refrigerant sensor unit that detects the vaporized refrigerant, the refrigerant sensor unit having a sensor main body, a storage space that accommodates the sensor main body, and a housing having a refrigerant inlet that guides the refrigerant into the storage space, the sensor main body having a substrate with a mounting surface, a sensor element mounted on the mounting surface, and a cylindrical element case that is fixed to the mounting surface, surrounds the sensor element, and extends in a direction perpendicular to the mounting surface, the end of the element case opposite the mounting surface having a case opening that guides the refrigerant into the element case, the housing having a housing main body and a lid body that is assembled to the housing main body from an assembly direction and surrounds the storage space together with the housing main body, the refrigerant inlet extending horizontally or downward from the storage space and opening toward the external space.

[0007] One aspect of an air conditioner according to the present disclosure includes the indoor unit described above, the refrigerant circuit, and an outdoor unit.

[0008] According to the present disclosure, it is possible to provide an indoor unit and an air conditioner having a refrigerant sensor unit that allows for greater freedom in the placement of each component.

[0009] Fig. 1 is a schematic diagram showing a general configuration of an air conditioner according to an embodiment. Fig. 2 is a perspective view showing an indoor unit according to an embodiment. Fig. 3 is an exploded perspective view showing an indoor unit according to an embodiment. Fig. 4 is a perspective view of a refrigerant sensor unit according to an embodiment. Fig. 5 is an exploded perspective view of a refrigerant sensor unit according to an embodiment. Fig. 6 is a cross-sectional view of the refrigerant sensor unit taken along line VI-VI in Fig. 4. Fig. 7 is a cross-sectional view of the refrigerant sensor unit taken along line VII-VII in Fig. 4. Fig. 8 is a cross-sectional view of the wiring and insertion holes of the refrigerant sensor unit according to an embodiment. Fig. 9 is an exploded perspective view of a sensor main body and a tubular member according to an embodiment.

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, a Z-axis indicating the up-down direction is shown as appropriate. The side of the up-down direction toward which the arrow of the Z-axis points (+Z side) is upward, and the opposite side of the up-down direction toward which the arrow of the Z-axis points (-Z side) is downward. Note that the orientation of the indoor unit 10 relative to the up-down direction described in this embodiment is merely an example, and does not limit the assembly orientation of the indoor unit 10.

[0011] Fig. 1 is a schematic diagram showing the general configuration of an air conditioner 100 according to the present embodiment. As shown in Fig. 1, the air conditioner 100 includes an indoor unit 10, an outdoor unit 20, and a refrigerant circuit 30. The indoor unit 10 is located indoors. The outdoor unit 20 is located outdoors. The indoor unit 10 and the outdoor unit 20 are connected to each other by the refrigerant circuit 30, through which a refrigerant 33 circulates. The indoor unit 10 and the outdoor unit 20 are heat exchange units that exchange heat with the air.

[0012] The air conditioner 100 can adjust the temperature of the indoor air by exchanging heat between the refrigerant 33 flowing through the refrigerant circuit 30 and the air in the room where the indoor unit 10 is located. Examples of the refrigerant 33 include fluorine-based refrigerants or hydrocarbon-based refrigerants with low global warming potential (GWP). Examples of the refrigerant 33 include a single refrigerant selected from R1234yf, R1234ze, R32, and R290, a mixture of two or more of these refrigerants, or a mixture of any of these refrigerants with another refrigerant. Examples of the refrigerant 33 include a mixture of R1132(E) and R1123. Examples of the refrigerant 33 include a mixed refrigerant of R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

[0013] The outdoor unit 20 has a compressor 21, an outdoor heat exchanger 23, a flow rate adjustment valve 24, a blower 25, and a four-way valve 22. The compressor 21, the outdoor heat exchanger 23, the flow rate adjustment valve 24, and the four-way valve 22 are connected by a refrigerant circuit 30.

[0014] The four-way valve 22 is disposed in a portion of the refrigerant circuit 30 that is connected to the discharge side of the compressor 21. The four-way valve 22 switches a portion of the paths in the refrigerant circuit 30, thereby reversing the direction of the refrigerant 33 flowing through the refrigerant circuit 30. When the paths connected by the four-way valve 22 are the paths shown by solid lines in the four-way valve 22 in Fig. 1, the refrigerant 33 flows through the refrigerant circuit 30 in the direction shown by the solid arrows in Fig. 1. On the other hand, when the paths connected by the four-way valve 22 are the paths shown by dashed lines in the four-way valve 22 in Fig. 1, the refrigerant 33 flows through the refrigerant circuit 30 in the direction shown by the dashed arrows in Fig. 1.

[0015] The indoor unit 10 has a centrifugal blower 40 and an indoor heat exchanger (heat exchanger) 14 arranged around the centrifugal blower 40. The indoor unit 10 is capable of cooling operation to cool the air in the room where the indoor unit 10 is arranged, and heating operation to warm the air in the room where the indoor unit 10 is arranged.

[0016] When the indoor unit 10 is in cooling operation, the refrigerant 33 flowing in the refrigerant circuit 30 flows in the direction shown by the solid arrow in Fig. 1. In other words, when the indoor unit 10 is in cooling operation, the refrigerant 33 flowing in the refrigerant circuit 30 circulates through the compressor 21, the outdoor heat exchanger 23 of the outdoor unit 20, the flow control valve 24, and the indoor heat exchanger 14 of the indoor unit 10 in that order, before returning to the compressor 21. During cooling operation, the outdoor heat exchanger 23 in the outdoor unit 20 functions as a condenser, and the indoor heat exchanger 14 in the indoor unit 10 functions as an evaporator.

