KR102388903B1 - Joining method for pipe of different materials - Google Patents

Abstract

The present invention relates to a method for bonding two pipes made of different metal materials such as an aluminum pipe and a copper pipe. In particular, disclosed is a method for bonding heterogeneous-material pipes, which comprises: a first bonding unit forming step of processing the inner circumference of the end portion of a first pipe in a tapered manner to form a first bonding unit; a second bonding unit forming step of processing the inner circumference and the outer circumference of the end portion of a second pipe in a tapered manner to form a second bonding unit inserted into the first bonding unit; a pipe assembly step of inserting the second bonding unit of the second pipe into the first bonding unit of the first pipe; an electrode installation step of allowing a first electrode to come in contact with the outer circumference of the first bonding unit of the first pipe, and allowing a second electrode to come in contact with the outer circumference of the second pipe; and a diffusion-bonding step of allowing the first bonding unit and the second bonding unit to conduct by using the first electrode and the second electrode, and inserting a mandrill into the second pipe such that the shaping unit formed at the mandrill may pressurize the second bonding unit on the outside to perform diffusion-bonding between the first bonding unit and the second bonding unit. Therefore, the end portion of the pipes may be more solidly bonded.

Description

Pipe joining method of different materials {Joining method for pipe of different materials}

The present invention relates to a method for joining pipes of different materials, and more particularly, to a method for joining two pipes made of different metal materials, such as an aluminum pipe and a copper pipe.

As a technology related to a method for joining pipes of different materials, 'dissimilar metal pipe connection device and connection method' (hereinafter referred to as 'prior art') of Republic of Korea Patent Publication No. 10-1825939 (registered on Jan. 31, 2018) is proposed. .

The prior art is, "In a dissimilar metal tube connection method using a device for connecting a copper (copper) tube and an aluminum tube of different materials by fusion bonding in an electric current manner, inserting the detached end of the expansion port from the insertion end of the copper tube to expose the opposite end of the copper tube and at the same time to expose the extension ball to the front of the insertion end After going through the aluminum tube installation step, the copper tube installation step in which the insertion end of the copper tube is inserted into one end of the aluminum tube and fixed using a second clamp, and after the copper tube installation step, the exiting end of the expansion port is inserted into the locking hole of the discharge part After passing through the engaging action installation step, the current-carrying part connecting step of connecting the current-carrying parts to the aluminum tube and the copper tube, respectively, after the engaging action installation step, and after passing the current-conducting part connection step, the copper tube while applying a current to the aluminum tube and the copper tube When the inner surface of the aluminum tube in contact with the outer surface of the insertion end of the aluminum tube is melted to form a molten alloy, the third actuator of the discharge part pulls the detached end caught in the locking hole, and the expansion ball releases the inner surface of the insertion end while pressurizing and contacting it. Connection using a dissimilar metal tube connecting device, characterized in that it consists of a dismantling step of disassembling an aluminum tube and a copper tube that are integrally connected by releasing the clamping force of the first and second clamps after going through the expansion opening separation step and the expansion opening separation step method" is disclosed.

The prior art is a technology in which a pipe made of copper and a pipe made of aluminum are joined using an electrical conduction method in which different poles are connected, but the bonding force can be increased by expanding the diameter of the insertion end during bonding.

However, according to the method as in the prior art, there is a problem in that the insertion end of the copper tube is not completely joined and thus partially peeled off. There is a problem that noise may be generated by the flow of the fluid passing through the peeled part, or in severe cases, the fluid may leak through the gap of the peeled part.

[Document 1] Republic of Korea Patent Publication No. 10-1825939 (registered on Jan. 31, 2018)

The present invention has been devised to solve the above problems, and by applying a diffusion bonding method using electricity, two pipes of different materials are joined, in particular, so that the end of the pipe inserted inside can be more firmly joined. An object of the present invention is to provide a method for joining pipes of different materials.

The problems to be solved by the present invention are not limited to the aforementioned problems. Other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

In order to solve the above problems, a pipe joining method of dissimilar materials according to an embodiment of the present invention is a method for joining a first pipe and a second pipe having different materials from each other, and the inner periphery of the end of the first pipe is a first joint forming step of tapering to form a first joint; a second joint forming step of forming a second joint to be inserted into the first joint by tapering the inner and outer periphery of the end of the second pipe; a pipe assembly step of inserting a second joint portion of the second pipe into the first joint portion of the first pipe; an electrode installation step of contacting the first electrode with the outer periphery of the first junction of the first pipe and contacting the second electrode with the outer periphery of the second pipe; and using the first electrode and the second electrode to energize the first junction and the second junction, and insert a mandrel into the second pipe so that a molded part formed on the mandrel presses the second junction to the outside. and a diffusion bonding step of diffusion bonding the first junction part and the second junction part by doing so.

In an embodiment of the present invention, the molded part of the mandrel is formed in a circular shape along the circumference of the mandrel to make line contact along the inner periphery of the second joint, and the molded part is the mandrel from the inside of the second pipe. By moving forward toward the first pipe, the second joint portion is continuously pressed from the larger diameter side to the smaller side.

