KR102622040B1 - Branching pipe for system air conditioner and manufacturing method therof - Google Patents

Abstract

The present invention relates to a method of manufacturing a branch pipe for installing a system air conditioner, which includes a hollow pipe supply step of supplying a cylindrical hollow pipe to the lower mold, a mold joining step of closing the mold, and a branch pipe that protrudes obliquely downward from the hollow pipe using a fluid. It includes a molding step of deforming the hollow pipe to form a part, and a finishing step of taking out the formed branch pipe and post-processing it, and it is possible to prevent parting lines from occurring in the branch portion of the branch pipe.

Description

Branch pipe for system air conditioner installation and its manufacturing method {BRANCHING PIPE FOR SYSTEM AIR CONDITIONER AND MANUFACTURING METHOD THEROF}

The present invention relates to a branch pipe manufacturing method, and relates to a branch pipe for installing a system air conditioner capable of manufacturing a branch pipe usable in a system air conditioner, and a method for manufacturing the same.

In general, an air conditioner (hereinafter referred to as an air conditioner) is an air conditioner that includes cooling equipment and is a mechanical device that lowers the indoor temperature or maintains a comfortable condition. Recently, in addition to individual air conditioners, system air conditioners are mainly used. System air conditioners have the advantage of allowing the indoor unit to be freely selected and placed according to the structure and balance of the building even if only one outdoor unit is installed.

Most of these air conditioners perform cooling using the phase change phenomenon. In other words, an air conditioner utilizes the physical phenomenon of absorbing or releasing heat when the phase of a substance changes. A refrigerant is used to circulate between the outdoor and indoor units, and for this purpose, the refrigerant can circulate in the air conditioning system. Various piping and joints are required.

In addition, when there are multiple indoor or outdoor units installed, or when parts with individual functions need to be connected in parallel to the piping, branch pipes (branch pipes) are used to allow the refrigerant to branch from the piping. do. In other words, two connectors are connected to each branch pipe. One of the connected pipes is connected to an indoor unit, and the other branch pipe is connected to the other pipe. The branch pipe splits the high-pressure refrigerant. It is used as a pipe for

In this way, branch pipes are intended to distribute fluid in two or more directions and are often formed in a T- or Y-shape. T-shaped or Y-shaped branch pipes can be manufactured by the hydroforming method. For example, the tube hydroforming process is a process technology that forms by applying hydrostatic pressure to the inside of the tube and simultaneously applying a compressive load in the axial direction of the tube to generate gradual plastic deformation according to the shape of the external mold. In this way, in the hydroforming method, after the pipe is mounted inside the mold and fluid is supplied to the inside of the pipe at a preset pressure, a part of the pipe is fired into a branch pipe in the shape of a forming hole formed in the mold by the pressure of the fluid. By deforming, a branched pipe (branch pipe) is produced.

Related prior art literature includes ‘Manufacturing method of Y branch pipe for system air conditioner and Y branch pipe thereof’ of Republic of Korea Patent No. 10-0611330.

In the conventional branch pipe manufacturing method, as shown in FIG. 1, in order to manufacture a branch pipe, a copper pipe is placed in a mold (1) and high pressure hydraulic pressure is applied to inflate one side of the copper pipe to form a branch pipe, thereby changing the shape of the branch pipe. will be produced. At this time, the mold frame 1 is composed of an upper mold 1a and a lower mold 1b, and the cavities 1c and 1d formed in each mold are joined to form a branch pipe, so that the branch pipe is formed. It can be produced.

However, according to the conventional branch pipe manufacturing method, a method is used in which a part of the copper pipe protrudes laterally as fluid is supplied to the copper pipe at a preset pressure (high pressure) while the mold frame 1 is joined. Due to the nature of the mold frame 1 that is joined up and down, a parting line 2a (see FIG. 2) is inevitably generated in the branch pipe 2 due to the mold gap as the compressive load is transmitted by the mold and the high-pressure fluid moves.

Accordingly, since the relevant part becomes a structurally weak part, there is a risk of damage due to cumulative fatigue, etc., and there is a problem of cracks occurring even if not completely damaged. In other words, normal cooling was performed without any problems immediately after installation, but as the refrigerant was distributed at high pressure, the parting line burst due to the high pressure refrigerant, which caused the problem that normal cooling could not be performed. .

In particular, in the conventional manufacturing method, the cavity for the branch line of the branch pipe is provided to protrude in the side direction of the mold, so the branch pipe protrudes to one side from the pipe and a branch line of a bent shape is formed, and the branch line of the branch pipe is formed. There is a high risk of damage to the parting line, and problems with refrigerant leakage and foreign matter inflow continue to occur while the pipes are connected due to damage at the bent part.