[0017] On the other hand, when the indoor unit 10 is in heating operation, the refrigerant 33 flowing in the refrigerant circuit 30 flows in the direction shown by the dashed line in Fig. 1. In other words, when the indoor unit 10 is in heating operation, the refrigerant 33 flowing in the refrigerant circuit 30 circulates through the compressor 21, the indoor heat exchanger 14 of the indoor unit 10, the flow control valve 24, and the outdoor heat exchanger 23 of the outdoor unit 20 in that order, before returning to the compressor 21. In heating operation, the outdoor heat exchanger 23 in the outdoor unit 20 functions as an evaporator, and the indoor heat exchanger 14 in the indoor unit 10 functions as a condenser.

[0018] Next, the indoor unit 10 of this embodiment will be described in more detail. Figure 2 is a perspective view showing the indoor unit 10. Figure 3 is an exploded perspective view of the indoor unit 10. Note that in Figures 2 and 3, the decorative panel covering the underside of the indoor unit 10 is omitted from the illustration.

[0019] As shown in Figures 2 and 3, the indoor unit 10 has a centrifugal blower 40 centered on a rotation axis R. In this embodiment, the direction in which the rotation axis R extends is the up-down direction. In the following description, the axial direction of the rotation axis R, i.e., the direction parallel to the Z-axis, may be simply referred to as the "axial direction," the radial direction centered on the rotation axis R may be simply referred to as the "radial direction," and the circumferential direction centered on the rotation axis R may be simply referred to as the "circumferential direction." Furthermore, in the following description, "radially outer" refers to the side in the radial direction that is away from the rotation axis R, and "radially inner" refers to the side in the radial direction that is opposite the radially outer side and approaches the rotation axis R.

[0020] The indoor unit 10 of this embodiment is a ceiling-mounted indoor unit that is installed by being embedded in a ceiling. As shown in Figure 3, the indoor unit 10 includes the centrifugal fan 40 and the indoor heat exchanger 14 described above, as well as a housing 11, a refrigerant sensor unit 50, a drain pan 41, a bell mouth 42, a control unit 43, and a decorative panel (not shown).

[0021] The housing 11 covers the centrifugal blower 40 and the indoor heat exchanger 14 from above and the sides. The housing 11 is fixed to the ceiling of the building in which the indoor unit 10 is installed. The fan motor of the centrifugal blower 40, the indoor heat exchanger 14, and a drain pan 41 are fixed to the housing 11. The drain pan 41 covers the indoor heat exchanger 14 from below. The drain pan 41 has a rectangular frame when viewed axially. An air outlet 41a is provided in the drain pan 41. The drain pan 41 collects condensation water that occurs as a result of heat exchange by the indoor heat exchanger 14. A bell mouth 42 is fixed to the drain pan 41. The bell mouth 42 is positioned below the centrifugal blower 40. An air inlet 42a is provided in the bell mouth 42. The air inlet 42a is circular and has a center on the rotation axis R. The control unit 43 is fixed to the underside of the bell mouth 42. The control unit 43 has a control board (not shown) that controls each part of the indoor unit 10. The control unit 43 controls the components necessary for heating and cooling operation of the air conditioner 100. In addition, wiring extending from the refrigerant sensor unit 50 is connected to the control unit 43, and the presence or absence of a refrigerant leak is determined based on the detection result of the refrigerant gas by the refrigerant sensor unit 50.

[0022] The centrifugal blower 40 has an impeller 40a and a fan motor (not shown) that rotates the impeller 40a. The impeller 40a covers the fan motor from below. The impeller 40a rotates around a rotation axis R. The centrifugal blower 40 draws indoor air through an intake port 42a and sends the air radially outward. The indoor heat exchanger 14 is disposed radially outward of the centrifugal blower 40.

[0023] The indoor heat exchanger 14 has a rectangular frame shape when viewed in the axial direction, and surrounds the centrifugal blower 40 from the radial outside. A refrigerant flows inside the indoor heat exchanger 14. The indoor heat exchanger 14 exchanges heat between the refrigerant and the air sent from the centrifugal blower 40. A refrigerant sensor unit 50 is attached to the surface of the indoor heat exchanger 14 facing radially inward.

[0024] The refrigerant sensor unit 50 is disposed radially inward of the pipe connection portion 14a of the indoor heat exchanger 14. The refrigerant sensor unit 50 is disposed between the centrifugal blower 40 and the indoor heat exchanger 14. The refrigerant sensor unit 50 is also disposed above the drain pan 41. When refrigerant leaks from the indoor heat exchanger 14, the refrigerant vaporizes and becomes refrigerant gas. Because refrigerant gas is heavier than air, it flows downward and accumulates above the drain pan 41. The refrigerant sensor unit 50 detects the refrigerant gas that accumulates above the drain pan 41. Generally, refrigerant leakage is more likely to occur at the pipe connection portion 14a of the indoor heat exchanger 14 than at other locations. According to this embodiment, by disposing the refrigerant sensor unit 50 radially outward of the pipe connection portion 14a, the refrigerant sensor unit 50 can easily immediately detect refrigerant gas leaking from the pipe connection portion 14a.

[0025] Figure 4 is a perspective view of the refrigerant sensor unit 50. Figure 5 is an exploded perspective view of the refrigerant sensor unit 50. Figure 6 is a cross-sectional view of the refrigerant sensor unit 50 taken along line VI-VI in Figure 4. Figure 7 is a cross-sectional view of the refrigerant sensor unit 50 taken along line VII-VII in Figure 4. As shown in Figure 4, the refrigerant sensor unit 50 has a sensor main body 70, a tubular member 80, and a housing 60. The sensor main body 70 and the tubular member 80 are housed inside the housing 60.

