Centrifugal fan

Abstract

The present invention provides a centrifugal fan in which the welding of a vane member to a shroud can be confirmed by visual observation. The centrifugal fan of the present invention is a centrifugal fan including a main plate, a shroud, and a plurality of vane members, wherein an engaging portion that can be engaged with the shroud is provided on the vane member, a rib is provided on the engaging portion, the engaging portion is engaged with the shroud by welding the rib on the shroud, and a through-hole is provided on the shroud at a position overlapping the rib in a height direction of the rib.

Description

TECHNICAL FIELD

[0001] The present application relates to a centrifugal fan. BACKGROUND

[0002] Patent Document 1 discloses a centrifugal fan which is mounted in an indoor unit of an air conditioner or the like, and includes a main plate, a case, and a plurality of blade members of a turbo fan. The case and the plurality of blade members of the centrifugal fan are integrally formed by a thermoplastic resin, the case has engaging portions which engage the plurality of blade members, the plurality of engaging portions of the case engage the plurality of blade members respectively, and the engagement is achieved by ultrasonic welding.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENT

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-206084 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present application provides a centrifugal fan which does not require a destructive test of welding of blade members to a case, and allows a judgment of a good product to be made by visual observation.

[0008] METHOD FOR SOLVING THE PROBLEMS

[0009] The centrifugal fan of the present application is a centrifugal fan including a main plate, a case, and a plurality of blade members, wherein an engaging portion which is capable of engaging with the case is provided in the blade member, a rib is provided in the engaging portion, the engaging portion is engaged to the case by welding the rib to the case, and a through-hole is provided in the case at a position overlapping the rib in a height direction of the rib.

[0010] EFFECT OF THE INVENTION

[0011] According to the present application, an operator can visually recognize the rib via the through-hole. Therefore, the operator can make a judgment of a good product by visual observation without performing a destructive test of welding of blade members to a case. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a perspective view of an indoor unit of an air conditioning device to which the centrifugal fan in the embodiment is applied.

[0013] Figure 2 is a longitudinal sectional view of the indoor unit.

[0014] Figure 3 is an exploded perspective view of the centrifugal fan.

[0015] Figure 4 is a plan view of the centrifugal fan as viewed from a drain pan side.

[0016] Figure 5 is a perspective view of the blade member as viewed from the drain pan side.

[0017] Figure 6 is a plan view of the cover as viewed from the main plate side.

[0018] Figure 7 is a VII-VII sectional view of Figure 4

[0019] Figure 8 is a VIII-VIII sectional view of Figure 4

[0020] Figure 9 is a plan view of the soldering engaging portion as viewed from the drain pan side.

[0021] BRIEF DESCRIPTION OF DRAWINGS

[0022] 1 air conditioning device

[0023] 10 indoor unit

[0024] 20 blower

[0025] 21 fan motor

[0026] 22 rotation shaft

[0027] 23 centrifugal fan

[0028] 24 main plate

[0029] 25 motor housing portion

[0030] 26 cover

[0031] 27 blade member

[0032] 30 indoor heat exchanger

[0033] 31 drain pan

[0034] 46 engaging portion

[0035] 56, 76 soldering rib

[0036] 70 soldering engaging portion

[0037] 78 confirmation hole (through hole) DETAILED DESCRIPTION

[0038] (Insights, etc. as a basis of the present invention)

[0039] Before the inventors conceived the present invention, a centrifugal fan was known, which is mounted in an indoor unit of an air conditioning machine or the like, and includes a main plate, a cover, and a plurality of wings of a turbo fan.​​

[0040] The cover and the plurality of blade members of the centrifugal fan are each formed of a thermoplastic resin. The cover has engaging portions that engage the plurality of blade members, and the blade members have engaging portions that engage the engaging portions of the cover. Moreover, the centrifugal fan engages the engaging portions of the plurality of blade members to the engaging portions of the cover by ultrasonic welding to form an integrated body.

[0041] However, the inventors found the following technical problem: in the existing turbofan, the engaging portions of the plurality of blade members are covered by the engaging portions of the cover, so it is not possible to confirm whether the blade members and the cover are integrated by ultrasonic welding. To solve this technical problem, the subject matter of the present invention is proposed.