In addition, branch pipes manufactured using conventional manufacturing methods require post-processing (surface finishing, etc.) for the parting line because a parting line is formed. In the case of the branched part, post-processing is difficult due to the curved shape, resulting in surface roughness. ) is not good.

In addition, branch pipes manufactured using conventional manufacturing methods have a single diameter size, so branch pipes of various sizes must be provided to connect to pipes of various sizes, which increases the cost of system construction. In other words, since it is a single size, the air conditioner constructor must be equipped with branch pipes of various sizes in order to connect various branch pipes, which has the problem of reducing flexibility in field work.

Republic of Korea Patent No. 10-0611330 (registered on August 3, 2006)

The present invention was created to solve the above-mentioned problems, and the purpose of the present invention is to provide a method of manufacturing a branch pipe for installing a system air conditioner that can produce a durable branch pipe.

In particular, another object of the present invention is to provide a branch pipe manufacturing method for system air conditioner installation that can minimize the risk of cracks by preventing the occurrence of parting lines in the branch portion of the branch pipe and improve surface roughness. will be.

In addition, another object of the present invention is to provide a method of manufacturing a branch pipe for installing a system air conditioner that can be connected to pipes of various sizes with a single product.

The branch pipe manufacturing method of the present invention to achieve the above-described object includes a hollow tube supply step of supplying a cylindrical hollow tube to the lower mold, a mold joining step of closing the mold, and a mold forming step of protruding inclined downward into the hollow tube using a fluid. It includes a forming step of deforming the hollow pipe to form a branch pipe, and a finishing step of taking out the formed branch pipe and post-processing it.

And, according to the branch pipe manufacturing method of the present invention, the mold joining step includes the step of coupling the upper mold to the lower mold, and the step of coupling the side mold to the combined mold.

In addition, the forming step includes the step of supplying fluid to the joined mold, generating fluid at high pressure and transferring compressive load from the mold to pressurize the hollow tube, and discharging fluid from the mold.

In addition, the finishing step includes a drilling step of forming a through hole in the branch pipe, cutting and finishing each end of the branch pipe and forming a step connection, and joining a connection pipe to each step connection.

Moreover, the branch pipe manufactured by the manufacturing method according to the present invention includes a straight pipe portion extending in the longitudinal direction and a branch pipe portion branched from the straight pipe portion and protruding downward, and the length of the branch pipe portion is 25 mm to 45 mm, It is disposed inclined at an angle of 35° to 45° with respect to the straight pipe portion, and has an inner radius extending from the straight pipe portion of 3 mm to 5 mm and an outer radius of 9 mm to 13 mm.

The branch pipe manufacturing method according to the present invention as described above can produce a durable branch pipe.

In particular, the branch pipe manufacturing method according to the present invention can minimize the risk of cracks by preventing parting lines from occurring in the branch portion of the branch pipe, and improve surface roughness.

In addition, the branch pipe manufacturing method according to the present invention forms connection parts of various sizes at the ends, so that a single product can be connected to pipes of various sizes, thereby increasing flexibility in field work.

1 is a diagram showing a conventional branch pipe manufacturing apparatus;
Figure 2 is a view showing a branch pipe manufactured by a conventional branch pipe manufacturing apparatus;
Figure 3 is a diagram schematically showing a branch pipe for installing a system air conditioner manufactured according to an embodiment of the present invention;
Figure 4 is a view for explaining the branch pipe of Figure 3;
Figures 5 and 6 are diagrams each showing an exemplary form of a branch pipe for installing a system air conditioner according to an embodiment of the present invention;
Figure 7 is a view showing a state in which each mold of the manufacturing device for installing a branch pipe system air conditioner according to an embodiment of the present invention is not molded;
Figure 8 is a view showing a state in which each mold of the manufacturing device for installing a branch pipe system air conditioner according to an embodiment of the present invention is assembled;
Figure 9 is a view showing another type of mold of the branch pipe manufacturing apparatus for system air conditioner installation according to an embodiment of the present invention;
Figure 10 is a flowchart showing a method of manufacturing a branch pipe for installing a system air conditioner according to an embodiment of the present invention; and
Figure 11 is a flowchart showing a method of manufacturing a branch pipe for installing a system air conditioner according to an embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms.

Hereinafter, the technical features of the present invention will be described in detail with reference to the attached drawings.

Figure 3 is a diagram schematically showing a branch pipe for installing a system air conditioner manufactured according to an embodiment of the present invention. The branch pipe 10 can be manufactured using a manufacturing apparatus and manufacturing method that will be described later. Figure 4 is a diagram for explaining the branch pipe of Figure 3. And, Figures 5 and 6 are diagrams each showing an exemplary form of a branch pipe according to an embodiment of the present invention.

