The present disclosure relates to a heat-exchanger fixing plate to be used for fixing a heat exchanger of an air-conditioning apparatus to a housing, and also relates to an indoor unit of an air-conditioning apparatus.
Some heat exchanger included in an indoor unit of an air-conditioning apparatus is fixed to a heat-exchanger fixing plate located on at least one of the left and right side portions of the heat exchanger. The heat-exchanger fixing plate is fixed to a housing of the indoor unit, so that the heat exchanger is held in the indoor unit (see, for example, Patent Literature 1). The heat-exchanger fixing plate disclosed in Patent Literature 1 is made of resin, and has insertion holes through which hairpin portions of heat transfer tubes are inserted, the hairpin portions protruding from the side portion of the heat exchanger. The heat-exchanger fixing plate is fixed to the heat exchanger by inserting the hairpin portions of the heat transfer tubes through the insertion holes. The heat-exchanger fixing plate fixed to the heat exchanger is fastened to a housing panel of the housing with screws inserted through round holes on fixing portions provided on the heat-exchanger fixing plate, so that the heat exchanger is fixed to the housing.
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2007-64623
The housing panel of the indoor unit is detached from and attached to the heat-exchanger fixing plate at the time of parts replacement, maintenance, and other work. Each time the housing panel is detached and attached, the screws are removed and tightened. Due to this structure, the fixing portions of the heat-exchanger fixing plate with the housing panel are required to have a strength sufficient to withstand repeated screw tightening. However, in Patent Literature 1, the heat-exchanger fixing plate is only described as being made of resin, and the strength of the heat-exchanger fixing plate is not considered.
It is conceivable that a heat-exchanger fixing plate is made of high-strength material to improve the strength of the heat-exchanger fixing plate. However, depending on the material, the heat-exchanger fixing plate may expand and contract due to a temperature change during cooling operation or heating operation. This leads to a problem in that friction, generated between insertion holes and hairpin portions inserted through the insertion holes, may cause unusual noise.
The present disclosure has been made in view of such an issue, and it is an object of the present disclosure to provide a heat-exchanger fixing plate that makes it possible to reduce unusual noise, while improving the strength at a fixing portion of the heat-exchanger fixing plate with a housing panel, and also provide an indoor unit of an air-conditioning apparatus.
A heat-exchanger fixing plate according to one embodiment of the present disclosure is a heat-exchanger fixing plate to fix a side portion of a heat exchanger to a housing panel of an air-conditioning apparatus, the heat exchanger including a heat radiation fin and a heat transfer tube. The heat-exchanger fixing plate includes a heat-exchanger support portion facing the side portion of the heat exchanger, and having an insertion hole through which a hairpin portion of the heat transfer tube of the heat exchanger is inserted; and a housing-panel fixing portion formed separately from the heat-exchanger support portion and fitted to the heat-exchanger support portion, the housing-panel fixing portion being fastened with a screw to the housing panel such that the heat exchanger is fixed to the housing panel. The housing-panel fixing portion is made of material having a higher mechanical strength than a mechanical strength of material of which the heat-exchanger support portion is made, and the heat-exchanger support portion is made of the material having a lower friction coefficient than a friction coefficient of the material of which the housing-panel fixing portion is made.
According to one embodiment of the present disclosure, the housing-panel fixing portion fastened with a screw to the housing panel such that the heat exchanger is fixed to the housing panel is formed separately from the heat-exchanger support portion, and the housing-panel fixing portion is made of material having a higher mechanical strength than a mechanical strength of material of which the heat-exchanger support portion is made. This can improve the strength of a fixing portion of the heat-exchanger fixing plate with the housing panel. As the heat-exchanger support portion is made of material having a lower friction coefficient than a friction coefficient of material of which the housing-panel fixing portion is made, unusual noise can be reduced compared to the case where the heat-exchanger support portion is made of material that is the same as that of the housing-panel fixing portion.
A housing 10 of an indoor unit 1 includes a back casing 2 to be mounted on a wall surface, a top panel 3, a right side panel 4, a left side panel 5, and a front design panel 6. Hereinafter, these panels are sometimes collectively referred to as “housing panel” when these panels are not distinguished from each other.
In the housing 10, a fan 11, an electrical component box 12, a heat exchanger 13, and a drain pan 14 to receive condensed water generated in the heat exchanger 13 are located.
In the top panel 3, an air inlet 3a is formed to be used as an entrance into the indoor unit 1 for airflow generated by rotations of the fan 11. The drain pan 14 has an air outlet (not illustrated) that is used as an exit for the airflow.