In an embodiment of the present invention, the forming part of the mandrel is formed in a circular shape along the circumference of the mandrel to make line contact along the inner periphery of the second joint part, and two or more parts are arranged to be spaced apart along the longitudinal direction of the mandrel. is formed, and the two molded parts disposed adjacent to each other among the respective molded parts have a larger diameter than the one disposed at the rear than the one disposed at the front.

In an embodiment of the present invention, the two molding parts disposed adjacent to each other among the molding parts are spaced apart from each other so that the molding part disposed in the rear can contact the second joint part after the molding part disposed in the front passes the second joint part. do.

In an embodiment of the present invention, the forming part of the mandrel is composed of a plurality of balls arranged along the circumference of the mandrel and each rotatably installed, and in the diffusion bonding step, the mandrel moves from the inside of the second pipe to the first pipe. By rotating the shaft at the same time as the forward operation, each ball continuously presses the second joint portion from a larger diameter to a smaller diameter.

According to the pipe joining method of dissimilar materials according to an embodiment of the present invention, the end of the second joint of the second pipe is the first joint of the first pipe by pressing the second joint formed to be tapered with the mandrel outward and performing diffusion joining. It has the effect of being able to bond more firmly with

1 is a flowchart of a pipe joining method of different materials according to an embodiment of the present invention.
2 to 5 are cross-sectional views showing a step-by-step method for joining pipes of different materials according to an embodiment of the present invention.
6 to 8 are cross-sectional views each showing another embodiment of the mandrel in the pipe joining method of different materials according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. For convenience of description, components shown in the drawings may be exaggerated, omitted, or schematically represented.

1 is a flowchart of a pipe joining method of dissimilar materials according to an embodiment of the present invention, and FIGS. 2 to 5 are cross-sectional diagrams showing the pipe joining method of dissimilar materials in stages according to an embodiment of the present invention.

1 to 5, the pipe joining method of dissimilar materials according to an embodiment of the present invention is largely a first joint forming step (S10), a second joint forming step (S20), and a pipe assembling step (S30). , including an electrode installation step (S40) and a diffusion bonding step (S50).

The first joint forming step (S10) is a step of forming the first joint 110 by processing the inner periphery of the end of the first pipe 100 to be tapered, as shown in FIG. 2 .

In this step, at least the inner periphery of the end of the first pipe 100 is tapered by swaging the end of the first pipe 100 or cutting the inner periphery of the end of the first pipe 100 . A true first junction 110 is formed.

Here, the first pipe 100 may be made of, for example, an aluminum pipe.

In the second joint forming step (S20), as shown in FIG. 2 , the inner periphery and the outer periphery of the second pipe 200 are tapered to form a second joint 210 inserted into the first joint 110 . ) is formed.

In this step, by swaging the end of the second pipe 200 , the second joint portion 210 having a tapered inner periphery and an outer periphery is formed at the end of the second pipe 200 .

Here, the second pipe 200 may be formed of, for example, a copper (copper) pipe.

The pipe assembling step (S30) is a step of inserting the second joint portion 210 of the second pipe 200 into the first joint portion 110 of the first pipe 100 as shown in FIG. 3 .

In the electrode installation step (S40), as shown in FIG. 4 , the first electrode 300 is brought into contact with the outer periphery of the first junction part 110 of the first pipe 100 , and the This is a step of contacting the second electrode 400 to the outer periphery.

In this step, the electrodes 300 and 400 for conducting electricity to the first pipe 100 and the second pipe 200 in the diffusion bonding step (S50) to be described later are connected to the first pipe 100 and the second pipe. (200) are brought into contact with each other. Accordingly, one of the first electrode 300 and the second electrode 400 becomes an anode (+) electrode, and the other becomes a cathode (-) electrode.

The first electrode 300 and the second electrode 400 have a vertically divided structure, respectively, when in contact with the first pipe 100 and the second pipe 200, each pipe 100, 200 It is installed to surround the outer periphery of In particular, the first electrode 300 wraps around the outer periphery of the first junction part 110 and supports it, so that in a diffusion bonding step (S50) to be described later, the first junction part 110 and the first junction part 110 by a mandrel 500 It enables the second joint portion 210 to be strongly adhered.

In the diffusion bonding step (S50), as shown in FIG. 5, the first junction part 110 and the second junction part 210 are energized using the first electrode 300 and the second electrode 400, By inserting the mandrel 500 into the inside of the second pipe 200 so that the forming part 510 formed on the mandrel 500 presses the second joint part 210 to the outside, the first joint part 110 and This is a step of diffusion bonding the second junction part 210 .

Here, the forming part 510 of the mandrel 500 is formed in a circular shape along the periphery of the mandrel 500 to make line contact along the inner periphery of the second joint part 210 . Accordingly, the forming part 510 moves the mandrel 500 forward from the inside of the second pipe 200 toward the first pipe 100 so that the second joint part 210 is formed from the larger diameter side. It is continuously pressurized from the small side to the smallest side.