Referring to FIGS. 3 to 6, the branch pipe 10 may be composed of a straight pipe portion 11 extending in the longitudinal direction and a branch pipe portion 13 branching from the straight pipe portion 11. At this time, the branch pipe 10 may be provided as a combination body in which a separate connection pipe 20 is connected to each open pipe portion. That is, as shown in FIGS. 5 and 6, the connection pipe 20 is fixedly installed in the branch pipe 10 by welding or the like, so that the entire length can be extended.

The straight pipe portion 11 may be composed of a straight tubular member extending in the longitudinal direction.

The branch pipe portion 13 may be provided to protrude from the straight pipe portion 11 to one side, and may be obliquely extended to have a predetermined inclination with the straight pipe portion 11. The branch pipe portion 13 may be formed to protrude as the shape of the straight pipe portion 11 is deformed during manufacturing of the branch pipe 10. That is, the branch pipe portion 13 may be provided to protrude in a branch shape from the straight pipe portion 11, which is a straight pipe.

Here, the branch pipe 10 shown in FIG. 3 shows a form in which molding has been completed using a manufacturing device or manufacturing method to be described later, and the end of the branch pipe portion 13 is shown as closed, but the end side is closed. After the process, it may be transformed into the end shape of the branch pipe 10 of Figure 5 or Figure 6.

This branch pipe 10 may have a parting line 11a formed on the side of the straight pipe portion 11. That is, while in the conventional branch pipe, a parting line is formed across the part connected to the branch pipe, in the embodiment of the present invention, the parting line 11a is formed on the side, so that the straight pipe portion 11 and the branch pipe portion 13 ) can be minimized.

In addition, since the parting line 11a is formed only on the outer surface of the straight pipe portion 11, it has the advantage of easily performing surface finishing work.

Meanwhile, the branch pipe 10 according to an embodiment of the present invention is composed of a copper pipe, which is a commonly used pipe for air conditioner refrigerant, and may have an appropriate size through which the refrigerant can flow, and its diameter (D1) is 6 mm to 6 mm. It can be formed as 23mm. Preferably, the diameter size may be 9.5 mm to 22.2 mm. The length L1 of the branch pipe 10 may be within the range of 250 mm to 450 mm, and may be shorter or longer.

For example, the branch pipe 10 may be composed of a tubular member with a diameter of about 9.5 mm and a total length of about 300 mm. The diameter of the branch pipe 10 may vary depending on the capacity of the indoor unit of the air conditioner being used.

Here, the branch pipe portion 13 may be formed to extend from the straight pipe portion 11 to a length L2 of about 30 mm. If the branch pipe portion 13 is formed short in length, it is difficult to connect the connecting pipe 20, and if the length is formed long, the branch portion that protrudes from the straight pipe portion 11 and is deformed during the hydroforming process step. Since the thickness may be formed somewhat thin, which may lead to durability problems, it is desirable to have an appropriate length. For example, the branch pipe portion 13 may be formed with a length L2 within the range of about 25 mm to 45 mm.

In addition, the branch pipe 10 of the present invention may have a pipe thickness T of 0.5 mm to 1.0 mm, preferably 0.6 mm to 0.8 mm. For example, the branch pipe 10 may have a pipe thickness of 0.65 mm.

In addition, the branch pipe portion 13 may be disposed so that the angle α formed with the straight pipe portion 11 is 35° to 45°, for example, 40°. At this time, the branch pipe portion 13 may be formed to have an inner radius R1 of 3 mm to 5 mm on the acute angle side obliquely extending from the straight pipe portion 11 and an outer radius R2 of 9 mm to 13 mm on the obtuse angle side. For example, the inner radius R1 may be 3.5 mm and the outer radius R2 may be 10 mm.

In this way, in the branch pipe 10 according to an embodiment of the present invention, the branch pipe portion 13 extends from the straight pipe portion 11 to have a predetermined inclination rather than a right angle, so that the refrigerant in the branch portion is smoothly absorbed. It can provide flow.

Referring to Figures 5 and 6, the branch pipe 10 according to an embodiment of the present invention may be configured to further include a step connection portion 15.

The step connection portion 15 may be provided in a stepped form in the form of an expanded or axial pipe in a section of a predetermined length at both ends of the straight pipe portion 11 or at the end of the branch pipe portion 13. This step connection portion 15 is provided to connect the connection pipe 20 to a corresponding diameter portion as necessary, as the thickness of the pipe is formed differently depending on the capacity of the air conditioner indoor unit in which the branch pipe 10 is used. .

At this time, the step connection portion 15 may be configured in such a way that a plurality of stepped expansion portions or axial pipe portions extend in a multi-stage form. That is, as the step connection portion 15 is provided in a plurality with a specific diameter size of a commonly used pipe, the portion corresponding to the corresponding pipe diameter is provided so that it can be coupled to the connection pipe 20.