[0026] The housing 60 has an upper surface 60b facing upward, a lower surface 60c facing downward, and a peripheral side surface 60d connecting the upper surface 60b and the lower surface 60c. The peripheral side surface 60d faces in a direction intersecting the vertical direction. The housing 60 also has an accommodation space A that accommodates the sensor main body 70 and the tubular member 80, a refrigerant inlet 60a that introduces refrigerant gas into the accommodation space A, and an insertion hole 60h through which a wiring 79 extends from the accommodation space A to the outside. The wiring 79 is connected to the control unit 43 (see FIG. 3).

[0027] In this embodiment, the refrigerant inlet 60a is provided on the peripheral side surface 60d of the housing 60. In this embodiment, the refrigerant inlet 60a faces radially outward from the rotation axis R (see FIG. 5 ) of the centrifugal blower 40. The refrigerant inlet 60a takes in vaporized refrigerant gas leaking from the indoor heat exchanger 14 into the storage space A. In this embodiment, the refrigerant inlet 60a extends horizontally from the storage space A and opens toward the exterior. Foreign gases, such as insecticides, that may be erroneously detected as refrigerant gas are heavier than air. If the refrigerant inlet 60a opens upward, foreign gases may flow into the storage space A, causing erroneous detection. In this embodiment, the refrigerant inlet opens horizontally, making it difficult for foreign gases to flow into the storage space A. This effect can also be achieved when the refrigerant inlet 60a is provided on the lower surface 60c of the housing 60 and extends downward from the storage space A and opens toward the exterior. That is, the refrigerant inlet 60a may extend horizontally or downward from the accommodation space A and open toward the external space.

[0028] Here, "the refrigerant inlet 60a extends horizontally or downward" means that the extension direction of the refrigerant inlet 60a has only a positive vector component pointing horizontally or downward, or a vector component that is a combination of these. In other words, "the refrigerant inlet 60a extends horizontally or downward from the storage space A" means that the extension direction of the refrigerant inlet 60a with respect to the storage space A does not include a positive vector component pointing upward.

[0029] As shown in Figure 5, the housing 60 has a housing main body 61, a lid 62, and a sealing member 69. The housing main body 61 and the lid 62 are assembled together. In the following description, the direction in which the lid 62 is assembled to the housing main body 61 is referred to as the assembly direction D1. In this embodiment, the assembly direction D1 is a direction perpendicular to the up-down direction. The housing main body 61 and the lid 62 surround an accommodation space A.

[0030] The housing body 61 has a first box-shaped portion 61b, a first flange portion 61c, a rib 61e, and a pair of protrusions 61d. The first box-shaped portion 61b has a bottom surface 61g disposed perpendicular to the assembly direction D1. The first box-shaped portion 61b also has a first opening 61a that opens toward the lid 62 in the assembly direction D1.

[0031] As shown in Figure 6, a stepped portion 61h is provided on the bottom surface 61g of the housing main body 61. The stepped portion 61h is located closer to the lid 62 than other areas of the bottom surface 61g. The stepped portion 61h has a plate shape that is perpendicular to the assembly direction D1. The stepped portion 61h is provided with a refrigerant inlet 60a that penetrates the stepped portion 61h in the thickness direction.

[0032] As shown in FIG. 5, the first flange portion 61c is connected to the outer edge of the first opening 61a. The first flange portion 61c protrudes in a direction perpendicular to the assembly direction D1 and away from the first opening 61a. The first flange portion 61c surrounds the first opening 61a when viewed from the assembly direction D1. The first flange portion 61c has a first sealing surface 61f that faces the lid 62 in the assembly direction D1. The first sealing surface 61f is a flat surface perpendicular to the assembly direction D1 in an area excluding a notch 60u (see FIG. 8) described below.

[0033] The rib 61e extends along the inner edge of the first sealing surface 61f on the first opening 61a side. That is, the rib 61e protrudes from the edge of the first sealing surface 61f on the accommodation space A side. The rib 61e surrounds the first opening 61a when viewed from the assembly direction D1. The rib 61e protrudes toward the cover 62 in the assembly direction D1 relative to the first sealing surface 61f.

[0034] The pair of protrusions 61d are provided on the side surfaces of the first flange portion 61c. The pair of protrusions 61d are arranged on both sides of the first opening 61a so as to sandwich the first opening 61a. The pair of protrusions 61d each protrude in a direction perpendicular to the assembly direction D1 and away from the first opening 61a. The tip surfaces of the protrusions 61d are inclined in a direction that increases the protruding height as they move away from the cover 62 in the assembly direction D1.

[0035] The cover 62 has a second box-shaped portion 62b, a second flange portion 62c, and a pair of arms 62d. The second box-shaped portion 62b has a second opening 62a that opens toward the housing main body 61 in the assembly direction D1. The second opening 62a faces the first opening 61a. When the cover 62 is assembled to the housing main body 61, the first opening 61a and the second opening 62a overlap each other. This connects the internal spaces of the first box-shaped portion 61b and the second box-shaped portion 62b to form the storage space A.

[0036] The second flange portion 62c is connected to the outer edge of the second opening 62a. The second flange portion 62c protrudes in a direction perpendicular to the assembly direction D1 and away from the second opening 62a. The second flange portion 62c surrounds the second opening 62a when viewed from the assembly direction D1. The second flange portion 62c has a second sealing surface 62f facing the housing main body 61 in the assembly direction D1. The second sealing surface 62f is a flat surface perpendicular to the assembly direction D1 in an area excluding a protrusion 60t (see FIG. 8 ), which will be described later. The second sealing surface 62f faces the first sealing surface 61f in the assembly direction D1. A sealing member 69 is disposed between the first sealing surface 61f and the second sealing surface 62f.