[0042] Here, the present invention provides a centrifugal fan in which welding of the blade members and the cover can be confirmed by visual observation.

[0043] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, detailed description of unnecessary matters will be omitted at times. For example, detailed description of matters that are widely known will be omitted at times, or repeated description of substantially identical structures will be omitted. This is to avoid the following description from being excessively long, so that those skilled in the art can easily understand the present invention.

[0044] In addition, the drawings and the following description are provided to enable those skilled in the art to fully understand the present invention, and do not limit the scope of the present invention.

[0045] (Embodiments)

[0046] Hereinafter, the following Figures 1-9 An embodiment will be described.

[0047] [1-1. Structure]

[0048] [1-1-1. Structure of indoor unit]

[0049] Figure 1 is a perspective view of an indoor unit 10 of an air conditioning device 1 to which the centrifugal fan 23 in the present embodiment is applied. Figure 2 is a longitudinal sectional view of the indoor unit 10.

[0050] The air conditioning device 1 includes a refrigeration cycle formed of an indoor heat exchanger 30 housed in the indoor unit 10, a compressor and a pressure reducing device housed in an outdoor unit, an outdoor heat exchanger, an expansion valve, a switching valve, and the like, and air conditioning of an indoor space provided with the indoor unit 10 is performed by circulating a refrigerant in the refrigeration cycle.

[0051] As Figure 1As shown, the indoor unit 10 of the air conditioning apparatus 1 of the present embodiment is a so-called ceiling recessed type indoor unit capable of blowing air in four directions. This indoor unit 10 is provided with a heat exchanger 19, a fan 20, and a control unit 30. Figure 2 As shown, a ceiling space 13 is provided between a ceiling 11 of a house and a ceiling 12 provided below the ceiling 11. Hereinafter, for convenience of explanation, the upper and lower directions are set to mean the upper and lower directions in a state in which the indoor unit 10 is provided, and in each drawing, the upper direction is indicated by UP and the lower direction is indicated by DN.

[0052] The indoor unit 10 includes an indoor unit main body 14 formed in a box shape with an open lower surface, and a hanger 18 is attached to the outer corner portion of the indoor unit main body 14. The indoor unit main body 14 is provided in a state of being suspended from the ceiling 11 by a lifting bolt 15 connected to the hanger 18. Inside the indoor unit main body 14, a foamed styrene heat insulating member 16 is provided. The heat insulating member 16 is arranged in a state of contacting the inner surface of a side plate 17 of the indoor unit main body 14, and prevents dew condensation on the side plate 17.

[0053] A fan motor 21 is attached to the lower surface of the upper plate of the indoor unit main body 14, and a rotation shaft 22 that is rotationally driven by the driving of the fan motor 21 is provided extending downward in the fan motor 21. A centrifugal fan 23 is attached to the lower end portion of the rotation shaft 22, and the fan 20 is constituted by the fan motor 21 and the centrifugal fan 23.

[0054] The centrifugal fan 23 includes a main plate 24 formed in a ring-shaped plate shape. A motor housing portion 25 in the shape of an inverted truncated cone extending downward is formed in the center portion of the main plate 24.

[0055] The fan motor 21 is housed in the motor housing portion 25, and the rotation shaft 22 of the fan motor 21 extends downward and is connected to the bottom surface of the motor housing portion 25. Further, by rotationally driving the fan motor 21, the centrifugal fan 23 is rotationally driven by the rotation shaft 22.

[0056] A main plate extension portion 29 in the shape of a so-called flat plate extending outward and forming the outer periphery of the main plate 24 is provided on the outer periphery of the motor housing portion 25.

[0057] A shroud 26 in the shape of a ring with an arc-shaped peripheral surface is provided below the main plate 24. A plurality of blade members 27 are integrally formed in a predetermined interval in the circumferential direction between the main plate 24 and the inner peripheral surface of the shroud 26.

[0058] An orifice 28 in the shape of a ring with an arc-shaped peripheral surface is provided below the shroud 26.

[0059] Between the fan 20 and the thermal insulation member 16, an indoor heat exchanger 30 which is bent to be substantially quadrangular in plan view is arranged so as to surround the lateral side of the fan 20.