For example, the step connection part 15 may be used by cutting off unnecessary parts, and the part corresponding to a specific diameter may be provided at the end and connected to the connection pipe 20.

Here, the step connection portion 15 may be formed to expand or condense the pipe at each end using a pipe forming machine or the like.

For example, the step connection portion 15 of the branch pipe 10 according to this embodiment may be configured to include a first connection end (15a), a second connection end (15b), and a third connection end (15c). there is.

The first connection end (15a) is provided at one end of the straight pipe portion 11, the second connection end (15b) is provided at the end opposite to the first connection end (15a), and the third connection end (15c) is It may be provided at the end of the branch pipe 13. Each step connection portion 15 can be maintained at a size of 0.5 to 1.0 times the diameter after expansion and axial pipe.

Each of these connection ends 15a, 15b, and 15c may be formed in a multi-stage tube shape, each of which is expanded or axial.

Referring to FIG. 5 as an example, the straight pipe portion 11 of the branch pipe 10 may be formed as a pipe with a diameter of about 9.52 mm and a length of about 291 mm, and the first connection end (15a) and the second connection end (15a). 2 The connection end (15b) is expanded from both ends of the straight pipe portion 11 to form an expanded pipe with a diameter of 9.62 mm in a section of about 40 mm, and the diameter of a section of about 15 mm extending from the end of the expanded pipe is 6.45 mm. Each can be formed as an axial pipe. The third connection end 15c may be formed as an expanded pipe having a diameter of 9.62 mm in a section approximately 10 mm from the end of the branch pipe 13.

The branch pipe 10 according to this embodiment may have a configuration in which both ends of the straight pipe portion 11 have the same shape and the expanded pipe portion and the shaft pipe portion are formed continuously. The total length of the branch pipe 10 after the step connection portion 15 is formed can be shortened from about 291 mm to about 281 mm.

Meanwhile, referring again to FIG. 5, at least one dimple 16 may be provided in the branch pipe 10. The dimple 16 may be formed in the shape of a groove or hole for coupling with the connection pipe 20, and if it is in the shape of a groove, it may be formed concavely on the inner peripheral surface of the branch pipe 10. These dimples 16 can be used to temporarily fix the connection pipe 20 or improve the bonding force by being combined with protrusions formed on the connection pipe 20.

Referring to FIG. 6 as another example, the total length of the straight pipe portion 11 of the branch pipe 10 may be about 401 mm and the diameter may be about 15.88 mm, and the first connection end 15a is the straight pipe portion 15a. It is expanded from one end of (11) to form a first expansion section with a diameter of 19.15 mm in a section of about 40 mm, and a second expansion section with a diameter of 22.32 mm in a section of about 20 mm that is secondarily expanded from the end of the first expansion section. It may be formed as an expanded part.

In addition, the second connection end 15b is expanded from the other end of the straight pipe portion 11 to form a first expanded portion having a diameter of 15.98 mm in a section of about 40 mm, and the second connecting end 15b is expanded from the end of the first expanded portion to about 40 mm. It may be formed as a second expansion section with a diameter of 19.15 mm, and a section of about 15 mm axially extending from the second expansion section may be formed as a shaft section with a diameter of 12.8 mm. At this time, the branch pipe portion 13 may be provided to protrude from the straight pipe portion 11 to a length of about 44 mm, and the third connection end 15c has a diameter size of about 15 mm from the end of the branch pipe portion 13 of 15.98. It can be formed with an expansion part of mm. The branch pipe 10 according to this embodiment may be configured to have a continuous expansion portion provided at one end of the straight pipe portion 11, and a composite expansion portion and an axial pipe portion being provided at the other end. The total length of the branch pipe 10 after the step connection portion 15 is formed can be shortened to about 371 mm.

Such branch pipe 10 is first processed through a hydroforming process to form the branch pipe portion 13, and then each end is post-processed to form a step connection portion 15.

Therefore, the branch pipe 10 according to an embodiment of the present invention can be connected to pipes of various sizes by the step connection portion 15, and thus can be used in various air conditioning systems.

7 to 9 are diagrams schematically showing an apparatus for manufacturing a branch pipe for installing a system air conditioner according to an embodiment of the present invention. Figure 7 shows each component of the branch pipe manufacturing apparatus for system air conditioner installation of the present invention in an unassembled state, and Figure 8 shows an assembled state. And, Figure 9 shows another type of mold of the branch pipe manufacturing apparatus for installing a system air conditioner according to an embodiment of the present invention.

Referring to Figures 7 to 9, the branch pipe manufacturing apparatus 100 for system air conditioner installation according to an embodiment of the present invention may be made of a hydroforming processing apparatus, and includes a lower mold 110, an upper mold 120, and a side mold. It may include a mold 130 and a fluid supply unit 140.

