WO2017188608A1

WO2017188608A1 - Method for manufacturing air conditioner

Info

Publication number: WO2017188608A1
Application number: PCT/KR2017/003315
Authority: WO
Inventors: 이주형
Original assignee: 엘지전자 주식회사
Priority date: 2016-04-28
Filing date: 2017-03-28
Publication date: 2017-11-02
Also published as: KR20170123130A

Abstract

The present invention relates to a method for manufacturing an air conditioner including a heat exchanger having a plurality of tubes and one or more return bends for connecting the tubes, the method comprising: a cladding step of cladding the inside of the return bend with an aluminum alloy; an expansion step of expanding the end of the return bend; a tube insertion step of inserting the tube into an expanded part of the return bend; and a brazing step of heating the return bend into which the tube is inserted.

Description

Air Conditioner Manufacturing Method

The present invention relates to a method of manufacturing a heat exchanger provided in an air conditioner.

An air conditioner is a device that cools / heats a room or purifies the air in order to create a more comfortable indoor environment for a user.

Such an air conditioner may be classified into a separate type air conditioner that separates the indoor unit and the outdoor unit, and an integrated air conditioner in which the indoor unit and the outdoor unit are combined into one device. In addition, a single air conditioner configured to be used in a small space with a capacity to drive one indoor unit according to the capacity of the air conditioner, a medium to large air conditioner composed of a very large capacity for use in a company or a restaurant It can also be divided into a multi-air conditioner composed of a capacity capable of sufficiently driving the indoor unit.

At this time, the separate air conditioner is composed of an indoor unit which is installed indoors and supplies an air or cold air into the air conditioning space and an outdoor unit that compresses or expands the refrigerant so that sufficient heat exchange can be performed in the indoor unit.

The air conditioner has a cycle in which the refrigerant circulating inside circulates in the order of compression, condensation, expansion, and evaporation to transfer heat. According to the cycle, the air conditioner operates as a cooling cycle for discharging the heat of the room to the outside during the summer, and operates as a heating cycle of the heat pump for supplying heat to the room by circulating opposite to the cooling cycle in the winter.

1 is a configuration diagram showing a cooling cycle of a general air conditioner. As shown in FIG. 1, the air conditioner includes a compressor (1), a four-way valve (2), an outdoor heat exchanger (3), an outdoor fan (4), an expansion valve (5), an indoor heat exchanger (6), and an indoor fan. It consists of (7).

When the air conditioner is operated in the cooling mode, the outdoor heat exchanger 3 functions as a condenser and the indoor heat exchanger 6 functions as an evaporator. If the air conditioner is operated in the heating mode by reversing the flow of the refrigerant, the outdoor heat exchanger 3 functions as an evaporator and the indoor heat exchanger 6 functions as a condenser.

On the other hand, the indoor heat exchanger and the outdoor heat exchanger constituting the air conditioner includes a tube 20 through which the refrigerant can move. In the process, a plurality of tubes are connected side by side to the fin 40 which can increase the heat exchange rate. At this time, the return bend 10 is used to connect the tubes to each other.

When joining multiple tubes and return bends, it uses a torch brazing method for welding each tube and return bend separately, and a controlled atmospheric brazing (CAB) brazing method for welding multiple parts at once. However, when using the CAB method, there is a problem that the pressure resistance is lowered due to the unwinding of the material, there is a problem that the non-bonded portion is generated and the refrigerant leaks.

An object of the present invention is to provide a method of manufacturing an air conditioner that can prevent the pressure resistance of a tube from being lowered without increasing the thickness of the tube.

It is another object of the present invention to provide a method for manufacturing an air conditioner capable of improving the bonding rate between a tube and a return bend.

In order to solve the above problems, the present invention provides a method of manufacturing an air conditioner including a heat exchanger having a plurality of tubes and at least one return bend connecting the tubes, the inside of the return bend clad with an aluminum alloy A cladding step; An expansion step of expanding an end of the return bend; A tube insertion step of inserting the tube into the expanded portion of the return bend; It provides a method for manufacturing an air conditioner comprising a; brazing step of heating the return bend the tube is inserted.

In addition, the inner diameter of the return bend and the inner diameter of the tube may be the same.

The method may further include a filler insertion step of inserting a filler into the return bend after the expansion step and before the tube insertion step.