[0037] The pair of arms 62d are connected to the second flange portion 62c. The pair of arms 62d are arranged on both sides of the second opening 62a. Each arm 62d has a pair of connecting pieces 62i extending toward the housing main body 61 in the assembly direction D1 and a locking piece 62j connecting the tips of the pair of connecting pieces 62i. When the cover 62 is assembled to the housing main body 61, the protrusions 61d of the housing main body 61 are inserted into the area surrounded by the pair of connecting pieces 62i, the locking piece 62j, and the outer edge of the second flange portion 62c. The pair of protrusions 61d are respectively hooked onto the pair of locking pieces 62j, thereby fixing the cover 62 to the housing main body 61. Furthermore, because the tip surfaces of the protrusions 61d are inclined, the locking pieces 62j slide along the tip surfaces of the protrusions 61d when the cover 62 is assembled to the housing main body 61, causing the pair of arms 62d to elastically deform. This allows the operator to easily hook the locking piece 62j onto the projection 61d.

[0038] The sealing member 69 is made of a sponge-like elastic material and is sandwiched between the housing main body 61 and the lid body 62. The sealing member 69 contacts a first sealing surface 61f of the housing 60 and a second sealing surface 62f of the lid body 62.

[0039] The sealing member 69 is frame-shaped when viewed from the assembly direction D1. The cross-sectional shape of the sealing member 69 is rectangular. The sealing member 69 is arranged to surround the rib 61 e of the housing main body 61. By arranging the sealing member 69 so that it fits around the outer periphery of the rib 61 e, a worker performing the assembly process can sandwich the sealing member 69 between the housing main body 61 and the lid 62 while preventing the sealing member 69 from shifting relative to the housing main body 61.

[0040] As shown in FIG. 6 , the sealing member 69 is compressed in the assembly direction D1 between the first sealing surface 61f and the second sealing surface 62f. This causes the sealing member 69 to close the gap between the housing main body 61 and the lid body 62, sealing the storage space A from the outside. As described above, the inner edge of the first sealing surface 61f is provided with a rib 61e that protrudes toward the lid body 62. Meanwhile, the second box-shaped portion 62b of the lid body 62 has a recess 62e that opens toward the housing main body 61 at the second opening 62a. The recess 62e is continuous with the edge of the second sealing surface 62f on the storage space A side. By assembling the housing main body 61 and the lid body 62, the rib 61e is inserted into the recess 62e. As a result, the rib 61e is surrounded by the recess 62e, and the outer surface of the rib 61e faces the inner surface of the recess 62e. Therefore, when the lid 62 is assembled to the housing main body 61, the rib 61e acts as a guide, making it difficult for the lid 62 to become misaligned in a direction intersecting the assembly direction D1 relative to the housing main body 61. As a result, the assembly process is simplified and twisting and separation of the sealing member 69 during the assembly process are suppressed.

[0041] FIG. 8 is a cross-sectional view of the wiring 79 and the insertion hole 60h of the housing 60. Note that the internal structure of the wiring 79 is not shown in FIG. 8 . As shown in FIG. 8 , a notch 60u is provided in the first sealing surface 61f of the housing main body 61, opening toward the lid body 62 in the assembly direction D1. The inner surface of the notch 60u facing the opening is a curved surface that is concave toward the housing main body 61 and has a uniform radius of curvature. Meanwhile, a protrusion 60t is provided in the second sealing surface 62f of the lid body 62, protruding toward the housing main body 61 in the assembly direction D1. The protrusion 60t is inserted into the notch 60u. The tip surface of the protrusion 60t is a curved surface that is concave toward the housing main body 61 and has a uniform radius of curvature. The insertion hole 60h is surrounded by the inner surface of the notch 60u and the tip surface of the protrusion 60t. In addition, since the protrusion 60t is provided on the second sealing surface 62f, the sealing member 69 arranged along the second sealing surface 62f bends along the protrusion 60t.

[0042] A strip-shaped wire sealing member 68 is wrapped around the outer periphery of the wire 79. The wire sealing member 68 is made of, for example, the same material as the sealing member 69. The wire sealing member 68 is fixed to the outer periphery of the wire 79 by, for example, a cable tie. The wire sealing member 68 may be adhesively fixed to the outer periphery of the wire 79. The wire sealing member 68 may be wrapped around the outer periphery of the wire 79 two or more times. The wire 79 is placed in the insertion hole 60h with the wire sealing member 68 wrapped around it.

[0043] The wire sealing member 68 is compressed by the inner surface of the cutout 60u and the tip surface of the protrusion 60t. Furthermore, the wire sealing member 68 and the sealing member 69 are overlappingly disposed between the tip surface of the protrusion 60t and the wire 79, and are compressed together. The wire sealing member 68 and the sealing member 69 fill the gap between the protrusion 60t and the wire 79. This prevents foreign gases or foreign matter from entering the accommodation space A from the external space via the insertion hole 60h.

[0044] In the present embodiment, the case where the notch 60u is provided in the first sealing surface 61f and the protrusion 60t is provided in the second sealing surface 62f has been described. However, the sealing surfaces on which the notch 60u and the protrusion 60t are provided may be opposite to those in the embodiment. That is, it is sufficient that the notch 60u is provided on one of the first sealing surface 61f or the second sealing surface 62f, and the protrusion 60t is provided on the other of the first sealing surface 61f or the second sealing surface 62f.