The lower mold 110 may be fixedly installed on mold equipment and may be configured as a part of a mold frame that is joined with the upper mold 120. For example, the lower mold 110 may be made of a core on the fixed side of the mold frame. This lower mold 110 may have at least one lower cavity 111 formed on the upper surface in which the cylindrical hollow tube 30 is seated. The lower cavity 111 may be formed as a long groove with a semicircular (i.e. hemispherical) cross-sectional shape corresponding to the lower half of the cylindrical hollow tube 30, and together with the upper cavity 121 of the upper mold 120 to be described later. It is formed to surround the hollow tube (30).

The upper mold 120 may be placed on top of the lower mold 110 to enable molding. For example, the upper mold 120 may be made of a core on the movable side of the mold frame. The upper mold 120 can be operated to fit with the lower mold 110 as it moves in the vertical direction. This upper mold 120 is coupled to the lower cavity 111, and an upper cavity 121 provided to cover the hollow tube 30 may be formed on the lower surface. The upper cavity 121 is formed to correspond to the lower cavity 111 and may be formed as a semicircular long groove in cross-section corresponding to the upper half of the hollow tube 30.

The side mold 130 may be disposed on both sides of the hollow tube 30 mounted on the lower mold 110 and the upper mold 120. This side mold 130 may be provided with a pair of cylindrical movable cores 131 and 133 respectively disposed on both sides of the hollow tube 30. Each movable core 131, 133 includes a protruding core (not shown) in the form of a punch or plunger that protrudes toward the hollow tube 30, and a shield that shields both ends of the cavity on the outside of the protruding core. A portion (not shown) may be formed to protrude.

Accordingly, the side mold 130 can be operated to press and fix both ends of the hollow tube 30, and can apply a compressive load in the axial direction of the hollow tube 30. That is, the side mold 130 is provided to be movable in the axial direction of the hollow tube 30, and may be configured to seal the space between them in a molded state. For this purpose, a sealing member (not shown) external to the mold frame may be provided on the side of the protruding core, which is a protruding portion of the side mold 130. The sealing member may be provided as a single piece on the outer peripheral surface of each end of the side mold 130, or may be provided in plural pieces and arranged to be spaced apart at a predetermined interval.

The fluid supply unit 140 may be connected to the side mold 130 and may supply fluid to the inside of the hollow tube 30 through the side mold 130. To this end, fluid supply holes 131a and 133a capable of communicating with the fluid supply unit 140 may be formed in the side mold 130. In addition, the lower mold 110 or the upper mold 120 may be separately provided with a fluid delivery hole (not shown) connected closely to the end side of each cavity via each mold from the fluid supply unit 140. . The fluid delivery hole is provided to penetrate each mold and communicate with the cavity, and may be placed on the end side shielded by the side mold 130. This fluid supply unit 140 can inject fluid into the interior of the hollow tube 30 using a fluid such as water-soluble hydroforming oil or deep drawing lubricant.

The branch pipe manufacturing apparatus 100 according to the present embodiment configured as described above supplies fluid provided through the fluid supply unit 140 to the hollow pipe 30 disposed between the lower mold 110 and the upper mold 120. As it is supplied at high pressure, the hollow tube 30 can be deformed into the shape of the cavity by the pressure.

At this time, a protruding cavity 113 extending from the lower cavity 111 may be formed in the lower mold 110.

The protruding cavity 113 is a portion extending downwardly from the lower side of the lower cavity 111 and may be provided to form a branch pipe from the hollow pipe 30. This protruding cavity 113 may be composed of a through hole formed in the lower cavity 111 and allows the hollow tube 30 to be deformed.

Additionally, the protruding cavity 113 may be formed to extend downwardly from the lower cavity 111 . At this time, the protruding cavity 113 extends from the lower cavity 111 to have a predetermined inclination rather than a right angle, thereby improving processability. In other words, it is possible to provide smooth flow of fluid flowing through the fluid supply unit 140.

In addition, the protruding cavity 113 is formed as a branch from the lower cavity 111, and the protruding cavity 113 has a curved portion 114 in the form of a curved surface having a predetermined curvature at a position adjacent to the branch point with the lower cavity 111. can be formed.

As shown in the drawing, the curved portion 114 may be provided in a curved shape on at least one of the acute angle side or the obtuse angle side of the protruding cavity 113 that is formed at a predetermined angle rather than at a right angle, and the curvature of the curved portion 114 is It may be formed to correspond to the inner or outer radius of the branch pipe 10 described above. That is, when the curved portion 114 is formed on the acute angle side, it may be formed with a radius of 3 mm to 5 mm, preferably 3.5 mm, and when formed on the obtuse angle side, the curved portion 114 may be formed with a radius of 9 mm to 13 mm, preferably 10 mm. You can.

This curved portion 114 forms a curved bent portion when the hollow tube 30 is deformed by fluid pressure, thereby further increasing processability.

