KR101966016B1 - A device for continuous welding of the back bead on welding of the long-directional joint of a cylindrical tube by MIG or MAG and welding method using thereof - Google Patents

Abstract

The present invention relates to an apparatus for continuously welding a back bead when welding an end of a longitudinal joint of a cylindrical tube by an MIG or an MAG and a welding method using the same apparatus and, more specifically, to an apparatus for continuously welding a back bead when welding an end of a longitudinal joint of a cylindrical tube by an MIG or an MAG and a welding method using the same apparatus, in order to be able to form the back bead having regularity and continuity while being appropriate for welding the end of the joint of the tube, to be able to perform continuous welding by preventing overheat of a back support forming a recess, and to minimize welding deformation by making the back support come into close contact with an inside surface of a tube base by mechanical force like pneumatic pressure or hydraulic pressure, wherein the apparatus comprises: a table (100) having a through hole (110) with predetermined length; a water tank (200) which is arranged at the bottom of the through hole (110), in which cooling water is circulated, which is able to cradle welding base metal (500), and which has a recess for forming the back bead at an upper part; a welding rod (300) supplied to the through hole (110) to form the bead by a welding machine (210); and a feeding means (400) performing welding while reciprocating along the through hole at an upper part of the table (100) and feeding the welding rod.

Description

Technical Field [0001] The present invention relates to an apparatus for continuously welding a back bead in welding of a longitudinal joint end of a cylindrical pipe by MIG or MAG, and a welding method using the apparatus for continuous bead welding of a long-directional joint of a cylindrical tube by MIG or MAG and welding method using thereof)

The present invention relates to a device capable of continuous welding of back beads for doubling the stability and continuity of a back bead formed in an inside of a pipe in an MIG or MAG welding process at a longitudinal joint end of a cylindrical pipe, And a welding method using the apparatus.

Generally, a back bead refers to a bead formed on the back surface after welding of the joint, and it is the core of the welding that the back bead has continuity and uniformity.

Particularly, when the back beads formed in the inside of the pipe through which the fluid flows are irregularly protruded or rugged without uniformity or continuity, not only the durability of the piping is lowered but also the flow resistance of the fluid is caused to act as a kind of orifice, In this case, there is a problem that the design of the first intended piping flow rate can not be achieved.

Therefore, a bead formed by metal inert gas (MIG) welding using an inert gas as a protective gas or metal active gas (MAG) welding using an active gas transmits a radiation through a bead, A radiographic test is performed to check for the presence of internal defects. The back bead formation to satisfy these tests is only possible with a welder with a highly skilled welding expertise and not easily accomplished by unskilled persons Therefore, there is a problem that productivity of piping due to welding is very low.

 In order to solve such a problem, Korean Patent No. 10-1257755 (Patent Document 1) discloses a welding apparatus for welding a separated base material, which can move on a base material, forms an arc on the front surface, And a backing module disposed at a position spaced apart from the welding module and forming a back bead below the welded portion between the base materials, wherein the backing module comprises: And a backing unit formed integrally with the other end of the fixing unit and having a groove for forming a back bead on one side of the back body, A welding apparatus for welding has been proposed.

However, in the method of Patent Document 1, since the fixing unit and the backing unit constituting the backing module are manually assembled and disassembled, the workability is not good, and when the welding operation is performed for a long time, the backing unit is overheated and deformed, The back bead uniformity and continuity can not be guaranteed.

Further, it is difficult to apply the welding end of the cylindrical pipe to the welded structure due to its structure, the welding work can not be performed for a long time, and the back bead must be frequently replaced.

Korean Patent No. 10-1257755

The present invention for solving the above-mentioned problems of the prior art can form a back bead having uniformity and continuity, which is suitable for welding the joint end of a pipe, and prevents continuous heating by preventing overheating of the grooved back support. And the back support is adhered to the inside surface of the piping base material by mechanical force such as pneumatic or hydraulic pressure so that the deformation can be minimized during the welding so that the radiographic test can be satisfied. And an object of the present invention is to provide a device for continuously welding a back bead when welding the end portion of the longitudinal direction joint, and a welding method using the device.

