Patent Application
20200370784
The present invention relates to an outdoor unit of an air-conditioning apparatus and a method for manufacturing an outdoor unit of an air-conditioning apparatus, and more particularly, to protection of a tip of a screw for use in fixation of a heater.
In an outdoor unit of a conventional air-conditioning apparatus, a drain hole is formed in a central part of a bottom plate in a horizontal direction in order to discharge drain water generated by dew condensation in a heat exchanger during a heating operation. Also, in cold districts, a heater is attached to the bottom plate, since drain water on the bottom plate may freeze before discharged through the drain hole (see, for example, Patent Literature 1).
According to Patent Literature 1, part of a heater tube is pressed against an upper surface of the bottom plate by a heater fixing tool, and overlapping portions of the heater fixing tool and the bottom plate are fixed by screws, thereby attaching the heater to the bottom plate. The screws are each pressed into the header fixing tool and the bottom plate from the heater fixing device toward the bottom plate. A tip of each screw is projected downwards from the bottom plate. In order to ensure safety at the time of performing an attachment operation, the tip of the screw is covered with a leg portion fixed to a lower surface of the bottom plate, and is thus not exposed to the outside of the outdoor unit. To be more specific, a pair of leg portions are located at both end portions of the bottom plate in the horizontal direction, and one of the leg portions covers the tip of the screw.
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2014-105954
In the configuration described in Patent Literature 1, since the tip of a screw is covered with a leg portion, a fixing position of the screw is also set to an end portion of the bottom plate in the horizontal direction to conform to the position of the leg portion. By contrast, the drain hole is formed in a central part of the bottom plate in the horizontal direction, and the fixing position of the screw is thus located away from the drain hole. Therefore, the heater cannot be fastened to part of the bottom plate which surrounds the drain hole. Thus, at the part surrounding the drain hole, the heater is displaced or moved upwards. Inevitably, the heater cannot effectively heat the part surrounding the drain hole.
The present invention has been made in view of the above, and an object of the invention is to provide an outdoor unit of an air-conditioning apparatus, in which tips of screws can be protected, and at the same time a heater can be fixed to a surrounding area which surrounds a drain hole, and also a method for manufacturing the outdoor unit of the air-conditioning apparatus.
An outdoor unit of an air-conditioning apparatus, according to an embodiment of the present invention, includes a bottom plate having a drain hole formed therein to discharge drain water generated in a heat exchanger; a heater provided on an upper surface of the bottom plate; a heater fixing tool configured to fix the heater to the bottom plate, with the heater interposed between the heater fixing tool and the upper surface of the bottom plate; a screw fastened after inserted into a screw hole from above to fasten the heater fixing tool to the bottom plate, the screw hole being provided in overlapping portions of the heater fixing tool and the bottom plate; and a protective cap configured to cover a tip of the screw below, which projects downward from a lower surface of the bottom plate. The screw hole is located in a surrounding area which surrounds the drain hole, and the heater fixing tool is fixed to the bottom plate in the surrounding area.
Also, a method for manufacturing the outdoor unit of the air-conditioning apparatus, according to an embodiment of the present invention, includes providing a protective cap and a pair of leg portions at the bottom plate after turning over the bottom plate, the pair of leg portions being provided to support the outdoor unit; and joining the protective cap and the pair of leg portions to the bottom plate by caulking the protective cap and the pair of leg portions simultaneously.
The embodiments of the present invention provide an outdoor unit of an air-conditioning apparatus, in which tips of screws can be protected, and at the same time a heater can be fixed to a surrounding area which surrounds a drain hole, and also a method for manufacturing the outdoor unit of the air-conditioning apparatus.
An air-conditioning apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that in figures to be referred to below, there is a case where the relationship in size between components as illustrated is different from that between actual components. Also, in the figures, components which are the same as or equivalent to components previously referred to will be denoted by the same reference signs. The same is true of the entire text of the specification. Furthermore, the configurations of the components described in the entire text are explained by way of example, that is, they are not limited to the configurations described in the text.
A casing of the outdoor unit of the air-conditioning apparatus includes a bottom plate 1, a front plate 2, a side plate 3, a protective cover 3a attached to the side plate 3, and a top plate 4. Components provided in the outdoor unit are held on an upper surface of the bottom plate 1. A pair of leg portions 8 are formed on a lower surface of the bottom plate 1, and support the outdoor unit. The inside of the casing is partitioned into a fan compartment 5 and a machine compartment 6 by a partition plate 7.
In the fan compartment 5, a heat exchanger 10 and a motor mount 13 are provided. The motor mount 13 is provided to hold a motor 12 including a propeller fan 11, in front of the heat exchanger 10.