As described above, the branch pipe manufacturing apparatus 100 according to the embodiment of the present invention forms a cylindrical shape by forming a branch pipe portion 13 that protrudes obliquely from the straight pipe portion 11 modified from the hollow pipe 30. The pipe can be manufactured in the form of a branch pipe.

Ultimately, since the present invention is formed by expanding the pipe by high hydraulic pressure, it is possible to manufacture a branch pipe with a smooth inner surface, and the protruding cavity 113 is configured to protrude downward from the lower mold 110, thereby forming a branch pipe with a smooth inner surface. Durability can be improved by reducing the risk of cracks occurring in products caused by existing manufacturing equipment where parting lines are formed laterally. In other words, the risk of damage due to the presence of the parting line can be reduced by preventing the parting line from occurring on the side adjacent to the branch pipe portion 13.

In addition, according to the present invention, since the parting line is formed only on the side portion of the straight pipe portion 11, workability such as surface finishing is further improved. That is, since no parting line is formed in the portion adjacent to the branch pipe portion 13, surface finishing work can be easily performed.

Meanwhile, in the branch pipe manufacturing apparatus 100 according to an embodiment of the present invention, the upper mold 120 and the lower mold 110 may be provided with a plurality of upper cavities 121 and lower cavities 111, respectively. .

For example, a plurality of upper cavities 121 may be arranged to be spaced apart from each other along the width direction in the upper mold 120, and a plurality of lower cavities 111 may be arranged to correspond to the lower mold 110. A lower mold 110 composed of a plurality of lower cavities 111a, 111b, and 111c is shown in FIG. 9.

That is, the branch pipe manufacturing apparatus 100 according to an embodiment of the present invention may be configured so that the cavities provided in the mold are arranged in parallel in a plurality of shapes rather than a single shape, and a plurality of branch pipes are used during the hydroforming process. It has the advantage of being able to manufacture simultaneously.

On the other hand, the branch pipe manufacturing apparatus 100 according to an embodiment of the present invention may further include a vacuum unit 150.

The vacuum unit 150 may be installed in the lower mold 110 and connected to the end of the protruding cavity 113. This vacuum unit 150 forms the inside of the protruding cavity 113 in a vacuum state or generates a suction force in a direction corresponding to the moving direction of the branch pipe 13, so that the hollow pipe ( It is possible to induce smooth expansion of the branch portion 13 that is formed to protrude into the protruding cavity 113 while being deformed from 30). That is, the vacuum unit 150 may generate suction force along the inclined direction of the protruding cavity 113 formed to have a predetermined inclination.

Ultimately, the branch pipe manufacturing apparatus 100 according to an embodiment of the present invention increases processability by inducing smooth expansion during the molding process of the branch pipe portion 13 by the pressure of the fluid, and increases the processability of the branch pipe portion 13 by suction force. ), durability can be improved by applying a tensile force from the part where the thickness is formed to prevent the thickness of a specific part from being formed thin.

Therefore, the branch pipe manufacturing apparatus 100 according to an embodiment of the present invention can manufacture a hollow pipe in the form of a branch pipe and improve the durability of the manufactured branch pipe. Accordingly, the present invention can be constructed by piping a branch pipe with improved durability to a refrigerant pipe, thereby preventing minor breakdowns in system air conditioners, etc., in which the branch pipe is installed.

Figures 10 and 11 are flowcharts showing a method of manufacturing a branch pipe for installing a system air conditioner according to an embodiment of the present invention.

The method of manufacturing a branch pipe for installing a system air conditioner according to an embodiment of the present invention may include a hollow pipe supply step (S10), a mold joining step (S20), a forming step (S30), and a finishing step (S40).

In the hollow tube supply step (S10), a cylindrical hollow tube 30 can be supplied to the mold frame. That is, in the hollow tube supply step (S10), the hollow tube 30 can be placed in the mold by seating it in the lower cavity 111 of the lower mold 110.

And, in the mold joining step (S20), the mold can be closed by joining the mold. In the mold joining step (S20), the upper mold 120 may be coupled to the lower mold 110 (S21), and the side mold 130 may be coupled to the combined mold (S22). That is, in the mold joining step (S20), each mold is operated and joined.

In the forming step (S30), the hollow pipe 30 can be deformed using fluid to form a branch portion 13 that protrudes obliquely downward in the hollow pipe 30.

To elaborate, the forming step (S30) may include a fluid supply step (S11), a pressurizing step (S12), and a fluid discharge step (S13).

In the fluid supply step (S11), fluid can be injected into the hollow tube 30 through the fluid supply unit 140 into the molded mold.

In the pressurizing step (S12), the hollow tube 30 is deformed as the fluid is injected at high pressure and the mold frame is completely closed and pressurized. In particular, the axial compressive load of the hollow tube 30 can be provided by the side mold 130.