In addition, the filler may be inserted into the site expanded in the expansion step.

In addition, the method may further include a re-expansion step of expanding the end of the expanded site once more.

In addition, the filler may be inserted into the site expanded in the re-expansion step.

In addition, the filler may be provided in a ring shape.

In addition, the end of the enlarged portion may be bent to have an inner diameter larger than that of the enlarged portion.

In addition, the aluminum alloy may be a four series aluminum alloy.

In addition, the method may further include an application step of applying flux to the surface of the tube before the tube insertion step.

In addition, the brazing step may use a CAB method.

In another aspect, the present invention is the inner surface is clad with an aluminum alloy and the return bend end is expanded; A tube inserted into the return bend; And a filler provided inside the return bend, wherein the filler provides an air conditioner that can fill a gap between the return bend and the tube when brazing.

In addition, the difference between the diameter of the expanded portion of the return bend and the diameter of the non-expanded portion may be equal to the thickness of the tube.

In addition, the filler may be provided at the end of the tube.

In addition, the end of the expanded portion of the return bend may include a second expansion portion having a diameter larger than the diameter of the expanded portion.

In addition, the filler may be provided in the second expansion portion.

In addition, the filler may have a hollow ring shape.

In addition, the brazing may be a CAB brazing method.

In addition, the present invention the inner surface is clad with an aluminum alloy return bend; A tube inserted into the return bend and flux coated on an outer surface thereof; After the tube is inserted into the return bend, the aluminum alloy clad on the return bend and the flux applied to the tube react with each other to provide an air conditioner that can fill a gap between the tube and the return bend.

[Effects of the Invention]

The present invention has an effect that can prevent the pressure resistance of the tube is lowered.

In addition, the present invention has the effect of improving the bonding rate between the tube and the return bend.

1 is a schematic diagram of the refrigerant flow inside the heat exchanger.

2 shows the structure of a heat exchanger.

Figure 3 shows a welding method between the return bend and the tube according to an embodiment of the present invention.

Figure 4 shows a welding method between the return bend and the tube according to another embodiment of the present invention.

Figure 5 shows the structure of a filler according to another embodiment of the present invention.

Figure 6 shows a welding method according to another embodiment of the present invention.

7 is a flowchart illustrating a method of manufacturing an air conditioner.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. On the other hand, the configuration or control method of the device to be described below is not intended to limit the scope of the present invention, but to describe the embodiment of the present invention, the same reference numerals are used throughout the specification the same components Indicates.

As illustrated in FIG. 2, a heat exchanger corresponding to either an outdoor unit or an indoor unit may include a plurality of fins 40, a plurality of tubes 20 passing through the plurality of fins 40, and the tubes 20. It is composed of a return bend 10 or a Y branch pipe 10 '.

The plurality of pins 40 are formed in a thin plate shape and are provided side by side with a width enough to form a fine space. This is to allow the heat exchange between the refrigerant flowing through the inside of the tube 20 and the air in contact with the outside of the tube 20 to actively occur between the minute spaces. In addition, the thin plate shape constituting the body of each fin 40 so that heat exchange can occur more may be further provided with a fine gap to allow air to pass through.

The plurality of tubes 20 are provided to penetrate through the plurality of fins 40 while being perpendicular to the plurality of fins 40 provided in parallel. The plurality of tubes 20 may be connected to each other by a return bend 10 or a Y branch tube 10 ', which allows the refrigerant flowing through the tube 20 to reciprocate between the plurality of fins 40 several times. Allow as much heat exchange as possible. For example, the refrigerant flowing through the Y branch pipe 10 'flows in a zigzag fashion between the plurality of fins 40, such as toward the tube 20 and back through the return bend 10 to the tube 20. Heat exchange with air. After the heat exchange, the refrigerant will be discharged to the outside of the heat exchanger through the opposite Y branch pipe (10 ').

In the present invention, as an embodiment, but deals with the coupling or welding method between the return bend 10 and the tube 20, the coupling or welding between the Y branch pipe (10 ') and the tube 20 is also the same way. Will be made.

In addition, in the present invention, the return bend 10 and the tube 20 may be made of an aluminum material, but is not necessarily limited to aluminum.

The coupling between the return bend 10 and the tube 20 uses a manner in which the tube 20 is inserted into the return bend 10. Basically, the tube 20 is not subjected to any other processing, and the ends of the return bend 10 are expanded and then extrapolated to the tube 20.

