Automatic Pipe Welding System

Abstract

The present invention relates to an automatic pipe welding system, comprising a lower roller (10) and an upper roller (20) that rotately support a pipe (1) so as to automatically load a flange while mechanically concentrically aligning the pipe and the flange and perform rotary welding while maintaining the alignment state, a centering unit (30) that concentrically aligns a flange (2) at the end of the pipe (1), a flange loading unit (40) that supplies a flange (2), and a welding torch (50).

Description

Technology Field

[0001] The present invention relates to an automatic pipe welding system, and more specifically, to an automatic pipe welding system capable of performing welding after precisely positioning the pipe and the flange in a concentric state through a roller structure that rotates and supports the pipe, a centering unit that automatically aligns and loads the flange, and a flange loading unit. Background Technology

[0003] Generally, the process of welding flanges to the outer surface or ends of pipes is a critical step for ensuring the airtightness and structural stability of piping systems; therefore, it is crucial to accurately align the pipe and flange concentrically and perform uniform welding in the circumferential direction. In particular, since the final weld quality is determined by the complex interplay of factors such as pipe rotational stability, flange alignment accuracy, and welding torch tracking precision, various technologies are being proposed to automate this process.

[0004] Accordingly, the previously disclosed registered patent No. 10-1749733 discloses an automatic pipe welding system in which a pipe is placed on a turning roller and rotated, and automatic welding is performed using a TIG welding torch while the flange is supported from the outer circumference. This improves welding precision by performing welding while rotating the pipe through the turning roller, and by detecting the voltage value applied to the TIG welding torch in real time to control it to automatically track the welding line. In addition, it is characterized by being configured to enable continuous welding even on long pipes by arranging multiple main bodies in-line.

[0005] However, the aforementioned prior art is limited to a structure that supports the outer circumference of the flange for aligning the flange to the pipe, and thus lacks a structure that mechanically enforces center alignment between the flange and the pipe. Consequently, there is a problem in that concentricity errors may occur depending on the initial position setting.

[0006] Furthermore, since weld line tracking relies on voltage-based control, it is difficult to reliably ensure weld quality in the event of fundamental misalignment, and minute eccentricity or wobble occurring during pipe rotation may lead to non-uniformity in the weld. Moreover, because the flange feeding and loading processes are not integrated with the automatic alignment structure, positional errors may accumulate during the operation, and there is a limitation in that the consistency of alignment precision deteriorates during repetitive tasks.

[0007] As such, the aforementioned conventional technology focuses on pipe rotation-based automatic welding and weld line tracking control technology, but it has structural limitations in that the mechanical centering structure for accurately positioning the flange at the center of the pipe is not sufficiently combined with the automatic loading and alignment functions of the flange. Consequently, problems such as misalignment of the center between the flange and the pipe, deviations in the contact gap, and uneven weld beads may occur. These issues can lead not only to a deterioration in welding quality but also, in the long term, to reduced durability of the pipe joint and an increased risk of leakage.

[0008] Therefore, there is an urgent need to develop technology that can simultaneously improve welding quality and operational reliability by mechanically aligning pipes and flanges accurately concentrically, automatically and stably feeding and positioning flanges, and maintaining the alignment state throughout the welding process. Prior art literature

[0010] (Patent Document 0001) KR 10-1749733 B1 The problem to be solved

[0011] Accordingly, the present invention was conceived to solve the aforementioned problems, and the purpose of the present invention is to provide an automatic pipe welding system capable of mechanically concentrically aligning the pipe and the flange, automatically loading the flange, and performing rotary welding while maintaining the alignment state. means of solving the problem

[0013] To achieve this purpose, the present invention features an automatic pipe welding system for welding a flange to the outer surface of a pipe, comprising: a pair of lower rollers (10) spaced apart and configured to rotatably support the pipe (1); an upper roller (20) configured to be configured to be configured to press the pipe (1) from above and configured to be configured to press the pipe (1) from above and configured to be configured to be configured to press the pipe (1) from above and configured to be configured to be configured to be configured to press the flange (2) to the end of the pipe (1) and configured to be configured to rotate the flange (2) while guiding it into a centering hole (31) and aligning it with the pipe (1) in a concentric circle; a flange loading unit (40) configured to supply the flange (2) individually to the centering unit (30); and a welding torch (50) configured to weld the contact portion between the flange (2) and the pipe (1).