[0060] The indoor heat exchanger 30 functions as an evaporator of the refrigerant during cooling operation and functions as a condenser of the refrigerant during heating operation. The indoor heat exchanger 30 is configured to perform heat exchange between the air in the indoor space and the refrigerant, and to cool the air in the indoor space during cooling operation and to heat the air in the indoor space during heating operation.

[0061] On the lower side of the indoor heat exchanger 30, a drain pan 31 is arranged so as to correspond to the lower surface of the indoor heat exchanger 30. The drain pan 31 is used to receive drain water generated in the indoor heat exchanger 30. Further, in the central portion of the drain pan 31, a suction port 32 of the fan 20 is formed.

[0062] On the lower surface of the indoor unit main body 14, a substantially quadrangular decorative panel 33 is installed so as to cover the lower side opening of the indoor unit main body 14.

[0063] In the central portion of the decorative panel 33, a suction port 34 which communicates with the suction port 32 of the drain pan 31 is formed, and a suction grille 35 which covers the suction port 34 is detachably installed in the suction port 34 portion of the decorative panel 33. On the indoor unit main body 14 side of the suction grille 35, a filter 36 for removing dust and the like in the air is provided.

[0064] Outside the suction port 34 of the decorative panel 33, blow ports 37 which send the air adjusted by the air conditioner to the indoor space are formed at positions along each side of the decorative panel 33. In each blow port 37, a swing piece 38 which changes the opening and closing of each blow port 37 and the direction of the wind from each blow port 37 is provided.

[0065] In the indoor unit 10 of the present embodiment, air in the indoor space is sucked in from the suction port 34 by driving the fan 20. The sucked air is heat-exchanged by the indoor heat exchanger 30 after passing through the filter 36, and the air adjusted by the air conditioner is sent to the indoor space as wind from the blow ports 37.

[0066] [1-1-2. Structure of centrifugal fan]

[0067] Next, the centrifugal fan 23 will be described in detail.

[0068] Figure 3 is an exploded perspective view of the centrifugal fan 23. Figure 4 is a plan view of the centrifugal fan 23 as viewed from the drain pan 31 side (lower side).

[0069] like Figure 3 , Figure 4 As shown, the centrifugal fan 23 is a so-called turbo fan, which is formed by a main board 24, a cover 26, and a plurality of blade components 27. The centrifugal fan 23 is formed by assembling the components after they have been manufactured separately. In this embodiment, the main board 24, the cover 26, and the plurality of blade components 27 are all formed of thermoplastic resin.

[0070] The main body 24, the cover 26, and the multiple blade components 27 are all formed of a thermoplastic resin material. The cover 26 and the multiple blade components 27 use materials with different colors to each other.

[0071] Figure 5 This is a perspective view of the blade component 27 viewed from the side (below) of the drainage tray 31.

[0072] like Figure 5 As shown, each blade component 27 is formed as a flat plate. Each blade component 27 is integrally formed with the main board 24. Each blade component 27 includes: a positive pressure surface 40 disposed opposite to the motor housing 25 and located on the positive pressure side of the centrifugal fan 23; and a negative pressure surface 41 disposed opposite to the indoor heat exchanger 30 and located on the negative pressure side of the centrifugal fan 23. Each blade component 27 includes a leading edge 48 located on the front side and a trailing edge 49 located on the rear side in the rotational direction of the centrifugal fan 23.

[0073] A flat surface is formed at the upper end 43 of each blade component 27, and a flange portion 45 extending outward along the entire circumference is provided at this upper end 43. The upper surface of the flange portion 45 forms a plane that is continuous with the flat surface at the upper end of each blade component 27. This flange portion 45 forms part of the main board extension 29 in the assembled centrifugal fan 23.

[0074] At the lower end 44 of each blade component 27, a downwardly protruding joint portion 46 is provided. The joint portion 46, when viewed from above, extends from the leading edge 48 side to the trailing edge 49 side. The joint portion 46 is formed in a stepped shape with different heights from the leading edge 48 side to the trailing edge 49 side. In this embodiment, the joint portion 46 has an upper stepped portion 52 on the leading edge 48 side and a lower stepped portion 54 that protrudes downwards from the upper stepped portion 52 on the trailing edge 49 side.

[0075] The upper surfaces of both the upper step 52 and the lower step 54 are formed as flat surfaces. The upper surfaces of the upper step 52 and the lower step 54 are connected by an inclined surface 42.