3 is an algorithm illustrating a manufacturing method for joining or welding between the return bend 10 and the tube 20. Looking at the manufacturing method of the present invention, the step of cladding the inside of the return bend 10 with an aluminum alloy (S100), the step of expanding both ends of the return bend (10) (S200), inserting the filler in the expanded portion And pressing the filler to fix the filler (S300), inserting the tube 20 into the expanded return bend 10 (S400), and the return bend 10 and the tube 20 to be completely coupled. Brazing may be configured as a step (S500).

The alloy clad in the return bend 10 may correspond to an aluminum four series alloy. Four-series aluminum alloys correspond to aluminum mixed with silicon (Si) and other metals, and have a lower melting point than aluminum. The reason why the melting point should be lower than that of aluminum will be explained later. An embodiment of the present invention has been described with reference to the aluminum 4-based alloy, but is not limited thereto.

Cladding is a technique of joining another metal to one surface of a specific metal. When the desired metal is placed on a specific metal and pressed at a high pressure, the surfaces of the two metals are bonded to each other. In the case of the present invention, the four series aluminum alloy is cladding on the entire return bend 10 or at least the portion to be expanded.

If the cladding is not performed, the four series aluminum alloy may be inserted into the expanded portion inside the return bend 10 before the tube 20 is inserted into the return bend 10.

In step S200 of expanding the return bend 10, the end of the return bend 10 is heated, and then the core bar is press-fitted to expand the return bend 10. However, the method is not limited to the expansion method using the core bar, and any method that can be expanded may be used.

The inner diameter of the return bend 10 may be the same as the inner diameter of the tube 20 before expansion. This is because when the return bend 10 and the tube 20 have the same inner diameter, when used as an actual heat exchanger, the refrigerant flow pressure loss is reduced. Therefore, the inner diameter of the expansion portion of the return bend 10 is preferably equal to or slightly longer than the outer diameter of the tube 20. In the case of heating the return bend 10 in the brazing step S500 later, the return of the expanded portion is such that a welding material such as a filler penetrates the surface where the return bend 10 and the tube 20 come into contact with each other by capillary action. It is preferable that the inner diameter of the bend 10 is longer than the outer diameter of the tube 20.

Meanwhile, inserting the filler (S300) may be omitted. An embodiment in which the filler insertion step is omitted will be described later with reference to FIG. 7.

The filler 30 may be inserted into an extended portion of the return bend 10, and when heated in the brazing step S500, the filler 30 may be changed into a liquid state by capillary action between the surfaces of the return bend 10 and the tube 20. It will soak in.

After the filler 30 is inserted into the return bend 10, the outer circumferential surface of the return bend 10 may be compressed to be fixed on the inner circumferential surface of the return bend 10. This is to prevent the filler 30 from being disturbed or changed in position when the tube 20 is inserted. In addition, since the filler 30 and the return bend 10 are evenly contacted, the heat transfer is smoothed during brazing, so that the filler can be more melted.

In addition, the filler 30 may be provided in a hollow donut shape. When the filler 30 melts by brazing and then seeps into between the return bend 10 and the tube 20, the filler 30 in the center falls down by gravity, which may soon lead to welding failure. . Therefore, it is preferable that only the appropriate amount of filler 30 is installed so that all of the melted filler 30 penetrates between the return bend 10 and the tube 20 by capillary action, and the inside is provided in the form of an empty ring. something to do.

In addition, the filler 30 may correspond to a material in which the 4-series aluminum alloy and the Nocolok flux are mixed. The filler 30 is lower than the melting point of aluminum, and the flux serves to allow the filler 30 to melt well.

In addition, the brazing step (S500) is a torch brazing method for heating each return bend 10 individually using a torch, and CAB (Controlled) which can heat a plurality of return bends 10 at once by increasing the temperature of ambient air. Atmospheric Brazing).

In the case of using the CAB brazing method, the same heat can be applied to the plurality of return bends 10 so that the joining or welding between the return bends 10 and the tube 20 is made even and the variation in the joining or welding is lowered. There is an advantage.