[0014] At this time, the centering unit (30) comprises a rail body (32) having a first vertical rail (32a) and a second vertical rail (32b) installed on both sides, a balancing roller (33) installed on the upper part of the rail body (32) and rotated by a driving unit, a brake (34) installed on the rail body (32) and stopping operation by pressing the balancing roller (33), a lifting and transfer body (35) that moves up and down along the first vertical rail (32a) and has a horizontal rail (35a) installed on the upper part, a balancing weight (36) that moves up and down along the second vertical rail (32b), a balancing wire (37) having one end connected to the lifting and transfer body (35) and the other end connected to the balancing weight (36) via the balancing roller (33), and riding along the horizontal rail (35a). It is characterized by including a horizontal transfer body (38) that moves in a horizontal direction, a connecting chuck (39) that is installed on the horizontal transfer body (38) and rotates to operate in conjunction with a plurality of jaws (39a) that clamp the flange (2), and a conical centering hole (31) that is formed in a recess on one side of the connecting chuck (39) corresponding to the end of the pipe (1) and whose diameter decreases as it goes inward.

[0015] Additionally, the lifting and transfer body (35) is configured such that the gravity-direction transfer force is offset by a balance weight (36) connected via a balance wire (37), and a pipe (1) is loaded between the upper roller (20) and the lower roller (10). When the brake (34) is in the off state and the interlocking chuck (39) moves and rotates toward the pipe (1) by the forward operation of the horizontal transfer body (38), the end of the pipe (1) engages with the inner surface of the centering hole (31), and the interlocking chuck (39) moves up and down together with the lifting and transfer body (35). After the position is corrected so that the rotation center of the interlocking chuck (39) aligns with the center of the pipe (1), the brake (34) is turned on, the height of the interlocking chuck (39) is fixed, and after the interlocking chuck (39) moves to a position spaced apart from the end of the pipe (1) by the backward operation of the horizontal transfer body (38), to the flange loading part (40 The flange (2) is supplied between the interlocking chuck (39) and the end of the pipe (1) by means of the forward operation of the horizontal transfer body (38), and the interlocking chuck (39) is moved toward the end of the pipe (1) to bring the flange (2) into close contact with the end of the pipe (1). Then, when a plurality of jaws (39a) are clamped, the flange (2) is positioned at the center of the pipe (1) by aligning with the rotation center of the interlocking chuck (39). The welding torch (50) moves to weld the contact portion between the flange (2) and the pipe (1), and the interlocking chuck (39) is rotated to rotate the flange (2) and the pipe (1) while performing the welding process.

[0016] Additionally, the flange loading unit (40) comprises a loading bar (41) positioned below the pipe (1) loaded on the upper roller (20) and lower roller (10) and installed parallel to each other to support the flange (2) in an upright state from below, a transfer body (42) that moves up and down through the space between the interlocking chuck (39) and the end of the pipe (1) and has a pair of transfer arms (42a) installed at the bottom, and an electromagnet (43) installed at the bottom of the transfer arm (42a) and detachably provided on both sides of the upper flange (2) by magnetic force, wherein the flange (2) is waiting in an upright state on the loading bar (41) and the gap between the interlocking chuck (39) and the end of the pipe (1) is spaced apart, and the transfer body (42) moves downward through the space between the interlocking chuck (39) and the end of the pipe (1) to attach the flange (2) waiting on the loading bar (41) to the electromagnet (43), and thereafter, The transfer body (42) is configured to move upward to load the flange (2) between the interlocking chuck (39) and the end of the pipe (1).

[0017] Additionally, the electromagnet (43) is rotatably coupled to the end of the transfer arm (42a) via a horizontal axis (43a), and the horizontal axis (43a) is installed at an eccentric position from the center of gravity of the electromagnet (43), so that the electromagnet (43) is tilted to one side around the horizontal axis (43a) due to its own weight, and the magnetic surface of the electromagnet (43) is arranged to form an angle of inclination, and when the electromagnet (43) contacts the upper surface of the flange (2), the magnetic surface of the electromagnet (43) is self-aligned to correspond to the outer circumference of the flange (2). Effects of the invention