[0045] As shown in FIG. 4 , the insertion hole 60h in this embodiment is provided in the peripheral side surface 60d of the housing 60. Therefore, like the refrigerant inlet 60a, the insertion hole 60h extends horizontally from the storage space A and opens toward the external space. According to this embodiment, even if a slight gap is provided inside the insertion hole 60h, foreign gases, foreign matter, and the like are unlikely to flow into the storage space A through the insertion hole 60h. This effect can also be achieved when the insertion hole 60h is provided in the lower surface 60c of the housing 60 and extends downward from the storage space A and opens toward the external space. That is, the insertion hole 60h only needs to extend horizontally or downward from the storage space A and open toward the external space.

[0046] Fig. 9 is an exploded perspective view of the sensor main body 70 and the cylindrical member 80. As shown in Fig. 9, the sensor main body 70 has a substrate 73, a sensor element 71, an element case 72, and wiring 79. The cylindrical member 80 is attached to the element case 72.

[0047] The substrate 73 is fixed to the inner surface of the housing 60. In this embodiment, the substrate 73 is fixed to the housing main body 61. The substrate 73 extends in the vertical direction. The substrate 73 has a mounting surface 73a on which a plurality of elements are mounted. In this embodiment, the mounting surface 73a extends in the vertical direction. Therefore, the mounting surface 73a is disposed parallel to the rotation axis R of the centrifugal blower 40 shown in FIG. 3 .

[0048] The sensor element 71 detects vaporized refrigerant gas. The sensor element 71 is mounted on a mounting surface 73a of a substrate 73. The sensor element 71 is surrounded by an element case 72. Thus, the sensor element 71 is protected by the element case 72.

[0049] The element case 72 has a cylindrical shape extending perpendicularly from the mounting surface 73a. The element case 72 has a base end 72a fixed to the mounting surface 73a and a tip end 72b opposite the base end 72a. The base end 72a of the element case 72 is covered by the mounting surface 73a. The base end 72a is fixed tightly to the mounting surface 73a with an adhesive or the like. A case opening 72h is provided at the tip end 72b of the element case 72 to introduce refrigerant gas into the element case 72. The case opening 72h is circular.

[0050] The cylindrical member 80 is a sponge-like member made of a resin material. More specifically, the cylindrical member 80 is an elastic body made of a closed-cell structure. Here, a closed-cell structure refers to a porous material with multiple air bubbles arranged inside, and the individual air bubbles are not connected to each other. In a closed-cell structure, the individual air bubbles are independent of each other, making it difficult for the individual air bubbles to serve as a passageway for gas and liquid. For this reason, a closed-cell structure is characterized by high sealing performance.

[0051] The cylindrical member 80 is cylindrical and surrounds the outer peripheral surface of the element case 72. The outer shape of the cylindrical member 80 is a rectangular parallelepiped. The cylindrical member 80 is provided with a through hole 80h that connects the end faces of the cylindrical member 80 facing opposite directions. The through hole 80h is circular. The element case 72 is disposed inside the through hole 80h. The inner diameter of the through hole 80h is slightly smaller than the outer diameter of the element case 72. Therefore, the cylindrical member 80 is assembled to the element case 72 in a state where it is compressed against the element case 72 in a direction that widens the inner diameter of the through hole 80h.

[0052] 7 , the cylindrical member 80 has a base end surface 81 and a tip end surface 82 that face opposite each other and into which a through hole 80h opens, and an outer circumferential surface 83 that connects the base end surface 81 and the tip end surface 82. The entire base end surface 81 contacts the mounting surface 73a of the substrate 73. A portion of the tip end surface 82 contacts the inner surface of the housing 60. A portion of the outer circumferential surface 83 contacts the inner surface of the housing 60.

[0053] The base end surface 81 of the tubular member 80 and the base end 72a of the element case 72 both contact the mounting surface 73a. Furthermore, the tip end surface 82 of the tubular member 80 contacts the inner surface of the housing 60, while a gap is provided between the tip end of the element case 72 and the inner surface of the housing 60. Thus, the overall length of the through hole 80h is greater than the overall length of the element case 72. An introduction path F, which does not house the element case 72, is provided in a region inside the through hole 80h that is farther from the mounting surface 73a than the tip end 72b of the element case 72. The opening in the tip end surface 82 of the through hole 80h connects to the refrigerant inlet 60a of the housing 60. Therefore, the introduction path F connects the refrigerant inlet 60a and the case opening 72h. The introduction path F guides refrigerant gas from the refrigerant inlet 60a to the case opening 72h. That is, the refrigerant gas that enters the storage space A of the housing 60 through the refrigerant inlet 60 a passes through the introduction path F, enters the element case 72 through the case opening 72 h, and is detected by the sensor element 71 inside the element case 72 .

[0054] Here, the area of ​​the surface of the cylindrical member 80 that comes into contact with the outer peripheral surface of the element case 72 is called a first sealing portion 86, and the area that comes into contact with the inner surface of the housing 60 is called a second sealing portion 87. In other words, the cylindrical member 80 has the first sealing portion 86 and the second sealing portion 87.

[0055] As shown in FIG. 6 , in this embodiment, the first sealing portion 86 is disposed to surround the introduction path F. The tubular member 80 comes into contact with the outer peripheral surface of the element case 72 at the first sealing portion 86 and is compressed by the outer peripheral surface. As a result, the gap between the first sealing portion 86 and the outer peripheral surface of the element case 72 is sealed. As shown in FIG. 7 , the mounting surface 73 a of the substrate 73 has an exposed portion 73 p that is exposed inside the element case 72 and a shielding portion 73 q that is the other area. According to this embodiment, the first sealing portion 86 allows gas and moisture passing through the introduction path F to reach the exposed portion 73 p, while preventing them from reaching the shielding portion 73 q.