The heat exchanger 13 exchanges heat between refrigerant and indoor air suctioned from the air inlet 3a to cool or heat the indoor air. The heat exchanger 13 is a fin-and-tube heat exchanger, and includes heat radiation fins 13a and heat transfer tubes 13b (see
In the indoor unit 1 configured as described above, when the fan 11 rotates, indoor air is suctioned from the air inlet 3a, and the suctioned indoor air passes through the heat exchanger 13 to be cooled or heated. The cooled air or heated air is then discharged from the air outlet into the room to cool or heat the room.
A heat-exchanger fixing plate 20 is fixed to the left side portion of the heat exchanger 13. At the time of fixing the heat exchanger 13 to the back casing 2, the heat exchanger 13 along with the heat-exchanger fixing plate 20 is inserted into the back casing 2 in the direction of arrows. Then, screws 16 are inserted into through holes (not illustrated) provided in the heat-exchanger fixing plate 20, and tightened into screw holes 2a provided in the back casing 2, so that the heat exchanger 13 is fixed to the back casing 2.
The right side panel 4 and the left side panel 5 are each made up of a resin-molded plate-like part. The right side panel 4 includes a base portion 4a facing the right side portion of the heat exchanger 13, and flange portions extending from the upper edge, the lower edge, and the front edge of the base portion 4a toward the leftward direction. The flange portions include an upper flange 4b, a lower flange 4c, and a front flange 4d. The left side panel 5 includes a base portion 5a facing the left side portion of the heat exchanger 13, and flange portions extending from the upper edge, the lower edge, and the front edge of the base portion 5a toward the rightward direction. The flange portions include an upper flange 5b, a lower flange 5c, and a front flange 5d.
The right side panel 4 is fixed to the back casing 2 by engaging a latch (not illustrated) provided on the right side panel 4 with an engagement portion (not illustrated) formed on the back casing 2, and further screwing the right side panel 4 to the back casing 2. The right side panel 4 is opened on the left side, and has low rigidity. Thus, the support force of the back casing 2 is insufficient for the moment in the leftward-rightward direction when the right side panel 4 is only latched to the back casing 2. Accordingly, to prevent the right side panel 4 from being unlatched from the back casing 2 by some kind of impact and from being removed from the back casing 2, the far-side portion of the lower flange 4c of the right side panel 4 is fastened to the front lower portion of the back casing 2 with a screw 7 to increase the support force.
The same applies to the left side panel 5. The left side panel 5 is fixed to the back casing 2 by engaging a latch (not illustrated) provided on the left side panel 5 with an engagement portion (not illustrated) formed on the back casing 2, and further screwing the left side panel 5 to the back casing 2. The left side panel 5 is opened on the right side, and has low rigidity. Thus, the support force of the back casing 2 is insufficient for the moment in the leftward-rightward direction when the left side panel 5 is only latched to the back casing 2. Accordingly, to prevent the left side panel 5 from being unlatched from the back casing 2 by some kind of impact and from being removed from the back casing 2, the far-side portion of the lower flange 5c of the left side panel 5 is fastened to the front lower portion of the back casing 2 with a screw 8 to increase the support force. The front flange 5d of the left side panel 5 is provided with a through hole 5f to be used for fixing the left side panel 5 to the heat-exchanger fixing plate 20.
Next, the heat-exchanger fixing plate 20, which is a characteristic part of the present embodiment, is described.
The heat-exchanger fixing plate 20 includes a heat-exchanger support portion 30 to support the heat exchanger 13 with the hairpin portions 13c of the heat exchanger 13 inserted through the heat-exchanger support portion 30, and a housing-panel fixing portion 40 to be used for fixing the heat-exchanger fixing plate 20 to the left side panel 5, which is the housing panel. In
The present embodiment is characterized in that the housing-panel fixing portion 40 is formed separately from the heat-exchanger support portion 30, and is made of material having a higher mechanical strength than a mechanical strength of material of which the heat-exchanger support portion 30 is made, while the heat-exchanger support portion 30 is made of the material having a lower friction coefficient than a friction coefficient of the material of which the housing-panel fixing portion 40 is made.
Hereinafter, the respective structures of the heat-exchanger support portion 30 and the housing-panel fixing portion 40 will be described.