According to an aspect of the present invention,

A table on which a through hole having a predetermined length is formed;

The water tank has a predetermined length so as to be disposed at the bottom of the through hole and circulates cooling water therein. The water tank penetrates the inner space of the cylindrical welding preform to allow the welding preform to be mounted. A water tank provided with a support block having a groove for preventing overheating of the support block by the cooling water;

A welding rod which is supplied to the through hole by a welding machine and forms a bead at the joint end of the welding base material;

A conveying means disposed above the table and capable of performing welding while transferring the welding rod along the through hole; / RTI >

And a back bead is formed by the groove of the support block by welding while the joint end of the welding base material is placed on the support block.

According to another aspect of the present invention,

Circulating cooling water into the water tank to prevent overheating of the support block having grooves;

Mounting the piping so that the joint end of the welding base material is located above the support block in a state where the water tank is lowered;

The water tank is raised so that the support block is brought into close contact with the inside of the joint end and the outside of the joint end is brought into close contact with the lower side of the through hole of the table;

Transferring a welding rod supplied from the welding machine by the transferring means along the through hole to perform welding;

Lowering the water tank when the welding is completed and removing the welding base material from the water tank; And a control unit.

According to the apparatus for continuously welding the back bead at the welding of the longitudinal joint ends of the cylindrical pipe by the MIG or MAG of the present invention and the welding method using the apparatus, A back bead having performance continuity can be formed.

In addition, it is possible to perform continuous welding by preventing overheat of the grooved back support through the cooling device, and it is possible to minimize deformation during welding by bringing the back support into close contact with the inside surface of the piping base material by mechanical force such as pneumatic pressure or hydraulic pressure, Can be greatly improved.

Therefore, the present invention can form a white bead satisfying a radiographic test even for a non-welded expert, and can also reduce the defect rate, thereby greatly improving the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general schematic view showing a welding apparatus according to the present invention; FIG.
2 is a front view schematically showing a main part of a welding apparatus according to the present invention;
3 is a plan view schematically showing a main part of a welding apparatus according to the present invention.
4 is a side view schematically showing a main part of a welding apparatus according to the present invention.
5 is a side view showing a process of setting a base material of a welding apparatus according to the present invention.
6 is a side view showing a base material welding process of a welding apparatus according to the present invention.
FIG. 7 is an enlarged view of the portion 'A' in FIG. 6, wherein (a) shows a state before welding, and (b) shows a state after welding.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Before describing the present invention, it is to be noted that the following terms are defined in consideration of the function of the present invention, and it should be construed as a concept consistent with the technical idea of the present invention and interpreted as being commonly or commonly understood in the technical field of the present invention.

In the following description, well-known functions or constructions are not described in detail to avoid obscuring the subject matter of the present invention.

Here, the attached drawings are exaggerated or simplified in order to facilitate understanding and clarification of the structure and operation of the technology, and the components do not exactly coincide with actual sizes.

2 is a front view schematically showing a main part of a welding apparatus according to the present invention, and Fig. 3 schematically shows a main part of a welding apparatus according to the present invention. Fig. Fig. 4 is a side view schematically showing a main part of a welding apparatus according to the present invention. Fig.

1 to 4, the welding apparatus of the present invention includes a table 100, a water tank 200, a welding rod 300, and a conveying means 400, Is a cylindrical pipe as a " welding base material " for performing welding using the welding apparatus of the present invention.

The table 100 is formed in a flat plate shape, and a through hole 110 having a predetermined length is formed on the inner side for welding. The table 100 may be spaced apart from the ground by a plurality of supports 130.

The water tank 200 is formed in a cylindrical shape having a predetermined length so as to be able to mount the welding base material. The water tank 200 is disposed at the bottom of the through hole 110, and the cooling water is stored therein.