[0056] In FIG. 6 , a distal end region 87A of the second sealing portion 87, which is provided on the distal end surface 82 of the tubular member 80, is illustrated by a two-dot chain line. When viewed from the planar direction of the distal end surface 82, the distal end region 87A is formed in a C-shape that surrounds the opening of the through-hole 80h and opens toward the refrigerant inlet 60a. Furthermore, an outer peripheral region 87B of the second sealing portion 87, which is on the outer peripheral surface 83 of the tubular member 80 and contacts the stepped portion 61h of the housing main body 61, is positioned to cover the opening of the distal end region 87A. As shown in FIG. 6 , in this embodiment, the second sealing portion 87 is positioned to surround the introduction path F. The tubular member 80 contacts the inner surface of the housing 60 at the second sealing portion 87 and is compressed by the inner surface. Therefore, a seal is formed between the second sealing portion 87 and the inner surface of the housing 60. According to this embodiment, the second sealing portion 87 prevents gas and moisture passing through the introduction path F from passing between the tubular member 80 and the inner surface of the housing 60 and reaching the shielding portion 73q of the substrate 73.

[0057] Here, when the first sealing portion 86 and the second sealing portion 87 "surround the introduction path F," this means that the first sealing portion 86 and the second sealing portion 87 are arranged in a closed loop shape surrounding the introduction path F when viewed from the flow direction of the refrigerant gas in the introduction path F.

[0058] As shown in FIG. 7 , a pair of protrusions 60g, 60k are provided on the inner surface of the case, protruding toward the second sealing portion 87 of the tubular member 80. The pair of protrusions 60g, 60k face each other in the assembly direction D1. Of the pair of protrusions 60g, 60k, a first protrusion 60g is provided on the housing main body 61, and the other, a second protrusion 60k, is provided on the lid body 62. The first protrusion 60g is provided on the step portion 61h. The first protrusion 60g is disposed around the refrigerant inlet 60a. The pair of protrusions 60g, 60k compress the tubular member 80 and improve the sealing function of the tubular member 80 at the second sealing portion 87.

[0059] <Summary> The indoor unit 10 of this embodiment is an indoor unit 10 of an air conditioner 100 having a refrigerant circuit through which refrigerant circulates. The indoor unit 10 is equipped with a refrigerant sensor unit 50 that detects vaporized refrigerant. The refrigerant sensor unit 50 has a sensor main body 70 and a housing 60. The housing 60 is provided with an accommodation space A that accommodates the sensor main body 70 and a refrigerant inlet 60a that introduces refrigerant into the accommodation space A. The sensor main body 70 has a substrate 73, a sensor element 71, and an element case 72. The substrate 73 has a mounting surface 73a. The sensor element 71 is mounted on the mounting surface 73a. The element case 72 is fixed to the mounting surface 73a. The element case 72 surrounds the sensor element 71. The element case 72 is cylindrical and extends in a direction perpendicular to the mounting surface 73a. A case opening 72h that introduces refrigerant into the element case 72 is provided at a tip end 72b on the opposite side of the mounting surface 73a of the element case 72. The housing 60 has a housing main body 61 and a lid 62. The lid 62 is assembled to the housing main body 61 from an assembly direction D1 and, together with the housing main body 61, encloses the storage space A. The refrigerant inlet 60a extends horizontally or downward from the storage space A and opens toward the outside space.

[0060] According to the above-described configuration, the sensor element 71 is surrounded and protected by the element case 72. The element case 72 also has a case opening 72h on the opposite side of the mounting surface 73a, restricting the path of gas reaching the sensor element 71. This prevents dirt from adhering to the sensor element 71 and prevents erroneous detection of foreign gases. The refrigerant sensor unit 50 is disposed near the indoor heat exchanger 14, which is prone to condensation. Surrounding the storage space A with the housing 6 restricts moisture from entering the storage space A, protecting the sensor body 70 disposed in the storage space A from moisture. According to the above-described configuration, the housing 60 restricts the inflow of gas from the outside into the storage space A at portions other than the refrigerant inlet 60a. Therefore, foreign gases, such as insecticides, are less likely to enter the storage space A through portions other than the refrigerant inlet 60a. According to the above-described configuration, the refrigerant inlet 60a opens horizontally or downward. Therefore, the refrigerant sensor unit 50 detects refrigerant gas that accumulates below the refrigerant sensor unit 50 and reaches the refrigerant inlet 60a by allowing it to flow into the storage space A. The amount of foreign gas scattered is significantly less than the amount of refrigerant gas that would be scattered if a refrigerant leak occurred. Therefore, foreign gas does not accumulate to the extent that it reaches the refrigerant inlet 60a and is less likely to flow into the storage space A through the refrigerant inlet 60a. Furthermore, because the refrigerant inlet 60a does not open upward, foreign gas that is scattered above the refrigerant sensor unit 50 and flows downward is less likely to enter through the refrigerant inlet 60a. In addition, since the refrigerant inlet 60a does not open upward, the intrusion of foreign matter such as dust and moisture into the storage space A is suppressed, preventing contamination and moisture from adhering to the sensor element 71 and improving detection reliability. Furthermore, with the above-described configuration, the element case 72 surrounding the sensor element 71 is provided inside the storage space A, making the path within the storage space A complex. Therefore, not only when the refrigerant inlet 60a of the housing 60 opens downward, but also when it opens horizontally, it is difficult for small amounts of foreign gas to reach the refrigerant inlet 60a to the sensor element 71, thereby suppressing false detection of foreign gas by the element case 72.