[0019] According to the above configuration and operation, the present invention fundamentally eliminates concentricity deviations that occurred in conventional periphery support methods by mechanically forcibly aligning the centers of the flange and the pipe through the conical centering hole of the centering section and the interlocking chuck structure. Furthermore, by enabling the interlocking chuck to automatically align to the center of the pipe through the interconnected structure of the lifting and transfer body, the balance weight, and the balance wire, it can be applied to pipes of various sizes without separate manual adjustment. Additionally, the flange can be securely fixed in a precise position through the forward and backward movement of the horizontal transfer body and the clamping operation of the interlocking chuck, thereby suppressing positional fluctuations during welding. Moreover, the reliability of the automated process is improved by stably picking up and transporting the flange through the transfer body and electromagnet structure of the flange loading section. In particular, flange contact stability can be further enhanced by implementing a self-alignment function that naturally adheres to the outer surface of the flange through a structure in which the electromagnet tilts due to its own weight by an eccentric horizontal axis. Through this series of configurations, the entire process from pre-welding alignment, loading, clamping, and welding is consistently and automatically performed, minimizing work deviations, ensuring uniformity of welding quality, and simultaneously increasing productivity. and it has the effect of significantly improving process reliability. Brief explanation of the drawing

[0021] FIG. 1 is a schematic diagram showing the overall configuration of an automatic pipe welding system according to an embodiment of the present invention. FIGS. 2 to 5 are configuration diagrams showing the operating state of an automatic pipe welding system according to an embodiment of the present invention. FIG. 6 is a configuration diagram showing a flange loading section of an automatic pipe welding system according to an embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Furthermore, in describing the present invention, detailed descriptions of related known functions are omitted if they are deemed obvious to those skilled in the art and could unnecessarily obscure the essence of the invention.

[0023] FIG. 1 is a configuration diagram showing the overall structure of an automatic pipe welding system according to an embodiment of the present invention, FIG. 2 to 5 are configuration diagrams showing the operating state of an automatic pipe welding system according to an embodiment of the present invention, and FIG. 6 is a configuration diagram showing the flange loading section of an automatic pipe welding system according to an embodiment of the present invention.

[0024] The present invention relates to an automatic pipe welding system, comprising a lower roller (10) and an upper roller (20) that rotately support a pipe (1) to automatically load a flange while mechanically concentrically aligning the pipe and the flange and to perform rotary welding while maintaining the alignment state, a centering unit (30) that concentrically aligns a flange (2) at the end of the pipe (1), a flange loading unit (40) that supplies a flange (2), and a welding torch (50). For example, the outer surface of the flange is formed in a circular shape.

[0025] According to the present invention, a pair of lower rollers (10) are spaced apart and positioned at the bottom of the pipe (1) to support the weight of the pipe (1) and form a rotational center axis, and an upper roller (20) is positioned above the lower roller (10) to press the pipe (1) from above, thereby restraining the pipe (1) so that it does not detach during rotation, and accordingly, the pipe (1) performs stable rotational movement while simultaneously securing axial restraint force and radial support force.

[0026] According to the present invention, a pair of lower rollers (10) are spaced apart and positioned at the bottom of the pipe (1) to support the weight of the pipe (1) and form a rotational center axis, and an upper roller (20) is positioned above the lower roller (10) to press the pipe (1) from above, thereby restraining the pipe (1) so that it does not detach during rotation, and accordingly, the pipe (1) performs stable rotational movement while simultaneously securing axial restraint force and radial support force.

[0027] In addition, the lower roller (10) may be configured to be driven by a separate drive motor, and accordingly, the pipe (1) rotates in conjunction with the rotation of the lower roller (10), thereby allowing the welding process described later to be performed stably.

[0028] In addition, the centering part (30) according to the present invention is installed to correspond to one end of the pipe (1), and the flange (2) is guided into the centering hole (31) and positioned so as to coincide with the pipe (1) on a concentric circle, and is configured to rotate while pressing the flange (2) against the end of the pipe (1).

[0029] At this time, the reaction force generated when the inner surface of the conical centering hole (31) and the end of the pipe (1) come into contact is broken down into a radial component and an axial component, thereby inducing the interlocking chuck (39), which is in an initial eccentric state, to be corrected to a position that coincides with the center of the pipe (1), and accordingly, an alignment state is formed in which the rotation center of the interlocking chuck (39) and the center of the pipe (1) coincide.

[0030] In FIG. 1, the centering unit (30) comprises a rail body (32) having a first vertical rail (32a) and a second vertical rail (32b) installed on both sides, a balancing roller (33) installed on the upper part of the rail body (32) and rotated by a driving unit, a brake (34) installed on the rail body (32) to stop the balancing roller (33) by applying pressure, a lifting and transfer body (35) that moves up and down along the first vertical rail (32a) and has a horizontal rail (35a) installed on its upper part, a balancing weight (36) that moves up and down along the second vertical rail (32b), a balancing wire (37) connecting the lifting and transfer body (35) and the balancing weight (36), a horizontal transfer body (38) that moves laterally along the horizontal rail (35a), and a plurality of clamping flanges (2). The jaw (39a) includes a linkage chuck (39) and a conical centering hole (31) that are operated in conjunction.