However, when a disc-shaped filler is inserted into the return bend, instead of the hollow ring-shaped filler 30, and the CAB brazing method is used together, the air trapped inside the return bend 10 by the filler 30. This can lead to poor welding. CAB brazing must be performed in an inert gas atmosphere of high purity, and even if only a small amount of oxygen or water vapor can cause a poor bonding during brazing. Therefore, by inserting the ring-shaped filler 30 into the return bend 10 to create a flow passage to prevent the air is trapped so that the welding can occur better.

Tube insertion is preferably inserted all the way to the end of the returned return bend 10, when the filler 30 is inserted, it is preferable to insert so that the filler 30 is in contact with the installed position.

4 to 7 illustrate various embodiments in which the return bend 10 and the tube 20 are coupled to the air conditioner according to the present invention.

4, the inner surface of the return bend 10 is clad with a four series aluminum alloy. However, the cladding treatment may be performed only on the entire inside of the return bend 10 or a portion to be expanded. In addition, the four series aluminum alloy may be inserted into the return bend 10 before the tube 20 is inserted without a separate cladding treatment.

Both ends of the cladding return bend 10 is expanded in the return bend expansion step (S200), and then undergoes a re-expansion step of expanding the end of the portion expanded in the expansion step (S200) once more.

Through the re-expansion step, both ends of the return bend 10 may be expanded into a two-step staircase shape. The inner diameter L1 expanded in the expansion step S200 is larger than the existing inner diameter L of the return bend 10, and the inner diameter L2 expanded in the re-expansion step is expanded in the expansion step S200. It is larger than the inner diameter L1.

The site expanded in the expansion step (S200) corresponds to the first expansion unit 12, and the site expanded through the re-expansion step corresponds to the second expansion unit (13). The inner diameter of the second expanding portion 13 is larger than the inner diameter of the first expanding portion 12.

The filler 30 may have an annular shape and may have an outer diameter such that the filler 30 is inserted into the expanded portion in the re-expansion step. The ring portion of the filler 30 may have a width equal to the difference between the inner diameter L2 expanded in the re-expansion step and the inner diameter L1 expanded in the expansion step S200. Therefore, when the tube 20 is inserted, the filler 30 and the tube 20 may come into contact with each other.

In addition, in order to fix the filler 30 to the inner circumferential surface of the return bend 10 before inserting the tube 20, the outer circumferential surface of the return bend 10 of the portion where the filler 30 is positioned is compressed.

The difference between the inner diameter L1 expanded in the expansion step S200 and the existing inner diameter L of the return bend 10 is preferably equal to the thickness of the tube 20. That is, the inner diameter of the tube 20 is equal to the inner diameter L of the return bend 10. This is to minimize the pressure loss of the refrigerant flow when the refrigerant passes after the coupling between the return bend 10 and the tube 20.

Insertion of the tube 20 is inserted up to the portion expanded in the expansion step (S200) and the outer peripheral surface of the tube 20 and the inner peripheral surface expanded in the expansion step (S200) is in contact with each other.

The insertion of the filler 30 and the tube 20 is completed by brazing. Brazing uses the CAB brazing method and the filler 30 is melted as a result of brazing soaked by the capillary phenomenon between the tube 20 and the inner circumferential surface expanded in the expansion step (S200) in contact with the outer circumferential surface of the tube 20.

5 is an embodiment of proceeding the manufacturing process without the re-expansion step as shown in FIG. After inserting the filler 30 to the deepest part of the portion expanded in the expanding step (S200), the outer surface of the return bend 10 of the portion provided with the filler 30 is compressed to allow the filler 30 to be fixed. do. In addition, the inner diameter of the return bend 10 is the same as the inner diameter of the tube 20, as shown in Figure 4,

On the other hand, the filler 30 may be provided in the form of a donut with an empty center, which is to prevent the defect of the brazing by preventing the air trapped inside the return bend 10 when CAB brazing as mentioned above.

6 corresponds to a further improvement of the return bend 10 in FIG. 5. In the expansion step (S200), the end of the expanded portion is bent to be larger than the inner diameter of the expanded portion. This helps the insertion of the tube 20 to be smooth by increasing the inner diameter of the expanded end of the return bend 10 at which the insertion of the tube 20 begins.

6 and 4, the inner diameter of the return bend 10 is provided to be the same as the inner diameter of the tube 20, and the filler 30 is looped to prevent trapping of air inside the return bend 10 when CAB brazing. It may be provided in the form.