[0061] Furthermore, with the above-described configuration, the inflow of foreign gases, foreign matter, and moisture into the storage space A of the housing 60 is restricted, eliminating the need to devise a positioning scheme for the sensor main body 70 to prevent foreign gases, foreign matter, and moisture from reaching the sensor element 71 in the storage space A. In other words, with this configuration, the sensor main body 70 can be positioned in a relatively flexible manner within the storage space A. This increases the degree of freedom in the positioning of the components of the refrigerant sensor unit 50, such as the circuit board 73. As a result, the degree of freedom in the external shape of the refrigerant sensor unit 50 also increases, enabling more effective use of the interior space of the indoor unit 10 and enabling the indoor unit 10 to be made more compact.

[0062] In the indoor unit 10 of this embodiment, the refrigerant sensor unit 50 has a tubular member 80 that is disposed in the storage space A and surrounds the outer circumferential surface of the element case 72. An introduction path F that connects the refrigerant inlet 60a and the case opening 72h is provided inside the tubular member 80 ( FIG. 7 ). With this configuration, by disposing the tubular member 80 in the storage space A, the introduction path F that connects the refrigerant inlet 60a and the case opening 72h can be formed. This makes it easier for refrigerant gas that has entered the storage space A of the housing 60 through the refrigerant inlet 60a to flow into the element case 72, thereby improving the responsiveness of the refrigerant sensor unit 50.

[0063] In the indoor unit 10 of this embodiment, the tubular member 80 is an elastic body made of a closed-cell structure. The tubular member 80 has a first sealing portion 86 that contacts the outer surface of the element case 72 and a second sealing portion 87 that contacts the inner surface of the housing 60. The first sealing portion 86 and the second sealing portion 87 each surround the introduction path F. With this configuration, the first sealing portion 86 seals the path between the tubular member 80 and the outer surface of the element case 72. The second sealing portion 87 seals the path between the tubular member 80 and the inner surface of the housing 60. This makes it difficult for moisture to reach areas other than the introduction path F and the internal space of the element case 72, even if moisture enters the storage space A through the refrigerant inlet 60a. This protects the shielding portion 73q of the substrate 73 and elements other than the sensor element 71 mounted on the shielding portion 73q from moisture. Furthermore, with this configuration, the refrigerant gas in the introduction path F is less likely to pass between the first sealing portion 86 and the element case 72, and between the second sealing portion 87 and the inner surface of the housing 60, allowing it to flow more smoothly into the element case 72. As a result, the responsiveness of the refrigerant sensor unit 50 can be further improved.

[0064] In indoor unit 10 of this embodiment, convex portions 60g, 60k that protrude toward second sealing portion 87 and compress tubular member 80 are provided on the inner surface of housing 60. According to this configuration, convex portions 60g, 60k compress tubular member 80, causing tubular member 80 to come into close contact with the inner surface of housing 60 at second sealing portion 87. This can improve the sealing function of tubular member 80 at second sealing portion 87.

[0065] In the indoor unit 10 of this embodiment, the housing 60 has a sealing member 69. The sealing member 69 is sandwiched between the housing main body 61 and the lid body 62. The housing main body 61 has a first sealing surface 61f that surrounds the storage space A and contacts the sealing member 69 when viewed from the assembly direction D1, and a rib 61e that protrudes from the edge of the first sealing surface 61f on the storage space A side toward the lid body 62 in the assembly direction D1. The lid body 62 has a second sealing surface 62f that surrounds the storage space A and contacts the sealing member 69 when viewed from the assembly direction D1, and a recess 62e that is continuous with the edge of the second sealing surface 62f on the storage space A side and surrounds the rib 61e. With this configuration, the sealing member 69 is disposed between the housing main body 61 and the lid body 62 that surround the storage space A of the housing 60. This more reliably prevents condensation water and foreign gases from entering the storage space A. Furthermore, with the above-described configuration, the rib 61e is accommodated in the recess 62e, making it possible to easily position and assemble the lid 62 relative to the housing main body 61. Furthermore, the frame-shaped sealing member 69 can be positioned outside the rib 61e, facilitating positioning of the sealing member 69 during the assembly process. This eliminates the need to adhesively fix the sealing member 69 to the sealing surfaces of the housing main body 61 or the lid 62, facilitating disassembly of the refrigerant sensor unit 50. As a result, a refrigerant sensor unit 50 with high maintainability can be provided. In this embodiment, the housing main body 61 has a continuous annular rib 61e extending along the inner edge of the first sealing surface 61f. However, multiple ribs 61e may be provided discretely along the inner edge of the first sealing surface 61f.

[0066] In the indoor unit 10 of this embodiment, the refrigerant sensor unit 50 has a wiring 79 connected to the substrate 73. As shown in FIG. 8 , the housing 60 is provided with an insertion hole 60h through which the wiring 79 is pulled from the storage space A to the outside. A notch 60u is provided in one of the first sealing surface 61f or the second sealing surface 62f, and a protrusion 60t is provided on the other to be inserted into the notch 60u. The insertion hole 60h is surrounded by the inner surface of the notch 60u and the tip surface of the protrusion 60t. A strip-shaped wiring sealing member 68 is wrapped around the outer periphery of the wiring 79. The wiring sealing member 68 is compressed by the inner surface of the notch 60u and the tip surface of the protrusion 60t. This configuration allows the wiring sealing member 68 to fill the gap between the wiring 79 and the inner surface of the insertion hole 60h. This prevents foreign gases, foreign matter, moisture, and the like from entering the accommodating space A of the housing 60 from the external space through the insertion hole 60h. In addition, the wire sealing member 68 is compressed by the inner surface of the cutout portion 60u and the tip surface of the protrusion 60t, which sufficiently prevents gaps from occurring within the insertion hole 60h.