[0031] The above lifting and transfer body (35) is configured such that the gravity-direction transfer force is offset by a balance weight (36) connected via a balance wire (37), and accordingly, the interlocking chuck (39) maintains a semi-neutral state that allows it to move up and down with minimal driving force when its position changes due to an external force.

[0032] With the pipe (1) loaded between the upper roller (20) and the lower roller (10), the brake (34) is kept off so that the restraint on the balance roller (33) is released, and the interlocking chuck (39) is set to move freely up and down together with the lifting and transfer body (35).

[0033] In this state, when the interlocking chuck (39) moves and rotates toward the pipe (1) by the forward operation of the horizontal transfer body (38), as shown in FIG. 2, the end of the pipe (1) engages with the inner surface of the centering hole (31), and the interlocking chuck (39) moves up and down together with the lifting transfer body (35) by the contact reaction force, and accordingly, the position correction is performed so that the rotation center of the interlocking chuck (39) aligns with the center of the pipe (1).

[0034] After alignment is completed, the brake (34) is switched to the ON state, thereby restraining the balance roller (33), and the vertical position of the interlocking chuck (39) is fixed, preventing positional changes in subsequent processes.

[0035] Next, the interlocking chuck (39) is moved to a position spaced apart from the end of the pipe (1) by the reverse operation of the horizontal transfer body (38), and at this time, a spaced state is formed between the interlocking chuck (39) and the end of the pipe (1) such that a predetermined gap is secured for inserting the flange (2).

[0036] Subsequently, as shown in FIG. 3, a flange (2) is supplied between the interlocking chuck (39) and the end of the pipe (1) by the flange loading unit (40), and at this time, the flange loading unit (40) is configured to supply a plurality of flanges (2) one by one.

[0037] And, as shown in FIG. 4, the interlocking chuck (39) moves back toward the end of the pipe (1) by the forward operation of the horizontal transfer body (38), thereby bringing the flange (2) into close contact with the end of the pipe (1), and the plurality of jaws (39a) operate in conjunction to uniformly clamp the flange (2), so that the center of the flange (2) coincides with the rotation center of the interlocking chuck (39) and is accurately positioned at the center of the pipe (1).

[0038] Afterward, the flange (2) clamped by the above interlocking chuck (39) is maintained to rotate while continuously applying an axial pressure to the end of the pipe (1).

[0039] The welding torch (50) moves along the contact portion of the center-aligned flange (2) and pipe (1) to perform welding, and in this process, as shown in FIG. 5, the interlocking chuck (39) rotates to rotate the flange (2) and pipe (1), thereby forming a uniform welding bead in the circumferential direction. At this time, the flange (2) and pipe (1) are constrained to rotate synchronously with the same rotation center and angular velocity.

[0040] That is, the centering part (30) is formed with respect to the rail body (32) and a vertical and lateral degree of freedom structure, and a gravity cancellation mechanism formed by the balance wire (37) and the balance weight (36) is combined to implement a semi-neutral state in which the position of the interlocking chuck (39) is automatically corrected according to the external force, and accordingly, rotational center alignment can be achieved solely by the reaction force generated during the contact process between the end of the pipe (1) and the centering hole (31).

[0041] In addition, the radial alignment force induced by the conical centering hole (31) gradually resolves the eccentricity of the pipe (1) and aligns the rotation center of the interlocking chuck (39) with the center of the pipe (1), and then fixes the alignment state so that it is maintained by the on operation of the brake (34), thereby ensuring precise center alignment before the welding process.

[0042] In addition, the separation state and approach state formed by the forward and backward operation of the horizontal transfer body (38) allow the supply, positioning, and clamping processes of the flange (2) to be performed in stages, and stable automatic loading is possible without interference between processes as the flange (2) is supplied individually by the flange loading unit (40).

[0043] In addition, by maintaining a state in which the flange (2) is uniformly clamped by the plurality of jaws (39a) of the interlocking chuck (39) and the axial pressure is continuously applied, relative slippage between the flange (2) and the pipe (1) does not occur, and synchronous rotation is achieved with the same center of rotation and angular velocity, thereby preventing positional error or the recurrence of eccentricity during welding.