[0076] Engaging pins 47 are provided on the upper surfaces of both the upper step 52 and the lower step 54. The engaging pins 47 are formed into cylindrical shapes with a straight diameter that is approximately the same as the width of the engaging part 46, and protrude downward from the upper surfaces of the upper step 52 and the lower step 54.

[0077] Multiple welding ribs 56 are provided on the upper surfaces of both the upper step 52 and the lower step 54. Each welding rib 56 forms a triangular shape when viewed in cross-section. Figure 7 Each welding rib 56 is configured to extend along its edge in a direction orthogonal to the long side direction of the joint 46, within the periphery of the upper surface of the upper step 52 and the lower step 54, respectively. That is, each welding rib 56 is configured to extend along the long side direction of the joint 46 near the edges located on the positive pressure surface 40 and the negative pressure surface 41, respectively, on the upper surface of the upper step 52 and the lower step 54. Therefore, welding ribs 56 are provided in pairs on the upper surface of the upper step 52 and the lower step 54 in a direction orthogonal to the long side direction of the joint 46, i.e., in the width direction of the joint 46.

[0078] In addition, each welding rib 56 is positioned on the upper surface of the upper step 52 and the lower step 54, avoiding the position of each connecting pin 47.

[0079] In addition, in this embodiment, the welding rib 56 is omitted on the positive pressure surface 40 side on the leading edge 48 side of the upper step 52.

[0080] Figure 6 This is a plan view of the cover 26 viewed from the side (above) of the motherboard 24.

[0081] like Figure 6 As shown, the cover 26 is provided with a plurality of welding engagement portions 70 that respectively engage with the joint portions 46 of each blade component 27. Each welding engagement portion 70 is concave when viewed from the inner side of the cover 26, and each welding engagement portion 70 is configured to bulge out from the inner side to the outer side of the cover 26.

[0082] Figure 7 yes Figure 4 Section VII-VII. Figure 8 yes Figure 4 Sectional view of VIII-VIII.

[0083] like Figure 7 , Figure 8 As shown, the inner circumferential surface shape of each welding engagement portion 70 is formed to be approximately the same as the outer shape of the joint portion 46. When the welding engagement portion 70 is inserted and engages the joint portion 46 of the blade component 27, the blade component 27 and the cover 26 are stably supported by each other.

[0084] In a state where the welding engaging portion 70 is engaged with the joint portion 46 so as to be inserted therethrough, at a prescribed portion of the welding engaging portion 70, an upper step abutment surface 72 is provided so as to be arranged opposite to the upper surface of the upper step portion 52 of the joint portion 46, and a lower step abutment surface 74 is provided so as to be arranged opposite to the upper surface of the lower step portion 54. At each of the upper step abutment surface 72 and the lower step abutment surface 74, an insertion hole 71 is provided as a through hole that communicates the inner side surface side and the outer side surface side of the cover 26. When the joint portion 46 is engaged with the welding engaging portion 70 so as to be inserted therethrough, each of the insertion holes 71 is inserted by each of the joint pins 47.

[0085] At substantially the center of each of the upper step abutment surface 72 and the lower step abutment surface 74, a plurality of welding ribs 76 are provided so as to extend in the longitudinal direction of the welding engaging portion 70. The welding ribs 76 are arranged at positions that avoid each of the insertion holes 71 at each of the upper step abutment surface 72 and the lower step abutment surface 74.

[0086] When the joint portion 46 is engaged with the welding engaging portion 70 so as to be inserted therethrough, as shown in FIG. 6, the welding ribs 76 are arranged between the pair of welding ribs 56 in a direction orthogonal to the longitudinal direction of the joint portion 46. Figure 7

[0087] In a state where the joint portion 46 is engaged with the welding engaging portion 70 so as to be inserted therethrough, the upper end of each of the welding ribs 76 abuts against the upper surface of the upper step portion 52 or the upper surface of the lower step portion 54 of the joint portion 46. Further, in a state where the joint portion 46 is engaged with the welding engaging portion 70 so as to be inserted therethrough, the upper end of each of the welding ribs 56 abuts against the upper step abutment surface 72 or the lower step abutment surface 74.