[0067] As shown in Fig. 3 , the indoor unit 10 of this embodiment includes a centrifugal blower 40 having an impeller 40a that rotates about a rotation axis R and sends air radially outward, and an indoor heat exchanger 14 that is disposed radially outward of the centrifugal blower 40. The refrigerant sensor unit 50 is disposed between the centrifugal blower 40 and the indoor heat exchanger 14. The mounting surface 73a shown in Fig. 9 is disposed parallel to the rotation axis R. This configuration makes it possible to reduce the projected area of ​​the substrate 73 projected in the axial direction of the rotation axis R. As a result, the indoor unit 10 can be made smaller in size in the axial direction of the rotation axis R.

[0068] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-described embodiments, and the following configurations and methods may also be employed. Furthermore, the configurations and methods described in this specification may be combined as appropriate within the scope of not being mutually inconsistent.

[0069] For example, in the above-described embodiment, the refrigerant sensor unit is described as being used in a ceiling-mounted indoor unit. However, the refrigerant sensor unit of the embodiment can also be used in other types of indoor units, and can be widely used in various devices equipped with air blowing means other than air conditioners. Furthermore, in the above-described embodiment, the element case is described as being cylindrical, but the element case does not have to have a circular outer shape as long as it is cylindrical. Similarly, in the above-described configuration, the through-hole of the tubular member is described as being circular, but the through-hole may have a shape that follows the outer shape of the element case. Furthermore, in the above-described embodiment, the outer shape of the tubular member is described as being rectangular, but the outer shape of the tubular member is not limited.

[0070] DESCRIPTION OF SYMBOLS 10... Indoor unit, 14... Indoor heat exchanger (heat exchanger), 20... Outdoor unit, 25... Blower, 30... Refrigerant circuit, 40... Centrifugal blower, 40a... Impeller, 50... Refrigerant sensor unit, 60... Housing, 60a... Refrigerant inlet, 60g, 60k... Convex portion, 60h... Insertion hole, 60t... Protrusion, 60u... Notch, 61... Housing main body, 61e... Rib, 61f... First sealing surface, 62... Cover, 62e... Recess, 62f...second sealing surface, 68...wiring sealing member, 69...sealing member, 70...sensor body, 71...sensor element, 72...element case, 72h...case opening, 73...substrate, 73a...mounting surface, 79...wiring, 80...cylindrical member, 82...tip surface, 83...outer circumferential surface, 86...first sealing portion, 87...second sealing portion, 100...air conditioner, A...accommodation space, D1...assembly direction, F...introduction path, R...rotation axis

Claims

1. An indoor unit of an air conditioner having a refrigerant circuit through which a refrigerant circulates, A refrigerant sensor unit for detecting the vaporized refrigerant is provided. The refrigerant sensor unit includes: A sensor body; a housing provided with an accommodation space for accommodating the sensor body and a refrigerant inlet for introducing the refrigerant into the accommodation space; A cylindrical member, The sensor body includes: A substrate having a mounting surface; A sensor element mounted on the mounting surface; a cylindrical element case fixed to the mounting surface, surrounding the sensor element, and extending in a direction perpendicular to the mounting surface; a case opening for introducing the refrigerant into the element case is provided at an end portion of the element case opposite to the mounting surface, The housing includes: A housing body; a cover body that is assembled to the housing body in an assembly direction and surrounds the storage space together with the housing body, The refrigerant inlet opens horizontally or downwardly, the cylindrical member is an elastic body having a closed cell structure that is disposed in the housing space and surrounds an outer peripheral surface of the element case, an introduction path that connects the refrigerant inlet and the case opening is provided inside the cylindrical member; The cylindrical member is a first sealing portion that contacts an outer peripheral surface of the element case and seals a path between the cylindrical member and the outer peripheral surface of the element case; a second sealing portion that contacts the inner surface of the housing and seals a path between the tubular member and the inner surface of the housing; Indoor unit.

2. a protrusion that protrudes toward the second sealing portion and compresses the tubular member is provided on an inner surface of the housing; The indoor unit according to claim 1.

3. The housing has a sealing member sandwiched between the housing body and the lid, The housing body includes: a first sealing surface surrounding the accommodation space when viewed from the assembly direction and in contact with the sealing member; a rib protruding from an edge of the first sealing surface on the accommodation space side toward the lid body in the assembly direction, The lid body is a second sealing surface surrounding the accommodation space when viewed from the assembly direction and in contact with the sealing member; a recess that is continuous with an edge portion of the second sealing surface on the side of the accommodation space and surrounds the rib, The indoor unit according to claim 1.

4. the refrigerant sensor unit has wiring connected to the substrate, The housing has an insertion hole for leading the wiring from the accommodation space to the outside. A cutout portion is provided on one of the first sealing surface and the second sealing surface, and a protrusion portion to be inserted into the cutout portion is provided on the other of the first sealing surface and the second sealing surface. the insertion hole is surrounded by an inner surface of the cutout portion and a tip surface of the protrusion, A strip-shaped wire sealing member is wound around the outer periphery of the wire, The wiring sealing member is compressed by an inner side surface of the notch and a tip surface of the protrusion. The indoor unit according to claim 3.

5. A centrifugal fan having an impeller that rotates about a rotation axis and sends air radially outward; a heat exchanger disposed radially outward of the centrifugal blower, the refrigerant sensor unit is disposed between the centrifugal blower and the heat exchanger, The mounting surface is disposed parallel to the rotation axis. The indoor unit according to claim 1.

6. An indoor unit according to any one of claims 1 to 5; The refrigerant circuit; An outdoor unit; Air conditioner.