[0044] As such, the present invention is configured to continuously perform center alignment, position fixing, flange feeding, and welding processes within a single system, thereby enabling high-precision welding without operator intervention, ensuring consistent quality even in repetitive processes, and simultaneously achieving increased productivity through process automation along with a reduction in the defect rate.

[0045] In FIG. 6, the flange loading unit (40) comprises a loading bar (41) positioned below the pipe (1) loaded on the upper roller (20) and lower roller (10) and installed parallel to each other to support the flange (2) in an upright state from below, a transfer body (42) that moves up and down through the space between the interlocking chuck (39) and the end of the pipe (1) and has a pair of transfer arms (42a) installed at the bottom, and an electromagnet (43) installed at the bottom of the transfer arm (42a) and detachably provided on both sides of the upper flange (2).

[0046] At this time, the transfer body (42) moves downward while the gap between the interlocking chuck (39) and the end of the pipe (1) is separated, and the electromagnet (43) contacts the flange (2) that is standing upright on the loading bar (41) and is attached to each of the upper sides of the flange (2). At this time, the electromagnet (43) contacts both upper sides of the flange (2) and maintains a state of stable attachment by magnetic force.

[0047] Subsequently, as the transfer body (42) moves upward, the flange (2) is transferred between the interlocking chuck (39) and the end of the pipe (1) so that automatic loading is achieved.

[0048] Additionally, the electromagnet (43) is rotatably coupled to the end of the transfer arm (42a) via a horizontal axis (43a), and the horizontal axis (43a) is installed at an eccentric position from the center of gravity of the electromagnet (43) so that the electromagnet (43) maintains a state in which it is tilted to one side due to its own weight, and at this time, the magnetic surface of the electromagnet (43) is arranged to form an angle of inclination.

[0049] At this time, the electromagnet (43) is in a state where it can freely rotate around the horizontal axis (43a), and its orientation is automatically changed by the eccentric moment caused by its own weight. At the moment it comes into contact with the upper surface of the flange (2), the contact reaction force and the rotational moment caused by its own weight are combined, causing the electromagnet (43) to rotate further and self-align to correspond to the shape of the outer surface of the flange (2). Accordingly, the magnetic surface of the electromagnet (43) comes into close contact with the outer surface of the flange (2) (e.g., the outer curved surface of the circular flange (20)), thereby improving the adsorption stability.

[0050] As such, the electromagnet (43) is configured to rotate eccentrically around the horizontal axis (43a), thereby maintaining a basic state of always tilted in a certain direction due to its own weight, and as the rotation angle changes actively according to the contact reaction force during the process of contacting the upper surface of the flange (2), it self-aligns to correspond to the shape of the outer surface of the flange (2), so that even if the diameter of the flange (2) is different, the posture is adaptively corrected so that the magnetic surface of the electromagnet (43) comes into close contact with the corresponding outer surface.

[0051] Accordingly, the present invention enables stable adsorption and transport for flanges (2) of various specifications and diameters without separate replacement or alignment adjustment while using a single-structure electromagnet (43), and provides the effect of improving versatility by maintaining constant adsorption force and alignment stability regardless of changes in the outer diameter of the flange (2).

[0052] In this invention, the rotational support structure of the pipe (1), the active alignment structure by the centering hole (31), the automatic height correction structure by the balance wire (37) and the balance weight (36), the precision clamping structure by the interlocking chuck (39), and the self-aligning flange supply structure through the eccentric rotation structure of the electromagnet (43) are organically combined so that the alignment, supply, fixing, and welding of the flange (2) and the pipe (1) are automatically performed within a single process flow, and high precision and high reproducibility can be secured simultaneously.

[0053] As described above, the detailed description of the present invention has explained the most preferred embodiment of the present invention, but various modifications are possible within the scope of the technical scope of the present invention. Accordingly, the scope of protection of the present invention should not be limited to the above embodiment, but should be recognized to include the technologies of the claims described below and equivalent technical means derived from these technologies. Explanation of the symbols

[0055] 10: Lower roller 20: Upper roller 30: Centering section 40: Flange loading section 50: Welding torch