[0088] At each of the upper step abutment surface 72 and the lower step abutment surface 74, a confirmation hole 78 is provided. The confirmation hole 78 is a through hole that communicates the inner side surface side and the outer side surface side of the cover 26.

[0089] The above-described confirmation hole 78 is provided at a position overlapping at least any one of the welding ribs 56 when viewed in the height direction of the welding rib 56 in a state where the joint portion 46 is engaged with the welding engaging portion 70 so as to be inserted therethrough. That is, the above-described confirmation hole 78 is provided within the projection plane of at least any one of the welding ribs 56 when viewed in the height direction of the welding rib 56 in a state where the joint portion 46 is engaged with the welding engaging portion 70 so as to be inserted therethrough.

[0090] In the present embodiment, two confirmation holes 78 are provided at the upper step abutment surface 72, and one confirmation hole 78 is provided at the lower step abutment surface 74. That is, the confirmation holes 78 are provided at a prescribed interval in the longitudinal direction of the joint portion 46.

[0091] ​The two confirmation holes 78 provided in the upper step abutting surface 72 are provided at a predetermined interval in a direction orthogonal to the long side direction of the joint portion 46. Therefore, the two confirmation holes 78 provided in the upper step abutting surface 72 are respectively provided at positions where the welding ribs 56 provided at the edge portion on the side close to the positive pressure surface 40 and the welding ribs 56 provided at the edge portion on the side close to the negative pressure surface 41 overlap. In the present embodiment, the welding ribs 76 are provided at positions between the two confirmation holes 78 provided in the upper step abutting surface 72.

[0092] In addition, each of the confirmation holes 78 is provided in the vicinity of the insertion hole 71.

[0093] In addition, the confirmation holes 78 can be provided at any number at any arrangement position according to the shape and size of the joint portion 46 and the welding engagement portion 70.

[0094] Figure 9 is a plan view of the welding engagement portion 70 in which the joint portion 46 is inserted, viewed from the drain pan 31 side.

[0095] The diameter dimension of each of the confirmation holes 78 is formed larger than the width dimension of the welding ribs 56. Therefore, in a state where the joint portion 46 is engagedly inserted in the welding engagement portion 70, the entire width of the welding ribs 56 provided at a position overlapping each of the confirmation holes 78 can be visually recognized from the drain pan 31 side through each of the confirmation holes 78.

[0096] In addition, as described above, each of the blade members 27 and the cover 26 is formed of members having different colors from each other. Therefore, the welding ribs 56 and the welding engagement portion 70 are formed of members having different colors from each other. Thus, each of the welding ribs 56 corresponding to each of the confirmation holes 78 can be more reliably visually recognized through each of the confirmation holes 78.

[0097] [1-2. Assembly process flow]

[0098] Next, the assembly process flow of the centrifugal fan 23 will be described.

[0099] In the present embodiment, after the main plate 24 and each of the blade members 27 are housed in a predetermined mold and fixed, the main plate 24 and each of the blade members 27 are formed in one body by insert molding. Thus, each of the blade members 27 is provided on the upper surface of the main plate extension portion 29 of the main plate 24.

[0100] Next, each of the blade members 27 and the cover 26 are fixed in one body by ultrasonic welding.

[0101] Specifically, the joint portion 46 of each of the blade members 27 is engagedly inserted in the welding engagement portion 70. At this time, each of the joint pins 47 of each of the joint portions 46 is inserted in the insertion hole 71 of the welding engagement portion 70 and protrudes toward the outside surface side of the cover 26.

[0102] At this time, the operator can confirm whether or not the corresponding each welding rib 56 can be visually recognized via each confirmation hole 78. Thereby, it can be confirmed that each welding rib 56 has a rib shape, and it can be confirmed whether or not the joint portion 46 is reliably engaged to the welding engagement portion 70.

[0103] As described above, by the joint portion 46 being engaged to the welding engagement portion 70 in a penetrating manner, the welding engagement portion 70 and the joint portion 46 can be supported to each other.

[0104] Further, in this state, the upper end of each welding rib 76 abuts against the upper surface of the upper step portion 52 or the upper surface of the lower step portion 54 of the joint portion 46. Further, in the state in which the joint portion 46 is engaged to the welding engagement portion 70 in a penetrating manner, the upper end of each welding rib 56 abuts against the upper step abutment surface 72 or the lower step abutment surface 74.