In the fluid discharge step (S13), the molding process can be completed by discharging the fluid while opening the mold.

Meanwhile, the forming step (S30) may further include a vacuum step (S14).

The vacuum step (S14) may be performed together with the pressurizing step (S12), and in the vacuum step (S14), suction force for the protruding cavity 113 may be generated by the vacuum unit 150 described above. Accordingly, the vacuum step (S14) can improve the molding processability of the protruding branch portion 13 that is deformed by fluid and compressive load.

Afterwards, the mold is completely opened and the molded branch pipe 10 is taken out from the mold. This is called the finishing step (S40), and in the finishing step (S40), the formed branch pipe 10 can be post-processed.

This finishing step (S40) may include a drilling and cutting step (S41), an end processing step (S42), and a connector joining step (S43).

In the drilling and cutting step (S41), a drilling process and a cutting process can be performed, respectively, and in the drilling and cutting step (S41), a through hole can be formed in the branch pipe portion 13 of the branch pipe 10. A through hole may be formed through a separate through hole forming operation. At this time, in the drilling and cutting step (S41), a through hole can be formed in the branch pipe portion 13 by providing a movable punch in the manufacturing mold. That is, a through hole may be formed in the forming step (S30).

Then, each end of the branch pipe 10, that is, both ends of the straight pipe portion 11 or the end of the branch pipe portion 13, is subjected to finishing processing. That is, as compressive force is applied by the mold in the above-described pressing step (S12), each end of the formed branch pipe 10 is deformed into a bellows shape. Accordingly, a cutting process to remove the deformed shape is performed, and the cutting process of the end portion can be performed using a cutting machine.

Meanwhile, in the finishing step (S40), a process of processing the surface of the branch pipe 10 can be performed before and after the drilling and cutting step (S41), and the surface roughness can be maintained uniformly.

Thereafter, in the end processing step (S42), a step connection portion 15 is formed at each cut end. That is, in the end processing step (S42), the step connection portion 15 can be formed by expanding or condensing the pipe to an appropriate length and diameter corresponding to each connection end of the branch pipe 10 described above, and the corresponding process Can be performed using a pipe forming machine.

In the connecting pipe coupling step (S43), the connecting pipe 20 can be connected to each end of the branch pipe 10 finished in the above-described processing step. In this connecting pipe coupling step (S43), the connecting pipe 20 can be coupled to each end of the branch pipe 10 by a fixing method such as welding.

Additionally, a dimple forming step (S44) may be performed before and after the end processing step (S42), and a dimple 16 may be formed on the surface of the branch pipe 10. Accordingly, the dimple 16 helps ensure a stable connection of the connector 20.

In this way, according to the branch pipe manufacturing method according to an embodiment of the present invention, hydrostatic pressure is applied to the inside of the hollow pipe 30 and at the same time a compressive load is applied in the axial direction to the hollow pipe 30 to gradually form the hollow pipe 30 according to the shape of the cavity. This may cause plastic deformation. Accordingly, the material is plastically deformed so that it can be formed into a branch pipe.

Here, the branch pipe manufacturing method according to an embodiment of the present invention involves drilling the branch pipe portion, which was performed within the mold frame along with the branch pipe forming operation when manufacturing the conventional branch pipe, at each end after the forming in the mold is completed. By performing the finishing work in the form of post-processing, it is possible to solve the problem of deformation caused by drilling with a punch during the molding process where high pressure and compressive load is applied.

As described above, according to the branch pipe manufacturing method according to an embodiment of the present invention, the branch pipe is formed by expanding the pipe by high pressure hydraulic pressure, so it is possible to manufacture a branch pipe with a smooth inner surface, and the parting line at the bent portion is measured. Unlike the existing manufacturing method that forms in the direction, the branch pipe portion 13 is formed in the downward direction through the protruding cavity 113 provided to protrude downward in the lower mold 110 that is molded upward and downward during the pressurizing process. By eliminating the occurrence of a parting line at the part connected to the part 13, the risk of cracks occurring in the product can be reduced, thereby improving durability.

That is, according to the manufacturing method of the present invention, the parting line 16 is formed on the side portion of the straight pipe portion 11, so that it does not occur on the side adjacent to the branch pipe portion 13, thereby reducing the risk of damage due to the presence of the parting line. .

In particular, the present invention can increase the molding processability of the branch pipe portion 13 by adding a vacuum process, thereby further improving the durability of the branch pipe.

In addition, according to the present invention, since the parting line is formed only on the side portion of the straight pipe portion 11, workability such as surface finishing is further improved.