Claims

Claim 1 In an automatic pipe welding system for welding a flange to the outer surface of a pipe, a pair of lower rollers (10) are spaced apart and are provided to rotatably support the pipe (1); an upper roller (20) is provided to be positioned above the lower roller (10) and is provided to press the pipe (1) from above; a centering unit (30) is provided to be installed corresponding to one end of the pipe (1), and is provided to correct the position so that the flange (2) is guided into a centering hole (31) and coincides with the pipe (1) on a concentric circle, and is provided to rotate while pressing the flange (2) against the end of the pipe (1); and a flange loading unit (40) is provided to supply the flange (2) individually to the centering unit (30). It includes a welding torch (50) provided to weld the contact portion between the flange (2) and the pipe (1); and the centering unit (30) comprises a rail body (32) having a first vertical rail (32a) and a second vertical rail (32b) installed on both sides, a balancing roller (33) installed on the upper part of the rail body (32) and rotated by a driving unit, a brake (34) installed on the rail body (32) and stopping operation by pressing the balancing roller (33), a lifting and transfer body (35) that moves up and down along the first vertical rail (32a) and has a horizontal rail (35a) installed on the upper part, a balancing weight (36) that moves up and down along the second vertical rail (32b), and one end connected to the lifting and transfer body (35) and the other end passing through the balancing roller (33). An automatic pipe welding system comprising a balancing wire (37) connected to a balancing weight (36), a horizontal transfer body (38) that moves horizontally along a horizontal rail (35a), and a connecting chuck (39) provided such that a plurality of jaws (39a) installed on the horizontal transfer body (38) rotate and clamp a flange (2) are operated in conjunction, wherein a conical centering hole (31) is formed in intaglio on one side of the connecting chuck (39) corresponding to the end of the pipe (1), and the conical centering hole (31) is formed in a conical shape such that the diameter decreases as it goes inward. Claim 2 delete Claim 3 In claim 1, the lifting and transfer body (35) is provided such that the gravity-direction transfer force is offset by a balance weight (36) connected via a balance wire (37), and a pipe (1) is loaded between the upper roller (20) and the lower roller (10), and when the brake (34) is off and the interlocking chuck (39) moves and rotates toward the pipe (1) by the forward operation of the horizontal transfer body (38), the end of the pipe (1) engages with the inner surface of the centering hole (31), and the interlocking chuck (39) moves up and down together with the lifting and transfer body (35) so that the rotation center of the interlocking chuck (39) is aligned with the center of the pipe (1) and the posture is corrected, and then when the brake (34) is turned on, the height of the interlocking chuck (39) is fixed, and after the interlocking chuck (39) is moved to a position spaced apart from the end of the pipe (1) by the backward operation of the horizontal transfer body (38), A pipe automatic welding system characterized by the fact that a flange (2) is supplied between the interlocking chuck (39) and the end of the pipe (1) by the flange loading unit (40), and the interlocking chuck (39) is moved toward the end of the pipe (1) by the forward operation of the horizontal transfer body (38) to bring the flange (2) into close contact with the end of the pipe (1), and when a plurality of jaws (39a) are clamped, the flange (2) is positioned at the center of the pipe (1) by aligning with the rotation center of the interlocking chuck (39), and while the welding torch (50) moves to weld the contact portion between the flange (2) and the pipe (1), the interlocking chuck (39) is rotated to rotate the flange (2) and the pipe (1) to perform the welding process. Claim 4 In claim 3, the flange loading unit (40) comprises a loading bar (41) positioned below the pipe (1) loaded on the upper roller (20) and the lower roller (10) and installed parallel to each other to support the flange (2) in an upright state from below, a transfer body (42) that moves up and down through the space between the interlocking chuck (39) and the end of the pipe (1) and has a pair of transfer arms (42a) installed at the bottom, and an electromagnet (43) installed at the lower end of the transfer arm (42a) and detachably provided on both sides of the upper flange (2) by magnetic force, wherein the flange (2) is waiting in an upright state on the loading bar (41) and the gap between the interlocking chuck (39) and the end of the pipe (1) is spaced apart, and the transfer body (42) moves downward through the space between the interlocking chuck (39) and the end of the pipe (1) to the electromagnet (43) the flange (2) waiting on the loading bar (41). A pipe automatic welding system characterized by being attached, and subsequently, having a transfer body (42) moved upward to load the flange (2) between the interlocking chuck (39) and the end of the pipe (1). Claim 5 In claim 4, the electromagnet (43) is rotatably coupled to the end of the transfer arm (42a) via a transverse axis (43a), and the transverse axis (43a) is installed at an eccentric position from the center of gravity of the electromagnet (43), so that the electromagnet (43) is tilted to one side around the transverse axis (43a) due to its own weight, and the magnetic surface of the electromagnet (43) is arranged to form an angle of inclination, and when the electromagnet (43) contacts the upper surface of the flange (2), the magnetic surface of the electromagnet (43) is self-aligned to correspond to the outer circumference of the flange (2), characterized by an automatic pipe welding system.

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