7 is an embodiment in which the return bend 10 and the tube 20 can be connected without inserting the filler 30. The return bend 10 is clad with a four series aluminum alloy, and both ends of the return band 10 are expanded to allow the tube 20 to be inserted. Nocolok flux is applied to the tube 20 inserted into the return band 10.

The inner diameter of the return bend 10 and the inner diameter of the tube 20 are the same, and when the tube 20 is inserted into the return bend 10, the outer circumferential surface of the tube 20 and the inner circumferential surface of the extended portion of the return bend 10 are You will encounter each other.

When the tube 20 is brazed while being inserted into the return bend 10, the four series aluminum alloy clad inside the return bend 10 and the flux applied to the outer circumferential surface of the tube 20 react with each other to form a filler and It will play the same role.

The four series aluminum alloy has a lower melting point than the return bend 10 or the tube 20 composed of aluminum, and the brazing ambient air temperature is higher than the melting point of the four series aluminum alloy and lower than the melting point of the aluminum. Do.

In the case of FIG. 7, the filler 30 may be additionally inserted. If the manufacturing process is performed without the filler 30, there may be a lack of sufficient material to completely fill the space between the return bend 10 and the tube 20. As a result, the additional insertion of the filler 30 may reduce the defective rate. This can be

The present invention may be practiced in various forms and is not limited to the above-described embodiment. Therefore, if the modified embodiment includes the components of the claims of the present invention will be seen as belonging to the scope of the present invention.

Claims

In the manufacturing method of the air conditioner comprising a plurality of tubes and a heat exchanger having at least one return bend connecting the tubes,

A cladding step of cladding the inside of the return bend with an aluminum alloy;

An expansion step of expanding an end of the return bend;

A tube insertion step of inserting the tube into the expanded portion of the return bend;

Brazing step of heating the return bend the tube is inserted; manufacturing method of an air conditioner comprising a.
The method of claim 1,

The inner diameter of the return bend and the inner diameter of the tube is the manufacturing method of the air conditioner.
The method of claim 2,

And a filler insertion step of inserting a filler into the return bend after the expansion step and before the tube insertion step.
The method of claim 3,

Method of manufacturing an air conditioner, characterized in that the filler is inserted into the site of expansion in the expansion step.
The method of claim 3,

Re-expansion step of expanding the end of the expanded portion once more; air conditioning apparatus further comprising a.
The method of claim 5,

The method of manufacturing an air conditioner, characterized in that the filler is inserted into the site expanded in the re-expansion step.
The method of claim 3,

The end of the expanded portion is a method of manufacturing an air conditioner, characterized in that the bending process to have a larger inner diameter than the inner diameter of the expanded portion.
The method according to any one of claims 3 to 7,

The filler is a manufacturing method of the air conditioner, characterized in that provided in the form of a ring.
The method of claim 8,

The brazing step is a method of manufacturing an air conditioner, characterized in that the CAB method.
The method according to any one of claims 2 to 7,

The aluminum alloy is a manufacturing method of the air conditioner, characterized in that the four series aluminum alloy.
The method of claim 10,

And a coating step of applying flux to the surface of the tube before the tube insertion step.
A return bend whose inner surface is clad with an aluminum alloy and whose ends are extended;

A tube inserted into the return bend;

A filler provided inside the return bend; And,

The filler is an air conditioner, characterized in that for filling the gap between the return bend and the tube when brazing.
The method of claim 12,

And the inner diameter of the return bend and the inner diameter of the tube are the same.
The method of claim 13,

And wherein a difference between the diameter of the expanded portion of the return bend and the diameter of the non-expanded portion is equal to the thickness of the tube.
The method of claim 12,

The filler is an air conditioner, characterized in that provided at the end of the tube.
The method of claim 12,

An end of the expanded portion of the return bend comprises a second expansion portion having a diameter larger than the diameter of the expanded portion.
The method of claim 16,

The filler is an air conditioner, characterized in that provided in the second expansion portion.
The method according to any one of claims 15 to 17,

The filler is an air conditioner, characterized in that the ring-shaped hollow.
The method of claim 18,

The brazing is an air conditioner, characterized in that the CAB brazing method.
A return bend with an inner surface clad with an aluminum alloy;

A tube inserted into the return bend and flux coated on an outer surface thereof;

And the aluminum alloy clad on the return bend and the flux applied to the tube react to fill the gap between the tube and the return bend when the tube is inserted into the return bend.