In order to allow the cooling water to circulate, a water inlet 201 into which the water flows and a water outlet 202 through which water is discharged are formed at one side of the water tank 200, respectively. The water inlet 201 and the water outlet 202 are provided with first The pipe 231 and the second pipe 232 are connected to each other and the pipes 231 and 232 are connected to the heat exchanging means 230 for circulating the cooling water and cooling the water.

Accordingly, when the heat exchanging means 230 is operated, water is supplied to the water tank 200 and circulated while being recovered. At this time, the water heated in the water tank 200 by the welding is cooled in the heat exchanging means 230.

When the water inlet 201 and the water outlet 202 are provided at one end of the water tank 200 as in the example shown in the drawing, the water may not sufficiently circulate with respect to the entire inside of the water tank 200, The cooling efficiency of the block 210 deteriorates.

Therefore, in order to improve the cooling efficiency of the support block 210, it is preferable to have an extension pipe 201a extending from the inlet 201 to the other side via the inner space of the water tank 200, The water introduced through the water inlet 201 is ejected into the water tank 200 from the opposite side of the water outlet 202 through the extension pipe 201a and then discharged to the water outlet 202 on the opposite side of the water tank 200, The water stored in the water tank 200 can be passed through the whole section of the water tank 200, so that the cooling efficiency of the support block 210 can be improved.

Although the extension pipe 201a is connected to the inlet 201 in the figure, it is obvious that the extension pipe 201a may be connected to the outlet 202 to achieve the same effect.

A groove 211 for forming a back bead is formed at an upper end of the support block 210 and a groove 211 for forming a back bead is formed at an upper end of the support block 210 Is in contact with cooling water circulating in the water tank 200 to prevent overheating. At this time, the support block 210 may be a metal material having a high thermal conductivity, for example, a copper material.

The water tank 200 may be connected to the elevating means 220 including a pneumatic or hydraulic cylinder so as to be vertically movable up and down.

For this purpose, an air cylinder is provided at one end of the water tank 200, for example, in the vertical direction, and a rail 221 may be installed at right and left sides of the water tank 200 in the vertical direction.

Accordingly, when the elevating means 220 is operated, the water tank 220 is moved up and down on the rails 221 as needed. At this time, when the water tank 200 descends, the welding base material 500 is mounted or removed .

Conversely, when the water tank 200 is raised, the support block 210 can be welded while being in close contact with the inside 501 surface of the welding base material 500. This welding method is described with reference to FIGS. 5 to 7 And the present invention will be more specifically described.

The welding rod 300 is drawn out from the welding machine 310 and supplied to the through hole 110 by the feeder 320 and is welded by an arc to the joint end 510 of the welding base material 500 Since the welding machine 310, the feeder 320 and the welding base material 300 are generally applied to a welding apparatus such as MIG or MAG, a detailed description thereof will be omitted.

The transporting unit 400 may be made of, for example, a known magnetic carrier, and may be provided on the table 100 so as to reciprocate in a predetermined section.

A holder for receiving the welding rod 300 may be provided at one side of the transfer means 400 and the welding rod 300 is supplied while reciprocating along the through hole 110 to perform welding.

A limit sensor 410 is provided at each of the front and rear ends of the conveying means 400 and a stopper 120 contacting the limit sensor 410 may be provided on the table 100. Therefore, when the limit sensor 410 and the stopper 120 come into contact with each other during the movement of the conveying means 400, the conveying means 400 is automatically stopped to limit the moving period of the conveying means 400 to a predetermined section can do.

6 is a side view showing a welding process of a base material of a welding apparatus according to the present invention, and FIG. 7 is an enlarged view of a portion 'A' of FIG. 6, wherein FIG. 5 is a side view showing a base material setting process of the welding device according to the present invention, (a) shows a state before welding, (b) shows a state after welding, and a welding method using the apparatus of the present invention will be described.

The heat exchanging unit 230 is first operated to circulate the cooling water into the water tank 200 to prevent the support block 210 having the groove 211 from being overheated.

5, the water tank 200 is passed through the hollow portion of the welding base material 500 in a state where the water tank 200 is lowered by the elevating means 220. At this time, The end portion 510 of the support block 210 is positioned on the upper side of the support block 210 and the pipe is mounted.