Ultimately, the branch pipe manufacturing method according to an embodiment of the present invention increases processability by inducing smooth expansion in the forming process of the branch pipe portion 13 by the pressure of the fluid, and the branch pipe portion 13 is formed by suction force. Durability can be improved by applying a tensile force from the part where the material is exposed to prevent the thickness of a specific part from becoming thin.

Therefore, the branch pipe manufacturing method according to an embodiment of the present invention can manufacture a hollow pipe in the form of a branch pipe, and can improve the durability of the manufactured branch pipe. Accordingly, in the present invention, by manufacturing a branch pipe with improved durability, it can be configured by piping it to a refrigerant pipe, thereby preventing minor malfunctions in system air conditioners, etc., in which the branch pipe is installed.

The above description is merely an illustrative explanation of the technical idea of the present invention, and those skilled in the art will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are for illustrative purposes rather than limiting the technical idea of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments.

10: Branch pipe 11: Straight pipe section
13: Branch part 15: Step connection part
100: Branch pipe manufacturing device 110: Lower mold
111: lower cavity 113: protruding cavity
114: curved portion 120: upper mold
121: upper cavity 130: side mold
140: fluid supply unit 150: vacuum unit

Claims (10)

A hollow tube supply step of supplying a cylindrical hollow tube 30 to the lower mold 110;
Mold joining step of closing the mold;
A branch pipe (10) consisting of a straight pipe portion (11) in which the branch pipe portion (13) is formed by deforming the hollow pipe (30) so that a branch pipe portion (13) protruding obliquely downward is formed in the hollow pipe (30) using a fluid. ) Molding step of forming; and
It includes a finishing step of taking out the formed branch pipe 10 and post-processing it,
The mold joining step is,
coupling the upper mold 120 to the lower mold 110; and
It includes the step of coupling the side mold 130 to the combined mold,
The forming step is,
A fluid supply step of supplying fluid to the assembled mold;
A pressurizing step of pressing both ends of the hollow tube 30 with the side mold 130; and
Including a fluid discharge step of discharging fluid from the mold,
The pressurization step is,
A high pressure providing step of generating the fluid injected in the fluid supply step at high pressure; and
It includes a compressive load transfer step of transmitting the compressive load generated by the side mold 130 to the axial direction of the hollow pipe 30,
The finishing stage is,
A drilling step of forming a through hole in the branch pipe portion 13;
A cutting step of cutting and finishing both ends of the straight pipe portion 11 constituting the branch pipe 10;
A step connection forming step of forming step connection portions 15 at both ends of the straight pipe portion 11; and
It includes a connector connecting step of coupling the connector 20 to each of the step connectors 15,
The finishing stage is,
It is performed before and after the step connection forming step, and further includes a dimple forming step of forming at least one groove or hole-shaped dimple 16 at a position spaced apart from the end of the branch pipe 10,
The step connection forming step is,
A first connection end (15a) and a second connection end ( The step connection portion 15 consisting of 15b) and the third connection end 15c is formed in the form of an expansion pipe or shaft pipe, and the step connection portion 15 is formed to have a multi-stage shape with steps,
The step connection portion 15 is characterized in that the expansion pipe and the shaft pipe are formed continuously,
The mold joining step is,
A lower cavity 111 in which the hollow pipe 30 is seated to form the straight pipe portion 11, and a protruding cavity extending downwardly to protrude downward from the lower cavity 111 to form the branch pipe portion 13 ( The upper mold 120 is molded into the lower mold 110, where a plurality of cavities composed of 113) are formed in parallel, and is coupled to the lower cavity 111 of the lower mold 110 in a corresponding state. Characterized in that the upper mold 120, which is formed in plurality while the upper cavity 121 provided to cover the hollow tube 30 is parallel, is fitted to the upper part of the lower mold 110,
The forming step is,
The lower mold 110 is formed with a plurality of cavities including the lower cavity 111 and the protruding cavity 113, and the upper mold is formed with a plurality of upper cavities 121 and are molded to the lower mold 110. As the branch pipe 10 is formed through (120), a plurality of branch pipes 10 having the straight pipe portion 11 and the inclined branch pipe portion 13 are formed simultaneously. and
The branch pipe 10 is formed by the lower mold 110 and the upper mold 120 in the molding step, which are provided with the lower cavity 111, the protruding cavity 113, and the upper cavity 121. A parting line (11a) is formed on the side of the straight pipe portion (11) along the longitudinal direction of the straight pipe portion (11), and the parting line (11a) is formed only on the outer surface of the straight pipe portion (11). ,
The connector connection step is,
By combining the dimple 16 formed at the end of the branch pipe 10 and the protrusion of the connection pipe 20 coupled to the step connection portion 15 of the branch pipe 10, the connection pipe 20 ) A method of manufacturing a branch pipe, characterized in that by welding and fixing the step connection portion (15) in a temporarily fixed state. delete delete delete delete delete delete delete delete delete

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