In addition, the end of the mandrel 500 disposed in front of the forming part 510 is formed to have a narrower width toward the front, so that the mandrel 500 can easily pass through the second joint part 210 .

According to the pipe joining method of dissimilar materials according to the embodiment of the present invention configured as described above, the second pipe 210 is diffusion-bonded by pressing the second joint portion 210 in which the mandrel 500 is tapered outwardly. There is an effect that the end of the second joint 210 of the first pipe 100 can be more firmly joined to the first joint 110 of the pipe 100 .

In addition, according to the present invention, in a state in which the forming part 510 of the mandrel 500 is in line contact with the second joint part 210, the second joint part 210 is continuously pressed from the larger diameter side to the smaller diameter side. Since it is possible to minimize the deviation of the pressing force according to the contact position of the molding part 510 and the second joint part 210 , it is possible to prevent a bonding defect between the first joint part 110 and the second joint part 210 . there is

Hereinafter, another embodiment of the mandrel 500 will be described with further reference to FIGS. 6 and 8 .

6 to 8 are cross-sectional views each showing another embodiment of the mandrel in the pipe joining method of different materials according to an embodiment of the present invention.

6 and 7 , the forming part 510 of the mandrel 500 is formed in a circular shape along the circumference of the mandrel 500 to make line contact along the inner periphery of the second joint part 210 . However, two or more may be formed so as to be spaced apart from each other in the longitudinal direction of the mandrel 500 .

At this time, the two molded parts 510 disposed adjacent to each other among the respective molded parts 510 are formed to have a larger diameter than the one disposed at the rear side.

According to the structure as described above, the lifespan of the mandrel 500 may be improved by distributing the load applied to the forming part 510 .

On the other hand, each of the molding parts 510 may be disposed to be in contact with the second joint 210 at the same time as shown in FIG. 6 , and as shown in FIG. 7 , the molding parts 510 disposed in the front may be formed. After passing through the second joint portion 210 , the forming part 510 disposed at the rear may be disposed to be spaced apart from each other so as to be in contact with the second joint portion 210 . According to the former, the stroke of the mandrel 500 can be shortened, so that the processing time can be shortened. According to the latter, the second joint 210 can be pressed by applying a small force to the mandrel 500 compared to the former structure. Therefore, the load on the actuator for the operation of the mandrel 500 can be reduced.

In addition, as shown in FIG. 8 , the forming part 510 of the mandrel 500 may be formed of a plurality of balls 511 arranged along the circumference of the mandrel 500 and rotatably installed, respectively.

At this time, in the diffusion bonding step (S50), the mandrel 500 moves forward from the inside of the second pipe 200 toward the first pipe 100 and at the same time axially rotates, so that each ball 511 is The second joint portion 210 is continuously pressed from the larger diameter side to the smaller side.

According to the above configuration, the forming part 510 of the mandrel 500 is brought into rolling contact with the second joint part 210 , thereby reducing damage to the mandrel 500 and the second pipe 200 .

In the foregoing, the present invention has been described with reference to limited embodiments and drawings, but it will be apparent to those skilled in the art that various modifications are possible within the scope of the technical idea of the present invention. Accordingly, the protection scope of the present invention should be defined by the description of the claims and their equivalents.

100: first pipe 110: first joint
200: second pipe 210: second joint
300: first electrode 400: second electrode
500: mandrel 510: forming part
511: ball

Claims (5)

As a method for joining the first pipe 100 and the second pipe 200 having different materials,
a first joint forming step (S10) of tapering the inner periphery of the end of the first pipe 100 to form a first joint 110;
A second joint forming step (S20) of forming a second joint portion 210 inserted into the first joint portion 110 by processing the inner periphery and the outer periphery of the end of the second pipe 200 to be tapered;
a pipe assembly step (S30) of inserting the second joint portion 210 of the second pipe 200 into the first joint portion 110 of the first pipe 100;
An electrode installation step in which the first electrode 300 is brought into contact with the outer periphery of the first junction 110 of the first pipe 100 and the second electrode 400 is brought into contact with the outer periphery of the second pipe 200 . (S40); and
The first junction 110 and the second junction 210 are energized using the first electrode 300 and the second electrode 400 , and the mandrel 500 is inserted into the second pipe 200 . Diffusion bonding step (S50) of diffusion bonding the first junction part 110 and the second junction part 210 by inserting the molded part 510 formed on the mandrel 500 to press the second junction part 210 to the outside. ), including;
The forming portion 510 of the mandrel 500 is formed in a circular shape along the circumference of the mandrel 500 to make line contact along the inner periphery of the second joint portion 210 , in the longitudinal direction of the mandrel 500 . Two or more are formed so as to be spaced apart along the
The two molded parts 510 disposed adjacent to each other among the molded parts 510 are formed to have a larger diameter than the one disposed at the rear, and the one disposed at the front.
The two molded parts 510 disposed adjacent to each other among the molded parts 510 are formed at the rear after the molded part 510 disposed in the front passes through the second joint 210 . A pipe joining method of dissimilar materials, characterized in that spaced apart from each other so as to be in contact with the second joint (210).
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