As shown in
As shown in
In order that the housing-panel fixing portion 40 is fitted to the heat-exchanger support portion 30, first the lower engagement latch 43 is engaged with the lower engagement portion 32 of the heat-exchanger support portion 30 as shown by an arrow (1) in
As shown in
Note that in the case where the entirety of the heat-exchanger fixing plate 20 is made of ABS resin, when there is a temperature change during cooling operation or heating operation, the hairpin portions 13c contact the peripheral walls inside the insertion holes 31, through which the hairpin portions 13c are inserted, due to a difference in thermal expansion coefficient between the hairpin portions 13c and the peripheral walls. In this case, unusual noise is generated, such as rubbing sound produced by friction. There are countermeasures against the unusual noise, such as application of lubricant to the heat-exchanger fixing plate 20. However, as the heat-exchanger fixing plate 20 has a complicated shape, this leads to a workability problem in applying lubricant to the heat-exchanger fixing plate 20. Therefore, application of lubricant to the heat-exchanger fixing plate 20 is not preferable as countermeasures against the unusual noise.
In view of this, in the present embodiment, the heat-exchanger support portion 30 is made of polypropylene (PP) resin, Although PP resin has a lower mechanical strength compared to ABS resin, PP resin has a low friction coefficient and thus can be expected to be effective in reducing the unusual noise. Due to this configuration, the unusual noise can be reduced compared to the case where the heat-exchanger support portion 30 is also made of ABS resin similarly to the housing-panel fixing portion 40.
As described above, the present embodiment relates to the heat-exchanger fixing plate 20 to fix the side portion of the heat exchanger 13 to a housing panel of an air-conditioning apparatus, the heat exchanger 13 including the heat radiation fins 13a and the heat transfer tubes 13b. In the present embodiment, the left side panel 5 is shown as an example of the housing panel to be fixed to the heat-exchanger fixing plate 20. However, the housing panel to be fixed to the heat-exchanger fixing plate 20 may be the right side panel 4. The heat-exchanger fixing plate 20 of the present embodiment includes the heat-exchanger support portion 30 facing the side portion of the heat exchanger 13, and having the insertion holes 31 through which the hairpin portions 13c of the heat transfer tubes 13b of the heat exchanger 13 are inserted; and the housing-panel fixing portion 40 formed separately from the heat-exchanger support portion 30 and fitted to the heat-exchanger support portion 30, the housing-panel fixing portion 40 being fastened with a screw to the housing panel such that the heat exchanger 13 is fixed to the housing panel. The housing-panel fixing portion 40 is made of material having a higher mechanical strength than a mechanical strength of material of which the heat-exchanger support portion 30 is made. The heat-exchanger support portion 30 is made of the material having a lower friction coefficient than a friction coefficient of the material of which the housing-panel fixing portion 40 is made.
Due to this configuration, the heat-exchanger fixing plate 20 is capable of reducing unusual noise, while improving the fixing strength with the housing panel. As the heat-exchanger support portion 30 is made of material having a lower friction coefficient than a friction coefficient of material of which the housing-panel fixing portion 40 is made, the heat-exchanger fixing plate 20 can reduce unusual noise compared to the case where the heat-exchanger support portion 30 is made of material that is the same as that of the housing-panel fixing portion. There is no need to take countermeasures against unusual noise using lubricant. Thus, this can avoid the problem of workability that is required when lubricant is used.
In the present embodiment, the housing-panel fixing portion 40 is made of ABS resin.
As described above, the housing-panel fixing portion 40 can be made of ABS resin.
In the present embodiment, the heat-exchanger support portion 30 is made of PP resin.
As described above, the heat-exchanger support portion 30 can be made of PP resin.
In the present embodiment, the indoor unit 1 of an air-conditioning apparatus includes the heat-exchanger fixing plate 20 described above.
This configuration makes it possible to reduce unusual noise, while improving the strength at the fixing portion of the heat-exchanger fixing plate 20 with the housing panel.
1: indoor unit, 2: back casing, 2a: screw hole, 3: top panel, 3a: air inlet, 4: right side panel, 4a: base portion, 4b: upper flange, 4c: lower flange, 4d: front flange, 5: left side panel, 5a: base portion, 5b: upper flange, 5c: lower flange, 5d: front flange, 5f: through hole, 6: front design panel, 7: screw, 8: screw, 9: screw, 10: housing, 11: fan, 12: electrical component box, 13: heat exchanger, 13a: heat radiation fin, 13b: heat transfer tube, 13c: hairpin portion, 14: drain pan, 16: screw, 20: heat-exchanger fixing plate, 30: heat-exchanger support portion, 31: insertion hole, 32: lower engagement portion, 33: upper engagement portion, 40: housing-panel fixing portion, 41: body portion, 42: attachment portion, 42a: screw hole, 43: lower engagement latch, 44: upper engagement latch
Filing Document | Filing Date | Country | Kind |
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PCT/JP2019/017198 | 4/23/2019 | WO | 00 |