[0105] In the above-described state, the horn of the ultrasonic welding machine is pressed to a prescribed portion of the welding engagement portion 70 with a prescribed pressure, and the horn is ultrasonically vibrated, and thereby ultrasonic vibration is applied to the welding engagement portion 70 and the joint portion 46.

[0106] As described above, the welding engagement portion 70 and the joint portion 46 are in contact with each other via each welding rib 76 and each welding rib 56. Further, each welding rib 56 and each welding rib 76 are formed in a triangular shape in cross section. Therefore, when ultrasonic vibration is applied to the welding engagement portion 70 and the joint portion 46, each welding rib 56 and each welding rib 76 function as so-called energy directors that generate concentrated expansion and contraction movements. Thereby, each welding rib 56 and each welding rib 76 are heated by frictional heat caused by the vibration, and are melted in a short time to a prescribed resin melting temperature.

[0107] Thereby, the upper surface of the upper step portion 52 and the upper step abutment surface 72 are welded, the upper surface of the lower step portion 54 and the lower step abutment surface 74 are welded, and the welding engagement portion 70 and the joint portion 46 are joined. Therefore, the lower end of each vane member 27 can be fixed to the cover 26.

[0108] As described above, each confirmation hole 78 is opened in contact with the upper end of the welding rib 56 disposed at a position overlapping the confirmation hole 78 when viewed in the height direction of the welding rib 56. Therefore, by ultrasonic welding, each welding rib 56 is melted, and the melted welding rib 56 enters the inside of the confirmation hole 78 and protrudes to the side of the outer surface of the cover 26 located outside the confirmation hole 78.

[0109] The operator visually recognizes the state of the welding rib 56 that can be visually recognized from the confirmation hole 78 via the above-described confirmation hole 78, and thereby can confirm whether or not each welding rib 56 is melted.

[0110] Thus, the operator can easily confirm whether the blade member 27 is joined by welding to the cover 26.

[0111] Thus, for example, it is possible to suppress confirmation of whether the joining site of the welding engagement portion 70 and the joining portion 46 is damaged by the test. Specifically, the operator can make a judgment of a good product with the eyes even without performing a damage test of welding of the blade member and the cover. That is, in the present embodiment, it is possible to reduce the manufacturing cost of the centrifugal fan 23.

[0112] [1-3. Effects, etc.]

[0113] As described above, in the present embodiment, the centrifugal fan 23 includes the main plate 24, the cover 26, and the plurality of blade members 27. The joining portion 46 that is joined to the welding engagement portion 70 of the cover 26 is provided in each blade member 27, and the plurality of welding ribs 56 are provided in the joining portion 46. Each joining portion 46 is joined to the cover 26 by welding the welding rib 56 to the cover 26. Then, in the cover 26, the confirmation hole 78 is provided at a position overlapping the welding rib 56 in the height direction of the welding rib 56.

[0114] Thus, when the operator joins the blade member 27 to the cover 26 using ultrasonic welding, the operator visually recognizes the state of the welding rib 56 that can be visually recognized from the confirmation hole 78 via the confirmation hole 78, and thereby can confirm whether each welding rib 56 is melted. Thus, the operator can easily confirm whether the blade member 27 is joined by welding to the cover 26, and can judge a good product by the eyes without performing a damage test.

[0115] As in the present embodiment, it is also possible that the confirmation hole 78 is provided at least two in the longitudinal direction of the joining portion 46.

[0116] Thus, the operator can visually recognize the welding rib 76 via the confirmation hole 78 at at least two positions in the longitudinal direction of the joining portion 46. Thus, when the operator joins the blade member 27 to the cover 26, the operator can confirm whether there is a positional deviation of the joining portion 46 and the welding engagement portion 70 in the longitudinal direction of the joining portion 46, or unevenness in pressing of the welding head of the ultrasonic welding machine.

[0117] As in the present embodiment, it is also possible that the confirmation hole 78 is provided at least two in a direction orthogonal to the longitudinal direction of the joining portion 46.