In the machine compartment 6, a compressor 14, a refrigerant pipe 15 and an electrical component unit 16 are provided. Refrigerant sent from an indoor unit to the outdoor unit is compressed in the compressor 14, and is then sent to the heat exchanger 10 through the refrigerant pipe 15. Also, the electrical component unit 16 includes a control board, and is equipped with a power board 17 which, for example, supplies electric power to various components. A terminal block 18 for connection of the outdoor unit to the indoor unit (not illustrated) is fixed to the power board 17 by screws.
In the outdoor unit having the above configuration, when the propeller fan 11 is operated, air flows into the outdoor unit through the heat exchanger 10, then passes through the propeller fan 11, and flows out forwards from a front side of the outdoor unit. As a result, for example, during a cooling operation, refrigerant in the heat exchanger 10 is cooled by the air passing through the heat exchanger 10, that is, the air exchanges heat with the refrigerant, and is thus heated.
The bottom plate 1 has a flat portion 20 in central part thereof in a horizontal direction, and a drain hole 19 is formed in the flat portion 20. Drain water generated from dew condensation in the heat exchanger 10 during a heating operation flows down from the heat exchanger 10 to the bottom plate 1, and is then discharged to the outside of the outdoor unit through the drain hole 19.
On the bottom plate 1, a heater 21 is provided to prevent drain water from freezing. The heater 21 is fastened to the bottom plate 1 in the vicinity of the drain hole 19 by a heater fixing tool 22 and screws 23. To be more specific, the heater fixing tool 22 includes bent portions 22a which cover part of a tube of the heater 21 and attachment portions 22b having screw holes 22c (see
The heater fixing tool 22 having the above configuration is fastened to the bottom plate 1 by fastening the screws 23 after inserted into the screw holes 22c and the screw holes 1b in the raised portions 1a of the bottom plate 1. Tips 23a of the screws 23 are projected downward to a level lower than that of the bottom plate 1 as illustrated in
The protective cap 24 includes a cover 25 which covers the tip 23a of the screw 23, a pair of extension portions 25a extending from opposite sides of an opening edge of the cover 25, and flange portions 26 and 27 which extend outwards from respective tips of the pair of extension portions 25a. The flange portions 26 and 27 are formed flush with each other. It should be noted that by omitting the extension portions 25a, the flange portions 26 and 27 may be formed to extend outwards directly from the opposite sides of the opening edge of the cover 25. The flange portions 26 and 27 correspond to a pair of flange portions of the present invention.
The flange portions 26 and 27 are formed to have different shapes, and are also shaped to conform to an outer shape of the raised portion 1a. Thereby, they are prevented from being mistakenly reversed when the protective cap 24 is fixed to the lower surface of the raised portion 1a.
In the case where the protective cap 24 having the above configuration is fixed to the bottom plate 1, the bottom plate 1 is turned over as illustrated in
Then, the flange portion 26 of the protective cap 24 is joined to the raised portion 1a while caulking them using a device not shown. At this time, the pair of leg portions 8 are also simultaneously joined to the bottom plate 1 by caulking them. This joining using caulking is a joining method of locally pressing facing surfaces of two stacked objects with a punch, thereby mechanically joining the objects to each other. By the joining method using caulking, a caulked joint 30 (see
As described above, in embodiment 1, since the tips 23a of the screws 23 for fastening the heater fixing tool 22 to the bottom plate 1 are protected by the protective caps 24, the fixing positions of the screws 23 can be freely set without the need to consider the positions of the leg portions. Therefore, the heater 21 can be fixed at an appropriate position in the surrounding area which surrounds the drain hole 19. Thus, this surrounding area can be heated by the heater 21. As a result, it is possible to prevent drain water from freezing in the vicinity of drain hole 19, and thus also preventing stopping of flowing of the water in the drain hole 19. That is, the drain hole 19 is not blocked up. It is therefore possible to provide an outdoor having a high reliability.
Furthermore, fixation of the protective cap 24 to the bottom plate 1 is carried out by the joining method using caulking, as well as fixation of the pair of leg portions 8 to the bottom plate 1. Therefore, the protective cap 24 and pair of leg portions 8 can be joined to the bottom plate 1 at the same time. Therefore, the manufacturing process can be simplified, as compared with a method in which joining of the protective cap 24 and joining of the pair of leg portions 8 are carried out in different processes.
bottom plate 1a raised portion 1b screw hole 2 front plate 3 side plate 3a protective cover 4 top plate 5 fan compartment 6 machine compartment 7 partition plate 8 leg portion 8a caulked joint 10 heat exchanger 11 propeller fan motor 13 motor mount 14 compressor 15 refrigerant pipe 16 electrical component unit 17 power board 18 terminal block 19 drain hole 20 flat portion 21 heater 22 heater fixing tool 22a bent portion 22b attachment portion 22c screw hole 23 screw 23a tip 24 protective cap 25 cover 25a a pair of extension portions 26 flange 27 flange 30 caulked joint
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/036122 | 10/4/2017 | WO | 00 |