6 and 7 (a), when the water tank 200 is raised by operating the elevating means 220, the support block 210 is moved to the inside 501 of the joint end portion 510 And the outer side 502 of the joint end 510 is in close contact with the lower side of the through hole 110 of the table 100.

In this state, the transfer means 400 such as a magnetic carrier is operated to supply the welding rod 300 supplied from the welding machine 310 along the through hole 110 to perform welding.

7B, when the bead 330 is filled between the joint ends 510 of the welding base material 500 and the groove 211 formed at the upper end of the support block 210 The back beads 331 are formed, and such back beads can have continuity and uniformity.

When the welding is completed, the elevating means 220 is operated to lower the water tank 200, and the welding base material 500 is removed from the water tank 200 to obtain the piping product that has been welded.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It is to be understood that modifications and variations of the features of the present invention are intended to be included within the scope of the present invention.

100: Table 110: Through hole
120: stopper 130: support
200: water tank 201: inlet
202: Outlet 210: Base block
211: groove 220: elevating means
221: rail 230: heat exchange means
231: first piping 232: second piping
300: welding rod
310: welding machine 320: feeder
330: Bead 331: Back bead
400: Feeding means 410: Limit sensor
500: Weld metal matrix 501: Inside
502: Outside 510: Connecting end

Claims (6)

An apparatus for continuously welding a back bead when welding a longitudinal joint end of a cylindrical pipe by MIG or MAG,
A table on which a through hole having a predetermined length is formed;
A water tank having a predetermined length so as to be disposed at the bottom of the through hole and storing cooling water therein and allowing the welding base material to pass through an inner space of the cylindrical welding base material, A water tank provided with a support block having a groove for preventing contact with the cooling water to prevent overheating of the support block;
A welding rod which is supplied to the through hole by a welding machine and forms a bead at the joint end of the welding base material;
A conveying means disposed above the table and capable of performing welding while transferring the welding rod along the through hole; / RTI >
Wherein a back bead is formed by grooves of the support block by welding in a state where a joint end portion of the welding base material is placed on the support block,
The water tank is formed in a cylindrical shape, and a water inlet for discharging water and a water outlet for discharging water are formed on one side, and the water inlet and the water outlet are connected to heat exchange means for cooling water through a pipe, A device for continuously welding a back bead during welding of a lengthwise joint end of a cylindrical pipe by MIG or MAG.
The method according to claim 1,
Wherein the water tank is connected to the elevating means by pneumatic or hydraulic pressure so as to be vertically movable up and down and is capable of mounting or removing the welding base material when the water tank is lowered, Wherein the weld bead is welded in a state in which it is in close contact with the surface of the cylindrical piping by MIG or MAG.
delete The method according to claim 1,
The water inlet and the water outlet are provided at one end of the water tank and extend from the water inlet or the water outlet to the other side via the internal space of the water tank, And the continuous bead is continuously welded at the welding of the longitudinal joint ends of the cylindrical pipe by MIG or MAG.
The method according to claim 1,
Characterized in that a limit sensor is provided at each of the front and rear ends of the conveying means and a stopper in contact with the limit sensor is provided at an upper portion of the table and is restricted by the stopper to the conveying section of the conveying means. For continuous welding of the back bead during welding of the lengthwise joint end of the cylindrical pipe by means of welding.
A welding method using the apparatus according to any one of claims 1, 2, 4 and 5,
Circulating cooling water into the water tank to prevent overheating of the support block having grooves;
Mounting the piping so that the joint end of the welding base material is located above the support block in a state where the water tank is lowered;
The water tank is raised so that the support block is brought into close contact with the inside of the joint end and the outside of the joint end is brought into close contact with the lower side of the through hole of the table;
Transferring a welding rod supplied from the welding machine by the transferring means along the through hole to perform welding;
Lowering the water tank when the welding is completed and removing the welding base material from the water tank; Welded to each other.

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