[0118] Thus, the operator can visually recognize the welding rib 76 via the confirmation hole 78 at at least two positions in the direction orthogonal to the longitudinal direction of the joint 46. Therefore, the operator can confirm whether there is a positional deviation of the joint 46 from the welding engaging portion 70, or unevenness in the pressing of the welding head of the ultrasonic welding machine in the direction orthogonal to the longitudinal direction of the joint 46 when joining the blade member 27 to the cover 26.

[0119] As in the present embodiment, the diameter of the confirmation hole 78 can be formed larger than the width of the welding rib 56.

[0120] Thus, in the state where the welding engaging portion 70 is engaged with the joint 46, the operator can visually recognize the entire width of the welding rib 56 provided at the position overlapping the confirmation hole 78 from the drain pan 31 side via the confirmation hole 78. Therefore, when the welding engaging portion 70 is not welded to the joint 46, the operator can visually recognize the outer edge of the welding rib 56 in the width direction via the confirmation hole 78. Thus, the operator can confirm whether the welding engaging portion 70 and the joint 46 are welded together.

[0121] As in the present embodiment, the welding rib 56 can be formed of a member having a different color from the member forming the cover 26.

[0122] Thus, the operator can improve the visual recognition of the welding rib 56 via the confirmation hole 78. Therefore, the operator can more reliably confirm whether the welding engaging portion 70 and the joint 46 are properly engaged, or whether the welding engaging portion 70 and the joint 46 are welded.

[0123] (Other Embodiments)

[0124] As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology of the present application is not limited to this, and embodiments in which changes, substitutions, additions, omissions, and the like are made can also be applicable. Furthermore, new embodiments can also be realized by combining each of the constituent elements described in the above embodiments.

[0125] Other embodiments will be described below.

[0126] In the above embodiments, each of the confirmation holes 78 is provided near each of the insertion holes 71. However, this is not limiting, and each of the confirmation holes 78 can be provided near each of the positions close to both ends in the longitudinal direction of the joint 46.

[0127] Thus, the operator can visually recognize the welding rib 76 via the confirmation hole 78 in the vicinity of both ends in the longitudinal direction of the joint portion 46. Therefore, the operator can more reliably confirm whether or not there is a positional displacement of the joint portion 46 and the welding engaging portion 70 in a direction orthogonal to the longitudinal direction of the joint portion 46, or unevenness in the pressing of the horn of the ultrasonic welding machine, when joining the blade member 27 and the cover 26.

[0128] In the above-described embodiment, the ultrasonic welding is used as the method of welding each blade member 27 and the cover 26. However, the present application is not limited thereto, and other welding methods such as impulse welding (heater welding), infrared heater welding, or the like can be used.

[0129] In the above-described embodiment, the welding ribs 56, 76 are formed in a triangular shape in cross section. However, the present application is not limited thereto, and the welding ribs 56, 76 can be formed in other shapes such as a flat surface shape, a mountain shape, an arch shape, or the like at the upper end.

[0130] Industrial Applicability

[0131] The present application can be applied to a centrifugal fan in which an operator can confirm the welding of a blade member and a cover by eye observation. Specifically, the present application can be applied to an indoor unit of an air conditioning device or the like.

Claims

1. A centrifugal fan including a main plate, a shroud, and a plurality of vane members, the centrifugal fan characterized by: the vane member being provided with an engaging portion capable of engaging with the shroud, the engaging portion being provided with a rib at the engaging portion, the engaging portion being engaged to the shroud by the rib being fusion-welded to the shroud after being melted, the shroud being provided with a through-hole at a position overlapping the rib, as viewed in a height direction of the rib, the rib entering inside the through-hole when the rib is melted.

2. The centrifugal fan according to claim 1, characterized by: the through-hole being provided with at least two in a long direction of the engaging portion.

3. The centrifugal fan according to claim 2, characterized by: the through-holes being respectively provided at positions close to both ends in the long direction of the engaging portion.

4. The centrifugal fan according to any one of claims 1 to 3, characterized by: the through-hole being provided with at least two in a direction orthogonal to the long direction of the engaging portion.

5. The centrifugal fan according to any one of claims 1 to 4, characterized by: a diameter dimension of the through-hole being formed larger than a width dimension of the rib.

6. The centrifugal fan according to any one of claims 1 to 5, characterized by: the rib being formed of a member having a different color from a member forming the shroud.

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